ML19290A432

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RO on 720926:A & B Liquid Control Sys Pumps Inoperable at Same Time.Caused by Interlock in Starting Circuitry Preventing Pump B from Starting When Pump a Breaker Is in Racked Out Position.Operating Procedures Changed
ML19290A432
Person / Time
Site: Oyster Creek, Crane
Issue date: 10/06/1972
From: Finfrock I
JERSEY CENTRAL POWER & LIGHT CO.
To:
Shared Package
ML19290A429 List:
References
NUDOCS 7911070614
Download: ML19290A432 (2)


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Jersey Central Power & Light Company 3/~

MADI5ON AVENUE AT PUNCH BOWL RO AO e MORRi$rQWN, N.J. 07960 e 539 6111 October 6, 1972 J

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Mr. A. Gia=busso f>

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J Deputy Direc:or for Reactor Projects g g } j,,0Q Directorate of Licensing United Sta:es A:c=1c Energy Cc==ission

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Dear Mr. Gia=busso:

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Subj ect: Oyster Creek Station Docket No. 50-219 Inoperable Standby Liquid Control Syste=

Tie purpose of this letter is to report to yo'u an incident thet occursed at Oyster Creek on Sepec=ber 26, 1972 in which it was discovered tha: the two pu=ps in the standby liquid control syste vere inoperable at the same ti=e.

At 10:45 a.=.'on Sep:c=ber 25, 1972, the "A" standby liquid control pu=p was rc=oved frc= service fer replace =en: of the pu=p packing. The pu=p was taken out of service using Technical Specification 3.2.C.3 as the basis.

It states, "If one standby liquid control sys c= pu= ping circuit becc=es in-N operable during the run = ode and specifica:1on 3.2.A is =ct,

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the reactor =ay re=ain in operation for a period no: to excee /\\

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seven days, provided the pump in the other circuit is de=en Y

Specifica:icn 3.2.A is =et,C,{ g'h, 7n strated daily to be operable".

therefore, the "A" pu=p breaker was racked cc: and the pu=p -

secured in accordance with plan: safe:y procedures.

The wdC 61 t'.D., 6 ' " /$ 3

'h~f was not. co=picted by the end of the day shif t, and the "A" Th'D U'7 pu=p was left in an inoperable ccndition.

At 4:20 a.=.

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4 Septe=ber 26, 1972', the "3" liquid centrol syste= pu=p was c3

'qjf to be run to ec= ply with Technical Specification 3.2.C.3.

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When the operator depressed the start button, the pu=$ 5 7 2 8 6 did

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1 not start.

An interlock in the star:ing circuitry prevents two standby liquid centrol pu=ps f ro being run si=ultanccusly.

This interleck also preven:s :he "3" pu=p frc= starting when the "A" pu=p breaker is in :he racked cut positien.

'n.e interlock is cc= posed of a nor= ally closed contac: in :he starting circuit of each pump.

This centact is operated frc= a relay in the opposite pu=p circuit.

If the "A" standby liquid centrol pu=p is s:arted.either frc= the control roo= with the key lock switch or locally frc= the

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t Mr. A. Cia: buss Page II Cetober 6, 1972 0

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push but:en s:a:1ca, a relay is picked up which opens the nor: ally closed con:ac: in :he "3" standby liquid con:rol pump starting circuit which prevents this pu p frc: opera:ing vi:h the "A" pu=p running.

The revarse is true if the "3" pump is s:arted.

The probles developed when the breaker for :he "A" pu=p vas racked out.

It disabled the pu p and a: the sa=e :1:e 1: physically re=oved the con:ac: in :he s:ar:ing circuitry fcr the "3" pu=p which simula:ed an opt con:act.

This preven:ed the "3" pu=p fre: s:ar:ing.

As soon as the Shif: Fore:an was aware of the inoperability of both pu:ps, he star:ed a nor al shut.dcun of the plant.

In *,he meantine, he received per=issica to clear the maintenance safe:/

tags and rack :he "A" pump breaker to its ner:al pcsi:icn.

He then ran a successful cperabili:y check on :he "3"

pu.p.

The load redue:1cn was s:cpped and the plant re:urred to full lead.

In order to' prevent a recurrence of this event, operating procedures have been changed *so that operability tests cf redundan:

engineered saf puards sys:e= cc penents will be made 1::cdiately follewing any ac:ica : hat requires ene of the sys:c s to be inoperable for =ain:enance purposes.

We are enclosing forty copies of this letter.

Very truly yours, z?

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fairn.v&h,x?1c Ivan R. Finf ro~ck, J;.

Vice Presiden:

IRF/pk Enclosures cc: Mr. J. P. O'Reilly, Director Direc: ora:e of Regulatory Opera: ions, Region 1 1557 '287 4.

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