ML20010D663

Advises That NRC Has Decided to Discontinue Low Pressure Rotor Disc Insp Program.Recommends Util Perform Disc Insp & Work W/Ge to Establish Safe Insp Schedules & Rept Significant Degradation Promptly

ML20010D663
Person / Time
Site:	Nine Mile Point
Issue date:	08/21/1981
From:	Polk P Office of Nuclear Reactor Regulation
To:	Dise D NIAGARA MOHAWK POWER CORP.
References
NUDOCS 8108280475
Download: ML20010D663 (2)

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AUG 21 1981

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Docket No. 50-220

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\\ ', u.,,7?f$ej% %C jgg Mr. Donald P. Dise Vice President - Engineering N

c/o Miss Catherine R. Seibert h'/f

d. D Niagara Mohawk Power Coporation J

300 Erie Boulevard West Syracuse, New York 13202 N!l'8

Dear Mr. Dise:

In our letter of Hay 1980 we recommended that you initiate a program to inspect the keyway and bore areas of your low pressure turbine discs for stress corrosion cracking. This action was prompted by the discovery of such cracks in Westinghouse turbines.

So far, the inspection program has covered one or more low oressure rotors at 15 nuclear plants using GE turbines. No clear indicatior of stress corrosion cracking has been discovered, although indications of water cutting and/or erosion have been observed in several turbines.

i In view of these findings, we have decided to discontinue the HRR staff j

monitoring of these inspections. However, normal activities of the Office of Inspection and Enforcement will continue.

We recomend that you continue to perform disc inspections, as appropriate, and continue to work with Gener.'1 Electric Company to establish safe inspection schedules. Should 30u fird any significant degradation, such as stress corrosion cracking, we would expect you to promptly report it in the normal manner.

Sincerely, I

GRIGINE SIGNED BY Philip J. Polk,' Project Manager Operating Reactors Branch #2 Division of Licensing cc: See next page Distribution:

Docket File W. Ross J. Heltemes, AE00 NRC PDR S. Norris Local PDR-P. Polk ORB #2 Reading T. Ippolito D. Eisenhut NSIC 8108280475 810821 OELD TERA PDR ADOCK 05000220 OISE (3)

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Mr. Donald P. Dise cc:

Eugene B. Thomas, Jr., Esquire LeBoeuf Lamb, Leiby & MacRae 1333 New Hampshire Avenue, N. W.

Suite 1100 Washington, D. C.

20036 2

State University College at Oswego Penfield Library - Documents Oswego, New York 13126 Mr. Joseph J. Sunser, Manager System Security Niagara Mohawk Power Corporation (Securitymattersonly) 300. Erie Boulevard West Syracuse, New York 13202 Resident Inspector c/o U.S. NRC P. O. Box 126 Lycoming, New York 13093 I

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