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 4.

/ *afawasuf 08C@ SHOREHAM NUCLEAR POWER STATION 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@ l 1

. P. Nov rro 'y b g f//1 i Project hanager  !

Shoreham Nuclear Power Station GKP : j m cc: Mr. Victor Stello, Director Office of Inspection & Enforcement F C 8935 7908230 @ f