The following objectives were planned for this project. (1) Development of spinning data necessary for spinning Columbium and Columbium-1% Zirconium tubing from ingot, forged or welded tube blanks. (2) Determine mechanical & metallurgical properties of spun Columbium and Columbium-1% Zirconium tubing. (3) Determine dimensional and tolerance limits possible to attain on spun Columbium and Columbium-1% Zirconium tubing based on our present equipment, tooling limitations, and the spinning tests performed for objective No. 1.

The use of uranium mononitride as a nuclear fuel is being considered for a number of high temperature applications. In comparison with the most often applied high temperature fuels, UO2 and UC, one finds that UN has a combination of the high melting point of UO2 and the thermal conductivity and high uranium density of UC. However, interest in UN is often dampened by qualitative indications of its low thermal stability and by lack of experimental thermodynamic data. Is is the purpose of this study, therefore, to provide a quantitative measure of the thermal stability of UN and to establish some of its thermodynamic properties.

Abstract. Some recent analysis of certain Lid Tank fast neutron dose rates measured in oil and water indicates that there are some basic inconsistencies with reported oxygen and carbon removal cross sections and the reported data. These inconsistencies may be explained in several ways: (1) The reported carbon removal cross section is wrong. (2) The reported oil composition is wrong. (3) The reported oxygen removal cross section is wrong since it is based on an assumed rather than a measured oil composition. (4) Some of the experimental data are wrong. It is not possible to determine which of the above is most likely on the basis of analysis alone but the possibilities are pointed out and, based on the assumption that all the experimental data are correct, it appears most likely that the oil composition assumed in ORNL 2197 was in error.

Summary. A test rig has been designed to obtain basic two phase forced convection liquid metal heat transfer and pressure drop data for use in the design of liquid metal boilers. This engineering report includes background of the boiling problem, partial summary of work done by other investigators, the object, scope, engineering, and operations of this test rig, and a summary of reproducibility tests conducted in a water back-up rig.