Decontamination of alkali chloride baths containing nuclear material by precipitation and distillation techniques

Ibe, Junya*; Aso, Megumi*; Takahatake, Yoko  ; Watanabe, So  ; Watanabe, Masayuki; Matsuura, Haruaki*

Since waste salt generated from pyro-reprocessing test which contains uranium can easily capture moisture and corrode equipment, further treatment technology for decontamination. Oxides are added as oxygen donor in the melts, and then uranium is separated from the salt as precipitates. In the next step, melt bath components are evaporated by a vacuum distillation. First, LiCl-KCl eutectic and NaCl-2CsCl salts were used as melt baths, lithium oxide was used as a precipitant, and cerium chloride was used as uranium surrogate for testing the precipitation process. Next, a distillation line has been constructed and the best condition for distillation has been searched. Amount of the precipitates increased with increasing the amount of oxide, and recovery ratio of cerium must potentially depend on solubility of oxychloride into the bath salts. It is considered that oxychloride was formed by the similarity in EXAFS oscillation and X-ray diffraction patterns.