05000219/LER-1980-052, Forwards LER 80-052/03L-0

Forwards LER 80-052/03L-0

ML19345D691
Person / Time
Site:	Oyster Creek
Issue date:	12/08/1980
From:	Finfrock I JERSEY CENTRAL POWER & LIGHT CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19345D692	List: 05000219/LER-1980-052, Forwards LER 80-052/03L-0 05000219/LER-1980-052-03, /03L-0:on 801118,reactor Triple Low Water Level Indicator Switches RE-18A & RE-18D Tripped at Manometer Readings Higher than Tech Spec Limit.Caused by Sensor Repeatability.Switches Reset
References
NUDOCS 8012160482
Download: ML19345D691 (3)

LER-1980-052, Forwards LER 80-052/03L-0

Event date:
Report date:
2191980052R00 - NRC Website

text

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g OYSTER CREEK NUCLEAR GENERATING STATION pm 2:v7 c7 TIu%,fjl1 (609) 693-1551 P.O. BOX 388

• FORKED RIVER e NEW JERSEY e o8731 c

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December 8,1980 Mr. Boyce H. Grier, Director Of? ice of Inspection and Enforcement Region I United States Nuclear Regulatory Commission 641 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. 50-219/80-52/3L This letter forwards three copies of a Licensee Event Report to report Reportable Occurrence No. 50-219/80-52/3L in compliance with 2

pagggraph 6.9.2.b.1 of the Technical Specifications.

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Very truly yours,

[

Ivan R. Finfro

'j Vice President Generation c

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IRF:dh Enclosures cc:

Mr. John G. Davis, Acting Director (40 copies)

Office of Inspection and Enforcement United States Nuclear Regulatory Commission Washington, D.C.

20555 Mr. William G. Mcdonald, Director (3 copies)

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

20555 8012160 M g

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0YSTER CREEK NUCLEAR GENERATING STATION Forked River, New Jersey 08731 Licensee Event Report Reportable Occurrence No. 50-219/80-52/3L Report Date Ddcember8,1980 Occurrence Date November 18, 1980 Identification of Occurrence During surveillance testing, the reactor triple low water level indicator switches RE-18A and RE-18D both tripped at values higher than the desired setpoint as given in the Technical Specifications, Table 3.1.1, item G.2.

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

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

Major Plant Parameters:

Power:

Reactor 1927.7 MWt Generator 635 MWe Flow:

Recirculation 15.5 x 10 GPM Feedwater 7.15 x 10 lb/hr l

Description of Occurrence 1

On Tuesday morning November 18 during performance of the " Reactor Triple Low Water Level Test and Calibration" (Procedure 619.3.006), level indicator switches RE-18A and RE-18D both tripped at values greater than the Technical Specification setpoint of <126" H 0.

Testing of the four sensors gave the following data:

2 Desired Setpoint As Found As Left Switch Designation Manometer Reading ("H90)

("H O)

("Hp0) 2 System I - RE-18A

<126.0 129.5 121.5 RE-18C 7126.0 126.0 121.0 System II-RE-18B 7126.0 125.8 122.0 RE-18D

_7126.0 130.0 121.8 The "As Found" values of 129.5 "H O and 130.0 "H O correspond to levels of 52.5" 2

2 and 52.0" above the top of active fuel, which is less conservative than the Technical Specification limit of 56" above T.A.F.

l

Reportable Occurrence Page 2 Report No. 50-219/80-52/3L Apparent Cause of Occurrence The cause of the occurrence was attributed to sensor repeatability. The long-term repeatability of the sensors is approximately 3.0-4.5"H O (2-3% of full 2

range).

It is, therefore, possible for the manometer reading to be as high as 130.5"H O and the instrument will still operate within its design accuracy.

2 Analysis of Occurrence The failure of switches RE-18A and RE-18D to actuate at the desired setpoint would have delayed the initiation of triple low water level indications. However, each system contains redundant switches RE-18B ano RE-18C, which would have initiated the necessary functions at the specified Technical Specification limit. The safety significance is, therefore, considered minimal since sensors RE-18A and RE-18D's non-conservatism resulted in a temporary loss of redundancy in each system.

Corrective Action

The triple low level sensors RE-18A and RE-180 were reset to trip within the stated Technical Specification limit of between 121"H 0 and 123"H 0 (note the 7

3 "As Left" values under Description of Occurrence). ATso, an engiheering study is being made into the drift problem of the ITT Barton snap-action switches.

The reactor triple low set point will be evaluated to determine if it can be changed to account for instrument drift.

Failure Data Manufacturer:

ITT Barton Model:

288A Indicating Pressure Switch Range:

0-150"H O 2

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