The owner and operator of Three Mile Island has filed paperwork with the Nuclear Regulatory Commission that details plans for the power plant after its scheduled shutdown in September.
Exelon Generation said Friday that it continues to seek a legislative solution to save TMI but has a responsibility to prepare the plant for decommissioning.
In the federally required Post Shutdown Decommissioning Activities Report, Exelon outlined a plan to dismantle the station’s cooling towers and other large components, beginning in 2074.
Facility staffing will decrease in three phases from 675 employees in 2017 to 50 full-time employees in 2022.
Used nuclear fuel will be transitioned into a spent fuel pool then moved to dry cask storage by the end of 2022, Exelon said.
Spent fuel pools are where spent fuel assemblies are kept under at least 20 feet of water to shield anyone near the pool from radiation. The assemblies are moved into the water pools from the reactor along the bottom of water canals so that the spent fuel is always shielded to protect workers, according to the NRC’s website.
Dry cask storage allows spent fuel that has already been cooled in the spent fuel pool for at least one year to be surrounded by inert gas inside a container. The containers, or casks, are typically steel cylinders either welded or bolted closed to confine the spent fuel, according to the NRC. Each cylinder is surrounded by additional steel, concrete, or other material to shield workers and the public from radiation.
TMI’s used nuclear fuel in dry cask storage will be protected in a hardened facility with multiple layers of structural, human and electronic security, Exelon said.
Exelon announced in 2017 that it would shut down Three Mile Island unless the state stepped in to help. The Illinois-based company said TMI hasn’t turned a profit in years because of low wholesale power prices and the “lack of federal or Pennsylvania energy policies that value zero-emissions nuclear energy.”
Cheap natural gas from Marcellus Shale reservoirs has been flooding the power market. The nuclear power industry has been lobbying lawmakers in Pennsylvania and other states for a financial rescue.