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The Activation of Low-Reactivity Uranium Dioxide Particles

Description: A detailed study of the activation of low-reactivity UO2 particles toward HF by successive oxidation and reduction was carried out. The effect of repeated successive oxidation and reduction on the reactivity of the UO2 source material toward HF was evaluated by hydrofluorination.
Date: October 1955
Creator: Bard, R. J.; Bunker, D. L.; Greenough, R. C. & Kalmus, E. H.
open access

Los Alamos Power Reactor Experiment and its Associated Hazards

Description: The following report describes the high pressure and temperature homogeneous reactor experiment which has been started at Los Alamos, as well as the hazards and safety aspects for the experiments.
Date: December 2, 1953
Creator: King, L. D. P.
open access

Angular Distribution of Fragments from Neutron-Induced Fission

Description: The angular distribution of fission fragments from the neutron-induced fission of several isotopes has been studied. Distributions were observed for thermal neutrons on U233 and U235, Lady Godiva leakage neutrons on U235 and U238, and 14 Mev neutrons on U233, U235, U238, Th232, and Np237. No anisotropy was observed for thermal neutron fission, whereas for Lady Godiva neutrons and 14 Mev neutrons the probability of fission along the axis of the neutron beam was determined to be higher than for f… more
Date: May 7, 1953
Creator: Brolley, John Edward, 1919- & Dickinson, W. C.
open access

Average Fission Cross Section U238 for Fission Neutrons

Description: By means of measurements with a double ionization chamber, the average fission cross section of U238 for neutrons from the fission of U235 was determined in terms of v, the average number of neutrons per fission of U235. the number of fission of U238 was measured in one of the ionization chambers while the number of fissions from the fission neutron source of U235 was measured in the other chamber. In the nine runs made to determine the cross section, a variety of different methods was used to … more
Date: January 1953
Creator: Leachmanm R. B. & Schmitt, H. W.
open access

A Ball Holder for Coating Operations

Description: A device has been designed which will support small spheres and cylinders in a vacuum system during a plating operation. While supporting the object to be plated, the device automatically shifts the position of the supports so that the coating is evenly distributed. This report describes the mechanism by which this motion is achieved.
Date: April 8, 1953
Creator: Lilienthal, James R.
open access

Bibliography : Impact Testing of Materials

Description: The bibliography provided investigates the following sources: Chemical Abstracts 1947-1950., Metallurgical Abstracts Vols. 1-18., ASM Review of Metals Literature Vols. 1-6., J. Institute of Metals Vols. 78-80 (No. 7)., Physics Abstracts 1937-1950.
Date: June 8, 1952
Creator: Fick, Jean
open access

Biological Effectiveness of Nuclear Radiations From Fission Weapons

Description: Thermal neutron measurements made on five weapons during Operation Teapot indicated that these neutrons contribute at most 2 per cent of the total neutron dose in air. However, the total fluxes were high and thermal neutrons may become important under shielding conditions and may significantly affect the responses of the film badges and certain sensitive dose detectors, especially when the neutron to gamma flux ratio is high.
Date: August 1955
Creator: Harris, Payne S.
open access

Burst Characteristics Associated with the Slow Assembly of Fissionable Materials

Description: This technical report is a sequel to LA-596, "Efficiency for Very Slow Assembly" by K. Fuchs. Herein are given estimates of temperature rise and pressure developed as a result of active material slowly being driven supercritical. Marginal assembly rates can thus be determined for both metal and solution assemblies above which the disassembly by thermal expansion is explosive in the sense that the active material or containing vessel is ruptured.
Date: July 1952
Creator: Hansen, G. E.
open access

Calcium Oxalate Carrier Precipitation of Pu

Description: 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.
Date: February 25, 1954
Creator: Maraman, W. J.
open access

Calculations of the Critical Mass of UF6 as a gaseous Core, with Reflections of D2O, Be and C

Description: A class of critical assemblies has been considered in which the core consists of an oralloy bearing gas at more or less standard pressure and temperature and the reflector is an efficient moderator with a small thermal capture cross section. Age and diffusion theory have been applied to compute the probability that a fast neutron is thermalized by the reflector and them captured by the core. It is first assumed that fast or epithermal neutrons do not interact wit the core and it is later shown … more
Date: February 1955
Creator: Bell, George I., 1926- & Goldstein, Max
open access

The Calibration of Tritium Monitoring Devices

Description: 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… more
Date: June 1954
Creator: Robbins, M. Chain
open access

Collected Reports on Fission Cross Sections of U237 in Thermal Neutron, Intermediate Neutron, and Degraded Fission Neutron Spectra

Description: Part 1. The neutron fission cross section of U237 has been measured in a thermal neutron spectrum and in a somewhat degraded fission spectrum. The fission cross section for thermal neutrons is found to be <2 barns; the ratio of the fission cross section of U237 to that of U235 in the degraded fission spectrum is found to be 0.476 +- 15% which corresponds to [formula] in this spectrum equal to 0.66 +- 0.10 barns. Part 2. The average neutron fission cross section of U237 has been measured in a ne… more
Date: January 1, 1955
Creator: Cowan, G. A. (George A.), 1920-2012
open access

The Colorimetric Determination of Boron in Zirconium Hydride

Description: 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… more
Date: July 1954
Creator: Waterbury, Glenn R. & Metz, Charles F.
open access

Corrosion of Uranium in Moist Air

Description: The corrosion of uranium in moist air is more rapid than had been thought previously. Earlier recommendations were based on test of 300 hr duration. In tests which were conducted for over 1000 hr, moisture has less effect than in those tests made over shorter periods. The corrosion of uranium by dry and moist air has been studied at 38, 57, and 75 degrees C. Although moisture increases the rate of initial attack, after 200 to 500 hr the effect is reduced and an accelerating corrosion rate overs… more
Date: January 1952
Creator: Waber, James T. (James Thomas), 1920-
open access

Critical Masses of Graphite-Tamped Heterogeneous Oy-Graphite Systems

Description: 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.
Date: May 1954
Creator: Hoogterp, J. C.
open access

Critical Masses of Oralloy Lattices Immersed in Water

Description: Certain oralloy (Oy) lattices were immersed in infinite water for determining critical masses at various low-Oy densities. Three Oy unit sizes were used. In a broad sense the experiment shows safe and unsafe conditions for handling heterogeneous Oy-water mixtures.
Date: November 1955
Creator: Hoogterp, J. C.
open access

The DD and TD Cross Sections

Description: The total cross sections of the reactions DDp, DDn, TD at 10 kev to 10 Mev are estimated from a review of the experimental data up to January 1951. Maxwell averages for DDp and TD computed from these estimates are given, together with some fitted analytic expressions provided for machine use. A collection of the identifiable earlier estimates is also included for reference and for comparison with the new figures. For relative order of magnitude purposes, cross sections and the derived Maxwell a… more
Date: May 10, 1951
Creator: Tuck, J L
open access

The Decontamination of Uranium from Fission Products by the Use of the Uranyl Oxalate Precipitation Reaction

Description: Abstract: "Decontamination factors of the order of 10-4 were obtained for Beta and Gamma emitters present as fission products when uranium was precipitated from 50 mC activity level solutions as uranyl oxalate under normal uranium yield conditions for three cycles (~60%). Factors of the order of 10-3 were obtained by the use of this reaction with similar solutions under relatively high uranium yield conditions for three cycles (~90%). The uranium peroxide precipitation reaction proved to be of … more
Date: May 10, 1951
Creator: Kelchner, B. L.
open access

Dependence of the Oxidation of Uranium on Oxygen Pressure

Description: The oxidation of uranium metal has been studied from the standpoint of the oxygen dependence of the reaction rate in an effort to establish the mechanism. The experimental data of Perkins agree with the theoretical dependence of the oxygen pressure derived this report. This agreement supports the hypothesis that the rate-controlling step in the migration of cations in the DO2 lattice, although the observed time dependence is not necessarily in agreement with this conclusion. Experimental entrop… more
Date: March 20, 1952
Creator: Waber, James T. (James Thomas), 1920-
open access

A Design for a Rotary Reactivity Control for a Test Reactor

Description: Tests made on the Oy-Tu reacting assembly at Pajarito indicate that the lateral displacement of two halves of the active material within the assembly can be used as a control mechanism on this type of reacting assembly. This report describes a reacting assembly using a rotary control mechanism based on this principle and indicates the sensitivity of control possible with such a device.
Date: September 18, 1950
Creator: Josephson, V. (Vernal)
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