ML053220627
| ML053220627 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 11/14/2005 |
| From: | Scherer A Southern California Edison Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NSAL-05-6 | |
| Download: ML053220627 (1) | |
Text
. n IdSOU1HERN CALIFORNIA U EDISON An ElISON I TER\\N ITIONL I Company A. Edward Scherer Manager of Nuclear Regulatory Affairs November 14, 2005 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555-0001
Subject:
Docket Nos. 50-361 and 50-362 San Onofre Nuclear Generating Station, Units 2 and 3 Westinghouse COAST Code Error
Dear Sir or Madam:
On September 13, 2005, Southern California Edison (SCE) learned of a non-conservative error in a Westinghouse analysis for the Reactor Coolant Pump "Sheared Shaft" postulated accident scenario. Westinghouse discovered this error in April 2002 and has prepared a Nuclear Safety Advisory Letter (NSAL-05-6) to address this issue. In lieu of a possible voluntary Licensee Event Report, SCE is forwarding a copy of NSAL-05-6.
Based on the information recently supplied by Westinghouse, SCE completed an evaluation of the sheared shaft event for San Onofre Nuclear Generating Station (SONGS) Units 2 and 3. The results confirmed that the existing accident analyses contain sufficient conservatisms to bound the error.
Westinghouse is determining the extent of the condition and performing a root cause analysis of this event. SCE will inform the U.S. Nuclear Regulatory Commission of any new significant developments regarding this issue. If you require any additional information, please contact Mr. Clay E. Williams at 949-368-6707.
Sincerely,
Attachment:
As stated cc:
B.S. Mallett, NRC Regional Administrator, Region IV C. C. Osterholtz, NRC Senior Resident Inspector, San Onofre Units 2 & 3 P.O. Box 128 San Clemente, CA 92672 949-368-7501 Fax 949-368-7575 S.