05000219/LER-1982-047, Forwards LER 82-047/03L-0.Detailed Event Analysis Encl

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Forwards LER 82-047/03L-0.Detailed Event Analysis Encl
ML20066G836
Person / Time
Site: Oyster Creek
Issue date: 11/03/1982
From: Fiedler P
GENERAL PUBLIC UTILITIES CORP.
To: Haynes R
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20066G840 List:
References
NUDOCS 8211230072
Download: ML20066G836 (3)


LER-2082-047, Forwards LER 82-047/03L-0.Detailed Event Analysis Encl
Event date:
Report date:
2192082047R00 - NRC Website

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GPU Nuclear h .

g g7 P.O. Box 388 Forked River, New Jersey 08731 609-693-6000 Writer's Direct Dial Number:

November 3, 1982 Mr. Ronald C. Haynes, Administrator Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406

Dear Mr. Haynes:

Subj ect: Oyster Creek Nuclear Generating Station Docket No. 50-219 Licensee Event Report Reportable Occurrence No. 50-219 /82-47/03L This letter forwards three copies of a Licensee Event Report to report Reportable Occurrence No. 50-219/82-47/03L in compliance with paragraph 6.9.2.b.2 of the Technical Specifications.

Very truly yours, 1 x hn ) --

Pefer M'iedler Vice President and Director Oyster Creek PBF:lse Enclosure s cc: Director (40 copies)

Of fice of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Director (3)

Of fice of Management Information and Program Control U.S. Nuclear Regulatory Commission Washington, D.C. 20555 NRC Resident Inspector Oyster Creek Nuclear Generating Station Forked River, NJ 08731 0

S GPU Nuclear is a part of the General Public Utilities System p

4 OYSTER CREEK NUCLEAR GENERATING STATION Forked River, New Jersey 08731

, Licensee Event Report Reportable Occurrence No. 50-219/82-47/03L Report Date November 3,1982 Occur re nc e Da te October 4,1982 Identification of Occurrence

- A plant shutdown was initiated as required by a limiting condition for operation (Technical Specification 3.7.B) when, at approximately 1635 hours0.0189 days <br />0.454 hours <br />0.0027 weeks <br />6.221175e-4 months <br /> on the occurrence date, Reactor Protection System (RPS) Motor Generator (MG) Set No.1 failed and could not supply power to RPS Panel No.1.

Loss of RPS Panel No.1 is a configuration which is not allowed by Technical Specification 3.7.A.1.d and is considered to be a reportable occurrence as defined by Technical Specifications, paragraph 6.9.2.b.2.

Conditions Prior to Occurrence The plant was in steady state operation.

l Reactor Power: 1150 MWt Generator Power: 368 MW'e Mode Switch Position: Run Note: RPS MG Set No. 2 was tagged out of service for maintenance with power supplied to RPS Panel No. 2 by Motor Control Center (MCC) 1A2 through its alternative power supply (transformer).

. Description of Occurrence During normal plant operation, RPS No.1 MG set stopped supplying power to RPS Panel No. 1. This was identified by annunciators in the the control room and de-energization of Reactor Protection System I. An orderly plant shutdown was commenced and subsequently terminated upon correction of the deficiency.

Apparent Cause of Occurrence The apparent cause of the event was the failure of a relay in RPS No.1 MG set controls, and the inability of RPS Panel No. I to be powered by the alternate source transformer PS-1. The switching of power supplies for RPS Panel No.1 i (via contactor transfer relay GT-1) could not be performed because RPS Panel No. 2 was being powered by the alternate source transformer (via contactor transfer relay GT-2) at the time of the occurrence due t'o maintenance on RPS MG Se t No. 2. An interlock between transfer relays GT-1 and GT-2 prevents both RPS systems f rom being powered on the PS-1 transformer simultaneously.

RPS MG Set No.1 failed to provide power due to excessive wear (contact

" splash") and pitting on the K1 relay contacts. This relay senses main contact and motor overload conditions.

Licensee Event Report Page 2 Reportable Occurrence No. 50-219 /82-47/03L Analysis of Occurrence The Reactor Protection System (RPS) is designed to. protect plant equipment and personnel by initiating the rapid insertion of control rods and primary containment isolation in the event of a potentially unsafe condition. RPS is a two channel logic system. In order to cause reactor scram and isolation, both logic channels must sense a trip signal. Each channel is further divided into two trip systems. A trip condition must exist in both logic channels in order for' a full scram or isolation to occur. With the loss of RPS No. 1, we had in ef fect, a half scram.

The safety significance of the occurrence was minimized due to RPS No. 2 having been failed in a tripped condition, thereby performing its intended function.

Corrective Action The failed K1 relay in RPS MG Set No. I was replaced with an identical relay f rom RPS MG Set No. 2. As spares for this relay were not in stock, additional spares were ordered.

Since the failome was found due to wear in service (approximately 14 years), no further corrective action is planned other than replacing the K1 relay in MG set No. 2 prior to putting that unit back in service.

Failure Data Manufacturer : G.E.

CR120J Relay 120 Volts, 10 Amps O

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