High immobilizing capacity of natural granite as glass-ceramic matrix to simulated trivalent actinide waste

One kind of natural granite was selected as matrix for loading simulated trivalent actinide waste (Nd2O3) in an attempt to solve the two major problems of nuclear waste and granite waste simultaneously. The results show that the introduced waste ion plays an important role in the structure change of the matrix. After traditional sintering at 1300 °C for 60 min, the granite was a glass-ceramic structure without nuclear waste doping. With 10 mass % of waste doping, the introduced Nd3+ entered the final waste form, the bulk transformed to completely vitrified. With further waste doping, Nd3+ also entered into the crystal lattice and Nd related compounds grew gradually. Nd was uniformly distributed in the final waste form under the maximum doping amount (76 mass %) in the natural granite. The final waste form has enhanced physical stability. The Vickers hardness and density of the samples increased from 6.79 to 10.08 GPa and from 2.11 to 4.13 g cm−3 with the doping of Nd2O3, respectively. This may be a potential way to dispose both granite waste and nuclear waste.