ML13324A453
| ML13324A453 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 10/18/1984 |
| From: | Medford M Southern California Edison Co |
| To: | Paulson W Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML13324A454 | List: |
| References | |
| TAC-55928 NUDOCS 8410230285 | |
| Download: ML13324A453 (2) | |
Text
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 M.O. MEDFORD TELEPHONE MANAGER, NUCLEAR LICENSING (213) 572-1749 October 18, 1984 Director, Office of Nuclear Reactor Regulation Attention: W. A. Paulson, Acting Chief Operating Reactors Branch No. 5 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D.C.
20555 Gentlemen:
Subject:
Docket No. 50-206 Intake Structure Degradation and Repair San Onofre Nuclear Generating Station Unit 1
Reference:
Letter, J. G. Haynes, SCE, to USNRC,
Subject:
LER No.84-008, dated September 5, 1984 The San Onofre Unit 1 intake structure has recently undergone a modification program due to discovery of excessive rebar corrosion. The corroded rebar was discovered during maintenance of the saltwater cooling system when the stop logs which are normally used to dewater part of the intake would not properly function.
The tsunami gates were then used to dewater the structure for maintenance and to determine the cause and extent of the problem. The referenced LER was submitted as a result of investigations which concluded that the structure was in a significantly degraded state.
The enclosed report has been developed to describe the intake structure rebar corrosion and to give details of the repair program. The repairs to the structure were done under 10 CFR 50.59 as not involving an unreviewed safety question and therefore not requiring prior NRC approval.
This report is being provided for information as committed in earlier meetings with the NRC staff on this subject.
The result of the repair program is that the intake structure will be able to continue to perform its safety function even considering a 0.67g Housner seismic event. A surveillance program to monitor any further corrosion is being developed and further modifications are also being considered to mitigate the corrosion. The surveillance program will be 9410230295 641018 PDR ADOCK 05000206 P
PDR k
Mr. W.
October 18, 1984 provided for your information 90 days prior to the next refueling outage.
If you have any questions in this matter or would like further information, please let me know.
Very truly yours, cc:
A. E. Chaffee (USNRC Senior Resident Inspector, Units 1, 2 and 3)
- 3. B. Martin (Regional Administrator, USNRC Region V)