ML20058K529

Repts Incident That Occurred at Facility on 720926 Re Two Inoperable Pumps in Standby Liquid Control Sys

ML20058K529
Person / Time
Site:	Monticello, Oyster Creek
Issue date:	10/06/1972
From:	Finfrock I JERSEY CENTRAL POWER & LIGHT CO.
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20058K522	List: ML20058K518 ML20058K526 ML20058K529
References
NUDOCS 9102110364
Download: ML20058K529 (2)

Text

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/ .D Jersey Central Po]lwer & Light Company

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M ADi$oN AVENUE AT PUNCH BOWL Ro AD e MORRISToWN. N.J. 07960 e $39-6118 October 6, 1972 N

Mr. A. Giambusso N* I Deputy Director for Reactor Projects .J. h l Directorate of Licensing $ OCT l 01972> C United States Atomic Energy Corznission .- g Washington, D. C. 20545 g us.c$ $ N E ""I Regulato

Dear Mr. Giambusso:

M Sect

Subject:

Oyster Creek Station  !

Docket No. 50-219 Inoperable Standby Liquid Control System The purpose of this letter is to report to you an incident that occurred at Oyster Creek on September 26, 1972 in whi:.h it was discovered that the two pumps in the standby liquid control system were inoperable at the same time.

l At 10:45 a.m. on September 25, 1972, the "A" standby liquid control pump was removed from service for replacement of the pump packing. The pump was taken out of service using Technical Specification 3.2.C.3 as the basis. It states, "If one standby liquid control system pumping circuit becomes in-  ;

operabic during the run mode and specifiestion 3.2.A is met, ,

the reactor may remain in operation for a period not to exceed l ceven days, provided the pump in the other circuit is demon-  !

strated daily to be operable". Specification 3.2.A is tnet, j therefore, the "A" pump breaker was racked out and the pump l secured in accordance with plant safety procedures. The work j was not corpleted by the end of the day shif t, and the "A" pump was lef t in an inoperab'e condition. At 4:20 a.m. on September 26, 1972, the "B" liquid control system pump was to be run to comply with Technical Specification 3.2.C.3.

When the operator depressed the start button, the pump did not start. <

l An interlock in the starting circuitry prevents two standby liquid control pumps from being run simultaneously.

'Ihis interlock also prevents the "B" pump from starting when the "A" pump breaker is in the racked out position. The interlock is cc:rpoced of a normally closed contact in the starting circuit of each pump. This contact is operated from a relay in the opposite pump circuit. If the "A" standby liquid control pump is started either from the control room with the key lock switch or locally from the 5508

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9102110364 721222 CF ADOCK 05000263~

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Mr. A. Giambusso Page II October 6, 1972 I

push button station, a relay is picked up which opens the normally closed contact in the "B" standby liquid control pump startingpump circuit which prevents this pump from operating with the "A" running. The reverse is true if the "B" pump in started. The

problem developed when the breaker for the "A" pump was racked j out. It disabled the pump and at the same time it physically j

removed the contact in the starting circuitry for the "B" pump

which simulated an open. contact. This prevented the "B" pump ,

from starting.

l

• i As soon as tue Shift Foreman was aware of the inoperability i of both pumps, he started a normal shutdown of the plant. In the j meantime, he received permission to clear the maintenance safety i j tags and rack the "A" pump breaker to its normal position. He {

then ran a successful operability check on the "B" pump. The j

j load reduction was stopped and the plant returned to full load. j

(

). In order to prevent a recurrence of this event, operating

' procedures have been changed so that operability tests of redundant J engineered safeguards system components will be.made immediately f ollowing any action that requires one of the systems to be i inoperable for maintenance purposes.

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' We are. enclosing forty copies of this letter.

i Very truly yours, 3

i ,

-f(j11 h. . i fli {

l Ivan R. Finfr ek, .

j Vice presiden'

! IRF/pk  ?

! $nclosures tl i

7 cc: Mr. J. p. O'Reilly, Director

}

Directorate of Regulatory Operations, Region 1 i

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