05000219/LER-1981-020, Forwards LER 81-020/03L-0.Detailed Event Analysis Encl

Forwards LER 81-020/03L-0.Detailed Event Analysis Encl

ML19346A259
Person / Time
Site:	Oyster Creek
Issue date:	06/01/1981
From:	Finfrock I JERSEY CENTRAL POWER & LIGHT CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19346A260	List: 05000219/LER-1981-020, Forwards LER 81-020/03L-0.Detailed Event Analysis Encl 05000219/LER-1981-020-03, /03L-0:on 810501,isolation Condenser Shell Level Instrument IGO6B Found Reading High During Annual Calibr. Caused by Evaporation of Instrument Ref Column.Column Backfilled W/Water to Normal Operating Level
References
NUDOCS 8106050509
Download: ML19346A259 (3)

LER-1981-020, Forwards LER 81-020/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2191981020R00 - NRC Website

text

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• OYSTER CREEK NUCLEAR GENERATING STATION Me! Q:e dd]

gg,$*7l,,%.m,5g,q (609) 693-1951 P.O. BOX 088

• FORKED RIVER

• NEW JERSEY

• 08731 caw kw.

sm-June 1, 1981 Mr. Boyce H. Grier, Director Office of Inspection and Enforement Region I United States Nuclear Regulatory Ccmnission 631 Park Avenue.

King of Prussia, Pennsylvania 19406

Dear Mr. Grier:

SUBJECT: Oyster Creek Nuclear Generating Station Docket No. 50-219 Licensee Event Report Reportable Occurrence No. 50-219/81-20/3L l

This letter forwards three copies of a Licensee ' vent Report l

to report Reportable Occurrence No. 50-219/81-20/3L in cmpliance with paragraph 6.9.2.b(1) of the Technical Specifications.

Very truly yours, i

i f

van R. Finfrock, Vice President -

&L Director - Oyster Creek IRF:dh Enclosures 7

cc: Director (40 copies)

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Office of Inspection and Enforcement g

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United States Nuclear Regulatory Ccrmission

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'J dlfN 'l /Sgg 7 i

0 Washington, D.C.

20555

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Director (3)

Office of Management Information and Progra:n Control 4

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Unital Staws Nuclear Regulatcry Comnission 4

Washington, D. C. 20555 i

NRC Resident Inspector (1)

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

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81060505of J

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V OYSIER CREEK NUCIEAR GENERATING STATICN -

Forked River, New JerseyJ08731 Licensee Event. Report

. Reportable Occurrence No. 50-219/81-20/3L.

. Report cate June 1, 1981 Occurrence Date l

May 1, 1981 Identification of occurrence

~

' violation of the Tachnimi specifications, section 3.8(B)- when the volume of water in the "B". Isolation Condenser was less than the Technical Specification-limit of 22,730 gallons. This condition could not have existed for greater than one year based on the previous mlibration.

his event is considered to be a reportable occurrence.as defined in the Technical'

)

Specifications, paragraph 6.9.2.b(1).

I Conditions Prior to Occu m nce e

The plant was in the cold shutdown condition at the time the level disuccincy was identified.

Description of Occurrence i

On Friday, "ay 1, 1981, during the annual calibration of Isolation Condenser shell side level instruments, IG-06B was found to be rmeling high by approximately

.55 ft. The actual shell side level was found to be 6.75 ft which is less than the Technical-Specification required level of >7.2 ft.

This error, or false

- indication was due to a low reference column water level. mis condition could-not have existed for greater than one year based on the previous m1ihration.

. 3 Apparent Cause of Occurrence

]

The cause of the occurrence is attributed to a. low reference column water level.

Analysis of Occurrence The purpose of the isolation condenser is to depressurize the reactor and to 1

rmove reactor decay heat in the event that the main condenser is unavailable as a heat sink. Since the shell side of the isolation condenser operates at atmospheric pressure, it can accarglish this purpose when the reactor taperature is sufficiently above 2120F to pr(NK6 for the heat transfer corres;cndi.'g to reactor decay heat.

Reportable Occurrence Page 2 Report No. 50-219/81-20/3L Each condenser contains a minimLzu water volume on 22,730 gallons thus providing 11,060 gallons above the condensing tubes. One corx!enser with a minimum water votrme of 22,730 gallons or >7.2 ft. can aWate the reactor decay heat for 45 minutes after scram fran 1950 FWt before make up is required.

'Ihe level difference was less than Technical Specification limit by 1250 gallons which resulted in a reduction of operating time, before make-up, above the top of tube bundle of less than 5 minutes.

Effectively the reduction in time available left the operator with sufficient

, time to make up and maintain adequate water volume.

The occurrence had no effect on public health and safety.

Corrective Iction

'Ihe reference column was backfilled with water to its normal operating level i.e. spill-over to isolation condenser shell volume.

Until a scheduled check of the reference legs is incorporated into the Preventive Maintenance Program the calibration frequency for this instrument will be changed fran annually to quarterly to ensure that the reference legs rarain full.

i.

Failure Data Not applicable.

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