ML19247A383
| ML19247A383 | |
| Person / Time | |
|---|---|
| Site: | Atlantic Nuclear Power Plant  |
| Issue date: | 07/02/1979 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Collier A OFFSHORE POWER SYSTEMS (SUBS. OF WESTINGHOUSE ELECTRI |
| References | |
| NUDOCS 7907310282 | |
| Download: ML19247A383 (3) | |
Text
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UNITED ST ATES
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jul 2 1979 In Reply Refer To:
RII:JPO 50-437 Of fshore Power Systems ATTN:
A. R. Collier, President P. O. Box 8000 Jacksonville, FL 32211 Centlemen:
Written responses The enciesed Bulletin 79-14 is forwarded to you for action.
addiciaul inf ormation regarding this matter, please are required.
If yv. d? ire coatact this office.
Sincerely, Q}Nnn' A James P. O'Reilly t
Director
Enclosure:
1.
Listing of IE Bulletins Issued In Last Twelve Months
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20555 July 2, 1979 IE Bulletin No. 79-14 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 sumation of loads in so:se 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) 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 nonconformar~s to design documents which could potentially affect the validity of seisets 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 inrormation 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 dccuments from which seismic analysis input information was obtained, the licensee must consider the need to re-evaluate the seismic analyses to con-tider 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 safetyrelated pipirg systems. The safety related piping includes Seismic Category I systems as defined by Regulatory Guide 1.29, " Seismic Design Classification" Revision 1, dated August 1,1973 or as defined in the applicable FSAR.
For older plants. where Seismic Cateenrv T reonire.
ments did not exist at the time of lick ['"~""
actual configuration of these safety-r
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