• Neutron irradiation significantly slows deuterium permeation in SS316IG steel. • Permeation kinetics are governed by reversible radiation-induced traps below 450 °C. • Oriani model reproduces steady-state flux reduction under irradiation. • Deuterium trapping is diffusion-limited, while detrapping is thermally activated. This paper presents an analysis of the results of reactor experiments on deuterium permeation in SS316IG steel, performed at sample temperatures of 350–550 °C, with an inlet deuterium pressure of approximately 500 Pa and a thermal neutron flux of ∼ 2·10 13 n/cm 2 ·s. Based on a diffusion model with traps in the quasi-equilibrium (Oriani) approximation, the effect of neutron irradiation on the kinetics of deuterium permeation was analyzed, and the effective parameters of radiation-induced traps were determined for sample temperatures below 450 °C. The trap concentration values obtained at temperatures of 350 °C (0.83 mol/m 3 ) and 400 °C (0.5 mol/m 3 ) were found to be more robustly determined than the parameters of the Arrhenius dependence of the trapping equilibrium constant. The combinations of the pre-exponential factor K 0 and the binding energy E b were found to lie in the ranges K 0 ≈0.02–0.3 mol/m 3 and E b ≈5–20 kJ/mol. The results obtained contribute to the refinement of models describing hydrogen isotope transport in fusion reactor structural materials and can be used to predict their behavior under realistic operating conditions.
Kulsartov et al. (Wed,) studied this question.