Preparation and Characterization of Simulated Waste Forms Zr_xCe_1-xSiO₄

In order to investigate the capabilities of zircon immobilizing Pu(Ⅳ), Ce(Ⅳ) was used as the simulacrum for Pu(Ⅳ), and compounds in the system Zr_xCe_1-xSiO₄(0≤x≤0.5) were sintered for 72 h under 1 500 ℃, using ZrO₂, SiO₂ and CeO₂ powders as raw materials. The phases and structure of synthesized waste forms were characterized by XRD. Moreover, the Rietveld structural refinement method was employed to calculate the crystal cell parameters of samples. The results indicate that the phase of samples keeps the phase of zircon when the value of x is between 0 and 0.05, and the phase of cerium oxide is found when the value of x is more than 0.05. The parameters a, c, V and x in the system of Zr_xCe_1-xSiO₄ (0≤x≤0.05) respectively follow the linear relations.