ML20083D295

Special Rept:On 910825,Train a Emergency Diesel Generator Tripped on Low Lube Oil Pressure During post-maint Testing. Caused by Large Fluctuations in Engine Revolutions Per Minute.Procedures Re Auxiliary Lube Oil Pump Revised

ML20083D295
Person / Time
Site:	Seabrook
Issue date:	09/24/1991
From:	Feigenbaum T PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NYN-91153, NUDOCS 9109300154
Download: ML20083D295 (2)

Text

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New Hampshire 7 Ted C. Feigenbovm hh hh President and Ch;el becutive Of ficer NYN- 91153 September 24, 1991 United States Nuclear Regulatory Commission Washington, D.C. 20555 Attention: Document Control Desk

References:

(a) Facility Operating License No. NPF-86, Docket No. 50 443 (b) Seabrook Station Technical Specification 4.8.1.1.3 Susject: Diesel Generator Special Report Gentlemen:

( The following Diesel Generator Special Report documents a diesel generator failure that occurred at Seabrook Station and is reported pursuant to Technical Specification 4.8.L1.3. On August 25, 1991, the A Train Emergency Diesel Generator (EDG) tripped on low lube oil pressure during post maintenance testing. In accordance with Regulatory Position C.3.b of Regulatory Guide 1.108, Revision 1, August 1977, it was determined that this event is a non-valid EDG start failure. At the time of this failure the plant was in a refueling outnge with no fuel in the reactor vessel. Additionally, the 11 Train EDG was operable.

The A Train EDG tripped on low lube oil pressure during the initial starting sequence subsequent to the eighteen month maintenance engine overhaul. This is the fourth ,

occurrence of this type at Seabrook Station where the EDG tripped on low lube oil pressure during the initial starting following maintenance.

Root Cause The root cause of these low lube oil pressure trips is believed to be large fluctuations in engine revolutions per minute (r.p.m) which reduce the tube oil flow and pressure below the trip setpoint. '! he cause of the fluctuations in engine r.p.m. is believed to be air entr: pped in the fuel oil system during the mainter.ance overhaul, Corrective Actions Maintenance and Operations procedures will be revised to run the auxiliary tube oil pump until the engine speed has stabilized during initial post maintenance testing. This should prevent low lube oil pressure trips caused by engine speed fluctuations. These procedure revisions are scheduled to be completed by December 31, 1991.

9109300154 910924 PDR ADOCK 05000443

[, PDR p New Hampshire Yankee Division of Public Service Company of New Hampshire o P.O. Box 300

• Seabrook, NH 03874

• Telephone (603) 474 9521 kg

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r United States Nuclear Regulatory Commission September 24, 1991 Attention: Document Control Desk - Page two .

T' Should you require further information regarding this matter, please e ntact Mr. James

- M. Peschel, Regulatory Compliance Manager at (603) 474 9521, extension 3772.

Very t' uly yours, de&f'"

Ted C, Feigenbaum TCF:WJT/ss cc: Mr. Thomas T. Martia Regional Administrator United States Nuclear Regulatory Comrais; ion Region I-

'475 Allendt.le Road King of Prussia, PA 19406 Mr. Gordon E. Edison, Sr. Project Manager Project Directorate 1-3

. Division of Reacier Projects

U.S. Nuclear Regulatuey Commission Washington, DC 20555 Mr, Noel Dudley NRC Senior Resident inspector P,0. Box 1149

- Seabrook, NH - 03874 ,

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