COMPUTATIONAL STUDY OF DEFECTS EVOLUTION DURING IRRADIATION IN SINGLE-PHASE AUSTENITIC ALLOYS

A composite model of the point defect processes and the extended defec t evolution in irradiated materials was composed for a theoretical inv estigation of the response of fusion first wall materials to neutron b ombardment. The point defects model calculates the concentration chang es of single point defects including a transmutant helium, simple poin t defect clusters and complex clusters. The extended defect model cons ists 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 a n Fe-15Cr-20Ni ternary austenitic model alloy. Using the calibrated mo del, the effects of helium generation on point defect processes, cavit y nucleation, dislocation evolution and mechanical property change wer e investigated.