Silver tungstate–tellurite glass for radioactive iodine immobilization

Abstract

The use of 235U as a fuel in nuclear power plants results in the formation of various fission products. Among them, 129I exhibits a long half-life (t1/2 = 15.7 million years) and tends to easily volatilize, making its capture and treatment necessary. In this study, silver tungstate–tellurite glass (Ag2O·WO3·TeO2 with different mol% of AgI loading) was developed for radioactive iodine immobilization. The glass matrix was investigated by varying the fraction of Ag2O and/or WO3. AgI was added to each matrix, ranging from 0 to 40 mol% in increments of 10 mol%. The glass samples were prepared by the melt-quenching process at 850 °C for 90 min. X-ray fluorescence analysis indicated no significant loss of elements in the samples, whose amorphous phase was confirmed by X-ray diffraction analysis. The effects of increasing the amount of AgI on the glass matrix are discussed considering the results of X-ray photoelectron spectroscopy. The leaching properties of all samples were evaluated via the product consistency test-A. Finally, the normalized release of all elements satisfied the US regulation of 2 g/m2.