ML19225B130
| ML19225B130 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 06/21/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Counsil W NORTHEAST NUCLEAR ENERGY CO. |
| References | |
| NUDOCS 7907230681 | |
| Download: ML19225B130 (1) | |
Text
ma ara,
o s
'ffs, o,
UNITED STATES Mg y} *c(
j NUCLEAR REGULATORY COMMISSION 8
REGION I 7 Tij 3-
.. [
631 PA AK AVENUE S.
%, *....f KING OF PRUSSIA. PENNSYt.V ANIA 19406 Docket Nos. 50 245 21 JUN 1979 50 336 50-423 Northeast Nuclear Energy Company ATTN:
Mr. W. G. Counsil Vice President - Nuclear Engineering and Operations P. O. Box 270 Hartford, Connecticut 06101 Gentlemen:
Enclosed is IE Bulletin No. 79-02 Revision No. 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 any questions regarding this Bulletin or the actions required by you, please contact this office.
Sincerely, X(
M
[
coyce 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/encls:
J. F. Opeka, Station Superintendent D. G. Diedrick, Manager of Quality Assurance J. R. Himmelwright, Licensing Safeguards Engineer K. W. Gray, Construction Quality Assurance Lead H. R. Nims, Director of Nuclear Projects A. Z. Roisman, Natural Resources Defense Council 368 052 m
7901230 69/
ENCLOSURE 1 UNITED STATES NUCLEAR REGULATCRY 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 Bul'.etin 79-02 on Mai ch 8,1979, IE inspection
/M experience ar.d many inquiries from licensees indicate that additional informa-tion and cicrification is needed.
This revision is intended to serve that purpose.
'<one of tbc requirements of the original Bulletin have been deleted, and the due date for comoletion of the requested actions (July 6,1979) has not bee' cnanged.
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 undamaged supports showed a large percentage of the coperete anchor bolts were not tightened properly.
Deficiency recorts, 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
[h]
rigid plate assumptions has resulted in underestimation of loads on some c;)
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 cx3 fifty percent of the bolt installations to be deficient.
'C) m Vendor Inspection Audits by NRC at Architect Engineering firms have shown a wide range of design practices ar.d installation procedures which have been employed for the use of concrete expansion anchors.
The current trends in the industry are toward more rigorous controls and verification of the instal-lation of the bolts.
The data available on dynamic testing o' F"
~
~'
fatigue failures can occur at loads sub:
DUPLICATE DOCUMENT cities due to material imperfections or also show low cy-le dynamic failures at Entire document previously entered due to joint slippage.
into system under:
~
ANO 7 % h ?_. 9 0 2 3 2.
- Lines indicate changes to previous edi h
No. of pages:
10 v
~.