ST. LOUIS (AP) — A central Missouri nuclear plant is expected to remain shut down for several days while Ameren Missouri workers perform tests and repair damage from a small fire Friday night.

The fire was in the “non-nuclear” power-generation side of the Callaway County nuclear facility, and the plant will stay offline until the workers are finished.

Ameren spokesman Cleveland Reasoner says power cables that connect the plant to the electric grid shorted, causing some nearby insulation to catch fire.

Ameren says the nuclear reactor automatically shut down and no radioactivity was released.

The Callaway County reactor supplies about 20 percent of the electricity Ameren sells to its 1.2 million customers. Other Ameren plants will make up for the lost power while the nuclear plant is offline.