Development of the advanced mechanistic fuel performance and safety code using the multi-scale approach
The SFPR code designed for mechanistic modeling of single fuel rod behavior under various regimes ofLWR reactor operation (normal and off-normal, including severe accidents), is under development atIBRAE during the last two decades and currently, being extended to Fast Reactors, serves as a prototypefor a new mechanistic fuel performance code BERKUT. The SFPR meso-scale models include an extendedset of microscopic parameters, characterizing the crystal defect structure, thermo-physical and thermo-chemical properties of irradiated fuel. Increasing computational capabilities and rapid development ofeffective interatomic potentials allow micro-scale representations of the materials and physics to inform– via meso-scale code – the macro-level simulation. The first examples of atomistic calculations (bymolecular dynamics and Monte-Carlo methods) of the key microscopic parameters for input in SFPR andBERKUT, validation of the modified code and application of the 3D finite element method for improvementand verification of the 1D thermo-mechanical model, are presented.