ML20072H403
| ML20072H403 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 03/16/1983 |
| From: | Manno S NIAGARA MOHAWK POWER CORP. |
| To: | Starostecki R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8303290427 | |
| Download: ML20072H403 (2) | |
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- s M Y NIAGARA nUMOHAWK NIAGARA RIONAWK POWER CORPORATION /3OO ERIE BoVLEVARo WEST, SYRACUSE, N.Y.13202/ TELEPHONE (315) 474-1511 SAMUEL F. MANNO VICE PRC, IDENT S
N'UCLE AR CCNSTRUCTION March 16, 1983 Mr. R. W. Starostecki, Director U.S. Nuclear Regulatory Connission Region I Division of Project and Resident Programs 631 Park Avenue King of Prussia, PA 19406 Re: Nine Mile Point Unit 2 Docket No. 50-410
Dear Mr. Starostecki:
Enclosed is a final report in accordance with 10CFR50.55(e) for the problem regarding T-quencher holes. This condition was reported via telephone to Mr. Wiggins of your staff on July 29, 1982. An interim report on this matter was submitted to you with my letter dated August 25, 1982.
Very truly yours, S. F.' Manno Vice President Nuclear Construction xc: Director of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 Mr. R. D. Schulz, Resident Inspector 4
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NIAGARA M0 HAWK POWER CORPORATION NINE MILE POINT - UNIT 2 DOCKET NO. 50-410 Final Report for the Problem Concerning T-Quencher Holes Description of the Problem ITT Grinnell Industrial Piping Incorporated informed Stone & Webster Engineering Corporation by submitting fabrication nonconformance reports that T-quencher diffusion holes had been drilled out of tolerance on five T-q uenchers. Due to the identified nonconfomances, Stone & Webster Engineering Corporation investigated the problem and subsequently asked ITT Grinnell for further infonration on the 10 previously shipped T-quenchers. At that point, ITT Grinnell disclosed that a 100-percent dimensional check on the T-quenchers had not been perfonned, and documentation to substantiate that all the as-built dimensions conform to the tolerances set forth in the specification could not be provided.
Analysis of Safety Implications ITT Grinnell has since performed a 100-percent dimensional check of all 18 T-quenchers to be used at Nine Mile Point - Unit 2.
These as-built dimensions were submitted to Kraftwerk Union, designer of the T-quenchers, for eval uati on. Kraf twerk Union has determined that the as-built T-quencher hole diameters have no effect on the load definition in the suppression pool wall boundary and condensation perfonnance. However, due to asymetric loading within the hole patterns of the T-quencher arms, Kraftwerk Union had requested that Stone & Webster Engineering Corporation reanalyze the T-quencher for a 10-percent increase in mechanical loads.
Stone & Webster Engineering Corporation has reanalyzed the T-quencher for the increased load and has determined that the stresses are still within the ASME code allowables.
Therefore, if this condition were to have remained uncorrected, it would not have adversely affected the safe operation of the plant.