ML17056B965

Forwards Safety Evaluation Re Proposed Deferment of Facility Torus Mod.Requests Periodic Repts Containing Results of Monitoring Programs 60 Days After Completion of Each Insp

ML17056B965
Person / Time
Site:	Nine Mile Point
Issue date:	08/25/1992
From:	Brinkman D Office of Nuclear Reactor Regulation
To:	Sylvia B NIAGARA MOHAWK POWER CORP.
Shared Package
ML17056B966	List: ML17056B965 ML17056B967
References
TAC-M80214, NUDOCS 9209010069
Download: ML17056B965 (6)

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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555 August 25, 1992 Docket No. 50-220 Mr. B. Ralph Sylvia Executive Vice President, Nuclear Niagara Mohawk Power Corporation 301 Plainfield Road

Syracuse, New York 13212

SUBJECT:

PROPOSED DEFERMENT OF NINE MILE POINT NUCLEAR STATION UNIT NO.

1 TORUS MODIFICATIONS (TAC NO. H80214)

By letter dated Hay 14,

1991, Niagara Mohawk Power Corporation (NMPC) submitted an analysis which proposed to allow a reduction in the condensation oscillation loads applied to the Nine Mile Point Unit No.

1 torus during a

LOCA or during actuation of the safety/relief valves.

NRC staff acceptance of these reduced loads would allow NHPC to defer, until approximately

2007, implementation of torus modifications currently scheduled for implementation during the next refueling outage (currently scheduled to begin in January 1993).

Supplemental information, which was submitted in response to NRC staff requests for additional information, was provided in NMPC letters dated August 29,

1991, September 27,

1991, October 17,

1991, December 13, 1991'two submittals),

and January 17, 1992.

The NRC staff and its consultant, Brookhaven National Laboratory, have completed the requested review and have concluded that the proposed reduction in condensation oscillation loads on the torus shell is acceptable and this reduced load will produce a sufficient reduction in shell stresses such that code allowable stress in the torus shell will not be exceeded until the average thickness (within the provisions of Section NE-3213. 10 of the 1977 Edition, including the Summer 1977 Addenda, of the ASME Code) of the torus shell is reduced to less than 0.431 inches.

To provide assurance that the average wall thickness of the torus shell is not reduced to less than 0.431

inches, Niagara Mohawk is requested to commit to and perform the monitoring programs described in our attached safety evaluation.

This commitment should be provided in writing within 30 days of receipt of this letter.

NHPC is also requested to submit to the NRC periodic reports containing the results of the above requested monitoring programs.

These reports shall be submitted within approximately 60 days after the completion of each inspection.

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Hr. B. Ralph Sylvia August 25, 1992 This requirement affects one respondent and, therefore, is not subject to Office of Hanagement and Budget review under P.L.96-511.

Sincerely,

Enclosure:

Safety Evaluation cc w/enclosure:

See next page Donald S. Brinkman, Senior Project Hanager Project Directorate I-1 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation

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Mr. B. Ralph Sylvia Niagara Mohawk Power Corporation Nine Mile Point Nuclear Station Unit No.

1 CC Mark J. Wetterhahn, Esquire Winston

& Strawn 1400 L Street, NW Washington, DC 20005-3502 Supervisor Town of Scriba Route 8, Box 382

Oswego, New York 13126 Mr. Neil S.

Cams Vice President - Nuclear Generation Niagara Mohawk Power Corporation Nine Mile Point Nuclear Station Post Office Box 32

Lycoming, New York 13093 Resident Inspector U.S. Nuclear Regulatory Commission Post Office Box 126

Lycoming, New York 13093 Gary D. Wilson, Esquire Niagara Mohawk Power Corporation 300 Erie Boulevard West

Syracuse, New York 13202 Regional Administrator, Region I

U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, Pennsylvania 19406 Ms.

Donna Ross New York State Energy Office 2 Empire State Plaza 16th Floor

Albany, New York 12223 Hr. Kim Dahlberg Unit 1 Station Superintendent Nine Mile Point Nuclear Station Post Office Box 32

Lycoming, New York 13093 Hr. David K. Greene Manager Licensing Niagara Mohawk Power Corporation 301 Plainfield Road

Syracuse, New York 13212 Charles Donaldson, Esquire Assistant Attorney General New York Department of Law 120 Broadway New York, New York 10271 Hr. Paul D.

Eddy State of New York Department of Public Service Power Division, System Operations 3 Empire State Plaza

Albany, New York 12223