ML19210A268

RO 77-1/1P:on 770202,both a & B Diesel Generators Had Conditions Affecting Starting Capabilities in Response to Loss of Offsite Power.Both Problems Caused by Cranking Timer Timing Out Prior to Oil Low Speed Switch Operation

ML19210A268
Person / Time
Site:	Three Mile Island
Issue date:	02/03/1977
From:	Colitz J METROPOLITAN EDISON CO.
To:
References
NUDOCS 7910250548
Download: ML19210A268 (2)

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TROPOUTAN EDISON COMPANY svwormos erwmr.mecummnec rc mo TELEPHONE 717.944 4 Cut

~FICE BOX 480 MIDDLETOWN. PENNSYLVANIA 17057 3 February 1977

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• .- M ,J. P'.'4'Reilly - . .. O '

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'tDirectorate' oLRegulatory Oper'ations

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PNuclear: Reaulatory/Comission --

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_-d631..Parle-Avenue JCKing dP Prussfa7 Pennsylvania fl9406 _ _ , ,

Operating License DPR-50 Docket 50-289

~"SSubfect:5 Reportable Occurrence-NOT-77-1/IP .- .

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Dear Mr r. ~0* Reil.ly:

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~" NThis_telegra 1 is- to confim the conversation between- M6 A NJ-Fasano

+(Region "I'-f;RC)- and Mr- J. Ja Colitz"(TMI Unit: Superintendent)_ at~ ~ 0900

. hours on 3 February 1977.

~' The following report is submitted in accordance with Paragraph 6.9.2.A.2 of the Technical Specifications.

On 2 February 1977 both the "A" and "B" Diesel Generators whre found to have conditions affecting their capability to start in response to a loss of offsite power. Both diesels would have started successfully in the event of an Engineered Safeguards (ES) signal.

On both diesels the start failure resulted from the cranking tirer tining out before the OPLS pressure svitch operated. The OPLS pressure switch picks up when oil pressure is sufficient to indicate that the diesel has started. If the cranking tirer operates before the OPLS pressure switch operates, the shutdown relay is enenjized causing the diesel to trip. If an ES signal is present, the shutdown relay is blocked fron receiving the start failure signal.

On the B" Diesel the tire between OPLS operation and the cranking tirer sBtting was found to be inadequate and the timer setting was increased. On the "A" Diesel the OPLS was prevented fron operating because of mechanical binding of the pressure switch. The pressure switch linkage on the "A" Diesel Grerator was freed. The tirer settings were also increased on thera' Diesel f;enerator.

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F.r. J. P. O'Reilly -- 3 febevery -1977  !

The above action will prevent the start failures; however, evaluation of the final ti er setting is continuing and the 0"L5 switch will be replaced with a different type switch in the near future.

Very truly yours,

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, . Colitz Unit I Superintendent Three F.ile Island NJclear Station JJC/ par-:

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