ML15358A002

Request for Additional Information Email (Follow-up Pra), Request to Adopt National Fire Protection Association NFPA 805, Performance-Based Standard for Fire Protection for LWR Generating Plants (2001 Edition)

ML15358A002
Person / Time
Site:	Diablo Canyon
Issue date:	12/23/2015
From:	Siva Lingam Plant Licensing Branch IV
To:	Richardson M Pacific Gas & Electric Co
Lingam S
References
CAC MF2333, CAC MF2334
Download: ML15358A002 (1)

Text

Burkhardt, Janet From: Lingam, Siva Sent: Wednesday, December 23, 2015 3:34 PM To: 'mjrm@pge.com' Cc: Pascarelli, Robert; Rosenberg, Stacey; Miller, Barry; Hilsmeier, Todd; Robinson, Jay; Wu, Angela; Coles, Garill A (Garill.Coles@pnnl.gov); Schrader, Kenneth (KJSe@pge.com);

Thatipamala, Ramakrishna; Bemis, Paul R; Harris, Brenda A; Burkhardt, Janet

Subject:

Diablo Canyon 1 and 2 - Follow-up PRA RAI for NFPA-805 LAR (CAC Nos. MF2333 and MF2334)

By letter dated June 26, 2013, as supplemented, Pacific Gas and Electric Company (PG&E, the licensee) submitted a license amendment request (LAR) to adopt a new fire protection licensing basis for Diablo Canyon Power Plant (DCPP), Unit Nos. 1 and 2, which complies with the requirements in paragraphs 50.48(a) and (c) of Title 10 of the Code of Federal Regulations (10 CFR) (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13196A139). Specifically, DCPP, Unit Nos. 1 and 2, would transition to a fire protection licensing basis based on the National Fire Protection Association Standard 805 (NFPA 805)

Performance-Based Standard for Fire Protection For Light Water Reactor Generating Plants (2001 Edition).

PG&Es supplemental letter dated October 15, 2015 (ADAMS Accession No. ML15300A005), provided responses to U.S. Nuclear Regulatory Commission (NRC) staffs requests for additional information (RAIs). The NRC staff reviewed these responses and concluded that additional follow-up RAI is required for probabilistic risk assessment (PRA) RAI 03.b. Please note the following official follow-up RAI for the DCPP NFPA-805 LAR. Please provide your response by January 11, 2016, as suggested by you. We transmitted draft RAI to you on December 14, 2015, and we had a clarification call on December 23, 2015. Your timely responses will allow the NRC staff to complete its review on schedule.

PRA RAI 03.b.01 The response to PRA RAI 03.b, dated October 15, 2015, explains that incorporating consideration of State of Knowledge Correlation (SOKC) into the Fire PRA results would increase core damage frequency (CDF) and large early release frequency (LERF) by less than one percent, and therefore, point estimate means were used in the integrated analysis and will be used for self-approval of post-transition changes. The NRC staff notes that one percent of the total updated CDF for Units 1 and 2 (i.e., 9.4E-05/year and 9.6E-05/year, respectively) is about 1E-06/year, which is significant relative to the delta CDF risk criteria (i.e., 1E-07/year) for self-approval of post-transition changes. A similar observation can be made for LERF. Therefore, it is not clear that consideration of SOKC can only have a negligible impact on post-transition change evaluations. Further justify that consideration of SOKC have a negligible impact on self-approval of post-transition changes. Alternatively, explain how self-approval of post-transition change evaluations will consider SOKC when it can have an impact on the evaluations.

Siva P. Lingam U.S. Nuclear Regulatory Commission Project Manager (NRR/DORL/LPL41)

Diablo Canyon Nuclear Power Plant Location: O8D5; Mail Stop: O8B3 Telephone: 3014151564; Fax: 3014151222 Email address: siva.lingam@nrc.gov 1