Part I of this report covers critical-mass determinations for pseudospheres of oralloy hydride composition (approximating UH3) in 8"-thick Tu and Ni tampers and in the Tu tamper with Ni liner. The critical mass of a hydride cube in the thick Tu also is given. Data on weight and dimensional changes of hydride pieces during the period of use are included. In Part II are presented the results of Rossi time-scale measurements on the hydride assemblies. Values of alpha at delayed critical and its variation with mass in the neighborhood of delayed critical are given. Measurements on the activation of various detectors within the hydride assemblies are described in Part III. Results as a function of radial position are given for Au, for Au shielded by Au and by Cd, for S and for fission catchers with U235 and U238. Reactivity changes resulting from the introduction of foreign materials into the hydride assemblies are discussed in Part IV. Apparent regularities with respect to Z and qualitative interpretations of variations with radius are pointed out. From data for various radial positions, changes in critical mass corresponding to small changes in composition and density are computed.

This report follows the study of the oxidation of plutonium III and IV to the plutonyl state.

A series of pilot plant runs were made on the Jackpile ore, Jackpile mixed blend, Jackpile-Poison Valley blend, and Jackpile-Arrowhead blend.

A series of critical experiments with blocks of 2% U235-enriched UF4-C25H52 has been initiated at the ORNL Critical Experiments Facility. Thus far assemblies with H:U235 atomic ratios of 195 and 294 have been built in parallelepipedal and simulated cylindrical geometries, both reflected and unreflected. From the results the minimum critical masses for reflected spheres have been determined to be 16.3 and 8.5 kg of U235 for fuel mixtures with H:U235 atomic ratios of 195 and 294, respectively. The minimum critical masses for unreflected spheres of these two fuel mixtures are 24.3 and 12.7 kg of U235, respectively.

"Recent surveys by the Health Instrument Section have disclosed the presence of many small radioactive spots on ground surfaces in the T and B plant areas. Investigation has shown that representative samples of the spots when mechanically separated invariably end in a single radioactive particle."

This report discusses preliminary results acquired from investigations made on the ultrasonic properties of uranium, such as sonic vibrations in the megacycle frequency range.

Report discussing low and high acceleration flight mechanics for interplanetary missions, as well as the energy limitation for electric propulsion systems powered by a nuclear energy source. From abstract: "An optimization procedure for low acceleration systems is given which leads to a simple relationship between mission requirements, payload fraction, power plant specific power, and exhaust velocity."

This report discusses methods for preparing thin films of plutonium on metallic disks, which are used for alpha energy analysis, fission counting, and preparation of geometry standards in ordinary counting. Various methods of preparation were tested and analyzed, but electrodeposition was the most effective method. Deposition was then tested, but the yields were "somewhat erratic".

The objective is to establish, from test results, the relationship between pressure loss and orifice configuration, mass rate, and steam quality, for a Fuel Cycle fuel assembly.

This report discusses properties of the Redox process. Density, apparent molar volumes and viscosity are all described.

The NPR design calls for carbon steel to be the major constituent in the reactor coolant piping system. The piping and its associated fittings will, in all likelihood, be exposed to atmospheric weather conditions during the period of reactor construction. This type of exposure causes rusting. From experience gained during the startup of KER Loop 1 it is expected that there will be initially high NPR coolant activity levels. The high activity during the startup of KER Loop 1 was partially caused by the activation of rust that was eroded from pipe walls. Prevention of rusting on the carbon steel prior to its introduction into the coolant system would reduce the initial activity levels.

Mercury to be used in polarography as a dropping mercury electrode must be of the highest purity. The author has found that much of the commercial "triple-distilled" mercury as well as that which is repurified on site is not sufficiently pure and because of this, a study of mercury purification techniques was made and a very satisfactory procedure was tested thoroughly. This procedure is described in detail in this report.

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

From abstract: "An investigation of the radiation stabilities of aqueous solutions of sodium ethylenediamine tetraacetate and sodium acetate was made using a 3000-curie Co⁶⁰ source...A study of the behavior of the standard-size Beckman type glass pH electrodes in a solution containing 0.36 curie of Ce¹⁴⁴-Pr¹⁴⁴ activity per milliliter showed the useful electrode life to be of the order of two to eight days."

The development of nuclear reactors and other sources of nuclear particles has provided the analyst with a new method which has been successfully applied to the determination of microgram and even submicrogram quantities of many elements. In this method, known as "radioactivation analysis," the element to be determined is "activated" through some type of nuclear reaction which produces a radioactive isotope of the element. Since the radioisotope produced decays with its own characteristic radiation and half-life, it is possible, through radiochemical measurements following radioactivation, to devise a method of analysis which is very specific for particular elements. Whenever necessary, the radioisotope is separated by chemical means and its radioactivity is then measured by some type of radiation counter.

Below Richland, Washington there is a gradual decrease in the concentration of beta particle emitters in the Columbia River water. The concentration of alpha particle emitters in Columbia River water averages 5 X 10⁻⁹ μl/ml at all locations. The activity of alpha particle emitters in mud samples was less than the detection limit of 3 x 10⁻⁶ μl/gm; the average activity density of beta particle emitters approximates those reported for the previous quarter.

Report discussing tests of a new colorimetric method. From abstract: "A colorimetric method, which is a modification of the classical phosphomolybdic acid method, has been developed for the determination of phosphate in synthetic uranium waste solutions...The chief advantage of the method, over those presently included in HW Manuals, is the rapidity with which determinations may be carried out."

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 leaching behavior, thickening and filtering characteristics and recovery of uranium from high grade uranium ore from Rum Jungle, Northern Territory, Australia are described.

The fire involved approximately 30 liters of isopropyl alcohol as a result of the ignition of about 16-18 liters of isopropyl alcohol and a slurry of thoria and ammonium nitrate in a 20-liter glass carboy. This material was undergoing a volume reduction by boiling in a floor-type metal hood with Plexiglas sides and 3 sliding door on the front of ordinary glass. The alcohol vapor was vents directly into the hood (Fig1.)

This technical report provides a general description of the Brookhaven National Laboratory, describing the nuclear characteristics of the Brookhaven reactor and more detailed descriptions of the features and instrumentation of the reactor.

Soil chemistry studies have been carried on at Hanford for a number of years in support of the disposal of low and intermediate level liquid wastes to the ground. Equilibrium type experiments were carried out to investigate the mechanisms of the reactions of Sr, Cs, and rare earth ions with soils (1, 3, 4, 5). Experiments were also conducted with simulated and actual wastes in soil columns and an empirical method was developed for prediction of radionuclide breakthrough from ground disposal facilities into ground water on the basis of short, laboratory soil columns and equilibrium experiments (6,7). In this method it is assumed that the shape and position of the breakthrough curve is the same under laboratory conditions as in the larger scale field case. It is also assumed that the "column volume" or amount of soil effectively used for fission product sorption is that directly under a disposal facility without considering any spreading of waste solutions. These assumptions are known to be on the conservative side, but the degree of conservativeness is not known.

A report which summarizes the performance data obtained from Redox solvent extraction IC Column studies made prior to January 15, 1949 in accordance with conditions of the A.N.L. June 1, 1948, Flowsheet.

Abstract. Spectrographic procedures for determining small amounts of the common contaminants in beryllium and its compounds are described. Suggestions relative to the preparation of synthetic standards are also given.