ML19249B967

From kanterella
Jump to navigation Jump to search
Forwards IE Circular 79-17, Contact Problem in SB-12 Switches on GE Metalclad Circuit Breakers. No Action Required
ML19249B967
Person / Time
Site: Farley  
Issue date: 08/14/1979
From: James O'Reilly
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To: Clayton F
ALABAMA POWER CO.
References
NUDOCS 7909070159
Download: ML19249B967 (2)


Text

C Sa ntc UNITED STATES

'o, NUCLEAR REGULATORY COMMISSION 8'

,,c'j REGION 11 "t.. r b

[

101 MARIETT A ST,, N.W., SulTE 3100 o

P AT LANT A, GEORGI A 30303 o

In Reply Refer To:

RII:JPO O

C 0-3 @

Alabama Power Company ATTN:

F. L. Clayton, Jr.

Senior Vice President P. O. Box 2641 Birmingham, AL 35291 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 respoase is requested applicability to their facilities.If further NRC evalr.it'.ons so indicate, an IE Bulletin wC1 be at this time.

If you have questions issued to recommend or request sp2cific licensee actions.

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 Issued in the Last 6 Months 7909070(5 ct mJ t

Alab.ima Power Company

  • g(,g 3 4 jg79 cc w/ encl:

A. R. Barton Excentive Vice President Post Office Box 2641 Birmingham, Alabama 35291 J. T. Young Vice President-Production Post Office Box 2641 Birmingham, Alabama 15291 C. Hiddinger, Jr.

Ma:uger-Corporate Quality Assurance Post Office Box 2641 Birmingham, Alabama 35291 H. O. Thrash Manager-Nuclear Generation Post Office Box 25'41 Birmingham, Alabama 35291 H. G. Hairston, III Plant Manager Drawer 470 Ashford, Alabama 36312

h. t.

Hollands, Jr.

QA Sopervisor Pu:.t office Box U Ashford, Alabama 36312 5

i a t > ' u 41

, J'j n R (p3 E Eq j jp [

1:it j U, m a d u lfu b a :

J 2

.o;

Accession No:

7908090272 SSINS:

6830 UNITED STATES NUCLEAR REGUI.ATORY COMMISSION OFFICE OF INSPECTION AND ENTORCEMEh7 WASHIhGTON, D.C.

20555 August 14, 1979 IE Circular No. 79-17 CONTACT PROBLEM IN SB-12 SWITCIIES ON GENERAL ELECTRIC METALCLAD CIRCUIT BREAKERS The General Electric Company, Switchgear Department 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 breakar.

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 t $ move laterally relative to the contact arm, occasionally resulting in improper "a" contact wipe. The vorn die has been corrected, and all switches shipped on or after July 1, 1379, include this correction. A review of the history of these components indicates that switches shipped in the time period of August 1, :t978 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.

NOH

^

a.,

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 for Special Nuclear Training Records Material Licenses in Su eguards Greap I 79-04 Loose Locking Nut On 3/16/79 All Holders of Reactor OLs or cps Limitorque Valve Operators 79-05 Moisture Leakage In 3/20/79 All Holders of Reactor OLs or cps Strarded Wire Conductors 79-06 Failute to Use Syringe 4/19/79 All Holders of Medical Licensees and Battle Shields in 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 Licensed by NRC Enriched Uranium 79-09 Occurrences of Split or 6/22/79 All Materials Punctured Regulator Diaphragms Priority I, Fuel In Certain Self Contained Cycle and Operating Reactor Licensees Breathing Apparatus 79-10 Pipefittings Manufactured 6/26/79 All Power Reactor Licensees with a from Unacceptable Material CP and/or OL 79-11 Design / Construction 6/27/79 All Applicants Interface Problem for, and Holders of Power Reactor cps

(..,

L

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 Fire Pump Starting Operating Facilities and all Utilities Contactors having a CP 79-14 Unauthorized Procurement and 7/13/79 All Medical Licensees Distribution of XE-133 except Teletheraphy Medical 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 Licenstes And A Radiographer t '/ "

[} O U