Patent ID: 8351562

Claim:
A method of storing high level radioactive waste comprising: (a) providing a container comprising an inner shell forming a cavity having a top and a bottom, an outer shell surrounding the inner shell so as to form a space therebetween, a floor, the inner and outer shells extending upward from the floor, and at least one opening in the inner shell that forms a passageway from the space into the bottom of the cavity; (b) placing a canister containing high level radioactive waste into the cavity; and (c) subsequent to step (b), positioning a lid having at least one inlet vent and at least one outlet vent atop the inner and outer shells so that the at least one inlet vent forms a passageway from an ambient atmosphere to the space and the at least one outlet vent forms a passageway from the top of the cavity to the ambient atmosphere; wherein during step (b) the lid is not positioned atop the inner and outer shells and the container has an open top end.