ML19242A081
| ML19242A081 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 07/02/1979 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Cavanaugh W ARKANSAS POWER & LIGHT CO. |
| References | |
| NUDOCS 7907310207 | |
| Download: ML19242A081 (1) | |
Text
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July 2, 1974 Docket Nos.
50-313 50-368 Arkansas Power and Light Conpany ATTN:
Mr. Williac Cavanaugh III Vice President of Generation and Construction P. O. Box 551 Little Rock, Arkansas 72203 Gentlemen:
The enclosed IE Bulletin 79-14 is forwarded to you for ac* ion. Writtea responses are required.
If you desire additional information regarding this matter, please contact this office.
Sincerely,
[
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U Karl V.
Seyfri Director
Enclosures:
1.
List of IE Bulletins Issued in Last Twelve Months James P. O'Hanlon, Plant Manager cc:
Arkansas Nuclear One P. O. Box 608 Russellville, Arkansas 72801 L. Alexander, QC Supervisor 7 90 7310 e 07 1
UNI'IED STATES NUCLEAR REGULATORY CO?DlISSION WASill NGTON,
D.C.
20555 IE Bulletin No. 79-14 Date.
July 2, 1979 Page 1 of 3 SEISMIC ANALYSES FOR AS-BUILT SAFETY-RELATED PIPING SYSTEilS 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 was sent to all power reactor licen.saes.
The other issue involves the accuracy of the information input for seismic analyses.
In this regard, several potentially unconservative factors 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.
Nonconformances are identified in Appendix A to this bulletin.
Because apparently significant non-conformances to design documents have occurred in a nun ber of plants, this issua 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 essenttal for these documents to reflect as-built con-figuratians.
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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