ML20086D998

Updated AO 73-23:on 730802,gamma Radiation Monitor on Perimeter Fence Became Inoperable.Caused by Power Supply Associated W/Monitor Failing,Causing Immediate Downscale Indication.Component Replaced & Monitor Returned to Svc

ML20086D998
Person / Time
Site:	Vermont Yankee
Issue date:	08/09/1973
From:	Riley B VERMONT YANKEE NUCLEAR POWER CORP.
To:	US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20086E000	List: ML20086D998 ML20086E001
References
AO-73-23, VYV-2944, NUDOCS 8312060003
Download: ML20086D998 (1)

Text

- - . - _ - . . _ = .

O O VERMONT YANKIm NUCLMAR POWER CORPOR ATION i*

SEVENTY GEVEN OROVE STRECT

) RUTI,AND, VIMMONT O1701 NEPLY TO:

VYV-2944 e. o. nox is7 VERNON, VERMONT 05354 August 9,1973 11 0' DLrector

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Directorate of Licensing

+ 40 t

U.S. Atomic Energy Commission p AUG in 1973 o)

Washington, D.C. 20545 Cd g ageic satset commissten r

REFERENCE:

Operating License DPR-28 O- ,%% $

Abit rmal Occurre ce No. A0-73-23 /p M

Dear Sir:

As defined by Technical Specifications for the Vermont Yankee

... l . . '. . . C m m.. , o m m e l o.. * ,. 7.L.1, . o.. . .. . 1..,, *.. Zo l lo l.. ,,

Abnormal Occurrence as A0-73-23.

At 2330 on August 2, 1973, the area gamma radiation monitor on the pe rime t er fence became inoperable. Since this instrumentation is requireel at all times as a Limiting Condition for Operation by T". chnical Specifications, Section 3.8. A.1, an orderly plant shutdown was initiated.

The reactor was fully shutdown at 0240 on August 4,1973.

Investigation indicated that the power supply associated with the monitor had failed causing an immediate downscale indication. This failure was caused by a faulty cicctronic component within the power supply. This component was subsequently replaced and the nonitor was returned to service prior to plant restart.

The Plant Operations Review Committee reviewed the incident and concluded that this failure was an isolated instance of component fatigue and that no further action at this time is necessary.

Very truly yours ,

VERMONT YANKEE NUCLEAR POWER CORPORATION 8312060003 730009 r PDR ADOCK 05000271 Q '

S PDR

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g B.W. Riley N q Plant Superintendent -

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PET /kbd f q' f .

C 6166 COPY SENT REGION._ _ ___