Recovery of Eu^<2+> and Sr^<2+>Using Liquid Metallic Cathodes in Molten NaC1-KC1 and KC1 System
In the pyrochemical reprocessing of spent metallic nuclear fuels using molten salt bath, recovery of Eu and Sr as fission products having electrochemically negative potentials is important. In order to develop the electrowinning method, cathodic deposition of Eu<SUP>2+</SUP> in the NaCl-KCl melt and Sr<SUP>2+</SUP> in the KCl melt at some metallic cathodes (Al, Bi, Pb, Sn and Zn) was examined by cyclic voltammetry and chronopo tentiometry. Transfer coefficient, standard rate constant and diffusion coefficient for Eu<SUP>2+</SUP> and Sr<SUP>2+</SUP> were determined by cyclic voltammetry with conventional, semi-integral and semi-differential methods and by chronopotentiometry. It was revealed that a quasi-reversible cathodic reaction Eu<SUP>2+</SUP>2e<SUP>-</SUP>+3Pb→EuPb<SUP>3</SUP> on liquid Pb electrode takes place in the NaCl-KCl melt at 1, 073K. As for Sr<SUP>2+</SUP>, a quasi-reversible cathodic reaction Sr<SUP>2+</SUP>+2e<SUP>-</SUP>+3Pb→SrPb<SUB>3</SUB> takes place at liquid Pb electrode in the KCl melt at 1, 073K. These propose possibility to recover Eu into Pb cathode and Sr into Pb cathode as well as into Al cathode.
- Journal of nuclear science and technology
Journal of nuclear science and technology 34(3), 310-317, 1997-03-25
Atomic Energy Society of Japan