ML19322E092
| ML19322E092 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/07/1980 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Arnold R METROPOLITAN EDISON CO. |
| References | |
| NUDOCS 8003190258 | |
| Download: ML19322E092 (1) | |
Text
e
,,e Yb
+
b UNITED STATES 8
NUCLEAR REGULATORY COMMISSION 3
j REGION I gy 631 PARK AVENUE 4,*****,#g KING OF PRUSSIA, PENNSYLVANIA 19406 March 7, 1980 Docket Nos. 50-289 50-320 THIS DOCUMENT CONTAINS POOR QUAUTY PAGES Metropolitan Edison Company ATTN:
Mr. R. C. Arnold Senior Vice President 100 Interpace Parkway Parsippany, New Jersey 07054 Gentlemen:
The enclosed IE Information Notice No. 80-08, The States Company Sliding Link Electrical Terminal Block, is forwarded to you for information.
No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely, 3
.Mdff Boyce H. Grier Director
Enclosures:
1.
IE Information Notice No. 80-08 with Attachment 2.
List of Recently Issued IE Information Notices CONTACT:
S. D. Ebneter (215-337-5296) cc w/encls:
J. G. Herbein, Vica President Nuclear Operations E. G. Wallace, Licensing Manager R. J. Toole, Manager, TMI-1 W. E. Potts, Radiological Controls Manager, TMI-1 R. W. Heward, Radiological Controls Manager, TMI-2 J. J. Colitz, Plant Engineering Manager, TMI-1 J. J. Barton, Manager Site Operations, TMI-2 B. Elam, Plant Engineering Manager, TMI-2 L. W. Harding, Supervisor of Licensing R. F. Wilson, Director, TMI-2 I. R. Finfrock, Jr.
R. W. Conrad J. B. Lieberman, Esquire G. F. Trowbridge, Esquire Ms. Mary V. Southard, Chairperson, Citizens for a Safe Environment 8003190258
.m ENCLOSURE 1 SSINS: 6870 UNITED STATES Accession No.:
NUCLEAR REGULATORY COMMISSION 7912190689 0FFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Information Notice No. 80-08 Date:
March 7, 1980 Page 1 of 1 THE STATES COMPANY SLIDING LINK ELECTRICAL TERMINAL BLOCK Description of Circumstances:
On July 19, 1979, the Consumers Power Company notified the Nuclear Regulatory Commission of a defect found in the sliding link electrical terminal block manufactured by the States Company, a subsidiary of Multi Amp Corp.
The defective terminal blocks were found at the Midland plant.
The connection between the two slotted bars on the terminal block is made by a U-shaped sliding link and spacer loc '.ed between the two bars.
The top of the U-shaped link and the spacer are dr ed and the bottom of the link is threaded to accept a 8-32 screw.
When the i ew is tightened it binds the link, spacer and bar together to make electrical connection.
Loosening the screw and sliding the link from between the bars breaks the connection.
The purpose of the link is to provide easy insertion of test instruments, etc. into the circuit!
The defect, which has been identified in 5% of the terminal blocks checked, occurs in the form of a crack between the threaded screwhole and the side of the U-shaped link.
When the screw is tightened the crack widens and a poor or intermittent electrical connection can result.
A defective link is impossible to cinch tightly in place and is difficult to detect visually. shows the States Company terminal block.
The defect, a crack in the bottom portion of the metal U-shaped link, is displayed in the exploded view of the terminal block assembly.
These terminal blocks are widely used in the nuclear industry and may be used as permanent installations in safety related systems.
The defective mechanical connection can cause an electrical circuit malfunction.
This Information Notice is provided to inform licensees of a potentially significant matter.
It is expected that recipients will review the informa-tion for applicability to their facilities.
No written response to this IE Information Notice is required.
However, the reporting requirements as set forth in the regulations must be met.
If you require additional information regarding this matter, contact the Director of the appropriate NRC Regional Office.
Attachment:
Graphic Display of Terminal Block
- -