HORUS3D: A consistent neutronics/thermohydraulics code package for the JHR modelization - abs16

The definition and the validation of the HORUS3D package are described in this paper. HORUS3D (Horowitz Reactor simulation Unified System) is dedicated to the design studies of the future European MTR, called Jules Horowitz Reactor. A rigorous methodology, based on the decomposition of the validation problem, is applied. HORUS3D/N based on APOLLO2 and CRONOS2 codes, allows the neutronics modeling of the Horowitz reactor with a great confidence: compared to expensive reference calculation the discrepancy on the initial reactivity level is less than 200 pcm, the maximum difference on the assembly power distribution is 1.4% at the beryllium reflector interface (hot spot) and reactivity discrepancies don't exceed 150 pcm along the burn-up. An experimental program is planned. It is organized in two phases. The first phase, called VALMONT, will allow the qualification of the calculation of the JHR fuel reactivity. The second phase, called AMMON, much more extensive than the first, will allow the qualification of the assembly power map, control rod efficiency, reactivity coefficients, Beryllium reflector effect with the actual characteristics of the JHR assemblies. HORUS3D/Th, the core thermal-hydraulics part, is based on the FLICA4 code and HORUS3D/Sys allows the resolution of System thermal-hydraulics problems. The specific characteristics of the JHR element leads to elaborate an adapted experimental program on the test facility called SULTAN-JHR. The first version HORUS3D package is actually operational and allows the modeling of JHR core with a great confidence. It will be used for the Definition Studies of the Horowitz Reactor. (authors)