高放废液中微量Am的放化分析

THE RADIOCHEMICAL ANALYSIS METHOD OF Am CONTENT IN HIGH-LEVEL LIQUID WASTE(1AW)

为了对后处理厂储存的高放废液(1AW)进一步处理处置,需要对废液组分进行分析。Am是重要的α放射体之一,因此,要求对废液中Am含量进行测定。高放废液中,除了Am之外,还有U、Np、Pu、裂片元素以及大量的无机盐,Am的含量极低,必须先进行Am的放化分离。我们曾相继报道过有关Am的纯化工作,本文着重介绍Am的分离纯化程序。

It is suggested to analyse Am content in high-level liquid waste (1AW) using radiochemical method. The chemical separation process is divided into three steps. The first step is to remove Pu and Np from Am using HDEHP extraction. The second one is to separate Am from RE, ^(137)Cs,^(90)Sr using HEHEHP-Levextrel-TTHA-lactic acid complex elution chromatography. Finally, the above Am frac- tion is purified with PMBP-TBP extraction and with HNO_3 stripping to remove TTHA-lactic acid agent and become salt-free solution. After that the detector of ZnS(Ag) is used to measure the α activity of Am. The recovery of Am for the whole process is about 94%, DF_(Pu)=1.7×10~3, DF_(Np)=1.0×10~4, DF_(Eu)=2.7×10~3. This method was used successfully to analyse Am content in high-level liquid waste in reproeessing plant.