05000219/LER-1981-013, Forwards LER 81-013/03L-0.Detailed Event Analysis Encl

Forwards LER 81-013/03L-0.Detailed Event Analysis Encl

ML20003G186
Person / Time
Site:	Oyster Creek
Issue date:	04/20/1981
From:	Finfrock I JERSEY CENTRAL POWER & LIGHT CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20003G187	List: 05000219/LER-1981-013, Forwards LER 81-013/03L-0.Detailed Event Analysis Encl 05000219/LER-1981-013-03, /03L-0:on 810319,core Spray Hi Drywell Pressure Switch RV46B Tripped in Excess of 2 Psi Tech Spec.Caused by Sensor Repeatability.Sensor Recalibr.Replacement of Sensors Recommended by PORC
References
NUDOCS 8104280443
Download: ML20003G186 (3)

LER-1981-013, Forwards LER 81-013/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2191981013R00 - NRC Website

text

o OYSTER CREEK NUCLEAR GENERATING STATION d

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Dear Mr. Grier:

SLRTECP: Oyster Creek Nuclear Gerarating Station Docket No. 50-219 Licensee Event Report Reportable Occurrence No. 50-219/81-13/3L This letter forwards three copies of a Licensee Event Report to report Reportable Occurrence No. 50-219/81-13/3L in mmlinnce with paragra @ 6.9.2.b.1 of the Technical Specifications.

Very truly yours,

/

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/EW',

van R. Finfrock y.

b Vice President - CCP&

Director - Oyster Creek IRF:dh Enclosures cc: Director (40 copies)

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

20555 Director (3)

Office of Managenent Information j

and Program Contrrl l

Lhited States Nuclear Regulatory Ccmnission Washington, D. C. 20555 NRC Resident Inspector (1)

Oyster Creek Nuclear Generating Station l

Forked River, N. J.

8104280 %

t OYSIER CREEK NUCLEAR GENERATING STATION Forked River, New Jersey 08731 Licensee Event Report Reportable Occurrence No. 50-219/81-13/3L Report Date April 20, 1981 Occurrence Date March 19, 1981 Identification of Occurrence During survaillance testing, the Core Spray high drywell pressure sensor RV46B tripped at a value greater than the limit as given in Tech. Spec., Table 3.1.1, itan D2.

This event is considered to be a reportable occurrence as defined in the Tachnical Specifications, paragraph 6.9.2.b.1.

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

Major Plant Pararreters Power:

Reactor 1730 mt Generator 590 se Flow:

Recirculation 14 x 104 p /hr Feedwater 6.33 x 100 lb Description of Occurrence On Thursday, March 19, while performing " Core Spray Instrument Channel calibration and Test" (Surveillance Procedure 610.3.005), high drywell pressure sensor RV46B tripped at a value greater than the Tech. Spec. limit of 1 0 psig. The'as 2

found trip set point was 2.18 psig.

Apparent Cause of Occurren

'Ihe cause of the occurren was attribu The sensor was raca14hrated to trip at 2.0 g to instruTent repeatability.

_ 1 psig, long term repeatability of this sensor is approximately 3% of full scale (.3 psig). It is, therefore, possible for the sensor to function within its design accuracy and exceed the Tech. Spec.

limit of 1 psig.

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Reportable Occurrence Page 2 Report No. 50-219/81-13/3L Analysis of Occurrence The Core Spray Syst.en is made up of two independent locps, each of which provides heat reeval from the fuel assablies in the event of a loss of coolant amWt.

In order to initiate the Core Spray System, a trip signal frm 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.

Although one (1) high drywell pressure sensor would have tripped at a higher pressure (.18 psig) than Tech. Spec. limit of <2.0 psig it would have operated, on increasing drywell pressure, with sme delay.

We three (3) renaining high drywell sensors would have tripped at or below the setpoint limit initiating the intended function of the Core Spray Systen, therefore, the safety significance of the occurrence is considered minimal.

Corrective Action

t e pressure sensor RV46B was racalibrated to trip within the Tech. Spec limit of <2 psig. An engineenng study is currently underway to investigate the pro 5lem of repeatability associated with this type of sensor. After reviewing the frequency of out of Spec. occurrences, the PORC rm -..erded replacanent sensors gnalified and with considerably inproved accura.y.

Failure Data Manufacturer: ITT Barton Model:

228A Pressure Indicating Switch Range:

0-10 psig y,--- - ---

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