Chemical Behavior of Europium Ion in a LiCl-KCl Eutectic Melt

The use of pyrochemical processing of spent nuclear fuel is emerging as a promising option in the near future. However, rare earth elements (REEs) contained in spent fuel may pose a potential problem for related pyrochemical processes. Therefore, it is necessary to understand the chemical behavior of the actinides and lanthanides in high-temperature melt. In high temperature molten salt, europium oxide exhibited abnormal behavior in solubility and redox chemistry. The solubility of europium oxide was measured to be ∼3 orders of magnitude higher than those of other lanthanide oxides. It is necessary to get further insight on the chemical behavior of europium ion in those conditions. Here, we report some basic chemical redox properties of europium ion and its reactivity with oxide ion in a LiCl-KCl eutectic melt at 450 .deg. C