Long-term storage of depleted uranium in rock salts - 5366

Depleted uranium is a waste product of nuclear fuel cycle based on thermal reactors, but it can be used in future. More than a million tons of depleted uranium has accumulated in the world and its safe storage is an expensive and dangerous task. The concept of long-term storage of uranium in rock salts was developed in the Radium Institute. The concept is based on the experience of isotopes production by peaceful nuclear explosions in rock salts. High isolating properties of rock salts to radionuclides were demonstrated during tests. The rate of radionuclide migration in the rock salts is less than 5 mm/year. We suggest storing depleted uranium in the form of oxides in the cavities created in rock salts by hydro washout. Low solubility of uranium oxide U₃O₈ in brines has been demonstrated. Airlift technology can be used to extract uranium from depths of up to 400 m. The safety of depleted uranium long-term storage has been verified by modeling of its migration in the halite. (authors)