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.
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.
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2011年第6期938-943,共6页
China Environmental Science
基金
国家"863"项目(2009AA050703)
国家自然科学基金委员会-中国工程物理研究院联合基金资助(10676030)
西南科技大学核废物与环境安全国防重点学科实验室资助项目(10zxnk03)
关键词
锆英石
四价
锕系核素
固化
性能
zircon
tetravalence
actinides
immobilization
capability
