Mitigation of Degradation in Polymers by Gamma Rays

In nuclear power plants, polymers used for electrical insulation are irradiated by radioactive rays, depending on the places where they are installed. If an accident occurs, such polymers may also suffer high-temperature steam exposure. We have conducted several experiments that aim at clarifying the effects of thermal stresses, gamma-ray irradiation, and steam exposure on various insulating polymers and have found that gamma-ray irradiation can mitigate the degradation induced by the steam exposure in several polymers.