This webinar demonstrates how Flownex can be used to model an integrated nuclear reactor and turbine power cycle and simulate accident scenarios such as a reactor trip followed by a turbine trip. The model combines a helium-cooled prismatic block reactor, steam generator, turbines, pumps, valves, and control systems to analyse plant-wide transient behaviour. During the simulated accident, reactor shutdown, circulator rundown, turbine trip, and steam bypass valve operation were successfully modelled, allowing key temperatures, pressures, flow rates, and reactor parameters to be evaluated. The results showed that decay heat could be safely removed by maintaining reduced helium circulation, while steam pressures and temperatures remained within acceptable limits after control actions were applied. The webinar highlights Flownex’s ability to rapidly simulate complex nuclear systems, support safety and accident analysis, and assist with reactor design, control system development, and licensing activities.