ML17053B707
| ML17053B707 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 05/16/1980 |
| From: | Ippolito T Office of Nuclear Reactor Regulation |
| To: | Dise D NIAGARA MOHAWK POWER CORP. |
| References | |
| NUDOCS 8006200577 | |
| Download: ML17053B707 (6) | |
Text
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--tlS~N>VYMUKfHilt SPY MAY 1 6 1980 Docket No. 50-220 Hr. Donald P. Disc Vice President - Engineering c/o Hiss Catherine R. Seibert Niagara Mohawk Power Corporation 300 Erie Boulevard West
- Syracuse, New York 13202
Dear fir. Disc:
On December 28, 1979 the NRC Office of Inspection and Enforcement (IE) issued Information Notice No. 79-37 that discussed the discovery of cracks in the keyway and bore sections of discs in Westinghouse low-pressure turbines.
A copy of this Information Notice with an errata sheet is enclosed.
Subsequently, all licensee/
users of low-pressure turbines..-
manufactured by General Electric were invited to meet with-the NRC staff and representatives of the vendor on January 9,
1980 to di'scuss the probability of disc cracking in these turbines.
A summary, of this meeting and the General Electric Compare 's presentation are also enclosed with this letter.
CP O
CP O
Sp At the time of the January 9 meeting General Electric did not have any recent results of ultrasonic inspections of its low-pressure turbines.
Since that date full UT inspections have been performed on six rotors at five nuclear power plants.
Some indications in the keyway region have been reported in discs at three of these plants.
General Electric personnel believe that these indications were caused by water erosion rather than by stress corrosion-The staff'esires to learn rrore about the underlying reasons for the indications found and the probable rate of growth of these indications and their effects on turbine disc integrity.
For this purpose we request that you provide the information sought in Enclosure 3 to this letter and address its safety significance.
Under the provisions of 10 CFR 50.54(f) your response is requested within 30 days of the receipt of this letter.
A copy of this letter is being telecopied to you, along with Enclosure 3.
r It is my understanding that additional UT inspections are to be performed by General Electric in the-near future.
We encourage this action as being the only certain means of determining the integrity of turbine discs.
We also recommend that if you have not already done so, that you develop a
schedule for performing a full UT inspection of at least one of your low-ressure t hines u
n trna OFFICE/
SURNAME DATEP.
NRC FORM 318 (9.761 NRCM 0240 4 U.S. GOVERNMENT PRINTING OFFICE: 1979'289'369
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ttr. Donald P. Disc QY i 6 iSSO This request for generic information was approved by GAO under clearance number 8-180226
{S79014); this clearance expires June 30, 1980.
Sincerely, QgglR4I Slgnbd T,A,lp~
Thomas A. Ippolito, Chief Operating Reactors Branch 82 Division of Licensing Encl osures:
l.
Information Bul1etin 79-37 2.
Meeting Surrmary 3.
Information Requests cc n/o enclosures:
See next page Distribution Docket ORB g2
'ocal PDR HRC PDR NRR Reading TIppo1 ito SNorris Atty, OELD OI8IE (3)
TERA NSIC TERA PPolk OFFICE P SURNAME ORB g2 SN res 5/1g/80 ORB J PP
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2 TI ol i 5/igj80
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NRC FORM 318 {9 76) NRCM 0240 AU.S. GOVERNMENT PRINTING OFFICE! 1979 289 389
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Mr. Donald P. Disc Niagara Mohawk Power Corporation May 16, 1980 CC:
Eugene B. Thomas, Jr., Esquire LeBoeuf,.Lamb, Leiby 5 MacRae 1757 N Street, N.W.
Washington, D. C.
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