ML19249B685
| ML19249B685 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 08/14/1979 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Gary R TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| References | |
| NUDOCS 7909040668 | |
| Download: ML19249B685 (1) | |
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August 14, 1979 la Reply Refer To:
RIV Docket Nos.
30 45/IE Circular No. 79-17 5: ~46/IE Circular No. 79-17 Texas L':12:les Generating Co=pany ATTN: 12. 1. J. Gary, Executive Vice President and General Manager 2001 Bry'an Tower Dallas, Texas 75201 Gentlemen:
This IE Circular is provided as an early notification of a possible significant r.la t t e r.
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 further NRC evaluations so indicate, an IE Bulletin will be issucd to recommend or request specific licensee actions.
If you have questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
Sincerely, 9
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I Karl V. Seyfrit Director
Enclosures:
1.
IE Circular No. 79-17 2.
List of IE Circulars Issued in the Last 6 Months 7 909 04pf6T 9 s
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UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AVD ENFORCE!ENT WASHINGTON, D.C.
20555 IE Circular No. 79-17 Date:
August 14, 1979 Page 1 of I CON C ?= E 121 IN 51-1.' SWITCIES ON GENERAL ELECTRIC METALCLAD CIRCUIT BRIA: --
The C - ni Electric C pany, Switchgear Department in Philadelphia, reported ~
to the XI: an July 3,1979, an intermittent contact problem in SB-12 switches.
This in
--"ttent contact problem will cause a lack of continuity through the "a" cc ;n;; of the switch that is used to energize the trip coil of the circuit breaker.
Investigation disclosed that e die used to form a hole in the contact arms of tce switch had worn, resulting in elongated holes.
This condition could permit the contact bridge member to move laterally relative to the contact arm, occasionally resulting in improper "a" contact wipe.
The worn die has been corrected, and all switches chipped on or af ter July 1, 1979, include this correction.
A review of the history of these components indicates that switches shipped in the time period of August 1, 1978 to July 1, 1979, could have this problea. The trip coil and auxiliary switch portion of the trip circuit is monitored for continuity by a red light on the front door of the switchgear.
This light is lit when the breaker is closed and the control circuits are energized.
If the red light is lit, this indicates that the "a" contacts of the switch are closed, and that a trip signal will trip the breaker.
Based on the above, the licensees are advised to do the fol* lowing:
1.
Insure that all General Electric Company Metalclad Circuit Breakers shipped to your facilities during the period from August 1, 1978 to July 1, 1979 and used in or af fecting the operation of safety related equipment are furnished with new SB-12 control switches as promptly
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as possible.
2.
Pending replacement of SB-12 control switches, administrative controls should be initiated to assure the red light which demonstrates ccatact continuity, is lit and remains lit each time these circuit breakers are closed.
No written response to this circular is required.
If you require additional information regarding this subject, contact the Director of the appropriate NRC Regional Office.
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IE Circular No. 79-17 August 14, 1979 LISTING OF IE CIRCULARS ISSUED IN LAST SIX ?!ONTHS Circu_r Subject Date of Issued To No.
Issue 79-03 Inadequate Guard 2/23/79 All Holders of and Training - qualifica-applicants for Special tion and Falsified Nuclear tlaterial Licenses Training P.ecords in Safeguards Group I 79-04 Loose Locking Nut 3/16/79 All llolders of Reactor On Liaitorque Valve Operating License (0L) or Operators Construction Permits (CP) 79-05
?!oisture Leakage in 3/2'/79 All Holders of Reactor Stranded Wire Conductors Operating License (0L) or Construction Permits (CP) 79-06 Failure to Use Syriuge 4/19/79 All Holders of Fledical and Battle Shields in Licensees except Teletherapy Nuclear ?!edicine Licensees 79-07 Unexpected Speed Increase 5/2/79 All Holders of BWR Operating of Reactor Recirculation Licenses (OLs) or Construc-
?!G Set Resulted in Reactor tion Permits (cps)
Power Increase 79-08 Attempted Extortion - Low 5/18/79 All. Fuel Facilities and Enriched Uranium Reactors Licensed by NRC 79-09 Occurrences of Split or 6/22/79 All ?!aterials Priority I, Punctured Regulator Fuel Cycle and Operating Diaphragms in Certain Reactor Licenses (OL)
Self Contained Breathing Apparatus 79-10 Pipefittings fianufactured 6/26/79 All Power 2eactor Licensees frora Unacceptable flaterial with a Construction Permit and/or Operating License (OL) 79-11 Design / Construction 6/27/79 All Holders of and Applicants Interface Problem for Power Reactor Construction Permits (CP) ao Enclosure D
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IE Circular No. 79-17 August 14, 1979 79-12 Potential Liesel Generator 6/28/79 All Power Reactor Licensee with Turbocharger Problem a Construction Permit (CP) and/or Operating License (OL) 79-12 9eplacacent ;f Diesel 7/13/79 All Power Reactor Licensee 7 ire Purp 5 tarting with a Construction Permit
'Cantac::rs (CP) and/or Operating Licensee (OL) 79-14 Unauthorized Procurement 7/13/79 All Medical Licensees and Distribution of Except Teletheraphy IE-133 Medical Licensees and to all Radiopharmaceutical Suppliers 79-15 Bursting of High Pressure 8/8/79 All Materials Priority I, Hose and Malfunction of Fuel Cycle and Operating Relief Valve "0" Ring in Power Reactor Licensees Certain Self-contained Breathing Apparatus 79-16 Excessive-Radiation 8/16/79 All Radiography Exposures to Members Licensees of the General Public and a Radiographer Enclosure Page 2 of 2 D ""
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