The effect of pulsed irradiation on the swelling of 316 stainless steel in fusion reactors

A time-dependent rate theory formulation has been used to study the effects of pulsed irradiation on point defect and void behavior at elevated temperatures. It is found that point defects in pulsed tokamaks, θ-pinchs and inertial confinement fusion reactors (ICFR) display non-steady-state behavior. The pulsed nature of the irradiation has been shown to produce considerable deviations from steady-state void growth behavior at high temperatures (0.3 T_m to 0.5 T_m). In particular, the amount of swelling in the first-wall can be reduced for ICFR pulsing conditions and pulse widths ranging from a nanosecond to a microsecond. The amount of reduction increases with increased pellet yield at a fixed operating temperature, geometry and ICFR plant power output.