Modelling 3D crack propagation in ageing graphite bricks of Advanced Gas-cooled Reactor power plant

Abstract

In this paper, crack propagation in Advanced Gas-cooled Reactor (AGR) graphite bricks with

ageing properties is studied using the eXtended Finite Element Method (X-FEM). A parametric study for crack

propagation, including the influence of different initial crack shapes and propagation criteria, is conducted. The

results obtained in the benchmark study show that the crack paths from X-FEM are similar to the experimental

ones. The accuracy of the strain energy release rate computation in a heterogeneous material is also evaluated

using a finite difference approach. Planar and non-planar 3D crack growth simulations are presented to

demonstrate the robustness and the versatility of the method utilized. Finally, this work contributes to the better

understanding of crack propagation behaviour in AGR graphite bricks and so contributes to the extension of

the AGR plants' lifetimes in the UK by reducing uncertainties.