| Abstract Scope |
Oxygen content in fluoride salts is critical for controlling redox chemistry, corrosion, and fission product behavior in molten salt reactors (MSRs). Inert Gas Fusion (IGF) offers a direct method for oxygen analysis but faces skepticism when applied to fluoride salts. High temperatures are needed to thermodynamically drive oxygen reactions with carbon, which can exceed the boiling point of lithium, causing volatilization and secondary reactions—such as fluorides attacking the metal or glass components that cause spurious oxygen signals or contaminations. These effects raise concerns about accuracy, precision, and signal linearity. This work brings together Natura Resources, defining nuclear-grade requirements; Bruker AXS, optimizing IGF instrument design; and USREL, developing and validating the method with oxygen-doped standards and spike recovery. Together, we demonstrate that with tailored thermal profiles, fluxes, and calibration protocols, IGF can provide accurate, reproducible oxygen analysis in salts like FLiBe and FLiNaK, supporting broader deployment in nuclear material qualifications. |