05000277/LER-1980-020, Forwards LER 80-020/01T-0

Forwards LER 80-020/01T-0

ML19340B276
Person / Time
Site:	Peach Bottom
Issue date:	10/10/1980
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19340B277	List: 05000277/LER-1980-020, Forwards LER 80-020/01T-0 05000277/LER-1980-020-01, /01T-0:on 800926,breaker Which Supplies Power to B Standby Liquid Control Sys Pump & B Squib Valve Found Open. Caused by Accidental Tripping of Pump Breaker.Breaker Switches of All Sblc Pumps Locked
References
NUDOCS 8010210725
Download: ML19340B276 (3)

LER-1980-020, Forwards LER 80-020/01T-0

Event date:
Report date:
2771980020R00 - NRC Website

text

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PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREt.T P.O. BOX 8699 PHILADELPHI A, PA.19101 (21588414000 October 10, 1980 l

Mr. Boyce H.

Grier, Director

' Office of Inspection and Enforcement R e r,1 o n I United States Nuclear Regulato y Commission 631 Park Avenue King of Prussia, PA 19406 l

Dear Mr. Grier:

(

SUBJECT:

Licensee Event icport Narrative Descriptity, Referenec:

Docket Number 50-277 Report Eo.:

LER 2-80-20/lT-0 Report Date:

October 10, 1980 L

Occurrance Date:

September 26, 1930 i

Facility:

Peach Bottom Atomic Power Station l

R.D.

1,~ Delta, PA 17314 i

TechnicaljSpecification Reference:

Technica Specification 3.4.A.1 states in part that "During l

periods when fuel is in the reactor...the Standby Liquid Control System shall be operable, except as specified in 3.4.3 below."

Technical Specification 3.4.3.1 states _that "From and after the date that a redundant component is made or found to bc i no p e ra h '.e, Specification 3.4.A.l_shall be considered fulfilled and continued operation permitted provided that the compuncut is returned to an operable condition within seven days."

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6' P a c, e 2 Mr..Soyce !I. Crier October 10, 1900 LER 2-30-20/IT-0 Description of the Event:

annunciator "SHLC Loss a.

With the unit operating at 997. power, of Continuity" alarmed, alerting the operator to a possible failure.or firing of the

'B' Standby Liquid Control Squib valve..This explosive valve is continuously mc:.tored by a light sensitive meter circuit in series with the squib firing mcchanism.. A loss of continuity ~in the circuit or the firing squib valve will activate the continuity alarm.

of a The valve firing and monitoring circuitry is fed from a 480V/120V step doun transformer in the pump breaker compartment.

Investigation following the alarm found the becaker (52-1723) to be open.

The feed was immediately restored.

The NRC Resident Inspector was notified of the permissabic under Tech situation.

Continued operation was Spec limiting condition for operation 3.4.B.1.

Since the system was promptly returned to service, no testing on the

'A' SBLC pump was performed.

Consequences of the Event:

The SBLC system is dostgned to be used as a redundant and independent system.co bring the reactor from full power to a cold, xenon. free shutdown condition in the event of a failure of a large number of control rods to fully insert.

The system is manually initiated from the Control Room through a three position key switch, lla d initiation been required, the operator would have observed the failure of the

'B' pump-to start and no flow, lie would then have been able to turn the switch to start the

'A' pump.

Upon actuation of the switch both valves are designed to fire.

Only the

'A' would have opened under these conditions, Iowever, the system design only allows for one pump operation in order to limit the rate at which the boron solution is pumped into the reactor.

Canaa af Event:

The pump breaker compartment is located adjacent to a step-off-

- pad at.approximately knee level.

It is believed that the breaker tripped accidentally by someone bumping into the switch whi'.e

.was entering or exiting the area.

Corrective Action

After the pump breaker was reclosed, satisfactory operation was verified-by manually cycling'the pump breaker.' To preclude further inadvertent operation, the breaker switches of all SULCS pumps were locked in the 'on' position.

The area-to which the step-off pad provided access has been decontaminated, and-the step-off pad removed.

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'!!r.-Soycesil. Crier.

O c t ois e r 10, 1930

LERl2-80-20/lT-0--

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4 Provious.Sicilar Occurrences:

..None.

Very truly yours, i

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?g N^' ' ly-/bff[bG

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M. J. Cooney' t

S ujie rin t e nd en t i.

Generation Division / Nuclear r

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..etachment cc: Director, NRC - Office of Inspection and Enforcement

.Mr. Norman M.

Ita lle r, NRC - Office c,f Management &

Program Analysis T

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