ML063250099
| ML063250099 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 01/29/2007 |
| From: | Wang A NRC/NRR/ADRO/DORL/LPLIV |
| To: | |
| Wang A, NRR/DORL/LPL4, 301-415-1445 | |
| Shared Package | |
| ML063250103 | List: |
| References | |
| TAC MD0386, TAC MD0387 | |
| Download: ML063250099 (5) | |
Text
January 29, 2007 LICENSEE Pacific Gas and Electric Company FACILITY:
Diablo Canyon Power Plant, Unit Nos. 1 and 2
SUBJECT:
SUMMARY
OF NOVEMBER 6, 2006, MEETING WITH PACIFIC GAS AND ELECTRIC COMPANY ON DIGITAL UPGRADE PROJECT (TAC NOS. MD0386 AND MD0387)
On November 6, 2006, the U.S. Nuclear Regulatory Commission (NRC) staff conducted an open meeting with Pacific Gas and Electric Company (PG&E) to discuss a digital upgrade project for Diablo Canyon Power Plant, Units 1 and 2 (DCPP).
PG&E stated that this was the second meeting with the NRC staff to discuss its digital upgrade project for the DCPP. Based on NRC staff comments from the last meeting, PG&E had revised its design approach and schedule. PG&E wanted to keep the NRC informed of the progress and schedule it was pursuing in this effort. The NRC staff stated that the NRC encourages the industry to have such meetings to assure that the licensees expectations are achievable and that the licensee has the guidance to provide a quality product that the NRC staff can review in a timely manner. The Nrc staff also noted that no decisions about the scope or acceptability of the project would be made as a result of this meeting.
PG&E proposes to replace the legacy analog process protection system (combined reactor trip system (RTS) and engineered safety features actuation system (ESFAS)) with a solid-state protection system. In previous designs, PG&E proposed to combine the RTS and ESFAS in one digital module. The NRC staff did not approve of this design because a postulated digital common cause failure could disable the RTS and ESFAS functions concurrent with an FSAR Chapter 15 accident or event. To mitigate this issue, PG&E proposes a new design so that the RTS and ESFAS utilizes different processors. While these two safety functions will use different processors, PG&E will request to use the same platform for the control systems, the RTS, and the ESFAS. This will be a first-of-its-kind request by the industry. PG&E proposed a two-step approach where it would submit a plant-specific topical report that will provide an evaluation, for NRC approval, of the potential for a common design error that could disable redundant channels of the protection systems through a common-cause failure. Upon this approval, PG&E would submit a license amendment to implement the change referencing the topical report. PG&E wanted to know if the NRC staff felt that the proposed approach using a common platform and operating systems in multiple echelons violated regulations. The general understanding was that the approach could be reviewed and approved. However, the NRC staff stated this would be a very complicated review and completion on the proposed schedule would be highly dependent on the thoroughness of the licensees submittal. The licensee proposed to submit the topical report in early 2007 with the amendment application to follow in 2008. The NRC staff stated that a detailed design in the topical report will enhance the review process. The NRC staff stated that when PG&E was prepared to issue the topical report, a kick-off meeting would be beneficial.
The NRC staff thanked the licensee for the presentation and agreed that a follow-up meeting would be appropriate. A list of attendees is enclosed. The licensee presented information and the non-proprietary presentation slides are available in the Agencywide Documents Access and Management System under Accession Number ML063170445.
Please direct any inquiries to me at 301-415-1445, or abw@nrc.gov.
/RA/
Alan B. Wang, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Licensing Docket Nos. 50-275 and 50-323
Enclosure:
List of Attendees cc w/encl: See next page
Pkg ML063250103 (Summary/Attendees ML063250099, Handouts ML063170445)
OFFICE NRR/LPL4/PM NRR/LPL4/LA ADES/EICB/BC NRR/LPL4/BC NAME AWang LFeizollahi AHowe - HCG for AH DTerao DATE 12/1/07 12/6/07 1/26/07 1/29/07
MEETING WITH PACIFIC GAS AND ELECTRIC (PG&E)
LIST OF ATTENDEES November 6, 2006 PG&E Westinghouse INVENSYS Altran, et al.
NRC K. Schrader E. Quinn S. Patterson L. Erin J. Murray J. Hefler J. Mauck K. Keithline A. Howe W. Kemper A. Wang M. Waterman P. Loeser D. Zhang M. Chiramal
January 2007 Diablo Canyon Power Plant, Units 1 and 2 cc:
NRC Resident Inspector Diablo Canyon Power Plant c/o U.S. Nuclear Regulatory Commission P.O. Box 369 Avila Beach, CA 93424 Sierra Club San Lucia Chapter ATTN: Andrew Christie P.O. Box 15755 San Luis Obispo, CA 93406 Ms. Nancy Culver San Luis Obispo Mothers for Peace P.O. Box 164 Pismo Beach, CA 93448 Chairman San Luis Obispo County Board of Supervisors 1055 Monterey Street, Suite D430 San Luis Obispo, CA 93408 Mr. Truman Burns Mr. Robert Kinosian California Public Utilities Commission 505 Van Ness, Room 4102 San Francisco, CA 94102 Diablo Canyon Independent Safety Committee ATTN: Robert R. Wellington, Esq.
Legal Counsel 857 Cass Street, Suite D Monterey, CA 93940 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission Harris Tower & Pavillion 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 Antonio Fernández, Esq.
Pacific Gas & Electric Company P.O. Box 7442 San Francisco, CA 94120 City Editor The Tribune 3825 South Higuera Street P.O. Box 112 San Luis Obispo, CA 93406-0112 Director, Radiologic Health Branch State Department of Health Services P.O. Box 997414, MS 7610 Sacramento, CA 95899-7414 Mr. James D. Boyd, Commissioner California Energy Commission 1516 Ninth Street (MS 31)
Sacramento, CA 95814 Mr. James R. Becker, Vice President Diablo Canyon Operations and Station Director Diablo Canyon Power Plant P.O. Box 56 Avila Beach, CA 93424 Jennifer Tang Field Representative United States Senator Barbara Boxer 1700 Montgomery Street, Suite 240 San Francisco, CA 94111 Mr. John S. Keenan Senior Vice President - Generation and Chief Nuclear Officer Pacific Gas and Electric Company Diablo Canyon Power Plant P.O. Box 770000, Mail Code B32 San Francisco, CA 94177-0001