Method of storing high level radioactive waste

A method of storing high level radioactive waste comprising:

• (a) providing a body portion comprising a floor, an open top end, an inner shell extending upward from the floor and forming a cavity, an outer shell extending upward from the floor and surrounding the inner shell so as to form a space therebetween, and at least one opening in the inner shell that forms a passageway from a bottom of the space into a bottom of the cavity;
• (b) placing a canister containing high level radioactive waste into the cavity;
• and
• (c) positioning a lid having at least one outlet vent atop the inner and outer shells so as to enclose the open top end of the body portion and the at least one outlet vent forms a passageway from a top of the cavity to the ambient atmosphere;
• and
• wherein at least one inlet vent forms a passageway from an ambient atmosphere to a top of the space to facilitate natural convective cooling of the canister containing high level radioactive waste.