Text

Record of Review, Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Internal Events, Internal Flooding, Seismic, and Fire PRA Facts and Observations
	ML16019A224
Person / Time
Site:	Diablo Canyon
Issue date:	02/01/2016
From:	Todd Hilsmeier; NRC/NRR/DRA/APLA
To:	;
	Todd Hilsmeir, NRR/DRA 415-6788
References
	Download: ML16019A224 (22)
	v • d • e

Record of Review, Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Internal Events, Internal Flooding, Seismic, and Fire PRA Facts and Observations By letter dated June 26, 2013 (Reference 1), Pacific Gas and Electric Company (PG&E, licensee) submitted a license amendment request (LAR) for Diablo Canyon Nuclear Plant, Units 1 and 2, to transition to National Fire Protection Association Standard (NFPA) 805.

Tables U-1, U-2, and U-3 in Attachment U of the LAR provides the licensee's dispositions to 148 Facts and Observations (F&Os) from the internal events, internal flooding, and seismic probabilistic risk assessment (PRA) peer reviews, respectively, most of which are characterized in LAR Attachment U as findings per Nuclear Energy Institute (NEI) 05-04 (Reference 2) peer review guidelines. The Nuclear Regulatory Commission (NRC) staff evaluated each F&O and the licensees disposition in Attachment U to determine whether the F&O had any significant impact for the application. Attachment A of this document summarizes the NRC staffs review and conclusion for the licensees resolution of each F&O associated with the internal events, internal flooding, and seismic PRAs and for the basis of acceptability of Supporting Requirements (SRs) that are not met or only meet Capability Category (CC) I.

Table V-2 in Attachment V of the LAR provides the licensee's dispositions to 98 F&Os from the 2008 and 2010 fire PRA peer reviews. The 2008 peer review was performed against PRA Standard ANSI/ANS 58.23-2007 (Reference 3). The 2010 peer review was performed against PRA Standard ASME/ANS RA-Sa-2009 (Reference 4) as clarified by Regulatory Guide (RG) 1.200, Revision 2 (Reference 5). Table V-3 in Attachment V of the LAR identifies all SRs that were determined by the peer review to be met only at CC I and provides an evaluation of those SRs. Only two SRs were identified in Table V-3 that are not addressed by the F&Os in Table V-2. The NRC staff evaluated each F&O as well as the licensee's disposition in LAR Attachment V to determine whether the issue had any significant impact for the application.

Attachment B of this document summarizes the NRC staffs review and conclusion for the licensees resolution of each F&O associated with the fire PRA and for the basis of acceptability of SRs that are not met or only meet CC I.

REFERENCES:

1. PG&E Letter DCL-13-065 to U.S. Nuclear Regulatory Commission Document Control Desk, License Amendment Request 13-03, License Amendment Request to Adopt NFPA 805 Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants (2001 Edition), dated June 26, 2013 (ADAMS Accession No. ML13196A139).

January 14, 2016 1

2. NEI 05-04, Process for Performing Internal Events PRA Peer Reviews Using the ASME/ANS PRA Standard, Revision 2, Nuclear Energy Institute (NEI), Washington, DC, November 2008.

3. American Nuclear Society (ANS), ANSI/ANS 58.23-2007, Fire PRA Methodology, November 2007.

4. American Society of Mechanical Engineers (ASME) and American Nuclear Society (ANS),

ASME/ANS RA-Sa-2009, Addenda to ASME/ANS RA-S-2008, Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment for Nuclear Power Plant Applications, ASME, New York, NY. February 2, 2009.

5. Regulatory Guide 1.200, An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities, Revision 2, U. S.

Nuclear Regulatory Commission, Washington, DC, March 2009 (ADAMS Accession No. ML090410014).

January 14, 2016 2

ATTACHMENT A Record of Review, Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Internal Events, Internal Flooding, and Seismic PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I January 14, 2016 A-1

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Internal Events, Internal Flooding, and Seismic PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I Finding/ ACCEPTABLE TO STAFF VIA Suggestion (F&O) ID or Review of RAI Response Supporting Plant Requirement Disposition Not Discussed in SE Discussed in (SR) (A/B/C) SE IE-A5-01 A IE-A7-01 C IE-C5-01 C IE-C10-01 B IE-C14-01 C IE-C15-01 C IE-D1-01 C IE-D2-01 C AS-A11-01 A AS-B3-01 See PRA RAI 18, PRA RAI 03, and F&O response. Acceptable to staff because the licensee explains potential phenomenological impacts are considered in the internal events and fire event PRAs. The response to PRA RAI 18 clarifies that credit was removed in the Internal events PRA for instrument Air for certain Main Steam and Feedwater line scenarios because phenomenological impacts could not be verified. The response to PRA RAI 18 explains that credit for operator action to make-up to the RSWT in event of an Interfacing LOCA was removed because of high radiation conditions in the area, and that changes to the Fire PRA are included in the integrated analysis provided in response to PRA RAI 03.

AS-B7-01 A January 14, 2016 A-2

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Internal Events, Internal Flooding, and Seismic PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I Finding/ ACCEPTABLE TO STAFF VIA Suggestion (F&O) ID or Review of RAI Response Supporting Plant Requirement Disposition Not Discussed in SE Discussed in (SR) (A/B/C) SE AS-C2-01 A SC-A1-01 A SC-A4-01 See PRA RAI 10 in Section 3.4.2 SC-A5-01 See PRA RAI 02.a, PRA RAI 18, and PRA RAI 03 in Section 3.4.2 SC-A5-02 A SC-B3-01 See PRA RAI 18, PRA RAI 03, and F&O response. Acceptable to staff because the licensee explains that thermal-hydraulic calculations were performed to determine the plant specific break size that differentiates Small LOCAs (SLOCAs) from Medium LOCAs (MLOCAs). In the response to PRA 18, the licensee explains that this change in definition affects initiator frequencies which impacts the Internal Event PRA results but not the Fire PRA results, and is included in the integrated analysis provided in response to PRA RAI 03 for total risk.

SC-B3-02 See PRA RAI 18, PRA RAI 03, and F&O response. Acceptable to staff because the licensee explains that thermal-hydraulic calculations were performed to determine the plant specific break size defining Small LOCAs (SLOCAs) including interfacing LOCAs (ISLOCAs). In the response to PRA 18, the January 14, 2016 A-3

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Internal Events, Internal Flooding, and Seismic PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I Finding/ ACCEPTABLE TO STAFF VIA Suggestion (F&O) ID or Review of RAI Response Supporting Plant Requirement Disposition Not Discussed in SE Discussed in (SR) (A/B/C) SE licensee explains that this change in definition affects initiator frequencies which impacts the Internal Event PRA results but not the Fire PRA results, and is included in the integrated analysis provided in response to PRA RAI 03 for total risk.

SC-B4-01 A SC-B4-02 C SC-B5-01 See PRA RAI 18, PRA RAI 03, and F&O response. Acceptable to staff because the licensee explains in the F&O response that the impact of not modeling the PORVs is conservative with respect to the total risk and given NCSA does not credit depressurization of the RCS using PORVs there is no impact on risk from VFDRs. The licensees response to PRA RAI 18 explains that feed and bleed is now added to model to remove conservatism and incorporated into the integrated analysis provided in response to PRA RAI 03. The resolution of this F&O remains acceptable.

SC-C2-01 A SC-C3-01 A SY-A4-01 A SY-A11-01 C SY-A16-01 See PRA RAI 02.b. Acceptable to NRC staff because the licensee explains that additional pre-initiator Human Failure Events (HFEs) were systemically identified and included in the PRA model after the peer review and, therefore, were included in the integrated analysis.

SY-A20-01 A SY-A23-01 C SY-B3-01 A January 14, 2016 A-4

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Internal Events, Internal Flooding, and Seismic PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I Finding/ ACCEPTABLE TO STAFF VIA Suggestion (F&O) ID or Review of RAI Response Supporting Plant Requirement Disposition Not Discussed in SE Discussed in (SR) (A/B/C) SE SY-B8-01 See PRA RAI 2.d. Acceptable to NRC staff because the licensee explains that the results of room heat-up calculations provide the basis for time allowed for required operator actions or demonstrate that loss of HVAC would not impact PRA components.

SY-B10-01 See PRA RAI 02.c, PRA RAI 18, and PRA RAI 03 in Section 3.4.2 SY-B15-01 See PRA RAI 02.b. Acceptable to NRC staff because the licensee explains that additional pre-initiator Human Failure Events (HFEs) were systemically identified and included into the PRA model after the peer review and, therefore, were included in the integrated analysis.

SY-C2-01 See PRA RAI 2.d. Acceptable to NRC staff because the licensee explains that the results of room heat-up calculations provide the basis for time allowed for required operator actions or demonstrate that loss of HVAC would not impact PRA components.

HR-A1-01 See PRA RAI 02.b. Acceptable to NRC staff because the licensee explains that additional pre-initiator Human Failure Events (HFEs) were systemically identified and included into the PRA model after the peer review and, therefore, were included in the integrated analysis.

HR-A3-01 See PRA RAI 02.b. Acceptable to NRC staff because the licensee explains that additional pre-initiator Human Failure Events (HFEs) were systemically identified and included into the PRA model after the peer review and, therefore, were included in the integrated analysis.

HR-C3-01 See PRA RAI 02.b. Acceptable to NRC staff because the licensee explains that additional pre-initiator Human Failure Events (HFEs) were January 14, 2016 A-5

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Internal Events, Internal Flooding, and Seismic PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I Finding/ ACCEPTABLE TO STAFF VIA Suggestion (F&O) ID or Review of RAI Response Supporting Plant Requirement Disposition Not Discussed in SE Discussed in (SR) (A/B/C) SE systemically identified and included into the PRA model after the peer review and, therefore, were included in the integrated analysis.

HR-D3-01 See PRA RAI 02.b. Acceptable to NRC staff because the licensee explains that additional pre-initiator Human Failure Events (HFEs) were systemically identified and included into the PRA model after the peer review and, therefore, were included in the integrated analysis.

HR-E1-01 C HR-E3-01 C HR-E4-01 C HR-G5-01 A HR-G6-01 C HR-G7-01 See PRA RAI 18 and PRA RAI 03. Acceptable to staff because the licensee explains that the degree of dependence between HFEs is evaluated and joint human error probabilities determined according to PPA standard Supporting Requirement HR-G7-01.

HR-H2-01 A HR-I2-01 A HR-I2-02 C DA-C1-01 See PRA RAI 18, PRA RAI 03, and F&O response. Acceptable to staff because the licensee explains that CCF data from NRC guidelines is used and clarifies in the response to RAI 18 that updated CCF factors from NUREG/CR-5485 are used in the integrated analysis provided in response to PRA RAI 03.

DA-C4-01 C DA-C5-01 C January 14, 2016 A-6

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Internal Events, Internal Flooding, and Seismic PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I Finding/ ACCEPTABLE TO STAFF VIA Suggestion (F&O) ID or Review of RAI Response Supporting Plant Requirement Disposition Not Discussed in SE Discussed in (SR) (A/B/C) SE DA-C6-01 A DA-C10-01 A DA-C14-01 A DA-C16-01 C DA-D4-01 See PRA RAI 2.e. Acceptable to NRC staff because the licensee explains that after the peer review that a Bayesian update check was performed for all failures rates and initiating event frequencies using the five specific criteria defined in Supporting Requirement DA-D4a through DA-D4e. This confirmation demonstrated that the distributions used in the PRA were reasonable.

DA-D6-01 A DA-D8-01 A DA-E2-01 C QU-B1-01 A QU-C2-01 A QU-D4-01 C QU-E1-01 A QU-F2-01 C QU-F6-01 C LE-C1-01 C LE-C2-01 C LE-C3-01 C LE-C4-01 C LE-C9-01, C LE-C13-01 C January 14, 2016 A-7

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Internal Events, Internal Flooding, and Seismic PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I Finding/ ACCEPTABLE TO STAFF VIA Suggestion (F&O) ID or Review of RAI Response Supporting Plant Requirement Disposition Not Discussed in SE Discussed in (SR) (A/B/C) SE LE-D7-01 See PRA RAI 18, PRA RAI 03, and F&O response. Acceptable to staff because the licensee explains that as result of the F&O, systematic review of all containment penetrations were performed. The response to PRA RAI 18 explains that as a result two new LERF penetrations were identified and included in the integrated analysis provided in response to PRA RAI 03.

LE-E2-01 A LE-E2-02 A LE-F2-01 A LE-G3-01 C LE-G5-01 A IFSO-A1-01 See PRA RAI 02.f, PRA RAI 18, and PRA RAI 03 in Section 3.4.2 IFSO-A6-01 C IFSO-B3-01 C IFSN-A3-01 C IFSN-A4-01 C IFSN-A6-01 C IFSN-A7-01 C IFSN-A8-01 C IFSN-A9-01 C IFSN-A10-01 C IFSN-A11-01 C IFSN-A12-01 C January 14, 2016 A-8

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Internal Events, Internal Flooding, and Seismic PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I Finding/ ACCEPTABLE TO STAFF VIA Suggestion (F&O) ID or Review of RAI Response Supporting Plant Requirement Disposition Not Discussed in SE Discussed in (SR) (A/B/C) SE IFPP-A5-01 C SHA-A1-01 C SHA-A1-02 N/A This F&O was assignment of a Best Practice SHA-A3-01 C SHA-A4-01 C SHA-B1-01 C SHA-B3-01, C CCIII SHA-B3-02 C SHA-C3-01 C SHA-D3-01 C SHA-D3-02 C SHA-E1-01 C SHA-E2-01 C SHA-F1-01 C SHA-F1-02 C SHA-F1-03 C SHA-F2-01 C SHA-F3-01 C SHA-G1-01 C SHA-J1-01 C SHA-J3-01 C SFR-A1-01 C SFR-A2-01 C SFR-B1-01 C January 14, 2016 A-9

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Internal Events, Internal Flooding, and Seismic PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I Finding/ ACCEPTABLE TO STAFF VIA Suggestion (F&O) ID or Review of RAI Response Supporting Plant Requirement Disposition Not Discussed in SE Discussed in (SR) (A/B/C) SE SFR-B2-01 C SFR-C1-01 C SFR-D1-01 C SFR-E1-01 C SFR-F1-01 C SFR-F3-01 C SFR-G1-01 C SFR-G3-01 C SPR-B1-01 C SPR-B1-02 C SPR-B1-03 C SPR-B2-01 C SPR-B2-02 C SPR-B2-03 C SPR-B2-04 C SPR-B3-01 C SPR-B4-01 C SPR-B4-02 C SPR-B5-01 C SPR-B8-01 C SPR-B9-01 C SPR-B11-01 C SPR-C1-01 C SPR-E1-01 C SPR-E1-02 C January 14, 2016 A-10

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Internal Events, Internal Flooding, and Seismic PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I Finding/ ACCEPTABLE TO STAFF VIA Suggestion (F&O) ID or Review of RAI Response Supporting Plant Requirement Disposition Not Discussed in SE Discussed in (SR) (A/B/C) SE SPR-E1-03 C SPR-E1-04 C SPR-E1-05 C SPR-E5-01 C SPR-E6-01 C SPR-F1-01 C SPR-F1-02 C SPR-F1-03 C SPR-F1-04 C SPR-F1-05 C SPR-F1-06 C SPR-F3-01 C A: For F&Os, the NRC staff finds that the disposition of the F&O as described by the licensee in the LAR provides confidence that the issues raised by the F&O have been addressed and, if needed, the PRA has been modified, and therefore the resolution of the F&O is acceptable for this application. For Not Met or met at CC-I SRs, the NRC staff finds that the acceptability basis for the capability category of the SR as described by the licensee in the LAR provides confidence that the requirements of the SR have been addressed and, if needed, the PRA has been modified, and therefore the PRA quality with respect to the SR is acceptable for this application.

Examples of acceptable Not Met and CC-I SRs are modeling methods that yield conservative FRE and change evaluation results.

B: For F&Os, the NRC staff finds that the disposition of the F&O as described by the licensee in the LAR and further clarified during the audit provides confidence that the issues raised by the F&O have been addressed and, if needed, the PRA has been modified, and therefore the resolution of the F&O is acceptable for this application. For Not Met or met at CC-I SRs, the NRC staff finds that the acceptability basis for the capability category of the SR as described by the licensee in the LAR and further clarified during the audit provides confidence that requirements of the SR have been addressed and, if needed, the PRA has been modified, and therefore the PRA quality with respect to the SR is acceptable for this application. Examples of acceptable Not Met and CC-I SRs are modeling methods that yield conservative FRE and change evaluation results.

January 14, 2016 A-11

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Internal Events, Internal Flooding, and Seismic PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I Finding/ ACCEPTABLE TO STAFF VIA Suggestion (F&O) ID or Review of RAI Response Supporting Plant Requirement Disposition Not Discussed in SE Discussed in (SR) (A/B/C) SE C: For F&Os, the NRC staff finds that the resolution of the F&O, as described by the licensee in the LAR, would have a negligible effect on the evaluations relied upon to support fire risk evaluations and has no impact on the conclusions of the risk assessment and therefore the resolution of the F&O is acceptable for this application. Examples of such F&Os may be suggestions, as well as those F&Os that don't affect the fire PRA. Documentation issues may fall into this category as well. For Not Met or met at CC-I SRs, the NRC staff finds that the acceptability basis for the capability category of the SR, as described by the licensee in the LAR, would have a negligible effect on the evaluations relied upon to support fire risk evaluations and has no impact on the conclusions of the risk assessment and therefore the PRA quality with respect to the SR is acceptable for this application. Examples are those SRs that don't affect the fire PRA.

January 14, 2016 A-12

ATTACHMENT B Record of Review, Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Fire PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I January 14, 2016 B-1

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Fire PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I ACCEPTABLE TO STAFF VIA Finding/

Suggestion (F&O) Review RAI Response of Plant ID or Supporting Disposi Not Discussed in SE Discussed in Requirement (SR)i tion SE (A/B/C)

PP-B1-01 (2008) A PP-C2-01 (2008) A ES-A1-01 (2008) A ES-B1-01(2008) See PRA RAI 01.a and PRA RAI 03 in Section 3.4.2.2 ES-B1-02 (2008) See PRA RAI 01.a and PRA RAI 03 in Section 3.4.2.2 ES-B1-03 (2008) A ES-B1-01 (2010) See PRA RAI 01.a and PRA RAI 03 in Section 3.4.2.2 ES-B2-01 (2008) A ES-B2-01 (2010) A CS-A1-01 (2008) A CS-A2-01 (2008) A CS-A2-03 (2008) A CS-A2-01 (2010) A CS-A6-01 (2008) See PRA RAI 01.b. Acceptable to NRC staff because the licensee explains that a more comprehensive evaluation of nonsafety 4.16 kV Buses D and E was performed than existed at the time of the peer review finding that considered both primary and backup overcurrent protection for the buses, and found that the protection devices provide adequate overcurrent protection and will prevent secondary fires.

CS-A7-01 (2008) See PRA RAI 01.c in Section 3.4.2.2 January 14, 2016 B-2

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Fire PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I ACCEPTABLE TO STAFF VIA Finding/

Suggestion (F&O) Review RAI Response of Plant ID or Supporting Disposi Not Discussed in SE Discussed in Requirement (SR)i tion SE (A/B/C)

CS-A8-01 (2008) See PRA RAI 01.d and PRA RAI 03 in Section 3.4.2.2 CS-A10-01 (2008) A CS-A10-02 (2008) A CS-A11-01 (2008) See PRA RAI 01.a and PRA RAI 03 in Section 3.4.2.2 CS-B1-01 (2008) A CS-B1-02 (2008) A CS-C1-01 (2008) A PRM-A1-01 (2008) C PRM-A4-01 (2008) A PRM-B2-01 (2010) C PRM-B13 (2008) A PRM-B15-01 (2010) A PRM-C1-01 (2010) See PRA RAI 01.e in Section 3.4.6 PRM-C1-02 (2010) See PRA RAI 01.f, PRA RAI 03, and PRA RAI 01.f.01 in Section 3.4.2.2 PRM-D1-01 (2008) A FSS-A1-01 (2010) See PRA RAI 01.g, PRA RAI 03, and PRA RAI 01.g.01 in Section 3.4.2.2 January 14, 2016 B-3

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Fire PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I ACCEPTABLE TO STAFF VIA Finding/

Suggestion (F&O) Review RAI Response of Plant ID or Supporting Disposi Not Discussed in SE Discussed in Requirement (SR)i tion SE (A/B/C)

FSS-A5-01 (2008) A FSS-A6-01 (2008) A FSS-B1-01 (2008) See PRA RAI 01.h and PRA RAI 03 in Section 3.4.2.2 FSS-C1-01 (2008) A FSS-C2-01 (2008) A FSS-C4-01 (2008) A FSS-C5-01 (2008) A FSS-C5-01 (2010) A FSS-C8-01 (2008) See PRA RAI 01.i. Acceptable to NRC staff because the licensee explains that all fire wrap credited in the Fire PRA is qualified to at least a one-hour or equivalent fire resistance rating and identified the corresponding supporting technical justification.

FSS-D3-01 (2008) A FSS-D5-01 (2008) A FSS-D7-01 (2010) See PRA RAI 01.j. Acceptable to NRC staff because the licensee explains that maintenance and testing data for all credited fire detection and suppression systems in the years from 2008 to 2011 was evaluated, and that plant specific experience revealed no outlier behavior for credited systems.

FSS-D8-01 (2008) A FSS-D9-01 (2008) A FSS-D10-01 (2008) A FSS-D11-01 (2008) A FSS-D11-01 (2010) A FSS-E1-01 (2008) A January 14, 2016 B-4

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Fire PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I ACCEPTABLE TO STAFF VIA Finding/

Suggestion (F&O) Review RAI Response of Plant ID or Supporting Disposi Not Discussed in SE Discussed in Requirement (SR)i tion SE (A/B/C)

FSS-E1-01 (2010) A FSS-E2-01 (2010) See PRA RAI 01.j. Acceptable to NRC staff because the licensee explains that maintenance and testing data for all credited fire detection and suppression systems in the years from 2008 to 2011 was evaluated, and that plant specific experience revealed no outlier behavior for credited systems.

FSS-E3-01 (2008) See PRA RAI 01.k, PRA RAI 03, and PRA RAI 03.b.01 in Section 3.4.2.2 FSS-F1-01 (2008) A FSS-G1-01 (2008) A FSS-G5-01 (2010) A FSS-H1-01 (2008) A FSS-H4-01 (2008) A FSS-H5-01 (2008) A FSS-H5-01 (2010) A IGN-A4-01 (2008) A IGN-A9-01 (2008) A IGN-B5-01 (2008) C QNS-A1-01 (2008) A QNS-B1-01 (2008) A QNS-B1-02 (2008) A CF-A1-01 (2008) C CF-A1-02 (2008) A CF-A1-03 (2008) See PRA RAI 01.c in Section 3.4.2.2 January 14, 2016 B-5

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Fire PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I ACCEPTABLE TO STAFF VIA Finding/

Suggestion (F&O) Review RAI Response of Plant ID or Supporting Disposi Not Discussed in SE Discussed in Requirement (SR)i tion SE (A/B/C)

CF-A1-04 (2008) C CF-A1-05 (2008) A CF-A1-06 (2008) A CF-A1-01 (2010) A CF-A2-01 (2008) A CF-B1-01 (2010) A HRA-A3-01 (2010) A HRA-B1-01 (2008) A HRA-B3-01 (2008) A HRA-C1-01 (2008) A HRA-C1-02 (2008) A HRA-C1-01 (2010) See PRA RAI 01.l and PRA RAI 03 in Section 3.4.2.2 HRA-D1-01 (2008) A HRA-E1-01 (2008) A HRA-E1-02 (2008) A SF-A1-01 (2010) A SF-A3-01 (2010) C SF-A5-01 (2010) C SF-B1-01 (2010) C FQ-A1-01 (2008) A FQ-B1-01 (2008) A FQ-B1-01 (2010) A FQ-E1-01 (2010) A FQ-F1-01 (2010) A UNC-A1-01 (2008) A UNC-A1-01 (2010) A January 14, 2016 B-6

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Fire PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I ACCEPTABLE TO STAFF VIA Finding/

Suggestion (F&O) Review RAI Response of Plant ID or Supporting Disposi Not Discussed in SE Discussed in Requirement (SR)i tion SE (A/B/C)

MU-A1-01 (2008) See PRA RAI 01.m. Acceptable to NRC staff because the licensee explains that the 2010 Fire PRA peer review report concluded that these two SRs were met based on the new administrative procedure AWP E-028, PRA Model Maintenance and Update.

MU-A2-01 (2008) See PRA RAI 01.m. Acceptable to NRC staff because the licensee explains that the 2010 Fire PRA peer review report concluded that these two SRs were met based on the new administrative procedure AWP E-028, PRA Model Maintenance and Update.

MU-B3-01 (2008) A MU-C1-01 (2008) See PRA RAI 01.m. Acceptable to NRC staff because the licensee explains that the 2010 Fire PRA peer review report concluded that this SR was met based on the new administrative procedure AWP E-028, PRA Model Maintenance and Update.

SF-A2i C Not Reviewed (2008)

SF-A4i C Not Reviewed (2008)

A: For F&Os, the NRC staff finds that the disposition of the F&O as described by the licensee in the LAR provides confidence that the issues raised by the F&O have been addressed and, if needed, the PRA has been modified, and therefore the resolution of the F&O is acceptable for this application. For Not Met or met at CC-I SRs, the NRC staff finds that the acceptability basis for the capability category of the SR as described by the licensee in the LAR provides confidence that the requirements of the SR have been addressed and, if needed, the PRA has been modified, and therefore the PRA quality with respect to the SR is acceptable for this application. Examples of acceptable Not Met and CC-I SRs are modeling methods that yield conservative FRE and change evaluation results.

B: For F&Os, the NRC staff finds that the disposition of the F&O as described by the licensee in the LAR and further clarified during the audit provides confidence that the issues raised by the F&O have been addressed and, if needed, the PRA has been modified, and therefore the resolution of the F&O is acceptable for this application. For Not Met or met at CC-I SRs, the NRC staff finds that the acceptability basis for the capability category of the SR as described by the licensee in the LAR and further clarified during the audit provides confidence that requirements of the SR have been addressed and, if needed, the PRA has been modified, and therefore the PRA quality with respect to the SR is acceptable for this January 14, 2016 B-7

Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Fire PRA Facts and Observations and Supporting Requirements Not Met or Met at Capability Category I ACCEPTABLE TO STAFF VIA Finding/

Suggestion (F&O) Review RAI Response of Plant ID or Supporting Disposi Not Discussed in SE Discussed in Requirement (SR)i tion SE (A/B/C) application. Examples of acceptable Not Met and CC-I SRs are modeling methods that yield conservative FRE and change evaluation results.

C: For F&Os, the NRC staff finds that the resolution of the F&O, as described by the licensee in the LAR, would have a negligible effect on the evaluations relied upon to support fire risk evaluations and has no impact on the conclusions of the risk assessment and therefore the resolution of the F&O is acceptable for this application. Examples of such F&Os may be suggestions, as well as those F&Os that don't affect the fire PRA. Documentation issues may fall into this category as well. For Not Met or met at CC-I SRs, the NRC staff finds that the acceptability basis for the capability category of the SR, as described by the licensee in the LAR, would have a negligible effect on the evaluations relied upon to support fire risk evaluations and has no impact on the conclusions of the risk assessment and therefore the PRA quality with respect to the SR is acceptable for this application. Examples are those SRs that don't affect the fire PRA.

i The licensee identified in Table V-3 of the LAR the SRs that were not met or met only Capability Category I. In all cases, except the two indicated in the last two entries in this table (SF-A2 and SF-A4),

those SRs are addressed by an F&O in Table V-2 of the LAR. All F&Os from Table V-2 of the LAR are addressed in this table.

January 14, 2016 B-8