Hazardous waste disposal using salt

A hazardous material storage repository, comprising:

• a borehole that extends into the Earth from a terranean surface, the borehole comprising a first portion that comprises an entry at the terranean surface that extends a first depth from the terranean surface, a second portion that extends from the first portion into a subterranean salt formation, and a hazardous material storage borehole portion formed in the subterranean salt formation, the first portion larger than the second portion;
• at least one storage canister positioned in the hazardous material storage borehole portion, the storage canister sized to fit from the borehole entry through a substantially vertical borehole portion of the borehole, and into the hazardous material storage borehole portion of the borehole, the at least one storage canister comprising an inner cavity sized to enclose nuclear waste material that comprises TRansUranic (TRU) waste that comprises transuranic radioisotopes;
• a seal positioned in the borehole, the seal isolating the hazardous material storage borehole portion of the borehole from the entry of the borehole;
• and
• a shelf formed within the borehole and at an interface between the first portion and the second portion, the shelf sized to support a TRU waste container configured to enclose a plurality of storage canisters including the at least one storage canister.