ML20084C151

Supplemental RO-76-21:on 760819,two Control Rods Dropped. Westinghouse Recommendations for Cause Later Determined Not to Be Actual Cause.New Recommendations to Be Carried Out During Next Refueling Outage

ML20084C151
Person / Time
Site:	Ginna
Issue date:	12/21/1976
From:	White L ROCHESTER GAS & ELECTRIC CORP.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
RO-76-21, NUDOCS 8304070547
Download: ML20084C151 (1)

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R0(IIESTER CAS AND ELECTRIC CORPORATION e 89 EAST AVENUE, ROCliESTER, fl.y.14649 Leon o weert.;se v e i. e.-os, v.ca ears. >sen a.s a c ost A '.>.t o.2 700 - t* * '

December 21, 1976 -

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Mr. Jame's P. O'Reilly, Director '

h U. S. Nuclear Regulatory Commission t- h/g Office of Inspection and Enforcement .

Region I ~

631 Park Avenue King of Prussia, Pennsylvania 19406 *

Subject:

Supplemental Report on Reportable Occurrence 76-21, Drop of -

Two Control Rods R. E. Ginna Nuclear Power Plant, Unit No.1 Docket No. 50-244

Dear Mr. O'Reilly:

In the August 19, 1976 Reportable Occurrence LER 76-21/3L lt was stated that Westinghouse specialists assisted in the investigation of the problem with the 2BD power cabinet. Although no exact cause could be iden-tified at that time, Westinghouse provided further recommendations for con-sideration. All these proposals were reviewed by the Ginna Station I & C Group and the PORC. EWR-1646 was issued for design review and safety analysis by the RG&E Engineering Department for these proposals,-and they will be followed as conditions warrant.

Subsequently, the Westinghouse PWR Engineering Group has examined and tested the fuses and sampling resistors which had been removed and reported that only one fuse had any sign of deterioration. It was determined that this would not have caused the dropped rod problem. Further, the sampling resistors could not be faulted. Two new recommendations concerning the sampling resistors will be carried out during the next refueling outage.

CAR 1082, issued previously for the investigation of the dropped rods associated with the 2BD Power Cabinet, remains in effect.

Two additional copies of this letter are encbsed to conform to the original submittal of LER 76-21/3L.

Very truly yours, COPY SENT REGION-gdg,gg.

L. D. White , Jr. .

cc: Dr. Ernst Volgenau (30)

Mr. William G. Mcdonald (3) .

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