ML17056B847

Discusses Results of Ultrasonic Insp of Facility High Pressure Core Spray Nozzle Safe End to Safe End Extension Weld.Proposals to Restart Facility W/O Repairing Weld KC-32 Acceptable

ML17056B847
Person / Time
Site:	Nine Mile Point
Issue date:	05/06/1992
From:	Menning J Office of Nuclear Reactor Regulation
To:	Sylvia B NIAGARA MOHAWK POWER CORP.
References
NUDOCS 9205210232
Download: ML17056B847 (12)

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Docket No. 50-410 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHlNGTON, D.C. 20555 Hay 6, 1992 Hr. B. Ralph Sylvia Executive Vice President, Nuclear Niagara Mohawk Power Corporation 301 Plainfield Road

Syracuse, New York 13211

SUBJECT:

RESULTS OF ULTRASONIC INSPECTION OF NINE MILE POINT NUCLEAR STATION UNIT 2 HIGH PRESSURE CORE SPRAY NOZZLE SAFE END TO SAFE END EXTENSION WELD (TAC NO. M83240)

By letter dated March 3,

1992, Niagara Mohawk Power Corporation (NMPC) submitted for NRC staff review and approval ultrasonic inspection (UT) acceptance criteria and a proposed revision to the previously-approved repair procedure for the flaw in the weld (KC-32) joining the high pressure core spray nozzle safe end to safe end extension at Nine Mile Point Unit 2 (NHP-2).

The submittal applied to the UT and possible repair of this flaw during the second refueling outage which began on March 4, 1992.

The NRC staff approved NHPC's proposed UT acceptance criteria subject to certain conditions in a letter dated March 30, 1992.

Approval of the acceptance criteria was contingent upon NMPC's commitment to replace the safe end extension during the third refueling outage.

Additionally, UT results were to be submitted for NRC review and approval prior to resumption of NHP-2 operation.

The NRC letter of Harch 30, 1992, stated that the staff had not completed its review of NHPC's revised repair plan.

It was indicated at that time that a supplement to the safety evaluation would be provided if repair of the flaw was required subsequent to UT.

By letter dated April 24,

1992, NMPC submitted for NRC staff review and approval the results of the UT performed on weld KC-32 during the second refueling outage.

This inspection showed a depth of 0.25 inches (0.29t) and a

length of 3.3 inches (11.0X of weld circumference).

Acceptable flaw growth had been established as less than 10K of the depth or length of the original flaw size (i.e.,

ION of 0.41t or IOX of 11.3%).

Since the UT response of the flaw was well within the established limit for growth, NMPC proposed to restart NHP-2 without repairing the weld.

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Hr. B. Ralph Sylvia ofay 6, 1992 Additionally, since the UT showed no flaw growth, NHPC proposed that:

(1) no later than 3 months prior to exceeding 9700 hours0.112 days <br />2.694 hours <br />0.016 weeks <br />0.00369 months <br /> of operation in Cycle 3 it would submit its justification for continuing to operate the unit through to the third refueling outage, or (2) it would repair or replace the weld prior to exceeding 9700 hours0.112 days <br />2.694 hours <br />0.016 weeks <br />0.00369 months <br /> of operations in Cycle 3.

The NHPC submittal of April 24, 1992, further stated that the weld would be repaired or replaced during the third refueling outage if it is not repaired or replaced during Cycle 3.

In a subsequent telephone conversation, with Hr. David Baker of your staff on Hay 1, 1992, to clarify this latter point, the NRC staff confirmed that if the unit operates through to the third refueling outage NHPC would replace the safe end extension rather than repair the weld.

The NRC staff has completed its review of the NHPC submittal of April 24, 1992.

We have concluded that the NHPC proposals to restart NHP-2 without repairing weld KC-32 and for operations up to 9700 hours0.112 days <br />2.694 hours <br />0.016 weeks <br />0.00369 months <br /> during Cycle 3 are acceptable since they are consistent with the UT acceptance criteria approved in our letter of Harch 30, 1992.

Sincerely, cc:

See next page John E. Henning, Project Hanager Project Directorate I-1 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation

\\

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

2 CC:

Hark J. Wetterhahn, Esquire Winston L Strawn 1400 L Street, NW.

Washington, DC 20005-3502 Hr. Richard Goldsmith Syracuse University College of Law

. E. I. White Hall Campus

Syracuse, New York 12223 Resident Inspector Nine Mile Point Nuclear Station P. 0.

Box 126

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

Syracuse, New York 13202 Hr. David K. Greene Manager Licensing Niagara Mohawk Power Corporation 301 Plainfield Road

Syracuse, New York 13212 Hs.

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

Albany, New York 12223 Supervisor Town of Scriba Route 8, Box 382

Oswego, New York 13126 Regional Administrator, Region I U. S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Charles Donaldson, Esquire Assistant Attorney General New York Department of Law 120 Broadway New York, New York 10271 Hr. Richard M. Kessel Chair and Executive Director State Consumer Protection Board 99 Washington Avenue

Albany, New York 12210 Hr. Hartin J.

HcCormick Jr.

Plant Manager, Unit 2 Nine Mile Point Nuclear Station Niagara Mohawk Power Corporation P. 0.

Box 32

Lycoming, New York 13093 Mr. Joseph F. Firlit Vice President - Nuclear Generation Nine Mile Point Nuclear Station Niagara Mohawk Power Corporation P. 0.

Box 32

Lycoming, New York 13093

I

Mr. B. Ralph Sylvia 1fay 6, 1992 Additionally, since the UT showed no flaw growth, NMPC proposed that:

(1) no later than 3 months prior to exceeding 9700 hours0.112 days <br />2.694 hours <br />0.016 weeks <br />0.00369 months <br /> of operation in Cycle 3 it would submit its justification for continuing to operate the unit through to the third refueling out'age, or (2) it would repair or replace the weld prior to exceeding 9700 hours0.112 days <br />2.694 hours <br />0.016 weeks <br />0.00369 months <br /> of operations in Cycle 3.

The NHPC submittal of April 24, 1992, further stated that the weld would be repaired or replaced during the third refueling outage if it is not repaired or replaced during Cycle 3.

In a subsequent telephone conversation, with Hr. David Baker of your staff on Hay 1, 1992, to clarify this latter point, the NRC staff confirmed that if the unit operates through to the third refueling outage NHPC would replace the safe end extension rather than repair the weld.

The NRC staff has completed its review of the NHPC submittal of April 24, 1992.

We have concluded that the NMPC proposals to restart NMP-2 without repairing weld KC-32 and for operations up to 9700 hours0.112 days <br />2.694 hours <br />0.016 weeks <br />0.00369 months <br /> during Cycle 3 are acceptable since they are consistent with the UT acceptance criteria approved in our letter of March 30, 1992.

Sincerely, Original Signed By John E. Henning, Project Manager Project Directorate I-l Division of Reactor Projects I/II Office of Nuclear Reactor Regulation cc:

See next page DISTRIBUTION:

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Hr. B. Ralph Sylvia ditionally, since the UT showed no flaw growth, NHPC proposed that:

(1) no la er than 3 months 'prior to exceeding 9700'hours of operation in Cycle 3 it wou submit its justification for continuing to operate the unit through to the ird refueling outage, or,(2) it would repair or replace the weld prior to exc eding, 9700 hours0.112 days <br />2.694 hours <br />0.016 weeks <br />0.00369 months <br /> of operations in Cycle 3.

The NHPC submittal of April 24, 199 further stated that the weld would be repaired or replaced during the thir refueling outage if it is not repaired or replaced during Cycle 3.

In a subse uent telephone conversation to clarify this latter point with Hr. David B ker of your staff on Hay 1, 1992, the NRC staff confirmed that if the unit ope tes through to the third refueling outage NHPC would replace the safe end exte ion rather than repair the weld.

The NRC staff ha completed its review of the NHPC submittal of April 24, 1992.

We have co luded that the NMPC proposals to restart NMP-2 without repairing weld KC-and for operations up to 9700 hours0.112 days <br />2.694 hours <br />0.016 weeks <br />0.00369 months <br /> during Cycle 3 are acceptable since the are consistent with the UT acceptance criteria approved in our letter of Hare 30, 1992.

Sincerely, John E. Henning, Project Manager Project Directorate I-1 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation cc:

See next page DISTR IBUTION:

Docket File NRC 5 Local PDRs PDI-1 Reading SAVarga JACalvo RACapra CSVogan JEHenning

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JWiggins, 7D4

WKoo, 7D4 OGC ACRS (10)

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Hr. B. Ralph Sylvia Addi ionally, since the UT showed no flaw growth, NHPC proposed to either (1) submit justification for continuing operation until the third refueling outage three m

ths prior to exceeding 9700 hours0.112 days <br />2.694 hours <br />0.016 weeks <br />0.00369 months <br /> of operation in Cycle 3 or (2) repair or replace the weld prior to exceeding 9700 hours0.112 days <br />2.694 hours <br />0.016 weeks <br />0.00369 months <br /> of operation.

The NHPC submi al of April 24, 1992, further stated that the weld would be repaired or eplaced during the third refueling outage if it is not repaired or replaced d

ing Cycle 3.

In a subsequent telephone conversation with Hr. David Baker of your staff on May. 1, 1992, the NRC staff confirmed that NHPC intends to place the safe end extension during the third refueling outage.

The NRC staff has corn leted its review of the NHPC submittal of April 24, 1992.

We have conclud that the NHPC proposals to restart NHP-2 without repairing weld K-32 and r operations during Cycle 3 are acceptable since they are consistent with e

UT acceptance criteria approved in our letter of March 30, 1992.

Sincerely, John E. Henning Project Manager roject Directorate I-1

'vision of Reactor Projects I/II 0

ice of Nuclear Reactor Regulation cc:

See next page DISTRIBUTION:

Docket Fi1 e NRC 5 Local PDRs PDI-1 Reading SAVarga JACalvo RACapra CSVogan JEHenning

JTsao, 7D4

JWiggins, 7D4

WKoo, 7D4 OGC ACRS (10)

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