【作者】 张东； 康厚军； 傅依备；

【Author】 ZHANG Dong, KANG Hou-jun, FU Yi-bei (China Academy of Engineering Physics, P.O.Box 919-215, Mianyang 621900, China)

【机构】 中国工程物理研究院核物理与化学研究所；

【摘要】 通过热力学计算得到的铀在场址地下水中的主要存在形态为UO2(CO3)22-、UO2(CO3)34-、 UO2CO30、UO2(HPO4)22-,它们占99％以上。本工作对4种场址土壤进行表面电荷及Kd值测定。测定结果表明:场址Ⅲ土壤有最大的表面正电荷值,且对铀有极高的吸附比,是铀的良好吸附屏障物料。采用测定Kd的方法研究了8种添加剂对4种场址土壤以及炭质砂岩、Ca(OH)2对Ⅲ号土壤的改良作用。结果表明:大部分添加剂未对铀产生屏障作用;炭质砂岩、Ca(OH)2改善了Ⅲ号土壤的吸附性能,且 Ca(OH)2是比炭质砂岩更为优越的添加剂。更多还原

【Abstract】 The selection research of geochemical engineering barrier material for the buried disposal of very low-level radioactive waste containing uranium was performed. The thermodynamics calculation results indicate that the overwhelming majority (more than 99%) of U(Ⅳ) in the groundwater exit as the complex species, such as UO2(CO3)22- , UO2(CO3)34- , UO2CO30 and UO2(HPO4)22-. Surface electric charge of the four samples was measured, and the result shows that the soil sample Ⅲ has the highest positive charge value among the investigated soil samples, and it is high Kd value. The experiment of additive selection was performed through measuring the sorption rate. There are eight additives and four kinds of basic material in our experiment. The results show that the most of investigated additives can not remarkably improve the adsorption performance of the soil for uranium, but the additive of charry gritstone and Ca(OH)2 have great effect on the improving sorption rate. The effection of Ca(OH)2 is better than charry gritstone.更多还原