Fissioning, or splitting of uranium atoms within nuclear fuel, produces energy in the form of heat that is used to generate electricity, power nuclear vessels like submarines, or create medical isotopes.

Fission by-products created within the spent nuclear fuel continue to emit radiation until they achieve a stable form. This emission of energy is called radioactivity. Because of potential harm from radiation, the spent nuclear fuel must be stored in shielded basins of water, or in dry storage vaults or containers until its radioactivity decreases naturally ("decays") to safe levels. This can take days or thousands of years, depending on the type of fuel.

The Idaho Chemical Processing Plant's Irradiated Fuel Storage Facility is an example of an air-cooled, vault-type dry storage facility for spent nuclear fuel.

Spent nuclear fuel that has been cooled may be moved to a "dry" storage area. Using remotely handled equipment, the spent fuel is removed from the pool, dried, and placed in specially designed canisters. The canisters are either stored in a shielded container or in a shielded vault-type dry storage facility where the circulation of air provides cooling. Dry storage reduces corrosion concerns associated with extended storage of fuel under water, provides all the safety characteristics of wet storage, and is less expensive to operate.