ML19312C404
| ML19312C404 | |
| Person / Time | |
|---|---|
| Site: | Oconee, Mcguire, McGuire  |
| Issue date: | 04/14/1978 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Parker W DUKE POWER CO. |
| References | |
| NUDOCS 7912130927 | |
| Download: ML19312C404 (1) | |
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RII:JPO 50-369, 50-370 50-269, 50-270 50-287 Duke Power Company Attn:
Mr. William O. Parker, Jr.
- Vice President, Steam Production P. O. Box 2178 422 South Church Street Charlotte. North Carolina 28242 Gentlemen:
Enclosed is IE Bulletin No. 78-05 which requires action by you with reEard to your power reactor facility (ies) with an operating license or a cor.struction permit.
Should you have questions regarding this Bulletin or the actions required of you, please contact this office.
Sincerely, Jaraes P. O' dilly
/
Director
Enclosures:
1.
List of IE Bulletins Issued in 1978 cc w/ encl:
J. f Rogers, Project Manager McGuire Nuclear Station P. O. Box 2178 Charlotte, North Carolina 28242 M. D. McIntosh, Plant Manager McGuire Nuclear Station P. O. Box 488 Cornelius, North Carolina 28031 J. E. Smith, Station Manager Oconee Nuclear Station
^^
79121307/ '/
P. O. Box 1175 Seneca, South Carolina 29678
UNITED STATES NUCLEAR PIGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D. C.
20555 April 14, 1978 IE Bulletin No. 78-05 MALFUNCTIONING OF CIRCUIT BREAKER AUXILIARY CONTACT MECHANISM -
GENERAL ELECTRIC }ODEL CR105X Description of Circu= stances:
The Sacramento Municipal Utility District recently reported a proble:
encountered with the operation of the GE Model CR105X auxiliary contact mechanism installed in a 480 volt circuit breaker. Investigation into the cause for the inability to shutdovn a booster supply fan (SF-A-7) in the control roo: emergency air conditioning system 7,caled that an auxiliary contact (GE Model CR105X) had failed in the closed position, preventing the fan's power supply circuit breaker from opening. The specific cause for failure was binding of the plunger arm due to burrs and nicks on its surface.
An investigation was conducted by the licensee to determine the extent of usage of this type auxiliary contact in other circuits throughout the reactor power plant.
Approximately fifty (50) positions in the nuclear service motor control centers were identified as having a similar type auxiliary contact mechanism.
It was also determined that many of the affected systems which require contact operation similar to that described above, either permit or provide a safety feature function during e=ergency conditions.
An example of this type application is auxiliary contacts that must open to permit closing of certain safety related valves fro = 480 volt motor control centers.
The attached GE Service Advice Letter and associated instruction / drawing sheet were sent to all nuclear power reactor facilities by GE Field Service Offices.
The letter, together with the instruction / drawing sheet identifies the problec and provides the recommended corrective ai:t ion.
Action To Be Taken By Licensees:
FOR ALL PO*n'ER REACTOR FACILITIES WITH AN OPERATING LICENSE OR CONSTRUCTION PERMIT:
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