ML20198F260
| ML20198F260 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 10/30/1985 |
| From: | Mangan C NIAGARA MOHAWK POWER CORP. |
| To: | Starostecki R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| (55(E)85-28), (NMP2L-0522), (NMP2L-522), NUDOCS 8511140305 | |
| Download: ML20198F260 (2) | |
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i M Y NIAGARA RUMOHAWK 5
NIAGARA MOHAWK POWER CORPORATION /300 ERIE BOULEVARD WEST, SYRACUSE, N Y.13202/ TELEPHONE (315) 4741511 October 30, 1985 (NMP2L 0522)
Mr. R. W. Starostecki, Director U.S. Nuclear Regulatory Comission Region I Division of Reactor Projects 631 Park Avenue King of Prussia, PA 19406 Re: Nine Mile Point - Unit 2 Docket No. 5-410
Dear Mr. Starostecki:
Enclosed is an interim report in accordance with 10CFR50.55(e) for the problem concerning Gould Service Water Pumps - Motor Holddown Bolts.
This problem was reported via tel-con to J. Stair of your staff on September 30, 1985 Very truly yours, M14/b.1dA\\
C. V. Mangan b Senior Vice President CVM/GG/cla (1294H) xc: Director of Inspection and Enforcement U.S. Nuclear Regulatory Comission Washington, DC 20555 R. A. Gram, NRC Senior Resident Inspector 8511140305 851030 PDR ADOCK 05000410 S
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NIAGARA M0 HAWK POWR CORPOR/. TION l
NINE MILE POINT - UNIT 2 j
DOCKET NO. 50-410 f
Interim Report for a Problem Concerning Gould Service Water Pumps Motor Holddown Bolts (55(e)85-28) 4 i
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Description of the Problem 1
i A review of the 2SWP*P1A-F motor hold-down bolts identified a potential overstress condition in the threads of these bolts due to insufficient thread
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engagement with the pump assembly baseplate.
The thread engagement is less j
than that expected based on calculations made from measurements in the field.
1 If the bolts with the actual measured thread engagement and pretorqued as j
specified were to experience the design load, the bolt threads could fail in shear.
Wi th the bolt threads stripped, the motor would not be held down 4
i properly with the possible consequence of pump / motor misalignment and risk to the operability of the pump.
The service water pumps provide cooling water to l
safety-related components, and their loss could adverseiy affect the safety of j
operations of the plant.
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Motor hold-down bolts on all six service water pumps will be checked to 1
determine if a similar problem exists.
The result of this investigation and an analysis of the safety inplications will be submitted in a final report by j
January 3,1986 i
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