^(237)Np,^(239)Pu,^(241)Am在膨润土和矿物上的吸附

SORPTION OF ^(237)Np,^(238)Pu AND ^(241)Am ON BENTONITES AND MINERALS

一、引言 在高放废物地质处置中,膨润土因其具有低渗透率、高吸附容量和塑性被公认为最有希望的候选回填材料。按照多层屏障概念,用膨润土作为工程屏障需要满足多种性能要求。化学屏障性能是其中重要的一个方面。要求它对废物处置中普遍关心的核素(长寿命的锕系核素及裂变产物)有高的阻滞能力。很明显这主要取决于膨润土本身的矿物学。

In this paper,the sorption ratios of actinides 237Np,239Pu and 241Am on several kinds of bentonites and some minerals are studied with batch experiments. The results show that among all of raw bentonites used for tests,Mg-Na-bentonite from Gansu province possesses the best sorption property,and the Rd values for 237Np,239Pu and 241Am are 57,≥4. 2×104 and 3. 1×104ml/g,respectively. Therefore,it might be used as a backfill material candidate for HLW deep underground repository. In addition, anti-monite has high sorption ratio for 237Np with Rd= 1. 7× 103ml/g,so it is suggested to be used as an additive for backfill materials to enhance the retardation capacity for 237Np.