模拟处置条件下钚在地下水-膨润土体系中的胶体行为研究  

Colloidal Behavior of Plutonium in Groundwater-bentonite System Simulated under Disposal Conditions

作　　者：龙浩骑[1] 周舵[1] 刘晨 陈曦[1] 李遥 王波[1] 谭盛恒 LONG Haoqi;ZHOU Duo;LIU Chen;CHEN Xi;LI Yao;WANG Bo;TAN Shengheng(Department of Radiochemistry,China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院放射化学研究所,北京102413

出　　处：《原子能科学技术》2025年第2期310-317,共8页Atomic Energy Science and Technology

摘　　要：钚是高放废物中的一种高毒性超铀元素,在深地质处置过程中存在向生态环境迁移的严重隐患,影响高放废物的安全处置。为深入研究其在地下水中的胶体行为,本文在低氧条件下研究了钚在地下水-膨润土体系中的胶体行为,测定了钚胶体的粒径分布,并探究了pH(6.0~10.0)和离子强度(0.10~0.3 mol/L)对钚在北山地下水-膨润土体系中的胶体稳定性和粒径的影响。结果表明:pH对钚胶体、膨润土胶体粒径和Zeta电位的影响不大;离子强度对Zeta电位的影响不大,但会加速胶体的团聚。钚的迁移行为和GMZ膨润土的胶体行为密切相关。在本实验条件下,约有85%的钚吸附在膨润土胶体上,膨润土胶体的存在不利于阻滞钚的迁移。Plutonium is a highly toxic transuranic element in high-level radioactive waste.Because of the variety of species of plutonium,it has a serious potential to migrate to the ecological environment in the process of deep geological disposal.The deep geological disposal project of high-level radioactive waste needs to solve the key problem of how to prevent the release of plutonium into the biosphere.Bentonite is considered by many countries as a buffer material for deep geological disposal of highlevel radioactive waste due to its high adsorption,low conductivity,chemical buffering,and mechanical stability.Colloid is a very important factor in the adsorption and migration of radioactive pollutants.The main sources of colloids in groundwater are underground minerals,hydrolysis of metal ions produced after the dissolution of underground minerals,underground humic acid complexes and colloids formed by radionuclides(hydrolyzed polymers such as plutonium and uranium).The soil conditions in different regions are not the same,and the hydrological conditions are also very different,which has a great impact on the formation and stability of colloids.Bentonite can produce colloids due to the erosion of groundwater,and the interaction between radioactive nuclides and bentonite colloids can affect the release of nuclides into the environment.The colloidal behavior of plutonium in the bentonite groundwater system was studied under anaerobic conditions,and the particle size distribution of plutonium colloids was measured.The effects of pH(6.0-10.0)and ion strength(0.10-0.3 mol/L)on the colloidal stability and particle size of plutonium in the Beishan groundwater-bentonite system were obtained,and the interaction between plutonium and bentonite colloids was preliminarily explored.The experimental results show that pH has little effect on the particle size and Zeta potential of plutonium colloids and bentonite colloids.The increase of ion strength has little effect on the Zeta potential,but it accelerates the aggregation of colloid

关 键 词：膨润土 地下水 胶体 钚 

分 类 号：TL942[核科学技术—辐射防护及环境保护]