Synthesis of pyrochlore-borosilicate glass-ceramics for immobilization of high-level nuclear waste

In this work, borosilicate based glass-ceramics with pyrochlore as crystalline phase for immobilization of high-level nuclear wastes (HLWs) were successfully synthesized by a one-step heat-treatment method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS) demonstrate that the obtained glass-ceramics show a regularly and uniformly distributed single pyrochlore (Ca,Na) (Nb,Ti)(2)Nd0.67O6F crystalline phase. Moreover, the glass-ceramics prepared show LRNa, LRB, LRAl, LRsi, LRNd, LRTi, and LR(Nb )of about 6.8 x 10(-3), 3.7 x 10(-4), 1.5 x 10(-2), 2.2 x 10(-3), 3.0 x 10(-5), 5.1 x 10(-5) and 5.5 x 10(-6) g m(-2 )d(-1) respectively after 28 leaching days, which are comparable to stable glass-ceramics for HLW immobilization. The results of this study are expected to provide an experimental reference for the engineering synthesis of glass-ceramics for the immobilization of certain HLWs.