ML19224D460
| ML19224D460 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 06/21/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Howell S CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| References | |
| NUDOCS 7907120221 | |
| Download: ML19224D460 (1) | |
Text
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NUCLEAR REGULATORY COMMISSION NC
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GL EN E LLYN, lLLINOIS 60137 0,
Jim 2119/9 Docket No. 50-329 Docket No. 50-330 Consumers Power Company ATTE.
Mr. Stephen H. Howell Vice President 1945 West Parnall Road Jackson, MI 49201 Gentlemen:
Enclosed is IE Bulletin No. 79-02 Revision No.
1, which requires action by you with regard to your power reactor facility 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, b-h
/ James G. Keppler l' Director
Enclosure:
IE Bulletin Nc. 79-02 Revision No. 1 cc w/ encl:
Central Files Director, NRR/DPM Director, NRR/ DOR PDR Local PDR NSIC TIC Ronald Callen, Michigan Public Service Commission Dr. Wayne E. North Myron M. Cherry, Chicago t.
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U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT REGION III June 21, 1979 IE Bulletin No. 79-02 (Revision No. 1)
(/906200183)
PIPE SUPPORT BASE PLATE DESIGNS USING CONCRETE EXPANSION ANCHOR BOLTS Description of Circumstances:
Since the issuance of IE Bulletin 79-02 on March 8, 1979, IE i spection 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 inspecticns 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 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 expans3 a anchors. The current trends in the industry are toward more rigorous (,atrols and verification of the instal-lation of the bolts.
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The data available on dynamic testing of thq DUPLICATE DOCUMENT fatigue failures can occur at loads substana cities due to material imperfections c,r notf Entire document previously entered d]
also show low cycle dynamic failures at load into system under:
due to joint slippage.
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