ML19249C001
| ML19249C001 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 08/14/1979 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Stampley N MISSISSIPPI POWER & LIGHT CO. |
| References | |
| NUDOCS 7909070204 | |
| Download: ML19249C001 (2) | |
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NUCLEAR REGULATORY COMMISSION y
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o 000 I4 l970 In Reply Refer To:
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Mississippi Power and Light Company ATTN:
N. L. Stampley Vice President of Production P. O. Box 1640 Jackson, MS 39203 Gentlemen:
This Circular is provided as an early notification of a possible significant is expected that recipients will review the information for possible matter.
It No specific action or response is requested applicability to their facilities.If further NRC evaluations so indicate, an IE Bulletin will be at this time.
issued 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, p.D' ames P. O'Reilly rector
Enclosures:
1.
IE Circular No. 79-17 2.
List of IE Circulars I, sued in the Last 6 Manths "G 3
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C. K. McCoy Plant Manager Post Office Box 756 Port Gibson, Mississippi 39150 I
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Accession No:
7908090272 SSINS:
6830 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 August 14, 1979 IE Circular No. 79-17 CONTACT PE'JBLEM IN SB-12 SWITCHES ON GENERAL ELECTRIC METALCLAE CIRCUIT BREAKERS The General Electric Company, Switchgear Department in Philadelphia, reported to the LRC on July 3,1979, an intermittent contact problem in SB-12 switches.
This irtermittent contact problem will cause a lack of continuity through the "a" coatact of the switch that is used to energize the trip coil of the circuit breaker.
Investigation disclosed that a die used to form a hole in the contact arms of the switch had worn, resulting in elongated holes.
This condition could perr.it the contact bridge member to move laterally telative to the contact arm, occasionally resulting in improper "a" contact wipe. The worn die has been corrected, and all switches shipped on or after July 1, 1979, include this A review of the history of these components indicates that switches carrection.
shipped in the time period of August 1, 1978 to July 1, 1979, could have this The trip coil and auxiliary switch portion of the trip circuit is problem.
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 following:
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 affecting the operation of safety related equipment are furnished with new SB-12 control switches as promptly as possible.
Pending replacement of SB-12 control switches administrative controls 2.
should be initated to assure the red light which demonstrates contact 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.
V23 003
Enclosure IE Circular No. 79-17 Page 1 of 2 August 14, 1979 LISTING OF IE CIRCULARS ISSUED IN LAST SIX MONTHS Date of Issued to Circular Subject Issue No.
79-03 Inadequate Guard Training-2/23'79 All Holders of Qualification and Falsified and applicants Training Records for Special Nuclear Material Licenses in Safeguards Group I 79-04 Loose Locking Nut On 3/16/79 All Holders of Reactor OLs or cps Limitorque Valve Operators 79-05 Moisture Leakage Jn 3/20/79 All He'ders of Strand : Wire Conductors Reactor OLs or cps 79-06 Failure to Use Syringe 4/19/79 All Holders of and Battle Shields in Medical Licensees Nuclear Medicine except teletherapy licensees 79-07 Unexpected Speed Increase 5/2/79 All Holders of of Reactor Recirculation BWR OL's or CP's MG Set Resulted in Reactor Power Increase 79-08 Attempted Extortion - Low 5/18/79 All Fuel Facilities Enriched Uranium Licensed by 6RC 79-09 Occurrences of Split or 6/22/79 All Materials Punctured Regulator Diapnragms Priority I, Fuel In Certain Self Contained Cycle and Operating Reactor Licensees Breathing Apparatus 79-10 Pipefittings Manufactured 6/26/79 All Power Reactor from Unacceptable Material Licensees with a CP and/or OL 79-11 Design / Construction 6/27/79 All Applicants Interface Problem for, and Holders of Power Reactor cps bOh
Enclosure IE Circular No. 79-17 Page 2 of 2 August 14, 1979 LISTING OF IE CIRCULARS ISSUED IN LAST SIX MONTHS Date of Issued to Circular Subject Issued No.
79-12 Potential Disel Generator 6/28/79 All Power Reactors Turbocharger Problem Operating Facilities and all Utilities having a CP 79-13 Replacement of Diesel 7/10/79 All Power Reactor Operating Facilities Fire Pump Starting and all Utilities Contactors having a CP 79-14 Unauthorized Procurement and 7/13/'
A1.1 Medical Licensees Distribution of XE-133 exc ept Tele'.nerapay Meciral Licensees and to all Radiopharmaceu-tical Suppliers 79-15 Bursting of High Pressure Hose 8/8/79 All Materials Priority I, and Malfunction of Relief Fuel Cycle and Operating Valve "0" Ring in Certain Self-Power Reactor Licensees Contained Breathing Apparatus 79-16 Excessive Radiation Exposures 8/16/79 All Radiography To Members Of The General Public Licensees and A Radiographer
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