Extraction of impurities of rare-earth elements from uranium dioxide using bromine trifluoride for their preconcentration and analytical determination

The behavior of impurities of rare-earth elements in the fluorination of UO2 with bromine trifluoride is studied by the radioactive tracer method using152Eu radionuclide. It is demonstrated that uranium is completely removed as hexafluoride, whereas impurities of rare-earth elements quantitatively remain in the crucible because of the nonvolatility of their fluorides. Based on this fact, the concentrations of rare-earth elements in UO2 is determined. Results of analysis are in agreement with the data that were obtained using the conventional technique for the extraction of rare-earth elements from UO2