ML19344E977
| ML19344E977 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 08/27/1980 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Tallman W PUBLIC SERVICE CO. OF NEW HAMPSHIRE |
| References | |
| NUDOCS 8009120211 | |
| Download: ML19344E977 (1) | |
Text
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UNITED STATES 8
NUCLEAR REGULATORY COMMISSION o
,E REGION I Q
4 631 PARK AVENUE 9.....,o',
KING OF PRUSSIA, PENNSYLVANI A 19406 4
August 27, 1980 Docket Nos. 50-443 50-444 Public Service Company of New Hampshire ATTN:
Mr. W. C. Tallman Chairman and Chief Executive Officer.
1000 Elm Street Manchester, New Hampshire 03105 Gentlemen:
The enclosed IE Information Notice No. 80-31, "Maloperation of Gould-Brown Boveri Type 480 Volt Type K-6005 and K-DON 6005 Circuit Breakers," is forwarded to you for information.
No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely, ce Boyce H. Grier Director
Enclosures:
1.
IE Information Notice No. 80-31 2.
List of Recently Issued IE Information Notices CONTACT:
S. D. Ebneter (215-337-5283) cc w/encls:
John DeVincentis, Project Manager
.80091eo 2Il
SSINS No.: 6870 Accession No.j-8006190040 g >7>4 IN 80-31 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555 August 27, 1980 IE Information Notice No. 80-31:
MALOPERATION OF GOULD-BROWN BOVERI 480 VOLT-TYPE K-6005 AND K-DON 6005 CIRCUIT BREAKERS Description of Circumstances:
The Cincinnati Gas & Electric Company reported problems with the Gould-Brown Boveri Type K-6005 and K-DON 6005 circuit breakers used in 480 volt a.c.
circuits at the William H. Zimmer nuclear stations.
The problem involved inadvertent circuit breaker closure during operation of the breaker charging springs when the breaker was racked out to the test position.
The problem resulted from the use of undersized bushings in the circuit breaker secondary close latches.
The undersized. bushings caused the secondary close latch to hang-up on the shunt trip device resulting in an inadvertent circuit breaker closure when the spring charging motor was energized, The vendor has stated that the problem does not exist during normal operations with the circuit breaker in the connected position.
Recommended Action for Licensees and Holders of Construction Permits:
All ifcensees of operating nuclear power reactors and holders of coastruction permits should be aware of the potential problems described above.
The vendor has stated that a small number of circuit breakers were assembled with under-sized secondary latch bushings between 1969 and 1977.
It is recommended that the following actions be taken:
(1) Determine if the subject circuit breakers are installed in any safety-related application at your facility.
The affected circuit breakers are manufactured by Gould-Brown Boveri and are types K-6005 and K-DON 600S, 480-volt a.c. electrically operated, drawout type with static trip device.
(2) If it is determined that your facility has the circuit breakers described in Item (1) above, perform the K-600S, K-DON 6005 Field Test Procedure attached to this information notice (Gould-Brown Boveri I.B.-9.1.7-6 Issue F, Addendum 2, dated March J ' :.:.:1 (3)
If maloperation of the circuit br DUPLICATE DOCUMENT field test procedure described ir action described in the attached Entire document previous 1 0.050 shim to the secondary clos entered into system under ANO _
foob190040 No. of pages:
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