Solidification of simulated actinides by natural zircon

摘要

Natural zircon was used as precursor material to produce a zircon waste form bearing 20wt% simulated actinides (Nd_2O_3 and UO_2) through a solid state reaction by a typical synroc fabrication process. The fabricated zircon waste form has relatively good physical properties (density 5.09g/cm~3, open porosity 4.0%, Vickers hardness 715kg/mm~2). The XRD, SEM/EDS and TEM/EDS analyses indicate that there are zircon phases containing waste elements formed through the reaction. The chemical durability and radiation stability are determined by the MCC-1 method and heavy ion irradiation; the results show that the zircon waste form is highly leach resistance and relatively stable under irradiation (amorphous dose 0.7dpa). From this study, the method of using a natural mineral to solidify radioactive waste has proven to be feasible.