05000219/LER-1982-024, Forwards LER 82-024/03L-0.Detailed Event Analysis Encl

Forwards LER 82-024/03L-0.Detailed Event Analysis Encl

ML20053A706
Person / Time
Site:	Oyster Creek
Issue date:	05/17/1982
From:	Fiedler P GENERAL PUBLIC UTILITIES CORP.
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20053A707	List: 05000219/LER-1982-024, Forwards LER 82-024/03L-0.Detailed Event Analysis Encl 05000219/LER-1982-024-03, /03L-0:on 820414,while Performing Surveillance on Electromatic Relief Valve Pressure Switches,Three of Five Switches Tripped Below Tech Spec Limit.Caused by Instrument Repeatability & Drift.Instruments Reset
References
NUDOCS 8205270160
Download: ML20053A706 (4)

LER-1982-024, Forwards LER 82-024/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2191982024R00 - NRC Website

text

D GPU Nuclear h,.

',j QQ gg P.O. Box 388 Forked River, New Jersey 08731 609-693-6000 Writer's Direct Dial Number:

May 17, 1982 Mr. Ronalo C. Haynes, Administrator Region i U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406

Dear Mr. Haynes:

Subject:

Oyster Creek Nuclear Generating Station Docke t No. 50-219 Licensee Event Report Report able Occurrence No. 50-219/82-24/03L This letter forwards three copies of a Licensee Event Report to report Reportable Occurrence No. 50-219/82-24/03L in compliance with paragraph 6.9.2.b.1 of the Technical Specifications.

Very truly yours, Peter'B. Fiedler Vice President & Director Oyster Creek PBF:Ise Enc losure s c c: Director (40 copies)

Of fice of Inspection and Enforcement U. S. Nuclear Regulatory Commission l

Washington, D.C.

20555 i

l Director (3) l Of fice o f Management Inf ormation and Program Control U.S. Nuclear Regulatory Commission Washington, D.C.

20555 NRC Resident Inspector (1)

Oyster Creek Nuclear Generating Station Forked River, NJ 08731 820527 0 160 g GPU Nuclear is a part of the General Pubhc Utihties System g@

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.D OYSTER CREEK NUCLEAR GENERATING STATION Forked River, New Jersey 08731 Licensee Event Report Reportable Occurrence No. 50-219/82-24/03L Report Date May 17, 1982 Occurrence Date April 14, 1982 Identification of Occurrence Three reactor high pressure Electromatic Relief Valve (EMRV) initiation switches (I A83's) actuated at a value greater than that specified in the s tation's Technical Specifications, Section 2.3.4.

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

Conditions Prior to Occurrence The plant was in the cold shutdown condition.

De scription o f Occurrence The results of a surveillance test on the five EMRV initiation pressure switches indicated that three switch initiation setpoints had drif ted to a value less conservative than that allowed in the station's Technical Specifications.

The following table presents the pertinent data relating to the surveillance of the IA83 pressure switches Switch Tech Spec Des ired Inst.

As As Desig.

Limit (A)

Setpoint (B)

Found (PSIG)

Le f t (PSIG)

I A83A 1079 1059

+0/-5 1058 1058 I A8 3B 10 84 1084

+0/-5 1099 1083 I A83C 1076 1076 +0/ -5 1084 1076 I A8 3D 1082 1062

+0 /-5 1067 1060 I A83E 1082 1082

+0/-5 1089 1080 (A)

Includes head correction f actors.

Values in PSIG.

(B)

Setpoint in PSIG on increasing pressure. Values indicated include head correction factors.

Licensee Event Report Page 2 Reportable Occurrence No. 50-219/82-24/03L The following conclusions are based on the above table:

1.

IA83B, C, and E drif ted high since the last time they were surveilled.

The previous surveillance was performed early in January 1982.

(The normal surveillance schedule is prior to start up when the reactor is shutdown and the reactor coolant is below 2120F. The reactor was placed in a cold shutdown condition in early December 1981. ) The test results I

presented in the table above were from the restart surveillance performed on 4/14/82, following a reactor scram from an attempted start on 4/12/82.

2.

I A83E, setpoint was found within the manufacturer's stated accuracy (+1/2%

of 1500 PSIC Proof or +7.5 PSIG).

Appa ren t Cause of Occurrence The cause of this event is attributed to instrument repeatability and drif t, of which one of the three switches that exceeded the Technical Specification limit was within the manufacturer's published accuracy.

Analysis of Occurrence The Electromatic Relief Valves (EMRV) are used in the Auto Depressurization System (ADS) to depressurize the reactor as a prerequisite for Core Spray System initiation and for relieving reactor pressure during high pressure transients.

The IA83 switches sequentially control the EMRVs for relieving reactor pressure to the Torus, and all five DiRVs would have actuated before reactor pressure could reach the setting of any of the Safety Valves with substantial margin.

The three pressure switches which drif ted above the Technical Specification limit would still have operated, if called upon to do so.

The safety significance of the three I A83 pressure switches which drif ted above the Technical Specification limit is considered minimal since the setpoint i

variations were minor and generally consistent with the design of the pressure switch.

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Licensee Event Report Page 3

{

Reportable Occurrence No. 50-219/82-24/03L I

Corrective Action

i Immediate corrective action was to readjust the pressure switches to actuate within the Technical Specification limit.

The results. of the next surveillance will be conpared to the results presented in the Description of Occurrence to determine if the switch setpoint should be lowered to allow for upward drift.

I A83C preasure switch will be replaced if found outside the manufacturer's stated accuracy range during the next scheduled surveillance.

Parts are on order to replace pressure switch IA83B.

These switches are scheduled to be replaced by a model with an improved design during the Cycle 11. refueling outage.

j Failure Data Ma nufacturer :

Barksdale Catalog No.:

B2S-M12S S Proof Pressure:

1500 Adjustable Range:

77-1200 s

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