An unusual event forces the shutdown of a nuclear plant in Byron, Illinois. Officials at Exelon say a nuclear reactor unit went down Monday morning. A spokeswoman says the off-site supply of power went down, forcing Exelon to take Unit Number Two offline. The unit had to be depressurized, which let off radioactive steam into the air.

Officials say the amount of radioactivity was minimal and well within federal guidelines. The spokesperson says the incident was considered the lowest of the four emergency classifications established by the U.S. Nuclear Regulatory Commission. The plant was not evacuated and there were no injuries reported. Byron is located about 10 miles southwest of Rockford.

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