MARSEILLES, Ill. — Exelon Generation’s La Salle County Generating Station re-energized power to the switchyard and terminated the “unusual event” at 8:14 a.m. Thursday.
The unusual event was declared at 3:11 p.m. Wednesday when power from a switchyard to the station was interrupted. Station technical experts believe the power interruption was a result of a lightning strike within the station’s switchyard.
A switchyard is a large substation that carries electricity to and from the plant.
The plant responded as expected, safely and without incident. The station’s multiple layers of safety and protection systems are designed to ensure safe shutdown of the plant in cases of electrical disturbances. The station’s locomotive-sized backup diesel generators immediately started up and provided electricity to the site until the power was restored.
Both Unit 1 and Unit 2 remain offline. Station operators will perform multiple safety checks and follow detailed procedures to return both units to service.
An unusual event is the lowest of the four emergency classifications as established by the Nuclear Regulatory Commission.
La Salle Generating Station is located about 75 miles southwest of Chicago near Marseilles, Ill. At full power, the facility’s two generating units produce more than 2,200 megawatts around the clock, enough electricity for 2.3 million typical homes.