A spectrometer has been used with a hollow prism electrically heated to 70 C to measure the refractive indices of solutions of uranium hexafluoride in bromine trifluoride and uranium hexafluoride in bromine pentafluoride. The refractive indices of the two binary systems have been expressed as a function of composition.

This report is a record of experimentation conducted intermittently over a period of two years and directed toward preventing deposition of transport corrosion products on fuel elements and other critical components in high-temperature, circulating water nuclear reactor. It includes the postulated mechanism for deposition, a description of experimental equipment, experimental data, results obtained from the experiments, and recommendations for future study.