ML19246B862
| ML19246B862 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 07/02/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Tallman W PUBLIC SERVICE CO. OF NEW HAMPSHIRE |
| References | |
| NUDOCS 7907180818 | |
| Download: ML19246B862 (1) | |
Text
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631 PARK AVENUE KING Of PRUSSIA, PENNSYLVANI A 19406 Docket Nos. 50-443 JUL 2 mg 50-444 Public Service Company of New Hampshire ATTN:
Mr. W. C. Tallman Presidant 1000 Elm Street Manchester, New Hampshire 03105 Gentlemen:
The enclosed Bulletin 79-14 is forwarded to you for action. Written responses are required.
If you desire additional information regarding this matter, please contact this office.
Sincerely, m
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x Boyce H. Grier W irector
Enclosures:
1.
List of IE Bulletins Issued in Last 12 Months cc w/encls:
John D. Haseltine, Project Manager 79071808\\8' b. :w-. 1
ENCLOSURE 1 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C.
20555 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 issues were identified which can cause seismic analysis of safety-related piping systems to yield nonconservative results.
One issue involved algebraic summation of lo;Js 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 Bulletin 79-02 (pipe supports) aad /9-04 (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 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-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 as-built configuration.
Action to be taken by Licensees and Permit Holders:
All power reactor facility licensees and construction permit holders are requested to verify, unless verified to an equivalent degree within the last 12 months, that the seismic analysis applies to the actual configura-tion of safety-related piping systems.
The safety related piping includes Seismic Category I systems as defined by Regulatory Guide 1.29, "Sei,smic_ _. m i DUP ICATE DOCUMENT _
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