Small Pressurized Water Reactor (SPWR) Simulation Platform Development for its Design Verification

Abstract

Small pressurized water reactors (SPWRs) are under development in the world. Lots of efforts have been made to the Research & Development. SPWR has its unique design features. The integral design is adopted. The reactor, coolant pump and steam generator are in the reactor vessel. The coolant inventory is large. Once-through steam generator is chosen. The pressurizer is also large in the volume. Because many years operation experiences of commercial PWRs, some old operation strategies may be modified or new strategies are derived for the new development. When the operation strategies are chosen, a simulation platform is needed to verify whether they are suitable for SPWRs. In this paper, an SPWR simulation platform is developed to verify the operation strategies of SPWR. The platform is developed based on an engineering simulator and Relap5 has been integrated in the simulator. Operation transient or accident scenarios can be simulated with the simulator. To improve the operation flexibility and implementation of control logics, the engineering simulator is couple with MATLAB/Simulink using shared memory technology. Shared memory is an efficient means of passing data between programs. The dynamic data exchange and simulation time synchronization methods are carefully treated. To verify the platform, an SPWR with its control system is modeled with the platform and the simulator. The thermal-hydraulic modeling of the SPWR is carried out using Relap5. The preliminary SPWR control system is designed with conditional proportional-integral-derivative (PID) controllers and implemented in MATLAB/Simulink. Abrupt load changes are simulated to evaluate the performance of the platform. The results obtained from two different platforms match well with each other. It is proved that the coupling is successfully and the platform can simulate the transient behavior of the SPWR with its control system.