ML20080F714
| ML20080F714 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 01/19/1995 |
| From: | Ray D COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9501300198 | |
| Download: ML20080F714 (1) | |
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Commonwealth Edison L-S:lle County Nuctur Ststion 2001 N. 21st Road Marseilles, Illinois 61341 Jcnuary 19, 1995 Telephone 815/3574761 i
U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C.
10555 This special report is submitted in accordance with LaSalls Unit 2 Operating License NPF-18, Appendix A, and Technical Specifications 4.8.1.1.3 and 6.6.c i
regarding the Unit 2 Diesel Generator (E22.2E22-S001), manufactured by the Electro-Motive Division of General Motors Lorporation.
On December 21, 1994, with LaSalle Unit 2 at 100% power, the Unit 2B HPCS Diesel Generator (DG) was being operated per LaSalle Operating Surveillance LOS-DG-M3, "1B(2B) Diesel Generator Ope; ability Test", following a modification associated with the engine's governor. After the engine had reached its rated speed (900 rpm), the Nucitar Station Operator (NSO) began to adjust the speed of the engine's governor to obtain the required frequency to allow engine synchronization to the grid. When these adjustments were made, it was noted by the NSO that the speed of the governor reacted opposite of the given signal (a raise demand signal resulted in actual lowering of speed).
This abnormal operation also occurred using the local engine controls in the Diesel Room.
The 2B DG was then shutdown for further investigation by System Engineering and Electrical Maintenance Personnel. This failure was not a valid failure in accordance with Regulatory Guide 1.108 and Technical Specification 4.8.1.1.3.
The abnormal yeration of the 2B DG governor was caused by a design error made on the governor synchronizing motor during the engine construction period.
The investigation of this event revealed that the synchronizing motor for the 2B DG Governor was ir. correctly wired during original installation in the 1980's.
The wiring problem was cortected at that time by reversing leads in the connector, and the appropriate drawings were revised. This wiring change allowed the synchronizing motor to operate properly.
In December 1994, the synchronizing motor was replaced for the first time since original installation. There was no documentation available to alert the station to the fact that a wiring change would be needed during replacement of the synchronizing motor. The synchronizing motor external circuit has now been modified and drawings are being updated accordingly. On December 22, 1994, the 2;) DG was successfully operatsd in accordance with LOS-DC W3 and declared operable.
D. J. Ray Station Manager LaSalle County Station DJR/CTK/lja
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cc NRC Region III Administrator
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NRC Senior Resident Inspector l
INPO - Records Center IDNS Resident Inspector Nuclear Licensing Administrator
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