A simplified model for dynamic simulation of the primary circuit of pressurized water reactors

In this paper, we present a mathematical model for the simulation of transient neutronic and thermohydraulic behaviour of the PWR core and the primary circuit of a nuclear power plant. The point kinetics equations are used to model the core neutronics and the improved lumped parameter formulation is used to model the fuel dynamics. A two-region model is used for the pressurizer and for the primary-side of the steam generator. A pump model is implemented to obtain the flowrate variation during total or partial loss of flow. Several transient events and accidents are simulated and qualitatively agree with the results of more detailed engineering models. While the proposed model predicts reasonably well the main physical phenomena, its accuracy needs to be assessed in comparison with more accurate computational codes