Several fire crews were called to the Byron Exelon Plant late Monday morning for what's being called a rare and unusual event that involved a power outage in one of its two towers.
A spokesman from the plant tells 13 News, Unit 2 was taken off line for regular maintenance and the facility lost power. The exact cause of the outage is under investigation.
The company issued a news release saying, "the nuclear facility's diesel generators activated as designed to provide power to the facility when there is a loss of offsite power to the facility. The facility remains in a safe condition. Station engineering experts are looking into the cause of the loss of offsite power."
The incident is classified as an "Unusual Event," the lowest of four emergency classifications established by the U.S. Nuclear Regulatory Commission.
Several area fire departments were called in as a precaution.
Unit 1 was not affected by the outage.
Wisconsin Emergency Management issued a statement saying it assists with nuclear offsite emergency plans for the Byron plant for Walworth, Rock, Lafayette and Green Counties.