Disposal in mines and salt domes

The use of mined underground space for storage and disposal of hazardous materials has a long history of successful application in industrial societies. The current technology for storing hazardous waste in underground openings allows the disposal or storage of a wide range of wastes. Conventional mines can store packaged, dry, nonexplosive, nonflammable, zero-vapor-pressure wastes. Solution mines can store nonreactive liquids and slurries in bulk form; no packages are required. Design considerations for use of conventional mines include mine type, depth, rock mechanics, layout and access, safety, ventilation, and surface facilities. Considerations for solution mines are depth range, rock mechanics, layout and access, safety, cavern discharges, and surface facilities. Case studies and evaluations have been conducted for mines in Germany, Minnesota, Missouri, Ohio, and Canada. Case studies for solution mines were conducted in Canada, Holland, Texas, Louisiana, and New York. Environmental effects of the process are highly variable depending on the mine type, waste, and handling. The EPA has sponsored studies and development projects in recent years covering the fields of encapsulation, storage, and fixation technologies. Present studies, tests, and demonstrations for nuclear-waste storage are continuing in salt, basalt, tuff, and crystalline-rock formations. 14 refs., 3 figs