ML19207A961

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Responds to IE Bulletin 79-11 Re Westinghouse Type DB-50 & DB-75 Circuit Breakers.Circuit Breakers Are Not in Use in safety-related Sys
ML19207A961
Person / Time
Site: Shoreham File:Long Island Lighting Company icon.png
Issue date: 07/27/1979
From: Novarro J
LONG ISLAND LIGHTING CO.
To: Grier B
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
SNRC-409, NUDOCS 7908230095
Download: ML19207A961 (1)


Text

72 LONG ISLAND LIGHTING COM PANY

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SHOREHAM NUCLEAR POWER STATION 4.

afawasuf EO. BOX G10, NORTH COUNTRY RO AD e WADING RIVER, N.Y.11792 July 27, 1979 SNRC-409 Mr. Boyce 11. Grier Office of Inspection & Enforcement Region 1 U.S.

Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 l

l Long Island Lighting Company Shoreham Huclear Power Station - Unit 1 Docket No. 50-322 l

l

Dear Mr. Grier:

l I

dRC Inspection & Enforcement Bulletion No. 79-11, dated May 22, 1979, requires that we determine whether Westinghouse Type DB-50 or Type DB-75 circuit breakers with over cucrent trip devices are I

used in safety-related Class IE systems at the Shoreham Nuclear Plant.

The need for this review originated in a Licensee Event Report which noted that during surveillance testing the overcur-rent trip time for these devices had been found to have drifted from the manufacturer's design minimum of 6 seconds to 5.50 and 5.12 seconds.

Subsequent visual inspections revealed hairline I

crachc in the dachpot end caps of the devices, which the manu-facturer later attributed to a raw material batch problem.

I Our survey has determined that Westinghouse Type DB circuit breakers have not been directly purchased for use in safety-related systems at Shoreham, nor have they been employed in any safety-related equipment supplied to us by other manufacturers.

Accordingly, no further action is required by us with regard to this bulletin.

I V

y huly yours,

tW@

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Nov rro

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Project hanager Shoreham Nuclear Power Station GKP : j m cc:

Mr. Victor Stello, Director Office of Inspection & Enforcement 7908230 @ f F C 8935