ML20096G453
| ML20096G453 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 08/23/1984 |
| From: | Mangan C NIAGARA MOHAWK POWER CORP. |
| To: | Starostecki R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| (NMP21-0140), (NMP21-140), NUDOCS 8409110036 | |
| Download: ML20096G453 (2) | |
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NIAGARA MOHAWK POWER CORPORATION /300 ERIE BOULEVARD WEST SYRACUSE, N Y.13202/ TELEPHONE (315) 474-1511 August 23, 1984 (NMP2L 0140)
Mr. R. W. Starostecki, Director U.S. Nuclear Regulatory Commission Region I Division of Project and Resident Programs 631 Park Avenue King of Prussia, PA 19406 Re: Nine Mile Point Unit 2 Docket No. 50-410
Dear Mr. Starostecki:
Enclosed is an interim report in accordance with 10CFR50.55(e) for the problem concerning potentially unacceptable operation of General Electric SAM rel:ys. This problem was reported via telecon to S. Collins of your staff on July 23, 1984.
Very truly yours, Vice President Nuclear Engineering & Licensing NLR:ja Enclosure xc: Director of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 Project File (2) 8409110036 840823 PDR ADOCK 05000410 8
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r NIAGARA M0 HAWK POWER CORPORATION NINE MILE POINT UNIT 2 DOCKET NO. 50-410 Interim Report for a Problem Concerning the Misoperation of General Electric SAM Relays (55(e)-84-27)
Description of the Problem General Electric has advised Niagara Mohawk Power Corporation that it is possible for certain SAM relays (Mooel Nos. SAM 11, 13, 15 and certain SAM 99 special-relays) to operate in less than the set time delay if the initiating contact experiences a very specific mode of contact bounce.
In the Nine Mile Point Unit 2 design, these relays are used in various Category I switchgear lineup applications (e.g., load sequencing of emergency buses). These timing relays are used primarily to facilitate coordination of relays with other downstream protection.
In such applications, the time delay is critical.
The matter is still under investigation, and a final report will be submitted by November 15, 1984.
J
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