KINETICS OF DISSOLUTION OF URANIUM METAL FOIL BY ALKALINE HYDROGEN-PEROXIDE

To develop a new process for the production of Mo-99 using low-enriche d uranium targets, uranium dissolution in alkaline hydrogen peroxide w as studied. Molybdenum-99 is a parent of the widely used medical isoto pe Tc-99m. The rates of uranium dissolution in alkaline hydrogen perox ide solution were measured in an open, batch-type reactor and were fou nd to be a 0.25th order reaction with respect to equilibrium hydrogen peroxide concentration. In general, uranium dissolution can be classif ied as a tow-base (<0.2 M hydroxide) and a high-base (>0.2 M hydroxide ) process. In the low-base process, both the equilibrium hydrogen pero xide and the hydroxide concentrations affect the rate of uranium disso lution. In the high-base process, uranium dissolution is independent o f alkali concentration; the presence of base affects only the equilibr ium concentration of hydrogen peroxide. An empirical kinetics model is proposed and discussed.