05000219/LER-1982-035, Forwards LER 82-035/03L-0.Detailed Event Analysis Encl

Forwards LER 82-035/03L-0.Detailed Event Analysis Encl

ML20062C754
Person / Time
Site:	Oyster Creek
Issue date:	07/19/1982
From:	Fiedler P GENERAL PUBLIC UTILITIES CORP.
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20062C757	List: 05000219/LER-1982-035, Forwards LER 82-035/03L-0.Detailed Event Analysis Encl
References
NUDOCS 8208050346
Download: ML20062C754 (3)

LER-2082-035, Forwards LER 82-035/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2192082035R00 - NRC Website

text

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GPU Nuclear Q g7 P.O. Box 388 Forked River, New Jersey 08731 609-693-6000 Writer's Direct Dial Number:

July 19, 1982 Mr. Ronald C. Haynes, Administrator Region I U.S. Nuclear Regulatory Com:aission 631 Park Avenue King of Prussia, PA 19406

Dear Mr. Haynes:

Subj ect : Oyster Creek Huclear Generating Station l Docket No. 50-219 Licensee Event Report l Reportable Occurrence No. 50-219/82-35/03L l This letter forwards three copies of a Licensee Event Report to report Reportable Occurrence No. 50-219/82-35/03L in compliance with paragraph 6.9 2.b.2 of the Technical Specifications.

Very truly yours, Peter'B. Fiedler Vice President and Director Oyster Creek PBF:1se Enclosures cc: Director -(40 copies)

Office of Inspection and Enforcement U.S. Nuclear Regulatory Conmission Washington, D.C . 20555 Director (3)

Office of Management Information and Program Control U.S. Nuclear Regulatory Commission Washington, D.C. 20555 NRC Resident Inspector Oyster Creek Nuclear Generating Station Forked River, NJ 08731 8208050346 820719 DR ADOCK 05000219 1 PDR GPU Nuclear is a part of the Generai Dubhc Utihties System

OYSTER CREEK NUCLEAR GENERATING STATION Forked River, New Jersey 08731 Licensee Event Report Reportable Occurrence No. 50-219/82-35/03L Report Date July 19, 1982 Occurrence Date June 15, 1982 June 16, 1982 Identification of Occurrence Operation under a Limiting Condition for Operation as defined in Technical Specifications, paragraphs 3 1.1-I.

This event is considered to be a reportable occurrence as defined in the Technical Speci."ications, paragraph 6.9 2.b.2.

Conditions Prior to Occurrence Major plant parameters were as follows:

Power: Reactor 1459.4 MWt 502 MWe Mode Switch: RUN Description of Occurrence On Monday, June 14, 1982, af ter placing the Augmented Off-Gas Facility ( A0G) in s ervic e, operators noticed that isolation vslve V-7-31 did not indicate closed in the control room. Procedure 630 3 002, "A0G Isolation Valve Test" was performed and the valve operated satisfactorily.

On Tuesday, June 15, 1982, as a second check, the valve was cycled three times. During this cycling, proper valve indication was not obtained. In addition, when the A0G inlet flow and stack gas activity were compared to readings taken prior to cycling, there was a drop in the A0G inlet flow; and stack gas activity increased from 120 to 180 cps on one monitor and from 130 to 180 cps on another. This indicated that the off-gas isolation valve did not fully close. A normal plant shutdown was commenced.

Subsequent investigation revealed that one of two redundant solenoid valves had failed, not allowing the A0G isolation valve to fully close. The defective solenoid valve was removed from the system and the remaining solenoid valve was used for control. It should be noted that two solenoid valves are used in a "non-redundant" control scheme to improve mechanical reliability for certain failure modes (each is capable of operating the valve independently).

Procedure 630 3 002 was performed once again, and it was found to be operating properly. At tl.2s point, the normal plant shutdown was terminated.

On Friday, June 18, 1982, the new solenoid valve was installed and the A0G facility was returned to service with two solenoid valves in operation.

Licensee Event Report Page 2 Reportable Occurrence No. 50-219/82-35/03L b

Apparent Cause of Occurrence It has been determined that the off-gas isolation valve failed to fully close due to a piece of foreign matter (apparently a piece of an old gasket) lodged I

under the seat. of the solenoid valve. The present configuration is such that when a closed signal was initiated, one solenoid operated as expected, but the I defective or.e allowed come air to the isolation valve diaphragm, not allowing

! it to fully'close.

l 3 l Analysis of Occurrence When high radiation is detected in the off-gas system, the holdup line is automatically isolated via V-7-31, the off-gas isolation valve, af ter a 15 minute delay, which is provided to permit corrective action to be: taken. '"

Closing the eff-gas isolation. valve will prevent the release of high concentrations cf radioaotivity through the stack and will also isolate the Augmented Of f-Gas Facility.

Had the off-gas isolation' valve, V-7-31, failed to close (isolate) from an off-gas high radiation signal, the main steam line radiation monitor would have simultaneoaaly detected a high radiaticn condition which would have closed the MSIV's, thereby preventing additional radioactive steam from entering the off-gas system. The MSIV's are designed to close within 3 to 10 seconds. (

Corrective Action .

The immediate corrective action taken was to remove the defective solenoid valve that prevented the off-gas isolation valve from fully closing. The system functioned satisfactorils with the one remaining solenoid. Within two days of the removal of the defective solenoid valve, a new replacement was '

installed. No future corrective action is warranted since it was found that the solenoid valve did not, in fact, " fail". Additionally, this valve is tested prior to each startup.

Failure Data -

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i Manufacturer: A300 Model Number: 8300B59RF

• 5 Size: 1/4",

i 'l Note: Valve itself 'did not fail (foreign material under seat) *

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