Exelon reports 'small fire' in LaSalle 1 unit transformer

Exelon Corp. said a lightning protection device that malfunctioned yesterday at its LaSalle nuclear station in Illinois caused a small fire in the main transformer and resulted in the shutdown of the unit 1 reactor.

The fire was extinguished in about 10 seconds, said Adam Slahor, a plant spokesman. Workers are still assessing the damage and there is no timeline for the reactor's return, according to the spokesman.

Slahor said he couldn't say if the main transformer would need to be replaced or could be repaired. There is an investigation into the extent of the damage.

The unit is one of two reactors at the LaSalle station, located about 75 miles southwest of Chicago. LaSalle 1 can supply 1,138 megawatts to the grid and LaSalle 2 about 1,150 megawatts, according to Exelon's Web site.

LaSalle 2 is operating at full capacity, according to the U.S. Nuclear Regulatory Commission.