ML20062C174

Interim 30-day Deficiency Rept Re Failed Stud on Control Bldg Termination Cabinet Support Sills.Initialy Reported on 820615.Investigation Continuing.Final Rept Will Be Submitted by 820924

ML20062C174
Person / Time
Site:	Nine Mile Point
Issue date:	07/15/1982
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 8208050187
Download: ML20062C174 (2)

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Y NIAGARA NUMOHAWK i NIAGARA MOHAWK POWER CORPORATION /300 ER!E BOULEVARD WEST, SYRACUSE, N Y.13202/ TELEPHONE (315) 474-1511 July 15, 1982 U.S. Nuclear Regulatory Commission Region I Attention: Mr. R.W. Starostecki, Director Division of Project and Resident Programs 631 Park Avenue King of Prussia, PA 19406 Re: Nine Mile Point Unit 2 00_cket No. 50-410

Dear Mr. Starostecki:

Enclosed is an interim 30-day report in accordance with 10CFR50.55(e) for the potential deficiency regarding the control building termination cabinet support sills. This condition was reported by telephone to Mr. H. Kister of your staff on June 15, 1982, as a potentially reportable deficiency.

Very truly yours, NIAGARA MOHAWK POWER CORPORATION

/ .

Samuel F. Manno Vice President Nuclear Construction PEF:bd cc: Director of Inspection and Enforcement U.S. Nuclear Regulatory Commission Wa shington, D.C. 20555 Mr. R.D. Schulz, Resident Inspector 8208050187 820715 PDR ADOCK 05000410 6 PDR Y

i NIAGARA M0 HAWK POWER CORPORATION Nine Mile Point Unit 2 Docket No. 50-410 Interim Report for a Potentially Reportable Deficiency Under 10CFR50.55(e) Regarding The Control Building Termination  :

Cabinet Support Sills Description of the Deficiency The potential deficiency pertains to channels in the control building designed for use as embedded sills to support termination cabinets. These channels are located at elevation 288 feet 6 inches between column lines AC and AK.

The problem was discovered when a stud f ailed during torque testing of the studs welded on top of the channels. An investigation revealed that a C 6x8.2 channel was inadvertently installed instead of a C 6x13 channel as specified in the design.

SWEC's preliminary evaluation indicates that the C 6x8.2 channel may be overstressed when subjected to assumed maximum design loads. Though the loading used in designing the channels has yet to be confirmed by General Electric, the supplier of the termination cabinets, the termination cabinet loading assumed for the channel design represents SWEC's assessment of the upper bound.

This matter is still under investigation. A final report will be submitted by September 24, 1982.

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