ML20087D338

Interim Deficiency Rept Re Hydrostatic Uplift Pressure Not Considered in Reactor Bldg Mat Design.Initially Reported on 840130.Final Rept Will Be Submitted by 840518

ML20087D338
Person / Time
Site:	Nine Mile Point
Issue date:	02/29/1984
From:	Mangan C NIAGARA MOHAWK POWER CORP.
To:	Starostecki R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
(8114), NUDOCS 8403130363
Download: ML20087D338 (2)

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M V NIAGARA RuMOHAWK NIAGARA MOHAWK POWER CORPORATION /300 ERIE BOULEVARD WEST, SYRACUSE, N.Y.13202/ TELEPHONE (315) 474-1511 February 29, 1984 (8114) l Mr. R. W. Starostecki, Director U.S. Nuclear Regulatory Concission 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 an interim 30-day report in accordance with 10CFR50.55(e) for the problem concerning hydrostatic uplift pressure in the reactor building mat design (55(e) 04). This problem was reported via telecon to S. Collins of your staff on January 30, 1984.

Very truly yours, C. V.Mangarv

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Vice President Nuclear Engineering & Licensirg CVM/TL:ja Enclosure xc: Director of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 8403130363 840229 PDR ADOCK 05000410 S PDR 1

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NIAGARA M0 HAWK POWER CORPORATION NINE MILE POINT UNIT 2 DOCKET NO. 50-410 Interim 30-Day Report for a Problem Concerning Reactor Building Mat Design (55(e) 04)

Description of the Problem The reactor building mat design did not consider hydrostataic uplift pressure because at the time it was believed that this pressure would not exist due to the mat drainage system. However, during final design verification of the mat, it was concluded that since the drainage pumps are non-Category I, the hydrostatic uplift pressure should be included in the mat design. This problem is still under investigation. A final report will be submitted by May 18, 1984.

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