T/H and transient analyses to confirm EFIT preliminary design

One of the main objectives of the EUROTRANS Integral Project is the design of a several hundreds MWth transmutator based on the accelerator driven system (ADS) concept. The preliminary layout of European Facility for Industrial Transmutation (EFIT) has started with a set of basic options derived from the previous ADS demo design (PDS-XADS) with the adoption of U-free fuel instead of MOX and taking into account the economic requirements needed for an industrial power plant. To support the project, a thermal-hydraulic numerical model of the reactor has been developed for the RELAP5 system code with the support of multidimensional SIMMER code to improve the representation of the natural circulation paths in the reactor vessel. The presented analyses, addressed to verify the capability of EFIT to face up the high power densities and temperatures, have allowed a first positive evaluation of the inherent safety behavior of the plant mainly relying on the natural circulation.