ML19340E121

Initial Interim Deficiency Rept Re Seismic Calculations for Category I Structures.Calculations,Drawings & Other Design Considerations Will Be Corrected as Required.Next Interim Rept Will Be Issued by 810622

ML19340E121
Person / Time
Site:	Beaver Valley
Issue date:	01/02/1981
From:	Woolever E DUQUESNE LIGHT CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
2DLC-3874, 80-07, 80-7, NUDOCS 8101060458
Download: ML19340E121 (2)

Text

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s: s n January , 1981 L

N United States Nuclear Regulatory Commission Region I 601 Park Avenue King of Prussia, PA 19405 ATTENTION: MR. BOYCE H. GRIER, DIRECTOR

SUBJECT:

Beaver Valley Power Station-Unit No. 2 Docket No. 50-412 Seismic Calculations for Category I Structures Significant Deficiency Report 30-07 Ge n tlemt. :

Enclosed is the " Initial Interim Report" on the tbove subject.

If you have any questions concerning this report, we are available to meet with Nuclear Regulatory Comnission personnel at their convenience.

DUQUESNE LIGHT COMPANY By 'd

([,/ J5 Woolever VICE PRESIDENT cc: Dr. V. Stello (15) 3101060 yg

i 1

l Initial Interim Report 9"

Seismic Calculations for Category I Structures at Beaver Valley Power Station - Unit No. 2 1.0 Summary A review of seismic calculations for the Auxiliary Building (Category I) of Millstone Unit No. 3 has shown that the analysis used to design the portions of the structure transferring horizontal seismic forces down through the structure to the mat was incomplete.

Beaver Valley Power Station-Unit 2 has used similar design methods for analysis of the following Category I structures:

Auxiliary Building, Control Room Extension and Valve Pit, Service Building, Main Steam and Cable Vault Area, Fuel and Decontamination j Building, Safeguards Building, and the Diesel Generator Building.

2.0 Immediate Action Taken An initial review of the calculations of the above structures was performed and indicates that there is no structural deficiency in the design of the structures. The detailed review and completion of Auxiliary Building seismic calculations is finished and the structure has been found adequate. The completion of such calculations for the other structures listed above has been initiated and is scheduled for completion by December 1981.

3.0 Description of Deficiency The analysis used to design the portions of the structure transferring horizontal seismic forces down through the structure to the mat was incomplete to the extent that the cumulative effect of the vertical force couple resisting flexure was not carried down through the structure to the mat, although the analysis used to design the mat did consider this cumulative ef fect.

l 4.0 Analysis of Safety Implications Analysis of safety implications will be provided in the final report.

l 5.0 Corrective Action to Remedy Deficiency l

I Pending the outcome of the detailed review of the seismic calculations of the Category I structures listed above, the calculations, drawings and any other design considerations will be corrected as required.

! 6.0 Additional Reports l

l An interim report will be issued on June 22, 1981. The date l for the submittal of the final report will be indicated at that i

time.

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