ML20090D850

AO-50-219/74-59:on 741112,during Load Test,Diesel Generator 2 Trouble Alarm Received.Caused by Failure of Louver Control Temp Switch.Switch Replaced

ML20090D850
Person / Time
Site:	Oyster Creek
Issue date:	11/22/1974
From:	Ross D JERSEY CENTRAL POWER & LIGHT CO.
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
References
AO-50-219-74-59, NUDOCS 8303030250
Download: ML20090D850 (3)

Text

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Jersey Central Power & Light Company

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MADISON AVENUE AT PUNCH BOW 1. ROAD

• MORRISTOWN, N.J. 07960

• 201-539-6111 n,..,w r.,,

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Deputy Director for Reactor Projects (2 C[

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United States Atomic Energy Commission N ,- [ '

Washington, D. C. 20545 dgV

Subject:

Oyster Creek Station Docket No. 50-219 t

Abnormal Occurrence Report No. 50-219/74-59 The purpose of this letter is to forward to you the attached Abnormal Occurrence Report in compliance with paragraph 6.6.2.a of the

, Technical Specifications.

Enclosed are forty copies of this submittal.

Very, truly yours, l

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Donald A. Ross 5fanager, Generating Stations-Nuc1 car I

cs Enclosures cc: Str. J. P. O'Reilly, Director Directorate of Regulatory Operations, Region 1 11 4

NN 8303030250 gQ2 q PDR ADOCK O s

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Jersey Central Power & Light Company m

MADISON AVENUE AT PUNCH BOWL ROAD

• MORRISTOWN N.J.07960

• 201-539-6111

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, OYSTER CREEK NUCLEAR GENERATING STATION FORKED RIVER, NEW JERSEY 08751 Abnormal Occurrence , ,

Report No. 50-219/74-59 Report Date ,

November 22, 1974 Occurrence Date November 12, 1974 Identification of Occurrence Trip of diesel generator #2 during surveillance testing. This event is con-

'sidered to be an abnormal occurrence as defined in the Technical Specifications, .

paragraph 1.15D.

i Conditions Prior to Occurrence The reactor was shut down with coolant temperature less than 212*F.

e Description of Occurrence ,

At approximately 1055 on November 12, 1974, a routine bi-weekly load test of the #2 diesel generator was begun as required by the Technical Specifications, paragraph 4.7.A.1. At 1106, with the #2 diesel generator loaded to 2000 KW, the unit troubic alarm was received in the station control room, and a normal ,

shutdown sequence was automatically initiated. Investigation by the operator '

stationed at the diesel generator revealed that the trouble alarm and shut-down were caused by excessive cooling water temperature (200*F). This high temperature condition was caused by a failure of the shutters (radiator louvers) to open and admit cooling air as the engine warmed up.

Apparent Cause of Occurrence The shutters failed to open because of the failure of the louver control temperature switch.

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Page 2 Abnormal Occurrence Report No. 50-219/74-59 Analysis of Occurrence Appendix L to the Oyster Creek Facility Description and Safety Analysis Report (FDSAR) contains a probability analysis regarding the availability of standby cooling systems and ir}cludes an analysis of off-site power. availability con-current with a loss at coolant accident. The results indicate that the re-liability of availabic power from off-site sources or from a self-contained unit (i.e. only one diesel generator was considered in the analysis) is quite ,

high. Since the station is provided with two separate diesel generator units,' '

having one unit out of service has no effect at all upon the results of the analysis. In addition, the effects of single bus operation during a loss of coolant accident is analyzed in Amendment 32 to the FDSAR and the unit loading under this condition is shown to be within the normal KVA rating of the diesel '

generator. Thus, there is no additional safety significance associated with this event beyond that aircady analyzed.

The high temperature shutdown circuit is operable only in the peaking mode.

" This circuit is bypassed in the fast start mode and the diesel would therefore not have tripped in this mode.

Corrective Action ,

The louver control temperature switch was removed and its failure verified.

The switch was replaced by a calibrated louver control temperature switch which was field set and successfully tested. In addition, a louver control itemperature switch modification has been approved for installation per General '

Motors Corporation, Electro-Motive Division, Modification.No. 9.

Failure Data ,

Manufacturer - Square D Company Type - BGW352 Class - 9025 Series-B 175* '

e Serial Number - 421 (hand inscribed) f s ,

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