ML22240A067
| ML22240A067 | |
| Person / Time | |
|---|---|
| Issue date: | 05/27/2015 |
| From: | NRC/NRR/DSS/STSB |
| To: | |
| Craig Harbuck NRR/DSS 301-415-3140 | |
| Shared Package | |
| ML22240A001 | List:
|
| References | |
| Download: ML22240A067 (29) | |
Text
GTST AP1000-O34-3.4.13, Rev. 1 Date report generated:
Wednesday, May 27, 2015 Page 1 Advanced Passive 1000 (AP1000)
Generic Technical Specification Traveler (GTST)
Title:
Changes Related to LCO 3.4.13, Automatic Depressurization System (ADS) -
Shutdown, RCS Open I.
Technical Specifications Task Force (TSTF) Travelers, Approved Since Revision 2 of STS NUREG-1431, and Used to Develop this GTST TSTF Number and
Title:
Not Applicable NRC Approval Date:
Not Applicable TSTF Classification:
Not Applicable
GTST AP1000-O34-3.4.13, Rev. 1 Date report generated:
Wednesday, May 27, 2015 Page 2 II.
Reference Combined License (RCOL) Standard Departures (Std. Dep.), RCOL COL Items, and RCOL Plant-Specific Technical Specifications (PTS) Changes Used to Develop this GTST RCOL Std. Dep. Number and
Title:
There are no Vogtle departures applicable to GTS 3.4.13.
RCOL COL Item Number and
Title:
There are no Vogtle COL items applicable to GTS 3.4.13.
RCOL PTS Change Number and
Title:
VEGP LAR DOC A003: References to various Chapters and Sections of the Final Safety Analysis Report (FSAR) are revised to include FSAR.
VEGP LAR DOC A038: Numerous TS surveillances are revised by deletion of word that from the surveillance VEGP LAR DOC A056: TS 3.4.13 is revised VEGP LAR DOC A057: TS 3.4.13, Condition B is revised VEGP LAR DOC A058: SR 3.4.13.1 is revised VEGP LAR DOC A059: TS 3.4.13, Condition C and Condition D are revised VEGP LAR DOC L01:
TS Definition for Actuation Device Test is deleted
GTST AP1000-O34-3.4.13, Rev. 1 Date report generated:
Wednesday, May 27, 2015 Page 3 III.
Comments on Relations Among TSTFs, RCOL Std. Dep., RCOL COL Items, and RCOL PTS Changes This section discusses the considered changes that are: (1) applicable to operating reactor designs, but not to the AP1000 design; (2) already incorporated in the GTS; or (3) superseded by another change.
None
GTST AP1000-O34-3.4.13, Rev. 1 Date report generated:
Wednesday, May 27, 2015 Page 4 IV.
Additional Changes Proposed as Part of this GTST (modifications proposed by NRC staff and/or clear editorial changes or deviations identified by preparer of GTST)
Clarification is added in several places in the Bases and grammatical errors corrected in the Bases.
The phrase The time to RCS boiling is maximized by increasing RCS inventory is removed from the Action D.1 and D.2 Bases discussion because RCS inventory is not increased by Actions D.1 and D.2.
The discussion of SR 3.4.13.2 in the Surveillance Requirements section of the Bases is clarified by replacing the phrase are applicable to the stage 4 ADS valves required to be OPERABLE. with are applicable to the valves in the two stage 4 ADS flow paths required to be OPERABLE.
APOG Recommended Changes to Improve the Bases Throughout the Bases, references to Sections and Chapters of the FSAR do not include the FSAR clarifier. Since these Section and Chapter references are to an external document, it is appropriate to include the FSAR modifier. (DOC A003)
Revise various TS Bases stating withdrawal of reactivity control assemblies to withdrawal of control rods for editorial improvement and consistency with other TS Bases discussions.
Specifically, in the Actions section of the Bases, revise the second sentence in the second paragraph in the discussions of Required Actions C.1 and C.2 and Required Actions D.1 and D.2, as indicated:
Additionally, action to suspend positive reactivity additions is required to ensure that the SDM is maintained. Sources of positive reactivity addition include boron dilution, withdrawal of reactivity control rods assemblies, and excessive cooling of the RCS.
GTST AP1000-O34-3.4.13, Rev. 1 Date report generated:
Wednesday, May 27, 2015 Page 5 V.
Applicability Affected Generic Technical Specifications and Bases:
Section 3.4.13, Automatic Depressurization System (ADS) - Shutdown, RCS Open Changes to the Generic Technical Specifications and Bases:
Statement of LCO Specification and Applicability is revised. This is an editorial change for clarity. (DOC A056)
The word required is deleted from Condition A. This is an editorial change for clarity.
(DOC A056)
Condition B and Required Action B.2 are revised. This is an editorial change for clarity.
(DOC A057)
Condition C and Condition D are revised to delete Requirements of. This is an editorial change for clarity. (DOC A056)
Condition C and Condition D are revised to add of Condition A or B. This is an editorial change for clarity. The associated Bases discussion is also revised. (DOC A059)
The phrase The time to RCS boiling is maximized by increasing RCS inventory is removed from the Action D.1 and D.2 Bases. (NRC Staff Comment)
The word that is removed from SR 3.4.13.1. This is an editorial change for clarity. (DOC A038)
The word fully is removed from SR 3.4.13.1. This is an editorial change for clarity. (DOC A058)
The second sentence in the second paragraph in the discussions of Required Actions C.1 and C.2 and Required Actions D.1 and D.2 are revised. (APOG Comment)
The SR 3.4.13.2 Bases discussion is revised. (NRC Staff Comment)
SR 3.4.11.5 is added to list of SRs under SR 3.4.13.2. This provides administrative support of SRs added by VEGP LAR DOC L01. (DOC L01)
The acronym FSAR is added to modify Section and Chapter in references to the FSAR throughout the Bases. (DOC A003) (APOG Comment)
GTST AP1000-O34-3.4.13, Rev. 1 Date report generated:
Wednesday, May 27, 2015 Page 6 VI.
Traveler Information Description of TSTF changes:
Not Applicable Rationale for TSTF changes:
Not Applicable Description of changes in RCOL Std. Dep., RCOL COL Item(s), and RCOL PTS Changes:
VEGP LAR DOC A038 deletes the word that from various surveillance descriptions.
VEGP LAR DOC A056 revises the first LCO statement by deleting the comma following Stage 3. The second LCO statement is revised from ADS stage 4 with 2 flow paths shall be OPERABLE, to Two ADS stage 4 flow paths shall be OPERABLE. The Mode 5 Applicability is editorially revised into two Applicabilities. The first Applicability is MODE 5 with pressurizer level < 20%. The second Applicability is MODE 5 with RCS pressure boundary open.
Condition A is revised by deleting required. Required Action B.2 is revised by replacing two with required. The second entry condition of Condition C is revised by deleting Requirements of from the condition statement and revising Conditions to Condition. The second entry condition of Condition D is revised by deleting Requirements of from the condition statement and revising Conditions to Condition. SR 3.4.13.1 is revised by deleting that, from the Surveillance. SR 3.4.13.2 is revised by deleting of LCO 3.4.11, Automatic Depressurization System (ADS) - Operating, from the Surveillance.
VEGP LAR DOC A057 revises Condition B by deleting closed and.
VEGP LAR DOC A058 revises SR 3.4.13.1 by deleting fully, from the Surveillance.
VEGP LAR DOC A059 revises the first entry condition of Condition C by adding of Condition A or B to the condition statement. The first entry condition of Condition D is also revised by adding of Condition A or B to the condition statement. The associated Bases discussion is updated.
VEGP LAR DOC L01 revises SR 3.4.13.2 to include listing proposed SR 3.4.11.5 in the surveillance description.
A more detailed description of each DOC can be found in Reference 2, VEGP TSU LAR, and the NRC staff safety evaluation can be found in Reference 3, VEGP LAR SER. The VEGP TSU LAR was modified in response to NRC staff RAIs in Reference 5 and the Southern Nuclear Operating Company RAI Response in Reference 6.
GTST AP1000-O34-3.4.13, Rev. 1 Date report generated:
Wednesday, May 27, 2015 Page 7 Rationale for changes in RCOL Std. Dep., RCOL COL Item(s), and RCOL PTS Changes:
Editorial changes per VEGP LAR DOC A038, DOC A056, DOC A057, DOC A058, and DOC A059 are consistent with the guidance provided in the Writer's Guide.
GTS 3.3.2, SR 3.3.2.7 (Perform ACTUATION DEVICE TEST) and SR 3.3.2.8 (Perform ACTUATION DEVICE TEST for squib valves) are deleted from GTS 3.3.2 and Table 3.3.2-1, Function 26.a, ESF Actuation Subsystem per VEGP LAR DOC L01. The equivalent requirement (using phrasing generally consistent with NUREG-1431) must be included in individual Specifications for the actuated devices with the same 24 month Frequency as the deleted SRs.
This requires the SR references in SR 3.4.13.2 to be updated.
Description of additional changes proposed by NRC staff/preparer of GTST:
Clarification is added in several places in the bases and grammatical errors corrected in the bases.
The phrase The time to RCS boiling is maximized by increasing RCS inventory is removed from the Action D.1 and D.2 bases discussion.
The discussion of SR 3.4.13.2 in the Surveillance Requirements section of the Bases is revised by replacing the phrase are applicable to the stage 4 ADS valves required to be OPERABLE. with are applicable to the valves in the two stage 4 ADS flow paths required to be OPERABLE. (NRC Staff Comment)
Revise the second sentence in the second paragraph in the discussions of Required Actions C.1 and C.2 and Required Actions D.1 and D.2 as indicated (APOG Comment):
Additionally, action to suspend positive reactivity additions is required to ensure that the SDM is maintained. Sources of positive reactivity addition include boron dilution, withdrawal of reactivity control rods assemblies, and excessive cooling of the RCS.
The acronym FSAR is added to modify Section and Chapter in references to the FSAR throughout the Bases. (DOC A003) (APOG Comment)
Rationale for additional changes proposed by NRC staff/preparer of GTST:
Clarifying remarks are necessary to make the bases discussion complete.
RCS inventory is not increased by Actions D.1 and D.2.
The Bases discussion for SR 3.4.13.2 is revised for improved clarity and to be more consistent with the language in the surveillance.
Various TS Bases referencing reactivity control assemblies are revised to control rods for editorial improvement and consistency with other TS Bases discussions.
Since Bases references to FSAR Sections and Chapters are to an external document, it is appropriate to include the FSAR modifier.
GTST AP1000-O34-3.4.13, Rev. 1 Date report generated:
Wednesday, May 27, 2015 Page 8 VII. GTST Safety Evaluation Technical Analysis:
VEGP LAR DOC L01 adds STS SR 3.4.11.5 to the list in GTS SR 3.4.13.2. SR 3.4.13.2 references several GTS 3.4.11 SRs that are applicable to the ADS system when the reactor is shutdown and the RCS is open as defined by GTS 3.4.13. STS SR 3.4.11.5 is applicable in this situation.
The remaining changes are editorial, clarifying, grammatical, or otherwise considered administrative. These changes do not affect the technical content, but improve the readability, implementation, and understanding of the requirements, and are therefore acceptable.
Having found that this GTSTs proposed changes to the GTS and Bases are acceptable, the NRC staff concludes that AP1000 STS Subsection 3.4.13 is an acceptable model Specification for the AP1000 standard reactor design.
References to Previous NRC Safety Evaluation Reports (SERs):
None
GTST AP1000-O34-3.4.13, Rev. 1 Date report generated:
Wednesday, May 27, 2015 Page 9 VIII. Review Information Evaluator Comments:
None Randy Belles Oak Ridge National Laboratory 865-574-0388 bellesrj@ornl.gov Review Information:
Availability for public review and comment on Revision 0 of this traveler approved by NRC staff on 5/16/2014.
APOG Comments (Ref. 7) and Resolutions:
- 1.
(Internal #3) Throughout the Bases, references to Sections and Chapters of the FSAR do not include the FSAR clarifier. Since these Section and Chapter references are to an external document, it is appropriate (DOC A003) to include the FSAR modifier. This is resolved by adding the FSAR modifier as appropriate.
- 2.
(Internal # 6) The GTST sections often repeat VEGP LAR DOCs, which reference existing and current requirements. The inclusion in the GTST of references to existing and current, are not always valid in the context of the GTS. Each occurrence of existing and current should be revised to be clear and specific to GTS, MTS, or VEGP COL TS (or other), as appropriate. Noted ambiguities are corrected in the GTST body.
- 3.
(Internal #7)Section VII, GTST Safety Evaluation, inconsistently completes the subsection References to Previous NRC Safety Evaluation Reports (SERs) by citing the associated SE for VEGP 3&4 COL Amendment 13. It is not clear whether there is a substantive intended difference when omitting the SE citation. This is resolved by removing the SE citation in Section VII of the GTST and ensuring that appropriate references to the consistent citation of this reference in Section X of the GTST are made.
- 4.
(Internal # 273) The GTST Section IV discussion of VEGP LAR DOC A056 incorrectly describes a change to the Bases. The DOC does not address Bases changes.
Furthermore, there are no differences in the AP1000 NUREG STS draft from the VEGP Amended TS or associated Bases changes. ThisSection IV discussion appears to be a mistake. Remove the GTST Section IV discussion related to VEGP LAR DOC A056. This is resolved by removing reference to DOC A056 from the affected paragraph. However, the NRC staff proposed change to the Bases for SR 3.4.13.2 replacing the phrase are applicable to the stage 4 ADS valves required to be OPERABLE. with are applicable to the valves in the two stage 4 ADS flow paths required to be OPERABLE is incorporated.
- 5.
(Internal # 274) Text added to first entry condition of Condition C incorrectly states plural Conditions. The discussion of VEGP LAR DOC A059 states that the first entry condition of Condition C is revised by adding of Condition A or B (i.e., singular) to the condition statement. Revise the added text by making Conditions singular. This is resolved by
GTST AP1000-O34-3.4.13, Rev. 1 Date report generated:
Wednesday, May 27, 2015 Page 10 making the recommended change for the Condition C statement and the Condition D statement.
- 6.
(Internal # 275) To be consistent with the Writer's Guide; when making an or statement, Condition is singular. In the Actions section of the Bases, revise discussions of Required Actions C.1 and C.2 and Required Actions D.1 and D.2 to say... Condition A or B...
instead of... Conditions A or B... which is incorrect. This is resolved by making the recommended change.
- 7.
(Internal # 276) Revise various TS Bases stating withdrawal of reactivity control assemblies to withdrawal of control rods for editorial improvement and consistency with other TS Bases discussions. Specifically, in the Actions section of the Bases, revise the second sentence in the second paragraph in the discussions of Required Actions C.1 and C.2 and Required Actions D.1 and D.2, as indicated:
Additionally, action to suspend positive reactivity additions is required to ensure that the SDM is maintained. Sources of positive reactivity addition include boron dilution, withdrawal of reactivity control rods assemblies, and excessive cooling of the RCS.
This is resolved by making the recommended change.
NRC Final Approval Date: 5/27/2015 NRC
Contact:
Hien Le United States Nuclear Regulatory Commission 301-415-1511 Hien.Le@nrc.gov
GTST AP1000-O34-3.4.13, Rev. 1 Date report generated:
Wednesday, May 27, 2015 Page 11 IX.
Evaluator Comments for Consideration in Finalizing Technical Specifications and Bases None
GTST AP1000-O34-3.4.13, Rev. 1 Date report generated:
Wednesday, May 27, 2015 Page 12 X.
References Used in GTST
- 1.
AP1000 DCD, Revision 19, Section 16, Technical Specifications, June 2011 (ML11171A500).
- 2.
Southern Nuclear Operating Company, Vogtle Electric Generating Plant, Units 3 and 4, Technical Specifications Upgrade License Amendment Request, February 24, 2011 (ML12065A057).
- 3.
NRC Safety Evaluation (SE) for Amendment No. 13 to Combined License (COL) No.
NPF-91 for Vogtle Electric Generating Plant (VEGP) Unit 3, and Amendment No. 13 to COL No. NPF-92 for VEGP Unit 4, September 9, 2013, ADAMS Package Accession No. ML13238A337, which contains:
ML13238A355 Cover Letter - Issuance of License Amendment No. 13 for Vogtle Units 3 and 4 (LAR 12-002).
ML13238A359 - Amendment No. 13 to COL No. NPF-91 ML13239A256 - Amendment No. 13 to COL No. NPF-92 ML13239A284 Enclosure 3 - Revised plant-specific TS pages (Attachment to Amendment No. 13)
ML13239A287 - Safety Evaluation (SE), and Attachment 1 - Acronyms ML13239A288 SE Attachment 2 - Table A - Administrative Changes ML13239A319 SE Attachment 3 - Table M - More Restrictive Changes ML13239A333 SE Attachment 4 - Table R - Relocated Specifications ML13239A331 SE Attachment 5 - Table D - Detail Removed Changes ML13239A316 SE Attachment 6 - Table L - Less Restrictive Changes The following documents were subsequently issued to correct an administrative error in :
ML13277A616 Letter - Correction To The Attachment (Replacement Pages) - Vogtle Electric Generating Plant Units 3 and 4-Issuance of Amendment Re:
Technical Specifications Upgrade (LAR 12-002) (TAC No. RP9402)
ML13277A637 - Revised plant-specific TS pages (Attachment to Amendment No. 13) (corrected)
- 4.
TSTF-GG-05-01, Writer's Guide for Plant-Specific Improved Technical Specifications, June 2005.
- 5.
RAI Letter No. 01 Related to License Amendment Request (LAR)12-002 for the Vogtle Electric Generating Plant Units 3 and 4 Combined Licenses, September 7, 2012 (ML12251A355).
- 6.
Southern Nuclear Operating Company, Vogtle Electric Generating Plant, Units 3 and 4, Response to Request for Additional Information Letter No. 01 Related to License Amendment Request LAR-12-002, ND-12-2015, October 04, 2012 (ML12286A363 and ML12286A360)
GTST AP1000-O34-3.4.13, Rev. 1 Date report generated:
Wednesday, May 27, 2015 Page 13
- 7.
APOG-2014-008, APOG (AP1000 Utilities) Comments on AP1000 Standardized Technical Specifications (STS) Generic Technical Specification Travelers (GTSTs), Docket ID NRC-2014-0147, September 22, 2014 (ML14265A493).
GTST AP1000-O34-3.4.13, Rev. 1 Date report generated:
Wednesday, May 27, 2015 Page 14 XI.
MARKUP of the Applicable GTS Subsection for Preparation of the STS NUREG The entire section of the Specifications and the Bases associated with this GTST is presented next.
Changes to the Specifications and Bases are denoted as follows: Deleted portions are marked in strikethrough red font, and inserted portions in bold blue font.
GTST AP1000-O34-3.4.13, Rev. 1 ADS - Shutdown, RCS Open 3.4.13 AP1000 STS 3.4.13-1 Amendment 0Rev. 0 Revision 19 Date report generated:
Wednesday, May 27, 2015 Page 15 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.13 Automatic Depressurization System (ADS) - Shutdown, RCS Open LCO 3.4.13 ADS stage 1, 2, and 3, flow paths shall be open.
Two ADS stage 4 with 2 flow paths shall be OPERABLE.
NOTE---------------------------------------------
In MODE 5, the ADS valves may be closed to facilitate RCS vacuum fill operations to establish a pressurizer level 20%, provided ADS valve OPERABILITY meets LCO 3.4.12, ADS - Shutdown, RCS Intact.
APPLICABILITY:
MODE 5 with RCS pressure boundary open or pressurizer level < 20%,
MODE 5 with RCS pressure boundary open, MODE 6 with upper internals in place.
ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One required ADS stage 1, 2, or 3 flow path not open.
A.1 Open the affected flow path.
OR 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> A.2 Open an alternative flow path with an equivalent area.
72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> B. One required ADS stage 4 flow path closed and inoperable.
B.1 Open an alternative flow path with an equivalent area.
OR 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> B.2 Restore required two ADS stage 4 flow paths to OPERABLE status.
36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />
GTST AP1000-O34-3.4.13, Rev. 1 ADS - Shutdown, RCS Open 3.4.13 AP1000 STS 3.4.13-2 Amendment 0Rev. 0 Revision 19 Date report generated:
Wednesday, May 27, 2015 Page 16 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME C. Required Action and associated Completion Time of Condition A or B not met while in MODE 5.
OR Requirements of LCO not met for reasons other than Conditions A or B while in MODE 5.
C.1 Initiate action to fill the RCS to establish 20%
pressurizer level.
AND Immediately C.2 Suspend positive reactivity additions.
Immediately D. Required Action and associated Completion Time of Condition A or B not met while in MODE 6.
OR Requirements of LCO not met for reasons other than Conditions A or B while in MODE 6.
D.1 Initiate action to remove the upper internals.
AND Immediately D.2 Suspend positive reactivity additions.
Immediately SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.13.1 Verify that each ADS stage 1, 2, and 3 valve is in the fully open position.
12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />
GTST AP1000-O34-3.4.13, Rev. 1 ADS - Shutdown, RCS Open 3.4.13 AP1000 STS 3.4.13-3 Amendment 0Rev. 0 Revision 19 Date report generated:
Wednesday, May 27, 2015 Page 17 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.4.13.2 For each ADS stage 4 flow path required to be OPERABLE, the following SRs of LCO 3.4.11, Automatic Depressurization System (ADS) -
Operating are applicable:
SR 3.4.11.1 SR 3.4.11.3 SR 3.4.11.5 In accordance with applicable SRs
GTST AP1000-O34-3.4.13, Rev. 1 ADS - Shutdown, RCS Open B 3.4.13 AP1000 STS B 3.4.13-1 Amendment 0Rev. 0 Revision 19 Date report generated:
Wednesday, May 27, 2015 Page 18 B 3.4 REACTOR COOLANT SYSTEM (RCS)
B 3.4.13 Automatic Depressurization System (ADS) - Shutdown, RCS Open BASES BACKGROUND A description of the ADS is provided in the Bases for LCO 3.4.11, Automatic Depressurization System (ADS) - Operating.
APPLICABLE SAFETY ANALYSES When the plant is shutdown with the RCS depressurized, the core makeup tanks (CMTs) are isolated to prevent CMT injection. Since the ADS is actuated by low CMT level, automatic actuation of the ADS is not available. The required ADS stage 1, 2, and 3 vent paths are opened and two ADS stage 4 flow paths are OPERABLE to ensure that in-containment refueling water storage tank (IRWST) injection and containment recirculation can occur, if needed to mitigate events requiring RCS makeup, boration or core cooling (Ref. 1).
The ADS vent path must be maintained until the upper internals are removed, providing an adequate vent path for IRWST injection.
The ADS satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).
LCO The requirement that ADS stage 1, 2, and 3 flow paths be open, from the pressurizer through the spargers into the IRWST, and that two ADS stage 4 flow paths be OPERABLE ensures assures that sufficient vent area is available to support IRWST injection.
The Note allows closure of the RCS pressure boundary when the pressurizer level is < 20% to facilitate vacuum refill following mid-loop operations to establish a pressurizer water level 20%. Prior to closure of the ADS valves, compliance with LCO 3.4.12, ADS - Shutdown, RCS Intact, must should be verified.
APPLICABILITY In MODE 5 with the reactor coolant system pressure boundary (RCPB) open or pressurizer level < 20%, in MODE 5 with the reactor coolant system pressure boundary (RCPB) open, and in MODE 6 with the upper internals in place, the stage 1, 2, and 3 ADS flow vent paths must be open and two ADS stage 4 flow paths be OPERABLE.
GTST AP1000-O34-3.4.13, Rev. 1 ADS - Shutdown, RCS Open B 3.4.13 AP1000 STS B 3.4.13-2 Amendment 0Rev. 0 Revision 19 Date report generated:
Wednesday, May 27, 2015 Page 19 BASES APPLICABILITY (continued)
The requirements for the ADS in MODES 1 through 4 are specified in LCO 3.4.11, Automatic Depressurization System (ADS) - Operating and in MODE 5 with the RCPB intact in LCO 3.4.12, Automatic Depressurization System (ADS) - Shutdown, RCS Intact.
ACTIONS A.1 and A.2 If one required ADS stage 1, 2, or 3 flow path is closed, action must be taken to open the affected path or establish an alternative flow path within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. In this Condition the remaining open ADS stage 1, 2, and 3 flow paths and the OPERABLE ADS stage 4 flow paths are adequate to perform the required safety function without an additional single failure. The stage 4 valves would have to be opened by the operator in case of an event while in the applicable MODES and other specified conditions of this Specification in this MODE. The required vent area may be restored by opening the affected ADS flow path or an alternate vent path with an equivalent area. Considering that the required function is available in this Condition a Completion Time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is acceptable.
B.1 and B.2 If one required ADS stage 4 flow path is closed and inoperable, action must be taken to establish an alternative flow path, or restore both of the at least two required ADS stage 4 flow paths to OPERABLE status within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. In this Condition the remaining open ADS stage 1, 2, and 3 flow paths and the one remaining OPERABLE ADS stage 4 flow path are adequate to perform the required safety function without an additional single failure. The required vent area may be restored by opening an alternate vent path with an equivalent area. Acceptable alternate vent paths exclude the use of the pressurizer manway as pressurizer surge line flooding phenomena can negate the IRWST elevation head necessary for successful gravity injection. Alternatively, two stage 4 flow paths may be restored to OPERABLE status. Therefore a Completion Time of 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> is considered acceptable.
GTST AP1000-O34-3.4.13, Rev. 1 ADS - Shutdown, RCS Open B 3.4.13 AP1000 STS B 3.4.13-3 Amendment 0Rev. 0 Revision 19 Date report generated:
Wednesday, May 27, 2015 Page 20 BASES ACTIONS (continued)
C.1 and C.2 If the Required Actions and associated Completion Times of Condition A or B are not met or the requirements of LCO 3.4.13 is are not met for reasons other than Conditions A or B while in MODE 5, the plant must be placed in a condition which minimizes the potential for requiring ADS venting and IRWST injection. The time to RCS boiling is maximized by increasing RCS inventory to 20% pressurizer level and maintaining RCS temperature as low as practical.
Additionally, action to suspend positive reactivity additions is required to ensure that the SDM is maintained. Sources of positive reactivity addition include boron dilution, withdrawal of reactivity control rods assemblies, and excessive cooling of the RCS.
D.1 and D.2 If the Required Actions and associated Completion Times of Condition A or B are not met or the requirements of LCO 3.4.13 is are not met for reasons other than Conditions A or B while in MODE 6, the plant must be placed in a condition which precludes the need for the ADS vent paths.
Action must be initiated, immediately, to remove the upper internals, which provides providing the required vent path. The time to RCS boiling is maximized by increasing RCS inventory and maintaining RCS temperature as low as practical.
Additionally, action to suspend positive reactivity additions is required to ensure that the SDM is maintained. Sources of positive reactivity addition include boron dilution, withdrawal of reactivity control rods assemblies, and excessive cooling of the RCS.
SURVEILLANCE REQUIREMENTS SR 3.4.13.1 Each required ADS flow path is verified to be open by verifying that the ADS stage 1, 2, and 3 valves are in their fully open position every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, as indicated in the control room. This Surveillance Frequency is acceptable based on administrative controls which preclude repositioning the valves.
GTST AP1000-O34-3.4.13, Rev. 1 ADS - Shutdown, RCS Open B 3.4.13 AP1000 STS B 3.4.13-4 Amendment 0Rev. 0 Revision 19 Date report generated:
Wednesday, May 27, 2015 Page 21 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.4.13.2 The LCO 3.4.11 Surveillance Requirements (SR 3.4.11.1, and SR 3.4.11.3, and SR 3.4.11.5) are applicable to the valves in the two stage 4 ADS flow paths valves required to be OPERABLE. The Frequencies associated with each specified SR are applicable. Refer to the corresponding Bases for LCO 3.4.11 for a discussion of each SR.
REFERENCES
- 1.
FSAR Section 19E.4, Safety Analyses and Evaluations.
GTST AP1000-O34-3.4.13, Rev. 1 Date report generated:
Wednesday, May 27, 2015 Page 22 XII. Applicable STS Subsection After Incorporation of this GTSTs Modifications The entire subsection of the Specifications and the Bases associated with this GTST, following incorporation of the modifications, is presented next.
GTST AP1000-O34-3.4.13, Rev. 1 ADS - Shutdown, RCS Open 3.4.13 AP1000 STS 3.4.13-1 Rev. 0 Date report generated:
Wednesday, May 27, 2015 Page 23 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.13 Automatic Depressurization System (ADS) - Shutdown, RCS Open LCO 3.4.13 ADS stage 1, 2, and 3 flow paths shall be open.
Two ADS stage 4 flow paths shall be OPERABLE.
NOTE---------------------------------------------
In MODE 5, the ADS valves may be closed to facilitate RCS vacuum fill operations to establish a pressurizer level 20%, provided ADS valve OPERABILITY meets LCO 3.4.12, ADS - Shutdown, RCS Intact.
APPLICABILITY:
MODE 5 with pressurizer level < 20%,
MODE 5 with RCS pressure boundary open, MODE 6 with upper internals in place.
ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One ADS stage 1, 2, or 3 flow path not open.
A.1 Open the affected flow path.
OR 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> A.2 Open an alternative flow path with an equivalent area.
72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> B. One required ADS stage 4 flow path inoperable.
B.1 Open an alternative flow path with an equivalent area.
OR 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> B.2 Restore required ADS stage 4 flow paths to OPERABLE status.
36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />
GTST AP1000-O34-3.4.13, Rev. 1 ADS - Shutdown, RCS Open 3.4.13 AP1000 STS 3.4.13-2 Rev. 0 Date report generated:
Wednesday, May 27, 2015 Page 24 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME C. Required Action and associated Completion Time of Condition A or B not met while in MODE 5.
OR LCO not met for reasons other than Condition A or B while in MODE 5.
C.1 Initiate action to fill the RCS to establish 20%
pressurizer level.
AND Immediately C.2 Suspend positive reactivity additions.
Immediately D. Required Action and associated Completion Time of Condition A or B not met while in MODE 6.
OR LCO not met for reasons other than Condition A or B while in MODE 6.
D.1 Initiate action to remove the upper internals.
AND Immediately D.2 Suspend positive reactivity additions.
Immediately SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.13.1 Verify each ADS stage 1, 2, and 3 valve is in the open position.
12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />
GTST AP1000-O34-3.4.13, Rev. 1 ADS - Shutdown, RCS Open 3.4.13 AP1000 STS 3.4.13-3 Rev. 0 Date report generated:
Wednesday, May 27, 2015 Page 25 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.4.13.2 For each ADS stage 4 flow path required to be OPERABLE, the following SRs are applicable:
SR 3.4.11.1 SR 3.4.11.3 SR 3.4.11.5 In accordance with applicable SRs
GTST AP1000-O34-3.4.13, Rev. 1 ADS - Shutdown, RCS Open B 3.4.13 AP1000 STS B 3.4.13-1 Rev. 0 Date report generated:
Wednesday, May 27, 2015 Page 26 B 3.4 REACTOR COOLANT SYSTEM (RCS)
B 3.4.13 Automatic Depressurization System (ADS) - Shutdown, RCS Open BASES BACKGROUND A description of the ADS is provided in the Bases for LCO 3.4.11, Automatic Depressurization System (ADS) - Operating.
APPLICABLE SAFETY ANALYSES When the plant is shutdown with the RCS depressurized, the core makeup tanks (CMTs) are isolated to prevent CMT injection. Since the ADS is actuated by low CMT level, automatic actuation of the ADS is not available. The ADS stage 1, 2, and 3 vent paths are opened and two ADS stage 4 flow paths are OPERABLE to ensure that in-containment refueling water storage tank (IRWST) injection and containment recirculation can occur, if needed to mitigate events requiring RCS makeup, boration or core cooling (Ref. 1).
The ADS vent path must be maintained until the upper internals are removed, providing an adequate vent path for IRWST injection.
The ADS satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).
LCO The requirement that ADS stage 1, 2, and 3 flow paths be open, from the pressurizer through the spargers into the IRWST, and that two ADS stage 4 flow paths be OPERABLE ensures that sufficient vent area is available to support IRWST injection.
The Note allows closure of the RCS pressure boundary when the pressurizer level is < 20% to facilitate vacuum refill following mid-loop operations to establish a pressurizer water level 20%. Prior to closure of the ADS valves, compliance with LCO 3.4.12, ADS - Shutdown, RCS Intact, must be verified.
APPLICABILITY In MODE 5 with pressurizer level < 20%, in MODE 5 with the reactor coolant system pressure boundary (RCPB) open, and in MODE 6 with the upper internals in place, the stage 1, 2, and 3 ADS flow paths must be open and two ADS stage 4 flow paths be OPERABLE.
GTST AP1000-O34-3.4.13, Rev. 1 ADS - Shutdown, RCS Open B 3.4.13 AP1000 STS B 3.4.13-2 Rev. 0 Date report generated:
Wednesday, May 27, 2015 Page 27 BASES APPLICABILITY (continued)
The requirements for the ADS in MODES 1 through 4 are specified in LCO 3.4.11, Automatic Depressurization System (ADS) - Operating and in MODE 5 with the RCPB intact in LCO 3.4.12, Automatic Depressurization System (ADS) - Shutdown, RCS Intact.
ACTIONS A.1 and A.2 If one ADS stage 1, 2, or 3 flow path is closed, action must be taken to open the affected path or establish an alternative flow path within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. In this Condition the remaining open ADS stage 1, 2, and 3 flow paths and the OPERABLE ADS stage 4 flow paths are adequate to perform the required safety function without an additional single failure.
The stage 4 valves would have to be opened by the operator in case of an event while in the applicable MODES and other specified conditions of this Specification. The required vent area may be restored by opening the affected ADS flow path or an alternate vent path with an equivalent area. Considering that the required function is available in this Condition a Completion Time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is acceptable.
B.1 and B.2 If one required ADS stage 4 flow path is inoperable, action must be taken to establish an alternative flow path, or restore both of the two required ADS stage 4 flow paths to OPERABLE status within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. In this Condition the remaining open ADS stage 1, 2, and 3 flow paths and the one remaining OPERABLE ADS stage 4 flow path are adequate to perform the required safety function without an additional single failure.
The required vent area may be restored by opening an alternate vent path with an equivalent area. Acceptable alternate vent paths exclude the use of the pressurizer manway as pressurizer surge line flooding phenomena can negate the IRWST elevation head necessary for successful gravity injection. Alternatively, two stage 4 flow paths may be restored to OPERABLE status. Therefore a Completion Time of 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> is considered acceptable.
GTST AP1000-O34-3.4.13, Rev. 1 ADS - Shutdown, RCS Open B 3.4.13 AP1000 STS B 3.4.13-3 Rev. 0 Date report generated:
Wednesday, May 27, 2015 Page 28 BASES ACTIONS (continued)
C.1 and C.2 If the Required Actions and associated Completion Times of Condition A or B are not met or LCO 3.4.13 is not met for reasons other than Condition A or B while in MODE 5, the plant must be placed in a condition which minimizes the potential for requiring ADS venting and IRWST injection. The time to RCS boiling is maximized by increasing RCS inventory to 20% pressurizer level.
Additionally, action to suspend positive reactivity additions is required to ensure that the SDM is maintained. Sources of positive reactivity addition include boron dilution, withdrawal of control rods, and excessive cooling of the RCS.
D.1 and D.2 If the Required Actions and associated Completion Times of Condition A or B are not met or LCO 3.4.13 is not met for reasons other than Condition A or B while in MODE 6, the plant must be placed in a condition which precludes the need for the ADS vent paths. Action must be initiated immediately to remove the upper internals, which provides the required vent path.
Additionally, action to suspend positive reactivity additions is required to ensure that the SDM is maintained. Sources of positive reactivity addition include boron dilution, withdrawal of control rods, and excessive cooling of the RCS.
SURVEILLANCE REQUIREMENTS SR 3.4.13.1 Each required ADS flow path is verified to be open by verifying that the ADS stage 1, 2, and 3 valves are in their open position every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, as indicated in the control room. This Surveillance Frequency is acceptable based on administrative controls which preclude repositioning the valves.
GTST AP1000-O34-3.4.13, Rev. 1 ADS - Shutdown, RCS Open B 3.4.13 AP1000 STS B 3.4.13-4 Rev. 0 Date report generated:
Wednesday, May 27, 2015 Page 29 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.4.13.2 SR 3.4.11.1, SR 3.4.11.3, and SR 3.4.11.5 are applicable to the valves in the two stage 4 ADS flow paths required to be OPERABLE. The Frequencies associated with each specified SR are applicable. Refer to the corresponding Bases for LCO 3.4.11 for a discussion of each SR.
REFERENCES
- 1.
FSAR Section 19E.4, Safety Analyses and Evaluations.