NRC-89-0253, Ro:On 891110,emergency Diesel Generator Start Failure Occurred.Caused by Human Error During Test Start.Wire at Terminal B2803 Determinated & Correctly Reterminated W/No Stray Strands.Engine Restarted & Surveillance Completed

Ro:On 891110,emergency Diesel Generator Start Failure Occurred.Caused by Human Error During Test Start.Wire at Terminal B2803 Determinated & Correctly Reterminated W/No Stray Strands.Engine Restarted & Surveillance Completed

ML19332F781
Person / Time
Site:	Fermi
Issue date:	12/11/1989
From:	Orser W DETROIT EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CON-NRC-89-0253, CON-NRC-89-253 NUDOCS 8912190017
Download: ML19332F781 (3)

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• l I '4 Wilham S. or.or t X'flllT[,j,;Lon, Reg. Guide 1.108  ;

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(40 North Dme ughw'{ Nuclear h [i%,h"p,$$,"9'" " Generation December 11 1989 ,

NRC-89-0253 i

U. S. Nuclear Regulatory Commission Attention: Document Control Desk l Washington. D. C. 20555 i Reference Fermi 2  :

NRC Docket No. 50-341  :

NRC License No. NPF-43  !

Subject:

Emergency Diesel Generator Start Failure Please find attached our report on one start failure of Emergency Diesel Generator (EDG) 13 which occurred on November 10, 1989. This report is sybmitted to you in accordance with Fermi 2 Technical Specificationa 4.8.1.1.3 and 6.9.2.

If you have any questions regarding this report, please contact .

Patricia Anthony. Compliance Engineer at (313) 586-1617.

Sincerely.

Attachment cct A. B. Davis R. W. Defayette/W. L. Axelson l W. G. Rogers J. 7. Stang Region III -

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- 8912190017 891211 PDR ADOCK 05000341 S PDC

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O P Emergency Diesel Generator Start' Failure Emergency Diese1 Generator Involved t

Emergency Diesel Generator (EDG) 13 1

Identification of Failuret Failure Date: November 10 1989 1307 hours0.0151 days <br />0.363 hours <br />0.00216 weeks <br />4.973135e-4 months <br />

Description of Event i

This.the the seventh start failure of EDG 13 that occurred during

.what is considered an " invalid test" since issuance of the Fermi 2 l operating license. At the time of the start failure, there had been 171. valid test starts since the operating license was issued.

The November 10, 1989, start failure is considered a failure as an

" invalid test" under section c.2.e.(2) of HRC Regulatory Guide 1.108 because the inadvertent overspeed trip signal was caused by human error during a test start. The number of start failures incurred during " valid tests" for EDG 13 since issuance of the operating license remains unchnnged at one.

Cause of Failure:

During performance of an ECCS Start and Load Rejection surveillance test on November 10 1989. EDG 13 tripped as-a result of an inadvertent overspeed trip signal. Prior to the trip. EDG 13 was operating unloaded at a voltage and frequency of 4160V and 60Hz (900 RPM) respectively and with a manually initiated ECCS-start signal present. The surveillance test required that all non-emergency tr;ps are verified to be automatically bypassed with an emergency start signal present. St ep 5.3.19 of the surveillance was parformed and verified the Lube Oil Temperature High Trip (non-emergency) signal was initiated but did not trip the' engine while the EDG was running with an ECCS start signal present. This step required lifting a wire at terminal B2803 in the EDG 13 relay cabinet to initiate the Lube Oil Temperature High

. Trip signal. However. EDG 13 tripped on an inadvertent overspeed trip signal when the lifted lead was being reterminated at terminal B2803-in subsequent step 5.3.20 of the-surveillance test. During performance of step 5.3.20 a stray strand from the lifted wire inadvertently contacted adjacent terminal B2804 as it was being'reterminated at B2803. This caused a momentary energization of the engine overspeed relay (EOR) which tripped the engine. The overspeed trip signal is not bypassed during emergency starts.

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Emergency Diesel Generator Start Failure Corrective Measures Takent ,,

i The wire at terminal B2803 was determinated and' correctly ['

roterminated with no~ stray strands. The engine was restarted and

-the survelliance was successfully completed. This ECCS Start and Load Rejection surveillance is performed on each of the four EDG's ,

once'every 18 months. This particular trip-was the first time's problem has been encountered due to lifting leads during the surveillance. This event is considered an isolated occurrence and i no further corrective action is required.

i Lene,th of Time EDC Unit Unavailablet EDG 13 was out of service for approximately four hours due to the ,

November 10 1989 inadvertent trip.

Current Surveillance Test Intervalt

-The current surveillance test interval remains unchanged at-once  !

per 31 days. )

Verification of Conformance of Test Int e rval t i i

The' surveillance test interval is in conformance with Regulatory Position c.2.d. of Regulatory Guide 1.108 and in conformance with Fermi'2 Technical Specifications.

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