Zion Nuclear Power Station

Zion Nuclear Power Station was the third dual-reactor nuclear power plant in the Commonwealth Edison network and served Chicago and the northern quarter of Illinois. The plant was built in 1973, and the first unit started producing power in December 1973. The second unit came online in September 1974. This power generating station is located on 257 acres of Lake Michigan shoreline, in the city of Zion, Lake County, Illinois. It is approximately 40 direct-line miles north of Chicago, Illinois and 42 miles south of Milwaukee, Wisconsin.

The Zion Nuclear Power Station was retired on February 13, 1998. The plant had not been in operation since February 21, 1997, after a control-room operator inserted the control rods too far during a shut down of Reactor 1 and then withdrew the control rods without following procedures or obtaining supervisory permission. Reactor 2 was already shut down for refueling at the time of the incident. ComEd concluded that the plant could not produce competitively priced power because it would have cost $435 million to order steam generators which would not pay for themselves before the plant's operating license expired in 2013.

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