The METEOR/TOUTATIS Code: A 2-D/3-D Code for Fuel Behaviour Simulation

Abstract

TOUTATIS is the 2D/3D part of the METEOR project developed by the CEA. CASTEM2000, finite element code, is the root of the modular TOUTATIS code. First the thermal field, which is the driving force of all other thermal phenomena, is computed. Then the thermo-mechanical part is established in the first loop. Other parameters (swelling, burn-up...) can be calculated for known power and time, in many additional loops. It can be noticed that creep deformations are computed for the pellet-clad system, and hence the pellet-cladding interactions (PCI) is automatically treated, owing to the notion of unilateral, punctual or distributed contact, with or without friction. The creep, plasticity and stress corrosion are likewise studied (residual stresses when returning to room temperature, dish filling of the pellets from the center, thermo-mechanical feedback...). Lastly all the problems characterized by asymetry (off-centering, pellet dispersion .,) must be solved with 3D calculations to explain accurately the stresses and strains in a rod (particularly the influence of the fuel fracturation).