TSTF-09-26, Comment (2) of Kenneth J. Schrader, John Messina, Thomas W. Raidy and Wendy E. Croft on Behalf of Technical Specifications Task Force on Proposed Model Safety Evaluation for Plant-Specific Adoption of Traveler-493, Rev. 4, Clarify Applica: Difference between revisions

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{{#Wiki_filter:TSTF TECHNICAL SPECIFICATIONS TASK FORCE A J01INT/ 0 UWANERS GR? OUP A CTIVITY November 25, 2009 100,07 TSTF-09-26 PROJ0753 Michael T. Lesar Chief, Rulemaking and Directives Branch (RDB)Division of Administrative Services Office of Administration Mail Stop: TWB B01M U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 "4
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==SUBJECT:==
Technical Specification Task Force (TSTF) Response to November 10, 2009 Federal Register Notice, "Notice of Opportunity for Public Comment on the Proposed Model Safety Evaluation for Plant-Specific Adoption of Technical Specification Task Force Traveler-493, Revision 4, 'Clarify Application of Setpoint Methodology for LSSS Functions'," Docket ID NRC-2009-0487 Enclosed for NRC consideration are comments prepared by the Technical Specification Task Force (TSTF) on the subject November 10, 2009 Federal Register Notice on TSTF-493, Revision 4, "Clarify Application of Setpoint Methodology for LSSS Functions." ...During the NRC's review of the Traveler, changes were identified to make TSTF-493 consistent with the justification and the NRC's model Safety Evaluation published in the Notice for Comment. The TSTF confirmed that these changes are consistent with the intent of TSTF-493 and agreed to provide revised pages.Attachment A contains the affected pages for Option A of TSTF-493.
Attachment B contains the affected pages for Option B of TSTF-493.
Unless otherwise indicated, the original TSTF-493, Revision 4, changes are shown in red and the revisions are shown in blue. When necessary for clarity, pages unaffected are included.The TSTF will submit a complete copy of TSTF-493, Revision 4, incorporating the revised pages in December, 2009.'50 11921 Rockville Pike, Suite 100, Rockville, MD 20852 Phone: 301-984-4400, Fax: 301-984-7600 Administration by EXCEL Services Corporation PWROG",p O _Ocý OWNERS' GROUP 01VnerS G TSTF-09-26 November 25, 2009 Should you have any questions, please do not hesitate to contact us.Kenneth J. Schrader (PWROG/W)
J ohn Me Thomas W. Raidy (PWROG/CE)
Wendy]Enclosure Attachments cc: Robert Elliott, Technical Specifications Branch, NRC Michelle Honcharik, Special Projects Branch, NRC~ssina (BWvROG)lro ft (PWG/&W)
Technical Specification Task Force (TSTF) Response to November 10, 2009 Federal Register Notice, "Notice of Opportunity for Public Comment on the Proposed Model Safety Evaluation for Plant-Specific Adoption of Technical Specification Task Force Traveler-493, Revision 4, 'Clarify Application of Setpoint Methodology for LSSS Functions'," Docket ID NRC-2009-0487 General Comments 1. In the Notice, the model application, and the proposed model Safety Evaluation there are statements such as, "includes the calculation basis for the Limiting Trip Setpoint (LTSP), Nominal Trip Setpoint (NTSP), Allowable Value (AV), As-Found Tolerance band, and As-Left Tolerance band for each change." This wording implies that there are two distinct values to be presented
-an LTSP and an NTSP. As stated in Footnote 3 of the proposed model Safety Evaluation, "Throughout this SE and the proposed TS changes, the terms'Limiting Trip Setpoint' and 'Nominal Trip Setpoint' and their abbreviations, 'LTSP' and'NTSP' are shown in brackets (e.g., '[LTSP]').
In all cases, the term 'Limiting Trip Setpoint'may be replaced in the Technical Specifications and in the TS Bases by a term (e.g., NTSP)consistent with the plant-specific setpoint methodology." In some cases, the Notice correctly states, "[LTSP/NTSP]," but not in all cases. The Notice should be searched and it should be clear in all instances that only the LTSP or NTSP should be specified, not both.Comments on the Notice 2. The Notice states, "The Proposed Models for Plant-Specific Adoption of TSTF Traveler-493, Revision 4, are available electronically under ADAMS Accession Number ML093080028." For clarity, the sentence should be revised to state that the proposed model application, model Safety Evaluation, and proposed No Significant Hazards Consideration Determination are available electronically under ADAMS Accession Number ML093080028.
: 3. The Notice, in the section titled "Applicability," states, "The Traveler revises the TS instrument function values related to those variables that have a significant safety function." This sentence would only be applicable to plants adopting Option A with changes to setpoint values. In addition, as noted in comments below, the reference to "variables that have a significant safety function" is incorrect.
We recommend the sentence be deleted.4. The Notice, in two locations in the section entitled "Applicability," states "The licensee must propose to add footnotes to all the functions identified in TSTF Traveler-493, Revision 4, Appendix A, and must incorporate the related TS Bases changes." Similar statements are made in the proposed model Safety Evaluation.
These statements are not correct. As stated on Page 10 of the justification of TSTF-493, "Each licensee proposing to adopt this Traveler must review the list of Functions in Attachment A to confirm that the identified functions are consistent with their plant specific design." These sentences should be revised to state that the licensee must propose footnotes to the applicable functions identified in TSTF Traveler-493, Revision 4, Appendix A.5. The Notice, in the section titled, "Adoption of TSTF Traveler-493 with Option B -the Setpoint Control Program Option," states, "The licensee must provide the content and application of the plant-specific setpoint methodology required by the SCP TS 5.5.[18]Paragraph
: b. This includes the calculation basis for the LTSP, NTSP, AV, As-Found Tolerance band, and As-Left Tolerance band for each automatic protection instrumentation function." This section should be clarified to state that it is not necessary to describe the Page 1 Technical Specification Task Force (TSTF) Response to November 10, 2009 Federal Register Notice, "Notice of Opportunity for Public Comment on the Proposed Model Safety Evaluation for Plant-Specific Adoption of Technical Specification Task Force Traveler-493, Revision 4, 'Clarify Application of Setpoint Methodology for LSSS Functions'," Docket ID NRC-2009-0487 calculation basis for the current setpoint value. The current setpoint values were approved by the NRC. The Setpoint Control Program controls future changes to the subject setpoints." Comments on the Model Application
: 6. The mailing address specified in the model application is not consistent with the address specified in 10 CFR 50.4. The regulations require submitting license amendments to ATTN: Document Control Desk, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001.
The model application should be revised.7. The model application cover letter states, "[Discuss any differences with Traveler-493, Revision 4.] This level of detail is not included in a license amendment request cover letter.We recommend that the bracketed sentence be deleted.8. The model application states that Attachment 4 (for Option A) or Attachment 7 (for Option B) contains a listing of the proposed regulatory commitments.
The model application and model Safety Evaluation do not specify any regulatory commitments.
Therefore, reference to these attachments should be deleted.9. Section 1.0, "Description," of Attachment I to the model application, third paragraph, contains the sentence, "[Minor differences between the proposed plant-specific TS changes, and the changes proposed by Traveler-493 are listed in Section 2.0.]" We recommend that this sentence be deleted. The sentence adds no value. Section 2.0 describes all differences (minor or otherwise) or states that there are no differences.
Note that the bracketed sentence appears in both the Option A and Option B paragraphs.
: 10. The model application, Attachment 1, "Evaluation of Proposed Change," Section 1.0,"Description," states, "The proposed amendment would revise the Technical Specifications (TS) by adding new test requirements to instrument Functions related to those variables that have a significant safety function, thereby ensuring instruments will function as required to initiate protective systems or actuate mitigating systems at the point assumed in the applicable safety analysis." This appears both under the Option A and Option B paragraphs.
This statement is overly broad and does not describe the proposed changes in TSTF-493, Revision 4. It should be revised to state, "The proposed amendment would revise the Technical Specifications (TS) by applying additional testing requirements on the applicable instrument Functions listed in TSTF-493, Revision 4, Appendix A, in order to ensure the instruments will function as assumed in the applicable safety analysis." 11. The model application, Attachment 1, "Evaluation of Proposed Change," Section 1.0,"Description," the fifth paragraph, states, "These TS changes are made by adoption of a Setpoint Control Program that contains the setpoint methodology and parameters used in the calculation and ...". The phrase "parameters used in the calculation" is not consistent with any of the proposed requirements in the Setpoint Control Program and should, therefore, be eliminated.
Page 2 Technical Specification Task Force (TSTF) Response to November 10, 2009 Federal Register Notice, "Notice of Opportunity for Public Comment on the Proposed Model Safety Evaluation for Plant-Specific Adoption of Technical Specification Task Force Traveler-493, Revision 4, 'Clarify Application of Setpoint Methodology for LSSS Functions'," Docket ID NRC-2009-0487
: 12. The proposed Model Safety Evaluation, Section 3.0, "Technical Evaluation," quotes Notes 1 and 2. The quote of Note 2 in Section 3.1.1 is correct only for NUREG-1431.
The NUREG-1431 Note 2 states "(field setting)" after "Surveillance procedures." The other STS NUREGs have the term "(Nominal Trip Setpoint)" in lieu of "(field setting)." As a general comment, whenever Note 2 is discussed in a general context for all five STS NUREGs, it should use bracketed terms such as [field setting or NTSP], or the discussion should include STS NUREG-specific annotations such as found in Sections 3.1.2 and 3.1.4 of the model Safety Evaluation.
: 13. In previous Notices, the NRC stated that use of plant-specific system names, specification numbers, and titles is acceptable.
This Notice does not make such a statement.
We recommend it be added to the end of Attachment 1, Section 2.0, "Proposed Change," of the model application.
: 14. Section 5.1 of Attachment I to the proposed model application is titled "No Significant Hazards Determination." In order to be consistent with the terminology used in Regulatory Issue Summary 2001-22, "Attributes of a Proposed No Significant Hazards Consideration Determination," and industry practice, we recommend using the title, "No Significant Hazards Consideration Determination" (NSHCD) in the model application.
: 15. Section 5.1 of Attachment 1 to the proposed model application, "No Significant Hazards Determination," (NSHD) [sic] contains two conflicting statements.
It first states that the licensee has reviewed the NSHCD published in the Federal Register and concluded that it is applicable.
It then states that the licensee has performed an NSHCD evaluation and requires that the licensee provide their analysis.Regulatory Issue Summary 2000-06, "Consolidated Line Item Improvement Process for Adopting Standard Technical Specifications Changes for Power Reactors," states (emphasis added): In an effort to make the NRC workprocesses more visible, the NRC staff will solicit stakeholder comments on the associated change to the STS, the staff's safety evaluation (SE), and the proposed no significant hazards consideration determination (PNSHCD)before finalizing its acceptance of a TSTF change. Following NRC acceptance of a TSTF change, licensees, as well as the NRC staff will be able to use the relevant documentation from the NRC-accepted TSTF change in the preparation and processing of license amendment applications.
The licensees desiring to adopt a specific TSTF change using the CLIIP will need to verify that the proposed change is applicable to their facilities.
The NRC announcement and the staff's SE will specify any plant-specific verification or other information required in licensees' applications.
The licensees may apply for license amendments by Page 3 Technical Specification Task Force (TSTF) Response to November 10, 2009 Federal Register Notice, "Notice of Opportunity for Public Comment on the Proposed Model Safety Evaluation for Plant-Specific Adoption of Technical Specification Task Force Traveler-493, Revision 4, 'Clarify Application of Setpoint Methodology for LSSS Functions'," Docket ID NRC-2009-0487 citing the applicability of the PNSHCD and the SE for the accepted TSTF change and addressing any plant-specific information needed to support the staff's review.Finally, with the licensee's adoption of the uniform description of the proposed change, the PNSHCD and the SE for a TSTF change request, the CLIIP would provide more disciplined and consistent adoption of the STS by way of a streamlined amendment process.Referencing the NSHCD published in the Federal Register has been used in the 35 model applications published by the NRC to date under the CLIIP.We acknowledge that the NRC has chosen to apply the term "CLIIP" to only those TSTF Travelers that may be adopted by a license amendment request reviewed by only the NRC Technical Specification Branch. However, the process described in RIS 2000-06 is applied to all TSTF Travelers approved by the NRC, including TSTF-493.Requiring each licensee to submit a NSHCD reduces public involvement in the CLIIP by rendering the NSHCD published in the Federal Register essentially irrelevant and undermines the "disciplined and consistent adoption" of the Traveler under a streamlined amendment process. The proposed model amendment also places the licensee in the position of either deviating from the model application or submitting an NRC developed NSHCD as if it were their own.The TSTF has considered the legal requirements regarding the submittal of a NSHCD.10 CFR 50.91, "Notice for public comment; State consultation," states, "(a) Notice for public comment. (1) At the time a licensee requests an amendment, it must provide to the Commission, in accordance with the distribution requirements specified in § 50.4, its analysis about the issue of no significant hazards consideration using the standards in § 50.92." There is no prohibition from referencing a NSHCD in a publically available source, such as the Federal Register.
Licensees frequently reference other sources in their license amendment requests, such as NRC-approved Topical Reports, Regulatory Guides, and Codes and Standards.
There is no basis for requiring that the NSHCD be repeated in the licensee's amendment request when doing so undermines the public involvement in the CLIIP.The TSTF recommends that Section 5.1 be revised to reference the NSHCD published in the Federal Register, consistent with the process described in RIS 2000-06.16. Attachment 1, Section 6.0, "Environmental Consideration," contains two conflicting statements.
It first states that the licensee has reviewed the environmental evaluation published in the Federal Register and concluded that it is applicable.
It then restates the environmental consideration.
Page 4 Technical Specification Task Force (TSTF) Response to November 10, 2009 Federal Register Notice, "Notice of Opportunity for Public Comment on the Proposed Model Safety Evaluation for Plant-Specific Adoption of Technical Specification Task Force Traveler-493, Revision 4, 'Clarify Application of Setpoint Methodology for LSSS Functions'," Docket ID NRC-2009-0487 The environmental considerations section of the model application satisfies 10 CFR 51.22,"Criterion for categorical exclusion; identification of licensing and regulatory actions eligible for categorical exclusion or otherwise not requiring environmental review." Paragraph 10 CFR 51.22(b) states, "Except in special circumstances, as determined by the Commission upon its own initiative or upon request of any interested person, an environmental assessment or an environmental impact statement is not required for any action within a category of actions included in the list of categorical exclusions set out in paragraph (c) of this section." The purpose of the "Environmental Consideration" section is to demonstrate that a categorical exclusion applies and an environmental review is not required.
Referencing the Environmental Consideration section of the Federal Register Notice satisfies the requirement and increases public involvement in the determination through the CLIIP Notice for Comment.The TSTF recommends that Section 6.0 be revised to reference the Environmental Consideration published in the Federal Register.Comments on the Proposed No Si2nificant Hazards Determination
: 17. The proposed Model No Significant Hazards Consideration Determination (NSHCD), Question 1 response for Option B, states, "The proposed change also allows the relocation of the plant-specific setpoints to licensee control provided the NRC has approved the methodology used to calculate the setpoints and that future changes to the setpoints are controlled under a TS Setpoint Control Program (SCP)." This sentence incorrectly implies that the NRC must have approved the methodology used to calculate the current setpoints as a condition of their relocation.
It should be revised to state, "The proposed change also allows the relocation of the plant-specific setpoints to licensee control provided the NRC has approved the methodology used to calculate future changes to the setpoints and that future changes to the setpoints are controlled under a TS Setpoint Control Program (SCP).Comments on the Proposed Model Safety Evaluation
: 18. The proposed model Safety Evaluation contains multiple instances of the phrase, "a document controlled under 10 CFR 50.59." The TSTF and the NRC agreed to replace this phrase with a phrase similar to "a document incorporated by reference into the facility UFSAR." The model Safety Evaluation should be searched and the appropriate phrase used.19. Section 1.0, "Introduction," of the proposed model Safety Evaluation, states, "The proposed changes would revise the TSs with respect to limiting safety system settings (LSSSs)assessed during periodic testing and calibration of instrumentation that may have an adverse effect on equipment operability." This statement, and statements similar to it, appear throughout the proposed model Safety Evaluation.
These statements are incorrect.
TSTF-493 proposes to add footnotes or requirements in an Administrative Controls program with respect to periodic testing and calibration of instrumentation associated with the Functions listed in Appendix A of TSTF-493.
TSTF-493 does not state, and the TSTF does not agree, that all of the Functions in Appendix A are limiting safety system settings.
As Page 5 Technical Specification Task Force (TSTF) Response to November 10, 2009 Federal Register Notice, "Notice of Opportunity for Public Comment on the Proposed Model Safety Evaluation for Plant-Specific Adoption of Technical Specification Task Force Traveler-493, Revision 4, 'Clarify Application of Setpoint Methodology for LSSS Functions'," Docket ID NRC-2009-0487 stated in the TSTF's February 23, 2009 letter to the NRC, "Industry Plan to Resolve TSTF-493, 'Clarify Application of Setpoint Methodology for LSSS Functions'," "The industry agreement to annotate these functions with the TSTF-493 footnotes does not represent industry acceptance of the NRC's definition of SL-LSSS in Reference 2 or agreement that the functions to be annotated are LSSS,' that the functions protect a Safety Limit, or that the functions meet a 10 CFR 50.36(c)(2) criteria." The NRC's safety evaluation for a license amendment cannot be based on arguments that were not presented by the applicant.
All references to "limiting safety system settings" and phrases such as "variables that have a significant safety function", which are based on the 10 CFR 50.36 definition of limiting safety system settings, must be removed and replaced with a reference to the functions in listed in TSTF-493, Revision 4, Attachment A.20. Section 1.0, "Introduction," of the proposed model Safety Evaluation, states, "Additionally, as part of the review process it was determined that TSTF Traveler-41 1 had not been correctly implemented in NUREG-1431.
Corrections have been made to TS 3.3.6, Containment Purge and Exhaust Isolation Instrumentation, Table 3.3.6-1 and TS 3.3.7, Control Room Emergency Filtration System (CREFS) Actuation Instrumentation, Table 3.3.7-1 ." The proposed model Safety Evaluation is for plant-specific adoption of TSTF-493.These sentences should be bracketed, to indicate that they are plant-specific, and revised to state "not been correctly implemented in NUREG-1431 and [PLANT]'s Technical Specifications." 21. Section 1.0, "Introduction," of the proposed model Safety Evaluation, states, "The new program, entitled the Setpoint Control Program (SCP or the program), references an NRC-approved methodology for determining and verifying instrument setpoints and ...". The Setpoint Control Program is structured to allow more than one setpoint methodology to be referenced.
We recommend that the sentence be revised to state, "... references an NRC-approved methodology or methodologies for determining
...". This is correctly stated in the second paragraph of the cover letter of the model application, but is incorrectly stated as singular in many other locations throughout the Notice.22. The proposed model Safety Evaluation, Section 1.0, "Introduction," states "The new program, entitled the Setpoint Control Program (SCP or the program), references an NRC-approved methodology for determining and verifying instrument setpoints and includes requirements that serve the same purpose as the Notes added to SRs under Option A of TSTF Traveler-493, Revision 4." It is unclear what is meant by "determining" in the phrase"references an NRC-approved methodology for determining and verifying instrument setpoints...".
The Notes in Option A are not related to determining setpoints.
We recommend that the phrase "determining and" be deleted from the sentence.23. The proposed model Safety Evaluation, Section 1.0, "Introduction," in the discussion of Note 1 states, "The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. The performance of these channels Page 6 Technical Specification Task Force (TSTF) Response to November 10, 2009 Federal Register Notice, "Notice of Opportunity for Public Comment on the Proposed Model Safety Evaluation for Plant-Specific Adoption of Technical Specification Task Force Traveler-493, Revision 4, 'Clarify Application of Setpoint Methodology for LSSS Functions'," Docket ID NRC-2009-0487 will be evaluated under the plant Corrective Action Program (CAP). Entry into the CAP will ensure required review and documentation of the condition to establish a reasonable expectation for continued operability." In Section 1.1 of the proposed model Safety Evaluation, it states, "To address Concept 7, the revised TS Bases state that when a channel's As-Found value is outside the As-Found Tolerance band, the potentially degraded instrument must be entered into the licensee's CAP. The CAP evaluation is expected to be performed promptly to validate the determination that was performed prior to returning the channel to service and to confirm that the channel is operable and performing as expected." These statements could be misinterpreted to mean that the CAP evaluation must be completed prior to returning the channel to service. We recommend the Section 1.0 paragraph be revised to state, "The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. In addition, the performance of these channels will be evaluated under the plant Corrective Action Program (CAP). Entry into the CAP will ensure required review and documentation of the condition to establish a reasonable expectation for continued operability." We recommend that the Section 1.1 paragraph be revised to state, "To address Concept 7, the revised TS Bases state that when a channel's As-Found value is outside the As-Found Tolerance band, channel Operability must be evaluated prior to returning the channel to service. In addition, the potentially degraded instrument must be entered into the licensee's CAP. The CAP evaluation is expected to be performed promptly to validate the determination that was performed prior to returning the channel to service and to confirm that the channel is e, parable ani performing as expected." 24. The TSTF recommends that Section 1.1 of the proposed model Safety Evaluation, entitled,"Development of TSTF-493, Revision 4," be substantially revised. The section is confusing because many of the discussions and issues discussed were superseded by the industry approach described in the February 23, 2009 letter. The discussion of the historical development of TSTF-493 is only applicable to the wording of the Option A footnotes or the equivalent requirements in the Option B Setpoint Control Program. Section 1.1 should be revised to discuss only the seven concepts and how those concepts were expressed in the Option A footnotes and the Option B Setpoint Control Program. The discussion of RIS 2006-17 should be eliminated.
While the NRC staff may be satisfied that TSTF-493, Revision 4, satisfies the position in RIS 2006-17, it is not the technical basis for TSTF-493, Revision 4, and the TSTF does not agree that all of RIS 2006-17 is applicable to TSTF-493.25. The proposed model Safety Evaluation, Section 2.0, "Regulatory Evaluation," states, "Plant protective systems are designed to initiate reactor trips (scrams) or other protective actions before selected unit parameters exceed ALs assumed in the safety analysis in order to prevent violation of the Reactor Core SLs and RCS Pressure SL from postulated Anticipated Operational Occurrences (AOOs) and accidents." This statement is incorrect.
Safety Limits are not protected during accidents, only during AOOs. The phrase "and accidents" should be deleted from the sentence.Page 7 Technical Specification Task Force (TSTF) Response to November 10, 2009 Federal Register Notice, "Notice of Opportunity for Public Comment on the Proposed Model Safety Evaluation for Plant-Specific Adoption of Technical Specification Task Force Traveler-493, Revision 4, 'Clarify Application of Setpoint Methodology for LSSS Functions'," Docket ID NRC-2009-0487
: 26. Section 3.1.2, "Technical Bases," of the proposed model Safety Evaluation states, "Setpoint calculations calculate a [LTSP/NTSP]
based on the AL of the Safety Analysis to ensure that trips or protective actions will occur prior to the process parameter exceeding the SL as required by the Safety Analysis calculations." This is an incorrect statement.
Safety Limits may be exceeded in safety analysis calculations for design basis accidents.
The sentence should be revised to state, "Setpoint calculations calculate a [LTSP/NTSP]
based on the AL of the Safety Analysis to ensure that trips or protective actions will occur prior to exceeding the process parameter value assumed in the Safety Analysis calculations." 27. Section 3.2, "Technical Evaluation for Option A Without Changes to Setpoint Values," Section 3.2.1, "Addition of Footnote to TS Tables," of the proposed model Safety Evaluation states, "Furthermore, the licensee stated that if during calibration testing the setpoint is found to be conservative with respect to the LSSS but outside its predefined calibration tolerance, then the channel shall be brought back to within its predefined calibration tolerance before returning the channel to service." This is incorrect.
The sentence should be revised to state,"Furthermore, the licensee stated that if during calibration testing the setpoint is found to be conservative with respect to the LSSS A Vbut outside its predefined As-Found Tolerance band, then the channel shall be brought back to within its predefined calibration tolerance before returning the channel to service." The text in this section should match that in Section 3.2, "Technical Evaluation for Option A with Changes to Setpoint Values," Section 3.2.2,"Addition of Footnotes to TS Tables." The latter should also contain the following two sentences from the former: "The calibration tolerances are specified in the TRM or a document incorporated by reference in the UFSAR. Changes to the values will be controlled by 10 CFR 50.59." 28. Section 3.2, "Option B Technical Evaluation of TS Changes Using the Setpoint Control Program," Section 3.2.1, "Setpoint Control Program TS 5.5.[18]," of the proposed model Safety Evaluation contains a typographical error. The reference to 10 CFR 50.369 should state 10 CFR 50.36.Comments on Attachment A of the Proposed Model Safety Evaluation
: 29. Attachment A of the proposed model Safety Evaluation is titled, "TS Instrumentation Functions LSSS." This title is incorrect and should be revised to eliminate the acronym"LSSS." TSTF-493 does not state, and the TSTF does not agree, that all of the Functions in Appendix A are limiting safety system settings.
As stated in the TSTF's February 23, 2009 letter to the NRC, "Industry Plan to Resolve TSTF-493, 'Clarify Application of Setpoint Methodology for LSSS Functions'," "The industry agreement to annotate these functions with the TSTF-493 footnotes does not represent industry acceptance of the NRC's definition of SL-LSSS in Reference 2 or agreement that the functions to be annotated are LSSS, that the functions protect a Safety Limit, or that the functions meet a 10 CFR 50.36(c)(2) criteria." 30. Attachment A, "TS Instrumentation Functions LSSS," of the proposed model Safety Evaluation incorrectly describes the list of functions to which the Option A footnotes will be applied as LSSS functions.
TSTF-493 does not state, and the TSTF does not agree, that all of the Functions in Appendix A are limiting safety system settings.
As stated in the TSTF's Page 8 Technical Specification Task Force (TSTF) Response to November 10, 2009 Federal Register Notice, "Notice of Opportunity for Public Comment on the Proposed Model Safety Evaluation for Plant-Specific Adoption of Technical Specification Task Force Traveler-493, Revision 4, 'Clarify Application of Setpoint Methodology for LSSS Functions'," Docket ID NRC-2009-0487 February 23, 2009 letter to the NRC, "Industry Plan to Resolve TSTF-493, 'Clarify Application of Setpoint Methodology for LSSS Functions'," "The industry agreement to annotate these functions with the TSTF-493 footnotes does not represent industry acceptance of the NRC's definition of SL-LSSS in Reference 2 or agreement that the functions to be annotated are LSSS, that the functions protect a Safety Limit, or that the functions meet a 10 CFR 50.36(c)(2) criteria." 31. Attachment A, "TS Instrumentation Functions LSSS," of the proposed model Safety Evaluation states, "Therefore, NRC staff concludes that all the functions identified in TS 3.3.1 and TS 3.3.2 meet the requirements of 10 CFR 50.36(c)(1)(ii)(A)." It is not clear to which STS NUREG the statement is referring, but regardless the statement should be deleted.TSTF-493, Revision 4, provided no evaluation of whether the functions in TS 3.3.1 and 3.3.2 meet the requirements of 10 CFR 50.36(c)(1)(ii)(A) and such a conclusion is not related to TSTF-493, Revision 4.32. Attachment A, "TS Instrumentation Functions LSSS," of the proposed model Safety Evaluation states, " ...except for the functions which met the three exclusion criteria discussed above. The NRC staff finds these exceptions acceptable because these instrument functions do not have components required to meet As-Left and As-Found acceptance bands;values necessary to make the determination during testing whether the instrument is operable or needs'to be replaced." The statement includes the unsupported conclusion that the functions being excepted cannot be repaired, only replaced.
We recommend deleting the ending of the sentence following the semicolon.
: 33. Attachment A, "TS Instrumentation Functions LSSS," of the proposed model Safety Evaluation provides a list of functions for each ISTS NUREG. For those unfamiliar with the list of functions, the numbering may be confusing.
We recommend adding the following sentence prior to the list ofNUREG-1430 functions, "The function numbers listed below are from the corresponding ISTS NUREG." 34. To improve usability of Attachment A, "TS Instrumentation Functions LSSS," of the proposed model Safety Evaluation, we recommend that the Notes "(Permissive or interlock excluded from footnote)" be expanded to include "it if derives input from a sensor or adjustable device that is tested as part of another TS function." 35. In Attachment A of the proposed model Safety Evaluation, "TS Instrumentation Functions LSSS," under the list of Functions to be annotated in NUREG-1431, Specification 3.3.2,"Engineered Safety Feature Actuation System Instrumentation," delete Function 3, "a. Phase A Isolation," and Function 5, "c. Safety Injection (Automatic actuation logic circuit excluded from footnotes)." They are listed under the excluded functions.
: 36. There is a typographical error in Attachment A of the proposed model Safety Evaluation, "TS Instrumentation Functions LSSS," under the list of Functions Excluded from Notes in Page 9 Technical Specification Task Force (TSTF) Response to November 10, 2009 Federal Register Notice, "Notice of Opportunity for Public Comment on the Proposed Model Safety Evaluation for Plant-Specific Adoption of Technical Specification Task Force Traveler-493, Revision 4, 'Clarify Application of Setpoint Methodology for LSSS Functions'," Docket ID NRC-2009-0487 NUREG-1431, Specification 3.3.2, "Engineered Safety Feature Actuation System Instrumentation," Function 4.g. There is an extraneous "t" between "excluded" and "from".37. In Attachment A of the proposed model Safety Evaluation, "TS Instrumentation Functions LSSS," under the list of Functions to be annotated in NUREG-1432, Specification 3.3.5,""Engineered Safety Features Actuation System Instrumentation (Digital)," delete Function 2, "b. Automatic SIAS." The function is listed under the excluded functions.
: 38. In Attachment A of the proposed model Safety Evaluation, "TS Instrumentation Functions LSSS," under the list of Functions to be annotated in NUREG-1433, Specification 3.3.5.1,"Emergency Core Cooling System Instrumentation," delete Function 2, "f Low Pressure Coolant Injection Pump Start -Time Delay Relay." The function is listed under the excluded functions.
Page 10 Attachment A TSTF-493, Revision 4, "Clarify Application of Setpoint Methodology for LSSS Functions" Revised Option A Pages TSTF-493, Rev. 4 1.0 Description The proposed change revises the Technical Specifications to address NRC concerns that the Technical Specification (TS) requirements for Limiting Safety System Settings (LSSS) may not be fully in compliance with the intent of 10 CFR 50.36. Specifically, the NRC is concerned that the existing Surveillance Requirements (SRs) do not provide adequate assurance that instruments will always actuate safety functions at the point assumed in the applicable safety analysis.
While the industry does not necessarily agree with the NRC's concern, this Traveler addresses the issue. The agreement to resolve the issue is documented in a letter from the Technical Specification Task Force (TSTF) to the NRC dated February 23, 2009 (ADAMS accession number ML090540849) and was accepted in a letter from the NRC to the TSTF dated March 9, 2009 (ADAMS accession number ML090560592).
These letters are attached to this Traveler.
This proposed change is consistent with the agreement.
2.0 Proposed Change The agreement provides for two separate options to address the issue. The first option (Option A) results in the placement of Notes in Technical Specification Tables for the agreed upon functions.
The second option (Option B) adds a program to the Administrative Controls section of the Technical Specifications.
The new program, titled the Setpoint Control Program, references an NRC-approved methodology for determining and verifying instrument setpoints.
In addition to addressing the NRC's concern, Option B allows the relocation of the instrument setpoint values from the Technical Specifications to licensee control.Throughout this document and the proposed TS changes, the terms "Limiting Trip Setpoint" and "Nominal Trip Setpoint" and their abbreviations, "LTSP" and "NTSP" are shown in brackets (e.g., "[LTSP]").
In all cases, the term "Limiting Trip Setpoint" may be replaced in the Technical Specifications and in the Bases by a term (e.g. NTSP) consistent with the plant-specific setpoint methodology.
Description of Option A Proposed Changes Under Option A, two Notes are added in the Surveillance Requirements column in the specification's Function table. if the specification does not contain a Fuanction table with a Sutweillanee Requir-ements eoluimn, the Notes arc added to the table's Allowable Value elu=k. If the specification does not include a Surveillance Requirements column or a Function table, then the Notes are added to the applicable Surveillance Requirements.
Notes are added to SRs that verify trip setpoint settings.
The Surveillance Requirements to which the Notes are applied vary due to vendor-specific testing terminology.
In NUREG-1430, 1432, 1433, and 1434, the Notes are added to the Channel Calibration SRs, and to Channel Functional Test SRs that verify trip setpoints.
In NUREG-1431, the Notes are added to the Channel Calibration, and Channel Operational Test (COT), SRs that verify trip setpoints.
Page 1 TSTF-493, Rev. 4 These two Notes are applied to the Functions listed in Appendix A. They include instrument functions in the LCOs for the Reactor Trip System (also called the Reactor Protection System), the Engineered Safety Feature Actuation System (also called the Emergency Core Cooling System and some instrument functions in other LCOs identified in the boiling water reactor (BWR) specifications (i.e., NUREG-1433 and NUREG-1434).
The two Notes added to the Surveillance Requirements are: 1: If the as-found channel setpoint is outside its predefined as-found tolerance, then the channel shall be evaluated to verify that it is functioning as required before returning the channel to service.2: The instrument channel setpoint shall be reset to a value that is within the as-left tolerance around the [Limiting Trip Setpoint (LTSP) or Nominal Trip Setpoint (NTSP)] at the completion of the surveillance; otherwise, the channel shall be declared inoperable.
Setpoints more conservative than the [LTSP or NTSP] are acceptable provided that the as-found and as-left tolerances apply to the actual setpoint implemented in the Surveillance procedures to confirm channel performance.
The [Limiting Trip Setpoint or Nominal Trip Setpoint and the] methodologies used to determine the as-found and the as-left tolerances are specified in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by reference]
inseit the name of a docuiment eontr-elled under- 10 CFR 50.59 suceh as the Techniceal Requir.ements Manual or- any d..ument inco..Porated int the facility FSA R].In NUREG-1430, 1432, 1433, and 1434, the Technical Specification Function tables contain the Allowable Value. These specifications are referred to as having the "single column" format. In NUREG- 1431, the option is given to list only the Allowable Value or to list the Allowable Value and the [Nominal Trip Setpoint (NTSP)]. This second option is referred to as the "multiple columns" format; in this presentation, the [NTSP] is the LSSS. Those plants that utilize the "multiple column" format are not required to incorporate the NTSP value in the last sentence in Note 2 because any change to the value requires prior NRC review and the values cannot be changed by the licensee under 10 CFR 50.59. For plants that specify the[NTSP] or [LTSP] instead of the Allowable Value, the same restrictions apply and the identification of the [LTSP] or [NTSP] in the last sentence in Note 2 is not required.The Bases are revised to reflect the addition of the Notes to the applicable Functions.
The Bases are also revised to define the term "Limiting Trip Setpoint" or "Nominal Trip Setpoint," and to discuss the relationship of the LSSS to other values, such as the Allowable Value and the [NTSP] or [LTSP]. The Bases provide details on the implementation of the requirements described in the Notes and the relationship between the as-found value and Function OPERABILITY.
Where necessary to provide context for the other changes, a description of the use of [LTSP] and Allowable Value is added to the Specification Bases, similar to the discussion in the reactor trip system Specification Bases.In addition, for each ISTS Section 3.3 instrumentation trip or actuation function not annotated with the Notes described above, the Surveillance Requirement Bases for surveillances that verify the setpoint are modified to state: Page 2 TSTF-493, Rev. 4 tolerance will ensure that channel operation is consistent with the assumptions or design inputs used in the setpoint calculations and that there is a high confidence of acceptable channel performance in the future. Because the tolerance is two sided, changes in channel performance that are conservative will also be detected and evaluated for possible effects on expected performance.
Implementation of Note 1 requires the licensee to calculate an as-found tolerance.
One acceptable method of calculating the as-found tolerance is the Square Root Sum of the Squares (SRSS) combination of either a) Reference Accuracy (RA), Measurement and Test Equipment (M&TE) error, M&TE readability (M&TEr) and projected drift, or b) as-left tolerance and the projected drift (assuming that as-left tolerance is < SRSS combination of RA, M&TE error, M&TEr). Different methods of calculating the as-found tolerance (including the inclusion of additional uncertainties (e.g., normal radiation effect, temperature effect between calibrations, capillary tubing error) may be acceptable.
Alternate methods must result in an as-found tolerance that is small enough to detect abnormal channel performance.
Any additional uncertainties included in the as-found tolerance calculation must be justified.
Verification that the measured setpoint is within the as-found tolerance is determined by calculating the difference between the current as-found value and the [Limiting Trip Setpoint]
or by calculating the difference between the current as-found value and the previous as-left value. In order to use the as-found minus [LTSP] methodology, the as-left tolerance must be less than or equal to the SRSS combination of the RA, M&TE, and M&TE readability.
The methodology used to determine the as-found and as-left tolerance must be stated in the document controlled under 10 CFR 50.59 referenced in Note 2, as described below.For NUREG-1431 (Westinghouse plants), Technical Specifications Note 2 states: "The instrument channel setpoint shall be reset to a value that is within the as-left tolerance around the Nominal Trip Setpoint (NTSP) at the completion of the surveillance; otherwise, the channel shall be declared inoperable.
Setpoints more conservative than the NTSP are acceptable provided that the as-found and as-left tolerances apply to the actual setpoint implemented in the Surveillance procedures (field setting) to confirm channel performance.
The Nominal Trip Setpoint and the methodologies used to determine the as-found and the as-left tolerances are specified in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by reference1[inse-the name of a  contr-olled under- 10 CFR 50.59 suceh as the Technical Requirements Manual or- any documffent inor-oated into the facaility FSAR]." For NUREG-1430, 1432, 1433, and 1434, Note 2 states: "The instrument channel setpoint shall be reset to a value that is within the as-left tolerance around the Limiting Trip Setpoint (LTSP) at the completion of the surveillance; otherwise, the channel shall be declared inoperable.
Setpoints more conservative than the LTSP are acceptable provided that the as-found and as-left tolerances apply to the actual setpoint implemented in the Surveillance procedures (Nominal Trip Setpoint) to confirm channel Page 7 TSTF-493, Rev. 4 performance.
The Limiting Trip Setpoint and the methodologies used to determine the as-found and the as-left tolerances are specified in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencell[inset the name ef a docuiment ccntrolled under- 10 CFR 50.59 suceh as the Tec-hnic-al Rcguireffcnts Manuial or- anfy dofufmenit into the faility FSAR]." Setpoint calculations assume that the instrument setpoint is left at the [NTSP or LTSP] within a specific as-left tolerance (e.g., 25 psig + 2 psig). A tolerance is necessary because no device perfectly measures the process. Additionally, it is not possible to read and adjust a setting to an absolute value due to the readability and/or accuracy of the test instruments or the ability to adjust potentiometers.
The as-left tolerance is normally as small as possible considering the tools and ALARA concerns of the calibration.
The as-left tolerance is always considered in the setpoint calculation.
Failure to set the actual plant trip setpoint to the [NTSP or LTSP] (or more conservative than the [NTSP or LTSP]), and within the as-left tolerance, would invalidate the assumptions in the setpoint calculation because any subsequent instrument drift would not start from the expected as-left setpoint.The NRC Staff is concerned that some plants may have used as-left tolerances much larger than necessary for proper reading and adjustment of the channels.
In this situation, the large tolerances could prevent or mask detection of instrument degradation or failure. However, large as-left tolerances do have the advantage of minimizing the number of times that a channel must be adjusted, and can provide a true indication of long term instrument performance if the results are trended using "as-found minus as-left" techniques.
Implementation of Note 2 may require some licensees to recalculate the as-left tolerance for some channels to ensure that realistic values are used that do not mask instrument performance.
During the process of checking the setpoint there are four possible results in best case to worst case order: 1. The setpoint is found within the as-left tolerance; the results are recorded in the procedure, and the Technical Specifications require no further action.2. The setpoint is outside the as-left tolerance but within the as-found tolerance; the setpoint is reset to within the as-left tolerance, and the Technical Specifications require no further action.3. The setpoint is found conservative with respect to the Allowable Value but outside the as-found tolerance.
In this case the channel is OPERABLE, but degraded.
The degraded condition will be further evaluated during performance of the SR. This evaluation will consist of resetting the channel setpoint to the [NTSP or LTSP] (within the allowed tolerance), and evaluating the channel response.
If the channel is functioning as required and expected to pass the next surveillance, then the channel is Operable and can be restored to service at the completion of the surveillance.
Page 8 TSTF-493, Rev. 4 3. The two Notes are not normally applied to Functions and Surveillance Requirements which test only digital components.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the requirements would apply.Discussion:
The two Notes do not apply to Functions and Surveillances which test only digital components.
For purely digital components, such as actuation logic circuits, relays, and any other tests using a digital or on/off input, there is no expected change in result between surveillance performances and any test result other than the identified Technical Specification surveillance acceptance criteria would be considered inoperable.
Where separate as-left and as-found tolerance is established for digital component SRs, the requirements would apply.An evaluation resulted in the two Notes being applied to the Functions shown in Attachment A. Each licensee proposing to adopt this Traveler must review the list of Functions in Attachment A to confirm that the identified functions are consistent with their plant specific design. The two Notes are not required to be applied to any of the listed Functions which meet any of the exclusion criteria based on the plant specific design and analysis.
In particular the licensee's evaluation must include all bypass, permissives and interlocks to verify they meet the exclusion criteria (for permissive that derives input from an adjustable device that is not tested as part of another function, the Notes would be applied).
Note that Attachment A NUREG-1433, Specification 3.3.5-1 Function 1 .d has been revised to indicate that if the valve is locked open, the Function can be removed from Technical Specifications.
The TSTF-09-07 letter dated February 23, 2009 contained incorrect information for this Function.The Allowable Value may still be the only value included in the Technical Specifications to indicate the least conservative value that the as-found setpoint may have during testing. In this case the [NTSP or LTSP] values must be contained in the facility FSAR or in any document incorporated into the facility FSAR by referencea document controlled under 10 CFR 50.59, such as the Technical Requirements Manual (or- equivalent) or- any document... 'crpated inte the UFSAR, and and the title of this document must be identified in Note 2 in order to satisfy the 10 CFR 50.36 requirement that the LSSS be in the Technical Specifications.
Additionally, to ensure proper use of the Allowable Value, [Limiting Trip Setpoints], and [Nominal Trip Setpoints or field settings], the methodology for calculating the as-left and as-found tolerances, as discussed above, must also be included in the facility FSAR or in any document incorporated into the facility FSAR by reference eeidm controlled under 10 CFR 50.59 and listed in the second Note.For TS with a multiple column format which lists the [NTSP] (as shown as an option in NUREG-143 1), the last sentence of Note2 is modified to remove the requirement that the[NTSP] be identified in the facility FSAR or in any document incororated into the facility FSAR by reference.
a 10 CFR 50.59 controlled document.
If the [NTSP] is specified in the Technical Specifications, any change to the [NTSP] requires prior NRC review and approval.As a result, it is not necessary for the [NTSP] to be specified in the facility FSAR or in any document incorporated into the facility FSAR by reference a docume;#nt contolled under 10 CFR 50.59. It will still be necessary to identify the methodologies used to determine the as-Page 10 TSTF-493, Rev. 4 found and the as-left tolerances in the facility FSAR or in any document incorporated into the facility FSAR by referencea document conteolled under- 10 CFR 50.59 -and identify this document in Note 2.Addition of the Definition of "Limiting Trip Setpoint" to the Bases The term "[Limiting Trip Setpoint]" is added as generic terminology for the setpoint value calculated by means of the plant-specific setpoint methodology documented in the facility FSAR or in any document incorporated into the facility FSAR by reference deeumfee controlled under 10 CFR 50.59. The trip setpoint (field setting for Westinghouse NUREG, NTSP for all other NUREGs) may be more conservative than the Limiting or Nominal Trip Setpoint, but for the purpose of Technical Specifications compliance with 10 CFR 50.36, the plant-specific value for the LSSS must be in the specifications or the facility FSAR or in any document incorporated into the facility FSAR by reference contained in a document eo-natrc-l Ied- un4Hd-er 10 C F R 5 0. 59.Instead of referencing the title of the document that contains the [LTSPs] in Note 2, it is also acceptable to list the [LTSPs] directly in the Technical Specifications, and revise Note 2 to only identify the title of the document that describes the methodology for determining the as-found and as-left tolerances.
Option B Option B requires the implementation of a Setpoint Control Program (SPC). The requirements for the SPC are stated in the Administrative Controls section of the Technical Specifications.
Implementation of a SPC allows the relocation of setpoints from the Technical Specifications to licensee control. The SPC also requires NRC approval of the setpoint methodology used to calculate the changes to the relocated setpoints.
Lastly, the SPC includes the requirements to address the NRC's concern that are included as Notes in Option A.The SCP proposed in the Traveler assumes that all setpoints from Specifications in Section 3.3, "Instrumentation," are relocated.
An approved methodology must be listed in the Technical Specification program for each relocated setpoint and the licensee program must identify which methodology is used for each setpoint.
Paragraph
: a. of the TS Setpoint Control Program lists the Specifications which are controlled by the program. This list includes those Specifications which include Functions that are automatic protective devices related to variables having significant safety functions as delineated by 10 CFR 50.36(c)(1)(ii)(A), and other Specifications in Section 3.3 with Functions having Allowable Values or Trip Setpoints that are relocated from the Specifications to licensee control. All applicable Section 3.3 Specifications are included in this Traveler.
A licensee adopting this Traveler may choose to relocate the Allowable Values or Trip Setpoints from more or less Specifications.
The Surveillances which verify Allowable Values or Trip Setpoints in the Specifications for which Allowable Values or Trip Setpoints are relocated are revised to state that the Page 11 TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation 3.3.5 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.3.5.2----------------
NOTE ---------------
: 1. When an ESFAS channel is placed in an inoperable status solely for performance of this Surveillance, entry into associated Conditions and Required Actions may be delayed for up to 8 hours, provided the remaining two channels of ESFAS instrumentation are OPERABLE or tripped.2. If the as-found channel setpoint is outside its Dredefined as-found tolerance, then the channel shall be evaluated to verify that it is functioning as required before returning the channel to service.3. The instrument channel setpoint shall be reset to a value that is within the as-left tolerance around the Limitincg TriD Setpoint (LTSP) at the completion of the surveillance; otherwise, the channel shall be declared inoperable.
Setpoints more conservative than the LTSP are acceptable provided that the as-found and as-left tolerances apply to the actual setpoint implemented in the Surveillance procedures (Nominal Trio SetDoint) to confirm channel performance.
The LTSP and the methodolo-gies used to determine the as-found and the as-left tolerances are specified in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
--------------------------------------------------------------------
31 days Perform CHANNEL FUNCTIONAL TEST.SR 3.3.5.3 ---------------------
NOTES--------------
: 1. If the as-found channel setpoint is outside its predefined as-found tolerance, then the channel shall be evaluated to verify that it is functioning as required before returning the channel to service.2. The instrument channel setpoint shall be reset to a value that is within the as-left tolerance BWOG STS 3.3.5-3 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation 3.3.5 around the Limitina TriD Setpoint (LTSP) at the completion of the surveillance:
otherwise, the channel shall be declared inoperable.
Setpoints more conservative than the LTSP are acceptable provided that the as-found and as-left tolerances apply to the actual setpoint implemented in the Surveillance procedures (Nominal Trip Setpoint) to confirm channel performance.
The LTSP and the methodologies used to determine the as-found and the as-left tolerances are specified in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR bv referencel.
Perform CHANNEL CALIBRATION.
[18] months SR 3.3.5.4 Verify ESFAS RESPONSE TIME within limits. [18] months on a STAGGERED TEST BASIS BWOG STS 3.3.5-4 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation 3.3.5 Table 3.3.5-1 (page 1 of 1)Engineered Safety Feature Actuation System Instrumentation APPLICABLE MODES OR OTHER SPECIFIED ALLOWABLE PARAMETER CONDITIONS VALUE 1. Reactor Coolant System Pressure -Low > [1800] psig > [1600] psigl Setpoint (HPI Actuation, RB Isolation, RB Cooling, EDG Start)2. Reactor Coolant System Pressure -Low Low > [900] psig _ [400] psig&#xfd;4 Setpoint (HPI Actuation, LPI Actuation, RB Isolation, RB Cooling)3. Reactor Building (RB) Pressure -High 1,2,3,4 < [5] Setpoint (HPI Actuation, LPI Actuation, RB Isolation, RB Cooling)4. Reactor Building Pressure -High High 1,2,3,4 < [30] psigfa6w Setpoint (RB Spray Actuation)(a 4NSERT-4 BWOG STS 3.3.5-5 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1 B 3.3 INSTRUMENTATION B 3.3.1 Reactor Protection System (RPS) Instrumentation BASES BACKGROUND The RPS initiates a reactor trip to protect against violating the core fuel design limits and the Reactor Coolant System (RCS) pressure boundary during anticipated operational occurrences (AOOs). By tripping the reactor, the RPS also assists the Engineered Safety Feature (ESF)Systems in mitigating accidents.
The protection and monitoring systems have been designed to assure safe operation of the reactor. This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RPS, as well as the LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to reetaiAinclude LSSS for variables that have significant safety functions.
LSSS are defined by the regulation as "...settings for de4ee&-G6se"Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Anieyt4cAnalytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.
Any automatic protection action that occurs on reaching the AR Analtical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic prmtcctive d.v.....rotection channels must be chosen to be more conservative than the ARaalyAnalytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur.--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip settinq (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP1" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP] implemented in the Surveillance procedures to confirm channel performance.
BWOG STS B 3.3.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1 BASES BACKGROUND (continued)
The Allowable Values listed in Table 3.3.1-1 are based on the methodology described in "[Unit Specific Setpoint Methodology]" (Ref. 5), which incorporates all of the known uncertainties applicable for each channel. The magnitudes of those uncertainties are factored into the determination of each trip setp-l;t.[LTSP]
.All field sensors and signal processing equipment for these channels are assumed to operate within the allowances of these uncertainty magnitudes.
APPLICABLE The RPS Functions to preserve the SLs durinq all AOOs and mitigates the consequences of DBAs.Each of the analyzed accidents and transients can be detected by one SAFETY or more RPS Functions.
The accident analysis contained in Reference 6 ANALYSES, LCO, takes credit for most RPS trip Functions.
Functions not specifically and APPLICABILITY credited in the accident analysis were implicitlyeuaitatively credited in the safety analysis and the NRC staff approved licensing basis for the unit.These Functions are high RB pressure, high temperature, turbine trip, and loss of main feedwater.
These Functions may provide protection for conditions that do not require dynamic transient analysis to demonstrate Function performance.
These Functions also serve as backups to Functions that were credited in the safety analysis.Permissive and interlock setpoints allow the blocking of trips during plant startups, and restoration of trips when the permissive conditions are not satisfied, but they are not explicitly modeled in the Safety Analyses.These permissives and interlocks ensure that the starting conditions are consistent with the safety analysis, before preventive or mitigating actions occur. Because these permissives or interlocks are only one of multiple conservative starting assumptions for the accident analysis, they are generally considered as nominal values without regard to measurement accuracy.The LCO requires all instrumentation performing an RPS Function to be OPERABLE.
Failure of any instrument renders the affected channel(s) inoperable and reduces the reliability of the affected Functions.
The four channels of each Function in Table 3.3.1-1 of the RPS instrumentation shall be OPERABLE during its specified Applicability to ensure that a reactor trip will be actuated if needed. Additionally, during shutdown bypass with any CRD trip breaker closed, the applicable RPS Functions must also be available.
This ensures the capability to trip the withdrawn CONTROL RODS exists at all times that rod motion is possible.
The trip Function channels specified in Table 3.3.1-1 are considered OPERABLE when all channel components necessary to provide a reactor trip are functional and in service for the required MODE or Other Specified Condition listed in Table 3.3.1-1.BWOG STS B 3.3.1-14 Rev. 3.0, 03/31/04 (Includes Errata)
I TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1 Required Actions allow maintenance (protection channel) bypass of individual channels, but the bypass activates interlocks that prevent operation with a second channel bypass. Bypass effectively places the unit in a two-out-of-three logic configuration that can still initiate a reactor trip, even with a single failure within the system.For most RPS Functions, the [LTSP1 ensures that the departure from nucleate boiling (DNB) or the RCS Pressure SLs is not challenged.
Cycle specific figures for use during operation are contained in the COLR.BWOG STS B 3.3.1-15 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1 BASES ACTIONS (continued)
G.1 If the Required Action and associated Completion Time of Condition A or B are not met and Table 3.3.1-1 directs entry into Condition G, the unit must be brought to a MODE in which the specified RPS trip Function is not required to be OPERABLE.
To achieve this status, THERMAL POWER must be reduced < [151% RTP. The allowed Completion Time of 6 hours is reasonable, based on operating experience, to reach[15]% RTP from full power conditions in an orderly manner without challenging plant systems.SURVEILLANCE The SRs for each RPS Function are identified by the SRs column of REQUIREMENTS Table 3.3.1-1 for that Function.
Most Functions are subject to CHANNEL CHECK, CHANNEL FUNCTIONAL TEST, CHANNEL CALIBRATION, and RPS RESPONSE TIME testing.The SRs are modified by a Note. The [first] Note directs the reader to Table 3.3.1-1 to determine the correct SRs to perform for each RPS Function.---------------------
REVIEWER'S NOTE -----------------------------------
The CHANNEL FUNCTIONAL TEST Frequencies are based on approved topical reports. For a licensee to use these times, the licensee must justify the Frequencies as required by the NRC Staff SER for the topical report.--------------------
REVIEWER'S NOTE ------------------------------------
Notes c and d are applied to the setpoint verification Surveillances for each RPS Instrumentation Function in Table 3.3.1-1 unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or to instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.
, 2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected chanqe in BWOG STS B 3.3.1-29 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1 The second Note also requires that [LTSP1 and the methodologies for calculatinq the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.Tho .oon.d Nt alco reguire. th-t the [LTSP Rdl thr !
fr.r ini4 h-n -,n th fni G1ti+nlrrnno h ;-.r~na, nam ofrn a dOGr.. 1 .nan rA#9rtI19l undrig. 4A 'EPh I LI l I W t4W A' 'AR AR tPQ 4-RAPP'Gal RegwiFememg maRual 9F aRY QGGUgWMn#0 RGFE~Fatedpr n+,t. the fa,.1.,el D SR 3.3.1.5 A Note to the Surveillance indicates that neutron detectors are excluded from CHANNEL CALIBRATION.
This Note is necessary because of the difficulty in generating an appropriate detector input signal. Excluding the detectors is acceptable because the principles of detector operation ensure a virtually instantaneous response.A CHANNEL CALIBRATION is a complete check of the instrument channel, including the sensor. The test verifies that the channel responds to the measured parameter within the necessary range and accuracy.CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drift to ensure that the instrument channel remains operational between successive tests. CHANNEL CALIBRATION shall find that measurement errors and bistable setpoint errors are within the assumptions of the unit specific setpoint analysis.
CHANNEL CALIBRATIONS must be performed consistent with the assumptions of the unit specific setpoint analysis.BWOG STS B 3.3.1-34 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
Whenever a sensing element is replaced, the next required CHANNEL CALIBRATION of the resistance temperature detectors (RTD) sensors is accomplished by an inplace cross calibration that compares the other sensing elements with the recently installed sensing element.The Frequency is justified by the assumption of an [18] month calibration interval in the determination of the magnitude of equipment drift in the"etpointL[TSP]
analysis.SR 3.3.1 5 -is modified by two Notes as identified in Table 3.3.1-1. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP], then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.The sccnd Note also requires that the [LTSP a''d th"e! metholgies , as. left .,a, th a f,+VaIarI&#xb6;nrvac han in rnpa.4 tha n,,mal Vl Ann .Vr~~nan I.n In V, CD vvA vv p~.,In o + av .a. h n an, w I Da, , ira rn,, p i ,v, arn , r. ivv r,,, ,, RGGFPEnFate inite the flarilitCC SR 3.3.1.6 This SR verifies individual channel actuation response times are less than or equal to the maximum values assumed in the accident analysis.BWOG STS B 3.3.1-35 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1 Individual component response times are not modeled in the analyses.The analyses model the overall, or total, elapsed time from the point at which the parameter exceeds the analytical limit at the sensor to the point of rod insertion.
Response time testing acceptance criteria for this unit are included in Reference 2.A Note to the Surveillance indicates that neutron detectors are excluded from RPS RESPONSE TIME testing. This Note is necessary because of the difficulty in generating an appropriate detector input signal. Excluding the detectors is acceptable because the principles of detector operation ensure a virtually instantaneous response.Response time tests are conducted on an [18] month STAGGERED TEST BASIS. Testing of the final actuation deviceseha;wiei&, which make up the bulk of the response time, is included in the testing of each channel. Therefore, staggered testing results in response time verification of these deta4eschannels every [18] months. The [18] month Frequency is based on unit operating experience, which shows that random failures of instrumentation components causing serious response time degradation, but not channel failure, are infrequent occurrences.
BWOG STS B 3.3.1-36 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)B 3.3 INSTRUMENTATION B 3.3.5 Engineered Safety Feature Actuation System (ESFAS) Instrumentation BASES BACKGROUND The ESFAS initiates necessary safety systems, based on the values of selected unit Parameters, to protect against violating core design limits and reactor coolant pressure boundary and to mitigate accidents.
This is achieved by specifyingq limiting safety system settings (LSSS) in terms of parameters directly monitored by the ESFAS, as well as the LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 4--GFR 50.36()(1
)(i.)(A.)
ro.uirs that Toc.hnic,.
SpcifiationtF include LSSSs for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the settinq must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur.--------------------
REVIEWER'S NOTE ----------------------
The term "Limiting Trip Setpoint" [LTSP1 is gqeneric terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term FLTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP]" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
Licensees are to insert the name of the document(s) controlled under 10 CFR 50.59 that contain the methodology for calculating the as-left and as-found tolerances, in Note b of Table 3.3.5-1 for the phrase "rinsert the name of a document controlled under 10 CFR 50.59 such as the Technical Requirements Manual or any document incorporated into the facility FSAR]" throughout these Bases.Where the [LTSP1 is not included in Table 3.3.5-1, the plant-specific location for the [LTSP1 OR NTSP must be cited in Note b of Table 3.3.5-1.The brackets indicate plant-specific terms may apply, as reviewed and approved by the NRC.BWOG STS B 3.3.5-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)BASES SURVEILLANCE REQUIREMENTS (continued)
----------------------
REVIEWER'S NOTE Notes a and b are applied to the setpoint verification Surveillances for each ESFAS Function in Table 3.3.5-1 unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or te instrument functions that derive input from contacts which have no associated sensor or adjustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc..are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the requirements would apply.SR 3.3.5.1 Performance of the CHANNEL CHECK every 12 hours ensures that a gross failure of instrumentation has not occurred.
A CHANNEL CHECK is normally a comparison of the parameter indicated on one channel to a similar parameter on other channels.
It is based on the assumption that instrument channels monitoring the same parameter should read approximately the same value. Significant deviations between the two instrument channels could be an indication of excessive instrument drift in one of the channels or of something even more serious. CHANNEL CHECK will detect gross channel failure; therefore, it is key in verifying that the instrumentation continues to operate properly between each CHANNEL CALIBRATION.
Agreement criteria are determined by the unit staff, based on a combination of the channel instrument uncertainties, including isolation, indication, and readability.
If a channel is outside the criteria, it may be an indication that the transmitter or the signal processing equipment has drifted outside its limit. If the channels are normally off scale during times when surveillance is required, the CHANNEL CHECK will only verify that they are off scale in the same direction.
Off scale low current loop channels are verified to be reading at the bottom of the range and not failed downscale.
BWOG STS B 3.3.5-19 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)BASES SURVEILLANCE REQUIREMENTS (continued)
A CHANNEL FUNCTIONAL TEST is performed on each required ESFAS channel to ensure the entire channel will perform the intended functions.
A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable CHANNEL FUNCTIONAL TEST of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
Any setpoint adjustment shall be consistent with the assumptions of the current unit specific setpoint analysis.The Frequency of 31 days is based on unit operating experience, with regard to channel OPERABILITY and drift, which demonstrates that failure of more than one channel of a given function in any 31 day interval is a rare event.SR 3.3.5 2 is modified by two Notes as identified in Table 3.3.5-1. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a settinq within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in finsert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.The
..ocond Note al, o that th [LTSP atndj the! methtererrgninc fn-r r'.,iru ,Iengtmn a6 n left onRd theasn fo. mA tnlnr;;r.ncs be hn Rnser+t the nRAMA of A do nt enotrelled I 1Arlor Ifl (APC RGo..orne~ate tno he fnolari+,lA SR 3.3.5.3 BWOG STS B 3.3.5-21 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)CHANNEL CALIBRATION is a complete check of the instrument channel, including the sensor. The test verifies that the channel responds to a measured parameter within the necessary range and accuracy.CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drift to ensure that the instrument channel remains operational between successive tests. CHANNEL CALIBRATION shall find that measurement errors and bistable setpoint errors are within the assumptions of the unit specific setpoint analysis.
CHANNEL CALIBRATIONS must be performed consistent with the assumptions of the unit specific setpoint analysis.This Frequency is justified by the assumption of an [18] month calibration interval to determine the magnitude of equipment drift in the setpoint analysis.SR 3.3.5.3 is modified by two Notes as identified in Table 3.3.5-1. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [LTSPI. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP], then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.The
..cond Noto. Alo requires that tho [LTS tellar-A.r~aes -h8 OR mPR68 the Rame ef a EinA-,-.PP..An nA-GRtaI~eaAe Q --ia I- 'C-50-59 gp .m, the Teruhnm~a-IDn ajrrwn-aaner.
Ann ..Iarp MR-r--Aa larl naG F, t he flaijfy-P,,t iD SR 3.3.5.4 SR 3.3.5.4 ensures that the ESFAS actuation channel response times are less than or equal to the maximum times assumed in the accident analysis.
The response time values are the maximum values assumed in BWOG STS B 3.3.5-22 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)the safety analyses.
Individual component response times are not modeled in the analyses.
Response time testing acceptance criteria for this unit are included in Reference 4-.2. The analyses model the overall or total elapsed time from the point at which the parameter exceeds the actuation setpoint value at the sensor to the point at which the end device is actuated.
Thus, this SR encompasses the automatic actuation logic components covered by LCO 3.3.7 and the operation of the mechanical ESF components.
Response time tests are conducted on an [18] month STAGGERED TEST BASIS. Testing of the final actuation devices, which make up the bulk of the response time, is included in the testing of each channel.Therefore, staggered testing results in response time verification of these deoi~eschannels every [18] months. The 18 month test Frequency is based on unit operating experience, which shows that random failures of instrumentation components causing serious response time degradation but not channel failure are infrequent occurrences.
REFERENCES
: 1. Regulatory Guide 1.105, Revision 3, "Setpoints for Safety Related Instrumentation."FSAR, Chaptor [71.2. FSAR, Chapter [71.3. 10 CFR 50.49.4.3. [Unit Specific Setpoint Methodology.]
5.4.FSAR, Chapter [14].BWOG STS B 3.3.5-23 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RTS Instrumentation B 3.3.1 B 3.3 INSTRUMENTATION B 3.3.1 Reactor Trip System (RTS) Instrumentation BASES BACKGROUND The RTS initiates a unit shutdown, based on the values of selected unit parameters, to protect against violating the core fuel design limits and Reactor Coolant System (RCS) pressure boundary during aft!Gipated oporational occurroncosAnticipated Operational Occurrences (AOOs) and to assist the Engineered Safety Features (ESF) Systems in mitigating accidents.
The protection and monitoring systems have been designed to assure safe operation of the reactor. This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RTS, as well as specifying LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to eentaininclude LSSS for variables that have significant safety functions.
LSSS are defined by the regulation as !!"seftiigS fGWhere a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective doviceos.. .s chosen that automatic protective actionactions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The ARnI!ytGAnalytical Limit is the limit of the process variable at which a safetyprotective action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.Any automatic protection action that occurs on reaching the AnaahiteAnalytical Limit therefore ensures that the SL is not exceeded.However, in practice, the actual settings for automatic P-eteetPiV9 deviGesprotection channels must be chosen to be more conservative than the ARaly4ieAnalytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur.--------------------
REVIEWER'S NOTE The t4p-term "Limiting Trip Setpoint (LTSP)" is generic terminology for the calculated field setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting.For most Westinghouse plants the term Nominal Trip Setpoint (NTSP) is used in place of the term LTSP, and NTSP will replace LTSP in the Bases descriptions. "Field setting" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated field setting. The as-found and as-left WOG STS B 3.3.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RTS Instrumentation B 3.3.1 BASES ACTIONS (continued)
S.1 and S.2 Condition S applies to the RTB Undervoltage and Shunt Trip Mechanisms, or diverse trip features, in MODES 1 and 2. With one of the diverse trip features inoperable, it must be restored to an OPERABLE status within 48 hours or the unit must be placed in a MODE where the requirement does not apply. This is accomplished by placing the unit in MODE 3 within the next 6 hours (54 hours total time). The Completion Time of 6 hours is a reasonable time, based on operating experience, to reach MODE 3 from full power in an orderly manner and without challenging unit systems. With the unit in MODE 3, ACTION C would apply to any inoperable RTB trip mechanism.
The affected RTB shall not be bypassed while one of the diverse features is inoperable except for the time required to perform maintenance to one of the diverse features.
The allowable time for performing maintenance of the diverse features is 2 hours for the reasons stated under Condition P.The Completion Time of 48 hours for Required Action S.1 is reasonable considering that in this Condition there is one remaining diverse feature for the affected RTB, and one OPERABLE RTB capable of performing the safety function and given the low probability of an event occurring during this interval.SURVEILLANCE
---------------------
REVIEWER'S NOTE ------------------
REQUIREMENTS In Table 3.3.1-1, Functions 11 .a and 11 .b were not included in the generic evaluations approved in either WCAP-10271, as supplemented, or WCAP-14333.
In order to apply the WCAP-10271, as supplemented, and WCAP-14333 TS relaxations to plant specific Functions not evaluated generically, licensees must submit plant specific evaluations for NRC review and approval.--------------------
REVIEWER'S NOTE Notes b and c are applied to the setpoint verification Surveillances for each RTS instrumentation Function in Table 3.3.1-1 unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or te instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, Proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.WOG STS B 3.3.1-50 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RTS Instrumentation B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.7 SR 3.3.1.7 is the performance of a COT every 184 days.A COT is performed on each required channel to ensure the entire channel will perform the intended Function.
A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable COT of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
Setpoints must be withieiconservative with respect to the Allowable Values specified in Table 3.3.1-1.The difference between the current "as found" values and the previous test "as left" values must be consistent with the drift allowance used in the setpoint methodology.
The setpoint shall be left set consistent with the assumptions of the current unit specific setpoint methodology.
The "as-found" land "as-left"]
values must also be recorded and reviewed for consistency with the assumptions of Reference 9.SR 3.3.1.7 is modified by a Note that provides a 4 hours delay in the requirement to perform this Surveillance for source range instrumentation when entering MODE 3 from MODE 2. This Note allows a normal shutdown to proceed without a delay for testing in MODE 2 and for a short time in MODE 3 until the RTBs are open and SR 3.3.1.7 is no longer required to be performed.
If the unit is to be in MODE 3 with the RTBs closed for > 4 hours this Surveillance must be performed prior to 4 hours after entry into MODE 3.The Frequency of 184 days is justified in Reference 9.SR 3.3.1.7 is modified by two Notes as identified in Table 3.3.1-1. The first Note requires evaluation of channel performance for the condition where the as-found settinq for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the channels will be evaluated under the plant Corrective Action WOG STS B 3.3.1-57 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RTS Instrumentation B 3.3.1 Proqram. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [NTSP]. Where a setpoint more conservative than the[NTSP1 is used in the plant surveillance procedures (field setting), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient marqin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel settinq cannot be returned to a settinq within the as-left tolerance of the [NTSP1, then the channel shall be declared inoperable.
---------------------
REVIEWER'S NOTE ------------------
The bracketed section [NTSP and thel' of the sentence in Note (c) in Table 3.3.1-1 is not required in plant-specific Technical Specifications which include a [Nominal Trio SetDointi column in Table 3.3.1-1.... .. ..... .......I ..... ... ......r ------------------------ --r ...............The second Note also requires that the FNTSP and the] methodologies for calculatinq the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of a documcnt controlled under 10 CFR 50.59 su-ch as the Technical Requroemonts .Manu-al or any document incorporated into the facility FSAR by referencel.
WOG STS B 3.3.1-58 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RTS Instrumentation B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.8 SR 3.3.1.8 is the performance of a COT as described in SR 3.3.1.7, except it is modified by a Note that this test shall include verification that the P-6 and P-10 interlocks are in their required state for the existing unit condition.
A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable COT of a relay.This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
The Frequency is modified by a Note that allows this surveillance to be satisfied if it has been performed within 184 days of the Frequencies prior to reactor startup and four hours after reducing power below P-1 0 and P-6. The Frequency of "prior to startup" ensures this surveillance is performed prior to critical operations and applies to the source, intermediate and power range low instrument channels.
The Frequency of [12] hours after reducing power below P-10 (applicable to intermediate and power range low channels) and 4 hours after reducing power below P-6 (applicable to source range channels) allows a normal shutdown to be completed and the unit removed from the MODE of Applicability for this surveillance without a delay to perform the testing required by this surveillance.
The Frequency of every 92 days thereafter applies if the plant remains in the MODE of Applicability after the initial performances of prior to reactor startup and [12] and four hours after reducing power below P-10 or P-6, respectively.
The MODE of Applicability for this surveillance is < P-10 for the power range low and intermediate range channels and < P-6 for the source range channels.Once the unit is in MODE 3, this surveillance is no longer required.
If power is to be maintained
< P-10 for more than [12] hours or < P-6 for more than 4 hours, then the testing required by this surveillance must be performed prior to the expiration of the time limit. [Twelve] hours and four hours are reasonable times to complete the required testing or place the unit in a MODE where this surveillance is no longer required.
This test ensures that the NIS source, intermediate, and power range low channels are OPERABLE prior to taking the reactor critical and after reducing power into the applicable MODE (< P-1 0 or < P-6) for periods > [12] and 4 hours, respectively.
The Frequency of 184 days is justified in Reference 13.SR 3.3.1.8 is modified by two Notes as identified in Table 3.3.1-1. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will WOG STS B 3.3.1-59 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RTS Instrumentation B 3.3.1 continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returninq the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [NTSP1. Where a setpoint more conservative than the [NTSP1 is used in the plant surveillance procedures (field setting), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [NTSP1, then the channel shall be declared inoperable.
---------------------
REVIEWER'S NOTE ------------------
The bracketed section '[NTSP and thel' of the sentence in Note (c) in Table 3.3.1-1 is not required in plant-specific Technical Specifications which include a [Nominal Trip Setpointi column in Table 3.3.1-1.The second Note also requires that the [NTSP and thel methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of a document controlled under 10 CFR 50.59 uc ..s. tho Mau,.l or any document incorporated into the facility FSAR by referencel.
WOG STS B 3.3.1-60 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RTS Instrumentation B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.9 SR 3.3.1.9 is the performance of a TADOT and is performed every[92] days, as justified in Reference
: 9. A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable TADOT of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
The SR is modified by a Note that excludes verification of setpoints from the TADOT. Since this SR applies to RCP undervoltage and underfrequency relays, setpoint verification requires elaborate bench calibration and is accomplished during the CHANNEL CALIBRATION.
SR 3.3.1.10 A CHANNEL CALIBRATION is performed every [18] months, or approximately at every refueling.
CHANNEL CALIBRATION is a complete check of the instrument loop, including the sensor. The test verifies that the channel responds to a measured parameter within the necessary range and accuracy.CHANNEL CALIBRATIONS must be performed consistent with the assumptions of the unit specific setpoint methodology.
The difference between the current "as-found" values and the [NTSP or previous test"as-left" valuesi must be consistent with the drift allowance used in the setpoint methodology.
The Frequency of 18 months is based on the assumption of an 18 month calibration interval in the determination of the magnitude of equipment drift in the setpoint methodology.
SR 3.3.1.10 is modified by a Note stating that this test shall include verification that the time constants are adjusted to the prescribed values where applicable.
SR 3.3.1.10 is modified by two Notes as identified in Table 3.3.1-1. The first Note requires evaluation of channel performance for the condition where the as-found settinq for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The WOG STS B 3.3.1-61 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RTS Instrumentation B 3.3.1 purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [NTSP1. Where a setpoint more conservative than the [NTSP1 is used in the plant surveillance procedures (field setting), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [NTSP], then the channel shall be declared inoperable.
-------------
--------REVIEWER'S NOTE ------------------
The bracketed section '[NTSP and thel' of the sentence in Note (c) in Table 3.3.1-1 is not required in plant-specific Technical Specifications which include a [Nominal Trip Setpoint]
column in Table 3.3.1-1.The second Note also requires that the [NTSP and thel methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of a dcumont controlled -ndor 10 CFR 50.59 .uch a;- the Techna-'l Requirements Manual o. any document incorporated into the facility FSAR by referencel.
B 3.3.1-62 Rev. 3.0, 03/31/04 WOG STS B 3.3.1-62 Rev. 3.0, 03/31/04 (includes Errata)
TSTF-493, Rev. 4 (Option A)RTS Instrumentation B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.11 SR 3.3.1.11 is the performance of a CHANNEL CALIBRATION, as described in SR 3.3.1.10, every [18] months. This SR is modified by a Note stating that neutron detectors are excluded from the CHANNEL CALIBRATION.
The CHANNEL CALIBRATION for the power range neutron detectors consists of a normalization of the detectors based on a power calorimetric and flux map performed above 15% RTP. The CHANNEL CALIBRATION for the source range and intermediate range neutron detectors consists of obtaining the detector plateau or preamp discriminator curves, evaluating those curves, and comparing the curves to the manufacturer's data. This Surveillance is not required for the NIS power range detectors for entry into MODE 2 or 1, and is not required for the NIS intermediate range detectors for entry into MODE 2, because the unit must be in at least MODE 2 to perform the test for the intermediate range detectors and MODE 1 for the power range detectors.
The[18] month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power. Operating experience has shown these components usually pass the Surveillance when performed on the [18] month Frequency.
SR 3.3.1.11 is modified by two Notes as identified in Table 3.3.1-1. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [NTSP1. Where a setpoint more conservative than the [NTSP1 is used in the plant surveillance procedures (field setting), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [NTSP1, then the channel shall be declared inoperable.
WOG STS B 3.3.1-63 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RTS Instrumentation B 3.3.1---------------------
REVIEWER'S NOTE -----------------------------------
The bracketed section '[NTSP and thel' of the sentence in Note (c) in Table 3.3.1-1 is not required in plant-specific Technical Specifications which include a [Nominal Trip Setpointl column in Table 3.3.1-1.The second Note also requires that the [NTSP and thel methodologies for calculatinq the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of a dc'ument controlled unrder 10 CFR 50.59 Such as the Technical Requirements Manuall o any document incorporated into the facility FSAR by referencel.
SR 3.3.1.12 SR 3.3.1.12 is the performance of a CHANNEL CALIBRATION, as described in SR 3.3.1.10, every [18] months. This SR is modified by a Note stating that this test shall include verification of the RCS resistance temperature detector (RTD) bypass loop flow rate. Whenever a sensing element is replaced, the next required CHANNEL CALIBRATION of the resistance temperature detectors (RTD) sensors is accomplished by an inplace cross calibration that compares the other sensing elements with the recently installed sensing element.This test will verify the rate lag compensation for flow from the core to the RTDs.The Frequency is justified by the assumption of an 18 month calibration interval in the determination of the magnitude of equipment drift in-the setpoint analysis.SR 3.3.1.12 is modified by two Notes as identified in Table 3.3.1-1. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [NTSP1. Where a setpoint more conservative than the [NTSP1 is used in the plant surveillance procedures (field setting), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will WOG STS B 3.3.1-64 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RTS Instrumentation B 3.3.1 ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a settinq within the as-left tolerance of the [NTSP1, then the channel shall be declared inoperable.
---------------------
REVIEWER'S NOTE ------------------
The bracketed section '[NTSP and thel' of the sentence in Note (c) in Table 3.3.1-1 is not required in plant-specific Technical Specifications which include a [Nominal Trip Setpointl column in Table 3.3.1-1.The second Note also requires that the [NTSP and thel methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of a documont controlled -ndor 10 CFR 50.59 such ;r tho Technical Reguiromentc Manual or any document incorporated into the facility FSAR bv referencel.
WOG STS B 3.3.1-65 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Engineered Safety Feature Actuation System (ESFAS) Instrumentation B 3.3.2 B 3.3 INSTRUMENTATION B 3.3.2 Engineered Safety Feature Actuation System (ESFAS) Instrumentation BASES BACKGROUND The ESFAS initiates necessary safety systems, based on the values of selected unit parameters, to protect against violating core design limits and the Reactor Coolant System (RCS) pressure boundary, and to mitigate accidents.
This is achieved by specifying limiting safety system settings (LSSS) in terms of Parameters directly monitored by the ESFAS, as well as specifying LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to include LSSS for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a protective action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur.--------------------
REVIEWER'S NOTE ------------------------------------
The term "Limiting Trip Setpoint (LTSP)" is generic terminology for the calculated field setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting.For most Westinghouse plants the term Nominal Trip Setpoint (NTSP) is used in place of the term LTSP, and NTSP will replace LTSP in the Bases descriptions. "Field setting" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated field setting. The as-found and as-left tolerances will apply to the field setting implemented in the Surveillance procedures to confirm channel performance.
Licensees are to insert the name of the document(s) controlled under 10 CFR 50.59 that contain the methodology for calculating the as-left and as-found tolerances, in Note c of Table 3.3.2-1 for the phrase "[insert the name of a document controlled under 10 CFR 50.59 such as the WOG STS B 3.3.2-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Engineered Safety Feature Actuation System (ESFAS) Instrumentation B 3.3.2 BASES BACKGROUND (continued)
Generally, if a parameter is used for input to the SSPS and a control function, four channels with a two-out-of-four logic are sufficient to provide the required reliability and redundancy.
The circuit must be able to withstand both an input failure to the control system, which may then require the protection function actuation, and a single failure in the other channels providing the protection function actuation.
Again, a single failure will neither cause nor prevent the protection function actuation.
These requirements are described in IEEE-279-1971 (Ref. 45). The actual number of channels required for each unit parameter is specified in Reference 2-3.Allo.^-able Valuos[NTSPs]
and ESFAS Setpoints
[Allowable Values]The trip setpoints used in the bistables are based on the analytical limits stated in Reference
: 2. The solctinof theso,. trip setpeints3.
The calculation of the Nominal Trip Setpoints specified in Table 3.3.2-1 is such that adequate protection is provided when all sensor and processing time delays are taken into account. To allow for calibration tolerances, instrumentation uncertainties, instrument drift, and severe environment errors for those ESFAS channels that must function in harsh environments as defined by 10 CFR 50.49 (Ref. _6), the Allowable Values specified in Table 3.3.2-1 in the accompanying LCO are conservative with respect to the analytical limits. A detailed description of the methodology used to calculate the Allowable Values and ESFAS setpa.s[NTSPs]
including their explicit uncertainties, is provided in the plant specific setpoint methodology study (Ref. 6 7) which incorporates all of the known uncertainties applicable to each channel. The as-left tolerance and as-found tolerance band methodology is provided in [insert the name of a document controlled under 10 CFR 50.59 such as the Technical Requirements Manual or any document incorporated into the facility FSAR]. The magnitudes of these uncertainties are factored into the determination of each ESFAS setpe"[N[TSP]
and corresponding Allowable Value. The nominal ESFAS setpoint entered into the bistable is more conservative than that specified by the AlloWbe Valuo[NTSP1 to account for measurement errors detectable by the COT. The Allowable Value serves as the as-found Technical Specification OPERABILITY limit for the purpose of the COT. One example of such a change in moasuroemont orror is drift dur1ing thoureilac novl If thole measured setpoint does not exceed the Allowable Value, the bistable is considorod OPERA\BLE.
The ESFAS setpoints are[NTSP]
is the Y'aIesvalue at which the bistables are set and is the expected value to be achieved during calibration.
The ESPAS setp [NTSP] value is the LSSS and ensures the safety analysis limits are met for the surveillance interval selected when a WOG STS B 3.3.2-6 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Engineered Safety Feature Actuation System (ESFAS) Instrumentation B 3.3.2 BASES BACKGROUND (continued)
Each SSPS train has a built in testing deviceeha;niAl that can automatically test the decision logic matrix functions and the actuation 4eVOAeschannels while the unit is at power. When any one train is taken out of service for testing, the other train is capable of providing unit monitoring and protection until the testing has been completed.
The testing deviceehaRel is semiautomatic to minimize testing time.The actuation of ESF components is accomplished through master and slave relays. The SSPS energizes the master relays appropriate for the condition of the unit. Each master relay then energizes one or more slave relays, which then cause actuation of the end devices.ehaiPel.
The master and slave relays are routinely tested to ensure operation.
The test of the master relays energizes the relay, which then operates the contacts and applies a low voltage to the associated slave relays. The low voltage is not sufficient to actuate the slave relays but only demonstrates signal path continuity.
The SLAVE RELAY TEST actuates the devicesehafwels if their operation will not interfere with continued unit operation.
For the latter case, actual component operation is prevented by the SLAVE RELAY TEST circuit, and slave relay contact operation is verified by a continuity check of the circuit containing the slave relay.------------------
REVIEWER'S NOTE ---------------------
No one unit ESFAS incorporates all of the Functions listed in Table 3.3.2-1. In some cases (e.g., Containment Pressure -High 3, Function 2.c), the Table reflects several different implementations of the same Function.
Typically, only one of these implementations are used at any specific unit.APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY Each of the analyzed accidents can be detected by one or more ESFAS Functions.
One of the ESFAS Functions is the primary actuation signal for that accident.
An ESFAS Function may be the primary actuation signal for more than one type of accident.
An ESFAS Function may also be a secondary, or backup, actuation signal for one or more other accidents.
For example, Pressurizer Pressure -Low is a primary actuation signal for small loss of coolant accidents (LOCAs) and a backup actuation signal for steam line breaks (SLBs) outside containment.
Functions such as manual initiation, not specifically credited in the accident safety analysis, are implicitlyqa~ta4vel credited in the safety analysis and the NRC staff approved licensing basis for the unit. These Functions may provide protection for conditions that do not require dynamic transient analysis to demonstrate Function performance.
These Functions may also serve as backups to Functions that were credited in the accident analysis (Ref. 34).WOG STS B 3.3.2-10 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Engineered Safety Feature Actuation System (ESFAS) Instrumentation B 3.3.2 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)
Permissive and interlock setpoints allow the blocking of trips during plant startups, and restoration of trips when the permissive conditions are not satisfied, but they are not explicitly modeled in the Safety Analyses.These permissives and interlocks ensure that the starting conditions are consistent with the safety analysis, before preventive or mitigating actions occur. Because these permissives or interlocks are only one of multiple conservative starting assumptions for the accident analysis, they are generally considered as nominal values without regard to measurement accuracy., (i.e. the value ind-cated is sufficiently close to the necessa,;value nI ate eRau~ wepe naeana f the a ,fety p6,ptarnc tG IErr thaAfl'The LCO requires all instrumentation performing an ESFAS Function, listed in Table 3.3.2-1 in the accompanying LCO, to be OPERABLE.AThe Allowable Value specified in Table 3.3.2-1 is the least conservative value of the as-found setpoint that the channel can have when tested, such that a channel is OPERABLE with a trip stp"int value A'--tsido its calibration tolerance band provided therpif the as-found setpoint !as-found" value does n,-xcved its, ,-sciaed, AlloVable Value. A-n pFev4dedis within the as-found tolerance and is conservative with respect to the Allowable Value during the CHANNEL CALIBRATION or CHANNEL OPERATIONAL TEST (COT). As such, the Allowable Value differs from the [NTSP1 by an amount [greater than orn equal to the expected instrument channel uncertainties, such as drift, during the surveillance interval.
In this manner, the actual setting of the channel ([NTSP]) will ensure that a SL is not exceeded at any given point of time as long as the channel has not drifted beyond expected tolerances during the surveillance interval.
Note that, although the channel is OPERABLE under these circumstances, the trip setpoint 2as-must be left!-value-is adjusted to a value within the caibrFation tlerFance band of the ,NominAlpetpe*R4-as-left tolerance, in accordance with uncertainty assumptions stated in the referenced setpoint methodology (as-left criteria), and confirmed to be operating within the statistical allowances of the uncertainty terms assigned (as-found criteria).
If the actual setting of the channel is found to be conservative with respect to the Allowable Value but is beyond the as-found tolerance band, the channel is OPERABLE but degraded.
The degraded condition of the channel will be further evaluated durinq performance of the SR. This evaluation will consist of resettinq the channel setpoint to the [NTSP1 (within the allowed tolerance) and evaluating the channel.response If the channel is functioning as required and expected to pass the next surveillance, then the channel can be restored to service at the completion of the surveillance.
WOG STS B 3.3.2-11 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Engineered Safety Feature Actuation System (ESFAS) Instrumentation B 3.3.2 BASES SURVEILLANCE
------------------
REVIEWER'S NOTE ------------------------------------------
REQUIREMENTS In Table 3.3.2-1, Functions 7.b and 7.c were not included in the generic evaluations approved in either WCAP-10271, as supplemented, or WCAP-14333.
In order to apply the WCAP-10271, as supplemented, and WCAP-14333 TS relaxations to plant specific Functions not evaluated generically, licensees must submit plant specific evaluations for NRC review and approval.------------
------- REVIEWER'S NOTE ----------
....................
Notes b and c are applied to the setpoint verification Surveillances for all Engineered Safety Feature Actuation System (ESFAS) Instrumentation Function in Table 3.3.2-1 unless one or more of the following exclusions
&#xfd;ial&#xfd;1. Manual actuation circuits, automatic actuation logic circuits or-te instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the requirements would apply.The SRs for each ESFAS Function are identified by the SRs column of Table 3.3.2-1.A Note has been added to the SR Table to clarify that Table 3.3.2-1 determines which SRs apply to which ESFAS Functions.
Note that each channel of process protection supplies both trains of the ESFAS. When testing channel I, train A and train B must be examined.Similarly, train A and train B must be examined when testing channel II, channel Ill, and channel IV (if applicable).
The CHANNEL CALIBRATION and COTs are performed in a manner that is consistent with the WOG STS B 3.3.2-54 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Engineered Safety Feature Actuation System (ESFAS) Instrumentation B 3.3.2 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.2.4 SR 3.3.2.4 is the performance of a MASTER RELAY TEST. The MASTER RELAY TEST is the energizing of the master relay, verifying contact operation and a low voltage continuity check of the slave relay coil;. Upon master relay contact operation, a low voltage is injected to the slave relay coil. This voltage is insufficient to pick up the slave relay, but large enough to demonstrate signal path continuity.
This test is performed every 92 days on a STAGGERED TEST BASIS. The time allowed for the testing (4 hours) is justified in Reference 44-12-_. The Frequency of 92 days is justified in Reference 410.SR 3.3.2.5 SR 3.3.2.5 is the performance of a COT.A COT is performed on each required channel to ensure the entire channel will perform the intended Function.
Setpoints must be found withinconservative with respect to the Allowable Values specified in Table 3.3.42-1._A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable COT of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
The difference between the current "as-found" values and the previous test "as left" values must be consistent with the drift allowance used in the setpoint methodology.
The setpoint shall be left set consistent with the assumptions of the current unit specific setpoint methodology.
The "as-found" and "as-left" values must also be recorded and reviewed for consistency with the assumptions of Reference 67.The Frequency of 184 days is justified in Reference 14-12.SR 3.3.2.5 is modified by two Notes as identified in Table 3.3.2-1. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel WOG STS B 3.3.2-57 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Engineered Safety Feature Actuation System (ESFAS) Instrumentation B 3.3.2 performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [NTSPI. Where a setpoint more conservative than the [NTSP1 is used in the plant surveillance procedures (field setting), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [NTSP1, then the channel shall be declared inoperable.
---------------------
REVIEWER'S NOTE ------------------
The bracketed section INTSP and thel of the sentence in Note (c) in Table 3.3.2-1 is not required in plant-specific Technical Specifications which include a [Nominal Trip Setpointl column in Table 3.3.2-1.The second Note also requires that the [NTSP and thel methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
The GeGGRd kNete a1GG~ FGQn,.G that~ thef+k rkITSP a,-~fnld the! ineth dnk~t'es of a; douen-ret cnA-trolled unde 10 CFR 50 cuch a the TochnRica4 Re .t M an O aR do n ' t u" o u "I t. fa" 'ul '" F, S R -v-, ., v , , v ~ , .V ~ ,, WOG STS B 3.3.2-58 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Engineered Safety Feature Actuation System (ESFAS) Instrumentation B 3.3.2 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.2.8 SR 3.3.2.8 is the performance of a TADOT. This test is a check of the Manual Actuation Functions and AFW pump start on trip of all MFW pumps. It is performed every [18] months. Each Manual Actuation Function is tested up to, and including, the master relay coils. A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable TADOT of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
In some instances, the test includes actuation of the end device (i.e., pump starts, valve cycles, etc.). The Frequency is adequate, based on industry operating experience and is consistent with the typical refueling cycle.SR 3.3.2.8 is modified by two Notes as identified in Table 3.3.2-1. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [NTSP1. Where a setpoint more conservative than the [NTSP1 is used in the plant surveillance procedures (field setting), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [NTSP1, then the channel shall be declared inoperable.
---------------------
REVIEWER'S NOTE -----------------------------------
The bracketed section '[NTSP and thel' of the sentence in Note (c) in Table 3.3.2-1 is not required in plant-specific Technical Specifications which include a [Nominal Trip Setpointl column in Table 3.3.2-1.WOG STS B 3.3.2-60 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Engineered Safety Feature Actuation System (ESFAS) Instrumentation B 3.3.2 The second Note also requires that the [NTSP and thel methodolo-gies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of a document controlled-under 10 CFR 50.59 SUch as the Technic.l Reguiroments Manual or any document incorporated into the facility FSAR by referencel.
The SR is modified by a Note that excludes verification of setpoints during the TADOT for manual initiation Functions.
The manual initiation Functions have no associated setpoints.
SR 3.3.2.9 SR 3.3.2.9 is the performance of a CHANNEL CALIBRATION.
A CHANNEL CALIBRATION is performed every [18] months, or approximately at every refueling.
CHANNEL CALIBRATION is a complete check of the instrument loop, including the sensor. The test verifies that the channel responds to measured parameter within the necessary range and accuracy.CHANNEL CALIBRATIONS must be performed consistent with the assumptions of the unit specific setpoint methodology.
The difference between the current "as:found" values and the previous test "as-left" values must be consistent with the drift allowance used in the setpoint methodology.
The Frequency of [18] months is based on the assumption of an[18] month calibration interval in the determination of the magnitude of equipment drift in the setpoint methodology.
This SR is modified by a Note stating that this test should include verification that the time constants are adjusted to the prescribed values where applicable.
SR 3.3.2.9 is modified by two Notes as identified in Table 3.3.2-1. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be WOG STS B 3.3.2-61 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Engineered Safety Feature Actuation System (ESFAS) Instrumentation B 3.3.2 returned to within the as-left tolerance of the [NTSP1. Where a setpoint more conservative than the [NTSP1 is used in the plant surveillance procedures (field setting), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [NTSP1, then the channel shall be declared inoperable.'
---------------------
REVIEWER'S NOTE ------------------
The bracketed section '[NTSP and thel' of the sentence in Note (c) in Table 3.3.2-1 is not required in plant-specific Technical Specifications which include a [Nominal Trip Setpointl column in Table 3.3.2-1.--The second Note also requires that the [NTSP and thel methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
r--A-Rn t reI e d -,s P d em r 1- I R- Qrn. 9 hr ;i s t +h e I P- Gh~ A G l WOG STS B 3.3.2-62 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Digital)3.3.5 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.3.5.1 Perform a CHANNEL CHECK of each ESFAS 12 hours channel.SR 3.3.5.2-------------------------
NOTES ---------------------
: 1. If the as-found channel setpoint is outside its Dredefined as-found tolerance, then the channel shall be evaluated to verify that it is functioninq as required before returninq the channel to service.2. The instrument channel setpoint shall be reset to a value that is within the as-left tolerance around the Limiting Trip Setpoint (LTSP) at the completion of the surveillance; otherwise, the channel shall be declared inoperable.
Setpoints more conservative than the LTSP are acceptable provided that the as-found and as-left tolerances apply to the actual setpoint implemented in the Surveillance procedures (Nominal TriD Setooint) to confirm channel performance.
The LTSP and the methodologies used to determine the as-found and the as-left tolerances are specified in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
Perform a CHANNEL FUNCTIONAL TEST of each ESFAS channel.92 days SR 3.3.5.3------ ------------
NOTES--------------
: 1. If the as-found channel setpoint is outside its Dredefined as-found tolerance.
then the channel shall be evaluated to verify that it is functioninq as required before returninq the channel to service.2. The instrument channel setpoint shall be reset to a value that is within the as-left tolerance around the Limiting TriD Setooint (LTSP) at the completion of the surveillance:
otherwise, the channel shall be declared inoperable.
Setpoints more conservative than the LTSP are CEOG STS 3.3.5-3 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Digital)3.3.5 SURVEILLANCE FREQUENCY acceotable Drovided that the as-found and as-left tolerances apply to the actual setpoint implemented in the Surveillance procedures (Nominal Trip Setpoint) to confirm channel performance.
The LTSP and the methodologies used to determine the as-found and the as-left tolerances are specified in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by reference].
Perform a CHANNEL CALIBRATION of each ESFAS channel, including bypass removal functions.
[18] months SR 3.3.5.4 Verify ESF RESPONSE TIME is within limits. [18] months on a STAGGERED TEST BASIS SR 3.3.5.5 Perform a CHANNEL FUNCTIONAL TEST on each Once within automatic bypass removal channel. 92 days prior to each reactor startup CEOG STS 3.3.5-4 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Digital)3.3.5 Table 3.3.5-1 (page 1 of 2)Engineered Safety Features Actuation System Instrumentation APPLICABLE MODES OR OTHER SPECIFIED FUNCTION CONDITIONS ALLOWABLE VALUE 1. Safety Injection Actuation Signal(a)a. Containment Pressure -High 1,2,3 < [3.14] psigf4=*r b. Pressurizer Pressure -Low(bj-) 1,2,3 > [1763] psial4 2. Containment Spray Actuation Signal a. Containment Pressure-High High 1,2,3 <[16.83] psial&#xfd;b. Automatic SIAS 1,2,3 NA 3. Containment Isolation Actuation Signal a. Containment Pressure-High 1,2,3 <[3.14] psigfbr b. Pressurizer Pressure -Low(db) 1,2,3 > [1763] psiafl)&#xfd;4. Main Steam Isolation Signal a. Steam Generator Pressure -Low~&#xfd;) 1 , 2 (d-D),3(dt)
_> [711] b. Containment Pressure -High 1 , 2 (d-), 3 (d!) < [3.14] psig~w4Q 5. Recirculation Actuation Signal a. Refueling Water Storage Tank Level -1,2,3 [> 17.73 and < 19.27]%11 Low (a) Automatic SIAS also initiates a Containment Cooling Actuation Signal (CCAS).(bd) The setpoint may be decreased to a minimum value of [300] psia, as pressurizer pressure is reduced, provided the margin between pressurizer pressure and the setpoint is maintained
[400] psia. Trips may be bypassed when pressurizer pressure is < [400] psia. Bypass shall be automatically removed when pressurizer pressure is _ [500] psia. The setpoint shall be automatically increased to the normal setpoint as pressurizer pressure is increased.
(_ec) The setpoint may be decreased as steam pressure is reduced, provided the margin between steam pressure and the setpoint is maintained
_< [200] psig. The setpoint shall be automatically increased to the normal setpoint as steam pressure is increased.(df)LThe Main Steam Isolation Signal (MSIS) Function (Steam Generator Pressure -Low and Containment Pressure -High signals) is not required to be OPERABLE when all associated valves isolated by the MSIS Function are closed and [de-activated].
CEOG STS 3.3.5-5 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Digital)3.3.5 Table 3.3.5-1 (page 2 of 2)Engineered Safety Features Actuation System Instrumentation APPLICABLE MODES FUNCTION OR OTHER SPECIFIED CONDITIONS ALLOWABLE VALUE 6. Emergency Feedwater Actuation Signal SG #1 (EFAS-1)a. Steam Generator Level -Low 1,2,3 >
: b. SG Pressure Difference
-High 1,2,3 < [66.25] psidfb&#xfd;&#xfd;[c. Steam Generator Pressure -Low 1,2,3 > [711] psig ]=7. Emergency Feedwater Actuation Signal SG #2 (EFAS-2)a. Steam Generator Level -Low 1,2,3 > [24.23]%b-
: b. SG Pressure Difference
-High 1,2,3 < [66.25] psid&#xfd;[c. Steam Generator Pressure -Low 1,2,3 > [711] psig ]N INSERT-4 (G) !NSERT-2 CEOG STS 3.3.5-6 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Analog)B 3.3.1 B 3.3 INSTRUMENTATION B 3.3.1 Reactor Protective System (RPS) Instrumentation
-Operating (Analog)BASES BACKGROUND The Reactor Protective System (RPS) initiates a reactor trip to protect against violating the core specified acceptable fuel design limits and breaching the reactor coolant pressure boundary (RCPB) during aRticipatod eperatfinal occu........Anticipated Operational Occurrences (AOOs). By tripping the reactor, the RPS also assists the Engineered Safety Features (ESF) systems in mitigating accidents.
The protection and monitoring systems have been designed to ensure safe operation of the reactor. This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RPS, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to includeG9RtaWn LSSS for variables that have significant safety functions.
LSSS are defined by the regulation as "...settings for awtematicp denpees--se"Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The AR Analtical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.
Any automatic protection action that occurs on reaching the A Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic prtctiV" doVicotecS must be chosen to be more conservative than the A Analytical Limit to account for ietIument Jeepchannel uncertainties related to the setting at which the automatic protective action would actually occur.--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP]" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
CEOG STS B 3.3.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Analog)B 3.3.1 BASES ACTIONS (continued)
G._ 1 Condition G is entered when the Required Action and associated Completion Time of Conditions A, B, C, D, E, or F are not met.If the Required Actions associated with these Conditions cannot be completed within the required Completion Times, the reactor must be brought to a MODE in which the Required Actions do not apply. The allowed Completion Time of 6 hours to be in MODE 3 is reasonable, based on operating experience, for reaching the required MODE from full power conditions in an orderly manner and without challenging plant systems.SURVEILLANCE The SRs for any particular RPS Function are found in the SR column of REQUIREMENTS Table 3.3.1-1 for that Function.
Most Functions are subject to CHANNEL CHECK, CHANNEL FUNCTIONAL TEST, CHANNEL CALIBRATION, and response time testing.---------------------
REVIEWER'S NOTE ------------------
In order for a plant to take credit for topical reports as the basis for justifying Frequencies, topical reports must be supported by an NRC staff SER that establishes the acceptability of each topical report for that plant (Ref. 9).--------------------
REVIEWER'S NOTE ----------------------..
Notes a and b are applied to the setpoint verification Surveillances for each RPS Instrumentation
-Operating (Analog) Function in Table 3.3.1-1 unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or-4e instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected chan-ge in result between SR performances for these components.
Where CEOG STS B 3.3.1-32 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Analog)B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
Bistable Tests The bistable setpoint must be found to trip whitRconservative with respect to the Allowable Values specified in the LCO and left set consistent with the assumptions of the plant specific setpoint analysis (Ref. 7). As:found and as:left values must also be recorded and reviewed for consistency with the assumptions of the frequency extension analysis.
The requirements for this review are outlined in Reference 10.A test signal is superimposed on the input in one channel at a time to verify that the bistable trips within the specified tolerance around the setpoint.
This is done with the affected RPS channel trip channel bypassed.
Any setpoint adjustment shall be consistent with the assumptions of the current plant specific setpoint analysis.SR 3.3.1.4 is modified by two Notes as identified in Table 3.3.1-1. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returninq the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into.the facility FSAR by referencel.Tho
;econndeote also requires that [L=TSP.a, t-h -nethedelooh-h *-f;r gal gulafipgmr.
ao lefl,, idd th fain.G1 telenReesn be., OR- [R;.-..,..
the finn, ef a rdnr..meRnn nnn)Rtllnrj w ndr-a Il 'E 50fig CO -r ;;r thp o+1. Tpr~hnirGl DR.,-.. .manp ... .... el aR Y nf.,sIn,...rn R neno,-te tn he flar,ilitEC D CEOG STS B 3.3.1-36 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Analog)B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.5 A CHANNEL CALIBRATION of the excore power range channels every 92 days ensures that the channels are reading accurately and within tolerance.
The Surveillance verifies that the channel responds to a measured parameter within the necessary range and accuracy.CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drift between successive calibrations to ensure that the channel remains operational between successive tests. CHANNEL CALIBRATIONS must be performed consistent with the plant specific setpoint analysis.The as found and as left values must also be recorded and reviewed for consistency with the assumptions of the frequency extension analysis.The requirements for this review are outlined in Reference
[110].A Note is added stating that the neutron detectors are excluded from CHANNEL CALIBRATION because they are passive devicesgha4%es with minimal drift and because of the difficulty of simulating a meaningful signal. Slow changes in detector sensitivity are compensated for by performing the daily calorimetric calibration (SR 3.3.1.2) and the monthly linear subchannel gain check (SR 3.3.1.3).
In addition, associated control room indications are continuously monitored by the operators.
SR 3.3.1.5 is modified by two Notes as identified in Table 3.3.1-1. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entrv into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a settinq within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
CEOG STS B 3.3.1-38 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Analog)B 3.3.1 The second Note also requires that rLTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.The sccond .oto alsc rFcQuirs that [LTSP]m n- tnrrr l~.-J'P imn"P +hk f,-I+.il&#xf7;, CQAD1 The Frequency of 92 days is acceptable, based on plant operating experience, and takes into account indications and alarms available to the operator in the control room.SR 3.3.1.6 A CHANNEL FUNCTIONAL TEST on the Loss of Load and Power Rate of Change channels is performed prior to a reactor startup to ensure the entire channel will perform its intended function if required.
A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable CHANNEL FUNCTIONAL TEST of a relay.This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
The Loss of Load pressure sensor cannot be tested during reactor operation without closing the high pressure TSV, which would result in a turbine trip or reactor trip. The Power Rate of Change -High trip Function is required during startup operation and is bypassed when shut down or > 15% RTP.SR 3.3.1.6 is modified by two Notes as identified in Table 3.3.1-1. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, CEOG STS B 3.3.1-39 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Analog)B 3.3.1 will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting, within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.Thc second Note also reguiro that [LTLP1 t,,.elFeh
',,nn rl .i,-e f Ghr r ,--,,nI ,-.. ,- ,, +- , , , fni mid 6Q.6 CO m nh tn hp Tprh 6 I an ma m~ena np ts Manu al am any, dei ane.. ra ,mnFOOa tedm~a tma he flar-,ll+,t AD CEOG STS B 3.3.1-40 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Analog)B 3.3.1 where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.The Rseco..,4nd Note also requiroes that [,eT',S',nA the rnatkarjalargia fa-r r 'nn,;iti, heas lef aRdnr the as fain m talnranao han rmoa the Rama af a, dGMeai pm.am naGmIlar und 10~a GPl '50 A sO or.-Ah ;;r +hA TnhmrWI an.,ama Rt~1FR Aamui M atP -;; nmAnmApt mnRGQPGateda m.+a the fant.,~a D The Frequency is based upon the assumption of an 18 month calibration interval for the determination of the magnitude of equipment drift.CEOG STS B 3.3.1-42 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Analog)B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
The Surveillance is modified by a Note to indicate that the neutron detectors are excluded from CHANNEL CALIBRATION because they are passive devicesehe;4=se with minimal drift and because of the difficulty of simulating a meaningful signal. Slow changes in detector sensitivity are compensated for by performing the daily calorimetric calibration (SR 3.3.1.2) and the monthly linear subchannel gain check (SR 3.3.1.3).SR 3.3.1.9 This SR ensures that the RPS RESPONSE TIMES are verified to be less than or equal to the maximum values assumed in the safety analysis.Individual component response times are not modeled in the analyses.The analyses model the overall or total elapsed time from the point at which the parameter exceeds the trip setpoint value at the sensor to the point at which the RTCBs open. Response times are conducted on an[18] month STAGGERED TEST BASIS. This results in the interval between successive surveillances of a given channel of n x 18 months, where n is the number of channels in the function.
The Frequency of[18] months is based upon operating experience, which has shown that random failures of instrumentation components causing serious response time degradation, but not channel failure, are infrequent occurrences.
Also, response times cannot be determined at power, since equipment operation is required.
Testing may be performed in one measurement or in overlapping segments, with verification that all components are tested.---------------------
REVIEWER'S NOTE ------------------
Applicable portions of the following TS Bases are applicable to plants adopting CEOG Topical Report CE NPSD-1167-1, "Elimination of Pressure Sensor Response Time Testing Requirements." Response time may be verified by any series of sequential, overlapping or total channel measurements, including allocated sensor response time, such that the response time is verified.
Allocations for sensor response times may be obtained from records of test results, vendor test data, or vendor engineering specifications.
Topical Report CE NPSD-1 167-A,"Elimination of Pressure Sensor Response Time Testing Requirements," (Ref. 11) provides the basis and methodology for using allocated sensor response times in the overall verification of the channel response time for specific sensors identified in the Topical Report. Response time verification for other sensor types must be demonstrated by test. The allocation of sensor response times must be verified prior to placing a new component in operation and reverified after maintenance that may adversely affect the sensor response time.CEOG STS B 3.3.1-43 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Analog)B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
A Note is added to indicate that the neutron detectors are excluded from RPS RESPONSE TIME testing because they are passive deviceschAR.AIR
' with minimal drift and because of the difficulty of simulating a meaningful signal. Slow changes in detector sensitivity are compensated for by performing the daily calorimetric calibration (SR 3.3.1.2).REFERENCES
: 1. Regulatory Guide 1.105, Revision 3, "Setpoints for Safety-Related Instrumentation." 2. 10 CFR 50, Appendix A, GDC 21.3. 10 CFR 100.4. IEEE Standard 279-1971, April 5, 1972.5. FSAR, Chapter [14].6. 10 CFR 50.49.7. "Plant Protection System Selection of Trip Setpoint Values." 8. FSAR, Section [7.2].9. NRC Safety Evaluation Report, [Date].10. CEN-327, June 2, 1986, including Supplement 1, March 3, 1989.11. CEOG Topical Report CE NPSD-1 167-A, "Elimination of Pressure Sensor Response Time Testing Requirements." CEOG STS B 3.3.1-44 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Analog)B 3.3.4 B 3.3 INSTRUMENTATION B 3.3.4 Engineered Safety Features Actuation System (ESFAS) Instrumentation (Analog)BASES BACKGROUND The ESFAS initiates necessary safety systems, based upon the values of selected unit parameters, to protect against violating core design limits and the Reactor Coolant System (RCS) pressure boundary and to mitigate accidents.
This is achieved by specifying limiting safety system settings (LSSS) in terms of Parameters directly monitored by the ESFAS, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 1--G 50q..6(c( roguiro .that Tec.hnical Spcificatione include LSSSs for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a Safety Limit (SL) is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the settinq at which the automatic protective action would actually occur.--------------------
REVIEW ER'S NOTE ----------------------.............
The term "Limitinq Trip Setpoint" [LTSP1 is generic terminology for the calculated trip settingq (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP] indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP1" is the suqoqested terminology for the actual setpoint implemented in the plant surveillance procedures where mar-gin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
Licensees are to insert the name of the document(s) controlled under 10 CFR 50.59 that contain the methodology for calculating the as-left and as-found tolerances, in Note b of Table 3.3.4-1 for the phrase "[insert the name of a document controlled under 10 CFR 50.59 such as the CEOG STS B 3.3.4-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Analog)B 3.3.4 Technical Requirements Manual or any document incorporated into the facility FSAR1" throughout these Bases.Where the [LTSP] is not included in Table 3.3.4-1, the plant-specific location for the [LTSP1 or NTSP must be cited in Note b of Table 3.3.4-1.The brackets indicate plant-specific terms may apply, as reviewed and approved by the NRC. Tho.. r foun and as left toloran.o.
il -pplh to the nctu, ! ..,;,4 .n .',.inmR .... ., 1..1 +. ... n,,,Aiinnl , ... 9......, ..W ... f.,r.M.channel t ,i "f, crmn Rn ..BASES BACKGROUND (continued)
The [Limitinq Trip Setpoint (LTSP)1 specified in Table 3.3.4-1 is a predetermined setting for a protection channel chosen to ensure automatic actuation prior to the process variable reachinq the Analytical Limit and thus ensuring that the SL would not be exceeded.
As such, the[LTSP1 accounts for uncertainties in setting the channel (e.g., calibration), uncertainties in how the channel might actually perform (e..g., repeatability), chanaqes in the point of action of the channel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the [LTSP1 ensures that SLs are not exceeded.
As such, the[LTSP1 meets the definition of a LSSS (Ref. 1).Technical Specifications contain values related to the OPERABILITY of equipment required for safe operation of the facility.
OPERABLE is defined in Technical Specifications as "...being capable of performinq its safety function(s)." Relying solely on the [LTSP1 to define OPERABILITY in Technical Specifications would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as-found" value of a protection channel setting during a Surveillance.
This would result in Technical Specification compliance problems, as well as reports and corrective actions required by the rule which are not necessary to ensure safety. For example, an automatic protection channel with a setting that has been found to be different from the [LTSP1 due to some drift of the setting may still be OPERABLE because drift is to be expected.
This expected drift would have been specifically accounted for in the setpoint methodology for calculating the fLTSP1 and thus the automatic protective action would still have ensured that the SL would not be exceeded with the "as-found" setting of the protection channel. Therefore, the channel would still be OPERABLE because it would have performed its safety function and the only corrective action required would be to reset the channel within the established as-left tolerance around the [LTSP1 to account for further drift during the next surveillance interval.
Note that, although the channel is OPERABLE under these circumstances, the trip setpoint must be left adiusted to a value within the as-left tolerance, in CEOG STS B 3.3.4-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Analog)B 3.3.4 BASES BACKGROUND (continued)
In order to take full advantage of the four channel design, adequate channel to channel independence must be demonstrated, and approved by the NRC staff. Plants not currently licensed-as to credit four channel independence that may desire this capability must have approval of the NRC staff documented by an NRC Safety Evaluation Report (Ref. 35).Adequate channel to channel independence includes physical and electrical independence of each channel from the others. Furthermore, each channel must be energized from separate inverters and station batteries.
Plants not demonstrating four channel independence may operate in a two-out-of-three logic configuration for 48 hours.Since no single failure will either cause or prevent a protective system actuation and no protective channel feeds a control channel, this arrangement meets the requirements of IEEE Standard 79-1971 (Ref. 46).Bistable Trip Units Bistable trip units receive an analog input from the measurement channels, compare the analog input to trip setpoints, and provide contact output to the Actuation Logic. They also provide local trip indication and remote annunciation.
There are four channels of bistables, designated A through D, for each ESF Function, one for each measurement channel. In cases where two ESF Functions share the same input and trip setpoint (e.g., containment pressure input to CSAS, CIAS, and SIAS and a Pressurizer Pressure -Low input to the RPS and SIAS), the same bistable may be used to satisfy both Functions.
The trip setpoints and Allowable Values used in the bistables are based on the analytical limits stated in Reference
: 5. The selection of theso trip setpei ts7. The selection of these trip setpointSGaGUlat".n of the Limiting T-.'oo S , .... fG, @R 2 2 4 -' is such that adequate protection is provided when all sensor and processing time delays are taken into account. To allow for calibration tolerances, instrumentation uncertainties, instrument drift, and severe environment effects, for those ESFAS channels that must function in harsh environments as defined by 10 CFR 50.49 (Ref. 68), Allowable Values specified in Table 3.3.4-1, in the accompanying LCO, are conservatively adjusted with respect to the analytical limits. A detailed description of the method used to calculate the trip setpoints, including their explicit uncertainties, is provided in the"Plant Protection System Selection of Trip Setpoint Values" (Ref. 79).The actual R~ilal trip CEOG STS B 3.3.4-6 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Analog)B 3.3.4 BASES BACKGROUND (continued) setpoint entered into the bistable is normally still more conservative than that specified by the Allowable Value to account for changes in random measurement errors detectable by a CHANNEL FUNCTIONAL TEST.One example of such a change in measurement error is drift during the interval between surveillances.
If the- measuro--'d Getpoint doeS no~t eXceedic conserative With Fepctt the Allowable Value, the bistablo is considered OPER BLE.Setpoints in accordance withThe [LTSP] is the value at which the bistable is set and is the expected value to be achieved durinq calibration.
The[LTSP1 value is the LSSS and ensures the safety analysis limits are met for the surveillance interval selected when a channel is adiusted based on stated channel uncertainties.
[Limiting Trip Setpoints], in coniunction with the use of as-found and as-left tolerances, consistent with the requirements of the Allowable Value will ensure that Safety Limits of Chapter 2.0, "SAFETY LIMITS (SLs)," are not violated during anticipated operational occurrences (AOOs) and that the consequences of Design Basis Accidents (DBAs) will be acceptable, providing the plant is operated from within the LCOs at the onset of the AOO or DBA and the equipment functions as designed.Note that in the accompanyinq LCO 3.3.4, the Allowable Values of Table 3.3.4-1 are the least conservative value of the as-found setpoint that a channel can have during a periodic CHANNEL CALIBRATION or CHANNEL FUNCTIONAL TEST.ESFAS Logic It is possible to change the two-out-of-four ESFAS logic to a two-out-of-three logic for a given input parameter in one channel at a time by disabling one channel input to the logic. Thus, the bistables will function normally, producing normal trip indication and annunciation, but ESFAS actuation will not occur since the bypassed channel is effectively removed from the coincidence logic. Trip channel bypassing can be simultaneously performed on any number of parameters in any number of channels, providing each parameter is bypassed in only one channel at a time. At some plants an interlock prevents simultaneous trip channel bypassing of the same parameter in more than one channel. Trip channel bypassing is normally employed during maintenance or testing.ESFAS Logic is addressed in LCO 3.3.5.APPLICABLE Each of the analyzed accidents can be detected by one or more ESFAS SAFETY Functions.
One of the ESFAS Functions is the primary actuation signal CEOG STS B 3.3.4-7 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Analog)B 3.3.4 BASES ACTIONS (continued)
F.1 and F.2 If the Required Actions and associated Completion Times of Condition A, B, C, D, or E are not met, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours and to MODE 4 within[12] hours. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.SURVEILLANCE The SRs for any particular ESFAS Function are found in the SRs column REQUIREMENTS of Table 3.3.4-1 for that Function.
Most functions are subject to CHANNEL CHECK, CHANNEL FUNCTIONAL TEST, CHANNEL CALIBRATION, and response time testing.---------------------
REVIEWER'S NOTE -----------------------------------
In order for a unit to take credit for topical reports as the basis for justifying Frequencies, topical reports should be supported by an NRC staff Safety Evaluation Report that establishes the acceptability of each topical report for that unit.--------------------
REVIEWER'S NOTE Notes a and b are applied to the setpoint verification Surveillances for each ESFAS Instrumentation (Analog) Function in Table 3.3.4-1 unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation lo-gic circuits or te instrument functions that derive input from contacts which have no associated sensor or adjustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs. the requirements would apply.CEOG STS B 3.3.4-23 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Analog)B 3.3.4 BASES SURVEILLANCE REQUIREMENTS (continued) times when Surveillance is required, the CHANNEL CHECK will only verify that they are off scale in the same direction.
Offscale low current loop channels are verified to be reading at the bottom of the range and not failed downscale.
The Frequency of about once every shift is based on operating experience that demonstrates channel failure is rare. Since the probability of two random failures in redundant channels in any 12 hour period is extremely low, the CHANNEL CHECK minimizes the chance of loss of protective function due to failure of redundant channels.
The CHANNEL CHECK supplements less formal, but more frequent, checks of CHANNEL OPERABILITY during normal operational use of displays associated with the LCO required channels.SR 3.3.4.2 A CHANNEL FUNCTIONAL TEST is performed every [92] days to ensure the entire channel will perform its intended function when needed. A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable CHANNEL FUNCTIONAL TEST of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
The CHANNEL FUNCTIONAL TEST tests the individual sensor subsystems using an analog test input to each bistable.A test signal is superimposed on the input in one channel at a time to verify that the bistable trips within the specified tolerance around the setpoint.
Any setpoint adjustment shall be consistent with the assumptions of the current plant specific setpoint analysis.The as:found land as:leftl values must also be recorded and reviewed for consistency with the assumptions of the surveillance interval extension analysis.
The requirements for this review are outlined in Reference
[8101.SR 3.3.4.2 is modified by two Notes as identified in Table 3.3.4-1. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and CEOG STS B 3.3.4-25 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Analog)B 3.3.4 the channel oerformance assumptions in the setpoint methodology.
The Purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [ILTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP], then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.The .ocond Note also reguirecs that UTP1.ann the. rnethodelnlnnui fGF nnGaIGWinfin,.theas le ft nan theasn fat In Mfig r,, p. h As thp 'TPAhnin'a E)t miar anlof an l arae ia Rnat 0 GEFEearaen onte the faaui+,H y-AR1 CEOG STS B 3.3.4-26 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Analog)B 3.3.4 BASES SURVEILLANCE REQUIREMENTS (continued)
The Frequency is based upon the assumption of an [18] month calibration interval for the determination of the magnitude of equipment drift in the setpoint analysis.SR 3.3.4.4 is modified by two Notes as identified in Table 3.3.4-1. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the Plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP] and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.Theo ocond No94t .ro, that ,LTSP[*Rd tnh m-ethendnlnniop fr G'GaIG'1flnn tha no a'sf IR-' the aso f-U-d.tAIeramancP han [flRset the name af ia d mnt+ c lntrle 'i-Inr !0 'CF 50 fig r', -k ;IF; tha; TAnhmnl 9F. rmmc I.'n i, aRY inn, i-nn. mn flaaprnatedi-onto the faai+, 9 AD SR 3.3.4.5 This Surveillance ensures that the train actuation response times are the maximum values assumed in the safety analyses.
Individual component response times are not modeled in the analyses.
The analysis models the overall or total elapsed time, from the point at which the parameter exceeds the trip setpoint value at the sensor to the point at which the equipment in both trains reaches the required functional state (e.g., pumps at rated discharge pressure, valves in full open or closed position).
CEOG STS B 3.3.4-28 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Digital)B 3.3.1 B 3.3 INSTRUMENTATION B 3.3.1 Reactor Protective System (RPS) Instrumentation
-Operating (Digital)BASES BACKGROUND The RP-SReactor Protective System (RPS) initiates a reactor trip to protect against violating the core specified acceptable fuel design limits and breaching the reactor coolant pressure boundary (RCPB) during aRnticipated operational occurrencesAnticipated Operational Occurrences (AOOs). By tripping the reactor, the RPS also assists the Engineered Safety Features (ESF) systems in mitigating accidents.
The protection and monitoring systems have been designed to ensure safe operation of the reactor. This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RPS, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to includeeeRtaiR LSSS for variables that have significant safety functions.
LSSS are defined by the regulation as "...settings automat""ic  deViees-.se"Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will-correct the abnormal situation before a Safety Limit (SL) is exceeded." The Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.
Any automatic protection action that occurs on reaching the Aala4iGAnalytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protoctivo dovicocprotection channels must be chosen to be more conservative than the AnaIlyieAnalytical Limit to account for i eFFt'met Ieopchannel uncertainties related to the setting at which the automatic protective action would actually occur.--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is gqeneric terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP]" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP]. The as-found and as-left tolerances will apply to the [NTSPI implemented in the Surveillance procedures to confirm channel performance.
CEOG STS B 3.3.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Digital)B 3.3.1 Licensees are to insert the name of the document(s) controlled under 10 CFR 50.59 that contain the methodology for calculatinq the as-left and as-found tolerances, in Note b of Table 3.3.1-1 for the phrase "[insert the name of a document controlled under 10 CFR 50.59 such as the Technical Requirements Manual or any document incorporated into the facility FSAR1" throughout these Bases.Where the [LTSP1 is not included in Table 3.3.1-1, the plant-specific location for the [LTSP1 or NTSP must be cited in Note b of Table 3.3.1-1.The brackets indicate plant-specific terms may apply, as reviewed and approved by the NRC. The as fouRd and as leof toleranceswi aDDIM to tk~n,+ ~, etonrnt umplemR tednr *R the .m~dInn Surnr'lnrl.
We Ge .f nmer rGh n nn nph~Gn~RmGG
.The [Limiting Trip Setpoint (LTSP1 specified in Table 3.3.1-1 is a predetermined setting for a protective 4eeviGechannel chosen to ensure automatic actuation prior to the process variable reaching the AR Analtical Limit and thus ensuring that the SL would not be exceeded.
As such, the t.4P set,---;-*[LTSP1 accounts for uncertainties in setting the (e.g., calibration), uncertainties in how the devieechannel might actually perform (e.g., repeatability), changes in the point of action of the de-Aeechannel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the trip plays, an impeortant role in ensuring[LTSP1 ensures that SLs are not exceeded.
As such, the t[Psetpei-4[LTSP1 meets the definition of apa LSSS (Ref. 1) and coueld be used to meet the requirement that they be on.taie.d.
in the T-echn,.ical, Specificatiens.).
CEOG STS B 3.3.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Digital)B 3.3.1 BASES ACTIONS (continued)
If the Required Actions associated with these Conditions cannot be completed within the required Completion Time, the reactor must be brought to a MODE where the Required Actions do not apply. The allowed Completion Time of 6 hours is reasonable, based on operating experience, for reaching the required MODE from full power conditions in an orderly manner and without challenging plant systems.SURVEILLANCE The SRs for any particular RPS Function are found in the SR column of REQUIREMENTS Table 3.3.1-1 for that Function.
Most Functions are subject to CHANNEL CHECK, CHANNEL FUNCTIONAL TEST, CHANNEL CALIBRATION, and response time testing.---------------------
REVIEWER'S NOTE ------------------
In order for a plant to take credit for topical reports as the basis for justifying Frequencies, topical reports must be supported by an NRC staff SER that establishes the acceptability of each topical report for that unit.--------------------
REVIEWER'S NOTE Notes a and b are applied to the setpoint verification Surveillances for each RPS Instrumentation
-Operating (Digital)
Function in Table 3.3.1-1 unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or4G instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the requirements would apply.SR 3.3.1.1 CEOG STS B 3.3.1-34 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Digital)B 3.3.1 Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entrv into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.Tho socond Noto also requires that [LTSP=t ,a ", the mnehnrllunes fGF G,&#xb6;, atf,,imRsthe asf ' eft nl .trheda '.'"'u-n-. , n F elneranrones h-9e ;F Rsnen.th +ka 'rne of ';; doln, g m ,rnan+ nnroll , n-RLawU QFIRC~50.5 SUO as the To*-eaTahR!GI an. dRegw*Fmet Manu. a' 9F any, i-lan.. iAp ,pnF19GatedJ t the flan-Aelhl C CEOG STS B 3.3.1-39 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Digital)B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.8 A Note indicates that neutron detectors are excluded from CHANNEL CALIBRATION.
A CHANNEL CALIBRATION of the power range neutron flux channels every 92 days ensures that the channels are reading accurately and within tolerance (Ref. 10). The Surveillance verifies that the channel responds to a measured parameter within the necessary range and accuracy.
CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drift between successive calibrations to ensure that the channel remains operational between successive tests.CHANNEL CALIBRATIONS must be performed consistent with the plant specific setpoint analysis.The as-found and as-left values must also be recorded and reviewed for consistency with the assumptions of the interval between surveillance interval extension analysis.
The requirements for this review are outlined in Reference
: 10. Operating experience has shown this Frequency to be satisfactory.
The detectors are excluded from CHANNEL CALIBRATION because they are passive devicesehewiele with minimal drift and because of the difficulty of simulating a meaningful signal. Slow changes in detector sensitivity are compensated for by performing the daily calorimetric calibration (SR 3.3.1.4) and the monthly linear subchannel gain check (SR 3.3.1.6).
In addition, the associated control room indications are monitored by the operators.
SR 3.3.1.8 is modified by two Notes as identified in Table 3.3.1-1. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left settinq for the channel be returned to within the as-left tolerance of the [LTSP]. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a settinq CEOG STS B 3.3.1-41 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Digital)B 3.3.1 within the as-left tolerance of the [LTSP], then the channel shall be declared inoperable.
The second Note also requires that [LTSP] and the methodologies for calculatinq the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.The .o.ond Note al orgiuifr1.
.that T.[I=-...A k,~ ~ n.-nnl , .,i+ f -. no. , +k,, n, &#xa3;-.., ,i --I ,A Pthdo'P'e hr .... *, .n. ,-Inn ,the.R.aen
.+ a. oIGU,.Ie ,o,.... A ('CP 50fig r,- -Ah ;;r, thp T-Pnkrdnl an iRe~*enmnPofAh m h ~nr , Ann at[SR 3.3.1.9 The characteristics and Bases for this Surveillance are as described for SR 3.3.1.7. This Surveillance differs from SR 3.3.1.7 only in that the CHANNEL FUNCTIONAL TEST on the Loss of Load functional unit is only required above 55% RTP. When above 55% and the trip is in effect, the CHANNEL FUNCTIONAL TEST will ensure the channel will perform its equipment protective function if needed. A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable CHANNEL FUNCTIONAL TEST of a relay.This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
The Note allowing 2 hours after reaching 55% RTP is necessary for Surveillance performance.
This Surveillance cannot be performed below 55% RTP, since the trip is bypassed.
]SR 3.3.1.9 is modified by two Notes as identified in Table 3.3.1-1. The first Note requires evaluation of channel performance for the condition where the as-found settinq for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [LTSPI. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is CEOG STS B 3.3.1-42 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Digital)B 3.3.1 maintained.
If the as-left channel setting cannot be returned to a settinq within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.Tho-;
on te al.o r,.uoc. -that ,LTSP1;,n w ;v in innn the met P ;q n an .dln fli the as f nI (if0.10 SU mh as the Ter~hnrPIo~al.
RqieeRnnn~
tSn MaR, or any dOGW, pnRt.n CEOG STS B 3.3.1-43 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Digital)B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.10 SR 3.3.1.10 is the performance of a CHANNEL CALIBRATION every[18] months.CHANNEL CALIBRATION is a complete check of the instrument channel including the sensor. The Surveillance verifies that the channel responds to a measured parameter within the necessary range and accuracy.CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drift between successive calibrations to ensure that the channel remains operational between successive tests. CHANNEL CALIBRATIONS must be performed consistent with the plant specific setpoint analysis.The as:found and as-left values must also be recorded and reviewed for consistency with the assumptions of the surveillance interval extension analysis.
The requirements for this review are outlined in Reference
[10].The Frequency is based upon the assumption of an [18] month calibration interval for the determination of the magnitude of equipment drift in the setpoint analysis as well as operating experience and consistency with the typical [18] month fuel cycle.The Surveillance is modified by a Note to indicate that the neutron detectors are excluded from CHANNEL CALIBRATION because they are passive devicesehanwels with minimal drift and because of the difficulty of simulating a meaningful signal. Slow changes in detector sensitivity are compensated for by performing the daily calorimetric calibration (SR 3.3.1.4) and the monthly linear subchannel gain check (SR 3.3.1.6).SR 3.3.1.10 is modified by two Notes as identified in Table 3.3.1-1. The first Note requires evaluation of channel performance for the condition where the as-found settinq for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance CEOG STS B 3.3.1-44 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Digital)B 3.3.1 procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also reguires that [LTSP] and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.The .Gecd Note also requires that [=.TS1 andr +hr. rnnthndc.Icqips nr ....i I,, ,,+,... , no.. ,aft .nrj., h , ,c... ( ... ,A 1~Iprn hn OR Fa iIncsnr the nnnma of a dGGU~mi neRtn GRtFn~rr'.
Us Rder 10 GFl.50.599 sugh as the. Tr-r~hn~Rwal Recren urneRtn6 Mtan.al anF any, Apr.en. mn R.-.cOrp ar.ted the- .ih, QA D SR 3.3.1.11 Every [18] months, a CHANNEL FUNCTIONAL TEST is performed on the CPCs. The CHANNEL FUNCTIONAL TEST shall include the injection of a signal as close to the sensors as practicable to verify OPERABILITY including alarm and trip Functions.
A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable CHANNEL FUNCTIONAL TEST of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
CEOG STS B 3.3.1-45 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Digital)B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
The basis for the [18] month Frequency is that the CPCs perform a continuous self monitoring function that eliminates the need for frequent CHANNEL FUNCTIONAL TESTS. This CHANNEL FUNCTIONAL TEST essentially validates the self monitoring function and checks for a small set of failure modes that are undetectable by the self monitoring function.Operating experience has shown that undetected CPC or CEAC failures do not occur in any given [18] month interval.SR 3.3.1.11 is modified by two Notes as identified in Table 3.3.1-1. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP] is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.The socond Note also requires that [ILTSP amd .the fE)t F.nLInat*R.
as left RR] the a found falarnnrao ha i r~noa. +ha nrna f p a. d gmgmt R#anfralWanl 81 1n,. -If -1 50fg s- -Ah no;r, at ~Tar~hn' an Iart, i rar,,nAtc Mai -Wn 9F aRY n n Gj MR., Rnn M GGPGa..nfa OPU-4 flthta fruf. G SR 3.3.1.12 The three excore detectors used by each CPC channel for axial flux distribution information are far enough from the core to be exposed to flux from all heights in the core, although it is desired that they only read their CEOG STS B 3.3.1-46 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation
-Operating (Digital)B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
Response time may be verified by any series of sequential, overlapping or total channel measurements, including allocated sensor response time, such that the response time is verified.
Allocations for sensor response times may be obtained from records of test results, vendor test data, or vendor engineering specifications.
Topical Report CE NPSD-1 167-A,"Elimination of Pressure Sensor Response Time Testing Requirements," (Ref. 11) provides the basis and methodology for using allocated sensor response times in the overall verification of the channel response time for specific sensors identified in the Topical Report. Response time verification for other sensor types must be demonstrated by test. The allocation of sensor response times must be verified prior to placing a new component in operation and reverified after maintenance that may adversely affect the sensor response time.A Note is added to indicate that the neutron detectors are excluded from RPS RESPONSE TIME testing because they are passive devicesGhaR~els with minimal drift and because of the difficulty of simulating a meaningful signal. Slow changes in detector sensitivity are compensated for by performing the daily calorimetric calibration (SR 3.3.1.4).REFERENCES
: 1. Regulatory Guide 1.105, Revision 3, "Setpoints for Safety-Related Instrumentation." 2. 10 CFR 50, Appendix A, GDC 21.3. 10 CFR 100.4. NRC Safety Evaluation Report.5. IEEE Standard 279-1971, April 5, 1972.6. FSAR, Chapter [14].7. 10 CFR 50.49.8. "Plant Protection System Selection of Trip Setpoint Values." 9. FSAR, Section [7.2].10. CEN-327, June 2, 1986, including Supplement 1, March 3, 1989.11. CEOG Topical Report CE NPSD-1 167-A, "Elimination of Pressure Sensor Response Time Testing Requirements." CEOG STS B 3.3.1-49 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)CEACs (Digital)B 3.3.3 BASES SURVEILLANCE REQUIREMENTS (continued)
Agreement criteria are determined by the plant staff, based on a combination of the channel instrument uncertainties, including indication and readability.
If a channel is outside the criteria, it may be an indication that the sensor or the signal processing equipment has drifted outside its limits.The Frequency, about once every shift, is based on operating experience that demonstrates the rarity of channel failure. Since the probability of two random failures in redundant channels in any 12 hour period is extremely low, the CHANNEL CHECK minimizes the chance of loss of protective function due to failure of redundant channels.
The CHANNEL CHECK supplements less formal, but more frequent, checks of channel OPERABILITY during normal operational use of the displays associated with the LCO required channels.SR 3.3.3.2 The CEAC autorestart count is checked every 12 hours to monitor the CPC and CEAC for normal operation.
If three or more autorestarts of a nonbypassed CPC occur within a 12 hour period, the CPC may not be completely reliable.
Therefore, the Required Action of Condition D must be performed.
The Frequency is based on operating experience that demonstrates the rarity of more than one channel failing within the same 12 hour interval.SR 3.3.3.3 A CHANNEL FUNCTIONAL TEST on each CEAC channel is performed every 92 days to ensure the entire channel will perform its intended function when needed. The quarterly CHANNEL FUNCTIONAL TEST is performed using test software.
The Frequency of 92 days is based on the reliability analysis presented in topical report CEN-327, "RPS/ESFAS Extended Test Interval Evaluation" (Ref. 5). A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable CHANNEL FUNCTIONAL TEST of a relay.This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
There is a plant specific program which verifies that the instrument channel functions as required by verifying the as-left and as-found settinq are consistent with those established by the setpoint methodology.
CEOG STS B 3.3.3-8 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)CEACs (Digital)B 3.3.3 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.3.4 SR 3.3.3.4 is the performance of a CHANNEL CALIBRATION every[18] months.CHANNEL CALIBRATION is a complete check of the instrument channel including the sensor. The Surveillance verifies that the channel responds to a measured parameter within the necessary range and accuracy.CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drift between successive calibrations to ensure that the channel remains operational between successive surveillances.
There is a plant specific program which verifies that the instrument channel functions as required by verifying the as-left and as-found setting are consistent with those established by the setpoint methodology.
CHANNEL CALIBRATIONS must be performed consistent with the plant specific setpoint analysis.The as foundl And -as loft v-alues muSt also be ooddand- revie~eod_
for-I consistencY with the assumptions Of the surwoillance inteR4a extension analysis.
The requirem~ents_
for- thisroio are ou tlinod inRoforneR[5]
The Frequency is based upon the assumption of an [18] month calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis and includes operating experience and consistency with the typical [18] month fuel cycle.SR 3.3.3.5 Every [18] months, a CHANNEL FUNCTIONAL TEST is performed on the CEACs. The CHANNEL FUNCTIONAL TEST shall include the injection of a signal as close to the sensors as practicable to verify OPERABILITY, including alarm and trip Functions.
A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable CHANNEL FUNCTIONAL TEST of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
There is a plant specific program which verifies that the instrument channel functions as required by verifying the as-left and as-found setting are consistent with those established by the setpoint methodology.
The basis for the [18] month Frequency is that the CEACs perform a continuous self monitoring function that eliminates the need for frequent CHANNEL FUNCTIONAL TESTS. This CHANNEL FUNCTIONAL TEST essentially validates the self monitoring function and checks for a small CEOG STS B 3.3.3-9 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Digital)B 3.3.5 B 3.3 INSTRUMENTATION B 3.3.5 Engineered Safety Features Actuation System (ESFAS) Instrumentation (Digital)BASES BACKGROUND The ESFAS initiates necessary safety systems, based upon the values of selected unit parameters, to protect against violating core design limits and the Reactor Coolant System (RCS) pressure boundary during anticipated operational occurrences (AOOs) and ensures acceptable consequences during accidents.
This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the ESFAS, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 40-GF-R 50.36(00)(00)(AiiA)
...u:o t-h.at Spocifications include LSSSs for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the settingq must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a Safety Limit (SL) is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for channel uncertainties related to the setting at which the automatic protective action would actually occur.--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP1" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP]. The as-found and as-left tolerances will apply to the [NTSPI implemented in the Surveillance procedures to confirm channel performance.
Licensees are to insert the name of the document(s) controlled under 10 CFR 50.59 that contain the methodology for calculating the as-left and as-found tolerances, in Note c of Table 3.3.5-1 for the phrase "[insert the name of a document controlled under 10 CFR 50.59 such as the CEOG STS B 3.3.5-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Digital)B 3.3.5 Technical Requirements Manual or any document incorporated into the facility FSAR]" throuahout these Bases.Where the [LTSP] is not included in Table 3.3.5-1, the plant-specific location for the [LTSP1 or NTSP must be cited in Note c of Table 3.3.5-1.The brackets indicate plant-specific terms may apply, as reviewed and approved by the NRC. The ac- found. and- ,;,;loft torIAnc. .i -pplh to+,n ,v ~ ,,,+.-.v...+
;m, lpn,,v, vnA ,., +kn Q ,
nrtrl..,vv rav +n tv,,tn.,., Gha nn l f n iD.rf- rm nrm" The [Limiting Trip Setpoint (LTSP)] specified in Table 3.3.5-1 is a predetermined setting for a protection channel chosen to ensure automatic actuation prior to the process variable reaching the Analytical Limit and thus ensuring that the SL would not be exceeded.
As such, the[LTSP1 accounts for uncertainties in setting the channel (e.g.,calibration), uncertainties in how the channel might actually perform (e.g., repeatability), changes in the point of action of the channel over time (e.g., drift durinq surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the [LTSP1 ensures that SLs are not exceeded.
As such, the[LTSP1 meets the definition of a LSSS (Ref. 1).Technical Specifications contain values related to the OPERABILITY of equipment required for safe operation of the facility.
OPERABLE is defined in Technical Specifications as "...being capable of performing its safety function(s)." Relying solely on the [LTSP1 to define OPERABILITY in Technical Specifications would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as-found" value of a protection channel setting during a Surveillance.
This would result in Technical Specification compliance problems, as well as reports and corrective actions required by the rule which are not necessary to ensure safety. For example, an automatic protection channel with a setting that has been found to be different from the [LTSP] due to some drift of the setting may still be OPERABLE because drift is to be expected.
This expected drift would have been specifically accounted for in the setpoint methodology for calculating the [LTSP1 and thus the automatic protective action would still have ensured that the SL would not be exceeded with the "as-found" setting of the protection channel. Therefore, the channel would still be OPERABLE because it would have performed its safety function and the only corrective action required would be to reset the channel within the established as-left tolerance around the [LTSP1 to account for further drift during the next surveillance interval.
Note that, although the channel is OPERABLE under these circumstances, the trip setpoint must be left adiusted to a value within the as-left tolerance, in accordance with uncertainty assumptions stated in the referenced setpoint methodology (as-left criteria), and confirmed to be operating within the statistical allowances of the uncertainty terms assigned (as-found criteria).
CEOG STS B 3.3.5-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Digital)B 3.3.5 BASES BACKGROUND (continued)
The trip setpoints and Allowable Values used in the bistables are based on the analytical limits stated in Reference
: 5. The selection of these trip-etpeif,-,.
The selection of these trip setpointsclculation the" Limitin T-.ti- ge wt&#xf7;- .... ier "R.k, a- 2-2-6 is such that adequate protection is provided when all sensor and processing time delays are taken into account. To allow for calibration tolerances, instrumentation uncertainties, instrument drift, and severe environment effects, for those ESFAS channels that must function in harsh environments as defined by 10 CFR 50.49 (Ref. 68), Allowable Values specified in Table 3.3.5-1, in the accompanying LCO, are conservatively adjusted with respect to the analytical limits. A detailed description of the methodology used to calculate the trip setpoints, including their explicit uncertainties, is provided in the "Plant Protection System Selection of Trip Setpoint Values" (Ref. 7-9). The actual Remifal trip setpoint entered into the bistable is normally still more conservative than that specified by the Allowable Value to account for changes in random measurement errors detectable by a CHANNEL FUNCTIONAL TEST..A chAnn elis inoperable ifsae l Wpt't One example of such a change in measurement error is drift during the interval between surveillances.
If +hp n.npI urn, setpea.nt-1 Wn~,th! tha-e as fu i telenR-, e~ andr t GEMennya+', Withk FG~ent, tA thq A 11intnh tI abl Value thie -holsae considered OPERABLE.The [LTSP1 is the value at which the bistable is set and is the expected value to be achieved during calibration.
The [LTSP1 value is the LSSS and ensures the safety analysis limits are met for the surveillance interval selected when a channel is adjusted based on stated channel uncertainties.
[Limiting Trip Setpointsl, in coniunction with the use of as-found and as-left tolerances, consistent with-the requirements of setpoint is net w::ithin its required Allowable Value.
iR accordance wi. ,the Allowable Value will ensure that Safety Limits of LCO Section 2.0, "Safety Limits," are not violated during AD0s and the consequences of Design Basis Accidents (DBAs) will be acceptable, providing the plant is operated from within the LCOs at the onset of the AOO or DBA and the equipment functions as designed.Note that in LCO 3.3.5, the Allowable Values of Table 3.3.5-1 are the least conservative value of the as-found setpoint that a channel can have during a periodic CHANNEL CALIBRATION or CHANNEL FUNCTIONAL TEST.Functional testing of the ESFAS, from the bistable input through the opening of initiation relay contacts in the ESFAS Actuation Logic, can be CEOG STS B 3.3.5-7 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Digital)B 3.3.5 determined to be OPERABLE but de-graded, after returninq the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Pro-gram will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.Tho socond Noto also rguirc *h-at [LTSPF to!ear;nGcs be ha fense,-t the nRmne of a ,....mmnn+
nnMr,"l-"' , , ,.,4. '0 C DFR 50.9 Fic q h As thp TAchn'c Dn R r n t,,,, ml ..am"-, rn r ,rA,.t i r-rr .rr Rer1Wafnl irn&#xf7;ra +ha Ma-aGoili4V 0 ....AD1 ,., FE11.. t, d the ' '  CEOG STS B 3.3.5-32 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Digital)B 3.3.5 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.5.3 CHANNEL CALIBRATION is a complete check of the instrument channel including the detector and the bypass removal functions.
The Surveillance verifies that the channel responds to a measured parameter within the necessary range and accuracy.
CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drift between successive calibrations to ensure that the channel remains operational between successive surveillances.
CHANNEL CALIBRATIONS must be performed consistent with the plant specific setpoint analysis.The as found and as left values must also be recorded.
and reviewed for consistency with the assumptions of the surveillance interval extension analysis.
The requirements for this review are outlined in Reference
[9I1.The [18] month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power.SR 3.3.5.3 functions are modified by two Notes as identified in Table 3.3.5-1. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be returned to within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility CEOG STS B 3.3.5-33 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ESFAS Instrumentation (Digital)B 3.3.5 FSAR reference or the name of any document incorporated into the facility FSAR by referencel.Tho second Noto alG, o r..u.rs that [LTSP1.l. aRn.... .be i*. *Rsot the ... .of ,n n. i ....,nm ...l i., I ,,.4. '1 n FR iGGnFPtnFnat i tn h eha faG1ilft IOAD1 SR 3.3.5.4 This Surveillance ensures that the train actuation response times are within the maximum values assumed in the safety analyses.Response time testing acceptance criteria are included in Reference 4-912.---------------------
REVIEWER'S NOTE ------------------
Applicable portions of the following TS Bases are applicable to plants adopting CEOG Topical Report CE NPSD-1167-1, "Elimination of Pressure Sensor Response Time Testing Requirements." Response time may be verified by any series of sequential, overlapping or total channel measurements, including allocated sensor response time, such that the response time is verified.
Allocations for sensor response times may be obtained from records of test results, vendor test data, or vendor engineering specifications.
Topical Report CE NPSD-1 167-A, CEOG STS B 3.3.5-34 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)EOC-RPT Instrumentation 3.3.4.1 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.3.4.1.2
--------------------
NOTES ----------------
[92] days]1. For the TCV Function, if the as-found channel setpoint is outside its predefined as-found tolerance, then the channel shall be evaluated to verify that it is functioning as required before returning the channel to service.2. For the TCV Function, the instrument channel setpoint shall be reset to. a value that is within the as-left tolerance around the Limiting Trip Setpoint (LTSP) at the completion of the surveillance; otherwise, the channel shall be declared inoperable.
Setpoints more conservative than the LTSP are acceptable provided that the as-found and as-left tolerances apply to the actual setpoint implemented in the Surveillance procedures (Nominal Trip Setpoint) to confirm channel performance.
The LTSP and the methodologies used to determine the as-found and the as-left tolerances are specified in [insert the facility FSAR reference or the name of coPntrolled u nder 10 CF=R 50.59 suc-h as, the TecrhniRwl Reque ,rents Mau 9Fmnu any document incorporated into the facility FSAR by referencel.
[ Calibrate the trip units.SR 3.3.4.1.3 NOTES ----------------
[18] months 1. For the TCV Function, if the as-found channel setpoint is outside its predefined as-found tolerance, then the channel shall be evaluated to verify that it is functioninq as required before returning the channel to service.2. For the TCV Function, the instrument channel setpoint shall be reset to a value that is within the as-left tolerance around the Limiting Trip Setpoint (LTSP) at the completion of the surveillance; otherwise, the channel shall be declared inoperable.
Setpoints more conservative than the LTSP are acceptable provided that the as-found and as-left BWR/4 STS 3.3.4.1-3 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)EOC-RPT Instrumentation 3.3.4.1 tolerances apply to the actual setpoint implemented in the Surveillance procedures (Nominal Trip Setpoint) to confirm channel performance.
The LTSP and the methodologies used to determine the as-found and the as-left tolerances are specified in [insert the facility FSAR reference or the name of a-denument T9_,n111. , RQurmonnmt6 Man'ia lr any document incorporated into the facility FSAR by referencel.
Perform CHANNEL CALIBRATION.
The Allowable Perform CHANNEL CALIBRATION.
The Allowable Values shall be: a. TSV -Closure: < [10]% closed and b. TCV Fast Closure, Trip Oil Pressure -Low:> [600] psig.SR 3.3.4.1.4 Perform LOGIC SYSTEM FUNCTIONAL TEST [18] months including breaker actuation.
SR 3.3.4.1.5 Verify TSV -Closure and TCV Fast Closure, Trip Oil [18] months Pressure -Low Functions are not bypassed when THERMAL POWER is > [30]% RTP.SR 3.3.4.1.6
--------------------
NOTE---------------
Breaker [interruption]
time may be assumed from the most recent performance of SR 3.3.4.1.7.
Verify the EOC-RPT SYSTEM RESPONSE TIME is [18] months on a within limits. STAGGERED TEST BASIS SR 3.3.4.1.7 Determine RPT breaker [interruption]
time. 60 months BWR/4 STS 3.3.4.1-4 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1.1 B 3.3 INSTRUMENTATION B 3.3.1.1 Reactor Protection System (RPS) Instrumentation BASES BACKGROUND The RPS initiates a reactor scram when one or more monitored parameters exceed their specified limits, to preserve the integrity of the fuel cladding and the Reactor Coolant System (RCS) and minimize the energy that must be absorbed following a loss of coolant accident (LOCA). This can be accomplished either automatically or manually.The protection and monitoring functions of the RPS have been designed to ensure safe operation of the reactor. This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RPS, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to eentaininclude LSSS for variables that have significant safety functions.
LSSS are defined by the regulation as "...settings for automatic protective doeviGes-7.-se"Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The A Analytical Limit is the limit of the process variable at which a 6afetyprotective action is initiated, as established by the safety analysis, to ensure that a safety limit (SL) is not exceeded.Any automatic protection action that occurs on reaching the ARalytAnalytical Limit therefore ensures that the SL is not exceeded.However, in practice, the actual settings for automatic p-teetive deViGeesrotection channels must be chosen to be more conservative than the AniayticAnalytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur.--------------------
REVIEWER'S NOTE -----------------------------------The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP]" is the suqgested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
BWR/4 STS B 3.3.1.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1.1 Licensees are to insert the name of the document(s) controlled under 10 CFR 50.59 that contain the methodology for calculating the as-left and as-found tolerances in Note b of Table 3.3.1.1-1, for the phrase "[insert the name of a document controlled under 10 CFR 50.59 such as the Technical Requirements Manual or any document incorporated into the facility FSAR]" throughout these Bases.If the [LTSP1 is not included in Table 3.3.1.1-1, the plant-specific location for the [LTSP1 or NTSP must be cited in Note b of Table 3.3.1.1-1.
The brackets indicate plant-specific terms may apply, as reviewed and approved by the NRC. The as found aRnd as left toleraces will appy, to rGha nen l Irpe 4 r% mm', m. i The [Limitinq Trip Setpoint (LTSP)] specified in Table 3.3.1.1-1 is a predetermined setting for a protective dovicoprotection channel chosen to ensure automatic actuation prior to the process variable reaching the AR, ytGAnalytical Limit and thus ensuring that the SL would not be exceeded.
As such, the tFip setpeh4-[LTSP1 accounts for uncertainties in setting the devieechannel (e.g., calibration), uncertainties in how the dev-Mechannel might actually perform (e.g., repeatability), changes in the point of action of the de~oGechannel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the trip s"tpefint plays an important role in eosurig[LTSP1 ensures that SLs are not exceeded.
As ..4.Therefore, the tFIp [et--;f1LTSP1 meets the definition of an LSSS (Ref. 1) and coud bo usedd to moot tho requirement that they be contained in the Technical Spccifications.).
BASES BACKGROUND (continued)
Technical Specifications contain values related to the OPERABILITY of equipment required for safe operation of the facility.
Operable is defined in Technical Specifications as "...being capable of performing its safety function(s)." For automatic protective devices,Relying solely on the required safet function is to ensure that a SL Is not exceededan thcrcforc the as defined by 40 CGFR 5/0.36 is; the same as th OPER-ABILITY Iimit for thoe deVices. However, u.e of the tFrip 6etp9in[LTSP1 to define OPERABILITY in Technical Specifications afid its co~rGresoding designation as the L959 required by 10 CFIR 50.36 would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as:found" value of a PF4,eGt*Ye d4efeeprotection channel setting during a Surveillance.
This would result in Technical Specification compliance problems, as well as reports and corrective actions required by the rule which are not necessary to ensure safety. For example, an automatic pretective deieprotection channel with a setting that has been found to be different from the #ip BWR/4 STS B 3.3.1.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1.1 The OPERABILITY of the RPS is dependent on the OPERABILITY of the individual instrumentation channel Functions specified in Table 3.3.1.1-1.
Each Function must have a required number of OPERABLE channels per RPS trip system, with their setpoints set within the Gpocifiod AlloQ4Awble Valuesettinq tolerance of the [LTSPs1, where appropriate.
The actual setpoint is calibrated consistent with applicable setpoint methodology assumptions.
Each channel must also respond within its assumed response time.BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)
Allowable Values for RPS Instrumentation Functions are specified fei eAcR-Ah RPS2 Func*tion specified in the Table. Nominal trip s.tpoin..
3.3.1.1-1. [Limitingq Trip Setpointsl and the methodologies for calculation of the as-left and as-found tolerances are Speelfie4described in *8 Getpeiht Gai-,.atiel-.
[insert the name of a document controlled under 10 CFR 50.59 such as the Technical Reguirements Manual or any document incorporated into the facility FSAR]. The nominal setpoints[LTSPs]
are selected to ensure that the actual setpoints de net exceed the Allowable Val;eremain conservative with respect to the as-found tolerance band between successive CHANNEL CALIBRATIONS.
OperatiOe with-a-After each calibration the trip setpoint less censer-vative than the norinal trip setpeitRtbutshall be left within its Al.l'oable Value, is acceptable.
A channel isioeal fits actuial trip sctpoint is nOt Within its required Allowab~le lal-.the as-left band around the [LTSP1.T4Fipsetpeiits[LTSPs]
are those predetermined values of output at which an action should take place. The setpoints are compared to the actual process parameter (e.g., reactor vessel water level), and when the measured output value of the process parameter exceeds the setpoint, the associated deviceehan.nel (e.g., trip unit) changes state. The afayteanalytical limits are derived from the limiting values of the process parameters obtained from the safety analysis.
The Allowable Values are derived from the aRal4ieanaytica limits, corrected for calibration, process, and some of the instrument errors. The tWip-setpeia4[LTSPs]
are then determined accounting for the remaining instrument errors (e.g., drift). The t#ip-setpGints[LTSPs1 derived in this manner provide adequate protection because instrumentation uncertainties, process effects, calibration tolerances, instrument drift, and severe environment errors (for channels that must function in harsh environments as defined by 10 CFR 50.49) are accounted for.The OPERABILITY of scram pilot valves and associated solenoids, backup scram valves, and SDV valves, described in the Background section, are not addressed by this LCO.The individual Functions are required to be OPERABLE in the MODES specified in the table, which may require an RPS trip to mitigate the BWR/4 STS B 3.3.1.1-6 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE REQUIREMENTS (continued)
---------------------
REVIEWER'S NOTE ------------------------------------
Notes a and b are applied to the setpoint verification Surveillances for each RTS instrumentation Function in Table 3.3.1.1-1 unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or-4e instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, Proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected chan-qe in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the requirements would apply.As noted at the beginning of the SRs, the SRs for each RPS ,.strumonta~t.instrument Function are located in the SRs column of Table 3.3.1.1-1.
The Surveillances are modified by a Note to indicate that when a channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed for up to 6 hours, provided the associated Function maintains RPS trip capability.
Upon completion of the Surveillance, or expiration of the 6 hour allowance, the channel must be returned to OPERABLE status or the applicable Condition entered and Required Actions taken. This Note is based on the reliability analysis (Ref. 4) assumption of the average time required to perform channel Surveillance.
That analysis demonstrated that the 6 hour testing allowance does not significantly reduce the probability that the RPS will trip when necessary.
SR 3.3.1.1.1 Performance of the CHANNEL CHECK once every 12 hours ensures that a gross failure of instrumentation has not occurred.
A CHANNEL CHECK BWR/4 STS B 3.3.1.1-26 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.1.7 and SR 3.3.1.1.10 A CHANNEL FUNCTIONAL TEST is performed on each required channel to ensure that the entire channel will perform the intended function.
A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable CHANNEL FUNCTIONAL TEST of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical SPeGatieRSpecifications and non-Technical tests at least once per refueling interval with applicable extensions.
Any setpoint adjustment shall be consistent with the assumptions of the current plant specific setpoint methodology.
The 92 day Frequency of SR 3.3.1.1.7 is based on the reliability analysis of Reference 10.The 18 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power. Operating experience has shown that these components usually pass the Surveillance when performed at the 18 month Frequency.
SR 3.3.1.1.7 for Function 3.3.1.1-1.2.d is modified by two Notes as identified in Table 3.3.1.1-1.
The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document BWR/4 STS B 3.3.1.1-31 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1.1 incorporated into the facility FSAR by referencel.The sccrnd Nete -aso Fe u.'a,, that+ fIi TSP andtl he fnteolge &#xa3;... Ga ,'GU fiR. the as' left ,ad t h 'e fa s;- ond +aleaRt~nna he in r~PaR+e the~ nme rf -A dArip,. ,rAAr.n+rAnGR#Gllar nv~p." ' "IA I('E I~ ."r ,,h a,.,+ha.l phn,v..lv D,.. v v,i ....pn .f.a,v l ,a.~ an., SR 3.3.1.1.8 GaCibratkenThe calibation of trip units provides a check of the actual trip setpoints.
The channel must be declared inoperable if the trip setting is discovered to be less conservative than the Allowable Value specified in Table 3.3.1.1-1.
If-the trip setting is discovered to be less conservative than accounted for in the appropriate setpoint methodology, but is ilet beyG dconservative with respect to the Allowable Value, the channel performance is still within the requirements of the plant safety analysis.Under these conditions, the setpoint must be readjusted to be--equal, e ef more cens,--ti'-e thathe [LTSP1 within the as-left tolerance as accounted for in the appropriate setpoint methodology.
The Frequency of 92 days is based on the reliability analysis of Reference 10.Numerous SR 3.3.1.1.8 functions are modified by two Notes as identified in Table 3.3.1.1-1.
The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP], then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.Tho second Nete -als reqaures that -f TQDp andr tha fr c.aI,.uatfniqh, the, lft ,-ate I the a,. (am itel alRanna, be On Fonseft th e iairam ef. a Adr-,u.e.
niat GR#Gnralar BWR/4 STS B 3.3.1.1-32 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1.1-ndpr 10 r-F=R 90 fig r,- -ph Ar, thp T-P FPFAPRtf; DAR-GhR!Gal Reaull-111-11-61.1-R61al GFaRl dAr'-ment in the faGillty FSARI.BWR/4 STS B 3.3.1.1-33 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1.1 procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.Tho sccond ,Noto alsc Fewu res th.at rT-SPI &#xf7;h, mpthp.,do,. -Ip.. cRc~tnq*".
.d,,, the aS fnmd tGn +nRGnmn be 2R ;,-. m he i ahn of al GIn#GI,'r irmA fir '10 Gl FIR 5D 0 Em Ak .,rh;.q tht; TtA hnkm D~a Ra61. mar~nr tqAt M niR in- a mn ,Ian im.amm m~m n~a mn thek fnaoinm, FSARD1 SR 3.3.1.1.12 The Average Power Range Monitor Flow Biased Simulated Thermal Power -High Function uses an electronic filter circuit to generate a signal proportional to the core THERMAL POWER from the APRM neutron flux signal. This filter circuit is representative of the fuel heat transfer dynamics that produce the relationship between the neutron flux and the core THERMAL POWER. The Surveillance filter time constant must be verified to be < 7 seconds to ensure that the channel is accurately reflecting the desired parameter.
The Frequency of 18 months is based on engineering judgment considering the reliability of the components.
SR 3.3.1.1.12 for Function 3.3.1.1-1.2.b is modified by two Notes as identified in Table 3.3.1.1-1.
The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note reguires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be BWR/4 STS B 3.3.1.1-35 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1.1 declared inoperable.
The second Note also requires that [LTSP] and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by reference].Tho socond Notoe-ak r...I. a.,ae. tha-t i !L DI a d,-the methed, Ieges i- .... L ., a .t*Rq th e h a .1 -.,-theasn fOUa mi- +leaRnresac ha OR F*npart the nnaane of a dE-Jan.~ GGan+nnRaIenrJ a a a .r 10 GFl 5.' 59 s-l -A ;;rn thA TrAnh *a l R I Do a. ra ma inoNAna a'i .s BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.1.13 The LOGIC SYSTEM FUNCTIONAL TEST demonstrates the OPERABILITY of the required trip logic for a specific channel. The functional testing of control rods (LCO 3.1.3), and SDV vent and drain valves (LCO 3.1.8), overlaps this Surveillance to provide complete testing of the assumed safety function.The 18 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant.outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power. Operating experience has shown that these components usually pass the Surveillance when performed at the 18 month Frequency.
SR 3.3.1.1.14 This SR ensures that scrams initiated from the Turbine Stop Valve -Closure and Turbine Control Valve Fast Closure, Trip Oil Pressure -Low Functions will not be inadvertently bypassed when THERMAL POWER is> 30% RTP. This involves calibration of the bypass channels.
Adequate margins for the instrument setpoint methodologies are incorporated into the actual setpoint.
Because main turbine bypass flow can affect this setpoint nonconservatively (THERMAL POWER is derived from turbine first stage pressure), the main turbine bypass valves must remain closed at THERMAL POWER > 30% RTP to ensure that the calibration remains valid.If any bypass channel's setpoint is nonconservative (i.e., the Functions are bypassed at > 30% RTP, either due to open main turbine bypass valve(s) or other reasons), then the affected Turbine Stop Valve -Closure and Turbine Control Valve Fast Closure, Trip Oil Pressure -Low Functions are considered inoperable.
Alternatively, the bypass channel can be placed in the conservative condition (nonbypass).
If placed in the nonbypass condition, this SR is met and the channel is considered OPERABLE.BWR/4 STS B 3.3.1.1-36 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Control Rod Block Instrumentation B 3.3.2.1 B 3.3 INSTRUMENTATION B 3.3.2.1 Control Rod Block Instrumentation BASES BACKGROUND Control rods provide the primary means for control of reactivity changes.Control rod block instrumentation includes channel sensors, logic circuitry, switches, and relays that are designed to ensure that specified fuel design limits are not exceeded for postulated transients and accidents.
During high power operation, the rod block monitor (RBM)provides protection for control rod withdrawal error events. During low power operations, control rod blocks from the rod worth minimizer (RWM)enforce specific control rod sequences designed to mitigate the consequences of the control rod drop accident (CRDA). During shutdown conditions, control rod blocks from the Reactor Mode Switch -Shutdown Position Function ensure that all control rods remain inserted to prevent inadvertent criticalities.
The protection and monitoring functions of the control rod block instrumentation has been designed to ensure safe operation of the reactor. This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RPS, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 40-GF-R 50.36(n)(1
)(ii(A) r.guir', TA-c.hni-gal Spocificattons include LSSS for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a Safety Limit (SL) is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the settinq at which the automatic protective action would actually occur.--REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting.BWR/4 STS B 3.3.2.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Control Rod Block Instrumentation B 3.3.2.1"Nominal Trip Setpoint [NTSP]" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
Licensees are to insert the name of the document(s) controlled under 10 CFR 50.59 that contain the methodology for calculating the as-left and as-found tolerances, in Note c of Table 3.3.2.1-1 for the phrase "[insert the name of a document controlled under 10 CFR 50.59 such as the Technical Reguirements Manual or any document incorporated into the facility FSAR]" throughout these Bases.If the [LTSP1 is not included in Table 3.3.2.1-1, the plant-specific location for the [LTSP1 or [NTSP1 must be cited in Note c of Table 3.3.2.1-1.
The brackets indicate plant-specific terms may apply, as reviewed and approved by the NRC. Tho as s l; tolerances will apply to thp gm .;4 1 narFa i i t ifluF W G R g GhaRmmel , '. ,-.----------
---------
---------
-- ---- ----------------------------The [Limitingq Trip Setpoint (LTSP)] specified in Table 3.3.2.1-1 is a predetermined setting for a protection channel chosen to ensure automatic actuation prior to the process variable reaching the Analytical Limit and thus ensuring that the SL would not be exceeded.
As such, the[LTSP] accounts for uncertainties in setting the channel (e.g.. calibration), uncertainties in how the channel might actually perform (e.g., repeatability), changes in the point of action of the channel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the [LTSP1 ensures that SLs are not exceeded.
Therefore, the [LTSP1 meets the definition of an LSSS (Ref. 1).The Allowable Values specified in Table 3.3.2.1-1 serves as the LSSS such that a channel is OPERABLE if the trip setpoint is found not to exceed the Allowable Value. As such, the Allowable Value differs from the trip setpoint by an amount primarily equal to the expected instrument loop uncertainties, such as drift, during the surveillance interval.
In this manner, the actual setting of the device will still meet the LSSS definition and ensure that a SL is not exceeded at any given point of time as long as the device has not drifted beyond that expected during the surveillance interval.Technical Specifications contain values related to the OPERABILITY of equipment reguired for safe operation of the facility.
Operable is defined in Technical Specifications as "...being capable of performing its safety function(s)." Relying solely on the [LTSP1 to define OPERABILITY in Technical Specifications would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as found" value of a protection channel setting during a Surveillance.
This would result in BWR/4 STS B 3.3.2.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Control Rod Block Instrumentation B 3.3.2.1 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY Allowable Values are specified for each Rod Block Function specified in SR 3.3.2.1.7, [[Limitingq Trip Setpoints]
and the methodologies for calculation of the as-left and as-found tolerances are described in [insert the name of a document controlled under 10 CFR 50.59 such as the Technical Requirements Manual or any document incorporated into the facility FSAR1. The [LTSP1s are selected to ensure that the actual setpoints remain conservative with respect to the as-found tolerance band between successive CHANNEL CALIBRATIONS.
After each calibration the trip setpoint shall be left within the as-left band around the [LTSP1.[LTSPs1 are those predetermined values of output at which an action should take place. The setpoints are compared to the actual process parameter (e.g., reactor vessel water level), and when the measured output value of the process parameter exceeds the setpoint, the associated deviceehaRwe (e.g., trip unit) changes state. The analytical limits are derived from the limiting values of the process parameters obtained from the safety analysis.
The Allowable Values are derived from the analytical limits, corrected for calibration, process, and some of the instrument errors. The [LTSPs1 are then determined accounting for the remaining instrument errors (e.g., drift). The [LTSPs1 derived in this manner provide adequate protection because instrumentation uncertainties, process effects, calibration tolerances, instrument drift, and severe environment errors (for channels that must function in harsh environments as defined by 10 CFR 50.49) are accounted for.The specific Applicable Safety Analyses, LCO, and Applicability discussions are listed below on a Function by Function basis.1. Rod Block Monitor The RBM is designed to prevent violation of the MCPR SL and the cladding 1% plastic strain fuel design limit that may result from a single control rod withdrawal error (RWE) event. The analytical methods and assumptions used in evaluating the RWE event are summarized in Reference 3,4. A statistical analysis of RWE events was performed to determine the RBM response for both channels for each event. From these responses, the fuel thermal performance as a function of RBM Allowable Value was determined.
The Allowable Values are chosen as a function of power level. Based on the specified Allowable Values, operating limits are established.
The RBM Function satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).
BWR/4 STS B 3.3.2.1-5 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Control Rod Block Instrumentation B 3.3.2.1 BASES ACTIONS (continued)
E.1 and E.2 With one Reactor Mode Switch -Shutdown Position control rod withdrawal block channel inoperable, the remaining OPERABLE channel is adequate to perform the control rod withdrawal block function.However, since the Required Actions are consistent with the normal action of an OPERABLE Reactor Mode Switch -Shutdown Position Function (i.e., maintaining all control rods inserted), there is no distinction between having one or two channels inoperable.
In both cases (one or both channels inoperable), suspending all control rod withdrawal and initiating action to fully insert all insertable control rods in core cells containing one or more fuel assemblies will ensure that the core is subcritical with adequate SDM ensured by LCO 3.1.1. Control rods in core cells containing no fuel assemblies do not affect the reactivity of the core and are therefore not required to be inserted.
Action must continue until all insertable control rods in core cells containing one or more fuel assemblies are fully inserted.SURVEILLANCE
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REVIEWER'S NOTE -----------------------------------
REQUIREMENTS Certain Frequencies are based on approved topical reports. In order for a licensee to use these Frequencies, the licensee must justify the Frequencies as required by the staff SER for the topical report.--------------------
REVIEWER'S NOTE ..................................
Notes b and c are applied to the setpoint verification Surveillances for the Control Rod Block Instrumentation Functions in Table 3.3.2.1-1 unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or te instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, Proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where BWR/4 STS B 3.3.2.1-11 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Control Rod Block Instrumentation B 3.3.2.1 requires evaluation of channel performance for the condition where the as-found settinq for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the[LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that fLTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.The socond ,Io , reguires that [TDSP1 and tho rnpthprjnlwoef fnr nR'. iI~ther +a.,p lefI thRl WAMe n ,r +lrnne hA FaRS84 a ..,,a.+ ,eat+.aI'aA w-A-,I I " GFR" &#xa3;.A LO as thA TAh-r, DAm)t[ Miam A d BWR/4 STS B 3.3.2.1-16 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)EOC-RPT Instrumentation B 3.3.4.1 B 3.3 INSTRUMENTATION B 3.3.4.1 End of Cycle Recirculation Pump Trip (EOC-RPT)
Instrumentation BASES BACKGROUND The EOC-RPT instrumentation initiates a recirculation pump trip (RPT) to reduce the peak reactor pressure and power resulting from turbine trip or generator load rejection transients to provide additional margin to core thermal MCPR Safety Limits (SLs).The need for the additional negative reactivity in excess of that normally inserted on a scram reflects end of cycle reactivity considerations.
Flux shapes at the end of cycle are such that the control rods may not be able to ensure that thermal limits are maintained by inserting sufficient negative reactivity during the first few feet of rod travel upon a scram caused by Turbine Control Valve (TCV) Fast Closure, Trip Oil Pressure -Low or Turbine Stop Valve (TSV) -Closure. The physical phenomenon involved is that the void reactivity feedback due to a pressurization transient can add positive reactivity at a faster rate than the control rods can add negative reactivity.
The protection functions of the EOC-RPT have been designed to ensure safe operation of the reactor during load reiection transients.
This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the EOC-RPT, as well as LCOs on other system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 4-G-R 59.36(. r.guir. s that Specificatncns include LSSSs for variables that have significant safety functions.
LSSS are defined by the regulation as'Where a LSSS is specified for a variable on which a safety limit has been placed, the settinq must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the Safety Limit (SL) is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur.--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint'
[LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin BWR/4 STS B 3.3.4.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)EOC-RPT Instrumentation B 3.3.4.1 has been added between the Analytical Limit and the calculated trip setting.'Nominal Trip Setpoint [NTSPT is the suqqested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP]. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
Licensees are to insert the name of the document(s) controlled under 10 CFR 50.59 that contain the methodology for calculating the as-left and as-found tolerances, in Note 2 of SIR 3.3.4.1.2 or 3.3.4.1.3 for the phrase"[insert the name of a document controlled under 10 CFR 50.59 such as the Technical Requirements Manual or any document incorporated into the facility FSAR]" throughout these Bases.If the [LTSP1 is not included in SR 3.3.4.1.2 or 3.3.4.1.3 for the purpose of compliance with 10 CFR 50.36, the plant-specific location for the [LTSP]or NTSP must be cited in Note 2 of the SRs in the SIR table. The brackets indicate plant-specific terms may apply, as reviewed and approved by the NRC. T-ha -f,- -, ... ,d a i ,,arl I eft tnA-1,,, ..i,, m,,,,,,, +n, ahe .,. .-l n,, ni-,R d mnlnmen~nl i IltheQu ,nuvefl~a~
Ipnr~n n renl u tn GEnnffFRm rGhaRnina The [Limiting Trip Setpoint (LTSP)] specified in SR 3.3.4.1.2 and SR 3.3.4.1.3 is a predetermined setting for a protection channel chosen to ensure automatic actuation prior to the process variable reaching the Analytical Limit and thus ensuring that the SL would not be exceeded.
As such, the [LTSP1 accounts for uncertainties in setting the channel (e.g., calibration), uncertainties in how the channel might actually perform (e.g., repeatability), changes in the point of action of the channel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the [LTSP1 ensures that SLs are not exceeded.
Therefore, the [LTSP1 meets the definition of an LSSS (Ref. 1).The Allowable Value specified in SR 3.3.4.1.3 serves as the LSSS such that a channel is OPERABLE if the trip setpoint is found not to exceed the Allowable Value. As such, the Allowable Value differs from the trip setpoint by an amount primarily equal to the expected instrument loop uncertainties, such as drift, during the surveillance interval.
In this manner, the actual setting of the device will still meet the LSSS definition and ensure that a SL is not exceeded at any given point of time as long as the device has not drifted beyond that expected during the surveillance interval.Technical Specifications contain values related to the OPERABILITY of eguipment required for safe operation of the facility.
Operable is defined in Technical Specifications as "...being capable of performing its safety BWR/4 STS B 3.3.4.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)EOC-RPT Instrumentation B 3.3.4.1 BASES ACTIONS (continued)
C.1 and C.2 With any Required Action and associated Completion Time not met, THERMAL POWER must be reduced to < 30% RTP within 4 hours.Alternately, the associated recirculation pump may be removed from service, since this performs the intended function of the instrumentation.
The allowed Completion Time of 4 hours is reasonable, based on operating experience, to reduce THERMAL POWER to < 30% RTP from full power conditions in an orderly manner and without challenging plant systems.Required Action C.1 is modified by a Note which states that the Required Action is only applicable if the inoperable channel is the result of an inoperable RPT breaker. The Note clarifies the situations under which the associated Required Action would be the appropriate Required Action.SURVEILLANCE
---------------------
REVIEWERS NOTE ------------------
REQUIREMENTS Certain Frequencies are based on approved topical reports. In order for a licensee to use these Frequencies, the licensee must justify the Frequencies as required by the staff SER for the topical report.-------------------
REVIEWERS NOTE -------------------
Notes 1 and 2 are applied to the setpoint verification Surveillances for the TCV Fast Closure Function unless one or more of the followinq exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or-te instrument functions that derive input from contacts which have no associated sensor or admustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where BWR/4 STS B 3.3.4.1-11 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)EOC-RPT Instrumentation B 3.3.4.1 condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint BASES SURVEILLANCE REQUIREMENTS (continued) more conservative than the [LTSPI is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
Thc socond Note also requires that [LTSP1 and the methedelmnlnra fE) ar -iG.Iatw~aRq the as left + thel f a s fGRE.. itele+narnnre&-b SRn FiRS9n4 thr. InnAme n-f ap dA-rn. m t rmntrllrlI tA-r 10- C- FIR~ f ~ ~kn the facility FSAR]. The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by reference].
SR 3.3.4.1.3 CHANNEL CALIBRATION is a complete check of the instrument loop and the sensor. This test verifies the channel responds to the measured parameter within the necessary range and accuracy.
CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drifts between successive calibrations consistent with the plant specific setpoint methodology.
The Frequency is based upon the assumption of an 18 month calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.SR 3.3.4.1.3 for the TCV Fast Closure function is modified by two Notes in the SR table. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance BWR/4 STS B 3.3.4.1-14 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)EOC-RPT Instrumentation B 3.3.4.1 procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-BASES SURVEILLANCE REQUIREMENTS (continued) left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also rogu-ros that [LTSPI and the'.-, +hn nm r u.-f. n# rlu.- , u.. rna-f r.nmfrrulhnJ , unrlnr 'If ('C Cflt: CO pu. k u,.h.'Fnthe T e lchnc s .... GaGI ..... ln.he .. 24f... a " Rdr the ....... id tele.......
*,e&-" t he, PS^D The second Note also requires that [LTSP] and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
SR 3.3.4.1.4 The LOGIC SYSTEM FUNCTIONAL TEST demonstrates the OPERABILITY of the required trip logic for a specific channel. The system functional test of the pump breakers is included as a part of this test, overlapping the LOGIC SYSTEM FUNCTIONAL TEST, to provide complete testing of the associated safety function.
Therefore, if a breaker is incapable of operating, the associated instrument channel(s) would also be inoperable.
The 18 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power. Operating experience has shown these components usually pass the Surveillance when performed at the 18 month Frequency.
SR 3.3.4.1.5 This SR ensures that an EOC-RPT initiated from the TSV -Closure and TCV Fast Closure, Trip Oil Pressure -Low Functions will not be inadvertently bypassed.when THERMAL POWER is > 30% RTP. This involves calibration of the bypass channels.
Adequate margins for the instrument setpoint methodologies are incorporated into the actual setpoint.
Because main turbine bypass flow can affect this setpoint nonconservatively (THERMAL POWER is derived from first stage pressure) the main turbine bypass valves must remain closed at THERMAL POWER > 30% RTP to ensure that the calibration remains BWR/4 STS B 3.3.4.1-15 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ECCS Instrumentation B 3.3.5.1 B 3.3 INSTRUMENTATION B 3.3.5.1 Emergency Core Cooling System (ECCS) Instrumentation BASES BACKGROUND The purpose of the ECCS instrumentation is to initiate appropriate responses from the systems to ensure that the fuel is adequately cooled in the event of a design basis accident or transient.
This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the ECCS, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 40-GF-R 50.36nW,-O A) Fr. uro^ thAt Tolehrnicial Spoecifications include LSSSs for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a Safety Limit (SL) is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur.--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP1" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
Licensees are to insert the name of the document(s) controlled under 10 CFR 50.59 that contain the methodology for calculating the as-left and as-found tolerances in Note f of Table 3.3.5.1-1, for the phrase "finsert the name of a document controlled under 10 CFR 50.59 such as the Technical Requirements Manual or any document incorporated into the facility FSAR1" throughout these Bases.BWR/4 STS B 3.3.5.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ECCS Instrumentation B 3.3.5.1 If the [LTSP1 is not included in Table 3.3.5.1-1 for the Purpose of compliance with 10 CFR 50.36, the plant-specific location for the [LTSP1 or NTSP must be cited in Note f of Table 3.3.5.1-1.
The brackets indicate plant-specific terms may apply, as reviewed and approved by the NRC.The as fn a .a left ele ..ply to the aGt, ,al setpnf R t ,rv,~~~~ drnnn -k .n,, nnnrr rt:nrl maran n~nnfWr rh;kn nra BASES BACKGROUND (continued)
The [Limiting Trip Setpoint (LTSP)1 specified in Table 3.3.5.1-1 is a predetermined setting for a protection channel chosen to ensure automatic actuation prior to the process variable reaching the Analytical Limit and thus ensurinq that the SL would not be exceeded.
As such, the[LTSP1 accounts for uncertainties in setting the channel (e.g., calibration), uncertainties in how the channel might actually perform (e.g., repeatability), changes in the point of action of the channel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the [LTSP1 ensures that SLs are not exceeded.
Therefore the [LTSP] meets the definition of an LSSS (Ref. 1).The Allowable Value specified in Table 3.3.5.1-1 serves as the LSSS such that a channel is OPERABLE if the trip setpoint is found not to exceed the Allowable Value. As such, the Allowable Value differs from the trip setpoint by an amount primarily equal to the expected instrument loop uncertainties, such as drift, during the surveillance interval.
In this manner, the actual setting of the device will still meet the LSSS definition and ensure that a SL is not exceeded at any given point of time as long as the device has not drifted beyond that expected during the surveillance interval.Technical Specifications contain values related to the OPERABILITY of equipment required for safe operation of the facility.
Operable is defined in Technical Specifications as "...being capable of performing its safety function(s)." Relying solely on the [LTSP1 to define OPERABILITY in Technical Specifications would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as found" value of a protection channel setting during a Surveillance.
This would result in Technical Specification compliance problems, as well as reports and corrective actions required by the rule which are not necessary to ensure safety. For example, an automatic protection channel with a setting that has been found to be different from the [LTSP1 due to some drift of the setting may still be OPERABLE because drift is to be expected.
This expected drift would have been specifically accounted for in the setpoint methodology for calculating the [LTSP1 and thus the automatic protective BWR/4 STS B 3.3.5.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ECCS Instrumentation B 3.3.5.1 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)
Oporation with a trip 6otpoint loec concrativo;t*A th;An the nominal trip Getpoint, but wi.9thin its Allowable Value, is accoptable.
A channel i inprl If 1it4 actual trip setpoint is no~t wihnits required Allowablo Value.'a,, Tr-ip c-tpin [LTSPs] are those predetermined values of output at which an action should take place. The setpoints are compared to the actual process parameter (e.g., reactor vessel water level), and when the measured output value of the process parameter exceeds the setpoint, the associated devicedovicochanno4 (e.g., trip unit) changes state. The aimeytiianalytical limits are derived from the limiting values of the process parameters obtained from the safety analysis.
The Allowable Values are derived from the anayti~analvtical limits, corrected for calibration, process, and some of the instrument errors. The tr etp-,-iRs[LTSPsj are then determined, accounting for the remaining instrument errors (e.g., drift). The setpeifts[LTSPs1 derived in this manner provide adequate protection because instrumentation uncertainties, process effects, calibration tolerances, instrument drift, and severe environment errors (for channels that must function in harsh environments as defined by 10 CFR 50.49) are accounted for.In general, the individual Functions are required to be OPERABLE in the MODES or other specified conditions that may require ECCS (or DG)initiation to mitigate the consequences of a design basis transient or accident.
To ensure reliable ECCS and DG function, a combination of Functions is required to provide primary and secondary initiation signals.The specific Applicable Safety Analyses, LCO, and Applicability discussions are listed below on a Function by Function basis.Core Spray and Low Pressure Coolant Iniection Systems 1 .a, 2.a. Reactor Vessel Water Level -Low Low Low, Level 1 Low reactor pressure vessel (RPV) water level indicates that the capability to cool the fuel may be threatened.
Should RPV water level decrease too far, fuel damage could result. The low pressure ECCS and associated DGs are initiated at Level 1 to ensure that core spray and flooding functions are available to prevent or minimize fuel damage. The Reactor Vessel Water Level -Low Low Low, Level 1 is one of the Functions assumed to be OPERABLE and capable of initiating the ECCS during the transients analyzed in References 42 and 3-A. In addition, the Reactor Vessel Water Level -Low Low Low, Level 1 Function is directly assumed in the analysis of the recirculation line break (Ref. 23). The core cooling function of the ECCS, along with the scram action of the Reactor Protection System (RPS), ensures that the fuel peak cladding temperature remains below the limits of 10 CFR 50.46.BWR/4 STS B 3.3.5.1-11 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ECCS Instrumentation B 3.3.5.1 BASES ACTIONS (continued)
Because of the diversity of sensors available to provide initiation signals and the redundancy of the ECCS design, an allowable out of service time of 8 days has been shown to be acceptable (Ref. 56) to permit restoration of any inoperable channel to OPERABLE status if both HPCI and RCIC are OPERABLE (Required Action G.2). If either HPCI or RCIC is inoperable, the time shortens to 96 hours. If the status of HPCI or RCIC changes such that the Completion Time changes from 8 days to 96 hours, the 96 hours begins upon discovery of HPCI or RCIC inoperability.
However, the total time for an inoperable channel cannot exceed 8 days. If the status of HPCI or RCIC changes such that the Completion Time changes from 96 hours to 8 days, the "time zero" for beginning the 8 day "clock" begins upon discovery of the inoperable channel. If the inoperable channel cannot be restored to OPERABLE status within the allowable out of service time, Condition H must be entered and its Required Action taken. The Required Actions do not allow placing the channel in trip since this action would not necessarily result in a safe state for the channel in all events.H.1 With any Required Action and associated Completion Time not met, the associated feature(s) may be incapable of performing the intended function, and the supported feature(s) associated with inoperable untripped channels must be declared inoperable immediately.
SURVEILLANCE
---------------------
REVIEWER'S NOTE ------------------
REQUIREMENTS Certain Frequencies are based on approved topical reports. In order for a licensee to use these Frequencies, the licensee must justify the Frequencies as required by the staff SER for the topical report.--------------------
REVIEWER'S NOTE Notes e and f are applied to the setpoint verification Surveillances for each ECCS Instrumentation Functions in Table 3.3.5.1-1 unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or to instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.BWR/4 STS B 3.3.5.1-35 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ECCS Instrumentation B 3.3.5.1 BASES SURVEILLANCE REQUIREMENTS (continued)
Any setpoint adjustment shall be consistent with the assumptions of the current plant specific setpoint methodology.
The Frequency of 92 days is based on the reliability analyses of Reference 56.SR 3.3.5.1.3 Calibration of trip units provides a check of the actual trip setpoints.
The channel must be declared inoperable if the trip setting is discovered to be less conservative than the Allowable Value specified in Table 3.3.5.1-1.
If the trip setting is discovered to be less conservative than accounted for in the appropriate setpoint methodology, but is Ret beyoi4conservative with respect to the Allowable Value, the channel performance is still within the requirements of the plant safety analyses.
Under these conditions, the setpoint must be readjusted to be equal to or more conservative than the setting accounted for in the appropriate setpoint methodology.
The Frequency of 92 days is based on the reliability analysis of Reference 56.SR 3.3.5.1.3 for selected functions is modified by two Notes as identified in Table 3.3.5.1-1.
The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document BWR/4 STS B 3.3.5.1-38 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ECCS Instrumentation B 3.3.5.1 incorporated into the facility FSAR by referencel.Tho sccond ,Note alsc iwo that rLTSCi 1 n ,,I and the m the eleng.a f &#xa3;. a, ,,, +ha -- the na n, lf 4d ,ndJar !0 CF CO CO ..h no fhae neRaaIlR -rltA... o- aWn SR 3.3.5.1.4 and SR 3.3.5.1.5 A CHANNEL CALIBRATION is a complete check of the instrument loop and the sensor. This test verifies the channel responds to the measured parameter within the necessary range and accuracy.
CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drifts between successive calibrations consistent with the plant specific setpoint methodology.
The Frequency of SR 3.3.5.1.4 is based upon the assumption of a 92 day calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.The Frequency of SR 3.3.5.1.5 is based upon the assumption of an 18 month calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.SR 3.3.5.1.5 for selected functions is modified by two Notes as identified in Table 3.3.5.1-1.
The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning thei channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the fLTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by reference].
BWR/4 STS B 3.3.5.1-39 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ECCS Instrumentation B 3.3.5.1 Thiz c;PnP-d N.iIn,-.,--..
,,r,-PG14 that. FI T-S1 ,,m,. the- ~~ alan.,,,-.E 09*I, .;-,,I&#xf7;:,, +i.. nc-. lp 4-f n.m,-,. +ha -..F,,,. fn...,A* larnm' -, o h.a I':, a. &#xf7;I.., i--nn-of a -,ntrolled.
.nder 10 --R 50.59 e Iuh as the Technica.Requ. imRa ,pjtS Ma n.l 9Fr ,. nny can.n lrvn m nnn'rRn!t the fa n nl i BWR/4 STS B 3.3.5.1-40 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RCIC System Instrumentation B 3.3.5.2 B 3.3 INSTRUMENTATION B 3.3.5.2 Reactor Core Isolation Cooling (RCIC) System Instrumentation BASES BACKGROUND The purpose of the RCIC System instrumentation is to initiate actions to ensure adequate core cooling when the reactor vessel is isolated from its primary heat sink (the main condenser) and normal coolant makeup flow from the Reactor Feedwater System is unavailable, such that initiation of the low pressure Emergency Core Cooling Systems (ECCS) pumps does not occur. A more complete discussion of RCIC System operation is provided in the Bases of LCO 3.5.3, "RCIC System." This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RCIC, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are reguired by 10 CFR 50.36 to 10-GF 50.36(c)(1
)(.')(A) r.guires that Tohnical Specifications include LSSSs for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a Safety Limit (SL) is not exceeded.
Any automatic protection action that occurs on reachinq the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur.-REVIEW ER'S NOTE ----------------------------------
The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP]" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
Licensees are to insert the name of the document(s) controlled under 10 CFR 50.59 that contain the methodology for calculatinq the as-left and as-BWR/4 STS B 3.3.5.2-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RCIC System Instrumentation B 3.3.5.2 found tolerances in Note b of Table 3.3.5.2-1, for the phrase "[insert the name of a document controlled under 10 CFR 50.59 such as the Technical Requirements Manual or any document incorporated into the facility FSAR]" throughout these Bases.If the [LTSP1 is not included in Table 3.3.5.2-1, the plant-specific location for the [LTSP1 or NTSP must be cited in Note b of Table 3.3.5.2-1.
The brackets indicate plant-specific terms may apply, as reviewed and approved by the NRC. The as found aRnd as le# tolerFances will pply to thn ;nnt ;;I cn r i I tn i thp RF.merennllwpn6 449- GA-M.frr GhaRmeI veadarmfl m fi The [Limiting Trip Setpoint (LTSP)] specified in Table 3.3.5.2-1 is a predetermined setting for a protection channel chosen to ensure automatic actuation prior to the process variable reachinq the Analytical Limit and thus ensuring that the SL would not be exceeded.
As such, the[LTSP] accounts for uncertainties in setting the channel (e.g., calibration), uncertainties in how the channel might actually perform (e.g., repeatability), changes in the point of action of the channel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the [LTSP1 ensures that SLs are not exceeded.
Therefore the [LTSP1 meets the definition of an LSSS (Ref. 1).The Allowable Value specified in Table 3.3.5.2-1 serves as the LSSS such that a channel is OPERABLE if the trip setpoint is found not to exceed the Allowable Value. As such, the Allowable Value differs from the trip setpoint by an amount primarily equal to the expected instrument loop uncertainties, such as drift, during the surveillance interval.
In this manner, the actual setting of the device will still meet the LSSS definition and ensure that a SL is not exceeded at any given point of time as long as the device has not drifted beyond that expected during the surveillance interval.Technical Specifications contain values related to the OPERABILITY of equipment required for safe operation of the facility.
Operable is defined in Technical Specifications as "...being capable of performing its safety function(s)." Relying solely on the [LTSP1 to define OPERABILITY in Technical Specifications would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as found" value of a protection channel setting during a Surveillance.
This would result in Technical Specification compliance problems, as well as reports and corrective actions required by the rule which are not necessary to ensure safety. For example, an automatic protection channel with a setting that has been found to be different from the [LTSP1 due to some drift of the setting may still be OPERABLE because drift is to be expected.
This expected drift would have been specifically accounted for in the setpoint methodoloqv for calculating the [LTSP1 and thus the automatic protective action would still have ensured that the SL would not be exceeded with BWR/4 STS B 3.3.5.2-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RCIC System Instrumentation B 3.3.5.2[LTSPs1 are those predetermined values of output at which an action should take place. The setpoints are compared to the actual process parameter (e.g., reactor vessel water level), and when the measured output value of the process parameter exceeds the setpoint-ess conservative than the nominal trip setpoint, bu6t within its Allowable Value, is accGeptable.
Each Allowable Valuo specified accounts for ,the associated deviceGhanpe (e.g., trip unit) changes state. The analytical limits are derived from the limiting values of the process parameters obtained from the safety analysis.
The Allowable Values are derived from the analytical limits, corrected for calibration, process, and some of the instrument errors. The [LTSPs1 are then determined, accountin-g for the remaining instrument errors (e.g., drift). The trip setpoints derived in this manner provide adequate protection because instrumentation uncertainties appropriate to the Funcion9.
These described in th m&#xf7;ethodology, process effects, calibration tolerances, instrument drift, and severe environment errors (for channels that must function in harsh environments as defined by 10 CFR 50.49)are accounted for.The individual Functions are required to be OPERABLE in MODE 1, and in MODES 2 and 3 with reactor steam dome pressure > 150 psig since this is when RCIC is required to be OPERABLE. (Refer to LCO 3.5.3 for Applicability Bases for the RCIC System.)The specific Applicable Safety Analyses, LCO, and Applicability discussions are listed below on a Function by Function basis.BWR/4 STS B 3.3.5.2-6 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RCIC System Instrumentation B 3.3.5.2 BASES SURVEILLANCE
---------------------
REVIEWER'S NOTE -----------------------------------
REQUIREMENTS Certain Frequencies are based on approved topical reports. In order for a licensee to use these Frequencies, the licensee must justify the Frequencies as required by the staff SER for the topical report.-------------------
REVIEWER'S NOTE Notes a and b are applied to the setpoint verification Surveillances for all RCIC System Instrumentation Functions in Table 3.3.5.2-1 unless one or more of the followinq exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or-4e instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the requirements would apply.A generic evaluation of RCIC System Instrumentation Functions resulted in Notes a and b being applied to the Functions shown in TS 3.3.5.2.Each licensee adopting this change must review the list of potential Functions to identify whether any of the identified functions meet any of the exclusion criteria based on the plant-specific design and safety analysis (AOOs). The footnotes applied to Function 3.3.5.2-1.[21, Reactor Vessel Water Level -High, Level 8 are optional.As noted in the beginning of the SRs, the SRs for each RCIC System in.t.mn.iinstrument Function are found in the SRs column of Table 3.3.5.2-1.
The Surveillances are modified by a Note to indicate that when a channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed as follows: (a) for up to 6 hours for Functions 2 and 5; and BWR/4 STS B 3.3.5.2-13 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RCIC System Instrumentation B 3.3.5.2 plant Corrective Action Program. Entry into the Corrective Action Procqram will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient mar-gin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSPI, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.Tho .econd Note alo reguires that [LTSP1 and the mfnehr~d9lnG c fnr r,;41A, .I,;4 n 4hzA IPAzf ~lr  R FkIglRS84 th FgrP Afjn A pi, dG hr.ne o GGnFlIe W.,mA -0r CPR 50-59,tl rn r.no as;thkg ~Tgrh i n ID~.I rvg ,.I s n Maualg nnrg..ir~
+i ~ Enrngr Mnt the faG*l+*, EQAD SR 3.3.5.2.4 and SR 3.3.5.2.5 A CHANNEL CALIBRATION is a complete check of the instrument loop and the sensor. This test verifies the channel responds to the measured parameter within the necessary range and accuracy.
CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drifts between successive calibrations consistent with the plant specific setpoint methodology.
BWR/4 STS B 3.3.5.2-16 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RCIC System Instrumentation B 3.3.5.2 BASES SURVEILLANCE REQUIREMENTS (continued)
The Frequency of SR 3.3.5.2.4 is based upon the assumption of a 92 day calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.The Frequency of SR 3.3.5.2.5 is based upon the assumption of an 18 month calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.
SR 3.3.5.2.4 and SR 3.3.5.2.5 are modified by two Notes as identified in Table 3.3.5.2-1.
The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP]. Where a setpoint more conservative than the[LTSP] is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a settinq within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSPI and the methodologies for calculatinq the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.Tho second Note also requires that FLTSP1 aRd thedhAIf-.e,-.,-, fn" , .'- nqh- the;-. s, ' and the, *n' e , .r-. hN R P Ime Ft the ofrn -Adn r~wnr.p .emi-r-,+n-PmtrmI I Ad nd m r 1ll fCE I= R 0 em ig-&uh-;1,-, Tn,- hm ,+ ,- f t-',- m. .m, ,- a..'r mm-.-.l~ l, 4 ("r-l::) + m n r -.pr c,,+ .-.h m  SR 3.3.5.2.6 The LOGIC SYSTEM FUNCTIONAL TEST demonstrates the OPERABILITY of the required initiation logic for a specific channel. The system functional testing performed in LCO 3.5.3 overlaps this Surveillance to provide complete testing of the safety function.BWR/4 STS B 3.3.5.2-17 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Control Rod Block Instrumentation 3.3.2.1 Table 3.3.2.1-1 (page 1 of 1)Control Rod Block Instrumentation APPLICABLE MODES OR OTHER SPECIFIED REQUIRED SURVEILLANCE FUNCTION CONDITIONS CHANNELS REQUIREMENTS
: 1. Rod Pattern Control System a. Rod withdrawal limiter [(a)] 2 SR 3.3.2.1.1 SR 3.3.2.1.6 SR 3.3.2.1.7]b' 00)2 SR 3.3.2.1.2 SR 3.3.2.1.5b UC SR 3.3.2.1.7]b
: b. Rod pattern controller I(G2), 2(- 2 SR 3.3.2.1.3 SR 3.3.2.1.4 SR 3.3.2.1.5 SR 3.3.2.1.7 SR 3.3.2.1.9 2. Reactor Mode Switch -Shutdown Position (Of) 2 SR 3.3.2.1.8 (a) THERMAL POWER > [70]% RTP.(b) INSERT 1 (c) INSERT 2 (bd) THERMAL POWER > [35]% RTP and < [70]% RTP.(ee) With THERMAL POWER < [101% RTP.(df) Reactor mode switch in the shutdown position.BWR/6 STS 3.3.2.1-4 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)EOC-RPT Instrumentation 3.3.4.1 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME B. One or more Functions B.1 Restore EOC-RPT trip 2 hours with EOC-RPT trip capability.
capability not maintained.
OR AND [B.2 Apply the MCPR limit for 2 hours]inoperable EOC-RPT as[MCPR limit for specified in the COLR.inoperable EOC-RPT not made applicable.]
C. Required Action and C.1 Remove the associated 4 hours associated Completion recirculation pump fast Time not met. speed breaker from service.OR C.2 Reduce THERMAL 4 hours POWER to < [40]% RTP.SURVEILLANCE REQUIREMENTS
------------------------------
NOTE------------------------------
When a channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed for up to 6 hours, provided the associated Function maintains EOC-RPT trip capability.
SURVEILLANCE FREQUENCY SR 3.3.4.1.1 Perform CHANNEL FUNCTIONAL TEST. [92] days SR 3.3.4.1.2
-- ----------------
NOTES ----------------
[92] days ]1. If the as-found channel setpoint is outside its predefined as-found tolerance, then the channel shall be evaluated to verify that it is functioning as required before returning the channel to service.2. The instrument channel setpoint shall be reset BWR/6 STS 3.3.4.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)EOC-RPT Instrumentation 3.3.4.1 SURVEILLANCE FREQUENCY to a value that is within the as-left tolerance around the Limitina Trip Setpoint (LTSP) -at the completion of the surveillance:
otherwise.
the channel shall be declared inoperable.
Setpoints more conservative than the LTSP are acceptable provided that the as-found and as-left tolerances apply to the actual setpoint implemented in the Surveillance Procedures (Nominal Trip Setpoint) to confirm channel performance.
The LTSP and the methodoloaies used to determine the as-found and the as-left tolerances are specified in [insert the facility FSAR reference or the name of a.dAR men document incorporated into the facility FSAR by referencel.
.[ Calibrate the trip units.BWR/6 STS 3.3.4.1-3 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)EOC-RPT Instrumentation 3.3.4.1 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.3.4.1.3--- --- --- ------------
NOTES -------------------
[18] months 1. If the as-found channel setpoint is outside its predefined as-found tolerance, then the channel shall be evaluated to verify that it is functioning as reauired before returninq the channel to service.2. The instrument channel setpoint shall be reset to a value that is within the as-left tolerance around the Limiting Trip Setpoint (LTSP) at the completion of the surveillance:
otherwise, the channel shall be declared inoperable.
Setpoints more conservative than the LTSP are acceptable provided that the as-found and as-left tolerances apply to the actual setpoint implemented in the Surveillance procedures t(Ilrnminol Trin -Q=f ninfl fr- r-rnnfir rnh~nnngal performance.
The LTSP and the methodoloqies used to determine the as-found and the as-left tolerances are specified in [insert the facility FSAR reference or the name of a-deeumea4 conntrolle~d unmdor 10 CEFR 50.5 fiuc -h ;;F thoq T-echR ca. Requeremects AMnn'--n Ir any document incorporated into the facility FSAR by referencel.
Perform CHANNEL CALIBRATION.
The Allowable Values shall be: a. TSV Closure, Trip Oil Pressure -Low:> [37] psig and b. TCV Fast Closure, Trip Oil Pressure -Low: > [42] psig.SR 3.3.4.1.4 Perform LOGIC SYSTEM FUNCTIONAL TEST, [18] months including breaker actuation.
SR 3.3.4.1.5 Verify TSV Closure, Trip Oil Pressure -Low and [18] months TCV Fast Closure, Trip Oil Pressure -Low Functions are not bypassed when THERMAL POWER is > [40]% RTP.BWR/6 STS 3.3.4.1-4 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Relief and LLS Instrumentation 3.3.6.5 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.3.6.5.2-----------
----:-----------
NOTES ---------------------
[92] days ]1. If the as-found channel setpoint is outside its predefined as-found tolerance, then the channel shall be evaluated to verify that it is functioning as required before returning the channel to service.2. The instrument channel setpoint shall be reset to a value that is within the as-left tolerance around the [Limitina Trip SetDoint (LTSP) or Nominal Trip Setpoint (NTSP)] at the completion of the surveillance:
otherwise, the channel shall be declared inoperable.
Setpoints more conservative than the [LTSP or NTSP1 are acceptable provided that the as-found and as-implemented in the Surveillance procedures to confirm channel performance.
The [Limitingq Trip Setpoint or Nominal Trip Setpoint and thel methodoloaies used to determine the as-found and the as-left tolerances are specified in [insert the facility FSAR reference or the name of a under 10 CFR 50,59 ,u to +he Te-.hniR,.-n Reqiua irm ts A ..... n ,,an'document incorporated into the facility FSAR by referencel.
.[ Calibrate the trip unit.i SR 3.3.6.5.3---------------------
NOTES-------------------
[18] months 1. If the as-found channel setpoint is outside its predefined as-found tolerance, then the channel shall be evaluated to verify that it is functioninq as required before returningq the channel to service.2. The instrument channel setpoint shall be reset to a value that is within the as-left tolerance around the [Limiting Trip Setpoint (LTSP) or Nominal Trip SetDoint (NTSP)l at the completion of the surveillance; otherwise, the channel shall be declared inoperable.
Setpoints more conservative than the [LTSP or NTSP1 are~cc~nt~hI~
nrn~,ir1c~d that th0 ~i~-fni int'l ~nv'l ~nrrantnhho nmViripri th-qt the g-fn"nrj nnri -I BWR/6 STS 3.3.6.5-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Relief and LLS Instrumentation 3.3.6.5 left tolerances anolv to the actual setnoint implemented in the Surveillance procedures to confirm channel performance.
The [Limitina Trip Setpoint or Nominal Trip Setpoint and thel methodologies used to determine the as-found and the as-left tolerances are specified in [insert the facility FSAR reference or the name of a documtnt contronlod
'-ndor 10 CPR 50.59 '-uch ,no thA TA-hnin-l D ... ;ramnr -NA, , ,m'1 a ny document incorporated into the facility FSAR by referencel.
Perform CHANNEL CALIBRATION.
The Allowable Values shall be: a. Relief Function Low: Medium: High: b. LLS Function[1103 +/- 15 psig][1113 +/- 15 psig][1123 +/- 15 psig][1033 +/- 15 psig][926 +/- 15 psig][1073 +/- 15 psig][936 +/- 15 psig][1113 +/- 15 psig][946 +/- 15 psig]Low open: close: Medium open: close High open: close: SR 3.3.6.5.4 Perform LOGIC SYSTEM FUNCTIONAL TEST. [18] months BWR/6 STS 3.3.6.5-3 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1.1 B 3.3 INSTRUMENTATION B 3.3,1.1 Reactor Protection System (RPS) Instrumentation BASES BACKGROUND The RPS initiates a reactor scram when one or more monitored parameters exceed their specified limit, to preserve the integrity of the fuel cladding and the Reactor Coolant System (RCS), and minimize the energy that must be absorbed following a loss of coolant accident (LOCA). This can be accomplished either automatically or manually.The protection and monitoring functions of the RPS have been designed to ensure safe operation of the reactor. This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RPS, as well as LCOs on other reactor system parameters, and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to contain LSSS defined by the regulation as"...settings for automatic protective devices.. .so chosen that automatic protective action will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytic Limit is tho limit of the prcess -variable at Whi~h a safety Technical Specifications are required by 10 CFR 50.36 toW40-4.-R 50.36(c)U Ii)^A) re..uir, that include LSSS for variables that have significant safety functions.
LSSS are defined by the regulation as'Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a protective action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.
Any automatic protection action that occurs on reaching the ARa!AiGAnalytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protective eeVieeschannels must be chosen to be more conservative than the ARaIy4iGAnalytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur.--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint'
[LTSP1 is -generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting.'Nominal Trip Setpoint [NTSP1' is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin BWR/6 STS B 3.3.1.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1.1 has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
Licensees are to insert the name of the document(s) controlled under 10 CFR 50.59 that contain the methodology for calculating the as-left and as-found tolerances in Note b of Table 3.3.1.1-1, forthe phrase "[insert the name of a document controlled under 10 CFR 50.59 such as the Technical Requirements Manual or any document incorporated into the facility FSAR]" throughout these Bases.If the [LTSP1 is not included in Table 3.3.1.1-1, the plant-specific location for the [LTSP1 or NTSP must be cited in Note b of Table 3.3.1.1-1.
The brackets indicate plant-specific terms may apply, as reviewed and approved by the NRC. The a. f .nd ,, -oft tolera..o. .ill pl a #toh,,, The FLTSP1 specified in Table 3.3.1.1-1 is a predetermined setting for a preteetPve-deAprotection channel chosen to ensure automatic actuation prior to the process variable reaching the ARalytieAnalytical Limit and thus ensuring that the SL would not be exceeded.
As such, the t~ie-setpeiR
[LTSP1 accounts for uncertainties in setting the dev4eechannel (e.g., calibration), uncertainties in how the 4evieechannel might actually perform (e.g., repeatability), changes in the point of action of the dev4eechannel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the trip ,.tp"i"t plays an ro-l in ... ,-r/gLTSPl ensures that SLs are not exceeded.
As such, the tip setpeif'[LTSP1 meets the definition of an LSSS (Ref. 1-)-a&#xfd;i could be used to moo the req uirement that they be contained in the TochnRcal Specifications.).
BASES BACKGROUND (continued)
Technical Specifications contain values related to the OPERABILITY of equipment required for safe operation of the facility.
OPERABLE is defined in Technical Specifications as "...being capable of performing its safety function(s)." For automatic protective dovic-,,Relying solely on the rcquired safety function is to ensure that a SL is not exceededan therefore the LSSS as;F-; d-efined by 10 C-=R 50.36- is, the c.ame. a-;hA O"DERAII ITY limit for those deViGcs. However, use of the trip to define OPERABILITY in Technical Specifications-ald itS corresponding designation as the L=SSS reqluired by 10 CF=R 50.36 would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as found" value of a pFeteetPve BWR/6 STS B 3.3.1.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS instrumentation B 3.3.1.1 BASES BACKGROUND (continued)
Two scram pilot valves are located in the hydraulic control unit (HCU) for each control rod drive (CRD). Each scram pilot valve is solenoid operated, with the solenoids normally energized.
The scram pilot valves control the air supply to the scram inlet and outlet valves for the associated CRD. When either scram pilot valve solenoid is energized, air pressure holds the scram valves closed and, therefore, both scram pilot valve solenoids must be de-energized to cause a control rod to scram.The scram valves control the supply and discharge paths for the CRD water during a scram. One of the scram pilot valve solenoids for each CRD is controlled by trip system A, and the other solenoid is controlled by trip system B. Any trip of trip systemA in conjunction with any trip in trip system B results in de-energizing both solenoids, air bleeding off, scram valves opening, and control rod scram.The backup scram valves, which energize on a scram signal to depressurize the scram air header, are also controlled by the RPS.Additionally, the RPS System controls the SDV vent and drain valves such that when both trip systems trip, the SDV vent and drain valves close to isolate the SDV.APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY The actions of the RPS are assumed in the safety analyses of References_3, 4, and 5. The RPS initiates a reactor scram when monitored parameter values are exceededexceod the Allowable Valucs speGif led-by the sctpoint mcthodol.gy and listod in Table 3.3.1.1 ito preserve the integrity of the fuel cladding, the reactor coolant pressure boundary (RCPB), and the containment by minimizing the energy that must be absorbed following a LOCA.RPS instrumentation satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).
Functions not specifically credited in the accident analysis are retained for the overall redundancy and diversity of the RPS as required by the NRC approved licensing basis.Permissive and interlock setpoints allow the blocking of trips during plant startups, and restoration of trips when the Permissive conditions are not satisfied, but they are not explicitly modeled in the Safety Analyses.These permissives and interlocks ensure that the starting conditions are consistent with the safety analysis, before preventive or mitigating actions occur. Because these permissives or interlocks are only one of multiple conservative starting assumptions for the accident analysis, they are generally considered as nominal values without regard to measurement accuracy.BWR/6 STS B 3.3.1.1-6 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE REQUIREMENTS (continued)
-------------------
REVIEWERS NOTE Notes a and b are applied to the setpoint verification Surveillances for all RPS Instrumentation Functions in Table 3.3.1.1-1 unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or tG instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing proaram.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the requirements would apply.As noted at the beginning of the SRs, the SRs for each RPS inetrumontationinstrument Function are located in the SRs column of Table 3.3.1.1-1.
The Surveillances are modified by a Note to indicate that, when a channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed for up to 6 hours, provided the associated Function maintains trip capability.
Upon completion of the Surveillance, or expiration of the 6 hour allowance, the channel must be returned to OPERABLE status or the applicable Condition entered and Required Actions taken. This Note is based on the RPS reliability analysis (Ref. 10) assumption of the average time required to perform channel surveillance.
That analysis demonstrated that the 6 hour testing allowance does not significantly reduce the probability that the RPS will trip when necessary.
SR 3.3.1.1.1 BWR/6 STS B 3.3.1.1-26 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1.1 The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by reference]., ,,r. v,.n + .-.p g ,o .nf ,.1 ,, + ,,n no ,I m , Innnm~c k" n m" ..,., m 4,.~v ,h .of docu-mont controled u-nder 10 CFR 50.59 su-ch as tho Tochnicsa D ,l ft an, ,, nr gm, a lY ,, pmrM nm imnprmnr',+P
,,G nth f*-, i , SR 3.3.1.1.8 The calibration of trip units provides a check of the actual trip setpoints.
The channel must be declared inoperable if the trip setting is discovered to be less conservative than the Allowable Value specified in Table 3.3.1.1-1.
If the trip setting is discovered to be less conservative than accounted for in the appropriate setpoint methodology, but is oet beyeRconservative with respect to the Allowable Value, the channel performance is still within the requirements of the plant safety analysis.Under these conditions, the setpoint must be readjusted to beeequal e- e more cnseret'ie thapnthe [LTSP1 within the as-left tolerance as accounted for in the appropriate setpoint methodology.
The Frequency of 92 days for SR 3.3.1.1.8 is based on the reliability analysis of Reference 10.BWR/6 STS B 3.3.1.1-32 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.1.8 for the designated functions is modified by two Notes as identified in Table 3.3.1.1-1.
The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the rLTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that rLTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
GalGrit.R
: h. th aslft na, the as fnid Io + "lnRne b"e inNR" 4 the Ravme of a documenRt controlleQd wundoPr 10( CFIR 5-0-.59A 16uch astho Tochnia R-.-l,', s, fh n l o- r -,I , -r-r.I , ,-,IRn -,.-n ,.n I :n ' -+kn t he n I,  SR 3.3.1.1.9 and SR 3.3.1.1.11 A CHANNEL CALIBRATION is a complete check of the instrument loop and the sensor. This test verifies the channel responds to the measured parameter within the necessary range and accuracy.
CHANNEL CALIBRATION leaves the channel adjusted to the [LTSP] within the as-left tolerance to account for instrument drifts between successive calibrations consistent with the plant specific setpoint methodology.
Note 1 states that neutron detectors are excluded from CHANNEL CALIBRATION because they are passive devices, with minimal drift, and because of the difficulty of simulating a meaningful signal. Changes in neutron detector sensitivity are compensated for by performing the 7 day BWR/6 STS B 3.3.1.1-33 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1.1 calorimetric calibration (SR 3.3.1.1.2) and the 1000 MWD/T LPRM calibration against the TIPs (SR 3.3.1.1.6).
A second Note is provided that requires the APRM and IRM SRs to be performed within 12 hours of entering MODE 2 from MODE 1. Testing of the MODE 2 APRM and IRM Functions cannot be performed in MODE 1 without utilizing jumpers, lifted leads, or movable links. This Note allows entry into MODE 2 from MODE 1 if the associated Frequency is not met per SR 3.0.2. Twelve hours is based on operating experience and in consideration of providing a reasonable time in which to complete the SR.The Frequency of SR 3.3.1.1.9 is based upon the assumption of a 184 day calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.
The Frequency of SR 3.3.1.1.11 is based on the assumption of an 18 month calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.SRs 3.3.1.1.9 and 3.3.1.1.11 for the designated functions are modified by two Notes as identified in Table 3.3.1.1-1.
The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note reguires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the[LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
of a dcuc-nRt controlled under 10 CFR 50.59 cuch as the Technical D Reill iReR,,Go ~n, Mawa 9F aRo. ringumeint thegnfr o~ k faAul t, BWR/6 STS B 3.3.1.1-34 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RPS Instrumentation B 3.3.1.1 SR 3.3.1.1.12 The Average Power Range Monitor Flow Biased Simulated Thermal Power -High Function uses an electronic filter circuit to generate a signal proportional to the core THERMAL POWER from the APRM neutron flux signal. This filter circuit is representative of the fuel heat transfer dynamics that produce the relationship between the neutron flux and the core THERMAL POWER. The filter time constant must be verified to ensure that the channel is accurately reflecting the desired parameter.
The Frequency of 18 months is based on engineering judgment and reliability of the components.
SR 3.3.1.1.12 is modified by two Notes as identified in Table 3.3.1.1-1.
The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
Ther~ InGORGn +Net rno -re tnf,~n hn at [[TSP n +lrmrtohe
:Frnetedaue fhamam of a doc,-mont controlled under 10 CFR 50.59 'cuch A,; tho Tochpnica 0 Remdawnaemem trnn A- aR ny dG1nanm.an narapanit the f-RA-5+, BWR/6 STS B 3.3.1.1-35 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)SRM Instrumentation B 3.3.1.2 BASES SURVEILLANCE REQUIREMENTS (continued)
Frequency ensures that the channels are OPERABLE while core reactivity changes could be in progress.
This 7 day Frequency is reasonable, based on operating experience and on other Surveillances (such as a CHANNEL CHECK) that ensure proper functioning between CHANNEL FUNCTIONAL TESTS.SR 3.3.1.2.6 is required in MODE 2 with IRMs on Range 2 or below and in MODES 3 and 4. Since core reactivity changes do not normally take place, the Frequency has been extended from 7 days to 31 days. The 31 day Frequency is based on operating experience and on other Surveillances (such as (CHANNEL CHECK) that ensure proper functioning between CHANNEL FUNCTIONAL TESTS.Verification of the signal to noise ratio also ensures that the detectors are inserted to a normal operating level. In a fully withdrawn condition, the detectors are sufficiently removed from the fueled region of the core to essentially eliminate neutrons from reaching the detector.
Any count rate obtained while fully withdrawn is assumed to be "noise" only.The Note to the Surveillance allows the Surveillance to be delayed until entry into the specified condition of the Applicability.
The SR must be performed in MODE 2 within 12 hours of entering MODE 2 with IRMs on Range 2 or below. The allowance to enter the Applicability with the 31 day Frequency not met is reasonable, based on the limited time of 12 hours allowed after entering the Applicability and the inability to perform the Surveillance while at higher power levels. Although the Surveillance could be performed while on IRM Range 3, the plant would not be expected to maintain steady state operation at this power level. In this event, the 12 hour Frequency is reasonable, based on the SRMs being otherwise verified to be OPERABLE (i.e., satisfactorily performing the CHANNEL CHECK) and the time required to perform the Surveillances.
SR 3.3.1.2.7 Performance of a CHANNEL CALIBRATION verifies the performance of the SRM detectors and associated circuitry.
The Frequency considers the plant conditions required to perform the test, the ease of performing the test, and the likelihood of a change in the system or component status. The neutron detectors are excluded from the CHANNEL CALIBRATION because they cannot readily be adjusted.
The detectors are fission chambers that are designed to have a relatively constant sensitivity over the range, and with an accuracy specified for a fixed useful life.BWR/6 STS B 3.3.1.2-7 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)SRM Instrumentation B 3.3.1.2 BASES SURVEILLANCE REQUIREMENTS (continued)
Note 2 to the Surveillance allows the Surveillance to be delayed until entry into the specified condition of the Applicability.
The SR must be performed in MODE 2 within 12 hours of entering MODE 2 with IRMs on Range 2 or below. The allowance to enter the Applicability with the 18 month Frequency not met is reasonable, based on the limited time of 12 hours allowed after entering the Applicability and the inability to perform the Surveillance while at higher power levels. Although the Surveillance could be performed while on IRM Range 3, the plant would not be expected to maintain steady state operation at this power level. In this event, the 12 hour Frequency is reasonable, based on the SRMs being otherwise verified to be OPERABLE (i.e., satisfactorily performing the CHANNEL CHECK) and the time required to perform the Surveillances.
There is a plant specific program which verifies that the instrument channel functions as required by verifying the as-left and as-found setting are consistent with those established by the setpoint methodology.
REFERENCES None.BWR/6 STS B 3.3.1.2-8 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Control Rod Block Instrumentation B 3.3.2.1 B 3.3 INSTRUMENTATION B 3.3.2.1 Control Rod Block Instrumentation BASES BACKGROUND Control rods provide the primary means for control of reactivity changes.Control rod block instrumentation includes channel sensors, logic circuitry, switches, and relays that are designed to ensure that specified fuel design limits are not exceeded for postulated transients and accidents.
During high power operation, the rod withdrawal limiter (RWL)provides protection for control rod withdrawal error events. During low power operations, control rod blocks from the rod pattern controller (RPC)enforce specific control rod sequences designed to mitigate the consequences of the control rod drop accident (CRDA). During shutdown conditions, control rod blocks from the Reactor Mode Switch -Shutdown Position ensure that all control rods remain inserted to prevent inadvertent criticalities.
The protection and monitoring functions of the control rod block instrumentation have been designed to ensure safe operation of the reactor. This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RPS, as well as LCOs on other reactor system paramneters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 10-CPR 5.36(-)(1
)(ii)(A) r.quiroc that Tochnic--
Specifications include LSSSs for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a Safety Limit (SL) is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur.--------------------
REVIEWER'S NOTE -------------------The term "Limitinq Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting.BWR/6 STS B 3.3.2.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Control Rod Block Instrumentation B 3.3.2.1"Nominal Trip Setpoint [NTSP]" is the su-qgested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
Licensees are to insert the name of the document(s) controlled under 10 CFR 50.59 that contain the methodology for calculating the as-left and as-found tolerances in Note c of Table 3.3.2.1-1.
for the phrase "[insert the name of a document controlled under 10 CFR 50.59 such as the Technical Requirements Manual or any document incorporated into the facility FSAR1" throuahout these Bases.If the fLTSP1 is not included in SR 3.3.2.1.7.
the plant-specific location for the [LTSP1 or fNTSP1 must be cited in Note c of Table 3.3.2.1-1.
The brackets indicate plant-specific terms may apply, as reviewed and approved by the The a fou.nd and as lof
:il appl,, t Ghannnal pegqFnmn nre The [Limiting Trip Setpoint (LTSP)] specified in Table 3.3.2.1-1 is a predetermined setting for a protection channel chosen to ensure automatic actuation prior to the process variable reaching the Analytical Limit and thus ensuring that the SL would not be exceeded.
As such, the[LTSP1 accounts for uncertainties in setting the channel (e.g., calibration), uncertainties in how the channel might actually perform (e.g..repeatability), changes in the point of action of the channel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the [LTSP] ensures that SLs are not exceeded.
Therefore, the [LTSP1 meets the definition of an LSSS (Ref. 1).The Allowable Values specified in SR 3.3.2.1.7 serves as the LSSS such that a channel is OPERABLE if the trip setpoint is found not to exceed the Allowable Value. As such, the Allowable Value differs from the trip setpoint by an amount primarily equal to the expected instrument loop uncertainties, such as drift, during the surveillance interval.
In this manner, the actual setting of the device will still meet the LSSS definition and ensure that a SL is not exceeded at any given point of time as long as the device has not drifted beyond that expected during the surveillance interval.Technical Specifications contain values related to the OPERABILITY of equipment required for safe operation of the facility.
Operable is defined in Technical Specifications as "being capable of performing its safety function(s)." Relying solely on the [LTSP] to define OPERABILITY in Technical Specifications would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as found" value of a protection channel setting during a Surveillance.
This would result in BWR/6 STS B 3.3.2.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Control Rod Block Instrumentation B 3.3.2.1 BASES SURVEILLANCE
-----------------------
REVIEWER'S NOTE-------------------
REQUIREMENTS Certain Frequencies are based on approved topical reports. In order for a licensee to use these Frequencies, the licensee must justify the Frequencies as required by the staff SER for the topical report.--------------------
REVIEWER'S NOTE Notes b and c are applied to the setpoint verification Surveillances for the Rod Withdrawal Limiter functions in SR 3.3.2.1.7 unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or-te instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the requirements would apply.As noted at the beginning of the SR, the SRs for each Control Rod Block instrumentation Function are found in the SRs column of Table 3.3.2.1-1.
The Surveillances are also modified by a Note to indicate that when an RWL channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed for up to 6 hours, provided the associated Function maintains control rod block capability.
Upon completion of the Surveillance, or expiration of the 6 hour allowance, the channel must be returned to OPERABLE status or the applicable Condition entered and Required Actions taken. This Note is based on the reliability analysis (Ref. 89) assumption of the average time required to perform channel Surveillance.
That analysis demonstrated that the 6 hour testing allowance does not significantly reduce the probability that a control rod block will be initiated when necessary.
SR 3.3.2.1.1, SR 3.3.2.1.2, SR 3.3.2.1.3, and SR 3.3.2.1.4 BWR/6 STS B 3.3.2.1-10 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Control Rod Block Instrumentation B 3.3.2.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.2.1.5 The LPSP is the point at which the RPCS makes the transition between the function of the RPC and the RWL. This transition point is automatically varied as a function of power. This power level is inferred from the first stage turbine pressure (one channel to each trip system).These power setpoints must be verified periodically to be within the Allowable Values. If any LPSP is nonconservative, then the affected Functions are considered inoperable.
Since this channel has both upper and lower required limits, it is not allowed to be placed in a condition to enable either the RPC or RWL Function.
Because main turbine bypass steam flow can affect the LPSP nonconservatively for the RWL, the RWL is considered inoperable with any main turbine bypass valves open. The Frequency of 92 days is based on the setpoint methodology utilized for these channels.SR 3.3.2.1.5 for the Rod withdrawal limiter functions is modified by two Notes as identified in Table 3.3.2.1-1.
The first Note requires evaluation of channel performance for the condition where the as-found settinq for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
BWR/6 STS B 3.3.2.1-12 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Control Rod Block Instrumentation B 3.3.2.1 BASES SURVEILLANCE REQUIREMENTS (continued)
The Frequency is based upon the assumption of the magnitude of equipment drift inthe 6etpoint analysis&#xfd;.
The Frequency is based upon the assumption of the magnitude of equipment drift in the setpoint analysis.
SR 3.3.2.1.7 for the Rod withdrawal limiter functions is modified by two Notes as identified in Table 3.3.2.1-1.
The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found-tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
hIG6 ....n the ,as Ie# ,,nRd thn -e s-f'r g n h kl grr TsD h, flnst rt +hr. n"r-p of a docuament controlled u-nder 10 FR 50.59 such as the TeGhn-.a4l R ..an .r.e fA..... -,I "r anRy Ar,6.. .. e ,nrporGr ated the fn,.ia ,, SR 3.3.2.1.8 The CHANNEL FUNCTIONAL TEST for the Reactor Mode Switch -Shutdown Position Function is performed by attempting to withdraw any control rod with the reactor mode switch in the shutdown position and verifying a control rod block occurs. A successful test of the required contact(s) of a channel relay may be performed by the verification of the BWR/6 STS B 3.3.2.1-14 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)EOC-RPT Instrumentation B 3.3.4.1 B 3.3 INSTRUMENTATION B 3.3.4.1 End of Cycle Recirculation Pump Trip (EOC-RPT)
Instrumentation BASES BACKGROUND The EOC-RPT instrumentation initiates a recirculation pump trip (RPT) to reduce the peak reactor pressure and power resulting from turbine trip or generator load rejection transients to provide additional margin to core thermal MCPR Safety Limits (SLs).The need for the additional negative reactivity in excess of that normally inserted on a scram reflects end of cycle reactivity considerations.
Flux shapes at the end of cycle are such that the control rods may not be able to ensure that thermal limits are maintained by inserting sufficient negative reactivity during the first few feet of rod travel upon a scram caused by Turbine Control Valve (TCV) Fast Closure, Trip Oil Pressure -Low, or Turbine Stop Valve Closure, Trip Oil Pressure -Low (TSV). The physical phenomenon involved is that the void reactivity feedback due to a pressurization transient can add positive reactivity at a faster rate than the control rods can add negative reactivity.
The protection functions of the EOC-RPT have been designed to ensure safe operation of the reactor during load reiection transients.
This is achieved by specifying limiting safety system settings (LSSS) in terms of Parameters directly monitored by the EOC-RPT, as well as LCOs on other system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 1-0-CF-R 50.36(c.)(1
)(iiA) roguFier, that T".hn*,ial SpccificatiOns include LSSSs for variables that have siqnificant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a Safety Limit (SL) is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur.--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP] is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP] indicates that no additional margin BWR/6 STS B 3.3.4.1-1 Rev. 3.0, 03/31/04.(Includes Errata)
TSTF-493, Rev. 4 (Option A)EOC-RPT Instrumentation B 3.3.4.1 has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP]" is the sugqqested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP]. The as-found and as-left tolerances will apply to the [NTSP] implemented in the Surveillance procedures to confirm channel performance.
Licensees are to insert the name of the document(s) controlled under 10 CFR 50.59 that contain the methodology for calculating the as-left and as-found tolerances in Note 2 of the SRs, for the phrase "[insert the name of a document controlled under 10 CFR 50.59 such as the Technical Requirements Manual or any document incorporated into the facility FSAR]" throughout these Bases.If the [LTSP1 is not included in SR 3.3.4.1.2 or SR 3.3.4.1.3 for the purpose of compliance with 10 CFR 50.36, the plant-specific location for the [LTSP1 or NTSP must be cited in Note 2 of the SRs in the SR table.The brackets indicate plant-specific terms may apply, as reviewed and approved by the NRC. The an found ,;nd -, lo-.ft r l al, to channne i3 1'f ... ..BASES BACKGROUND (continued)
The [Limiting Trip Setpoint (LTSP)] specified in SR 3.3.4.1.3 is a predetermined setting for a protection channel chosen to ensure automatic actuation prior to the process variable reaching the Analytical Limit and thus ensuring that the SL would not be exceeded.
As such, the[LTSP] accounts for uncertainties in setting the channel (e.g., calibration), uncertainties in how the channel might actually perform (e.g., repeatability), changes in the point of action of the channel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
Therefore, the [LTSP1 ensures that SLs are not exceeded.
As such, the[LTSP] meets the definition of an LSSS (Ref. 1).The Allowable Value specified in SR 3.3.4.1.3 serves as the LSSS such that a channel is OPERABLE if the trip setpoint is found not to exceed the Allowable Value. As such, the Allowable Value differs from the trip setpoint by an amount primarily equal to the expected instrument loop uncertainties, such as drift, during the surveillance interval.
In this manner, the actual setting of the device will still meet the LSSS definition and ensure that a SL is not exceeded at any given point of time as long BWR/6 STS B 3.3.4.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)EOC-RPT Instrumentation B 3.3.4.1 BASES ACTIONS (continued)
C.1 and C.2 With any Required Action and associated Completion Time not met, THERMAL POWER must be reduced to < 40% RTP within 4 hours.Alternately, the associated recirculation pump may be removed from service since this performs the intended function of the instrumentation.
The allowed Completion Time of 4 hours is reasonable, based on operating experience, to reduce THERMAL POWER to < 40% RTP from full power conditions in an orderly manner and without challenging plant systems.SURVEILLANCE
---------------------
REVIEWER'S NOTE -----------------------------------
REQUIREMENTS Certain Frequencies are based on approved topical reports. In order for a licensee to use these Frequencies, the licensee must justify the Frequencies as required by the staff SER for the topical report.-------------------
REVIEWER'S NOTE Notes 1 and 2 are applied to the setpoint verification Surveillances for all EOC-RPT Instrumentation Functions unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or-te instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the requirements would apply.The Surveillances are modified by a Note to indicate that when a channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed for up to 6 hours, provided the associated Function maintains BWR/6 STS B 3.3.4.1-11 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)EOC-RPT Instrumentation B 3.3.4.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.4.1.2 The calibration of trip units provides a check of the actual trip setpoints.
The channel must be declared inoperable if the setting is discovered to be less conservative than the Allowable Value specified in SR 3.3.4.1.3.
If the trip setting is discovered to be less conservative than accounted for in the appropriate setpoint methodology, but is Ret-beyGndconservative with respect to the Allowable Value, the channel performance is still within the requirements of the plant safety analysis.
Under these conditions, the setpoint must be readjusted to be equal to or more conservative than accounted for in the appropriate setpoint methodology.
The Frequency of 92 days is based on assumptions of the reliability analysis (Ref. 56) and on the methodology included in the determination of the trip setpoint.SR 3.3.4.1.2 is modified by two Notes in the SR table. The first Note requires evaluation of channel performance for the condition where the as-found settinq for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the[LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the rLTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
II"I R "nPd NW ' ;;aff ., ires tha 'I,',"p In. hI9 *n8lnrn nnoh , f A of a documonRt controlled-undo~r 10- CF=R 50.59 R'uch as the Technical nfl I *Feama ntt I.41 ;-a l Aip I r nn., G 61Rjn RtmI pn nr~mann the far''t.BWR/6 STS B 3.3.4.1-13 Rev. 3.0. 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)EOC-RPT Instrumentation B 3.3.4.1 SR 3.3.4.1.3 CHANNEL CALIBRATION is a complete check of the instrument loop and the sensor. This test verifies the channel responds to the measured parameter within the necessary range and accuracy.
CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drifts between successive calibrations consistent with the plant specific setpoint methodology.
The Frequency is based upon the assumption of an 18 month calibration interval, in the determination of the magnitude of equipment drift in the setpoint analysis.SR 3.3.4.1.3 is modified by two Notes in the SR table. The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the[LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safet Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
Thp senodN Nte alcs req'nJros that [IJTSP1 and the m+thedetaIwes fQ.r of adocuont ontolled under 10 CFR 50.59 Such" A6 the Technical oReQ.,.. meRnn tc.f n.m, rt,. ia. inn rnnms tm the flarsinl*SR 3.3.4.1.4 The LOGIC SYSTEM FUNCTIONAL TEST demonstrates the OPERABILITY of the required trip logic for a specific channel. The system functional test of the pump breakers is included as a part of this test, overlapping the LOGIC SYSTEM FUNCTIONAL TEST, to provide BWR/6 STS B 3.3.4.1-14 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ECCS Instrumentation B 3.3.5.1 B 3.3 INSTRUMENTATION B 3.3.5.1 Emergency Core Cooling System (ECCS) Instrumentation BASES BACKGROUND The purpose of the ECCS instrumentation is to initiate appropriate responses from the systems to ensure that fuel is adequately cooled in the event of a design basis accident or transient.
This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the ECCS, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 40-GF-R 50.36(-)(1
)(i)(A) roguir.. that T-c.hn.cal Specifications include LSSSs for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a Safety Limit (SL) is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur.--------------------
REVIEWER'S NOTE ------------------------------------
The term "Limitind Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP]" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
Licensees are to insert the name of the document(s) controlled under 10 CFR 50.59 that contain the methodology for calculating the as-left and as-found tolerances in Note f of Table 3.3.5.1-1.
for the phrase "[insert the name of a document controlled under 10 CFR 50.59 such as the Technical Requirements Manual or any document incorporated into the facility FSAR]" throughout these Bases.BWR/6 STS B 3.3.5.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ECCS Instrumentation B 3.3.5.1 If the [LTSP1 is not included in Table 3.3.5.1-1 for the purpose of compliance with 10 CFR 50.36, the plant-specific location for the [LTSP1 or NTSP must be cited in Note f of Table 3.3.5.1-1.
The brackets indicate plant-specific terms may apply, as reviewed and approved by the NRC-.Vh no nu int l u 4 O n th e S-; lnrnnriI~
a c. P FG~ ed w e Wui k +n + OH 4 n gt, m l w~ re i BASES BACKGROUND (continued)
The [Limiting Trip Setpoint (LTSP)] specified in Table 3.3.5.1-1 is a predetermined setting for a protection channel chosen to ensure automatic actuation prior to the process variable reaching the Analytical Limit and thus ensuring that the SL would not be exceeded.
As such, the[LTSP1 accounts for uncertainties in setting the channel (e.g., calibration), uncertainties in how the channel might actually perform (e.g., repeatability), changes in the point of action of the channel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the [LTSP1 ensures that SLs are not exceeded.
Therefore the [LTSP1 meets the definition of an LSSS (Ref. 1).The Allowable Value specified in Table 3.3.5.1-1 serves as the LSSS such that a channel is OPERABLE if the trip setpoint is found not to exceed the Allowable Value. As such, the Allowable Value differs from the trip setpoint by an amount primarily equal to the expected instrument loop uncertainties, such as drift, during the surveillance interval.
In this manner, the actual setting of the device will still meet the LSSS definition and ensure that a SL is not exceeded at any given point of time as long as the device has not drifted beyond that expected during the surveillance interval.Technical Specifications contain values related to the OPERABILITY of equipment required for safe operation of the facility.
Operable is defined in Technical Specifications as "...being capable of performing its safety function(s)." Relying solely on the [LTSP1 to define OPERABILITY in Technical Specifications would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as found" value of a protection channel setting during a Surveillance.
This would result in Technical Specification compliance problems, as well as reports and corrective actions required by the rule which are not necessary to ensure safety. For example, an automatic protection channel with a setting that has been found to be different from the [LTSP] due to some drift of the setting may still be OPERABLE because drift is to be expected.
This expected drift would have been specifically accounted for in the setpoint methodology for calculating the [LTSP1 and thus the automatic protective action would still have ensured that the SL would not be exceeded with BWR/6 STS B 3.3.5.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ECCS Instrumentation B 3.3.5.1 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued) measured output value of the process parameter exceeds the setpoint, the associated deviceehaRel (e.g., trip unit) changes state. The arahnianalytical limits are derived from the limiting values of the process parameters obtained from the safety analysis.
The Allowable Values are derived from the aalytieanalvtical limits, corrected for calibration, process, and some of the instrument errors. The t"4p.setp9'is[rLTSPs.
are then determined, accounting for the remaining instrument errors (e.g., drift). The trip setpoints derived in this manner provide adequate protection because instrumentation uncertainties, process effects, calibration tolerances, instrument drift, and severe environment errors (for channels that must function in harsh environments as defined by 10 CFR 50.49) are accounted for.In general, the individual Functions are required to be OPERABLE in the MODES or other specified conditions that may require ECCS (or DG)initiation to mitigate the consequences of a design basis accident or transient.
To ensure reliable ECCS and DG function, a combination of Functions is required to provide primary and secondary initiation signals.The specific Applicable Safety Analyses, LCO, and Applicability discussions are listed below on a Function by Function basis.Low Pressure Core Spray and Low Pressure Coolant Injection Systems 1.a, 2.a. Reactor Vessel Water Level -Low Low Low, Level 1 Low reactor pressure vessel (RPV) water level indicates that the capability to cool the fuel may be threatened.
Should RPV water level decrease too far, fuel damage could result. The low pressure ECCS and associated DGs are initiated at Level 1 to ensure that core spray and flooding functions are available to prevent or minimize fuel damage. The Reactor Vessel Water Level -Low Low Low, Level 1 is one of the Functions assumed to be OPERABLE and capable of initiating the ECCS during the transients analyzed in References 4-2 and 34. In addition, the Reactor Vessel Water Level -Low Low Low, Level 1 Function is directly assumed in the analysis of the recirculation line break (Ref. 2_3). The core cooling function of the ECCS, along with the scram action of the Reactor Protection System (RPS), ensures that the fuel peak cladding temperature remains below the limits of 10 CFR 50.46.Reactor Vessel Water Level -Low Low Low, Level 1 signals are initiated from four level transmitters that sense the difference between the pressure due to a constant column of water (reference leg) and the pressure due to the actual water level (variable leg) in the vessel. The Reactor Vessel Water Level -Low Low Low, Level 1 Allowable Value is BWR/6 STS B 3.3.5.1-12 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ECCS Instrumentation B 3.3.5.1 BASES ACTIONS (continued)
H.1 With any Required Action and associated Completion Time not met, the associated feature(s) may be incapable of performing the intended function and the supported feature(s) associated with the inoperable untripped channels must be declared inoperable immediately.
SURVEILLANCE
---------------------
REVIEWER'S NOTE ------------------
REQUIREMENTS Certain Frequencies are based on approved topical reports. In order for a licensee to use these Frequencies, the licensee must justify the Frequencies as required by the staff SER for the topical report.--------------------
REVIEWER'S NOTE Notes c and d are applied to the setpoint verification Surveillances for each ECCS Instrumentation Functions in Table 3.3.5.1-1 unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or te instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the requirements would apply.A generic evaluation of ECCS Instrumentation Functions resulted in Notes e and f being applied to the Functions shown in TS 3.3.5.1. Each licensee adopting this change must review the list of potential Functions to identify whether any of the identified functions meet any of the exclusion criteria based on the plant-specific design and safety analysis (AOOs). The footnotes applied to Function 3.3.5.1-1.[3.cl, Reactor Vessel Water Level -High, Level 8 are optional.
Functions 3.3.5.1-1.[3.fl, High Pressure Coolant System Pump Discharge Pressure -High (Bypass) and 3.3.5.1-1
[3.,q High Pressure Coolant System Flow Rate -BWR/6 STS B 3.3.5.1-36 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ECCS Instrumentation B 3.3.5.1 SR 3.3.5.1.3 for designated functions is modified by two Notes as identified in Table 3.3.5.1-1.
The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1.Where a setpoint more conservative than the [LTSP] is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safely Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in finsert the facility FSAR reference or the name of a document controlled u-nder 10 CFR 50.59 Sc.h a S tho Tec-hncal Requiremnts Manual. o any document incorporated into the facility FSAR by referencel.
BWR/6 STS B 3.3.5.1-39 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ECCS Instrumentation B 3.3.5.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.5.1.4 and SR 3.3.5.1.5 A CHANNEL CALIBRATION is a complete check of the instrument loop and the sensor. This test verifies the channel responds to the measured parameter within the necessary range and accuracy.
CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drifts between successive calibrations consistent with the plant specific setpoint methodology.
The Frequency of SR 3.3.5.1.4 is based upon the assumption of a 92 day calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.
For SR 3.3.5.1.4 there is a plant specific program which verifies that the instrument channel functions as required by verifying the as-left and as-found setting are consistent with those established by the setpoint methodology.
The Frequency of SR 3.3.5.1.5 is based upon the assumption of an[18] month calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.SR 3.3.5.1.5 for designated functions is modified by two Notes as identified in Table 3.3.5.1-1.
The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left settinq for the channel be within the as-left tolerance of the [LTSP1.Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculatinq the as-left and the as-found tolerances be in [insert the facility BWR/6 STS B 3.3.5.1-40 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)ECCS Instrumentation B 3.3.5.1 FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
The Note,-,m~
l l,-ef FequIme t~ ~r* hatJ rL"T-S 1 ,-I a &#xf7; f.Q-,-GaIU .th, thea n e# aR f, , , tAlar";mr h, ,, PR,, , theR na, of a documonA.t conetropllod udr10 CFIR 550.559- cuc--h ars the Tochnical Requfi meRamto ftanmi l 9F n, ,.Irany EGFet naranal, the ao *niI SR 3.3.5.1.6 The LOGIC SYSTEM FUNCTIONAL TEST demonstrates the OPERABILITY of the required initiation logic for a specific channel. The system functional testing performed in LCO 3.5.1, LCO 3.5.2, LCO 3.8.1, and LCO 3.8.2 overlaps this Surveillance to provide complete testing of the assumed safety function.The [18] month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for unplanned transients if the Surveillance were performed with the reactor at power. Operating experience has shown these components usually pass the Surveillance when performed at the [18] month Frequency.
SR 3.3.5.1.7 This SR ensures that the individual channel response times are less than or equal to the maximum values assumed in the accident analysis.Response time testing acceptance criteria are included in Reference 56.ECCS RESPONSE TIME may be verified by actual response time measurements in any series of sequential, overlapping, or total channel measurements.
BWR/6 STS B 3.3.5.1-41 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RCIC System Instrumentation B 3.3.5.2 B 3.3 INSTRUMENTATION B 3.3.5.2 Reactor Core Isolation Cooling (RCIC) System Instrumentation BASES BACKGROUND The purpose of the RCIC System instrumentation is to initiate actions to ensure adequate core cooling when the reactor vessel is isolated from its primary heat sink (the main condenser) and normal coolant makeup flow from the Reactor Feedwater System is unavailable, such that initiation of the low pressure Emergency Core Cooling Systems (ECCS) pumps does not occur. A more complete discussion of RCIC System operation is provided in the Bases of LCO 3.5.3, "RCIC System." This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RCIC instrumentation, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 40-GF-R 50.36(n)(1
)(^)(A) requi*ies that Tecrhnical Specifications include LSSSs for variables that have si-gnificant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the settinq must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safely analysis, to ensure that a SL is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur.-REV IEW ER'S NO TE ----------------------............
The term "Limitinq Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP]" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
Licensees are to insert the name of the document(s) controlled under 10 CFR 50.59 that contain the methodology for calculating the as-left and as-found tolerances in Note b of Table 3.3.5.2-1, for the phrase "[insert the BWR/6 STS B 3.3.5.2-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RCIC System Instrumentation B 3.3.5.2 name of a document controlled under 10 CFR 50.59 such as the Technical Requirements Manual or any document incorporated into the facility FSAR]" throughout these Bases.If the [LTSP1 is not included in Table 3.3.5.2-1, the plant-specific location for the [LTSP1 or NTSP must be cited in Note b of Table 3.3.5.2-1.
The brackets indicate plant-specific terms may apply, as reviewed and approved by the NRC. Tho ac foundn-Ad
,;,loft tooranco ";ill appyPtot" the actual s"tn"ont tm, ..&#xf7;,, , h, -ppf11jr .....ti n, ... prc d res .. .Gha. ~l n Ph ar- .rrnc. A P..BASES BACKGROUND (continued)
The [Limiting Trip Setpoint (LTSP)] specified in Table 3.3.5.2-1 is a predetermined setting for a protection channel chosen to ensure automatic actuation prior to the process variable reaching the Analytical Limit and thus ensuring that the SL would not be exceeded.
As such, the[LTSP1 accounts for uncertainties in setting the channel (e.g., calibration), uncertainties in how the channel might actually perform (e.g., repeatability), changes in the point of action of the channel over time (e.g., drift durinq surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the [LTSP1 ensures that SLs are not exceeded.
Therefore the [LTSP1 meets the definition of an LSSS (Ref. 1).The Allowable Value specified in Table 3.3.5.2-1 serves as the LSSS such that a channel is OPERABLE if the trip setpoint is found not to exceed the Allowable Value. As such, the Allowable Value differs from the trip setpoint by an amount primarily equal to the expected instrument loop uncertainties, such as drift, during the surveillance interval.
In this manner, the actual setting of the device will still meet the LSSS definition and ensure that a SL is not exceeded at any given point of time as long as the device has not drifted beyond that expected during the surveillance interval.Technical Specifications contain values related to the OPERABILITY of equipment required for safe operation of the facility.
Operable is defined in Technical Specifications as "...beinq capable of performing its safety function(s)." Relying solely on the [LTSP1 to define OPERABILITY in Technical Specifications would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as found" value of a protection channel settinq during a Surveillance.
This would result in Technical Specification compliance problems, as well as reports and corrective actions required by the rule which are not necessary to ensure safety. For example, an automatic protection channel with a setting that has been found to be different from the [LTSP1 due to some drift of the setting may still be OPERABLE because drift is to be expected.
This expected drift would have been specifically accounted for in the setpoint BWR/6 STS B 3.3.5.2-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RCIC System Instrumentation B 3.3.5.2[LTSPs] are those predetermined values of output at which an action should take place. The setpoints are compared to the actual process parameter (e.g., reactor vessel water level), and when the measured output value of the process parameter exceeds the setpoint4ess consrveativo than; the nomin!al trip setpeint, buit Within itsAlW~ablo Value,:s acceptable.
E-ac..,rh Value .pe.ifi. d acGcount" for.the associated deviceGhafwie (e.q., trip unit) changes state; The analytical limits are derived from the limiting values of the process parameters obtained from the safety analysis.
The Allowable Values are derived from the analytical limits, corrected for calibration, process, and some of the instrument errors. The [LTSPs] are then determined, accounting for the remaining instrument errors (e.g., drift). The trip setpoints derived in this manner provide adequate protection because instrumentation uncertainties appropriate to the Furnto. Theso unceFtaintfies ar describedintho, process effects, calibration tolerances, instrument drift, and severe environment errors (for channels that must function in harsh environments as defined by 10 CFR 50.49) are accounted for.Note that, although the channel is OPERABLE under these circumstances, the trip setpoint must be left adjusted to a value within the as-left tolerance, in accordance with uncertainty assumptions stated in the referenced setpoint methodology (as-left criteria), and confirmed to be operating within the statistical allowances of the uncertainty terms assigned (as-found criteria).
The individual Functions are required to be OPERABLE in MODE 1, and in MODES 2 and 3 with reactor steam dome pressure > 150 psig, since this is when RCIC is required to be OPERABLE. (Refer to LCO 3.5.3 for Applicability Bases for the RCIC System.)The specific Applicable Safety Analyses, LCO, and Applicability discussions are listed below on a Function by Function basis.BWR/6 STS B 3.3.5.2-6 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RCIC System Instrumentation B 3.3.5.2 BASES SURVEILLANCE
---------------------
REVIEWER'S NOTE ------------------
REQUIREMENTS Certain Frequencies are based on approved topical reports. In order for a licensee to use these Frequencies, the licensee must justify the Frequencies as required by the staff SER for the topical report.-----------
-------- REVIEW ER'S NOTE ----------------------..............
Notes a and b are applied to the setpoint verification Surveillances for all RCIC System Instrumentation Functions in Table 3.3.5.2-1 unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation lo-gic circuits or-te instrument functions that derive input from contacts which have no associated sensor or adiustable device, e..., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the requirements would apply.A generic evaluation of RCIC System Instrumentation Functions resulted in Notes a and b being applied to the Functions shown in TS 3.3.5.2.Each licensee adopting this change must review the list of potential Functions to identify whether any of the identified functions meet any of the exclusion criteria based on the plant-specific design and safety analysis (AOOs). The footnotes applied to Function 3.3.5.2-1.[21, Reactor Vessel Water Level -High, Level 8 are optional.As noted in the beginning of the SRs, the SRs for each RCIC System ,tR#umenta tininstrument Function are found in the SRs column of Table 3.3.5.2-1.
The Surveillances are modified by a Note to indicate that when a channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed as follows: (a) for up to 6 hours for Functions 2 and 5; and BWR/6 STS B 3.3.5.2-13 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RCIC System Instrumentation B 3.3.5.2 within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
GalculatRnaq the a ,s. lef ann the ...+as f d t .l ..a. ...s be tkh .a..o-f -A documonRt conroGlled under 10 CER 50.59 SUch asF- tho- Tecrhnical Re aw,-- he ;m Rtg; ig ..an. , ry ,.. +A;;R- -n'grr.grg
,4nl aa 1.t faR. i+,, SR 3.3.5.2.4 CHANNEL CALIBRATION is a complete check of the instrument loop and the sensor. This test verifies the channel responds to the measured parameter with the necessary range and accuracy.
CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drifts between successive calibrations consistent with the plant specific setpoint methodology.
The Frequency is based on the assumption of an 18 month calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.SR 3.3.5.2.4 is modified by two Notes as identified in Table 3.3.5.2-1.
The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
BWR/6 STS B 3.3.5.2-16 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)RCIC System Instrumentation B'3.3.5.2 If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
T-rh8--Gn
...... , -; r-,A&#xf7;-.. reawm... th.at r,-92 "rc~o he. m thedele~erss f."-F GaIG61Iat*RQ the asn 19# lafnR thA '0n r telenRG86nc 198 *R FORpnrt thes Rami of a docugment controlled uJndor 10 CFR 50.59 s'uch as the  Re uiem ns o ... I anne iAn nIi .. .. n .,4 1.......a rn :n ........ r'5fr .'.+,. +his fnr,.lal,, B 3.3.5.2-17 Rev. 3.0, 03/31/04 BWR/6 STS B 3.3.5.2-17 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Primary Containment Isolation Instrumentation B 3.3.6.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.6.1.2 A CHANNEL FUNCTIONAL TEST is performed on each required channel to ensure that the entire channel will perform the intended function.
A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable CHANNEL FUNCTIONAL TEST of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
Any setpoint adjustment shall be consistent with the assumptions of the current plant specific setpoint methodology.
The Frequency is based on reliability analysis described in References 5 and 6.SR 3.3.6.1.3 The calibration of trip units consists of a test to provide a check of the actual trip setpoints.
The channel must be declared inoperable if the trip setting is discovered to be less conservative than the Allowable Value specified in Table 3.3.6.1-1.
There is a plant specific program which verifies that the instrument channel functions as required by verifying the as-left and as-found setting are consistent with those established by the setpoint methodology.
If the trip setting is discovered to be less conservative than accounted for in the appropriate setpoint methodology, but is not beyond the Allowable Value, the channel performance is still within the requirements of the plant safety analysis.
Under these conditions, the setpoint must be readjusted to be equal to or more conservative than accounted for in the appropriate setpoint methodology.
The Frequency of 92 days is based on the reliability analysis of References 5 and 6.SR 3.3.6.1.4 and SR 3.3.6.1.5 CHANNEL CALIBRATION is a complete check of the instrumentloop and the sensor. This test verifies the channel responds to the measured parameter within the necessary range and accuracy.
There is a plant specific program which verifies that the instrument channel functions as required by verifying the as-left and as-found settingq are consistent with those established by the setpoint methodology.
CHANNEL BWR/6 STS B 3.3.6.1-30 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Relief and LLS Instrumentation B 3.3.6.5 B 3.3 INSTRUMENTATION B 3.3.6.5 Relief and Low-Low Set (LLS) Instrumentation BASES BACKGROUND The safety/relief valves (S/RVs) prevent overpressurization of the nuclear steam system. Instrumentation is provided to support two modes of S/RV operation
-the relief function (all valves) and the LLS function (selected valves). Refer to LCO 3.4.4, "Safety/Relief Valves (S/RVs)," and LCO 3.6.1.6, "Low-Low Set (LLS) Safety/Relief Valves (S/RVs)," for Applicability Bases for additional information of these modes of S/RV operation.
This is achieved by specifying limiting safety system settings (LSSS) in terms of Parameters directly monitored by the Safety/Relief valve instrumentation, as well as LCOs on other reactor system parameters, and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 4-0-GF-R)(ii^(A) r..uiros that Specifications include LSSS for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that an SL is'not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur.--- REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP]" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP]. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
Licensees are to insert the name of the document(s) controlled under 10 CFR 50.59 that contain the methodology for calculating the as-left and as-found tolerances in Note 2 of SR 3.3.6.5.2 and SR 3.3.6.5.3, for the BWRP6 STS B 3.3.6.5-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Relief and LLS Instrumentation B 3.3.6.5 phrase '[insert the name of a document controlled under 10 CFR 50.59 such as the Technical Requirements Manual or any document incorporated into the facility FSAR]' throughout these Bases.Where the [LTSP1 is not documented in SR 3.3.6.5.2 and 3.3.6.5.3.
the plant-specific location for the [LTSP1 or NTSP must be cited in Note 2 of SR 3.3.6.5.2 and 3.3.6.5.3.
The brackets indicate plant-specific terms may apply, as reviewed and approved by the NRC. Tho ac fo-.ud and -Ifl +- .... ... I,;,, w l .l f ,, ,l, thel -t,,, , e t BASES BACKGROUND (continued) implemented in the Surveillance procedures to confirm channel performance.
The [Limiting Trip Setpoint (LTSP)] specified in SR 3.3.6.5.2 and SR 3.3.6.5.3 is a predetermined settinq for a protection channel chosen to ensure automatic actuation prior to the process variable reachingq the Analytical Limit and thus ensuring that the SL would not be exceeded.
As such, the fLTSP] accounts for uncertainties in settinq the channel (e..g., calibration), uncertainties in how the channel might actually perform (e.gq., repeatability), chanoes in the point of action of the channel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the t[LTSP1 ensures that SLs are not exceeded.
Therefore the [LTSP1 meets the definition of an LSSS (Ref. 1).The Allowable Value specified in SR 3.3.6.5.2 and 3.3.6.5.3 serves as the LSSS such that a channel is OPERABLE if the trip setpoint is found not to exceed the Allowable Value. As such, the Allowable Value differs from the trip setpoint by an amount primarily equal to the expected instrument loop uncertainties, such as drift, during the surveillance interval.
In this manner, the actual setting of the device will still meet the LSSS definition and ensure that a SL is not exceeded at any given point of time as long as the device has not drifted beyond that expected during the surveillance interval.Technical Specifications contain values related to the OPERABILITY of equipment required for safe operation of the facility.
OPERABLE is defined in Technical Specifications as "...being capable of performing its safety function(s)." Relying solely on the [LTSP1 to define OPERABILITY in Technical Specifications would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as found" value of a protection channel setting during a Surveillance.
This would result in Technical Specification compliance problems, as well as reports and corrective actions required by the rule which are not necessary to ensure BWR/6 STS B 3.3.6.5-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Relief and LLS Instrumentation B 3.3.6.5 1. Manual actuation circuits, automatic actuation logic circuits or te instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, Proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the requirements would apply.The Surveillances are modified by a Note to indicate that when a channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed for up to 6 hours, provided the associated Function maintains relief or LLS initiation capability, as applicable.
Upon completion of the BWR/6 STS B 3.3.6.5-9 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option A)Relief and LLS Instrumentation B 3.3.6.5 safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a settingq within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
TIe ....I.. Note Fe..... th" an 4. .. I=-" andnrpnrato the Inehon +h 0 , fnt Of a dIocum~ent conRtrolled un~der 10 CFR 50.59 5Uch aq thc Tecghnica a.IR ,...,r~r+c.
n A.- Mana i -rnl , 9F .~.u aR GIO UF~ nn n,.s.rrnnd n,. fq,.I+BWR/6 STS B 3.3.6.5-11 Rev. 3.0, 03/31/04 (includes Errata)
TSTF-493, Rev. 4 (Option A)Relief and LLS Instrumentation B 3.3.6.5 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.6.5.3 A CHANNEL CALIBRATION is a complete check of the instrument loop and the sensor. This test verifies the channel responds to the measured parameter within the necessary range and accuracy.
CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drifts between successive calibrations consistent with the plant specific setpoint methodology.
The Frequency is based upon the assumption of an 18 month calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.SR 3.3.6.5.3 is modified by two Notes. The first Note requires evaluation of channel performance for the condition where the as-found settinq for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the rLTSP1. Where a setpoint more conservative than the rLTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculatina the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
GaIGp I mlra , fn -th lsWfl a,,Rd lht- n-' n f d- tlA-.
RAro.cr, 198 +h ,-t,-,.o-f aR docu-Wmont controlled under 10 CFIR 50.59i-A isuch ars tho- TocGhnical aReEK0FeR8RrtaG MRwann 9Ft aRY Et~ InE.. rnent naraanithe tham '~.I~BWR/6 STS B 3.3.6.5-12 Rev. 3.0, 03/31/04 (Includes Errata)
Attachment B TSTF-493, Revision 4, "Clarify Application of Setpoint Methodology for LSSS Functions" Revised Option B Pages TSTF-493, Rev. 4 (Option B)Programs and Manuals 5.5 5.5 Programs and Manuals 5.5.17 Battery Monitoring and Maintenance Program This Program provides for battery restoration and maintenance, based on [the recommendations of IEEE Standard 450-1995, "IEEE Recommended Practice for Maintenance, Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications," or of the battery manufacturer]
including the following:
: a. Actions to restore battery cells with float voltage < [2.13] V, and b. Actions to equalize and test battery cells that had been discovered with electrolyte level below the minimum established design limit.5.5.18 Setpoint Control Program This program shall establish the requirements for ensuring that setpoints for automatic protective devices are initially within and remain within the assumptions of the applicable safety analyses, provides a means for processinq changes to instrumentation setpoints, and identifies setpoint methodologies to ensure instrumentation will function as required.
The program shall ensure that testing of automatic protective devices related to variables having significant safety functions as delineated by 10 CFR 50.36(c)(1)(ii)(A) verifies that instrumentation will function as required.a. The program shall list the Functions in the following specifications to which it applies: 1. LCO 3.3.1, "Reactor Protection System (RPS) Instrumentation;" 2. LCO 3.3.3, "Reactor Protection System (RPS) -Reactor Trip Module (RTM):" 3. LCO 3.3.4, "CONTROL ROD Drive (CRD) Trip Devices;" 4. LCO 3.3.5, "Engineered Safety Feature Actuation System (ESFAS)Instrumentation;" 5. LCO 3.3.8, "Emergency Diesel Generator (EDG) Loss of Power Start (LOPS);" 6. LCO 3.3.9, "Source Range Neutron Flux:" 7. LCO 3.3.10, "Intermediate Range Neutron Flux;" 8. LCO 3.3.11, "Emergency Feedwater Initiation and Control (EFIC) System Instrumentation;" 9. LCO 3.3.15, "Reactor Building (RB) Purge Isolation
-High Radiation:" 10. LCO 3.3.16, "Control Room Isolation
-High Radiation." b. The program shall require the Limiting Trip Setpoint (LTSP), Nominal Trip Setpoint (NTSP), Allowable Value (AV). As-Found Tolerance (AFT), and As-Left Tolerance (ALT) (as applicable) of the Functions described in Paragraph a. are calculated using the NRC approved setpoint methodology, as listed below. In addition, the program shall contain the value of the LTSP, NTSP, AV, AFT, and ALT (as applicable) for each Function described in paragraph a. and shall identify the setpoint methodology used to calculate these values.BWOG STS 5.5-18 Rev. 3.1, 12/01/05 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Programs and Manuals 5.5----------------------
Reviewer's Note List the NRC safety evaluation report by letter, date, and ADAMS accession number (if available) that approved the setpoint methodologies.
: 1. [Insert reference to NRC safety evaluation that approved the setpoint methodology.1
: c. The program shall establish methods to ensure that Functions described in Paragraph
: a. will function as required by verifying the as-left and as-found settings are consistent with those established by the setpoint methodology.
: d. REVIEWER'S NOTE -------------------
A license amendment request to implement a Setpoint Control Program must list the instrument functions to which the program requirements of paragraph d. will be applied. Paragraph
: d. shall apply to all Functions in the Reactor Protection System and Engineered Safety Feature Actuation System specifications unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or to instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adjustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the requirements would apply.The program shall identify the Functions described in Paragraph
: a. that are automatic protective devices related to variables having significant safety functions as delineated by 10 CFR 50.36(c)(1)(ii)(A).
The LTSP of these Functions are Limiting Safety System Settings.
These Functions shall be demonstrated to be functioning as required by applying the following requirements during CHANNEL CALIBRATIONS and CHANNEL FUNCTIONAL TESTS that verify the [LTSP or NTSP].1 The as-found value of the instrument channel trip setting shall be compared with the previous as-left value or the specified
[LTSP or NTSP1.BWOG STS 5.5-19 Rev. 3.1, 12/01/05 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Programs and Manuals 5.5 2. If the as-found value of the instrument channel trip setting differs from the previous as-left value or the specified
[LTSP or NTSP] by more than the pre-defined test acceptance criteria band (i.e., the specified AFT), then the instrument channel shall be evaluated before declaring the SR met and returning the instrument channel to service. This condition shall be entered in the plant corrective action program.3. If the as-found value of the instrument channel trip setting is less conservative than the specified AV, then the SR is not met and the instrument channel shall be immediately declared inoperable.
: 4. The instrument channel setpoint shall be reset to a value that is within the as-left tolerance around the [LTSP or NTSP] at the completion of the surveillance test; otherwise, the channel is inoperable(setpoints may be more conservative than the [LTSP or NTSP1 provided that the as-found and as-left tolerances apply to the actual setpoint used to confirm channel performance).
: e. The program shall be specified in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by rnI~ z r= fF ~ p~ +^ +k^..* *1.I p .,rtgr&#xfd; rJ, ! k-., IJ&#xfd;I I At on~ tA rj~J n.JI' At4IIbJ t rYL I II reaw. irarnantsefn 101 G 50.i5,1. Revisionsm r'r 66i *nlemeate W tha rn.sJnIhal beai~r wewe WFan pp. .,lnlru te the I.RI.t'BWOG STS 5.5-20 Rev. 3.1, 12/01/05 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1 B 3.3 INSTRUMENTATION B 3.3,1 Reactor Protection System (RPS) Instrumentation BASES BACKGROUND The RPS initiates a reactor trip to protect against violating the core fuel design limits and the Reactor Coolant System (RCS) pressure boundary during anticipated operational occurrences (AOOs). By tripping the reactor, the RPS also assists the Engineered Safety Feature (ESF)Systems in mitigating accidents.
The protection and monitoring systems have been designed to assure safe operation of the reactor. This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RPS, as well as the LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to geetahninclude LSSS for variables that have significant safety functions.
LSSS are defined by the regulation as "...settings for autemat!c protoctivo deveies...
se"Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The An Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.
Any automatic protection action that occurs on reaching the A Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automaticr-,octiv, dvico.protection channels must be chosen to be more conservative than the AnaltleAnalytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP)controlled by 10.CFR.50.59.
--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP1" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
BWOG STS B 3.3.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1 BASES BACKGROUND (continued)
The Allowable Values listed in T1bleh .3. 1-1-the SCP are based on the methodology described in " -Rt Se~ithe Setpoint MethelegyF Proqram, which incorporates all of the known uncertainties applicable for each channel. The magnitudes of those uncertainties are factored into the determination of each t4p[etpeW44LTSPL.
All field sensors and signal processing equipment for these channels are assumed to operate within the allowances of these uncertainty magnitudes.
APPLICABLE The RPS Functions to preserve the SLs during all AOOs and mitigates the consequences of DBAs. Each of the analyzed accidents and transients can be detected by one SAFETY or more RPS Functions.
The accident analysis contained in Reference 6 ANALYSES, LCO, takes credit for most RPS trip Functions.
Functions not specifically and APPLICABILITY credited in the accident analysis were implicitlyltatW credited in the safety analysis and the NRC staff approved licensing basis for the unit.These Functions are high RB pressure, high temperature, turbine trip, and loss of main feedwater.
These Functions may provide protection for conditions that do not require dynamic transient analysis to demonstrate Function performance.
These Functions also serve as backups to Functions that were credited in the safety analysis.Permissive and interlock setpoints allow the blocking of trips durinq plant startups, and restoration of trips when the permissive conditions are not satisfied, but they are not explicitly modeled in the Safety Analyses.These permissives and interlocks ensure that the starting conditions are consistent with the safety analysis, before preventive or mitigating actions occur. Because these permissives or interlocks are only one of multiple conservative starting assumptions for the accident analysis, they are generally considered as nominal values without regard to measurement accuracy.The LCO requires all instrumentation performing an RPS Function to be OPERABLE.
Failure of any instrument renders the affected channel(s) inoperable and reduces the reliability of the affected Functions.
The four channels of each Function in Table 3.3.1-1 of the RPS instrumentation shall be OPERABLE during its specified Applicability to ensure that a reactor trip will be actuated if needed. Additionally, during shutdown bypass with any CRD trip breaker closed, the applicable RPS Functions must also be available.
This ensures the capability to trip the withdrawn CONTROL RODS exists at all times that rod motion is possible.
The trip Function channels specified in Table 3.3.1-1 are considered OPERABLE when all channel components necessary to provide a reactor trip are functional and in service for the required MODE or Other Specified Condition listed in Table 3.3.1-1.BWOG STS B 3.3.1-14 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1 Required Actions allow maintenance (protection channel) bypass of individual channels, but the bypass activates interlocks that prevent operation with a second channel bypass. Bypass effectively places the unit in a two-out-of-three logic configuration that can still initiate a reactor trip, even with a single failure within the system.BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)
Only the Allowablo Valuos are spocificd for oach RPS trip Function in the LCO. Nominaltria p Setpits arc sp.ifiod inR the unit .pocific setpoin, calculations.
The nomina&#xfd;l ao selected to ensuro that the setpOint ,measured by CHANNEL FUNCTIONAL TESTS dees not exceed the Allowablo Value if the bistablo is Pe~fGrming as required.
Oporation with a trip setpoin. t les ...e... ative than the nom.inal trip sotp.int, but Within its Allowable Value, iS acc-ptable p-rvided that operation and toeting are cnRsise~tntwith the assumptions of the unit specfific setpEint caIculations.
Each Allowable Value pecifitedI i- more 9 than insru#ment un~ertainties appropriate to the trip Function.
These uncertainties are defined in the "[UiJ~t Specific Sotpeint Methodology]F (Ref. 5).For most RPS Functions, the trip setpOint Allowable Value is te ensures that the departure from nucleate boiling (DNB) or the RCS p -ess Pressure SLs is are-not challenged.
Cycle specific figures for use during operation are contained in the COLR.BWOG STS B 3.3.1-15 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
Whenever a sensing element is replaced, the next required CHANNEL CALIBRATION of the resistance temperature detectors (RTD) sensors is accomplished by an inplace cross calibration that compares the other sensing elements with the recently installed sensing element.The Frequency is justified by the assumption of an [18] month calibration interval in the determination of the magnitude of equipment drift in the setpew4[LTSP1 analysis.SR 3.3.1.6 This SR verifies individual channel actuation response times are less than or equal to the maximum values assumed in the accident analysis.Individual component response times are not modeled in the analyses.The analyses model the overall, or total, elapsed time from the point at which the parameter exceeds the analytical limit at the sensor to the point of rod insertion.
Response time testing acceptance criteria for this unit are included in Reference 2.A Note to the Surveillance indicates that neutron detectors are excluded from RPS RESPONSE TIME testing. This Note is necessary because of the difficulty in generating an appropriate detector input signal. Excluding the detectors is acceptable because the principles of detector operation ensure a virtually instantaneous response.Response time tests are conducted on an [18] month STAGGERED TEST BASIS. Testing of the final actuation devicesche;eIs, which make up the bulk of the response time, is included in the testing of each channel. Therefore, staggered testing results in response time verification of these deViGeeschannels every [18] months. The [18] month Frequency is based on unit operating experience, which shows that random failures of instrumentation components causing serious response time degradation, but not channel failure, are infrequent occurrences.
BWOG STS B 3.3.1-34 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)ESFAS Instrumentation B 3.3.5 B 3.3 INSTRUMENTATION B 3.3.5 Engineered Safety Feature Actuation System (ESFAS) Instrumentation BASES BACKGROUND The ESFAS initiates necessary safety systems, based on the values of selected unit Parameters, to protect against violating core design limits and reactor coolant pressure boundary and to mitigate accidents.
This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the ESFAS, as well as the LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to--g-GF-R 50.36(.)(1)(ii)(A) reguir.s that Toc.-hnial include LSSSs for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP) controlled by 10.CFR.50.59.
--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP] is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP1" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP]. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
The [LTSP1 and NTSP are located in the SCP.The [Limiting Trip Setpoint (LTSP)] specified in the SCP, is a predetermined setting for a protection channel chosen to ensure BWOG STS B 3.3.5-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Programs and Manuals 5.5 5.5 Programs and Manuals 5.5.16 Containment Leakage Rate Testing Program (continued)
: 1. Containment leakage rate acceptance criterion is < 1.0 La. During the first unit startup following testing in accordance with this program, the leakage rate acceptance criteria are < 0.60 La for the Type B and C tests and [< 0.75 La for Option A Type A tests] [< 0.75 La for Option B Type A tests].2. Air lock testing acceptance criteria are: a) Overall air lock leakage rate is < [0.05 La] when tested at > Pa.b) For each door, leakage rate is < [0.01 La] when pressurized to[> 10 psig].e. The provisions of SR 3.0.3 are applicable to the Containment Leakage Rate Testing Program.f. Nothing in these Technical Specifications shall be construed to modify the testing Frequencies required by 10 CFR 50, Appendix J.5.5.17 Battery Monitoring and Maintenance Program This Program provides for battery restoration and maintenance, based on [the recommendations of IEEE Standard 450-1995, "IEEE Recommended Practice for Maintenance, Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications," or of the battery manufacturer]
including the following:
: a. Actions to restore battery cells with float voltage < [2.13] V, and b. Actions to equalize and test battery cells that had been discovered with electrolyte level below the minimum established design limit.5.5.18 Setpoint Control Program This program shall establish the requirements for ensuring that setpoints for automatic protective devices are initially within and remain within the assumptions of the applicable safety analyses, provides a means for processing changes to instrumentation setpoints, and identifies setpoint methodologies to ensure instrumentation will function as required.
The program shall ensure that testing of automatic protective devices related to variables having significant safety functions as delineated by 10 CFR 50.36c)(c1
)(ii)(A) verifies that instrumentation will function as required.a. The program shall list the Functions in the following specifications to which it applies: WOG STS 5.5-18 Rev. 3.1, 12/01/05 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Programs and Manuals 5.5 1. LCO 3.3.1, "Reactor Trip System (RTS) Instrumentation;" 2. LCO 3.3.2, "Engineered Safety Feature Actuation System (ESFAS)Instrumentation Functions," 3. LCO 3.3.5, "Loss of Power (LOP) Diesel Generator (DG) Start Instrumentation;" 4. LCO 3.3.6, "Containment Purge and Exhaust Isolation Instrumentation:" 5. LCO 3.3.7, "Control Room Emergency Filtration System (CREFS)Actuation Instrumentation;" 6. LCO 3.3.8, "Fuel Building Air Cleanup System (FBACS) Actuation Instrumentation;" and 7. LCO 3.3.9, "Boron Dilution Protection System (BDPS)." b. The program shall require the Nominal Trip Setpoint (NTSP), Allowable Value (AV), As-Found Tolerance (AFT), and As-Left Tolerance (ALT) (as applicable) of the Functions described in Paragraph
: a. are calculated using the NRC approved setpoint methodology, as listed below. In addition, the program shall contain the value of the NTSP, AV, AFT, and ALT (as applicable) for each Function described in paragraph
: a. and shall identify the setpoint methodology used to calculate these values.----------------------
Reviewer's Note List the NRC safety evaluation report by letter, date, and ADAMS accession number (if available) that approved the setpoint methodologies.
: 1. [Insert reference to NRC safety evaluation that approved the setpoint methodology.1
: c. The program shall establish methods to ensure that Functions described in Paragraph
: a. will function as required by verifying the as-left and as-found settings are consistent with those established by the setpoint methodology.
: d. .REVIEWER'S NOTE -------------------
A license amendment request to implement a Setpoint Control Program must list the instrument functions to which the program requirements of paragraph d. will be applied. Paragraph
: d. shall apply to all Functions in the Reactor Trip System and Engineered Safety Feature Actuation System specifications unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or to instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with WOG STS 5.5-19 Rev. 3.1, 12/01/05 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Programs and Manuals 5.5 as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testinq program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the reauirements would aODlv.The proqram shall identify the Functions described in Paragraph
: a. that are automatic protective devices related to variables havinq siqnificant safety functions as delineated by 10 CFR 50.36(c)(1)(ii)(A).
The NTSP of these Functions are Limiting Safety System Settings.
These Functions shall be demonstrated to be functioninq as required by applying the followinq requirements during CHANNEL CALIBRATIONS, CHANNEL OPERATIONAL TESTS, and TRIP ACTUATING DEVICE OPERATIONAL TESTS that verify the NTSP.1 The as-found value of the instrument channel trip setting shall be compared with the previous as-left value or the specified NTSP.2.If the as-found value of the instrument channel trip setting differs from the previous as-left value or the specified NTSP by more than the pre-defined test acceptance criteria band (i.e., the specified AFT), then the instrument channel shall be evaluated before declaring the SR met and returning the instrument channel to service. This condition shall be entered in the plant corrective action Droaram.3. If the as-found value of the instrument channel trip setting is less conservative than the specified AV, then the SR is not met and the instrument channel shall be immediately declared inoperable.
: 4. The instrument channel setpoint shall be reset to a value that is within the as-left tolerance around the NTSP at the completion of the surveillance test; otherwise, the channel is inoperable(setpoints may be more conservative than the NTSP provided that the as-found and as-left tolerances apply to the actual setpoint used to confirm channel performance).
: e. The program shall be specified in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.Ghangoe to the progrnm s-hall be mOe n acco~rdtance itthhle, rcquIIha r amints " I nn :.01 ,anr=a +rtio .. .. ... ...ID&#xf7;, 'WOG STS 5.5-20 Rev. 3.1, 12/01/05 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RTS Instrumentation B 3.3.1 B 3.3 INSTRUMENTATION B 3.3.1 Reactor Trip System (RTS) Instrumentation BASES BACKGROUND The RTS initiates a unit shutdown, based on the values of selected unit parameters, to protect against violating the core fuel design limits and Reactor Coolant System (RCS) pressure boundary during poratiO3tal occurroncoAnticipated Operational Occurrences (AOOs) and to assist the Engineered Safety Features (ESF) Systems in mitigating accidents.
The protection and monitoring systems have been designed to assure safe operation of the reactor. This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RTS, as well as specifying LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to ee4takiinclude LSSS for variables that have significant safety functions.
LSSS are defined by the regulation as "...settings fer-"Where a LSSS is specified for a variable on which a safety limit has been placed, the settincq must be chosen so that automatic protective deVi-coc...
co choson th3t 3u-t9matic protectie-actionactions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The ARaly4eAnalytical Limit is the limit of the process variable at which a safetyprotective action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.Any automatic protection action that occurs on reaching the Ar Analytical Limit therefore ensures that the SL is not exceeded.However, in practice, the actual settings for automatic PaeteetiV8 deVieesprotection channels must be chosen to be more conservative than the ARalytleAnalytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP) and controlled by 10.CFR.50.59.
--------------------
REVIEWER'S NOTE The teip-term "Limiting Trip Setpoint (LTSP)" is generic terminology for the calculated field setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting.For most Westinghouse plants the term Nominal Trip Setpoint (NTSP) is in place of the term LTSP and NTSP will replace LTSP in the Bases descriptions. "Field setting" is the suggested terminology for the actual WOG STS B 3.3.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RTS Instrumentation B 3.3.1 setpoint where margin has been added to the calculated field setting.The as-found and as-left tolerances will apply to the field settinq implemented in the Surveillance procedures to confirm channel performance.
The [NTSP1 and field setting are located in the SCP The [Nominal Trip Setpoint (NTSP)1 specified in the SCP is a predetermined setting for a .""t"e"iw..-dcv4ceprotection channel chosen to ensure automatic actuation prior to the process variable reaching the AR Analtical Limit and thus ensuring that the SL would not be exceeded.
As such, the 44p setpe-[NTSPJ accounts for uncertainties in setting the devieechannel (e.g., calibration), uncertainties in how the 4evieechannel might actually perform (e.g., repeatability), changes in the point of action of the devieechannel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the trip setpoi't plays an impo.tant role OR einns-ring[NTSP]
ensures that SLs are not exceeded.
A suc1hTherefore, the tup [etpe44iNTSPI meets the definition of an LSSS (Ref. 1) and could be used to meet the r.quiremont that they be cont-nod in n the Specificatiens.).
BASES BACKGROUND (continued)
Technical Specifications contain values related to the OPERABILITY of equipment required for safe operation of the facility.
OPERABLE is defined in Technical Specifications as "...being capable of performing its safety functions(s)." Fer autematic pretective dovices,Relying solely on the oqui- rod safoty funct'fion i6 to ons-re that a SL is not excodod and therefore the L=SSS as defined by 10 CI&#xfd;FR-50.30i the same as the OPERA~BILITY limiot for these devices. Howeyer, use of the trip sepi&#xf7;FNTSPl to define OPERABILITY in Technical Specifications ai4 its corresponding designation as the LSSS required by 10 CER 50.36 would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as:found" value of a PFetee deVieeprotection channel setting during a surveillance.
This would result in Technical Specification compliance problems, as well as reports and corrective actions required by the rule which are not necessary to ensure safety. For example, an automatic Pttiprotection channel with a setting that has been found to be different from the #ip due to some drift of the setting may still be OPERABLE since drift is to be expected.
This expected drift would have been specifically accounted for in the setpoint methodology for calculating the tFip setpaif[NTSPl and thus the automatic protective action would still have ensured that the SL would not be exceeded with the "as:found" setting of the dvce.protection channel. Therefore, the devoeechannel would still be OPERABLE since it would have performed WOG STS B 3.3.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RTS Instrumentation B 3.3.1 BASES BACKGROUND (continued)
The RTS instrumentation is segmented into four distinct but interconnected modules as illustrated in Figure [ ], FSAR, Chapter [7](Ref. 2), and as identified below: 1. Field transmitters or process sensors: provide a measurable electronic signal based upon the physical characteristics of the parameter being measured, 2. Signal Process Control and Protection System, including Analog Protection System, Nuclear Instrumentation System (NIS), field contacts, and protection channel sets: provides signal conditioning, bistable setpoint comparison, process algorithm actuation, compatible electrical signal output to protection systemand control board/control room/miscellaneous indications, 3. Solid State Protection System (SSPS), including input, logic, and output bays: initiates proper unit shutdown and/or ESF actuation in accordance with the defined logic, which is based on the bistable outputs from the signal process control and protection system, and 4. Reactor trip switchgear, including reactor trip breakers (RTBs) and bypass breakers:
provides the means to interrupt power to the control rod drive mechanisms (CRDMs) and allows the rod cluster control assemblies (RCCAs), or "rods," to fall into the core and shut down the reactor. The bypass breakers allow testing of the RTBs at power.Field Transmitters or Sensors To meet the design demands for redundancy and reliability, more than one, and often as many as four, field transmitters or sensors are used to measure unit parameters.
To account for the calibration tolerances and instrument drift, which are assumed to occur between calibrations, statistical allowances are provided in the tFr-iset-ei4[NTSP1 and Allowable Value&.Value.
The OPERABILITY of each transmitter or sensor is determined by either "as-found" calibration data evaluated during the CHANNEL CALIBRATION or by qualitative assessment of field transmitter or sensor as related to the channel behavior observed during performance of the CHANNEL CHECK. The specifc as. f'nWId 'a'-st el.r -. 8t..; he e F Pk F R, A RID I R a R d t h -d;; + :,;t4,. Apt, WOG STS B 3.3.1-5 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RTS Instrumentation B 3.3.1 BASES BACKGROUND (continued)
During normal operation the output from the SSPS is a voltage signal that energizes the undervoltage coils in the RTBs and bypass breakers, if in use. When the required logic matrix combination is completed, the SSPS output voltage signal is removed, the undervoltage coils are de-energized, the breaker trip lever is actuated by the de-energized undervoltage coil, and the RTBs and bypass breakers are tripped open.This allows the shutdown rods and control rods to fall into the core. In addition to the de-energization of the undervoltage coils, each breaker is also equipped with a shunt trip device that is energized to trip the breaker open upon receipt of a reactor trip signal from the SSPS. Either the undervoltage coil or the shunt trip mechanism is sufficient by itself, thus providing a diverse trip mechanism.
The decision logic matrix Functions are described in the functional diagrams included in Reference
: 3. In addition to the reactor trip or ESF, these diagrams also describe the various "permissive interlocks" that are associated with unit conditions.
Each train has a built in testing device that can automatically test the decision logic matrix Functions and the actuation dev-i4echannels while the unit is at power. When any one train is taken out of service for testing, the other train is capable of providing unit monitoring and protection until the testing has been completed.
The testing device is semiautomatic to minimize testing time.APPLICABLE The RTS functions to maintain the SLs during all AOOs and mitigates SAFETY the consequences of DBAs in all MODES in which the Rod Control ANALYSES, LCO, System is capable of rod withdrawal or one or more rods are not fully and APPLICABILITY inserted.Each of the analyzed accidents and transients can be detected by one or more RTS Functions.
The accident analysis described in Reference 4 takes credit for most RTS trip Functions.
RTS trip Functions not specifically credited in the accident analysis are implicitlyquahsI credited in the safety analysis and the NRC staff approved licensing basis for the unit. These RTS trip Functions may provide protection for conditions that do not require dynamic transient analysis to demonstrate Function performance.
They may also serve as backups to RTS trip Functions that were credited in the accident analysis.Permissive and interlock setpoints allow the blocking of trips duringq plant startups, and restoration of trips when the permissive conditions are not satisfied, but they are not explicitly modeled in the Safety Analyses.These permissives and interlocks ensure that the starting conditions are consistent with the safety analysis, before preventive or mitigating actions occur. Because these permissives or interlocks are only one of multiple conservative starting assumptions for the accident analysis, they are WOG STS B 3.3.1-10 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Engineered Safety Feature Actuation System (ESFAS) Instrumentation B 3.3.2 B 3.3 INSTRUMENTATION B 3.3.2 Engineered Safety Feature Actuation System (ESFAS) Instrumentation BASES BACKGROUND The ESFAS initiates necessary safety systems, based on the values of selected unit parameters, to protect against violating core design limits and the Reactor Coolant System (RCS) pressure boundary, and to mitigate accidents.
This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the ESFAS, as well as specifying LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to include LSSS for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a protective action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP) controlled by 1 0.CFR.50.59.
--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint (LTSP)" is generic terminology for the calculated field setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting.For most Westinghouse plants the term Nominal Trip Setpoint (NTSP) is used in place of the term LTSP, and NTSP will replace LTSP in the Bases descriptions. "Field setting" is the suqgested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated field setting. The as-found and as-left tolerances will apply to the field setting implemented in the Surveillance procedures to confirm channel performance.
The [NTSP1 is included in the SCP.WOG STS B 3.3.2-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Engineered Safety Feature Actuation System (ESFAS) Instrumentation B 3.3.2 BASES BACKGROUND (continued)
Generally; if a parameter is used for input to the SSPS and a control function, four channels with a two-out-of-four logic are sifficient to provide the required reliability and redundancy.
The circuit must be able to withstand both an input failure to the control system, which may then require the protection function actuation, and a single failure in the other channels providing the protection function actuation.
Again, a single failure will neither cause nor prevent the protection function actuation.
These requirements are described in IEEE-279-1971 (Ref. 45). The actual number of channels required for each unit parameter is specified in Reference 2-3.Allow;A-ble Va4ue&[NTSPs]
and ESFAS Setpoints
[Allowable Values]The trip setpoints used in the bistables are based on the analytical limits stated in Reference 2-.3. The seleetieicalculation of thesee4r t setpoithe Nominal Trip Setpoints is such that adequate protection is provided when all sensor and processing time delays are taken into account. To allow for calibration tolerances, instrumentation uncertainties, instrument drift, and severe environment errors for those ESFAS channels that must function in harsh environments as defined by 10 CFR 50.49 (Ref. 56), the Allowable Values specified in Tah' 3.3.24 R-the accompany"ng LCOSCP are conservative with respect to the analytical limits. A detailed description of the methodology used to calculate the Allowable Values and ESFAS .setpE49&#xf7;'"[NTSPs1 including their explicit uncertainties, is provided in the plant specific setpoint methodology study (Ref. 67) which incorporates all of the known uncertainties applicable to each channel. The as-left tolerance and as-found tolerance band methodology is provided in the SCP. The magnitudes of these uncertainties are factored into the determination of each ESFAS 69tpaii4[NTSP]
and corresponding Allowable Value. The nominal ESFAS setpoint entered into the bistable is more conservative than that specified by the Allowable VaWlu[NTSP1 to account for measurement errors detectable by the COT. The Allowable Value serves as the as-found trip setpoint Technical Specification OPERABILITY limit for the purpose of the COT. One oxample of su-ch a change in mceasurmemnt error is dr~ift durig the surveillane inteirval.
if the mea-sure-d setpeint does not exceed the 'Allo4' "9wabl Value, the bistpblo i considered OPE.,BLE.The ESFAS setpoints aro[NTSP]
is the va4uesvalue at which the bistables are set and is the expected value to be achieved during calibration.
The ESFAS-setp FNTSPl value, is the LSSS and ensures the safety analysis limits are met for the surveillance interval selected when a channel is adjusted based on stated channel uncertainties.
Any bistable WOG STS B 3.3.2-6 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Engineered Safety Feature Actuation System (ESFAS) Instrumentation B 3.3.2 BASES BACKGROUND (continued)
Each SSPS train has a built in testing deviceehaFnne that can automatically test the decision logic matrix functions and the actuation dte~vreschannels while the unit is at power. When any one train is taken out of service for testing, the other train is capable of providing unit monitoring and protection until the testing has been completed.
The testing devicerhAnnel is semiautomatic to minimize testing time.The actuation of ESF components is accomplished through master and slave relays. The SSPS energizes the master relays appropriate for the condition of the unit. Each master relay then energizes one or more slave relays, which then cause actuation of the end The master and slave relays are routinely tested to ensure operation.
The test of the master relays energizes the relay, which then operates the contacts and applies a low voltage to the associated slave relays. The low voltage is not sufficient to actuate the slave relays but only demonstrates signal path continuity.
The SLAVE RELAY TEST actuates the devicesghappie&#xfd;s if their operation will not interfere with continued unit operation.
For the latter case, actual component operation is prevented by the SLAVE RELAY TEST circuit, and slave relay contact operation is verified by a continuity check of the circuit containing the slave relay.------------------
REVIEWER'S NOTE ---------------------
No one unit ESFAS incorporates all of the Functions listed in Table 3.3.2-1. In some cases (e.g., Containment Pressure -High 3, Function 2.c), the Table reflects several different implementations of the same Function.
Typically, only one of these implementations are used at any specific unit.APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY Each of the analyzed accidents can be detected by one or more ESFAS Functions.
One of the ESFAS Functions is the primary actuation signal for that accident.
An ESFAS Function may be the primary actuation signal for more than one type of accident.
An ESFAS Function may also be a secondary, or backup, actuation signal for one or more other accidents.
For example, Pressurizer Pressure -Low is a primary actuation signal for small loss of coolant accidents (LOCAs) and a backup actuation signal for steam line breaks (SLBs) outside containment.
Functions such as manual initiation, not specifically credited in the accident safety analysis, are implicitlyyq ata'e~y credited in the safety analysis and the NRC staff approved licensing basis for the unit. These Functions may provide protection for conditions that do not require dynamic transient analysis to demonstrate Function performance.
These Functions may also serve as backups to Functions that were credited in the accident analysis (Ref. 34).WOG STS B 3.3.2-10 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Engineered Safety Feature Actuation System (ESFAS) Instrumentation B 3.3.2 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)
Permissive and interlock setpoints allow the blocking of trips during plant startups, and restoration of trips when the permissive conditions are not satisfied, but they are not explicitly modeled in the Safety Analyses.These permissives and interlocks ensure that the starting conditions are consistent with the safety analysis, before preventive or mitigating actions occur. Because these permissives or interlocks are only one of multiple conservative starting assumptions for the accident analysis, they are generally considered as nominal values without regard to measurement accuracy, (i.o. the value indicatod is suffciently cGose to the cc r'The LCO requires all instrumentation performing an ESFAS Function, listed in Table 3.3.2-1 in the accompanying LCO, to be OPERABLE.
A The Allowable Value specified in the SCP is the least conservative value of the as-found setpoint that the channel can have when tested, such that a channel is OPERABLE with a trip setpeit value o.utsido.'
its c"ali"bration tolerance band pr.vided the ripif the as-found setpoint "as found" V doeG Rnt exceed its Allowable Value and pm.vidodis within the as-found tolerance and is conservative with respect to the Allowable Value during the CHANNEL CALIBRATION or CHANNEL OPERATIONAL TEST (COT). As such, the Allowable Value differs from the [NTSP1 by an amount [.reater than orn equal to the expected instrument channel uncertainties, such as drift, duringq the surveillance interval.
In this manner, the actual settingq of the channel ([NTSP]) will ensure that a SL is not exceeded at any given point of time as long as the channel has not drifted beyond expected tolerances during the surveillance interval.
Note that, although the channel is OPERABLE under these circumstances, the trip setpoint %!a&must be leftLya4+e4s adjusted to a value within the calibration to!lerance baRd of the Nominal tolerance, in accordance with uncertainty assumptions stated in the referenced setpoint methodology (as-left criteria), and confirmed to be operating within the statistical allowances of the uncertainty terms assigned (as-found criteria).
If the actual setting of the channel is found to be conservative with respect to the Allowable Value but is beyond the as-found tolerance band, the channel is OPERABLE, but degraded.
The degraded condition of the channel will be evaluated during performance of the SR. This evaluation will consist of resettinq the channel setpoint to the [NTSP] (within the allowed tolerance) and evaluating the channel response.
If the channel is functioning as required and expected to pass the next surveillance, then the channel can be restored to service at the completion of the surveillance.
After the surveillance is completed, the channel's as-found setting will be entered into the Corrective Action Program for further evaluation.
WOG STS B 3.3.2-11 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)CEACs (Digital)3.3.3 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME D. One or two CEACs with D.1 Perform CHANNEL 24 hours three or more auto FUNCTIONAL TEST on restarts during a 12 hour affected CEAC.period.E. Required Action and E.1 Be in MODE 3. 6 hours associated Completion Time of Condition B, C, or D not met.SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.3.3.1 Perform a CHANNEL CHECK. 12 hours SR 3.3.3.2 Check the CEAC auto restart count. 12 hours SR 3.3.3.3 Perform a CHANNEL FUNCTIONAL TEST. 92 days SR 3.3.3.4 Perform a CHANNEL CALIBRATION in accordance
[18] months with the Setpoint Control Program.SR 3.3.3.5 Perform a CHANNEL FUNCTIONAL TEST in [18] months accordance with the Setpoint Control Progqram.SR 3.3.3.6 Verify the isolation characteristics of each CEAC [18] months isolation amplifier and each optical isolator for CEAC to CPC data transfer in accordance with the Setpoint Control Program.CEOG STS 3.3.3-3 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Programs and Manuals 5.5 5.5 Programs and Manuals 5.5.17 Battery Monitoring and Maintenance Program This Program provides for battery restoration and maintenance, based on [the recommendations of IEEE Standard 450-1995, "IEEE Recommended Practice for Maintenance, Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications," or of the battery manufacturer]
including the following a. Actions to restore battery cells with float voltage < [2.13] V, and b. Actions to equalize and test battery cells that had been discovered with electrolyte level below the minimum established design limit.5.5.18 Setpoint Control Proqram This program shall establish the requirements for ensuring that setpoints for automatic protective devices are initially within and remain within the assumptions of the applicable safety analyses, provides a means for processing changes to instrumentation setpoints, and identifies setpoint methodologies to ensure instrumentation will function as required.
The program shall ensure that testing of automatic protective devices related to variables having significant safety functions as delineated by 10 CFR 50.36(c)(1
)(ii)(A) verifies that instrumentation will function as required.a. The program shall list the Functions in the following specifications to which it applies: 1. LCO 3.3.1, "Reactor Protective System (RPS) Instrumentation
-Operating
[(Analoa)]
[(Digital)];" 2. LCO 3.3.2, "Reactor Protective System (RPS) Instrumentation
-Shutdown [(Analoa)l r(Diqital)1:" 3. LCO [3.3.3, "Control Element Assembly Calculators (CEACs) (Digital)l;" 4. [LCO 3.3.4,"Engineered Safety Features Actuation System (ESFAS)Instrumentation (Analogq);"1
[LCO 3.3.5, "Engineered Safety Features Actuation System (ESFAS) Instrumentation (Digital):"1
: 5. [LCO 3.3.6. "Diesel Generator (DG) -Loss of Voltage Start (LOVS)(Analog);"]
[LCO 3.3.7, "Diesel Generator (DG) -Loss of Voltage Start (LOVS) (Digital):"]
: 6. [LCO 3.3.7, "Containment Purge Isolation Signal (CPIS) (Analog);"1
[LCO 3.3.8, "Containment Purge Isolation Signal (CPIS) (Digital);"1
: 7. [LCO 3.3.8, "Control Room Isolation Signal (CRIS) (Analog):"1 ILCO 3.3.9"Control Room Isolation Signal (CRIS) (Digital);"1;
: 8. fLCO 3.3.9, "Chemical and Volume Control System (CVCS) Isolation Signal (Analog):"1
: 9. [LCO 3.3.10, "Fuel Handlinq Isolation Signal (FHIS) (Digital);']
: 10. LCO 3.3.13, "[Logarithmic]
Power Monitoring Channels [(Analog)."]
[(Digital)."l CEOG STS 5.5-18 Rev. 3.1, 12/01/05 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Programs and Manuals 5.5 b. The program shall require the Limitinq Trip Setpoint (LTSP), Nominal Trip Setpoint (NTSP), Allowable Value (AV), As-Found Tolerance (AFT), and As-Left Tolerance (ALT) (as applicable) of the Functions described in Paragraph a. are calculated using the NRC approved setpoint methodology, as listed below. In addition, the program shall contain the value of the LTSP, NTSP, AV, AFT, and ALT (as applicable) for each Function described in paragraph a. and shall identify the setpoint methodology used to calculate these values.----------------------
Reviewer's Note List the NRC safety evaluation report by letter, date, and ADAMS accession number (if available) that approved the setpoint methodologies.
: 1. [Insert reference to NRC safety evaluation that approved the setpoint methodology.]
: c. The program shall establish methods to ensure that Functions described in Paragraph
: a. will function as required by verifying the as-left and as-found settings are consistent with those established by the setpoint methodology.
: d. REVIEWER'S NOTE -------------------
A license amendment request to implement a Setpoint Control Program must list the instrumentfunctions to which the program reguirements of paragraph d. will be applied. Paragraph
: d. shall apply to all Functions in the Reactor Protection System and Engineered Safety Feature Actuation System specifications unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or to instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the requirements would apply.The program shall identify the Functions described in Paragraph
: a. that are automatic protective devices related to variables havinq significant safety functions as delineated by 10 CFR 50.36(c)(1)(ii)(A).
The LTSP of these CEOG STS 5.5-19 Rev. 3.1, 12/01/05 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Programs and Manuals 5.5 /Functions are Limiting Safety System Settings.
These Functions shall be demonstrated to be functioning as required by applying the following requirements during CHANNEL CALIBRATIONS and CHANNEL FUNCTIONAL TESTS that verify the [LTSP or NTSP].1 The as-found value of the instrument channel trip setting shall be compared with the previous as-left value or the specified
[LTSP or NTSP1.2. If the as-found value of the instrument channel trip setting differs from the previous as-left value or the specified
[LTSP or NTSP] by more than the pre-defined test acceptance criteria band (i.e., the specified AFT), then the instrument channel shall be evaluated before declaring the SR met and returning the instrument channel to service. This condition shall be entered in the plant corrective action program.3. If the as-found value of the instrument channel trip setting is less conservative than the specified AV, then the SR is not met and the instrument channel shall be immediately declared inoperable.
: 4. The instrument channel setpoint shall be reset to a value that is within the as-left tolerance around the [LTSP or NTSP] at the completion of the surveillance test; otherwise, the channel is inoperable (setpoints may be more conservative than the [LTSP or NTSP1 provided that the as-found and as-left tolerances apply to the actual setpoint used to confirm channel performance).
: e. The program shall be specified in finsert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.Cha..GS to the program &hall be made in accordance .ith4the KRO aiEi&#xfd;L .I,. .... J,,I J , 4- K 4 -M .. , .- I... bidE mtju 10 tHe 1 41 r -.CEOG STS 5.5-20 Rev. 3.1, 12/01/05 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation
-Operating (Analog)B 3.3.1 B 3.3 INSTRUMENTATION B 3.3.1 Reactor Protective System (RPS) Instrumentation
-Operating (Analog)BASES BACKGROUND The Reactor Protective System (RPS) initiates a reactor trip to protect against violating the core specified acceptable fuel design limits and breaching the reactor coolant pressure boundary (RCPB) during anticipated
.pcrat,.inal occurrcncosAnticipated Operational Occurrences (AOOs). By tripping the reactor, the RPS also assists the Engineered Safety Features (ESF) systems in mitigating accidents.
The protection and monitoring systems have been designed to ensure safe operation of the reactor. This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RPS, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to includeeeRtaiR LSSS for variables that have significant safety functions.
LSSS are defined by the regulation as "...settings for automatic protoctivo a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The AnalyticAnalytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.
Any automatic protection action that occurs on reaching the ARalytieAnalytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protctwo channels must be chosen to be more conservative than the AR... ,.Analyical Limit to account for iiiebucent legpchannel uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP) controlled by 10.CFR.50.59.
--------------------
REVIEWER'S NOTE The term "Limitincq Trip Setpoint" [LTSP1 is -generic terminologqy for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term fLTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP]" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP]. The as-found and as-CEOG STS B 3.3.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation
-Operating (Analog)B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.5 A CHANNEL CALIBRATION of the excore power range channels every 92 days ensures that the channels are reading accurately and within tolerance.
The Surveillance verifies that the channel responds to a measured parameter within the necessary range and accuracy.CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drift between successive calibrations to ensure that the channel remains operational between successive tests. GrHANE-k=CALIBRA\TlONS mnust be porfoFrmod consistent With the plant specifi etTpein4aRalyijhe test is performed in accordance with the SCP. If the actual setting of the channel is found to be conservative with respect to the Allowable Value but is beyond the as-found tolerance band, the channel is OPERABLE but degraded.
The degraded condition of the channel will be further evaluated during performance of the SR. This evaluation will consist of resetting the channel setpoint to the [NTSP1 (within the allowed tolerance), and evaluating the channel response.
If the channel is functioning as required and is expected to pass the next surveillance, then the channel is OPERABLE and can be restored to service at the completion of the surveillance.
After the surveillance is completed, the channel as-found condition will be entered into the Corrective Action Program for further evaluation.
The a6 found nd-s ;left valu's mu-st also be recorded and re'Vie'w-ed for conSistencY With the assumptions of the frequency extension analysis-.
The requirements for this roview are outlinod in Reference
[101.A Note is added stating that the neutron detectors are excluded from CHANNEL CALIBRATION because they are passive devicesGha4Rels with minimal drift and because of the difficulty of simulating a meaningful signal. Slow changes in detector sensitivity are compensated for by performing the daily calorimetric calibration (SR 3.3.1.2) and the monthly linear subchannel gain check (SR 3.3.1.3).
In addition, associated control room indications are continuously monitored by the operators.
The Frequency of 92 days is acceptable, based on plant operating experience, and takes into account indications and alarms available to the operator in the control room.SR 3.3.1.6 A CHANNEL FUNCTIONAL TEST on the Loss of Load and Power Rate of Change channels is performed prior to a reactor startup to ensure the entire channel will perform its intended function if required.
The test is performed in accordance with the SCP. If the actual settinq of the CEOG STS B 3.3.1-38 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation
-Operating (Analog)B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
The Surveillance is modified by a Note to indicate that the neutron detectors are excluded from CHANNEL CALIBRATION because they are passive devicesehaaRReI with minimal drift and because of the difficulty of simulating a meaningful signal. Slow changes in detector sensitivity are compensated for by performing the daily calorimetric calibration (SR 3.3.1.2) and the monthly linear subchannel gain check (SR 3.3.1.3).SR 3.3.1.9 This SR ensures that the RPS RESPONSE TIMES are verified to be less than or equal to the maximum values assumed in the safety analysis.Individual component response times are not modeled in the analyses.The analyses model the overall or total elapsed time from the point at which the parameter exceeds the trip setpoint value at the sensor to the point at which the RTCBs open. Response times are conducted on an[18] month STAGGERED TEST BASIS. This results in the interval between successive surveillances of a given channel of n x 18 months, where n is the number of channels in the function.
The Frequency of[18] months is based upon operating experience, which has shown that random failures of instrumentation components causing serious response time degradation, but not channel failure, are infrequent occurrences.
Also, response times cannot be determined at power, since equipment operation is'required.
Testing may be performed in one measurement or in overlapping segments, with verification that all components are tested.---------------------
REVIEWER'S NOTE ------------------
Applicable portions of the following TS Bases are applicable to plants adopting CEOG Topical Report CE NPSD-1 167-1, "Elimination of Pressure Sensor Response Time Testing Requirements." Response time may be verified by any series of sequential, overlapping or total channel measurements, including allocated sensor response time, such that the response time is verified.
Allocations for sensor response times may be obtained from records of test results, vendor test data, or vendor engineering specifications.
Topical Report CE NPSD-1 167-A,"Elimination of Pressure Sensor Response Time Testing Requirements," (Ref. 1044) provides the basis and methodology for Using allocated sensor response times in the overall verification of the channel response time for specific sensors identified in the Topical Report. Response time verification for other sensor types must be demonstrated by test. The allocation of sensor response times must be verified prior to placing a new component in operation and reverified after maintenance that may adversely affect the sensor response time.CEOG STS B 3.3.1-41 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation
-Operating (Analog)B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
A Note is added to indicate that the neutron detectors are excluded from RPS RESPONSE TIME testing because they are passive devicesrh;A..e with minimal drift and because of the difficulty of simulating a meaningful signal. Slow changes in detector sensitivity are compensated for by performing the daily calorimetric calibration (SR 3.3.1.2).REFERENCES
: 1. Regulatory Guide 1.105, Revision 3, "Setpoints for Safety-Related Instrumentation." 2. 10 CFR 50, Appendix A, GDC 21.3. 10 CFR 100.4. IEEE Standard 279-1971, April 5, 1972.5. FSAR, Chapter [14].6. 10 CFR 50.49.7. Pant WFErotocIOn 6Yct8om ;boioctio OT +FI riep ~OIfl! values.,-78. FSAR, Section [7.2].8_9. NRC Safety Evaluation Report, [Date].941-. CEN-327, June 2, 1986, including Supplement 1, March 3, 1989.4-1-7 10. CEOG Topical Report CE NPSD-1167-A, "Elimination of Pressure Sensor Response Time Testing Requirements." CEOG STS B 3.3.1-42 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)ESFAS Instrumentation (Analog)B 3.3.4 B 3.3 INSTRUMENTATION B 3.3.4 Engineered Safety Features Actuation System (ESFAS) Instrumentation (Analog)BASES BACKGROUND The ESFAS initiates necessary safety systems, based upon the values of selected unit parameters, to protect against violating core design limits and the Reactor Coolant System (RCS) pressure boundary and to mitigate accidents.
This is achieved by specifying limitinq safety system settings (LSSS) in terms of parameters directly monitored by the RPS, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 44-G-R 50.36(-)(.
)(00)(A) r.quiroc that Tocrghn.,i,.al Specifications include LSSSs for variables that have siqnificant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a Safety Limit (SL) is not exceeded.
Any automatic protection action that occurs on reachinq the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP) controlled by 1 0.CFR.50.59.
--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term'[LTSP]
indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint fNTSP1" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
The [LTSP1 and NTSP are located in the SCP.CEOG STS B 3.3.4-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)ESFAS Instrumentation (Analog)B 3.3.4 BASES BACKGROUND (continued) setpoint entered into the bistable is normally still more conservative than that specified by the Allowable Value to account for changes in random measurement errors detectable by a CHANNEL FUNCTIONAL TEST.One example of such a change in measurement error is drift during the interval between surveillances.If the m..a.urod setpoint doee not oxc..dis concorvative wthrpc to theAllowqable Value, the bistable i6 considered OPERABLE.The [LTSP1 is the value at which the bistable is set and is the expected value to be achieved during calibration.
The [LTSP1 value is the LSSS and ensures the safety analysis limits are met for the surveillance interval selected when a channel is adiusted based on stated channel uncertainties.
[Limitina Trip SetpointsL, in aeeG4aRGeconuunction with the use of as-found and as-left tolerances, consistent with the requirements of the Allowable Value will ensure that Safety Limits of Chapter 2.0, "SAFETY LIMITS (SLs)," are not violated during anticipated operational occurrences (AOOs) and that the consequences of Design Basis Accidents (DBAs) will be acceptable, providing the plant is operated from within the LCOs at the onset of the AOO or DBA and the equipment functions as designed.Note that in the accompanying LCO 3.3.4, the Allowable Values of the SCP are the least conservative value of the as-found setpoint that a channel can have during a periodic CHANNEL CALIBRATION or CHANNEL FUNCTIONAL TEST.ESFAS Logic It is possible to change the two-out-of-four ESFAS logic to a two-out-of-three logic for a given input parameter in one channel at a time by disabling one channel input to the logic. Thus, the bistables will function normally, producing normal trip indication and annunciation, but ESFAS actuation will not occur since the bypassed channel is effectively removed from the coincidence logic. Trip channel bypassing can be simultaneously performed on any number of parameters in any number of channels, providing each parameter is bypassed in only one channel at a time. At some plants an interlock prevents simultaneous trip channel bypassing of the same parameter in more than one channel. Trip channel bypassing is normally employed during maintenance or testing.ESFAS Logic is addressed in LCO 3.3.5.APPLICABLE Each of the analyzed accidents can be detected by one or more ESFAS SAFETY Functions.
One of the ESFAS Functions is the primary actuation signal CEOG STS B 3.3.4-7 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation
-Operating (Digital)B 3.3.1 B 3.3 INSTRUMENTATION B 3.3.1 Reactor Protective System (RPS) Instrumentation
-Operating (Digital)BASES BACKGROUND The RPSReactor Protective System (RPS) initiates a reactor trip to protect against violating the core specified acceptable fuel design limits and breaching the reactor coolant pressure boundary (RCPB) during aRnticipated opor.ational o......Rr..sAnticipated Operational Occurrences (AOOs). By tripping the reactor, the RPS also assists the Engineered Safety Features (ESF) systems in mitigating accidents.
The protection and monitoring systems have been designed to ensure safe operation of the reactor. This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RPS, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to includeeeitaWR LSSS for variables that have sigqnificant safety functions.
LSSS are defined by the regulation as "...settings for automatic protectiVe deies.-..se"Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The A.... ,,Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.
Any automatic protection action that occurs on reaching the ARalytimAnalytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protective must be chosen to be more conservative than the ARalytleAnalytical Limit to account for iRetFLefe-leechannel uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP) controlled by 10.CFR.50.59.
--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is -generic terminology for the calculated trip settinq (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term fLTSP] indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSPI" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-CEOG STS B 3.3.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation
-Operating (Digital)B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.10 SR 3.3.1.10 is the performance of a CHANNEL CALIBRATION every[18] months.CHANNEL CALIBRATION is a complete check of the instrument channel including the sensor. The Surveillance verifies that the channel responds to a measured parameter within the necessary range and accuracy.CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drift between successive calibrations to ensure that the channel remains operational between successive tests. CH.ANNEL CALIBR\ATIONS must be performed consistent With the plant spocifi;setpei4anal i The test is performed in accordance with the SCP. If the actual setting of the channel is found to be conservative with respect to the Allowable Value but is beyond the as-found tolerance band, the channel is OPERABLE but degraded.
The degraded condition of the channel will be further evaluated during performance of the SR. This evaluation will consist of resetting the channel setpoint to the [NTSP1 (within the allowed tolerance), and evaluating the channel response.
If the channel is functioning as required and is expected to pass the next surveillance, then the channel is OPERABLE and can be restored to service at the completion of the surveillance.
After the surveillance is completed, the channel as-found condition will be entered into the Corrective Action Proaram for further evaluation.
The as found and as, left values must also be recorded and revfiewed for consistency wt the- a46sumptions of the surweillance inter:Val extension analysis.
The requirem~ents forF this review~h are otine i Reference
[10]1.The Frequency is based upon the assumption of an [18] month calibration interval for the determination of the magnitude of equipment drift in the setpoint analysis as well as operating experience and consistency with the typical [18] month fuel cycle.The Surveillance is modified by a Note to indicate that the neutron detectors are excluded from CHANNEL CALIBRATION because they are passive with minimal drift and because of the difficulty of simulating a meaningful signal. Slow changes in detector sensitivity are compensated for by performing the daily calorimetric calibration (SR 3.3.1.4) and the monthly linear subchannel gain check (SR 3.3.1.6).SR 3.3.1.11 Every [18] months, a CHANNEL FUNCTIONAL TEST is performed on the CPCs. The CHANNEL FUNCTIONAL TEST shall include the injection of CEOG STS B 3.3.1-42 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation
-Operating (Digital)B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)
Response time may be verified by any series of sequential, overlapping or total channel measurements, including allocated sensor response time, such that the response time is verified.
Allocations for sensor response times may be obtained from records of test results, vendor test data, or vendor engineering specifications.
Topical Report CE NPSD-1 167-A,"Elimination of Pressure Sensor Response Time Testing Requirements," (Ref. 1014-) provides the basis and methodology for using allocated sensor response times in the overall verification of the channel response time for specific sensors identified in the Topical Report. Response time verification for other sensor types must be demonstrated by test. The allocation of sensor response times must be verified prior to placing a new component in operation and reverified after maintenance that may adversely affect the sensor response time.A Note is added to indicate that the neutron detectors are excluded from RPS RESPONSE TIME testing because they are passive devicesehannels with minimal drift and because of the difficulty of simulating a meaningful signal. Slow changes in detector sensitivity are compensated for by performing the daily calorimetric calibration (SR 3.3.1.4).REFERENCES
: 1. Regulatory Guide 1.105, Revision 3, "Setpoints for Safety-Related Instrumentation." 2. 10 CFR 50, Appendix A, GDC 21.3. 10 CFR 100.4. NRC Safety Evaluation Report.5. IEEE Standard 279-1971, April 5, 1972.6. FSAR, Chapter [14].7. 10 CFR 50.49.8. "PlIt Protcction System of Trip Setpoint Valuos." 89. FSAR, Section [7.2].94_. CEN-327, June 2, 1986, including Supplement 1, March 3, 1989.CEOG Topical Report CE NPSD-1 167-A, "Elimination of Pressure Sensor Response Time Testing Requirements." CEOG STS B 3.3.1-46 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)CEACs (Digital)B 3.3.3 the as-left and as-found setting are consistent with those established by the setpoint methodology.
BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.3.4 SR 3.3.3.4 is the performance of a CHANNEL CALIBRATION every[18] months.CHANNEL CALIBRATION is a complete check of the instrument channel including the sensor. The Surveillance verifies that the channel responds to a measured parameter within the necessary range and accuracy.CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drift between successive calibrations to ensure that the channel remains operational between successive surveillances.
CHANNEL CALIBRATIONS must be po-FReorm conR-is;f-qtent 4.:ith the plant spccific setpeint analysisThe SCP has controls which reguire verification that the instrument channel functions as required by verifying the as-left and as-found setting are consistent with those established by the setpoint methodology.
The as found and as left valu es mu st also be rocordedl and reVOieWed for consstony wih th assmptins f the cur.'oillance interall extonio_analysis.
The requiremonsfrthsrve are outlined in Roferenco
[5].The Frequency is based upon the assumption of an [18] month calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis and includes operating experience and consistency with the typical [18] month fuel cycle.SR 3.3.3.5 Every [18] months, a CHANNEL FUNCTIONAL TEST is performed on the CEACs. The CHANNEL FUNCTIONAL TEST shall include the injection of a signal as close to the sensors as practicable to verify OPERABILITY, including alarm and trip Functions.
A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable CHANNEL FUNCTIONAL TEST of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
The SCP has controls which require verification that the instrument channel functions as required by verifying the as-left and as-found settincl are consistent with those established by the setpoint methodoloqy.
CEOG STS B 3.3.3-9 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)ESFAS Instrumentation (Digital)B 3.3.5 B 3.3 INSTRUMENTATION B 3.3.5 Engineered Safety Features Actuation System (ESFAS) Instrumentation (Digital)BASES BACKGROUND The ESFAS initiates necessary safety systems, based upon the values of selected unit parameters, to protect against violating core design limits and the Reactor Coolant System (RCS) pressure boundary during anticipated operational occurrences (AOOs) and ensures acceptable consequences during accidents.
This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the ESFAS, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 4-O-&F-R 50.36(00400)(iA) that Tochnical Spocification include LSSSs for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a Safety Limit (SL) is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for channel uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP) controlled by IOCFR.50.59.
--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is generic terminoloqy for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP1" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and. as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
The [LTSP1 and NTSP are located in the SCP.CEOG STS B 3.3.5-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)ESFAS Instrumentation (Digital)B 3.3.5 BASES BACKGROUND (continued)
The trip setpoints and Allowable Values used in the bistables are based enderived from the analytical limits stated in Reference 5.9. The selectioncalecu!etie of these trip setpoints t f4" I *. -" I '....ofo.,,,-J iR th, SG-D is such that adequate protection is provided when all sensor and processing time delays are taken into account. To allow for calibration tolerances, instrumentation uncertainties, instrument drift, and severe environment effects, for those ESFAS channels that must function in harsh environments as defined by 10 CFR 50.49 (Ref. 68), Allowable Values specified in Table 3.3.5-the SCP, in the accompanying LCO, are conservatively adjusted with respect to the analytical limits. A detailed description of the methodology used to calculate the trip setpoints, including their explicit uncertainties, is provided in the "Plant Proto n S,,ttom Solection of Trip Sotpoint Values" (Rof. 7).SCP. The actual Re9iea trip setpoint entered into the bistable is normally still more conservative than that specified by the Allowable Value to account for changes in random measurement errors detectable by a CHANNEL FUNCTIONAL TEST. One example of such a change in measurement error is drift durinq the interval between surveillances.-
A hanRie-l inoperable ifisactual triplf the measu-ro Getpoint is not MithNAit FqiFedtheas-t feWa te 1 +alplrup-a;1A1 GGR68wp am a t n,,+ a aah Feapnar.+
theI Allo'wable Value, the bistabhlok ips cnidorod OPERA9BLE-.
The [LTSPI is the value at which the bistable is set and is the expected value to be achieved during calibration.
The [LTSP1 value is the LSSS and ensures the safety analysis limits are met for the surveillance interval selected when a channel is adiusted based on stated channel uncertainties.
[Limiting Trip- SetpointsL in a~ee. da..econlunction with the use of as-found and as-left tolerances, consistent with the requirements of the Allowable Value will ensure that Safety Limits of LCO Section 2.0, "Safety Limits," are not violated during AOOs and the consequences of Design Basis Accidents (DBAs) will be acceptable, providing the plant is operated from within the LCOs at the onset of the AOO or DBA and the equipment functions as designed.Note that in the accompanying LCO 3.3.5, the Allowable Values of the SCP are the least conservative value of the as-found setpoint that a channel can have during a periodic CHANNEL CALIBRATION or CHANNEL FUNCTIONAL TEST.Functional testing of the ESFAS, from the bistable input through the opening of initiation relay contacts in the ESFAS Actuation Logic, can be performed either at power or at shutdown and is normally performed on a quarterly basis. FSAR, Section [7.21 (Ref. 810), provides more detail on ESFAS testing. Process transmitter calibration is normally performed on CEOG STS B 3.3.5-7 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Primary Containment Isolation Instrumentation 3.3.6.1 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.3.6.1.3
[Calibrate the trip unit in accordance with the [92] days ]Setpoint Control Program.SR 3.3.6.1.4 Perform CHANNEL CALIBRATION in accordance 92 days with the Setpoint Control Procqram.SR 3.3.6.1.5
[ Perform CHANNEL FUNCTIONAL TEST--4i [184] days]SR 3.3.6.1.6 Perform CHANNEL CALIBRATION in accordance
[18] months with the Setpoint Control Program.SR 3.3.6.1.7 Perform LOGIC SYSTEM FUNCTIONAL TEST. [18] months------REVIEWER'S NOTE ---------------------------------
This SR is applied only to Functions of Table 3.3.6.1-1 with required response times not corresponding to DG start time.SR 3.3.6.1.8
--------------------
NOTE---------------
[ Radiation detectors may be excluded.
]Verify the ISOLATION SYSTEM RESPONSE TIME [18] months on a is within limits. STAGGERED TEST BASIS BWR/4 STS 3.3.6.1-4 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Programs and Manuals 5.5 5.5 Programs and Manuals 5.5.14 Battery Monitoring and Maintenance Program This Program provides for battery restoration and maintenance, based on [the recommendations of IEEE Standard 450-1995, "IEEE Recommended Practice for Maintenance, Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications," or of the battery manufacturer]
of the following:
: a. Actions to restore battery cells with float voltage < [2.13] V, and b. Actions to equalize and test battery cells that had been discovered with electrolyte level below the minimum established design limit.5.5.15 Setpoint Control Program This program shall establish the requirements for ensuring that setpoints for automatic protective devices are initially within and remain within the assumptions of the applicable safety analyses, provides a means for processing changes to instrumentation setpoints, and identifies setpoint methodologies to ensure instrumentation will function as required.
The program shall ensure that testing of automatic protective devices related to variables having significant safety functions as delineated by 10 CFR 50.36(c)(1
)(ii)(A) verifies that instrumentation will function as required.a. The program shall list the Functions in the following specifications to which it applies: 1. LCO 3.3.1.1, "Reactor Protection System (RPS) Instrumentation:" 2. LCO 3.3.1.2, "Source Range Monitor (SRM) Instrumentation;" 3. LCO 3.3.2.1, "Control Rod Block Instrumentation;" 4. LCO 3.3.2.2, "Feedwater and Main Turbine High Water Level Trip Instrumentation:" 5. LCO 3.3.4.1, "End of Cycle Recirculation Pump Trip (EOC-RPT)
, Instrumentation;" 6. LCO 3.3.4.2. "Anticipated Transient Without Scram Recirculation Pump Trip (ATWS-RPT)
Instrumentation;" 7. LCO 3.3.5.1, "Emergency Core Cooling System (ECCS) Instrumentation;" 8. LCO 3.3.5.2, "Reactor Core Isolation Cooling (RCIC) System Instrumentation:" 9. LCO 3.3.6.1, "Primary Containment Isolation Instrumentation;" 10. LCO 3.3.6.2, "Secondary Containment Isolation Instrumentation;" 11. LCO 3.3.6.3, "Low-Low Set (LLS) Instrumentation;" 12. LCO 3.3.7.1, "[Main Control Room Environmental Control (MCREC)1 System Instrumentation;" 13. LCO 3.3.8.1, "Loss of Power (LOP) Instrumentation;" 14. LCO 3.3.8.2, "Reactor Protection System (RPS) Electric Power Monitoring." BWR/4 STS 5.5-14 Rev. 3.1, 12/01/05 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Programs and Manuals 5.5 b. The program shall require the Limitinq Trip Setpoint (LTSP), Nominal Trip Setpoint (NTSP), Allowable Value (AV), As-Found Tolerance (AFT), and As-Left Tolerance (ALT) (as applicable) of the Functions described in Paragraph a. are calculated using the NRC approved setpoint methodology, as listed below. In addition, the program shall contain the value of the LTSP, NTSP, AV, AFT, and ALT (as applicable) for each Function described in paragraph a. and shall identify the setpoint methodology used to calculate these values.----------------------
Reviewer's Note List the NRC safety evaluation report by letter, date, and ADAMS accession number (if available) that approved the setpoint methodologies.
: 1. [insert reference to NRC safety evaluation that approved the setpoint methodology.1
: c. The program shall establish methods to ensure that Functions described in Paragraph
: a. will function as reguired by verifying the as-left and as-found settings are consistent with those established by the setpoint methodology.
: d. REVIEWER'S NOTE A license amendment request to implement a Setpoint Control Program must list the instrument functions to which the program requirements of paragraph d. will be applied. Paragraph
: d. shall apply to all Functions in the Reactor ,Protection System (RPS) Instrumentation, Control Rod Block Instrumentation, End of Cycle-Recirculation Pump Trip (EOC-RPT)
Instrumentation, Emergency Core Cooling System (ECCS) Instrumentation, and Reactor Core Isolation Cooling (RCIC) instrumentation specifications unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or to instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Reguirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the reguirements would apply.BWR/4 STS 5.5-15 Rev. 3.1, 12/01/05 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Programs and Manuals 5.5 The program shall identify the Functions described in Paragraph
: a. that are automatic protective devices related to variables having significant safety functions as delineated by 10 CFR 50.36(c)(1)(ii)(A).
The LTSP of these Functions are Limiting Safety System Settings.
These Functions shall be demonstrated to be functioning as required by applying the followinq requirements durinq CHANNEL CALIBRATIONS, trip unit calibrations and CHANNEL FUNCTIONAL TESTS that verify the [LTSP or NTSPI.1 The as-found value of the instrument channel trip setting shall be compared with the previous as-left value or the specified
[LTSP or NTSP1.2. If the as-found value of the instrument channel trip setting differs from the previous as-left value or the specified
[LTSP or NTSP] by more than the pre-defined test acceptance criteria band (i.e., the specified AFT), then the instrument channel shall be evaluated before declaring the SR met and returning the instrument channel to service. This condition shall be entered in the plant corrective action program.3. If the as-found value of the instrument channel trip setting is less conservative than the specified AV, then the SR is not met and the instrument channel shall be immediately declared inoperable.
: 4. The instrument channel setpoint shall be reset to a value that is within the as-left tolerance around the [LTSP or NTSP1 at the completion of the surveillance test: otherwise, the channel is inoperable (setpoints may be more conservative than the [LTSP or NTSP1 provided that the as-found and as-left tolerances apply to the actual setpoint used to confirm channel performance).
: e. The program shall be specified in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencelI s to iproam hal m ORi accordanc withth shall be. nrn.Ardpr i nn ieR *&swaG to the NI D BWRI4 STS 5.5-16 Rev. 3.1, 12/01/05 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 B 3.3 INSTRUMENTATION B 3.3.1.1 Reactor Protection System (RPS) Instrumentation BASES BACKGROUND The RPS initiates a reactor scram when one or more monitored parameters exceed their specified limits, to preserve the integrity of the fuel cladding and the Reactor Coolant System (RCS) and minimize the energy that must be absorbed following a loss of coolant accident (LOCA). This can be accomplished either automatically or manually.The protection and monitoring functions of the RPS have been designed to ensure safe operation of the reactor. This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RPS, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to Geetaipinclude LSSS for variables that have significant safety functions.
LSSS are defined by the regulation as ".....ttingG for automatic pr.tc.tiV.
devees&...se"Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The An Analtical Limit is the limit of the process variable at which a 6afetyprotective action is initiated, as established by the safety analysis, to ensure that a safety limit (SLI is not exceeded.Any automatic protection action that occurs on reaching the AnalytlcAnalytical Limit therefore ensures that the SL is not exceeded.However, in practice, the actual settings for automatic pFeteetPe dev4eesprotection channels must be chosen to be more conservative than the ARalytieAnalytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP) controlled by 10.CFR.50.59.
--------------------
REVIEWER'S NOTE ------------------
The term "Limiting Trip Setpoint" [LTSP1 is -generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP1" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
BWR/4 STS B 3.3.1.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 The OPERABILITY of the RPS is dependent on the OPERABILITY of the individual instrumentation channel Functions specified in Table 3.3.1.1-1.
Each Function must have a required number of OPERABLE channels per RPS trip system, with their setpoints set within the spocified Al.o'Ablo Valuesetting tolerance of the [LTSPs], where appropriate.
The actual setpoint is calibrated consistent with applicablo setpo-nt mnethodology ass. pti-nsthe SCP. Each channel must also respond within its assumed response time.BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)
Allowable Values for RPS Instrumentation Functions are specified fei e;;Ach RPS F unction spocifiod in the Table. Nominal trip stpoi,,+SCP.
[Limiting Trip Setpointsl and the methodologies for calculation of the as-left and as-found tolerances are peelffieddescribed in the setpeif4 eac'JdatieRs.-SCP controlled under 10 CFR 50.59. The nm*iRa4 setpeiats[LTSPs]
are selected to ensure that the actual setpoints do-Pet exceed tho Allowable Va ueremain conservative with respect to the as-found tolerance band between successive CHANNEL CALIBRATIONS.
each calibration the trip setpoint less cners-tiv-c than the nomin.al trip setpoint, butshall be left within its Allowable Value, is acceptable.
A hannRel is iwnoprabl if ;te actl trip is not within itS Allowable Va ue.the as-left band around the [LTSP1.Fp etiR[LTSPsl are those predetermined values of output at which an action should take place. The setpoints are compared to the actual process parameter (e.g., reactor vessel water level), and when the measured output value of the process parameter exceeds the setpoint, the associated deviceehaRwel (e.g., trip unit) changes state. The anaI4yioanalytical limits are derived from the limiting values of the process parameters obtained from the safety analysis.
The Allowable Values are derived from the aneyieanalytical limits, corrected for calibration, process, and some of the instrument errors. The ti4.6setp9ins[LTSPs]
are then determined accounting for the remaining instrument errors (e.g., drift). The tlip setpeiRts[LTSPs1 derived in this manner provide adequate protection because instrumentation uncertainties, process effects, calibration tolerances, instrument drift, and severe environment errors (for channels that must function in harsh environments as defined by 10 CFR 50.49) are accounted for.The OPERABILITY of scram pilot valves and associated solenoids, backup scram valves, and SDV valves, described in the Background section, are not addressed by this LCO.The individual Functions are required to be OPERABLE in the MODES specified in the table, which may require an RPS trip to mitigate the consequences of a design basis accident or transient.
To ensure a BWR/4 STS B 3.3.1.1-6 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE REQUIREMENTS (continued)
As noted, SR 3.3.1.1.4 is not required to be performed when entering MODE 2 from MODE 1, since testing of the MODE 2 required IRM and APRM Functions cannot be performed in MODE 1 without utilizing jumpers, lifted leads, or movable links. This allows entry into MODE 2 if the 7 day Frequency is not met per SR 3.0.2. In this event, the SR must be performed within 12 hours after entering MODE 2 from MODE 1.Twelve hours is based on operating experience and in consideration of providing a reasonable time in which to complete the SR.A Frequency of 7 days provides an.acceptable level of system average unavailability over the Frequency interval and is based on reliability analysis (Ref. 910).SR 3.3.1.1.5 A CHANNEL FUNCTIONAL TEST is performed on each required channel to ensure that the entire channel will perform the intended fuRctiec Function.
A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable CHANNEL FUNCTIONAL TEST of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
In accordance with Reference 10, the scram contacts must be tested as part of the Manual Scram Function.
A Frequency of 7 days provides an acceptable level of system average availability over the Frequency and is based on the reliability analysis of Reference 44r10. (The Manual Scram Function's CHANNEL FUNCTIONAL TEST Frequency was credited in the analysis to extend many automatic scram Functions' Frequencies.)
SR 3.3.1.1.6 LPRM gain settings are determined from the local flux profiles measured by the Traversing Incore Probe (TIP) System. This establishes the relative local flux profile for appropriate representative input to the APRM System. The 1000 MWD/T Frequency is based on operating experience with LPRM sensitivity changes.BWR/4 STS B 3.3.1.1-28 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option'B)
RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.1.7 and SR 3.3.1.1.10 A CHANNEL FUNCTIONAL TEST is performed on each required channel to ensure that the entire channel will perform the intended function.
A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable CHANNEL FUNCTIONAL TEST of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions..Any sotpoint adjuetmont shall bo consistent with the assum.ption of the c ntl spcific ,etpoi-t mothodlogy.
The 92 day FrequoncY Of SR 3.30.1.1.i7.
isbado the roliability analysi o A Note states that SR 3.3.1.1.7 for Function 3.3.1.1-1.2.d must be performed in accordance with the SCP. If the actual setting of the channel is found to be conservative with respect to the Allowable Value but is beyond the as-found tolerance band, the channel is OPERABLE but degraded.
The degraded condition of the channel will be further evaluated during performance of the SR. This evaluation will consist of resetting the channel setpoint to the [NTSP1 (within the allowed tolerance), and evaluating the channel response.
If the channel is functioning as required and is expected to pass the next surveillance, then the channel is OPERABLE and can be restored to service at the completion of the surveillance.
After the surveillance is completed, the channel as-found condition will be entered into the Corrective Action Program for further evaluation.
The 92 day Frequency of SR 3.3.1.1.7 is based on the reliability analysis of Reference 10.The 18 month Frequency of SR 3.3.1.1.10 is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power. Operating experience has shown that these components usually pass the Surveillance when performed at the 18 month Frequency.
SR 3.3.1.1.8 C2r;librinnThe calibration of trip units provides a check of the actual trip setpoints.
The channel must be declared inoperable if the trip setting is discovered to be less conservative than the Allowable Value specified in Table 3.3.1.1 1. if the trip setting iGiovered to be lGSs consevwative BWR/4 STS B 3.3.1.1-29 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 The Average Power Range Monitor Flow Biased Simulated Thermal Power -High Function uses an electronic filter circuit to generate a signal proportional to the core THERMAL POWER from the APRM neutron flux signal. This filter circuit is representative of the fuel heat transfer dynamics that produce the relationship between the neutron flux and the core THERMAL POWER. The SurVeillance filter time constant must be Vorifiod to be 9 7 SecondIS to onsuro that the channol is, accuratoly reflecting the dGo1siod The filter time constant must be verified consistent with the SCP to ensure that the channel is accurately reflecting the desired parameter.
The test is performed in accordance with the SCP. If the actual setting of the channel is found to be conservative with respect to the Allowable Value but is beyond the as-found tolerance band, the channel is OPERABLE but degraded.
The degraded condition of the channel will be further evaluated during performance of the SR. This evaluation will consist of resetting the channel setpoint to the [NTSP1 (within the allowed tolerance), and evaluating the channel response.
If the channel is functioning as required and is expected to pass the next surveillance, then the channel is OPERABLE and can be restored to service at the completion of the surveillance.
After the surveillance is completed, the channel as-found condition will be entered into the Corrective Action Program for further evaluation.
The Frequency of 18 months is based on engineering judgment considering the reliability of the components.
BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.1.13 The LOGIC SYSTEM FUNCTIONAL TEST demonstrates the OPERABILITY of the required trip logic for a specific channel. The functional testing of control rods (LCO 3.1.3), and SDV vent and drain valves (LCO 3.1.8), overlaps this Surveillance to provide complete testing of the assumed safety function.The 18 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power. Operating experience has shown that these components usually pass the Surveillance when performed at the 18 month Frequency.
SR 3.3.1.1.14 This SR ensures that scrams initiated from the Turbine Stop Valve -Closure and Turbine Control Valve Fast Closure, Trip Oil Pressure -Low Functions will not be inadvertently bypassed when THERMAL POWER is> 30% RTP. This involves calibration of the bypass channels.
Adequate BWR/4 STS B 3.3.1.1-32 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Control Rod Block Instrumentation B 3.3.2.1 B 3.3 INSTRUMENTATION B 3.3.2.1 Control Rod Block Instrumentation BASES BACKGROUND Control rods provide the primary means for control of reactivity changes.Control rod block instrumentation includes channel sensors, logic circuitry, switches, and relays that are designed to ensure that specified fuel design limits are not exceeded for postulated transients and accidents.
During high power operation, the rod block monitor (RBM)provides protection for control rod withdrawal error events. During low power operations, control rod blocks from the rod worth minimizer (RWM)enforce specific control rod sequences designed to mitigate the consequences of the control rod drop accident (CRDA). During shutdown conditions, control rod blocks from the Reactor Mode Switch -Shutdown Position Function ensure that all control rods remain inserted to prevent inadvertent criticalities.
The protection and monitoring functions of the control rod block instrumentation has been designed to ensure safe operation of the reactor. This is achieved by specifying limiting safety system settinqgs (LSSS) in terms of parameters directly monitored by the RPS, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 40-GF-R 50.36(c)(1
)(i)(A) ....ouir. that T-chRnial Spcificatitons include LSSS for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a Safety Limit (SL) is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP) controlled by I0.CFR.50.59.
--- REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP] is generic terminology for the calculated trip settinq (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSPI indicates that no additional margin BWR/4 STS B 3.3.2.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Control Rod Block Instrumentation B 3.3.2.1 has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP]" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP]. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
The [LTSP] and NTSP are located in the SCP.The [Limiting Trip Setpoint (LTSP)] specified in the SCP, is a predetermined setting for a protection channel chosen to ensure automatic actuation prior to the process variable reaching the Analytical Limit and thus ensuring that the SL would not be exceeded.
As such, the[LTSP1 accounts for uncertainties in setting the channel (e.g., calibration), uncertainties in how the channel might actually perform (e.g., repeatability), changes in the point of action of the channel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the fLTSP1 ensures that SLs are not exceeded.
Therefore, the [LTSP1 meets the definition of an LSSS (Ref. 1).The Allowable Values specified in the SCP serves as the LSSS such that a channel is OPERABLE if the trip setpoint is found not to exceed the Allowable Value. As such, the Allowable Value differs from the trip setpoint by an amount primarily equal to the expected instrument loop uncertainties, such as drift, during the surveillance interval.
In this manner, the actual setting of the device will still meet the LSSS definition and ensure that a SL is not exceeded at any given point of time as long as the device has not drifted beyond that expected during the surveillance interval.Technical Specifications contain values related to the OPERABILITY of equipment required for safe operation of the facility.
Operable is defined in Technical Specifications as "...being capable of performing its safety function(s)." Relying solely on the [ILTSP] to define OPERABILITY in Technical Specifications would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as found" value of a protection channel setting during a Surveillance.
This would result in Technical Specification compliance problems, as well as reports and corrective actions required by the rule which are not necessary to ensure safety. For example, an automatic protection channel with a setting that has been found to be different from the [ILTSPI due to some drift of the setting may still be OPERABLE because drift is to be expected.
This expected drift would have been specifically accounted for in the setpoint methodology for calculating the [LTSP1 and thus the automatic protective action would still have ensured that the SL would not be exceeded with the "as found" setting of the protection channel. Therefore, the channel BWR/4 STS B 3.3.2.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Control Rod Block Instrumentation B 3.3.2.1 setpoints remain conservative with respect to the as-found tolerance band between successive CHANNEL CALIBRATIONS.
After each calibration the trip setpoint shall be left within the as-left band around the [LTSP1.[LTSPs] are those predetermined values of output at which an action should take place. The setpoints are compared to the actual process BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued) parameter (e.g., reactor vessel water level), and when the measured output value of the process parameter exceeds the setpoint, the associated deviceGhaiiel (e.g., trip unit) changes state. The analytical limits are derived from the limiting values of the process parameters obtained from the safety analysis.
The Allowable Values are derived from the analytical limits, corrected for calibration, process, and some of the instrument errors. The [LTSPs1 are then determined accounting for the remaining instrument errors (e.g., drift). The [LTSPs1 derived in this manner provide adequate protection because instrumentation uncertainties, process effects, calibration tolerances, instrument drift, and severe environment errors (for channels that must function in harsh environments as defined by 10 CFR 50.49) are accounted for.The specific Applicable Safety Analyses, LCO, and Applicability discussions are listed below on a Function by Function basis.1. Rod Block Monitor The RBM is designed to prevent violation of the MCPR SL and the cladding 1% plastic strain fuel design limit that may result from a single control rod withdrawal error (RWE) event. The analytical methods and assumptions used in evaluating the RWE event are summarized in Reference 3-4. A statistical analysis of RWE events was performed to determine the RBM response for both channels for each event. From these responses, the fuel thermal performance as a function of RBM Allowable Value was determined.
The Allowable Values are chosen as a function of power level. Based on the specified Allowable Values, operating limits are established.
The RBM Function satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).
Two channels of the RBM are required to be OPERABLE, with their setpoints within the appropriate Allowable Value for the associated power range, to ensure that no single instrument failure can preclude a rod block from this Function.
The actual setpoints are calibrated consistent with applicable setpoint methodology.
BWR/4 STS B 3.3.2.1-5 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)EOC-RPT Instrumentation B 3.3.4.1 B 3.3 INSTRUMENTATION B 33.4.1 End of Cycle Recirculation Pump Trip (EOC-RPT)
Instrumentation BASES BACKGROUND The EOC-RPT instrumentation initiates a recirculation pump trip (RPT) to reduce the peak reactor pressure and power resulting from turbine trip or generator load rejection transients to provide additional margin to core thermal MCPR Safety Limits (SLs).The need for the additional negative reactivity in excess of that normally inserted on a scram reflects end of cycle reactivity considerations.
Flux shapes at the end of cycle are such that the control rods may not be able to ensure that thermal limits are maintained by inserting sufficient negative reactivity during the first few feet of rod travel upon a scram caused by Turbine Control Valve (TCV) Fast Closure, Trip Oil Pressure -Low or Turbine Stop Valve (TSV) -,Closure.
The physical phenomenon involved is that the void reactivity feedback due to a pressurization transient can add positive reactivity at a faster rate than the control rods can add negative reactivity.
The protection functions of the EOC-RPT have been designed to ensure safe operation of the reactor during load rejection transients.
This is achieved by specifying limiting safety system settings (LSSS) in terms of Parameters directly monitored by the EOC-RPT, as well as LCOs on other system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 40-GF-R 50.36(0(1 400)(A) r.gu*iro that Toc-hnical Spocifications include LSSSs for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the Safety Limit (SL) is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP) controlled by 10.CFR.50.59.
--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-BWR/4 STS B 3.3.4.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)EOC-RPT Instrumentation B 3.3.4.1 specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP1" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP]. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
The [LTSP1 and NTSP are located in the SCP.The [Limiting Trip Setpoint (LTSP)1 specified in the SCP is a predetermined setting for a protection channel chosen to ensure automatic actuation prior to the process variable reaching the Analytical Limit and thus ensuring that the SL would not be exceeded.
As such, the[LTSP1 accounts for uncertainties in setting the channel (e.g., calibration), uncertainties in how the channel might actually perform (e.g., repeatability), changes in the point of action of the channel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the [LTSP1 ensures that SLs are not exceeded.
Therefore, the [LTSP1 meets the definition of an LSSS (Ref. 1).The Allowable Value specified in the SCP serves as the LSSS such that a channel is OPERABLE if the trip setpoint is found not to exceed the Allowable Value. As such, the Allowable Value differs from the trip setpoint by an amount primarily equal to the expected instrument loop uncertainties, such as drift, during the surveillance interval.
In this manner, the actual setting of the device will still meet the LSSS definition and ensure that a SL is not exceeded at any given point Of time as long as the device has not drifted beyond that expected during the surveillance interval.Technical Specifications contain values related to the OPERABILITY of equipment required for safe operation of the facility.
Operable is defined in Technical Specifications as "...being capable of performing its safety function(s)." Relying solely on the [LTSP1 to define OPERABILITY in Technical Specifications would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as found" value of a protection channel setting during a Surveillance.
This would result in Technical Specification compliance problems, as well as reports and corrective actions required by the rule which are not necessary to ensure safety. For example, an automatic protection channel with a setting that has been found to be different from the [LTSPI due to some drift of the setting may still be OPERABLE because drift is to be expected.
This expected drift would have been specifically accounted for in the setpoint BWR/4 STS B 3.3.4.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)ECCS Instrumentation B 3.3.5.1 B 3,3 INSTRUMENTATION B 3,3.5.1 Emergency Core Cooling System (ECCS) Instrumentation BASES BACKGROUND The purpose of the ECCS instrumentation is to initiate appropriate responses from the systems to ensure that the fuel is adequately cooled in the event of a design basis accident or transient.
This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the ECCS, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 40-GF-R 50.36()(1
)(ii)(A) re..u.ire.
that Tec.hnic.l Specffificatioens include LSSSs for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a Safety Limit (SL) is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP) controlled by 1 0.CFR.50.59.
--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP]" is the suggested terminoloqy for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
The [LTSP1 and NTSP are located in the SCP.BWR/4 STS B 3.3.5.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)ECCS Instrumentation B 3.3.5.1 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)
Operation with a trip setpoint less consoR.'AtiVo thAn tho noial tRriFpbut its Allowable Value, ,ptable. A l i inopr.bl if i-ts actual trip cotpoiRt i6 not ,i:thin it roquirod Allow.bhlo Valu-e. Trip stpointc [LTSPs1 are those predetermined values of output at which an action should take place. The setpoints are compared to the actual process parameter (e.g., reactor vessel water level), and when the measured output value of the process parameter exceeds the setpoint, the associated devicedoVicechannol (e.g., trip unit) changes state. The an analtical limits are derived from the limiting values of the process parameters obtained from the safety analysis.
The Allowable Values are derived from the aia4.analytical limits, corrected for calibration, process, and some of the instrument errors. The t&#xa2; are then determined, accounting for the remaining instrument errors (e.g., drift). The t4 setpei~4[LTSPs]
derived in this manner provide adequate protection because instrumentation uncertainties, process effects, calibration tolerances, instrument drift, and severe environment errors (for channels that must function in harsh environments as defined by 10 CFR 50.49) are accounted for.In general, the individual Functions are required to be OPERABLE in the MODES or other specified conditions that may require ECCS (or DG)initiation to mitigate the consequences of a design basis transient or accident.
To ensure reliable ECCS and DG function, a combination of Functions is required to provide primary and secondary initiation signals.The specific Applicable Safety Analyses, LCO, and Applicability discussions are listed below on a Function by Function basis.Core Spray and Low Pressure Coolant Injection Systems 1 .a, 2.a. Reactor Vessel Water Level -Low Low Low, Level 1 Low reactor pressure vessel (RPV) water level indicates that the capability to cool the fuel may be threatened.
Should RPV water level decrease too far, fuel damage could result. The low pressure ECCS and associated DGs are initiated at Level 1 to ensure that core spray and flooding functions are available to prevent or minimize fuel damage. The Reactor Vessel Water Level -Low Low Low, Level 1 is one of the Functions assumed to be OPERABLE and capable of initiating the ECCS during the transients analyzed in References 42 and 3-4. In addition, the Reactor Vessel Water Level -Low Low Low, Level 1 Function is directly assumed in the analysis of the recirculation line break (Ref. 23). The core cooling function of the ECCS, along with the scram action of the Reactor Protection System (RPS), ensures that the fuel peak cladding temperature remains below the limits of 10 CFR 50.46.BWR/4 STS B 3.3.5.1-11 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RCIC System Instrumentation B 3.3.5.2 B 3.3 INSTRUMENTATION B 3.3.5.2 Reactor Core Isolation Cooling (RCIC) System Instrumentation BASES BACKGROUND The purpose of the RCIC System instrumentation is to initiate actions to ensure adequate core cooling when the reactor vessel is isolated from its primary heat sink (the main condenser) and normal coolant makeup flow from the Reactor Feedwater System is unavailable, such that initiation of the low pressure Emergency Core Cooling Systems (ECCS) pumps does not occur. A more complete discussion of RCIC System operation is provided in the Bases of LCO 3.5.3, "RCIC System." This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RCIC, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 4-4-GF-R 50.36(00 (00)(A) ro.uf.ir.s that T"echnical Spocifications include LSSSs for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the settingq must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a Safety Limit (SL) is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the settinq at which the automatic protective action would actually occur.The LSSS values are identified and maintained in the Setpoint Control Program (SPC) controlled by 10.CFR.50.59.-REVIEWER'S NOTE ----------------------
The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip settinq (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSPI indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP]" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP] implemented in the Surveillance procedures to confirm channel performance.
BWR/4 STS B 3.3.5.2-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RCIC System Instrumentation B 3.3.5.2[LTSPs1 are those predetermined values of output at which an action should take place. The setpoints are compared to the actual process parameter (e.g., reactor vessel water level), and when the measured output value of the process parameter exceeds the setpoint-4ess consR68atfive than the- nomin~al trip sotpoint, but within isAlloWablo VaIlup, is acceptable.
Each Allowable Value rs8pcfied acGcoUntS  associated deviceGhapE4 (e.g., trip unit) chan-ges state. The analytical limits are derived from the limiting values of the process parameters obtained from the safety analysis.
The Allowable Values are derived from the analytical limits, corrected for calibration, process, and some of the instrument errors. The [LTSPs1 are then determined, accounting for the remaining instrument errors (e.g., drift). The trip setpoints derived in this manner provide adequate protection because instrumentation uncertainties to the Functi. T"hee Unce.taintie, are described in the setpint mnethodology, process effects, calibration tolerances, instrument drift, and severe environment errors (for channels that must function in harsh environments as defined by 10 CFR 50.49)are accounted for.The individual Functions are required to be OPERABLE in MODE 1, and in MODES 2 and 3 with reactor steam dome pressure > 150 psig since this is when RCIC is required to be OPERABLE. (Refer to LCO 3.5.3 for Applicability Bases for the RCIC System.)The specific Applicable Safety Analyses, LCO, and Applicability discussions are listed below on a Function by Function basis.BWR/4 STS B 3.3.5.2-6 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Primary Containment Isolation Instrumentation B 3.3.6.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.6.1.2 and SR 3.3.6.1.5 A CHANNEL FUNCTIONAL TEST is performed on each required channel to ensure that the entire channel will perform the intended function.
A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable CHANNEL FUNCTIONAL TEST of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
+Re &#xfd;!i"P haS GGRtFG16 WRIGR FeauiFe YeFIRGMOR
!Ra* tnp !A14r, me4#II i Pi i P I llw Gh ane ,nIR *Gu~nn tast.*ko Fealnh~rean pyyeRY theas lenfit au-nsnthnr
-1nu~Any setpoint adjustment shall be consistent with the assumptions of the current plant specific setpoint methodology.
The 92 day Frequency of SR 3.3.6.1.2 is based on the reliability analysis described in References 6 and 7. The 184 day Frequency of SR 3.3.6.1.5 is based on engineering judgment and the reliability of the components (time delay relays exhibit minimal drift).SR 3.3.6.1.3 Calibration of trip units provides a check of the actual trip setpoints.
The channel must be doclarcd inoperable if the trip Getting is discovorod to be les~s cnevtv than the Allowable Value specified in Tabloe..611 If the trip setting is discovored to be le6s consRveativo than accountod for the appropriate setpoiRt methodology, but is not beyond the Allowable Value, tho channel porform-anco is till withfin tho reAquirements ofth plant safety analysis.
Under these conditions, the setpeint mustb readjusted to be equal to Or more conservative than that accounted for ii The SCP has controls which require verification that the instrument channel functions as required by verifying the as-left and as-found setting are consistent with those established by the setpoint methodology.
The Frequency of 92 days is based on the reliability analysis of References 5 and 6.SR 3.3.6.1.4 and SR 3.3.6.1.6 In II l I BWR/4 STS B 3.3.6.1-29 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Control Rod Block Instrumentation 3.3.2.1 SURVEILLANCE REQUIREMENTS
-----------------------------
NOTES------------------------------
: 1. Refer to Table 3.3.2.1-1 to determine which SRs apply for each, Control Rod Block Function.2. When an RWL channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed for up to 6 hours provided the associated Function maintains control rod block capability.
SURVEILLANCE FREQUENCY SR 3.3.2.1.1
--------------------
NOTE ---------------
Not required to be performed until 1 hour after THERMAL POWER is > [70]% RTP.Perform CHANNEL FUNCTIONAL TEST. [92] days SR 3.3.2.1.2
-------------------
NOTE ---------------
Not required to be performed until 1 hour after THERMAL POWER is > 35% RTP and 70% RTP.Perform CHANNEL FUNCTIONAL TEST. [92] days SR 3.3.2.1.3
-------------------
NOTE ---------------
Not required to be performed until 1 hour after any control rod is withdrawn at  [101% RTP in MODE 2.Perform CHANNEL FUNCTIONAL TEST. [92] days SR 3.3.2.1.4
--------------------
NOTE ---------------
Not required to be performed until 1 hour after THERMAL POWER is  [10]% RTP in MODE 1.Perform CHANNEL FUNCTIONAL TEST. [92] days SR 3.3.2.1.5 Calibrate the trip unit in accordance with the 92 days Setpoint Control Program.BWR/6 STS 3.3.2.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)ECCS Instrumentation 3.3.5.1 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME H. Required Action and H.1 Declare associated Immediately associated Completion supported feature(s)
Time of Condition B, C, inoperable.
D, E, F, or G not met.SURVEILLANCE REQUIREMENTS
-----------------------------
NOTES ------------------------------
: 1. Refer to Table 3.3.5.1-1 to determine which SRs apply for each ECCS Function.2. When a channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed as follows: (a) for up to 6 hours for Functions 3.c, 3.f, 3.g, and 3.h; and (b) for up to 6 hours for Functions other than 3.c, 3.f, 3.g, and 3.h, provided the associated Function or the redundant Function maintains ECCS initiation capability.
SURVEILLANCE FREQUENCY SR 3.3.5.1.1 Perform CHANNEL CHECK. 12 hours SR 3.3.5.1.2 Perform CHANNEL FUNCTIONAL TEST. [92] days SR 3.3.5.1.3
[ Calibrate the trip unit in accordance with the [92] days]Setpoint Control Program.SR 3.3.5.1.4
[ Perform CHANNEL CALIBRATION in accordance 92 days]with the Setpoint Control Program.SR 3.3.5.1.5 Perform CHANNEL CALIBRATION in accordance
[18] months with the Setpoint Control Program.SR 3.3.5.1.6 Perform LOGIC SYSTEM FUNCTIONAL TEST. [18] months SR 3.3.5.1.7 Verify the ECCS RESPONSE TIME is within limits. [18] months on a STAGGERED BWR/6 STS 3.3.5.1-5 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 B 3.3 INSTRUMENTATION B 3.3.1.1 Reactor Protection System (RPS) Instrumentation BASES BACKGROUND The RPS initiates a reactor scram when one or more monitored parameters exceed their specified limit, to preserve the integrity of the fuel cladding and the Reactor Coolant System (RCS), and minimize the energy that must be absorbed following a loss of coolant accident (LOCA). This can be accomplished either automatically or manually.The protection and monitoring functions of the RPS have been designed to ensure safe operation of the reactor. This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RPS, as well as LCOs on other reactor system parameters, and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to contain LSSS defined by the regulation as"...settings for automatic protective devices.. .so chosen that automatic protective action will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytic Limit is the limit of the pro.ess variable at which a safoty Technical Specifications are required by 10 CFR 50.36 to 4-O-,FR 50.36()W(*1i;A) r.uir.s that Tcchnical include LSSS for variables that have significant safety functions.
.LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a protective action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.
Any automatic protection action that occurs on reaching the AnaaytieAnalytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protective devieeschannels must be chosen to be more conservative than the A Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP) controlled by 10.CFR.50.59.
--------------------
REVIEWER'S NOTE -------------------
The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP] indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting.BWR/6 STS B 3.3.1.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1"Nominal Trip Setpoint fNTSP]" is the suaqested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
The [LTSP1 and NTSP are located in the SCP.The [LTSP1 specified in the SCP, is a predetermined setting for a teGtie protection channel chosen to ensure automatic actuation prior to the process variable reaching the Anc4teAnalytical Limit and thus ensuring that the SL would not be exceeded.
As such, the tip -etpoint[LTSP1 accounts for uncertainties in setting the deeViechannel (e.g., calibration), uncertainties in how the deviechannel might actually perform (e.g., repeatability), changes in the point of action of the eAWA~echannel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the trip setpeint play, an impotant roFe in ensuring[LTSP]
ensures that SLs are not exceeded.
As such, the tgtp-set-pei-LTSP1 meets the definition of an LSSS (Ref. 1)-aAdt could be u.ed to meo. the requirement that the,, be ontained, in th Technical Specifications.).
BASES BACKGROUND (continued)
Technical Specifications contain values related to the OPERABILITY of equipment required for safe operation of the facility.
OPERABLE is defined in Technical Specifications as "...being capable of performing its safety function(s)." For d"viesRelying solely on the required safety fu.tion is to ensure that a SL i not exceeded on therefore the LSSS as defined by 10 CFR 50.36 is the same as th OPERABIL ITY i~mit fo these4 devices;.
However, use of the trip seepetRt[LTSP]
to define OPERABILITY in Technical Specifications-a*d its corr.espo.nding designatio as the ILSSS required by 10 CFR 50.23-6 would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as found" value of a preteGtPve devieeprotection channel setting during a Surveillance.
This would result in Technical Specification compliance problems, as well as reports and corrective actions required by the rule which are not necessary to ensure safety. For example, an automatic
.protection channel with a setting that has been found to be different from the t4p 6etpeiR4[LTSP]
due to some drift of the setting may still be OPERABLE swAeebecause drift is to be expected.
This expected drift would have been specifically accounted for in the setpoint methodology for calculating the tF[pseVpifLTSPl and thus the automatic protective action would still have ensured that the SL would not be exceeded with the "as found" setting of teptci.. .protection channel. Therefore, the BWR/6 STS B 3.3.1.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 devin4,echannel would still be OPERABLE ewAebecause it would have performed its safety function and the only corrective action required would be to reset the device to the trip setpoit channel within the established as-left tolerance around the [LTSP] to account for further drift during the next surveillance interval.UIe Of the Stp9Rt tG "as 1I1 ITY its designation -AG thes L-S6SS unRder the eXpocGted circu1MstaRcos desc-ribod-above would result in required by both the rule T-eGhic-l Specifications that -Are cleR-arly not warran;t-d-.
HowoMVor, thore is also somoe point beyond which the device would have not been able to porfoFrm t,, due, for example, to greate than expected drift. This value needs to be specified in the Technical Specifications in orFder to define OPERABILITY o-f the devices and is designated ars the Allowable Value Which, as, stated above, is the Game as the 1SSS.The Valuable Specified in TAbAl2 331 -1 ceR's. as the I S such that A. s OQPERAB--IE if the trip setpiRnt is funRd  exceed the Allowable Value. As such, the Allowable Value differf from the trip setpiR;t by an amout pri; maFily equal to the expected instru mneht loop uncertainties, such as drift, duFrig the suvilneitra.In this BWR/6 STS B 3.3.1.1-3 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 BASES BACKGROUND (continued) manner, the actal soting of tho device illm t the LSSS dof nitionn and onSuroe that a SL= is not cXceeded at anY givon point of time as, long as the doVico- has not dftdboyond that oxpected during the 6surVeillanco inter.R'al.
If th- ActuWAl1 setting of the device is found to hAVAo oxcoeA-dod the4 Alliowable Value the aeVic would be conSiderea Inoporaleo TFrom a Technical Specification perspective.
This requireS corrective action Incl ..udig those actins required by 10 CFR 50.36 when automatic protective devices do, not func.tion -as required.
Note that, although the channel is !"OPERABLE" under these circumstances, the trip setpoint be left adjusted to a value within the established-trip .etp9lRt Gin bFatoenas-left tolerance-bad-_
in accordance with uncertainty assumptions stated in the referenced setpoint methodology (as-left criteria), and confirmed to be operating within the statistical allowances of the uncertainty terms assigned-(as-found criteria).
However, there is also some point beyond which the channel may not be able to perform its function due to, for example, greater than expected drift. This value needs to be specified in the Technical Specifications in order to define OPERABILITY of the channels and is designated as the Allowable Value.If the actual setting (as-found setpoint) of the channel is found to be conservative with respect to the Allowable Value but is beyond the as-found tolerance band, the channel is OPERABLE, but degraded.
The degraded condition will be further evaluated during performance of the SR. This evaluation will consist of resetting the channel setpoint to the[LTSP1 (within the allowed tolerance), and evaluating the channel response.
If the channel is functioning as required and expected to pass the next surveillance, then the channel is OPERABLE and can be restored to service at the completion of the surveillance.
After the surveillance is completed, the channel as-found condition will be entered into the Corrective Action Program for further evaluation.
The RPS, as shown in the FSAR, Figure [] (Ref. 2), includes sensors, relays, bypass circuits, and switches that are necessary to cause initiation of a reactor scram. Functional diversity is provided by monitoring a wide range of dependent and independent parameters.
The input parameters to the scram logic are from instrumentation that monitors reactor vessel water level, reactor vessel pressure, neutron flux main steam line isolation valve position, turbine control valve (TCV) fast closure trip oil pressure low, turbine stop valve (TSV)'trip oil pressure low, drywell pressure and scram discharge volume (SDV) water level, as well as reactor mode switch in shutdown position and manual scram signals.There are at least four redundant sensor input signals from each of these parameters (with the exception of the reactor mode switch in shutdown BWR/6 STS B 3.3.1.1-4 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 scram signal). Most channels include electronic equipment (e.g., trip units) that compares measured input signals with pre-established setpoints.
When athe setpoint is exceeded, the channel output relay actuates, which then outputs an RPS trip signal to the trip logic.Table B 3.3.1.1-1 summarizes the diversity of sensors capable of initiating scrams during anticipated operating transients typically analyzed.The RPS is comprised of two independent trip systems (A and B), with two logic channels in each trip system (logic channels Al and A2, B1 and B2), as shown in Reference
: 2. The outputs of the logic channels in a trip system are combined in a one-out-of-two logic so either channel can trip the associated trip system. The tripping of both trip systems will produce a reactor scram. This logic arrangement is referred to as one-out-of-two taken twice logic. Each trip system can be reset by use of a reset switch. If a full scram occurs (both trip systems trip), a relay prevents reset of the trip systems for 10 seconds after the full scram signal is received.
This 10 second delay on reset ensures that the scram function will be completed.
BWR/6 STS B 3.3.1.1-5 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 BASES BACKGROUND (continued)
Two scram pilot valves are located in the hydraulic control unit (HCU) for each control rod drive (CRD). Each scram pilot valve is solenoid operated, with the solenoids normally energized.
The scram pilot valves control the air supply to the scram inlet and outlet valves for the associated CRD. When either scram pilot valve solenoid is energized, air pressure holds the scram valves closed and, therefore, both scram pilot valve solenoids must be de-energized to cause a control rod to scram.The scram valves control the supply and discharge paths for the CRD water during a scram. One of the scram pilot valve solenoids for each CRD is controlled by trip system A, and the other solenoid is controlled by trip system B. Any trip of trip system A in conjunction with any trip in trip system B results in de-energizing both solenoids, air bleeding off, scram valves opening, and control rod scram.The backup scram valves, which energize on a scram signal to depressurize the scram air header, are also controlled by the RPS.Additionally, the RPS System controls the SDV vent and drain valves such that when both trip systems trip, the SDV vent and drain valves close to isolate the SDV.APPLICABLE The actions of the RPS are assumed in the safety analyses of SAFETY References 3, 4, and 5. The RPS initiates a reactor scram when ANALYSES, LCO, monitored parameter values are exceeded oxceed the Allowable Valus and APPLICABILITY the .otpint methodology and li.ted in Table 3.3.1" 1 1 4 Ito preserve the integrity of the fuel cladding, the reactor coolant pressure boundary (RCPB), and the containment by minimizing the energy that must be absorbed following a LOCA.RPS instrumentation satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).
Functions not specifically credited in the accident analysis are retained for the overall redundancy and diversity of the RPS as required by the NRC approved licensing basis.Permissive and interlock setpoints allow the blockinq of trips during plant startups, and restoration of trips when the permissive conditions are not satisfied, but they are not explicitly modeled in the Safety Analyses.These permissives and interlocks ensure that the starting conditions are consistent with the safety analysis, before preventive-or mitigating actions occur. Because these permissives or interlocks are only one of multiple conservative starting assumptions for the accident analysis, they are generally considered as nominal values without regard to measurement accuracy.The OPERABILITY of the RPS is dependent on the OPERABILITY of the individual instrumentation channel Functions specified in Table 3.3.1.1-1.
BWRI6 STS B 3.3.1.1-6 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 Each Function must have a required number of OPERABLE channels per RPS trip system, with their setpoints set within the specified Allowable Valuesettinq tolerance of the [LTSPs1, where appropriate.
The actual setpoint is calibrated consistent with app"icabl" s-tp-eint methodology a..s..p.ien,-he SCP. Each channel must also respond within its assumed response time.Allowable Values for RPS Instrumentation Functions are specified fe6 each RPS specified in the Table. Noml,-inal trip s-tp.oitSCP.
[Limiting Trip Setpointsl and the methodologies for calculation of the as-left and as-found tolerances are epeelfieddescribed in the setpefit GaIGcu1atieRSCP controlled under 10 CFR 50.59. The nWia{[etpeiFAsrLTSPs]
are selected to ensure that the actual setpoints deAnet exceed the Allowable Va uoremain conservative with respect to the as-found tolerance band between successive CHANNEL CALIBRATIONS.
GpeFatiei-with-a-After each calibration the trip setpoint less cOnser-ativ-than tho norminal trip sotpoint, butshall be left within its Allow';able Value, is acceptable.
A channel is inoperable if its actual trip setpoint is not i;thin its required Allowablo Va'lP o.the as-left band around the [LTSP1.T4--setPe#itsjLTSPs1 are those predetermined values of output at which an action should take place. The setpoints are compared to the actual process parameter (e.g., reactor vessel water level), and when the measured output value of the process parameter exceeds the setpoint, the associated device (e.g., trip unit) changes state. The a.alytie limit-sAnalvtical Limits are derived from the limiting values of the process parameters obtained from the safety analysis.
The Allowable Values are derived from the aRaly&#xfd;40analytical limits, corrected for calibration, process, and some of the instrument errors. The tFip-setpe*Rts[LTSPs]
are then determined, accounting for the remaining instrument errors (e.g., drift). The tF~p setpets[LTSPs]
derived in this manner provide adequate protection because instrumentation uncertainties, process effects, calibration tolerances, instrument drift, and severe environment errors (for channels that must function in harsh environments as defined by 10 CFR 50.49) are accounted for.The OPERABILITY of scram pilot valves and associated solenoids, backup scram valves, and SDV valves, described in the Background section, are not addressed by this LCO.The individual Functions are required to be OPERABLE in the MODES specified in the Table that may require an RPS trip to mitigate the consequences of a design basis accident or transient.
To ensure a reliable scram function, a combination of Functions is required in each MODE to provide primary and diverse initiation signals.RPS is required to be OPERABLE in MODE 5 with any control rod withdrawn from a core cell containing one or more fuel assemblies.
Control rods withdrawn from a core cell containing no fuel assemblies do not affect the reactivity of the core and therefore are not required to have BWR/6 STS B 3.3.1.1-7 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)
The Average Power Range Monitor Fixed Neutron Flux -High Function is required to be OPERABLE in MODE 1 where the potential consequences of the analyzed transients could result in the SLs (e.g., MCPR and RCS pressure) being exceeded.
Although the Average Power Range Monitor Fixed Neutron Flux -High Function is assumed in the CRDA analysis that is applicable in MODE 2, the Average Power Range Monitor Neutron Flux-High, Setdown Function conservatively bounds the assumed trip and, together with the assumed IRM trips, provides adequate protection.
Therefore, the Average Power Range Monitor Fixed Neutron Flux -High Function is not required in MODE 2.2.d. Average Power Range Monitor -Inop This signal provides assurance that a minimum number of APRMs are OPERABLE.
Anytime an APRM mode switch is moved to any position other than Operate, an APRM module is unplugged, the electronic operating voltage is low, or the APRM has too few LPRM inputs (< 11), an inoperative trip signal will be received by the RPS, unless the APRM is bypassed.
Since only one APRM in each trip system may be bypassed, only one APRM in each trip system may be inoperable without resulting in an RPS trip signal. This Function was not specifically credited in the accident analysis, but it is retained for the overall redundancy and diversity of the RPS as required by the NRC approved licensing basis.Four channels of Average Power Range Monitor -Inop with two channels in each trip system are required to be OPERABLE to ensure that no single failure will preclude a scram from this Function on a valid signal.There is no Allowable Value for this Function.This Function is required to be OPERABLE in the MODES where the APRM Functions are required.3. Reactor Vessel Steam Dome Pressure -High An increase in the RPV pressure during reactor operation compresses the steam voids and results in a positive reactivity insertion.
This causes the neutron flux and THERMAL POWER transferred to the reactor coolant to increase, which could challenge the integrity of the fuel cladding and the RCPB. No specific safety analysis takes direct credit for this Function.
However, the Reactor Vessel Steam Dome Pressure -High Function initiates a scram for transients that results in a pressure increase, counteracting the pressure increase by rapidly reducing core BWR/6 STS B 3.3.1.1-14 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)
ASME Code limits. That is, the direct scram on position switches for MSIV closure events is not assumed in the overpressurization analysis.Additionally, MSIV closure is assumed in the transients analyzed in Reference 5 (e.g., low steam line pressure, manual closure of MSIVs, high steam line flow). The reactor scram reduces the amount of energy required to be absorbed and, along with the actions of the ECCS, ensures that the fuel peak cladding temperature remains below the limits of 10 CFR 50.46.MSIV closure signals are initiated from position switches located on each of the eight MSIVs. Each MSIV has two position switches; one inputs to RPS trip system A while the other inputs to RPS trip system B. Thus, each RPS trip system receives an input from eight Main Steam Isolation Valve -Closure channels, each consisting of one position switch. The logic for the Main Steam Isolation Valve -Closure Function is arranged such that either the inboard or outboard valve on three or more of the main steam lines (MSLs) must close in order for a scram to occur.The Main Steam Isolation Valve -Closure Allowable Value is specified to ensure that a scram occurs prior to a significant reduction in steam flow, thereby reducing the severity of the subsequent pressure transient.
Sixteen channels of the Main Steam Isolation Valve -Closure Function with eight channels in each trip system are required to be OPERABLE to ensure that no single instrument failure will preclude the scram from this Function on a valid signal. This Function is only required in MODE 1 since, with the MSIVs open and the heat generation rate high, a pressurization transient can occur if the MSIVs close. In MODE 2, the heat generation rate is low enough so that the other diverse RPS functions provide sufficient protection.
: 7. Drywell Pressure -High High pressure in the drywell could indicate a break in the RCPB. A reactor scram is initiated to minimize the possibility of fuel damage and to reduce the amount of energy being added to the coolant and the drywell.The Drywell Pressure -High Function is a secondary scram signal to Reactor Vessel Water Level -Low, Level 3 for LOCA events inside the drywell. Thio, FnctGion WaS not -p.cifically credited in the. accident value is retained for the overall redundancy and diversity of the RPS as required by the NRC approved licensing basis.BWR/6 STS B 3.3.1.1-17 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE REQUIREMENTS (continued)
As noted at the beginning of the SRs, the SRs for each RPS%nstr'Umentatmninstrument Function are located in the SRs column of Table 3.3.1.1-1.
The Surveillances are modified by a Note to indicate that, when a channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed for up to 6 hours, provided the associated Function maintains trip capability.
Upon completion of the Surveillance, or expiration of the 6 hour allowance, the channel must be returned to OPERABLE status or the applicable Condition entered and Required Actions taken. This Note is based on the RPS reliability analysis (Ref. 10) assumption of the average time required to perform channel surveillance.
That analysis demonstrated that the 6 hour testing allowance does not significantly reduce the probability that the RPS will trip when necessary.
SR 3.3.1.1.1 Performance of the CHANNEL CHECK once every 12 hours ensures that a gross failure of instrumentation has not occurred.
A CHANNEL CHECK is normally a comparison of the parameter indicated on one channel to a similar parameter on other channels.
It is based on the assumption that instrument channels monitoring the same parameter should read approximately the same value. Significant deviations between the instrument channels could be an indication of excessive instrument drift on one of the channels or something even more serious. A CHANNEL CHECK will detect gross channel failure; thus, it is key to verifying the instrumentation continues to operate properly between each CHANNEL CALIBRATION.
Agreement criteria are determined by the plant staff based on a combination of the channel instrument uncertainties, including indication and readability.
If a channel is outside the criteria, it may be an indication that the instrument has drifted outside its limit.The agreement criteria includes an expectation of one decade of overlap when transitioning between neutron flux instrumentation.
The overlap between SRMs and IRMs must be demonstrated prior to withdrawing SRMs from the fully inserted position since indication is being transitioned from the SRMs to the IRMs. This will ensure that reactor power will not be increased into a neutron flux region without adequate indication.
The overlap between IRMs and APRMs is of concern when reducing power into the IRM range (entry into MODE 2 from MODE 1). On power BWR/6 STS B 3.3.1.1-26 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.1.7 and SR 3.3.1.1.10 A CHANNEL FUNCTIONAL TEST is performed on each required channel to ensure that the entire channel will perform the intended function.
A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable CHANNEL FUNCTIONAL TEST of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
Any setpoint adjustment shall be consistent with the assumptions of the current plant specific setpoint methodology.
The 92 day Frequency of SR 3.3.1.1.7 is based on the reliability analysis of Reference 10.The 18 month Frequency of SR 3.3.1.1.10 is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power. Operating experience has shown that these components usually pass the Surveillance when performed at the 18 month Frequency.
SR 3.3.1.1.8 The calibration of trip units provides a check of the actual trip setpoints.
The channel must be dclred inoR-perable if the trip settiRng is to be loss consewative than the Allowable Value dpecified on Table9 3.3.1.1 1. If the trip setting is disorvored-to he loss, consorvativo than acco)unted for in the appropriate Sotpoint mnethodology, but iS not beyond the Allowable Value, the channel performance is still within the requirements of the plant safety analysisF-.
U-nder thesecodiiosth sotpoint must be readjusted to be equal to Or MoA-re conservative than acc.untcd for in the setpeint test is performed in accordance with the SCP. If the actual setting of the channel is found to be conservative with respect to the Allowable Value but is beyond the as-found tolerance band, the channel is OPERABLE but degraded.
The degraded condition of the channel will be further evaluated during performance of the SR. This evaluation will consist of resetting the channel setpoint to the [NTSP1 (within the allowed tolerance), and evaluating the channel response.
If the channel is functioning as required and is expected to pass the next surveillance, then the channel is OPERABLE and can be restored to service at the completion of the surveillance.
After the surveillance is completed, the BWR/6 STS B 3.3.1.1-30 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 channel as-found condition will be entered into the Corrective Action Program for further evaluation.
The Frequency of 92 days for SR 3.3.1.1.8 is based on the reliability analysis of Reference 10.BWR/6 STS B 3.3.1.1-31 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.1.9 and SR 3.3.1.1.11 A CHANNEL CALIBRATION is a complete check of the instrument loop and the sensor. This test verifies the channel responds to the measured parameter within the necessary range and accuracy.
CHANNEL CALIBRA\TION leaves tho channol adjusted to acco)unt for inStrument drifts between suc siecalibrations cositot ith the plant SPocific setp-int metheodelo The test is performed in accordance with the SCP.If the actual setting of the channel is found to be conservative with respect to the Allowable Value but is beyond the as-found tolerance band, the channel is OPERABLE but degraded.
The degraded condition of the channel will be further evaluated during performance of the SR. This evaluation will consist of resetting the channel setpoint to the [NTSP](within the allowed tolerance), and evaluating the channel response.
If the channel is functioning as reguired and is expected to pass the next surveillance, then the channel is OPERABLE and can be restored to service at the completion of the surveillance.
After the surveillance is completed, the channel as-found condition will be entered into the Corrective Action Program for further evaluation.
Note 1 states that neutron detectors are excluded from CHANNEL CALIBRATION because they are passive devices, with minimal drift, and because of the difficulty of simulating a meaningful signal. Changes in neutron detector sensitivity are compensated for by performing the 7 day calorimetric calibration (SR 3.3.1.1.2) and the 1000 MWD/T LPRM calibration against the TIPs (SR 3.3.1.1.6).
A second Note is provided that requires the APRM and IRM SRs to be performed within 12 hours of entering MODE 2 from MODE 1. Testing of the MODE 2 APRM and IRM Functions cannot be performed in MODE 1 without utilizing jumpers, lifted leads, or movable links. This Note allows entry into MODE 2 from MODE 1 if the associated Frequency is not met per SR 3.0.2. Twelve hours is based on operating experience and in consideration of providing a reasonable time in which to complete the SR.The Frequency of SR 3.3.1.1.9 is based upon the assumption of a 184 day calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.
The Frequency of SR 3.3.1.1.11 is based on the assumption of'an 18 month calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.SR 3.3.1.1.12 BWR/6 STS B 3.3.1.1-32 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 The Average Power Range Monitor Flow Biased Simulated Thermal Power -High Function uses an electronic filter circuit to generate a signal proportional to the core THERMAL POWER from the APRM neutron flux signal. This filter circuit is representative of the fuel heat transfer dynamics that produce the relationship between the neutron flux and the core THERMAL POWER. The filter time constant must be verified to ensure that the channel is accu.Fately reflecting the .The filter time constant must be verified consistent with the SCP to ensure that the channel is accurately reflecting the desired parameter.
The test is performed in accordance with the SCP. If the actual setting of the channel is found to be conservative with respect to the Allowable Value but is beyond the as-found tolerance band, the channel is OPERABLE but degraded.
The degraded condition of the channel will be further evaluated during performance of the SR. This evaluation will consist of resetting the channel setpoint to the [NTSP] (within the allowed tolerance), and evaluating the channel response.
If the channel is functioning as required and is expected to pass the next surveillance, then the channel is OPERABLE and can be restored to service at the completion of the surveillance.
After the surveillance is completed, the channel as-found condition will be entered into the Corrective Action Program for further evaluation.
The Frequency of 18 months is based on engineering judgment and reliability of the components.
BWRJ6 STS B 3.3.1.1-33 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.1.15 This SR ensures that the individual channel response times are less than or equal to the maximum values assumed in the accident analysis.
The RPS RESPONSE TIME acceptance criteria are included in Reference 11.RPS RESPONSE TIME may be verified by actual response time measurements in any series of sequential, overlapping, or total channel measurements.
----------------------
REVIEWER'S NOTE--- --------------
The following Bases are applicable for plants adopting NEDO-32291-A and/or Supplement 1.However, the sensors for Functions 3, 4, and 5 are allowed to be excluded from specific RPS RESPONSE TIME measurement if the conditions of Reference 12 are satisfied.
If these conditions are satisfied, sensor response time may be allocated based on either assumed design sensor response time or the manufacturer's stated design response time.When the requirements of Reference 12 are not satisfied, sensor response time must be measured.
Furthermore, measurement of the instrument loops response times for Functions 3, 4, and 5 is not required if the conditions of Reference 13 are satisfied.]
As noted, neutron detectors are excluded from RPS RESPONSE TIME testing because the principles of detector operation virtually ensure an instantaneous response time.RPS RESPONSE TIME tests are conducted on an 18 month STAGGERED TEST BASIS. Note 2 requires STAGGERED TEST BASIS Frequency to be determined based on 4 channels per trip system, in lieu of the 8 channels specified in Table 3.3.1.1-1 for the MSIV Closure Function.
This Frequency is based on the logic interrelationships of the various channels required to produce an RPS scram signal. Therefore, staggered testing results in response time verification of these deviGeschannels every 18 months. The 18 month Frequency is consistent with the typical industry refueling cycle and is based upon plant operating experience, which shows that random failures of instrumentation components causing serious time degradation, but not channel failure, are infrequent.
BWR/6 STS B 3.3.1.1-35 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Programs and Manuals 5.5 5.5 Proagrams and Manuals 5.5.15 Setpoint Control Program This program shall establish the requirements for ensuring that setpoints for automatic protective devices are initially within and remain within the assumptions of the applicable safety analyses, provides a means for processing changes to instrumentation setpoints, and identifies setpoint methodologies to ensure instrumentation will function as required.
The program shall ensure that testing of automatic protective devices related to variables having significant safety functions as delineated by 10 CFR 50.36(c)(1
)(ii)(A) verifies that instrumentation will function as required.a. The program shall list the Functions in the following specifications to which it applies: 1. LCO 3.3.1.1, "Reactor Protection System (RPS) Instrumentation;" 2. LCO 3.3.1.2, "Source Range Monitor (SRM) Instrumentation:" 3. LCO 3.3.2.1, "Control Rod Block Instrumentation:" 4. LCO 3.3.2.2, "Feedwater and Main Turbine High Water Level Trip Instrumentation;" 5. LCO 3.3.4.1, "End of Cycle Recirculation Pump Trip (EOC-RPT)Instrumentation:" 6. LCO 3.3.4.2, "Anticipated Transient Without Scram Recirculation Pump Trip (ATWS-RPT)
Instrumentation:" 7. LCO 3.3.5.1, "Emergency Core Cooling System (ECCS) Instrumentation;" 8. LCO 3.3.5.2, "Reactor Core Isolation Cooling (RCIC) System Instrumentation:" 9. LCO 3.3.6.1, "Primary Containment Isolation Instrumentation;" 10. LCO 3.3.6.2, "Secondary Containment Isolation Instrumentation;" 11. LCO 3.3.6.3, "Low-Low Set (LLS) Instrumentation;" 12. LCO 3.3.7.1, "[Main Control Room Environmental Control (MCREC)]System Instrumentation;" 13. LCO 3.3.8.1, "Loss of Power (LOP) Instrumentation;" and 14. LCO 3.3.8.2, "Reactor Protection System (RPS) Electric Power Monitoring." b. The program shall reguire the Limiting Trip Setpoint (LTSP), Nominal Trip Setpoint (NTSP). Allowable Value (AV), As-Found Tolerance (AFT), and As-Left Tolerance (ALT) (as applicable) of the Functions described in Paragraph a. are calculated using the NRC approved setpoint methodology, as listed below. In addition, the program shall contain the value of the LTSP, NTSP, AV, AFT, and ALT (as applicable) for each Function described in paragraph a. and shall identify the setpoint methodology used to calculate these values.--- --------------
Reviewer's Note List the NRC safety evaluation report by letter, date, and ADAMS accession number (if available) that approved the setpoint methodologies.
BWR/6 STS 5.5-14, Rev. 3.1, 12/01/05 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Programs and Manuals 5.5 1. [Insert reference to NRC safety evaluation that approved the setpoint methodology.1
: c. The program shall establish methods to ensure that Functions described in Paragraph
: a. will function as required by verifying the as-left and as-found settings are consistent with those established by the setpoint methodology.
: d. REVIEW ER'S NOTE -------------------------------------
A license amendment request to implement a Setpoint Control Program must list the instrument functions to which the program requirements of paragraph d. will be applied. Paraqraph
: d. shall apply to all Functions in the Reactor Protection System (RPS) Instrumentation, Control Rod Block Instrumentation, End of Cycle-Recirculation Pump Trip (EOC-RPT)
Instrumentation, Emergency Core Cooling System (ECCS) Instrumentation, Reactor Core Isolation Cooling (RCIC) Instrumentation and Relief and Low-Low Set (LLS)Instrumentation specifications unless one or more of the following exclusions apply.1. Manual actuation circuits, automatic actuation logic circuits or to instrument functions that derive input from contacts which have no associated sensor or adiustable device, e.g., limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the reguirements would apply.The program shall identify the Functions described in Paragraph
: a. that are automatic protective devices related to variables having significant safety functions as delineated by 10 CFR 50.36(c)(1)(ii)(A).
The LTSP of these Functions are Limiting Safety System Settings.
These Functions shall be demonstrated to be functioning as required by applying the following requirements during CHANNEL CALIBRATIONS, trip unit calibrations and CHANNEL FUNCTIONAL TESTS that verify the [LTSP or NTSPI.1 The as-found value of the instrument channel trip setting shall be compared with the previous as-left value or the specified
[LTSP or NTSP1.BWR/6 STS 5.5-15 Rev. 3.1, 12/01/05 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Programs and Manuals 5.5 2. If the as-found value of the instrument channel trip setting differs from the previous as-left value or the specified
[LTSP or NTSP1 by more than the pre-defined test acceptance criteria band (i.e., the specified AFT), then the instrument channel shall be evaluated before declarinq the SR met and returning the instrument channel to service. This condition shall be entered in the plant corrective action program.3. If the as-found value of the instrument channel trip setting is less conservative than the specified AV, then the SR is not met and the instrument channel shall be immediately declared inoperable.
: 4. The instrument channel setpoint shall be reset to a value that is within the as-left tolerance around the [LTSP or NTSP1 at the completion of the surveillance test; otherwise, the channel is inoperable (setpoints may be more conservative than the [LTSP or NTSP] provided that the as-found and as-left tolerances apply to the actual setpoint used to confirm channel performance).
: e. The program shall be specified in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencelCha..e.
to the .ro.ram shall be made in ac..dano .with th-mr..qurf m.i nte nf of D 1n gp D50.,5o9 ... ... R v....~s eF +, t a p nroQrnm 4- 4+Kr MI Qf SHall be i3rey ded U13GR S-S U, o H. &#xfd;- "S -"S -1 1 &#xfd;-BWR/6 STS 5.5-16 Rev. 3.1, 12/01/05 (Includes Errata)
TST F-493, Rev. 4 (Option B)NOTE: The BWR/6 3.3.1.1 Bases errata changes are shown in RED. RPS Instrumentation The TSTF-493, Rev. 4 changes B 3.3.1.1 are shown in blue.B 3.3 INSTRUMENTATION B 3.3.1.1 Reactor Protection System (RPS) Instrumentation BASES BACKGROUND The RPS initiates a reactor scram when one or more monitored parameters exceed their specified limit, to preserve the integrity of the fuel cladding and the Reactor Coolant System (RCS), and minimize the energy that must be absorbed following a loss of coolant accident (LOCA). This can be accomplished either automatically or manually.The protection and monitoring functions of the RPS have been designed to ensure safe operation of the reactor. This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RPS, as well as LCOs on other reactor system parameters, and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to contain LSSS defined by the regulation as"...settings for automatic protective devices.. .so chosen that automatic protective action will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Limit is the limit Of the process variable at hGh a safety Technical Specifications are required by 10 CFR 50.36 to!0 -GFR 50.36(Gc)P,, (A) that SpocificttionS include LSSS for variables that have siqnificant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a protective action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.
Any automatic protection action that occurs on reaching the AnIyticAnalytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protective devieeschannels must be chosen to be more conservative than the ARny!Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur.--------------------
REVIEWER'S NOTE ------------------------------------
The term "Limiting Trip Setpoint" [LTSP] is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSPI" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where BWR/6 STS B 3.3.1.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 mar-gin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the fNTSP1 implemented in the Surveillance procedures to confirm channel performance.
Licensees are to insert the name of the document(s) controlled under 10 CFR 50.59 that contain the methodology for calculating the as-left and as-found tolerances in Note b of Table 3.3.1.1-1, for the phrase "[insert the name of a document controlled under 10 CFR 50.59 such as the Technical Requirements Manual or any document incorporated into the facility FSAR]" throughout these Bases.If the [LTSP1 is not included in Table 3.3.1.1-1, the plant-specific location for the [LTSP1 or NTSP must be cited in Note b of Table 3.3.1.1-1.
The brackets indicate plant-specific terms may apply, as reviewed and approved by the NRC. The "" found and as left il ap.lh to the ',nt, ml setnnmt nlr nfl the Suyfila G ,n3pII.,nnp tennl u rge AM nnf 0.M The [LTSP1 specified in Table 3.3.1.1-1 is a predetermined setting for a proteGtive deiprotection channel chosen to ensure automatic actuation prior to the process variable reaching the AnlyAnalytical Limit and thus ensuring that the SL would not be exceeded.
As such, the tip-setpeif4
[LTSP1 accounts for uncertainties in setting the deeV4echannel (e.g., calibration), uncertainties in how the devieechannel might actually perform (e.g., repeatability), changes in the point of action of the d4e4eachannel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the trip setpoint plays an impotant role in ens-ringfLTSP]
ensures that SLs are not exceeded.
As such, the tlip ret--;f[LTSP1 meets the definition of an LSSS (Ref. 1)-and could be use'd tmetterqimntthat they be coent-ained inth Technical Specfificatins.).
BASES BACKGROUND (continued)
Technical Specifications contain values related to the OPERABILITY of equipment required for safe operation of the facility.
OPERABLE is defined in Technical Specifications as "...being capable of performing its safety function(s)." For autematic protective d8vicos,Relvincq solely on the required Safety function is to ensure that a SL= is Rot exceededan the;reforo the; SRSSa defined by 10 CFR 50.36 isthe sameM as the OPERABILITY limit fo-r these devices. However, use of the trip eetpei-4[LTSP]
to define OPERABILITY in Technical Specifications-and its corresponding deGsignation as the L=SSS required by 10 CFR 50.36 would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as found" value of a PFeteetP~e BWR/6 STS B 3.3.1.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 BASES BACKGROUND (continued)
Two scram pilot valves are located in the hydraulic control unit (HCU) for each control rod drive (CRD). Each scram pilot valve is solenoid operated, with the solenoids normally energized.
The scram pilot valves control the air supply to the scram inlet and outlet valves for the associated CRD. When either scram pilot valve solenoid is energized, air pressure holds the scram valves closed and, therefore, both scram pilot valve solenoids must be de-energized to cause a control rod to scram.The scram valves control the supply and discharge paths for the CRD water during a scram. One of the scram pilot valve solenoids for each CRD is controlled by trip system A, and the other solenoid is controlled by trip system B. Any trip of trip systemA in conjunction with any trip in trip system B results in de-energizing both solenoids, air bleeding off, scram valves opening, and control rod scram.The backup scram valves, which energize on a scram signal to depressurize the scram air header, are also controlled by the RPS.Additionally, the RPS System controls the SDV vent and drain valves such that when both trip systems trip, the SDV vent and drain valves close to isolate the SDV.APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY The actions of the RPS are assumed in the safety analyses of References_3, 4, and_5. The RPS initiates a reactor scram when monitored parameter values are exceededexceed the Allowable Valucs GP86ified byj th scetpoint m+ethodology and listed in Tablo 3.3.1.1 Ito preserve the integrity of the fuel cladding, the reactor coolant pressure boundary (RCPB), and the containment by minimizing the energy that must be absorbed following a LOCA.RPS instrumentation satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).
Functions not specifically credited in the accident analysis are retained for the overall redundancy and diversity of the RPS as required by the NRC approved licensing basis.Permissive and interlock setpoints allow the blocking of trips during plant startups, and restoration of trips when the Permissive conditions are not satisfied, but they are not explicitly modeled in the Safety Analyses.These permissives and interlocks ensure that the starting conditions are consistent with the safety analysis, before preventive or mitigating actions occur. Because these permissives or interlocks are only one of multiple conservative starting assumptions for the accident analysis, they are generally considered as nominal values without regard to measurement accuracy.BWR/6 STS B 3.3.1.1-6 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE REQUIREMENTS (continued)
---------------------
REVIEWER'S NOTE -------------------
Notes a and b are applied to the setpoint verification Surveillances for all RPS Instrumentation Functions in Table 3.3.1.1-1 unless one or more of the following exclusions apply: 1. Manual actuation circuits, automatic actuation logic circuits or te instrument functions that derive input from contacts which have no associated sensor or adjustable device, e.g.. limit switches, breaker position switches, manual actuation switches, float switches, proximity detectors, etc. are excluded.
In addition, those permissives and interlocks that derive input from a sensor or adiustable device that is tested as part of another TS function are excluded.2. Settings associated with safety relief valves are excluded.
The performance of these components is already controlled (i.e., trended with as-left and as-found limits) under the ASME Code for Operation and Maintenance of Nuclear Power Plants testing program.3. Functions and Surveillance Requirements which test only digital components are normally excluded.
There is no expected change in result between SR performances for these components.
Where separate as-left and as-found tolerance is established for digital component SRs, the requirements would apply.As noted at the beginning of the SRs, the SRs for each RPS intr-umentationinstrument Function are located in the SRs column of Table 3.3.1.1-1.
The Surveillances are modified by a Note to indicate that, when a channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed for up to 6 hours, provided the associated Function maintains trip capability.
Upon completion of the Surveillance, or expiration of the 6 hour allowance, the channel must be returned to OPERABLE status or the applicable Condition entered and Required Actions taken. This Note is based on the RPS reliability analysis (Ref. 10) assumption of the average time required to perform channel surveillance.
That analysis demonstrated that the 6 hour testing allowance does not significantly reduce the probability that the RPS will trip when necessary.
SR 3.3.1.1.1 BWR/6 STS B 3.3.1.1-26 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.1.7 and SR 3.3.1.1.10 A CHANNEL FUNCTIONAL TEST is performed on each required channel to ensure that the entire channel will perform the intended function.
A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable CHANNEL FUNCTIONAL TEST of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.
Any setpoint adjustment shall be consistent with the assumptions of the current plant specific setpoint methodology.
The 92 day Frequency of SR 3.3.1.1.7 is based on the reliability analysis of Reference 10.The 18 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power. Operating experience has shown that these components usually pass the Surveillance when performed at the 18 month Frequency.
SR 3.3.1.1.7 for the designated function is modified by two Notes as identified in Table 3.3.1.1-1.
The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
BWR/6 STS B 3.3.1.1-31 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 The second Note also requires that [LTSP1 and the methodologies for calculatina the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
The s-r-nnA NIe. .- .-,,- ,, o'h'+ rt h t D1 [.It- A fh,8I- h6,kAnum.,e fn.r fIG.-lminia+
tha no Inft th-e a fat tA fNlnrnPr'nc.
he ;n the Rnmn of a dcu'-mont controllod
'undor 10 CER 50.59 ficuch ; tho Tochnigal R ri m I r e n.- tr4 .....i ...l ..r ,,Y A ......OR G F Onr p r a t d k i -t --t h e fl -,-, ,;I h , SR 3.3.1.1.8 The calibration of trip units provides a check of the actual trip setpoints.
The channel must be declared inoperable if the trip setting is discovered to be less conservative than the Allowable Value specified in Table 3.3.1.1-1.
If the trip setting is discovered to be less conservative than accounted for in the appropriate setpoint methodology, but is 44G4 with respect to the Allowable Value, the channel performance is still within the requirements of the plant safety analysis.Under these conditions, the setpoint must be readjusted to be-equal te-eo moro conR.A3tive tha4nthe [ILTSP1 within the as-left tolerance as accounted for in the appropriate setpoint methodology.
The Frequency of 92 days for SR 3.3.1.1.8 is based on the reliability analysis of Reference 10.BWR/6 STS B 3.3.1.1-32 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev.A4 (Option B)RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.1.1.8 for the desiqnated functions is modified by two Notes as identified in Table 3.3.1.1-1.
The first Note requires evaluation of channel performance for the condition where the as-found settinq for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the [LTSP] is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
TalG Wlafinr the as left ..R theas no-.d&#xf7; rl"rnnnc1 bI eR mFtodp. the forn of a document controloed unrder 10 50.59 Guch as the Technical RD.... a .... u+. f al .., .n .......t Rtn ptrhted fh" n 'nn..i+.SR 3.3.1.1.9 and SR 3.3.1.1.11 A CHANNEL CALIBRATION is a complete check of the instrument loop and the sensor. This test verifies the channel responds to the measured parameter within the necessary range and accuracy.
CHANNEL CALIBRATION leaves the channel adjusted to the [LTSP] within the as-left tolerance to account for instrument drifts between successive calibrations consistent with the plant specific setpoint methodology.
Note 1 states that neutron detectors are excluded from CHANNEL CALIBRATION because they are passive devices, with minimal drift, and because of the difficulty of simulating a meaningful signal. Changes in neutron detector sensitivity are compensated for by performing the 7 day BWR/6 STS B 3.3.1.1-33 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 calorimetric calibration (SR 3.3.1.1.2) and the 1000 MWD/T LPRM calibration against the TIPs (SR 3.3.1.1.6).
A second Note is provided that requires the APRM and IRM SRs to be performed within 12 hours of entering MODE 2 from MODE 1. Testing of the MODE 2 APRM and IRM Functions cannot be performed in MODE 1 without utilizing jumpers, lifted leads, or movable links. This Note allows entry into MODE 2 from MODE 1 if the associated Frequency is not met per SR 3.0.2. Twelve hours is based on operating experience and in consideration of providing a reasonable time in which to complete the SR.The Frequency of SR 3.3.1.1.9 is based upon the assumption of a 184 day calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.
The Frequency of SR 3.3.1.1.11 is based on the assumption of an 18 month calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.SRs 3.3.1.1.9 and 3.3.1.1.11 for the designated functions are modified by two Notes as identified in Table 3.3.1.1-1.
The first Note requires evaluation of channel performance for the condition where the as-found settinq for the channel setpoint is outside its as-found tolerance but conservative with 'respect to the Allowable Value. Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Proqram will ensure reguired review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the [LTSP1. Where a setpoint more conservative than the[LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referencel.
Thea 6,aaa.,A Notea requore that~ i ~1 fl-TSIa~ h ne."thedeleaoe-an-.F~..'l t h-e as , 1AA il- -t a foundI fhn lArnA c. h- i_ fhn ,,,name of a dIocument contrgolld undor 10 CFR 50.5 fisuch as the Tochnical BWR/6 STS B 3.3.1.1-34 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RPS Instrumentation B 3.3.1.1 SR 3.3.1.1.12 The Average Power Range Monitor Flow Biased Simulated Thermal Power -High Function uses an electronic filter circuit to generate a signal proportional to the core THERMAL POWER from the APRM neutron flux signal. This filter circuit is representative of the fuel heat transfer dynamics that produce the relationship between the neutron flux and the core THERMAL POWER. The filter time constant must be verified to ensure that the channel is accurately reflecting the desired parameter.
The Frequency of 18 months is based on engineering judgment and reliability of the components.
SR 3.3.1.1.12 is modified by two Notes as identified in Table 3.3.1.1-1.
The first Note requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is outside its as-found tolerance but conservative with respect to the Allowable Value.Evaluation of channel performance will verify that the channel will continue to behave in accordance with safety analysis assumptions and the channel performance assumptions in the setpoint methodology.
The purpose of the assessment is to ensure confidence in the channel performance prior to returning the channel to service. For channels determined to be OPERABLE but degraded, after returning the channel to service the performance of these channels will be evaluated under the plant Corrective Action Program. Entry into the Corrective Action Program will ensure required review and documentation of the condition.
The second Note requires that the as-left setting for the channel be within the as-left tolerance of the fLTSP1. Where a setpoint more conservative than the [LTSP1 is used in the plant surveillance procedures (NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.
This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.
If the as-left channel setting cannot be returned to a setting within the as-left tolerance of the [LTSP1, then the channel shall be declared inoperable.
The second Note also requires that [LTSP1 and the methodologies for calculating the as-left and the as-found tolerances be in [insert the facility FSAR reference or the name of any document incorporated into the facility FSAR by referenceL.
The". Gi ulG u Nee alG Gi nu tnules tha I[nn i n nI the ueh eeuen e ufrU4 +k n of a docuHMon-t coentrolled ude 10 C-F=R 50.5 fiuc-,h ac the TechnicAl&#xfd; BWR/6 STS B 3.3.1.1-35 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Control Rod Block Instrumentation B 3.3.2.1 B 3.3 INSTRUMENTATION B 3.3.2.1 Control Rod Block Instrumentation BASES BACKGROUND Control rods provide the primary means for control of reactivity changes.Control rod block instrumentation includes channel sensors, logic circuitry, switches, and relays that are designed to ensure that specified fuel design limits are not exceeded for postulated transients and accidents.
During high power operation, the rod withdrawal limiter (RWL)provides protection for control rod withdrawal error events. During low power operations, control rod blocks from the rod pattern controller (RPC)enforce specific control rod sequences designed to mitigate the consequences of the control rod drop accident (CRDA). During shutdown conditions, control rod blocks from the Reactor Mode Switch -Shutdown Position ensure that all control rods remain inserted to prevent inadvertent criticalities.
The protection and monitoring functions of the control rod block instrumentation have been designed to ensure safe operation of the reactor. This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RPS, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 4-4-GF-R 50.36(n )(ii(A) rg"u.ro. that Tochnicr,,.
al Spocificatincr include LSSSs for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a Safety Limit (SL) is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP) controlled by 1 0.CFR.50.59.
--- REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin BWR/6 STS B 3.3.2.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Control Rod Block Instrumentation B 3.3.2.1 has been added between the Analytical Limit and the calculated trip settinci."Nominal Trip Setpoint [NTSP]" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
The [LTSP1 and NTSP are located in the SCP.The [Limiting Trip Setpoint (LTSP)] specified in the SCP, is a predetermined setting for a protection channel chosen to ensure automatic actuation prior to the process variable reaching the Analytical Limit and thus ensuring that the SL would not be exceeded.
As such, the[LTSP1 accounts for uncertainties in setting the channel (e.g., calibration), uncertainties in how the channel might actually perform (e.g., repeatability), changes in the point of action of the channel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
In this manner, the [LTSP1 ensures that SLs are not exceeded.
Therefore, the [LTSP1 meets the definition of an LSSS (Ref. 1).The Allowable Values specified in the SCP serves as the LSSS such that a channel is OPERABLE if the trip setpoint is found not to exceed the Allowable Value. As such, the Allowable Value differs from the trip setpoint by an amount primarily equal to the expected instrument loop uncertainties, such as drift, during the surveillance interval.
In this manner, the actual setting of the device will still meet the LSSS definition and ensure that a SL is not exceeded at any given point of time as long as the device has not drifted beyond that expected during the surveillance interval.Technical Specifications contain values related to the OPERABILITY of equipment required for safe operation of the facility.
Operable is defined in Technical Specifications as "...being capable of performing its safety function(s)." Relying solely on the [LTSP1 to define OPERABILITY in Technical Specifications would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as found" value of a protection channel setting during a Surveillance.
This would result in Technical Specification compliance problems, as well as reports and corrective actions required by the rule which are not necessary to ensure safety. For example, an automatic protection channel with a setting that has been found to be different from the [LTSP] due to some drift of the setting may still be OPERABLE because drift is to be expected.
This expected drift would have been specifically accounted for in the setpoint methodology for calculating the [LTSP1 and thus the automatic protective action would still have ensured that the SL would not be exceeded with the "as found" setting of the protection channel. Therefore, the channel BWR/6 STS B 3.3.2.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Control Rod Block Instrumentation B 3.3.2.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.2.1.5 The LPSP'is the point at which the RPCS makes the transition between the function of the RPC and the RWL. This transition point is automatically varied as a function of power. This power level is inferred from the first stage turbine pressure (one channel to each trip system).These power setpoints must be verified periodically to be within the SCP limits. The test for the Rod withdrawal limiter is performed in accordance with the SCP. If the actual setting of the channel is found to be conservative with respect to the Allowable Value but is beyond the as-found tolerance band, the channel is OPERABLE but degraded.
The degraded condition of the channel will be further evaluated during performance of the SR. This evaluation will consist of resetting the channel setpoint to the [NTSP1 (within the allowed tolerance), and evaluatinq the channel response.
If the channel is functioning as required and is expected to pass the next surveillance, then the channel is OPERABLE and can be restored to service at the completion of the surveillance.
After the surveillance is completed, the channel as-found condition will be entered into the Corrective Action Program for further evaluation.
Allowable Valuos. if any LPSP is nOncOnsR'-ative, then the affected Fu'nctions are considered ineperable.
Since this channel has both upper and lower required limits, it is not allowed to be placed in a condition to enable either the RPC or RWL Function.
Because main turbine bypass steam flow can affect the LPSP nonconservatively for the RWL, the RWL is considered inoperable with any main turbine bypass valves open. The Frequency of 92 days is based on the setpoint methodology utilized for these channels.SR 3.3.2.1.6 This SR ensures the high power function of the RWL is not bypassed when power is above the HPSP. The power level is inferred from turbine first stage pressure signals. Periodic testing of the HPSP channels is required to verify the setpoint to be less than or equal to the limit.Adequate margins in accordance with setpoint methodologies are included.
If the HPSP is nonconservative, then the RWL is considered inoperable.
Alternatively, the HPSP can be placed in the conservative condition (nonbypass).
If placed in the nonbypassed condition, the SR is met and the RWL would not be considered inoperable.
Because main turbine bypass steam flow can affect the HPSP nonconservatively for the RWL, the RWL is considered inoperable with any main turbine bypass valve open. The Frequency of 92 days is based on the setpoint methodology utilized for these channels.BWRJ6 STS B 3.3.2.1-11 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Control Rod Block Instrumentation B 3.3.2.1 SR 3.3.2.1.7 A CHANNEL CALIBRATION is a complete check of the instrument loop and the sensor. This test verifies that the channel responds to the measured parameter within the necessary range and accuracy.CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drifts between successive calibrations consistent with the ple#SPocific cotp0int mothodology.
Any setpeint adjuSAtmont shall be consistont with the assumptionS Of the current plant specific setpin-ethedelegVSCP.
The test for the Rod withdrawal limiter is performed in accordance with the SCP. If the actual settinq of the channel is found to be conservative with respect to the Allowable Value but is beyond the as-found tolerance band, the channel is OPERABLE but degraded.
The degraded condition of the channel will be further evaluated during performance of the SR. This evaluation will consist of resetting the channel setpoint to the [NTSP1 (within the allowed tolerance), and evaluating the channel response.
If the channel is functioning as required and is expected to pass the next surveillance, then the channel is OPERABLE and can be restored to service at the completion of the surveillance.
After the surveillance is completed, the channel as-found condition will be entered into the Corrective Action Program for further evaluation.
BWR/6 STS B 3.3.2.1-12 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)EOC-RPT Instrumentation B 3.3.4.1 B 3.3 INSTRUMENTATION B 3.3.4.1 End of Cycle Recirculation Pump Trip (EOC-RPT)
Instrumentation BASES BACKGROUND The EOC-RPT instrumentation initiates a recirculation pump trip (RPT) to reduce the peak reactor pressure and power resulting from turbine trip or generator load rejection transients to provide additional margin to core thermal MCPR Safety Limits (SLs).The need for the additional negative reactivity in excess of that normally inserted on a scram reflects end of cycle reactivity considerations.
Flux shapes at the end of cycle are such that the control rods may not be able to ensure that thermal limits are maintained by inserting sufficient negative reactivity during the first few feet of rod travel upon a scram caused by Turbine Control Valve (TCV) Fast Closure, Trip Oil Pressure -Low, or Turbine Stop Valve Closure, Trip Oil Pressure -Low (TSV). The physical phenomenon involved is that the void reactivity feedback due to a pressurization transient can add positive reactivity at a faster rate than the control rods can add negative reactivity.
The protection functions of the EOC-RPT have been designed to ensure safe operation of the reactor during load rejection transients.
This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the EOC-RPT, as well as LCOs on other system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 4-G-R 50.36(c)( flii ..A) roguios that Specifications include LSSSs for variables that have significant safety functions.
.LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the settinq must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a Safety Limit (SL) is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP) controlled by 1 0.CFR.50.59.
--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip settincq (setpoint) value calculated by means of the plant-BWR/6 STS B 3.3.4.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)EOC-RPT Instrumentation B 3.3.4.1 specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional mar-gin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP]" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP] implemented in the Surveillance procedures to confirm channel performance.
The [LTSP1 and NTSP are located in the SCP.The [Limiting Trip Setpoint (LTSP)] specified in the SCP is a predetermined setting for a protection channel chosen to ensure automatic actuation prior to the process variable reaching the Analytical Limit and thus ensuring that the SL would not be exceeded.
As such, the[LTSP1 accounts for uncertainties in setting the channel (e.g., calibration), uncertainties in how the channel might actually perform (e.g., repeatability), changes in the point of action of the channel over time (e.g., drift during surveillance intervals), and any other factors which may influence its actual performance (e.g., harsh accident environments).
Therefore, the [LTSP1 ensures that SLs are not exceeded.
As such, the[LTSP1 meets the definition of an LSSS (Ref. 1).The Allowable Value specified in the SCP serves as the LSSS such that a channel is OPERABLE if the trip setpoint is found not to exceed the Allowable Value. As such, the Allowable Value differs from the trip setpoint by an amount primarily equal to the expected instrument loop uncertainties, such as drift, during the surveillance interval.
In this manner, the actual setting of the device will still meet the LSSS definition and ensure that a SL is not exceeded at any given point of time as long as the device has not drifted beyond that expected during the surveillance interval.Technical Specifications contain values related to the OPERABILITY of equipment required for safe operation of the facility.
Operable is defined in Technical Specifications as "...being capable of performing its safety function(s)." Relying solely on the [LTSP1 to define OPERABILITY in Technical Specifications would be an overly restrictive requirement if it were applied as an OPERABILITY limit for the "as found" value of a protection channel setting during a Surveillance.
This would result in Technical Specification compliance problems, as well as reports and corrective actions required by the rule which are not necessary to ensure safety. For example, an automatic protection channel with a setting that has been found to be different from the [LTSP1 due to some drift of the setting may still be OPERABLE because drift is to be expected.
This expected drift would have been specifically accounted for in the setpoint methodolocqv for calculating the [LTSP1 and thus the automatic protective BWR/6 STS B 3.3.4.1-2 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)ECCS Instrumentation B 3.3.5.1 B 3.3 INSTRUMENTATION B 3.3.5.1 Emergency Core Cooling System (ECCS) Instrumentation BASES BACKGROUND The purpose of the ECCS instrumentation is to initiate appropriate responses from the systems to ensure that fuel is adequately cooled in the event of a design basis accident or transient.
This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the ECCS, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to4-Q-,F-Rc A Fro^uguiro that Technical include LSSSs for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a Safety Limit (SL) is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP) controlled by 1 0.CFR.50.59.
--------------------
REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP] indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP]" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSPI implemented in the Surveillance procedures to confirm channel performance.
The [LTSP1 and NTSP are located in the SCP.BWR/6 STS B 3.3.5.1-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)ECCS Instrumentation B 3.3.5.1 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued) measured output value of the process parameter exceeds the setpoint, the associated deviceeheiine (e.g., trip unit) changes state. The amaItieanalytical limits are derived from the limiting values of the process parameters obtained from the safety analysis.
The Allowable Values are derived from the an analtical limits, corrected for calibration, process, and some of the instrument errors. The are then determined, accounting for the remaining instrument errors (e.g., drift). The trip setpoints derived in this manner provide adequate protection because instrumentation uncertainties, process effects, calibration tolerances, instrument drift, and severe environment errors (for channels that must function in harsh environments as defined by 10 CFR 50.49) are accounted for.In general, the individual Functions are required to be OPERABLE in the MODES or other specified conditions that may require ECCS (or DG)initiation to mitigate the consequences of a design basis accident or transient.
To ensure reliable ECCS and DG function, a combination of Functions is required to provide primary and secondary initiation signals.The specific Applicable Safety Analyses, LCO, and Applicability discussions are listed below on a Function by Function basis.Low Pressure Core Spray and Low Pressure Coolant Iniection Systems 1.a, 2.a. Reactor Vessel Water Level -Low Low Low, Level 1 Low reactor pressure vessel (RPV) water level indicates that the capability to cool the fuel may be threatened.
Should RPV water level decrease too far, fuel damage could result. The low pressure ECCS and associated DGs are initiated at Level 1 to ensure that core spray and flooding functions are available to prevent or minimize fuel damage. The Reactor Vessel Water Level -Low Low Low, Level 1 is one of the Functions assumed to be OPERABLE and capable of initiating the ECCS during the transients analyzed in References 42 and 3,4. In addition, the Reactor Vessel Water Level -Low Low Low, Level 1 Function is directly assumed in the analysis of the recirculation line break (Ref. 23). The core cooling function of the ECCS, along with the scram action of the Reactor Protection System (RPS), ensures that the fuel peak cladding temperature remains below the limits of 10 CFR 50.46.Reactor Vessel Water Level -Low Low Low, Level 1 signals are initiated from four level transmitters that sense the difference between the pressure due to a constant column of water (reference leg) and the pressure due to the actual water level (variable leg) in the vessel. The Reactor Vessel Water Level -Low Low Low, Level 1 Allowable Value is BWR/6 STS B 3.3.5.1-11 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)ECCS Instrumentation B 3.3.5.1 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.3.5.1.4 and SR 3.3.5.1.5 A CHANNEL CALIBRATION is a complete check of the instrument loop and the sensor. This test verifies the channel responds to the measured parameter within the necessary range and accuracy.A ....... A A i A Ak I I I CHANNEL CALIBRA\TION leaves theo cflannl adjiusted to accoun~t tor-- __! ... .. I!I .... ... ....I. .L LA --I----.L insRtumrenl
..ri..S o.e!... .SUccessive c aIi.. .O. S .O. sisict Wn inc ig.an.the SCCD if ,r,-+,,, se onq .f the + h, nn-hA....
I los flbulpld-a .h. A+m9.A..-
+,n,,A i,,mf rap.a..f fa vh,, A ' A. m m ifor,, b"'R. I the a fain '' ,  bapd,- the Gahnip-A-sIo.m, GIPFERARI F h, t -f- -rar Ih -~rir ,,Rdtme Of fliarh pn a G.1 1 haR e be mfl-marri,-
1..,a i-lu im, 0rFMArm-iRA-A-f fl8-mn C T-iim, t,,alI IAti;A ..... P1t1.... ; f rsFtRn,,' ,-t h ... .-I setpe- Rt to tha IMTCD1 (wtifthen the allowged tolelrance),, aind -vafuatinqr the chaRnn 1 reponRse.
If the Gak.i.. l 46 fi ,n ..,,,inn as , ura e, ae- or, xpe- a a. f l a gi the R,,x.urcmpleted, the chahnne as foEd oR'toGnd wca! be ertered toed the C'aranf ii ,a A~tG ninfm)n D a~nrr far fwt rha r ev la, n i mnifa The Frequency of SR 3.3.5.1.4 is based upon the assumption of a 92 day calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.
SR 3.3.5.1.4 is performed in accordance with the SCP. For SR 3.3.5.1.4 the SCP has controls which require verification that the instrument channel functions as required by verifyingq the as-left and as-found setting are consistent with those established by the setpoint methodoloyv.
The Frequency of SR 3.3.5.1.5 is based upon the assumption of an-[18] month calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.
SR 3.3.5.1.5 is performed in accordance with the SCP. If the actual setting of the channel is found to be conservative with respect to the Allowable Value but is beyond the as-found tolerance band, the channel is OPERABLE but deqraded.
The degraded condition of the channel will be further evaluated durinq performance of the SR. This evaluation will consist of resetting the channel setpoint to the [NTSP1 (within the allowed tolerance), and evaluatinq the channel response.
If the channel is functioning as required and is expected to pass the next surveillance, then the channel is OPERABLE and can be restored to service at the completion of the surveillance.
After the surveillance is completed, the channel as-found condition will be entered into the Corrective Action Program for further evaluation.
BWR/6 STS B 3.3.5.1-38 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RCIC System Instrumentation B 3.3.5.2 B 3.3 INSTRUMENTATION B 3.3.5.2 Reactor Core Isolation Cooling (RCIC) System Instrumentation BASES BACKGROUND The purpose of the RCIC System instrumentation is to initiate actions to ensure adequate core cooling when the reactor vessel is isolated from its primary heat sink (the main condenser) and normal coolant makeup flow from the Reactor Feedwater System is unavailable, such that initiation of the low pressure Emergency Core Cooling Systems (ECCS) pumps does not occur. A more complete discussion of RCIC System operation is provided in the Bases of LCO 3.5.3, "RCIC System." This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the RCIC instrumentation, as well as LCOs on other reactor system parameters and equipment performance.
Technical Specifications are required by 10 CFR 50.36 to 40-CF-R 50.36(n)(1.)(ii)(A) that T-ochic.al Specifications include LSSSs for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that a SL is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP) controlled by 10.CFR.50.59.
--- REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is generic terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP1" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
The [ILTSP1 and NTSP are located in the SCP.BWR/6 STS B 3.3.5.2-1 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)RCIC System Instrumentation B 3.3.5.2[LTSPs1 are those predetermined values of output at which an action should take place. The setpoints are compared to the actual process parameter (e.g., reactor vessel water level), and when the measured output value of the process parameter exceeds the setpoint-Iess consoryative than th_ no-minal trip sotpoint, but within its UAlWAblo Valuo, is acceptablc.
Each Allo....blo Valul .pec rifid a.ccount for e associated deviceehappE4 (e.g., trip unit) changes state. The analytical limits are derived from the limiting values of the process parameters obtained from the safety analysis.
The Allowable Values are derived from the analytical limits, corrected for calibration, process, and some of the instrument errors. The [LTSPs1 are then determined, accounting for the remaining instrument errors (e.g., drift). The trip setpoints derived in this manner provide adequate protection because instrumentation uncertainties appropriate to the Fu=nction.
Those unce.ai*ntieS ar desr.ibed iR process effects, calibration tolerances, instrument drift, and severe environment errors (for channels that must function in harsh environments as defined by 10 CFR 50.49) are accounted for.Note that, although the channel is OPERABLE under these circumstances, the trip setpoint must be left adjusted to a value within the as-left tolerance, in accordance with uncertainty assumptions stated in the referenced setpoint methodology (as-left criteria), and confirmed to be operating within the statistical allowances of the uncertainty terms assigned (as-found criteria).
The individual Functions are required to be OPERABLE in MODE 1, and in MODES 2 and 3 with reactor steam dome pressure > 150 psig, since this is when RCIC is required to be OPERABLE. (Refer to LCO 3.5.3 for Applicability Bases for the RCIC System.)The specific Applicable Safety Analyses, LCO, and Applicability discussions are listed below on a Function by Function basis.BWR/6 STS B 3.3.5.2-6 Rev. 3.0, 03/31/04 (Includes Errata)
TSTF-493, Rev. 4 (Option B)Relief and LLS Instrumentation B 3.3.6.5 B 3.3 INSTRUMENTATION B 3.3.6.5 Relief and Low-Low Set (LLS) Instrumentation BASES BACKGROUND The safety/relief valves (S/RVs) prevent overpressurization of the nuclear steam system. Instrumentation is provided to support two modes of S/RV operation
-the relief function (all valves) and the LLS function (selected valves). Refer to LCO 3.4.4, "Safety/Relief Valves (S/RVs)," and LCO 3.6.1.6, "Low-Low Set (LLS) Safety/Relief Valves (S/RVs)," for Applicability Bases for additional information of these modes of S/RV operation.
This is achieved by specifying limiting safety system settings (LSSS) in terms of parameters directly monitored by the Safety/Relief valve instrumentation, as well as LCOs on other reactor system parameters, and equipment performance..
Technical Specifications are required by 10 CFR 50.36 to 40-GF-R 50.36(00400)(iiflA)
Frq..eus that Tech.nical Spccificat*ons include LSSS for variables that have significant safety functions.
LSSS are defined by the regulation as "Where a LSSS is specified for a variable on which a safety limit has been placed, the setting must be chosen so that automatic protective actions will correct the abnormal situation before a Safety Limit (SL) is exceeded." The Analytical Limit is the limit of the process variable at which a safety action is initiated, as established by the safety analysis, to ensure that an SL is not exceeded.
Any automatic protection action that occurs on reaching the Analytical Limit therefore ensures that the SL is not exceeded.
However, in practice, the actual settings for automatic protection channels must be chosen to be more conservative than the Analytical Limit to account for instrument loop uncertainties related to the setting at which the automatic protective action would actually occur. The LSSS values are identified and maintained in the Setpoint Control Program (SCP) controlled by 10.CFR.50.59.
--- REVIEWER'S NOTE The term "Limiting Trip Setpoint" [LTSP1 is gqeneric terminology for the calculated trip setting (setpoint) value calculated by means of the plant-specific setpoint methodology documented in a document controlled under 10 CFR 50.59. The term [LTSP1 indicates that no additional margin has been added between the Analytical Limit and the calculated trip setting."Nominal Trip Setpoint [NTSP]" is the suggested terminology for the actual setpoint implemented in the plant surveillance procedures where margin has been added to the calculated
[LTSP1. The as-found and as-left tolerances will apply to the [NTSP1 implemented in the Surveillance procedures to confirm channel performance.
The [LTSP] and NTSP are located in the SCP.BWR/6 STS B 3.3.6.5-1 Rev. 3.0, 03/31/04 (Includes Errata)}}

Latest revision as of 07:47, 14 January 2025

Comment (2) of Kenneth J. Schrader, John Messina, Thomas W. Raidy and Wendy E. Croft on Behalf of Technical Specifications Task Force on Proposed Model Safety Evaluation for Plant-Specific Adoption of Traveler-493, Rev. 4, Clarify Applicati
ML093500358
Person / Time
Site: Technical Specifications Task Force
Issue date: 11/25/2009
From: Croft W, Joseph Messina, Raidy T, Schrader K
BWR Owners Group, Combustion Engineering, PWR Owners Group, Technical Specifications Task Force, Westinghouse
To: Lesar M
Rulemaking, Directives, and Editing Branch
References
74FR58065 00002, NRC-2009-0487, TSTF-09-26
Download: ML093500358 (270)
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