2025 年 24 巻 1 号 p. 26-37
Reinforced concrete is generally used as a shielding wall for radiation facilities where gamma rays and X-rays are generated. The shielding effect should be varied by adjusting the diameter and pitch (spacing) of the reinforcing bars (rebars) in the reinforced concrete as well as the radiation energy. We simulated the leakage radiation dose from concrete with and without rebars. The radiation was confined to be gamma rays and X-rays emitted from a point source. The shielding effect was evaluated by the ratio (the decrease ratio) of the leakage radiation dose of reinforced concrete to the dose of concrete without rebars. The decrease ratio decreased linearly as the diameter of the rebars increased. The decrease ratio increased exponentially as the gamma-ray energies and the distance between the point source and the concrete increased.