Zion, on the shores of Lake Michigan, housed two sets of water under pressure: Unit 1 operated from 1973 to 1997; Unit 2 from 1974 to 1996. Both were declared permanently closed in 1998 through the factory operator at that time, Commonwealth Edison (which is the component of Exelon). In 2010, reactor licenses were transferred to the Energy Subsidiary Zionasolutions in a first degree provision for accelerated degradation. Zion sets are now components of the energy constellation portfolio from the separation of regulated and competitive energy corporations of the Exelon generation.
The way we were: Zion’s two units operated until the late 1990s. (Image: NRC)
Releasing the site for unrestricted use means that any residual radiation is below NRC’s limits and will no longer be under NRC regulatory controls, the regulator said. The NRC’s determination that ZionSolutions has satisfactorily finished decommissioning of the plant and decontamination of the site to meet the agency’s radiation protection standards clears the way for ZionSolutions to transfer the spent fuel storage facility licence to Constellation Energy Generation, which will be responsible for the security and protection of Zion’s spent fuel facility until an offsite storage facility or permanent disposal site becomes available.
According to Constellation, the USD1 billion, 10-year project to decommission the Zion plant is the largest commercial nuclear plant dismantling ever undertaken in the USA.
Constellation is free to use the remainder of the former plant site for any application, the NRC said.