ML20055J387
| ML20055J387 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 07/30/1990 |
| From: | Nandy F SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9008020195 | |
| Download: ML20055J387 (1) | |
Text
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_f*?W Southem Califomia Edison Company 23 PARKER STREcT.
IRVINE. CALIFORNIA 92718 F. R. N ANDY TELEPHONE MANAGER. NUCLE AR UCt N& LNG (714) 687-6400 July 30,1990
. U. S. Nuclear Regulatory Commission
' Document Control Desk Washington, D. C, 20555
Subject:
Docket No. 50-361 Special Report San Onofre Nuclear Generating Station, Unit 2 This report is being submitted in accordance with Technical Specification (TS) 33.3.3, Action a, of Facility.
Operating License NPF-10, San Onofre Unit 2. The TS requires Southern California Edison (SCE) to submit a Special Report when the scismic monitoring instrumentation becomes inoperable for more than 30 days.
On June 20,1990, with Unit 2 in Mode 1 at 100% power, reactor coolant pump strong motion accelerometer (SMA) 2XT-8020C was determined inoperable following performance of a routine monthly surveillance test, due to the failure to meet certain requirements of Procedure S023-11-2.1. Specifically, the longitudinal sensor playback readmgs of SMA 2XT-8020C were outside the test acceptance criteria.
Investigation results to date have not been able to establish when the SMA failed. Initial troubleshooting of the scismic instrumentation components and circuitry could not fully determine the cause of the deficiency.
Further troubicshooting will require containment entry for accessing 2XT-8020C, Due to ALARA considerations during power operations, personnel are precluded from performing further investigative efforts. Troubleshooting and repair efforts for 2XT-8020C will be performed during the current Unit 2 steam generator inspection outage and 2XT 8020C will be returned to service prior to Mode 4 entry.
- If you require any additional information, please let me know.-
Very truly yours, t-l
/
l cc:
J. B. Martin (Regional Administrator, NRC Region V)
C. W. Caldwell (NRC Senior Resident inspector, Units 1,2 and 3)
L J. E. Tatum (NRR SONGS Project Manager)
Institute of Nuclear Power Operations (INPO) l:
9006020195 900730 PDR ADOCK 05000361 M/
S PDC
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