ML19340D707

Forwards LER 80-055/03L-0

ML19340D707
Person / Time
Site:	Oyster Creek
Issue date:	12/22/1980
From:	Finfrock I JERSEY CENTRAL POWER & LIGHT CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19340D708	List: ML19340D707 ML19340D711
References
NUDOCS 8101050197
Download: ML19340D707 (3)

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OYSTER CREEK NUCLEAR GENERATING STATION -

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c("gy'f27Ja L uu.s s,$?O, om.

(609) 693-1951 P.O. BOX 388

• FORKED RIVER e NEW JERSEY

• 08731 l

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{ Decmber 22, 1980 Mr. Boyce H. Grier, Director ',

Office of Inspection and Enforcement .>

Region I t.

United States Nuclear Regulatory Commission Q-641 Park Avenue 14qE; ,

f King of Prussia, Pennsylvania 19406 .p 1*f l

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Dear Mr. Grier:

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j EUBJECT: Oyster Creek Nuclear Generating Station Docket No. 50-219 Licensee Event Report Reportable Occurrence No. 50-219/80-55/3L This letter forwards three copies of a Licensee Event Report to report Reportable Occurrence No. 50-219/80-55/3L in compliance with paragraph 6.9.2.b.1 of the Technical Specifications.

Very truly yours, 1'

/ /W$ u i van R. Finfrock, Jr l Vice President Generati n IRF:dh Enclosures cc: Mr. John G. Davis, Acting Director (40 copies) 1 Office of Inspection and Enforcement

United States Nuclear Regulatory Commission Washington, D.C. 20555 l

Mr. William G. Mcdonald, Director (3 copies)

Office of Management Information and Program Control United States Nuclear Regulatory Comission Washington, D.C. 20555 8101050 M '

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n 0YSTER CREEK NUCLEAR GENERATING STATION i Forked River, New Jersey 08731 f Licensee Event Report i Reportable Occurrence No. 50-219/80-55/3L 1

i l Report Date I

! December 22, 1980 Occurrence Date December 3,1980 1

j Identification of Occurrence During surveillance testing, the Core Spray high drywell pressure indicator switches RV-46B, RV-46C and RV-46D tripped at values greater than the desired j setpoint as given in the Technical Specifications, Table 3.1.1, item D.2.

This event is considered to be a reportable occurrence as defined in the Technical Specifications, paragraph 6.9.2.b.l.

- Conditions Prior to Occurrence The plant was operating at steady state power.

Major Plant Parameters:

• Power: Reactor 1725 MWt Generator 590 MWe 4

Flow: Recirculation 15.2 x 10 GPM Feedwater 6.37 x 106 lb/hr i

Description of Occurrence On Wednesday, December 3, during performance of the " Core Spray Instrument Channel Calibration and Test" (Surveillance Procedure 610.3.005), high drywell pressure indicator switches RV-46B, RV-46C and RV-460 tripped at values greater than the Technical Specification limit of <2.0 psig. The testing yielded the l

l following trip points for the three switches: RV-46B 2.14 psig, RV-46C 2.11 psig, and RV-46D 2.05 psig.

Apparent Cause of Occurrence The cause of the occurren e was attributed to instrument repeatability. The switches are set is approximately at 2.01, 2-3% of O ll range (0.2-0.3 psig).psig and the long-term It is, therefore, possible repeatability for the instruments to operate within their design accuracy, yet exceed the

! Technical Specification limit of 2.0 psig by as much as 0.3 psig.

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Reportable Occurrence Page 2 Report No. 50-219/80-55/3L Analysis of Occurrence l

The Core Spray System is made up of two independent loops, each of which provides heat removal from the fuel assemblies in the event of a loss of coolant accident.

1 In order to initiate the Core Spray System, a trip signal from any one of the four (4) high drywell pressure sensors or any one of the four (4) reactor low-low water level sensors must be received. .

j Although the three (3) high-drywell pressure switches would have tripped at a slightly higher pressure than the desired setpoint, their actuation would have only been delayed by a fraction of a second (approximately 0.1 second). However, the fourth high drywell pressure switch would have already initiated the required Core Spray System functions, and, therefore, the safety significance of the occurrence is considered minimal.

I Corrective Action l The pressure switches RV-468, RV-46C, and RV-46D were adjusted to trip within l the Technical Specification limit of 12 0 psig. An engineering study is currently under way to investigate the problem of drifting associated with these snap-action type pressure switches. After consideration of the frequency of occurrence of set point drift associated with ITT Barton differential pressure indicating switches with snap action switches, the PORC recommended replacement of these devices with a more suitable, qualified model.

Failure Data Manufacturer: ITT Barton .

Model: 228A Pressure Indicating Switch Range: 0-10 psig l

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