Abstract: "Because of the radiation hazards inherent in processing large volumes of radioactive solutions by solvent extraction techniques, there is need for a system with small hold-up which can be contained within a minimum of shielding and yet which is versatile enough to be used as a research tool. A system utilizing a miniature mixer-settler has been constructed and its successful operation by remote means demonstrated. The unit is semiportable and employs a number of novel features of value in studying a wide variety of solvent extraction flowsheets. Data on the distribution of nitric acid between water and tributyl phosphate (in kerosene) are included as a demonstration of the operability of the unit."