偏高岭土基地聚合物在处理低水平放射性废液中的应用研究  

Application of metakaolin based polymer in the treatment of low level radioactive waste liquid

作　　者：成建峰 张奇 宗自华[1,2] 董艳辉 曹胜飞[1,2] 彭立园[1,2] CHENG Jianfeng;ZHANG Qi;ZONG Zihua;DONG Yanhui;CAO Shengfei;PENG Liyuan(Beijing Research Institute of Uranium Geology,Beijing 100029,China;CAEA Innovation Center for Geological Disposal of High-Level Radioactive Waste,Beijing 100029,China;Key Laboratory of Shale Gas and Geoengineering,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China)

机构地区：[1]核工业北京地质研究院,北京100029 [2]中国国家原子能机构高放废物地质处置创新中心,北京100029 [3]中国科学院地质与地球物理研究所,北京100029

出　　处：《世界核地质科学》2025年第1期123-133,共11页World Nuclear Geoscience

基　　金：科技部国家重点研发计划资助项目(编号:2022YFE0120500)资助。

摘　　要：随着核能的快速发展,放射性废液的有效处理与处置是目前亟需解决的问题,地聚合物是一种很有前途的放射性废物固化材料。^(137)Cs是低放废液中主要的辐射源,用偏高岭土作为基材,合成偏高岭土基地聚合物,通过抗压强度、孔隙度、微观结构和浸出行为等试验研究地聚合物对Cs的固化行为。在探明偏高岭土基地聚合物对Cs固化行为的基础上,将所制备的偏高岭土基地聚合物用于真实放射性废液的固化,通过在真实地下水环境中的浸出试验,评价偏高岭土基地聚合物在放射性废液固化领域的应用。研究结果表明:偏高岭土基地聚合物具有较高的抗压强度,孔隙度较小,微观结构稳定,并且对Cs有较好的固化性。在42 d时,真实低水平放射性废液地聚合物固化体中的^(137)Cs在去离子水和真实地下水中均具有较低的浸出率和累积浸出分数,且优于国标中规定的值。说明偏高岭土基地聚合物在固化核素方面是一种非常有应用潜力的材料。The development of nuclear energy is inseparable from the treatment and disposal of radioactive waste.Geopolymer is a promising radioactive waste solidification material.In this study,metakaolin was used as the substrate to prepare metakaolin polymer,which was used to solidify Cs and real radioactive waste.The properties of metakaolin geopolymer were investigated by characterization and leaching experiments.Characterization experiments show that metakaolin geopolymer with three-dimensional network structure has high compressive strength,which can meet the strength requirements of radioactive waste solidified body.At the same time,the solidification of Cs in metakaolin polymer is uniform.However,the incorporation of Cs will hinder the growth of silicon and aluminum network skeleton and reduce the gel structure of the system,resulting in the increase of porosity and the decrease of compressive strength of geopolymer cured body.The leaching experiments of Cs and real waste water in deionized water and real groundwater show that metakaolin polymer has excellent Cs retention ability,and has low leaching rate and cumulative leaching fraction,which is better than the value specified in the national standard.In general,metakaolin geopolymer performs well in physical compression resistance and Cs retention,and is a material with great application potential.

关 键 词：偏高岭土 地聚合物 放射性废液 浸出率 累积浸出分数 

分 类 号：TL941[核科学技术—辐射防护及环境保护]