ML19310A363

Ro:On 800509,emergency Generator Failed to Start When Starting Sequence Was Initiated by Automatic Weekly Exerciser.Caused by Tripped Starter Motor.Generator Inspected & Retested W/New Starter Motor

ML19310A363
Person / Time
Site:	University of Missouri-Columbia
Issue date:	06/02/1980
From:	Brugger R, Mckibben J MISSOURI, UNIV. OF, COLUMBIA, MO
To:
References
NUDOCS 8006110137
Download: ML19310A363 (2)

Text

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Research Reactor Facility UNIVERSITY OF MISSOURI Research Park Columbia. Missoun 65211 June 2, 1980 T*' epa ne (314) es2-42n Director of Licensing U. S. Nuclear Regulatory Commission Washington, D. C. 20555

Reference:

Docket 50-186 University of Missouri License R-103

Subject:

Failure of Emergency Electrical Generator to Start Description On May 9,1980, the emergency generator failed to start when the start-ing sequence was initiated by the automatic weekly exerciser. A senior reactor operetor checked the generator, verified the generator had not started and the reactor was shut down by rod run-in.

The generator had been run normally on May 5,1980 when it was run as part of the normal pre-startup checksheet. Therefore, it may be assumed t sat the generator was not operable during the previous four days of operation which is a deviation from Technical Specification 3.10.a.

Analysis The weekly operability test of the emergency electrical generator is performed through the use of an automatic exerciser. When control room indi-cation failed to indicate the generator was running at the expected time, a senior reactor operator immediately went to inspect the emergency generator.

He found the starter motor had tripped due to failure to start the generator within one minute. Further investigation showed that there was no fuel in the emergency generator day tank. Fuel is supplied from an underground tank to a small " day" tank by an electric pump which is powered by the generator.

When the engine starting circuit is energized, a solenoid opens in the supply g, ,f 7, V ,

Ec g jh COLUMBIA KANSAS CITY ROLLA ST. LOUIS l an equal opportunity institution 1 80 06110/3 7, y

Director of Licensing June 2, 1980 Page 2 line between the day tank and the carburetor, allowing fuel to gravity drain into the carburetor float bowl.

The empty day tank had not been observed since there is no level indi-cation for it.

Corrective Action The generator was immediately inspected and retested with a new starter motor. It performed satisfactorily.

A sight glass was added to the day tank to allow fuel level to be veri-fled on the routine patrols conducted at four hour intervals.

Additionally, the policy concerning not using the day tank als a source of fuel was reviewed with operating and machine shop personnel.

Sigerely

-/ )

J. C. McKibben Reactor Manager Endorsement Reviewed and approved j j t Robert M. Brugger Director h1 VV JCMK:vs cc: James Keppler, Director Regulatory Operations - Region III Reactor Advisory Committee Reactor Safety Subcommittee