ML19246C184
| ML19246C184 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 06/21/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Boyer V PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| References | |
| NUDOCS 7907230695 | |
| Download: ML19246C184 (1) | |
Text
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'#[ y ) s, c;y(o,j NUCLEAR REGULATORY COMMISSION UNITED STATES
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631 PARK AVENUE KING OF PRUSSIA, PENNSYLVANIA 19406 Docket Nos. 50-352 21 JUN 1979 50-353 Philadelphia Electric Ccmpany Attention:
Mr. V. S. Boyer Vice P"esident Engineering and Research 2301 Market Street Philadelphia, Pennsylvania 19101 Gentlemen:
Enclosed is IE Bulletin No. 79-02 Revision No.1, which requires action by you with regard to your power reactor facility (ics) with an operating license or a construction permit.
Should you have any questions regarding this Bulletin or the actions required by you, please co.-tact this office.
Sincerely, gyjf
.oyce H. Grier Director
Enclosures:
1.
IE Bulletin No. 79-02 (Revision No. 1) 2.
List of IE Bulletins Issued in Last Twelve Months 359 197 7907230 6'
ENCLOSURE 1 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Bulletin No. 79-02 (Revision No. 1)
Date:
June 21, 1979 Page 1 of 6 PIPE SUPPORT BASE PLATE DESIGNS USING CONCRETE EXPANSION ANCHOR BOLTS Description of Circumstances:
Since the issuance of IE Bulletin 79-02 on Marcn 8, 1979, IE inspection M
experience and many inquiries from licensees indicate that additional informa-tion and clarification is needed.
This revision is intended to serve that purpose.
None of the requirements of the original Bulletin have been deleted, and the due date for completion of the requested actions (July 6, 1979) has not been changed.
The following text supersedes the text of Bulletin 79-02.
Changes from the original text are identified by lines in the margin.
The purpose of this revision is to identify acceptable ways of satisfying the Bulletin requirements.
While performing inservice inspections during a March-April 1978 refueling outage at Millstone Unit 1, structural failures nf piping supports for safety equipment were observed by the licensee.
Subsequent licensee inspections of undamaged supports showed a large percentage of the concrete anchor bolts were not tightened properly.
Deficiency reports, in accordance with 10 CFR 50.55(e), filed by Long Island Lighting Company on Shoreham Unit 1, indicate that design of base plates using rigid plate assumptions has resulted in underestimation of loads on some anchor bolts.
Initial investigation indicated that nearly fifty percent of the base plates could not be assumed to behave as rigid plates.
In addition, licensee inspection of anchor bolt installations at Shoreham has shown over fifty percent of the bolt installations to be deficient.
Vendor Inspection Audits by NRC at Architect Engineering firms have shown a wide range of design practices and installation procedures which have been employed for the use of concrete expansion anchors.
The current trends in the industry are toward more rigorous co.ntrols and verification of the instal-lation of the bolts.
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