The Byron Nuclear Generating Station is a nuclear power plant located in Ogle County, Illinois, 2 miles east of the Rock River. The reactor buildings were constructed by Commonwealth Edison and house two Westinghouse pressurized water reactors, Unit 1 and Unit 2, which first began operation in September 1985 and August 1987 respectively. The plant was built for Commonwealth Edison and is currently owned and operated by its parent company, Exelon Corporation.