Swelling Analysis of Structural Materials For Fusion Demo Reactor

Abstract

Fusion reactor structural material is subjected to heavy neutron flux and it causes significant damage in structural material. Interaction of high energy neutrons with material produces the void, defect cluster, bubbles, matrix etc. All this material defects will result in swelling of material. Swelling will cause volumetric expansion and material property changes which has significant implication in fusion reactor design. This paper covers implication of material property changes due to swelling in design, swelling calculation, Simulation and thermal analysis of vacuum vessel for neutron wall loading. From stand point of structural design criteria, most significant issue stem from irradiation induced material property changes, specially reduction in ductility, strain hardening capability, and fracture toughness with neutron irradiation. In this work, effort is made to understand and incorporate the effect of material property changes in design by taking ITER (International Thermonuclear Experimental Reactor) as case study. This paper also covers calculation of swelling for ITER machine and DEMO-Reactor with CW (Cold worked) 316 stainless steel and further high swelling resisting steels such as Indian RAFMS (Reduce Activation Ferritic Martensitic Steel) steel-1, Indian RAFMS steel-2, HT-9 and F82H, as structural materials. To simulate the heat generation due to neutrons, Thermal analysis is carried out in ANSYS for ITER and SST-2 vacuum vessel which is part of work.