Purex流程1A工艺单元锝萃取行为研究

Extraction Behavior Research of Technetium in 1A Unit of Purex Process

通过计算机模拟研究了不同燃耗和不同工艺条件下,硝酸、锆、铀、钚和锝在Purex流程1A中的萃取行为,获得了相应萃取行为数据,测定了不同硝酸浓度下锝锆共存时锝的分配比D Tc(Zr)、锆的分配比D Zr以及锝的分配比D Tc,再结合1A中硝酸、锆、铀和钚萃取行为数据,解析锝的萃取行为。结果表明,萃取段锝因锆锝共萃进入有机相,洗涤段锝因铀锝共萃和钚锝共萃留在有机相,相比于硝酸浓度变化对锝萃取的影响,洗涤段铀锝共萃和钚锝共萃的作用更重要。

The routing of nitric acid,uranium,plutonium,technetium and zirconium in 1A unit of Purex process under different burnups and process conditions was researched by computer simulation,and the extraction behavior data of acid,zirconium,technetium,uranium and plutonium were obtained.Otherwise,distribution ratio curves of D Tc(Zr),D Zr and D Tc were determined by experiments.Combining the computer simulation results and distribution ratio data determined,the extraction behavior of technetium was excused.In extraction process section,technetium is extracted into organic phase because of the co-extraction of zirconium and technetium,in washing process section,technetium remains in organic phase because of the co-extraction of technetium with uranium and plutonium.Compared with the influence of nitric acid on the extraction of technetium in washing process section,the co-extraction of technetium with uranium and plutonium is more important.