Two-Point Reactor Core Model for Pressurized Water Reactor and Its Application

Based on the nodal method,a two-point core model for pressurized water reactor is developed in this paper.Furthermore,the model is formulated through the linearization of the nonlinear model,and then a Linear Time-Invariant model is obtained.To simulate the control rod system more accurately,a two-point control rod system is built.Referring to the mechanical shim control strategy in AP1000,the average temperature control system and the axial offset control system simulation program are built on the Matlab/Simulink platform and are applied to simulate load transient of step power.The simulation results show that the power derivation remains in the target band,and the steady state deviations between the actual values and target values for the reactor power and mean coolant temperature are in the dead bands.Therefore,the developed model is available for the simulation and design of the power control system and the power distribution control system.