DCL-15-156, Response to NRC Request for Additional Information - National Fire Protection Association Standard 805 and Supplement

Response to NRC Request for Additional Information - National Fire Protection Association Standard 805 and Supplement

ML15365A534
Person / Time
Site:	Diablo Canyon
Issue date:	12/31/2015
From:	Welsch J Pacific Gas & Electric Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
Shared Package
ML16011A410	List: DCL-15-156, Response to NRC Request for Additional Information - National Fire Protection Association Standard 805 and Supplement
References
DCL-15-156
Download: ML15365A534 (4)

Text

Attachment 1 of the Enclosure contains Security-Related Information--- Withhold under 10 CFR 2.390 lrl Pacific Gas and

~&~ Electric Company James M. Welsch Diablo Canyon Power Plant Site Vice President Mail Code 104/6 P. 0. Box 56 Avila Beach, CA 93424 December 31, 2015 805.545.3242 Internal: 691.3242 Fax: 805.545.4884 PG&E Letter DCL-15-156 U.S. Nuclear Regulatory Commission A TIN: Document Control Desk Washington, DC 20555-0001 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2 Response to NRC Request for Additional Information - National Fire Protection Association Standard 805 and Supplement

References:

(1) PG&E Letter DCL-13-065, "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 (2) PG&E Letter DCL-15-119, "Response to NRC Request for Additional Information- National Fire Protection Association Standard 805," dated October 15, 2015 (3) NRC E-mail from S. Lingam, "Diablo Canyon 1 and 2 - Follow-up PRA RAI for NFPA-805 LAR (CAC Nos. MF2333 and MF2334)," dated December 23, 2015

Dear Commissioners and Staff:

In Reference 1, Pacific Gas and Electric Company (PG&E) submitted a license amendment request to adopt National Fire Protection Association Standard 805.

In Reference 2, PG&E provided responses to the Nuclear Regulatory Commission's (NRC) requests for additional information. In Reference 3, the NRC requested additional information regarding the responses in Reference 2. Enclosed are PG&E's responses to the latest questions.

In addition, Attachment 1 to the Enclosure includes two pages that replace those previously provided in Reference 2. Attachment 1 of the Enclosure contains security-related information and should be withheld under 10 CFR 2.390.

A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek Attachment 1 of the Enclosure contains Security-Related Information --- Withhold under 10 CFR 2.390 (When separated from Attachment 1, this document is decontrolled.)

Attachment 1 of the Enclosure contains Security-Related Information --- Withhold under 10 CFR 2.390

• 1 Document Control Desk PG&E Letter DCL-15-156

~&~ December 31, 2015 Page 2 PG&E makes a new regulatory commitment (as defined by NEI 99-04) in this letter.

If you have any questions or require additional information, please contact Mr. Michael Richardson at 805-545-4557.

I state under penalty of perjury that the foregoing is true and correct.

Executed on December 31, 2015.

Sincerely,

~ /11~ u)~

mes M. Welsch - ~

Site Vice President e1d7/4418/50037411 Enclosure cc: Diablo Distribution cc/enc: Marc L. Dapas, NRC Region IV Administrator Siva P. Ling am, NRR Senior Project Manager Gonzalo L. Perez, California Department of Public Health John P. Reynoso, Acting NRC Senior Resident Inspector A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek Attachment 1 of the Enclosure contains Security-Related Information-- Withhold under 10 CFR 2.390 (When separated from Attachment 1, this document is decontrolled.)

Enclosure PG&E Letter DCL-15-156 Response to NRC Request for Additional Information - National Fire Protection Association Standard 805 and Supplement of this Enclosure provides two pages that replace those previously provided in Reference 2, which did not show the changes from the original submittal.

NRC PRA RAI 03.b.01 The response to PRA RAJ 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.

PG&E Response The State of Knowledge Correlation (SOKC) has minimal impact on the difference between the mean and the point estimate value of the fire induced total Core Damage Frequency (CDF) and total Large Early Release Frequency (LERF), that is an impact of less than 1 percent for CDF and LERF and significantly less than 1 percent for delta CDF and delta LERF. Therefore, the use of point estimate CDF and LERF as a surrogate for the mean value of the risk metrics in Attachment W of the National Fire Protection Association Standard 805 (NFPA 805) License Amendment Request is a reasonable approach.

However, PG&E will consider the impact of SOKC on delta CDF and delta LERF against the self-approval acceptance criteria (i.e., delta CDF less than 1E-07 per year) for post-transition changes. The consideration of SOKC for self-approval of post-transition changes will be incorporated into the PG&E implementation procedures.

1

Enclosure Attachment 1 PG&E Letter DCL-15-156 Supplemental Replacement Pages C-487 and C-505 1

Attachment 1 of the Enclosure contains Security-Related Information--- Withhold under 10 CFR 2.390 lrl Pacific Gas and

~&~ Electric Company James M. Welsch Diablo Canyon Power Plant Site Vice President Mail Code 104/6 P. 0. Box 56 Avila Beach, CA 93424 December 31, 2015 805.545.3242 Internal: 691.3242 Fax: 805.545.4884 PG&E Letter DCL-15-156 U.S. Nuclear Regulatory Commission A TIN: Document Control Desk Washington, DC 20555-0001 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2 Response to NRC Request for Additional Information - National Fire Protection Association Standard 805 and Supplement

References:

(1) PG&E Letter DCL-13-065, "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 (2) PG&E Letter DCL-15-119, "Response to NRC Request for Additional Information- National Fire Protection Association Standard 805," dated October 15, 2015 (3) NRC E-mail from S. Lingam, "Diablo Canyon 1 and 2 - Follow-up PRA RAI for NFPA-805 LAR (CAC Nos. MF2333 and MF2334)," dated December 23, 2015

Dear Commissioners and Staff:

In Reference 1, Pacific Gas and Electric Company (PG&E) submitted a license amendment request to adopt National Fire Protection Association Standard 805.

In Reference 2, PG&E provided responses to the Nuclear Regulatory Commission's (NRC) requests for additional information. In Reference 3, the NRC requested additional information regarding the responses in Reference 2. Enclosed are PG&E's responses to the latest questions.

In addition, Attachment 1 to the Enclosure includes two pages that replace those previously provided in Reference 2. Attachment 1 of the Enclosure contains security-related information and should be withheld under 10 CFR 2.390.

A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek Attachment 1 of the Enclosure contains Security-Related Information --- Withhold under 10 CFR 2.390 (When separated from Attachment 1, this document is decontrolled.)

Attachment 1 of the Enclosure contains Security-Related Information --- Withhold under 10 CFR 2.390

• 1 Document Control Desk PG&E Letter DCL-15-156

~&~ December 31, 2015 Page 2 PG&E makes a new regulatory commitment (as defined by NEI 99-04) in this letter.

If you have any questions or require additional information, please contact Mr. Michael Richardson at 805-545-4557.

I state under penalty of perjury that the foregoing is true and correct.

Executed on December 31, 2015.

Sincerely,

~ /11~ u)~

mes M. Welsch - ~

Site Vice President e1d7/4418/50037411 Enclosure cc: Diablo Distribution cc/enc: Marc L. Dapas, NRC Region IV Administrator Siva P. Ling am, NRR Senior Project Manager Gonzalo L. Perez, California Department of Public Health John P. Reynoso, Acting NRC Senior Resident Inspector A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek Attachment 1 of the Enclosure contains Security-Related Information-- Withhold under 10 CFR 2.390 (When separated from Attachment 1, this document is decontrolled.)

Enclosure PG&E Letter DCL-15-156 Response to NRC Request for Additional Information - National Fire Protection Association Standard 805 and Supplement of this Enclosure provides two pages that replace those previously provided in Reference 2, which did not show the changes from the original submittal.

NRC PRA RAI 03.b.01 The response to PRA RAJ 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.

PG&E Response The State of Knowledge Correlation (SOKC) has minimal impact on the difference between the mean and the point estimate value of the fire induced total Core Damage Frequency (CDF) and total Large Early Release Frequency (LERF), that is an impact of less than 1 percent for CDF and LERF and significantly less than 1 percent for delta CDF and delta LERF. Therefore, the use of point estimate CDF and LERF as a surrogate for the mean value of the risk metrics in Attachment W of the National Fire Protection Association Standard 805 (NFPA 805) License Amendment Request is a reasonable approach.

However, PG&E will consider the impact of SOKC on delta CDF and delta LERF against the self-approval acceptance criteria (i.e., delta CDF less than 1E-07 per year) for post-transition changes. The consideration of SOKC for self-approval of post-transition changes will be incorporated into the PG&E implementation procedures.

1

Enclosure Attachment 1 PG&E Letter DCL-15-156 Supplemental Replacement Pages C-487 and C-505 1