Study of reaction kinetics in continuous processes fot actinide separations

The main objectives of this PhD project are to study the reaction kinetics and mass transfer efficiency of different novel solvent extraction systems for actinide separations, and to investigate how the efficiency of solvent extraction processes can be influenced by changing the contact time in a centrifugal contactor. The current lack of reliable experimental data makes is difficult to define suitable process parameters, and optimize processes to obtain maximum throughput with as little solvent degradation as possible. The first focus of the PhD project will be on two reference systems, namely the (modified) PUREX process, and on the (modified) GANEX 1st cycle process. The second focus will be on partitioning processes with main attention to americium separation and purification. Kinetic data obtained from highly stirred tanks, constant interfacial area stirred cells and moving drop methods will be used as the starting point for this research. An existing annular centrifugal contactor will be redesigned for more flexibility so it becomes possible to control the average residence time in the annular mixing zone, temperature in the system, A/O in the mixing zone, and will allow to determine the specific interfacial area. Modelling of the multi-stage system will be applied to support the experiments and vice versa.