ML22240A088

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Changes Related to AP1000 Gts Subsection 3.6.8, Containment Penetrations
ML22240A088
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Issue date: 05/13/2015
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Craig Harbuck NRR/DSS 301-415-3140
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GTST AP1000-P17-3.6.8, Rev. 1 Advanced Passive 1000 (AP1000)

Generic Technical Specification Traveler (GTST)

Title:

Changes Related to LCO 3.6.8, Containment Penetrations 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:

Wednesday, May 13, 2015 Page 1

GTST AP1000-P17-3.6.8, 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:

VEGP COL Item B3.6.8: Figure B 3.6.8-1, removal of brackets RCOL PTS Change Number and

Title:

VEGP LAR DOC A031: TS 3.6.8 Required Action B revision VEGP LAR DOC A038: SR 3.6.8.2 clarification revision VEGP LAR DOC A052: TS 3.6.8 Condition B revision VEGP LAR DOC A088: SR 3.6.8.2 revision VEGP LAR DOC M13: Combined TS 3.6.6 and TS 3.6.7 VEGP LAR DOC D07: TS 3.6.8 LCO statement revision VEGP LAR DOC L18: TS 3.6.8 LCO statement revision and deletion of SR 3.6.8.3 Date report generated:

Wednesday, May 13, 2015 Page 2

GTST AP1000-P17-3.6.8, 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(1) applicable to operating reactor designs, but not to the AP1000 design; (2) already incorporated in the GTS; or (3) superseded by another change.

TSTF-425 is deferred for future consideration.

In the bases discussion of Actions B.1.1, B.1.2, and B.2, the term reactor is replaced with refueling to be consistent with the original text prior to changes under VEGP LAR DOC A031.

Also, due to NRC staff proposed changes the refueling cavity is changed to a refueling cavity.

Date report generated:

Wednesday, May 13, 2015 Page 3

GTST AP1000-P17-3.6.8, 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)

In the bases discussion of Actions B.1.1, B.1.2, and B.2, the term reactor is replaced with refueling.

Revise the Actions section of the Bases, under heading B.1.1, B.1.2, and B.2 by starting a new paragraph for MODE 6 discussion, start a new paragraph for SDM discussion, remove reference to PRHR HX from MODE 6 discussion, and add a sentence to the end of the MODE 5 discussion. The changes are as follows:

In MODE 5, action must be initiated, immediately, to establish a pressurizer level 20% with the RCS intact so that the PRHR HX operation is available. The time to RCS steaming to containment is maximized by maximizing RCS inventory, and allowing PRHR HX operation.

In MODE 6, action must be initiated, immediately, to increase RCS inventory by establishing athe refueling cavity water level 23 feet above the top of the reactor vessel flange. The time to RCS steaming to containment is maximized by maximizing RCS inventory, and allowing PRHR HX operation.

Additionally, in either MODE action to immediately suspend positive reactivity additions is required to ensure that the SDM is maintained.

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 Actions section of the Bases, under heading B.1.1, B.1.2, and B.2 from

...withdrawal of reactivity control assemblies... to withdrawal of control rods...

Date report generated:

Wednesday, May 13, 2015 Page 4

GTST AP1000-P17-3.6.8, Rev. 1 V. Applicability Affected Generic Technical Specifications and Bases:

Section 3.6.8, Containment Penetrations Changes to the Generic Technical Specifications and Bases:

TS 3.6.8 is renumbered as TS 3.6.7. (DOC M13)

TS 3.6.8 LCO statement and associated bases is revised to remove clarifying detail clear of obstructions. (DOC D07)

TS 3.6.8 LCO statement and associated bases for containment atmosphere to the outside atmosphere is revised. (DOC L18)

Condition B is revised to clarify that the Action and associated Completion Time not met is of Condition A. (DOC A052)

Required Action B.1.1 and B.1.2 and associated bases are revised for clarification. (DOC A031)

SR 3.6.8.2 is revised by deleting the word that and changing the word install to close from the SR statement. (DOC A038 and DOC A088)

SR 3.6.8.3 and the associated bases is deleted. (DOC L18)

The Background section of the bases is revised by deleting AP1000 from the discussion of overdraining the RCS. (VEGP LAR change)

The Action A.1 of the Actions section of the bases is revised to clarify the bases for restoring containment penetrations to required status when one or more containment penetrations not required status. (DOC L18)

The Actions section of the Bases is revised to correct an editorial error; the term reactor is replaced with refueling. (NRC staff proposed change)

The Actions section of the Bases, under heading B.1.1, B.1.2, and B.2 is revised by starting a new paragraph for MODE 6 discussion, start a new paragraph for SDM discussion, removing the reference to PRHR HX from MODE 6 discussion, and add a sentence to the end of the MODE 5 discussion. (NRC staff proposed change)

Bases for SR 3.6.8.1 is revised to remove clarifying detail clear of obstructions and adds for purge and exhaust penetration may be verified closed or capable of being closed prior to steaming into the containment. (DOC D07 and DOC L18)

Figure B 3.6.8-1 in the bases is revised by removing brackets from the figure. (COL Item B3.6.8)

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

Date report generated:

Wednesday, May 13, 2015 Page 5

GTST AP1000-P17-3.6.8, Rev. 1 The Actions section of the Bases, under heading B.1.1, B.1.2, and B.2 is revised from

...withdrawal of reactivity control assemblies... to withdrawal of control rods... (APOG Comment)

Date report generated:

Wednesday, May 13, 2015 Page 6

GTST AP1000-P17-3.6.8, 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 A031 revises Required Action B.1.1 and B.1.2. Required Action B.1.1 is revised from If in MODE 5, initiate action to be in MODE 5 with the Reactor Coolant System (RCS) pressure boundary intact and 20% pressurizer level to If in MODE 5, initiate action to establish 20% pressurizer level with the Reactor Coolant System (RCS) pressure boundary intact. Required Action B.1.2 is revised from If in MODE 6, initiate action to be in MODE 6 with the water level 23 feet above the top of the reactor vessel flange, to If in MODE 6, initiate action to establish water level 23 feet above the top of the reactor vessel flange. Action B.1.1, B.1.2, and B.2 of the Actions section of the bases is revised to be consistent with changes made to Required Action B.1.1 and B.1.2.

VEGP LAR DOC A038 deletes the word that from SR 3.6.8.2.

VEGP LAR DOC A052 revises the first entry condition of Condition B by specifying Condition A in the statement.

VEGP LAR DOC A088 revises SR 3.6.8.2 statement hardware, tools, equipment and power source necessary to install the equipment hatch are available. by replacing install with close.

SR 3.6.8.2 in the Surveillance Requirements section of the bases is revised to be consistent with changes to SR 3.6.8.2.

VEGP LAR DOC M13 renumbers TS 3.6.8 to TS 3.6.7.

VEGP LAR DOC D07 revises LCO 3.6.8.a, b, and c by deleting the statement clear of obstructions. The LCO section of the bases is also revised to reflect these changes.

VEGP LAR DOC L18 revises LCO 3.6.8.d.1 and the last paragraph of the Background section of the bases by adding the statement prior to steaming into the containment and LCO 3.6.8.d.2 is deleted. The LCO section of the bases is also revised to reflect these changes. Action A.1 of the Actions section of the bases is revised from , including the containment isolation function not capable of actuation when automatic isolation valves are open, to , including the containment isolation capability when automatic isolation valves are open,. SR 3.6.8.1 in the Surveillance Requirements section of the bases is revised to be consistent with changes to LCO 3.6.8.d and adding the statement Alternately, purge and exhaust penetrations may be verified closed or capable of being closed prior to steaming into the containment, which will limit loss of the cooling water inventory from containment.

VEGP LAR changes the Background section of the bases by deleting AP1000 from the discussion of overdraining the RCS.

Date report generated:

Wednesday, May 13, 2015 Page 7

GTST AP1000-P17-3.6.8, Rev. 1 VEGP COL Item B3.8.6 removes the brackets from Figure B 3.6.8-1 in the Bases.

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

VEGP LAR DOC A031 changes to Required Action B.1.1 and B.1.2 clarifies the Required Action statement by removing unnecessary reference to the Mode.

VEGP LAR DOC A038 deletes the word that from SR 3.6.8.2, which is consistent with guidance provided in TSTF-GG-05-01.

VEGP LAR DOC A052 Changes to the first entry condition of Condition B clarifies the statement by specifying the applicable Condition.

VEGP LAR DOC A088 revises SR 3.6.8.2 statement hardware, tools, equipment and power source necessary to install the equipment hatch are available. by replacing install with close.

SR 3.6.8.2 in the Surveillance Requirements section of the bases is revised to be consistent with changes to SR 3.6.8.2.

VEGP LAR DOC M13 deletes TS 3.6.7 and subsequent sections are renumbered.

VEGP LAR DOC D07 changes to LCO 3.6.8.a, b, and c removes an unnecessary statement clear of obstructions. The LCO continues to require the equipment hatches, air lock doors, and containment spare penetrations to be closed prior to steaming into the containment.

VEGP LAR DOC L18 changes to LCO 3.6.8.d remove requirements for Operable containment isolation signals in Modes 5 and 6. The only Containment Isolation Signals required by GTS 3.3.2 in Modes 5 and 6 are the manual initiation functions. There are no automatic isolation functions required.

VEGP LAR changes the Background section of the bases by deleting AP1000 is editorial.

Referencing the type of reactor is not necessary in discussing how the risk of overdraining the RCS has been significantly reduced.

VEGP COL Item B3.8.6 removes brackets from Figure B 3.6.8-1 since the figure is for illustration only and should not have been bracketed. VEGP COL Item B3.6.8 (see Reference 2), removal of the Reviewer's Note in B3.6.8 was in error by the applicant. Instead this item was meant to remove the brackets from Figure B 3.6.8-1.

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

In the bases discussion of Actions B.1.1, B.1.2, and B.2, the term reactor is replaced with refueling.

The Actions section of the Bases, under heading B.1.1, B.1.2, and B.2 is revised by starting a new paragraph for MODE 6 discussion, start a new paragraph for SDM discussion, removing the reference to PRHR HX from MODE 6 discussion, and add a sentence to the end of the MODE 5 discussion.

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

Date report generated:

Wednesday, May 13, 2015 Page 8

GTST AP1000-P17-3.6.8, Rev. 1 The Actions section of the Bases, under heading B.1.1, B.1.2, and B.2 is revised from

...withdrawal of reactivity control assemblies... to withdrawal of control rods... (APOG Comment)

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

The term refueling is consistent with the original text prior to changes under VEGP LAR DOC A031.

Revising the Actions section of the Bases, under heading B.1.1, B.1.2, and B.2 by starting a new paragraph for MODE 6 discussion, start a new paragraph for SDM discussion, removing the reference to PRHR HX from MODE 6 discussion, and add a sentence to the end of the MODE 5 discussion are editorial technical improvements.

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

Revising the Actions section of the Bases, under heading B.1.1, B.1.2, and B.2 from

...withdrawal of reactivity control assemblies... to withdrawal of control rods... is an editorial technical improvement. (APOG Comment)

Date report generated:

Wednesday, May 13, 2015 Page 9

GTST AP1000-P17-3.6.8, Rev. 1 VII. GTST Safety Evaluation Technical Analysis:

VEGP LAR DOC D07: GTS LCO 3.6.8.a, b, and c require the equipment hatches, air lock doors, and containment spare penetrations to be in the correct condition. This includes an allowance to have the penetrations open, provided they can be closed prior to steaming into the containment. The revised TS LCO continues to require the equipment hatches, air lock doors, and containment spare penetrations to be in the correct condition, and capable of being closed in time. The removal of the statement clear of obstructions from current GTS 3.6.8.a, b, and c is acceptable because this type of information is not necessary to be included in the TS to provide adequate protection of public health and safety.

The specific statement concerning clear of obstructions is not necessary since the LCO continues to require the equipment hatches, air lock doors, and containment spare penetrations to be closed prior to steaming into the containment. Obstructions are allowed such that they would not hamper closure time. The proposed TS retain the necessary requirements to ensure the components can be closed prior to steaming into the containment. The clear of obstructions such that clarification is cited in the Bases. This change is acceptable because these types of details are adequately controlled in the TS Bases.

VEGP LAR DOC L18: GTS LCO 3.6.8.d provides the requirements for each penetration providing direct access from the containment atmosphere to the outside atmosphere. The penetrations covered by this LCO requirement are those providing direct access to the outside atmosphere, which includes the containment air filter supply and exhaust penetrations, and the vent and purge valves and the vacuum relief valves. The only Containment Isolation Signals required by GTS 3.3.2 in Modes 5 and 6 are the manual initiation functions. There are no automatic isolation functions required. Thus, LCO 3.6.8.d.2 is currently requiring the associated valves to be capable of closing from a Manual signal only.

For postulated shutdown events in Modes 5 and 6, RCS heat removal is provided by either passive residual heat removal (PRHR) or IRWST injection and containment sump recirculation.

To support RCS heat removal, containment closure is required to limit the loss of the cooling water inventory from containment. GTS LCO 3.6.8.a, b, and c provide the requirements for the equipment hatches, air locks doors, and containment spare penetrations. All three of these requirements allow the associated penetration to be open, provided that it is capable of being closed prior to steaming into the containment. This capability is not reliant on any remote closure signals or automatic features. Manual closure capability is acceptable. The equipment hatches and personnel air locks have openings that are much larger than the containment air filter supply and exhaust penetrations. Closing these larger penetrations may involve more protracted procedures to affect manual closure than would be for the containment air filter supply and exhaust penetrations. Therefore, it is acceptable to allow the purge valve penetrations to be open, provided they can be closed prior to steaming into the containment.

This allows all four major penetration flow paths to be controlled in a similar manner. GTS SR 3.6.8.3 is deleted, consistent with this change. GTS SR 3.6.8.1 is adequate for ensuring the requirements of LCO 3.6.8.d.2, if being used to comply with the LCO, are verified on a periodic basis.

This change is less restrictive since the proposed LCO would remove requirements for operable containment isolation signals in Modes 5 and 6, allowing manual operator action to affect any required isolation. The design provisions for instrumented closure signals are unaffected.

However, provided the appropriate closure timing capability is provided commensurate with the Date report generated:

Wednesday, May 13, 2015 Page 10

GTST AP1000-P17-3.6.8, Rev. 1 timing necessary to achieve the closure prior to steaming into the containment, this change will not adversely impact public health and safety.

Other Changes: 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 3.6.7 is an acceptable model Specification for the AP1000 standard reactor design.

References to Previous NRC Safety Evaluation Reports (SERs):

None Date report generated:

Wednesday, May 13, 2015 Page 11

GTST AP1000-P17-3.6.8, Rev. 1 VIII. Review Information Evaluator Comments:

The AP1000 GTS 3.6.8 is for Containment Penetrations and is APPLICABLE in MODES 5 and 6. There is no equivalent Specifications in NUREG-1430 or NUREG-1431.

The markup to remove the brackets from figure B 3.6.8-1 was manually done in the Word document.

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 #2) Approved TSTF-523 is not dispositioned in the material provided to support the GTSTs. Include TSTF-523 in the reference disposition tables, as TSTF deferred for future consideration. This is resolved by dispositioningTSTF-523, Rev. 1 as not applicable to the GTS and stating that the concerns of the TSTF have been addressed by GTS Rev.19.
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.

Date report generated:

Wednesday, May 13, 2015 Page 12

GTST AP1000-P17-3.6.8, Rev. 1 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 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 #377) 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. This is resolved by making the APOG recommended changes and NRC staff proposed changes to the Actions section of the Bases under heading B.1.1, B.1.2, and B.2.

NRC Final Approval Date: 5/13/2015 NRC

Contact:

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

Wednesday, May 13, 2015 Page 13

GTST AP1000-P17-3.6.8, Rev. 1 IX. Evaluator Comments for Consideration in Finalizing Technical Specifications and Bases None Date report generated:

Wednesday, May 13, 2015 Page 14

GTST AP1000-P17-3.6.8, Rev. 1 X. References Used in GTST

1. AP1000 DCD, Revision 19, Section 16, Technical Specifications, June 2011 (ML11171A500).
2. Vogtle Electric Generating Plant (VEGP), Units 3 & 4 COL Application, Part 4, Technical Specifications, Revision 3 (ML11180A102).
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).
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:

Wednesday, May 13, 2015 Page 15

GTST AP1000-P17-3.6.8, 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:

Wednesday, May 13, 2015 Page 16

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations 3.6.87 3.6 CONTAINMENT SYSTEMS 3.6.87 Containment Penetrations LCO 3.6.87 The containment penetrations shall be in the following status:

a. The equipment hatches closed and held in place by four bolts or, if open, clear of obstructions such that the hatches can be closed prior to steaming into the containment.
b. One door in each air lock closed or, if open, the containment air locks shall be clear of obstructions such that they can be closed prior to steaming into the containment.
c. The containment spare penetrations, if open, shall be clear of obstructions such that the penetrations can be closed prior to steaming into the containment.
d. Each penetration providing direct access from the containment atmosphere to the outside atmosphere either:, if open, can be
1. closed by a manual or automatic isolation valve, blind flange, or equivalent, or prior to steaming into the containment.
2. capable of being closed by an OPERABLE Containment Isolation signal.

APPLICABILITY: MODES 5 and 6.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One or more 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 /> containment penetrations to required penetrations not in status.

required status.

AP1000 STS 3.6.87-1 Amendment 0Rev. 0 Revision 19 Date report generated:

Wednesday, May 13, 2015 Page 17

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations 3.6.87 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. Required Action and B.1.1 If in MODE 5, initiate action Immediately associated Completion to be in MODE 5establish Time of Condition A not 20% pressurizer level met. with the Reactor Coolant System (RCS) pressure OR boundary intact and 20%

pressurizer level.

LCO not met for reasons other than Condition A. OR B.1.2 If in MODE 6, initiate action Immediately to be in MODE 6 with theestablish water level 23 feet above the top of the reactor vessel flange.

AND B.2 Suspend positive reactivity Immediately additions.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.87.1 Verify each required containment penetration is in the 7 days required status.

AP1000 STS 3.6.87-2 Amendment 0Rev. 0 Revision 19 Date report generated:

Wednesday, May 13, 2015 Page 18

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations 3.6.87 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.6.87.2 -------------------------------NOTE------------------------------

Only required to be met for an open equipment hatch.

Verify that the hardware, tools, equipment and power Prior to hatch source necessary to installclose the equipment hatch removal are available.

AND 7 days SR 3.6.8.3 -------------------------------NOTE------------------------------

Not required to be met for automatic isolation valve(s) in penetrations closed to comply with LCO 3.6.8.d.1.

Verify one automatic isolation valve in each open 24 months penetration providing direct access from the containment atmosphere to the outside atmosphere actuates to the isolation position on an actual or simulated actuation signal.

AP1000 STS 3.6.87-3 Amendment 0Rev. 0 Revision 19 Date report generated:

Wednesday, May 13, 2015 Page 19

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.87 B 3.6 CONTAINMENT SYSTEMS B 3.6.87 Containment Penetrations BASES BACKGROUND Containment closure capability is required during shutdown operations when there is fuel inside containment. Containment closure is required to maintain within containment the cooling water inventory. Due to the large volume of the In-Containment Refueling Water Storage Tank (IRWST) and the reduced sensible heat during shutdown, the loss of some of the water inventory can be accepted. Further, accident analyses have shown that containment closure capability is not required to meet offsite dose requirements. Therefore, containment does not need to be leak tight as required for MODES 1 through 4.

In MODES 5 and 6, the LCO requirements are referred to as containment closure rather than containment OPERABILITY.

Containment closure means that all potential escape paths are closed or capable of being closed. Since there is no requirement for containment leak tightness, compliance with the Appendix J leakage criteria and tests are not required.

In MODES 5 and 6, there is no potential for steam release into the containment immediately following an accident. Pressurization of the containment could only occur after heatup of the IRWST due to Passive Residual Heat Removal Heat Exchanger (PRHR HX) operation (MODE 5 with RCS intact) or after heatup of the RCS with direct venting to the containment (MODE 5 with reduced RCS inventory or MODE 6 with the refueling cavity not fully flooded) or after heatup of the RCS and refueling cavity (MODE 6 with refueling cavity fully flooded). The time from loss of normal cooling until steam release to the containment for four representative sets of plant conditions is shown in Figure B 3.6.87-1 as a function of time after shutdown. Because local manual action may be required to achieve containment closure it is assumed that the containment hatches, air locks and penetrations must be closed prior to steaming into containment.

Figure B 3.6.87-1 provides allowable closure times for four representative sets of plant conditions. The time to steaming is dependent on various plant parameters (RCS temperature, IRWST temperature, etc.) and plant configuration (RCS Pressure Boundary Intact, RCS Open, etc.).

Therefore, the actual representation of the time to steaming may be different than that provided in Figure B 3.6.87-1. In determining the minimum time to steaming, conservative assumptions regarding core AP1000 STS B 3.6.87-1 Amendment 0Rev. 0 Revision 19 Date report generated:

Wednesday, May 13, 2015 Page 20

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.87 BASES BACKGROUND (continued) decay heat, RCS configuration, and initial RCS inventory are used to minimize the calculated time to steaming. The curves are based on the core decay heat prior to refueling so that closure times are longer following the core reload.

As presented in Tables 54-1 and 54-4 of Reference 2, the most risk significant events during shutdown are events that lead to a loss of Normal Residual Heat Removal System (RNS) cooling. Of these, the limiting events that lead to steaming to containment are the loss of shutdown cooling events, specifically:

  • Loss-of-offsite power during drained conditions; and

These events are further discussed in FSAR Section 19.59.5 of Reference 1. Time to steaming is dependent on the postulated RCS configuration (intact versus open), and is based on the response of the plant considering features such as the operation of the 4th stage Automatic Depressurization System (ADS) valves if necessary, status of the upper internals, status of refueling cavity, etc. Conservative assumptions regarding these features are made in the determination of the minimum time to steaming. The time assumed in the PRA to close the penetrations before steaming to containment included 15 minutes for the diagnosis and decision-making time, in addition to the time required to physically complete the closure action.

The risk of overdraining the RCS has been significantly reduced in the AP1000 due to the automatic protection features associated with the hot leg level instruments which isolate letdown on low hot leg water level.

Overdraining the RCS is no longer a significant contributor to core damage, as shown in Table 54-4 of Reference 2.

The assumptions used in determining the required closure time for the various containment openings should be conservative, and should be consistent with the plant operating procedures, staffing levels, and status of the containment openings. The evaluation should consider the ability to close the containment for the limiting loss of shutdown cooling event, AP1000 STS B 3.6.87-2 Amendment 0Rev. 0 Revision 19 Date report generated:

Wednesday, May 13, 2015 Page 21

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.87 BASES BACKGROUND (continued) and considering the possibility of a station blackout. In determining if containment can be closed within the time permitted to containment closure specified in Figure B 3.6.87 -1, the time to close containment penetrations must include both the diagnosis and decision-making time and the time required to physically complete the closure action.

Containment should be closed during the initial mid-loop period for a refueling since the time permitted to containment closure is shorter than the time to diagnose and make a decision that closure is needed following an event. The need to close containment for the mid-loop period following a refueling must be evaluated since decay heat varies with the time after shutdown and the impact of the partial core replacement with new fuel. It is expected that containment will be closed for activities where drain-down is planned, such as the RCS drain-down from no-load pressurizer level for the initial mid-loop period during a refueling. Containment is not expected to be closed for minor, unplanned RCS volume transients, such as a short-term inventory where the pressurizer level may be reduced, but not emptied, and where recovery actions are within the time to containment closure.

The containment equipment hatches, which are part of the containment pressure boundary, provide a means for moving large equipment and components into and out of containment. If closed, the equipment hatch must be held in place by at least four bolts. Good engineering practice dictates that bolts required by this LCO be approximately equally spaced.

Alternatively, if open, each equipment hatch can be installed using a dedicated set of hardware, tools and equipment. A self-contained power source is provided to drive each hoist while lowering the hatch into position. Large equipment and components may be moved through the hatches as long as they can be removed and the hatch closed prior to steaming into the containment.

The design of the equipment hatch is such that the four bolts would only be needed to support the hatch in place and provide adequate strength to support the hatch dead weight and associated loads. The hatch is installed on the inside containment and is held in place against a matching flange surface with mating bolt pattern by the bolts. Once the dead weight is supported, any pressure (greater than atmospheric) within containment will serve to exert closure force on the hatch toward the mating flange surface serving to reduce stresses on bolts. Therefore the determination of the number of bolts is limited to the quantity required to AP1000 STS B 3.6.87-3 Amendment 0Rev. 0 Revision 19 Date report generated:

Wednesday, May 13, 2015 Page 22

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.87 BASES BACKGROUND (continued) support the hatch itself and not related to any potential containment pressure.

The containment air locks, which are also part of the containment pressure boundary, provide a means for personnel access during MODES 1, 2, 3, and 4 unit operation in accordance with LCO 3.6.2, Containment Air Locks. Each air lock has a door at both ends. The doors are normally interlocked to prevent simultaneous opening when containment OPERABILITY is required. During periods of unit shutdown when containment closure is required, the door interlock mechanism may be disabled, allowing both doors of an air lock to remain open for extended periods when frequent containment entry is necessary.

Temporary equipment connections (e.g., power or communications cables) are permitted as long as they can be removed to allow containment closure prior to steaming into the containment.

Containment spare penetrations which also provide a part of the containment boundary provide for temporary support services (electrical, I&C, air, and water supplies) during MODES 5 and 6. Each penetration is flanged and normally closed. During periods of plant shutdown, temporary support systems may be routed through the penetrations; temporary equipment connections (e.g., power or communications cables) are permitted as long as they can be removed to allow containment closure prior to steaming into the containment. The spare penetrations must be closed or, if open, capable of closure prior to steaming to containment.

Containment penetrations, including purge system flow paths, that provide direct access from containment atmosphere to outside atmosphere must be isolated or capable of being isolated prior to steaming into the containment on at least one side. Isolation may be achieved by an OPERABLE automatic isolation valve, or by a manual isolation valve, blind flange, or equivalent. Equivalent isolation methods must be approved and may include use of a material that can provide a temporary barrier for the containment penetrations. The equivalent isolation barrier must be capable of maintaining containment isolation at the containment design pressure of 59 psig (Ref. 1).

AP1000 STS B 3.6.87-4 Amendment 0Rev. 0 Revision 19 Date report generated:

Wednesday, May 13, 2015 Page 23

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.87 BASES APPLICABLE For postulated shutdown events in MODES 5 and 6, RCS heat removal SAFETY is provided by either passive residual heat removal (PRHR) or IRWST ANALYSES injection and containment sump recirculation. To support RCS heat removal, containment closure is required to limit the loss of the cooling water inventory from containment (Ref. 1).

Containment penetrations satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).

LCO This LCO limits the loss of cooling water inventory in containment to assure continued coolant inventory by limiting the potential escape paths for water released within containment. Penetrations closed in accordance with these requirements are not required to be leak tight.

The LCO requires any penetration providing direct access from the containment atmosphere to the outside atmosphere to be closed or capable of being closed prior to steaming into the containment. The equipment hatches may be open; however, the hatches shall be clear of obstructions such that capability to close the hatch within the indicated time period is maintained. The hardware, tools, equipment and power sources necessary to install the hatches shall be available when the hatch is open. Both doors in each containment air lock may be open; however, the air locks shall be clear of obstructions such that the capability to close at least one door within the indicated time period is maintained. Alternatively, one door in an air lock may be closed.

Containment spare penetrations may be open; however, the penetrations shall be clear of obstructions such that the penetrations are capable of being closed within the indicated time period. Direct access penetrations shall be closed by at least one manual or automatic isolation valve, blind flange or equivalent, or capable of being closed by at least one valve actuated by a containment isolation signal. If direct access penetrations are open, then they must be capable of being closed prior to steaming into the containment.OPERABILITY of the containment isolation instrumentation is required for the open penetrations by LCO 3.3.2, Function 3.a, Containment Isolation, Manual Initiation. An OPERABLE Containment Isolation Function includes LCO 3.3.2, Function 19.b, Containment Air Filtration System Isolation, Containment Isolation. Figure B 3.6.87-1 provides the acceptable required closure times for various representative MODES and conditions.

AP1000 STS B 3.6.87-5 Amendment 0Rev. 0 Revision 19 Date report generated:

Wednesday, May 13, 2015 Page 24

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.87 BASES APPLICABILITY The containment penetration requirements are applicable during conditions for which the primary safety related core cooling and boration capabilities are provided by IRWST or injection or PRHR - MODES 5 and 6. The capability to close containment is required to ensure that the cooling water inventory is not lost in the event of an accident.

In MODES 1, 2, 3, and 4, containment penetration requirements are addressed by LCO 3.6.1.

ACTIONS A.1 If the containment equipment hatches, air locks, or any containment penetration that provides direct access from the containment atmosphere to the outside atmosphere is not in the required status, including the containment isolation function not capable of actuationcapability when automatic isolation valves are open, the penetration(s) must be restored to the required status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

B.1.1, B.1.2, and B.2 If Required Action A.1 is not completed within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> or the LCO is not met for reasons other than Condition A, action must be taken to minimize the probability and consequences of an accident.

In MODE 5, action must be initiated, immediately, to be in MODE 5 withestablish a pressurizer level 20% and to closewith the RCS intact so that the PRHR HX operation is available. The time to RCS steaming to containment is maximized by maximizing RCS inventory, and allowing PRHR HX operation.

In MODE 6, action must be initiated, immediately, to be in MODE 6 with the refuelingincrease RCS inventory by establishing athe reactorrefueling cavity water level 23 feet above the top of the reactor vessel flange. The time to RCS steaming to containment is maximized by maximizing RCS inventory, and allowing PRHR HX operation.

Additionally, in either MODE action to immediately 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 assembliesrods, and excessive cooling of the RCS.

AP1000 STS B 3.6.87-6 Amendment 0Rev. 0 Revision 19 Date report generated:

Wednesday, May 13, 2015 Page 25

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.87 BASES SURVEILLANCE SR 3.6.87.1 REQUIREMENTS This Surveillance demonstrates that each of the containment penetrations required to be in its closed position is in that position. For any open purge and exhaust valves, The Surveillance on the open purge and exhaust valves this SR will demonstrate that the valves are not blocked from closing. Also if the purge and/or exhaust valves are open and relying on automatic closure, thethis Surveillance will demonstrate that each valve operator has motive power, which will ensure that each valve is capable of being closed by an OPERABLE automatic containment purge and exhaust isolation signal prior to steaming into containment. Alternately, purge and exhaust penetrations may be verified closed or capable of being closed prior to steaming into the containment, which will limit loss of the cooling water inventory from containment. Open containment spare penetrations shall be verified capable of being closed prior to steaming into the containment by removal of obstructions and installation of the flange or by other closure means which will limit loss of the cooling water inventory from containment.

The Surveillance is performed every 7 days. The Surveillance interval is selected to ensure that the required penetration status is maintained during shutdown inspections, testing, and maintenance.

SR 3.6.87.2 Each of the two equipment hatches is provided with a set of hardware, tools, equipment, and self-contained power source for moving the hatch from its storage location and installing it in the opening. The required set of hardware and tools shall be visually inspected to ensure that they can perform the required functions. The equipment and power source shall be inspected and/or operated as necessary to verify that the hatch can be installedclosed properly. The power source shall be verified as containing sufficient energy to install the hatch from the storage location.

The 7 day Frequency is adequate considering that the hardware, tools, equipment, and power sources are dedicated to the associated equipment hatch and not used for any other functions.

The SR is modified by a Note which only requires that the surveillance be met for an open equipment hatch. If the equipment hatch is installed in position, then the availability of the means to install the hatch is not required.

AP1000 STS B 3.6.87-7 Amendment 0Rev. 0 Revision 19 Date report generated:

Wednesday, May 13, 2015 Page 26

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.87 BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.6.8.3 This Surveillance demonstrates that at least one valve in each open penetration actuates to its isolation position on manual initiation or on an actual or simulated containment isolation signal. The 24 month Frequency maintains consistency with other similar valve testing requirements. The OPERABILITY requirements for the Containment Isolation function are specified in LCO 3.3.2.

The SR is modified by a Note stating that this Surveillance is not required to be met for valves in isolated penetrations. The LCO provides the option to close penetrations in lieu of requiring automatic actuation capability.

REFERENCES 1. DCDFSAR Chapter 19.

2. AP1000 Probabilistic Risk Assessment.

AP1000 STS B 3.6.87-8 Amendment 0Rev. 0 Revision 19 Date report generated:

Wednesday, May 13, 2015 Page 27

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.87 Figure B 3.6.87-1 (page 1 of 1)

Time Prior to Coolant Inventory Boiling AP1000 STS B 3.6.87-9 Amendment 0Rev. 0 Revision 19 Date report generated:

Wednesday, May 13, 2015 Page 28

GTST AP1000-P17-3.6.8, 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:

Wednesday, May 13, 2015 Page 29

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations 3.6.7 3.6 CONTAINMENT SYSTEMS 3.6.7 Containment Penetrations LCO 3.6.7 The containment penetrations shall be in the following status:

a. The equipment hatches closed and held in place by four bolts or, if open, can be closed prior to steaming into the containment.
b. One door in each air lock closed or, if open, can be closed prior to steaming into the containment.
c. The containment spare penetrations, if open, can be closed prior to steaming into the containment.
d. Each penetration providing direct access from the containment atmosphere to the outside atmosphere, if open, can be closed by a manual or automatic isolation valve, blind flange, or equivalent prior to steaming into the containment.

APPLICABILITY: MODES 5 and 6.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One or more 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 /> containment penetrations to required penetrations not in status.

required status.

AP1000 STS 3.6.7-1 Rev. 0 Date report generated:

Wednesday, May 13, 2015 Page 30

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations 3.6.7 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. Required Action and B.1.1 If in MODE 5, initiate action Immediately associated Completion to establish 20%

Time of Condition A not pressurizer level with the met. Reactor Coolant System (RCS) pressure boundary OR intact.

LCO not met for reasons OR other than Condition A.

B.1.2 If in MODE 6, initiate action Immediately to establish water level 23 feet above the top of the reactor vessel flange.

AND B.2 Suspend positive reactivity Immediately additions.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.7.1 Verify each required containment penetration is in the 7 days required status.

AP1000 STS 3.6.7-2 Rev. 0 Date report generated:

Wednesday, May 13, 2015 Page 31

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations 3.6.7 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.6.7.2 -------------------------------NOTE------------------------------

Only required to be met for an open equipment hatch.

Verify the hardware, tools, equipment and power Prior to hatch source necessary to close the equipment hatch are removal available.

AND 7 days AP1000 STS 3.6.7-3 Rev. 0 Date report generated:

Wednesday, May 13, 2015 Page 32

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.7 B 3.6 CONTAINMENT SYSTEMS B 3.6.7 Containment Penetrations BASES BACKGROUND Containment closure capability is required during shutdown operations when there is fuel inside containment. Containment closure is required to maintain within containment the cooling water inventory. Due to the large volume of the In-Containment Refueling Water Storage Tank (IRWST) and the reduced sensible heat during shutdown, the loss of some of the water inventory can be accepted. Further, accident analyses have shown that containment closure capability is not required to meet offsite dose requirements. Therefore, containment does not need to be leak tight as required for MODES 1 through 4.

In MODES 5 and 6, the LCO requirements are referred to as containment closure rather than containment OPERABILITY.

Containment closure means that all potential escape paths are closed or capable of being closed. Since there is no requirement for containment leak tightness, compliance with the Appendix J leakage criteria and tests are not required.

In MODES 5 and 6, there is no potential for steam release into the containment immediately following an accident. Pressurization of the containment could only occur after heatup of the IRWST due to Passive Residual Heat Removal Heat Exchanger (PRHR HX) operation (MODE 5 with RCS intact) or after heatup of the RCS with direct venting to the containment (MODE 5 with reduced RCS inventory or MODE 6 with the refueling cavity not fully flooded) or after heatup of the RCS and refueling cavity (MODE 6 with refueling cavity fully flooded). The time from loss of normal cooling until steam release to the containment for four representative sets of plant conditions is shown in Figure B 3.6.7-1 as a function of time after shutdown. Because local manual action may be required to achieve containment closure it is assumed that the containment hatches, air locks and penetrations must be closed prior to steaming into containment.

Figure B 3.6.7-1 provides allowable closure times for four representative sets of plant conditions. The time to steaming is dependent on various plant parameters (RCS temperature, IRWST temperature, etc.) and plant configuration (RCS Pressure Boundary Intact, RCS Open, etc.).

Therefore, the actual representation of the time to steaming may be different than that provided in Figure B 3.6.7-1. In determining the minimum time to steaming, conservative assumptions regarding core AP1000 STS B 3.6.7-1 Rev. 0 Date report generated:

Wednesday, May 13, 2015 Page 33

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.7 BASES BACKGROUND (continued) decay heat, RCS configuration, and initial RCS inventory are used to minimize the calculated time to steaming. The curves are based on the core decay heat prior to refueling so that closure times are longer following the core reload.

As presented in Tables 54-1 and 54-4 of Reference 2, the most risk significant events during shutdown are events that lead to a loss of Normal Residual Heat Removal System (RNS) cooling. Of these, the limiting events that lead to steaming to containment are the loss of shutdown cooling events, specifically:

  • Loss-of-offsite power during drained conditions; and

These events are further discussed in FSAR Section 19.59.5 of Reference 1. Time to steaming is dependent on the postulated RCS configuration (intact versus open), and is based on the response of the plant considering features such as the operation of the 4th stage Automatic Depressurization System (ADS) valves if necessary, status of the upper internals, status of refueling cavity, etc. Conservative assumptions regarding these features are made in the determination of the minimum time to steaming. The time assumed in the PRA to close the penetrations before steaming to containment included 15 minutes for the diagnosis and decision-making time, in addition to the time required to physically complete the closure action.

The risk of overdraining the RCS has been significantly reduced due to the automatic protection features associated with the hot leg level instruments which isolate letdown on low hot leg water level.

Overdraining the RCS is no longer a significant contributor to core damage, as shown in Table 54-4 of Reference 2.

The assumptions used in determining the required closure time for the various containment openings should be conservative, and should be consistent with the plant operating procedures, staffing levels, and status of the containment openings. The evaluation should consider the ability to close the containment for the limiting loss of shutdown cooling event, AP1000 STS B 3.6.7-2 Rev. 0 Date report generated:

Wednesday, May 13, 2015 Page 34

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.7 BASES BACKGROUND (continued) and considering the possibility of a station blackout. In determining if containment can be closed within the time permitted to containment closure specified in Figure B 3.6.7 -1, the time to close containment penetrations must include both the diagnosis and decision-making time and the time required to physically complete the closure action.

Containment should be closed during the initial mid-loop period for a refueling since the time permitted to containment closure is shorter than the time to diagnose and make a decision that closure is needed following an event. The need to close containment for the mid-loop period following a refueling must be evaluated since decay heat varies with the time after shutdown and the impact of the partial core replacement with new fuel. It is expected that containment will be closed for activities where drain-down is planned, such as the RCS drain-down from no-load pressurizer level for the initial mid-loop period during a refueling. Containment is not expected to be closed for minor, unplanned RCS volume transients, such as a short-term inventory where the pressurizer level may be reduced, but not emptied, and where recovery actions are within the time to containment closure.

The containment equipment hatches, which are part of the containment pressure boundary, provide a means for moving large equipment and components into and out of containment. If closed, the equipment hatch must be held in place by at least four bolts. Good engineering practice dictates that bolts required by this LCO be approximately equally spaced.

Alternatively, if open, each equipment hatch can be installed using a dedicated set of hardware, tools and equipment. A self-contained power source is provided to drive each hoist while lowering the hatch into position. Large equipment and components may be moved through the hatches as long as they can be removed and the hatch closed prior to steaming into the containment.

The design of the equipment hatch is such that the four bolts would only be needed to support the hatch in place and provide adequate strength to support the hatch dead weight and associated loads. The hatch is installed on the inside containment and is held in place against a matching flange surface with mating bolt pattern by the bolts. Once the dead weight is supported, any pressure (greater than atmospheric) within containment will serve to exert closure force on the hatch toward the mating flange surface serving to reduce stresses on bolts. Therefore the determination of the number of bolts is limited to the quantity required to AP1000 STS B 3.6.7-3 Rev. 0 Date report generated:

Wednesday, May 13, 2015 Page 35

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.7 BASES BACKGROUND (continued) support the hatch itself and not related to any potential containment pressure.

The containment air locks, which are also part of the containment pressure boundary, provide a means for personnel access during MODES 1, 2, 3, and 4 unit operation in accordance with LCO 3.6.2, Containment Air Locks. Each air lock has a door at both ends. The doors are normally interlocked to prevent simultaneous opening when containment OPERABILITY is required. During periods of unit shutdown when containment closure is required, the door interlock mechanism may be disabled, allowing both doors of an air lock to remain open for extended periods when frequent containment entry is necessary.

Temporary equipment connections (e.g., power or communications cables) are permitted as long as they can be removed to allow containment closure prior to steaming into the containment.

Containment spare penetrations which also provide a part of the containment boundary provide for temporary support services (electrical, I&C, air, and water supplies) during MODES 5 and 6. Each penetration is flanged and normally closed. During periods of plant shutdown, temporary support systems may be routed through the penetrations; temporary equipment connections (e.g., power or communications cables) are permitted as long as they can be removed to allow containment closure prior to steaming into the containment. The spare penetrations must be closed or, if open, capable of closure prior to steaming to containment.

Containment penetrations, including purge system flow paths, that provide direct access from containment atmosphere to outside atmosphere must be isolated or capable of being isolated prior to steaming into the containment on at least one side. Isolation may be achieved by an OPERABLE automatic isolation valve, or by a manual isolation valve, blind flange, or equivalent. Equivalent isolation methods must be approved and may include use of a material that can provide a temporary barrier for the containment penetrations. The equivalent isolation barrier must be capable of maintaining containment isolation at the containment design pressure of 59 psig (Ref. 1).

AP1000 STS B 3.6.7-4 Rev. 0 Date report generated:

Wednesday, May 13, 2015 Page 36

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.7 BASES APPLICABLE For postulated shutdown events in MODES 5 and 6, RCS heat removal SAFETY is provided by either passive residual heat removal (PRHR) or IRWST ANALYSES injection and containment sump recirculation. To support RCS heat removal, containment closure is required to limit the loss of the cooling water inventory from containment (Ref. 1).

Containment penetrations satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).

LCO This LCO limits the loss of cooling water inventory in containment to assure continued coolant inventory by limiting the potential escape paths for water released within containment. Penetrations closed in accordance with these requirements are not required to be leak tight.

The LCO requires any penetration providing direct access from the containment atmosphere to the outside atmosphere to be closed or capable of being closed prior to steaming into the containment. The equipment hatches may be open; however, the hatches shall be clear of obstructions such that capability to close the hatch within the indicated time period is maintained. The hardware, tools, equipment and power sources necessary to install the hatches shall be available when the hatch is open. Both doors in each containment air lock may be open; however, the air locks shall be clear of obstructions such that the capability to close at least one door within the indicated time period is maintained. Alternatively, one door in an air lock may be closed.

Containment spare penetrations may be open; however, the penetrations shall be clear of obstructions such that the penetrations are capable of being closed within the indicated time period. Direct access penetrations shall be closed by at least one manual or automatic isolation valve, blind flange or equivalent, or capable of being closed by at least one valve actuated by a containment isolation signal. If direct access penetrations are open, then they must be capable of being closed prior to steaming into the containment. Figure B 3.6.7-1 provides the acceptable required closure times for various representative MODES and conditions.

APPLICABILITY The containment penetration requirements are applicable during conditions for which the primary safety related core cooling and boration capabilities are provided by IRWST or injection or PRHR - MODES 5 and 6. The capability to close containment is required to ensure that the cooling water inventory is not lost in the event of an accident.

AP1000 STS B 3.6.7-5 Rev. 0 Date report generated:

Wednesday, May 13, 2015 Page 37

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.7 BASES APPLICABILITY (continued)

In MODES 1, 2, 3, and 4, containment penetration requirements are addressed by LCO 3.6.1.

ACTIONS A.1 If the containment equipment hatches, air locks, or any containment penetration that provides direct access from the containment atmosphere to the outside atmosphere is not in the required status, including the containment isolation capability when automatic isolation valves are open, the penetration(s) must be restored to the required status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

B.1.1, B.1.2, and B.2 If Required Action A.1 is not completed within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> or the LCO is not met for reasons other than Condition A, action must be taken to minimize the probability and consequences of an accident.

In MODE 5, action must be initiated, immediately, to establish a pressurizer level 20% with the RCS intact so that PRHR HX operation is available. The time to RCS steaming to containment is maximized by maximizing RCS inventory, and allowing PRHR HX operation.

In MODE 6, action must be initiated, immediately, to increase RCS inventory by establishing a refueling cavity water level 23 feet above the top of the reactor vessel flange. The time to RCS steaming to containment is maximized by maximizing RCS inventory, and allowing PRHR HX operation.

Additionally, in either MODE action to immediately 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.

AP1000 STS B 3.6.7-6 Rev. 0 Date report generated:

Wednesday, May 13, 2015 Page 38

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.7 BASES SURVEILLANCE SR 3.6.7.1 REQUIREMENTS This Surveillance demonstrates that each of the containment penetrations required to be in its closed position is in that position. For any open purge and exhaust valves, this SR will demonstrate that the valves are not blocked from closing. Also if the purge and/or exhaust valves are open and relying on automatic closure, this Surveillance will demonstrate that each valve operator has motive power, which will ensure that each valve is capable of being closed by an automatic containment purge and exhaust isolation signal prior to steaming into containment. Alternately, purge and exhaust penetrations may be verified closed or capable of being closed prior to steaming into the containment, which will limit loss of the cooling water inventory from containment. Open containment spare penetrations shall be verified capable of being closed prior to steaming into the containment by removal of obstructions and installation of the flange or by other closure means which will limit loss of the cooling water inventory from containment.

The Surveillance is performed every 7 days. The Surveillance interval is selected to ensure that the required penetration status is maintained during shutdown inspections, testing, and maintenance.

SR 3.6.7.2 Each of the two equipment hatches is provided with a set of hardware, tools, equipment, and self-contained power source for moving the hatch from its storage location and installing it in the opening. The required set of hardware and tools shall be visually inspected to ensure that they can perform the required functions. The equipment and power source shall be inspected and/or operated as necessary to verify that the hatch can be closed properly. The power source shall be verified as containing sufficient energy to install the hatch from the storage location.

The 7 day Frequency is adequate considering that the hardware, tools, equipment, and power sources are dedicated to the associated equipment hatch and not used for any other functions.

The SR is modified by a Note which only requires that the surveillance be met for an open equipment hatch. If the equipment hatch is installed in position, then the availability of the means to install the hatch is not required.

AP1000 STS B 3.6.7-7 Rev. 0 Date report generated:

Wednesday, May 13, 2015 Page 39

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.7 BASES REFERENCES 1. FSAR Chapter 19.

2. AP1000 Probabilistic Risk Assessment.

AP1000 STS B 3.6.7-8 Rev. 0 Date report generated:

Wednesday, May 13, 2015 Page 40

GTST AP1000-P17-3.6.8, Rev. 1 Containment Penetrations B 3.6.7 Figure B 3.6.7-1 (page 1 of 1)

Time Prior to Coolant Inventory Boiling AP1000 STS B 3.6.7-9 Rev. 0 Date report generated:

Wednesday, May 13, 2015 Page 41

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