Reaction between simulated high-level radioactive waste and Y 2O 3-stabilized zirconia in air

Abstract

The reaction behavior and phase formation have been studied in the reaction between simulated high-level radioactive waste (HLW) and Y 2O 3-stabilized zirconia with fluorite structure at temperatures up to 1550°C in air. In the temperature range from 1000 to 1200°C, a single phase with fluorite structure has been made in the composition range from 0 to 9 mol% simulated HLW. In the range of 9–20 wt% simulated HLW, there has been a two-phase region of the fluorite and scheelite phases. The lattice parameter of the fluorite phase, in which the actinide and rare earth elements have been incorporated, increases with the content of simulated HLW according to the equation: a(nm) = 0.5144 + 0.00015x, where x is the content of simulated HLW in wt%. The scheelite phase SrMoO 4 was made of Sr and Mo excluded from the fluorite lattice, of which tetragonal lattice parameters were a(nm) = 0.538 − 0.539 and c(nm) = 1.15 − 1.19.