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

摘要

The behavior of impurities of rare-earth elements in the fluorination of UO_2 with bromine trifluoride is studied by the radioactive tracer method using ~(152)Eu 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-earch elements in UO_2 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 UO_2.