Abstract: A method for separating small amounts of scandium (1 to 10 mg.) from a gram of uranium depends upon formation of insoluble uranium peroxide while the scandium in solution is complexed with ethylenediamine-tetraacetic acid. The precipitated peroxide carries down less than 30 p.p.m. of scandium. Uranium left in solution, less than one milligram in amount, does not interfere when the scandium is precipitated as ammonium scandium tartrate and determined gravimetrically by ignition of the tartrate to the oxide.

Report discussing a proposed electron probe that is connected to the discharge current from a device called the Perhapsatron. "The Perhapsatron is an apparatus for the study of the type of magnetic containment known as the 'pinch effect.'"

Abstract: "A method for determining hydrogen in lithium hydride by heating samples with lead at 600 C, was developed. The hydrogen evolved during thermal decomposition of the hydride is purified and oxidized to water with cupric oxide at 400 C. The analysis is completed by collecting and weighing this water. Success in development of the analytical procedure has depended upon a careful design and assembly of equipment for handling samples in a dry, inert atmosphere. For seven pure hydride samples analyzed by the recommended method the estimates of the standard deviation varied between 0.12 and 0.41 percent lithium hydride (or 1.3 and 4.2 parts per thousand) for 8 to 18 determinations on each sample. The procedure is relatively insensitive to variations in certain conditions. For single-piece samples weighing 0.2 to 0.5 gram it was found to be more satisfactory than a method which uses mercury in place of lead for sample decomposition. For powdered lithium hydride samples the lead and mercury methods are equally satisfactory."

Report describing Racah and Z coefficients. Formulas and results are detailed in the report.

The following report presents a discussion of the method for hydrodynamic problems, together with some new considerations that have arisen concerning the method.

The capillary trap method for the determination of carbon in metals (LA-1128) has been modified to give a fivefold improvement in sensitivity (0.1 microgram of carbon per millimeter). Samples from pure uranium buttons gave standard deviations ranging from 1.4 to 3.2 p.p.m. Varying sample size, in the range from 100 to 250 milligrams, did not affect the results significantly. The time required for an analysis is about 13-14 minutes. The method should be equally useful for plutonium.

Four uranium alloys containing nominally 0.5, 1.0, 1.5, and 2.0 w/o molybdenum were investigated with respect to their response to hardening by heat treatment. The several alloys were heated at elevated temperatures to secure solid solution, then quenched and reheated at lower temperatures to obtain hardening. The procedure followed the well known industrial practice of solution treatment and precipitation hardening. The results showed that all the alloys could be hardened by a suitable heat treatment. No specific temperatures are recommended; however, within the limits of the investigations, a solution treatment at 850 degree C followed by a water quench and reheat at 450 degree C gave a considerable increase in hardness. The time at temperature to secure maximum hardness would need to be determined as a function of mass and section shape. It is presumed that other mechanical properties of the alloys would be influence by heat treatment in a similar manner corresponding tot he effect upon hardness.

Critical mass measurements on graphite-tamped, heterogeneous oralloy-graphite systems have been made as a safety guide for certain oralloy casting procedures. Various concentrations were obtained by alternately stacking 10.5 in. diameter oralloy and graphite plates. In the relation Oralloy critical mass = constant x (fraction of oralloy in the core volume) -n values for the exponent, n, in the neighborhood of 0.70 were obtained.

A method is developed for using the relatively easily measured fission parameters, together with the mass equation of fission and the evaporation model of the nucleus, to determine the emission probabilities of the fission neutrons. The distribution of the kinetic energies of the fragment pairs enters into these calculations in a sensitive manner. Neutron emission probabilities are computed for the fission of the compound nuclei U/sup 234/ U/sup 236/, and Pu/sup 240/, for which cases reasonably adequate data on the fragment pair energies are available. Although the corresponding data for the fission of the compound nuclei Th/sup 233/, U/sup 238/, and U/sup 239/ are considerably poorer, neutron emission probabilities are also computed. The calculated results from this method are in good agreement with direct measurements of fission neutrons.

The effects of certain process variables on the production of uranium tetrafluoride from U3O8 on the 250 g. (uranium) scale, and smaller scales in a few cases, have been studied. It was found that the initial step (reduction of U3O8 to UO2 by hydrogen) is essentially complete in 15 minutes at 700 degree C. The rate of conversion was shown to be temperature dependent, the greatest increase in rate of conversion occurring in the vicinity of 500 degree C. In the conversion of UO2 to UF4 by hydrogen fluoride, the optimum temperature was found to be abut 600 degree C. For a reaction time of 5-1/2 hours, both higher and lower temperatures yielded less completely converted products. An increase in rate of conversion, both in reduction and hydro-fluorination, resulted when smaller quantities of material were used. Changes resulting from the present study and yielding an increased efficiency in the production process are described.

The index of refraction of PuO2 made by thermal decomposition of PU(C2O2, 6H2O gradually increases from a value < 1.9 to 2.40 as the decomposition temperature is increased from 150 degree to l000 degree C. This change in refractive index parallels a gradual change in the x-ray diffraction pattern from weak, diffuse lines for PuO2 ignited at 150° to sharp, well resolved lines for PuO2 ignited at 1000°C. Similar results are observed for PuO2 made by thermal decomposition of Pu2(C2O4)3*11H2O. The refractive index of PuO2 made from Pu metal at 170°C is 2.40 and is not affected by further ignition at higher temperatures, although crystal growth does occur. The rate of solution of PuO2 in an HCl-KI solution is greatest for samples prepared at low temperatures and decreases markedly for oxides ignited at higher temperatures. These observations hive been interpreted to mean that ignition at higher temperatures causes a gradual perfection of the originally highly distorted and impurity-containing PuO2 lattice obtained by low temperature decomposition of the oxalates and promotes the slow growth of crystallites. Both factors decrease the reactivity of the PuO2.

This report brings together an extensive accumulation of material replacement (danger coefficient) data for the various oralloy critical assemblies at Pajarito. Corresponding values of effective absorption and transport cross sections are derived. In certain favorable cases, inelastic scattering contributions to the effective absorption cross sections are estimated. Special applications of material replacement data include computation of the relationship between oralloy critical mass and concentration of a diluent and hydrogen isotopic analysis of heavy water and heavy polythene.

A method of numerical solution is developed for calculating the Lapre coolant pressure drop and power output with variable coolant inlet pressure, flow rate, and reactor solution temperature. The results of a series of calculations are presented that show excessive pressure drops and sonic exit flow as the flow rate is increased and the inlet pressure is decreased. Both supercritical and subcritical coolant flow regions are investigated. Reactor power is shown to be strongly dependent on the solution temperature in the region of 70O-75O degree F. At the design flow of 12 gal/min, excessive coolant pressure drops are encountered at inlet pressures of 2000 lb/in. and below.

The fluorometric method for determining microgram quantities of uranium dissolved in concentrated sulfuric acid was reinvestigated for the purpose of measuring any interference caused by plutonium in uranium samples. No plutonium fluorescence, and therefore no positive errors due to plutonium, were observed. Limited transmittance of hexavalent plutonium in sulfuric acid at 513, and especially at 360 millimicrons, produces variable negative errors in uranium determinations.

The opacity and thermodynamic properties of air at temperatures above 10 e.v. and densities below normal have been calculated under the guidance of H. Mayer in accordance with the prescription given in AECD 1870 (LA-647). Corresponding to given densities and temperatures, self-consistent distributions of electrons in bound states and their eigen energies are determined. With this information we compute the thermodynamic properties of air and the frequency-dependent absorption coefficients. Finally the opacity--a weighted average of the latter--is found

A spectrophotometric method used in the determination of thorium was modified for the purpose of analyzing plutonium alloys which contained 0.01 to 0.8 percent thorium. Absorbance values were measured at 545 millimicrons for solutions containing thorium and thorin, the organic reagent added to form a colored complex with thorium in the presence of plutonium (III) . With plutonium-thorium 0.8 percent thorium, the average recovery of thorium was 99.6 +- 1.5 percent. For similar samples containing 0.01 to 0.2 percent thorium, the average recovery 101.0 +- 3.4 percent, after the thorium was separated from plutonium by precipitation of thorium fluoride with the aid of lanthanum fluoride as a carrier.

The conductivity of ionized gases is treated by a method similar to that used by Alfven in his book "Cosmical Electrodynamics". The results differ from those of Alfven. In particular, it is shown that Alfven's conclusion, that whenever the Hall current disappears the conductivity becomes independent of the magnetic field, is not true in general. Moreover, it is not true under just the conditions of interest for the "Pinch Effect". The main conclusions of the present paper are (1) of currents down a tube, the ion component is the small fraction of m/M of the electron current, regardless of the magnitude of the magnetic field; (2) the conduction along the tube depends on the transverse motion of neutral mass, i.e. on the radial velocity of u(r) of the gas in the tube.

With the assumption of infinite conductivity a simple model may be constructed for the dynamic construction of a current carrying plasma, i.e., the pinch effect. The magneto-hydrodynamic equations of this model are discussed and solved. It is also shown that the infinite conductivity model can be derived from a picture of particles orbiting without collisions in the fields set up by their motions.

The quantitative estimation of submicrogram amounts of boron in zirconium hydride using a colorimetric procedure is described. Solution of the sample in sulfuric acid or hydrofluoric acid and subsequent distillation of methyl borate without boron loss or contamination is shown to be possible. Using the curcumin color reaction, quantities of boron as low as 0.01 microgram can be detected. The method should apply equally well to zirconium metal and compounds, providing they can be dissolved under conditions that do not result in loss of boron and if the resulting solution will permit the quantitative removal of boron by distillation as methyl borate.

Specific surface and bulk density measurements were made on samples of 22 U308 materials which had been prepared by calcination at 900°C of widely differing uranium peroxide precipitates and had been evaluated as to "reactivity" by successive treatment with hydrogen and a mixture of anhydrous hydrogen fluoride and hydrogen in a production-type batch process for the preparation of UF4. Specific surface and bulk density measurements were also made on samples of the 22 corresponding U02 intermediates. The ranges of values encountered in the U308 samples and in the U02 samples were 0.05 m /g to 0.37 m /g and 0.03 m /g to 0.33 m /g, respectively, for specific surface and 3.7 g/cm to 1.8 g/cm and 4.9 g/cm to 2.7 g/cm3, respectively, for packed bulk density. Specific surface varied inversely with packed bulk density for U308, the data showing a good correlation. A very poor correlation between specific surface and packed bulk density of U02 was obtained. The conversion of U308 to UF4 n the standard process varied from 22% for the lowest specific surface, highest bulk density oxide to 98 to 99% for the high specific surface, low bulk density oxides. The observed values for properties of the …

The sample, water or urine, is prepared for counting in a vacuum line. Urine or water is dropped onto metallic calcium, and hydrogen and tritium are evolved. The gas flowing into the evacuated system is passed through liquid nitrogen cooled traps to remove unreacted water and condensable gases. The gas is allowed to flow into a tube similar to a Geiger-Muller tube until a pressure of 15 cm of mercury is attained. Ethylene and argon are added to give a total pressure of 22 cm of mercury. The beta activity is counted with a scaling circuit having an input sensitivity of 1/4 volt. A tube similarly filled with inert hydrogen is counted simultaneously to determine the environmental background. The background count is subtracted from the sample count to obtain the true sample count. The method has a precision of ± 5% in the range of 1 to 250 pc of tritium per liter of sample. Samples with higher concentrations may be determined with appropriate dilutions. An experienced operator can do approximately 50 determinations per day. The tolerance used at LASL for tritium in urine is 250 pc/liter.

The proposed Los Alamos Omega West Reactor is designed to be a research tool delivering a maximum neutron flux of approximately 5 x 10/sup 13/ n/sec/cm/ sup 2/ at its maximum operation power level of 5 megawatts. Solid fuel elements of the type developed for the Materials Testing Reactor will be utilized. Cooling will be accomplished with circulating demineralized water and evaporative coolers. Experimental facilities will include numerous horizontal ports, two of which will incorporate built-in rotary beam shutters, and a thermal column. If all the radioactive material contained in the fuel elements during normal reactor operation were to become spread through the residential area of Los Alamos, persons in some parts of the city would be exposed to greater than lethal doses. It does not appear that known mechanisms could operate to produce this situation. Because of geographical relationships and low ground-water flow velocities, there seems to be no likelihood of water supply contamination in the event of a reactor disaster. Care has been taken in the reactor design to insure against sudden draining of the main reactor tank containing the fuel assembly, as such a sudden loss in cooling might lead to damage of the fuel elements. Conservative …

A glass vacuum manifold and ionization chamber are evacuated and filled to atmospheric pressure with hydrogen and tritium. The hydrogen and tritium are evolved by dropping liquid, urine or water, on calcium metal and dried by passing through a suitable freezing bath. The current produced by the beta activity due to tritium is measured with a vibrating reed electrometer. The method has a precision of +3 per cent between the ranges of 100 and 1500 pc of tritium per liter. From O to 100 pc of tritium per liter the precision is +-5 to 10 per cent. The glass vacuum manifold has been constructed to fit in an aluminum suitcase which contains all the auxiliary equipment for the determination except the vacuum pump, vibrating reed electrometer, and the freezing bath solutions. The apparatus is sturdy and readily transported. The procedure is simple and adapted for use by untrained personnel.

This technical report describes a plant-scale procedure for concentrating plutonium and americium in slag and crucible (metal reduction residues) and other recovery solutions by a calcium oxalate carrier precipitation Conclusions from exploratory laboratory tests on the variables affecting the efficiency are included.