Zion Nuclear Power Station
Zion Nuclear Power Station was the third dual-reactor nuclear power plant in the Commonwealth Edison (ComEd) 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 (1.04 km 2) of Lake Michigan coastline, in the city of Zion, Lake County, Illinois. It is approximately 40 direct-line miles north of Chicago, Illinois and 42 miles (68 km) south of Milwaukee, Wisconsin. The Zion Nuclear Power Station was retired on February 13, 1998. The plant had not been in operation since February, 1997, after a control-room operator accidentally shut down Reactor 1 and then tried to restart it without following procedures. 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. This analysis was predicated on no license extension which at the time was the norm, however since then multiple plants have replaced steam generators and extended the license by 20 years. All nuclear fuel was removed permanently from the reactor vessel and placed in the plant's on-site spent fuel pool by March 9, 1998. Plans were to keep the facility in long-term safe storage ( SAFSTOR) until Unit 2's operating license expires on November 14, 2013. Decontamination and dismantlement were to begin after this date. The estimated date for closure was December 31, 2026. On August 23, 2010, it was announced that the Nuclear Regulatory Commission approved the transfer of Exelon's (ComEd's parent company) license to EnergySolutions of Salt Lake City. The company will begin the 7-10 year process of dismantling the site, and will eventually haul away pieces of the plant to its property in Utah. After this is complete, Exelon will resume responsibility and transfer the spent fuel into concrete casks from its current pool. The power plant is the tallest structure in Lake County, IL.

Unit 1 Unit 2 Operating status Permanently closed Permanently closed Reactor type Pressurized water Pressurized water Reactor manufacturer Westinghouse Westinghouse Generation capacity 1,040 megawatts 1,040 megawatts Operational date June 1973 December 1973 Closure date January 1998 January 1998