Effect of matrix type on leachability of radionuclides from solidified wastes

The knowledge is summed up of the effect of chemical composition of borosilicate glass used in radioactive waste vitrification. The effect is discussed of B2O3 on corrosion stability of solidified wastes, of Al2O3 on chemical resistance of the glass, of ZnO on resistance to hydrolysis. The effects of other compounds are also discussed. In more detail, the possible effect is described of devitrification on the rate of leaching. The knowledge is also presented on the leachability of radionuclides in other materials used in radioactive waste solidification, such as ceramics, bitumens, cements, concretes. Leachability from various materials is compared for cesium and other components. Basic knowledge of this topic is summarized. (E.S.)