ML19330B983
| ML19330B983 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 04/02/1980 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Eric Turner HOUSTON LIGHTING & POWER CO. |
| References | |
| NUDOCS 8008070351 | |
| Download: ML19330B983 (1) | |
Text
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UNITED STATES C
NUCLEAR REGULATORY COMMISSION TRAL FILES 8 'i REGION IV I f I S 611 RYAN PLAZA oRIVE. SulTE 1000 7 (,..
,j ARLINGTON, TEXAS 76012 g ~;s,/
April 2, 1980 In Reply Refer To*
RIV j
Docket Nos. 50-498/IE Information Notice No. 80-13 50-499/IE Information Notice No.10-13 Houston Lighting & Power Company ATTN:
Mr. E. A. Turner, Vice President Power Plant Construction and i
Technical Services Post Office Box 1700 Houston, Texas 77001 Gentlemen:
l This IE Information Notice is provided as an early notification of a possibly significant matter.
It is expected that recipients will review the information for possible applicability to their facilities. No specific action or response is requested at this time; however, an IE Circular or Bulletin will be issued to recommend or request specific licensee actions, if required.
If you have 4
questions regarding this matter, please contact the director of the appropriate NRC regional office.
Sincerely, 1
r1V.Seyfrit/
Director
Enclosures:
1.
IE Information Notice No. 80-13 2.
List of IE Information Notices Recently Issued 8008070351
~
SSIhS No.: 6870 Accession No.:
UNITED STATES 8002280650 NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT T D
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WASHINGTON, D.C.
20555 E
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- n IE Information Notice No. 80-13 Date:
April 2, 1980 Page 1 of 1 GENERAL ELECTRIC TYPE SBM CONTROL SWITCHES DEFECTIVE CAM FOLLOWERS Description of Circumstances:
This IE Information Notice alerts licensees and holders of construction permits of a potential defect in the cam followers of General Electric (GE) Type SBN control switches. Based on preliminary information, it appears that the defect is limited to switches manufactured prior to 1976 with cam followers of polycarbonate material, such as Lexan.
In brief, the problem is initiated by exposing such polycarbonate material to hydrocarbons.
Such exposure leads to severe cracking having a rock salt appearance which ultimately could progress to mechanical failure. It has been determined that such exposure has occurred during fabrication and could occur while performing maintenance (e.g., cleaning the contacts).
On February 22 and March 10, 1980, we were informed that SBM switches with defective cam followers had been found at Diablo Canyon Unit I and at the Cooper Station, respectively. Although the information was preliminary and sketchy, the problem is a long-standing one for which GE has issued " Service Information Letters" to its BWR customers. The problems associated with such switches, however, are not restricted to GE customers as evidenced by the Diablo Canyon case. Furthermore, these switches have a broad range of applica-tion. For example, the defective switches at the Cooper Station were used principally as hand control switches, most of which were located in the control room.
In contrast, those at Diablo Canyon Unit I were used as auxiliary contacts on the 4KV and 12KV "Magna Blast" circuit breakers, with three SBM switches used per breaker: (1) a breaker mounted auxiliary switch, (2) a cell mounted auxiliary switch, and (3) a cell interlock switch.
This information is provided as notification of a possibly significant matter that is rtill under review by the NRC staff.
It is expected that recipients will review the information for possible applicability to their facilities.
No specific action or response is requested at this time.
If you have questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
I
IE Information Notice No. 80-13 April 1, 1980 LISTING OF RECENTLY ISSUED IE INFOPJiATION NOTICES Information Subject Date Issued To Notice No.
Issued 80-08 The States Company Sliding 3/7/80 All power reactor Link Electrical Terminal facilities with an Operating License (OL) or a Construction Permit 80-09 Possible Occupational 3/7/80 All holders of power Health Hazard Associated reactor Operating With Closed Cooling Systems Licenses (OLs) and For Operating Power Plants near term Construction Permits (cps) 80-l'O Partial Loss of Non-Nuclear 3/7/80 All Power reactor Instrument System Power facilities holding Supply During Operation Operating Licenses (OLs) and Construction Permits (cps) 80-11 General Problems with ASCO 3/14/80 All holders of Reactor Valves in Nuclear Application Operating License (OL),
Including Fire Protection Construction Permit (CP),
Systems fuel fabrication and processing facilities 80-12 Instrument Failure Causes 3/31/80 All holders of Power Opening of PORV and Block Reactor Operating Valve Licenses (OLs) and Construction Permits (cps)
Enclosure O
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