Solvent Extraction Systems for Separation of An(III) and Ln(III): Overview of Static and Dynamic Tests

The management of high-level radioactive waste generated during the reprocessing of spent nuclear fuel in the PUREX process is among of the main problems of modern radiochemistry. This waste contains half of the periodic table of elements in the range from As to Cm. To reduce the total radioactivity of the disposed waste, the concept of partioning and transmutation is developed. The implementation of this concept implies the separation of Am(III), Cm(III), and lanthanides(III) from each other. This separation is a complex chemical problem, since these elements have similar physical and chemical properties. In chemical engineering, liquid extraction is considered to be the most suitable method for the separation of Am(III), Cm(III), and lanthanides(III). In this review, we analyzed the published solvent extraction systems, in which americium and lanthanides are separated at the stages of extraction into the organic phase or selective back-extraction from the organic phase by water-soluble complexones. For some extraction systems, dynamic tests carried out over the past 10 years are also described.