Safeguards By Design Considerations For Modular Molten Salt Reactors

Current international safeguards approaches for power reactors were developed and optimized for standard light water reactors and are not directly applicable to molten salt reactors. This paper presents specific novel safeguards measures that might be considered by the International Atomic Energy Agency and design considerations that might be incorporated by advanced reactor designers to improve the future effectiveness and efficiency of safeguards implementation into a modular molten salt-fueled reactor design (e.g., ThorCon’s molten salt reactor). Novel safeguards measures may take advantage of the homogeneous nature of the fuel salt in liquid salt-fueled molten salt reactors, which allows for remotely-obtained samples that are representative of the isotopic concentration of all fuel salt in the loop at the time of sampling. Additionally, intrinsic characteristics of the reactor system (e.g., the frequency response to intentional perturbations) could be leveraged to provide a unique and real-time indication of diversion of nuclear material from the fuel salt. Effectively inventorying nuclear material during maintenance periods, when components will be changed out, will be a unique challenge for the IAEA. This paper presents suggested design considerations that designers might consider to reduce the burden of independently verifying quantities of nuclear material.