VITARS platform: Development and application in nuclear power plant safety analysis

A Visual Interactive Transient Analysis code for nuclear Reactor System (VITARS) platform was developed to enhance the efficiency of nuclear reactor simulation analysis and replicate real-time operational conditions of reactor circuits. The comprehensive platform encompasses the entire simulation process, including model establishment, real-time operation, and post-processing analysis. It supports multi-process parallel computing and incorporates a specialized interface for data exchange with Distributed Control System (DCS) virtual machines. The platform enables graphical construction of thermal-hydraulic models, logic configuration, and operational interfaces. During simulation, interaction with DCS virtual machines facilitates the simulation of measurement points and equipment status, enabling the application and verification of DCS closed-loop control logic. To validate its functionality, simulation analyses were conducted with a three-loop comprehensive thermal-hydraulic test facility from China as the target. In this case study, all platform modules were effectively utilized. Steady-state results demonstrated that key model parameters could be stabilized at correct values through DCS Proportional-Integral-Derivative (PID) closed-loop logic control. Transient analysis verified the effectiveness of protection logic triggers and the accuracy of the thermal-hydraulic model. Results indicated that safety systems activated promptly, and parameter variations followed expected patterns, yielding reasonable outcomes. These findings collectively validate the platform's effectiveness in both modeling and operational phases.