- 219 - The Georges Besse I plant Enrichment by isotopic separation implemented in Eurodif's Georges Besse I plant (GB I) is based on the gaseous diffusion process. The plant comprises 1400 cascaded enrichment modules, divided into 70 sets of 20 modules grouped in leak-tight areas. The plant was authorised by a decree dated 8 September 1977. The gaseous enrichment principle consists in diffusing gaseous uranium hexafluoride (UF6) through porous walls called "barriers". These barriers give preferential passage to the uranium 235 isotope contained in the gas, thereby increasing the proportion of this fissile isotope in the UF6 at each passage. The UF6 is introduced in the middle of the cascade, with the enriched product drawn off at one end and the depleted residue at the other. In 2010 the licensee announced the shut down of plant operation at the end of 2012. This will be followed by rinsing with ClF3 for 3 years. The final shutdown and decommissioning operations that will follow should span ten years or so. The uranium enrichment activity will be taken over by the Georges Besse II plant (GB II), in which the enrichment process is based on gas ultra centrifugation. The Georges Besse I plant (Eurodif) comprises: a gaseous diffusion cascade for isotopic separation of UF6 in several stages: o small-sized stages: Low Enrichment Plant; o medium-sized stages: Very Large Plant; o large-sized stages: Extremely Large Plant; the UF6 container storage areas; diverse auxiliary facilities: control room, reception/shipping/inspection facilities, transformation station, cooling towers, workshops and fluid production units, effluent treatment units, storerooms and storage yards. The main risks intrinsic to the operation of this facility result from the quantities of UF6 present on the premises: 800 tonnes of gaseous UF6 in the diffusion cascade (90 tonnes in rinsing phase); 114 tonnes of liquid UF6 in annex U for the infeed, drawing off, etc.(74 tonnes in rinsing phase); 40 tonnes of liquid UF6 in the DRP (Programme Resource Department) shop (called REC1: UF6 container reception and reconditioning shop; 30,000 tonnes of solid UF6 in the storage yards (50,000 tonnes maximum); storage of chlorine trifluoride (CIF3): 15 tonnes in 500 kg containers. In accordance with the specifications, the complementary safety assessment was carried out considering the status of the facility on 30 June 2011. The Comurhex plant The plant comprises: ICPEs for chemical transformation of natural uranium tetrafluoride (UF4) into uranium hexafluoride (UF6) to supply the enrichment plants: o one anhydrous hydrofluoric acid (HF) electrolysis unit for producing the gaseous fluorine necessary for fluoridation of the UF4 (structure 200); o flame reactors for fluorination of the UF4 to obtain the gaseous UF6 that is subsequently crystallised (structure 400) ; o an auxiliary chlorine trifluoride (CIF3) production activity (structure 600); o effluent processing and maintenance units (structures 900, 100E, 1000, 800) ; o storage areas; BNI 105, shut down since 31 December 2008, which transformed the uranyl nitrate (UO2(NO3)) resulting from spent fuel reprocessing into uranium sesquioxide (U3O8) and uranium hexafluoride (UF6) (structures 2000 and 2450).
RkJQdWJsaXNoZXIy NjQ0NzU=