The French approach for management of depleted uranium a constantly improved technology

COGEMA provides uranium enrichment services to the nuclear industry worldwide. To meet general French safety requirements related to environmental protection issues, COGEMA has developed, as an extension of the enrichment operation, a facility to convert DUF6 into a stable, fluorine-free compound. After 5 years demonstration of the process on a pilot plant, COGEMA placed a facility in industrial operation in 1984 to convert DUF6 into stable oxide U3O8; a second facility was commissioned in 1993, doubling the capacity. Since the beginning of its industrial de-fluorination operations, COGEMA has ever been concerned to make its technology as reliable and as cost effective as possible. Accordingly, an improvement work has been constantly under way which already benefited to the construction of the second facility, completed in 1993. This paper will give an overview of the improvement work performed over the years, relating not only to the technology (optimizing the de-fluorination output, reducing the corrosion inside the kilns, improving the uranium oxide powder compaction factor,...), but also to the process itself (hydrodynamic modeling of the process reactions inside the kiln) and maintenance issues (systematic monitoring of filters plugging, recycling of cartridge filters,...). (authors)