ML20011A252

Final Deficiency Rept Re Gilbert/Commonwealth Use of Deficient Steel Design Details for Small Bore Design Work, Initially Reported 810417.Typical Load Ratings Revised to Meet Code Requirements

ML20011A252
Person / Time
Site:	Columbia
Issue date:	09/23/1981
From:	Matlock R WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
10CFR-050.55E, 10CFR-50.55E, DEFE-810923, GO2-81-0137, GO2-81-137, NUDOCS 8110080373
Download: ML20011A252 (2)

Text

c' ' a Docket No. 50-397 4J 50.55(e) Report-Washington Public Power Supply System P.O. Box 968 3000GeorgeWashingtonWay Richland, Washington 99352 (509)372-5000 September 23, 1981 G02-81-0137 Docket No. 50-397 Mr. R.-H. Engelken U.S. Nuclear Regulate.y Commission Region V Suite 202, W'inut Creek Plaza 1990 North Casi.3rnia Boulevard Walnut Creek, California 94596

Subject:

SUPPLY SYSTEM NUCLEAR PROJECT NO. 2 10CFR50.55(e) POTENTIALLY REPORTABLE CONDITION #151 GILBERT COMMONWEALTH USE OF DEFICIENT STEEL DESIGN DETAILS FOR SMALL BORE DESIGN WORK In accordance with 10CFR50.55(e), your office was informed by telephone on April 17, 1981, of a potential reportable condition on steel design details for small bore design work. An interim report was sent on July 31, 1981. In this report we stated that Burns and Roe had completed its evaluation of the basic design criteria for all twenty-five (25) small diameter standard support details and confirmed that ten (10) out of twenty-five (25) details contained discrepancies.

The concern was raised that failure of these hangers could possibly constitute a "significant safety hazard" because the design was not to ASME Code.

This office has concluded that the hangers would not have failed under actual operating conditions. These hangers are designed using stress allowances which are significantly lower than the actual yield strength for the materials used. The incrcmental amounts by which these supports exceeded design criteria was minimal compared to the margin of conser-

.vation provided for by the ASME Code. The maximum load reduction for any of the typical supports was 40%. The typical load ratings had to be revised to meet Code requirements.

Although this condition represents a Code violation, it does not represent a significant safety deficiency and, therefore, is not reportable under 10CFR50.55(e), p

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The Project. Engineering Directive mentioned in the interim report

' (PED-0208-H-0129)'was issued on September 4, 1981, directing the L , contractor-to identity by hanger work number, where the discrepant

!^ small diameter support details were used and to provide revised designs-to the construction contractor for each hanger work number - -

i. with a discrepant. condition.

'This letter constitutes our final.repodt on the subject condition.

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Very truly yo" s,

$$$ {b,vtGcu ff;.A.'~G.Matlock

/ Program Director, WNP-2 RGM/SLN/kd cc: W.S. Chin, BPA - Site E. Beckett, NRC J.A. Forrest, burnstand Roe - HAPO.

N.D. Lewis,.NRC '

T.A. Mangehdorf, Bechtel - Site R.E. Snaith, Burns and Roe, NY

.V. Stello,.NRC A.D. Toth, NRC~- Site E. Wood, NRC

.WNP-2 Files 4