Influence of azimuth and radial neutron and thermal sources anisotropy on contact problem simulation in real fuel pellet-cladding configuration using FEM

Paper summarises results of development and testing effort to model 2D and 3D nonsymmetric contact problem between fuel pellet and cladding using FEM. Interface between neutron and thermo-mechanical calculation models will be described. Corrosion layers and irradiation induced material properties degradation are treated in problem solution as well. Special interface programme for surface and volumetric source automatic input into the FEM COSMOS/M system was developed. Discussion of qualitative analysis of the results obtained by the new system using parametric simulation will be presented with accent to the contact problem solution and the stress-strain field distribution in contact regions. Conclusions will be given for the further development effort and validation approach will be presented. (authors)