Capability of Resisting γ-ray Irradiation and Immobilization for Simulated Trivalent Actinides on Synthesized Zircon

In order to investigate zircon immobilization for trivalent actinides and its γ-ray irradiation stability, zircon was synthesized at 1 500 ℃ for 22 h using ZrO₂, SiO₂ and Eu₂O₃ (2.5%-10% in mole) powders as the starting materials and trivalent europium (Eu³⁺) as the simulacrum. Then, γ-ray irradiation experiment of the condensates was conducted. The phases, structure and surface morphology of the synthesized condensates and the corresponding irradiated condensates were characterized by X-ray diffraction (XRD), laser Raman microprobe (RMP) and scanning electron microscopy (SEM). The results indicate that the main phase of the synthesized condensates is zircon, and it still shows a high crystallinity although 2.5%-10% of Eu₂O₃ is added in the starting materials. With the increase of Eu₂O₃ in the starting materials, the metamict degree of the synthesized condensates is slightly increased. Zircon is still the main phase in the irradiated condensates though they are irradiated by 579.1 kGy of γ-ray. The crystallinity of irradiated samples is slightly weakened hence the degree of metamict slightly increased.