ML20063P390

Ro:On 820829,reactor Startup Conducted W/Inoperable Rod Worth Minimizer.Minimizer Failed Due to Defective Clock Drive Module in Slot 4J of CPM Unit,Damaging Several Components.All Damaged Components Replaced

ML20063P390
Person / Time
Site:	Oyster Creek
Issue date:	09/28/1982
From:	Fiedler P GENERAL PUBLIC UTILITIES CORP.
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
NUDOCS 8210130357
Download: ML20063P390 (2)

Text

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

September 28, 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 Reactor Start-Up with Inoperable Rod Worth Minimizer On August 29, 1982, a reactor start-up was conducted with the Rod Worth Minimizer (RWM) inoperable. The attachment to this letter fulfills the reporting requirements in accordance with Technical Specification 3 2.B.2.b.

If there are additional questions, please contact Mr. Michael Laggart of my staff at (609) 971-4643 Very truly yours, Peter B. Fiedler Vice President and Director Oyster Creek PBF:MWL:lse At tachment cc: NRC Resident Inspector Oyster Creek Nuclear Generating Station Forked River, NJ 08731 f 8210130357 020928 l

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ATTACHMENT INOPERABLE ROD WORTH MINIMIZER DURING REACTOR START-UP Start-Up Date:

August 29, 1982 Identification of Problem:

Failure to initiate Rod Worth Minimizer (RWM) prior to reactor start-up on 8/29/82.

Apparent Cause for Failure of RWM:

On August 28, 1982, the Instrument Department, while performing a surveillance check of the RWM, detected a short circuit in the voter interlock section of the output buffer. The short circuit was caused by a small electric fire in the output buffer display panel. The fire was initiated by a defective clock drive module in slot 4J of the CPU unit which damaged several components in the display panel.

Conduct of Start-Up in the Absence of RWM:

The purpose of the RWM is to provide procedural controls on limiting control rod worths of in-sequence control rods to less than 1.25% Delta K until reactor power reaches 10% of rated power.

Technical Specification 3 2.B.2.b allows one (1) start-up per calendar year with the RWM inoperable, provided a second licensed operator and a station nuclear engineer from the technical group verify that rod program is being followed.

During the August 29, 1982 start-up, a second licensed operator and a core engineer were present to verify that the rod program was followed to achieve 10% power. In addition, control rod pattern templates were used in lieu of the RWM. Instructions for using control rod pattern templates in lieu of the RWM are contained in Oyster Creek Procedure 218. These intructions were fully complied with during start-up.

Corrective Action:

All damaged components in the display panel were repaired. The clock drive module in slot 4J of the CPU unit was replaced. A preliminary sequence loading and initialization test has been succensfully completed. Final tests to insure operability of the RWM are presently being conducted.

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