ML19290F203
| ML19290F203 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 03/07/1980 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Hancock J FLORIDA POWER CORP. |
| References | |
| NUDOCS 8003180303 | |
| Download: ML19290F203 (2) | |
Text
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/pn nuouq'o, UNITED STATES 8
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NUCLEAR REGULATORY COMMISSION 3, ).. oE REGION 11 g....[.,o o
101 MARIETTA ST N.W., SUITE 3100 8
g ATLANTA, GEORGIA 30303 In Reply Refer To:
MAR 0 71980 RI1:JP0 Q 0-302 Florida Power Corporation Attn:
J. A. Hancock, Director Nuclear Operations P. O. Box 14042, Mail Stop C-4 St. Petersburg, Florida 33733 Gentlemen:
This Information Notice is provided as notification of a potentially significant matter.
It is expected that recipients will review the infor-mation for possibic 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 questions regarding this matter, please con-tact the Director of the appropriate NRC Regional Office.
Sincerely, s
5!
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/ " James P. O'Reilly Director
Enclosures:
1.
IE Information Notice No. 80-08 w/its Enclosure 2.
List of Recently Issued IE Information Notices 8003180303
Florida Power Corporation,
cc w/ enc 1:
D. C. Poole Nuclear Plant Manager Post Office Box 1240 Crystal River, Florida 32629 A
SSINS: 6870 UNITED STATES Accession No.
NUCLEAR REGULATORY COMMISSION 7912190689 0FFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
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March 7, 1980 L
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 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.
Enclosure I 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.
Enclosure:
Graphic Display of Terminal Block
1 ENCLOSURE 1 TO IE INFORMATION NOTICE 80-08 L
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Side View of States Company Terminal Block in Assembled Position
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Fans Cracks in U-Shaped Unk y
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I b b $ $ll@~ g" Exploded View of States Company Terminal Block
1 IE Information Notic< ho. 80-08 Enclosure March 7, 1980 g
RECENTLY ISSUED IE INFORMATION NOTICES Info rma tion Subject Date Issued To Notice No.
Issued 80-08 The States Company Sliding 3/07/80 All holders of an OL or Link Electrical Terminal Block a CP 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 nea r, 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 80-03 Main Turbine Electro-1/31/80 All holders of power Ilydraulic Control System reactor OLs and cps 80-02 8X8R Water 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 c f 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