A Coordinated Control Strategy for NHR200-II Under Load Rejection Condition

Abstract In recent years, the safety and stability of power plant operations have attracted more and more attention. As a clean and safe energy, nuclear power is up-and-coming in China. However, external interruption is hard to avoid and usually causes negative consequences. The load rejection condition may occur in nuclear power plants due to environmental influences, external power grid shock, or failure. This paper mainly discussed the load rejection process of NHR200-II, one of the steam generator outlet valves closed unexpectedly and the reactor load changed from 100% to 50%. The load rejection condition was simulated in MATLAB SIMULINK and analyzed in detail. A control strategy for this abnormal condition was proposed and a cascade control over the steam pressure control loop was introduced. This control strategy was validated by conducting simulation experiments. By comparing the responding curves of critical parameters before and after the control is applied, the result showed that the severe consequence could be avoided after applying the control strategy and the stable operation was realized.