Preparation and Leaching Reliability of Multi-Pyrochlore Ceramic Immobilizations Materials

Pyrochlore has been extensively studied as one of the most ideal candidates for nuclear wastes immobilization, due to its excellent geological stability, radiation tolerance, low chemical leaching rate, and high thermal stability. However, the artificial pyrochlore has a relatively high selectivity for curing nuclides, which limits the types and quantity of its target species. To tackle the challenge, a variety of simulated nuclides(Eu, Sm and Nd) were successfully incorporated into the pyrochlore lattice by solid-state reactions. The experimental results show that the multi-pyrochlore exhibits a homogeneous structure with single phase. Leaching tests indicate that the multi-pyrochlore owns excellent leaching resistance and chemical stability, which enables multi-pyrochlore a promising immobilization material for high-level waste.