ML19290F112
| ML19290F112 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 03/07/1980 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Papay L SOUTHERN CALIFORNIA EDISON CO. |
| References | |
| NUDOCS 8003180115 | |
| Download: ML19290F112 (1) | |
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UNITED STATES 8 Y,.n NUCLEAR REGULATORY COMMISSION 5.l j
REGION V 1990 N. CALIFOHNIA BOULEVARD o,,
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SUITE 202, WALNUT CHEEK PLAZA
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WALNUT CREE K, CALIFORNI A 9459G March 7, 1980 Docket flos. 50-206, 50-361 & 50-362 Southern California Edison Company P. O. Box 800 2244 Walnut Grove Avenue Rosemead, California 91770 Attention:
Dr. L. T. Papay, Vice President Advanced Engineering Gentlemen:
This Information flotice is provided as notification of a potentially significant matter.
It is expected that recipients will review the information for possible applicability to their facilities.
No spe-ci'ic action or response is requested at this time.
If further NRC evaluations indicate the need, an IE Circular or pulletin will be issued to request specific licensee actions.
If you have questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
Sincerely, f& r3d%L R. H. Engelken Director
Enclosures:
1.
IE Information flotice No. 80-08 2.
List of Recently Issued IE Information flotices cc w/ enclosures:
J. M. Curran, SCE R. Dietch, SCE 8003'8 US
I SSIftS: 6870 utlITED STATES Accession flo.:
fiUCLEAR REGULATORY COMMISSI0ft 7912190689 0FFICE OF IriSPECTI0fl ATID EfiFORCEf'ErlT WASHINGT0ft, D.C.
20555 March 7, 1980 U/
IE Information Notice flo. 80-08 THE STATES COMPANY SLIDING LINK ELECTRICAL TERMINAL BLOCK Description of Circumstances:
On July 19, 1979, the Consumers Power Conpany 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 located between the two bars.
The top of the U-shaped link and the spacer are drilled and the bottom of the link is threaded to accept a 8-32 screw. When the screw 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, occ'.'rs 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.
D e defect, a crack in the bottoa portion of the metal U-shaped link, is disp'.syed in the exploded view of the terminal block assembly.
These terminal blocks are widely use.d in the nuclear industry and may be used as permanent installations in safety related systems. The defective mechanical connect hn 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 info wa-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 net.
If you require additional information regarding this matter, contact the Director of the appropriate NRC Regicqal Office.
Enclosure:
Graphic Display of Terminal Block
IE Information Notice No. 80-08 Enclosure March 7, 1980 RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued To Notice No.
Issued 80-07 Pump Shaft Fatigue Cracking 2/29/80 All Light Water Reactor Facilities holder power reactor OLs and cps 80-06 Notification of Significant 2/27/80 All holders of Reactor Events OLs and to near term OL applicants 80-05 Chloride Contamination 2/8/80 All licensees of nuclear of Safety Related Piping power reactor facilities and applicants and holders of nuclear power reactor cps 80-04 BWR Fuel Exposure in 2/4/80 All BWR's holding a Excess of Limits power reactor OL or CP 83-03 Main Turbine Electro-1/31/80 All holders of power Hydraulic Control System reactor OLs and cps 80-02' 8X8R Uater Rod Lower 1/25/80 All BWR Facilities End Plug Wear holder power reactor OLs or cps 80-01 Fuel Handling Events 1/4/80 All holders of power reactor OLs and cps 79-37 Cracking in Low Pressure 12/28/79 All power reactor OLs Turbine Discs and cps 79-36 Computer Code Defect in 12/31/79 All power reactor OLs Stress Analysis of Piping and cps Elbow 79-35 Control of Maintenance 12/31/79 All power reactor facilities and Essential Equipment with an OL or CP 79-34 Inadequate Design of 12/27/79 All holders of power reactor Safety-Related Heat OLs and cps Exchangers
ENCLOSURE 1 TO IE INFORMATION NOTICE 80- 08 m ""'
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.j Side View of States Company Terminal Block in Assembled Position i
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Exploded View of States Company Terminal Block a