Complex FEM based system of computer codes to model nuclear fuel rod thermomechanical behaviour

The paper presents long-term effort to establish closed chain of computer codes, which allow computer modeling of the thermo-mechanical fuel rod behaviour from the 1D representation to the 3D detailed problem description. The whole complex uses the same FEM based mathematical approach. The principle of this modular approach is to handle boundary and initial conditions by the similar transfer independent on the complexity of solved problem. The goal of our modeling work was to develop model (FRA - Fuel Rod Analyser) capable of computing the spatial distribution of temperature and stress-strain in the fuel and cladding especially during power transients