| The paper based on the best estimate thermal-hydraulic program RELAP5/MOD3.3,and has established the model of AP1000 nuclear power plant system. The primary system model consists of reactor vessel model, coolant pipes model, pressurizer model, steam generators model, reactor coolant pump model, steam outlet pipes model; passive core cooling system model, passive residual heat removal system model, passive safety injection system model, automatic depressurization system model. Debug the program to a steady-state basing on the system model. The steady-state parameters meet the reference range of AP1000 initial conditions.After the system program parameters correspond to the requirements, introduce the ADS Malfunction accident and passive residual heat removal system malfunction accident model, and carry on transient calculations. The ADS Malfunction accident calculations results meet the acceptance criteria, and proof that AP1000 nuclear power plant which occur ADS Malfunction accident can export decay heat and do not lead to serious accident.The passive residual heat removal system malfunction accident calculations results meet the acceptance criteria, the results proof that the pump is not running and nuclear reactor do not shutdown, AP1000 nuclear power plant which occur passive residual heat removal system malfunction accident can export decay heat and do not lead to serious accident. Then through decrease the water temperature in containment refueling water storage tank (IRWST) and the heat transfer area of heat exchanger, make the PRHR heat exchanger malfunction accident sensitivity analysis. The results shows that decrease the water temperature has little effect on the natural circulation within PRHR heat exchanger,decrease the heat transfer area of heat exchanger has large effect on the natural circulation.The important parameters of sensitivity analysis meet the acceptance criteria, and do not lead to serious accident. |
