The stochastic finite element method for nuclear applications

Abstract

Nuclear materials are subjected to demanding environments, encountering high temperature gradients and fast neutron fluxes that gradually damage its structure and therefore change the material properties. Some components of a nuclear reactor determine its lifetime, such as the graphite core and steel pressure vessel for fission reactors. In case of fusion reactors the tungsten divertor is expected to be replaced several times during its lifespan. All these materials contain defects and spatial material variability that may contribute to the failure of the component. The Stochastic Finite Element Method or a Random Finite Element Method was chosen in this research to model the spatial material variability in nuclear graphite and other key components of nuclear reactors. This research describes how a direct Monte Carlo Simulation approach was adapted to simulate the calibration of a random field and the modelling of these defects for nuclear graphite. It is also suggested that this methodology can be applied to fusion reactor modelling.