A computational study of defects evolution during irradiation in single-phase austenitic alloys

A composite model of the point defect processes and the extended defect evolution in irradiated materials was composed for a theoretical investigation of the response of fusion first wall materials to neutron bombardment. The point defects model calculates the concentration changes of single point defects including a transmutant helium, simple point defect clusters and complex clusters. The extended defect model consists of individual rate theory models of evolution of cavities, Frank faulted loops, network dislocation and other microstructural features. The model was calibrated based on the dual-ion experimental data on an Fe-15Cr-20Ni ternary austenitic model alloy. Using the calibrated model, the effects of helium generation on point defect processes, cavity nucleation, dislocation evolution and mechanical property change were investigated.