ML18138A090
| ML18138A090 | |
| Person / Time | |
|---|---|
| Site: | Surry, North Anna  |
| Issue date: | 03/07/1980 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Ferguson J VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| References | |
| NUDOCS 8003180324 | |
| Download: ML18138A090 (5) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION REGION II In Reply Refer To:
RII :JPO 50-338, 50-339 jJ);4-04-----§0,,,,(+ 0 5
~o: 50-2-si'::::>
101 MARIETTA ST., N.W., SUITE 3100 ATLANTA, GEORGIA 30303 Virginia Electric and Power Company Attn:
J, H. Ferguson Executive Vice President-Power P. Q, Box 26666 Richmond, Virginia Gentlemen:
23261 This Information Notice is provided as notification of a potentially significant matter. It is expected that recipients will review the infor-mation for possible applicability to their facilities.
No specific action or response is requested at this time.
If further NRC evaluations indicate the need, an IE Circular or Bulletin will be issued to request specific licensee actions. If you have qriestions regarding this matter, please con-
'.::r..:,
tact the Director of the appropriate NRC Regional Office.
Enclosures:
- 1.
IE Information Notice Sincerely,
/C~~
--~James P. O'Reilly Director No. 80-08 w/its Enclosure
- 2.
List of Recently Issued IE Information Notices
Virginia Electric and Power Company cc w/encl:
W.R. Cartwright, Station Manager Post Office Box 402 Mineral, Virginia 23117 P. G. Perry Senior Resident Engineer Post Office Box 38 Mineral, Virginia 23117 W. L. Stewart, Manager Post Office Box 315 Surry, Virginia 23883.,,..
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UNITF;D STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 March 7, 1980 SSINS: 6870 Accession No.:
7912190689 IE Information Notice No. 80-08 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 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 0 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.
TheseJterminal 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.
Enclosure:
Graphic Display of Terminal Block
e ENCLOSURE 1 TO IE INFORMATION NOTICE 80-08 Side View of States Company Terminal Block in Assembled Position Cracks In U-SherUnk Exploded View of States Company Terminal Block
e IE Information Notice No. 80-08 March 7, 1980 Information Notice No. 80-08 80-07 80-06 80-05 80-04 80-03 80-02 80-01 79-37 79-36 79-35 34 RECENTLY ISSUED IE INFORMATION NOTICES Subject Date Issued The States Company Sliding 3/07/80 Link Electrical Terminal Block Pump Shaft Fatigue Cracking 2/29/80 Notification of Significant 2/27/80 Events Chloride Contamination of Safety Related Piping BWR Fuel Exposure in Excess of Limits Main Turbine Electro-Hydraulic Control System 8X8R Water Rod Lower End Plug Wear Fuel Handling Events Cracking in Low Pressure Turbine Discs Computer Code Defect in Stress Analysis of Piping Elbow Control of Maintenance and Essential Equipment Inadequate D~sign of Safety-Related Heat Exchangers 2/8/80 2/4/80 1/31/'80 1/25/80 1/4/80
~
12/28/79 12/31/79 12/31/79 12/27/79
- Enclosure Issued To All holders of an 01 or a CP Ail Light Water Reactor Facilities holder power reactor OLs and CPs All holders of Reactor OLs and to near,term 01 applicants All licensees of nuclear power reactor facilities and applicants and holders of nuclear power react;or CPs All BWR's holding a power reactor 01 or CP All holders of power reactor 01s and CPs All BWR Facilities holder power reactor OLs or CPs All holders of power reactor OLs and CPs All power reactor 01s and CPs All power reactor 01s and CPs All power reactor facilities with an 01 or CP All holders of power reactor 01s a*nd CPs