ML19343C339
| ML19343C339 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 09/21/1973 |
| From: | Bryan S US ATOMIC ENERGY COMMISSION (AEC) |
| To: | |
| References | |
| PNO-730921, RO-96, NUDOCS 8103100303 | |
| Download: ML19343C339 (2) | |
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No. 96 Date 9/21/73-DIRECTORATEOFREGULATdRYOPERATIONS NOTIFICATION OF AN INCIDENT OR OCCURRENCE 50-21S Facility:
CONNECTICUT YANKEE ATOMIC POWEP, COMPANY (CONNECTICUT YANKEE)
Problem:
During an RO inspection at the site on August 29-31,1973, it was determined that several seismic support hold-down bolts on the sliding supports _for the steam generators had been found by the licensee to be loose. On September 19 the licensee reported by telephone and-telegraph that the continuing investigation of this condition has identified 8 bolts to be broken and 15 other bolts suspected of being broken. There are a total of 256 hold-down bolts on he 4 steam generators.
An evaluation by a licensee's contractor concluded that all 256 bolts are required to assure that the supports will perform their intended function, which is to restrain motion due to a seismic effect or a primary loop piping rupture. The evoidation also concluded that the bolt failures probably occurred at initial installation when the bolts were prestressed. Therefore, the_ condition has existed since initial operation of the plant.
The licensee reported that all bolts will be tested and all failed bolts will be replaced before further reactor operation. This is expected to require four weeks but should not extend the present shutdown because this can be done concurrently with other work which is schedule limiting.
Action by Regulatory Operations:
1.
R0:I will review the results of the completed investigation and corrective action.
2.
The licensee will submit a written report as required by the Technical Specifications.
3.
R0 is evaluating the generic aspects relative to seismic support hold-down bolts since this is the second instance of a significant bolt failure attributed to prestressing.
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i No. 96 Date 9/21/73 4.
The State of Connecticut will be notified by R0:1.
5.
Chairman Ray's Special Assistant, Commissioner Doub's Technical Assistant, Comissioner Larson's Technical Assistant, Comissioner Anders' Temporary Assistant, Commissioner Kriegsman's Assistant, the staff of the Joint Comittee on Atomic Energy, and the Office cf Information Services have been informed by telephone.
Contact:
Further information ccacerning this occurrence can be obtained from:
S. E. Bryan
- X7353 H. D. Thornburg - X7353 J. G. Davis
- X7541 Distribution:
Chairman Ray (3)
V. Stello, L S. A. Schwartz, DR3L Comaissioner Larson V. A. lbore, L J. C. Kouts, RSR Ccraissie - Doub G. R.* Grove, L Commiss Kriegsman H. Lowenberg, L Cormi ss'.
Anders F. Schroeder, L L. M. liui 1, DR S. H. Smiley, L A. W. Jac ATDR D. J. Skovholt, L L. V. Goss ADR R. C. DeYoung, L C. K. Beck, UKGL D. R. Muller, L S. H. Hanauer, DRTA R. R. !!accary, L E. G. Triner, DRPA R. L. Tedesco, L D. J. Donoghue, DRA H. R. Denton, L (2)
W. G. Dooly, DPA D. A. !!ussbaumer, L General llanager (2)
R. E. Cunningham, L Secretary (2)
R. J. Schemel, L F. L. Ingram, IS D. F. Knuth, R0 J. Fouchard, IS L. I. Ccbb, R0 J. A. Harris, IS J. G. Davis, R0 Clare liiles, IS
- r. A. !! orris, R0 E. J. Causer, JCAE T. R.'Hilson, R0 J. H. Rubin, AGM B. H. Grier, R0 J. D. Anderson, INS D. Thompson, R0 M. Biles, OS C. W. Kuhlman, R0 R. F. Fraley, ACRS (18)
R. D. O'Neill, OCR L. R. Rogers, RS J. L. Liverman, DBER R. B. !!inogue, RS J. D. Goldstein, DBER G. A. Arlotto, RS C. F. Eason. AUCRR, AGMES J. J. Davis, RS S, Levine, RSS R. 5. Smith, RS R0 Regional Offices W. G. I:cDonald, OPS DR Reading File J
F. O' Leary, L REG Central Files E. G. Case, L PDR (5)
J. M. Hendrie, L Local PDR A. Giambusso, L P00R ORIGINAL