Material for glass vitrification of low level radioactive waste

Vitrifying materials for glass vitrification of low level radioactive wastes are controlled to provide a glass comprising 40 to 60% of SiO2, 3 to 15% of Al2O3, 7.5 to 15% of B23, 1 to 10% of CaO, 0.1 to 10% of P2O6 and 0 to 30% of Na2O by weight%. SiO2 and Al2O3 are ingredients as the skeleton of vitrification products and have a great effect of improving chemical durability. B2O3 has a function as a melting accelerator and it also improves the chemical durability. P2O5 improves devitrification stability as well as it improves the chemical durability. Na2O has an effect of devoluming sodium nitrate which is low level radioactive liquid waste dry powders and impregnating them into the glass. Accordingly, when they are vitrified in admixture with low level radioactive wastes, sodium nitrate and calcium pyrophosphate, as the main ingredients, can be devolumed in an industrial scale, as well as the chemical durability can be improved. (T.M.)