Fuel Qualification Guidance for Molten Salt Fuel

Description of Molten Salt Fuel

Liquid-fueled Molten Salt Reactors (MSRs) have certain unique aspects that must be considered in order to meet the advanced reactor fuel qualification process. For in-reactor performance, perhaps the most unique aspect of a liquid-fueled MSR design is that the fuel is also the coolant. Thus, while the fuel is not only the principal heat source, it also plays a major role in heat removal both for normal operations and off-normal events, as well as during shutdown (decay heat removal). Since fission products are produced in the fuel because of the fission process, the presence of these materials will change the chemical composition of the fuel salt, and in turn they will change the thermophysical properties of the fuel/coolant.

Based on earlier studies of MSRs, it is well established that changing the composition of salt can affect properties such as melting point, boiling point, density, and viscosity. Understanding the impact of changes in the thermophysical properties of the fuel/coolant resulting from the addition of fission products and possible corrosion product impurities will be essential to the analyses of the ability to remove heat from the fuel during normal and off-normal conditions and after shutdown.

Document Description Type
NUREG/CR-7299, "Fuel Qualification for Molten Salt Reactors" This report supports development of an efficient, appropriate methodology or process for liquid salt fuel system qualification. This report also describes the technical issues encountered when developing an adequate understanding of the fuel salt’s chemical and physical behavior under both normal and accident conditions. contractor report
ORNL/TM-2020/1576, "Molten Salt Reactor Fuel Salt Qualification Methodology" Defines the extent of the liquid fuel salt system, identifies the regulatory requirements associated with fuel qualification, and discusses the regulatory elements necessary to implement the envisioned alternative liquid salt fuel qualification methodology contractor report
ORNL/TM-2019/1195, "Review of Hazards for Molten Salt Reactor Fuel Processing Operations" Describes processes for storing, synthesizing, using, treating, and disposing of MSR fuel salts and the hazards associated with each process contractor report
ORNL/LTR-2018/1045, "Molten Salt Reactor Fuel Qualification Considerations and Challenges" Describes the considerations for and challenges to fuel qualification for liquid-fueled molten salt reactors (MSRs) contractor report