中文摘要：

为研究锆英石基An4＋（四价锕系核素）放射性核素固化体的性能,利用Ce4＋作为An4＋的模拟替代物质,以ZrO2、SiO2和CeO2粉体为原料,采用高温固相法制备出包容20%（物质的量,下同）Ce4＋的锆英石基固化体,利用60Co源γ射线辐照装置对其进行572.1kGy的γ射线辐照.利用粉末X射线衍射仪、扫描电子显微镜和电感耦合等离子体质谱仪对γ射线辐照前后固化体的物相、结构、微观形貌及模拟核素的浸出行为进行了研究.结果表明,固化体中虽包容有20%的Ce4＋,但其主物相仍以锆英石物相为主,与标准样品相比晶胞参数发生10-4nm量级的变化,经γ射线辐照后样品晶胞参数仅发生了10-5～10-4nm量级的微弱变化,在pH6.5的HCI浸出液中Ce4＋的平衡浓度低于0.30μg/L.

英文摘要：

In order to investigate the capability of zircon as radioactive waste forms for immobilizing tetravalent actinides,tetravalent europium（Ce4＋） was used as the simulacrum for tetravalent actinides,the waste forms containing 20% Ce4＋ were successfully synthesized by high temperature solid reaction and using ZrO2,SiO2 and CeO2 powders as starting materials.Then,the as-gained samples were irradiated using a 60Co γ-ray source with 572.1kGy doses.The phases,structure,microcosmic shape and leaching yield of synthesized waste forms before and after γ-ray irradiation were characterized by the help of X-ray diffraction（XRD）,scanning electron microscopy（SEM） and inductively coupled plasma mass spectrometry（ICP-Mass）.The zircon phase was the major phase for the as-gained waste forms although containing 20% Ce4＋.The alteration of 10-4 nm magnitude in the crystal cell parameters was measured（cf the standard XRD card of zircon）.The crystal cell parameters of samples changed between 10-5 and 10-4nm magnitude before and after irradiation.The equilibrium concentration of Ce4＋ in HCI lixivium（pH=6.5） was less than 0.30μg/L.