Conversion of reprocessed uranium

The operations of spent fuel reprocessing lead to separate 1% of the plutonium reprocessed in the MOX, 3 % of fission products, ultimate vitrified waste waiting for disposal and 96% of reprocessing uranium in the form of uranyl nitrates. Two solutions exist: either the conversion in UF6 for immediate re enrichment ( realized at the Comurhex plant at Pierrelatte); or the conversion in U3O8, the most steady form of uranium and the most adapted to a storage. The management of the irradiation risk is made by the efficiency of protection barriers and the coherence of the delimitation and the classifying of areas against external exposure. The management of the contamination risk is made by a ventilation with very high efficiency filters before release and monitoring of these releases. The criticality risk is taken in account by instructions of minimum space and maximum filling up of casks. The fire risk is managed by fire detectors. With the experience return it is possible to improve some more the safety. (N.C.)