At UP3 reprocessing plant, nuclear measurements contribute to the criticality control and process control. These measurements with their interpretation softwares constitute the process nuclear monitoring system. In UP3/T1 (Shearing-Dissolution building), different devices are located on the process from the burn-up control of irradiated fuel assemblies until the hulls drum characterization. In the other parts of UP3, nuclear measurements are mainly used for the monitoring of solutions (Measurement of beta/gamma contamination with ZEBULON device, measurement of alpha contents with ANPu, measurement of Pu concentration, Pu distribution and fissile material accumulation with neutron counters). The different stations, measurement methods and their relationship with the reprocessing process are described in this paper. The qualification results, obtained in laboratories and in site as well as the first results since UP3 start-up are presented.
Lamarque, G;  Bernard, P; Le Guillou, G; Martin-Deidier, L;  Chabert, J;  Fournier, W; Laloe, M 
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