Effects of additives on the thermal stability of silver tellurite glass system.

• Al, Bi, Pb, V, Mo, W were added to silver tellurite glass for I immobilization. • The thermal properties of matrix for radioactive I immobilization were evaluated. • The glass stability decreased by adding Bi 2 O 3 or PbO in silver tellurite glass. • The addition of MoO 3 or WO 3 raised T g and T c while keeping the glass stability. 129I is notable for its long half-life of 1.57 × 107 y and high mobility in the environment. It should be immobilized in a geological disposal environment through a stable waste form. In this study, additives including Al, Bi, Pb, V, Mo, and W were added to silver tellurite glass, and the thermal properties of this matrix for radioactive iodine immobilization were evaluated. The glasses were prepared by the melt-quenching method, including the melting of the glass precursor mixtures at 800 °C for 1 h. The loading of iodine in the matrix was approximately 11–15% by weight, excluding the oxygen element. Differential scanning calorimetry was performed to evaluate the thermal properties of the glass samples. The glass transition temperature (T g), crystallization temperature (T c), and glass stability were investigated. The addition of MoO 3 or WO 3 in the glass system increases T g and T c while maintaining the glass stability. [ABSTRACT FROM AUTHOR]