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in subjects: "Actinide Isotopes"

open access

Quadrupole mass spectrometer for a mobile laboratory to measure isotope ratios

A mobile laboratory has been assembled for on-site inspection of plant operations handlng special nuclear materials. The isotopic composition of U, Pu, and other elements can be analyzed using a quadrupole mass spectrometer. Some results of analysis of uranium and boron standards are given. (DLC)

Date: January 1, 1981

Creator: Walton, J. R.; Smith, D. H.; McKown, H. S. & Carter, J. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Intrinsic densitometry techniques for high-burnup plutonium solutions

Two intrinsic densitometry techniques for determining plutonium concentrations (and isotopic distributions) that require no external radioactive sources or x-ray generators and rely only on the natural radiation from the plutonium have been tested with high-burnup solutions. We found that these techniques can determine the plutonium concentration of high-burnup solutions to between 2.4% and 3.5% in a 1-h assay. 3 refs., 5 figs., 4 tabs.

Date: January 1, 1990

Creator: Hsue, S.-T. (Los Alamos National Lab., NM (USA)) & Cromboom, O. (Commission of the European Communities, Karlsruhe (Germany, F.R.). European Inst. for Transuranium Elements)

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Ion exchange in the nuclear industry

Ion exchange is used in nearly every part of the nuclear fuel cycle -- from the purification of uranium from its ore to the final recovery of uranium and transmutation products. Ion exchange also plays a valuable role in the management of nuclear wastes generated in the fuel cycle.

Date: December 31, 1990

Creator: Bibler, J. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Improved calculation of the prompt fission neutron spectrum from the spontaneous fission of /sup 252/Cf: Preliminary results

An improved calculation is presented for the prompt fission neutron spectrum N(E) from the spontaneous fission of /sup 252/Cf. In this calculation the fission-spectrum model of Madland and Nix is used, but with several improvements leading to a physically more accurate representation of the spectrum. Specifically, the contributions to N(E) from the entire fission-fragment mass and charge distributions will be calculated instead of calculating on the basis of a seven- point approximation to the … more

Date: January 1, 1988

Creator: Madland, D. G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Californium-252 in situ activation and photon detection techniques for uranium ore deposit evaluation

Four different techniques are evaluated for borehole analysis of uranium and thorium ores. Methods involving (1) detection of fission product photons following /sup 252/Cf activation, (2) detection of low-energy uranium and thorium gamma-rays, (3) direct measurement of the 1001-keV photon from /sup 234m/Pa, a progeny of /sup 238/U, and (4) isotopic excitation x-ray fluorescence spectroscopy are evaluated. The first two techniques are found too unsuitable for most low grade ores. The third is fo… more

Date: January 1, 1976

Creator: Brodzinski, R. L. & Wogman, N. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Biomedical Engineering support. Semiannual progress report

The basic goal of the ERDA Artificial Heart Program is to develop and construct an artificial heart, powered by a /sup 238/Pu heat source, which can be successfully employed as an emplantable total artificial heart system for animal experiments. Future studies will be directed at developing and evaluating a satisfactory system for total heart replacement in humans. A total of 32 ERDA artificial hearts have been implanted since the initiation of the program. During the reporting period ten total… more

Date: January 1, 1976

Creator: Kolff, W. J.; Smith, L. M. & Sandquist, G. M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Power spectral density measurements with /sup 252/Cf for a light water moderated research reactor

A method of determining the reactivity of far subcritical systems from neutron noise power spectral density measurements with /sup 252/Cf has previously been tested in fast reactor critical assemblies: a mockup of the Fast Flux Test Facility reactor and a uranium metal sphere. Calculations indicated that this measurement was feasible for a pressurized water reactor (PWR). In order to evaluate the ability to perform these measurements with moderated reactors which have long prompt neutron lifeti… more

Date: January 1, 1979

Creator: King, W. T. & Mihalczo, J. T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Real time analysis under EDS

This paper describes the analysis component of the Enrichment Diagnostic System (EDS) developed for the Atomic Vapor Laser Isotope Separation Program (AVLIS) at Lawrence Livermore National Laboratory (LLNL). Four different types of analysis are performed on data acquired through EDS: (1) absorption spectroscopy on laser-generated spectral lines, (2) mass spectrometer analysis, (3) general purpose waveform analysis, and (4) separation performance calculations. The information produced from this … more

Date: July 1, 1985

Creator: Schneberk, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The file of evaluated decay data in ENDF/B

One important application of nuclear decay data is the Evaluated Nuclear Data File/B, the base of evaluated nuclear data used in reactor research and technology activities within the US. This report discusses the decay data file.

Date: January 1, 1991

Creator: Reich, C.W. (Idaho National Engineering Lab., Idaho Falls, ID (USA)) & England, T.R. (Los Alamos National Lab., NM (USA))

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Total and spontaneous fission half-lives of the uranium and plutonium nuclides

The total half-life and the half-life for spontaneous fission are evaluated for the various long-lived nuclides of interest. Recommended values are presented for /sup 232/U, /sup 233/U, /sup 234/U, /sup 235/U, /sup 236/U, /sup 238/U, /sup 236/Pu, /sup 238/Pu, /sup 239/Pu, /sup 240/Pu, /sup 241/Pu, /sup 242/Pu, and /sup 244/Pu. The uncertainties are provided at the 95% confidence limit for each of the recommended values.

Date: January 1, 1984

Creator: Holden, Norman E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Plutonium story

The first nuclear synthesis and identification (i.e., the discovery) of the synthetic transuranium element plutonium (isotope /sup 238/Pu) and the demonstration of its fissionability with slow neutrons (isotope /sup 239/Pu) took place at the University of California, Berkeley, through the use of the 60-inch and 37-inch cyclotrons, in late 1940 and early 1941. This led to the development of industrial scale methods in secret work centered at the University of Chicago's Metallurgical Laborat… more

Date: September 1, 1981

Creator: Seaborg, G T

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Cascade design considerations for cascades composed of stages with large separation factors

The unit cost of product from ideal and nonideal cascades are calculated and compared for a given separation task, that of producing reactor grade uranium containing 3.2% U-235 from normal feed containing 0.72% U-235, under the assumption that the total cascade costs are directly proportional to the total inter-stage flow of the cascade. For the examples chosen, in which the stage separation factors are in the range 2 < ..cap alpha.. < 5 and the resulting cascades contain from four to six stage… more

Date: February 1, 1978

Creator: Von Halle, E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Environmental impacts of the release of a transuranic actinide, americium-241, from a contaminated facility

Americium-241 is widely used as a radiation source, but it also has some potential risk if taken into the body because of its high dose conversion factor. Although the radiotoxicity of americium-241 is small compared to other transuranic actinides, its effects on the reproductive system and on development of the placenta are more damaging than the effects of plutonium-239. In Ohio, a gemologist's laboratory was contaminated with americium-241. Prior to decontamination of the laboratory, potenti… more

Date: October 29, 1985

Creator: Want, J. & Merry-Libby, P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Resolved-resonance neutron widths from a consistent reanalysis of the most recent /sup 238/U transmission data

The /sup 238/U neutron differential capture cross sections are one of the most important nuclear data for reactor physics calculations. Nevertheless, differential data have persistently over-predicted the ratio of the /sup 238/U capture rate relative to the /sup 239/Pu fission rate in fast-reactor spectra as measured by integral experiments. One of the possible ways of perhaps reducing this discrepancy is to extend the theoretically sound resolved-resonance range upwards in energy from the pres… more

Date: January 1, 1984

Creator: Olsen, D.K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Portable computer to reduce gamma-ray spectra for plutonium isotopic ratios

In response to Task A.63 of the International Safeguards Project Office (ISPO), to upgrade measurement technology used by the International Atomic Energy Agency (IAEA), a portable data-reduction microprocessor was designed and programmed which allows in-field reduction of gamma-ray spectra and interfaces with the IAEA's multichannel analyzers - the 1000 or 2000-channel memory Silena BS27/N. This report describes the components used in assembling the microprocessor unit: hardware, software used … more

Date: May 15, 1981

Creator: Ruhter, Wayne D. & Camp, David C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Covalency of neptunium(IV) triscyclopentadienyl compounds from Moessbauer spectra

Isomer shifts measured from the /sup 237/Np Moessbauer spectra of NpCp/sub 3/OR (R = alkyl) NpCp/sub 3/R and NpCpAr (Ar = aryl) are used as a measure of the covalency in Np(IV) ligand bonding. The isomer shifts in NpCp/sub 3//sup n/Bu and NpCp/sub 3/C/sub 6/H/sub 4/C/sub 2/H/sub 5/ show a strong sigma character to the Np--/sup -n/Bu and Np--C/sub 6/H/sub 4/C/sub 2/H/sub 5/ bonds. The sigma character of Np--OR bonding is definite, but less pronounced. The comparatively low covalency in the bondi… more

Date: January 1, 1978

Creator: Karraker, D.G. & Stone, J.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Role of criticality models in ANSI standards for nuclear criticality safety

Two methods used in nuclear criticality safety evaluations in the area of neutron interaction among subcritical components of fissile materials are the solid angle and surface density techniques. The accuracy and use of these models are briefly discussed. (TFD)

Date: January 1, 1976

Creator: Thomas, J. T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Laser chemistry and the nuclear fuel cycle

The application of lasers to isotope enrichment and to the study and process of photochemical improvements to the fuel recycle process is discussed. Laser power and laser specifications for these areas are indicated. (JSR)

Date: January 1, 1976

Creator: Jensen, R. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Californium production at the transuranium processing plant. [Transuranium processing plant design, equipment, and facilities]

The Transuranium Processing Plant (TRU) at ORNL, which is the production, storage, and distribution center for the ERDA heavy element research program, is described. About 0.5 percent of /sup 252/Cf is currently being produced. TRU is a hot-cell, chemical processing facility of advanced design. New concepts have been incorporated into the facility for absolute containment, remote operation, remote equipment installation, and remote maintenance. The facilities include a battery of nine heavily s… more

Date: January 1, 1976

Creator: King, L. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Adsorption and Diffusion of Plutonium in Soil

The behavior of plutonium (Pu) was studied in three soils that varied in texture, CEC, pH, organic matter content and mineralogy (Fuquay, Muscatine, Burbank). Two isotopes, /sup 238/Pu and /sup 239/Pu, were used in order to detect Pu over a range of several orders of magnitude. Unless added in a chelated form, Pu was added to the soil as a nitrate in .01 N HNO/sub 3/ to simulate the release of acidic waste on the soil and to prevent rapid Pu hydrolysis or polymerization.

Date: unknown

Creator: Brown, D. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Investigations of the Natural Fission Reactor Program. Progress report, October 1976--September 1977

During Fiscal Year 1977, efforts of the Natural Fission Reactor Program have been directed toward (1) further measurements and predictions of reactor product migration at Oklo, (2) uraninite solubility studies, (3) radiogenic equilibria studies of natural Pu, Ra, and Th in U ores, (4) search for evidence of other natural fission reactors, and (5) supportive analytical measurements and procedures development.

Date: November 1, 1977

Creator: Apt, K.E. (ed.)

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

A comparison of the neutron response of CR-39 made by different manufacturers

CR-39 was obtained from American Acrylics and Plastics, Inc. (A.A), N. E. Technology, Ltd. (N.E), and Tech/Ops Landauer, Inc. (LT). The dosemeters were exposed to radioisotopic neutron sources at SLAC, and moderated {sup 252}Cf at ORNL. The A.A. and N.E. dosemeters were electrochemically etched (pre-etch in 6.5 N KOH at 60{degrees}C for 1 hour and 45 minutes, a 5 hour etch at 3000 V and 60 Hz, a 23 minute blow-up step at 2 kHz and a post-etch for 15 minutes). Track densities were determined wit… more

Date: September 1, 1991

Creator: Ipe, N.E.; Liu, J.C. (Stanford Linear Accelerator Center, Menlo Park, CA (United States)); Buddemeier, B.R. (Lawrence Livermore National Lab., CA (United States)); Miles, C.J. (Radiation Detection Co., Sunnyvale, CA (United States)) & Yoder, R.C. (Tech/OPS Landauer, Inc., Glenwood, IL (United States))

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Robust estimation of standard deviation using ordered samples

A robust estimate for the standard deviation of a normal distribution is developed. We choose the contaminated normal distribution as our outlier model and demonstrate the method with two examples representing data from international interlaboratory experiments.

Date: July 1, 1982

Creator: Beedgen, R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Delayed-fission properties of neutron-deficient americium nuclei

Characteristics of the delayed-fission decay mode in light americium nuclei have been investigated. Measurements on the unknown isotopes {sup 230}Am and {sup 236}Am were attempted, and upper limits on the delayed-fission branches of these nuclei were determined. Evidence of the existence of {sup 236}Am was observed in radiochemical separations. Total kinetic energy and mass-yield distributions of the electron-capture delayed-fission mode were measured for {sup 232}Am (t{sub 1/2} = 1.31 {plus mi… more

Date: October 23, 1989

Creator: Hall, H.L. (California Univ., Berkeley, CA (USA). Dept. of Chemistry)

Item Type: Report

Partner: UNT Libraries Government Documents Department