Methodology for Source Term Analysis of a Molten Salt Reactor

Interest in MSRs has increased in recent years due to the changing needs and goals of nuclear energy. The ARE and MSRE set the stage early on for MSR research. There are many different options for MSRs including different salt compositions, neutron spectrum, fuel choice, and purposes. Thermophysical and thermochemical properties, such as melting point, density, and viscosity must be known for the salt composition chosen for the reactor. Some neutronics differences that set MSRs apart from LWRs are changes in treatment of delayed neutron precursors and point reactor kinetics. MSRs allow the ability to process the fuel during operation to remove or add desired nuclides. The NRC's experience is mainly focused on LWRs, but they have started exploring some advanced reactor source terms from a regulatory perspective. A MSDR and MSRE were modeled in SCALE/TRITON and when compared to a Westinghouse PWR the results showed that MSR source terms were less than 20% compared to PWR dependent of specific radionuclides.