Study of minor actinide recovery prosece for the oxide pyro-process

None

明珍 宗孝; 水口 浩司; Kormilitsyn, M. V.*; Ossipenko, A.*

Myochin, Munetaka; Mizuguchi, Koji; Kormilitsyn, M. V.*; Ossipenko, A.*

酸化物電解法におけるMA回収方法について検討した。その結果、液体金属抽出法がもっとも有望で回収率95、除染係数10程度となると予想された。炭酸沈殿法については、MAPLE法を追加すれば回収率99%、除染係数10程度と期待される。

In the Oxide Pyro-process, oxides of U, Np and Pu can be co-deposited as MOX from their oxide ions in the melt. Due to the difference of their deposition potential, neither Am nor Cm will co-deposit in the MOX. An additional process must be developed to recover them without FP especially the lanthanides. Various processes were reviewed based on existing experimental data and thermodynamic considerations. As the result, the liquid metal extraction seems to be most promising. Based on the measured separation factor of Am against Nd in the LiCl-KCl/Bi system, MA recovery rate can be higher than 95% with DF equals 10. The number of steps can be reduced if there is any other liquid metal such as Al and Ga with higher separation factor. As for the carbonate precipitation, some subsequent separation process will be needed. A new process named MAPLE is proposed for it; where Li is applied to reduce only MA oxide into metal in LiCl melt while keeping lanthanides as their oxide. If it works as expected, it will have high recovery rate such as 99% without lowering the DF.