Preliminary design studies by a complete academic simulation toolbox of a water-cooled thorium-fueled small modular reactor core

International audienceA simple methodology has been developed for the design of competitive PWR-likereactors. It is illustrated by a Small Modular Reactor (SMR) loaded with thorium fuel andtargeting an ambitious final burnup. The complexity of the tested nuclear cores is managed byprogressively increasing the level of simulation detail and taking into account the relatedoperating constraints. For sufficient design margin, various moderation ratio values have beenconsidered. By means of our C++ framework SMURE (Serpent/MCNP Utility for ReactorEvolution), fuel evolution is first computed at the mirrored assembly scale, then at the full corescale with power flattening. Particular care is taken to make reactivity management, by standardsoluble boron completed by an optimized suite of burnable poisons, realistic at both scales. Safetyrequirements are finally tested on a typical Rod Ejection Accident (REA). This core transientcalculation relies on our diffusion-based Nodal Drift Method (NDM) coupled to our 1D-RZtime-dependent code BATH (Basic Approach to Thermal-Hydraulics)