ML19224D636

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Forwards IE Bulletin 79-14, Seismic Analysis for As-Built Safety-Related Piping Sys. Action Required
ML19224D636
Person / Time
Site: Trojan File:Portland General Electric icon.png
Issue date: 07/02/1979
From: Engelken R
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To: Goodwin C
PORTLAND GENERAL ELECTRIC CO.
References
TAC-12369, NUDOCS 7907130208
Download: ML19224D636 (1)


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SUIT E 202, V/ALNUT CRE E K PL AZA WALNUT CREE K, CAllFOHNI A 94396 July 2,1979 Docket rio. 50-344 Portland General Electric Company 121 S. W. Salr. con Street Portland, Oregon 97204 Attention:

Mr. Charles Goodwin Assistant Vice President Gentlemen:

The enclosed Sulletin 79-14 is foniarded to you for action.

Wri tten responses are required.

If you desire additional information regarding this matter, please contact this office.

Sincerely,

fha,
CC.-.

R. H. Engelken Director

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Enclosures:

1.

IE Bulletin rio. 79-14 with Appendix A 2.

Listing of IE Bulletins Issued in Last 12 Months cc w/ enclosures:

B. Withers, PGE F. Gaidos, PGE 369 088 7 9 0 713 0 +0S k

VillTED STATES tlVCLEAR REGULATORY COMMISSI0tl WASHIllGT0ll, D.C.

20555 July 2,1979 IE Bulletin t;o. 79-14 SEISMIC ATJALYSES FOR AS-BUILT SAFETY-RELATED PIPItiG SYSTEMS Description of Circumstances:

Recently two issues were identified which can cause seismic analysis of safety-related piping systems to yield nonconservative results.

One issue involved algebraic summation of loads in some seismic analyses.

This was addressed in show cause orders for Beaver Valley, Fitzpatrick, Maine Yankee and Surry.

It was also addressed in IE Bulletin 79-07 which wee-sent to all power reactor licensees.

The other issue involves the accuracy of the information input for seismic analyses.

In this regard, several potentially unconservative

ors were discovered and subsequently addressed in IE Bulletin 79-02 (pipe supports) and 79-04 (valve weights).

During resolution of these concerns, inspection by IE and by licensees of the as-built configuration of several piping systems revealed a number of nonconformances to design documents which could potentially affect the validity of seismic analyses.

tionconformances are identified in Appendix A to this bulletin.

Because apparently significant non-conformances to design documents have occurred in a number of plants, this issue is generic.

The staff has determined, where design specifications and drawings are used to obtain input information for seismic analysis of safety-related piping systems, that it is essential for these documents to reflect as-built con-figura tions.

Where subsequent use, damage or modifications affect the con-dition or configuration of safety-related piping systems as described in documents from which seismic analysis input information was obtained, the licensee must consider the need to re-evaluate the seismic analyses to con-sider the as-built configuration.

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