Photochemically Produced U(IV) as a Reductant for Pu(IV) and Applications in Nuclear Fuel Reprocessing

U(IV) can be photochemically produced in tri-n-butyl phosphate solutions from uranyl nitrate and used to reduce Pu(IV). Nitrite production can be controlled by filtering out light having wavelengths of <350 nm and by keeping the temperature of the reaction mixture below 10°C. Another product of the photolysis, di-n-butyl phosphate, can interfere with the reduction, but no effect was apparent in our experiments. Conventional solvent cleanup procedures should remove photolysis side products. The application of this process to the reprocessing of nuclear fuel would require commercially available light sources that can be located outside the hot zone of the plant and a reactor vessel with windows within the hot zone.