Verification of the AP1000 Nuclear Power Plant Simulator NPPSim Against RELAP5 for Transient Analysis

To thoroughly investigate the AP1000 reactor system, an AP1000 Nuclear Power Plant Simulator (NPPSim) was built and applied to the AP1000 transient and control system analysis in MATLAB/Simulink environment. In this study, a 100%–90%FP load step transient condition of AP1000 PWR was simulated by both NPPSim and RELAP5 simultaneously to verify the NPPSim’s capability of transient analysis. To realize this objective, a RELAP5 model of AP1000 PWR was firstly developed and relevant control systems were implemented in the input deck of RELAP5. Then the transient was performed to conduct this verification under the same conditions. The comparisons show a good agreement in terms of the changing trends. In addition, the deviations of the NPPSim simulation results and the RELAP5 calculating results are in the acceptable range. Therefore, the NPPSim is capable to implement the 100%–90%FP load step transient analysis for AP1000. More transient conditions should be simulated and studied for further verification.