ML19224D465
| ML19224D465 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 06/21/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Gerstner W ILLINOIS POWER CO. |
| References | |
| NUDOCS 7907120233 | |
| Download: ML19224D465 (1) | |
Text
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UNITED STATES
! \\*,,, cf(' g NUCLEAR REGULATORY COMMISSION
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c REGION 111 b,
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799 ROOSEVELT ROAD
%s' GLE N E LLYN, ILLINOls 60137
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JUN 211979 Docket No. 50-461 Dock.et No. 50-462 Illinois Power Company ATTN:
Mr. W. C. Gerstner Executive Vice President 500 South 27th Street Decatur, IL 62525 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 construc' ton permit.
Should you have any questions regarding this Dalle:.in or the actions required by you, please contact this office.
Sincerely,
( lb.
M James G. Keppler Director
Enclosure:
IE Bulletin No. 79-02 Revision No. I cc w/ encl:
Central Files Director, NRR/DPM Director, hTR/ DOR PDR Local PDR FSIC TIC Mr. Dean Hansell, Office of Assistant Attorney General 7)io ld g 90q 120 2 3$
I U.S. NUCLEAR REGULATORY COMMISSION OFFICE CF INSPECTION AND ENFORCEMENT REGION III June 21, 1979 IE Bulletin No. 79-02 (Revision No. 1)
(7906200183)
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 inspection cxperience 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 receirements.
While performing inservice inspections during a March-April 1978 refueling outage at Millstone Unit 1, s+ructural failures of piping supports for safety equipment vere cbserved by th 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 Shorcham has shown over fifty percent of the bett installations to be deficient.
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Vendor Inspection Audits by NRC at Architect Engineering firms have shown a J 'i a wide range of design practices and installation procedures which have been employed for the use of concrete expansian anchors. The current trends in the industry are toward more rigorous centrols and verification of the instal-lation of the bolts.
m----v 11 The data available on dynamic testing of th fatigue failures can occur at loads substr' cities due to material imperfections or nc DUPLICATE DOCUMENT s
et also show low cycle dyna-ic failures at Ic Entire document previously entered vi due to joint slippage.
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