An X-ray photoelectron spectroscopy study of the products of the interaction of gaseous IrF6 with fine UO2F2

Nuclear fuel reprocessing by fluorination, a dry method of regeneration of spent nuclear fuel, uses UO2F2 for the separation of plutonium from gaseous mixtures. Since plutonium requires special treatment, IrF6 was used as a thermodynamic model of PuF6. The model reaction of the interaction of gaseous IrF6 with fine UO2F2 in the sorption column revealed a change of color of the sorption column contents from pale-yellow to gray and black, indicating the formation of products of such an interaction. The X-ray photoelectron spectroscopy study showed that the interaction of gaseous IrF6 with fine UO2F2 at 125 °C results in the formation of stable iridium compounds where the iridium oxidation state is close to Ir3+. The dependence of the elemental compositions of the layers in the sorption column on the penetration depth of IrF6 was established

THE PROD UCTS OF THE IN TER AC TION OF GAS EOUS IrF6 WITH FINE UO2F2 by

Nu clear fuel re pro cess ing by flu o ri na tion, a dry method of re gen er a tion of spent nu-clear fuel, uses UO 2F 2 for the sep a ra tion of plu to nium from gas eous mix tures. Since plu to nium re quires spe cial treat ment, IrF 6 was used as a ther mo dy namic model of PuF 6. The model re ac tion of the in ter ac tion of gas eous IrF 6 with fine UO 2F 2 in the sorp tion col umn re vealed a change of color of the sorp tion col umn con tents from pale-yel low to grey and black, in di cat ing the for ma tion of prod ucts of such an in ter ac-tion. The X-ray pho to elec tron spec tros copy study showed that the in ter ac tion of gas-eous IrF 6 with fine UO 2F 2 at 125 °C re sults in the for ma tion of sta ble irid ium com-pounds where the irid ium ox i da tion state is close to Ir 3+. The de pend ence of the el e men tal com po si tions of the lay ers in the sorp tion col umn on the pen e tra tion depth of IrF 6 was es tab lished. Key words: X-ray pho to elec tron spec tros copy, ura nyl flu o rite, irid ium hexafluoride, tech nol ogy of iso la tion of actinides from gas mix tures IN TRO DUC TION Nu clear fuel re pro cess ing by flu o ri na tion, a (dry) method of re gen er a tion of spent nu clear fuel (SNF), uses ura nyl flu o rite (UO 2F 2) for the sep a ra tion of plu to nium from gas eous mix tures [1]. The Gibbs en ergy (�G 0 298) of 74 kcal/mole for the sug gested re ac tions of UO 2F 2 with PuF 6, un like that of UO 2F 2 with UF 6 (51 kcal/mole), in-di cates a pos si ble PuF 6 se lec tiv ity from the mix ture (PuF 6, UF 6, F 2, N 2, and vol a tile flu o rides) [2]. It has to be Sci en tific pa pe