ML17059A392

Forwards SE Approving Util Request for Reduction Factors for Condensation Oscillation Loads in Plant

ML17059A392
Person / Time
Site:	Nine Mile Point
Issue date:	08/11/1994
From:	Brinkman D Office of Nuclear Reactor Regulation
To:	Sylvia R NIAGARA MOHAWK POWER CORP.
Shared Package
ML17059A393	List: ML17059A392 ML17059A394
References
TAC-M85003, NUDOCS 9408180080
Download: ML17059A392 (8)

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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 August 11, 1994 Docket No. 50-220 Hr. B. Ralph Sylvia Executive Vice President, Nuclear Niagara Mohawk Power Corporation Nine Mile Point Nuclear Station P.O.

Box 63

Lycoming, New York 13093

SUBJECT:

APPROVAL OF REDUCTION FACTORS FOR CONDENSATION OSCILLATION LOADS IN NINE NILE POINT NUCLEAR STATION UNIT NO.

1 (NMP1)

TORUS (TAC NO. H85003)

By letter dated Hay 14,

1991, Niagara Mohawk Power Corporation (NHPC) submitted for NRC staff review, NMPC's analysis for a proposed method which woul.d allow a reduction in the NHPl suppression pool (torus) hydrodynamic loads.

The NRC staff issued its safety evaluation (SE) on August 25,

1992, regarding NHPC's analysis.

However, by letter dated November 23,

1992, NHPC informed the NRC that NHPC had determined that our August 25, 1992, evaluation was inconsistent with NHPC's method of analysis.

Therefore, in its November 23, 1992, letter, NMPC requested the NRC to rereview NHPC's Hay 14,

1991, submittal in conjunction with additional information provided in a Teledyne Engineering Services Report submitted with the November 23, 1992, letter.

NMPC also proposed in its November 23, 1992, letter to continue operation of NMP1 for one more fuel cycle (until the 1995 refueling outage) without modifications to the NMPl torus.

The NRC staff agreed in a December 23, 1992,.letter that NHPC could continue to operate NHPl for one more fuel cycle.in accordance with our previously approved criteria (January 25,

1985, SE which required a minimum torus wall thickness of 0.447 inch) provided NHPC also performed the torus monitoring programs outlined in our August 25,

1992, SE.

The NRC staff and NHPC representatives conducted a meeting on Harch 23,

1993, (meeting summary dated April 9, 1993) in which the differences in analysis methodologies were discussed and in which the NRC staff agreed to perform the requested re-review.

The NRC staff; with assistance from its contractor, Brookhaven National Laboratory (BNL), has completed the requested rereview.

Based on the NRC staff's own rereview and the technical evaluation report (TER) by BNL, we have concluded that the proposed method for calculation of condensation oscillation load reduction is acceptable.

We have also concluded that the NHPl torus currently meets the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASHE Code) requirements and with the implementation of the corrosion monitoring programs described in the enclosed SE, we have

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Mr. B. Ralph Sylvia August 11, 1994 further determined that NMPC has provided sufficient justification for concluding that the torus will continue to meet the ASME Code requirements provided that the average minimum wall thickness of the torus shell is not reduced to less than 0.431 inch.

NMPC is requested to provide a written commitment to the proposed corrosion monitoring program described in the attached SE.

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

The requirement affects one respondent and, therefore, is not subject to Office of Management and Budget review under P.L.96-511.

A copy of our SE and BNL's TER is enclosed.

Sincerely,

Enclosures:

1.

Safety Evaluation 2.

Technical Evaluation Report cc w/enclosures:

See next page Donald S.

Brinkman, Senior Project Manager Project Directorate I-1 Division of Reactor Projects I/II Office of Nuclear Reactor Regulation

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Hr. B. Ralph Sylvia August 11, 1994 furth'er determined that NHPC has provided sufficient justification for concluding that the torus will continue to meet the ASHE Code requirements provided that the average minimum wall thickness of the torus shell is not reduced to less than 0.431 inch.

NHPC is requested to provide a written commitment to the proposed corrosion monitoring program described in the attached SE.

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

The requirement affects one respondent and, therefore, is not subject to Office of Hanagement and Budget review under P.L.96-511.

A copy of our SE and BNL's TER is enclosed.

Sincerely, QRlG1NAt. SlGNED BYz

Enclosures:

1.

Safety Evaluation 2.

Technical Evaluation Report i

cc w/enclosures:

See next page DISTRIBUTION:

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CCow ill, RGN-I Donald S. Brinkman, Senior Project Hanager Project Directorate I-1 Division of Reactor Projects I/II Office of Nuclear Reactor Regulation OFFLCE

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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. Louis F. Storz Vice President Nuclear Generation Niagara Mohawk Power Corporation Nine Mile Point Nuclear Station P.O.

Box 63 Lycomi'ng, New York 13093 Resident Inspector U.S. Nuclear Regulatory Commission P.O.

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. Richard B. Abbott Unit 1 Plant Manager Nine Mile Point Nuclear Station P.O.

Box 63

Lycoming, New York 13093 Hr. David K. Greene Manager Licensing Niagara Hohawk Power Corporation Nine Mile Point Nuclear Station P.O.

Box 63

Lycoming, New York 13093 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 Hr. Hartin J.

HcCormick, Jr.

Vice President Nuclear Safety Assessment and Support Niagara Hohawk Power Corporation Nine Mile Point Nuclear Station P.O.

Box 63

Lycoming, New York 13093

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