A mined facility for the disposal of radioactive waste, using waste packages and the natural geological formations as barriers to provide waste isolation: The deep geological repository idea involves the encapsulation of used nuclear fuel in long-term engineered casks which are placed and sealed within excavated rooms in a geological formation at a determined depth of 500 to 1000 meters below the Earth's surface.

A geological repository involves the construction of a vault within a stable, low permeability bedrock using conventional mining techniques. The bedrock and other engineered barriers are supposed to provide ecological safety over an extended time.