Main steam system that reduces the release of radioactive material to the atmosphere under severe accident

摘要

The present invention provides a nuclear power plant main steam system capable of reducing release of radioactive materials into the atmosphere under accidents comprising: a decontamination tank including decontamination water; and a connection pipe connected with the decontamination tank through a main steam safety valve from a main steam pipe connecting a steam generator and a turbine. The main steam safety valve is formed of three-directional valves to release a steam generated in case of design standard accidents to the atmosphere and transfer the steam to the decontamination tank under severe accidents. According to the present invention, the main steam system has an effect of reducing release of radioactive materials into the atmosphere when containment building accidental accidents including steam generator tube rupture (SGTR) caused by the high temperature steam during severe accidents occur.