B16136, Application for Amend to License DPR-21,changing Plant,Unit 1 Instrument Calibration,Functional,Response Time,Resistance Temperature Detector & Thermocouple Testing Requirements & Clarifies Srs,Thereby Helping to Ensure Proper Testing
| ML20138K685 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 02/07/1997 |
| From: | Mcelwain J NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES SERVICE CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20138K690 | List: |
| References | |
| B16136, NUDOCS 9702190092 | |
| Download: ML20138K685 (14) | |
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(203) 4.** S 91 FEB - 7 SBT Docket No. 50-245 i
B16136 i
j U. S. Nuclear Regulatory Commission Attention: Document Control Desk j
Washington, DC 20555 i
Millstone Nuclear Power Station, Unit No.1 Proposed Technical Specification Revision - Response Time Testina i
Pursuant to 10CFR50.90, Northeast Nuclear Energy Company (NNECO) hereby proposes to amend its Facility Operating License, DPR-21, by incorporating the attached proposed changes into the Technical Specifications of Millstone Nuclear Power Station, Unit No.1.
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The proposed Technical Specification changes contained herein represent revisions to Technical Specification Section 1.0, " Definitions" and Section 3.1/4.1, " Reactor Protection System" including the associated bases.
The Technical Specification changes will clarify / modify Millstone Unit No.1 instrument calibration, functional, response time, Resistance Temperature Detector and thermocouple testing requirements. Also, certain definitions were clarified and/or modified using applicable i
wording of NUREG 1433, " Standard Technical Specifications" Revision 1 and Owners l
appmved Industry /TSTF Standard Technical Specification Change Traveler (TSTF-64).
j Additionally, the change relocates the Reactor Protection System logic response time i
value utilizing the guidance provided by Generic Letter 93-08, " Relocation of Technical i
Specification Tables of instrument Response Time Limits," with the exception of relocating the.value to the Technical Specifications Bases Section instead of the l
Updated Final Safety Analysis Report This amendment will clarify instrumentation surveillance requirements, thereby helping to ensure proper testing of safety related 4
components.
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[ of this letter provides supporting information and the safety assessment
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of the proposed change. Attachment 2 is the determination of no significant hazards l
considerations. Attachment 3 is the marked-up version of the current Technical Specifications. Attachment 4 is the retyped Technical Specification pages.
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NNECO has reviewed the proposed Technical Specification changes in accordance 1
with 10CFR50.92 and concludes that the changes do not involve a significant hazards f
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U.S. Nuclear Regul tory Commission B16136\\Page 2 consberation. NNECO has also reviewed the proposed license amendment against the criteria of 10CFR51.22 for environmental considerations and concludes that the change will not increase the types and amounts of effluent that may be released offsite, l
or significantly increase individual or cumulative occupational radiation exposures.
Thus, NNECO concludes that the proposed change satisfies 10CFR51.22(c)(9) for a categorical exclusion from the requirements for an environmental impact statement.
The Nuclear Safety Assessment Board has reviewed the proposed change to the Technical Specifications and concurs with the above determinations.
Pursuant to 10CFR50.91(b)(1), Millstone Unit No.1 has provided a copy of this license amendment request and the associated analysis regarding a no significant hazards consideration to the appropriate State of Connecticut representative. NNECO requests that the NRC l
issue a License Amendment which will be effective upon issuance and shall be implemented within 90 days of issuance. This latitude permits appropriate procedural /
program revisions and training necessary to implement the proposed changes.
Shou ld you have any questions or comments regarding this submittal, please contact Mr. R. Walpole at (860) 440-2191.
Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY
$?bn pohn P. McEl4ain Millstone Unit No.1 Recovery Officer Subscribed and sworn to before me this M day of bv6Mr.1997 a ' I)w(.
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Date Commission Expires:
My Commission Exp. April 30,2000 Attachments cc:
See Page 3
U.S. Nuclear Regulitory Commission B16136\\Page 3 cc:
H. J. Miller, Regional Administrator, Region 1 T. A. Easlick, Senior Resident inspector, Millstone Unit No.1 S. Dembek, NRC Project Manager, Millstone Unit No.1 W. D. Travers, Dr., Director, Special Proje::ts Mr. Kevin T.A. McCarthy, Director Bureau of Air Management Monitoring and Radiation Division Department of Environmental Protection 79 Elm Street Hartford, CT 06106-5127 i
Docket No. 50-245 B16136 l
1 Millstone Nuclear Power Station, Unit No.1 Proposed Technical Specification Revision Response Time Testing Supporting Information and Safety Assessment of Proposed Change 1
February 1997
U.S. Nuclear Regul tory Commission j
816136%ttachment 1\\Page 1 Millstone Nuclear Power Station, Unit No.1 Proposed Technical Specification Revision l
Response Time Testing Supporting Information and Safety Assessment of Proposed Change t
INTRODUCTION l
A self assessment performed on Millstone Unit No.1 Technical Specifications (TS) determined that instrument response time, as defined in the current TS definition of 1
i instrument Calibration, was unclear as to instrumentation applicability and scope. The only TS reference to a response time value is in TS Section 3.1, Reactor Protection System. This proposed revision will clarify the Millstone Unit No.1 response time j
licensing basis.
Revised wording for the definitions was adopted as appropriate from Standard Technical Specifications (STS), NUREG 1433, " Standard Technical Specification General Electric Plants, BWR/4," Revision 1.
A recent Owners approved industry / Technical Specification Task Force (TSTF) Standard Technical Specification Change Traveler (TSTF-64) providing additional clarification has been included in the revised wording.
Instrument calibrations for instrument channels having Resistance Temperature Detector (RTD) or thermocouple sensors are completed by performing an in-place qualitative assessment of sensor behavior and normal calibration of the remaining adjustable devices in the channel. This proposed change is more restrictive as the method of testing will be included in the TS; this requires that testing be done where none may be currently specified (i.e., the addition to the definition will impose a specific requirement for periodic testing as well as initial testing after replacement) thus ensuring the req' aired testing methodology aligns with standard industry methodology for instrument channels having a thermocouple or RTD as a sensor. In addition, this change prevents unnecessary removal and the consequent potential for damage of these sensors.
1 The Reactor Protection System logic response time value was relocated utilizing the guidance provided by Generic Letter 93-08, " Relocation of Technical Specification Tables of instrument Response Time Limits," with the exception of relocating the value to the TS Bases Section instead of the UFSAR.
DESCRIPTION OF THE PROPOSED CHANGES Revise TS Section 1.0 Definition E. " Instrument Calibration" to adopt the STS definition, including TSTF-64 wording, and move response time wording to a new
" Reactor Protection System (RPS) Logic Response Time" definition. The proposed changes clarify the licensing basis response time testing requirements and ensure
U.S. Nucl:ar Regul: tory Commission 816136\\ Attachment 1\\Page 2 the required testing methodology aligns with standard industry methodology for instrument channels having a thermocouple or RTD as a sensor.
i Revise TS Section 1.0 Definition F. " Instrument Functional Test" to adopt the STS e
definition including TSTF-64 wording to be consistent with the revised Instrument Calibration definition.
Add new definition SS. " Reactor Protection System (RPS) Logic Response Time" to clarify current TS LCO 3.1.B.
Relocate current TS Limiting Condition of Operation (LCO) 3.1.B. Response Time i
value (50 milliseconds) to TS Bases Section 4.1 Reactor Protection System.
Move / revise TS LCO 3.1.B wording to the new TS definition SS. " Reactor Protection l
e System (RPS) Logic Response Time".
l Replace " system" with " systems" (editorial) in TS Surveillance 4.1.A.
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Add response time testing requirement (from TS LCO 3.1.B) to TS Surveillance e
4.1.A and clarify by including applicable RPS trip functions and frequency.
Revise TS Section 4.1 Bases to include description of response time testing requirements.
SAFETY ASSESSMENT The preface to NUREG 1433 describes the development of the Standard Technical Specifications (STS) for General Electric (GE) BWR/4 plants. This NUREG is the result of extensive public technical meetings and discussions between the Nuclear Regulatory Commission (NRC) staff and nuclear power plant Licensees, Nuclear Steam Supply System (NSSS) Owners Groups, specifically the GE Owners Group, and the Nuclear Energy Institute (NEI).
Northeast Nuclear Energy Company (NNECO) proposes to adopt related requirements, as applicable to the licensing basis of the facility, of the portions of the STS to improve the degree of standardization and consistency.
The industry (Owners) have developed a generic traveler change process to raake revisions to STS. NNECO proposes to include Industry /TSTF Standard Technical l
Specification Change Traveler (TSTF64) and associated BWR clarifications which have been approved by the Owners.
Minor word differences from the STS are required to provide consistency with current TS wording and support the current licensing basis. These minor word differences, l
including TSTF-64, do not alter the meaning of instrument testing from the STS or change the current licensing basis.
Addition of a functional test to the channel l
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B16136\\ Attachment 1\\Page 3 i
calibration and allowing calibrations to be performed by means of any series of sequential, overlapping, or total channel steps aligns the testing methodology with industry practice and the STS calibration definition. The wording " response time" was l
moved to a new definition. Removing response time wording from the calibration j
definition will alleviate a literal compliance interpretation to perform response time l
testing on instruments calibrated per Technical Specifications, which were not intended to be part of Millstone Unit No.1 licensing basis.
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Calibration surveillance requirements adjust instruments to ensure their outputs l
accurately reflect and respond to changes in the monitored parameter.
Most i
instruments identified in the TS have a sensor whose output may vary over time without I
l a corresponding change in the monitored parameter. This is known as sensor drift.
Periodic adjustment during calibration of these sensors is necessary to ensure the 3
required accuracy is maintained. RTDs and thermocouples measure temperature l
directly by changes in physical properties of the sensing elements, resistance of an l
RTD or electromotive potential of a thermocouple, in a known, reproducible manner.
i As such, these sensors are relatively insensitive to sensor drift. Moreover, RTDs and j
thermocouples do not have components integral to the sensor that are adjustable.
i RTDs and thermocouples are calibrated during the manufacturing process. Subsequent i
verification of proper operation can only check response to the associated sensor
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response curve. Failures of these sensing devices typically manifest as downscale or i
full-scale indication. Changes to their output, independent of the state of the monitored j
parameter, can be observed by comparison with other channels measuring the same j
parameter. Thus, failures of these sensors tend to be gross and readily observable, l
3 The accuracy obtained by thermocouples is primarily dependent upon how closely the j
sensing junction can be brought to the temperature of the parameter being monitored.
j This is achieved by ensuring good physical contact at the sensing junction. The j
accuracy of RTDs can be affected by mechanical damage or by strains induced if these i
sensitive devices are mishandled. Thus, removal and subsequent reinstallation of the sensors introduces the potential for maintenance-related failures (separation of thermocouple junction or strain on RTDs) that may outweigh the benefit of verifying the RTD or thermocouple sensor curve since RTDs and thermocouples sensors can only be calibrated during the manufacturing process.
Also, in-place sensor curve verification efforts would result in additional personnel radiation exposure which is inconsistent with as low as reasonably achievable (ALARA) principles especially considering the minimal benefit, if any, expected. Adopting the STS wording ensures the testing methodology aligns with widely adopted standard industry practice for instrument channels having a thermocouple or RTD as a sensor and to prevent unnecessary removal of these sensors.
Moreover, calibrating the remaining components of an instrument channel is sufficient to maintain the required accuracy of the entire instrument without calibrating the sensor.
The current TS definition for instrument Functional Test requires injection of a simulated signal into the primary sensor to verify proper response. Current TS exempt the sensors of specific instrument channels where it is not practical to include them within the functional test boundaries. Some examples of these exemptions include
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B16136\\ Attachment 1\\Page 4 l
neutron monitoring system, turbine control valve fast closure, and standby gas j
treatment initiation radiation monitors. In these cases, TS permit the performance of j
the functional test by injection of a simulated electrical signal into the measurement l
channel. The STS definition for CHANNEL FUNCTIONAL TEST requires injection of the simulated signal "as close to the sensor as practicable." Therefore, the proposed l
definition, which is consistent with the STS definition, is consistent with the current TS definition and its exemptions. The primary sensor is the transmitter, switch or radiation
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l monitor. The definition does not include sensing elements, such as radiation detectors, I
i flow elements, acceleration relays or reference legs. Allowing the channel functional test to be performed by means of any series of sequential, overlapping, or total channel 1
i steps is a testing methodology consistent with industry standards (IEEE Std 338) and i
j the STS CHANNEL FUNCTIONAL TEST definition.
l The current TS definition for Instrument Functional Test requires the injection of a 1
simulated signal in order to perform the test. The STS definition allows either a i
simulated or actual signal to be used.
This change will allow some instrument i
Functional Tests to be satisfied during insertion of the actual signal into the logic. Use of an actual signal, instead of the existing requirement to use a simulated signal, will j
not affect the performance of the channel and recognizes that proper operation of a j
bistable device in response to a valid signal is sufficient to demonstrate functional trip j
capability.
Operability can be adequately demonstrated in either case as the L
i instrument itself cannot distinguish between sctual or simulated signals. Millstone Unit No.1 plans to convert to the STS, but deems these changes necessary in order to clarify the existing TS in the interim.
Millstone Unit No.1 Technical Specification LCO 3.1.B has a RPS Logic Response Time requirement of 50 milliseconds. The RPS Logic Response Time was changed from 100 milliseconds to 50 milliseconds in Amendment 78 to the Provisional Operating License, dated September 8,1981. The reduction in response time was necessary because the TS MCPR limits were established based on an RPS Logic Response Time safety analysis assumption of 50 milliseconds. NRC I&E Circular 80-08 was issued April 18,1980, alerting Licensees to the TS RPS Logic Response Time inconsistency.
At that time, testing was completed at Millstone Unit No.1 to verify the response time was within 50 milliseconds. NNECO has completed a review of the 50 millisecond requirement in LCO 3.1.B and verified that the value is consistent with the current
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safety analysis.
The RPS Logu Response Time value is being relocated to Millstone Unit No.1 TS Bases and any changes to this value will be performed under the requirements of 10CFR 50.59. This is consistent with the guidance provided by Generic Letter 93-08
" Relocation of Technical Specification Tables of instrument Response Time Limits."
with the exception of relocating the value to the TS Bases Section instead of the UFSAR.
The STS definition for RPS Response Time was not used because it is not consistent with the Millstone Unit No.1 licensing basis. Therefore, a new definition (RPS Logic Response Time) was developed from current TS LCO 3.1.B to be consistent with the
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current licensing basis. This is an administrative change because the term is being moved from one section of TS to another. Although the proposed new definition (RPS 4
Logic Response Time) differs from the STS definition for RPS Response Time by j
excluding the sensors, it is consistent with the current TS LCO 3.1.B and the Millstone Unit No.1 licensing basis, and is, therefore, justified.
The current TS RPS surveillance section 4.1.A will be revised to incorporate an j
editorial change and to address the RPS Logic Rosponse Time testing requirement covering applicable trip functions and specifying surveillance frequency. The editorial j
change does not alter the intent. The applicable trip functions, for which the RPS logic response times will be measured, are those trip functions that assume a logic system i
response time in the plant safety analyses. For trip functions where no explicit credit is taken in the safety analysis, the measurement of logic response time is not important and, therefore, not warranted.
This new surveillance is required to support the l
modified STS calibration definition which deletes the response time measurement as l
implied by the current TS definition for instrument Calibration and provides a i
surveillance interval for an item that was not specifically addressed before.
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j An evaluation has been completed which verified the applicable RPS trip functions j
requiring logic response time using the current safety analyses as the basis.
instrumentation response time requirements (specified limits) other than RPS logic are not important to test, especially considering the long delays already accounted for in the accident analyses associated with the start of emergency power sources, ECCS components, and containment isolations (i.e., the instrument response time for these functions is small compared to the total delays assumed in the analyses). Additionally, the non-RPS logic response times, including response times of other instrumentation such as radiation monitors, are not part of the licensing basis. The sensors associated with all TS instrumentation are functionally tested and calibrated to ensure proper operation. Notwithstanding the licensing basis, we plan to verify the sensor response times for selected parameters modeled in the accident analyses.
The specific acceptance criteria will be provided in the Technical Requirements Manual and changes controlled pursuant to the requirements of 10CFR 50.59.
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k Docket No. 50-245 1
B16136 Millstone Nuclear Power Station, Unit No.1 i
Proposed Technical Specification Revision j
Response Time Testing i
Determination of No Significant Hazards Consideration l
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February 1997 i
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U.S. Nucl:;r Regul: tory Commission j
.B16136\\ Attachment 2\\Page 1 Millstone Nuclear Power Station, Unit No.1 Proposed Technical Specification Revision i
Response Time Testing Determination of No Significant Hazards Consideration Pursuant to 10CFR50.92, NNECO has reviewed the proposed changes and concludes j
that the changes do not involve a significant hazards consideration (SHC) since the propsed changes satisfies the criteria in 10tER50.92(c).
That is, the proposed j
changes do not:
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Involve a significant increase in the probability or consequences of an accident previously evaluated.
The proposed amendment continues to ensure the surveillance requirements satisfy the licensing basis. The current TS definition for instrument Functional Test requires injection of a simulated signal into the primary sensor to verify proper response.
Current TS exempt the sensors of specific instrument i
channels where it is not practical to include them within the functional test boundaries. Some examples of these exemptions include neutron monitoring system, turbine control valve fast closure, and standby gas treatment initiation radiation monitors. In these cases, TS permit the performance of the functional test by injection of a simulated electrical signal into the measurement channel.
i The proposed definition, which is consistent with the STS definition, for CHANNEL FUNCTIONAL TEST requires injection of the simulated signal "as j
close to the sensor as practicable."
Therefore, the proposed definition is consistent with the current TS definition and its exemptions. The primary sensor is the transmitter or switch or radiation monitor. The definition does not include sensing elements such as radiation detectors, flow elements, acceleration relays or reference legs.
This change will allow the channel functional test to be perfomled by means of any series of sequential, overlapping, or total channel steps and aligns this methodology with industry practice.
This change does not affect accident precursors and thus does not involve a significant increase in the probability of an accident previously evaluated. The proposed change will allow a simulated or actual signal to be used to perform an Instrument or Channel Functional test.
This change does not impose a requirement to create an actual signal, nor does it eliminate any restriction on producing an actual signal. While creating an
" actual" signal could increase the probability of an event, existing procedures (and the 10CFR50.59 control of revisions to r em) dictate the acceptability of generating this signal. The proposed change does not affect the procedures governing plant operations or the acceptability of creating these synals; it simply would allow such a signal to be utilized in evaluating the acceptance criteria for the Instrument or Channel Functional Test requirements. Therefore,
U.S. Nuclear Regulatory Commission i
B16136%ttachment 2\\Page 2 l
the change does not involve a significant increase in the probability of an j
accident previously evaluated. Because the method of initiation will not affect the acceptance criteria of the instrument or Channel Functional Test, the change i
does not involve a significant increase in the consequences of an accident previously evaluated.
Minor word differences from STS are required to provide consistency with current TS wording and support the current licensing basis. These mincr word differences including industry 6STF Standard Technical Specification Change Traveler (TSTF-64) do not alter the meaning of instrument testing in the STS or change the current licensing basis.
Moving the RPS Logic Response Time LCO description to the TS definition i
section is an administrative change and does not alter the original intent or l
licensing basitt j.
l Relocation of the RPS Logic Response Time value from the TS to the Bases section involves the use of an alternate regulatory process for controlling the instrument response time limit. The change does not introduce any new modes l
of plant operation, make~ any physical changes, alter any operational setpoints, j
or change the surveillance requirements. Any change in the RPS logic response j
time value would be evaluated pursuant to the requirements of 10CFR 50.59.
The surveillance section editorial change does not alter the meaning of j
suiveillance applicability. Providing RPS Logic Response Time surveillance fr6quency and applicable trip functions ensures proper testing of RPS components and is consistent with industry practice. An evaluation completed by GE verified the applicable RPS trip functions that require a specific logic response time using the current accident analysis as the basis. For trip functions where no explicit credit is taken in the safety analysis, the measurement of logic response time is not important and, therefore, not warranted. In addition, we have concluded, that instrumentation response time requirements (specified limits) other than RPS logic are not important to test, especially considering the long delays already accounted for in the accident analyses associated with the start of emergency power sources, ECCS components, and containment isolations, and that the non-RPS logic response times, including response times of other instrumentation such as radiation monitors, are not part of the Millstone Unit No.1 licensing basis. The sensors associated with all TS instrumentation j
are functionally tested and calibrated to ensure proper operation.
i No physical change is being made to instrument channels, or to any systems or component that interfacee with the instrumentation channels, therefore there is no change in the probability or consequences of any accident analyzed in the UFSAR.
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Create the possibility of a new or different kind of accident from any accident previously evaluated.
4 The proposed change does not result in any design or physical configuration i
changes to the instrumentation channels. Operation incorporating the proposed j
change will not impair the instrumentation channels from performing as provided in the design basis.
Changing the TS to be consistent with current industry practice adopted in STS i
will help to prevent unnecessary removal and potential damage of the j
temperature detectors (for sensor calibration).
Clarification of RPS Logic Response Time testing requirements consistent with the current licensing basis j
will ensure proper testing of safety-related components.
I Woiding changes to instrument Calibration and Functional Test definitions do not involve a physical modification to the plant. The injection of an actual or simulated signal as close to the sensor as practical minimizes the likelihood of i
any transients.
Minor word differences from STS are required to provide consistency with current TS wording and support the current licensing basis. These minor word i
differences, including industry /TSTF Standard Technical Specification Change Traveler (TSTF 64), do not alter the meaning of instrument testing in the STS or change the current licensing basis.
Moving the RPS Logic Response Time LCO description to the TS definition section is an administrative change and does not alter the current licensing basis.
Relocation of the RPS Logic Response Time value involves the use of an alternate process for controlling the instrument response time limits. Therefore, the above change does not introduce any accident initiators as it does not involve any new modes of plant operation, make any physical changes, alter any operational setpoints, or change the sunreillance requirements.
The surveillance section editorial change does not alter the meaning of surveillance applicability. Providing RPS Logic Response Time surveillance frequency and applicable trip functions ensures proper testing of RPS components and is consistent with industry practice.
Since the proposed changes in the Technical Specifications do not adversely impact the reliability of the RPS and other automatic actuations, no new or different kind of accident is created.
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Involve a significant reduction in a margin of safety.
l Because the proposed change does not involve the addition or modification of plant equipment, is consistent with the existing Technical Specifications, current l
industry practices as outlined in NUREG 1433, " Standard Technical l
Specificat! sns GE Plants, BWR/4," Revision 1, and with the current design and licensing : asis of the Protective ir.strumentation systems including the accident i
analysis, no action will occur that wi!I involve a significant reduction in a margin j-of safety.
The proposed change to allow the use of an actual signal in addition to the existing requirement, which limits use to a simulated signal, will not affect functional test acceptance criteria. Therefore, the proposed change does not i
adversely affect the reliability of the RPS or other automatic actuation and does i
not involve a significant reduction h a margin of safety.
j Relocation of the RPS Logic Response Time value from the TS to the Bases section involves the use of an alternate regulatory process for controlling the instrument response time limit. Any change in the RPS logic response time j
value would be evaluated pursuant to the requirements of 10CFR50.59.
Therefore, the proposed change does not involve a significant reduction in a margin of safety.
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