Effect of the UO2 form on the electrochemical reduction rate in a LiCl–Li2O molten salt

Electrochemical reductions of various UO2 forms were investigated in a molten LiCl–Li2O electrolyte. The study focused on the influence of their sizes and densities on the reduction rate by running experiments with eight UO2 forms. They can be classified into porous and dense forms. The porous forms are one granule and four porous pellets with different densities (55%, 60%, 70% and 80%), all of which were fabricated in our laboratory. The dense forms were prepared by crushing dense pellets, and these were similar in size to the porous pellets and the granules. Systematic comparisons of the reduction rate among the tested UO2 forms revealed that a lower density and smaller size of UO2 led to a faster reduction rate. Particularly, attention was focused on the observation that the size of the UO2 provides more dominant effect on the reduction rate than the density.