05000361/LER-1982-015, Forwards LER 82-015/03L-0.Detailed Event Analysis Encl

Forwards LER 82-015/03L-0.Detailed Event Analysis Encl

ML20054L472
Person / Time
Site:	San Onofre
Issue date:	06/10/1982
From:	Ray H SOUTHERN CALIFORNIA EDISON CO.
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML20054L473	List: 05000361/LER-1982-015, Forwards LER 82-015/03L-0.Detailed Event Analysis Encl 05000361/LER-1982-015-03, /03L-0:on 820512,diesel Generator 2G003 Tripped During Monthly Surveillance Test.Caused by Failed Resistor within Power Supply Module,Cutting Power to Governor Control Module.Power Supply Module Replaced
References
NUDOCS 8207080153
Download: ML20054L472 (2)

LER-1982-015, Forwards LER 82-015/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
3611982015R00 - NRC Website

text

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• p,D y ;p &i Southern California Edison Company S A N ONO F R E H5J C L E A N GE N ER A TIN G S T A T TON F.o. e o n t a s S A N C L EMEN T E. C 4; f rORNI A 92672 g

H. B. R A Y istepwont June 10, 1982 o m m "a

$ratica Naaaaaa U. S. fluclear Regulatory Ccmmission Of fice Of Inspection and Enforcement Region V 1450 Maria Lane, Suite 210 Walnut Creek, California 92596-5368 Attenticn:

Mr. R. H. Engelken, Regional Administrator Dear Sir-

Subject:

Docket No. 50-361 Licensee Event Report No.82-015 San Cnofre Nuclear Generating Station, Unit 2 In accordance with Technieni Specifications 4.8.1.1.3 and 6.9.1.13.b of Appendix A to Operating License NPF-10 for San Onofre Nuclear Generating Station Unit 2, this letter is submitted as a 30 day report concerning a reportab!- s::urrence.

A completed copy of the LER 82-015 is enclosed.

On May 12, 1982, during the monthly Diesel Generator demonstration for operability in accordance with Technical Specification 4.8.1.1.2 and Surveillance Test Proctmure 5023-3-3.23, Diesel Generator 2G003 tripped on overspeed.

The test was declared a failure.

As required by Technical Specification 4.8.1.1.3 and Regulatory Position C.3.b of Regulatory Guide 1.103 the following information is provided as part of this report:

(1)

The diesel generator involved was 2G003.

(2)

This was the first failure of a diesel generator of the same design and size in the last 21 tests at this plant.

(3)

The source of the failure was identified as the Power Supply Module and the cause was a resistor, which failed in the open position.

This module supplies the power to the governor control module.

It was unable to do so and thus the generator tripped on everspeed.

(4)

The corrective measures taken included replacement of the entire Power Supply Module, shipping the affected module to the manufacturer for further analysis and tests performed by SCE on the identical resistor in the replacement module now in service in 2G003.

The conclusion from the above is that this failure was an isolated incident.

8207080153 820610 DRADOCKOSOOOg p,

o Mr. R. H. Engelken June 10, 1982 (5)

The length of time 2G003 was not available for service was approximately 50 hours5.787037e-4 days <br />0.0139 hours <br />8.267196e-5 weeks <br />1.9025e-5 months <br /> (15:25 hours on May 12, 1982 to 17:00 hours on May 14, 1982).

(6)

The current test interval is 31 days, per Table 4.8-1 of the Technical Specifications.

(7)

This test interval is in conformance with the schedule of Regulatory Position C.2.d.

During the period 2G003 was inoperable the companion Diesel Generator 2G002 was successfully tested every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> for operability.

If you have any questions or desire further information on this matter, please contact me.

Sincerely, jf' Ni Enclosure (LER 82-015) cc:

U.S. Nuclear Regulatory Commission Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Office of Management Information and Program Control Institute of Nuclear Power Operations (INPO) 1 A. E. Chaffee (USNRC Resident Inspector - San Onofre Unit 2)

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