The ERU fuel manufacturing at AREVA NP

Within the Fuel Manufacturing Business Unit (FMBU) of the AREVA NP Fuel Sector, the FBFC Romans fuel plant has manufactured enriched reprocess uranium (ERU) fuel assemblies. The plant has acquired a long standing experience in this manufacturing area. Since the first ERU manufacturing campaign took place at Romans in 1987 on behalf of Electricite de France (EDF), more than 400 tonnes ERU fuel assemblies were produced. Romans is currently licensed to manufacture 150 tonnes ERU fuel per year on the basis of a specification included into the general technical instructions of the plant with especially a maximal 232U content of 15 ppb. The following radiological issues has been considered in ERU fuel fabrication: i) the external exposure is mainly due to the 232U decay products, ii) the emission from ERU is 10% higher than from enriched natural uranium (ENU), iii) the contribution of neutrons to the external exposure is very low, and iv) the dose rate level increases with time. The main management principles regarding the internal and external exposure of the manufacturing personnel through all the manufacturing steps (UF6 re-conversion, pelletizing, rod and fuel assembly manufacturing) are the following ones: a) to reduce the lead time of the ERU material in the whole facility, b) to control the material storage areas regularly, c) to identify and inspect the places where the material can be accumulated, d) to control the full UF6 cylinders, e) to control the empty UF6 cylinders by knowing that the 232U decay products remain in the cylinder during the UF6 evaporation, f) to load the ERU fuel assemblies in the containers immediately after their manufacturing, and g) store the loaded assembly containers at the rear of the storage room with a specific labelling in a restricted access area. Moreover, the Romans fuel plant is being renewed to be able by the end of 2008 to manufacture both ENU and ERU fuel. After that renewal all the equipments will comply with the most stringent standards regarding safety and environmental protection and will achieve the highest quality and productivity level. (author)