ML19308A487

Abnormal Occurrence 74-09:on 740611,1A Makeup Pump Failed. Caused by Automatic Start W/Closed Suction Valve Resulting from Inadvertent Engineered Safeguards Signal.Pump Stopped & Incorrect Type Lamps Replaced

ML19308A487
Person / Time
Site:	Three Mile Island
Issue date:	06/13/1974
From:	Herbein J METROPOLITAN EDISON CO.
To:
References
NUDOCS 7910250669
Download: ML19308A487 (2)

Text

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OST OFFICE GOX 460 MIDDLETOWN.PENNSYLVANM 17c67 TELEPHONE 717-G44-404T June 13,1974

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]D Hr. J.P. O'Re111y, Director '

u.a JU Directorate of Regulatory a m, m T

D Region I -

631 Park Annue

?.fr.g of Pressf a, Pa. 19406 a; _fb _- U_ _ h; a' ,

Operatina License DPR-50 Docket 50-239 4 ,

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Subject:

Abnormal Occurrence B6. A3 74-9 1

Dear Hr. O'Reilly:

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This teicqran is to confim the telecon between Lee Spessard (Region I-AEC),

and J.G. RWaein (THI-Supstintendent) at 1800 39.5,11 June 1974.

The following report is sutaitted'in accordante with paragraph 6.7.2.a (page 6-11) of the Technical Specifiestiam. -

On 11 June the iA Fake-up Pcm failed as a result of an aute:utic start with a closed suction valve. The autc atic pcrp start was caused by ardnsdvartent4

,, engineered safeguards signal.

The inadvertent engineered safeguards signal occurred while investigating the cause for partially energized relsys in the unusi high pressure injection 1 # c circuits. ,

The 1A ltke-up Pu,p was imediately stopped and'cause for autostic start was investfgated.

The investigation subsepently revealed that auteestic start of the 1A Fake-up Pt=p was prchably caused by unintentional actuation of a prtially encrgized pump logic start relay, , ,,

Further investigation revealed that the pup logic start relay was maintained pzyttally emegized by excessive veltage applidation across the relay. The y f' ,, g

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excess voltage across the relay was traced to incorrect incandesant type icws ~

installed in back-lighted push-buttons which are in series with the pep logic start relays.

The incorrect incandest.nt type Ic.gs were replaced with correct type neon Itz;%

Yery truly yo'urs, .

.. . ] 6s $}' m

.G. Merbe1n Station SuperirAendent

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