Radioactivity reducing device

Purpose: To provide a radioactivity reducing device in a nuclear power plant, which prevents the discharge of radioactive substances into a building. Constitution: Drains and vent gases exhausted from main machinery and tools of a nuclear power plant are introduced into a sump tank and a vent tank, respectively, and treated in a radioactivity processing device comprising an iodine removing device, a rare gas removing device and the like. In this case, the sump tank, vent tank and various tanks in the radioactive waste processing device are all of enclosed structure, vent gases exhausted from these tanks are collected in the vent tank, and discharged into the atmosphere through the radioactivity processing device. (Kamimura, M.)