ML20214P962

Special Rept:On 861027,condenser Evacuation Sys wide-range Noble Gas Monitor Out of Svc for More than 72 H.Caused by Failure of low/mid-range Grab Sample Timer.Timing Unit Module Replaced & Sys Returned to Svc

ML20214P962
Person / Time
Site:	San Onofre
Issue date:	11/12/1986
From:	Morgan H SOUTHERN CALIFORNIA EDISON CO.
To:	Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
NUDOCS 8612040443
Download: ML20214P962 (2)

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] % aLY ~ /p Southem Califomia Edison Compahy 0/g SAN ONOFRE NUCLEAR GENERATING STATION k"g P. O. BOX 128 SAN CLEMENTE. CALIFORNIA 92672 H.E. MORGAN m EPHONE November 12, 1986 U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region V 1450 Maria Lane, Suite 210 Walnut Creek, California 94596-5368 Attention: Mr. J. B. Martin, Regional Adminstrator

Subject:

Docket No. 50-361 Special Report San Onofre Nuclear Generating Station, Unit 2 In accordance with Technical Specification 6.9.2 and Table 3.3-6, Action Stater..ent 19, of Facility Operating License No. NPF-10 for San Onofre Nuclear Generating Station, Unit 2, this letter provides the required Special Report for the Condenser Evacuation System Wide Range Noble Gas Monitor being out of service greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

On 10/27/86, at 1433, with Unit 2 at 100% power, the Condenser Evacuation System Wide Range Noble Gas Monitor 2RI-7870 was removed from service for the performance of the scheduled quarterly surveillance. During the performance of the surveillance the low /mid range grab sample timer, designed to be used during post accident sampling, failed to operate satisfactorily. The monitor remained inoperable to effect repairs, and, during this time, alternate monitoring was provided as required by the Technical Specifications. The timing unit module (Durgin and Browne Model 5023-R) was replaced and the monitor was returned to service on 11/01/86 at 1230 after successful completion of the quarterly surveillance.

The timing unit module had performed satisfactorily until this occurrence and this is therefore consitiered to be an isolated event. No additional corrective actions are planned.

Since the preolanned alternate method of monitoring was implemented, the health and safety of the plant personnel or the public was not affected.

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3 Mr. J. B. - Martin - -

2-Please contact us if we can be of further assistance.

Sincerely, dbb " -

Enclosure cc: F. R. Huey (USNRC Senior Resident Inspector, Units 1, 2 and 3)

U. S. Nuclear Regulatory Commission Document Control Desk Institute of Nuclear Power Operations (INPO) 4 i-s 1

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