ML20096G558
| ML20096G558 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 01/19/1996 |
| From: | Ray D COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9601250229 | |
| Download: ML20096G558 (2) | |
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Commonw ealth hiison Company 12Salle Generating Station l
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~Xd)1 North 21st Road Wrseilles. 11,613116757
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Tel 8153574761 i
i January 19,1996 United States Nuclear Regulatory Commission i
Washington,D.C 20555 l
Attention: Document Control Desk i
This special report is submitted in accordance with LaSalle Unit 2 Operating License NPF-18, Technical Specification 4.8.1.1.3 and 6.6.c. regarding the 2B Diesel Generator (E22, j
2E22-S001). The 2B DG is manufactured by the Electro-Motive Division (EMD) of GeneralMotors, model EMD20645E4.
i' On December 20,1995 with LaSalle Unit 2 at 100% power, the 2B Diesel Generator (DG) was being operated per LaSalle Operating Surveillance LOS-DG-M3, "lB(2B) l Diesel Generator Operability Test", following a maintenance window on the 2B DG. The purpose of this diesel run was to verify the 2B DG was prepared to be declared operable.
Approximately 10 minutes'after the 2B DG was started, the Nuclear Station Operator (NSO) unsuccessfully attempted to close Air Circuit Breaker (ACB) 2433, the 2B DG t
Output Breaker, onto Bus 243. The 2B DG was subsequently shutdown. Operations and l
Electrical Maintenance (EM) personnel were dispatched to the Unit 2 Division III Switchgear room to investigate the problem. A support arm for a limit switch on the 2B l
DG Output Breaker (ACB 2433) was bent, preventing the breaker from closing when a i
close signal was received. The arm was positioned back to its correct state and the l
breaker was reinstalled into its cubicle. The breaker was realigned and the 2B DG was successfully operated in accordance with LOS-DG-M3, "lB (2B) Diesel Generator Operability Test" and returned to service.
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This failure was not a valid failure in accordance with Regulatory Guide 1.108 and Technical Specification 4.8.1.1.3. The cause of the failure occurred during the racking of this breaker. The 2B DG output breaker, a General Electric Magneblast type breaker, is prone to this type of failure due to the process required to push the breaker back into its cubicle following maintenance activities. The DG was being operated to verify that all completed maintenance activities were done satisfactorily. The proper racking of this breaker was one of the maintenance items being checked.
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9601250229 960119
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PDR ADOCK 05000374 2
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If there are any questions or comments concerning this letter, please refer them to me at (815) 357-6761, extension 2212.
Respectfully, o
D.J. Ray Station Manager LaSalle County Station cc: H. J. Miller, Regional Administrator, Region III H. J. Simons, Acting Senior Resident Inspector, LaSalle IDNS Resident Inspector INPO - Records Center D. L. Farrar, Nuclear Regulatory Services Manager, NORS Central file 2