Fluidized-Bed Fluoride Volatility Processing of Irradiated UO₂ Fuels

In five laboratory-scale experiments in which irradiated UO₂ reactor fuel was processed in a fluidized bed, high removals of uranium and plutonium were achieved by oxidizing with O₂, fluorinating with BrF₅ to convert uranium to volatile UF₆, then fluorinating with F₂ to convert plutonium to volatile PuF₆. The principal activities volatilized during the oxidation step were ∼ 27% of the krypton and ∼ 3.5% of the ruthenium. During the uranium separation step, >99.5% of the uranium and <0.5% of the plutonium volatilized with ∼ 60% of the ruthenium, ∼ 67% of the krypton, ∼76% of the molybdenum, and ∼2.7% of the antimony. During the F₂ step, the principal activities that volatilized concurrently with the plutonium were ∼ 38% of the molybdenum, ∼8% of the ruthenium, ∼ 0.2% of the zirconium, ∼ 5.8% of the niobium, ∼ 1% of the antimony, and ∼ 5% of the krypton. Analyses for tellurium, technetium, and neptunium, which are other possible contaminants in the uranium and plutonium stream, were not completed.