Immobilization of Nd2O3 as a simulant for trivalent actinide waste in natural aluminosilicate glass

This study used Nd 2 O 3 as a simulant for trivalent actinides to systematically investigate the immobilization performance of a natural aluminosilicate glass (amphibolitic granulite). The microstructure and physicochemical properties of the waste forms were characterized in detail by XRD, FTIR, Nd L 3 -edge XANES, EXAFS, and electron microscopy. Their mechanical properties and chemical durability were evaluated via density and hardness measurements, as well as product consistency testing (PCT). The sample with the maximum solid solubility of 38  wt % Nd 2 O 3 exhibits a high density of 3.37 g/cm 3 , a Vickers hardness of approximately 8.19 GPa, and a normalized mass loss of 1.46 × 10 −6  g m −2 after 42 days. Overall, this natural aluminosilicate matrix is a promising candidate for the immobilization of high-level radioactive waste, indicating outstanding physical and chemical stability.