05000219/LER-1982-012, Forwards LER 82-012/01P-0.Detailed Event Analysis Encl

Forwards LER 82-012/01P-0.Detailed Event Analysis Encl

ML20042B290
Person / Time
Site:	Oyster Creek
Issue date:	03/15/1982
From:	Fiedler P GENERAL PUBLIC UTILITIES CORP.
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20042B291	List: 05000219/LER-1982-012, Forwards LER 82-012/01P-0.Detailed Event Analysis Encl 05000219/LER-1982-012-01, /01P-0:on 820226,air Operated Vacuum Breaker V-26-18 Exceeded Allowable Leak Rate.Caused by Improper Alignment of Valve Shaft & Operator Due to Inadequate Maint Instructions.Valve Realigned & Procedures Will Be Revised
References
NUDOCS 8203250185
Download: ML20042B290 (3)

LER-1982-012, Forwards LER 82-012/01P-0.Detailed Event Analysis Encl

Event date:
Report date:
2191982012R00 - NRC Website

text

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GPU Nuclear g

gf P.O. Box 388 Forked River, New Jersey 08731 609-693-6000 Writer's Direct Dial Number:

March 15, 1982

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Mr. Ibnald C. Ilaynes, Adminstrator B

Region I United States Nuclear Regulatory Comnission

' ' Q9., g 631 Park Avenue King of Prussia, Pennsylvania 19406

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Dear Mr. Ilaynes:

.qO SURIDCT: Oyster Creek Nuclear Cencrating Station Docket No. 50-219 Licensee Event Report Reportable Occurrence No. 50-219/82-12/lT This letter forwards three copies of a Licensee Event Report to report Reportable Occurrence No. 50-219/82-12/lT in compliance with paragraph 6.9.2.a.3 of the 'Ibchnical Specifications.

Very truly yours, Ad

~'

Pc.ter iedler Vice President - Director Oyster Creek PBP:dh Enclosures cc: Director (40 copies)

Office of Inspection and Enforcment United States Nuclear Regulatory Ccmnission Washington, D.C.

20555 Director (3)

Office of Managment Information and Program Control United States Nuclear Regulatory Ccmnission Washington, D. C. 20555-NRC Resident Inspector (1)

Oyster Creek Nuclear Generating Station Forked River, N. J.

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ADOCK 05000219 PDR y

GPU Nuclear is a part of the General Pubhc Utihties System

OYSTER CREEK NUCLEAR GENERATING STATION Forked River, New Jersey 08731 Licensee Event Report Reportable Occurrence No. 50-219/82-12/01P Report Date March 15, 1982 Occurrence Date February 26, 1982 Identification of Occurrence Reactor Building to Suppression Chamber vacuum breaker valve V-26-18 was found to be installed improperly.

This is suspected to have occurred following maintenance in May 1980.

The valve shaf t was misaligned with tne valve operator causing the valve to fully.open with a signal from the Control Room to close and vice versa.

This event is considered a violation of Technical Specification 3.5.A.3 and 3.5. A.4 and as such, reportable in accordance with paragraph 6.9.2.a.(3).

Conditions prior to Occurrence The plant has been operating in various modes.

Description of Occurrence On February 7,1982, while conducting local leak rate testing on the reactor building to suppression chamber vacuum breakers, it was found tnat air operated vacuum breaker valve V-26-18 exceeded the allowable leak rate.

Subsequent investigation revealed that the valve shaft was improperly aligned with the operator such that when the operator indicated closed, the disc was in the open position and when the operator indicated open, the disc was in the closed position. Maintenance records indicate that the valve was last disassembled and inspected in May, 1980.

Apparent Cause of Occurrence The cause of this occurrence is due to an inadequate procedure.

Ihe maintenance procedure does not provide adequate instructions on disassembly of the valve to ensure correct orientation of the valve shaf t and operator on reinstallation.

The valve shaf t has four (4) keyways to allow for a7 alternate valve operator configuration.

Although the procedure requires that a leak rate test of the valve be performed after maintenance, the results of that test did not indicata that a problem existed. As part of the investigation, a recent test revealed that with the valve shaf t keyed in the wrong position and tne valve operator indicating open (valve disc actually closed), acceptable leak rate dat: was acquired.

Reportable Occurrence Page 2 Report No. 50-219/82-12/01P In review, the following conclusion can be made.

The leak test was performed on V-26-18 with the valve operator in the open position and the disc closed.

Although the leak rate procedure requires the valve to be closed using the normal mode of operation, a requirement for verification in the control room prior to sign off is not specifically called for in the body of the procedure.

Analysis of Occurrence The vacuum relief system from the reactor building to the pressure suppression chaaber consists of two 100% vacuum relief breaker subsystems (2 parallel sets of 2 valves in series). The purpose of the vacuum relief valves is to equalize pressure so that containment external design pressure limits are not exceeded.

Operation of either subsystem will maintain the suppression chamber external pressure less than its design pressure of 1 psi. With recondant loop (V-26-15 and 16) performing its intended vacuum relief function, the safety significance is considered minimal.

Each redundant loop contains a vacuum breaker check valve and an air operated vacuum breaker in series (V-26-15, V-26-16 and V-26-17, V-26-18).

Both valves in each loop are considered primary containment isolation valves.

The air operated vacuum breakers (V-26-16 and V-26-18) are normally closed during reactor operation.

Also, they will close on a high drywell pressure signal.

Upon total loss of air supply to the valve operator, the valves will both fail in the open position.

With the incorrect valve shaf t alignment that existed, if V-26-18 indicated closed the disc was actually in the open position. The vacuum breaker check valve in this loop (V-26-17) was verified in the "as found" condition to be leak tight. With V-26-17 in this loop performing its intended isolation function and the redundant loop (V-26-15, V-26-16) performing its intended isolation function, the safety significance is considered minimal.

Corrective Action

Imrediate corrective actions taken included properly realigning the valve shaf t with the operator and performing a leak test on the valve. This test was completed satisf actorily on February 22, 1982. Maintenance and local leak rate procedures will be revised accordingly.

The unused keyway slots will be blocked to prevent inadvertant assembly using the wrong slot.

The valves have been propet ty identified with tags.

Failure Data Not applicsble.