Study on Control of Natural Circulation and Forced Circulation in Nuclear Power Plant

Nuclear Power Plant (NPP) is a complex multi-input & multi-output system, and its operating condition is very complicated, so it is very important to keep NPP safe in a variety of operation conditions including natural circulation, forced circulation, transferring from natural circulation to forced circulation, transferring from forced circulation to natural circulation, etc. It is very necessary to study the control strategies under different conditions based on aforementioned objectives. In order to study the control system, the nuclear power plant simulation model which can simulate the nuclear power plant operating characteristics is established by means of real-time simulation technology. The thermo-hydraulic model and the twogroup three-dimension space-time neutron kinetics model for the reactor and reactor coolant system (RCS) of a certain type of nuclear power plant have been established in the paper and simulation program based on these models have been completed. The different transition processes and different control conditions were simulated under the proposed control strategies. The results show that the proposed control strategies can guarantee the safety and rapid response to nuclear power plant.