ML20203A489
| ML20203A489 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 06/09/1986 |
| From: | Mangan C NIAGARA MOHAWK POWER CORP. |
| To: | Starostecki R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| (NMP2L-0738), (NMP2L-738), IEB-86-001, IEB-86-1, NUDOCS 8607170255 | |
| Download: ML20203A489 (3) | |
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1 Y NIAGARA NUMOHAWK NIAGARA MOHAWK POWER CORPOAATION/300 ERIE BOULEVARD WEST, SYRACUSE, N.Y.13202/ TELEPHONE (315) 474-1511 June 9, 1986 (NMP2L 0738)
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:
Per I.E.Bulletin 86-01, Niagara Mohawk has reviewed the Nine Mile Point Unit 2 Residual Heat Removal System and Emergency Core Cooling System for the potential problem identified in the Bulletin.
The conclusion of this review is that the potential problem does not exist for the Nine Mile Point Unit 2 design.
The Nine Mile Point Unit 2 Emergency Core Cooling / Residual Heat Removal systems consist of three electrically separate divisions. Division I consists of Residual Heat Removal pump A and Low Pressure Core Spray. Division 2 consists of Residual Heat Removal pumps B and C.
Division 3 consists of High Pressure Core Spray.
Each pump has its own minimum flow valve and dedicated ficw sens'ag instrumentation.
However, the minimum flow lines for the Division 1 pumps join and utilize a common, normally open (remote manual) motor operated valve in the return line to the suppression pool.
The Division 2 pumps also utilize a normally open common return line. The High Pressure Core Spray pump minimum flow system is completely independent of Division I and 2 minimum flow systems.
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' Mr. R. W. Starostecki
.Page 2 Therefore, the single failure of any component could not cause the failure of more than a single division, leaving the other two divisions available to mitigate any design basis accident.
Very truly yours, C. V. Mangan Senior Vice President AFZ:ja 1696G xc: Director of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 R. A. Gramm, Resident Inspector Project File (2) i f
i UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of
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Niagara Mohawk Power Corporation
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Docket No. 50-410 (Nine Mlle Point Unit 2)
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AFFIDAVIT C. V. Mangan
, being duly sworn, states that he is Senior Vice President of Niagara Mohawk Power Corporation; that he is authorized on the part of said Corporation to sign and file with the Nuclear Regulatory Commission the documents attached hereto; and that all such documents are true and correct to the best of his knowledge, information and belief.
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