用TRPO从高放废液中去除锕系元素的研究──微型离心萃取器串级冷实验

STUDIES ON REMOVING ACTINIDES FROM HLLW WITH TRPO──THE INACTIVE EXPERIMENT USING CENTRIFUGAL CONTACTORS FOR SEPARATION

采用微型离心萃取器进行了ＴＲＰＯ流程从模拟高放废液中去除锕系元素的冷实验。实验中用Ｎｄ代替Ａｍ，Ｚｒ代替Ｎｐ、Ｐｕ，在模拟高放废液稀释３倍、酸度为１．０ｍｏｌ／ｌ时，采用１２级萃取、４级洗涤能有效地去除模拟高放废液中９９．９％以上的Ｎｄ、Ｚｒ，满足了冷实验要求，并且萃取中不出现三相，可以使萃入的Ｆｅ洗下６０％，避免大量Ｆｅ进入后续流程。采用硝酸、草酸分别反萃Ｎｄ和Ｚｒ，使Ｎｄ和Ｚｒ分成二组，交叉污染很小。文中给出了硝酸、Ｎｄ、Ｚｒ等在各级的浓度剖面和它们在各物流中的分布。

The inactive experiment of removing actinides from simulated HLLW by TRPO process is completed. When the simulated HLLW is three times diluted and HNO_3 concentration is adjusted to 1.0mol/l, 99.9% of Zr and Nd (simulate Np, Pu and Am ) are removed from the simulated HLLW with twelve extraction stages and four scrub stages. 60% of Fe extracted into the organic phase is scrubbed out, so that the entering of too much Fe into the following step is avoided. Nd and Zr are separated into two groups by stripping with concentrated nitric acid and oxalic acid.The cross contamination between them is small. The concentration profile of nitric acid, Nd, Zr,etc. in various stages and their distribution in different process stream solutions are presented.