ML20237H014
| ML20237H014 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 08/19/1987 |
| From: | Morgan H SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8708240333 | |
| Download: ML20237H014 (2) | |
Text
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,; ws Southem Califomia Edison Company SAN ONOFRE NUCLE AR GENERATING ST ATION P O BOX t20 6AN CLEMENTE. CALIFORNIA 92672 I?
68 6 49 ST AT ON 84ANAC August 19, 1987' U.S. Nuclear Regulatory Commission Document Control Desk Washington,.D.C.
20555
Subject:
Docket No. 50-206 Special Report San Onofre Nuclear Generating Station, Unit 1 Pursuant to Section 3.14.B.4.b of' Appendix A, Technical Specifications to Provisional Operating License DPR-13 for San Onofre Unit 1, this submittal provides the required Special Report for Fire Detection Instrumentation being inoperable for greater than 14 ' days.
On July 7,1987, Fire Detection Instrumentation for fire zone 8 was removed from
. service to perform planned maintenance including cleaning of detectors and semi-annual functional testing required by Technical Specification 4.15.D.(1).
As this work progressed, computer alarms associated with zone 8 and other fire detection zones were received. As a result, maintenance was expanded to include troubleshooting of fire detector circuitry, data gathering panels (DGP) and associated computer circuitry. This effort required isolating fire zone detector-circuitry from the computer, essentially rendering various fire detection instrumentation inoperable.
Compensatory 1-hour fire watch patrols were initiated for zone 8 in accordance
-with Technical Specification 3.14.B.4.a, on July 7, and as the instrumentation for other zones was removed from service.
The spurious alarms were due to failed circuit boards in the Fire Computer System transmitting units (N-modules). The failed circuit boards have been replaced.
Zone 8 and all other affected fire detection instrumentation were returned to scrvice on August 7,1987, following satisfactory functional testing.
8708240333 870019 PDR ADOCK 05000206 g
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's DEcument Control Desk
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=If 'you require additional information, please so advise.
Sincerely, "N
- cc:
J.'B. Martin (Regional Administrator, USNRC Region V)
F. R. Huey (USNRC Resident Inspector, Units 1, 2 and 3)
Institute of Nuclear Power Operations-(INP0)'
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