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

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 …

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.

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.

A batch-type incinerator has been built which will dry and burn 12 liters of wet, packed rags or the equivalent in other organic matter in 8 hours. The material is ignited and burned in a stream of oxygen. Tars in the off-gas are trapped in a water bubble, residual contaminated particles are caught by a CWS filter, and acid vapors are reacted in a caustic scrubber. The unit was designed to processes plutonium residues; however, other radioactive materials could be handled by the use of appropriate shield and manipulators.

This technical report summarizes the work which has been done to date on the preparation of magnesium hydride and the attempted preparation of beryllium hydride. Although pure beryllium hydride has not yet been made, the work is continuing, and this report indicates which phases are thought to be worth further work.

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.

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."

This paper is issued in two volumes: LA-1664 and LA-1665. In LA-1664, the fundamental properties of a shock in free air are described, including the reasons for failure of similarity scaling. The results of an analytic solution for strong shocks are presented, which permit a determination of the energy in a shock wave from its rate of growth without recourse to similarity assumptions; from it the scaling laws for both homogeneous and inhomogeneous atmospheres are explicitly shown. The total energy is evaluated in a machine calculation for the blast wave and from this evaluation, the free air wave form for all hydrodynamic variables is presented. The general nature of the laws governing thermal radiation from atomic bombs is deduced, a new figure of merit for thermal radiation is suggested to replace the concepts of “thermal energy” and “critical calories,” which are considered ambiguous. Partition of energy is considered negligible in most cases of interest; the waste heat concept is reconsidered and the failures of scaling to TNT are regarded primarily as a failure of the ideal gas law. LA-1665 is concerned with preparation of height of burst curves. In the reflection process over ideal surfaces, the usual subdivision into regions …

This paper is issued in two volumes: LA-1664 and LA-1665. In LA-1664, the fundamental properties of a shock in free air are described, including the reasons for failure of similarity scaling. The results of an analytic solution for strong shocks are presented, which permit a determination of the energy in a shock wave from its rate of growth without recourse to similarity assumptions; from it the scaling laws for both homogeneous and inhomogeneous atmospheres are explicitly shown. The total energy is evaluated in a machine calculation for the blast wave and from this evaluation, the free air wave form for all hydrodynamic variables is presented. The general nature of the laws governing thermal radiation from atomic bombs is deduced, a new figure of merit for thermal radiation is suggested to replace the concepts of “thermal energy” and “critical calories,” which are considered ambiguous. Partition of energy is considered negligible in most cases of interest; the waste heat concept is reconsidered and the failures of scaling to TNT are regarded primarily as a failure of the ideal gas law. LA-1665 is concerned with preparation of height of burst curves. In the reflection process over ideal surfaces, the usual subdivision into regions …

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.

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.'"

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.

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.

The increased use of tritium monitoring devices has made it necessary to devise a scheme for the calibration of such instruments. Several methods for setting up known concentrations of tritium were considered. A dynamic system containing tritium as HTO vapor or gaseous HT was selected because of the ease of control of variables. The variables that have been considered are: ,1. The effect of rate of air flow through the instruments. 2. The effect of humidity on instrument response. 3. The effect of ion collection ahead of the ion chamber. 4. The variation of “hold time” from the generation of tritium to its passage through the ion chamber. 5. The instrument response to several concentrations of tritium as HTO vapor and gaseous HT. The following three types of monitoring devices have been calibrated:1. Model 101 Sniffer of Group P-1. 2. Cl-1 Vibrating Reed Electrometer of Group CMR-7. 3. Modified TIB of Group H-6.

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.

The development of sampling methods and some field results of the off- site air sampling stations at the Nevada Proving Ground are reviewed. A technique of radioautography is presented which yields information about the activities of individual fall-out particles. This technique gives a comparison of particle activities from air drops and tower shots and a reason for the greater contamination associated with the latter. It also indicates that air samplers do not capture the most active fall-out particles, presumably because of their large size.

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.

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 initial growth of irregularities on an interface between two compressible fluids is studied for impulsive (i.e., shock) acceleration. It was found that the ultimate rate of growth is roughly the same as that given by the incompressible theory, if the initial compression of the irregularities and of the fluids is taken into account.

From abstract: "An apparatus is described which automatically separates a flow of drops into a series of equal samples."

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.

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.

Am III and Pu III have been recovered on a plant scale by extraction with tributyl phosphate from slag and crucible and other recovery solutions. Process losses were 0.03% Am and 0.01% Pu. The product stream contained 0.08 gram Am per liter and 0.15 gram Pu per liter. The final solution cleanup to allow discard (total alpha activity equivalent to less than 10(-4) gram Pu per liter) was accomplished by tributyl phosphate extraction of Pu III under conditions of low acidity and high nitrate.