Typical Dry Cask Storage System

At some nuclear reactors across the country, spent fuel is kept on site, above ground, in systems basically similar to the ones shown here. Once the spent fuel has cooled, it is loaded into special canisters. Each canister is designed to hold approximately 2-6 dozen spent fuel assemblies, depending on the type of assembly. Water and air are removed. The canister is filled with inert gas, and sealed (welded or bolted shut).

Some canisters are designed to be placed vertically in robust above-ground concrete or steel structures.

Some canisters are designed to be stored horizontally in above-ground concrete bunkers, each of which is about the size of a one-car garage.