ML20086E101

AO 73-21:on 730711,microswitch Installed in DPIS-2-129B Failed to Actuate at Required Setpoint.Channel Made Operable by Realigning Actuating Arm & Rechecking Trip Point Actuation

ML20086E101
Person / Time
Site:	Vermont Yankee
Issue date:	07/12/1973
From:	Riley B VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20086E085	List: ML20086E081 ML20086E101
References
AO-73-21, VYV-2785, NUDOCS 8312060051
Download: ML20086E101 (2)

Text

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YicRMONT YANOcic NUCLEAR PowJcitOoi<eoi<am1oN 1 il SEVENTY UrVENtOMOVE STricef i i;

ROTLAND. YlittMONT' 03701 'l WV-2785 " "

• 0 P.' O. DOX ,157 ;l VEf1NON, VEftMoNT oS354 July 12'..1973 United Stntes Atoraic Energy Com:nission  !

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Directorate of Regulatory Operations, Region 1 l 970- Broad Street Newark, New Jersey 07102- I

REFERENCE:

Operating Licenno DPR-28 l Docket No. 50-271 Abnonmit occurrence No. AO-73-21 Contlemons. -

I As defined' by Technien1 Specificationn for the Vermont Yankco '

Nucinar pruar Station, Section 6.7.B.1, va are reporting the following-Abnormal Occurrenco an A0-73-21 and confirming our colophono conversation vith your office. [

l At approxitantoly 1100 on July 11, 1973, while perforsning. routino quarterly ourveillance on the LPCI break detection-logic, a micronvitch ,

installed ini DPIS-2-129B fnflod' to actuato at the required setpoint of i 1"( .5) puid, as opacified in Tablo' 3.2.1 of Technical Specifications. I The inicroswitch actuating arm van rechanically bound ~ and failed' toi drop into the cam. valley at its required netpoint. Functionally, this switch, l 2-129B,. operates in coujunction.with owitch 2-129D to actuate a: relay in  ;-

their respectivo atring to close Loop B. LPCI valves and. actuate. Loop A recirculationi valves. The reactor was operating at approxinately 75% power fy at the tice of thio- incident.

The channol' van promptly mado operable by realigning the actuating artn, and' rochocking the trip point actuation repeatedly ton tirnos. 1he outpoint of the switch had not drifted from its required trip setting. [

The channel was. declared operable by 1115 on July 11, 1973.

, i Very, truly, yours, NT. YANKEB NUCLEAR POWERrCORPORATION 8312060051 730719

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.1' PDR ADOCK 05000271

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S PDR

• Bradford V. Riley s A )

Plant. Superintendent..

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', ,y Licensec: Vermont Yathe Nuclear Power Corp.

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'll. D. Thornburg. Daic Docket No.: 50-271 Chief, FS6EB 'l. 6i.

Abnormal Occurrence: A0-73-21 a

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i DR Central Files (1) Dart The attached report from the subject licensee is Regulatory Standards 3)

I, Dir. of Licensing (13 foruarded in accordance with RO ifanual chanter 10M.

i i o e4.,e. .no ..o inmaa n ans RO Files The action taken by the licensec is considered

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Central Flail 6 Files cut appropriate. Followup will be performed during 1

the next inspection a's appropriate. Confes of s r nou v4 7. .ria .a.o atuaans i <

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the report have been forwarded to the PDR, Local R. T. Carlson, Chief I Fncility Operations PDR, NSIC, DTIE and State representatives. The

. Branch, RO:I licensee vill submit a 10 day written report to PHQht h(A DATE 7/18/73 Licensing.

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