ML19350B331
| ML19350B331 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 03/11/1981 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Rich Smith VERMONT YANKEE NUCLEAR POWER CORP. |
| References | |
| NUDOCS 8103200282 | |
| Download: ML19350B331 (1) | |
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Docket No. 50-271 Trint. I 1 198l y
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r-1 Vermont Yankee Nuclear Power Corporation C
oer ATTN: Mr. Robert L. Smith L-Licensing Engineer 1671 Worcester Road o>
'U Framingham, Massachusetts 01701 bl Gentlemen:
The enclosed IE Information Notice No. 81-06, " Failure of ITE Model K-600 Circuit Breaker," is forwarded to you for information.
No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely,
,1 2 Boy H. Grier Director
Enclosure:
1.
IE Information Notice No. 81-06 with I attach it,it CONTACT:
S. O. Ebneter (215-337-5283) cc w/ encl:
Mr. Warren P. Murphy, Plant Superintendent Mr. W. F. Conway, Vice President and Manager of Operations Mr. J. E. Griffin, President Mr. L. H. Heider, Vice President 810 32 0 042R;;L 0
SSINS No.:
6835 Accession No.:
8011040269 IN 81-06
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"/h ]f UNITED STATES a t n NUCLEAR REGULATORY COMMISSION 0FFICE OF INSPECTION AND ENFORCEMENT MU WASHINGTON, D.C.
20555 March 11, 1981 IE Information Notice NO. 81-06:
FAILURE OF ITE MODEL K-600 CIRCUIT BREAKER F;cpose:
The purpose of this information notice is to provide early notification of a matter that could adversely affect the safety of nuclear power plants.
Toward this end, this information notice alerts holders of operating licenses and construction permits of a possibly generic deficiency involving Model K-600 circuit breakers manufactured by ITE.
Description of Circimstance:
Cy letter dated Fetruary 20, 1981, the Sacramento Municipal Utility District informed us that, while performing preventive maintenance on electrical circuit breakers at its Rancho Seco facility, an ITE Model K-600 breaker was observed not to trip. An investigation revealed that a tripping coil wire had slipped out of its terminal.
Further examinations revealed that the coil wire size was AWG 20, whereas the mating lug was sized for AWG 16-14 wire. A check of other ITE electrical breakers indicated that the problem may be ganeric.
Subsequent to the letter, the Sacramento Municipal Utility District informed us orally that ITE Model K-1600 breakers have the same deficiency and that Model K-3000 breakers may be similarly affected.
The information provided by the Sacramento Municipal Utility District is pre-liminary and will be followed by a complete report.
Consequently, we have not yet evaluated the safety significance of this event.
Nevertheless, the information herein is being provided as an early notification of a possibly significant event. Although no specific action or response is requested at this time, recipients should review the information for possible applicability to their facilities.
If NRC evaluations so indicate, further licensee actions may be requested.
If you have any question regarding the information contained herein, please contact the Director of the appropriate NRC Regional Office.
Attachment:
Recently issued IE Information Notices
IN 81-06 March 11, 1981 RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued to Notice No.
Issued 81-05 Degraded DC System 3/10/81 All holders of at Palisades a power reactor OL or CP 81-04 Cracking in Main 2/27/81 All holders of a Steam Lines power reactor OL or CP 81-03 Checklist for 2/2/81 All holders of a Licensees Making power reactor Notifications of OL or NTOL Significant Events in Accordance with 10 CFR 50.72 81-02 Transportation of 1/23/81 All holders of a Radiography Devices radiography license 81-01 Possible Failures of 1/16/81 All holders of a General Electric power reactor OL Type HFA Relays or CP 80-45 Potential Failure of 12/17/80 All holders of a BWR Backup Manual power reactor Scram Capability OL or CP 80-44' Actuation of ECCS in 12/14/80 All holders of a the Recirculation Mode PWR power reactor OL While in Hot Shutdown or CP 80-43 Failures of the 12/5/80 All holders of a Continuous Water Level BWR power reactor Monitor for the Scram OL cr~CP Discharge Volume at Dresden Unit No. 2 80-29 Broken Studs on Terry 11/26/80
~All holders of a Supplement Turbine Steam Inlet power reactor No. 1 Flange OL or CP