ML20078S346
| ML20078S346 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 12/14/1994 |
| From: | Hutchinson C ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GNRO-94-00145, GNRO-94-145, NUDOCS 9412280246 | |
| Download: ML20078S346 (3) | |
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v ENTERGY l#W1""'" '"*'
Peet Gbyn MS 39150
%I601 437 2800 December 14, 1994 I[dj['"""
amm U.S. Nuclear Regulatory Commission o* ""
- Mail Station P1-137 Washington, D.C. 20555
- s Attention: Document Control Desk
Subject:
Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-29 Special Report 94-005 Invalid Failure of Emergency Diesel Generator 12 Due to Leaking Head Gasket GNRO-94/00145 Gentlemen:
On November 17,1904, Emergency Diesel Generator (EDG) 12 was started for a maintenance run following a maintenance outap. The EDG successfully started and completed the maintenance run. During engine coast down at the conclusion of the run, a noise indicating gas leakage was detected coming from the left cylinder bank in the area of number 7 (LB7) and 8 (LB8) cylinder head vent holes. The sound of the engine prevented detection of the leak during the maintenance run.
In order to locate the source of the leak, the engine was restarted. Trouble shooting confirmed that it was a leak frorr, the LB7 cylinder head vent holes. The vent holes M,
connected to a space located between the inner and outer cylinder head gasketc. Gaa from the vent holes indicated leakage of the inner head gasket.
Review of data on exhaust gas tempeatures did not indicate an adverse trend that would be indicative of cylinder power loss due to leakage.
Prior to the LB7 cylinder hem being removed, the nuts holding the head in place were verified to be properly torqued. This fmHliminates improper torque as a contributing factor to failure of the head gasket.
The cylinder head and head gasket have been replaced and investigation #.his incident is continuing in accordance with the GGNS corrective action program. The LB7 cylinder i
head will be removed and inspected during the next reft.eling outage.
94122eo246 941214 I
D PDR ADOCK 05o00416 S
l e
December 14, 1994 GNRO-94/00145 Page'2 of 3 -
-The failure of the inner head gasket would not have prevented the EDG from performing its intended function in the event of an emergency. Therefore this event is consida% an invalid failure as specified by RG 1.108. This invalid failure is being reported purseant to GGNS Surveillance Requirement 4.8.1.1.3.
Yours Truly,
/
CRH/JEO CC:
Mr. J. E. Tedrow Mr. H. W. Keiser Mr. R. B. McGehee Mr. N. S. Reynolds Mr. H. L. Thomas Mr. Stewart D. Ebneter Regional Admin:strator i
U.S. Nuclear Regulatory Commission Region ll 101 Marietta St., N.W., Suite 2000 Atlanta, GA 30323 Mr. P. W. O'Connor (w/2)
Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 13H3 Washington, D.C. 20555 k,
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December,14, 1994 GNRO-94/00145 Page'3 of 3 bec:
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File (RPTS)
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File (Central)
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INPO Records Center 700 Galleria Parkway Atlanta, GA 30339-5957 Mr. W. T. Donovan Illinois Power Company Clinton Power Station Mail Stop V-920 P.O. Box 678 Clinton, IL 61727 CC: Mail Mr. P. E. Alberstadt Mr. C. A. Bottemiller Mr. O. P. Bulich (RD)
Mr. J. H. Crabill (ANO)
Mr. L. F. Date Mr. L. F. Daughtery Mr. M. A. Dietrich Mr. J. P. Dimmette, Jr.
Mr. L. A. England Mr. J. O. Fowler Mr. T. W. Gates (RB)
Mr. T. J. Gaudet (W3)
Mr. C. C. Hayes Mr. J. M. Manzella (W3)
Mr. R. V. Moomaw Mr. D. L. Pace Mr. R. L. Patterson Mr. J. C. Roberts Mr. S. A. Saunders Mr. D. Vinci (W3)
Mr. D. Wells (RB)