ML20117A581
| ML20117A581 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 11/24/1992 |
| From: | Marsh W SOUTHERN CALIFORNIA EDISON CO. |
| To: | Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| NUDOCS 9211300183 | |
| Download: ML20117A581 (2) | |
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(714)454-4403 hurt $ AR FtEGs/LATORY AFF A Fig November 24, 1992 i
Mr. John B. Martin, Administrator U. S. Nuclear Regulatory Commission, Region V 1450 Maria Lane, Suite 210 Walnut Cret9, CA 94596-5368
Dear Mr. Martin:
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) 3.3.3.3.a of Facility Operating License NPF-10,-San Onofre Unit 2.
The TS requires Southern California Edison (SCE' to submit a special re) ort when the seismic monitoring instrumentation becomes inoperable for more t1an 30 days, i
On October 21, 1992, with Unit 2 in Mode 1 at 100% power, steam generator base support strong motion accelerometer (SMA) 2XT-8020B was determined to be Specifically, the vertical channel of 2XT-8020B did not respond as required by
_ l inoperable followino the performance of a routine monthly surveillance test.
procedure S023-11-2.1, " Surveillance Requirement Seismic Time History Accelerometer Model SMA-3 Functional Test."
Initial troubleshooting of the seismic instrumentation components and circuitry identified the malfunction to be associated with the 2XT-80208 field Further troubleshooting will require containment entry for accessing sensor.
2XT-80208. Due to radiation exposure considerations during power operations, personnel are precluded from performing further investigstive efforts.
. Troubleshooting and repair efforts for 2XT-8020B will be performed during the next Unit 2 shutdown of sufficient duration.
Other seismic instrumentation has remained operable (except for routine i
surveillances), so the ability to detect and measure the effects of an earthquake has not been significantly impaired.
l 30002S 9211300183 921124
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Mr. John B. Martin, Administrator November 24, 1992 If you require any additional information, please let me know.
Sincerely, 2lh0llfdi' cc:
U. S. Nuclear Regulatory Commission Document Control Desk M. B. Fields, NRC Project Manager, San Onofre Units 2 and 3 C. W. Caldwell, NRC Senior Resident inspector, San Onofre Units 1, 2 & 3
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