ABSTRACT
Consecutive microwave sintering is a method proposed in this study to dispose soil contaminated by Sr during a nuclear accident by rapidly solidifying the contaminated soil. The results show that soil contaminated with 20 wt% SrSO4 and 30 wt% SrSO4 can be completely solidified by microwave sintering at 1100-1200 and 1300 â, respectively, for 30 min. Sr was found to be cured into slawsonite (SrAl2Si2O8) and glass structures. Moreover, soil sintered at 1300 â has large cured solubility (30 wt.%), good uniformity, and excellent hardness (6.9-7.2 GPa) and chemical durability (below 1.46 × 10-5 g m-2 d-1 at 28 d). Thus, consecutive microwave sintering technology may provide a new method for treating Sr-contaminated soil in case of a nuclear accident emergency.
ABSTRACT
In the field of radioactive waste immobilization, the investigation of irradiation stability is of considerable importance. In this study, uranium-contaminated soil samples were irradiated by 1.5 MeV Xe20+ ions with fluences ranging from 1 × 1012 to 1 × 1015 ions/cm2. Xe20+ heavy-ion radiation was used to simulate the self-irradiation of actinide nuclides. The uranium-contaminated soil samples were sintered via microwaves. Grazing incidence X-ray diffraction results showed that irradiation can cause crystallization of the sample. After irradiation, the Vickers hardness of the samples decreased slightly. Comparative analysis showed that the sample had good radiation resistance, and the leaching rate (28 d) of the sample increased slightly after irradiation, but the overall performance was stable. Our investigation reveals the corresponding mechanism of uranium-contaminated soil irradiation of 1.5 MeV Xe20+ ions.
