A structurally-based model of irradiated graphite properties

In this paper, we describe a model of irradiated graphite properties that is based on an understanding of the interconnection of the structure. Simplified conceptual models have enabled us to explain many of the correlations that exist between irradiated graphite material properties and derive mathematical formulations that appear to be of widespread applicability. The principles of the model are illustrated with reference to the irradiation ‘structure term’ of Young’s modulus. It is shown that the currently used definition may be considered to be a combination of three separate processes – pore closure driven densification, increased structural interconnectivity and (latterly) pore generation. It is the structural interconnectivity component that is most closely linked to the changes in other properties such as dimensional change rate and coefficient of thermal expansion, and this relationship is used to direct the mathematical formulations.