ML22240A084

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Changes Related to AP1000 Gts Subsection 3.6.4, Containment Pressure
ML22240A084
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Issue date: 05/12/2015
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Craig Harbuck NRR/DSS 301-415-3140
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GTST AP1000-P13-3.6.4, Rev. 1 Advanced Passive 1000 (AP1000)

Generic Technical Specification Traveler (GTST)

Title:

Changes Related to LCO 3.6.4, Containment Pressure 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:

TSTF-425, Rev. 3, Relocate Surveillance Frequencies to Licensee Control - RITSTF Initiative 5b STS NUREGs Affected:

TSTF-425, Rev. 3: NUREG-1430, 1431, 1432, 1433, 1434 NRC Approval Date:

TSTF-425, Rev. 3: 06-Jul-09 TSTF Classification:

TSTF-425, Rev. 3: Technical Change Date report generated:

Tuesday, May 12, 2015 Page 1

GTST AP1000-P13-3.6.4, Rev. 1 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:

None RCOL COL Item Number and

Title:

None RCOL PTS Change Number and

Title:

VEGP LAR DOC A083: TS 3.6.4, Condition B Divided into Two Separate Conditions VEGP LAR DOC A084: TS 3.6.4, Applicability Editorial Change Date report generated:

Tuesday, May 12, 2015 Page 2

GTST AP1000-P13-3.6.4, Rev. 1 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(1) applicable to operating reactor designs, but not to the AP1000 design; (2) already incorporated in the GTS; or (3) superseded by another change.

The Actions section of the bases is revised by VEGP LAR DOC A083 to include discussion of Condition C. The NRC staff proposed changes that revise portions of the VEGP LAR DOC A083 changes.

TSTF-425 is deferred for future consideration.

Date report generated:

Tuesday, May 12, 2015 Page 3

GTST AP1000-P13-3.6.4, Rev. 1 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)

Applicability statement is revised to correct the punctuation after MODES 1, 2, 3, and 4. from a period to a comma.

Reference to LCO 3.6.8 is revised to LCO 3.6.7 in the Applicability and Actions sections of the Bases.

The Applicability Note is revised from ...MODES 5 or 6. to ...MODES 5 and 6.

In the Actions section of the Bases, under heading B.1, B.2, and C.1, revise second and third paragraphs as suggested by APOG comment but with additional changes to further clarify applicable plant conditions specified in the required actions.

APOG Recommended Changes to Improve the Bases Throughout the Bases, references to Sections and Chapters of the FSAR do not include the FSAR modifier. Since these Section and Chapter references are to an external document, it is appropriate to include the acronym FSAR to modify Section and Chapter in references to the FSAR throughout the Bases. (DOC A003)

Revise the Applicability section of the Bases, fourth paragraph from ...the cooling events... to

...the containment cooling events...

Revise the Actions section of the Bases, under heading B.1, B.2, and C.1, in the third paragraph capitalize the word Ccondition. In the fourth paragraph capitalize ...Ccontainment Aair Ffiltration Ssystem...

Revise the Actions section of the Bases, under heading B.1, B.2, and C.1, second and third paragraph as follows:

If the containment high low pressure limit is still not met, Condition C appliesonly Condition B applies since entry into MODE 5 is sufficient to exit the Applicability applies.

If the containment low pressure limit is not met both Conditions B and C apply.

Once in MODE 5 or 6, Required Action C.1 requires that a containment air flow path 6 inches in diameter shall be opened within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> from condition entry.

Revise the Surveillance Requirements section of the Bases, delete the word both from

...related to trending of both containment pressure variations...

Date report generated:

Tuesday, May 12, 2015 Page 4

GTST AP1000-P13-3.6.4, Rev. 1 V. Applicability Affected Generic Technical Specifications and Bases:

Section 3.6.4, Containment Pressure Changes to the Generic Technical Specifications and Bases:

Applicability statement is revised to correct punctuation. (NRC staff proposed change)

Applicability statement for TS 3.6.4 is formatted to meet requirements of TSTF-GG-05-01, subsection 2.5.4.b.1. (DOC A084)

Condition B is divided into two separate Conditions. The applicable Condition and MODES are added to Condition B entry statement. Required Action B.3 is moved to proposed Condition C and Completion Time is revised. The Actions section of the bases is revised to include Action C.1. (DOC A083)

The Applicability and Actions sections of the Bases reference to LCO 3.6.8 is revised to LCO 3.6.7. (NRC staff proposed change)

The Applicability Note is revised from ...MODES 5 or 6. to MODES 5 and 6. (NRC staff proposed change)

The acronym FSAR is added to modify Section and Chapter in references to the FSAR throughout the Bases. (DOC A003) (APOG Comment)

In the Applicability section of the Bases, fourth paragraph, the first sentence is revised from

...the cooling events... to ...the containment cooling events... (APOG Comment)

In the Actions section of the Bases, under heading B.1, B.2, and C.1, in the third paragraph the word Ccondition is capitalized. In the fourth paragraph ...Ccontainment Aair Ffiltration Ssystem... is capitalized. (APOG Comment)

In the Actions section of the Bases, under heading B.1, B.2, and C.1, the second and third paragraphs are revised for clarity. (APOG Comment) The proposed changes were revised by NRC staff to provide more clarity.

In the Surveillance Requirements section of the Bases, the word both is deleted from

...related to trending of both containment pressure variations... (APOG Comment)

Date report generated:

Tuesday, May 12, 2015 Page 5

GTST AP1000-P13-3.6.4, Rev. 1 VI. Traveler Information Description of TSTF changes:

None Rationale for TSTF changes:

None Description of changes in RCOL Std. Dep., RCOL COL Item(s), and RCOL PTS Changes:

VEGP LAR DOC A083 adds Condition C to the specification and moves Required Action B.3 to the added Condition C. The Completion Time for Required Action B.3 is revised from 44 hours5.092593e-4 days <br />0.0122 hours <br />7.275132e-5 weeks <br />1.6742e-5 months <br /> to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. Condition B entry statement is revised to include the applicable Condition and MODES.

VEGP LAR DOC A084 adds the appropriate hanging indent to the Applicability statement.

Rationale for changes in RCOL Std. Dep., RCOL COL Item(s), and RCOL PTS Changes:

VEGP LAR DOC A083 divides Action B into two separate Actions, which is an editorial change.

Adding the specific Condition and applicable Modes to Condition B provides clarification.

VEGP LAR DOC A084 is a reformatting change that provides consistency with TSTF-GG-05-01.

Description of additional changes proposed by NRC staff/preparer of GTST:

The Applicability statement is revised by changing the period after MODES 1, 2, 3, and 4. to a comma.

The Applicability and Actions sections of the bases reference LCO 3.6.8. Due to VEGP LAR DOC M13 changes the reference to LCO 3.6.8 is revised to LCO 3.6.7.

The Applicability Note is revised from ...MODES 5 or 6. to ...MODES 5 and 6.

The acronym FSAR is added to modify Section and Chapter in references to the FSAR throughout the Bases. (DOC A003) (APOG Comment)

The Applicability section of the Bases, fourth paragraph is revised from ...the cooling events... to the containment cooling events... (APOG Comment)

The Actions section of the Bases, under heading B.1, B.2, and C.1, the third paragraph is revised by capitalizing the word Ccondition. In the fourth paragraph the phrase

...Ccontainment Aair Ffiltration Ssystem... is capitalized. (APOG Comment)

The Actions section of the Bases, under heading B.1, B.2, and C.1, the second and third paragraphs are revised to clarify Condition applicability. (APOG Comment)

Date report generated:

Tuesday, May 12, 2015 Page 6

GTST AP1000-P13-3.6.4, Rev. 1 The Surveillance Requirements section of the Bases, the word both is deleted from ...related to trending of both containment pressure variations... (APOG Comment)

Rationale for additional changes proposed by NRC staff/preparer of GTST:

The change to the Applicability statement is a correction to the punctuation.

The reference to LCO 3.6.8 is renumbered to LCO 3.6.7 in the Applicability and Actions section of the bases, due to renumbering of TS 3.6 section based on VEGP LAR DOC M13 changes. VEGP LAR DOC M13 change combines TS 3.6.6 and TS 3.6.7 into a single new TS 3.6.6, which results in renumbering subsequent TS 3.6 sections.

Revising the Applicability Note from ...MODES 5 or 6. to ...MODES 5 and 6. is an editorial change.

Since Bases references to FSAR Sections and Chapters are to an external document, it is appropriate to include the FSAR modifier.

Revising the Applicability section of the Bases to include containment before cooling events is an editorial clarification.

Revising the Actions section of the Bases to capitalize the word Condition and the phrase

...Containment Air Filtration System... is an editorial change.

Revising the Actions section of the Bases to clarify Condition applicability is an editorial change for clarification.

Revising the Surveillance Requirements section of the Bases by deleting the word both is an editorial change.

Date report generated:

Tuesday, May 12, 2015 Page 7

GTST AP1000-P13-3.6.4, Rev. 1 VII. GTST Safety Evaluation Technical Analysis:

VEGP LAR DOC A083 revises Action B, which provides the actions required to be taken when the containment pressure is not restored to within limits in 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, as specified in Action A.

Splitting the GTS Action B into two separate Actions is an editorial change. The actions required to be taken when the Required Action and associated Completion Time of Condition A are not met is not changed. If the unit is initially in Mode 1, 2, 3, or 4, then proposed Condition B is entered, which requires a unit shutdown to Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to Mode 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. This is the same as the GTS requirements.

Once in Mode 5, proposed Condition C is entered. The actions required to be taken by proposed Condition C require a containment air flow path 6 inches in diameter be open within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. Currently, while 44 hours5.092593e-4 days <br />0.0122 hours <br />7.275132e-5 weeks <br />1.6742e-5 months <br /> is allowed to open a containment air flow path 6 inches in diameter, the time starts upon entry into Condition B. Since proposed Condition C is not entered until after Mode 5 is reached, and the proposed Required Action B.2 allows 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> for this, the proposed 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Completion Time of Required Action C.1 allows no more time than is currently allowed.

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 3.6.4 is an acceptable model Specification for the AP1000 standard reactor design.

References to Previous NRC Safety Evaluation Reports (SERs):

None Date report generated:

Tuesday, May 12, 2015 Page 8

GTST AP1000-P13-3.6.4, Rev. 1 VIII. Review Information Evaluator Comments:

None Steve Short Pacific Northwest National Laboratory 509-375-2868 steve.short@pnnl.gov Review Information:

Availability for public review and comment on Revision 0 of this traveler approved by NRC staff on 5/23/2014.

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 modifier. 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 to every FSAR reference in the Bases.
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. This is resolved by making the APOG recommended changes to the GTST.
3. (Internal #13) The NRC approval of TSTF-425, and model safety evaluation provided in the CLIIP for TSTF-425, are generically applicable to any designs Technical Specifications. As such, the replacement of certain Frequencies with a Surveillance Frequency Control Program should be included in the GTST for AP1000 STS NUREG.

However, implementation in the AP1000 STS should not reflect optional (i.e., bracketed) material showing retention of fixed Surveillance Frequencies where relocation to a Surveillance Frequency Control Program is acceptable. Since each represented AP1000 Utility is committed to maintaining standardization, there is no rationale for an AP1000 STS that includes bracketed options.

Consistent with TSTF-425 criteria, replace applicable Surveillance Frequencies with In accordance with the Surveillance Frequency control Program and add that Program as new AP1000 STS Specification 5.5.15.

NRC Staff disagreed with implementing TSTF-425 in the initial version of the STS.

Although the APOG thinks the analysis supporting this traveler is general enough to be applicable to AP1000, staff thinks an AP1000-specific proposal from APOG is needed to identify any GTS SRs that should be excluded. Also, with the adoption of a Surveillance Frequency Control Program (SFCP) in the AP1000 STS, bracketed Frequencies, which provide a choice between the GTS Frequency and the SFCP Frequency, are needed Date report generated:

Tuesday, May 12, 2015 Page 9

GTST AP1000-P13-3.6.4, Rev. 1 because the NRC will use the AP1000 STS as a reference, and to be consistent with NUREG-1431, Rev. 4. APOG was requested to consider proposing an AP1000 version of TSTF-425 for a subsequent revision of the STS.

4. (Internal #349) First paragraph of the Technical Analysis discusses DOC A083. The last two sentences discuss an action that is not in GTS and is not in the revised STS (i.e., going to MODE 6). These sentences should be deleted as they are not relevant to the change.

This portion of the DOC A083 discussion is related to a similar change in GTS 3.6.5.

Delete sentences that read While the Required Action B.2 does not specify that an option is to be in MODE 6, it is always an option. It is not necessary to state that the unit can go to a lower mode. This is resolved by making the APOG recommended change.

5. (Internal #350) GTS LCO 3.6.4 has Applicability Notes that are mistakenly moved in the GTST as LCO Notes. The GTS evaluation and the corresponding Bases, continue to reflect the existence of Applicability Notes. The GTST Section XI and Section XII TS pages appear to have typographical errors in the placement of the Notes. Revise Section XI and Section XII to present the LCO Notes as Applicability Notes. This is resolved by making the APOG recommended change and revising MODES 5 or 6 to MODES 5 and 6 in the Applicability Note.
6. (Internal #351) Revise TS 3.6.4 Bases for the Applicability to change from the cooling events to the containment cooling events for clarification. This is resolved by making the APOG recommended change to the Applicability section of the Bases, fourth paragraph, first sentence as follows:

Therefore, maintaining containment pressure within the low pressure limit is essential to ensure initial conditions assumed in the containment cooling events in MODES 1...

7. (Internal #352 and #353) Revise the Actions section of the Bases. The editorial changes provide clarity and correction. These changes are made for consistency with the TS 3.6.4 requirements being discussed in the Bases. This is resolved by making the APOG recommended changes and additional NRC staff proposed changes as follows:

Upon entry into MODE 5, Iif the containment highlow pressure limit is still not met, or if while in MODE 5 or 6 the containment pressure cannot be restored to within its low pressure limit within the required Completion Time, Condition C appliesentry into MODE 5 is sufficient to exit the Applicability. If the containment low pressure limit is not met, Required Action B.3 applies.

If in MODE 5 or 6 the containment low pressure limit is not met,Required Action C.1 requires that a containment air flow path 6 inches in diameter shall be opened within 448 hours0.00519 days <br />0.124 hours <br />7.407407e-4 weeks <br />1.70464e-4 months <br /> from cCondition entry. Any flow path (or paths) with an area equivalent to 6 inches in diameter is adequate to provide the necessary air flow.

The primary means of opening a containment air flow path is by establishing a cContainment aAir fFiltration sSystem (VFS) air flow path into...

8. (Internal #354) Editorial change is recommended. These non-technical changes provide improved clarity, consistency, and operator usability. This is resolved by making the APOG recommended changes to the Surveillance Requirements section of the Bases, by deleting the word both from the second sentence.

Date report generated:

Tuesday, May 12, 2015 Page 10

GTST AP1000-P13-3.6.4, Rev. 1 NRC Final Approval Date: 5/12/2015 NRC

Contact:

Hien M. Le United States Nuclear Regulatory Commission 301-415-1511 Hien.Le@nrc.gov Date report generated:

Tuesday, May 12, 2015 Page 11

GTST AP1000-P13-3.6.4, Rev. 1 IX. Evaluator Comments for Consideration in Finalizing Technical Specifications and Bases None Date report generated:

Tuesday, May 12, 2015 Page 12

GTST AP1000-P13-3.6.4, Rev. 1 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. 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).
4. TSTF-GG-05-01, Writer's Guide for Plant-Specific Improved Technical Specifications, June 2005 (ML070660229).
5. 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 Enclosure 1 - Amendment No. 13 to COL No. NPF-91 ML13239A256 Enclosure 2 - Amendment No. 13 to COL No. NPF-92 ML13239A284 Enclosure 3 - Revised plant-specific TS pages (Attachment to Amendment No. 13)

ML13239A287 Enclosure 4 - 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 Enclosure 3:

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 Enclosure 3 - Revised plant-specific TS pages (Attachment to Amendment No. 13) (corrected)

6. 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).

Date report generated:

Tuesday, May 12, 2015 Page 13

GTST AP1000-P13-3.6.4, Rev. 1

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).

Date report generated:

Tuesday, May 12, 2015 Page 14

GTST AP1000-P13-3.6.4, Rev. 1 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.

Date report generated:

Tuesday, May 12, 2015 Page 15

GTST AP1000-P13-3.6.4, Rev. 1 Containment Pressure 3.6.4 3.6 CONTAINMENT SYSTEMS 3.6.4 Containment Pressure LCO 3.6.4 Containment pressure shall be -0.2 psig and +1.0 psig.

APPLICABILITY: MODES 1, 2, 3, and 4.,

MODES 5 and 6 without an open containment air flow path 6 inches in diameter.

NOTE---------------------------------------------

The high pressure LCO limit is not applicable in MODES 5 orand 6.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. Containment pressure A.1 Restore containment 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> not within limits. pressure to within limits.

B. Required Action and B.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion Time of Condition A not AND met in MODE 1, 2, 3, or 4. B.2 Be in MODE 5. 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> AND B.3 Open a containment air 44 hours5.092593e-4 days <br />0.0122 hours <br />7.275132e-5 weeks <br />1.6742e-5 months <br /> flow path 6 inches in diameter.

AP1000 STS 3.6.4-1 Amendment 0Rev. 0 Revision 19 Date report generated:

Tuesday, May 12, 2015 Page 16

GTST AP1000-P13-3.6.4, Rev. 1 Containment Pressure 3.6.4 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME C. Required Action and C.1 Open a containment air 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> associated Completion flow path 6 inches in Time of Condition A diameter.

not met in MODE 5 or 6.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.4.1 Verify containment pressure is within limits. 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> AP1000 STS 3.6.4-2 Amendment 0Rev. 0 Revision 19 Date report generated:

Tuesday, May 12, 2015 Page 17

GTST AP1000-P13-3.6.4, Rev. 1 Containment Pressure B 3.6.4 B 3.6 CONTAINMENT SYSTEMS B 3.6.4 Containment Pressure BASES BACKGROUND The containment pressure is limited during normal operation to preserve the initial conditions assumed in the accident analyses for a loss of coolant accident (LOCA) or steam line break (SLB). These limits also prevent the containment pressure from exceeding the containment design negative pressure differential with respect to the outside atmosphere in the event of transients which result in a negative pressure.

Containment pressure is a process variable that is monitored and controlled. The containment pressure limits are derived from the operating band of conditions used in the containment pressure analyses for the Design Basis Events which result in internal or external pressure loads on the containment vessel. Should operation occur outside these limits, the initial containment pressure would be outside the range used for containment pressure analyses.

APPLICABLE Containment internal pressure is an initial condition used in the DBA SAFETY analyses to establish the maximum peak containment internal pressure.

ANALYSES The limiting DBAs considered, relative to containment pressure, are the LOCA and SLB, which are analyzed using computer pressure transients.

The worst case LOCA generates larger mass and energy release than the worst cast SLB. Thus, the LOCA event bounds the SLB event from the containment peak pressure standpoint (Ref. 1).

The initial pressure condition used in the containment analysis was 15.7 psia (1.0 psig). This resulted in a maximum peak pressure from a LOCA, Pa, of 58.3 psig. The containment analysis (Ref. 1) shows that the maximum peak calculated containment pressure results from the limiting LOCA. The maximum containment pressure resulting from the worst case LOCA does not exceed the containment design pressure, 59 psig.

AP1000 STS B 3.6.4-1 Amendment 0Rev. 0 Revision 19 Date report generated:

Tuesday, May 12, 2015 Page 18

GTST AP1000-P13-3.6.4, Rev. 1 Containment Pressure B 3.6.4 BASES APPLICABLE SAFETY ANALYSES (continued)

The containment was also designed for an external pressure load equivalent to 1.7 psid. The limiting negative pressure transient is a loss of all AC power sources coincident with extreme cold weather conditions which cool the external surface of the containment vessel. The initial pressure condition used in this analysis was -0.2 psig. This resulted in a minimum pressure inside containment, as illustrated in Reference 1, which is less than the design load. Other external pressure load events evaluated include:

Failed fan cooler control Malfunction of containment purge system Inadvertent Passive Containment Cooling System (PCS) actuation Containment pressure satisfies Criterion 2 of 10 CFR 50.36(c)(2)(ii).

LCO Maintaining containment pressure at less than or equal to the LCO upper pressure limit ensures that, in the event of a DBA, the resultant peak containment accident pressure will remain below the containment design pressure.

Maintaining containment pressure at greater than or equal to the LCO lower pressure limit ensures that the containment will not exceed the design negative differential pressure following negative pressure transients. If the containment pressure does not meet the low pressure limit, the containment vacuum relief capacity of one flow path may not be adequate to ensure the containment pressure meets the negative pressure design limit.

APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material to containment. Since maintaining containment pressure within the high pressure limit is essential to ensure initial conditions assumed in the accident analyses are maintained, the LCO is applicable in MODES 1, 2, 3, and 4.

In MODES 5 and 6, the probability and consequences of these events are reduced due to the pressure and temperature limitations of these MODES. Therefore, maintaining containment pressure within the high pressure limit of the LCO is not required in MODE 5 or 6.

AP1000 STS B 3.6.4-2 Amendment 0Rev. 0 Revision 19 Date report generated:

Tuesday, May 12, 2015 Page 19

GTST AP1000-P13-3.6.4, Rev. 1 Containment Pressure B 3.6.4 BASES APPLICABILITY (continued)

In MODES 1 through 6, the potential exists for excessive containment cooling events to produce a negative containment pressure below the design limit. However, in MODES 5 and 6, a containment air flow path may be opened (LCO 3.6.87, Containment Penetrations), providing a vacuum relief path that is sufficient to preclude a negative containment pressure below the design limit.

Therefore, maintaining containment pressure within the low pressure limit is essential to ensure initial conditions assumed in the containment cooling events in MODES 1 through 4 and in MODES 5 and 6 without an open containment air flow path 6 inches in diameter. With a 6 inch diameter or equivalent containment air flow path, the vacuum relief function is not needed to mitigate a low pressure event.

ACTIONS A.1 When containment pressure is not within the limits of the LCO, it must be restored within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. The Required Action is necessary to return operation to within the bounds of the containment analysis. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is consistent with the ACTIONS of LCO 3.6.1, Containment, which requires that containment be restored to OPERABLE status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

B.1, B.2, and B.3C.1 If the containment pressure cannot be restored to within its limits within the required Completion Time in MODE 1, 2, 3, or 4, the plant must be placed in a condition in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. 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.

Upon entry into MODE 5, Iif the containment highlow pressure limit is still not met, or if while in MODE 5 or 6 the containment pressure cannot be restored to within its low pressure limit within the required Completion Time, Condition C appliesentry into MODE 5 is sufficient to exit the Applicability. If the containment low pressure limit is not met, Required Action B.3 applies.

AP1000 STS B 3.6.4-3 Amendment 0Rev. 0 Revision 19 Date report generated:

Tuesday, May 12, 2015 Page 20

GTST AP1000-P13-3.6.4, Rev. 1 Containment Pressure B 3.6.4 BASES ACTIONS (continued)

If in MODE 5 or 6 the containment low pressure limit is not met,Required Action C.1 requires that a containment air flow path 6 inches in diameter shall be opened within 448 hours0.00519 days <br />0.124 hours <br />7.407407e-4 weeks <br />1.70464e-4 months <br /> from cCondition entry. Any flow path (or paths) with an area equivalent to 6 inches in diameter is adequate to provide the necessary air flow.

The primary means of opening a containment air flow path is by establishing a cContainment aAir fFiltration sSystem (VFS) air flow path into containment. Manual actuation and maintenance as necessary to open a purge supply, purge exhaust, or vacuum relief flow path are available means to open a containment air flow path. In addition, opening of a spare penetration is an acceptable means to provide the necessary flow path. Opening of an equipment hatch or a containment airlock is acceptable, but may not be possible due to the differential pressure condition. Containment air flow paths opened must comply with LCO 3.6.87, Containment Penetrations.

The 448 hour0.00519 days <br />0.124 hours <br />7.407407e-4 weeks <br />1.70464e-4 months <br /> Completion Time is reasonable for opening a containment air flow path in an orderly manner.

SURVEILLANCE SR 3.6.4.1 REQUIREMENTS Verifying that containment pressure is within limits ensures that unit operation remains within the limits assumed in the containment analysis.

The 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Frequency of this SR was developed based on operating experience related to trending of both containment pressure variations during the applicable MODES. Furthermore, the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Frequency is considered adequate in view of other indications available in the main control room, including alarms, to alert the operator to an abnormal containment pressure condition.

REFERENCES 1. FSAR Section 6.2, Containment Systems.

AP1000 STS B 3.6.4-4 Amendment 0Rev. 0 Revision 19 Date report generated:

Tuesday, May 12, 2015 Page 21

GTST AP1000-P13-3.6.4, Rev. 1 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.

Date report generated:

Tuesday, May 12, 2015 Page 22

GTST AP1000-P13-3.6.4, Rev. 1 Containment Pressure 3.6.4 3.6 CONTAINMENT SYSTEMS 3.6.4 Containment Pressure LCO 3.6.4 Containment pressure shall be -0.2 psig and +1.0 psig.

APPLICABILITY: MODES 1, 2, 3, and 4, MODES 5 and 6 without an open containment air flow path 6 inches in diameter.

NOTE---------------------------------------------

The high pressure LCO limit is not applicable in MODES 5 and 6.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. Containment pressure A.1 Restore containment 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> not within limits. pressure to within limits.

B. Required Action and B.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion Time of Condition A not AND met in MODE 1, 2, 3, or 4. B.2 Be in MODE 5. 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> C. Required Action and C.1 Open a containment air 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> associated Completion flow path 6 inches in Time of Condition A not diameter.

met in MODE 5 or 6.

AP1000 STS 3.6.4-1 Rev. 0 Date report generated:

Tuesday, May 12, 2015 Page 23

GTST AP1000-P13-3.6.4, Rev. 1 Containment Pressure 3.6.4 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.4.1 Verify containment pressure is within limits. 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> AP1000 STS 3.6.4-2 Rev. 0 Date report generated:

Tuesday, May 12, 2015 Page 24

GTST AP1000-P13-3.6.4, Rev. 1 Containment Pressure B 3.6.4 B 3.6 CONTAINMENT SYSTEMS B 3.6.4 Containment Pressure BASES BACKGROUND The containment pressure is limited during normal operation to preserve the initial conditions assumed in the accident analyses for a loss of coolant accident (LOCA) or steam line break (SLB). These limits also prevent the containment pressure from exceeding the containment design negative pressure differential with respect to the outside atmosphere in the event of transients which result in a negative pressure.

Containment pressure is a process variable that is monitored and controlled. The containment pressure limits are derived from the operating band of conditions used in the containment pressure analyses for the Design Basis Events which result in internal or external pressure loads on the containment vessel. Should operation occur outside these limits, the initial containment pressure would be outside the range used for containment pressure analyses.

APPLICABLE Containment internal pressure is an initial condition used in the DBA SAFETY analyses to establish the maximum peak containment internal pressure.

ANALYSES The limiting DBAs considered, relative to containment pressure, are the LOCA and SLB, which are analyzed using computer pressure transients.

The worst case LOCA generates larger mass and energy release than the worst cast SLB. Thus, the LOCA event bounds the SLB event from the containment peak pressure standpoint (Ref. 1).

The initial pressure condition used in the containment analysis was 15.7 psia (1.0 psig). This resulted in a maximum peak pressure from a LOCA, Pa, of 58.3 psig. The containment analysis (Ref. 1) shows that the maximum peak calculated containment pressure results from the limiting LOCA. The maximum containment pressure resulting from the worst case LOCA does not exceed the containment design pressure, 59 psig.

AP1000 STS B 3.6.4-1 Rev. 0 Date report generated:

Tuesday, May 12, 2015 Page 25

GTST AP1000-P13-3.6.4, Rev. 1 Containment Pressure B 3.6.4 BASES APPLICABLE SAFETY ANALYSES (continued)

The containment was also designed for an external pressure load equivalent to 1.7 psid. The limiting negative pressure transient is a loss of all AC power sources coincident with extreme cold weather conditions which cool the external surface of the containment vessel. The initial pressure condition used in this analysis was -0.2 psig. This resulted in a minimum pressure inside containment, as illustrated in Reference 1, which is less than the design load. Other external pressure load events evaluated include:

Failed fan cooler control Malfunction of containment purge system Inadvertent Passive Containment Cooling System (PCS) actuation Containment pressure satisfies Criterion 2 of 10 CFR 50.36(c)(2)(ii).

LCO Maintaining containment pressure at less than or equal to the LCO upper pressure limit ensures that, in the event of a DBA, the resultant peak containment accident pressure will remain below the containment design pressure.

Maintaining containment pressure at greater than or equal to the LCO lower pressure limit ensures that the containment will not exceed the design negative differential pressure following negative pressure transients. If the containment pressure does not meet the low pressure limit, the containment vacuum relief capacity of one flow path may not be adequate to ensure the containment pressure meets the negative pressure design limit.

APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material to containment. Since maintaining containment pressure within the high pressure limit is essential to ensure initial conditions assumed in the accident analyses are maintained, the LCO is applicable in MODES 1, 2, 3, and 4.

In MODES 5 and 6, the probability and consequences of these events are reduced due to the pressure and temperature limitations of these MODES. Therefore, maintaining containment pressure within the high pressure limit of the LCO is not required in MODE 5 or 6.

AP1000 STS B 3.6.4-2 Rev. 0 Date report generated:

Tuesday, May 12, 2015 Page 26

GTST AP1000-P13-3.6.4, Rev. 1 Containment Pressure B 3.6.4 BASES APPLICABILITY (continued)

In MODES 1 through 6, the potential exists for excessive containment cooling events to produce a negative containment pressure below the design limit. However, in MODES 5 and 6, a containment air flow path may be opened (LCO 3.6.7, Containment Penetrations), providing a vacuum relief path that is sufficient to preclude a negative containment pressure below the design limit.

Therefore, maintaining containment pressure within the low pressure limit is essential to ensure initial conditions assumed in the containment cooling events in MODES 1 through 4 and in MODES 5 and 6 without an open containment air flow path 6 inches in diameter. With a 6 inch diameter or equivalent containment air flow path, the vacuum relief function is not needed to mitigate a low pressure event.

ACTIONS A.1 When containment pressure is not within the limits of the LCO, it must be restored within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. The Required Action is necessary to return operation to within the bounds of the containment analysis. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is consistent with the ACTIONS of LCO 3.6.1, Containment, which requires that containment be restored to OPERABLE status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

B.1, B.2, and C.1 If the containment pressure cannot be restored to within its limits within the required Completion Time in MODE 1, 2, 3, or 4, the plant must be placed in a condition in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. 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.

Upon entry into MODE 5, if the containment low pressure limit is still not met, or if while in MODE 5 or 6 the containment pressure cannot be restored to within its low pressure limit within the required Completion Time, Condition C applies. Required Action C.1 requires that a containment air flow path 6 inches in diameter shall be opened within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> from Condition entry. Any flow path (or paths) with an area AP1000 STS B 3.6.4-3 Rev. 0 Date report generated:

Tuesday, May 12, 2015 Page 27

GTST AP1000-P13-3.6.4, Rev. 1 Containment Pressure B 3.6.4 BASES ACTIONS (continued) equivalent to 6 inches in diameter is adequate to provide the necessary air flow.

The primary means of opening a containment air flow path is by establishing a Containment Air Filtration System (VFS) air flow path into containment. Manual actuation and maintenance as necessary to open a purge supply, purge exhaust, or vacuum relief flow path are available means to open a containment air flow path. In addition, opening of a spare penetration is an acceptable means to provide the necessary flow path. Opening of an equipment hatch or a containment airlock is acceptable, but may not be possible due to the differential pressure condition. Containment air flow paths opened must comply with LCO 3.6.7, Containment Penetrations.

The 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Completion Time is reasonable for opening a containment air flow path in an orderly manner.

SURVEILLANCE SR 3.6.4.1 REQUIREMENTS Verifying that containment pressure is within limits ensures that unit operation remains within the limits assumed in the containment analysis.

The 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Frequency of this SR was developed based on operating experience related to trending of containment pressure variations during the applicable MODES. Furthermore, the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Frequency is considered adequate in view of other indications available in the main control room, including alarms, to alert the operator to an abnormal containment pressure condition.

REFERENCES 1. FSAR Section 6.2, Containment Systems.

AP1000 STS B 3.6.4-4 Rev. 0 Date report generated:

Tuesday, May 12, 2015 Page 28

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