Nuclear fuel and electric analytical chemistry

For operating smoothly and safely a series of nuclear fuel cycle, it is important to grasp the chemical behavior of the solutions of uranium, neptunium and plutonium. This is because the main part of nuclear fuel cycle consists of the processes of the chemistry of solution such as acid dissolution, ion exchange separation, solvent extraction separation and so on. The authors developed the column electrode electrolysis process, and applied it to the research on the chemistry of solution of uranium, neptunium and plutonium. First, the column electrode electrolysis process is explained. The coulopotentiograms (CP) for the oxidation and reduction of uranium, neptunium and plutonium ions are shown, and their oxidation and reduction behaviors in acid solutions are reported. As the application of the column electrode electrolysis process, the adjustment of oxidation condition, the speciation classified by the state of oxidation and electrolytic separation are explained. The spent fuel reprocessing process based on electrochemical extraction (SREEP) which was devised on the basis of the basic data obtained by the column electrode electrolysis process is proposed. (K.I.)