Molten Salt Reactors (MSRs) are nuclear reactors that use a circulating molten salt with liquid fuel. These reactors require modeling and simulation (M&S) to characterize plant dynamics, and nonlinear lumped parameter models have been developed in previous research. This paper presents an application of M&S for a conceptual MSR plant to refine key safety parameters. Neutronics, heat transfer, and fluid transport were modeled to simulate transients for an entire plant from the reactor to the steam-cycle components. Simulation results were compared to overall safety requirements to derive new system requirements. Further, Model-Based Systems Engineering (MBSE) parametric analysis was used to simulate multiple plant instances and derive specific equipment requirements. The results suggest that the modeling and simulation techniques can be used in other applications to derive general nuclear safety requirements to specific requirements in the conceptual design of nuclear plants.