A total of 104 thermal cycles between 250°F and 1350°F were imposed on a 3 1/2-in. and a 4-in. freeze flange to determine their susceptibility to thermal fatigue. The flange clamping arrangement was modified and various gaskets were used during the cycling in an effort to reduce the gas leakage problem.

The nuclide Cs-137 is a fission product commonly used for measurement of uranium burnup in irradiated uranium fuel by the fission product to uranium ratio method. In the application of this method, the largest single error introduced in the measurement of burnup is the uncertainty in the half-life of Cs-137. Because of the uncertainty in this value and its importance in nuclear fuel burnup analysis, a reinvestigation was undertaken to obtain a more accurate value using the mass spectrometric method.

Uranium carbide shows promise as a fuel material for reactors operating at relatively high temperatures based on its high melting point, high uranium density and high thermal conductivity. Before refined reactor designs can be made, however, good quantitative data on the thermal conductivity at temperatures in excess of 1000C is required. This technical report presents data gathered as part of a continuing study aimed at determining the thermal conductivity of refractory uranium fuels as a function of temperature, density and composition over the temperature range 1000-2200C. At the inception of this program it was felt that an absolute method capable of achieving high temperatures was necessary and that the difficulties encountered in fabricating the large complex specimens needed were justified. The steady state radial heat flow method and apparatus of Rasor and McClelland were therefore chosen. The technical report discusses the experimental equipment and presents results of measurements on three specimens of UC over a temperature range 900 to 1600C. An analysis of the data is made with respect to other physical properties of the material and the measured conductivities are compared with the work of other investigators.

From Abstract: "The diffusion cooling coefficient in graphite has been determined by measuring the change in the asymptotic average velocity with buckling, by pulsed neutron methods. The times necessary to establish equilibrium spectra in graphite and heavy water have been measured and are reported."

"The canonical (hamiltonlan) formulation of a relativistic dynamical theory is outlined, and the existence and explicit construction of general hamiltonian theories of relativiatic interacting particles are discussed. These hamiltonian theories are shown to contain certain elements of arbitrariness which are eliminated in manifestly coveriant formulations."

From introductory paragraph: "This report concerns the hydrolysis of rare-earth dicarbides, sesquicarbides, solid solutions of carbon in rare-earth metals as well as rare-earth carbon alloys of varying compositions. Many of the carbide samples used in this study were those which had been studied by Gschneider (9)(7) and had been preserved in evacuated, sealed tubes. Some additional preparations of the sesquicarbides were made especially for these studies. The hydrolytic reactions were carried out in water and hydrochloric acid solutions of varying concentrations. Assay of the gaseous products was by mass spectrometry and gas chromatography. Both instruments were carefully calibrated with pure hydrocarbons and hydrogen and mixture thereof."

The primary purpose of this joint USAEC-Euratom program is to obtain a better understanding of the maximum achievable operating characteristics of UO2 as a reactor fuel. During the program work will be performed in two areas that have been of concern to reactor core designers for a long time, namely, fission gas release and central melting in fuel rods.

Quarterly report describing the progress and development of improved zirconium alloys for service in superheated water and steam. This report covers the period between October 1 to December 31, 1960 and was conducted by the United States and the European Atomic Energy Community (EURATOM).

"A method and equipment are described for determining the surface parameters of contact required for heat transfer calculations. In this method, the output of a surface analyzer for one surface is recorded on one channel of magnetic tape and the output for the other surface of the contact pair on a second channel. The tape is played back to an analog computer which then integrates the analog voltage to compute the void volume thickness, the number of contact points, and the ratio of metallic contact area to the total area."

From summary: This report describes the 10-watt Sr-90 thermoelectric generator, the dc-to-dc converter, batteries and the method of installation in the light buoy.