ML19242A083
| ML19242A083 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 07/02/1979 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Pilant J NEBRASKA PUBLIC POWER DISTRICT |
| References | |
| NUDOCS 7907310210 | |
| Download: ML19242A083 (1) | |
Text
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UNITED STATES pDR:}iQ 7
NUCLEAP REGULATORY COTAT.11SSION y 'p.,[. (q'[ h flEGION IV t,, 9%@.
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July 2, 1979 Docket No.
50-298 Nebraska Public Power District ATIN:
J. M. Pilant, Director Licensing & Quality Assurance Post of fice Bo:< 499 Columbus, Nebraska 68601 Centlemen:
The enclosed IE Eulletin 79-14 is forwarded to you for action. Uritten responses are required.
If you desire additional information regarding this matter, please contact this office.
Sincerely,
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Director
Enclosures:
1.
IE Bulletin No. 79-1-4 2.
List ot IE Bulletir.s Issued in Last Twelve Mcaths cc:
L. C. Lessor, Superintendent Cooper Nuclear Station Post Of fice Eo:< 98 Brown"ille, Nebraska 68321 90 7310210 462 25b r
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C.
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IE Bulletin No. 79-14 Date:
July 2, 1979 Page 1 of 3 SEISMIC ANALYSES FOR AS-BUILT SAFETY-RELATED PIPING SYSTEMS Description of Circumstances:
Recently two isiues 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 licensees.
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 Eulletin 79-02 (pipe supports) and 79-04 (valve weights).
During resolution of these conc-
- , inspection by IE and by licensees of the as-built configuration of se
- si tiping systems revealed a numbe. of nonconformances to design dot
+ui; which could potentially affect the validity of seismic analyses.
Nonceau...ances are identified in Appendix A to this bulletin.
Because apparently significant non-conformances to design dot 2ments have occurred in a number of plants, this issue is gener:c.
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 esscatial for these documents to reflect as-built con-figurations.
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 c.s-built configuration.
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