Determination of U(VI) and Pu(IV) mass transfer constants with N,N-dialkylamides in liquid-liquid extraction

International audienceIn the frame of the development of Generation IV reactors, CEA is developing a new liquid-liquid extraction process for the multirecycling of plutonium from the future spent nuclear fuels. Thermodynamic data have already been acquired for the modelling of the extraction equilibriums in this process, however, a full phenomenological model requires kinetic data too. Thus, this paper summarizes the acquisition of mass transfer coefficients of uranium(VI) and plutonium(IV) between nitric acid and a monoamide-based solvent upon extraction with three different techniques using a constant interfacial area the single drop technique. They are compared to results obtained with Nitsch cell and rotating membrane cell (RMC) methods.The influence of temperature, nitric acidity, viscosity of the organic phase and, in the case of the moving drop technique, the drop size and the nature of the continuous phase (aqueous or organic) on the mass transfer coefficient of uranium and plutonium during the extraction step was studied