Waste disposal in underground salt cavities is considered. Theoretical Investigations for spherical and cylindrical cavities included analysis of elastic stress, thermal stress, and stress redistribution due to the development of a plastic zone around the cavity. The problems of temperature distribution and accompanying thermal stress, due to heat emission from the waste, were also studied. The reduction of the cavity volume, the development of the plastic zone, and the resulting stress redistribution around the cavity are presented as functions of cavity depth, internal pressure of cavity, strenzth of salt, and cavity teraperature rise. It is shown that a salt cavity can be designed such that it is structurally stable as a storage container assuming a chemical equilibrium can be established between the liquid waste and salt. (W.D.M.)