Conversion of uranium hexafluoride to uranium dioxide with minimum fluorine content

The review describes and assesses uranium hexafluoride conversion to uranium dioxide using the dry and wet routes. Their characteristic features, advantages and limitations together with the extent of their practical application are given. As far as the published papers allow, the behaviour of the residual fluorine during the defluorination step is explained. The framework for the conversion operations is given by the interconnections within the external fuel cycle. Some expected new elements in the cycle, e.g. connected with more extensive reprocessing of the spent fuel and new types of reactors and fuels, may cause new requirements for uranium hexafluoride conversion, leading to aqueous uranyl nitrate solutions as their immediate product. These questions are seen as prospects of the state of the art. (author)