Conditioning of radioactive waste by incorporation into clay ceramic materials

Various kinds of clay are used in radioactive waste management as absorbents, buffer materials of repositories and burial sites, and raw materials for obtaining ceramics to immobilize radionuclides. A shown by archaeological discoveries, clay ceramic withstands the action of natural factors for hundreds and thousands of years, which promises reliable immobilization of radionuclides in a ceramic matrix for burial of radioactive waste. The strength of clay ceramic is comparable to that of steel but has greater radiation resistance because of the absence of hydroxyl groups, which determine the radiolysis of compounds based on hydraulic binders. The ceramic does not contain readily soluble salts (e.g., nitrates), is not subject to degradation by microorganisms, and is thermally stable.