Report containing ongoing projects and experiments undertaken by the Oak Ridge National Laboratory's Molten-Salt Reactor Program.

Report issued by the Oak Ridge National Laboratory discussing quarterly progress of the Homogeneous Reactor Project. Progress of operations, design, development, and analysis is presented. This report includes tables, illustrations, and photographs.

A direct titrimetric method for the determination of trivalent uranium in uranium trifluoride and mixtures of fused fluoride salts was developed. The method is based on the stoichiometric oxidation of trivalent uranium to the tetravalent oxidation state with an acidic solution of methylene blue. The sample containing trivalent uranium is dissolved at room temperature in an excess of standard methylene blue solution in a carbon dioxide atmosphere; the excess oxidant is variation of the method is 1.5 per cent for 5 mg quantities of trivalent uranium. The method was applied to various mixtures of fluoride salts containing both trivalent and tetravalent uranium.

Diffusion in an arc plasma across a magnetic field is investigated. The geometry is similar to that reported in ORNL-1890 but with the addition of magnetic mirrors on the ends of the arc chamber. It is shown that mirrors do not eliminate the "short circuit" effect. Comparison of the e-folding length, rₒ, of the radial ion density with and without mirrors, affords a direct measurement of ℓ/λ where ℓ is the arc length and λ the mean-free-path. In addition rₒ is independent of gas pressure with mirrors and varies as √p without mirrors. The condition for the elimination of the "short circuit" effect is discussed, as well as the case in which the "short circuit" is still present but the ions diffuse (rather than stream) to the end walls. In this case rₒ is directly proportional to the gas pressure. These effects are compared to some experimental results of Neidigh

This quarterly progress report discusses ongoing work at the Metallurgy Division at the Oak Ridge National Laboratory. Topics discussed include thorium research, the preferred orientation of uranium, studies in the ceramics laboratory, the homogenous reactor program, studies in the x-ray laboratory, studies in the metallographic laboratory, the experimental plate-cladding program, and fuel and control element fabrication.

This report presents "Results of a critical literature review on pressure drop due to isothermal turbulent flow in noncircular geometries" (introduction).

Technical report summarizing one phase of work done to develop methods of bonding uranium to a metal which is a good conductor of heat. Silver was chosen for contact with uranium because it is easy to plate on uranium and there is no danger of brittle Ag-U compounds being formed at elevated temperatures. [From Abstract]