ML19309D670
| ML19309D670 | |
| Person / Time | |
|---|---|
| Site: | Humboldt Bay, Diablo Canyon |
| Issue date: | 04/02/1980 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Crane P PACIFIC GAS & ELECTRIC CO. |
| References | |
| NUDOCS 8004110111 | |
| Download: ML19309D670 (1) | |
Text
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UNITED STATES 4
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Ik NUCLEAR REGULATORY COMMISSION L.,
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1990 N. CALIFORNIA BOULEVARD U
o SUITE 202, WALNUT CREEK PLAZA
- e WALNUT CRE E K, CALIFORNI A 94596 April 2, 1980 Docket Nos. 50-133, 50-275, 50-323 Pacific Gas and Electric Company 77 Beale Street San Francisco, California 94106 Attention: Mr. Philip A. Crane, Jr.
Assistant General Counsel Gentlemen:
This 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 reconrnend or request specific licensee actions, if required.
If you have questions regarding this matter, please contact the director of the appropriate NRC regional office.
Sincerely,
, h.
R. H. Engelken Director
Enclosures:
1.
IE Information Notice No. 80-13 2.
List of IE Information Notice Recently i
Issued cc w/ enclosures:
W. Barr, PG&E W. Raymond, PG&E R. Ramsay, PG&E, Diablo Canyon E. Weeks, PG&E, Humboldt Bay E. B. Langley, Jr., PG&E 800433g q
SSINS No.: 6870 Accession No.:
UNITED STATES 8002280650 NUCLEAR REGULATORY COMMISSION OFFICE OF IflSPECTION AND ENFORCEMENT WASHINGTON, D.C.
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April 2, 1980 3o mJ Um IE Information Notice No. 80-13 4
GENERAL ELECTRIC TYPE SBM CONTROL SWITCHES DEFECTIVE CAM FOLLOWERS Description of Circumstances:
This Information Notice alerts licensees and holders of construction permits of a potential defect in the cam followers of General Electric (GE) Type SBM 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).
i On February 22 and March 10, 1980 we were informed that SBM switches with defective cam followers had been found at Diablo Canyon Unit 1 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 still under review by the NkC 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.
L
4 IE Information Notice No. 80-13 Enclosure April 2, 1980 RECENTLY ISSUED IE INFORMATION NOTICES i
Information Subject Date Issued To Notice No.
Issued 80-12 Instrument Failure Causes 3/31/80 All holders of Power Opening of PORV and Block Rector OLs and cps Valve 80-11 General Problems with ASCO 3/14/80 Ai! holders of Reactor Valves in Nuclear Application OL, CP, fuel fabrica-Including Fire Protection tiori and processing Systems facilities
- i.;
80-10 Partial loss of Non-Nuclear 3/7/80 All power reactor Instrument System Power facilities holding Supply During Operation OLs and cps 80-09 Possible Occupational 3/7/80 All holders of Health Hazard Associated power reactor Ols with Closed Cooling Systems and near term cps 80-08 The States Company Sliding 3/7/80 All power reactor Link Electrical Terminal facilities with an OL Block or a CP 80-07 Pump Shaft Fatigue Cracking 2/29/80 All Light Water Reactor
'i 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 pouer reactor OL or CP l
80-03 flain Turbine Electro-1/31/80 All holders of power Hydraulic 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 l
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