APOR后处理流程1B槽中锝的走向

在以甲基肼-二甲基羟胺为还原剂的APOR乏燃料后处理流程1B工艺中,锝主要走向1BP,但其走向的原因尚不清楚。本工作综合锝与还原剂的反应动力学、串级实验、台架实验结果,解释了锝在1B槽走向的原因。结果表明:锝在1B槽中被甲基肼还原为不被TBP萃取的低价锝形态,该反应在铀存在条件下会被大大加速,这是影响锝在1B槽走向的主要因素;还解释了串级萃取实验与混合澄清槽台架实验中锝走向差异的原因。

Distribution of Technetium in 1B Tank of APOR Process

In 1B tank of APOR,where monomethylhydrazine(MMH)-dimethylhydroxyla-mine(DMHAN) are adopted as reductants,most of technetium flows into 1BP for unknown reason.The phenomena was explained through the reaction kinetics between Tc(Ⅶ) and MMH or DMHAN,the results of multi-stage extraction experiments and continuous mixer-settler experiments.Experiment results show that technetium is reduced to unextractable low valent state by MMH,and the reduction reaction is greatly accelerated in the presence of uranium.The reduction of Tc is probably the factor to dominate the distribution of technetium in 1B tank.The difference between the distribution of technetium in multi-stage extraction experiment and mixer-settler experiment was also discussed in the present paper.