ML19225B113
| ML19225B113 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 06/21/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Dunn C DUQUESNE LIGHT CO. |
| References | |
| NUDOCS 7907230663 | |
| Download: ML19225B113 (1) | |
Text
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UNITED STATES 73 8)y,(;,i NUCLEAR REGULATORY COMMISSION 3 gh
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,o Docket No. 50-334 21 JUN 1379 Duquesne Light Company ATTN:
Mr. C. N. Dunn Vice President Operations Division 435 Sixth Avenue Pittsburgh, Pennsylvania 15219 Gentlemen:
Encloseo is IE Bdlletin No. 79-02 Revision No. 1, which requires action by you with regard to your power reactor facili_ty(ies) with an operating license or a construction permit.
Should you have any questions regarding this Bulletin or the actions required by you, please contact this office.
Sincerely, l
N n-Boyce H. Grier Director
~
Enclosures:
1.
IE Bulletin No. 79-02 (Revision No. 1) 2.
List of IE Bulletins Issued in Last Twelve Months cc w/encis:
F. Bissert, Technical Assistant Nuclear R. Washabaugh, QA Manager J. Werling, Station Superintendent G. Moore, General Superintendent, Power Stations Department J. J. Carey, Nuclear Technical Assistant 3LJ bbl e
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9330 W 200
ENCLOSURE 1 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE GF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Bulletin No. 79-02 (Revision No. 1)
Date:
June 21, 1979 Page 1 of 6 PIPE SUPDORT BASE PLATE DESIGNS USING CONCRETE EXPANSION ANCHOR BOLTS Description of Circumstances:
Since the issuance of IE Bulletin 79-02 on March o, i s, IE inspection R
experience and many inquiries from lic.ensees 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 of piping supports for safety equipment were observed by the licensee.
Subsequent licensee inspections of undataged supports showed a large percentage of the conc.cate ancher 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 cesign of base plates using rigid plate assumptions has resulted in underestimation of loads on some anchor'boltc.
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 dericient.
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 curre,gt trends in the industry are toward moge_rignr w
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1stal-lation of the bolts.
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also show low cycle dynamic E
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ities due to joint slippage.
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