The variance of the O/U stoichiometric ratio during storage of the U O2 nuclear fuel

This paper aims at following, the influence of the atmosphere in the variance of the O/U ratio during the storage of U O2. Complementary analyses such as specific surface area, determination of moisture contents, as well as the material characterization, were used to help the interpretation of the behavior of the stored powder. It was seen that the U O2 powder can be stored in common atmosphere environment, but with relative moisture around 30%. The relative moisture also influences the results of the stoichiometric ratios carried out by the gravimetric method and also in the results of specific surface area carried out by gaseous adsorption (Brunauer, Emmette and Tellet - B.E.T.). In order to determine the O/U ratio the techniques used were: volumetric, voltammetric and gravimetric, since they are the most appropriate. The analyses were performed at the chemical characterization laboratory in the IPEN. (author). 14 refs., 13 figs., 8 tabs