ML091070587
| ML091070587 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 04/17/2009 |
| From: | Short M Southern California Edison Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| GL-08-001 | |
| Download: ML091070587 (3) | |
Text
SOUTHERN CALIFORNIA EDISON Michael P. Short Vice President An EDISON lNTERNATIONAL Company April 17, 2009 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
Subject:
Docket Nos. 50-361 and 50-362 Revision to Commitment Completion Date and additional information associated with NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" San Onofre Nuclear Generating Station, Units 2 and 3
References:
- 1. NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" dated January 11, 2008
- 2. October 14,2008 letter from M. P. Short (SCE) to Document Control Desk (NRC),
Subject:
Nine-Month Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling,
, Decay Heat Removal, and Containment Spray Systems," San Onofre Nuclear Generating Station Units 2 and 3
- 3. February 12,2009, letter from M. P. Short (SCE) to Document Control Desk (NRC),
Subject:
Nine-Month Supplemental (Post-Outage)
Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," San Onofre Nuclear Generating Station, Unit 3
Dear Sir or Madam:
The Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2008-01 (Reference 1) to request that each licensee evaluate the licensing basis, design, testing, and corrective actions for the emergency core cooling, decay heat removal, and containment spray systems to ensure that gas accumulation is maintained less than the amount that challenges operability of these systems, and that appropriate action is taken when conditions adverse to quality are identified.
P.O. Box 128 San Clemente, CA 92674-0128 (949) 368-3780 Fax: (949) 368-3770
Document Control Desk April 17, 2009 Revision to Commitment Completion Date In Reference 2, Southern California Edison (SCE) committed to several corrective actions. This letter provides notification that SCE finds it necessary to extend the completion date for one of the actions. SCE has evaluated the commitment change and has determined that it is consistent with its internal commitment management procedure.
Specifically, Reference 2, Attachment 2, Corrective Action 7 states:
"SCE will conduct confirmatory walkdowns as identified in Item 6 of the Design Evaluation for Unit 2 accessible and inaccessible piping and submit a Nine-Month supplemental response with the results of these walkdowns and any resulting corrective actions."
This action was scheduled to be completed "60 days after completion of the Unit 2 outage" or April 20, 2009.
This letter provides notification of the extension of that completion date to 120 days after completion of the Unit 2 outage or June 18, 2009. The extension of this date will not affect the completion of any other commitments.
SCE performed walkdowns of the Unit 2 Safety Injection (SI), Shutdown Cooling (SOC) and Containment Spray (CS) systems based upon screening criteria, using a Photon Three-Dimensional Laser Scanning device. Upon analysis of the Unit 2 walkdown results, it appears that the scanner inclinometer was not functioning properly, thereby invalidating the results. The extended completion date provides the time necessary to return the scanner for calibration and/or repair, and re-perform the necessary walkdowns and analysis. The Unit 3 scan results were re-reviewed and determined to be unaffected. The results provided in Reference 3 are unchanged.
Design Basis Documents SCE performed an evaluation of the Units 2 and 3 Emergency Core Cooling System (ECCS) cold leg injection piping which was documented in the Nine-Month Response (Reference 2). The evaluation, which concluded the subject systems were operable, was based on an interim report issued for Combustion Engineering (CE) plants. Since the submittal of Reference 2, CE Report FAI/08-137, "Generic Criterion for Cold Leg Injection Gas-Water Waterhammer," has been reissued with a revised evaluation methodology. In response, SCE prepared Calculation M-0012-041, "Generic Letter 2008-01 Cold Leg Injection Piping Analysis." The SCE calculation concludes that the minimum pressure needed to initiate a gas-water waterhammer would be precluded due to the static head pressure of the Refueling Water Storage Tank. Therefore, a potential void would not generate a waterhammer in the cold leg injection piping, and the systems remain operable.
Document Control Desk April 17, 2009 This letter contains no additional regulatory commitments.
Should you have any questions, please contact Ms. Linda Conklin at (949) 368-9443.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on #r!z1XJ9 I Date cc:
E. E. Collins, Regional Administrator, NRC Region IV N. Kalyanam, NRC Project Manager, San Onofre Units 2 and 3 R. Hall, NRC Project Manager, San Onofre Units 2 and 3 G. G. Warnick, NRC Senior Resident Inspector, San Onofre Units 2 and 3