Research Methods and Protective Measures for Internal Flooding Analysis of Nuclear Islands

Abstract Internal flooding of the nuclear island in nuclear power plants is a common mode failure of systems and equipment, and the potential hazards must be considered during design. The protective design for such hazards should ensure the realization of various safety functions of the power plant system. Based on the analysis and research on internal flooding of the nuclear island in third-generation nuclear power units, this article follows the standards and specifications of advanced pressurized water reactors, draws on engineering design experience of nuclear power plants, and studies the analysis methods and protective measures for internal flooding of the nuclear island. Firstly, it determines the background and evaluation criteria for internal flooding protection design in nuclear power plants, compares the recommended flooding hazard evaluation methods in the standards, then analyzes in detail the steps and process of screening internal flooding sources, analyzes the spreading path of water sources and water level calculation methods, and conducts risk analysis on protective equipment within the subarea, so as to determine protective measures. The analysis results are given for the safety objectives of nuclear power plants.