Some Problems in Reprocessing of Fuel Spent by Modern Power Reactors

摘要

Some problems of reprocessing the spent fuel of power reactors have been considered. The process currently includes the extraction of uranium, plutonium, and neptunium with 30% tri-n-butylphosphate (TBP) in a hydrocarbon solvent. An aqueous phase that contains fission products, as well as americium and curium, is transferred into a glass matrix. An alternative process with the separation of americium and curium from the aqueous phase has been developed. Since the concentration of plutonium in the organic phase is very small, the organic phase can be thermodynamically described as the quinary H_2O-HNO_3-UO_2(NO_3)_2-TBP-diluent system. This system is divided into subsystems, which are described using component activities and rational activity coefficients. Some data on the calculation of three ternary subsystems and one quaternary subsystem are given.