A coprocessing solvent extraction flowsheet for recovery and purification of light water reactor (LWR) fuels has been developed. This flowsheet never completely separates uranium from plutonium. The flowsheet has changed operation of the partitioning contactor to achieve partial partitioning of uranium and plutonium. Partial partitioning has been demonstrated with simulated feeds and irradiated LWR fuel solutions with hydroxylamine nitrate reductant to concentrate the plutonium by factors of 6 to 27.4. Nitrite was shown to interfere with the reduction of plutonium. Increased hydroxylamine concentrations gave normal reduction behavior.