ML19207C163
| ML19207C163 | |
| Person / Time | |
|---|---|
| Site: | Hatch, Vogtle  |
| Issue date: | 08/14/1979 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | John Miller GEORGIA POWER CO. |
| References | |
| NUDOCS 7909070309 | |
| Download: ML19207C163 (2) | |
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' 7, NUCLEAR REGULATORY COMMISSION REGION 11 y, = ' '-'- [- [E b
101 MARIETT A. ST., N W., SUITE 3100 o
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In Reply Refer To:
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[50-424, 50-425 Georgia Power Company ATTN:
J. H. Miller, Jr.
Executive Vice President 270 Peachtree Street Atlanta, GA 30303 Gentlemen:
This Circular is provided as an early notification of a possible significant It is expected that recipients will review the information for possible matter.
applicability to their facilities.
No specific action or response is requested 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.O',
ames P. O'Reilly rector inclosures:
1.
IE Circular No. 79-17 2.
List of IE Circulars Issued in the Last 6 Months c. r~ m c; ~
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7909070 %
AUG 141979 Georgia Power Company cc w/ encl:
- h. Manry, Plant Manager Post Office Box 442 Baxley, Georgia 31513 C. E Belflower Site QA Supervisor Post Office Box 442 Baxley, Georgia 31513 K.
'i. Gillespie Cor.st ruction Project Manager Po.s : office Box 282 Waynesboro, Georgia 30830 E. D. Groover QA Site Supervisor Post Office Box 282 Waynesboro, Georgia 30830 i Tl l'F' @;
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6830 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFCRCEMENT WASHINGTON, D.C.
20555 August 14, 1979 IE Circular No. 79-17 CONTACT PROBLEM IN SB-12 SWITCHES ON GENERAL ELECTRIC METALCLAD CIRCUIT BREAKERS The General Electric Company, Switchgear Departnent in Philadelphia, reported to the NRC on July 3,1979, an intermittent contact problem in SB-12 switches.
This intermittent contact problem will cause a lack of continuity through the "a" contact 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 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 shipped on or after 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 problem. 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 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.
2.
Pending replacement of SB-12 control switches administrative controls 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.
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Enclosure IE Circular No. 79-17 August 14, 1979 Page 1 of 2 LISTING OF IE CIRCULARS ISSUED IN LAST SIX MONTHS Circular Subject Date of Issued to No.
Issue 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 Limitorque Valve Reactor OLs or cps Operators 79-05 Moisture Leakage In 3/20/79 All Holders of Stranded 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 U anium Licensed by KRC 79-09 Occurrences of Split or 6/22/79 All Materials Punctured Regulator Diaphragms Priority I, Fuel In Certain Self Contained Cycle and Operating Breathing Apparatus Reactor Licensees 79-10 Pipefittings Manufactured 6/26/79 All Power Reactor from Unacceptable Material Licensees with a LP and/or OL 79-11 Design / Construction 6/27/79 All Applicants Interface Problem for, and Holders of Power Reactor cps n 2 e "i t ' n v 2... v v v
Enclosure IE Circular No. 79-17 August 14, 1979 Page 2 of 2 LISTING OF IE CIRCULARS ISSUED IN LAST SIX MONTHS Circular Subject Date of Issued to No.
Issued 79-12 Potential Disel Generator 6/28/79 All Power Reactors Turbocharger Problem Operating Facilities and al? Utilities having a CP 79-13 Replacement of Diesel 7/10/79 All Power Reactor Fire Pump Starting Operating Facilities Contactors and all Utilities having a CP 79-14 Unauthorized Procurement and 7/13/79 All Medical Licensees Distribution of XE-133 excep Teletheraphy Medic,i Licensees and to all Raciopharmaceu-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 "O 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 q.1 o ir <T v Ao u.
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