Low-temperature fabrication of glass-based iodine waste forms via a novel preparation method

Abstract

Spent nuclear fuel contains 129I, which has deleterious effects on human health. This study focused on the immobilization of iodine waste forms via a novel preparation method with B2O3–Bi2O3–ZnO–SiO2 glass at 500–600 ​°C. The XRD results manifest that the sample with 30 ​wt% iodine sintered at 550 ​°C exhibits an obvious amorphous phase. The density of the samples with different iodine contents increases with the temperature increasing, so does the amorphous fraction except for 25 ​wt%. The FT-IR results reveal the matrix is mainly composed of [BO3], [BO4], [SiO4], and [BiO6]. TGA analysis shows high water content in the prepared samples. SEM-EDS results present that at 550 ​°C one part of the iodine is chemically immobilized into the glass matrix, and meanwhile, the other physically packed by the vitrified bulk. Our findings demonstrate the potential of the new preparation method for the disposal of iodine waste forms.