Used Fuel Storage
TMI Unit 1 uses spent fuel pools to store its used fuel. The used fuel is stored under at least 20 feet of water, which provides adequate shielding from radiation for anyone near the pool. Water is a natural shield from radiation. The used fuel assemblies are moved from the reactor vessel into the used fuel pool along the bottom of water canals, always remaining under water to protect workers. The movement of the fuel assemblies occurs during refueling outages, which take place every two years at TMI Unit 1. After the used fuel is removed from the reactor, it is replaced with new fuel for the next operating cycle.
Three Mile Island has ample space to safely store used fuel. TMI's used fuel storage facility was initially designed larger than most other nuclear plant's storage facilities. TMI will add 432 additional storage cells to its existing used fuel storage facility in 2009, bringing the total storage space to about 2000 used fuel assemblies. With the additional storage cells, TMI will have enough space in its existing used fuel storage facility to last until 2024, when we expect the U.S. Department of Energy to have a national storage facility in operation.
The U.S. Department of Energy announced plans in 2009 to form a blue-ribbon commission to evaluate alternatives to the proposed Yucca Mountain national storage facility. The blue-ribbon commission will evaluate the best options for a national storage facility that will store used fuel from the nation's nuclear plants.