ML20246D839

Special Rept:On 890328,during Operability Test,Diesel Generator 2A Engine Tripped Due to Low Vacuum.Caused by Improperly Seated Valve Covers.Section Will Be Added to Monthly Maint Procedure to Inspect Engine & Valves

ML20246D839
Person / Time
Site:	Mcguire
Issue date:	04/27/1989
From:	Tucker H DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 8905110064
Download: ML20246D839 (2)

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DUKE POWER GOMPANY L P.O. DOX 33180 CHARLOTTE, N.O. 28242 RAL B. TUCKEH TELEPHONE vrom ramminewt (704) 373-4531 WUUE.P4M PRODUCTION April 27, 1989 U.S. Nuclear Regualtory Commission Document Control Desk Washington, DC 20555

Subject:

McGuire Nuclear Station, Unit 2 Docket No. 50-370 Special Report Concerning Diesel Generator 2A Gentlemen:

Pursuant to Technical Specification (T.S.) 6.9.2 as specified by T.S. 4.8.1.1.3, find attached a special report concerning Diesel Generator 2A.

Should there be any questions concerning this matter, please contact S.E. LeRoy at (704) 373-6233.

Very truly yours, B/ A Hal B. Tucker SEL/402/sel xc: Mr. S.D. Ebneter, Administrator Mr. P.K. Van Doorn U.S. Nuclear Regulatory Commission NRC Senior Resident Inspector Region II McGuire Nuclear Station 101 Marietta St., NW, Suite 2900 Atlanta, Georgia 30323 Mr. Darl Hood Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555 INPO Records Center Suite 1500 1100 circle 75 Parkway Atlanta, Georgia 30339

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8905110064 890427 PDR ADOCK 05000370

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- April 27, 1989 Attachment Duke Power Company

, McGuire Nuclear Station Diesel Generator 2A Special Report on March 28, 1989 at 2151, Diesel Generator (DG) 2A was started to perform an operability test, (PT/2/A/4350/02A). This start attempt was No. 697. DG 2A started and loaded to 4000 KW with no problems. After approximately 2 minutes, the engine tripped due to low vacuum. A work request (no. 138212);was written to investigate the problem.

Instrument and Electrical (IAE) personnel connected a digital vacuum gage at a point close to where the sensing line enters the crankcase, and obtained a vacuum reading of 2.25 Inch WC. This indication agreed with the indication of the DG vacuum gage which indicated 2.0 Inch WC. Both indications were lower than expected, indicating an air in-leakage problem rather than a sensing line problem.

Maintenance (MNT) personnel removed and cleaned the mister filters, and inspected all. vacuum lines and the valve covers. Valve cover 2D was discovered slightly displaced and valve cover ID was loose. The vacuum was rechecked and found to be 3.13 Inch WC, (expected value).

DG 2A was started (no. 698) and the operability test was satisfactorily completed.

The improperly seated valve covers were the result of either not seating the covers properly after maintenance or due to vibration of the engine. As a result of this failure, a section will be added to the monthly preventative maintenance

- procedure to inspect' the engine for excessive leaks and/or any other visual

. defects, and to check the valve covers to assure they ars seated properly.

This failure has been classified as an Invalid Test Failure.

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