ML15348A170

Summary of Telephone Conference Call Held Between NRC and Pacific Gas and Electric Co., Concerning the RAI Responses Pertaining to the Diablo Canyon Power Plant LRA Environmental Review

ML15348A170
Person / Time
Site:	Diablo Canyon
Issue date:	12/17/2015
From:	Michael Wentzel Division of License Renewal
To:
Michael Wentzel 415-6459
References
CAC MF4019, CAC MF4020, DLR-15-0562
Download: ML15348A170 (5)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 December 17, 2015 LICENSEE:

Pacific Gas and Electric Co.

FACILITY:

Diablo Canyon Power Plant, Units 1 and 2

SUMMARY

OF TELEPHONE CONFERENCE CALL HELD ON DECEMBER 10, 2015, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION AND PACIFIC GAS AND ELECTRIC CO. CONCERNING THE RESPONSES TO A REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE DIABLO CANYON POWER PLANT, UNITS 1 AND 2, LICENSE RENEWAL APPLICATION (CAC NOS. MF4019 AND MF4020)

The U.S. Nuclear Regulatory Commission (NRC) staff and representatives of Pacific Gas and Electric Co. (PG&E) held a telephone conference call on December 10, 2015, to discuss and clarify the PG&Es responses to the NRC staffs request for additional information (RAI) concerning the severe accident mitigation alternatives review of the Diablo Canyon Power Plant, Units 1 and 2, license renewal application.

provides a listing of the participants and Enclosure 2 contains a listing of the responses discussed with PG&E, including a brief description of the status.

PG&E had an opportunity to comment on this summary.

Sincerely,

/RA/

Michael Wentzel, Project Manager Projects Branch 2 Division of License Renewal Office of Nuclear Reactor Regulation Docket Nos. 50-275 and 50-323

Enclosures:

As stated cc w/encls: Listserv

ML15348A170

• concurrence via email OFFICE LA:RPB2:DLR* PM:RPB2:DLR BC:RPB2:DLR PM:RPB2:DLR NAME IBetts MWentzel JDanna MWentzel DATE 12/16/15 12/17/15 12/17/15 12/17/15

SUMMARY

OF TELEPHONE CONFERENCE CALL HELD ON DECEMBER 10, 2015, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION AND PACIFIC GAS AND ELECTRIC CO. CONCERNING THE RESPONSES TO A REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE DIABLO CANYON POWER PLANT, UNITS 1 AND 2, LICENSE RENEWAL APPLICATION (CAC NOS. MF4019 AND MF4020)

DISTRIBUTION:

HARD COPY:

DLR RF E-MAIL:

PUBLIC RidsNrrDlr Resource RidsNrrDlrRpb1 Resource RidsNrrDlrRpb2 Resource RidsNrrDlrRerb Resource RidsNrrDlrRarb Resource RidsNrrDlrRasb Resource RidsNrrDlrRsrg Resource RidsNrrDraArcb Resource RidsOgcMailCenter Resource RidsNrrPMDiabloCanyon Resource MWentzel JDanna RPlasse JDozier SLingam CKanatas, OGC JLindell, OGC THipschman, SRI JReynoso, RI JGroom, RIV DMcIntyre, OPA LUselding, OPA WMaier, RIV AMoreno, OCA

ENCLOSURE 1 TELEPHONE CONFERENCE CALL DIABLO CANYON POWER PLANT, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION LIST OF PARTICIPANTS DECEMBER 10, 2015 PARTICIPANTS ORGANIZATION Jerry Dozier U.S. Nuclear Regulatory Commission (NRC)

Michael Wentzel NRC Bob Schmidt Pacific Northwest National Laboratory (PNNL)

Steve Short PNNL Nathan Barber Pacific Gas and Electric Co. (PG&E)

Terry Grebel PG&E Michelle Olsofsky PG&E John Pyo PG&E Philippe Soenen PG&E

ENCLOSURE 2 TELEPHONE CONFERENCE CALL CONCERNING THE RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION RELATED TO THE SEVERE ACCIDENT MITIGATION ALTERNATIVES REVIEW OF THE DIABLO CANYON POWER PLANT, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION DECEMBER 10, 2015 By letter dated October 22, 2015 (ADAMS Accession No. ML15287A165), the U.S. Nuclear Regulatory Commission (NRC) staff issued a request for additional information (RAI) to Pacific Gas and Electric Co. (PG&E) related to the severe accident mitigation alternatives (SAMA) review of the Diablo Canyon Power Plant, Units 1 and 2, license renewal application. By letter dated November 12, 2015 (ADAMS Accession No. ML15316A770), PG&E submitted responses to NRC staff RAIs. On December 10, 2015, the NRC staff and representatives of PG&E held a telephone conference call to discuss and clarify the following RAI responses.

1. Response to RAI 1.c.

Discussion: The NRC staff requested PG&E clarify what was meant by the statement and of the reactor coolant system (RCS) in item 1 on page 3 of the RAI responses. PG&E stated that the statement should be struck, as its inclusion was unintentional.

2. Response to RAI 1.d.

Discussion: The NRC staff requested that PG&E briefly describe the seismic hazard information used in probabilistic risk assessment (PRA) models DC02 and DC03, particularly in relation to the information provided in PG&Es 2010 RAI response, as discussed on pages F-34 and F-35 of PG&Es amended environmental report. PG&E stated that the 2010 RAI response incorporated the Shoreline fault seismic hazard into the model. PRA model DC03 also accounts for the Shoreline fault; however, it updates the seismic hazard from that provided in the 2010 RAI response.

3. Response to RAI 1.i.

Discussion: The NRC staff requested that PG&E identify the internal events model that was used as the basis for the interim fire PRA model that was peer reviewed in 2012 and provide the internal events core damage frequency (CDF). Additionally, the NRC staff requested PG&E to confirm that the fire PRA CDF given for DC02 was based on models predating PG&Es NFPA-805 revision and to provide the dates of models DC02 and DC02A.

PG&E stated that the interim fire PRA was based on PRA model DC01 and that the internal events CDF was 1.08 x 10-5. Relative to the fire CDF, PG&E stated that the fire PRA model developed for the NFPA-805 revisions was separated out from the plant model in December 2010. Finally, PG&E stated that the dates for models DC02 and DC02A are November 2012 and January 2013, respectively.