ML072420116
| ML072420116 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 09/07/2007 |
| From: | Catherine Haney NRC/NRR/ADRO/DORL/LPLIV |
| To: | Keenan J Pacific Gas & Electric Co |
| Wang, A B, NRR/DORL/LPLIV, 415-1445 | |
| References | |
| TAC MD4150, NRR-07-007 | |
| Download: ML072420116 (4) | |
Text
September 7, 2007 Mr. John S. Keenan Senior Vice President 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
SUBJECT:
DIABLO CANYON POWER PLANT, UNIT NO. 2 - EVALUATION OF FINITE ELEMENT ANALYSIS IN SUPPORT OF ALLOY 82/182 PRESSURIZER BUTT WELD INSPECTIONS IN 2008 AS PROVIDED BY CONFIRMATORY ACTION LETTER NRR-07-003 (TAC NO. MD4150)
Dear Mr. Keenan:
On March 15, 2007, the U.S. Nuclear Regulatory Commission (NRC) issued Confirmatory Action Letter (CAL) No. NRR-07-003 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML070670425) regarding dissimilar metal welds in the pressurizer surge, spray, and safety/relief nozzle-to-safe end welds at Diablo Canyon Power Plant (DCPP), Unit No. 2. The CAL and the supporting commitment letter (ADAMS Accession No. ML070580128) indicate that inspection and mitigation actions may be conducted during your spring 2008 refueling outage, contingent on the industry providing an analysis that demonstrates an acceptable level of safety to the NRC for the operation of these welds until spring 2008. This letter acknowledges receipt of your letter dated August 7, 2007 (ADAMS Accession No. ML072410199), informing the NRC that the analysis referred to by this CAL and the supporting commitment letter has been completed, and that the analysis is applicable to your plant.
The NRC received MRP-216, Rev. 1, Materials Reliability Program: Advanced FEA [Finite Element Analysis] Evaluation of Growth of Postulated Circumferential PWSCC [Primary Water Stress-Corrosion Cracking] Flaws in Pressurizer Nozzle Dissimilar Metal Welds, on August 13, 2007 (ADAMS Accession No. ML072410235). Based on our review of this report, the NRC concludes that the analysis provides adequate justification to permit inspections during your spring 2008 refueling outage, and that the analysis is applicable to DCPP, Unit No. 2. The results of the staffs review are contained in a safety assessment dated August 31, 2007 (ADAMS Accession No. ML072400199), and the associated contractor report (ADAMS Accession No. ML072470394).
Based on the above, the NRC concludes that a plant shutdown by December 31, 2007, is no longer required. Therefore, the pressurizer surge, spray, and safety/relief nozzle-to-safe end Alloy 82/182 butt weld inspections for DCPP, Unit No. 2 must be performed prior to exiting your scheduled spring 2008 refueling outage. All other requirements of the CAL and the supporting commitment letter regarding enhanced inspection and leakage monitoring requirements for the reactor coolant system and associated reports remain valid.
J. S. Keenan The CAL will remain open until all CAL commitments pertaining to DCPP, Unit No. 2 are complete.
Current NRC guidance regarding CALs is contained in the NRC Enforcement Policy and the NRC Enforcement Manual, which are available at the NRC web site at http://www.nrc.gov/about-nrc/regulatory/enforcement.html (click on Enforcement Policy or Enforcement Guidance) or by contacting the Government Printing Office (GPO) toll-free at 1-888-293-6498. The GPO is open from 7:00 a.m. to 9:00 p.m. EST, Monday through Friday (except Federal holidays).
In accordance with Section 2.390 of Title 10 of the Code of Federal Regulations, of the NRC's "Rules of Practice," a copy of this letter will be made available electronically for public inspection in the NRC Public Document Room or from the NRCs document system (ADAMS),
accessible from the NRC Web site at http://www.nrc.gov/reading-rm.html.
Sincerely,
/RA/
Catherine Haney, Director Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-323 cc: See next page
ML072420116 OFFICE DCI/CPNB DCI/CPNB LPL4/PM LPL4/LA LPL4/BC NAME TLupold TChan Awang, JND for JBurkhardt Thiltz, BKS for DATE 9/6/07 9/6/07 9/6/07 9/5/07 9/6/07 OFFICE DCI/D DRP/D, RGN4 DORL/D NAME MEvans DChamberlain CHaney DATE 9/7/07 9/7/07 WJones for 9/7/07
August 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 Adminstrator, Region IV U.S. Nuclear Regulatory Commission Harris Tower & Pavillion 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 Jennifer Post, 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 94306-0112 Director, Radiologic Health Branch State Department of Health Services P.O. Box 997414, MS 7610 Sacramento, CA 95899-7414 Mr. James Boyd, Commissioner California Energy Commission 1516 Ninth Street MS (31)
Sacramento, CA 95831 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 T. Conway Site Vice President Diablo Canyon Power Plant P. O. Box 56 Avila Beach, California 93424