Dynamics Modeling of Molten Salt Reactors

The abundance of energy is a necessity for the prosperity of humans. The rise in energy demand has created energy shortages and issues related to energy security. Nuclear energy can produce vast amounts of reliable energy without many of the negative externalities associated with other competing energy sources, such as coal and natural gas. As a result, public interest in nuclear power has increased in the past decade. Many new types of nuclear reactor are proposed. These nuclear reactor designs feature many passive technologies that can operate without external influence. Reactors that feature advanced passive safety features are catagorized as 4$^{th}$ generation advanced reactors. \acp{msr} are a type of advanced reactor that uses molten alkali halide salts as both the coolant and the fuel matrix. \ac{msr} remain as understudied systems with complex dynamic behaviors. Non-linear dynamic simulations allow modeling complex systems such as \acp{msr}. Non-linear modeling as such presented here can be used to understand the unique dynamic behaviors of \acp{msr}. The modeling methodology is implemented in Modelica, an open-source dynamic modeling environment, and is publicly available. Modeling capabilities include 1D thermal hydrolic coupled neutronics, dynamic decay heat production, fission product inventory tracking, and a collection of support utilities. The modeling toolkit \ac{smdmsr} is specifically geared toward modeling the thermal spectrum \ac{msr}. Its modular implementation allows the substitution of various physics modules to capture the specific functional requirements of a specific \ac{msr} system. The publication includes three dynamic models of \ac{msr} systems of varying compexities. They include \ac{msre}, \ac{msdr} and \ac{msrr}. Modeling of each system is discussed, and several transients including both normal and off-normal transients are performed to demonstrate the \ac{smdmsr} toolkit's modeling capabilities.