Investigation of manganese(II) behavior in molten chlorides at precipitate formation by oxide addition

Yamamoto, Yuri*; Minowa, Kazuki*; Takahatake, Yoko  ; Watanabe, So  ; Nakamura, Masahiro ; Matsuura, Haruaki*

In the pyro-reprocessing of spent nuclear fuel, salt bath is normally used in several times, but at final moment, spent salt containing small amount of chloride nuclear fuel material is generated. In terms of managing nuclear fuel materials, it is desirable that the nuclear fuel materials should be recovered from the spent salt. We are proposing methods for recovering nuclear fuel materials using precipitation by oxide addition and distillation for reducing pressure techniques. In this study, we have focused on the behavior of manganese(II), which is one of the radioactivated products. As a result of experiments and thermodynamic simulation, it was found that manganese(II) is likely to be entrained in nuclear fuel materials. Therefore, it is necessary to add a step to separate manganese(II) from nuclear fuel materials.