05000219/LER-1982-022, Forwards LER 82-022/03L-0.Detailed Event Analysis Encl

Forwards LER 82-022/03L-0.Detailed Event Analysis Encl

ML20053A877
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
ML20053A878	List: 05000219/LER-1982-022, Forwards LER 82-022/03L-0.Detailed Event Analysis Encl 05000219/LER-1982-022-03, /03L-0:on 820416,after 1B Breaker Closed & Startup Transformer S1B Breaker Failed to Operate,Operator Determined That Fuse Had Blown.Caused by Mild Momentary Overload.Fuse Replaced & Breaker Reset & Returned to Svc
References
NUDOCS 8205270384
Download: ML20053A877 (3)

LER-1982-022, Forwards LER 82-022/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2191982022R00 - NRC Website

text

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GPU Nuclear G

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

May 17, 1982 Mr. Ronald C. Ilayne s, Adminis trator Region I U.S, Nuclear Regulatory Commission 631 Pack Avenue King of Prussia, PA 19406

Dear Mr. Hayias:

Subject:

0;::ter Creek Nuclear Generating Station Docke t No. 50-219 Licensee Event Report Report able Occurre nce No. 50-219/82-22/03L This letter forwards three copies of a Licensee Event Report to report Reportable Occurrence No. 50-219/82-22/03L in compliance with paragraph 6.9.2.b.2 of the Technical Specifications.

Very truly yours,

((h A-

/D2A 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 Washington, D.C.

20555 Director (3)

Of fice of Management Information and Program Control U.S. Nuclear Regulatory Coa: mission Washington, D.C.

20555 l

NRC Resident Inspector (1)

Oyster Creek Nuclear Generating Station Forked River, NJ 08731 y

820527 0 39Y GPU Nuclear is a cart of the General Pubhc Utihties System

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OYSTER CREEK NUCLEAR GENERATING STATION Forked River, New Jersey 08731 Licensee Event Report Reportable Occurrence No. 50-219/82-22/03L Report Date May 17, 1982 Occurrence Date April 16, 1982 Identification of Occurrence On April 16, 1982, at approximately 1532 hours0.0177 days <br />0.426 hours <br />0.00253 weeks <br />5.82926e-4 months <br />, the Bank 6 start up transformer was not available for automatic operation.

This constitutes operation in a degraded mode permitted oy a limiting condition for operation as specified in the Technical Specifications, Section 3.7.B.

This event is considered to be a reportable occurrence as defined in the Technical Specifications, paragraph 6.9.2.b.2.

Conditions Prior to Occurrence The major plant parameters at the time of the occurrence were:

Power :

Reactor 1028 MWt El ectric 330 MWe Description of Occurrence On April 16, 1982, at approximately 1532 hours0.0177 days <br />0.426 hours <br />0.00253 weeks <br />5.82926e-4 months <br />, after the Bank 4 auxiliary transformer.1B breaker was closed and the Bank 6 start-up transformer SIB breaker automatically tripped, the operator reset the S1B breaker.

At this time, the operator noticed that the white breaker ready light was not on.

The Electrical Department was notified and an electrician was sent to investigate the problem.

The electrician found that one (1) control fuse on the closing circuit had blown.

It was also determined that the fuse blew af ter the springs were fully charged. The fuse was replaced and the breaker was reset and made available for automatic operation within one hour.

Appa ren t Cause o f Occurrence Analysis of the fuse element found that the fuse blew due to a mild, momentary overload condition. There were no problems found, af ter testing and preventive maintenance activities were performed, which would have caused the fuse to blow.

Licensee Event Report Page 2 Report able Occurrence No. 50-219/82-22/03L Analysis of Occurrence The S1B breaker supplies 4160V power to Bus 1B through the Bank 6 startup transformer when the station is shutdown.

The IB Bus in turn supplies power to the emergency Bus ID.

The e f fec t of one blown fuse in the closing circuit rendered the SIB breaker unavailable for automatic closure, thus offsite power would not have been automatically available to power the IB Bus and the emergency Bus ID.

It should be noted, however, that the S1B b reaker was available for manual i

operation since the springs, as mentioned above, were fully charged.

In addition, of fsite power was available to Bus lA and emergency Bus 1C through Ba nk 5 startup transformer for the redundant bus.

Diesel Generator #2 was available to supply onsite power to emergency Bus ID if the need arose.

Since redundant power sources were available in the event of an accident, the safet-j significance of the event is considered minimal.

Corrective Ac tion Immediate corrective action was to replace the blown fuse to make the breaker operable.

The breaker was reset, tested, and made available for operation.

Subsequently, a spare breaker was checked out and installed while more thorough preventive maintenance was performed on the existing breaker.

No reasons for the blown fuse have been found at this time.

Since it is not believed the fuse blew arbitrarily (such as due to age), a review will be conducted to ascertain any potential over-currents which could have caused fuse interruption and test methods will be devised to identify and verify such causes.

Failure Data Manufacturer data pertinent to the f ailure are as follows:

G.E. Magneblas t Breaker 1200 AMP Type:

AM-4.16-2 50-7H GEI-88761E i

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