Low temperature fluorination of uranium oxides in 3-inch diameter fluidized bed

In the R & D program of the fluoride volatility process, fluorination characteristics of UO₂ under low temperature have been studied in batch and semi-continuous operation with 3 inch diameter fluidized bed. Fluorination rates and technical experiences in handling kilogram quantities of fluorine and UF₆ were obtained. Major characteristics of low temperature fluorination around 350℃ and 20v/0 (F₂) are as follows: (1) The fluorination rate is not only lower, but the reaction behavior is more complex than that in high temperature over 400℃, where it could be approximated with a single step fluorination of UO₂F₂, a rate-controlling intermediate. (2) The high acceleration effect of simulated fision products on the reaction rate is observed and the reaction behavior is simplified to the similar pattern to that in high temperature. (3) On a technical problem, unstable fluidizability of the reactor results from the accumulation of complex intermediates in the reactor. (author)