ML13330A298
| ML13330A298 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 04/16/1981 |
| From: | Baskin K Southern California Edison Co |
| To: | Lainas G Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8104210318 | |
| Download: ML13330A298 (2) | |
Text
Southern California Edison Company P
- 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 K. P. BASKIN MANAGER OF NUCLEAR ENGINEERING.
April 16, 1981 (2131 572.1401 SAFETY. AND LICENSING Director of Nuclear Reactor Regulation W-k 14 t'J Attention: Gus C. Lainas, Assistant Director Safety Assessment Division of Licensing U. S. Nuclear Regulatory Commission Washington, D.C.
20555 Gentlemen:
Subject:
Docket No. 50-206 Environmental Qualification of Safety-Related Electrical Equipment San Onofre Nuclear Generating Station Unit 1 By letter dated March 5, 1981, we indicated to you that we would provide by April 15, 1981 additional information developed to date, including continued evaluation of the NRC staff's preliminary list of deficiencies contained in the report entitled, "Partial Review, Equipment Evaluation Report by the Office of Nuclear Reactor Regulation," for San Onofre Unit 1. This report was forwarded to us by your February 17, 1981 letter.
As noted in our March 5, 1981 letter, efforts to obtain additional qualification information for some equipment have continued since our October 31, 1980 submittal.
Our review of the additional information developed to date indicates that some safe shutdown cables, terminal blocks and long-term recirculation flow control valves may be adversely affected by the assumed environmental conditions (i.e., temperature, caustic spray and radiation).
Based on our evaluation to date, it is necessary to replace the non-metallic parts of the flow control valves operators and respective solenoid valves and replace the valves regulators. This will assure operation of the valves in the post-accident environment. We are continuing to evaluate the extent to which the cables and terminal blocks may be affected to determine whether they will perform their intended function and whether other unaffected components are available to perform a similar function. We expect to complete our evaluation by May 1, 1981. The need to replace the valve internals to ensure post-accident operation constitutes a reportable occurrence as defined in Technical Specification 6.9.2.a(9). A copy of this letter is being forwarded to the NRC Region V office as a written notification of this occurrence. This 00/
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Gus.
April 16, 1981 will be followed with a two week report and a licensee event report. With regards to the cable and terminal blocks, if we conclude that the intended function cannot be performed by the affected components or by other unaffected i components and remedial actions or corrective measures are required for a
continued safe operation, we will promptly notify the NRC Region V in accordance with the San Onofre Unit 1 Technical Specifications.
In order to provide a complete evaluation, we intend to delay 3
submittal of the additional information developed to date, including our evaluation of the NRC staff's preliminary list of deficiencies as discussed in our March 5, 1981 letter until May 1, 1981.
During this time, San Onofre Unit 1 will continue to be out-of-service pending completion of steam generator sleeving modifications.
If you have any questions, or desire further information concerning carin the plans discussed above, please contact me.
Very truly yours,