ML19256A147

RO 78-053/01P:on 781026 During Review of Stresscalculations for Safety Injection Piping Inside Containment,Errors in Piping Stress Analysis Were Discovered.Caused by Error in Hand Calculating Method

ML19256A147
Person / Time
Site:	Beaver Valley
Issue date:	10/27/1978
From:	Werling J DUQUESNE LIGHT CO.
To:
References
NUDOCS 7811030164
Download: ML19256A147 (1)

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7W DUQUESNELIGHTCOMPANY Beaver Valley Power Station

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Post Office Box 4

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Shippingport, PA 15077

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October 27,1978 BVPS: JAW:598 Beaver Valley Power Station, Onit No.1 Docket No. 50-334 License No. DPR-66 TR 78-53/01P Mr. B. H. Crier, Director of Regulation United States Nuclear Regulatory Consission

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631 Park Avenue ~ ~ " ~ ~ ~

King of Pruhia','lennsylvania 19406

Dear Mr. Crier:

In accordance with Technical specification 6.9.1.8.1, the following occurrence is reported. He report was discussed with Mr. D. R. Haverkamp and Mr. A. N. Fasano at 1630 hours0.0189 days <br />0.453 hours <br />0.0027 weeks <br />6.20215e-4 months <br /> on October 26,1978.

During a review by the Beaver Valley architect-engineer of stress calculations for the safety injection piping inside contain:nent, errors in the piping stress analysis were discovered. De errors resulted from an error in the hand-calculation method employed for the analysis. The stress levels have been recalculated and the levels exceed the allowable stress of ANSI B31.1,1967. However, since the recomputed stresses do not exceed the yield stress except in one case out of six flow paths, no loss of safety functions would have occurred, even under postulated accident conditions.

A review of a representative sa=pling of other lines of various sizes radii and locations inside the containment vill be performed to verify that the error in calculation for the safety injection system was unique for that systen. Newand/or

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edified pipe supports vill be installed to reduce the pipe stresses to within allowable stresses specified in the FSAR.

Any additional information vill be included in the follow-up report.

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Very truly yours, 4, i

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bv D 7.193 J ' l (c L/ Q J. A. Verling i Superintendent