ML20245G715

Ro:On 890316,train a Emergency Diesel Generator Tripped on Low Oil Pressure During Initial Startup.Caused by Engine Lube Oil Monitoring Circuit Becoming Active Before Engine Speed Developed Sufficient Lube Oil Pressure

ML20245G715
Person / Time
Site:	Seabrook
Issue date:	04/17/1989
From:	George Thomas PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
RTR-REGGD-01.108, RTR-REGGD-1.108 NYN-89039, NUDOCS 8905030216
Download: ML20245G715 (2)

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New Hamoshire "ce S2=

8 Vice President Nuclear Produchon l

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NYN-89039 April 17, 1989 United States Nuclear Regulatory Commission Washington, DC 20555 Attention: Document Control Desk

Reference:

Facility Operating License No. NPF-56, Docket No. 50-443

Subject:

Diesel Generator Special Report i

Gentlemen: 4 The A Train Emergency Diesel Generator (EDG) tripped on low lube oil i pressure while performing post-maintenance testing on March 16, 1989. In accordance with Regulatory Position C.3.b of Pagulatcry Guide 1.108, Revision 1. August, 1977, a determination hau been made that this event is a non-valid EDG start failure. This event is being reported pursuant to Technical Specifications 4.8.1.1.3 and 6.8.2. At the time of this event the plant was in MODE 5 (cold shutdown) with the B Train EDG operable.

The A Train EDG tripped on low lube oil pressure during the initial starting sequence after performance of an alghteen month maintenance engine overhaul. A review of activities just prior to this start, as well as previous starts after maintenance periods, was conducted and concluded that a slow engine start could result in a low lube oil pressure trip. These engine trips are apparently caused by the engine lube oil monitoring circuit becoming active before the engine speed has developed sufficient lube oil pressure.

Corrective actions ,

No immediate corrective actions are being taken at this time since this and two similar previous lube oil trips have occurred dering the first start following maintenance or extended outages. These EDG trips do not cause any excessive engine wear since by procedure the engine is adequately prelubricated before each post-maintenance start. An EDG monitoring program will collect data during EDG starts efter extended outages and maintenance periods. The results of this data will be used to develop corrective actions as appropriate.

The above non-valid start failure does not count toward events that are considered as a valid start failure and will not require additional EDG testing to be performed.

h 030226 890417 ADOCM 05000443

.s PNV New Hampshire Yonkee Division of Public Service Company of New Hampshire ,

P.O. Box 300

• Seabrook, NH 03874

• Telephone (603) 474 9521 ff

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4 United States Nuclear Regulatory Commission April 17, 1989 Attention: Document Control Desk Page 2 If you have any questions regarding this report, please contact Mr. Robert A. Gwinn at (603) 474-9521, extension 4056.

Very truly yours, C$ w George S. Thomas cc Mr. William T. Russell Regional Administrator United States Nuclear Regulatory Commission Region I 475 Allendale Road

. King of Prussia PA 19406 Mr. Victor Neroes, Project Manager Project Directorate I-3 United States Nuclear Regulatory Commission '

Division of Reactor Projects Washington, DC 20555 Mr. David G. Ruscitto NRC Senior Resident Inspector P.O. Box 1149 Seabrook, NH 03874 i

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