Properties of pellet cement-glass package

A new solidification technique using cement-glass, which is a mixture of sodium silicate, silicon phosphate and cement is presented. It was developed to solidify sodium sulfate or sodium borate pellets generated from nuclear power plants. The optimum composition of Na2O, SiO2 and P2O5 · 2SiO2, main components of cement-glass, was defined to be 1:2:1 by studying the solidification mechanism. Polymer impregnated concrete was selected as material of the container to increase the stability. Since the package consists of inorganic materials, it shows good fire resistance and radiation stability. Added cement absorbs free water which is generated by the solidification reaction of Na2O, SiO2 and P2O5 · 2SiO2. Then, soluble pellets can be solidified without dissolving some part of them. Since polymer impregnated concrete has little porosity, the pellet cement-glass package which uses a polymer impregnated concrete container shows very low leachability