Introduction: "Based on experimental data and on conservative theoretical considerations, an estimate has been made of the relation of the mining U-235 critical mass to the hydrogen moderation for uranium material at the U-235 assays for which experimental information is available. These estimates have been used in indicating maximum safe amounts for conditions where definite moderation limitations can be established."

Report discussing various procedures for recovering tuballoy from tuballoy tetrafluoride, also called "green salt." Results from trial runs of each procedure are presented.

Abstract: A simple process to recover the bulk of the uranium from ignited beta salvage residues was sought. In preliminary experiments a vapor phase chlorination with CCl₄ for about four hours followed by water and nitric acid leaching was found adequate. Recoveries are estimated at 60 to 90% of the total uranium content.

The following report covers the results of a general program that was conducted at the Oak Ridge National Laboratory to investigate the effects on plastic materials of exposure to radiation in the pile. In the investigation, several plastics were irradiated, and on removal from the pile, their rates of decay were determined by measurement of gamma activity in an ionization chamber.

This report follows calculations performed to determine the effect of epithermal capture on the value of eta to be used in lattice calculations.

Abstract: "The study of ten P.I.G. geometries with copper electrodes and d.c. voltage indicates that from a pressure of 0.1 to about 3.0 microns, depending upon the gage, there is a consistent change in the air pressure-current characteristics of a P.I.G. as the geometry and voltage are changed. At higher pressures discontinuities appear in the gage current and prohibit its use as a pressure gage. In all useful geometries, the greater the applied voltage above 1000 volts, the shorter the useful portion of the pressure-current curve became. Below 1000 volts the curve tended to be unstable. With other conditions constant, the pressure limit increased as the cathode separation decreased and as the anode diameter increased. The empirical equation for the current in certain Philips Ion Gages at certain pressures and voltages is I = a'Pe-p/b where I is the current, P the pressure, e the Naperian base and a' and b constants and dependent upon geometry and voltage."

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]

In solving the two-group, two medium equations for neutron diffusion in a finite one-dimensional multiplying system, the equations in each medium can be solved, and the boundary conditions used to determine the coefficients. This direct attack involves eight simultaneous linear equations. The opportunities for error are numerous, and, frequently, a great deal of accuracy is lost by subtractions; hence, it is felt that an alternative method of solution, in which numerical errors would be less likely to occur, would be desirable.

Technical report. From Abstract : "The acidity of a solution of acid, HX, and salt, MX, is affected by both the concentration of X- and M+ owing to incomplete dissociation of the salt, MX. it was possible to increase the acidity of a solution of 2,6-di-tert-butylphenol - tetrabutylammonium 2,6-di-tert-butylphenolate relative to a dilute solution of tetrabutylammonium hydroxide by increasing the tetrabutylammonium bromide content. This indicates that the dissociation constant of the hydroxide base is sufficiently large that extensive dissociation occurs in dilute solutions. The addition of tetrabutylammonium bromide is therefore recommended as a general method for increasing the acidity and improving the titration characteristics of extremely weak acids."

The decontamination of portable instruments by the Calibration Unit has presented a problem for some time. Most of the contamination is in the 100 to 500 c/m or 500 to 2000 d/m range. Higher levels of contamination can usually be reduced to these levels, but further cleaning proves quite difficult

From abstract: "In an attempt to gain some insight into the physiological condition of mice surviving massive doses of radiation, a study of their vitality was undertaken. It was assured that the ability of these animals to do forced work would be a measure of their vitality, Stimulating exposed animals to run in exercise wheels to their fullest capacity, has resulted in a demonstration of a striking vitality less during a post-irradiative period, when no other effects are demonstrable by gross examination. Mice subjected to a medium-lethal dose of fast neutrons show a continuous vitality loss over a 300 day period following exposure. Control animals show no appreciable loss of vitality up to about 8 months of age, after which a gradual loss can be noted, probably due to a normal gereologic process."

Abstract: The output signal of a linear accelerator may have a rise time of 1-2 x 10[minus]7 seconds. Therefore, the output of a pulse height selector operating on this signal has a variation of delay from the original signal of about this amount. In the instrument to be described in this technical report this difficulty is largely resolved.

Laboratory studies have shown that the double salt, CaF2-PuF4, can be precipitated by rapid addition of hydro-fluoric acid to solutions containing 25 to 75 g Pu/1, caleium equimolar to plutonium, and 1 to 10 M HNO3. The precipitate, which is subsequently washed with water and dried to 300 degrees C in dehumidified, deoxygenated argon, can be reduced thermally by calcium to give high yields of plutonium metal.

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.

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

Report discussing information relative to the pyrophoricity of uranium for the purpose of reactor core fire safety. The report includes physical and chemical properties of uranium.

Study carried out to determine a suitable reactor system or systems for the testing of water, gas, and liquid-metal cooled fuel assemblies.

Report describing a method of fitting "a weighted least square polynomial of order n to a set of m observation points" in order "to satisfy the need for a general curve fitting scheme" (p. 1).

From summary: "Report discussing the beta-gamma dosage rate at the surface of a natural uranium disc. Measurements were taken using a Ryerson electrometer and an extrapolation ionization chamber."

Report documenting the progress of the Army Gas-Cooled Reactor Systems Program to develop a mobile nuclear power plant for military field operation.

"Additional mixtures of polymers and multi-unsaturated monomers have been prepared, irradiated and the gel content determined. The gel content determination of crosslinked polyolefins has been investigated in detail. The multi-unsaturated monomers used and radiation conditions applied up to this time have not given significant gel contents for polypropylene. the polypropylene resin used has been characterized by differential extraction."

Report of the Geohydrology of the tatun salt done area of Lamar and Marion counties.

Abstract. Chemical analytical studies of graphite raw materials have revealed new sources of petroleum cokes and pitches of greater purity than those previously used in the manufacture of project graphite. The use of these raw materials of exceptional purity has resulted in an improvement in k of the order of one per cent as compared with the AGOT-AGNT graphite typical of the previous production. A study of the graphitizing process has shown that no dangerous impurities are introduced in the graphite in manufacture; rather, the process actually purifies. furthermore, impurities are distributed homogeneously within the furnace charge; thus the AGOT-AGNT distinction is no longer necessary. A comparison of the methods of graphite testing has demonstrated excellent correlations between chemical analytical data, the results of the function test at Argonne, and the sigma pile experiments. It may therefore be inferred that chemical testing should be an adequate control of the graphite purity. Methods are described for the analysis of ash, B, V, TI, FE, and Ca in petroleum coke, pitch, and graphite.

Technical report summarizing our knowledge of the chemical effects of ionizing radiation upon water and upon aqueous solutions of inorganic compounds. The types of radiation considered are beta rays, gamma and X rays, and heavy particles, notably neutrons, deuterons, alpha rays and fission recoils.