Establish Fuel Qualification Expectations

Abstract

The objective of this white paper is to provide an overview of the state of knowledge regarding issues associated with fuel qualification for a liquid-fueled molten salt reactor. The overview consists of fuel qualification expectations for heterogeneous reactors—conventional light water reactors, plus advanced reactors such as sodium fast reactors and modular high-temperature gas-cooled reactors—which consider the mechanical behavior of the fuel itself, interaction between fuel and its cladding, behavior of the cladding, and structural behavior of fuel assemblies. Fuel qualification expectations for molten salt reactors are viewed in contrast to the fuel qualification for heterogeneous reactors in that the fuel is liquid (molten) and there is no accumulation of mechanical effects such as stress, creep, or swelling. However, the liquid fuel salts do accumulate fission products, corrosion byproducts, and buildup of actinides which impact the chemistry of the fuel salt and thermal-physical properties that may impact the ability to remove heat from the core and retain radioactive materials in the fuel salt. Finally, the role of the US Department of Energy in research on tri-structural-isotropic and metal fuel for advanced reactors for fuel qualification purposes is briefly discussed as a potential model for the Department’s research to gather quality chemical and thermal-physical property data necessary to qualify MSR fuel performance under normal and accident conditions.