Effects of radiation on corrosion are not well understood but are highly relevant to the degradation of light water reactor core components. Previous work has shown that proton-induced radiolysis decreases the corrosion rate of 316L stainless steel in 320 °C water containing 3 mg/kg H2. Therefore, a low pressure steam environment was used to minimize radiolysis to isolate the effect of displacement damage on the corrosion rate. Steam was hydrogenated using an Ar-3%H2 gas mixture to emulate the oxidation potential of pressurized water reactor environments. The temperature chosen for steam exposure was 480 °C to compensate for reduced oxidation kinetics in low pressure steam. Two irradiation experiments were performed for 24 h and 72 h durations with a damage rate of 7 × 10–7 dpa/s at the steam-facing surface. An additional surface is provided by the sample geometry where the damage rate is negligible but radiolysis is present. Three regions—irradiated, non-irradiated, and radiolysis—are characterized for inner oxide thickness. Inner oxide thickness is highest in the irradiated region and lowest in the radiolysis region. The non-irradiated and radiolysis regions showed similar corrosion behavior, confirming that radiolysis effects are minimal in steam. Without significant radiolysis, increased oxidation in the irradiated region can be attributed to displacement damage. Porosity observed in the inner oxide was greatest in the irradiated region indicating increased porous transport of oxygen to the metal increased the corrosion rate, and that pore growth by displacement damage is the mechanism underlying the increased corrosion rate.