ML19256B479
| ML19256B479 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 06/21/1979 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| References | |
| NUDOCS 7907120005 | |
| Download: ML19256B479 (1) | |
Text
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y UNITED STATES 8Y G1
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i NUCLEAR REGUL ATORY COMMISSION E
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1930 N. CALIFORNI A BOULEVARD S-cI SUITE 202, WALNUT CREEK PLAZA
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WALNUT CR EE K. CA LIFORNI A 9459G June 21,1979 Docket ilos. 50-528 50-529 50-530 Arizona Fublic Service Company P. O. Box 21666 Phoenix, Arizona 83035 Attention: Mr. E. E. Van Brunt, Jr.
Vice President, Construction Projects Gentl emen:
Enclosed is IE Bulletin t'o. 79-02, Revision flo.1, which requires action by you with regard to your power reactor facility (ies) with an operating license or a construction permit.
Should you have questions regarding this Bulletin or the actions required of you, please contact this office.
Sincerely,
- f. l> S. z, t Ol ~
R. H. Engelken Director
Enclosure:
IE Bulletin flo. 79-02 Revision No. 1 cc w/ enclosures:
F. W. Hartley, APS
.A 835 065 79071200D T
UNITED STATES flUCLEAR REGULATORY COMMISSIO1 0FFICE OF IflSPFCTION AND ENFORCEMENT WASHINGT0ti, D.C.
20555 June 21, 1979 IE Bulletin No. 79-02 (Revision No. 1)
(7906200183)
PIPE SUPPORT BASE PLATE DESIGNS USING CONCRETE EXPANSION ANCHOR BOLTS Description of Circu"1 stances:
Since the issuance of IE Bulletin 79-02 on March 8,1979, IE inspection experience and many inquiries from licensees indicate that additional informa-tion and clarification is needed. This revision is intended to serve that purnose.
None of the reauirements of the oricinal 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 tb original text are identified by lines in the margin. The purpose of this revision is to identify acceptable ways of satisfyina the Bulletin requirements.
While performina inservice inspections durina a March-Aoril 1978 refuelina outaae at Millstone Unit 1, structural failures of pipina supports for safety equiprent were observed by the licensee.
Subsequent licensee inspections of undanaged supports showed a larae cercentace of the concrete anchor bolts were not tightened properly.
Deficiency reports, in accordarce with 10 CFR 50.55(e), filed by Lona Island Lighting Company on Shorehan Unit 1, indicate that design of base plates usina riaid 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 riaid 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 flRC at Architect Engineering firms have shown a wide rance of desian practices and installation procedures which have been employed for the use of concrete expansion anchors.
The current trends.in the industry are toward nore rigorous controls and verification of the instal-lation of the bolts.
The data available on dynamic testino o P"*m ~mW amew
&*mm fatigue failures can occur at loads sub
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cities due to naterial impecfecticas or DUPLICATE DOCUMENT also show low cycle dynamic failures at i
due to joint slippage.
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