Purex 流程铀钚分离工艺中锝对镎走向的影响

摘要

在HNO3‐U（Ⅳ）‐N2 H4‐Tc（Ⅶ）‐Np（Ⅴ）体系中，Np（Ⅴ）迅速还原为 Np（Ⅳ）。对比研究表明，Tc是该体系中Np（Ⅴ）迅速还原的主要原因。该体系中的主要反应是U （Ⅳ）将 Tc（Ⅶ）还原为 Tc（Ⅳ），进而Tc（Ⅳ）将Np（Ⅴ）还原为 Np（Ⅳ）。本文通过串级和台架实验研究了该体系中锝对镎走向的影响。结果表明，Np（Ⅴ）的还原速度随 HNO3浓度、初始Tc浓度的增大和温度的升高而加快。在模拟 Purex流程铀钚分离工艺的条件下，试管串级和微型混合澄清槽台架实验结果表明，提高1AP料液中 Tc（Ⅶ）的浓度、升高反应温度，Np进入1BU中的百分含量增加。%It was found that in the nitric acid solution containing U (Ⅳ ) ,hydrazine , Tc(Ⅶ) and Np(Ⅴ) ,Np(Ⅴ) was reduced to Np(Ⅳ ) quickly .The main reason of the fast reduction of Np(Ⅴ) was due to Tc(Ⅳ ) ,which was produced by the reduction of Tc(Ⅶ) in the presence of U (Ⅳ) .The routing of Np in U/Pu separation stage was stud‐ied by tube cascade experiments and bench scale experiments at a miniature mixing‐settler set .The results show that nearly 67 .7% of Np goes into 1BU in the presence of Tc in the 1AP ,but approximately 27 .0% of Np goes into the 1BU in the absence of Tc . The amount of Np going into 1BU increases with the reaction temperature and the concentration of Tc(Ⅶ) in 1AP .