WorldWideScience

Sample records for singly ionized uranium

  1. An atomic model for neutral and singly ionized uranium

    Science.gov (United States)

    Maceda, E. L.; Miley, G. H.

    1979-01-01

    A model for the atomic levels above ground state in neutral, U(0), and singly ionized, U(+), uranium is described based on identified atomic transitions. Some 168 states in U(0) and 95 in U(+) are found. A total of 1581 atomic transitions are used to complete this process. Also discussed are the atomic inverse lifetimes and line widths for the radiative transitions as well as the electron collisional cross sections.

  2. The multiphoton ionization of uranium hexafluoride

    International Nuclear Information System (INIS)

    Armstrong, D.P.

    1992-05-01

    Multiphoton ionization (MPI) time-of-flight mass spectroscopy and photoelectron spectroscopy studies of UF 6 have been conducted using focused light from the Nd:YAG laser fundamental (λ=1064 nm) and its harmonics (λ=532, 355, or 266 nm), as well as other wavelengths provided by a tunable dye laser. The MPI mass spectra are dominated by the singly and multiply charged uranium ions rather than by the UF x + fragment ions even at the lowest laser power densities at which signal could be detected. The laser power dependence of U n+ ions signals indicates that saturation can occur for many of the steps required for their ionization. In general, the doubly-charged uranium ion (U 2+ ) intensity is much greater than that of the singly-charged uranium ion (U + ). For the case of the tunable dye laser experiments, the U n+ (n = 1- 4) wavelength dependence is relatively unstructured and does not show observable resonance enhancement at known atomic uranium excitation wavelengths. The dominance of the U 2+ ion and the absence or very small intensities of UF x + fragments, along with the unsaturated wavelength dependence, indicate that mechanisms may exist other than ionization of bare U atoms after the stepwise photodissociation of F atoms from the parent molecule

  3. Feasibility study of the single particle analysis of uranium by laser ionization time-of-flight mass spectrometry

    International Nuclear Information System (INIS)

    Ha, Yeong Keong; Han, Sun Ho; Pyo, Hyung Yeol; Park, Yong Joon; Song, Kyu Seok

    2004-01-01

    The control of activities in nuclear facilities worldwide is one of the most important tasks of nuclear safeguard. To meet the needs for nuclear safeguard, International Atomic Energy Agency (IAEA) strengthened the control of nuclear activities to detect these activities earlier. Thus, it is very important to develop analytical techniques to determine the isotopic composition of hot particles from swipe samples. The precise measurement of the 234 U/ 238 U, 235 U/ 238 U and 236 U/ 238 U ratios is important because it provides information about the initial enrichment of reactor uranium, core history, and post accident story. Because conventional α-spectrometry is not sufficiently sensitive for the determination of long-lived radionuclides in environmental samples, several analytical techniques, such as SNMS (Sputtered Neutral Mass Spectrometry), RIMS (Resonance Ionization Mass Spectrometry), AMS (Accelerator Mass Spectrometry) etc., have been proposed for uranium isotope measurements. In case of microparticles, analytical techniques such as SIMS (Secondary Ion Mass Spectrometry) have been applied for the isotopic characterization. The aim of this work was the development of a sensitive analytical technique for determination of isotopic ratio of uranium in swipe samples. In this work, feasibility of LIMS (Laser Ionization Mass Spectrometry) for the determination of such particles has been evaluated using a reference material of natural uranium

  4. Ionization and Coulomb explosion of small uranium oxide clusters

    International Nuclear Information System (INIS)

    Ross, Matt W; Castleman, A W Jr

    2012-01-01

    Femtosecond pulses are used to study the strong-field ionization and subsequent Coulomb explosion of small uranium oxide clusters. The resulting high atomic charge states are explored as a function of laser intensity and compared to ionization rates calculated using semi-classical tunneling theory with sequential ionization potential values. The gap in laser intensity between saturation intensity values for the 7s, 6d, and 5f orbitals are identified and quantified. Extreme charge states of oxygen up to O 4+ are observed indicating multiple ionization enhancement processes occurring within the clusters. The peak splittings of the atomic charge states are explored and compared to previous results on transition metal oxide species. Participation of the 5f orbitals in bonding is clearly identified based on the saturation intensity dependence of oxygen to uranium metal.

  5. Understanding single-color multiphoton ionization spectra by pump--probe technique

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, K.; Manohar, K.G.; Bajaj, P.N.; Suri, B.M.; Talukdar, R.K.; Chakraborti, P.K.; Rao, P.R.K.

    1988-06-01

    A simple but elegant spectroscopic technique using two narrow-band dye lasers has been demonstrated for analyzing single-color resonant multi-photon-ionization spectra of atoms. This technique provides a direct identification of the starting level of the multi-photon-ionization pathway. This method can also be used to determine intermediate levels, which play an important role in the ionization process. Some typical results for uranium are presented.

  6. Electron impact single ionization of copper

    Indian Academy of Sciences (India)

    Electron impact single ionization cross sections of copper have been calculated in the binary encounter approximation using accurate expression for as given by Vriens and Hartree–Fock momentum distribution for the target electron. The BEA calculation based on the usual procedure does not show satisfactory ...

  7. Quantifying Uranium Isotope Ratios Using Resonance Ionization Mass Spectrometry: The Influence of Laser Parameters on Relative Ionization Probability

    Energy Technology Data Exchange (ETDEWEB)

    Isselhardt, Brett H. [Univ. of California, Berkeley, CA (United States)

    2011-09-01

    Resonance Ionization Mass Spectrometry (RIMS) has been developed as a method to measure relative uranium isotope abundances. In this approach, RIMS is used as an element-selective ionization process to provide a distinction between uranium atoms and potential isobars without the aid of chemical purification and separation. We explore the laser parameters critical to the ionization process and their effects on the measured isotope ratio. Specifically, the use of broad bandwidth lasers with automated feedback control of wavelength was applied to the measurement of 235U/238U ratios to decrease laser-induced isotopic fractionation. By broadening the bandwidth of the first laser in a 3-color, 3-photon ionization process from a bandwidth of 1.8 GHz to about 10 GHz, the variation in sequential relative isotope abundance measurements decreased from >10% to less than 0.5%. This procedure was demonstrated for the direct interrogation of uranium oxide targets with essentially no sample preparation. A rate equation model for predicting the relative ionization probability has been developed to study the effect of variation in laser parameters on the measured isotope ratio. This work demonstrates that RIMS can be used for the robust measurement of uranium isotope ratios.

  8. Single Photon Double Ionization of Atomic Oxygen

    Science.gov (United States)

    Wickramarathna, Madhushani; Gorczyca, Thomas; Ballance, Connor; Stolte, Wayne

    2017-04-01

    Single photon double ionization cross sections are calculated using an R-matrix with pseudostates (RMPS) method which was recently applied by Gorczyca et al. for the double photoionization of helium. With the convergence of these theoretical calculations for the simple case of helium, we extend this methodology to consider the more complex case of oxygen double photoionization. We compare our calculated results with recent measurements at the Advanced Light Source, as well as earlier experimental measurements. Our RMPS results agree well, qualitatively, with the experimental measurements, but there exist outstanding discrepancies to be addressed. This project is supported by NASA APRA award NNX17AD41G.

  9. Single and double ionization of gallium by electron impact

    Indian Academy of Sciences (India)

    It is concluded that the ionization of 3d shell contributes partly to single ionization and partly to double ionization. The results so obtained show reasonably good agreement with the experimental data. Author Affiliations. L K Jha1. Department of Physics, L N T College, Muzaffarpur 842 002, India. Dates. Manuscript received ...

  10. Characterizing uranium oxide reference particles for isotopic abundances and uranium mass by single particle isotope dilution mass spectrometry

    International Nuclear Information System (INIS)

    Kraiem, M.; Richter, S.; Erdmann, N.; Kühn, H.; Hedberg, M.; Aregbe, Y.

    2012-01-01

    Highlights: ► A method to quantify the U mass in single micron particles by ID-TIMS was developed. ► Well-characterized monodisperse U-oxide particles produced by an aerosol generator were used. ► A linear correlation between the mass of U and the volume of particle(s) was found. ► The method developed is suitable for determining the amount of U in a particulate reference material. - Abstract: Uranium and plutonium particulate test materials are becoming increasingly important as the reliability of measurement results has to be demonstrated to regulatory bodies responsible for maintaining effective nuclear safeguards. In order to address this issue, the Institute for Reference Materials and Measurements (IRMM) in collaboration with the Institute for Transuranium Elements (ITU) has initiated a study to investigate the feasibility of preparing and characterizing a uranium particle reference material for nuclear safeguards, which is finally certified for isotopic abundances and for the uranium mass per particle. Such control particles are specifically required to evaluate responses of instruments based on mass spectrometric detection (e.g. SIMS, TIMS, LA-ICPMS) and to help ensuring the reliability and comparability of measurement results worldwide. In this paper, a methodology is described which allows quantifying the uranium mass in single micron particles by isotope dilution thermal ionization mass spectrometry (ID-TIMS). This methodology is characterized by substantial improvements recently achieved at IRMM in terms of sensitivity and measurement accuracy in the field of uranium particle analysis by TIMS. The use of monodisperse uranium oxide particles prepared using an aerosol generation technique developed at ITU, which is capable of producing particles of well-characterized size and isotopic composition was exploited. The evidence of a straightforward correlation between the particle volume and the mass of uranium was demonstrated in this study

  11. Ionization dual-zone static detector having single radioactive source

    International Nuclear Information System (INIS)

    Ried, L. Jr.; Wade, A.L.

    1977-01-01

    This ionization detector or combustion product detector includes a single radioactive source located in an ionization chamber, and the ionization chamber includes portions comprising a reference zone and a signal zone. Electrical circuitry connected to the reference and signal zones provides an output signal directly related to changes in voltages across the signal zone in relation to the amount of particulates of combustion present in the ionization chamber

  12. Separation Techniques for Uranium and Plutonium at Trace Levels for the Thermal Ionization Mass Spectrometric Determination

    Energy Technology Data Exchange (ETDEWEB)

    Suh, M. Y.; Han, S. H.; Kim, J. G.; Park, Y. J.; Kim, W. H

    2005-12-15

    This report describes the state of the art and the progress of the chemical separation and purification techniques required for the thermal ionization mass spectrometric determination of uranium and plutonium in environmental samples at trace or ultratrace levels. Various techniques, such as precipitation, solvent extraction, extraction chromatography, and ion exchange chromatography, for separation of uranium and plutonium were evaluated. Sample preparation methods and dissolution techniques for environmental samples were also discussed. Especially, both extraction chromatographic and anion exchange chromatographic procedures for uranium and plutonium in environmental samples, such as soil, sediment, plant, seawater, urine, and bone ash were reviewed in detail in order to propose some suitable methods for the separation and purification of uranium and plutonium from the safeguards environmental or swipe samples. A survey of the IAEA strengthened safeguards system, the clean room facility of IAEA's NWAL(Network of Analytical Laboratories), and the analytical techniques for safeguards environmental samples was also discussed here.

  13. Separation Techniques for Uranium and Plutonium at Trace Levels for the Thermal Ionization Mass Spectrometric Determination

    International Nuclear Information System (INIS)

    Suh, M. Y.; Han, S. H.; Kim, J. G.; Park, Y. J.; Kim, W. H.

    2005-12-01

    This report describes the state of the art and the progress of the chemical separation and purification techniques required for the thermal ionization mass spectrometric determination of uranium and plutonium in environmental samples at trace or ultratrace levels. Various techniques, such as precipitation, solvent extraction, extraction chromatography, and ion exchange chromatography, for separation of uranium and plutonium were evaluated. Sample preparation methods and dissolution techniques for environmental samples were also discussed. Especially, both extraction chromatographic and anion exchange chromatographic procedures for uranium and plutonium in environmental samples, such as soil, sediment, plant, seawater, urine, and bone ash were reviewed in detail in order to propose some suitable methods for the separation and purification of uranium and plutonium from the safeguards environmental or swipe samples. A survey of the IAEA strengthened safeguards system, the clean room facility of IAEA's NWAL(Network of Analytical Laboratories), and the analytical techniques for safeguards environmental samples was also discussed here

  14. Time expansion chamber and single ionization cluster measurement

    International Nuclear Information System (INIS)

    Walenta, A.H.

    1978-10-01

    The time expansion chamber (TEC), a new type of drift chamber, allows the measurement of microscopic details of ionization. The mean drift time interval from subsequent sngle ionization clusters of a relativistic particle in the TEC can be made large enough compared to the width of a anode signal to allow the recording of the clusters separately. Since single primary electrons can be detected, the cluster counting would allow an improved particle separation using the relativistic rise of primary ionization. In another application, very high position accuracy for track detectors or improved energy resolution may be obtained. Basic ionization phenomena and drift properties can be measured at the single electron level

  15. Standard test method for uranium and plutonium concentrations and isotopic abundances by thermal ionization mass spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This test method covers the determination of the concentration and isotopic composition of uranium and plutonium in solutions. The purified uranium or plutonium from samples ranging from nuclear materials to environmental or bioassay matrices is loaded onto a mass spectrometric filament. The isotopic ratio is determined by thermal ionization mass spectrometry, the concentration is determined by isotope dilution. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish safety and health practices and determine the applicability of regulatory limitations prior to use.

  16. Simple method for identifying doubly ionized uranium (U III) produced in a hollow-cathode discharge

    International Nuclear Information System (INIS)

    Piyakis, K.N.; Gagne, J.M.

    1988-01-01

    We have studied by emission spectroscopy the spectral properties of doubly ionized uranium, produced in a vapor generator of hollow-cathode design, as a function of the nature of a pure fill gas (helium, neon, argon, krypton, xenon) and its pressure. The spectral intensity is found to increase with increasing ionization potential of the discharge buffer gas, except in the case of helium. Based on our preliminary results, a simple and practical method for the positive identification of the complex U III spectrum is suggested

  17. Two colour multiphoton ionization spectroscopy of uranium from a metastable state

    Energy Technology Data Exchange (ETDEWEB)

    Bajaj, P.N.; Manohar, K.G.; Suri, B.M.; Dasgupta, K.; Talukdar, R.; Chakraborti, P.K.; Rao, P.R.K.

    1988-09-01

    Using two pulsed tunable dye lasers, a two colour multiphoton ionization process has been utilised to explore the higher energy levels of uranium. One hundred and thirty eight new UI levels have been observed in the 37540-38420 cm/sup -1/ region. J assignments of these levels have been suggested on the basis of their excitation from intermediate levels with known and contiguous J values. In eight cases the J assignments are unique.

  18. Ionization and excitation of uranium in a hollow-cathode lamp

    International Nuclear Information System (INIS)

    Gagne, J.M.; Pianarosa, P.; Larin, G.; Saint-Dizier, J.P.; Bouchard, P.

    1981-01-01

    The influence of different carrier gases (Ne,Ar,Kr,Xe) their pressure, and discharge current on the excitation and ionization of uranium atoms in a vapor generator of hollow-cathode design has been investigated by monitoring emission line intensities. From our measurements of line intensities as a function of the carrier gas we obtain an indication of the role of Penning collisions on the excitation of radiative levels in U II

  19. Determination of ultra-low levels of uranium using resonance ionization mass spectrometry

    International Nuclear Information System (INIS)

    Kiran Kumar, P.V.; Acharyulu, G.V.S.G.

    2015-01-01

    The determination of isotopic composition of actinides like U and Pu is important, due to their distribution in the environment as a result of nuclear weapons testing, fuel reprocessing, reactor operations and to a smaller extent from accidental releases. The analytical methods like fission track analysis (FTA), thermal ionization mass spectrometry (TIMS), inductively coupled plasma mass spectrometry (ICPMS) and resonance ionization mass spectrometry (RIMS) have evolved as sensitive techniques. Resonance Ionization Mass Spectrometry yields rapid isotopic signature data for material containing actinides without requiring time-consuming sample preparation and chemical separation procedures. In this paper, authors presented the details of the methodology and results for low-level detection of uranium using RIMS

  20. Single and double ionization of gallium by electron impact

    Indian Academy of Sciences (India)

    case of electron impact single ionization of In·. In order to obtain satisfactory agree- ment with experimental data, the contribution of the electrons of 4d shells to the ionization cross sections was added at only one half of its calculated value. Use of only half of the d-shell contributions was first proposed by Rogers et al [8] and ...

  1. Molecular single photon double K-shell ionization

    International Nuclear Information System (INIS)

    Penent, F.; Nakano, M.; Tashiro, M.; Grozdanov, T.P.; Žitnik, M.; Carniato, S.; Selles, P.; Andric, L.; Lablanquie, P.; Palaudoux, J.; Shigemasa, E.; Iwayama, H.; Hikosaka, Y.; Soejima, K.; Suzuki, I.H.; Kouchi, N.; Ito, K.

    2014-01-01

    We have studied single photon double K-shell ionization of small molecules (N 2 , CO, C 2 H 2n (n = 1–3), …) and the Auger decay of the resulting double core hole (DCH) molecular ions thanks to multi-electron coincidence spectroscopy using a magnetic bottle time-of-flight spectrometer. The relative cross-sections for single-site (K −2 ) and two-site (K −1 K −1 ) double K-shell ionization with respect to single K-shell (K −1 ) ionization have been measured that gives important information on the mechanisms of single photon double ionization. The spectroscopy of two-site (K −1 K −1 ) DCH states in the C 2 H 2n (n = 1–3) series shows important chemical shifts due to a strong dependence on the C-C bond length. In addition, the complete cascade Auger decay following single site (K −2 ) ionization has been obtained

  2. Diode laser based resonance ionization mass spectrometry for spectroscopy and trace analysis of uranium isotopes

    International Nuclear Information System (INIS)

    Hakimi, Amin

    2013-01-01

    In this doctoral thesis, the upgrade and optimization of a diode laser system for high-resolution resonance ionization mass spectrometry is described. A frequency-control system, based on a double-interferometric approach, allowing for absolute stabilization down to 1 MHz as well as frequency detunings of several GHz within a second for up to three lasers in parallel was optimized. This laser system was used for spectroscopic studies on uranium isotopes, yielding precise and unambiguous level energies, total angular momenta, hyperfine constants and isotope shifts. Furthermore, an efficient excitation scheme which can be operated with commercial diode lasers was developed. The performance of the complete laser mass spectrometer was optimized and characterized for the ultra-trace analysis of the uranium isotope 236 U, which serves as a neutron flux dosimeter and tracer for radioactive anthropogenic contaminations in the environment. Using synthetic samples, an isotope selectivity of ( 236 U)/( 238 U) = 4.5(1.5) . 10 -9 was demonstrated.

  3. Single and double ionization of gallium by electron impact

    Indian Academy of Sciences (India)

    theoretical methods. They stated that the available published data were slightly contra- dictory and according to Kozlov [6], a large number of 3d 94s24p terms are .... brief outline of the method of calculation is given below. ..... ing qualitative features of contribution of 3d shell to single and double ionization cross sections.

  4. Development of a Portable Single Photon Ionization-Photoelectron Ionization Time-of-Flight Mass Spectrometer

    Directory of Open Access Journals (Sweden)

    Yunguang Huang

    2015-01-01

    Full Text Available A vacuum ultraviolet lamp based single photon ionization- (SPI- photoelectron ionization (PEI portable reflecting time-of-flight mass spectrometer (TOFMS was designed for online monitoring gas samples. It has a dual mode ionization source: SPI for analyte with ionization energy (IE below 10.6 eV and PEI for IE higher than 10.6 eV. Two kinds of sampling inlets, a capillary inlet and a membrane inlet, are utilized for high concentration and trace volatile organic compounds, respectively. A mass resolution of 1100 at m/z 64 has been obtained with a total size of 40 × 31 × 29 cm, the weight is 27 kg, and the power consumption is only 70 W. A mixture of benzene, toluene, and xylene (BTX, SO2, and discharging products of SF6 were used to test its performance, and the result showed that the limit of quantitation for BTX is as low as 5 ppbv (S/N = 10 : 1 with linear dynamic ranges greater than four orders of magnitude. The portable TOFMS was also evaluated by analyzing volatile organic compounds from wine and decomposition products of SF6 inside of a gas-insulated switchgear.

  5. Development of a Portable Single Photon Ionization-Photoelectron Ionization Time-of-Flight Mass Spectrometer

    Science.gov (United States)

    Huang, Yunguang; Li, Jinxu; Tang, Bin; Zhu, Liping; Hou, Keyong; Li, Haiyang

    2015-01-01

    A vacuum ultraviolet lamp based single photon ionization- (SPI-) photoelectron ionization (PEI) portable reflecting time-of-flight mass spectrometer (TOFMS) was designed for online monitoring gas samples. It has a dual mode ionization source: SPI for analyte with ionization energy (IE) below 10.6 eV and PEI for IE higher than 10.6 eV. Two kinds of sampling inlets, a capillary inlet and a membrane inlet, are utilized for high concentration and trace volatile organic compounds, respectively. A mass resolution of 1100 at m/z 64 has been obtained with a total size of 40 × 31 × 29 cm, the weight is 27 kg, and the power consumption is only 70 W. A mixture of benzene, toluene, and xylene (BTX), SO2, and discharging products of SF6 were used to test its performance, and the result showed that the limit of quantitation for BTX is as low as 5 ppbv (S/N = 10 : 1) with linear dynamic ranges greater than four orders of magnitude. The portable TOFMS was also evaluated by analyzing volatile organic compounds from wine and decomposition products of SF6 inside of a gas-insulated switchgear. PMID:26587023

  6. Alpha spectroscopy with ionization chamber to determine uranium and thorium in environmental samples

    International Nuclear Information System (INIS)

    Carvalho Conti, L.F. de.

    1983-01-01

    A high-resolution, parallel Frisch ionization chamber with an efficient area of 320 cm 2 was developed and applied as an alpha spectrometer. The resolution of the spectrum is approximatelly 40 KeV fwhm (full width half maximum) for 233 U point source. The spectrum is recorded by a 1024 channels pulse-height analyser. The counting gas is commercial available mixture of argon and methane. The counting efficiency for 233 U energy-window selected is in order of 42% for a calibration source placed on the cathode axis. No radial dependence of this efficiency was observed. The chamber was used for counting the activity of uranium and thorium isotopes on large area stainless steel planchets. The large area thin sources were prepared extracting the uranium and thorium isotopes from 1M HNO 3 - aqueous solution with polymeric membranes containing tri-n-octyl-phosphine oxide adhered on the surface of the 314 cm 2 planchet. The integral back-ground is typically 7 counts/min between 4 and 6 MeV. The sensitivity of the procedure used ofr 238 U is about 30 Bq/1 based on 3S of back-ground, 1 liter sample volume and 30 min counting time. (Author) [pt

  7. Kidney cancer mortality and ionizing radiation among French and German uranium miners

    Energy Technology Data Exchange (ETDEWEB)

    Drubay, Damien; Ancelet, Sophie; Laurier, Dominique; Rage, Estelle [Institut de Radioprotection et de Surete Nucleaire (IRSN), Laboratory of Epidemiology, Fontenay-aux-Roses cedex (France); Acker, Alain [AREVA NC, Paris (France); Kreuzer, Michaela [Federal Office for Radiation Protection and Health, Department of Radiation Protection and Health, Neuherberg (Germany)

    2014-08-15

    The investigation of potential adverse health effects of occupational exposures to ionizing radiation, on uranium miners, is an important area of research. Radon is a well-known carcinogen for lung, but the link between radiation exposure and other diseases remains controversial, particularly for kidney cancer. The aims of this study were therefore to perform external kidney cancer mortality analyses and to assess the relationship between occupational radiation exposure and kidney cancer mortality, using competing risks methodology, from two uranium miners cohorts. The French (n = 3,377) and German (n = 58,986) cohorts of uranium miners included 11 and 174 deaths from kidney cancer. For each cohort, the excess of kidney cancer mortality has been assessed by standardized mortality ratio (SMR) corrected for the probability of known causes of death. The associations between cumulative occupational radiation exposures (radon, external gamma radiation and long-lived radionuclides) or kidney equivalent doses and both the cause-specific hazard and the probability of occurrence of kidney cancer death have been estimated with Cox and Fine and Gray models adjusted to date of birth and considering the attained age as the timescale. No significant excess of kidney cancer mortality has been observed neither in the French cohort (SMR = 1.49, 95 % confidence interval [0.73; 2.67]) nor in the German cohort (SMR = 0.91 [0.77; 1.06]). Moreover, no significant association between kidney cancer mortality and any type of occupational radiation exposure or kidney equivalent dose has been observed. Future analyses based on further follow-up updates and/or large pooled cohorts should allow us to confirm or not the absence of association. (orig.)

  8. Kidney cancer mortality and ionizing radiation among French and German uranium miners

    International Nuclear Information System (INIS)

    Drubay, Damien; Ancelet, Sophie; Laurier, Dominique; Rage, Estelle; Acker, Alain; Kreuzer, Michaela

    2014-01-01

    The investigation of potential adverse health effects of occupational exposures to ionizing radiation, on uranium miners, is an important area of research. Radon is a well-known carcinogen for lung, but the link between radiation exposure and other diseases remains controversial, particularly for kidney cancer. The aims of this study were therefore to perform external kidney cancer mortality analyses and to assess the relationship between occupational radiation exposure and kidney cancer mortality, using competing risks methodology, from two uranium miners cohorts. The French (n = 3,377) and German (n = 58,986) cohorts of uranium miners included 11 and 174 deaths from kidney cancer. For each cohort, the excess of kidney cancer mortality has been assessed by standardized mortality ratio (SMR) corrected for the probability of known causes of death. The associations between cumulative occupational radiation exposures (radon, external gamma radiation and long-lived radionuclides) or kidney equivalent doses and both the cause-specific hazard and the probability of occurrence of kidney cancer death have been estimated with Cox and Fine and Gray models adjusted to date of birth and considering the attained age as the timescale. No significant excess of kidney cancer mortality has been observed neither in the French cohort (SMR = 1.49, 95 % confidence interval [0.73; 2.67]) nor in the German cohort (SMR = 0.91 [0.77; 1.06]). Moreover, no significant association between kidney cancer mortality and any type of occupational radiation exposure or kidney equivalent dose has been observed. Future analyses based on further follow-up updates and/or large pooled cohorts should allow us to confirm or not the absence of association. (orig.)

  9. Detection of single atoms by resonance ionization spectroscopy

    International Nuclear Information System (INIS)

    Hurst, G.S.

    1986-01-01

    Rutherford's idea for counting individual atoms can, in principle, be implemented for nearly any type of atom, whether stable or radioactive, by using methods of resonance ionization. With the RIS technique, a laser is tuned to a wavelength which will promote a valence electron in a Z-selected atom to an excited level. Additional resonance or nonresonance photoabsorption steps are used to achieve nearly 100% ionization efficiencies. Hence, the RIS process can be saturated for the Z-selected atoms; and since detectors are available for counting either single electrons or positive ions, one-atom detection is possible. Some examples are given of one-atom detection, including that of the noble gases, in order to show complementarity with AMS methods. For instance, the detection of 81 Kr using RIS has interesting applications for solar neutrino research, ice-cap dating, and groundwater dating. 39 refs., 7 figs., 2 tabs

  10. Auger transitions in singly and multiply ionized atoms

    International Nuclear Information System (INIS)

    Mehlhorn, W.

    1978-01-01

    Some recent progress in Auger and autoionizing electron spectrometry of free metal atoms and of multiply ionized atoms is reviewed. The differences which arise between the spectra of atoms in the gaseous and the solid state are due to solid state effects. This will be shown for Cd as an example. The super Coster-Kronig transitions 3p-3d 2 (hole notation) and Coster-Kronig transitions 3p-3d 4s have been measured and compared with free-atom calculations for free Zn atoms. The experimental width GAMMA(3p)=(2.1+-0.2)eV found for the free atom agrees with the value obtained for solid Zn but is considerably smaller than the theoretical value for the free atom. Autoionizing spectra of Na following an L-shell excitation or ionization by different particles are compared and discussed. The nonisotropic angular distribution of electrons from the transition 2p 5 3s 2 2 Psub(3/2)→2p 6 +e - is compared with theoretical calculations. Two examples for Auger spectrometry of multiply ionized atoms are given: (1) excitation of neon target atoms by light and heavy ions, and (2) excitation of projectile ions Be + and B + in single gas collisions with CH 4 . A strong alignment of the excited atoms has also been found here

  11. Uranium

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    Developments in the the uranium industry in Australia that took place during the quarter ended 30 June 1980 are reviewed. These include uranium mine production and uranium exploration. Prices for uranium oxide and uranium hexafluoride as at the end of June 1980 and figures for U 3 O 8 production and export from 1978 to March 1980 are listed

  12. Single ionization of helium by 730-eV electrons

    International Nuclear Information System (INIS)

    Stevenson, M. A.; Lohmann, B.; Bray, I.; Fursa, D. V.; Stelbovics, A. T.

    2007-01-01

    We present fully differential measurements of 730-eV electron-impact single ionization of the ground state of helium with 205- or 100-eV outgoing electrons. Internormalized data are obtained for coplanar geometries with the fast electron detected at θ A =6 degree sign , 9 degree sign , and 12 degree sign . The data are compared, where possible, with the corresponding data of Catoire et al. [J. Phys. B 39, 2827 (2006)] and the convergent close-coupling theory. An improved agreement is found between the present measurements and the theory

  13. Quasi free mechanism in single photon double ionization of helium

    Energy Technology Data Exchange (ETDEWEB)

    Schoeffler, Markus; Stuck, Christian [Frankfurt Univ., Frankfurt am Main (Germany). Inst. fuer Kernphysik; Lawrence Berkeley National Lab, Berkeley, CA (United States); Jahnke, Till; Waitz, Markus; Trinter, Florian; Lenz, Ute; Schmidt-Boecking, Horst; Doerner, Reinhard [Frankfurt Univ., Frankfurt am Main (Germany). Inst. fuer Kernphysik; Jones, Mathew; Landers, Allen [Auburn University, Auburn, AL (United States); Belkacem, Ali; Weber, Thorsten [Lawrence Berkeley National Lab, Berkeley, CA (United States); Cocke, Lew [Kansas State University, Manhattan, KS (United States)

    2012-07-01

    Double ionization of Helium by a single photon is widely believed to proceed through two mechanisms: knock-off (TS1) or shake-off, with the last one dominating at high photon energies. A new mechanism, termed ''Quasi Free Mechanism'' (QFM) was predicted 35 years ago by Amusia and coworkers, but escaped experimental observation till today. Here we provide the first proof of this mechanism using 800 eV photons from the Advanced Light Source. Fragments (electrons and ions) were measured in coincidence using momentum spectroscopy (COLTRIMS). He{sup (}2+) ions with zero momentum were found - the fingerprint for the QFM.

  14. Resonance-ionization mass spectrometry of uranium and neptunium. Resonanz-Ionisations-Massenspektrometrie an Uran und Neptunium

    Energy Technology Data Exchange (ETDEWEB)

    Sattelberger, P.

    1990-01-01

    The laser resonant three-stage photoionization with subsequent time-of-flight mass analysis of uranium and neptunium was studied. For uranium, excitation schemes were sought which, in addition to excitation from the initial state, permit the depopulation of a thermally occupied state at 620.3 cm{sup -1}. By means of narrow-band laser light, a large number of autoionizing states above the ionization limit could be found. For {sup 235}U the hyperfine structural splitting of transitions was studied. The examined inner atomic transitions showed a great isotopy shift between {sup 235}U and {sup 236}U which even permitted selective ionization of the individual isotopes. Preliminary measurements of neptunium resulted in autoionizing states for two schemes. By wide-band laser light the hyperfine structural splitting of {sup 237}Np for inner atomic transitions was examined and compared with reference values found in specialized literature. (BBR).

  15. Uranium

    International Nuclear Information System (INIS)

    Cuney, M.; Pagel, M.; Leroy, J.

    1992-01-01

    First, this book presents the physico-chemical properties of Uranium and the consequences which can be deduced from the study of numerous geological process. The authors describe natural distribution of Uranium at different scales and on different supports, and main Uranium minerals. A great place in the book is assigned to description and classification of uranium deposits. The book gives also notions on prospection and exploitation of uranium deposits. Historical aspects of Uranium economical development (Uranium resources, production, supply and demand, operating costs) are given in the last chapter. 7 refs., 17 figs

  16. Depolarizing collisions with hydrogen: Neutral and singly ionized alkaline earths

    Energy Technology Data Exchange (ETDEWEB)

    Manso Sainz, Rafael; Ramos, Andrés Asensio; Bueno, Javier Trujillo [Instituto de Astrofísica de Canarias, Vía Láctea s/n, E-38205 La Laguna, Tenerife (Spain); Roncero, Octavio; Sanz-Sanz, Cristina [Instituto de Física Fundamental (IFF-CSIC), CSIC, Serrano 123, E-28006 Madrid (Spain); Aguado, Alfredo, E-mail: octavio.roncero@csic.es [Departamento de Química Física, Unidad Asociada UAM-CSIC, Facultad de Ciencias M-14, Universidad Autónoma de Madrid, E-28049 Madrid (Spain)

    2014-06-20

    Depolarizing collisions are elastic or quasielastic collisions that equalize the populations and destroy the coherence between the magnetic sublevels of atomic levels. In astrophysical plasmas, the main depolarizing collider is neutral hydrogen. We consider depolarizing rates on the lowest levels of neutral and singly ionized alkali earths Mg I, Sr I, Ba I, Mg II, Ca II, and Ba II, due to collisions with H°. We compute ab initio potential curves of the atom-H° system and solve the quantum mechanical dynamics. From the scattering amplitudes, we calculate the depolarizing rates for Maxwellian distributions of colliders at temperatures T ≤ 10,000 K. A comparative analysis of our results and previous calculations in the literature is completed. We discuss the effect of these rates on the formation of scattering polarization patterns of resonant lines of alkali earths in the solar atmosphere, and their effect on Hanle effect diagnostics of solar magnetic fields.

  17. Uranium

    International Nuclear Information System (INIS)

    Mackay, G.A.

    1978-01-01

    The author discusses the contribution made by various energy sources in the production of electricity. Estimates are made of the future nuclear contribution, the future demand for uranium and future sales of Australian uranium. Nuclear power growth in the United States, Japan and Western Europe is discussed. The present status of the six major Australian uranium deposits (Ranger, Jabiluka, Nabarlek, Koongarra, Yeelerrie and Beverley) is given. Australian legislation relevant to the uranium mining industry is also outlined

  18. Uranium

    International Nuclear Information System (INIS)

    1982-01-01

    The development, prospecting, research, processing and marketing of South Africa's uranium industry and the national policies surrounding this industry form the headlines of this work. The geology of South Africa's uranium occurences and their positions, the processes used in the extraction of South Africa's uranium and the utilisation of uranium for power production as represented by the Koeberg nuclear power station near Cape Town are included in this publication

  19. Uranium

    International Nuclear Information System (INIS)

    Stewart, E.D.J.

    1974-01-01

    A discussion is given of uranium as an energy source in The Australian economy. Figures and predictions are presented on the world supply-demand position and also figures are given on the added value that can be achieved by the processing of uranium. Conclusions are drawn about Australia's future policy with regard to uranium (R.L.)

  20. Uranium

    International Nuclear Information System (INIS)

    Toens, P.D.

    1981-03-01

    The geological setting of uranium resources in the world can be divided in two basic categories of resources and are defined as reasonably assured resources, estimated additional resources and speculative resources. Tables are given to illustrate these definitions. The increasing world production of uranium despite the cutback in the nuclear industry and the uranium requirements of the future concluded these lecture notes

  1. Uranium Release from Acidic Weathered Hanford Sediments: Single-Pass Flow-Through and Column Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Guohui [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Um, Wooyong [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Pohang University of Science and Technology (POSTECH), Pohang, South Korea; Wang, Zheming [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Reinoso-Maset, Estela [Sierra; Washton, Nancy M. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Mueller, Karl T. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Perdrial, Nicolas [Department; Department; O’Day, Peggy A. [Sierra; Chorover, Jon [Department

    2017-09-21

    The reaction of acidic radioactive waste with sediments can induce mineral transformation reactions that, in turn, control contaminant fate. Here, sediment weathering by synthetic uranium-containing acid solutions was investigated using bench-scale experiments to simulate waste disposal conditions at Hanford’s cribs, USA. During acid weathering, the presence of phosphate exerted a strong influence over uranium mineralogy and a rapidly precipitated, crystalline uranium phosphate phase (meta-ankoleite [K(UO2)(PO4)·3H2O]) was identified using spectroscopic and diffraction-based techniques. In phosphate-free system, uranium oxyhydroxide minerals such as K-compreignacite [K2(UO2)6O4(OH)6·7H2O] were formed. Single-pass flow-through (SPFT) and column leaching experiments using synthetic Hanford pore water showed that uranium precipitated as meta-ankoleite during acid weathering was strongly retained in the sediments, with an average release rate of 2.67E-12 mol g-1 s-1. In the absence of phosphate, uranium release was controlled by dissolution of uranium oxyhydroxide (compreignacite-type) mineral with a release rate of 1.05-2.42E-10 mol g-1 s-1. The uranium mineralogy and release rates determined for both systems in this study support the development of accurate U-release models for prediction of contaminant transport. These results suggest that phosphate minerals may be a good candidate for uranium remediation approaches at contaminated sites.

  2. Ionization in matrix-assisted laser desorption/ionization: singly charged molecular ions are the lucky survivors.

    Science.gov (United States)

    Karas, M; Glückmann, M; Schäfer, J

    2000-01-01

    A new model for the ionization processes in UV matrix-assisted laser desorption/ionization (MALDI) which accounts for the major phenomena observed is presented and discussed. The model retains elements of earlier approaches, such as photoionization and photochemical reactions, but it redefines these in the light of new working questions, most importantly why only singly charged ions are detected. Based on experimental evidence, the formation of singly and multiply charged clusters by a deficiency/excess of ions and also by photoionization and subsequent photochemical processes is pointed out to be the major ionization processes, which typically occur in parallel. The generation of electrons and their partial loss into the surrounding vacuum and solid, on the one hand, results in a positively charged ion-neutral plume facilitating a high overall ionization yield. On the other hand, these electrons, and also the large excess of protonated matrix ions in the negative ion mode, induce effective ion reneutralization in the plume. These neutralization processes are most effective for the highly charged cluster ions initially formed. Their fragmentation behaviour is evidenced in fast metastable fragmentation characteristics and agrees well with an electron capture dissociation mechanism and the enthalpy transfer upon neutralization forms the rationale for the prominent fragmentation and intense chemical noise accompanying successful MALDI. Within the course of the paper, cross-correlations with other desorption/ionization techniques and with earlier discussions on their mechanisms are drawn. Copyright 2000 John Wiley & Sons, Ltd.

  3. Uranium

    International Nuclear Information System (INIS)

    Whillans, R.T.

    1981-01-01

    Events in the Canadian uranium industry during 1980 are reviewed. Mine and mill expansions and exploration activity are described, as well as changes in governmental policy. Although demand for uranium is weak at the moment, the industry feels optimistic about the future. (LL)

  4. Uranium

    International Nuclear Information System (INIS)

    Batley, G.C.; McKay, A.D.

    1986-01-01

    Production of uranium oxide in Australia for 1983 was 3786 t(3211 t U). Uranium exports for 1983 were 3273 t U 3 O 8 at an average f.o.b. value of $41.02/lb U 3 O 8 . Private exploration expenditure for uranium in Australia during the 1982-83 fiscal year was $36.5 million, 35% less than in 1981-82. In November 1983, the Government decided that uranium mining would be allowed only at the existing Ranger and Nabarlek mines and at the proposed Olympic Dam mine. Australia's Reasonably Assured Resources of uranium recoverable at less than US$80/kg U as at December 1983, totalled 474 000 t U. Australia's total now represents 30% of the Western world's low-cost RAR. In addition Australia has 235 000 t U in the low-cost Estimated Additional Resources Category 1, which represents 31% of the Western world's resources in this category

  5. Uranium tris-aryloxide derivatives supported by triazacyclononane: engendering a reactive uranium(III) center with a single pocket for reactivity.

    Science.gov (United States)

    Castro-Rodriguez, Ingrid; Olsen, Kristian; Gantzel, Peter; Meyer, Karsten

    2003-04-16

    The synthesis and spectroscopic characterization of the mononuclear uranium complex [((ArO)(3)tacn)U(III)(NCCH(3))] is reported. The uranium(III) complex reacts with organic azides to yield uranium(IV) azido as well as uranium(V) imido complexes, [((ArO)(3)tacn)U(IV)(N(3))] and [((ArO)(3)tacn)U(V)(NSi(CH(3))(3))]. Single-crystal X-ray diffraction, spectroscopic, and computational studies of this analogous series of uranium tris-aryloxide complexes supported by triazacyclononane are described. The hexadentate, tris-anionic ligand coordinates to the large uranium ion in unprecedented fashion, engendering coordinatively unsaturated and highly reactive uranium centers. The macrocyclic triazacyclononane tris-aryloxide derivative occupies six coordination sites, with the three aryloxide pendant arms forming a trigonal plane at the metal center. DFT quantum mechanic methods were applied to rationalize the reactivity and to elucidate the electronic structure of the newly synthesized compounds. It is shown that the deeply colored uranium(III) and uranium(V) species are stabilized via pi-bonding interaction, involving uranium f-orbitals and the axial acetonitrile and imido ligand, respectively. In contrast, the bonding in the colorless uranium(IV) azido complex is purely ionic in nature. The magnetism of the series of complexes with an [N3O3-N(ax)] core structure and oxidation states +III, +IV, and +V is discussed in context of the electronic structures.

  6. Uranium

    International Nuclear Information System (INIS)

    Villarreal, E.

    1986-01-01

    After the increase in oil prices in 1973, several European countries increased their power programs. As a result some uranium mining companies from the FRG, Spain and France invested in exploration of radioactive minerals in Colombia hoping to find uranium resources needed to fuel European reactors. In the article a historic review of foreign investment in uranium in Colombia is made; some recommendations about joint-venture contracts used to regulate the work of the foreign companies are included. The four companies involved in exploration left the country in the early eighties, due to the difficulties in finding a large deposit and the difficult world situation of nuclear power

  7. Evidence for Single Metal Two Electron Oxidative Addition and Reductive Elimination at Uranium

    OpenAIRE

    Gardner, Benedict M; Kefalidis, Christos E; Lu, Erli; Patel, Dipti; Mcinnes, Eric; Tuna, Floriana; Wooles, Ashley; Maron, Laurent; Liddle, Stephen

    2017-01-01

    Reversible single-metal two-electron oxidative addition and reductive elimination are common fundamental reactions for transition metals that underpin major catalytic transformations. However, these reactions have never been observed together in the f-block because these metals exhibit irreversible one- or multi-electron oxidation or reduction reactions. Here, we report that azobenzene oxidises sterically and electronically unsaturated uranium(III) complexes to afford a uranium(V)-imido compl...

  8. Time delay between singly and doubly ionizing wavepackets in laser-driven helium

    International Nuclear Information System (INIS)

    Parker, J S; Doherty, B J S; Meharg, K J; Taylor, K T

    2003-01-01

    We present calculations of the time delay between single and double ionization of helium, obtained from full-dimensionality numerical integrations of the helium-laser Schroedinger equation. The notion of a quantum mechanical time delay is defined in terms of the interval between correlated bursts of single and double ionization. Calculations are performed at 390 and 780 nm in laser intensities that range from 2 x 10 14 to 14 x 10 14 Wcm -2 . We find results consistent with the rescattering model of double ionization but supporting its classical interpretation only at 780 nm. (letter to the editor)

  9. Uranium

    International Nuclear Information System (INIS)

    Perkin, D.J.

    1982-01-01

    Developments in the Australian uranium industry during 1980 are reviewed. Mine production increased markedly to 1841 t U 3 O 8 because of output from the new concentrator at Nabarlek and 1131 t of U 3 O 8 were exported at a nominal value of $37.19/lb. Several new contracts were signed for the sale of yellowcake from Ranger and Nabarlek Mines. Other developments include the decision by the joint venturers in the Olympic Dam Project to sink an exploration shaft and the release of an environmental impact statement for the Honeymoon deposit. Uranium exploration expenditure increased in 1980 and additions were made to Australia's demonstrated economic uranium resources. A world review is included

  10. Uranium*

    Science.gov (United States)

    Grenthe, Ingmar; Drożdżyński, Janusz; Fujino, Takeo; Buck, Edgar C.; Albrecht-Schmitt, Thomas E.; Wolf, Stephen F.

    Uranium compounds have been used as colorants since Roman times (Caley, 1948). Uranium was discovered as a chemical element in a pitchblende specimen by Martin Heinrich Klaproth, who published the results of his work in 1789. Pitchblende is an impure uranium oxide, consisting partly of the most reduced oxide uraninite (UO2) and partly of U3O8. Earlier mineralogists had considered this mineral to be a complex oxide of iron and tungsten or of iron and zinc, but Klaproth showed by dissolving it partially in strong acid that the solutions yielded precipitates that were different from those of known elements. Therefore he concluded that it contained a new element (Mellor, 1932); he named it after the planet Uranus, which had been discovered in 1781 by William Herschel, who named it after the ancient Greek deity of the Heavens.

  11. The spectrum of singly ionized yttrium, Y II

    International Nuclear Information System (INIS)

    Nilsson, A.E.; Johansson, S.; Kurucz, R.L.

    1991-01-01

    Hollow-cathode spectra of yttrium have been registered in the wavelength region 1000-48800 A. Resonant charge transfer reactions in the light source favour the excitation of Y II, where 174 new levels have been established by means of 1284 newly classified lines. Altogether we report 1521 lines between 235 levels in Y II. The ground complex (4d+5s) 2 is now completely known and a number of Rydberg series have been extended. The new levels belong to the 4dnl (nl=7s, 8s, 9s, 6p, 7p, 4d, 5d, 6d, 7d, 8d, 4f, 5f, 6f, 7f, 5g) and 5snl (nl=7s, 8s, 6p, 6d, 4f, 5f) configurations. Eigenvector compositions, based on paramagnetic calculations including configuration interaction, are given for all levels. The ionization limit has been determined to 98590 ± 5 cm -1 . (orig.)

  12. Single- and multi-photon ionization studies of organosulfur species

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, Yu -San [Iowa State Univ., Ames, IA (United States)

    1999-02-12

    Accurate ionization energies (IE`s) for molecular species are used for prediction of chemical reactivity and are of fundamental importance to chemists. The IE of a gaseous molecule can be determined routinely in a photoionization or a photoelectron experiment. IE determinations made in conventional photoionization and photoelectron studies have uncertainties in the range of 3--100 meV (25--250 cm-1). In the past decade, the most exciting development in the field of photoionization and photoelectron spectroscopy has been the availability of high resolution, tunable ultraviolet (UV) and vacuum ultraviolet (VUV) laser sources. The laser pulsed field ionization photoelectron (PFI-PE) scheme is currently the state-of-the-art photoelectron spectroscopic technique and is capable of providing photoelectron energy resolution close to the optical resolution. The author has focused attention on the photoionization processes of some sulfur-containing species. The studies of the photoionization and photodissociation on sulfur-containing compounds [such as CS2, CH3SH, CH3SSCH3, CH3CH2SCH2CH3, HSCH2CH2SH and C4H4S (thiophene) and sulfur-containing radicals, such as HS, CS, CH3S, CH3CH2S and CH3SS], have been the major subjects in the group because sulfur is an important species contributing to air pollution in the atmosphere. The modeling of the combustion and oxidation of sulfur compounds represents important steps for the control of both the production and the elimination of sulfur-containing pollutants. Chapter 1 is a general introduction of the thesis. Chapters 2 and 6 contain five papers published in, or accepted for publication in, academic periodicals. In Chapter 7, the progress of the construction in the laboratory of a new vacuum ultraviolet laser system equipped with a reflectron mass

  13. Momentum spectra for single and double electron ionization of He in relativistic collisions

    International Nuclear Information System (INIS)

    Wood, C.J.; Olson, R.E.

    1997-08-01

    The complete momentum spectra for single and double ionization of He by 1GeV/u (β=0.88) U 92+ have been investigated using a classical trajectory Monte Carlo method corrected for the relativistic projectile. The 1/r 12 electron-electron interaction has been included in the post-collision region for double ionization to incorporate the effects of both the nuclear-electron and electron-electron ionizing interactions, and to access the effects of electron correlation in the electron spectra. Experimental measurements were able to determine the longitudinal momentum spectra for single ionization; these observations are in accordance with the theoretical predictions for the three-body momentum balance between projectile, recoil ion, and ionized electron. In particular, the Lorentz contraction of the Coulomb interaction of the projectile manifests itself in the decrease of the post-collision interaction of the projectile with the electron and recoil ion, causing them to recoil back-to-back as in the case for a short electromagnetic pulse. This feature is clearly displayed in both the theoretical and experimental longitudinal momentum spectra, and by comparing to calculations that are performed at the same collision speed but do not include the relativistic potentials. Moreover, collision plane spectra of the three particles demonstrate that the momenta of the recoil ion and ionized electron are preferentially equal, and opposite, to each other. The electron spectra for double ionization show that the inclusion of the electron-electron interaction in the post-collision regime partitions the combined ionization momentum of the electrons so that the electrons are preferentially emitted in opposite azimuthal angles to one another. This is in contrast to calculations made assuming independent electrons. (orig.)

  14. Formation of molecules in interstellar clouds from singly and multiply ionized atoms

    International Nuclear Information System (INIS)

    Langer, W.D.; and NASA, Institute for Space Studies, Goddard Space Flight Center, New York)

    1978-01-01

    Soft X-ray and cosmic rays produce multiply ionized atoms which may initiate molecule production in interstellar clouds. This molecule production can occur via ion-molecule reactions with H 2 , either directly from the multiply ionized atom (e.g.,C ++ + H 2 →CH + + H + ), or indirectly from the singly ionized atoms (e.g., N + + H 2 →NH + + H) that are formed from the recombination or charge transfer of the highly ionized atom (e.g., N ++ + e→N + + hv). We investigate the contribution of these reactions to the abundances of carbon-, nitrogen-, and oxygen-bearing molecules in isobaric models of diffuse clouds. In the presence of the average flux estimated for the diffuse soft X-ray background, multiply ionized atoms contribute only minimally (a few percent) to carbon-bearing molecules such as CH. In the neighborhood of diffuse structures or discrete sources, however, where the X-ray flux is enhanced, multiple ionization is considerably more important for molecule production

  15. Uranium

    International Nuclear Information System (INIS)

    Battey, G.C.; McKay, A.D.

    1988-01-01

    Production for 1986 was 4899 t U 3 O 8 (4154 t U), 30% greater than in 1985, mainly because of a 39% increase in production at Ranger. Exports for 1986 were 4166 t U 3 O 8 at an average f.o.b. unit value of $40.57/lb U 3 O 8 . Private exploration expenditure for uranium in Australia during the 1985-86 fiscal year was $50.2 million. Plans were announced to increase the nominal capacity of the processing plant at Ranger from 3000 t/year U 3 O 8 to 4500 t and later to 6000 t/year. Construction and initial mine development at Olympic Dam began in March. Production is planned for mid 1988 at an annual rate of 2000 t U 3 O 8 , 30 000 t Cu, and 90 000 oz (2800 kg) Au. The first long-term sales agreement was concluded in September 1986. At the Manyingee deposit, testing of the alkaline solution mining method was completed, and the treatment plant was dismantled. Spot market prices (in US$/lb U 3 O 8 ) quoted by Nuexco were generally stable. From January-October the exchange value fluctuated from US$17.00-US$17.25; for November and December it was US$16.75. Australia's Reasonably Assured Resources of uranium recoverable at less than US$80/kg U at December 1986 were estimated as 462 000 t U, 3000 t U less than in 1985. This represents 30% of the total low-cost RAR in the WOCA (World Outside the Centrally Planned Economy Areas) countries. Australia also has 257 000 t U in the low-cost Estimated Additional Resources Category I, 29% of the WOCA countries' total resources in this category

  16. Lattice location of helium in uranium dioxide single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Garrido, F.; Nowicki, L. E-mail: lech.nowicki@fuw.edu.pl; Sattonnay, G.; Sauvage, T.; Thome, L

    2004-06-01

    Lattice location of {sup 3}He atoms implanted into UO{sub 2} single crystals was performed by means of the channeling technique combined with nuclear reaction analysis (NRA) and Rutherford backscattering spectrometry (RBS). The {sup 3}He(d,p){sup 4}He reaction was used. The experimental angular scans show that helium atoms occupy octahedral interstitial positions.

  17. Design of polymetallic uranium assemblies for the development of single molecule magnets

    International Nuclear Information System (INIS)

    Chatelain, Lucile

    2016-01-01

    The study of actinide chemistry is not only essential for the development of nuclear fuel, nuclear fuel reprocessing or environmental clean up, but also for the understanding of fundamental actinide/ligand interactions and multiple bounding. The magnetic properties of polynuclear actinide molecules are of significant interest to investigate the magnetic communication between the metallic centres. Furthermore, they are highly promising for the design of molecular magnets. Uranium undergoes redox reactions due to a wide range of available oxidation states and easily forms polynuclear assemblies. However, only a few controlled synthetic routes towards these polynuclear uranium assemblies are described in the literature. In this context, the first part of this work was dedicated to the synthesis of oxo/hydroxo uranium clusters from the controlled hydrolysis of tetravalent uranium in the presence of an environmentally relevant ligand. This led to the synthesis of clusters with novel topologies, for which size could be varied as a function of the reaction conditions employed. However, the obtained clusters do not behave as SMM. In order to gain a stronger interaction between metallic centres, the cation-cation interaction was used to rationally design polynuclear uranyl(V) complexes. The isolation of uranyl(V) complexes had been limited in the past by its disproportionation, however, a fine tuning of the organic ligand and reaction conditions finally allowed to stabilise uranyl(V). We used stable uranyl(V) units as building block to form heteronuclear complexes with 3d and 4f metals with polymeric or discrete structures. The study of the magnetic properties of the uranium polynuclear assemblies was carried out and revealed single molecule or chain magnet behaviours with high energy barriers. The uranyl(V) unit was also used as a structural model for the more radioactive neptunium element, allowing the isolation of an isostructural trinuclear neptunyl(V) assembly in

  18. Accuracy of single count methods of WL determination for open-pit uranium mines

    International Nuclear Information System (INIS)

    Solomon, S.B.; Kennedy, K. N.

    1983-01-01

    A study of single count methods of WL determination was made using a database respresentative of Australian open pit uranium mine conditions. The aim of the study was to check the existence of the optimum time delay coresponding to the Rolle method, to determine the accuracy of the conversion factor for Australian conditions and to examine any systematic use of data bases of representative radon daughter concentration

  19. A mononuclear uranium(IV) single-molecule magnet with an azobenzene radical ligand

    Energy Technology Data Exchange (ETDEWEB)

    Antunes, Maria A.; Coutinho, Joana T.; Santos, Isabel C.; Marcalo, Joaquim; Almeida, Manuel; Pereira, Laura C.J. [C" 2TN, Instituto Superior Tecnico, Universidade de Lisboa, Bobadela (Portugal); Baldovi, Jose J.; Gaita-Arino, Alejandro; Coronado, Eugenio [Instituto de Ciencia Molecular, Universitat de Valencia, Paterna (Spain)

    2015-12-01

    A tetravalent uranium compound with a radical azobenzene ligand, namely, [{(SiMe_2NPh)_3-tacn}U{sup IV}(η{sup 2}-N{sub 2}Ph{sub 2{sup .}})] (2), was obtained by one-electron reduction of azobenzene by the trivalent uranium compound [U{sup III}{(SiMe_2NPh)_3-tacn}] (1). Compound 2 was characterized by single-crystal X-ray diffraction and {sup 1}H NMR, IR, and UV/Vis/NIR spectroscopy. The magnetic properties of 2 and precursor 1 were studied by static magnetization and ac susceptibility measurements, which for the former revealed single-molecule magnet behaviour for the first time in a mononuclear U{sup IV} compound, whereas trivalent uranium compound 1 does not exhibit slow relaxation of the magnetization at low temperatures. A first approximation to the magnetic behaviour of these compounds was attempted by combining an effective electrostatic model with a phenomenological approach using the full single-ion Hamiltonian. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Effect of giant plasmon excitations in single and double ionization of C60 in fast heavy-ion collisions

    Science.gov (United States)

    Kadhane, Umesh; Kelkar, A.; Misra, D.; Kumar, Ajay; Tribedi, Lokesh C.

    2007-04-01

    Single and multiple ionization of C60 in collisions with highly charged fast oxygen ions have been studied using the recoil-ion time-of-flight technique. The dependence of multiple-ionization cross sections on projectile charge state (qp) was found to be drastically different from those for an atomic target, such as Ne. A model based on the giant dipole plasmon resonance explains quite well the observed qp dependence for the single- and-double-ionization cross sections. But the same model deviates for triple and quadruple ionizations.

  1. Single-Particle Time-of-Flight Mass Spectrometry Utilizing a Femtosecond Desorption and Ionization Laser.

    Science.gov (United States)

    Zawadowicz, Maria A; Abdelmonem, Ahmed; Mohr, Claudia; Saathoff, Harald; Froyd, Karl D; Murphy, Daniel M; Leisner, Thomas; Cziczo, Daniel J

    2015-12-15

    Single-particle time-of-flight mass spectrometry has now been used since the 1990s to determine particle-to-particle variability and internal mixing state. Instruments commonly use 193 nm excimer or 266 nm frequency-quadrupled Nd:YAG lasers to ablate and ionize particles in a single step. We describe the use of a femtosecond laser system (800 nm wavelength, 100 fs pulse duration) in combination with an existing single-particle time-of-flight mass spectrometer. The goal of this project was to determine the suitability of a femtosecond laser for single-particle studies via direct comparison to the excimer laser (193 nm wavelength, ∼10 ns pulse duration) usually used with the instrument. Laser power, frequency, and polarization were varied to determine the effect on mass spectra. Atmospherically relevant materials that are often used in laboratory studies, ammonium nitrate and sodium chloride, were used for the aerosol. Detection of trace amounts of a heavy metal, lead, in an ammonium nitrate matrix was also investigated. The femtosecond ionization had a large air background not present with the 193 nm excimer and produced more multiply charged ions. Overall, we find that femtosecond laser ablation and ionization of aerosol particles is not radically different than that provided by a 193 nm excimer.

  2. Coupled Cluster Studies of Ionization Potentials and Electron Affinities of Single-Walled Carbon Nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Bo; Govind, Niranjan; Apra, Edoardo; Klemm, Michael; Hammond, Jeff R.; Kowalski, Karol

    2017-02-03

    In this paper we apply equation-of-motion coupled cluster (EOMCC) methods in studies of vertical ionization potentials (IP) and electron affinities (EA) for sin- gled walled carbon nanotubes. EOMCC formulations for ionization potentials and electron affinities employing excitation manifolds spanned by single and double ex- citations (IP/EA-EOMCCSD) are used to study IPs and EAs of nanotubes as a function of nanotube length. Several armchair nanotubes corresponding to C20nH20 models with n = 2 - 6 have been used in benchmark calculations. In agreement with previous studies, we demonstrate that the electronegativity of C20nH20 systems remains, to a large extent, independent of nanotube length. We also compare IP/EA- EOMCCSD results with those obtained with the coupled cluster models with single and double excitations corrected by perturbative triples, CCSD(T), and density func- tional theory (DFT) using global and range-separated hybrid exchange-correlation functionals.

  3. Evidence for single metal two electron oxidative addition and reductive elimination at uranium.

    Science.gov (United States)

    Gardner, Benedict M; Kefalidis, Christos E; Lu, Erli; Patel, Dipti; McInnes, Eric J L; Tuna, Floriana; Wooles, Ashley J; Maron, Laurent; Liddle, Stephen T

    2017-12-01

    Reversible single-metal two-electron oxidative addition and reductive elimination are common fundamental reactions for transition metals that underpin major catalytic transformations. However, these reactions have never been observed together in the f-block because these metals exhibit irreversible one- or multi-electron oxidation or reduction reactions. Here we report that azobenzene oxidises sterically and electronically unsaturated uranium(III) complexes to afford a uranium(V)-imido complex in a reaction that satisfies all criteria of a single-metal two-electron oxidative addition. Thermolysis of this complex promotes extrusion of azobenzene, where H-/D-isotopic labelling finds no isotopomer cross-over and the non-reactivity of a nitrene-trap suggests that nitrenes are not generated and thus a reductive elimination has occurred. Though not optimally balanced in this case, this work presents evidence that classical d-block redox chemistry can be performed reversibly by f-block metals, and that uranium can thus mimic elementary transition metal reactivity, which may lead to the discovery of new f-block catalysis.

  4. Double and single ionization of helium by 58-keV X-rays

    International Nuclear Information System (INIS)

    Spielberger, L.; Buslaps, T.; Braeuning, H.; Gemmell, D.S.; Schmidt-Boecking, H.

    1996-03-01

    We have measured the ratio of cross sections for double to single ionization of helium by Compton scattering, R c =σ c ++ /σ c + at a photon energy of 58 keV using Cold Target Recoil Ion Momentum Spectroscopy. We find a value R c =(0.84 -11 +08 )% that is in agreement with the asymptotic limits predicted by Andersson and Burgdoerfer (Phys. Rev. A 50, R2810 (1994)) and Suric et al. (Phys. Rev. Lett. 73, 790 (1994)). (orig.)

  5. Use of an internal standard 233U, 236U to improve the accuracy of isotopic uranium analysis by thermal ionization mass spectrometry. Application to isotope dilution analysis

    International Nuclear Information System (INIS)

    Chevalier, C.; Hagemann, R.; Lucas, M.; Devillers, C.

    1982-01-01

    A method using a calibrated mixture of isotopes 233 U and 236 U has been developed in order to correct the isotopic fractionation which limits the accuracy of isotopic analysis by thermal ionization mass spectrometry. The 236/233 internal standard ratio is calibrated against the 235/238 ratios of uranium isotopic standards. To perform the analysis of the unknown sample, the latter is mixed with the internal standard, the differences between the true value and the observed values of the 236/233 ratio allows the determination of a correction factor, which is applied to the measured 235/238 ratio values. Since 1978, 235 U abundance measurements on series of samples have been performed, using this technique; data are obtained with an accuracy better than 0,05%. It is intended to apply this method for precise determination of 238/233 ratio in the case of uranium concentration measurements by isotope dilution [fr

  6. Innovative alpha radioactivity monitor for clearance level inspection based on ionized air transport technology (2). CFD-simulated and experimental ion transport efficiencies for uranium-attached pipes

    International Nuclear Information System (INIS)

    Hirata, Yosuke; Nakahara, Katsuhiko; Sano, Akira; Sato, Mitsuyoshi; Aoyama, Yoshio; Miyamoto, Yasuaki; Yamaguchi, Hiromi; Nanbu, Kenichi; Takahashi, Hiroyuki; Oda, Akinori

    2007-01-01

    An innovative alpha radioactivity monitor for clearance level inspection has been developed. This apparatus measures an ion current resulting from air ionization by alpha particles. Ions generated in the measurement chamber of about 1 m 3 in volume are transported by airflow to a sensor and measured. This paper presents computational estimation of ion transport efficiencies for two pipes with different lengths, the inner surfaces of which were covered with a thin layer of uranium. These ion transport efficiencies were compared with those experimentally obtained for the purpose of our model validation. Good agreement was observed between transport efficiencies from simulations and those experimentally estimated. Dependence of the transport efficiencies on the region of uranium coating was also examined, based on which anticipated errors arising from unclear positions of contamination are also discussed. (author)

  7. Bonding xenon and krypton on the surface of uranium dioxide single crystal

    Directory of Open Access Journals (Sweden)

    Dąbrowski Ludwik

    2014-08-01

    Full Text Available We present density functional theory (DFT calculation results of krypton and xenon atoms interaction on the surface of uranium dioxide single crystal. A pseudo-potential approach in the generalised gradient approximation (GGA was applied using the ABINIT program package. To compute the unit cell parameters, the 25 atom super-cell was chosen. It has been revealed that close to the surface of a potential well is formed for xenon and krypton atom due to its interaction with the atoms of oxygen and uranium. Depth and shape of the well is the subject of ab initio calculations in adiabatic approximation. The calculations were performed both for the case of oxygenic and metallic surfaces. It has been shown that the potential well for the oxygenic surface is deeper than for the metallic surface. The thermal stability of immobilising the atoms of krypton and xenon in the potential wells were evaluated. The results are shown in graphs.

  8. Ionization of elements in medium power capacitively coupled argon plasma torch with single and double ring electrodes.

    Science.gov (United States)

    Ponta, Michaela; Frentiu, Maria; Frentiu, Tiberiu

    2012-06-01

    A medium power, low Ar consumption capacitively coupled plasma torch (275 W, 0.4 L min-1) with molybdenum tubular electrode and single or two ring electrodes in non-local thermodynamic equilibrium (LTE) was characterized with respect to its ability to achieve element ionization. Ionization degrees of Ca, Mg, Mn and Cd were determined from ionic-to-atomic emission ratio and ionization equilibrium according to Saha's equation. The ionization degrees resulted from the Saha equation were higher by 9-32% than those obtained from spectral lines intensity in LTE regime and closer to reality. A linear decrease of ionization with increase of ionization energy of elements was observed. Plasma torch with two ring electrodes provided higher ionization degrees (85 ± 7% Ca, 79 ± 7% Mn, 80 ± 7% Mg and 73 ± 8% Cd) than those in single ring arrangement (70 ± 6% Ca, 57 ± 7% Mn, 57 ± 8% Mg and 42 ± 9% Cd). The Ca ionization decreased linearly by up to 79 ± 4% and 53 ± 6% in plasma with two ring electrodes and single ring respectively in the presence of up to 400 µg mL-1 Na as interferent. The studied plasma was effective in element ionization and could be a potential ion source in mass spectrometry.

  9. Fast detection of narcotics by single photon ionization mass spectrometry and laser ion mobility spectrometry

    Science.gov (United States)

    Laudien, Robert; Schultze, Rainer; Wieser, Jochen

    2010-10-01

    In this contribution two analytical devices for the fast detection of security-relevant substances like narcotics and explosives are presented. One system is based on an ion trap mass spectrometer (ITMS) with single photon ionization (SPI). This soft ionization technique, unlike electron impact ionization (EI), reduces unwanted fragment ions in the mass spectra allowing the clear determination of characteristic (usually molecular) ions. Their enrichment in the ion trap and identification by tandem MS investigations (MS/MS) enables the detection of the target substances in complex matrices at low concentrations without time-consuming sample preparation. For SPI an electron beam pumped excimer light source of own fabrication (E-Lux) is used. The SPI-ITMS system was characterized by the analytical study of different drugs like cannabis, heroin, cocaine, amphetamines, and some precursors. Additionally, it was successfully tested on-site in a closed illegal drug laboratory, where low quantities of MDMA could be directly detected in samples from floors, walls and lab equipments. The second analytical system is based on an ion mobility (IM) spectrometer with resonant multiphoton ionization (REMPI). With the frequency quadrupled Nd:YAG laser (266 nm), used for ionization, a selective and sensitive detection of aromatic compounds is possible. By application of suited aromatic dopants, in addition, also non-aromatic polar compounds are accessible by ion molecule reactions like proton transfer or complex formation. Selected drug precursors could be successfully detected with this device as well, qualifying it to a lower-priced alternative or useful supplement of the SPI-ITMS system for security analysis.

  10. Threshold behavior in single-photon double ionization of atomic oxygen

    Science.gov (United States)

    He, Z. X.; Moberg, R.; Samson, J. A. R.

    1995-12-01

    The threshold behavior of the single-photon double-ionization cross section of atomic oxygen has been studied using vacuum uv radiation from a synchrotron storage ring. The double-ionization cross section appears to follow a power law Eα (where E is the kinetic energy of the two electrons) from its threshold to about 2.0 eV above with an exponent α=1.08+/-0.03, which is consistent with Wannier's theoretical value of 1.056. The cross section also shows the influence of the doubly excited 2s2p3nln'l' (n,n'>~3) neutral states, among which the first three converge to the 2s2p3(5So)4p(6Po) ionic state of oxygen.

  11. The low-temperature specific heat of pseudo-single-crystal and polycrystalline α uranium

    International Nuclear Information System (INIS)

    Hall, R.O.A.

    1978-01-01

    Low-temperature specific-heat measurements have been made on two samples of pseudo-single-crystal α uranium. Both show the expected first-order transitions of 23 K and 37 K and the second-order transition at 40 k. One pseudo-single crystal was re-measured after heat treatment to produce a fine, randomly orientated grain structure, and gave data showing modified transitions; after more drastic heat treatment, further refining and randomizing the grain structures, it showed no sign of either of the two first-order transitions. A comparison between the specific-heat data for the pseudo-single crystal and the subsequent heat-treated sample permits a determination of the latent heat involved in the various transitions. (author)

  12. Meas.of the Ratio Between Double and Single Ionization of Helium for Antiprotons

    CERN Multimedia

    2002-01-01

    The aim of this experiment is to measure the ratio between double and single ionization of helium by antiprotons in the energy range $>$~3~MeV. Comparison with already existing proton data will yield information on the mechanisms for double ionization, which could not be extracted from previous comparisons between ratios measured for equivelocity electrons and protons. The most basic information to be obtained from an antiproton experiment will be the amount of correlation existing between the two electrons in the ground-state helium atom.\\\\ \\\\ The equipment consists of a gas cell, which employs slow-ion collection via the so-called condenser-plate method for the absolute sum of partial-ionization cross sections and determination of the relative contribution of multiple charged ions by TOF. The gas cell has movable entrance and exit slits and a grid system to account for secondary emission from the collection of slow ions. Together with a field of 800~V/cm in the collision region, the potentials of the TOF sp...

  13. Comprehensive Wavelengths, Energy Levels, and Hyperfine Structure Parameters of Singly-Ionized Iron-Group Elements

    Science.gov (United States)

    Nave, Gillian

    We propose to measure wavelengths, energy levels, and hyperfine structure parameters of Ni II, Mn II, Sc II and other singly-ionized iron-group elements, covering the wavelength range 80 nm to 5500 nm. We shall use archival data from spectrometers at NIST and Kitt Peak National Observatory for spectra above 140 nm. Additional experimental observations will be taken if needed using Fourier transform spectrometers at NIST. Spectra will be taken using our normal incidence grating spectrograph to provide better sensitivity than the FT spectra and to extend the wavelength range down to 80 nm. We aim to produce a comprehensive description of the spectra of all singly-ionized iron- group elements. The wavelength uncertainty of the strong lines will be better than 1 part in 10^7. For most singly-ionized iron-group elements available laboratory data have uncertainties an order of magnitude larger than astronomical observations over wide spectra ranges. Some of these laboratory measurements date back to the 1960's. Since then, Fourier transform spectroscopy has made significant progress in improving the accuracy and quantity of data in the UV-vis-IR region, but high quality Fourier transform spectra are still needed for Mn II, Ni II and Sc II. Fourier transform spectroscopy has low sensitivity in the VUV region and is limited to wavelengths above 140 nm. Spectra measured with high-resolution grating spectrographs are needed in this region in order to obtain laboratory data of comparable quality to the STIS and COS spectrographs on the Hubble Space Telescope. Currently, such data exist only for Fe II and Cr II. Lines of Sc II, V II, and Mn II show hyperfine structure, but hyperfine structure parameters have been measured for relatively few lines of these elements. Significant errors can occur if hyperfine structure is neglected when abundances are determined from stellar spectra. Measurements of hyperfine structure parameters will be made using Fourier transform spectroscopy

  14. Effect of multiple plasmon excitation on single, double and multiple ionizations of C60 in collisions with fast highly charged Si ions

    International Nuclear Information System (INIS)

    Kelkar, A H; Kadhane, U; Misra, D; Kumar, A; Tribedi, L C

    2007-01-01

    We have investigated the single and multiple ionizations of the C 60 molecule in collisions with fast Si q+ projectiles for various projectile charge states (q) between q = 6 and 14. The q-dependence of the ionization cross sections and their ratios is compared with the giant dipole plasmon resonance (GDPR) model. The excellent qualitative agreement with the model in case of single and double ionizations and also a reasonable agreement with the triple (and to some extent with quadruple) ionization (without evaporation) yields signify dominant contributions of the single-, double- and triple-plasmon excitations on the single- and multiple-ionization process

  15. Effect of multiple plasmon excitation on single, double and multiple ionizations of C60 in collisions with fast highly charged Si ions

    Science.gov (United States)

    Kelkar, A. H.; Kadhane, U.; Misra, D.; Kumar, A.; Tribedi, L. C.

    2007-06-01

    We have investigated the single and multiple ionizations of the C60 molecule in collisions with fast Siq+ projectiles for various projectile charge states (q) between q = 6 and 14. The q-dependence of the ionization cross sections and their ratios is compared with the giant dipole plasmon resonance (GDPR) model. The excellent qualitative agreement with the model in case of single and double ionizations and also a reasonable agreement with the triple (and to some extent with quadruple) ionization (without evaporation) yields signify dominant contributions of the single-, double- and triple-plasmon excitations on the single- and multiple-ionization process.

  16. Effect of multiple plasmon excitation on single, double and multiple ionizations of C{sub 60} in collisions with fast highly charged Si ions

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, A H; Kadhane, U; Misra, D; Kumar, A; Tribedi, L C [Tata Institute of Fundamental Research, Colaba, Mumbai -5 (India)

    2007-06-28

    We have investigated the single and multiple ionizations of the C{sub 60} molecule in collisions with fast Si{sup q+} projectiles for various projectile charge states (q) between q = 6 and 14. The q-dependence of the ionization cross sections and their ratios is compared with the giant dipole plasmon resonance (GDPR) model. The excellent qualitative agreement with the model in case of single and double ionizations and also a reasonable agreement with the triple (and to some extent with quadruple) ionization (without evaporation) yields signify dominant contributions of the single-, double- and triple-plasmon excitations on the single- and multiple-ionization process.

  17. Uranium, depleted uranium, biological effects

    International Nuclear Information System (INIS)

    2001-01-01

    Physicists, chemists and biologists at the CEA are developing scientific programs on the properties and uses of ionizing radiation. Since the CEA was created in 1945, a great deal of research has been carried out on the properties of natural, enriched and depleted uranium in cooperation with university laboratories and CNRS. There is a great deal of available data about uranium; thousands of analyses have been published in international reviews over more than 40 years. This presentation on uranium is a very brief summary of all these studies. (author)

  18. Raman spectroscopy of single human tumour cells exposed to ionizing radiation in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Q; Jirasek, A [Department of Physics and Astronomy, University of Victoria, Victoria BC V8W 3P6 (Canada); Brolo, AG [Department of Chemistry, University of Victoria, Victoria BC V8W 3V6 (Canada); Lum, J; Duan, X, E-mail: qmatthew@uvic.c, E-mail: jirasek@uvic.c [Deeley Research Centre, BC Cancer Agency-Vancouver Island Centre, Victoria BC V8R 6V5 (Canada)

    2011-01-07

    This work investigates the capability of Raman spectroscopy (RS) to study the effects of ionizing radiation on single human tumour cells. Prostate tumour cells (cell line DU145) are cultured in vitro and irradiated to doses between 15 and 50 Gy with single fractions of 6 MV photons. Single-cell Raman spectra are acquired from irradiated and unirradiated cultures up to 5 days post-irradiation. Principal component analysis is used to distinguish the uniquely radiation-induced spectral changes from inherent sources of spectral variability arising from cell cycle differences and other known factors. We observe uniquely radiation-induced spectral changes which are correlated with both the irradiated dose and the incubation time post-irradiation. The spectral changes induced by radiation arise from biochemical differences in lipids, nucleic acids, amino acids and conformational protein structures between irradiated and unirradiated cells. To our knowledge, this study is the first use of RS to observe radiation-induced biochemical differences in single cells, and is the first use of vibrational spectroscopy to observe uniquely radiation-induced biochemical differences in single cells independent of concurrent cell-cycle- or cell-death-related processes.

  19. A laser desorption-electron impact ionization ion trap mass spectrometer for real-time analysis of single atmospheric particles

    Science.gov (United States)

    Simpson, E. A.; Campuzano-Jost, P.; Hanna, S. J.; Robb, D. B.; Hepburn, J. H.; Blades, M. W.; Bertram, A. K.

    2009-04-01

    A novel aerosol ion trap mass spectrometer combining pulsed IR laser desorption with electron impact (EI) ionization for single particle studies is described. The strengths of this instrument include a two-step desorption and ionization process to minimize matrix effects; electron impact ionization, a universal and well-characterized ionization technique; vaporization and ionization inside the ion trap to improve sensitivity; and an ion trap mass spectrometer for MSn experiments. The instrument has been used for mass spectral identification of laboratory generated pure aerosols in the 600 nm-1.1 [mu]m geometric diameter range of a variety of aromatic and aliphatic compounds, as well as for tandem mass spectrometry studies (up to MS3) of single caffeine particles. We investigate the effect of various operational parameters on the mass spectrum and fragmentation patterns. The single particle detection limit of the instrument was found to be a 325 nm geometric diameter particle (8.7 × 107 molecules or 22 fg) for 2,4-dihydroxybenzoic acid. Lower single particle detection limits are predicted to be attainable by modifying the EI pulse. The use of laser desorption-electron impact (LD-EI) in an ion trap is a promising technique for determining the size and chemical composition of single aerosol particles in real time.

  20. Standard test method for determination of uranium or plutonium isotopic composition or concentration by the total evaporation method using a thermal ionization mass spectrometer

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This method describes the determination of the isotopic composition and/or the concentration of uranium and plutonium as nitrate solutions by the thermal ionization mass spectrometric (TIMS) total evaporation method. Purified uranium or plutonium nitrate solutions are loaded onto a degassed metal filament and placed in the mass spectrometer. Under computer control, ion currents are generated by heating of the filament(s). The ion beams are continually measured until the sample is exhausted. The measured ion currents are integrated over the course of the run, and normalized to a reference isotope ion current to yield isotopic ratios. 1.2 In principle, the total evaporation method should yield isotopic ratios that do not require mass bias correction. In practice, some samples may require this bias correction. When compared to the conventional TIMS method, the total evaporation method is approximately two times faster, improves precision from two to four fold, and utilizes smaller sample sizes. 1.3 The tot...

  1. Giant plasmon excitation in single and double ionization of C60 by fast highly charged Si and O ions

    Science.gov (United States)

    Kelkar, A. H.; Kadhane, U.; Misra, D.; Tribedi, L. C.

    2007-09-01

    Se have investigated single and double ionization of C60 molecule in collisions with 2.33 MeV/u Siq+ (q=6-14) and 3.125 MeV/u Oq+ (q=5-8) projectiles. The projectile charge state dependence of the single and double ionization yields of C60 are then compared to those for an ion-atom collision system using Ne gas as a target. A large difference between the gas and the cluster target behaviour was partially explained in terms of a model based on collective excitation namely the giant dipole plasmon resonance (GDPR). The qualitative agreement between the data and GDPR model prediction for single and double ionization signifies the importance of single and double plasmon excitations in the ionization process. A large deviation of the GDPR model for triple and quadruple ionization from the experimental data imply the importance of the other low impact parameter processes such as evaporation, fragmentation and a possible solid-like dynamical screening.

  2. Giant plasmon excitation in single and double ionization of C60 by fast highly charged Si and O ions

    International Nuclear Information System (INIS)

    Kelkar, A H; Kadhane, U; Misra, D; Tribedi, L C

    2007-01-01

    Se have investigated single and double ionization of C 60 molecule in collisions with 2.33 MeV/u Si q+ (q=6-14) and 3.125 MeV/u O q+ (q=5-8) projectiles. The projectile charge state dependence of the single and double ionization yields of C 60 are then compared to those for an ion-atom collision system using Ne gas as a target. A large difference between the gas and the cluster target behaviour was partially explained in terms of a model based on collective excitation namely the giant dipole plasmon resonance (GDPR). The qualitative agreement between the data and GDPR model prediction for single and double ionization signifies the importance of single and double plasmon excitations in the ionization process. A large deviation of the GDPR model for triple and quadruple ionization from the experimental data imply the importance of the other low impact parameter processes such as evaporation, fragmentation and a possible solid-like dynamical screening

  3. Kinematically complete investigation of momentum transfer for single ionization in fast proton-helium collisions

    Energy Technology Data Exchange (ETDEWEB)

    Weber, T.; Mergel, V.; Jagutzki, O.; Schmidt, L.; Afaneh, F.; Schmidt-Boecking, H. [Institut fuer Kernphysik, August-Euler-Strasse 6, 60486 Frankfurt am Main (Germany); Khayyat, K. [Department of Physics, University of Missouri, Rolla, MO (United States); Doerner, R. [Fakultaet fuer Physik, Universitaet Freiburg (Germany); Gonzalez, A. [Centro Atomico Bariloche, 8400 S C de Bariloche (Argentina); Cocke, C.L. [Department of Physics, Kansas State University, Manhatten, KS (United States); Landers, A.L. [Department of Physics, Western Michigan University, Kalamazoo, MI (United States)

    2000-09-14

    The dynamics of singly ionizing proton-helium collisions have been studied experimentally for several energies of the projectile (0.2, 0.5, 1.0 and 1.3 MeV) with the technique of cold target recoil-ion momentum spectroscopy (COLTRIMS). The complete final-state distribution in momentum space of all three particles was determined by measuring the three momentum components of the emitted electron and the coincident recoiling target ion. The momentum transfer and energy loss of the outgoing projectile was determined by momentum and energy conservation laws. Doubly differential cross sections of the kinematically complete experimental investigation are presented. The present data are compared with results from fast highly charged heavy-ion impact experiments. (author)

  4. Analysis of laser-generated plasma ionizing radiation by synthetic single crystal diamond detectors

    Czech Academy of Sciences Publication Activity Database

    Marinelli, M.; Milani, E.; Prestopino, G.; Verona, C.; Verona-Rinati, G.; Cutroneo, M.; Torrisi, L.; Margarone, Daniele; Velyhan, Andriy; Krása, Josef; Krouský, Eduard

    2013-01-01

    Roč. 272, May (2013), s. 104-108 ISSN 0169-4332 R&D Projects: GA MŠk ED1.1.00/02.0061; GA MŠk EE2.3.20.0279; GA MŠk EE.2.3.20.0087; GA MŠk(CZ) 7E09092; GA MŠk(CZ) LC528 Grant - others:ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; OPVK 3 Laser Zdroj(XE) CZ.1.07/2.3.00/20.0279; OP VK 2 LaserGen(XE) CZ.1.07/2.3.00/20.0087; 7FP LASERLAB-EUROPE(XE) 228334 Program:EE; FP7 Institutional support: RVO:68378271 Keywords : single crystal diamond * diamond detector * laser-generated plasma * ionizing radiation * time-of-fight spectrometer Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.538, year: 2013

  5. The spectroscopy of the neutral and singly ionized transuranium elements, Np to Es

    International Nuclear Information System (INIS)

    Worden, E.F.

    1990-01-01

    This presentation will be a review of the optical spectroscopy of the neutral and singly ionized species of the elements Np through Es, the I and II spectra. Observation and energy level analyses of these spectra have been in progress for each element as soon as sufficient quantities were produced. A list of the researchers would exceed the allowed abstract length. Procedures for obtaining spectra of these highly radioactive elements and for energy level analysis will be described. The chemistry of these elements is usually well established before there is a substantial knowledge of the electronic structure. The regularities found in the electronic structure of the 5f actinide series will be shown and compared with that of the 4f lanthanide series. Some discussion of the structure as it relates to the chemistry of the transuranic elements will be given

  6. Electron paramagnetic resonance and optical absorption of uranium ions diluted in CdF2 single crystals

    International Nuclear Information System (INIS)

    Pereira, J.J.C.R.

    1976-08-01

    The electron paramagnetic resonance (EPR) has been studied in conection with the optical absortion spectra of Uranium ions diluted in CdF 2 single crystals. Analyses of the EPR and optical absorption spectra obtained experimentally, and a comparison with known results in the isomorfic CaF 2 , SrF 2 and BaF 2 , allowed the identification of two paramagnetic centers associated with Uranium ions. These are the U(2+) ion in cubic symmetry having the triplet γ 5 as ground state, and the U(3+) ion in cubic symmetry having the dublet γ 6 as ground state. (Author) [pt

  7. Investigation of the structure change of atomic shells due to uranium ionization by the Dirac-Fock-Slater method

    International Nuclear Information System (INIS)

    Shchornak, G.

    1979-01-01

    The influence of outer vacancies in the atomic shells of uranium on the atomic shell structure is claculated by the Dirac-Fock-Slater method. It is found out that the energy of the X-ray transitions increases due to the detachment of the electrons with the lowest binding energies. The electron detachment from the subshells of the 4f level gives rise to negative energy shifts of the X-ray transitions.(author)

  8. A practical theoretical formalism for atomic multielectron processes: direct multiple ionization by a single auger decay or by impact of a single electron or photon

    Science.gov (United States)

    Liu, Pengfei; Zeng, Jiaolong; Yuan, Jianmin

    2018-04-01

    Multiple electron processes occur widely in atoms, molecules, clusters, and condensed matters when they are interacting with energetic particles or intense laser fields. Direct multielectron processes (DMEP) are the most complicated among the general multiple electron processes and are the most difficult to describe theoretically. In this work, a unified and accurate theoretical formalism is proposed on the DMEP of atoms including the multiple auger decay and multiple ionization by an impact of a single electron or a single photon based on the atomic collision theory described by a correlated many-body Green's function. Such a practical treatment is made possible by taking consideration of the different coherence features of the atoms (matter waves) in the initial and final states. We first explain how the coherence characteristics of the ejected continuum electrons is largely destructed, by taking the electron impact direct double ionization process as an example. The direct double ionization process is completely different from the single ionization where the complete interference can be maintained. The detailed expressions are obtained for the energy correlations among the continuum electrons and energy resolved differential and integral cross sections according to the separation of knock-out (KO) and shake-off (SO) mechanisms for the electron impact direct double ionization, direct double and triple auger decay, and double and triple photoionization (TPI) processes. Extension to higher order DMEP than triple ionization is straight forward by adding contributions of the following KO and SO processes. The approach is applied to investigate the electron impact double ionization processes of C+, N+, and O+, the direct double and triple auger decay of the K-shell excited states of C+ 1s2{s}22{p}2{}2D and {}2P, and the double and TPI of lithium. Comparisons with the experimental and other theoretical investigations wherever available in the literature show that our

  9. Standard test method for isotopic analysis of hydrolyzed uranium hexafluoride and uranyl nitrate solutions by thermal ionization mass spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This method applies to the determination of isotopic composition in hydrolyzed nuclear grade uranium hexafluoride. It covers isotopic abundance of 235U between 0.1 and 5.0 % mass fraction, abundance of 234U between 0.0055 and 0.05 % mass fraction, and abundance of 236U between 0.0003 and 0.5 % mass fraction. This test method may be applicable to other isotopic abundance providing that corresponding standards are available. 1.2 This test method can apply to uranyl nitrate solutions. This can be achieved either by transforming the uranyl nitrate solution to a uranyl fluoride solution prior to the deposition on the filaments or directly by depositing the uranyl nitrate solution on the filaments. In the latter case, a calibration with uranyl nitrate standards must be performed. 1.3 This test method can also apply to other nuclear grade matrices (for example, uranium oxides) by providing a chemical transformation to uranyl fluoride or uranyl nitrate solution. 1.4 This standard does not purport to address al...

  10. Total and single differential cross sections for the electron impact ionization of the ground state of helium

    International Nuclear Information System (INIS)

    Singh, T.S.C.; Choudhury, K.B.; Singh, M.B.; Deb, N.C.; Mukherjee, S.C.; Mazumdar, P.S.

    1997-01-01

    Total cross sections (TCS) and single differential cross sections (SDCS) have been computed for the single ionization of the ground state of helium by electron impact in a distorted wave formalism which takes into account the effects of the initial and final channel distortions. The present TCS and SDCS results are in fair agreement with the measured values and other theoretical predictions for the incident electron energy E i > 150 eV. (orig.)

  11. An investigation into heterogeneity in a single vein-type uranium ore deposit: Implications for nuclear forensics

    International Nuclear Information System (INIS)

    Keatley, A.C.; Scott, T.B.; Davis, S.; Jones, C.P.; Turner, P.

    2015-01-01

    Minor element composition and rare earth element (REE) concentrations in nuclear materials are important as they are used within the field of nuclear forensics as an indicator of sample origin. However recent studies into uranium ores and uranium ore concentrates (UOCs) have shown significant elemental and isotopic heterogeneity from a single mine site such that some sites have shown higher variation within the mine site than that seen between multiple sites. The elemental composition of both uranium and gangue minerals within ore samples taken along a single mineral vein in South West England have been measured and reported here. The analysis of the samples was undertaken to determine the extent of the localised variation in key elements. Energy Dispersive X-ray spectroscopy (EDS) was used to analyse the gangue mineralogy and measure major element composition. Minor element composition and rare earth element (REE) concentrations were measured by Electron Probe Microanalysis (EPMA). The results confirm that a number of key elements, REE concentrations and patterns used for origin location do show significant variation within mine. Furthermore significant variation is also visible on a meter scale. In addition three separate uranium phases were identified within the vein which indicates multiple uranium mineralisation events. In light of these localised elemental variations it is recommended that representative sampling for an area is undertaken prior to establishing the REE pattern that may be used to identify the originating mine for an unknown ore sample and prior to investigating impact of ore processing on any arising REE patterns. - Highlights: • Demonstrating significant variation at meter scale distances. • Importance of understanding heterogeneity in aid of nuclear forensics interpretation. • Understanding local features prior to determining feed through of elements to UOCs. • Key elements, REE concentrations and patterns show significant variation

  12. Fully differential single-photon double ionization of neon and argon

    Science.gov (United States)

    Yip, Frank; Martin, Fernando; Rescigno, Thomas; McCurdy, C.

    2013-05-01

    Double photoionization of neon and argon differ significantly from helium in that three different final state couplings of the residual double ion (1 S , 1 D , and 3 P) are possible and greatly impact the observed angular distributions, but the multi-electron nature of such targets makes ab initio theoretical treatments of this correlated process a challenge. Triply differential cross sections (TDCS) have been calculated for single photon double ionization of these heavier rare gases at various photon energies by utilizing an expanded frozen-core treatment to represent the remaining N - 2 target electrons of the residual ion. The resulting angular distributions are compared with and show significant agreement with existing experimental data. Work supported by U. S. Dept. of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences Contract DE-AC02-05CH11231, by the MICINN Projects No. FIS2010-15127, No. ACI2008-0777,No. CSD 2007-00010, and ERC Advanced Grant 290853.

  13. Lifetimes of metastable levels of singly ionized titanium: theory and experiment

    International Nuclear Information System (INIS)

    Palmeri, P; Quinet, P; Biemont, E; Gurell, J; Lundin, P; Royen, P; Mannervik, S; Norlin, L-O; Blagoev, K

    2008-01-01

    This paper presents new theoretical lifetimes of metastable levels in singly ionized titanium, Ti II. Along with the lifetimes, transition probabilities for several decay channels from these metastable levels are presented. The calculations are supported by experimental lifetime determinations of the 3d 3 b 2 D 5/2 and 3d 2 ( 3 P)4s b 2 P 3/2 levels along with revised values of the previously published lifetimes of the 3d 2 ( 3 P)4s b 4 P 5/2 and 3d 2 ( 3 P)4s b 2 P 1/2 levels originating partly from a reanalysis utilizing a recently developed method applied on the previously recorded data and partly from new measurements. The presented theoretical investigation of lifetimes of metastable levels in Ti II shows that the HFR calculations are in general compatible with measurements performed using the ion storage ring CRYRING of Stockholm University. The transition probabilities of forbidden lines derived from the new lifetime values will be useful for the diagnostics of low density laboratory or astrophysical plasmas, particularly those encountered in the strontium filament found in the ejecta of η Carinae

  14. Exploring Redox Properties of Aromatic Amino Acids in Water: Contrasting Single Photon vs Resonant Multiphoton Ionization in Aqueous Solutions.

    Science.gov (United States)

    Roy, Anirban; Seidel, Robert; Kumar, Gaurav; Bradforth, Stephen E

    2018-04-12

    Direct measurements of the valence ionization energies and the reorganization energies of the three aromatic amino acids, l-tyrosine, l-tryptophan, and l-phenylalanine, in aqueous solution using the liquid microjet technique and two different photoemission methods-X-ray photoelectron spectroscopy (XPS) at 175 eV photon energy and resonant two-photon ionization (R2PI) using 2 × 267 nm (2 × 4.64 eV) UV laser light-are reported. l-Tryptophan has the lowest vertical ionization energy, 7.3 eV, followed by tyrosine (7.8 eV) and phenylalanine (∼8.7 eV). Essentially, no variation in recovered orbital energies is observed comparing near threshold ionization to X-ray ionization. Superior sensitivity of the (background-free) R2PI scheme for solutions with very low solute concentration (<2 mM) is demonstrated in contrast to the single-photon XPS measurements, which often requires solute concentrations of 0.1-1 molar. This higher sensitivity along with chemical selectivity of the R2PI technique can be exploited for both spectroscopic assignment and as an analytical tool. The nature of the adiabatic ionization energy for the three aromatic amino acids has been explored by the R2PI approach and by empirically formulating the correlation between the estimated ionization onset with electronic and nuclear relaxation on the excited state surface. Our results have implications for understanding one-electron transfer within enzymes and in redox situations where (ir)reversible deprotonation occurs such as those manifest in the biochemistry of oxidation damage.

  15. Effects of ionizing radiation on cell-matrix interactions at the single molecule level

    Energy Technology Data Exchange (ETDEWEB)

    Lauer, Florian

    2015-04-20

    Single molecule microscopy is a technology that allows for accurate assessment of the location and motion of single fluorescent molecules, even in the context of observations on living biological samples. In the present thesis, a flexible analysis tool for single molecule data as obtained in biological experiments was established. The development of a tool to faithfully detect and localize diffraction-limited images of individual fluorescent probes was necessary since data acquired under cell cultivation conditions that account for a three-dimensional microenvironment as experienced physiologically by cells in native tissue poses a challenge not faced ordinarily. After design, implementation, quantitative tests using simulations for comparisons and verification, and evaluation of the different steps of the analysis procedure including local background estimation, local noise estimation, de-noising approaches, detection, localization, and post-processing, analysis capabilities were utilized to evaluate the impact of x-ray irradiation on the plasma membrane architecture of U2OS human osteosarcoma cells as assessed by tracking individual fluorescent lipid-mimetic dye molecules diffusing in the outer membrane leaflet. It was shown that lateral diffusion in the plasma membrane is well described as two-phase anomalous subdiffusion and presence of 3D extracellular matrix leads to lower anomalous exponents of the fast fraction in comparison to monolayer cell culture. Interestingly, even high single-dose (25 Gy) treatments known to induce membrane-mediated apoptosis in tumor microvessel endothelium via membrane viscosity enhancing ceramide generation were not observed to alter membrane architecture in U2OS cells which can be related to amplifying, feedback-driven redox-signaling in the endothelium absent in U2OS. In summary, the sensitive and accurate framework developed in this thesis to assess minute changes of plasma membrane located dynamic processes did not uncover a

  16. Depleted uranium. Protecting against all possible sources of ionizing radiation through the development and application of state-of-the-art safety standards

    International Nuclear Information System (INIS)

    2001-01-01

    Under its Statute the IAEA has the specific mandate to establish, in consultation and collaboration with other United Nations and specialized agencies concerned, standards for the protection against ionizing radiation and for the safety of radiation sources and to provide for the application of these standards. With respect to potential radiation hazards, the Agency has jointly developed the International Basic Safety Standards with the World Health Organization, and the Food and Agriculture Organization. These standards, known as the BSS, cover a wide range of situations that give rise or could give rise to exposure to radiation, such as the radiation hazard posed by depleted uranium (DU). Based on the information currently available, DU ammunitions do not appear to present a significant risk to health from a radiological point of view. Since only limited studies have been undertaken in post-conflict areas where DU ammunitions were used, further assessment and studies of DU in such areas would increase the confidence in this observation. In addition to radiological assessment, the IAEA is also developing a training course to assist Member States in analytical methods and techniques that could be used to detect and measure DU in post-conflict areas

  17. Lifetime measurements and oscillator strengths in singly ionized scandium and the solar abundance of scandium

    Science.gov (United States)

    Pehlivan Rhodin, A.; Belmonte, M. T.; Engström, L.; Lundberg, H.; Nilsson, H.; Hartman, H.; Pickering, J. C.; Clear, C.; Quinet, P.; Fivet, V.; Palmeri, P.

    2017-12-01

    The lifetimes of 17 even-parity levels (3d5s, 3d4d, 3d6s and 4p2) in the region 57 743-77 837 cm-1 of singly ionized scandium (Sc II) were measured by two-step time-resolved laser induced fluorescence spectroscopy. Oscillator strengths of 57 lines from these highly excited upper levels were derived using a hollow cathode discharge lamp and a Fourier transform spectrometer. In addition, Hartree-Fock calculations where both the main relativistic and core-polarization effects were taken into account were carried out for both low- and high-excitation levels. There is a good agreement for most of the lines between our calculated branching fractions and the measurements of Lawler & Dakin in the region 9000-45 000 cm-1 for low excitation levels and with our measurements for high excitation levels in the region 23 500-63 100 cm-1. This, in turn, allowed us to combine the calculated branching fractions with the available experimental lifetimes to determine semi-empirical oscillator strengths for a set of 380 E1 transitions in Sc II. These oscillator strengths include the weak lines that were used previously to derive the solar abundance of scandium. The solar abundance of scandium is now estimated to logε⊙ = 3.04 ± 0.13 using these semi-empirical oscillator strengths to shift the values determined by Scott et al. The new estimated abundance value is in agreement with the meteoritic value (logεmet = 3.05 ± 0.02) of Lodders, Palme & Gail.

  18. Low-mobility-pass filter between atmospheric pressure chemical ionization and electrospray ionization sources and a single quadrupole mass spectrometer: computational models and measurements.

    Science.gov (United States)

    Menlyadiev, Marlen R; Tadjimukhamedov, Fatkhulla Kh; Tarassov, Alexander; Wollnik, Hermann; Eiceman, Gary A

    2014-01-15

    Mixtures of ions produced in sources at atmospheric pressure, including chemical ionization (APCI) and electrospray ionization (ESI) can be simplified at or near ambient pressure using ion mobility based filters. A low-mobility-pass filter (LMPF) based on a simple mechanical design and simple electronic control was designed, modeled and tested with vapors of 2-hexadecanone in an APCI source and with spray of peptide solutions in an ESI source. The LMPF geometry was planar and small (4 mm wide × 13 mm long) and electric control was through a symmetric waveform in low kHz with amplitude between 0 and 10 V. Computational models established idealized performance for transmission efficiency of ions of several reduced mobility coefficients over the range of amplitudes and were matched by computed values from ion abundances in mass spectra. The filter exhibited a broad response function, equivalent to a Bode Plot in electronic filters, suggesting that ion filtering could be done in blocks ~50 m/z units wide. The benefit of this concept is that discrimination against ions of high mobility is controlled by only a single parameter: waveform amplitude at fixed frequency. The effective removal of high mobility ions, those of low mass-to-charge, can be beneficial for applications with ion-trap-based mass spectrometers to remove excessive levels of solvent or matrix ions. Copyright © 2013 John Wiley & Sons, Ltd.

  19. Surface characterization of uranium metal and uranium dioxide using X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Allen, G.C.; Trickle, I.R.; Tucker, P.M.

    1981-01-01

    X-ray photoelectron spectra of pure uranium metal and stoichiometric uranium dioxide have been obtained using an AEI ES300 spectrometer. Binding energy values for core and valence electrons have been determined using an internally calibrated energy scale and monochromatic Al Kα radiation. Satellite peaks observed accompanying certain principal core ionizations are discussed in relation to the mechanisms by which they arise. Confirmation is obtained that for stoichiometric UOsub(2.00) a single shake-up satellite is observed accompanying the U 4fsub(7/2,5/2) principal core lines, separated by 6.8 eV to higher binding energy. (author)

  20. Numerical simulations of single and double ionization of H2 in short intense laser pulses

    International Nuclear Information System (INIS)

    Baier, Silvio

    2008-01-01

    Rescattering is the dominant process leading to double ionization in atoms and molecules interacting with linearly polarized laser pulses with wavelengths around 800 nm and in an intensity regime of 10 14 to 10 15 W/cm 2 . Using numerical integrations of the two-electron Schroedinger equation of the Hydrogen molecule in appropriate reduced dimensions two mechanisms, namely correlated emission of the electrons and excitation followed by field ionization after rescattering, could be identified and characterized. With the help of a planar model in reduced dimensions these mechanisms were quantitatively compared by their dependence on the molecular alignment with respect to the polarization axis. Two additional mechanisms, which are also related to rescattering, could be identified as well. (orig.)

  1. Observation of terahertz-radiation-induced ionization in a single nano island.

    Science.gov (United States)

    Seo, Minah; Kang, Ji-Hun; Kim, Hyo-Suk; Hyong Cho, Joon; Choi, Jaebin; Min Jhon, Young; Lee, Seok; Hun Kim, Jae; Lee, Taikjin; Park, Q-Han; Kim, Chulki

    2015-05-22

    Terahertz (THz) electromagnetic wave has been widely used as a spectroscopic probe to detect the collective vibrational mode in vast molecular systems and investigate dielectric properties of various materials. Recent technological advances in generating intense THz radiation and the emergence of THz plasmonics operating with nanoscale structures have opened up new pathways toward THz applications. Here, we present a new opportunity in engineering the state of matter at the atomic scale using THz wave and a metallic nanostructure. We show that a medium strength THz radiation of 22 kV/cm can induce ionization of ambient carbon atoms through interaction with a metallic nanostructure. The prepared structure, made of a nano slot antenna and a nano island located at the center, acts as a nanogap capacitor and enhances the local electric field by two orders of magnitudes thereby causing the ionization of ambient carbon atoms. Ionization and accumulation of carbon atoms are also observed through the change of the resonant condition of the nano slot antenna and the shift of the characteristic mode in the spectrum of the transmitted THz waves.

  2. Detection and mapping of Cannabinoids in single hair samples through rapid derivatization- Matrix-Assisted Laser Desorption Ionization Mass Spectrometry

    OpenAIRE

    Beasley, Emma; Francese, Simona; Bassindale, Thomas

    2016-01-01

    The sample preparation method reported in this work has permitted for the first time the application of Matrix Assisted Laser Desorption Ionization Mass Spectrometry Profiling and Imaging (MALDI-MSP and MALDI-MSI) for the detection and mapping of cannabinoids in a single hair sample. MALDI-MSI analysis of hair samples has recently been suggested as an alternative technique to traditional methods of GC-MS and LC-MS due to simpler sample preparation, the ability to detect a narrower time frame ...

  3. First observation of two-electron one-photon transitions in single-photon K-shell double ionization.

    Science.gov (United States)

    Hoszowska, J; Dousse, J-Cl; Szlachetko, J; Kayser, Y; Cao, W; Jagodziński, P; Kavčič, M; Nowak, S H

    2011-07-29

    Experimental evidence for the correlated two-electron one-photon transitions (1s(-2)→2s(-1)2p(-1)) following single-photon K-shell double ionization is reported. The double K-shell vacancy states in solid Mg, Al, and Si were produced by means of monochromatized synchrotron radiation, and the two-electron one-photon radiative transitions were observed by using a wavelength dispersive spectrometer. The two-electron one-photon transition energies and the branching ratios of the radiative one-electron to two-electron transitions were determined and compared to available perturbation theory predictions and configuration interaction calculations.

  4. Synergistic effects of total ionizing dose on single event upset sensitivity in static random access memory under proton irradiation

    International Nuclear Information System (INIS)

    Xiao Yao; Guo Hong-Xia; Zhang Feng-Qi; Zhao Wen; Wang Yan-Ping; Zhang Ke-Ying; Ding Li-Li; Luo Yin-Hong; Wang Yuan-Ming; Fan Xue

    2014-01-01

    Synergistic effects of the total ionizing dose (TID) on the single event upset (SEU) sensitivity in static random access memories (SRAMs) were studied by using protons. The total dose was cumulated with high flux protons during the TID exposure, and the SEU cross section was tested with low flux protons at several cumulated dose steps. Because of the radiation-induced off-state leakage current increase of the CMOS transistors, the noise margin became asymmetric and the memory imprint effect was observed. (interdisciplinary physics and related areas of science and technology)

  5. Reduction of uranium hexafluoride to uranium tetrafluoride

    International Nuclear Information System (INIS)

    Chang, I.S.; Do, J.B.; Choi, Y.D.; Park, M.H.; Yun, H.H.; Kim, E.H.; Kim, Y.W.

    1982-01-01

    The single step continuous reduction of uranium hexafluoride (UF 6 ) to uranium tetrafluoride (UF 4 ) has been investigated. Heat required to initiate and maintain the reaction in the reactor is supplied by the highly exothermic reaction of hydrogen with a small amount of elemental fluorine which is added to the uranium hexafluoride stream. When gases uranium hexafluoride and hydrogen react in a vertical monel pipe reactor, the green product, UF 4 has 2.5g/cc in bulk density and is partly contaminated by incomplete reduction products (UF 5 ,U 2 F 9 ) and the corrosion product, presumably, of monel pipe of the reactor itself, but its assay (93% of UF 4 ) is acceptable for the preparation of uranium metal with magnesium metal. Remaining problems are the handling of uranium hexafluoride, which is easily clogging the flowmeter and gas feeding lines because of extreme sensitivity toward moisture, and a development of gas nozzel for free flow of uranium hexafluoride gas. (Author)

  6. Standard test method for isotopic analysis of uranium hexafluoride by double standard single-collector gas mass spectrometer method

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This is a quantitative test method applicable to determining the mass percent of uranium isotopes in uranium hexafluoride (UF6) samples with 235U concentrations between 0.1 and 5.0 mass %. 1.2 This test method may be applicable for the entire range of 235U concentrations for which adequate standards are available. 1.3 This test method is for analysis by a gas magnetic sector mass spectrometer with a single collector using interpolation to determine the isotopic concentration of an unknown sample between two characterized UF6 standards. 1.4 This test method is to replace the existing test method currently published in Test Methods C761 and is used in the nuclear fuel cycle for UF6 isotopic analyses. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro...

  7. The electron-impact ionization of Ar and Kr revisited: A critical analysis of double-to-single ionization cross section ratio measurements using the fast-atom-beam technique

    International Nuclear Information System (INIS)

    Tarnovsky, V.; Becker, K.

    1992-01-01

    We report new measurements of the absolute electron-impact double ionization cross sections for Ar and Kr and of the ratios of double-to-single ionization for impact energies from threshold to 200 eV using the crossed electron-beam - fast-atom-beam technique. The work was motivated by the recently highlighted spread of about 30% in the Ar 2+ /Ar + ionization cross section ratios obtained by several groups using different experimental techniques. Such a spread is inconsistent with statistical uncertainties of typically 3% or less that were quoted for the various reported ratios. A similar situation exists for Kr where the spread among the recently published Kr 2+ /Kr + ionization cross section ratios is about 15%. We made an attempt to identify all potential systematic errors inherent to the fast-beam technique that could affect the measurement of cross section ratios with special emphasis on those systematic errors that could influence the detection of singly and doubly charged product ions differently. We found Ar 2+ /Ar + and Kr 2+ /Kr + cross section ratios of, respectively 0.066±0.007 and 0.087±0.008 at 100 eV which confirm earlier measurements using the same experimental technique. The error limits on cross sections ratios of multiple-to-single ionization for the same target atom and at least ±10% for ratios of single ionization cross sections for different target species. Our error limits are dominated by systematic uncertainties of the apparatus which do not cancel when cross section ratios are measured, since the ratios are obtained under similar, but not identical experimental conditions. (orig.)

  8. Single-carrier impact ionization favored by a limited band dispersion

    OpenAIRE

    Darbandi, A.; Rubel, O.

    2012-01-01

    A critical requirement for high gain and low noise avalanche photodiodes is the single-carrier avalanche multiplication. We propose that the single-carrier avalanche multiplication can be achieved in materials with a limited width of the conduction or valence band resulting in a restriction of kinetic energy for one of the charge carriers. This feature is not common to the majority of technologically relevant semiconductors, but it is observed in chalcogenides, such as Selenium and compound I...

  9. Calibration of uranium 232 solution

    International Nuclear Information System (INIS)

    Galan, M.P.; Acena, M.L.

    1988-01-01

    A method for acertainning the activity by alpha spectroscopy with semiconductor detectors, of a solution of Uranium-232 is presented. It consists of the comparison with a Uranium-233 solution activity previously measured in a gridded ionization chamber of 2 π geometry. The total measurement uncertainty is about +- 0,02. (Author)

  10. Giant plasmon excitation in single and double ionization of C{sub 60} by fast highly charged Si and O ions

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, A H; Kadhane, U; Misra, D; Tribedi, L C [Tata Institute of Fundamental Research, Colaba, Mumbai-5 (India)

    2007-09-15

    Se have investigated single and double ionization of C{sub 60} molecule in collisions with 2.33 MeV/u Si{sup q+} (q=6-14) and 3.125 MeV/u O{sup q+} (q=5-8) projectiles. The projectile charge state dependence of the single and double ionization yields of C{sub 60} are then compared to those for an ion-atom collision system using Ne gas as a target. A large difference between the gas and the cluster target behaviour was partially explained in terms of a model based on collective excitation namely the giant dipole plasmon resonance (GDPR). The qualitative agreement between the data and GDPR model prediction for single and double ionization signifies the importance of single and double plasmon excitations in the ionization process. A large deviation of the GDPR model for triple and quadruple ionization from the experimental data imply the importance of the other low impact parameter processes such as evaporation, fragmentation and a possible solid-like dynamical screening.

  11. Microarray analysis of the transcriptional response to single or multiple doses of ionizing radiation in human subcutaneous fibroblasts

    DEFF Research Database (Denmark)

    Rødningen, Olaug Kristin; Overgaard, Jens; Alsner, Jan

    2005-01-01

    cell lines after various ionizing radiation (IR) schemes in order to provide information on potential targets for prevention and to suggest candidate genes for SNP association studies aimed at predicting individual risk of radiation-induced morbidity. PATIENTS AND METHODS: Thirty different human......BACKGROUND AND PURPOSE: Transcriptional profiling of fibroblasts derived from breast cancer patients might improve our understanding of subcutaneous radiation-induced fibrosis. The aim of this study was to get a comprehensive overview of the changes in gene expression in subcutaneous fibroblast...... fibroblast cell lines were included in the study, and two different radiation schemes; single dose experiments with 3.5 Gy or fractionated with 3 x 3.5 Gy. Expression analyses were performed on unexposed and exposed cells after different time points. The IR response was analyzed using the statistical method...

  12. Response of microchannel plates in ionization mode to single particles and electromagnetic showers

    Science.gov (United States)

    Barnyakov, A. Yu.; Barnyakov, M. Yu.; Brianza, L.; Cavallari, F.; Cipriani, M.; Ciriolo, V.; del Re, D.; Gelli, S.; Ghezzi, A.; Gotti, C.; Govoni, P.; Katcin, A. A.; Malberti, M.; Martelli, A.; Marzocchi, B.; Meridiani, P.; Organtini, G.; Paramatti, R.; Pigazzini, S.; Preiato, F.; Prisekin, V. G.; Rahatlou, S.; Rovelli, C.; Santanastasio, F.; Tabarelli de Fatis, T.

    2018-01-01

    Hundreds of concurrent collisions per bunch crossing are expected at future hadron colliders. Precision timing calorimetry has been advocated as a way to mitigate the pileup effects and, thanks to their excellent time resolution, microchannel plates (MCPs) are good candidate detectors for this goal. We report on the response of MCPs, used as secondary emission detectors, to single relativistic particles and to electromagnetic showers. Several prototypes, with different geometries and characteristics, were exposed to particle beams at the INFN-LNF Beam Test Facility and at CERN. Their time resolution and efficiency are measured for single particles and as a function of the multiplicity of particles. Efficiencies between 50% and 90% to single relativistic particles are reached, and up to 100% in presence of a large number of particles. Time resolutions between 20 ps and 30 ps are obtained.

  13. Distribution of uranium, thorium, and isotopic composition of uranium in soil samples of south Serbia: Evidence of depleted uranium

    OpenAIRE

    Sahoo Sarata Kumar; Fujimoto Kenzo; Čeliković Igor; Ujić Predrag; Žunić Zora S.

    2004-01-01

    Inductively coupled plasma mass spectrometry and thermal ionization mass spectrom - etry were used to measure concentration of uranium and thorium as well as isotopic composition of uranium respectively in soil samples collected around south Serbia. An analytical method was established for a routine sample preparation procedure for uranium and thorium. Uranium was chemically separated and purified from soil samples by anion exchange resin and UTEVA extraction chromatography and its isotopic c...

  14. Hadron cascades in iron and uranium

    CERN Document Server

    Fabjan, Christian Wolfgang; Lankford, A J; Rehak, P; Struczinski, W; Willis, W J

    1975-01-01

    Cascade developments of hadrons and electrons are studied in iron and uranium-238 through the measurement of the total ionization produced in a fine grained multiplate ion chamber array. In iron the distribution of total ionization is dominated by nuclear binding energy fluctuations. In uranium-238, however, this fluctuation is compensated by correlated fission energy deposit resulting in a considerable reduction in the measured ionization fluctuation. (7 refs).

  15. Single and multiple ionization of C60 fullerenes and collective effects in collisions with highly charged C, F, and Si ions with energy 3 MeV/u

    Science.gov (United States)

    Kelkar, A. H.; Kadhane, U.; Misra, D.; Gulyas, L.; Tribedi, L. C.

    2010-10-01

    We have measured absolute cross sections for single, double, triple, and quadruple ionization of C60 in collisions with 3 MeV/u C, F, and Si projectile ions at various projectile charge states. The experiment was performed using the recoil-ion time-of-flight technique. Projectile charge state dependence of the ionization yields was compared mainly with a model based on the giant dipole plasmon resonance (GDPR). In some cases, the continuum-distorted-wave-eikonal-initial-state (CDW-EIS) model which is normally applied for ion-atom collisions was also used as a reference. An excellent qualitative agreement between the experimental data for single and double ionization and the GDPR model predictions was found for all projectile charge states.

  16. Single and multiple ionization of C60 fullerenes and collective effects in collisions with highly charged C, F, and Si ions with energy 3 MeV/u

    International Nuclear Information System (INIS)

    Kelkar, A. H.; Kadhane, U.; Misra, D.; Tribedi, L. C.; Gulyas, L.

    2010-01-01

    We have measured absolute cross sections for single, double, triple, and quadruple ionization of C 60 in collisions with 3 MeV/u C, F, and Si projectile ions at various projectile charge states. The experiment was performed using the recoil-ion time-of-flight technique. Projectile charge state dependence of the ionization yields was compared mainly with a model based on the giant dipole plasmon resonance (GDPR). In some cases, the continuum-distorted-wave-eikonal-initial-state (CDW-EIS) model which is normally applied for ion-atom collisions was also used as a reference. An excellent qualitative agreement between the experimental data for single and double ionization and the GDPR model predictions was found for all projectile charge states.

  17. Analytical standards for accountability of uranium hexafluoride - 1972

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    An analytical standard for the accountability of uranium hexafluoride is presented that includes procedures for subsampling, determination of uranium, determination of metallic impurities and isotopic analysis by gas and thermal ionization mass spectrometry

  18. Directional Sensitivity in Light-Mass Dark Matter Searches with Single-Electron-Resolution Ionization Detectors

    Science.gov (United States)

    Kadribasic, Fedja; Mirabolfathi, Nader; Nordlund, Kai; Sand, Andrea E.; Holmström, Eero; Djurabekova, Flyura

    2018-03-01

    We propose a method using solid state detectors with directional sensitivity to dark matter interactions to detect low-mass weakly interacting massive particles (WIMPs) originating from galactic sources. In spite of a large body of literature for high-mass WIMP detectors with directional sensitivity, no available technique exists to cover WIMPs in the mass range <1 GeV /c2 . We argue that single-electron-resolution semiconductor detectors allow for directional sensitivity once properly calibrated. We examine the commonly used semiconductor material response to these low-mass WIMP interactions.

  19. Hepatic transcriptional responses in Atlantic salmon (Salmo salar) exposed to gamma radiation and depleted uranium singly and in combination

    Energy Technology Data Exchange (ETDEWEB)

    Song, You, E-mail: yso@niva.no [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo (Norway); Salbu, Brit; Teien, Hans-Christian [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Evensen, Øystein [Norwegian University of Life Sciences (NMBU), Department of Basic Sciences and Aquatic Medicine, P.O. Box 8146 Dep., N-0033 Oslo (Norway); Lind, Ole Christian [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Rosseland, Bjørn Olav [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Norwegian University of Life Sciences (NMBU), Department of Ecology and Natural Resource Management (INA), P.O. Box 5003, N-1432 Ås (Norway); and others

    2016-08-15

    Radionuclides are a special group of substances posing both radiological and chemical hazards to organisms. As a preliminary approach to understand the combined effects of radionuclides, exposure studies were designed using gamma radiation (Gamma) and depleted uranium (DU) as stressors, representing a combination of radiological (radiation) and chemical (metal) exposure. Juvenile Atlantic salmon (Salmo salar) were exposed to 70 mGy external Gamma dose delivered over the first 5 h of a 48 h period (14 mGy/h), 0.25 mg/L DU were exposed continuously for 48 h and the combination of the two stressors (Combi). Water and tissue concentrations of U were determined to assess the exposure quality and DU bioaccumulation. Hepatic gene expression changes were determined using microarrays in combination with quantitative real-time reverse transcription polymerase chain reaction (qPCR). Effects at the higher physiological levels were determined as plasma glucose (general stress) and hepatic histological changes. The results show that bioaccumulation of DU was observed after both single DU and the combined exposure. Global transcriptional analysis showed that 3122, 2303 and 3460 differentially expressed genes (DEGs) were significantly regulated by exposure to gamma, DU and Combi, respectively. Among these, 349 genes were commonly regulated by all treatments, while the majority was found to be treatment-specific. Functional analysis of DEGs revealed that the stressors displayed similar mode of action (MoA) across treatments such as induction of oxidative stress, DNA damage and disturbance of oxidative phosphorylation, but also stressor-specific mechanisms such as cellular stress and injury, metabolic disorder, programmed cell death, immune response. No changes in plasma glucose level as an indicator of general stress and hepatic histological changes were observed. Although no direct linkage was successfully established between molecular responses and adverse effects at the organism

  20. Hepatic transcriptional responses in Atlantic salmon (Salmo salar) exposed to gamma radiation and depleted uranium singly and in combination

    International Nuclear Information System (INIS)

    Song, You; Salbu, Brit; Teien, Hans-Christian; Evensen, Øystein; Lind, Ole Christian; Rosseland, Bjørn Olav

    2016-01-01

    Radionuclides are a special group of substances posing both radiological and chemical hazards to organisms. As a preliminary approach to understand the combined effects of radionuclides, exposure studies were designed using gamma radiation (Gamma) and depleted uranium (DU) as stressors, representing a combination of radiological (radiation) and chemical (metal) exposure. Juvenile Atlantic salmon (Salmo salar) were exposed to 70 mGy external Gamma dose delivered over the first 5 h of a 48 h period (14 mGy/h), 0.25 mg/L DU were exposed continuously for 48 h and the combination of the two stressors (Combi). Water and tissue concentrations of U were determined to assess the exposure quality and DU bioaccumulation. Hepatic gene expression changes were determined using microarrays in combination with quantitative real-time reverse transcription polymerase chain reaction (qPCR). Effects at the higher physiological levels were determined as plasma glucose (general stress) and hepatic histological changes. The results show that bioaccumulation of DU was observed after both single DU and the combined exposure. Global transcriptional analysis showed that 3122, 2303 and 3460 differentially expressed genes (DEGs) were significantly regulated by exposure to gamma, DU and Combi, respectively. Among these, 349 genes were commonly regulated by all treatments, while the majority was found to be treatment-specific. Functional analysis of DEGs revealed that the stressors displayed similar mode of action (MoA) across treatments such as induction of oxidative stress, DNA damage and disturbance of oxidative phosphorylation, but also stressor-specific mechanisms such as cellular stress and injury, metabolic disorder, programmed cell death, immune response. No changes in plasma glucose level as an indicator of general stress and hepatic histological changes were observed. Although no direct linkage was successfully established between molecular responses and adverse effects at the organism

  1. Dynamics of the single and double ionization of helium in fast proton collisions

    International Nuclear Information System (INIS)

    Doerner, R.; Schmidt-Boecking, H.

    1991-08-01

    A new experimental approach, designed to measure differential ionisation and electron capture cross sections for relativistic heavy ion beams, has been developed and was used to investigate dynamic mechanisms of Helium single and double ionisation in collisions with fast protons. Detailed insight into the dynamics of the ionisation process has been obtained. The experimental results prove, that the many-body momentum exchange between all particles involved, the projectile and target nucleus as well as the emitted electrons, has to be incorporated in order to correctly describe the ionisation collision dynamics. For the proton on Helium collision system the transverse momenta of projectile and recoil-ion were found to be of comparable magnitude only for very close collisions and large scattering angles above 1 mrad, which contribute less than 3% to the total ionisation cross section. (orig./HSI) [de

  2. Total ionizing dose (TID) effect and single event effect (SEE) in quasi-SOI nMOSFETs

    International Nuclear Information System (INIS)

    Tan, Fei; Huang, Ru; An, Xia; Wu, Weikang; Feng, Hui; Huang, Liangxi; Fan, Jiewen; Zhang, Xing; Wang, Yangyuan

    2014-01-01

    This paper studies the total ionizing dose (TID) and single event effect (SEE) in quasi-SOI nMOSFETs for the first time. After exposure to gamma rays, the off-state leakage current (I off ) of a quasi-SOI device increases with the accumulating TID, and the on-state bias configuration is shown to be the worst-case bias configuration during irradiation. Although an additional TID-sensitive region is introduced by the unique structure of the quasi-SOI device, the influence of positive charge trapped in L-type oxide layers on the degradation of device performance is neglectable. Since the TID-induced leakage path in the quasi-SOI device is greatly reduced due to the isolation of L-type oxide layers, the TID-induced I off  degradation in the quasi-SOI device is greatly suppressed. In addition, 3D simulation is performed to investigate the SEE of the quasi-SOI device. The full-width at half-maximum (FWHM) of worst-case drain current transient and collected charges of the quasi-SOI device after single-ion-striking is smaller than in a bulk Si device, indicating that the quasi-SOI device inherits the advantage of an SOI device in single event transient immunity. Therefore, the quasi-SOI device, which has improved electrical properties and radiation-hardened characteristics for both TID and SEE, can be considered as one of the promising candidates for space applications. (paper)

  3. Charge enhancement of single-stranded DNA in negative electrospray ionization using the supercharging reagent meta-nitrobenzyl alcohol.

    Science.gov (United States)

    Brahim, Bessem; Alves, Sandra; Cole, Richard B; Tabet, Jean-Claude

    2013-12-01

    Charge enhancement of single-stranded oligonucleotide ions in negative ESI mode is investigated. The employed reagent, meta-nitrobenzyl alcohol (m-NBA), was found to improve total signal intensity (Itot), increase the highest observed charge states (zhigh), and raise the average charge states (zavg) of all tested oligonucleotides analyzed in negative ESI. To quantify these increases, signal enhancement ratios (SER1%) and charge enhancement coefficients (CEC1%) were introduced. The SER1%, (defined as the quotient of total oligonucleotide ion abundances with 1% m-NBA divided by total oligonucleotide abundance without m-NBA) was found to be greater than unity for every oligonucleotide tested. The CEC1% values (defined as the average charge state in the presence of 1% m-NBA minus the average charge state in the absence of m-NBA) were found to be uniformly positive. Upon close inspection, the degree of charge enhancement for longer oligonucleotides was found to be dependent upon thymine density (i.e., the number and the location of phospho-thymidine units). A correlation between the charge enhancement induced by the presence of m-NBA and the apparent gas-phase acidity (largely determined by the sequence of thymine units but also by the presence of protons on other nucleobases) of multiply deprotonated oligonucleotide species, was thus established. Ammonium cations appeared to be directly involved in the m-NBA supercharging mechanism, and their role seems to be consistent with previously postulated ESI mechanisms describing desorption/ionization of single-stranded DNA into the gas phase.

  4. Charge Enhancement of Single-Stranded DNA in Negative Electrospray Ionization Using the Supercharging Reagent Meta-nitrobenzyl Alcohol

    Science.gov (United States)

    Brahim, Bessem; Alves, Sandra; Cole, Richard B.; Tabet, Jean-Claude

    2013-12-01

    Charge enhancement of single-stranded oligonucleotide ions in negative ESI mode is investigated. The employed reagent, meta-nitrobenzyl alcohol (m-NBA), was found to improve total signal intensity (Itot), increase the highest observed charge states (zhigh), and raise the average charge states (zavg) of all tested oligonucleotides analyzed in negative ESI. To quantify these increases, signal enhancement ratios (SER1%) and charge enhancement coefficients (CEC1%) were introduced. The SER1%, (defined as the quotient of total oligonucleotide ion abundances with 1 % m-NBA divided by total oligonucleotide abundance without m-NBA) was found to be greater than unity for every oligonucleotide tested. The CEC1% values (defined as the average charge state in the presence of 1 % m-NBA minus the average charge state in the absence of m-NBA) were found to be uniformly positive. Upon close inspection, the degree of charge enhancement for longer oligonucleotides was found to be dependent upon thymine density (i.e., the number and the location of phospho-thymidine units). A correlation between the charge enhancement induced by the presence of m-NBA and the apparent gas-phase acidity (largely determined by the sequence of thymine units but also by the presence of protons on other nucleobases) of multiply deprotonated oligonucleotide species, was thus established. Ammonium cations appeared to be directly involved in the m-NBA supercharging mechanism, and their role seems to be consistent with previously postulated ESI mechanisms describing desorption/ionization of single-stranded DNA into the gas phase.

  5. An improved FT-TIMS method of measuring uranium isotope ratios in the uranium-bearing particles

    International Nuclear Information System (INIS)

    Chen, Yan; Wang, Fan; Zhao, Yong-Gang; Li, Li-Li; Zhang, Yan; Shen, Yan; Chang, Zhi-Yuan; Guo, Shi-Lun; Wang, Xiao-Ming; Cui, Jian-Yong; Liu, Yu-Ang

    2015-01-01

    An improved method of Fission Track technique combined with Thermal Ionization Mass Spectrometry (FT-TIMS) was established in order to determine isotope ratio of uranium-bearing particle. Working standard of uranium oxide particles with a defined diameter and isotopic composition were prepared and used to review the method. Results showed an excellent agreement with certified values. The developed method was used to analyze isotope ratio of single uranium-bearing particle in swipe samples successfully. The analysis results of uranium-bearing particles in swipe samples accorded with the operation history of the origin. - Highlights: • The developed method was successfully applied in the analysis of real swipe sample. • Uranium-bearing particles were confined in the middle of track detector. • The fission tracks of collodion film and PC film could be confirmed each other. • The thickness of collodion film should be no more than about 60 μm. • The method could avoid losing uranium-bearing particles in the etching step.

  6. Dissociation kinetics of excited ions: PEPICO measurements of Os3(CO)12 — The 7-35 eV single ionization binding energy region

    Science.gov (United States)

    Schalk, Oliver; Josefsson, Ida; Geng, Ting; Richter, Robert; Sa'adeh, Hanan; Thomas, Richard D.; Mucke, Melanie

    2018-02-01

    In this article, we study the photoinduced dissociation pathways of a metallocarbonyl, Os3(CO)12, in particular the consecutive loss of CO groups. To do so, we performed photoelectron-photoion coincidence (PEPICO) measurements in the single ionization binding energy region from 7 to 35 eV using 45-eV photons. Zero-energy ion appearance energies for the dissociation steps were extracted by modeling the PEPICO data using the statistical adiabatic channel model. Upon ionization to the excited ionic states above 13 eV binding energy, non-statistical behavior was observed and assigned to prompt CO loss. Double ionization was found to be dominated by the knockout process with an onset of 20.9 ± 0.4 eV. The oscillator strength is significantly larger for energies above 26.6 ± 0.4 eV, corresponding to one electron being ejected from the Os3 center and one from the CO ligands. The cross section for double ionization was found to increase linearly up to 35 eV ionization energy, at which 40% of the generated ions are doubly charged.

  7. Depleted uranium

    International Nuclear Information System (INIS)

    Huffer, E.; Nifenecker, H.

    2001-02-01

    This document deals with the physical, chemical and radiological properties of the depleted uranium. What is the depleted uranium? Why do the military use depleted uranium and what are the risk for the health? (A.L.B.)

  8. Uranium demand

    International Nuclear Information System (INIS)

    Roux, A.J.A.

    1976-01-01

    The estimated world resources of uranium as well as the estimated consumption of uranium over the next 25 years are briefly discussed. Attention is given to the prospecting of uranium in South Africa and elsewhere in the world

  9. Measured, calculated and predicted Stark widths of the singly ionized C, N, O, F, Ne, Si, P, S, Cl and Ar spectral lines

    Directory of Open Access Journals (Sweden)

    Djeniže S.

    2000-01-01

    Full Text Available In order to find reliable Stark width data, needed in plasma spectroscopy comparision between the existing measured, calculated and predicted Stark width values was performed for ten singly ionized emitters: C, N, O, F, Ne Si, P, S, Cl and Ar in the lower lying 3s - 3p, 3p - 3d and 4s - 4p transitions. These emitters are present in many cosmic light sources. On the basis of the agreement between mentioned values 17 spectral lines from six singly ionized spectra have been recommended, for the first time, for plasma spectroscopy as spectral lines with reliable Stark width data. Critical analysis of the existing Stark width data is also given.

  10. Single Photon Ionization Mass Spectroscopy of Hydrogen Bonded and van der Waals Cluster Systems Using a Capillary Discharge Soft X-Ray Laser

    Science.gov (United States)

    Heinbuch, S.; Dong, F.; Bernstein, E. R.; Rocca, J. J.

    We report the first use of a soft x-ray laser in photochemistry studies. A 46.9 nm capillary discharge soft x-ray laser was used to study hydrogen bonded and van der Waals cluster systems. The study of van der Waals cluster formation and growth in the gas phase can contribute to the understanding of solvation processes, solvation dynamics, and the nucleation and growth of small clusters. The comparative investigation of water, methanol, and ammonia clusters is of importance because these clusters demonstrate a wide range of van der Waals interactions and hydrogen bonding: water clusters are very strongly and dominantly hydrogen bonded; methanol clusters somewhat less so; and ammonia clusters perhaps not at all. Sulfur dioxide is the major contributor to acid rain and a generator of soot. The process of SO2 and water forming acid rain has been studied for some time in order to determine the atmospheric mechanism for this environmental issue. Carbon dioxide is the major gas phase pollutant responsible for the "green house effect" of the atmosphere. Many experiments employing supersonic expansion coupled with mass spectroscopic detection have been conducted in order to study monomeric and clustered structure and behavior of each of these systems. Spectroscopic and photochemical properties of the systems should be related to cluster structure. However, one of the most serious problems in the investigation of the distribution of neutral hydrogen-bonded and van der Waals clusters is the fragmentation or the intra-cluster ion-molecule reactions to the protonated cluster ions. Electron Impact (EI) ionization usually suffers considerably from fragmentation of parent cluster ions on account of the large excess energies during the ionization process. Multiphoton ionization (MPI) processes result in the predissociation of the neutral clusters before ionization. Single photon ionization is a more "gentle" way to study hydrogen-bonded and Van der Waals clusters since less

  11. Estimation of ionizing radiation impact on natural Vicia cracca populations inhabiting areas contaminated with uranium mill tailings and radium production wastes

    Energy Technology Data Exchange (ETDEWEB)

    Evseeva, T.; Majstrenko, T. [Institute of Biology, Komi Scientific Center, Ural Division RAS, Kommunisticheskaya 28, 167982 Syktyvkar (Russian Federation); Geras' kin, S. [Russian Institute of Agricultural Radiology and Agroecology RAAS, 249020 Obninsk, Kaluga region (Russian Federation); Brown, J.E., E-mail: Justin.brown@nrpa.no [Norwegian Radiation Protection Authority, Grini naeringspark 13, 1332 Osteras (Norway); Belykh, E. [Institute of Biology, Komi Scientific Center, Ural Division RAS, Kommunisticheskaya 28, 167982 Syktyvkar (Russian Federation)

    2009-10-01

    Industrial areas in proximity to the Vodny settlement in the Komi Republic, Russia, have been contaminated by uranium mill tailings and radium production wastes. These areas, exhibiting high activity concentrations of naturally occurring radionuclides in soils, constitute a field laboratory where the effects of combined chronic exposures to {alpha}-, {beta}- and {gamma}-emitting radionuclides on natural plant populations can be studied. The aim of the present work was to determine dose-effect relationships and the range of doses that cause biological effects in natural Vicia cracca L. populations inhabiting the study area. The studied plant species is native to the area and is found ubiquitously. Soil and vegetation samples were taken at a reference location and six contaminated sites characterized by distinct floodplain depositional units with different enhanced levels of naturally occurring radionuclides. A large fraction of the dose at the study sites (including the reference location) was attributable to internal irradiation and {sup 226}Ra was found to be an important contributor to this component of dose. The relationship between the frequency of chromosome aberrations in seedlings' root tip cells and the absorbed dose was found to be quadratic. An exponential model provided the best result in describing the empirical dependence between the absorbed dose and both the germination capacity of seeds and the survival rate of sprouts of V. cracca. For V. cracca plants inhabiting areas contaminated with uranium mill tailings and radium production wastes, a weighted absorbed dose of 0.2 Gy (weighting factor for alpha particles = 5) during the vegetation period could be considered to be a level below which no increase in genetic variability and decrease in reproductive capacity might be observed above background.

  12. Uranium exploration

    International Nuclear Information System (INIS)

    De Voto, R.H.

    1984-01-01

    This paper is a review of the methodology and technology that are currently being used in varying degrees in uranium exploration activities worldwide. Since uranium is ubiquitous and occurs in trace amounts (0.2 to 5 ppm) in virtually all rocks of the crust of the earth, exploration for uranium is essentially the search of geologic environments in which geologic processes have produced unusual concentrations of uranium. Since the level of concentration of uranium of economic interest is dependent on the present and future price of uranium, it is appropriate here to review briefly the economic realities of uranium-fueled power generation. (author)

  13. Second-order Born effects in the coplanar to perpendicular plane single ionization of Xe (5p)

    International Nuclear Information System (INIS)

    Singh, Prithvi; Purohit, G; Patidar, Vinod

    2013-01-01

    Differential cross section results for the coplanar to perpendicular plane ionization of xenon atoms at incident electron energies of 40 and 20 eV above ionization potential are reported. The cross sections have been calculated in the modified distorted wave Born approximation (DWBA) formalism including the second-order Born amplitude. Our present attempt verifies the role of second-order processes in the ionization of xenon atoms at low and intermediate energy ranges. We compare the (e, 2e) triple differential cross section results of our calculation with the very recent measurements of Nixon and Murray (2012 Phys. Rev. A 85 022716) and relativistic DWBA-G results of Illarionov and Stauffer (2012 J. Phys. B: At. Mol. Opt. Phys. 45 225202). Overall agreement with measurements has been improved by inclusion of a second-order term in the description of the collision process. (paper)

  14. Uranium dioxide electrolysis

    Science.gov (United States)

    Willit, James L [Batavia, IL; Ackerman, John P [Prescott, AZ; Williamson, Mark A [Naperville, IL

    2009-12-29

    This is a single stage process for treating spent nuclear fuel from light water reactors. The spent nuclear fuel, uranium oxide, UO.sub.2, is added to a solution of UCl.sub.4 dissolved in molten LiCl. A carbon anode and a metallic cathode is positioned in the molten salt bath. A power source is connected to the electrodes and a voltage greater than or equal to 1.3 volts is applied to the bath. At the anode, the carbon is oxidized to form carbon dioxide and uranium chloride. At the cathode, uranium is electroplated. The uranium chloride at the cathode reacts with more uranium oxide to continue the reaction. The process may also be used with other transuranic oxides and rare earth metal oxides.

  15. Single well field injection test of humate to enhance attenuation of uranium and other radionuclides in an acidic plume

    Energy Technology Data Exchange (ETDEWEB)

    Denham, M. [Savannah River Site (SRS), Aiken, SC (United States)

    2014-09-30

    This report documents the impact of the injected humate on targeted contaminants over a period of 4 months and suggests it is a viable attenuation-based remedy for uranium, potentially for I-129, but not for Sr-90. Future activities will focus on issues pertinent to scaling the technology to full deployment.

  16. Dual ionization chamber

    International Nuclear Information System (INIS)

    Mallory, J.; Turlej, Z.

    1981-01-01

    Dual ionization chambers are provided for use with an electronic smoke detector. The chambers are separated by electrically-conductive partition. A single radiation source extends through the partition into both chambers, ionizing the air in each. The mid-point current of the device may be balanced by adjusting the position of the source

  17. Gas gain operations with single photon resolution using an integrating ionization chamber in small-angle X-ray scattering experiments

    CERN Document Server

    Menk, R H; Besch, H J; Walenta, Albert H; Amenitsch, H; Bernstorff, S

    2000-01-01

    In this work a combination of an ionization chamber with one-dimensional spatial resolution and a MicroCAT structure will be presented. Initially, MicroCAT was thought of as a shielding grid (Frisch-grid) but later was used as an active electron amplification device that enables single X-ray photon resolution measurements at low fluxes even with integrating readout electronics. Moreover, the adjustable gas gain that continuously covers the entire range from pure ionization chamber mode up to high gas gains (30000 and more) provides stable operation yielding a huge dynamic range of about 10 sup 8 and more. First measurements on biological samples using small angle X-ray scattering techniques with synchrotron radiation will be presented.

  18. Electron-impact ionization of multicharged ions at ORNL: 1985--1992

    International Nuclear Information System (INIS)

    Gregory, D.C.; Bannister, M.E.

    1994-07-01

    Absolute cross sections are presented in graphs and tables for single ionization of forty-one ions, multiple ionization of four ions, and for dissociation and ionization of two molecular ions by electron impact. This memo is the third in a series of manuscripts summarizing previously published as well as unpublished ionization cross section measurements at ORNL; contents of the two previous memos are also referenced in this work. All work tabulated in this memo involved ion beams generated in the ORNL-ECR ion source and utilized the ORNL electron-ion crossed beams apparatus. Target ions range from atomic number Z = 8 (oxygen) to Z = 92 (uranium) in initial charge states from +1 to +16. Electron impact energies typically range from threshold to 1500 eV

  19. Total Ionizing Dose Influence on the Single Event Effect Sensitivity in Samsung 8Gb NAND Flash Memories

    Science.gov (United States)

    Edmonds, Larry D.; Irom, Farokh; Allen, Gregory R.

    2017-08-01

    A recent model provides risk estimates for the deprogramming of initially programmed floating gates via prompt charge loss produced by an ionizing radiation environment. The environment can be a mixture of electrons, protons, and heavy ions. The model requires several input parameters. This paper extends the model to include TID effects in the control circuitry by including one additional parameter. Parameters intended to produce conservative risk estimates for the Samsung 8 Gb SLC NAND flash memory are given, subject to some qualifications.

  20. Single window for issuing licenses for export and import of ionizing radiation sources and transit of radioactive sources

    International Nuclear Information System (INIS)

    Sandev, T.; Stamenov, R.; Misevska, A.; Georgievska-Dimitrevski, B.; Angelovski, G.

    2009-01-01

    In this paper we present the electronic system for application and issuing licenses for export, import and transit of goods (EXIM), particularly for ionizing radiation sources, in the Republic of Macedonia. This system is a modern and helpful tool for simple issuing licenses, for establishing a unique database and it represents a harmonized system for exchanging information between the governmental, public and private legal persons in the Republic of Macedonia. (author)

  1. Single photon simultaneous K-shell ionization and K-shell excitation. II. Specificities of hollow nitrogen molecular ions

    International Nuclear Information System (INIS)

    Carniato, S.; Selles, P.; Andric, L.; Palaudoux, J.; Penent, F.; Lablanquie, P.; Žitnik, M.; Bučar, K.; Nakano, M.; Hikosaka, Y.; Ito, K.

    2015-01-01

    The formalism developed in the companion Paper I is used here for the interpretation of spectra obtained recently on the nitrogen molecule. Double core-hole ionization K −2 and core ionization-core excitation K −2 V processes have been observed by coincidence electron spectroscopy after ionization by synchrotron radiation at different photon energies. Theoretical and experimental cross sections reported on an absolute scale are in satisfactory agreement. The evolution with photon energy of the relative contribution of shake-up and conjugate shake-up processes is discussed. The first main resonance in the K −2 V spectrum is assigned to a K −2 π ∗ state mainly populated by the 1s→ lowest unoccupied molecular orbital dipolar excitation, as it is in the K −1 V NEXAFS (Near-Edge X-ray Absorption Fine Structure) signals. Closer to the K −2 threshold Rydberg resonances have been also identified, and among them a K −2 σ ∗ resonance characterized by a large amount of 2s/2p hybridization, and double K −2 (2σ ∗ /1π/3σ) −1 1π ∗2 shake-up states. These resonances correspond in NEXAFS spectra to, respectively, the well-known σ ∗ shape resonance and double excitation K −1 (2σ ∗ /1π/3σ) −1 1π ∗2 resonances, all being positioned above the threshold

  2. Absolute experimental cross sections for the electron impact single, double, triple, and quadruple ionization of Cs/sup +/ ions. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Feeney, R.K.; Hertling, D.R.

    1981-02-28

    The absolute cross sections for the single, double, triple and quadruple ionization of Cs/sup +/ ions by electron impact have been measured from below their respective thresholds to approximately 5000 eV. This determination has been accomplshed using a crossed beam facility in which monoenergetic beams of ions and electrons are caused to intersect at right angles in a well-defined collision volume. Multiply charged, product ions born as a result of the electron impact are deflected into their respective detectors by cascaded electrostatic analyzers. The multiply charged beam current component is measured by means of a vibrating reed electrometer operating in the rate-of-charge mode.

  3. Distribution of uranium, thorium, and isotopic composition of uranium in soil samples of south Serbia: Evidence of depleted uranium

    Directory of Open Access Journals (Sweden)

    Sahoo Sarata Kumar

    2004-01-01

    Full Text Available Inductively coupled plasma mass spectrometry and thermal ionization mass spectrom - etry were used to measure concentration of uranium and thorium as well as isotopic composition of uranium respectively in soil samples collected around south Serbia. An analytical method was established for a routine sample preparation procedure for uranium and thorium. Uranium was chemically separated and purified from soil samples by anion exchange resin and UTEVA extraction chromatography and its isotopic composition was measured using a thermal ionization mass spectrometry. There was a little deviation of U/Th ratio from the average values in some soil samples. Presence of 236U as well as depleted uranium was observed in 235U/238U ratio measurement in the same soil sample.

  4. Purification of uranium metal

    International Nuclear Information System (INIS)

    Suzuki, Kenji; Shikama, Tatsuo; Ochiai, Akira.

    1993-01-01

    We developed the system for purifying uranium metal and its metallic compounds and for growing highly pure uranium compounds to study their intrinsic physical properties. Uranium metal was zone refined under low contamination conditions as far as possible. The degree of the purity of uranium metal was examined by the conventional electrical resistivity measurement and by the chemical analysis using the inductive coupled plasma emission spectrometry (ICP). The results show that some metallic impurities evaporated by the r.f. heating and other usual metallic impurities moved to the end of a rod with a molten zone. Therefore, we conclude that the zone refining technique is much effective to the removal of metallic impurities and we obtained high purified uranium metal of 99.99% up with regarding to metallic impurities. The maximum residual resistivity ratio, the r.r.r., so far obtained was about 17-20. Using the purified uranium, we are attempting to grow a highly pure uranium-titanium single crystals. (author)

  5. Single photon simultaneous K-shell ionization and K-shell excitation. II. Specificities of hollow nitrogen molecular ions

    Energy Technology Data Exchange (ETDEWEB)

    Carniato, S., E-mail: stephane.carniato@upmc.fr; Selles, P.; Andric, L.; Palaudoux, J.; Penent, F.; Lablanquie, P. [Laboratoire de Chimie Physique-Matière et Rayonnement, UMR 7614, Sorbonne Universités, UPMC University of Paris 6, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France); LCPMR(UMR 7614), CNRS, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France); Žitnik, M.; Bučar, K. [Jozef Stefan Institute, P.O. Box 3000, SI-1001 Ljubljana (Slovenia); Nakano, M. [Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551 (Japan); Photon Factory, Institute of Materials Structure Science, Tsukuba, Ibaraki 305-0801 (Japan); Hikosaka, Y. [Department of Environmental Science, Niigata University, Niigata 950-2181 (Japan); Ito, K. [Photon Factory, Institute of Materials Structure Science, Tsukuba, Ibaraki 305-0801 (Japan)

    2015-01-07

    The formalism developed in the companion Paper I is used here for the interpretation of spectra obtained recently on the nitrogen molecule. Double core-hole ionization K{sup −2} and core ionization-core excitation K{sup −2}V processes have been observed by coincidence electron spectroscopy after ionization by synchrotron radiation at different photon energies. Theoretical and experimental cross sections reported on an absolute scale are in satisfactory agreement. The evolution with photon energy of the relative contribution of shake-up and conjugate shake-up processes is discussed. The first main resonance in the K{sup −2}V spectrum is assigned to a K{sup −2}π{sup ∗} state mainly populated by the 1s→ lowest unoccupied molecular orbital dipolar excitation, as it is in the K{sup −1}V NEXAFS (Near-Edge X-ray Absorption Fine Structure) signals. Closer to the K{sup −2} threshold Rydberg resonances have been also identified, and among them a K{sup −2}σ{sup ∗} resonance characterized by a large amount of 2s/2p hybridization, and double K{sup −2}(2σ{sup ∗}/1π/3σ){sup −1}1π{sup ∗2} shake-up states. These resonances correspond in NEXAFS spectra to, respectively, the well-known σ{sup ∗} shape resonance and double excitation K{sup −1}(2σ{sup ∗}/1π/3σ){sup −1}1π{sup ∗2} resonances, all being positioned above the threshold.

  6. Natural uranium

    International Nuclear Information System (INIS)

    Ammerich, Marc; Frot, Patricia; Gambini, Denis-Jean; Gauron, Christine; Moureaux, Patrick; Herbelet, Gilbert; Lahaye, Thierry; Pihet, Pascal; Rannou, Alain

    2014-08-01

    This sheet belongs to a collection which relates to the use of radionuclides essentially in unsealed sources. Its goal is to gather on a single document the most relevant information as well as the best prevention practices to be implemented. These sheets are made for the persons in charge of radiation protection: users, radioprotection-skill persons, labor physicians. Each sheet treats of: 1 - the radio-physical and biological properties; 2 - the main uses; 3 - the dosimetric parameters; 4 - the measurement; 5 - the protection means; 6 - the areas delimitation and monitoring; 7 - the personnel classification, training and monitoring; 8 - the effluents and wastes; 9 - the authorization and declaration administrative procedures; 10 - the transport; and 11 - the right conduct to adopt in case of incident or accident. This sheet deals specifically with natural uranium

  7. Australia's uranium

    International Nuclear Information System (INIS)

    Hampson, D.C.

    1980-01-01

    The subject is discussed as follows: structure of the uranium industry in Australia (export policies; development of mining programme; table of export contracts approved by Australian government, 1972; government policy towards the industry 1972-75 and since 1975); reserves (table of Australia's major uranium deposits; estimated world resources of uranium, excluding USSR, Eastern Europe and China; comparison of exploration expenditures and discovery of uranium in Australia and the USA); enrichment; resource potential; future demand (table of nuclear power reactors above 30 MW in operation or under construction, mid-1979; projection of Australian uranium production to 1990); government and union action. (U.K.)

  8. Study of combinations of TL/OSL single dosimeters for mixed high/low ionization density radiation fields

    International Nuclear Information System (INIS)

    Oster, L.; Druzhyna, S.; Orion, I.; Horowitz, Y.S.

    2013-01-01

    In this paper we discuss and compare the potential application of combined OSL/TL measurements using 6 LiF:Mg,Ti (TLD-600 is enriched of isotope 6 Li which has a high cross-section for the reaction with slow neutrons) or 7 LiF:Mg,Ti ( TLD-700 is enriched of 7 Li isotope) and TLD-100 (natural isotopic composition) detectors. The OSL/TL duel readout of LiF:Mg,Ti as an ionization density discriminator avoids some of the difficulties inherent to the various types of discrimination mixed-field passive dosimeters, and in addition has several advantages. The preferential excitation of OSL compared to TL following high ionization density (HID) alpha irradiation, naturally explained via the identification of OSL with the “two-hit” F 2 or F 3 center, whereas the major component of composite TL glow peak 5 is believed to arise from a ''one-hit'' complex defect. This evidence allows near-total discrimination between HID radiation and low-ionization density (LID) radiation. Beta and alpha particle irradiations were carried out with 90 Sr/ 90 Y (∼500 keV average energy) and 241 Am sources (4.7 MeV) respectively and neutron irradiations were carried out at the PTB (Germany) (E n = 5 MeV) and RARAF (Columbia University, USA) (E n = 6 MeV) accelerator facilities. The highest values of the FOM obtained was ∼30 for neutron/gamma discrimination and ∼110 for alpha/gamma discrimination using OSL/TL – peak 5 measurements in TLD-700. -- Highlights: ► The increased response of OSL compared to TL following HID irradiation is observed. ► This evidence is explained via the identification of OSL with the ''two-hit'' F2 centers. ► The potential application of combined OSL/TL in discrimination dosimetry is discussed. ► The values of FOM were 110 for alpha/gamma and 30 for neutron/gamma discrimination

  9. Single photon ionization of van der Waals clusters with a soft x-ray laser: (CO2)n and (CO2)n(H2O)m.

    Science.gov (United States)

    Heinbuch, S; Dong, F; Rocca, J J; Bernstein, E R

    2006-10-21

    Pure neutral (CO2)n clusters and mixed (CO2)n(H2O)m clusters are investigated employing time of flight mass spectroscopy and single photon ionization at 26.5 eV. The distribution of pure (CO2)n clusters decreases roughly exponentially with increasing cluster size. During the ionization process, neutral clusters suffer little fragmentation because almost all excess cluster energy above the vertical ionization energy is taken away by the photoelectron and only a small part of the photon energy is deposited into the (CO2)n cluster. Metastable dissociation rate constants of (CO2)n+ are measured in the range of (0.2-1.5) x 10(4) s(-1) for cluster sizes of 5CO2-H2O clusters are studied under different generation conditions (5% and 20% CO2 partial pressures and high and low expansion pressures). At high CO2 concentration, predominant signals in the mass spectrum are the (CO2)n+ cluster ions. The unprotonated cluster ion series (CO2)nH2O+ and (CO2)n(H2O)2+ are also observed under these conditions. At low CO2 concentration, protonated cluster ions (H2O)nH+ are the dominant signals, and the protonated CO2(H2O)nH+ and unprotonated (H2O)n+ and (CO2)(H2O)n+ cluster ion series are also observed. The mechanisms and dynamics of the formation of these neutral and ionic clusters are discussed.

  10. Matrix-assisted laser-desorption/ionization mass spectrometric imaging of olanzapine in a single hair using esculetin as a matrix.

    Science.gov (United States)

    Wang, Hang; Wang, Ying; Wang, Ge; Hong, Lizhi

    2017-07-15

    Matrix-assisted laser desorption/ionization-mass spectrometric imaging (MALDI-MSI) for the analysis of intact hair is a powerful tool for monitoring changes in drug consumption. The embedding of a low drug concentration in the hydrophobic hair matrix makes it difficult to extract and detect, and requires an improved method to increase detection sensitivity. In this study, an MSI method using MALDI-Fourier transform ion cyclotron resonance was developed for direct identification and imaging of olanzapine in hair samples using the positive ion mode. Following decontamination, scalp hair samples from an olanzapine user were scraped from the proximal to the distal end three times, and 5mm hair sections were fixed onto an Indium-Tin-Oxide (ITO)-coated microscopic glass slide. Esculetin (6,7-dihydroxy-2H-chromen-2-one) was used as a new hydrophobic matrix to increase the affinity, extraction and ionization efficiency of olanzapine in the hair samples. The spatial distribution of olanzapine was observed using five single hairs from the same drug user. This matrix improves the affinity of olanzapine in hair for molecular imaging with mass spectrometry. This method may provide a detection power for olanzapine to the nanogram level per 5mm hair. Time course changes in the MSI results were also compared with quantitative HPLC-MS/MS for each 5mm segment of single hair shafts selected from the MALDI target. MALDI imaging intensities in single hairs showed good semi-quantitative correlation with the results from conventional HPLC-MS/MS. MALDI-MSI is suitable for monitoring drug intake with a high time resolution. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Standard Test Method for Isotopic Analysis of Uranium Hexafluoride by Single-Standard Gas Source Multiple Collector Mass Spectrometer Method

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This test method is applicable to the isotopic analysis of uranium hexafluoride (UF6) with 235U concentrations less than or equal to 5 % and 234U, 236U concentrations of 0.0002 to 0.1 %. 1.2 This test method may be applicable to the analysis of the entire range of 235U isotopic compositions providing that adequate Certified Reference Materials (CRMs or traceable standards) are available. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety health practices and determine the applicability of regulatory limitations prior to use.

  12. Ionization particle detector

    International Nuclear Information System (INIS)

    Ried, L.

    1982-01-01

    A new device is claimed for detecting particles in a gas. The invention comprises a low cost, easy to assemble, and highly accurate particle detector using a single ionization chamber to contain a reference region and a sensing region. The chamber is designed with the radioactive source near one electrode and the second electrode located at a distance less than the distance of maximum ionization from the radioactive source

  13. Compendium of Single-Event Latchup and Total Ionizing Dose Test Results of Commercial Analog to Digital Converters

    Science.gov (United States)

    Irom, Farokh; Agarwal, Shri G.

    2012-01-01

    This paper reports single-event latchup and total dose results for a variety of analog to digital converters targeted for possible use in NASA spacecraft's. The compendium covers devices tested over the last 15 years.

  14. Display of charged ionizing particles

    International Nuclear Information System (INIS)

    Cano S, D.; Ortiz A, M. D.; Amarillas S, L. E.; Vega C, H. R.

    2017-10-01

    The human being is exposed to sources of ionizing and non-ionizing radiation, both of natural or anthropogenic origin. None of these, except non-ionizing such as visible light and infrared radiation, can be detected by the sense of sight and touch respectively. The sun emits charged particles with speeds close to the light that interact with the atoms of the gases present in the atmosphere, producing nuclear reactions that in turn produce other particles that reach the surface of the Earth and reach the living beings. On Earth there are natural radioisotopes that, when they disintegrate, emit ionizing radiation that contributes to the dose we receive. A very old system that allows the visualization of the trajectories of the charged ionizing particles is the Fog Chamber that uses a saturated steam that when crossed by particles with mass and charge, as alpha and beta particles produce condensation centers along its path leaves a trace that can be seen. The objective of this work was to build a fog chamber using easily accessible materials. To measure the functioning of the fog chamber, cosmic rays were measured, as well as a source of natural metal uranium. The fog chamber allowed seeing the presence of traces in alcohol vapor that are produced in a random way. Introducing the uranium foil inside the fog chamber, traces of alpha particles whose energy varies from 4 to 5 MeV were observed. (Author)

  15. Prenatal exposition on ionizing radiations

    International Nuclear Information System (INIS)

    2001-01-01

    The Sessions on Prenatal Exposition on Ionizing Radiations was organized by the Argentine Radioprotection Society, in Buenos Aires, between 8 and 9, November 2001. In this event, were presented papers on: biological effects of ionizing radiation; the radiation protection and the pregnant woman; embryo fetal development and its relationship with the responsiveness to teratogens; radioinduced delayed mental; neonatal irradiation: neurotoxicity and modulation of pharmacological response; pre implanted mouse embryos as a model of uranium toxicity studies; hereditary effects of the radiation and new advances from the UNSCEAR 2001; doses estimation in embryo

  16. Cell and Tissue Damage after Skin Exposure to Ionizing Radiation: Short- and Long-Term Effects after a Single and Fractional Doses.

    Science.gov (United States)

    Kinoshita, Kahori; Ishimine, Hisako; Shiraishi, Kenshiro; Kato, Harunosuke; Doi, Kentaro; Kuno, Shinichiro; Kanayama, Koji; Mineda, Kazuhide; Mashiko, Takanobu; Feng, Jingwei; Nakagawa, Keiichi; Kurisaki, Akira; Itami, Satoshi; Yoshimura, Kotaro

    2014-01-01

    Ionizing radiation is often used to treat progressive neoplasms. However, the consequences of long-term radiation exposure to healthy skin tissue are poorly understood. We aimed to evaluate the short- and long-term radiation damage to healthy skin of the same irradiation given either as single or fractional doses. C57BL/J6 mice were randomly assigned to one of three groups: a control and two exposure groups (5 Gy ×2 or 10 Gy ×1). The inguinal area was irradiated (6-MeV beam) 1 week after depilation in the treatment groups. Skin samples were evaluated macroscopically and histologically for up to 6 months after the final exposure. After anagen hair follicle injury by irradiation, hair cycling resumed in both groups, but hair graying was observed in the 10 Gy ×1 group but not in the 5 Gy ×2 group, suggesting the dose of each fractional exposure is more relevant to melanocyte stem cell damage than the total dose. On the other hand, in the long term, the fractional double exposures induced more severe atrophy and capillary reduction in the dermis and subcutis, suggesting fractional exposure may cause more depletion of tissue stem cells and endothelial cells in the tissue. Thus, our results indicated that there were differences between the degrees of damage that occurred as a result of a single exposure compared with fractional exposures to ionizing radiation: the former induces more severe acute injury to the skin with irreversible depigmentation of hairs, while the latter induces long-term damage to the dermis and subcutis. © 2015 S. Karger AG, Basel.

  17. Ionizing radiation

    International Nuclear Information System (INIS)

    Kruger, J.

    1989-01-01

    Ionizing radiation results in biological damage that differs from other hazardous substances and is highly dangerous to man. Ionizing radiation cannot be perceived by man's sense organs and the biological damage cannot be detected immediately afterwards (except in very high doses). Every human being is exposed to low doses of radiation. The structure of the atom; sources of ionizing radiation; radiation units; biological effects; norms for radiation protection; and the national control in South Africa are discussed. 1 fig., 5 refs

  18. Uranium prospecting and uranium supply

    International Nuclear Information System (INIS)

    Kegel, K.E.

    1975-01-01

    Following of short historical survey, estimations of the uranium resources of the western world made in the middle of 1975 are presented and interpreted. The most common methods of prospecting and exploration of the mines and of production and processing of the uranium eres are described. A short survey of the situation of supply and demand is supplemented by a description of the activities of the two German companies in the field of uranium supply. (UA/AK) [de

  19. Uranium resources

    International Nuclear Information System (INIS)

    1976-01-01

    This is a press release issued by the OECD on 9th March 1976. It is stated that the steep increases in demand for uranium foreseen in and beyond the 1980's, with doubling times of the order of six to seven years, will inevitably create formidable problems for the industry. Further substantial efforts will be needed in prospecting for new uranium reserves. Information is given in tabular or graphical form on the following: reasonably assured resources, country by country; uranium production capacities, country by country; world nuclear power growth; world annual uranium requirements; world annual separative requirements; world annual light water reactor fuel reprocessing requirements; distribution of reactor types (LWR, SGHWR, AGR, HWR, HJR, GG, FBR); and world fuel cycle capital requirements. The information is based on the latest report on Uranium Resources Production and Demand, jointly issued by the OECD's Nuclear Energy Agency (NEA) and the International Atomic Energy Agency. (U.K.)

  20. Uranium enrichment

    International Nuclear Information System (INIS)

    1989-01-01

    GAO was asked to address several questions concerning a number of proposed uranium enrichment bills introduced during the 100th Congress. The bill would have restructured the Department of Energy's uranium enrichment program as a government corporation to allow it to compete more effectively in the domestic and international markets. Some of GAO's findings discussed are: uranium market experts believe and existing market models show that the proposed DOE purchase of a $750 million of uranium from domestic producers may not significantly increase production because of large producer-held inventories; excess uranium enrichment production capacity exists throughout the world; therefore, foreign producers are expected to compete heavily in the United States throughout the 1990s as utilities' contracts with DOE expire; and according to a 1988 agreement between DOE's Offices of Nuclear Energy and Defense Programs, enrichment decommissioning costs, estimated to total $3.6 billion for planning purposes, will be shared by the commercial enrichment program and the government

  1. Spectrum of Singly Charged Uranium (U II : Theoretical Interpretation of Energy Levels, Partition Function and Classified Ultraviolet Lines

    Directory of Open Access Journals (Sweden)

    Ali Meftah

    2017-06-01

    Full Text Available In an attempt to improve U II analysis, the lowest configurations of both parities have been interpreted by means of the Racah-Slater parametric method, using Cowan codes. In the odd parity, including the ground state, 253 levels of the interacting configurations 5 f 3 7 s 2 + 5 f 3 6 d 7 s + 5 f 3 6 d 2 + 5 f 4 7 p + 5 f 5 are interpreted by 24 free parameters and 64 constrained ones, with a root mean square (rms deviation of 60 cm − 1 . In the even parity, the four known configurations 5 f 4 7 s , 5 f 4 6 d , 5 f 2 6 d 2 7 s , 5 f 2 6 d 7 s 2 and the unknown 5 f 2 6 d 3 form a basis for interpreting 125 levels with a rms deviation of 84 cm − 1 . Due to perturbations, the theoretical description of the higher configurations 5 f 3 7 s 7 p + 5 f 3 6 d 7 p remains unsatisfactory. The known and predicted levels of U II are used for a determination of the partition function. The parametric study led us to a re-investigation of high resolution ultraviolet spectrum of uranium recorded at the Meudon Observatory in the late eighties, of which the analysis was unachieved. In the course of the present study, a number of 451 lines of U II has been classified in the region 2344 –2955 Å. One new level has been established as 5 f 3 6 d 7 p ( 4 I 6 K ( J = 5.5 at 39113.98 ± 0.1 cm − 1 .

  2. Highly resolved online organic-chemical speciation of evolved gases from thermal analysis devices by cryogenically modulated fast gas chromatography coupled to single photon ionization mass spectrometry.

    Science.gov (United States)

    Saraji-Bozorgzad, Mohammad R; Eschner, Markus; Groeger, Thomas M; Streibel, Thorsten; Geissler, Robert; Kaisersberger, Erwin; Denner, Thomas; Zimmermann, Ralf

    2010-12-01

    Multi-dimensional analysis (MDA) in analytical chemistry is often applied to improve the selectivity of an analytical device and, therefore, to achieve a better overview of a sample composition. Recently, the hyphenation of thermogravimetry with single photo ionization mass spectrometry (TG-SPIMS) using an electron beam pumped excimer lamp (EBEL) for VUV radiation was applied. The concept of MDA has been realized by upgrading the TG-SPIMS system with a quasi comprehensive chromatographic separation step before the soft ionization (TG-GCxSPIMS). The system was characterized by the thermal analysis of diesel fuel, which has often been investigated by the GCxGC-community and is therefore a well-known sample material in MDA. Data from this measurement are used to explain the three-dimensional data structure and the advantages of the online TG-GCxSPIMS as compared to TG-SPIMS. Subsequently, the thermal decomposition behavior of a polymer, acrylonitrile-butadiene-styrene (ABS), is investigated. TG-GCxSPIMS provides a two-dimensional analysis of the evolved gaseous products. TG relevant data are obtained as well as an improved resolution power to separate isobaric molecular structures without losing any fraction of the samples, as is often the case in heart cutting approaches. Additionally, this solution is not associated with any extension of the measurement time. The assignment of the substance pattern to distinct species is improved as compared to solely using mass spectrometry without a preceding separation step. Furthermore, hitherto undetected compounds have been found in the evolved gases from the thermal degradation of ABS. Finally, a first estimation of the limit of detection has been carried out. This results in a significant decrease of the LOD in case of TG-GCxSPIMS (500 ppt for toluene) as compared to 30 ppb, which could be reached with TG-SPIMS.

  3. Single thrombopoietin dose alleviates hematopoietic stem cells intrinsic short- and long-term ionizing radiation damage. In vivo identification of anatomical cell expansion sites.

    Science.gov (United States)

    Tronik-Le Roux, Diana; Nicola, Marie-Anne; Vaigot, Pierre; Nurden, Paquita

    2015-01-01

    Hematopoietic stem cells (HSC) are essential for maintaining the integrity of complex and long-lived organisms. HSC, which are self-renewing, reconstitute the hematopoietic system through out life and facilitate long-term repopulation of myeloablated recipients. We have previously demonstrated that when mice are exposed to sublethal doses of ionizing radiation, subsets of the stem/progenitor compartment are affected. In this study we examine the role of thrombopoietin (TPO) on the regenerative capacities of HSC after irradiation and report the first demonstration of efficacy of a single injection of TPO shortly after in vivo exposure to ionizing radiation for reducing HSC injury and improving their functional outcome. Our results demonstrate that TPO treatment not only reduced the number of apoptotic cells but also induced a significant modification of their intrinsic characteristics. These findings were supported by transplantation assays with long-term HSC that were irradiated or unirradiated, TPO treated or untreated, in CD45.1/CD45.2 systems and by using luciferase-labeled HSC for direct bioluminescence imaging in living animals. Of particular importance, our data demonstrate the skull to be a highly favorable site for the TPO-induced emergence of hematopoietic cells after irradiation, suggesting a TPO-mediated relationship of primitive hematopoietic cells to an anatomical component. Together, the data presented here: provide novel findings about aspects of TPO action on stem cells, open new areas of investigation for therapeutic options in patients who are treated with radiation therapy, and show that early administration of a clinically suitable TPO-agonist counteracts the previously observed adverse effects.

  4. Detection of uranium in industrial and mines samples by microwave plasma torch mass spectrometry.

    Science.gov (United States)

    Li, Yi; Yang, Meiling; Sun, Rong; Zhong, Tao; Chen, Huanwen

    2016-02-01

    Microwave plasma torch (MPT), traditionally used as the light source for atomic emission spectrophotometry, has been employed as the ambient ionization source for sensitive detection of uranium in various ground water samples with widely available ion trap mass spectrometer. In the full-scan mass spectra obtained in the negative ion detection mode, uranium signal was featured by the uranyl nitrate complexes (e.g. [UO2 (NO3 )3 ](-) ), which yielded characteristic fragments in the tandem mass spectrometry experiments, allowing confident detection of trace uranium in water samples without sample pretreatment. Under the optimal experimental conditions, the calibration curves were linearly responded within the concentration levels ranged in 10-1000 µg·l(-1) , with the limit of detection (LOD) of 31.03 ng·l(-1) . The relative standard deviations (RSD) values were 2.1-5.8% for the given samples at 100 µg·l(-1) . The newly established method has been applied to direct detection of uranium in practical mine water samples, providing reasonable recoveries 90.94-112.36% for all the samples tested. The analysis of a single sample was completed within 30 s, showing a promising potential of the method for sensitive detection of trace uranium with improved throughput. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Ionizing radiation from tobacco

    International Nuclear Information System (INIS)

    Westin, J.B.

    1987-01-01

    Accidents at nuclear power facilities seem inevitably to bring in their wake a great deal of concern on the part of both the lay and medical communities. Relatively little attention, however, is given to what may be the largest single worldwide source of effectively carcinogenic ionizing radiation: tobacco. The risk of cancer deaths from the Chernobyl disaster are tobacco smoke is discussed

  6. Ionization chambers

    International Nuclear Information System (INIS)

    Boag, J.W.

    1987-01-01

    Although a variety of solid-state and chemical methods for measuring radiation dose have been developed in recent decades and calorimetry can now provide an absolute standard of reference, ionization dosimetry retains its position as the most widely used, most convenient, and, in most situations, most accurate method of measuring either exposure or absorbed dose. The ionization chamber itself is the central element in this system of dosimetry. In this chapter the principles governing the construction and operation of ionization chambers of various types are examined. Since the ionization chambers now in general use are nearly all of commercial manufacture, the emphasis is on operating characteristics and interpretation of measurements rather than on details of construction, although some knowledge of the latter is often required when applying necessary corrections to the measured quantities. Examples are given of the construction of typical chambers designed for particular purposes, and the methods of calibrating them are discussed

  7. Collisional ionization

    International Nuclear Information System (INIS)

    Arnaud, M.

    1985-07-01

    In low density, thin plasmas (such as stellar coronae, interstellar medium, intracluster medium) the ionization process is governed by collision between electrons and ions in their ground state. In view of the recent improvements we thought an updating of ionization rates was really needed. The work is based on both experimental data and theoretical works and give separate estimates for the direct and autoionization rates

  8. Uranium loans

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    When NUEXCO was organized in 1968, its founders conceived of a business based on uranium loans. The concept was relatively straightforward; those who found themselves with excess supplies of uranium would deposit those excesses in NUEXCO's open-quotes bank,close quotes and those who found themselves temporarily short of uranium could borrow from the bank. The borrower would pay interest based on the quantity of uranium borrowed and the duration of the loan, and the bank would collect the interest, deduct its service fee for arranging the loan, and pay the balance to those whose deposits were borrowed. In fact, the original plan was to call the firm Nuclear Bank Corporation, until it was discovered that using the word open-quotes Bankclose quotes in the name would subject the firm to various US banking regulations. Thus, Nuclear Bank Corporation became Nuclear Exchange Corporation, which was later shortened to NUEXCO. Neither the nuclear fuel market nor NUEXCO's business developed quite as its founders had anticipated. From almost the very beginning, the brokerage of uranium purchases and sales became a more significant activity for NUEXCO than arranging uranium loans. Nevertheless, loan transactions have played an important role in the international nuclear fuel market, requiring the development of special knowledge and commercial techniques

  9. The measurement test of uranium in a uranium-contaminated waste by passive gamma-rays measurement method

    CERN Document Server

    Sukegawa, Y; Ohki, K; Suzuki, S; Yoshida, M

    2002-01-01

    This report is completed about the measurement test and the proofreading of passive gamma - rays measurement method for Non - destructive assay of uranium in a uranium-contaminated waste. The following are the results of the test. 1) The estimation of the amount of uranium by ionization survey meter is difficult for low intensity of gamma-rays emitted from uranium under about 50g. 2) The estimation of the amount of uranium in the waste by NaI detector is possible in case of only uranium, but the estimation from mixed spectrums with transmission source (60-cobalt) is difficult to confirm target peaks. 3) If daughter nuclides of uranium and thorium chain of uranium ore exist, measurement by NaI detector is affected by gamma-rays from the daughter nuclides seriously-As a result, the estimation of the amount of uranium is difficult. 4) The measurement of uranium in a uranium-contaminated waste by germanium detector is possible to estimate of uranium and other nuclides. 5) As to estimation of the amount of uranium...

  10. Laser Induced Fluorescence (LIF) Measurements of Neutral (ArI) and singly-ionized (ArII) Argon in a LargeScale Helicon Plasma

    Science.gov (United States)

    Kelly, R. F.; Fisher, D. M.; Hatch, M. W.; Gilmore, M.; Dwyer, R. H.; Meany, K.; Zhang, Y.; Desjardins, T. R.

    2017-10-01

    In order to investigate the role of neutral dynamics in helicon discharges in the HelCat (Helicon-Cathode) plasma device at U. New Mexico, a Laser Induced Fluorescence (LIF) system has been developed. The LIF system is based on a >250 mW, tunable diode laser with a tuning range between 680 and 700nm. For neutral Argon, the laser pumps the metastable (2P3/20) 4s level to the (2P1/20) 4p level using 696. 7352 nm light. The fluorescence radiation from decay to the (2P1/20) 4s level at 772. 6333 nm is observed. For singly ionized Argon, the laser pumps the 3s23p4(3 P)3d level to the 3s23p4(3 P)4p level using 686.3162nm light. The fluorescence radiation from the decay to the 3s23p4(3 P)4s level is observed. The system design, and velocity measurements in the axial, azimuthal and radial directions for ArI, and in the axial direction for ArII will be presented. Supported by U.S. National Science Foundation Award 1500423.

  11. Uranium extraction from gold-uranium ores

    Energy Technology Data Exchange (ETDEWEB)

    Laskorin, B.N.; Golynko, Z.Sh.

    1981-01-01

    The process of uranium extraction from gold-uranium ores in the South Africa is considered. Flowsheets of reprocessing gold-uranium conglomerates, pile processing and uranium extraction from the ores are presented. Continuous counter flow ion-exchange process of uranium extraction using strong-active or weak-active resins is noted to be the most perspective and economical one. The ion-exchange uranium separation with the succeeding extraction is also the perspective one.

  12. Uranium mining

    International Nuclear Information System (INIS)

    2008-01-01

    Full text: The economic and environmental sustainability of uranium mining has been analysed by Monash University researcher Dr Gavin Mudd in a paper that challenges the perception that uranium mining is an 'infinite quality source' that provides solutions to the world's demand for energy. Dr Mudd says information on the uranium industry touted by politicians and mining companies is not necessarily inaccurate, but it does not tell the whole story, being often just an average snapshot of the costs of uranium mining today without reflecting the escalating costs associated with the process in years to come. 'From a sustainability perspective, it is critical to evaluate accurately the true lifecycle costs of all forms of electricity production, especially with respect to greenhouse emissions, ' he says. 'For nuclear power, a significant proportion of greenhouse emissions are derived from the fuel supply, including uranium mining, milling, enrichment and fuel manufacture.' Dr Mudd found that financial and environmental costs escalate dramatically as the uranium ore is used. The deeper the mining process required to extract the ore, the higher the cost for mining companies, the greater the impact on the environment and the more resources needed to obtain the product. I t is clear that there is a strong sensitivity of energy and water consumption and greenhouse emissions to ore grade, and that ore grades are likely to continue to decline gradually in the medium to long term. These issues are critical to the current debate over nuclear power and greenhouse emissions, especially with respect to ascribing sustainability to such activities as uranium mining and milling. For example, mining at Roxby Downs is responsible for the emission of over one million tonnes of greenhouse gases per year and this could increase to four million tonnes if the mine is expanded.'

  13. Uranium mining sites - Thematic sheets

    International Nuclear Information System (INIS)

    2009-01-01

    A first sheet proposes comments, data and key numbers about uranium extraction in France: general overview of uranium mining sites, status of waste rock and tailings after exploitation, site rehabilitation. The second sheet addresses the sources of exposure to ionizing radiations due to ancient uranium mining sites: discussion on the identification of these sources associated with these sites, properly due to mining activities or to tailings, or due to the transfer of radioactive substances towards water and to the contamination of sediments, description of the practice and assessment of radiological control of mining sites. A third sheet addresses the radiological exposure of public to waste rocks, and the dose assessment according to exposure scenarios: main exposure ways to be considered, studied exposure scenarios (passage on backfilled path and grounds, stay in buildings built on waste rocks, keeping mineralogical samples at home). The fourth sheet addresses research programmes of the IRSN on uranium and radon: epidemiological studies (performed on mine workers; on French and on European cohorts, French and European studies on the risk of lung cancer associated with radon in housing), study of the biological effects of chronic exposures. The last sheet addresses studies and expertises performed by the IRSN on ancient uranium mining sites in France: studies commissioned by public authorities, radioactivity control studies performed by the IRSN about mining sites, participation of the IRSN to actions to promote openness to civil society

  14. Uranium enrichment

    International Nuclear Information System (INIS)

    Rae, H.K.; Melvin, J.G.

    1988-06-01

    Canada is the world's largest producer and exporter of uranium, most of which is enriched elsewhere for use as fuel in LWRs. The feasibility of a Canadian uranium-enrichment enterprise is therefore a perennial question. Recent developments in uranium-enrichment technology, and their likely impacts on separative work supply and demand, suggest an opportunity window for Canadian entry into this international market. The Canadian opportunity results from three particular impacts of the new technologies: 1) the bulk of the world's uranium-enrichment capacity is in gaseous diffusion plants which, because of their large requirements for electricity (more than 2000 kW·h per SWU), are vulnerable to competition from the new processes; 2) the decline in enrichment costs increases the economic incentive for the use of slightly-enriched uranium (SEU) fuel in CANDU reactors, thus creating a potential Canadian market; and 3) the new processes allow economic operation on a much smaller scale, which drastically reduces the investment required for market entry and is comparable with the potential Canadian SEU requirement. The opportunity is not open-ended. By the end of the century the enrichment supply industry will have adapted to the new processes and long-term customer/supplier relationships will have been established. In order to seize the opportunity, Canada must become a credible supplier during this century

  15. Radiological health aspects of uranium milling

    International Nuclear Information System (INIS)

    Fisher, D.R.; Stoetzel, G.A.

    1983-05-01

    This report describes the operation of conventional and unconventional uranium milling processes, the potential for occupational exposure to ionizing radiation at the mill, methods for radiological safety, methods of evaluating occupational radiation exposures, and current government regulations for protecting workers and ensuring that standards for radiation protection are adhered to. In addition, a survey of current radiological health practices is summarized

  16. Radiological health aspects of uranium milling

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, D.R.; Stoetzel, G.A.

    1983-05-01

    This report describes the operation of conventional and unconventional uranium milling processes, the potential for occupational exposure to ionizing radiation at the mill, methods for radiological safety, methods of evaluating occupational radiation exposures, and current government regulations for protecting workers and ensuring that standards for radiation protection are adhered to. In addition, a survey of current radiological health practices is summarized.

  17. Ultrasensitive analysis of thorium by resonance ionization mass spectroscopy (RIMS)

    International Nuclear Information System (INIS)

    Johnson, S.G.; Nogar, N.S.; Miller, C.M.; Murrell, M.T.; Fearey, B.L.

    1991-01-01

    This communication presents results on a RIMS analysis of thorium. Thorium is of interest for geochronological and geochemical purposes. The measurement of uranium series disequilibrium is a well established and valuable approach for geochronological studies: disequilibrium between 234/238 U and 230 Th can be used to date samples younger than 350,000 years. Both continuous wave (cw) and pulsed lasers were utilized in this study for resonantly exciting and subsequently ionizing thorium. In the case of the pulsed laser RIMS experiments, two excimer laser-pumped dye lasers were used in conjunction with a 0.4 m time-of-flight mass spectrometer. The cw RIMS experiments used an Ar + laser-pumped dye laser and a second Ar + in combination with a single magnetic sector mass spectrometer (NBS 12-90 design). Experiments performed with the pulsed RIMS apparatus were aimed at determining the autoionization state structure and re-determining the ionization potential (IP). By tuning one dye laser to a resonance and scanning the second laser such that the total energy was equal to or above the IP, over 150 autoionization states were determined. The IP was re-determined to be 6.211±.002 eV (50900 ± 20 cm -1 ). In addition, the typical cross section for ionization of an autoionizing state was determined to be 1 x 10 -15 cm 2

  18. Determination of residual 1,4-dioxane in surfactants and cleaning agents using headspace single-drop microextraction followed by gas chromatography-flame ionization detection.

    Science.gov (United States)

    Saraji, M; Shirvani, N

    2017-02-01

    Polyethoxylated surfactants are widely used in the formulation of different cleaning agents such as shampoo, dish washing and hand washing products and lotion formulation. During the production of polyethoxylated surfactants, 1,4-dioxane as a toxic and carcinogenic by-product is formed. A simple low-cost method based on headspace single-drop microextraction combined with gas chromatography-flame ionization detection was developed for the determination of 1,4-dioxane in surfactants and cleaning agents. In this method, 1,4-dioxane was extracted from 8.0 mL sample solution into a microdrop of an organic solvent, and then, it was injected to gas chromatography. The effects of such parameters as the solvent type, salt addition, microdrop volume, stirring rate, equilibrium time, extraction time and the temperature of sample solution on the extraction performance were studied and optimized. An ethoxylated surfactant containing 1,4-dioxane was used as the sample for the optimization of the extraction parameters. The linear range, determination coefficient, limit of detection and relative standard deviation of the method were 0.5-100 μg g -1 , 0.9977, 0.4 μg g -1 and 7.2% (n = 5), respectively. Different real samples including sodium lauryl ether sulphate, sodium lauryl sulphate (SLS), four brands of shampoo, and hand washing and dish washing liquids were analysed by the method. 1,4-Dioxane was detected at the concentration range of 2.4-201 μg g -1 in the samples, except dish washing liquid and SLS. A new method with the merits of simplicity, low cost, low organic solvent consumption, short analysis time, good repeatability and suitable detection limit was developed for the analysis of 1,4-dioxane in surfactants and cleaning agents. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  19. Machining of uranium and uranium alloys

    International Nuclear Information System (INIS)

    Morris, T.O.

    1981-01-01

    Uranium and uranium alloys can be readily machined by conventional methods in the standard machine shop when proper safety and operating techniques are used. Material properties that affect machining processes and recommended machining parameters are discussed. Safety procedures and precautions necessary in machining uranium and uranium alloys are also covered. 30 figures

  20. A single-electron picture based on the multiconfiguration time-dependent Hartree-Fock method: application to the anisotropic ionization and subsequent high-harmonic generation of the CO molecule

    Science.gov (United States)

    Ohmura, S.; Kato, T.; Oyamada, T.; Koseki, S.; Ohmura, H.; Kono, H.

    2018-02-01

    The mechanisms of anisotropic near-IR tunnel ionization and high-order harmonic generation (HHG) in a CO molecule are theoretically investigated by using the multiconfiguration time-dependent Hartree-Fock (MCTDHF) method developed for the simulation of multielectron dynamics of molecules. The multielectron dynamics obtained by numerically solving the equations of motion (EOMs) in the MCTDHF method is converted to a single orbital picture in the natural orbital representation where the first-order reduced density matrix is diagonalized. The ionization through each natural orbital is examined and the process of HHG is classified into different optical paths designated by a combinations of initial, intermediate and final natural orbitals. The EOMs for natural spin-orbitals are also derived within the framework of the MCTDHF, which maintains the first-order reduced density matrix to be a diagonal one throughout the time propagation of a many-electron wave function. The orbital dependent, time-dependent effective potentials that govern the dynamics of respective time-dependent natural orbitals are deduced from the derived EOMs, of which the temporal variation can be used to interpret the motion of the electron density associated with each natural spin-orbital. The roles of the orbital shape, multiorbital ionization, linear Stark effect and multielectron interaction in the ionization and HHG of a CO molecule are revealed by the effective potentials obtained. When the laser electric field points to the nucleus O from C, tunnel ionization from the C atom side is enhanced; a hump structure originating from multielectron interaction is then formed on the top of the field-induced distorted barrier of the HOMO effective potential. This hump formation, responsible for the directional anisotropy of tunnel ionization, restrains the influence of the linear Stark effect on the energy shifts of bound states.

  1. Uranium concentrates

    International Nuclear Information System (INIS)

    Boutonnet, G.

    1985-01-01

    Fabrication processes and main characteristics of the yellow coke are described. Choice of acidic or alkaline process, chemical reactions reagents, installation and efficiency are examined. Investment, cost and production are given. Extraction of uranium from phosphoric acid is briefly described [fr

  2. Uranium industry annual 1996

    International Nuclear Information System (INIS)

    1997-04-01

    The Uranium Industry Annual 1996 (UIA 1996) provides current statistical data on the US uranium industry's activities relating to uranium raw materials and uranium marketing. The UIA 1996 is prepared for use by the Congress, Federal and State agencies, the uranium and nuclear electric utility industries, and the public. Data on uranium raw materials activities for 1987 through 1996 including exploration activities and expenditures, EIA-estimated reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities for 1994 through 2006, including purchases of uranium and enrichment services, enrichment feed deliveries, uranium fuel assemblies, filled and unfilled market requirements, uranium imports and exports, and uranium inventories are shown in Chapter 2. A feature article, The Role of Thorium in Nuclear Energy, is included. 24 figs., 56 tabs

  3. Uranium industry annual 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    The Uranium Industry Annual 1996 (UIA 1996) provides current statistical data on the US uranium industry`s activities relating to uranium raw materials and uranium marketing. The UIA 1996 is prepared for use by the Congress, Federal and State agencies, the uranium and nuclear electric utility industries, and the public. Data on uranium raw materials activities for 1987 through 1996 including exploration activities and expenditures, EIA-estimated reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities for 1994 through 2006, including purchases of uranium and enrichment services, enrichment feed deliveries, uranium fuel assemblies, filled and unfilled market requirements, uranium imports and exports, and uranium inventories are shown in Chapter 2. A feature article, The Role of Thorium in Nuclear Energy, is included. 24 figs., 56 tabs.

  4. Uranium mining

    International Nuclear Information System (INIS)

    Cheeseman, E.W.

    1980-01-01

    The international uranium market appears to be currently over-supplied with a resultant softening in prices. Buyers on the international market are unhappy about some of the restrictions placed on sales by the government, and Canadian sales may suffer as a result. About 64 percent of Canada's shipments come from five operating Ontario mines, with the balance from Saskatchewan. Several other properties will be producing within the next few years. In spite of the adverse effects of the Three Mile Island incident and the default by the T.V.A. of their contract, some 3 600 tonnes of new uranium sales were completed during the year. The price for uranium had stabilized at US $42 - $44 by mid 1979, but by early 1980 had softened somewhat. The year 1979 saw the completion of major environmental hearings in Ontario and Newfoundland and the start of the B.C. inquiry. Two more hearings are scheduled for Saskatchewan in 1980. The Elliot Lake uranium mining expansion hearings are reviewed, as are other recent hearings. In the production of uranium for nuclear fuel cycle, environmental matters are of major concern to the industry, the public and to governments. Research is being conducted to determine the most effective method for removing radium from tailings area effluents. Very stringent criteria are being drawn up by the regulatory agencies that must be met by the industry in order to obtain an operating licence from the AECB. These criteria cover seepages from the tailings basin and through the tailings retention dam, seismic stability, and both short and long term management of the tailings waste management area. (auth)

  5. Uranium industry annual, 1991

    International Nuclear Information System (INIS)

    1992-10-01

    In the Uranium Industry Annual 1991, data on uranium raw materials activities including exploration activities and expenditures, resources and reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities including domestic uranium purchases, commitments by utilities, procurement arrangements, uranium imports under purchase contracts and exports, deliveries to enrichment suppliers, inventories, secondary market activities, utility market requirements, and uranium for sale by domestic suppliers are presented in Chapter 2. A feature article entitled ''The Uranium Industry of the Commonwealth of Independent States'' is included in this report

  6. Moving to world's best uranium address

    International Nuclear Information System (INIS)

    Noakes, Frank

    2006-01-01

    Most exploration dollars spent in South Australia are focused on exploiting uranium. This is for good reason as South Australia is the world's best address for uranium. Pressure to cut CO 2 emissions and the ballistic growth of the Chinese and Indian economies has heightened expectations that the worldwide use of uranium for power generation will mushroom beyond its current 17% market share. The recent Australia-China deal only seems to confirm this; hence uranium's growing popularity among miners and explorers. Such is the attractiveness of uranium-related floats, when Toro Energy sought $18m in March it was swamped with more than three times share application volume. In the north west, Southern Gold and Hindmarsh Resources are expectantly drilling for commercial uranium deposits all around the acreage that hosts the Challenger gold mine in the Gawler Craton. The first exploration drilling for uranium in quaternary-age river channels will take place in South Australia's far north in May. Red Metal says while older and deeper tertiary river channels in the area that host the Beverley uranium mine were explored for uranium, the younger near-surface channel has not had a single hole drilled for uranium. This is despite the area being one of the 'hottest radiogenic terrains in South Australia'. The company will target calcrete-style uranium mineralisation similar to the Yerrlirrie deposit in Western Australia (52,000t U308). Tasman Resources will start drilling to test seven uranium targets within 30km of Olympic Dam, the world's largest known uranium deposit, later this year. Tasman also holds tenements adjoining the Warrior uranium deposit near Tarcoola that contains known radiometric anomalies within the 40km-long Wynbring paleochannels. They are the fourth largest uranium explorer in South Australia. Alliance Resources and its JV partner Quasar Resources are exploring the Beverley 4 Mile uranium prospect at Arkaroola. Quasar is an affiliate of Heathgate Resources

  7. PREPARATION OF URANIUM MONOSULFIDE

    Science.gov (United States)

    Yoshioka, K.

    1964-01-28

    A process is given for preparing uranium monosulfide from uranium tetrafluoride dissolved in molten alkali metal chloride. A hydrogen-hydrogen sulfide gas mixture passed through the solution precipitates uranium monosulfide. (AEC)

  8. Recovery of uranium

    International Nuclear Information System (INIS)

    Clemens, D.H.; Walker, R.W.; Hurwitz, M.J.

    1974-01-01

    A process for recovering uranium from an uranium bearing liquid which comprises contacting the liquid with a crosslinkedvinyl benzyl chloride polymer, thereafter eluting from the resin the uranium in salt form

  9. Overview of Canada's uranium industry

    International Nuclear Information System (INIS)

    Lowell, A.F.

    1982-06-01

    This paper places Canada's uranium industry in its international context. Most uranium, except that produced in the United States, is traded internationally. A brief history of the industry worldwide is given to show how the principal producing areas have fared to date. The industry is young, highly cyclical, and still far from achieving stability. Uranium is a single end-use commodity, entirely dependent on the generation of electricity in nuclear stations, and is without price elasticity: lowering the price does not increase demand. The typical nuclear fuel processing chain has not encouraged or led to much vertical integration. Uranium is subject to more governmental control than any other commodity. The principal market is located in the industrial countries of western Europe, the United States, Canada, and the far east. The uranium supply-demand situation is reviewed, including the current and near-term oversupply and the longer term outlook to 1995. The major negative impact of reactor cancellations and deferments in the United States is discussed. Because of the difficulty in getting reactors on line, it has become easier to forecast the demand for uranium over the next 10 years. It is more difficult to predict how that demand will be met from the more than ample competing sources. Canada's potential for supplying a significant portion of this demand is considered in relation to producers and potential new producers in other countries

  10. Uranium mineralogy

    International Nuclear Information System (INIS)

    Smith, D.K. Jr.

    1984-01-01

    The subject is discussed under the headings: introduction; U 4+ minerals (uraninite; coffinite; brannerite; ningyoite; lermontovite; U 4+ molybdates; U 4+ pyrochlores; U 4+ columbites; petscheckite and liandratite) minerals (uranyl oxide hydrates; uranyl silicates; uranyl phosphates and arsenates; uranyl vanadates; uranyl molybdates; uranyl sulphates; uranyl carbonates; uranyl selenates and tellurates). Appendices contain X-ray data and optical data for uranium minerals. (U.K.)

  11. Groundwater prospecting for sandstone-type uranium deposits: the merits of mineral-solution equilibria versus single element tracer methods. Volume II

    Energy Technology Data Exchange (ETDEWEB)

    Wanty, R.B.; Langmuir, D.; Chatham, J.R.

    1981-08-01

    This report presents the results of further research on the groundwater geochemistry of 96 well waters in two uraniferous aquifers in Texas and Wyoming, and is a continuation of the work presented by Chatham et al. (1981). In this study variations in concentrations of U, As, Mo, Se and V were compared with the saturation state of the groundwater with respect to mineral phases of these elements known or expected to occur in each area. The non-radiogenic trace elements exhibited strong redox dependence consistent with thermodynamic predictions, but their variations did not pinpoint existing uranium ore bodies, because of a shift in groundwater flow patterns since the time of ore emplacement. Saturation levels of trace element minerals such as realgar, native Se, and molybdenite showed broad anomalies around the ore-bearing areas, similar to patterns found for U minerals by Langmuir and Chatham (1980), and Chatham et al. (1981). The radiogenic elements Ra and Rn showed significant anomalies directly within the ore zones. Helium anomalies were displaced in the direction of groundwater flow, but by their magnitude and areal extent provided strong evidence for the existence of nearby uranium accumulations. Uranium isotope ratios showed no systematic variations within the two aquifers studied. Saturation maps for kaolinite, illite, montmorillonite and the zeolites analcime and clinoptilolite provided 1 to 2 km anomalies around the ore at the Texas site. Saturation values for the gangue minerals pyrite and calcite defined the redox interface and often suggested the position of probable uranium mineralization. When properly used, the groundwater geochemical concepts for exploration can accurately pinpoint uranium mineralization at a fraction of the cost of conventional methods that involve test drilling and geophysical and core logging.

  12. Groundwater prospecting for sandstone-type uranium deposits: the merits of mineral-solution equilibria versus single element tracer methods. Volume II

    International Nuclear Information System (INIS)

    Wanty, R.B.; Langmuir, D.; Chatham, J.R.

    1981-08-01

    This report presents the results of further research on the groundwater geochemistry of 96 well waters in two uraniferous aquifers in Texas and Wyoming, and is a continuation of the work presented by Chatham et al. (1981). In this study variations in concentrations of U, As, Mo, Se and V were compared with the saturation state of the groundwater with respect to mineral phases of these elements known or expected to occur in each area. The non-radiogenic trace elements exhibited strong redox dependence consistent with thermodynamic predictions, but their variations did not pinpoint existing uranium ore bodies, because of a shift in groundwater flow patterns since the time of ore emplacement. Saturation levels of trace element minerals such as realgar, native Se, and molybdenite showed broad anomalies around the ore-bearing areas, similar to patterns found for U minerals by Langmuir and Chatham (1980), and Chatham et al. (1981). The radiogenic elements Ra and Rn showed significant anomalies directly within the ore zones. Helium anomalies were displaced in the direction of groundwater flow, but by their magnitude and areal extent provided strong evidence for the existence of nearby uranium accumulations. Uranium isotope ratios showed no systematic variations within the two aquifers studied. Saturation maps for kaolinite, illite, montmorillonite and the zeolites analcime and clinoptilolite provided 1 to 2 km anomalies around the ore at the Texas site. Saturation values for the gangue minerals pyrite and calcite defined the redox interface and often suggested the position of probable uranium mineralization. When properly used, the groundwater geochemical concepts for exploration can accurately pinpoint uranium mineralization at a fraction of the cost of conventional methods that involve test drilling and geophysical and core logging

  13. Uranium concentrations in groundwater, northeastern Washington

    Science.gov (United States)

    Kahle, Sue C.; Welch, Wendy B.; Tecca, Alison E.; Eliason, Devin M.

    2018-04-18

    A study of uranium in groundwater in northeastern Washington was conducted to make a preliminary assessment of naturally occurring uranium in groundwater relying on existing information and limited reconnaissance sampling. Naturally occurring uranium is associated with granitic and metasedimentary rocks, as well as younger sedimentary deposits, that occur in this region. The occurrence and distribution of uranium in groundwater is poorly understood. U.S. Environmental Protection Agency (EPA) regulates uranium in Group A community water systems at a maximum contaminant level (MCL) of 30 μg/L in order to reduce uranium exposure, protect from toxic kidney effects of uranium, and reduce the risk of cancer. However, most existing private wells in the study area, generally for single family use, have not been sampled for uranium. This document presents available uranium concentration data from throughout a multi-county region, identifies data gaps, and suggests further study aimed at understanding the occurrence of uranium in groundwater.The study encompasses about 13,000 square miles (mi2) in the northeastern part of Washington with a 2010 population of about 563,000. Other than the City of Spokane, most of the study area is rural with small towns interspersed throughout the region. The study area also includes three Indian Reservations with small towns and scattered population. The area has a history of uranium exploration and mining, with two inactive uranium mines on the Spokane Indian Reservation and one smaller inactive mine on the outskirts of Spokane. Historical (1977–2016) uranium in groundwater concentration data were used to describe and illustrate the general occurrence and distribution of uranium in groundwater, as well as to identify data deficiencies. Uranium concentrations were detected at greater than 1 microgram per liter (μg/L) in 60 percent of the 2,382 historical samples (from wells and springs). Uranium concentrations ranged from less than 1 to

  14. Evaluation exposure to the ionizing radiation of workers during the operation of first Brazilian uranium mine; Avaliacao da exposicao de trabalhadores a radiacao ionizante durante a operacao da primeira mina de uranio do Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Wagner de S.; Oliveira, Sergio Q. de; Py Junior, Delcy de A.; Dantas, Marcelino V.A.; Silva, Ana Claudia A.; Garcia Filho, Oswaldo, E-mail: wspereira@inb.gov.b, E-mail: sergioquinet@inb.gov.b, E-mail: delcy@inb.gov.b, E-mail: marcelino@inb.gov.b, E-mail: anasilva@inb.gov.b, E-mail: ogarcia@inb.gov.b [Industrias Nucleares do Brasil (UTM/INB), Pocos de Caldas, MG (Brazil). Unidade de Tratamento de Minerios. Servico de Radioprotecao

    2011-10-26

    The production of uranium in Brazil initiated, in industrial scale, in the year of 1982, in the Miner-Industrial Complex at Pocos de Caldas, Minas Gerais, Brazil. This paper analysed the data of 13410 individual historic of dose, registered along the years of work, bay the radioprotection service of installation. Descriptive statistics and frequency histograms based on dose historic, and the annual distribution doses and the accumulated doses were evaluated during the functioning period of the CIPC, and his adequacy to the in force legislation at the time of it operation

  15. A 0.18 micrometer CMOS Thermopile Readout ASIC Immune to 50 MRAD Total Ionizing Dose (SI) and Single Event Latchup to 174MeV-cm(exp 2)/mg

    Science.gov (United States)

    Quilligan, Gerard T.; Aslam, Shahid; Lakew, Brook; DuMonthier, Jeffery J.; Katz, Richard B.; Kleyner, Igor

    2014-01-01

    Radiation hardened by design (RHBD) techniques allow commercial CMOS circuits to operate in high total ionizing dose and particle fluence environments. Our radiation hard multi-channel digitizer (MCD) ASIC (Figure 1) is a versatile analog system on a chip (SoC) fabricated in 180nm CMOS. It provides 18 chopper stabilized amplifier channels, a 16- bit sigma-delta analog-digital converter (SDADC) and an on-chip controller. The MCD was evaluated at Goddard Space Flight Center and Texas A&M University's radiation effects facilities and found to be immune to single event latchup (SEL) and total ionizing dose (TID) at 174 MeV-cm(exp 2)/mg and 50 Mrad (Si) respectively.

  16. Uranium industry annual, 1986

    International Nuclear Information System (INIS)

    1987-01-01

    Uranium industry data collected in the EIA-858 survey provide a comprehensive statistical characterization of annual activities of the industry and include some information about industry plans over the next several years. This report consists of two major sections. The first addresses uranium raw materials activities and covers the following topics: exploration activities and expenditures, resources and reserves, mine production of uranium, production of uranium concentrate, and industry employment. The second major section is concerned with the following uranium marketing activities: uranium purchase commitments, uranium prices, procurement arrangements, uranium imports and exports, enrichment services, inventories, secondary market activities utility market requirements and related topics

  17. Uranium Mines and Mills Location Database

    Science.gov (United States)

    EPA has compiled mine location information from federal, state, and Tribal agencies into a single database as part of its investigation into the potential environmental hazards of wastes from abandoned uranium mines in the western United States.

  18. Uranium Industry Annual, 1992

    International Nuclear Information System (INIS)

    1993-01-01

    The Uranium Industry Annual provides current statistical data on the US uranium industry for the Congress, Federal and State agencies, the uranium and electric utility industries, and the public. The feature article, ''Decommissioning of US Conventional Uranium Production Centers,'' is included. Data on uranium raw materials activities including exploration activities and expenditures, resources and reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities including domestic uranium purchases, commitments by utilities, procurement arrangements, uranium imports under purchase contracts and exports, deliveries to enrichment suppliers, inventories, secondary market activities, utility market requirements, and uranium for sale by domestic suppliers are presented in Chapter 2

  19. Uranium Industry Annual, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-28

    The Uranium Industry Annual provides current statistical data on the US uranium industry for the Congress, Federal and State agencies, the uranium and electric utility industries, and the public. The feature article, ``Decommissioning of US Conventional Uranium Production Centers,`` is included. Data on uranium raw materials activities including exploration activities and expenditures, resources and reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities including domestic uranium purchases, commitments by utilities, procurement arrangements, uranium imports under purchase contracts and exports, deliveries to enrichment suppliers, inventories, secondary market activities, utility market requirements, and uranium for sale by domestic suppliers are presented in Chapter 2.

  20. Provision by the uranium and uranium products

    International Nuclear Information System (INIS)

    Elagin, Yu.P.

    2005-01-01

    International uranium market is converted from the buyer market into the seller market. The prices of uranium are high and the market attempts to adapt to changing circumstances. The industry of uranium enrichment satisfies the increasing demands but should to increase ots capacities. On the whole the situation is not stable and every year may change the existing position [ru

  1. Uranium recovery from slags of metallic uranium

    International Nuclear Information System (INIS)

    Fornarolo, F.; Frajndlich, E.U.C.; Durazzo, M.

    2006-01-01

    The Center of the Nuclear Fuel of the Institute of Nuclear Energy Research - IPEN finished the program of attainment of fuel development for research reactors the base of Uranium Scilicet (U 3 Si 2 ) from Hexafluoride of Uranium (UF 6 ) with enrichment 20% in weight of 235 U. In the process of attainment of the league of U 3 Si 2 we have as Uranium intermediate product the metallic one whose attainment generates a slag contend Uranium. The present work shows the results gotten in the process of recovery of Uranium in slags of calcined slags of Uranium metallic. Uranium the metallic one is unstable, pyrophoricity and extremely reactive, whereas the U 3 O 8 is a steady oxide of low chemical reactivity, what it justifies the process of calcination of slags of Uranium metallic. The calcination of the Uranium slag of the metallic one in oxygen presence reduces Uranium metallic the U 3 O 8 . Experiments had been developed varying it of acid for Uranium control and excess, nitric molar concentration gram with regard to the stoichiometric leaching reaction of temperature of the leaching process. The 96,0% income proves the viability of the recovery process of slags of Uranium metallic, adopting it previous calcination of these slags in nitric way with low acid concentration and low temperature of leaching. (author)

  2. Radiating toxicological and ecological consequences of extraction of uranium

    International Nuclear Information System (INIS)

    Svambaev, Z.A.; Svambaev, E.A.; Sultanbekov, G.A; Tusupbekova, S.T.

    2010-01-01

    In scientific work researchers take up questions of radiation, toxicity and ecological danger at extraction of natural uranium. In work it is resulted results of gauging of radiation in separate parts of a cycle, and also as a whole at underground extractions of uranium. The level of ionization actions of photon radiation in a radiating field with a productive solution which represents the big radiating, toxicological and ecological danger to Wednesday is shown on the average on cycles of feature of work.

  3. Resonance Ionization Laser Ion Sources

    CERN Document Server

    Marsh, B

    2013-01-01

    The application of the technique of laser resonance ionization to the production of singly charged ions at radioactive ion beam facilities is discussed. The ability to combine high efficiency and element selectivity makes a resonance ionization laser ion source (RILIS) an important component of many radioactive ion beam facilities. At CERN, for example, the RILIS is the most commonly used ion source of the ISOLDE facility, with a yearly operating time of up to 3000 hours. For some isotopes the RILIS can also be used as a fast and sensitive laser spectroscopy tool, provided that the spectral resolution is sufficiently high to reveal the influence of nuclear structure on the atomic spectra. This enables the study of nuclear properties of isotopes with production rates even lower than one ion per second and, in some cases, enables isomer selective ionization. The solutions available for the implementation of resonance laser ionization at radioactive ion beam facilities are summarized. Aspects such as the laser r...

  4. Uranium conversion; Urankonvertering

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, Lena; Peterson, Jenny; Wilhelmsen, Katarina [Swedish Defence Research Agency (FOI), Stockholm (Sweden)

    2006-03-15

    FOI, has performed a study on uranium conversion processes that are of importance in the production of different uranium compounds in the nuclear industry. The same conversion processes are of interest both when production of nuclear fuel and production of fissile material for nuclear weapons are considered. Countries that have nuclear weapons ambitions, with the intention to produce highly enriched uranium for weapons purposes, need some degree of uranium conversion capability depending on the uranium feed material available. This report describes the processes that are needed from uranium mining and milling to the different conversion processes for converting uranium ore concentrate to uranium hexafluoride. Uranium hexafluoride is the uranium compound used in most enrichment facilities. The processes needed to produce uranium dioxide for use in nuclear fuel and the processes needed to convert different uranium compounds to uranium metal - the form of uranium that is used in a nuclear weapon - are also presented. The production of uranium ore concentrate from uranium ore is included since uranium ore concentrate is the feed material required for a uranium conversion facility. Both the chemistry and principles or the different uranium conversion processes and the equipment needed in the processes are described. Since most of the equipment that is used in a uranium conversion facility is similar to that used in conventional chemical industry, it is difficult to determine if certain equipment is considered for uranium conversion or not. However, the chemical conversion processes where UF{sub 6} and UF{sub 4} are present require equipment that is made of corrosion resistant material.

  5. Label-free Quantification of Proteins in Single Embryonic Cells with Neural Fate in the Cleavage-Stage Frog (Xenopus laevis) Embryo using Capillary Electrophoresis Electrospray Ionization High-Resolution Mass Spectrometry (CE-ESI-HRMS).

    Science.gov (United States)

    Lombard-Banek, Camille; Reddy, Sushma; Moody, Sally A; Nemes, Peter

    2016-08-01

    Quantification of protein expression in single cells promises to advance a systems-level understanding of normal development. Using a bottom-up proteomic workflow and multiplexing quantification by tandem mass tags, we recently demonstrated relative quantification between single embryonic cells (blastomeres) in the frog (Xenopus laevis) embryo. In this study, we minimize derivatization steps to enhance analytical sensitivity and use label-free quantification (LFQ) for single Xenopus cells. The technology builds on a custom-designed capillary electrophoresis microflow-electrospray ionization high-resolution mass spectrometry platform and LFQ by MaxLFQ (MaxQuant). By judiciously tailoring performance to peptide separation, ionization, and data-dependent acquisition, we demonstrate an ∼75-amol (∼11 nm) lower limit of detection and quantification for proteins in complex cell digests. The platform enabled the identification of 438 nonredundant protein groups by measuring 16 ng of protein digest, or embryo. LFQ intensity was validated as a quantitative proxy for protein abundance. Correlation analysis was performed to compare protein quantities between the embryo and n = 3 different single D11 blastomeres, which are fated to develop into the nervous system. A total of 335 nonredundant protein groups were quantified in union between the single D11 cells spanning a 4 log-order concentration range. LFQ and correlation analysis detected expected proteomic differences between the whole embryo and blastomeres, and also found translational differences between individual D11 cells. LFQ on single cells raises exciting possibilities to study gene expression in other cells and models to help better understand cell processes on a systems biology level. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Label-free Quantification of Proteins in Single Embryonic Cells with Neural Fate in the Cleavage-Stage Frog (Xenopus laevis) Embryo using Capillary Electrophoresis Electrospray Ionization High-Resolution Mass Spectrometry (CE-ESI-HRMS)*

    Science.gov (United States)

    Lombard-Banek, Camille; Reddy, Sushma; Moody, Sally A.; Nemes, Peter

    2016-01-01

    Quantification of protein expression in single cells promises to advance a systems-level understanding of normal development. Using a bottom-up proteomic workflow and multiplexing quantification by tandem mass tags, we recently demonstrated relative quantification between single embryonic cells (blastomeres) in the frog (Xenopus laevis) embryo. In this study, we minimize derivatization steps to enhance analytical sensitivity and use label-free quantification (LFQ) for single Xenopus cells. The technology builds on a custom-designed capillary electrophoresis microflow-electrospray ionization high-resolution mass spectrometry platform and LFQ by MaxLFQ (MaxQuant). By judiciously tailoring performance to peptide separation, ionization, and data-dependent acquisition, we demonstrate an ∼75-amol (∼11 nm) lower limit of detection and quantification for proteins in complex cell digests. The platform enabled the identification of 438 nonredundant protein groups by measuring 16 ng of protein digest, or embryo. LFQ intensity was validated as a quantitative proxy for protein abundance. Correlation analysis was performed to compare protein quantities between the embryo and n = 3 different single D11 blastomeres, which are fated to develop into the nervous system. A total of 335 nonredundant protein groups were quantified in union between the single D11 cells spanning a 4 log-order concentration range. LFQ and correlation analysis detected expected proteomic differences between the whole embryo and blastomeres, and also found translational differences between individual D11 cells. LFQ on single cells raises exciting possibilities to study gene expression in other cells and models to help better understand cell processes on a systems biology level. PMID:27317400

  7. PRODUCTION OF URANIUM TETRACHLORIDE

    Science.gov (United States)

    Calkins, V.P.

    1958-12-16

    A process is descrlbed for the production of uranium tetrachloride by contacting uranlum values such as uranium hexafluoride, uranlum tetrafluoride, or uranium oxides with either aluminum chloride, boron chloride, or sodium alumlnum chloride under substantially anhydrous condltlons at such a temperature and pressure that the chlorldes are maintained in the molten form and until the uranium values are completely converted to uranlum tetrachloride.

  8. Uranium processing and properties

    CERN Document Server

    2013-01-01

    Covers a broad spectrum of topics and applications that deal with uranium processing and the properties of uranium Offers extensive coverage of both new and established practices for dealing with uranium supplies in nuclear engineering Promotes the documentation of the state-of-the-art processing techniques utilized for uranium and other specialty metals

  9. Uranium enrichment plans

    International Nuclear Information System (INIS)

    Gagne, R.W.; Thomas, D.C.

    1977-01-01

    The status of existing uranium enrichment contracts in the US is reviewed and expected natural uranium requirements for existing domestic uranium enrichment contracts are evaluated. Uncertainty in natural uranium requirements associated with requirements-type and fixed-commitment type contracts is discussed along with implementation of variable tails assay

  10. Issues in uranium availability

    International Nuclear Information System (INIS)

    Schanz, J.J. Jr.; Adams, S.S.; Gordon, R.L.

    1982-01-01

    The purpose of this publication is to show the process by which information about uranium reserves and resources is developed, evaluated and used. The following three papers in this volume have been abstracted and indexed for the Energy Data Base: (1) uranium reserve and resource assessment; (2) exploration for uranium in the United States; (3) nuclear power, the uranium industry, and resource development

  11. Irradiated uranium reprocessing

    International Nuclear Information System (INIS)

    Gal, I.

    1961-12-01

    Task concerned with reprocessing of irradiated uranium covered the following activities: implementing the method and constructing the cell for uranium dissolving; implementing the procedure for extraction of uranium, plutonium and fission products from radioactive uranium solutions; studying the possibilities for using inorganic ion exchangers and adsorbers for separation of U, Pu and fission products

  12. Uranium enrichment plans

    International Nuclear Information System (INIS)

    Thomas, D.C.; Gagne, R.W.

    1978-01-01

    The following topics are covered: the status of the Government's existing uranium enrichment services contracts, natural uranium requirements based on the latest contract information, uncertainty in predicting natural uranium requirements based on uranium enrichment contracts, and domestic and foreign demand assumed in enrichment planning

  13. Ionizing radiations

    International Nuclear Information System (INIS)

    2009-01-01

    After having recalled some fundamental notions and measurement units related to ionizing radiations, this document describes various aspects of natural and occupational exposures: exposure modes and sources, exposure levels, biological effects, health impacts. Then, it presents prevention principles aimed at, in an occupational context of use of radiation sources (nuclear industry excluded), reducing and managing these exposures: risk assessment, implementation of safety from the front end. Some practical cases illustrate the radiation protection approach. The legal and regulatory framework is presented: general notions, worker exposure, measures specific to some worker categories (pregnant and breast feeding women, young workers, temporary workers). A last part describes what is to be done in case of incident or accident (dissemination of radioactive substances from unsealed sources, anomaly occurring when using a generator or a sealed source, post-accident situation)

  14. Graphene-based filament material for thermal ionization

    Energy Technology Data Exchange (ETDEWEB)

    Hewitt, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Shick, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Siegfried, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-09-19

    The use of graphene oxide materials for thermal ionization mass spectrometry analysis of plutonium and uranium has been investigated. Filament made from graphene oxide slurries have been 3-D printed. A method for attaching these filaments to commercial thermal ionization post assemblies has been devised. Resistive heating of the graphene based filaments under high vacuum showed stable operation in excess of 4 hours. Plutonium ion production has been observed in an initial set of filaments spiked with the Pu 128 Certified Reference Material.

  15. Automated uranium determination in solutions

    International Nuclear Information System (INIS)

    Radil, V.; Bankova, Z.; Homolka, V.

    1983-01-01

    An extraction spectrophotometric method was developed for the automated determination of uranium in solutions used in chemical extraction and hydrometallurgical processing of uranium ore. The method is based on the separation of uranium from accompanying elements by extraction from the 6 N HCl medium using tributyl phosphate and on its reaction with the arsenazo 3 reagent in the single phase medium tributyl phosphate - benzene - ethanol - water. An analyzer has been designed and constructed operating on the same principle. The analyzer is discontinuous, peristaltic pumps are used for mixing and dosing the solutions. The evaluation cycle is electronically controlled, the results are recorded with a recorder or digital voltmeter with a printer. (M.D.)

  16. Uranium isotopic composition and uranium concentration in special reference material SRM A (uranium in KCl/LiCl salt matrix)

    International Nuclear Information System (INIS)

    Graczyk, D.G.; Essling, A.M.; Sabau, C.S.; Smith, F.P.; Bowers, D.L.; Ackerman, J.P.

    1997-07-01

    To help assure that analysis data of known quality will be produced in support of demonstration programs at the Fuel Conditioning Facility at Argonne National Laboratory-West (Idaho Falls, ID), a special reference material has been prepared and characterized. Designated SRM A, the material consists of individual units of LiCl/KCl eutectic salt containing a nominal concentration of 2.5 wt. % enriched uranium. Analyses were performed at Argonne National Laboratory-East (Argonne, IL) to determine the uniformity of the material and to establish reference values for the uranium concentration and uranium isotopic composition. Ten units from a batch of approximately 190 units were analyzed by the mass spectrometric isotope dilution technique to determine their uranium concentration. These measurements provided a mean value of 2.5058 ± 0.0052 wt. % U, where the uncertainty includes estimated limits to both random and systematic errors that might have affected the measurements. Evidence was found of a small, apparently random, non-uniformity in uranium content of the individual SRM A units, which exhibits a standard deviation of 0.078% of the mean uranium concentration. Isotopic analysis of the uranium from three units, by means of thermal ionization mass spectrometry with a special, internal-standard procedure, indicated that the uranium isotopy is uniform among the pellets with a composition corresponding to 0.1115 ± 0.0006 wt. % 234 U, 19.8336 ± 0.0059 wt. % 235 U, 0.1337 ± 0.0006 wt. % 236 U, and 79.9171 ± 0.0057 wt. % 238 U

  17. Uranium isotopic composition and uranium concentration in special reference material SRM A (uranium in KCl/LiCl salt matrix)

    Energy Technology Data Exchange (ETDEWEB)

    Graczyk, D.G.; Essling, A.M.; Sabau, C.S.; Smith, F.P.; Bowers, D.L.; Ackerman, J.P.

    1997-07-01

    To help assure that analysis data of known quality will be produced in support of demonstration programs at the Fuel Conditioning Facility at Argonne National Laboratory-West (Idaho Falls, ID), a special reference material has been prepared and characterized. Designated SRM A, the material consists of individual units of LiCl/KCl eutectic salt containing a nominal concentration of 2.5 wt. % enriched uranium. Analyses were performed at Argonne National Laboratory-East (Argonne, IL) to determine the uniformity of the material and to establish reference values for the uranium concentration and uranium isotopic composition. Ten units from a batch of approximately 190 units were analyzed by the mass spectrometric isotope dilution technique to determine their uranium concentration. These measurements provided a mean value of 2.5058 {+-} 0.0052 wt. % U, where the uncertainty includes estimated limits to both random and systematic errors that might have affected the measurements. Evidence was found of a small, apparently random, non-uniformity in uranium content of the individual SRM A units, which exhibits a standard deviation of 0.078% of the mean uranium concentration. Isotopic analysis of the uranium from three units, by means of thermal ionization mass spectrometry with a special, internal-standard procedure, indicated that the uranium isotopy is uniform among the pellets with a composition corresponding to 0.1115 {+-} 0.0006 wt. % {sup 234}U, 19.8336 {+-} 0.0059 wt. % {sup 235}U, 0.1337 {+-} 0.0006 wt. % {sup 236}U, and 79.9171 {+-} 0.0057 wt. % {sup 238}U.

  18. Highly sensitive detection of ionizing radiations by a photoluminescent uranyl organic framework

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Jian; Wang, Yaxing; Liu, Wei; Yin, Xuemiao; Chen, Lanhua; Diwu, Juan; Chai, Zhifang; Wang, Shuao [School for Radiological and interdisciplinary Sciences (RAD-X) and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou (China); Zou, Youming [High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui (China); Albrecht-Schmitt, Thomas E. [Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL (United States); Liu, Guokui [Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL (United States)

    2017-06-19

    Precise detection of low-dose X- and γ-radiations remains a challenge and is particularly important for studying biological effects under low-dose ionizing radiation, safety control in medical radiation treatment, survey of environmental radiation background, and monitoring cosmic radiations. We report here a photoluminescent uranium organic framework, whose photoluminescence intensity can be accurately correlated with the exposure dose of X- or γ-radiations. This allows for precise and instant detection of ionizing radiations down to the level of 10{sup -4} Gy, representing a significant improvement on the detection limit of approximately two orders of magnitude, compared to other chemical dosimeters reported up to now. The electron paramagnetic resonance analysis suggests that with the exposure to radiations, the carbonyl double bonds break affording oxo-radicals that can be stabilized within the conjugated uranium oxalate-carboxylate sheet. This gives rise to a substantially enhanced equatorial bonding of the uranyl(VI) ions as elucidated by the single-crystal structure of the γ-ray irradiated material, and subsequently leads to a very effective photoluminescence quenching through phonon-assisted relaxation. The quenched sample can be easily recovered by heating, enabling recycled detection for multiple runs. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Contribution to the study of highly excited states of the uranium atom

    International Nuclear Information System (INIS)

    Blancard, Pierre.

    1979-01-01

    Study of highly excited states and some autoionized states of uranium and particularly Rydberg states and behavior in a continuous electric field. The experimental equipment consists of three dye lasers allowing atom ionization or excitation in several steps. The aim is the study of a uranium enrichment process by lasers [fr

  20. Multiple chamber ionization detector

    International Nuclear Information System (INIS)

    Solomon, E.E.

    1982-01-01

    An ionization smoke detector employs a single radiation source in a construction comprising at least two chambers with a center or node electrode. The radioactive source is associated with this central electrode, and its positioning may be adjusted relative to the electrode to alter the proportion of the source that protrudes into each chamber. The source may also be mounted in the plane of the central electrode, and positioned relative to the center of the electrode. The central electrode or source may be made tiltable relative to the body of the detector

  1. Single photon simultaneous K-shell ionization and K-shell excitation. I. Theoretical model applied to the interpretation of experimental results on H2O

    International Nuclear Information System (INIS)

    Carniato, S.; Selles, P.; Andric, L.; Palaudoux, J.; Penent, F.; Lablanquie, P.; Žitnik, M.; Bučar, K.; Nakano, M.; Hikosaka, Y.; Ito, K.

    2015-01-01

    We present in detail a theoretical model that provides absolute cross sections for simultaneous core-ionization core-excitation (K −2 V ) and compare its predictions with experimental results obtained on the water molecule after photoionization by synchrotron radiation. Two resonances of different symmetries are assigned in the main K −2 V peak and comparable contributions from monopolar (direct shake-up) and dipolar (conjugate shake-up) core-valence excitations are identified. The main peak is observed with a much greater width than the total experimental resolution. This broadening is the signature of nuclear dynamics

  2. URANIUM DECONTAMINATION

    Science.gov (United States)

    Buckingham, J.S.; Carroll, J.L.

    1959-12-22

    A process is described for reducing the extractability of ruthenium, zirconium, and niobium values into hexone contained in an aqueous nitric acid uranium-containing solution. The solution is made acid-deficient, heated to between 55 and 70 deg C, and at that temperature a water-soluble inorganic thiosulfate is added. By this, a precipitate is formed which carries the bulk of the ruthenium, and the remainder of the ruthenium as well as the zirconium and niobium are converted to a hexone-nonextractable form. The rutheniumcontaining precipitate can either be removed from the solu tion or it can be dissolved as a hexone-non-extractable compound by the addition of sodium dichromate prior to hexone extraction.

  3. Single crystal structures and theoretical calculations of uranium endohedral metallofullerenes (U@C2n , 2n = 74, 82) show cage isomer dependent oxidation states for U.

    Science.gov (United States)

    Cai, Wenting; Morales-Martínez, Roser; Zhang, Xingxing; Najera, Daniel; Romero, Elkin L; Metta-Magaña, Alejandro; Rodríguez-Fortea, Antonio; Fortier, Skye; Chen, Ning; Poblet, Josep M; Echegoyen, Luis

    2017-08-01

    Charge transfer is a general phenomenon observed for all endohedral mono-metallofullerenes. Since the detection of the first endohedral metallofullerene (EMF), La@C 82 , in 1991, it has always been observed that the oxidation state of a given encapsulated metal is always the same, regardless of the cage size. No crystallographic data exist for any early actinide endohedrals and little is known about the oxidation states for the few compounds that have been reported. Here we report the X-ray structures of three uranium metallofullerenes, U@ D 3h -C 74 , U@ C 2 (5)-C 82 and U@ C 2v (9)-C 82 , and provide theoretical evidence for cage isomer dependent charge transfer states for U. Results from DFT calculations show that U@ D 3h -C 74 and U@ C 2 (5)-C 82 have tetravalent electronic configurations corresponding to U 4+ @ D 3h -C 74 4- and U 4+ @ C 2 (5)-C 82 4- . Surprisingly, the isomeric U@ C 2v (9)-C 82 has a trivalent electronic configuration corresponding to U 3+ @ C 2v (9)-C 82 3- . These are the first X-ray crystallographic structures of uranium EMFs and this is first observation of metal oxidation state dependence on carbon cage isomerism for mono-EMFs.

  4. Uranium management activities

    International Nuclear Information System (INIS)

    Jackson, D.; Marshall, E.; Sideris, T.; Vasa-Sideris, S.

    2001-01-01

    One of the missions of the Department of Energy's (DOE) Oak Ridge Office (ORO) has been the management of the Department's uranium materials. This mission has been accomplished through successful integration of ORO's uranium activities with the rest of the DOE complex. Beginning in the 1980's, several of the facilities in that complex have been shut down and are in the decommissioning process. With the end of the Cold War, the shutdown of many other facilities is planned. As a result, inventories of uranium need to be removed from the Department facilities. These inventories include highly enriched uranium (HEU), low enriched uranium (LEU), normal uranium (NU), and depleted uranium (DU). The uranium materials exist in different chemical forms, including metals, oxides, solutions, and gases. Much of the uranium in these inventories is not needed to support national priorities and programs. (author)

  5. Uranium industry annual 1994

    International Nuclear Information System (INIS)

    1995-01-01

    The Uranium Industry Annual 1994 (UIA 1994) provides current statistical data on the US uranium industry's activities relating to uranium raw materials and uranium marketing during that survey year. The UIA 1994 is prepared for use by the Congress, Federal and State agencies, the uranium and nuclear electric utility industries, and the public. It contains data for the 10-year period 1985 through 1994 as collected on the Form EIA-858, ''Uranium Industry Annual Survey.'' Data collected on the ''Uranium Industry Annual Survey'' (UIAS) provide a comprehensive statistical characterization of the industry's activities for the survey year and also include some information about industry's plans and commitments for the near-term future. Where aggregate data are presented in the UIA 1994, care has been taken to protect the confidentiality of company-specific information while still conveying accurate and complete statistical data. A feature article, ''Comparison of Uranium Mill Tailings Reclamation in the United States and Canada,'' is included in the UIA 1994. Data on uranium raw materials activities including exploration activities and expenditures, EIA-estimated resources and reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities, including purchases of uranium and enrichment services, and uranium inventories, enrichment feed deliveries (actual and projected), and unfilled market requirements are shown in Chapter 2

  6. Uranium industry annual 1998

    International Nuclear Information System (INIS)

    1999-01-01

    The Uranium Industry Annual 1998 (UIA 1998) provides current statistical data on the US uranium industry's activities relating to uranium raw materials and uranium marketing. It contains data for the period 1989 through 2008 as collected on the Form EIA-858, ''Uranium Industry Annual Survey.'' Data provides a comprehensive statistical characterization of the industry's activities for the survey year and also include some information about industry's plans and commitments for the near-term future. Data on uranium raw materials activities for 1989 through 1998, including exploration activities and expenditures, EIA-estimated reserves, mine production of uranium, production of uranium concentrate, and industry employment, are presented in Chapter 1. Data on uranium marketing activities for 1994 through 2008, including purchases of uranium and enrichment services, enrichment feed deliveries, uranium fuel assemblies, filled and unfilled market requirements, and uranium inventories, are shown in Chapter 2. The methodology used in the 1998 survey, including data edit and analysis, is described in Appendix A. The methodologies for estimation of resources and reserves are described in Appendix B. A list of respondents to the ''Uranium Industry Annual Survey'' is provided in Appendix C. The Form EIA-858 ''Uranium Industry Annual Survey'' is shown in Appendix D. For the readers convenience, metric versions of selected tables from Chapters 1 and 2 are presented in Appendix E along with the standard conversion factors used. A glossary of technical terms is at the end of the report. 24 figs., 56 tabs

  7. Uranium health physics

    International Nuclear Information System (INIS)

    1980-01-01

    This report contains the papers delivered at the Summer School on Uranium Health Physics held in Pretoria on the 14 and 15 April 1980. The following topics were discussed: uranium producton in South Africa; radiation physics; internal dosimetry and radiotoxicity of long-lived uranium isotopes; uranium monitoring; operational experience on uranium monitoring; dosimetry and radiotoxicity of inhaled radon daughters; occupational limits for inhalation of radon-222, radon-220 and their short-lived daughters; radon monitoring techniques; radon daughter dosimeters; operational experience on radon monitoring; and uranium mill tailings management

  8. Uranium: one utility's outlook

    International Nuclear Information System (INIS)

    Gass, C.B.

    1983-01-01

    The perspective of the Arizona Public Service Company (APS) on the uncertainty of uranium as a fuel supply is discussed. After summarizing the history of nuclear power and the uranium industries, a projection is made for the future uranium market. An uncrtain uranium market is attributed to various determining factors that include international politics, production costs, non-commercial government regulation, production-company stability, and questionable levels of uranium sales. APS offers its solutions regarding type of contract, choice of uranium producers, pricing mechanisms, and aids to the industry as a whole. 5 references, 10 figures, 1 table

  9. Regiospecific analysis of neutral ether lipids by liquid chromatography/electrospray ionization/single quadrupole mass spectrometry: validation with synthetic compounds

    DEFF Research Database (Denmark)

    Hartvigsen, Karsten; Ravandi, A.; Bukhave, Klaus

    2001-01-01

    A reversed-phase high-performance liquid chromatography (HPLC) method with on-line electrospray ionization/collision-induced dissociation/mass spectrometry (ESI/CID/MS) is presented for the regiospecific analysis of synthetic reference compounds of neutral ether lipids. The reference compounds were....... The diagnostic ions of directly analyzed 1-O-alkyl-2,3-diacyl-sn- glycerols were the [M - alkyl](+), [M - sn-2-acyl](+) and [M - sn-3-acyl](+) ions. Regiospecific characterization of the fatty acid identity and position was evident from the relative ion intensities, as fragmentation of the sn-2 fatty acids...... for each neutral ether lipid class. The present study demonstrates that reversed-phase HPLC and positive ion ESI/CID/MS provide direct and unambiguous information about the configuration and identity of molecular species in neutral 1-O-alkyl-sn-glycerol classes....

  10. Isolation and purification of uranium from environmental materials for mass spectrometric analysis

    Energy Technology Data Exchange (ETDEWEB)

    Essling, A.M.; Graczyk, D.G.; Horwitz, E.P.

    1988-01-01

    We describe a simple isolation and purification procedure for uranium involving a new one-step separation based on supported-liquid column chromatography, and present experimental results that demonstrate the separation's ability to provide consistent, high uranium recoveries from some typical environmental samples. The uranium product from this procedure is sufficiently pure that no solids are visible on a thermal-ionization mass spectrometer filament after the sample is deposited for analysis. We have used this procedure in determining total uranium in addition to uranium isotopy by adding an isotope-dilution spike to the sample digestate. Because the uranium recovery is good, direct assay of the uranium product by laser fluorimetry or counting techniques is also feasible. 1 fig., 1 tab.

  11. Uranium Processing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — An integral part of Y‑12's transformation efforts and a key component of the National Nuclear Security Administration's Uranium Center of Excellence, the Uranium...

  12. Price of military uranium

    International Nuclear Information System (INIS)

    Klimenko, A.V.

    1998-01-01

    The theoretical results about optimum strategy of use of military uranium confirmed by systems approach accounts are received. The numerical value of the system approach price of the highly enriched military uranium also is given

  13. Uranium in Niger

    International Nuclear Information System (INIS)

    Gabelmann, E.

    1978-03-01

    This document presents government policy in the enhancement of uranium resources, existing mining companies and their productions, exploitation projects and economical outcome related to the uranium mining and auxiliary activities [fr

  14. Uranium mining in Australia

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    Known uranium deposits and the companies involved in uranium mining and exploration in Australia are listed. The status of the development of the deposits is outlined and reasons for delays to mining are given

  15. Uranium from phosphate ores

    International Nuclear Information System (INIS)

    Hurst, F.J.

    1983-01-01

    The following topics are described briefly: the way phosphate fertilizers are made; how uranium is recovered in the phosphate industry; and how to detect covert uranium recovery operations in a phsophate plant

  16. Industrial realities: Uranium

    International Nuclear Information System (INIS)

    Thiron, H.

    1990-01-01

    In this special issue are examined ores and metals in France and in the world for 1988. The chapter on uranium gives statistical data on the uranium market: Demand, production, prices and reserves [fr

  17. Uranium mining in Australia

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    The mining of uranium in Australia is criticised in relation to it's environmental impact, economics and effects on mine workers and Aborigines. A brief report is given on each of the operating and proposed uranium mines in Australia

  18. Uranium: the recalcitrant commodity

    International Nuclear Information System (INIS)

    Crowson, P.C.F.

    1989-01-01

    During the past year dollar prices of virtually every mineral commodity have risen considerably on the back of strong demand, falling stocks and rising capacity utilization. Uranium has experienced the same economic influences, but measures of conditions in uranium spot markets display drift and even further decline. Does this mean that uranium is not really a commodity after all, or have special factors been at work? Some of the economic features of the uranium market are re-examined in this context. (author)

  19. Uranium in fossil bones

    International Nuclear Information System (INIS)

    Koul, S.L.

    1978-01-01

    An attempt has been made to determine the uranium content and thus the age of certain fossil bones Haritalyangarh (Himachal Pradesh), India. The results indicate that bones rich in apatite are also rich in uranium, and that the radioactivity is due to radionuclides in the uranium series. The larger animals apparently have a higher concentration of uranium than the small. The dating of a fossil jaw (elephant) places it in the Pleistocene. (Auth.)

  20. PREPARATION OF URANIUM HEXAFLUORIDE

    Science.gov (United States)

    Lawroski, S.; Jonke, A.A.; Steunenberg, R.K.

    1959-10-01

    A process is described for preparing uranium hexafluoride from carbonate- leach uranium ore concentrate. The briquetted, crushed, and screened concentrate is reacted with hydrogen fluoride in a fluidized bed, and the uranium tetrafluoride formed is mixed with a solid diluent, such as calcium fluoride. This mixture is fluorinated with fluorine and an inert diluent gas, also in a fluidized bed, and the uranium hexafluoride obtained is finally purified by fractional distillation.

  1. Radiation damage of uranium

    International Nuclear Information System (INIS)

    Lazarevic, Dj.

    1966-11-01

    Study of radiation damage covered the following: Kinetics of electric resistance of uranium and uranium alloy with 1% of molybdenum dependent on the second phase and burnup rate; Study of gas precipitation and diffusion of bubbles by transmission electron microscopy; Numerical analysis of the influence of defects distribution and concentration on the rare gas precipitation in uranium; study of thermal sedimentation of uranium alloy with molybdenum; diffusion of rare gas in metal by gas chromatography method

  2. Uranium mining in Australia

    International Nuclear Information System (INIS)

    Mackay, G.A.

    1978-01-01

    Western world requirements for uranium based on increasing energy consumption and a changing energy mix, will warrant the development of Australia's resources. By 1985 Australian mines could be producing 9500 tonnes of uranium oxide yearly and by 1995 the export value from uranium could reach that from wool. In terms of benefit to the community the economic rewards are considerable but, in terms of providing energy to the world, Australias uranium is vital

  3. Method for converting uranium oxides to uranium metal

    International Nuclear Information System (INIS)

    Duerksen, W.K.

    1988-01-01

    A method for converting uranium oxide to uranium metal is described comprising the steps of heating uranium oxide in the presence of a reducing agent to a temperature sufficient to reduce the uranium oxide to uranium metal and form a heterogeneous mixture of a uranium metal product and oxide by-products, heating the mixture in a hydrogen atmosphere at a temperature sufficient to convert uranium metal in the mixture to uranium hydride, cooling the resulting uranium hydride-containing mixture to a temperature sufficient to produce a ferromagnetic transition in the uranium hydride, magnetically separating the cooled uranium hydride from the mixture, and thereafter heating the separated uranium hydride in an inert atmosphere to a temperature sufficient to convert the uranium hydride to uranium metal

  4. Genetic engineering microbes for bioremediation/ biorecovery of uranium

    International Nuclear Information System (INIS)

    Apte, S.K.; Rao, A.S.; Appukuttan, D.; Nilgiriwala, K.S.; Acharya, C.

    2005-01-01

    Bioremediation (both bioremoval and biorecovery) of metals is considered a feasible, economic and eco-friendly alternative to chemical methods of metal extraction, particularly when the metal concentration is very low. Scanty distribution along with poor ore quality makes biomining of uranium an attractive preposition. Biosorption, bioprecipitation or bioaccumulation of uranium, aided by recombinant DNA technology, offer a promising technology for recovery of uranium from acidic or alkaline nuclear waste, tailings or from sea-water. Genetic engineering of bacteria, with a gene encoding an acid phosphatase, has yielded strains that can bioprecipitate uranium from very low concentrations at acidic-neutral pH, in a relatively short time. Organisms overproducing alkaline phosphatase have been selected for uranium precipitation from alkaline waste. Such abilities have now been transferred to the radioresistant microbe Deinococcus radiodurans to facilitate in situ bioremediation of nuclear waste, with some success. Sulfate-reducing bacteria are being characterized for bioremediation of uranium in tailings with the dual objective of uranium precipitation and reduction of sulfate to sulphide. Certain marine cyanobacteria have shown promise for uranium biosorption to extracellular polysaccharides, and intracellular accumulation involving metal sequestering metallothionin proteins. Future work is aimed at understanding the genetic basis of these abilities and to engineer them into suitable organisms subsequently. As photosynthetic, nitrogen-fixing microbes, which are considerably resistant to ionizing radiations, cyanobacteria hold considerable potential for bioremediation of nuclear waste. (author)

  5. Measurement of photoexcitation cross-sections of uranium by ...

    Indian Academy of Sciences (India)

    Abstract. We report the measurement of photoexcitation cross-sections of three first- step uranium transitions (0 → 16900.38 cm−1, 0 → 17361.89 cm−1 and 620 → 17361.89 cm−1) using saturation method. These measurements were performed on a resonance ionization mass spectrometry (RIMS) set-up consisting of ...

  6. Measurement of photoexcitation cross-sections of uranium by ...

    Indian Academy of Sciences (India)

    We report the measurement of photoexcitation cross-sections of three first-step uranium transitions (0 → 16900.38 cm-1 , 0 → 17361.89 cm-1 and 620 → 17361.89 cm-1) using saturation method. These measurements were performed on a resonance ionization mass spectrometry (RIMS) set-up consisting of ...

  7. Australian uranium today

    International Nuclear Information System (INIS)

    Fisk, B.

    1978-01-01

    The subject is covered in sections, entitled: Australia's resources; Northern Territory uranium in perspective; the government's decision [on August 25, 1977, that there should be further development of uranium under strictly controlled conditions]; Government legislation; outlook [for the Australian uranium mining industry]. (U.K.)

  8. Uranium resources, 1983

    International Nuclear Information System (INIS)

    1983-01-01

    The specific character of uranium as energy resources, the history of development of uranium resources, the production and reserve of uranium in the world, the prospect regarding the demand and supply of uranium, Japanese activity of exploring uranium resources in foreign countries and the state of development of uranium resources in various countries are reported. The formation of uranium deposits, the classification of uranium deposits and the reserve quantity of each type are described. As the geological environment of uranium deposits, there are six types, that is, quartz medium gravel conglomerate deposit, the deposit related to the unconformity in Proterozoic era, the dissemination type magma deposit, pegmatite deposit and contact deposit in igneaus rocks and metamorphic rocks, vein deposit, sandstone type deposit and the other types of deposit. The main features of respective types are explained. The most important uranium resources in Japan are those in the Tertiary formations, and most of the found reserve belongs to this type. The geological features, the state of yield and the scale of the deposits in Ningyotoge, Tono and Kanmon Mesozoic formation are reported. Uranium minerals, the promising districts in the world, and the matters related to the exploration and mining of uranium are described. (Kako, I.)

  9. Recycling of reprocessed uranium

    International Nuclear Information System (INIS)

    Randl, R.P.

    1987-01-01

    Since nuclear power was first exploited in the Federal Republic of Germany, the philosophy underlying the strategy of the nuclear fuel cycle has been to make optimum use of the resource potential of recovered uranium and plutonium within a closed fuel cycle. Apart from the weighty argument of reprocessing being an important step in the treatment and disposal of radioactive wastes, permitting their optimum ecological conditioning after the reprocessing step and subsequent storage underground, another argument that, no doubt, carried weight was the possibility of reducing the demand of power plants for natural uranium. In recent years, strategies of recycling have emerged for reprocessed uranium. If that energy potential, too, is to be exploited by thermal recycling, it is appropriate to choose a slightly different method of recycling from the one for plutonium. While the first generation of reprocessed uranium fuel recycled in the reactor cuts down natural uranium requirement by some 15%, the recycling of a second generation of reprocessed, once more enriched uranium fuel helps only to save a further three per cent of natural uranium. Uranium of the second generation already carries uranium-232 isotope, causing production disturbances, and uranium-236 isotope, causing disturbances of the neutron balance in the reactor, in such amounts as to make further fabrication of uranium fuel elements inexpedient, even after mixing with natural uranium feed. (orig./UA) [de

  10. Uranium energy dependence

    International Nuclear Information System (INIS)

    Erkes, P.

    1981-06-01

    Uranium supply and demand as projected by the Uranium Institute is discussed. It is concluded that for the industrialized countries, maximum energy independence is a necessity. Hence it is necessary to achieve assurance of supply for uranium used in thermal power reactors in current programs and eventually to move towards breeders

  11. The uranium production cycle and the environment. Proceedings

    International Nuclear Information System (INIS)

    2002-01-01

    Within the international community it is widely recognized that the responsibility for management of uranium production and all related activities should be independent of the organizations providing for the oversight and regulatory function. An important role of the IAEA is establishing international safety standards for protection of health and environment against exposure to ionizing radiation. Once legally binding laws, regulations and standards are established,either through national and international programmes, it becomes the responsibility of the management and operators of uranium production projects for carrying our all activities to meet these requirements. The major emphasis of the IAEA's Project on Raw Materials for Reactor Fuels is to improve and strengthen the practice of preventive measures by establishing guidelines for environmental impact assessment and mitigation and the recognition and promotion of good practice and modern technology. The Waste Technology programme provides advice on the cleanup and remediation of old production sites and wastes. One important mechanism for recognizing and promoting best practice in environmental management of uranium production is fostering information exchange among specialists. The IAEA exercises this mechanism, for examples though publications, electronic information exchange and, particularly, through large gatherings of specialists and decision makers at international conferences, symposia and seminars. The topics covered at the symposium were: Energy needs and challenges for the 21 st Century; uranium supply for the short and long term; sustainable development, energy resources and nuclear energy's role in greenhouse gas abatement; economic impact of world mining; impacts of mining on developed and developing countries; environmental and social impacts of uranium mining in several countries; examples of positive and negative impacts of uranium mining projects on local communities; environmental issues

  12. Size dependence of the polarizability and Haynes rule for an exciton bound to an ionized donor in a single spherical quantum dot

    Energy Technology Data Exchange (ETDEWEB)

    Feddi, E., E-mail: e.feddi@um5s.net.ma; Zouitine, A. [Université Mohamed V Souissi, Ecole Normale Supérieure de l' Enseignement Technique (ENSET), Rabat (Morocco); Oukerroum, A.; Zazoui, M. [Laboratory of Condensed Matter, Faculty of Sciences and Techniques, University of Hassan II-Mohammedia, B.P. 146, 20800 Mohammedia (Morocco); Dujardin, F. [LCP-A2MC, Université de Lorraine, ICPM, 1 Bd Arago, 57070 Metz (France); Assaid, E. [Laboratoire d' Électronique et Optique des Nanostructures de Semiconducteurs, Faculté des Sciences, B. P. 20, El Jadida (Morocco)

    2015-02-14

    We study the effect of an external electric field on an exciton bound to an ionized donor (D{sup +}, X) confined in a spherical quantum dot using a perturbative-variational method where the wave function and energy are developed in series of powers of the electric field strength. After testing this new approach in the determination of the band gap for some semiconductor materials, we generalize it to the case of (D{sup +}, X) in the presence of the electric field and for several materials ZnO, PbSe, and InAs, with significant values of the mass ratio. Three interesting results can be deduced: First, we show that the present method allows to determine the ground state energy in the presence of a weak electric field in a simple way (E = E{sub 0} − αf{sup 2}) using the energy without electric field E{sub 0} and the polarizability α. The second point is that our theoretical predictions show that the polarizability of (D{sup +}, X) varies proportionally to R{sup 3.5} and follows an ordering α{sub D{sup 0}}<α{sub X}<α{sub (D{sup +},X)}. The last point to highlight is that the Haynes rule remains valid even in the presence of a weak electric field.

  13. PROCESS OF RECOVERING URANIUM

    Science.gov (United States)

    Carter, J.M.; Larson, C.E.

    1958-10-01

    A process is presented for recovering uranium values from calutron deposits. The process consists in treating such deposits to produce an oxidlzed acidic solution containing uranium together with the following imparities: Cu, Fe, Cr, Ni, Mn, Zn. The uranium is recovered from such an impurity-bearing solution by adjusting the pH of the solution to the range 1.5 to 3.0 and then treating the solution with hydrogen peroxide. This results in the precipitation of uranium peroxide which is substantially free of the metal impurities in the solution. The peroxide precipitate is then separated from the solution, washed, and calcined to produce uranium trioxide.

  14. High loading uranium plate

    International Nuclear Information System (INIS)

    Wiencek, T.C.; Domagala, R.F.; Thresh, H.R.

    1990-01-01

    Two embodiments of a high uranium fuel plate are disclosed which contain a meat comprising structured uranium compound confined between a pari of diffusion bonded ductile metal cladding plates uniformly covering the meat, the meat hiving a uniform high fuel loading comprising a content of uranium compound greater than about 45 Vol. % at a porosity not greater than about 10 Vol. %. In a first embodiment, the meat is a plurality of parallel wires of uranium compound. In a second embodiment, the meat is a dispersion compact containing uranium compound. The fuel plates are fabricated by a hot isostatic pressing process

  15. URANIUM SEPARATION PROCESS

    Science.gov (United States)

    Hyde, E.K.; Katzin, L.I.; Wolf, M.J.

    1959-07-14

    The separation of uranium from a mixture of uranium and thorium by organic solvent extraction from an aqueous solution is described. The uranium is separrted from an aqueous mixture of uranium and thorium nitrates 3 N in nitric acid and containing salting out agents such as ammonium nitrate, so as to bring ihe total nitrate ion concentration to a maximum of about 8 N by contacting the mixture with an immiscible aliphatic oxygen containing organic solvent such as diethyl carbinol, hexone, n-amyl acetate and the like. The uranium values may be recovered from the organic phase by back extraction with water.

  16. First measurement of the ionization potential of astatine

    Energy Technology Data Exchange (ETDEWEB)

    Rothe, Sebastian [CERN, Geneva (Switzerland); Institut fuer Physik, Univ. Mainz (Germany); Andreyev, Andrei N. [University of the West of Scotland, Paisley (United Kingdom); Antalic, Stano [Comenius University, Bratislava (Slovakia); Cocolios, Thomas E.; Marsh, Bruce A.; Sjoedin, A. Marica; Fedosseev, Valentin N. [CERN, Geneva (Switzerland); Fedorov, Dimitry V. [PNPI, Gatchina (Russian Federation); Ghys, Lars; Huyse, Mark; Kudryavtsev, Yuri; Pauwels, Dieter; Radulov, Deyan; Duppen, Piet van [IKS, KU Leuven (Belgium); Lassen, Jens [TRIUMF, Vancouver (Canada); Raeder, Sebastian; Wendt, Klaus [Institut fuer Physik, Univ. Mainz (Germany); Seliverstov, Maxim [PNPI, Gatchina (Russian Federation); IKS, KU Leuven (Belgium); Venhart, Martin [Slovak Academy of Sciences, Bratislava (Slovakia)

    2011-07-01

    Since the discovery of element 85 in the year 1940 by D. R. Corson et al., the binding energy of the outer electron of astatine had not been determined. At the on-line isotope separator facility ISOLDE at CERN, Geneva radioactive isotopes of At were produced by impinging 1.4 GeV protons on a uranium carbide target, ionized using the Resonance Ionization Laser Ion Source (RILIS) and detected using alpha decay spectroscopy. In-source laser spectroscopy was performed in order to develop a multi-step ionization scheme for an efficient and highly selective At ion production, as requested by ISOLDE users. Two atomic transitions, previously observed by absorption spectroscopy were confirmed and assigned as first steps of the excitation and ionization scheme. A second laser beam was applied to non-resonantly ionize the excited At atoms. A wavelength scan of the ionizing step was performed to search for the ionization limit. From the observed ionization onset the first ionization potential of At was preliminary determined to be 9.3 eV. Results from these studies at CERN and consecutive measurements at TRIUMF, Canada and IKS, Belgium are presented.

  17. Uranium uptake by plants

    International Nuclear Information System (INIS)

    Singh, K.P.

    1997-01-01

    This paper highlights the transport of uranium present in the soil to plants. An increase in the uranium content in soil enhances its transport in various parts of plants. The transport of uranium from the soil to the grain follows the order: black gram>maize>lentil>chick-pea>rice>wheat. In certain vegetables and fruits, this order is: spinach>carrot>radish> brinjal>banana>tomato>beet. In vegetables and fruits, the stem reflects minimum percentage of uranium present in the soil. The uranium transport is appreciably high in arecanut plant. The chances of uranium transport to the human organs, are expected to be more through consumption of crops grown in uranium-rich soil. (author)

  18. Measurements of uranium in soils and small mammals

    International Nuclear Information System (INIS)

    Miera, F.R. Jr.

    1980-12-01

    The objective of this study was to evaluate the bioavailability of uranium to a single species of small mammal, Peromyscus maniculatus rufinus (Merriam), white-footed deer mouse, from two different source terms: a Los Alamos National Laboratory dynamic weapons testing site in north central New Mexico, where an estimated 70,000 kg of uranium have been expended over a 31-y period; and an inactive uranium mill tailings pile located in west central New Mexico near Grants, which received wastes over a 5-y period from the milling of 2.7 x 10 9 kg of uranium ore

  19. Ionization potentials of seaborgium

    International Nuclear Information System (INIS)

    Johnson, E.; Pershina, V.; Fricke, B.

    1999-01-01

    Multiconfiguration relativistic Dirac-Fock values were calculated for the first six ionization potentials of seaborgium and of the other group 6 elements. No experimental ionization potentials are available for seaborgium. Accurate experimental values are not available for all of the other ionization potentials. Ionic radii for the 4+ through 6+ ions of seaborgium are also presented. The ionization potentials and ionic radii obtained will be used to predict some physiochemical properties of seaborgium and its compounds

  20. Ionization of food products

    International Nuclear Information System (INIS)

    Vasseur, J.P.

    1991-01-01

    After general remarks on foods preservation, on international works and on ionization future prospects, main irradiation sources are described. Recalls on radioactivity, on radiation-matter interaction, on toxicology of ionized foods and on ionized foods detection are given. Ionization applications to various products are reviewed, especially in: - Poultry meat - Fishing products - Fresh fruits and vegetables - Dry fruits and vegetables - spices, tea, infusion - prepacked products... An evaluation of economics and sociocultural impacts is presented in connection with recent experiments [fr

  1. Deviation from Boltzmann distribution in excited energy levels of singly-ionized iron in an argon glow discharge plasma for atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lei; Kashiwakura, Shunsuke; Wagatsuma, Kazuaki, E-mail: wagatuma@imr.tohoku.ac.jp

    2012-01-15

    A Boltzmann plot for many iron ionic lines having excitation energies of 4.7-9.1 eV was investigated in an argon glow discharge plasma when the discharge parameters, such as the voltage/current and the gas pressure, were varied. A Grimm-style radiation source was employed in a DC voltage range of 400-800 V at argon pressures of 400-930 Pa. The plot did not follow a linear relationship over a wide range of the excitation energy, but it yielded a normal Boltzmann distribution in the range of 4.7-5.8 eV and a large overpopulation in higher-lying excitation levels of iron ion. A probable reason for this phenomenon is that excitations for higher excited energy levels of iron ion would be predominantly caused by non-thermal collisions with argon species, the internal energy of which is received by iron atoms for the ionization. Particular intense ionic lines, which gave a maximum peak of the Boltzmann plot, were observed at an excitation energy of ca. 7.7 eV. They were the Fe II 257.297-nm and the Fe II 258.111-nm lines, derived from the 3d{sup 5}4s4p {sup 6}P excited levels. The 3d{sup 5}4s4p {sup 6}P excited levels can be highly populated through a resonance charge transfer from the ground state of argon ion, because of good matching in the excitation energy as well as the conservation of the total spin before and after the collision. An enhancement factor of the emission intensity for various Fe II lines could be obtained from a deviation from the normal Boltzmann plot, which comprised the emission lines of 4.7-5.8 eV. It would roughly correspond to a contribution of the charge transfer excitation to the excited levels of iron ion, suggesting that the charge-transfer collision could elevate the number density of the corresponding excited levels by a factor of ca.10{sup 4}. The Boltzmann plots give important information on the reason why a variety of iron ionic lines can be emitted from glow discharge plasmas.

  2. Geology of hydrothermal uranium deposits

    International Nuclear Information System (INIS)

    Korolev, K.G.; Belov, V.K.; Putilov, G.S.

    1983-01-01

    Geological characteristics of hydrothermal phosphorus-uranium deposits placed in sedimentary, igneous-sedimentary, metamorphic and intrusion formations are presented. Attention is paid to mineral composition, texture and structure of ores, their genesis, tectonics. Geochemical peculiarities of ores and age of molybdenum-uranium and uranium deposits are described. Geological criteria and prospecting features of uranium and uranium-molybdenum deposits are given

  3. Exposure to uranium and cancer risk: a review of epidemiological studies

    International Nuclear Information System (INIS)

    Tirmarche, M.; Baysson, H.; Telle-Lamberton, M.

    2004-01-01

    Objective: At the end of 2000, certain diseases including leukemia were reported among soldiers who participated in the Balkan and in the Gulf wars. Depleted uranium used during these conflicts was considered as a possible cause. Its radiotoxicity is close to that of natural uranium. This paper reviews the epidemiological knowledge of uranium, the means of exposure and the associated risk of cancer. Methods: The only available epidemiological data concerns nuclear workers exposed to uranium. A review of the international literature is proposed by distinguishing between uranium miners and other workers of the nuclear industry. French studies are described in details. Results: In ionizing radiation epidemiology, contamination by uranium is often cited as a risk factor, but the dose-effect relationship is rarely studied. Retrospective assessment of individual exposure is generally insufficient. Moreover, it is difficult to distinguish between uranium radiotoxicity, its chemical toxicity and the radiotoxicity of its progeny. A causal relation between lung cancer and radon exposure, a gas derived from the decay of uranium, has been demonstrated in epidemiological studies of miners. Among other nuclear workers exposed to uranium, there is a mortality deficit from all causes (healthy worker effect). No cancer site appears systematically in excess compared to the national population; very few studies describe a dose-response relationship. Conclusion: Only studies with a precise reconstruction of doses and sufficient numbers of workers will allow a better assessment of risks associated with uranium exposure at levels encountered in industry or during conflicts using depleted uranium weapons. (author)

  4. Uranium of Kazakhstan

    International Nuclear Information System (INIS)

    Tsalyuk, Yu.; Gurevich, D.

    2000-01-01

    Over 25 % of the world's uranium reserves are concentrated in Kazakhstan. So, the world's largest Shu-Sarysu uranium province is situated on southern Kazakhstan, with resources exceeding 1 billion tonnes of uranium. No less, than 3 unique deposits with resources exceeding 100,000 tonnes are situated here. From the economic point of view the most important thing is that these deposits are suitable for in-situ leaching, which is the cheapest, environmentally friendly and most efficient method available for uranium extracting. In 1997 the Kazatomprom National Joint-Stock Company united all Kazakhstan's uranium enterprises (3 mine and concentrating plants, Volkovgeologiya Joint-Stock Company and the Ulbinskij Metallurgical plant). In 1998 uranium production came to 1,500 tonnes (860 kg in 1997). In 1999 investment to the industry were about $ 30 million. Plans for development of Kazakhstan's uranium industry provide a significant role for foreign partners. At present, 2 large companies (Comeco (Canada), Cogema (France) working in Kazakhstan. Kazakatomprom continues to attract foreign investors. The company's administration announced that in that in next year they have plan to make a radical step: to sell 67 % of stocks to strategic investors (at present 100 % of stocks belongs to state). Authors of the article regard, that the Kazakhstan's uranium industry still has significant reserves to develop. Even if the scenario for the uranium industry could be unfavorable, uranium production in Kazakhstan may triple within the next three to four years. The processing of uranium by the Ulbinskij Metallurgical Plant and the production of some by-products, such as rhenium, vanadium and rare-earth elements, may provide more profits. Obviously, the sale of uranium (as well as of any other reserves) cannot make Kazakhstan a prosperous country. However, country's uranium industry has a god chance to become one of the most important and advanced sectors of national economy

  5. Bioremediation of uranium contamination with enzymatic uranium reduction

    Science.gov (United States)

    Lovley, D.R.; Phillips, E.J.P.

    1992-01-01

    Enzymatic uranium reduction by Desulfovibrio desulfuricans readily removed uranium from solution in a batch system or when D. desulfuricans was separated from the bulk of the uranium-containing water by a semipermeable membrane. Uranium reduction continued at concentrations as high as 24 mM. Of a variety of potentially inhibiting anions and metals evaluated, only high concentrations of copper inhibited uranium reduction. Freeze-dried cells, stored aerobically, reduced uranium as fast as fresh cells. D. desulfuricans reduced uranium in pH 4 and pH 7.4 mine drainage waters and in uraniumcontaining groundwaters from a contaminated Department of Energy site. Enzymatic uranium reduction has several potential advantages over other bioprocessing techniques for uranium removal, the most important of which are as follows: the ability to precipitate uranium that is in the form of a uranyl carbonate complex; high capacity for uranium removal per cell; the formation of a compact, relatively pure, uranium precipitate.

  6. A discussion about maximum uranium concentration in digestion solution of U3O8 type uranium ore concentrate

    International Nuclear Information System (INIS)

    Xia Dechang; Liu Chao

    2012-01-01

    On the basis of discussing the influence of single factor on maximum uranium concentration in digestion solution,the influence degree of some factors such as U content, H 2 O content, mass ratio of P and U was compared and analyzed. The results indicate that the relationship between U content and maximum uranium concentration in digestion solution was direct ratio, while the U content increases by 1%, the maximum uranium concentration in digestion solution increases by 4.8%-5.7%. The relationship between H 2 O content and maximum uranium concentration in digestion solution was inverse ratio, the maximum uranium concentration in digestion solution decreases by 46.1-55.2 g/L while H 2 O content increases by 1%. The relationship between mass ratio of P and U and maximum uranium concentration in digestion solution was inverse ratio, the maximum uranium concentration in digestion solution decreases by 116.0-181.0 g/L while the mass ratio of P and U increase 0.1%. When U content equals 62.5% and the influence of mass ratio of P and U is no considered, the maximum uranium concentration in digestion solution equals 1 578 g/L; while mass ratio of P and U equals 0.35%, the maximum uranium concentration decreases to 716 g/L, the decreased rate is 54.6%, so the mass ratio of P and U in U 3 O 8 type uranium ore concentrate is the main controlling factor. (authors)

  7. Uranium: properties and biological effects after internal contamination

    International Nuclear Information System (INIS)

    Souidi, M.; Tissandie, E.; Racine, R.; Ben Soussan, H.; Rouas, C.; Grignard, E.; Dublineau, I.; Gourmelon, P.; Lestaevel, P.; Gueguen, Y.

    2009-01-01

    Uranium is a radionuclide present in the environment since the origin of the Earth. In addition to natural uranium, recent deposits from industrial or military activities are acknowledged. Uranium's toxicity is due to a combination of its chemical (heavy metal) and radiological properties (emission of ionizing radiations). Acute toxicity induces an important weight loss and signs of renal and cerebral impairment. Alterations of bone growth, modifications of the reproductive system and carcinogenic effects are also often seen. On the contrary, the biological effects of a chronic exposure to low doses are unwell known. However, results from different recent studies suggest that a chronic contamination with low levels of uranium induces subtle but significant levels. Indeed, an internal contamination of rats for several weeks leads to detection of uranium in many cerebral structures, in association with an alteration of short-term memory and an increase of anxiety level. Biological effects of uranium on the metabolisms of xenobiotics, steroid hormones and vitamin D were described in the liver, testis and kidneys. These recent scientific data suggest that uranium could participate to increase of health risks linked to environmental pollution. (authors)

  8. Ultraviolet laser desorption/ionization mass spectrometry of single-core and multi-core polyaromatic hydrocarbons under variable conditions of collisional cooling: insights into the generation of molecular ions, fragments and oligomers.

    Science.gov (United States)

    Gámez, Francisco; Hortal, Ana R; Martínez-Haya, Bruno; Soltwisch, Jens; Dreisewerd, Klaus

    2014-11-01

    The ultraviolet laser desorption/ionization of polyaromatic hydrocarbons (PAHs) has been investigated under different background pressures of an inert gas (up to 1.2 mbar of N2) in the ion source of a hybrid, orthogonal-extracting time-of-flight mass spectrometer (oTOF-MS). The study includes an ensemble of six model PAHs with isolated single polyaromatic cores and four ones with multiple cross-linked aromatic and polyaromatic cores. In combination with a weak ion extraction field, the variation of the buffer gas pressure allowed to control the degree of collisional cooling of the desorbed PAHs and, thus, to modulate their decomposition into fragments. The dominant fragmentation channels observed are related to dehydrogenation of the PAHs, in most cases through the cleavage of even numbers of C-H bonds. Breakage of C-C bonds leading to the fragmentation of rings, side chains and core linkages is also observed, in particular, at low buffer gas pressures. The precise patterns of the combined fragmentation processes vary significantly between the PAHs. The highest abundances of molecular PAH ions and cleanest mass spectra were consistently obtained at the highest buffer gas pressure of 1.2 mbar. The effective quenching of the fragmentation pathways at this elevated pressure improves the sensitivity and data interpretation for analytical applications, although the fragmentation of side chains and of bonds between (poly)aromatic cores is not completely suppressed in all cases. Moreover, these results suggest that the detected fragments are generated through thermal equilibrium processes rather than as a result of rapid photolysis. This assumption is further corroborated by a laser desorption/ionization post-source decay analysis using an axial time-of-flight MS. In line with these findings, covalent oligomers of the PAHs, which are presumably formed by association of two or more dehydrogenated fragments, are detected with higher abundances at the lower buffer gas

  9. Multiple ionization of atoms by ion impact

    International Nuclear Information System (INIS)

    DuBois, R.D.

    1988-01-01

    In order to model the energy deposition of fast ions as they slow down in gaseous media, information about the ionization occurring in collisions between ions and target atoms/molecules is required. Our measurements of doubly differential electron emission cross sections provide detailed information about the ionization process but do not provide any information about the final states of the target. They also do not distinguish between the emission of one or more target electrons in a single collision. It is important to know the relative importance of multiple-, with respect to single-, target ionization in order to accurately model the energy deposition. To date, multiple ionization of He, Ne, Ar, Kr, and Xe targets has been studied. Primarily, H and He ions were used, although some data for heavier ions (C,N and O) have also been obtained

  10. Geochemical exploration for uranium

    International Nuclear Information System (INIS)

    1988-01-01

    This Technical Report is designed mainly to introduce the methods and techniques of uranium geochemical exploration to exploration geologists who may not have had experience with geochemical exploration methods in their uranium programmes. The methods presented have been widely used in the uranium exploration industry for more than two decades. The intention has not been to produce an exhaustive, detailed manual, although detailed instructions are given for a field and laboratory data recording scheme and a satisfactory analytical method for the geochemical determination of uranium. Rather, the intention has been to introduce the concepts and methods of uranium exploration geochemistry in sufficient detail to guide the user in their effective use. Readers are advised to consult general references on geochemical exploration to increase their understanding of geochemical techniques for uranium

  11. Uranium purchases report 1992

    International Nuclear Information System (INIS)

    1993-01-01

    Data reported by domestic nuclear utility companies in their responses to the 1991 and 1992 ''Uranium Industry Annual Survey,'' Form EIA-858, Schedule B ''Uranium Marketing Activities,are provided in response to the requirements in the Energy Policy Act 1992. Data on utility uranium purchases and imports are shown on Table 1. Utility enrichment feed deliveries and secondary market acquisitions of uranium equivalent of US DOE separative work units are shown on Table 2. Appendix A contains a listing of firms that sold uranium to US utilities during 1992 under new domestic purchase contracts. Appendix B contains a similar listing of firms that sold uranium to US utilities during 1992 under new import purchase contracts. Appendix C contains an explanation of Form EIA-858 survey methodologies with emphasis on the processing of Schedule B data

  12. Politics of Uranium

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    Uranium is the most political of all the elements, the material for the production of both the large amounts of electricity and the most destructive weapons in the world. The problems that its dual potential creates are only now beginning to become evident. Author Norman Moss looks at this situation and sheds light on many of the questions that emerge. The nuclear issue always comes back to how much uranium there is, what can be done with it, and which countries have it. Starting with a concise history of uranium and explaining its technology in terms the nonspecialist can understand, The Politics of Uranium considers the political issues that technical arguments obscure. It tells the little-known story of the international uranium cartel, explains the entanglements of governments with the uranium trade, and describes the consequences of wrong decisions and blunders-especially the problems of nuclear waste. It also examines the intellectual and emotional roots of the anti-nuclear movement

  13. Titrimetric determination of uranium

    International Nuclear Information System (INIS)

    Florence, T.M.

    1989-01-01

    Titrimetric methods are almost invariably used for the high precision assay of uranium compounds, because gravimetric methods are nonselective, and not as reliable. Although precipitation titrations have been used, for example with cupferron and ferrocyanide, and chelate titrations with EDTA and oxine give reasonable results, in practice only redox titrations find routine use. With all redox titration methods for uranium a precision of 01 to 02 percent can be achieved, and precisions as high as 0.003 percent have been claimed for the more refined techniques. There are two types of redox titrations for uranium in common use. The first involves the direct titration of uranium (VI) to uranium (IV) with a standard solution of a strong reductant, such as chromous chloride or titanous chloride, and the second requires a preliminary reduction of uranium to the (IV) or (III) state, followed by titration back to the (VI) state with a standard oxidant. Both types of redox titrations are discussed. 4 figs

  14. Uranium Newsletter. No. 1

    International Nuclear Information System (INIS)

    1987-03-01

    The new Uranium Newsletter is presented as an IAEA annual newsletter. The organization of the IAEA and its involvement with uranium since its founding in 1957 is described. The ''Red Book'' (Uranium Resources, Production and Demand) is mentioned. The Technical Assistance Programme of the IAEA in this field is also briefly mentioned. The contents also include information on the following meetings: The Technical Committee Meeting on Uranium Deposits in Magmatic and Metamorphic Rocks, Advisory Group Meeting on the Use of Airborne Radiometric Data, and the Technical Committee Meeting on Metallogenesis. Recent publications are listed. Current research contracts in uranium exploration are mentioned. IAEA publications on uranium (in press) are listed also. Country reports from the following countries are included: Australia, Brazil, Canada, China (People's Republic of), Denmark, Finland, Germany (Federal Republic of), Malaysia, Philippines, Portugal, South Africa (Republic of), Spain, Syrian Arab Republic, United Kingdom, United States of America, Zambia, and Greece. There is also a report from the Commission of European Communities

  15. New procedure calculation of K-shell ionization cross sections by proton impact

    International Nuclear Information System (INIS)

    Kahoul, A.; Deghfel, B.; Abdellatif, A.; Nekkab, M.

    2011-01-01

    The database, which relies on different compilations available in the literature and on other experimental values extracted from papers published from 1992 till 2010, is used, within the individual treatment of the elements from beryllium ( 4 Be) to uranium ( 92 U), to deduce the empirical cross sections. These experimental data can be presented in a single curve, depending on a scaling law extracted from studies in the most familiar theories of collision (PWBA and BEA). Then, a fourth order polynomial was used to fit very well the existing database of K-shell ionization cross sections by proton. This procedure generates a new set of parameters to calculate empirical cross sections. Following the present procedure, our results are compared with those obtained using the ECPSSR model where a discrepancy is observed in the low-proton energy regime. - Highlights: → We used the experimental data to define the K-shell ionization cross sections. → These values are presented in a single curve used PWBA and BEA theories. → The empirical values are defined for each element separately.

  16. Ionizing radiations and cancer

    Directory of Open Access Journals (Sweden)

    Süleyman Daşdağ

    2010-06-01

    Full Text Available The aim of this study is to evaluate the biologic effects of ionizing radiation and relation between medical diagnosticradiation exposure and cancer risk. Many unnecessary ionizing radiation applications are performed in the medicalcenters and hospitals. Therefore the health staff and the patients expose to serious risks of radiation. On the other hand, recently some studies, which suggested relationshipsbetween low dose ionizing radiation and some cancers, have been published. The relationship between low dose ionizing radiation and cancer can be more understandablewhen the stochastic effects of ionizing radiationtake into consideration. This presented review calls attention to the fact that low dose ionizing radiation may be an important factor for increased cancer risk. Therefore,physicians, health workers and patients have to pay maximum attention to avoid hazards of low dose ionizing radiation.

  17. Process for continuous production of metallic uranium and uranium alloys

    Science.gov (United States)

    Hayden, Jr., Howard W.; Horton, James A.; Elliott, Guy R. B.

    1995-01-01

    A method is described for forming metallic uranium, or a uranium alloy, from uranium oxide in a manner which substantially eliminates the formation of uranium-containing wastes. A source of uranium dioxide is first provided, for example, by reducing uranium trioxide (UO.sub.3), or any other substantially stable uranium oxide, to form the uranium dioxide (UO.sub.2). This uranium dioxide is then chlorinated to form uranium tetrachloride (UCl.sub.4), and the uranium tetrachloride is then reduced to metallic uranium by reacting the uranium chloride with a metal which will form the chloride of the metal. This last step may be carried out in the presence of another metal capable of forming one or more alloys with metallic uranium to thereby lower the melting point of the reduced uranium product. The metal chloride formed during the uranium tetrachloride reduction step may then be reduced in an electrolysis cell to recover and recycle the metal back to the uranium tetrachloride reduction operation and the chlorine gas back to the uranium dioxide chlorination operation.

  18. Process for continuous production of metallic uranium and uranium alloys

    Science.gov (United States)

    Hayden, H.W. Jr.; Horton, J.A.; Elliott, G.R.B.

    1995-06-06

    A method is described for forming metallic uranium, or a uranium alloy, from uranium oxide in a manner which substantially eliminates the formation of uranium-containing wastes. A source of uranium dioxide is first provided, for example, by reducing uranium trioxide (UO{sub 3}), or any other substantially stable uranium oxide, to form the uranium dioxide (UO{sub 2}). This uranium dioxide is then chlorinated to form uranium tetrachloride (UCl{sub 4}), and the uranium tetrachloride is then reduced to metallic uranium by reacting the uranium chloride with a metal which will form the chloride of the metal. This last step may be carried out in the presence of another metal capable of forming one or more alloys with metallic uranium to thereby lower the melting point of the reduced uranium product. The metal chloride formed during the uranium tetrachloride reduction step may then be reduced in an electrolysis cell to recover and recycle the metal back to the uranium tetrachloride reduction operation and the chlorine gas back to the uranium dioxide chlorination operation. 4 figs.

  19. New french uranium mineral species

    International Nuclear Information System (INIS)

    Branche, G.; Chervet, J.; Guillemin, C.

    1952-01-01

    In this work, the authors study the french new uranium minerals: parsonsite and renardite, hydrated phosphates of lead and uranium; kasolite: silicate hydrated of uranium and lead uranopilite: sulphate of uranium hydrated; bayleyite: carbonate of uranium and of hydrated magnesium; β uranolite: silicate of uranium and of calcium hydrated. For all these minerals, the authors give the crystallographic, optic characters, and the quantitative chemical analyses. On the other hand, the following species, very rare in the french lodgings, didn't permit to do quantitative analyses. These are: the lanthinite: hydrated uranate oxide; the α uranotile: silicate of uranium and of calcium hydrated; the bassetite: uranium phosphate and of hydrated iron; the hosphuranylite: hydrated uranium phosphate; the becquerelite: hydrated uranium oxide; the curite: oxide of uranium and lead hydrated. Finally, the authors present at the end of this survey a primary mineral: the brannerite, complex of uranium titanate. (author) [fr

  20. Uranium industry annual, 1988

    International Nuclear Information System (INIS)

    1989-01-01

    This report presents data on US uranium raw materials and marketing activities of the domestic uranium industry. It contains aggregated data reported by US companies on the ''Uranium Industry Annual Survey'' (1988), Form EIA-858, and historical data from prior data collections and other pertinent sources. The report was prepared by the Energy Information Administration (EIA), the independent agency for data collection and analysis with the US Department of Energy

  1. Pine Creek uranium province

    International Nuclear Information System (INIS)

    Bower, M.B.; Needham, R.S.; Page, R.W.; Stuart-Smith, P.G.; Wyborn, L.A.I.

    1985-01-01

    The objective of this project is to help establish a sound geological framework of the Pine Creek region through regional geological, geochemical and geophysical studies. Uranium ore at the Coronation Hill U-Au mine is confined to a wedge of conglomerate in faulted contact with altered volcanics. The uranium, which is classified as epigenetic sandstone type, is derived from a uranium-enriched felsic volcanic source

  2. Uranium in Canada

    International Nuclear Information System (INIS)

    1985-09-01

    In 1974 the Minister of Energy, Mines and Resources (EMR) established a Uranium Resource Appraisal Group (URAG) within EMR to audit annually Canada's uranium resources for the purpose of implementing the federal government's uranium export policy. A major objective of this policy was to ensure that Canadian uranium supplies would be sufficient to meet the needs of Canada's nuclear power program. As projections of installed nuclear power growth in Canada over the long term have been successively revised downwards (the concern about domestic security of supply is less relevant now than it was 10 years ago) and as Canadian uranium supply capabilities have expanded significantly. Canada has maintained its status as the western world's leading exporter of uranium and has become the world's leading producer. Domestic uranium resource estimates have increased to 551 000 tonnes U recoverable from mineable ore since URAG completed its last formal assessment (1982). In 1984, Canada's five primary uranium producers employed some 5800 people at their mining and milling operations, and produced concentrates containing some 11 170 tU. It is evident from URAG's 1984 assessment that Canada's known uranium resources, recoverable at uranium prices of $150/kg U or less, are more than sufficient to meet the 30-year fuelling requirements of those reactors that are either in opertaion now or committed or expected to be in-service by 1995. A substantial portion of Canada's identified uranium resources, recoverable within the same price range, is thus surplus to Canadian needs and available for export. Sales worth close to $1 billion annually are assured. Uranium exploration expenditures in Canada in 1983 and 1984 were an estimated $41 million and $35 million, respectively, down markedly from the $128 million reported for 1980. Exploration drilling and surface development drilling in 1983 and 1984 were reported to be 153 000 m and 197 000 m, respectively, some 85% of which was in

  3. Gold and uranium extraction

    International Nuclear Information System (INIS)

    James, G.S.; Davidson, R.J.

    1977-01-01

    A process for extracting gold and uranium from an ore containing them both comprising the steps of pulping the finely comminuted ore with a suitable cyanide solution at an alkaline pH, acidifying the pulp for uranium dissolution, adding carbon activated for gold recovery to the pulp at a suitable stage, separating the loaded activated carbon from the pulp, and recovering gold from the activated carbon and uranium from solution

  4. International trade in uranium

    International Nuclear Information System (INIS)

    Two reports are presented; one has been prepared by the Uranium Institute and is submitted by the United Kingdom delegation, the other by the United States delegation. The report of the Uranium Institute deals with the influence of the government on international trade in uranium. This influence becomes apparent predominantly by export and import restrictions, as well as by price controls. The contribution submitted by the United States is a uranium market trend analysis, with pricing methods and contracting modes as well as the effect of government policies being investigated in the light of recent developments

  5. Uranium concentration in fossils

    International Nuclear Information System (INIS)

    Okano, J.; Uyeda, C.

    1988-01-01

    Recently it is known that fossil bones tend to accumulate uranium. The uranium concentration, C u in fossils has been measured so far by γ ray spectroscopy or by fission track method. The authors applied secondary ion mass spectrometry, SIMS, to detect the uranium in fossil samples. The purpose of this work is to investigate the possibility of semi-quantitative analyses of uranium in fossils, and to study the correlation between C u and the age of fossil bones. The further purpose of this work is to apply SIMS to measure the distribution of C u in fossil teeth

  6. analysis methods of uranium

    International Nuclear Information System (INIS)

    Bekdemir, N.; Acarkan, S.

    1997-01-01

    There are various methods for the determination of uranium. The most often used methods are spectrophotometric (PAR, DBM and Arsenazo III) and potentiometric titration methods. For uranium contents between 1-300 g/LU potentiometric titration method based on oxidation-reduction reactions gives reliable results. PAR (1-pyridiyl-2-azo resorcinol) is a sensitive reagent for uranium, forming complexes in aqueous solutions. It is a suitable method for determination of uranium at concentrations between 2-400microgram U. In this study, the spectrophotometric and potentiometric analysis methods, used in the Nuclear Fuel Department will be discussed in detail and other methods and their principles will be briefly mentioned

  7. Uranium production from phosphates

    International Nuclear Information System (INIS)

    Ketzinel, Z.; Folkman, Y.

    1979-05-01

    According to estimates of the world's uranium consumption, exploitation of most rich sources is expected by the 1980's. Forecasts show that the rate of uranium consumption will increase towards the end of the century. It is therefore desirable to exploit poor sources not yet in use. In the near future, the most reasonable source for developing uranium is phosphate rock. Uranium reserves in phosphates are estimated at a few million tons. Production of uranium from phosphates is as a by-product of phosphate rock processing and phosphoric acid production; it will then be possible to save the costs incurred in crushing and dissolving the rock when calculating uranium production costs. Estimates show that the U.S. wastes about 3,000 tons of uranium per annum in phosphoric acid based fertilisers. Studies have also been carried out in France, Yugoslavia and India. In Israel, during the 1950's, a small plant was operated in Haifa by 'Chemical and Phosphates'. Uranium processes have also been developed by linking with the extraction processes at Arad. Currently there is almost no activity on this subject because there are no large phosphoric acid plants which would enable production to take place on a reasonable scale. Discussions are taking place about the installation of a plant for phosphoric acid production utilising the 'wet process', producing 200 to 250,000 tons P 2 O 5 per annum. It is necessary to combine these facilities with uranium production plant. (author)

  8. METHOD OF ROLLING URANIUM

    Science.gov (United States)

    Smith, C.S.

    1959-08-01

    A method is described for rolling uranium metal at relatively low temperatures and under non-oxidizing conditions. The method involves the steps of heating the uranium to 200 deg C in an oil bath, withdrawing the uranium and permitting the oil to drain so that only a thin protective coating remains and rolling the oil coated uranium at a temperature of 200 deg C to give about a 15% reduction in thickness at each pass. The operation may be repeated to accomplish about a 90% reduction without edge cracking, checking or any appreciable increase in brittleness.

  9. One color multi-photon ionization of the Gadolinium atom in near UV region

    International Nuclear Information System (INIS)

    Kim, Jin Tae; Yi, Jong Hoon; Lhee, Yong Joo; Lee, Jong Min

    1999-01-01

    We have investigated the states of the gadolinium atom in near ultra-violet (UV) region (∼410 nm) using single photon excitation using resonance ionization mass spectrometry (RIMS). Around 70 transitions among observed 180 single color multi-photon ionization signals have been assigned. Most of the multi-photon processes of the assigned ion signals are through single photon resonant three photon ionization and through two photon resonant three photon ionization. (author)

  10. Laser-Induced Ionization Efficiency Enhancement On A Filament For Thermal Ionization Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Siegfried, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-14

    The evaluation of trace Uranium and Plutonium isotope ratios for nanogram to femtogram material quantities is a vital tool for nuclear counter-proliferation and safeguard activities. Thermal Ionization Mass Spectrometry (TIMS) is generally accepted as the state of the art technology for highly accurate and ultra-trace measurements of these actinide ratios. However, the very low TIMS ionization yield (typically less than 1%) leaves much room for improvement. Enhanced ionization of Nd and Sm from a TIMS filament was demonstrated using wavelength resonance with a nanosecond (pulse width) laser operating at 10 Hz when light was directed toward the filament.1 For this study, femtosecond and picosecond laser capabilities were to be employed to study the dissociation and ionization mechanisms of actinides/lanthanides and measure the enhanced ionization of the metal of interest. Since the underlying chemistry of the actinide/lanthanide carbides produced and dissociated on a TIMS filament is not well understood, the experimental parameters affecting the photodissociation and photoionization with one and two laser beams were to be investigated.

  11. Fast-electron impact ionization of molecular hydrogen: energy and angular distribution of double and single differential cross sections and Young-type interference

    Science.gov (United States)

    Chatterjee, S.; Kasthurirangan, S.; Kelkar, A. H.; Stia, C. R.; Fojón, O. A.; Rivarola, R. D.; Tribedi, L. C.

    2009-03-01

    We report the energy and angular distribution of absolute double differential cross sections (DDCSs) of ejected electrons in collisions of 8 keV projectile electrons with molecular hydrogen. The ejected electrons with energy between 1 eV and 400 eV and ejection angles between 30° and 150° are detected. The measured data are compared with the theoretical calculations based on two-effective centre (TEC) model. The first-order interference is derived from the energy distribution of DDCS and the resulting ratio spectra (H2 to 2H) exhibit oscillating behaviour. The signature of first-order interference is also demonstrated in the DDCS spectra as a function of the ejection angle. We have shown that the constructive interference prevails in soft- and binary-collision regions. The single differential cross sections (SDCS) are deduced by integrating the DDCS over the solid angle as well as ejection energy. We demonstrate that the SDCS and corresponding ratio spectra also preserve the signature of interference.

  12. Fast-electron impact ionization of molecular hydrogen: energy and angular distribution of double and single differential cross sections and Young-type interference

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, S; Kasthurirangan, S; Kelkar, A H; Tribedi, L C [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005 (India); Stia, C R; Fojon, O A; Rivarola, R D [Instituto de Fisica Rosario (CONICET-UNR) and Facultad de Ciencias Exactas, IngenierIa y Agrimensura, Universidad Nacional de Rosario, Av Pellegrini 250, 2000 Rosario (Argentina)], E-mail: lokesh@tifr.res.in

    2009-03-28

    We report the energy and angular distribution of absolute double differential cross sections (DDCSs) of ejected electrons in collisions of 8 keV projectile electrons with molecular hydrogen. The ejected electrons with energy between 1 eV and 400 eV and ejection angles between 30 deg. and 150 deg. are detected. The measured data are compared with the theoretical calculations based on two-effective centre (TEC) model. The first-order interference is derived from the energy distribution of DDCS and the resulting ratio spectra (H{sub 2} to 2H) exhibit oscillating behaviour. The signature of first-order interference is also demonstrated in the DDCS spectra as a function of the ejection angle. We have shown that the constructive interference prevails in soft- and binary-collision regions. The single differential cross sections (SDCS) are deduced by integrating the DDCS over the solid angle as well as ejection energy. We demonstrate that the SDCS and corresponding ratio spectra also preserve the signature of interference.

  13. Trends in uranium supply

    International Nuclear Information System (INIS)

    Hansen, M.

    1976-01-01

    Prior to the development of nuclear power, uranium ores were used to a very limited extent as a ceramic colouring agent, as a source of radium and in some places as a source of vanadium. Perhaps before that, because of the bright orange and yellow colours of its secondary ores, it was probably used as ceremonial paint by primitive man. After the discovery of nuclear fission a whole new industry emerged, complete with its problems of demand, resources and supply. Spurred by special incentives in the early years of this new nuclear industry, prospectors discovered over 20 000 occurrences of uranium in North America alone, and by 1959 total world production reached a peak of 34 000 tonnes uranium from mines in South Africa, Canada and United States. This rapid growth also led to new problems. As purchases for military purposes ended, government procurement contracts were not renewed, and the large reserves developed as a result of government purchase incentives, in combination with lack of substantial commercial market, resulted in an over-supply of uranium. Typically, an over-supply of uranium together with national stockpiling at low prices resulted in depression of prices to less than $5 per pound by 1971. Although forecasts made in the early 1970's increased confidence in the future of nuclear power, and consequently the demand for uranium, prices remained low until the end of 1973 when OPEC announced a very large increase in oil prices and quite naturally, prices for coal also rose substantially. The economics of nuclear fuel immediately improved and prices for uranium began to climb in 1974. But the world-wide impact of the OPEC decision also produced negative effects on the uranium industry. Uranium production costs rose dramatically, as did capital costs, and money for investment in new uranium ventures became more scarce and more expensive. However, the uranium supply picture today offers hope of satisfactory development in spite of the many problems to be

  14. Uranium industry annual 1993

    International Nuclear Information System (INIS)

    1994-09-01

    Uranium production in the United States has declined dramatically from a peak of 43.7 million pounds U 3 O 8 (16.8 thousand metric tons uranium (U)) in 1980 to 3.1 million pounds U 3 O 8 (1.2 thousand metric tons U) in 1993. This decline is attributed to the world uranium market experiencing oversupply and intense competition. Large inventories of uranium accumulated when optimistic forecasts for growth in nuclear power generation were not realized. The other factor which is affecting U.S. uranium production is that some other countries, notably Australia and Canada, possess higher quality uranium reserves that can be mined at lower costs than those of the United States. Realizing its competitive advantage, Canada was the world's largest producer in 1993 with an output of 23.9 million pounds U 3 O 8 (9.2 thousand metric tons U). The U.S. uranium industry, responding to over a decade of declining market prices, has downsized and adopted less costly and more efficient production methods. The main result has been a suspension of production from conventional mines and mills. Since mid-1992, only nonconventional production facilities, chiefly in situ leach (ISL) mining and byproduct recovery, have operated in the United States. In contrast, nonconventional sources provided only 13 percent of the uranium produced in 1980. ISL mining has developed into the most cost efficient and environmentally acceptable method for producing uranium in the United States. The process, also known as solution mining, differs from conventional mining in that solutions are used to recover uranium from the ground without excavating the ore and generating associated solid waste. This article describes the current ISL Yang technology and its regulatory approval process, and provides an analysis of the factors favoring ISL mining over conventional methods in a declining uranium market

  15. Uranium industry annual 1993

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

    Uranium production in the United States has declined dramatically from a peak of 43.7 million pounds U{sub 3}O{sub 8} (16.8 thousand metric tons uranium (U)) in 1980 to 3.1 million pounds U{sub 3}O{sub 8} (1.2 thousand metric tons U) in 1993. This decline is attributed to the world uranium market experiencing oversupply and intense competition. Large inventories of uranium accumulated when optimistic forecasts for growth in nuclear power generation were not realized. The other factor which is affecting U.S. uranium production is that some other countries, notably Australia and Canada, possess higher quality uranium reserves that can be mined at lower costs than those of the United States. Realizing its competitive advantage, Canada was the world`s largest producer in 1993 with an output of 23.9 million pounds U{sub 3}O{sub 8} (9.2 thousand metric tons U). The U.S. uranium industry, responding to over a decade of declining market prices, has downsized and adopted less costly and more efficient production methods. The main result has been a suspension of production from conventional mines and mills. Since mid-1992, only nonconventional production facilities, chiefly in situ leach (ISL) mining and byproduct recovery, have operated in the United States. In contrast, nonconventional sources provided only 13 percent of the uranium produced in 1980. ISL mining has developed into the most cost efficient and environmentally acceptable method for producing uranium in the United States. The process, also known as solution mining, differs from conventional mining in that solutions are used to recover uranium from the ground without excavating the ore and generating associated solid waste. This article describes the current ISL Yang technology and its regulatory approval process, and provides an analysis of the factors favoring ISL mining over conventional methods in a declining uranium market.

  16. Uranium geochemistry, mineralogy, geology, exploration and resources

    International Nuclear Information System (INIS)

    De Vivo, B.

    1984-01-01

    This book comprises papers on the following topics: history of radioactivity; uranium in mantle processes; transport and deposition of uranium in hydrothermal systems at temperatures up to 300 0 C: Geological implications; geochemical behaviour of uranium in the supergene environment; uranium exploration techniques; uranium mineralogy; time, crustal evolution and generation of uranium deposits; uranium exploration; geochemistry of uranium in the hydrographic network; uranium deposits of the world, excluding Europe; uranium deposits in Europe; uranium in the economics of energy; role of high heat production granites in uranium province formation; and uranium deposits

  17. Ionizing radiation in environment

    International Nuclear Information System (INIS)

    Jandl, J.; Petr, I.

    1988-01-01

    The basic terms are explained such as the atom, radioactivity, nuclear reaction, interaction of ionizing radiation with matter, etc. The basic dosimetric variables and units and properties of radionuclides and ionizing radiation are given. Natural and artificial sources of ionizing radiation are discussed with regard to the environment and the propagation and migration of radionuclides is described in the environment to man. The impact is explained of ionizing radiation on the cell and the somatic and genetic effects of radiation on man are outlined. Attention is devoted to protection against ionizing radiation and to radiation limits, also to the detection, dosimetry and monitoring of ionizing radiation in the environment. (M.D.). 92 figs., 40 tabs. 74 refs

  18. Advances in uranium enrichment processes

    International Nuclear Information System (INIS)

    Rae, H.K.; Melvin, J.G.; Slater, J.B.

    1986-05-01

    Advances in gas centrifuges and development of the atomic vapour laser isotope separation process promise substantial reductions in the cost of enriched uranium. The resulting reduction in LWR fuel costs could seriously erode the economic advantage of CANDU, and in combination with LWR design improvements, shortened construction times and increased operational reliability could allow the LWR to overtake CANDU. CANDU's traditional advantages of neutron economy and high reliability may no longer be sufficient - this is the challenge. The responses include: combining neutron economy and dollar economy by optimizing CANDU for slightly enriched uranium fuel; developing cost-reducing improvements in design, manufacture and construction; and reducing the cost of heavy water. Technology is a renewable resource which must be continually applied to a product for it to remain competitive in the decades to come. Such innovation is a prerequisite to Canada increasing her share of the international market for nuclear power stations. The higher burn-up achievable with enriched fuel in CANDU can reduce the fuel cycle costs by 20 to 40 percent for a likely range of costs for yellowcake and separative work. Alternatively, some of the benefits of a higher fissile content can take the form of a cheaper reactor core containing fewer fuel channels and less heavy water, and needing only a single fuelling machine. An opportunity that is linked to this need to introduce an enriched uranium fuel cycle into CANDU is to build an enrichment business in Canada. This could offer greater value added to our uranium exports, security of supply for enriched CANDUs, technological growth in Canada and new employment opportunities. AECL has a study in progress to define this opportunity

  19. Ionizing radiation in hospitals

    International Nuclear Information System (INIS)

    Blok, K.; Ginkel, G. van; Leun, K. van der; Muller, H.; Oude Elferink, J.; Vesseur, A.

    1985-10-01

    This booklet dels with the risks of the use of ionizing radiation for people working in a hospital. It is subdivided in three parts. Part 1 treats the properties of ionizing radiation in general. In part 2 the various applications are discussed of ionizing radiation in hospitals. Part 3 indicates how a not completely safe situation may be improved. (H.W.). 14 figs.; 4 tabs

  20. Australia and uranium

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    A brief justification of the Australian Government's decision to mine and export Australian Uranium is presented along with a description of the Alligator River Region in the Northern Territory where the major mines are to be located. Aboriginal interests and welfare in the region, the proposed Kakadu National Park and the economic benefits resulting from uranium development are also briefly covered. (J.R.)

  1. Preparation of uranium tetrafluoride

    International Nuclear Information System (INIS)

    Wirths, G.

    1981-01-01

    Uranium dioxide is converted to uranium tetrafluoride under stoichiometric excess of hydrogen fluoride. The water formed in the process and the unreacted hydrogen fluoride are cooled and the condensate fractionally distilled into water and approx. 40% hydrofluoric acid. The hydrofluoric acid and water-free hydrogen fluoride are fed back into the process. (WI) [de

  2. Uranium: biokinetics and toxicity

    International Nuclear Information System (INIS)

    Menetrier, F.; Renaud-Salis, V.; Flury-Herard, A.

    2000-01-01

    This report was achieved as a part of a collaboration with the Fuel Cycle Direction. Its aim was to give the state of the art about: the behaviour of uranium in the human organism (biokinetics) after ingestion, its toxicity (mainly renal) and the current regulation about its incorporation. Both in the upstream and in the downstream of the fuel cycle, uranium remains, quantitatively, the first element in the cycle which is, at the present time, temporarily disposed or recycled. Such a considerable quantity of uranium sets the problem of its risk on the health. In the long term, the biosphere may be affected and consequently the public may ingest water or food contaminated with uranium. In this way, radiological and chemical toxicity risk may be activated. This report emphasizes: the necessity of confirming some experimental and epidemiological biokinetic data used or not in the ICRP models. Unsolved questions remain about the gastrointestinal absorption according to chemical form (valency state, mixtures...), mass and individual variations (age, disease) further a chronic ingestion of uranium. It is well established that uranium is mainly deposited in the skeleton and the kidney. But the skeleton kinetics following a chronic ingestion and especially in some diseases has to be more elucidated; the necessity of taking into account uranium at first as a chemical toxic, essentially in the kidney and determining the threshold of functional lesion. In this way, it is important to look for some specific markers; the problem of not considering chemical toxicity of uranium in the texts regulating its incorporation

  3. Ranger uranium project

    International Nuclear Information System (INIS)

    1979-01-01

    Details are given of an agreement between Peko-Wallsend Operations Ltd., Electrolytic Zinc Company of Australasia Limited, the Australian Atomic Energy Commission and Ranger Uranium Mines Pty. Ltd. regarding the management of the joint Ranger uranium project in the Northern Territory of Australia

  4. Rheinbraun's Australian uranium business

    International Nuclear Information System (INIS)

    Kirschbaum, S.

    1989-01-01

    The leaflet argues against the mining activities of the Rheinische Braunkohlenwerke AG in Germany and especially against uranium mining in Australia. The ethno-ecological impact on flora and fauna, aborigines and miners are pointed out. Uranium mining and lignite mining are compared. (HSCH) [de

  5. Nuclear and uranium policies

    International Nuclear Information System (INIS)

    MacNabb, G.M.; Uranium Canada Ltd., Ottawa, Ontario)

    The background of the uranium industry in Canada is described. Government policies with respect to ownership of the uranium mining industry, price stabilization, and especially reservation of sufficient supplies of nuclear fuels for domestic utilities, are explained. Canadian policy re nuclear exports and safeguards is outlined. (E.C.B.)

  6. Uranium dioxide pellets

    International Nuclear Information System (INIS)

    Zawidzki, T.W.

    1979-01-01

    Sintered uranium dioxide pellets composed of particles of size > 50 microns suitable for power reactor use are made by incorporating a small amount of sulphur into the uranium dioxide before sintering. The increase in grain size achieved results in an improvement in overall efficiency when such pellets are used in a power reactor. (author)

  7. Uranium: A Dentist's perspective

    Science.gov (United States)

    Toor, R. S. S.; Brar, G. S.

    2012-01-01

    Uranium is a naturally occurring radionuclide found in granite and other mineral deposits. In its natural state, it consists of three isotopes (U-234, U-235 and U-238). On an average, 1% – 2% of ingested uranium is absorbed in the gastrointestinal tract in adults. The absorbed uranium rapidly enters the bloodstream and forms a diffusible ionic uranyl hydrogen carbonate complex (UO2HCO3+) which is in equilibrium with a nondiffusible uranyl albumin complex. In the skeleton, the uranyl ion replaces calcium in the hydroxyapatite complex of the bone crystal. Although in North India, there is a risk of radiological toxicity from orally ingested natural uranium, the principal health effects are chemical toxicity. The skeleton and kidney are the primary sites of uranium accumulation. Acute high dose of uranyl nitrate delays tooth eruption, and mandibular growth and development, probably due to its effect on target cells. Based on all previous research and recommendations, the role of a dentist is to educate the masses about the adverse effects of uranium on the overall as well as the dental health. The authors recommended that apart from the discontinuation of the addition of uranium to porcelain, the Public community water supplies must also comply with the Environmental Protection Agency (EPA) standards of uranium levels being not more than 30 ppb (parts per billion). PMID:24478959

  8. Uranium and transuranium analysis

    International Nuclear Information System (INIS)

    Regnaud, F.

    1989-01-01

    Analytical chemistry of uranium, neptunium, plutonium, americium and curium is reviewed. Uranium and neptunium are mainly treated and curium is only briefly evoked. Analysis methods include coulometry, titration, mass spectrometry, absorption spectrometry, spectrofluorometry, X-ray spectrometry, nuclear methods and radiation spectrometry [fr

  9. Near-threshold electron impact ionization of Ne and Xe

    International Nuclear Information System (INIS)

    Yates, B R; Khakoo, M A; Keane, K

    2009-01-01

    Doubly differential cross-sections for the single electron impact ionization of Ne and Xe have been measured at several energies below the second ionization energy. The results indicate that the ionization of Ne is strongly influenced by the polarization of the ionized 2 2 P 3/2,1/2 core, where as this influence is significantly reduced for Xe. Single differential cross-sections are derived from the doubly differential cross-sections and for Xenon these show profiles similar to Helium ('smile'), whereas for Neon they show a dissimilar profile ('frown').

  10. Rapid and precise determination of Sr and Nd isotopic ratios in geological samples from the same filament loading by thermal ionization mass spectrometry employing a single-step separation scheme.

    Science.gov (United States)

    Li, Chao-Feng; Li, Xian-Hua; Li, Qiu-Li; Guo, Jing-Hui; Li, Xiang-Hui; Yang, Yue-Heng

    2012-05-21

    Thermal ionization mass spectrometry (TIMS) offers the excellent precision and accuracy of the Sr and Nd isotopic ratio analysis for geological samples, but this method is labour intensive, expensive and time-consuming. In this study, a new analytical protocol by TIMS is presented that aims at improving analytical efficiency and cutting down experimental cost. Using the single-step cation exchange resin technique, mixed Sr and rare earth elements (REEs) fractions were separated from matrix and evaporated to dryness. Afterwards, mixed Sr+REEs fractions were dissolved and loaded onto the same Re filament using 1 μL of 2 M HCl. Then, Sr and Nd were sequentially measured without venting using TIMS. In contrast to conventional TIMS methods, the merits of this analytical protocol are its cost- and time-saving adaptations. The applicability of our method is evaluated by replicated measurements of (87)Sr/(86)Sr and (143)Nd/(144)Nd for nine international silicate rock reference materials, spanning a wide range of bulk compositions. The typical internal precision in this study is ca. 0.001% (RSE) for (87)Sr/(86)Sr and (143)Nd/(144)Nd; the analytical results obtained for these standard rocks show a good agreement with reported values, indicating the effectiveness of the proposed method. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Dosimetry of ionizing radiation

    International Nuclear Information System (INIS)

    Musilek, L.; Seda, J.; Trousil, J.

    1992-01-01

    The publication deals with a major field of ionizing radiation dosimetry, viz., integrating dosimetric methods, which are the basic means of operative dose determination. It is divided into the following sections: physical and chemical effects of ionizing radiation; integrating dosimetric methods for low radiation doses (film dosimetry, nuclear emulsions, thermoluminescence, radiophotoluminescence, solid-state track detectors, integrating ionization dosemeters); dosimetry of high ionizing radiation doses (chemical dosimetric methods, dosemeters based on the coloring effect, activation detectors); additional methods applicable to integrating dosimetry (exoelectron emission, electron spin resonance, lyoluminescence, etc.); and calibration techniques for dosimetric instrumentation. (Z.S.). 422 refs

  12. EPR of uranium ions

    International Nuclear Information System (INIS)

    Ursu, I.; Lupei, V.

    1984-02-01

    A review of the electron paramagnetic resonance data on the uranium ions is given. After a general account of the electronic structure of the uranium free atoms and ions, the influence of the external fields (magnetic field, crystal fields) is discussed. The main information obtained from EPR studies on the uranium ions in crystals are emphasized: identification of the valence and of the ground electronic state, determination of the structure of the centers, crystal field effects, role of the intermediate coupling and of the J-mixing, role of the covalency, determination of the nuclear spin, maqnetic dipole moment and electric quadrupole moment of the odd isotopes of uranium. These data emphasize the fact that the actinide group has its own identity and this is accutely manifested at the beginning of the 5fsup(n) series encompassed by the uranium ions. (authors)

  13. Jabiluka uranium project

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    The Jabiluka uranium and gold deposit located in the Northern Territory of Australia is the world's largest known primary uranium deposits and as such has the potential to become one of the most important uranium projects in the world. Despite the financial and structural challenges facing the major owner Pancontinental Mining Limited and the changing political policies in Australia, Jabiluka is well situated for development during the 1990's. With the availability of numerous financial and development alternatives, Jabiluka could, by the turn of the century, take its rightful place among the first rank of world uranium producers. The paper discusses ownership, location, property rights, licensing, environmental concerns, marketing and development, capital costs, royalties, uranium policy considerations, geologic exploration history, regional and site geology, and mining and milling operations

  14. Uranium deposit research, 1983

    International Nuclear Information System (INIS)

    Ruzicka, V.; LeCheminant, G.M.

    1984-01-01

    Research on uranium deposits in Canada, conducted as a prerequisite for assessment of the Estimated Additional Resources of uranium, revealed that (a) the uranium-gold association in rudites of the Huronian Supergroup preferably occurs in the carbon layers; (b) chloritized ore at the Panel mine, Elliot Lake, Ontario, occurs locally in tectonically disturbed areas in the vicinity of diabase dykes; (c) mineralization in the Black Sturgeon Lake area, Ontario, formed from solutions in structural and lithological traps; (d) the Cigar Lake deposit, Saskatchewan, has two phases of mineralization: monomineralic and polymetallic; (e) mineralization of the JEB (Canoxy Ltd.) deposit is similar to that at McClean Lake; (f) the uranium-carbon assemblage was identified in the Claude deposit, Carswell Structure; and (g) the Otish Mountains area, Quebec, should be considered as a significant uranium-polymetallic metallogenic province

  15. Strong suppression of the positronium channel in double ionization of noble gases by positron impact

    DEFF Research Database (Denmark)

    Bluhme, H.; Knudsen, H.; Merrison, J.P.

    1998-01-01

    Positron-induced double ionization of helium and neon has been studied at energies from threshold to 900 eV. A remarkable difference between the near-threshold behavior of the single and double ionization cross sections is found: Single ionization is dominated by positronium (Ps) formation, while...

  16. Mechanistic studies of ionizing radiation and oxidative mutagenesis: Genetic effects of a single 8-hydroxyguanine (7-hydro-8-oxoguanine) residue inserted at a unique site in a viral genome

    Energy Technology Data Exchange (ETDEWEB)

    Wood, M.L.; Essigmann, J.M. (Massachusetts Institute of Technology, Cambridge (USA)); Dizdaroglu, M.; Gajewski, E. (National Institute of Standards and Technology, Gaithersburg, MD (USA))

    1990-07-31

    T4 RNA ligase was used to construct a deoxypentanucleotide containing a single 8-hydroxyguanine (7-hydro-8-oxoguanine; G{sup 8-OH}) residue, which is one of the putatively mutagenic DNA adducts produced by oxidants and ionizing radiation. The pentamer d(GCTAG{sup 8-OH})p was prepared by the ligation of a chemically synthesized acceptor molecule, d(GCTA), to an adducted donor, 8-hydroxy-2{prime}-deoxyguanosine 5{prime},3{prime}-bisphosphate. Following 3{prime}-dephosphorylation, the pentamer was characterized by UV spectroscopy, by high-pressure liquid chromatography, and by gas chromatography-mass spectrometry of the nucleosides released by enzymatic hydrolysis. Both d(GCTAG{sup 8-OH}) and an unmodified control were 5{prime}-phosphorylated by using ({gamma}-{sup 32}P)ATP and incorporated covalently by DNA ligase into a five-base gap at a unique NheI restriction site in the otherwise duplex genome of an M13mp19 derivative. The adduct was part of a nonsense codon in a unique restriction site in order to facilitate the identification and selection of mutants generated by the replication of the modified genome in Escherichia coli. Both control and adducted pentamers ligated into the genome at 50% of the maximum theoretical efficiency, and nearly all of the site-specifically adducted products possessed pentanucleotides that were covalently linked at both 5{prime} and 3{prime} termini. Transformation of E. coli strain DL7 with the uniquely modified single-stranded genome resulted in {approximately}0.5-1.0% of the progeny phase showing the G {yields} T transversion mutation at the original position of G{sup 8-OH}. The vector containing G{sup 8-OH} also transformed 50-90% as efficiently as the unmodified control, indicating that the adduct can be both weakly cytotoxic and mutagenic to the phase genome.

  17. Uranium in Canada

    International Nuclear Information System (INIS)

    1987-09-01

    Canadian uranium exploration and development efforts in 1985 and 1986 resulted in a significant increase in estimates of measured uranium resources. New discoveries have more than made up for production during 1985 and 1986, and for the elimination of some resources from the overall estimates, due to the sustained upward pressure on production costs and the stagnation of uranium prices in real terms. Canada possesses a large portion of the world's uranium resources that are of current economic interest and remains the major focus of inter-national uranium exploration activity. Expenditures for uranium exploration in Canada in 1985 and 1986 were $32 million and $33 million, respectively. Although much lower than the $130 million total reported for 1979, expenditures for 1987 are forecast to increase. Exploration and surface development drilling in 1985 and 1986 were reported to be 183 000 m and 165σ2 000 m, respectively, 85 per cent of which was in Saskatchewan. Canada has maintained its position as the world's leading producer and exporter of uranium. By the year 2000, Canada's annual uranium requirements will be about 2 100 tU. Canada's known uranium resources are more than sufficient to meet the 30-year fuel requirements of those reactors in Canada that are either in operation now or expected to be in service by the late 1990s. A substantial portion of Canada's identified uranium resources is thus surplus to Canadian needs and available for export. Annual sales currently approach $1 billion, of which exports account for 85 per cent. Forward domestic and export contract commitments totalled 73 000 tU and 62 000 tU, respectively, as of early 1987

  18. Partially ionized plasmas including the third symposium on uranium plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, M. [ed.

    1976-09-01

    Separate abstracts are included for 28 papers on electrically generated plasmas, fission generated plasmas, nuclear pumped lasers, gaseous fuel reactor research, and applications. Five papers have been previously abstracted and included in ERA.

  19. Uranium producers foresee new boom

    International Nuclear Information System (INIS)

    McIntyre, H.

    1979-01-01

    The status of uranium production in Canada is reviewed. Uranium resources in Saskatchewan and Ontario are described and the role of the Cluff Lake inquiry in securing a government decision in favour of further uranium development is mentioned. There have been other uranium strikes near Kelowna, British Columbia and in the Northwest Territories. Increasing uranium demand and favourable prices are making the development of northern resources economically attractive. In fact, all uranium currently produced has been committed to domestic and export contracts so that there is considerable room for expanding the production of uranium in Canada. (T.I.)

  20. A uranium-based UO{sub 2}{sup +}-Mn{sup 2+} single-chain magnet assembled trough cation-cation interactions

    Energy Technology Data Exchange (ETDEWEB)

    Mougel, Victor; Chatelain, Lucile; Hermle, Johannes; Pecaut, Jacques; Mazzanti, Marinella [Laboratoire de Reconnaissance Ionique et Chimie de Coordination, SCIB, UMR-E3 CEA-UJF, INAC, CEA-Grenoble (France); Caciuffo, Roberto; Colineau, Eric [European Commission, Joint Research Centre, Institute for Transuranium Elements, Karlsruhe (Germany); Tuna, Floriana [EPSRC UK EPR Facility, School of Chemistry and Photon Science Institute, The University of Manchester (United Kingdom); Magnani, Nicola [Institute of Nanotechnology, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen (Germany); Geyer, Arnaud de [Service General des Rayons X, SP2M, INAC, CEA-Grenoble (France)

    2014-01-13

    Single-chain magnets (SCMs) are materials composed of magnetically isolated one-dimensional (1D) units exhibiting slow relaxation of magnetization. The occurrence of SCM behavior requires the fulfillment of stringent conditions for exchange and anisotropy interactions. Herein, we report the synthesis, the structure, and the magnetic characterization of the first actinide-containing SCM. The 5f-3d heterometallic 1D chains [{[UO_2(salen)(py)][M(py)_4](NO_3)}]{sub n}, (M=Cd (1) and M=Mn (2); py=pyridine) are assembled trough cation-cation interaction from the reaction of the uranyl(V) complex [UO{sub 2}(salen)py][Cp*{sub 2}Co] (Cp*=pentamethylcyclopentadienyl) with Cd(NO{sub 3}){sub 2} or Mn(NO{sub 3}){sub 2} in pyridine. The infinite UMn chain displays a high relaxation barrier of 134 ±0.8 K (93 ±0.5 cm{sup -1}), probably as a result of strong intra-chain magnetic interactions combined with the high Ising anisotropy of the uranyl(V) dioxo group. It also exhibits an open magnetic hysteresis loop at T <6 K, with an impressive coercive field of 3.4 T at 2 K. (Copyright copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. A uranium-based UO{sub 2}{sup +}-Mn{sup 2+} single-chain magnet assembled trough cation-cation interactions

    Energy Technology Data Exchange (ETDEWEB)

    Mougel, Victor; Chatelain, Lucile; Hermle, Johannes; Pecaut, Jacques; Mazzanti, Marinella [CEA-Grenoble (France). Lab. de Reconnaissance Ionique et Chimie de Coordination; Caciuffo, Roberto; Colineau, Eric [European Commission, Karlsruhe (Germany). Inst. for Transuranium Elements; Tuna, Floriana [Manchester Univ. (United Kingdom). School of Chemistry; Magnani, Nicola [KIT Karlsruhe (Germany). Inst. of Nanotechnology; Geyer, Arnaud de [CEA-Grenoble (France). Service General des Rayons X

    2014-01-13

    Single-chain magnets (SCMs) are materials composed of magnetically isolated one-dimensional (1D) units exhibiting slow relaxation of magnetization. The occurrence of SCM behavior requires the fulfillment of stringent conditions for exchange and anisotropy interactions. Herein, we report the synthesis, the structure, and the magnetic characterization of the first actinide-containing SCM. The 5f-3d heterometallic 1D chains [{[UO_2(salen)(py)][M(py)_4](NO_3)}]{sub n}, (M=Cd (1) and M=Mn (2); py=pyridine) are assembled trough cation-cation interaction from the reaction of the uranyl(V) complex [UO{sub 2}(salen)py][Cp{sup *}{sub 2}Co] (Cp{sup *}=pentamethylcyclopentadienyl) with Cd(NO{sub 3}){sub 2} or Mn(NO{sub 3}){sub 2} in pyridine. The infinite UMn chain displays a high relaxation barrier of 134±0.8 K (93±0.5 cm{sup -1}), probably as a result of strong intra-chain magnetic interactions combined with the high Ising anisotropy of the uranyl(V) dioxo group. It also exhibits an open magnetic hysteresis loop at T<6 K, with an impressive coercive field of 3.4 T at 2 K.

  2. A Comparative Study of Single-pulse and Double-pulse Laser-Induced Breakdown Spectroscopy with Uranium-containing Samples.

    Science.gov (United States)

    Skrodzki, Patrick J; Becker, Jason R; Diwakar, Prasoon K; Harilal, Sivanandan S; Hassanein, Ahmed

    2016-03-01

    Laser-induced breakdown spectroscopy (LIBS) holds potential advantages in special nuclear material (SNM) sensing and nuclear forensics, which require rapid analysis, minimal sample preparation, and stand-off distance capability. SNM, such as U, however, result in crowded emission spectra with LIBS, and characteristic emission lines are challenging to discern. It is well-known that double-pulse LIBS (DPLIBS) improves the signal intensity for analytes over conventional single-pulse LIBS (SPLIBS). This study investigates the U signal in a glass matrix using DPLIBS and compares it to signal obtained using SPLIBS. Double-pulse LIBS involves sequential firing of a 1.06 µm Nd:YAG pre-pulse and 10.6 µm TEA CO2 heating pulse in a near collinear geometry. Optimization of experimental parameters including inter-pulse delay and energy follows identification of characteristic lines for the bulk analyte Ca and the minor constituent analyte U for both DPLIBS and SPLIBS. Spatial and temporal coupling of the two pulses in the proposed DPLIBS technique yields improvements in analytical merits with a negligible increase in damage to the sample compared to SPLIBS. Subsequently, the study discusses optimum plasma emission conditions of U lines and relative figures of merit in both SPLIBS and DPLIBS. Investigation into plasma characteristics also addresses plausible mechanisms related to the observed U analyte signal variation between SPLIBS and DPLIBS. © The Author(s) 2016.

  3. Improvements in ionization chambers

    International Nuclear Information System (INIS)

    Whetten, N.R.; Zubal, C.

    1980-01-01

    A method of reducing mechanical vibrations transmitted to the parallel plate electrodes of ionization chamber x-ray detectors, commonly used in computerized x-ray axial tomography systems, is described. The metal plate cathodes and anodes are mounted in the ionizable gas on dielectric sheet insulators consisting of a composite of silicone resin and glass fibres. (UK)

  4. Social trust and ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Meadd, E. [Faculty of Environmental Studies, York University, Toronto, Ontario (Canada)

    2002-07-01

    The linkages that exist between the environmental risks associated with nuclear energy production (both perceived and real) and the myriad of social and political issues and processes that influence social trust are a current issue in literature, but are not well explored, particularly for the Canadian context. This paper will examine one particular issue and its relationship with social trust: ionizing radiation and public health. Social trust is defined for this paper as including interpersonal trust, but having a much broader focus, extending to public trust in governments, institutions, corporations, and the power elite, and across whole societies. Of particular interest for the nuclear energy issue is how waning social trust may impact the functioning of democratic decision-making processes, particularly those associated with the siting of waste facilities. Social trust is a central issue in the management of environmental risks, particularly those related to high technology; its absence is seen as a major cause of intractable conflict in decisions related to nuclear power generation and waste disposal. Understanding the dynamics of social trust is important if a resolution is to be found to the nuclear waste management debate in Canada, that is, one that involves broad public, or social, support. For instance, what factors cause distrust to emerge, and when distrust emerges, what authorities do members of affected communities seek out for information and support? This paper begins to examine social trust in relation to human health and ionizing radiation, particularly low dose radiation from radioactive wastes resulting from uranium and radium processing activities in Port Hope, Ontario. These activities date back to the 1930s and are of great concern to community members. This paper looks at some of the roots of public concern, for example, scientific uncertainty around whether or not human health is compromised by exposure to low dose ionizing radiation

  5. Social trust and ionizing radiation

    International Nuclear Information System (INIS)

    Meadd, E.

    2002-01-01

    The linkages that exist between the environmental risks associated with nuclear energy production (both perceived and real) and the myriad of social and political issues and processes that influence social trust are a current issue in literature, but are not well explored, particularly for the Canadian context. This paper will examine one particular issue and its relationship with social trust: ionizing radiation and public health. Social trust is defined for this paper as including interpersonal trust, but having a much broader focus, extending to public trust in governments, institutions, corporations, and the power elite, and across whole societies. Of particular interest for the nuclear energy issue is how waning social trust may impact the functioning of democratic decision-making processes, particularly those associated with the siting of waste facilities. Social trust is a central issue in the management of environmental risks, particularly those related to high technology; its absence is seen as a major cause of intractable conflict in decisions related to nuclear power generation and waste disposal. Understanding the dynamics of social trust is important if a resolution is to be found to the nuclear waste management debate in Canada, that is, one that involves broad public, or social, support. For instance, what factors cause distrust to emerge, and when distrust emerges, what authorities do members of affected communities seek out for information and support? This paper begins to examine social trust in relation to human health and ionizing radiation, particularly low dose radiation from radioactive wastes resulting from uranium and radium processing activities in Port Hope, Ontario. These activities date back to the 1930s and are of great concern to community members. This paper looks at some of the roots of public concern, for example, scientific uncertainty around whether or not human health is compromised by exposure to low dose ionizing radiation

  6. Analyses of uranium in some phosphate commercial products

    International Nuclear Information System (INIS)

    Kamel, N.H.M.; Sohsah, M.; Mohammad, H.M.; Sadek, M.

    2005-01-01

    The raw materials used in manufacturing of phosphate fertilizer products were derived from rocks. Rocks contain a remarkable of natural radioactivity. Uranium and phosphorous were originally initiated at the same time of the initiated rocks. The purpose of this research is to investigate solubility of uranium phosphate species at the phosphate fertilizer samples, samples including; raw phosphate material, single super phosphates (SSP) granules and powdered, triple super phosphates (TSP) and phosphogypsum samples were obtained from Abu-Zabal factory in Egypt. Solubility of uranium phosphate species was estimated. It was found that, less than half of the uranium phosphate species are soluble in water. The soluble uranium may be enter into the food chains by plant. Therefore, restriction should be done in order to limit contamination of land and the public

  7. Uranium tipped ammunition

    International Nuclear Information System (INIS)

    Roche, P.

    1993-01-01

    During the uranium enrichment process required to make nuclear weapons or fuel, the concentration of the 'fissile' U-235 isotope has to be increased. What is left, depleted uranium, is about half as radioactive as natural uranium, but very dense and extremely hard. It is used in armour piercing shells. External radiation levels from depleted uranium (DU) are low. However DU is about as toxic as lead and could be harmful to the kidneys if eaten or inhaled. It is estimated that between 40 and 300 tonnes of depleted uranium were left behind by the Allied armies after the Gulf war. The biggest hazard would be from depleted uranium shells which have hit Iraqui armoured vehicles and the resulting dust inhaled. There is a possible link between depleted uranium shells and an illness known as 'Desert Storm Syndrome' occurring in some Gulf war veterans. As these shells are a toxic and radioactive hazard to health and the environment their use and testing should be stopped because of the risks to troops and those living near test firing ranges. (UK)

  8. Uranium deposits in Africa

    International Nuclear Information System (INIS)

    Wilpolt, R.H.; Simov, S.D.

    1979-01-01

    Africa is not only known for its spectacular diamond, gold, copper, chromium, platinum and phosphorus deposits but also for its uranium deposits. At least two uranium provinces can be distinguished - the southern, with the equatorial sub-province; and the south Saharan province. Uranium deposits are distributed either in cratons or in mobile belts, the first of sandstone and quartz-pebble conglomerate type, while those located in mobile belts are predominantly of vein and similar (disseminated) type. Uranium deposits occur within Precambrian rocks or in younger platform sediments, but close to the exposed Precambrian basement. The Proterozoic host rocks consist of sediments, metamorphics or granitoids. In contrast to Phanerozoic continental uranium-bearing sediments, those in the Precambrian are in marginal marine facies but they do contain organic material. The geology of Africa is briefly reviewed with the emphasis on those features which might control the distribution of uranium. The evolution of the African Platform is considered as a progressive reduction of its craton area which has been affected by three major Precambrian tectonic events. A short survey on the geology of known uranium deposits is made. However, some deposits and occurrences for which little published material is available are treated in more detail. (author)

  9. The uranium in the environment

    International Nuclear Information System (INIS)

    2001-01-01

    The uranium is a natural element omnipresent in the environment, with a complex chemistry more and more understood. Many studies are always today devoted to this element to better improve the uranium behavior in the environment. To illustrate this knowledge and for the public information the CEA published this paper. It gathers in four chapters: historical aspects and properties of the uranium, the uranium in the environment and the impacts, the metrology of the uranium and its migration. (A.L.B.)

  10. Translocation of uranium from water to foodstuff while cooking

    Energy Technology Data Exchange (ETDEWEB)

    Krishnapriya, K.C.; Baksi, Ananya; Chaudhari, Swathi; Gupta, Soujit Sen; Pradeep, T.

    2015-10-30

    Highlights: • Rice can efficiently uptake uranium from water contaminated with uranyl nitrate hexahydrate (UO{sub 2}(NO{sub 3}) 2.6 H{sub 2}O), while cooking. • Unusual uranium uptake to the extent of about 1000 ppm is observed when rice is cooked in highly concentrated uranium contaminated water (1240 ppm). • Nature of interaction of uranium with carbohydrates is probed using small monosaccharides like glucose and mannose. • Electrospray ionization mass spectrometry showed UO{sub 2}{sup 2+} to be the most stable species in water in such solutions which can form complexes with sugars. • The species (UO{sub 2}{sup 2+}) is also observed in the case of water exposed to the common mineral, uranium oxide (UO{sub 2}) and similar type of complexation is observed with sugars. - Abstract: The present work report the unusual uranium uptake by foodstuff, especially those rich in carbohydrates like rice when they are cooked in water, contaminated with uranium. The major staple diet in South Asia, rice, was chosen to study its interaction with UO{sub 2}{sup 2+}, the active uranium species in water, using inductively coupled plasma mass spectrometry. Highest uptake limit was checked by cooking rice at very high uranium concentration and it was found to be good scavenger of uranium. To gain insight into the mechanism of uptake, direct interaction of UO{sub 2}{sup 2+} with monosaccharides was also studied, using electrospray ionization mass spectrometry taking mannose as a model. The studies have been done with dissolved uranium salt, uranyl nitrate hexahydrate (UO{sub 2}(NO{sub 3}){sub 2}·6H{sub 2}O), as well as the leachate of a stable oxide of uranium, UO{sub 2}(s), both of which exist as UO{sub 2}{sup 2+} in water. Among the eight different rice varieties investigated, Karnataka Ponni showed the maximum uranium uptake whereas unpolished Basmati rice showed the minimum. Interaction with other foodstuffs (potato, carrot, peas, kidney beans and lentils) with and

  11. Uranium resource assessments

    International Nuclear Information System (INIS)

    1981-01-01

    The objective of this investigation is to examine what is generally known about uranium resources, what is subject to conjecture, how well do the explorers themselves understand the occurrence of uranium, and who are the various participants in the exploration process. From this we hope to reach a better understanding of the quality of uranium resource estimates as well as the nature of the exploration process. The underlying questions will remain unanswered. But given an inability to estimate precisely our uranium resources, how much do we really need to know. To answer this latter question, the various Department of Energy needs for uranium resource estimates are examined. This allows consideration of whether or not given the absence of more complete long-term supply data and the associated problems of uranium deliverability for the electric utility industry, we are now threatened with nuclear power plants eventually standing idle due to an unanticipated lack of fuel for their reactors. Obviously this is of some consequence to the government and energy consuming public. The report is organized into four parts. Section I evaluates the uranium resource data base and the various methodologies of resource assessment. Part II describes the manner in which a private company goes about exploring for uranium and the nature of its internal need for resource information. Part III examines the structure of the industry for the purpose of determining the character of the industry with respect to resource development. Part IV arrives at conclusions about the emerging pattern of industrial behavior with respect to uranium supply and the implications this has for coping with national energy issues

  12. Depleted uranium management alternatives

    Energy Technology Data Exchange (ETDEWEB)

    Hertzler, T.J.; Nishimoto, D.D.

    1994-08-01

    This report evaluates two management alternatives for Department of Energy depleted uranium: continued storage as uranium hexafluoride, and conversion to uranium metal and fabrication to shielding for spent nuclear fuel containers. The results will be used to compare the costs with other alternatives, such as disposal. Cost estimates for the continued storage alternative are based on a life-cycle of 27 years through the year 2020. Cost estimates for the recycle alternative are based on existing conversion process costs and Capital costs for fabricating the containers. Additionally, the recycle alternative accounts for costs associated with intermediate product resale and secondary waste disposal for materials generated during the conversion process.

  13. Vacuum fusion of uranium

    International Nuclear Information System (INIS)

    Stohr, J.A.

    1957-01-01

    After having outlined that vacuum fusion and moulding of uranium and of its alloys have some technical and economic benefits (vacuum operations avoid uranium oxidation and result in some purification; precision moulding avoids machining, chip production and chemical reprocessing of these chips; direct production of the desired shape is possible by precision moulding), this report presents the uranium fusion unit (its low pressure enclosure and pumping device, the crucible-mould assembly, and the MF supply device). The author describes the different steps of cast production, and briefly comments the obtained results

  14. Uranium absorption study pile

    International Nuclear Information System (INIS)

    Raievski, V.; Sautiez, B.

    1959-01-01

    The report describes a pile designed to measure the absorption of fuel slugs. The pile is of graphite and comprises a central section composed of uranium rods in a regular lattice. RaBe sources and BF 3 counters are situated on either side of the center. A given uranium charge is compared with a specimen charge of about 560 kg, and the difference in absorption between the two noted. The sensitivity of the equipment will detect absorption variations of about a few ppm boron (10 -6 boron per gr. of uranium) or better. (author) [fr

  15. Uranium mining and milling

    International Nuclear Information System (INIS)

    Floeter, W.

    1976-01-01

    In this report uranium mining and milling are reviewed. The fuel cycle, different types of uranium geological deposits, blending of ores, open cast and underground mining, the mining cost and radiation protection in mines are treated in the first part of this report. In the second part, the milling of uranium ores is treated, including process technology, acid and alkaline leaching, process design for physical and chemical treatment of the ores, and the cost. Each chapter is clarified by added figures, diagrams, tables, and flowsheets. (HK) [de

  16. Uranium in coal

    International Nuclear Information System (INIS)

    Facer, J.F. Jr.

    1979-05-01

    United States production of coal in 1977 was 695 million short tons of which 477 million tons were burned in power plants. The ash from these power plants was about 67 million tons containing an estimated 900 tons U 3 O 8 , assuming 14 percent ash from the type of coal used by utilities and 12 ppM U contained in ash. Perhaps 1 to 3 percent of the domestic uranium requirement could be met from coal ash, provided processing technology could be developed for uranium recovery at acceptable costs. However, the environmental problems for disposal of the slimy leached ash would be enormous. The average uranium grade of coal in the United States is less than half of that of the Earth's crust. Burning the coal concentrates the contained uranium in the ash from 2 to 20 times. However, even at 20 times concentration, the percent uranium in coal ash is less than 1/100 of the grade of the uranium ore being processed today from conventional deposits. Although it is conceivable that some coal ash might contain enough uranium to make the ash an economic source of uranium, this is not now the case for ash from any major coal-fired power plant in the United States. During 1963 to 67, about 180,000 tons of uranium-bearing carbonaceous rock from the southwestern part of the Williston Basin were mined and processed to recover about 1 million pounds of U 3 O 8 . None of this material has been mined since 1967. The uranium reserves of the area are small, and the environmental problems with calcining the lignitic material may be prohibitive. Some other uraniferous coal and lignite could be mined and processed as a uranium ore, but less than half of one percent of the domestic $30 reserves are in coal. A few samples of mid-continent coal have been reported to contain about 100 ppM U but little is known about the size of such deposits or the likelihood that they will be mined and used for power plant fuel to produce a high-uranium ash

  17. Introduction to ionizing radiation physics

    International Nuclear Information System (INIS)

    Musilek, L.

    1979-01-01

    Basic properties are described of the atom, atomic nucleus and of ionizing radiation particles; nuclear reactions, ionizing radiation sources and ionizing radiation interaction with matter are explained. (J.P.)

  18. Electron impact single ionization of copper

    Indian Academy of Sciences (India)

    Holland Publishing Company, Ams- terdam, 1969) vol. I, p. 353. [16] G Catlow and M R C McDowell, Proc. Phys. Soc. 92, 875 (1967). [17] E Clementi and C Roetti, At. Data Nucl. Data Tables 14, 217 (1974). [18] D C Griffin and M S Pindzola, ...

  19. Electron impact single ionization of copper

    Indian Academy of Sciences (India)

    Author Affiliations. L K Jha1 O P Roy2 B N Roy3. Department of Physics, L.N.T. College, Muzaffarpur 842 002, India; Department of Physics, M.S.K.B. College, Muzaffarpur 842 002, India; Professor's Colony, Aghoria Bazar, Muzaffarpur 842 002, India ...

  20. Charge exchange between singly ionized helium ions

    International Nuclear Information System (INIS)

    Choi, B.H.; Poe, R.T.; Tang, K.T.

    1978-01-01

    The plane-wave Born approximation was used to evaluate the charge transfer cross sections for the reaction He + + He + → He ++ + He. The charge transfer cross section is graphed as a function of incident energy and compared with experimental measurements

  1. Mortality analysis in the French cohort of uranium miners

    International Nuclear Information System (INIS)

    Vacquier, B.

    2008-10-01

    The objective of this thesis is to contribute to the estimation of radiation-induced risks at low dose rates. This work is based on the cohort of uranium miners French presenting multiple exposures, contamination by internal (radon and uranium dust) and external exposure (gamma radiation). An analysis of the risk of death and the relationship risk exposure was carried out within the cohort of uranium miners after extension of the monitoring until 1999, for cancers diseases and non-cancers. In addition, an analysis taking into account multiple exposures to ionizing radiation was carried out within the framework of this thesis. This analysis has improved knowledge on the risk of mortality associated with low levels of exposure to radon. (author)

  2. Possible uranium sources of Streltsovsky uranium ore field

    International Nuclear Information System (INIS)

    Zhang Lisheng

    2005-01-01

    The uranium deposit of the Late Jurassic Streltsovaky caldera in Transbaikalia of Russia is the largest uranium field associated with volcanics in the world, its uranium reserves are 280 000 t U, and it is the largest uranium resources in Russia. About one third of the caldera stratigraphic pile consists of strongly-altered rhyolites. Uranium resources of the Streltsovsky caldera are much larger than any other volcanic-related uranium districts in the world. Besides, the efficiency of hydrothermal alteration, uranium resources appear to result from the juxtaposition of two major uranium sources; highly fractionated peralkaline rhyolites of Jurassic age in the caldera, and U-rich subalkaline granites of Variscan age in the basement in which the major uranium-bearing accessory minerals were metamict at the time of the hydrothermal ore formation. (authors)

  3. Occupational health problems of uranium mining and milling

    Energy Technology Data Exchange (ETDEWEB)

    Rathus, E.M.

    1972-08-23

    A discussion is given of some of the health problems in uraniur mining and milling which include exposure to ionizing radiations, silica dusts, toxicity of uranium, thermal environment, and diesel engine fumes. Maximum permissible concentrations of radon and its daughter products are given. Statistics are presented, which show the additive effect of cigarette smoking on the presumed pathological radiation effect. The toxicity of U/sub 3/O/sub 8/ is discussed. (AT)

  4. Biological Effects of Ionizing Radiation

    Science.gov (United States)

    Ingram, M.; Mason, W. B.; Whipple, G. H.; Howland, J. W.

    1952-04-07

    This report presents a review of present knowledge and concepts of the biological effects of ionizing radiations. Among the topics discussed are the physical and chemical effects of ionizing radiation on biological systems, morphological and physiological changes observed in biological systems subjected to ionizing radiations, physiological changes in the intact animal, latent changes following exposure of biological systems to ionizing radiations, factors influencing the biological response to ionizing radiation, relative effects of various ionizing radiations, and biological dosimetry.

  5. Uranium in alkaline rocks

    International Nuclear Information System (INIS)

    Murphy, M.; Wollenberg, H.; Strisower, B.; Bowman, H.; Flexser, S.; Carmichael, I.

    1978-04-01

    Geologic and geochemical criteria were developed for the occurrence of economic uranium deposits in alkaline igneous rocks. A literature search, a limited chemical analytical program, and visits to three prominent alkaline-rock localities (Ilimaussaq, Greenland; Pocos de Caldas, Brazil; and Powderhorn, Colorado) were made to establish criteria to determine if a site had some uranium resource potential. From the literature, four alkaline-intrusive occurrences of differing character were identified as type-localities for uranium mineralization, and the important aspects of these localities were described. These characteristics were used to categorize and evaluate U.S. occurrences. The literature search disclosed 69 U.S. sites, encompassing nepheline syenite, alkaline granite, and carbonatite. It was possible to compare two-thirds of these sites to the type localities. A ranking system identified ten of the sites as most likely to have uranium resource potential

  6. PURIFICATION OF URANIUM FUELS

    Science.gov (United States)

    Niedrach, L.W.; Glamm, A.C.

    1959-09-01

    An electrolytic process of refining or decontaminating uranium is presented. The impure uranium is made the anode of an electrolytic cell. The molten salt electrolyte of this cell comprises a uranium halide such as UF/sub 4/ or UCl/sub 3/ and an alkaline earth metal halide such as CaCl/sub 2/, BaF/sub 2/, or BaCl/sub 2/. The cathode of the cell is a metal such as Mn, Cr, Co, Fe, or Ni which forms a low melting eutectic with U. The cell is operated at a temperature below the melting point of U. In operation the electrodeposited uranium becomes alloyed with the metal of the cathode, and the low melting alloy thus formed drips from the cathode.

  7. Uranium market activities

    International Nuclear Information System (INIS)

    Patterson, J.A.

    1975-01-01

    Results are summarized from the 1974 ERDA annual survey of buyers and sellers and from a survey of uranium price data which provided information on additional domestic buying activity during the first half of 1975 through 1982

  8. Uranium industry seminar: proceedings

    International Nuclear Information System (INIS)

    1981-01-01

    The eleventh annual Uranium Industry Seminar, sponsored by the Grand Junction Area Office of the US Department of Energy (DOE), was held in Grand Junction, Colorado, on October 21 and 22, 1981. There were 491 registered attendees as compared to 700 attending the previous year. The attendees were largely from uranium and other energy resource companies, electric utility firms, energy consultants and service companies, and governmental agencies. In addition, there were representatives present from Indian tribes, universities, the media, DOE laboratories, and foreign countries and organizations. Papers presented at the seminar dealt with uranium policies, exploration, resources, supply, enrichment, and market conditions. There also were papers on the National Uranium Resource Evaluation Program and international activities. Thirteen papers included in this report have been abstracted and indexed

  9. Uranium extraction from seawater

    International Nuclear Information System (INIS)

    Bals, H.G.

    1978-01-01

    Problems and work of other institutes in the field of uranium extraction from sea water are presented. UEB developments, UEB processes, and work done to realize the UEB concept are discussed. (HK) [de

  10. Uranium dioxide pellets

    International Nuclear Information System (INIS)

    Zawidzki, T.W.

    1982-01-01

    A process for the preparation of a sintered, high density, large crystal grain size uranium dioxide pellet is described which involves: (i) reacting a uranyl nitrate of formula UO 2 (NO 3 ) 2 .6H 2 O with a sulphur source, at a temperature of from about 300 deg. C to provide a sulphur-containing uranium trioxide; (ii) reacting the thus-obtained modified uranium trioxide with ammonium nitrate to form an insoluble sulphur-containing ammonium uranate; (iii) neutralizing the thus-formed slurry with ammonium hydroxide to precipitate out as an insoluble ammonium uranate the remaining dissolved uranium; (iv) recovering the thus-formed precipitates in a dry state; (v) reducing the dry precipitate to UO 2 , and forming it into 'green' pellets; and (vi) sintering the pellets in a hydrogen atmosphere at an elevated temperature

  11. Uranium in alkaline rocks

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, M.; Wollenberg, H.; Strisower, B.; Bowman, H.; Flexser, S.; Carmichael, I.

    1978-04-01

    Geologic and geochemical criteria were developed for the occurrence of economic uranium deposits in alkaline igneous rocks. A literature search, a limited chemical analytical program, and visits to three prominent alkaline-rock localities (Ilimaussaq, Greenland; Pocos de Caldas, Brazil; and Powderhorn, Colorado) were made to establish criteria to determine if a site had some uranium resource potential. From the literature, four alkaline-intrusive occurrences of differing character were identified as type-localities for uranium mineralization, and the important aspects of these localities were described. These characteristics were used to categorize and evaluate U.S. occurrences. The literature search disclosed 69 U.S. sites, encompassing nepheline syenite, alkaline granite, and carbonatite. It was possible to compare two-thirds of these sites to the type localities. A ranking system identified ten of the sites as most likely to have uranium resource potential.

  12. Ontario's uranium mining industry

    International Nuclear Information System (INIS)

    Runnalls, O.J.C.

    1981-01-01

    This report traces the Ontario uranium mining industry from the first discovery of uranium north of Sault Ste. Marie through the uranium boom of the 1950's when Elliot Lake and Bancroft were developed, the cutbacks of the 1960s, the renewed enthusiasm in exploration and development of the 1970s to the current position when continued production for the domestic market is assured. Ontario, with developed mines and operational expertise, will be in a position to compete for export markets as they reopen. The low level of expenditures for uranium exploration and the lack of new discoveries are noted. The report also reviews and places in perspective the development of policies and regulations governing the industry and the jurisdictional relationships of the Federal and Provincial governments

  13. Uranium Research in Senegal

    International Nuclear Information System (INIS)

    Kanouté, Mamadou

    2015-01-01

    The work of mining companies have so far not proved economic uranium resources, but they have nevertheless contributed greatly to a better understanding of the geology, particularly in Eastern Senegal, on the upper Precambrian basin including which equivalents exist throughout West Africa (the uranium belt of Zaire) prospected by CEA-COGEMA teams. The researches carried out in Senegal, but also in Guinea and Mali helped establish a detailed map and understand the course of geological history. With new exploration techniques and data of airborne geophysical (radiometric) provided by the Mining Sector Support Programme (PASMI 9th EDF 9 ACP SE 09), AREVA, at the end of the first period validity of the exploration permit increased significantly, the resources. Prospects are favorable to a doubling of resources; objective of a uranium mine in Senegal. Synergies are possible and desirable with joint exploitation of uranium deposits located in Mali, near the border with Senegal.

  14. Uranium industry seminar

    International Nuclear Information System (INIS)

    1980-01-01

    The tenth annual Uranium Industry Seminar, sponsored by the US Department of Energy's (DOE) Grand Junction Office, was held in Grand Junction, Colorado, on October 22 and 23, 1980. There were 700 registered attendees as compared to 833 attending the previous year. The attendees were drawn largely from uranium and other energy resource companies, electric utility firms, energy consultants and service companies, and governmental agencies. In addition, there were representatives present from Indian tribes, universities, the media, DOE laboratories, and foreign countries and organizations. There were 14 papers presented at the seminar by speakers from the Department of Energy, US Geological Survey, and Bendix Field Engineering Corporation which is the on-site prime contractor for DOE's Grand Junction Office. The topics the papers dealt with were uranium policies, exploration, respources, supply, enrichment, and market conditions. There also were papers describing the National Uranium Resource Evaluation program and international activities. All 14 papers in this Proceedings have been abstracted and indexed

  15. The uranium market prospects

    International Nuclear Information System (INIS)

    Lloyd, R.

    1981-01-01

    A historical analysis of the uranium market points out the cyclical nature of the market and suggests that the spot price, exploration levels, and mill capacity utilization rate are dependent on economic factors. An examination of the current uranium market suggests that the effects of the forecasted surplus supply, the diminishing returns in exploration and the long lead times and high costs of development may mean that future production levels are uncertain. The general prospects for the uranium industry are also uncertain because of barriers to trade, environmental regulations and public opinion. The paper concludes that by the use of long term contracts, appropriate inventory policy and greater discussion between producers and consumers the prospects for the uranium market can be made more certain and further imbalances in demand and supply can be avoided. (author)

  16. Uranium in granites

    International Nuclear Information System (INIS)

    Maurice, Y.T.

    1982-01-01

    Recent research activities of the Canadian Uranium in Granites Study are presented in 18 papers and 3 abstracts. 'Granites' is used as a generic term for granitoids, granitic rocks, and plutonic rocks

  17. Uranium determination in zirconium

    International Nuclear Information System (INIS)

    Serdeiro, N.H.; Bianco de Salas, G.H.; Correia, R.J.

    1987-01-01

    The method used for the spectrometric uranium determination with 2-(2-thiolase)-5-diethylaminophenol was modified for its application in the zirconium samples analysis with an uranium content of the 0.1% order. The samples, previously dissolved in nitric acid, were submitted to a separative stage of liquid-liquid extraction, with a trioctylphosphine (TOPO) oxide diluted in cyclohexane. A sodium fluoride aqueous solution was necessary to be aggregated in the spectrometric determination so as to complex the zirconium vestiges, which could be present, originated by the Zr/U high relation of the initial sample. Under the established working conditions, different spectrometric assays, dyes absorption spectra and its uranium complex, complex stability, PH influence determination of the dyes-uranium relation, calculation of the complex's apparent formation constant and its molar absorption, were performed. (Author)

  18. Uranium purchases report 1993

    International Nuclear Information System (INIS)

    1994-01-01

    Data reported by domestic nuclear utility companies in their responses to the 1991 through 1993 ''Uranium Industry Annual Survey,'' Form EIA-858, Schedule B,'' Uranium Marketing Activities,'' are provided in response to the requirements in the Energy Policy Act 1992. Appendix A contains an explanation of Form EIA-858 survey methodologies with emphasis on the processing of Schedule B data. Additional information published in this report not included in Uranium Purchases Report 1992, includes a new data table. Presented in Table 1 are US utility purchases of uranium and enrichment services by origin country. Also, this report contains additional purchase information covering average price and contract duration. Table 2 is an update of Table 1 and Table 3 is an update of Table 2 from the previous year's report. The report contains a glossary of terms

  19. Uranium hexafluoride purification

    International Nuclear Information System (INIS)

    Araujo, Eneas F. de

    1986-01-01

    Uranium hexafluoride might contain a large amount of impurities after manufacturing or handling. Three usual methods of purification of uranium hexafluoride were presented: selective sorption, sublimation, and distillation. Since uranium hexafluoride usually is contaminated with hydrogen fluoride, a theoretical study of the phase equilibrium properties was performed for the binary system UF 6 -HF. A large deviation from the ideal solution behaviour was observed. A purification unity based on a constant reflux batch distillation process was developed. A procedure was established in order to design the re boiler, condenser and packed columns for the UF 6 -HF mixture separation. A bench scale facility for fractional distillation of uranium hexafluoride was described. Basic operations for that facility and results extracted from several batches were discussed. (author)

  20. Hydrogen in uranium

    International Nuclear Information System (INIS)

    Darras, R.; Caillat, R.

    1959-01-01

    Hydrogen impairs the properties of metals, in particular this can assume considerable importance with uranium when used as a fuel material. Hydrogen can be associated with uranium in two distinct ways: either dissolved in the metal, or in the form of a hydride. The solubility of hydrogen in uranium depends on the allotropic form of the metal; it is in addition greater in molten than in solid uranium. Two types of hydride, both given by the formula UH 3 , have been identified. The first, the α-type. is stable at low temperature. It is generally accompanied by small amounts of the β-type, into which it is wholly transformed above 140 deg.C. Reprint of a paper published in Progress in Nuclear Energy, Series V, Vol. 2, 'Metallurgy and Fuels', p. 19-27

  1. Uranium Location Database

    Data.gov (United States)

    U.S. Environmental Protection Agency — A GIS compiled locational database in Microsoft Access of ~15,000 mines with uranium occurrence or production, primarily in the western United States. The metadata...

  2. Kelvin spray ionization.

    Science.gov (United States)

    Özdemir, Abdil; Lin, Jung-Lee; Gillig, Kent J; Chen, Chung-Hsuan

    2013-11-21

    A novel self-powered dual spray ionization source has been developed for applications in mass spectrometry. This new source does not use any power supply and produces both positive and negative ions simultaneously. The idea behind this ionization source comes from the Kelvin water dropper. The source employs one or two syringes, two pneumatic sprays operated over a range of flow rates (0.15-15 μL min(-1)) and gas pressures (0-150 psi), and two double layered metal screens for ion formation. A variable electrostatic potential from 0 to 4 kV can be produced depending on solvent and gas flow rates that allow gentle ionization of compounds. There are several parameters that affect the performance during ionization of molecules including the flow rate of solvent, gas pressure, solvent acidity, position of spray and metal screens with respect to each other and distance between metal screens and the counter electrode. This ionization method has been successfully applied to solutions of peptides, proteins and non-covalent complexes. In comparison with ESI, the charge number of the most populated state is lower than that from ESI. It indicates that this is a softer ionization technique and it produces more protein ions with folded structures. The unique features of Kelvin spray ionization (KeSI) are that the method is self-powered and ionization occurs at very low potentials by providing very low internal energy to the ions. This advantage can be used for the ionization of very fragile molecules and investigation of non-covalent interactions.

  3. Uranium in Canada

    International Nuclear Information System (INIS)

    1989-01-01

    In 1988 Canada's five uranium producers reported output of concentrate containing a record 12,470 metric tons of uranium (tU), or about one third of total Western world production. Shipments exceeded 13,200 tU, valued at $Cdn 1.1 billion. Most of Canada's uranium output is available for export for peaceful purposes, as domestic requirements represent about 15 percent of production. The six uranium marketers signed new sales contracts for over 11,000 tU, mostly destined for the United States. Annual exports peaked in 1987 at 12,790 tU, falling back to 10,430 tU in 1988. Forward domestic and export contract commitments were more than 70,000 tU and 60,000 tU, respectively, as of early 1989. The uranium industry in Canada was restructured and consolidated by merger and acquisition, including the formation of Cameco. Three uranium projects were also advanced. The Athabasca Basin is the primary target for the discovery of high-grade low-cost uranium deposits. Discovery of new reserves in 1987 and 1988 did not fully replace the record output over the two-year period. The estimate of overall resources as of January 1989 was down by 4 percent from January 1987 to a total (measured, indicated and inferred) of 544,000 tU. Exploration expenditures reached $Cdn 37 million in 1987 and $59 million in 1988, due largely to the test mining programs at the Cigar Lake and Midwest projects in Saskatchewan. Spot market prices fell to all-time lows from 1987 to mid-1989, and there is little sign of relief. Canadian uranium production capability could fall below 12,000 tU before the late 1990s; however, should market conditions warrant output could be increased beyond 15,000 tU. Canada's known uranium resources are more than sufficient to meet the 30-year fuel requirements of those reactors in Canada that are now or are expected to be in service by the late 1990s. There is significant potential for discovering additional uranium resources. Canada's uranium production is equivalent, in

  4. US uranium market developments

    International Nuclear Information System (INIS)

    Krusiewski, S.V.; Thomas, D.C.

    1981-01-01

    Domestic uranium delivery commitments for the 1981 to 1990 period reached a peak in the July 1980 survey and then declined in the January 1981 survey and again in the July 1981 survey. However, there are sizable sales contracts through the mid-1980s. In the latter part of this decade, unfilled requirements increase which can provide a needed market for domestic producers. Older contracts are helping to keep the average contract prices, including market price settlements, rather stable. However, average market price settlements decreased from data reported in January 1981, but some of these deliveries represent settlement of litigation. Foreign uranium procurement is scheduled to exceed deliveries of US uranium to foreign buyers in the 1981 to 1990 period. However, the actual use of foreign uranium has been quite low as US enrichment services customers have preferred to buy US uranium. Based on over four and one-half years of data, only about 7% foreign uranium has been brought to the Department of Energy for enrichment. Inventories of natural and enriched uranium in buyers' hands continue to increase. This is a concern to the uranium-producing industry. However, the industry should not be concerned about DOE-owned inventories, which are needed to supply Government requirements. There is absolutely no plan to dispose of DOE inventories on the commercial market. Capital expenditures reached a peak of $800 million in 1979. This decreased to $780 million in 1980, although higher expenditures were planned for the year. A very sharp reduction in plans for 1981, from $830 to $450 million, has been reported. A further reduction to $350 million is planned for 1982. However, it is interesting to note that the planned expenditures for 1982 are above the expenditures for 1975, a period of industury expansion

  5. Recovery of uranium values

    International Nuclear Information System (INIS)

    Rowden, G.A.

    1982-01-01

    A process is provided for the recovery of uranium from an organic extractant phase containing an amine. The extractant phase is contacted in a number of mixing stages with an acidic aqueous stripping phase containing sulphate ions, and the phases are passed together through a series of mixing stages while maintaining a dispersion of droplets of one phase in the other. Uranium is precipitated from the final stage by raising the pH. An apparatus having several mixing chambers is described

  6. Uranium determination in water

    International Nuclear Information System (INIS)

    Prudenzo, E.J.; Puga, Maria J.; Cerchietti, Maria L.R.; Arguelles, Maria G.

    2005-01-01

    In our laboratory, a procedure has been assessed to determine uranium content of water in normal situations. The method proposed without sample pre-treatment, is simple and rapid. Uranium mass is measured by fluorimetry. For calculation of detection limit (Ld) and quantification level (Lq) we used blank samples and the results were analyzed for different statistical test. The calculation of total propagated uncertainty and sources contribution on real samples are presented. (author)

  7. Uranium project. Geochemistry prospection

    International Nuclear Information System (INIS)

    Lambert, J.

    1983-01-01

    Geochemistry studies the distribution of the chemicals elements in the terrestrial crust and its ways to migrate. The terminology used in this report is the following one: 1) Principles of the prospection geochemistry 2) Stages of the prospection geochemistry 3)utility of the prospection geochemistry 4) geochemistry of uranium 5) procedures used within the framework of uranium project 6) Average available 7) Selection of the zones of prospection geochemistry 8) Stages of the prospection, Sample preparation and analisis 9) Presentation of the results

  8. Worldwide developments in uranium

    International Nuclear Information System (INIS)

    Hoellen, E.E.

    1987-01-01

    World uranium production will continue to change in most major producing nations. Canadian production will increase and will be increasingly dominated by western producers as eastern Canadian high-cost production declines. Australian production will increase as major projects come into operation before 2000. US production will stabilize through the end of the century. South African production will be dependent upon the worldwide support for economic sanctions. China's entry into the world market injects yet another variable into the already cloudy supply picture. Many risks and uncertainties will face uranium producers through the 1980s. Recognizing that the uranium industry is not a fast-growing market, many existing and potential producers are seeking alternate investment courses, causing a restructuring of the world uranium production industry in ways not anticipated even a few years ago. During the restructuring process, world uranium production will most likely continue to exceed uranium consumption, resulting in a further buildup of world uranium inventories. Inventory sales will continue to redistribute this material. As inventory selling runs its course, users will turn to normal sources of supply, stimulating additional production to meet needs. Stimulation in the form of higher prices will be determined by how fast producers are willing and able to return to the market. Production costs are expected to have an increasing impact as it has become apparent that uranium resources are large in comparison to projected consumption. Conversely, security-of-supply issues have seemed to be of decreasing magnitude as Canada, Australia, and other non-US producers continue to meet delivery commitments

  9. U for uranium

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    The Beisa Mine is unique in South Africa - it is the only underground mine with uranium as its main product and gold as a by-product. At the rate of 1,2 Mt/a, the life of Beisa is estimated on 26 years. Beisa's metallurgical plant is designed to handle initially a monthly throughput of 100 000t of ore, from which uranium, gold and silver will be extracted

  10. Uranium leads political stakes

    International Nuclear Information System (INIS)

    James, D.

    2009-01-01

    Until the announcement by the federal Environment Minister Peter Garrett that the government would permit uranium mining at Beverly Four Mile, South Australia, there had been little news flow from the sector over the past year. Uranium was the first to turn down, even before the United States sub-prime mortgage crisis began to cause shock waves through the global economy, a report by BGF Equities analyst Warwick Grigor shows.

  11. Uranium purchases report 1994

    International Nuclear Information System (INIS)

    1995-07-01

    US utilities are required to report to the Secretary of Energy annually the country of origin and the seller of any uranium or enriched uranium purchased or imported into the US, as well as the country of origin and seller of any enrichment services purchased by the utility. This report compiles these data and also contains a glossary of terms and additional purchase information covering average price and contract duration. 3 tabs

  12. Ranger uranium environmental enquiry

    International Nuclear Information System (INIS)

    1976-07-01

    The submission is divided into three sections. Section A considers the international implications of the development of uranium resources including economic and resource aspects and environmental and social aspects. Section B outlines the government's position on export controls over uranium and its effect on the introduction of nuclear power in Australia. Section C describes the licensing and regulatory functions that would be needed to monitor the environmental and health aspects of the Ranger project. (R.L.)

  13. Uranium - the nuclear fuel

    International Nuclear Information System (INIS)

    Smith, E.E.N.

    1976-01-01

    A brief history is presented of Canadian uranium exploration, production, and sales. Statistics show that Canada is a good customer for its own uranium due to a rapidly expanding nuclear power program. Due to an average 10 year lag between commencement of exploration and production, and with current producers sold out through 1985, it is imperative that exploration efforts be increased. (E.C.B.)

  14. Uranium tailings bibliography

    International Nuclear Information System (INIS)

    Holoway, C.F.; Goldsmith, W.A.; Eldridge, V.M.

    1975-12-01

    A bibliography containing 1,212 references is presented with its focus on the general problem of reducing human exposure to the radionuclides contained in the tailings from the milling of uranium ore. The references are divided into seven broad categories: uranium tailings pile (problems and perspectives), standards and philosophy, etiology of radiation effects, internal dosimetry and metabolism, environmental transport, background sources of tailings radionuclides, and large-area decontamination

  15. Canada's uranium industry

    International Nuclear Information System (INIS)

    Runnalls, O.J.C.

    The history of uranium mining, exploration, and trade in Canada is outlined. Past complex variations in market conditions are analyzed and future prospects for production and demand are forecast. Canadian and world resources of uranium are compared. Export policies and their rationales are explained. The Canadian nuclear fuel industry is described and fuel performance in-reactor is shown to be excellent. (E.C.B.)

  16. URANIUM SEPARATION PROCESS

    Science.gov (United States)

    Lyon, W.L.

    1962-04-17

    A method of separating uranium oxides from PuO/sub 2/, ThO/sub 2/, and other actinide oxides is described. The oxide mixture is suspended in a fused salt melt and a chlorinating agent such as chlorine gas or phosgene is sparged through the suspension. Uranium oxides are selectively chlorinated and dissolve in the melt, which may then be filtered to remove the unchlorinated oxides of the other actinides. (AEC)

  17. The Streltsovskoye uranium district

    International Nuclear Information System (INIS)

    Ischukova, L.P.

    1997-01-01

    This paper describes the geology of the Streltsovskoye uranium district located in south-eastern Zabaikalie region, Chita Province, Siberia, Russia. This district hosts Russia's only currently active uranium production centre. The uranium ore was discovered from 1963 to 1967 by drilling below fluorite veins which had minor associated uranium mineralization and radioactive anomalies. The uranium occurs as large scale vein stockwork deposits of hydrothermal origin within a volcano-tectonic caldera formed by continental volcanism of Late Mesozoic age. Rocks occurring in the caldera include basalt and trachydacite, overlain by rhyolite, and with associated interbedded sediments. The ore bodies occur in steeply dipping faults, with the greatest concentrations located where faults along the margins of the caldera intersect steeply dipping, cross cutting, northeasterly and northwesterly striking faults. The Streltsovskoye caldera extends over an area of 150 km 2 and is underlain by a large batholith. The 19 identified uranium deposits occurred in structural features that cut through the caldera sequence and extend into the basement rocks. The caldera has a maximum thickness of 1400 metres. Details of several deposits are given, including descriptions of mineralization and associated alteration. (author). 10 figs

  18. Uranium deposits through time

    International Nuclear Information System (INIS)

    Derry, D.R.

    1980-01-01

    The distribution of different types of uranium deposits through geological time has been noted by various authors, especially as affecting deposits formed in the Precambrian era. While this is significant, it may have been oversimplified by grouping deposits within geological time limits that are very extensive when compared with Phanerozoic groupings. As more detailed information becomes available, we find that some of the higher-grade deposits have complicated histories involving several stages of concentration separated by long periods of time. A comparison of the proportion of uranium production and reserves contributed by individual classes (and geological ages) of deposits shows a changing trend in favour of the unconformity class. Possibly more attention should be paid to metallographic uranium areas and their localizations. Some areas, e.g. Gabon, West Africa and Baker Lake, N.W.T., have more than one type of uranium deposit. A further consideration is that much of the known uranium reserves in the non-Communist world lies within a dozen areas, each ranging between 3000 and 130 000 km 2 . It is possible that such uranium metallographic areas were localized by very ancient fracture systems, now not easily recognized, in the original Earth's crust

  19. Production of uranium peroxide

    International Nuclear Information System (INIS)

    Caropreso, F.E.; Kreuz, D.F.

    1977-01-01

    A process is claimed of recovering uranium values as uranium peroxide from an aqueous uranyl solution containing dissolved vanadium and sodium impurities by treating the uranyl solution with hydrogen peroxide in an amount sufficient to have an excess of at least 0.5 parts H 2 O 2 per part of vanadium (V 2 O 5 ) above the stoichiometric amount required to form the uranium peroxide, the hydrogen peroxide treatment is carried out in three sequential phases consisting of I, a precipitation phase in which the hydrogen peroxide is added to the uranyl solution to precipitate the uranium peroxide and the pH of the reaction medium maintained in the range of 2.5 to 5.5 for a period of from about 1 to 60 minutes after the hydrogen peroxide addition; II, a digestion phase in which the pH of the reaction medium is maintained in the range of 3.0 to 7.0 for a period of about 5 to 180 minutes and III, a final phase in which the pH of the reaction medium is maintained in the range of 4.0 to 7.0 for a period of about 1 to 60 minutes during which time the uranium peroxide is separated from the reaction solution containing the dissolved vanadium and sodium impurities. The excess hydrogen peroxide is maintained during the entire treatment up until the uranium peroxide is separated from the reaction medium

  20. Analytical method of uranium (IV) and uranium (VI) in uranium ores and uranium-bearing rocks

    International Nuclear Information System (INIS)

    Shen Zhuqin; Zheng Yongfeng; Li Qingzhen; Zhong Miaolan; Gu Dingxiang

    1995-11-01

    The best conditions for keeping the original valences of uranium during the dissolution and separation procedure of geological samples (especially those micro uranium-bearing rock) were studied. With the exist of high concentration protectants, the sample was decomposed with concentration HF at 40 +- 5 degree C. The U(VI) was dissolved completely and formed stable complex UO 2 F 2 , the U(IV) was precipitated rapidly and carried by carrier. Quantitative separation was carried out immediately with suction. The decomposition of sample and separation of solid/liquid phases was completed within two minutes. After separation, the U(IV) and U(VI) were determined quantitatively with laser fluorescence or voltametry respectively according to the uranium content. The limit of detection for this method is 0.7 μg/g, RSD is 10.5%, the determinate range of uranium is 2 x 10 -6 ∼10 -1 g/g. The uranium contents and their valence state ratio were measured for more than one hundred samples of sand stone and granite, the accuracy and precision of these results are satisfactory for uranium geological research. (12 tabs.; 11 refs.)

  1. Automated uranium titration system

    International Nuclear Information System (INIS)

    Takahashi, M.; Kato, Y.

    1983-01-01

    An automated titration system based on the Davies-Gray method has been developed for accurate determination of uranium. The system consists of a potentiometric titrator with precise burettes, a sample changer, an electronic balance and a desk-top computer with a printer. Fifty-five titration vessels are loaded in the sample changer. The first three contain the standard solution for standardizing potassium dichromate titrant, and the next two and the last two contain the control samples for data quality assurance. The other forty-eight measurements are carried out for sixteen unknown samples. Sample solution containing about 100 mg uranium is taken in a titration vessel. At the pretreatment position, uranium (VI) is reduced to uranium (IV) by iron (II). After the valency adjustment, the vessel is transferred to the titration position. The rate of titrant addition is automatically controlled to be slower near the end-point. The last figure (0.01 mL) of the equivalent titrant volume for uranium is calculated from the potential change. The results obtained with this system on 100 mg uranium gave a precision of 0.2% (RSD,n=3) and an accuracy of better than 0.1%. Fifty-five titrations are accomplished in 10 hours. (author)

  2. Uranium-scintillator device

    International Nuclear Information System (INIS)

    Smith, S.D.

    1979-01-01

    The calorimeter subgroup of the 1977 ISABELLE Summer Workshop strongly recommended investigation of the uranium-scintillator device because of its several attractive features: (1) increased resolution for hadronic energy, (2) fast time response, (3) high density (i.e., 16 cm of calorimeter per interaction length), and, in comparison with uranium--liquid argon detectors, (4) ease of construction, (5) simple electronics, and (6) lower cost. The AFM group at the CERN ISR became interested in such a calorimeter for substantially the same reasons, and in the fall of 1977 carried out tests on a uranium-scintillator (U-Sc) calorimeter with the same uranium plates used in their 1974 studies of the uranium--liquid argon (U-LA) calorimeter. The chief disadvantage of the scintillator test was that the uranium plates were too small to fully contain the hadronic showers. However, since the scintillator and liquid argon tests were made with the plates, direct comparison of the two types of devices could be made

  3. Uranium control in phosphogypsum

    International Nuclear Information System (INIS)

    Hurst, F.J.; Arnold, W.D.

    1980-01-01

    In wet-process phosphoric acid plants, both previous and recent test results show that uranium dissolution from phosphate rock is significantly higher when the rock is acidulated under oxidizing conditions than under reducing conditions. Excess sulfate and excess fluoride further enhance the distribution of uranium to the cake. Apparently the U(IV) present in the crystal lattice of the apatite plus that formed by reduction of U(IV) by FE(II) during acidulation is trapped or carried into the crystal lattice of the calcium sulfate crystals as they form and grow. The amount of uranium that distributes to hemihydrate filter cake is up to seven times higher than the amount that distributes to the dihydrate cake. About 60% of the uranium in hemihydrate cakes can be readily leached after hydration of the cake, but the residual uranium (20 to 30%) is very difficult to remove economically. Much additional research is needed to develop methods for minimizing uranium losses to calcium filter cakes

  4. Depleted uranium internal contamination of US soldiers deployed in Samawah, Iraq during operation Iraqi freedom

    International Nuclear Information System (INIS)

    Asaf Durakovic; Isaac Zimmerman; Axel Gerdes

    2004-01-01

    Purpose: The purpose of this study was to analyze the concentration and precise isotopic composition and ratios of four uranium isotopes ( 234 U, 235 U, 236 U, and 238 U) in the urine of United States soldiers deployed in Samawah, Iraq during the second Gulf War. Methods: Seven active duty US soldiers deployed as military police unit 442 presenting with non-specific symptoms of intractable headaches, excessive fatigue, intermittent fevers, musculoskeletal pains, respiratory impairment, affect changes, urinary tract symptoms, and neurological alterations were clinically evaluated. Each soldier signed a consent form to participate in our study. The collection of 24-hour urine samples of each subject was performed under controlled conditions. The urine samples were personally carried to the laboratory of the Institute of Geochemistry, JW Goethe University, Frankfurt, Germany. Each sample was analyzed in duplicate by multicollector inductively coupled plasma ionization mass spectrometry (MC-ICP-MS). Control samples consisting of an internal urine standard were also analyzed by the same procedure. The analytical methodology included pre-concentration of the urine samples using evaporation, oxidation of organic matter, uranium purification by ion-exchange chromatography, and analysis by mass spectrometry. The final analysis of the specimens was performed by using a double-focusing Thermo Finnigan Neptune multicollector ICP-MS equipped with retarding potential quadrupole lens and a secondary electron multiplier for ion counting. Results: The mean concentration of total uranium was 3.6±1.3 ng/L. The average 238 U/ 235 U ratio was 146.2±10.2. The ratio of 238 U/ 235 U, being considered as the single most important parameter in determining the quantitative state of depletion of the natural uranium ratio, demonstrates a significant internal contamination with depleted uranium in four soldiers. The 234 U/ 238 U ratio was 6.5 x 10 -5 ±5.7 x 10 -6 . The 236 U/ 238 U ratio was

  5. Recovery of uranium by chlorination

    International Nuclear Information System (INIS)

    Komoto, Shigetoshi; Taki, Tomihiro

    1988-01-01

    The recovery of uranium from uraniferous phosphate by conventional process is generally uneconomic, except that uranium is recovered as a by-product. If an economical process by which uranium is recovered efficiently as a chief product is discovered, uraniferous phosphate will be used effectively as uranium ore. By using chiorination which will be expected to be favorable in comparison with conventional process, the recovery of uranium from uraniferous phosphate has been carried out. The paper describes the reaction machanism and general characteristics of the uranium chiorination, and the research done so for. (author)

  6. Miniature ionization chamber

    International Nuclear Information System (INIS)

    Alexeev, V.I.; Emelyanov, I.Y.; Ivanov, V.M.; Konstantinov, L.V.; Lysikov, B.V.; Postnikov, V.V.; Rybakov, J.V.

    1976-01-01

    A miniature ionization chamber having a gas-filled housing which accommodates a guard electrode made in the form of a hollow perforated cylinder is described. The cylinder is electrically associated with the intermediate coaxial conductor of a triaxial cable used as the lead-in of the ionization chamber. The gas-filled housing of the ionization chamber also accommodates a collecting electrode shaped as a rod electrically connected to the center conductor of the cable and to tubular members. The rod is disposed internally of the guard electrode and is electrically connected, by means of jumpers passing through the holes in the guard electrode, to the tubular members. The tubular members embrace the guard electrode and are spaced a certain distance apart along its entire length. Arranged intermediate of these tubular members are spacers secured to the guard electrode and fixing the collecting electrode throughout its length with respect to the housing of the ionization chamber

  7. Process for electrolytically preparing uranium metal

    Science.gov (United States)

    Haas, Paul A.

    1989-01-01

    A process for making uranium metal from uranium oxide by first fluorinating uranium oxide to form uranium tetrafluoride and next electrolytically reducing the uranium tetrafluoride with a carbon anode to form uranium metal and CF.sub.4. The CF.sub.4 is reused in the fluorination reaction rather than being disposed of as a hazardous waste.

  8. Directed Field Ionization

    Science.gov (United States)

    Gregoric, Vincent C.; Kang, Xinyue; Liu, Zhimin Cheryl; Rowley, Zoe A.; Carroll, Thomas J.; Noel, Michael W.

    2017-04-01

    Selective field ionization is an important experimental technique used to study the state distribution of Rydberg atoms. This is achieved by applying a steadily increasing electric field, which successively ionizes more tightly bound states. An atom prepared in an energy eigenstate encounters many avoided Stark level crossings on the way to ionization. As it traverses these avoided crossings, its amplitude is split among multiple different states, spreading out the time resolved electron ionization signal. By perturbing the electric field ramp, we can change how the atoms traverse the avoided crossings, and thus alter the shape of the ionization signal. We have used a genetic algorithm to evolve these perturbations in real time in order to arrive at a target ionization signal shape. This process is robust to large fluctuations in experimental conditions. This work was supported by the National Science Foundation under Grants No. 1607335 and No. 1607377 and used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation Grant Number OCI-1053575.

  9. Oxidation of uranium and uranium alloys

    International Nuclear Information System (INIS)

    Orman, S.

    1976-01-01

    The corrosion behaviour of uranium in oxygen, water and water + oxygen mixtures is compared and contrasted. A considerable amount of work, much of it conflicting, has been published on the U + H 2 O and U + H 2 O + O 2 systems. An attempt has been made to summarise this data and to explain the reasons for the lack of agreement between the experimental results. The evidence for the mechanism involving OH - ion diffusion as the reacting entity in both the U + H 2 O and U + O 2 + H 2 O reactions is advanced. The more limited corrosion data on some lean uranium alloys and on some higher addition alloys referred to as stainless materials is summarised together with some previously unreported results obtained with these materials at AWRE. The data indicates that in the absence of oxygen the lean alloys behave in a similar manner to uranium and evolve hydrogen in approximately theoretical quantities. But the stainless alloys absorb most of the product hydrogen and assessments of reactivity based on hydrogen evolution would be very inaccurate. The direction that future corrosion work on these materials should take is recommended

  10. Resonantly enhanced inner-orbital ionization in molecular iodine

    Science.gov (United States)

    Smith, Dale L.; Gibson, George N.

    2018-02-01

    We present a wavelength study of the strong-field single-electron ionization of molecular iodine near its one-photon B -state resonance at 530 nm. We have previously identified two ionization channels [Phys. Rev. A 95, 013410 (2017), 10.1103/PhysRevA.95.013410]: ionization of the high-lying molecular orbitals and ionization of the deep orbitals in I2. We find a resonant enhancement of both channels, although the peak enhancement occurs at different wavelengths for the different channels. Moreover, the branching ratio of the ionization of the deep orbitals shows a dispersion-like function, with the branching ratio of the deep orbitals reaching over 98% at 519 nm. Finally, the branching ratio of double ionization into an excited state of I22+ as a function of wavelength closely matches the branching ratio of the single ionization of deep orbitals, implying that excitation of molecular ions generally comes about through inner orbital ionization. These findings are inconsistent with current molecular ionization theory.

  11. Influence of uranium hydride oxidation on uranium metal behaviour

    International Nuclear Information System (INIS)

    Patel, N.; Hambley, D.; Clarke, S.A.; Simpson, K.

    2013-01-01

    This work addresses concerns that the rapid, exothermic oxidation of active uranium hydride in air could stimulate an exothermic reaction (burning) involving any adjacent uranium metal, so as to increase the potential hazard arising from a hydride reaction. The effect of the thermal reaction of active uranium hydride, especially in contact with uranium metal, does not increase in proportion with hydride mass, particularly when considering large quantities of hydride. Whether uranium metal continues to burn in the long term is a function of the uranium metal and its surroundings. The source of the initial heat input to the uranium, if sufficient to cause ignition, is not important. Sustained burning of uranium requires the rate of heat generation to be sufficient to offset the total rate of heat loss so as to maintain an elevated temperature. For dense uranium, this is very difficult to achieve in naturally occurring circumstances. Areas of the uranium surface can lose heat but not generate heat. Heat can be lost by conduction, through contact with other materials, and by convection and radiation, e.g. from areas where the uranium surface is covered with a layer of oxidised material, such as burned-out hydride or from fuel cladding. These rates of heat loss are highly significant in relation to the rate of heat generation by sustained oxidation of uranium in air. Finite volume modelling has been used to examine the behaviour of a magnesium-clad uranium metal fuel element within a bottle surrounded by other un-bottled fuel elements. In the event that the bottle is breached, suddenly, in air, it can be concluded that the bulk uranium metal oxidation reaction will not reach a self-sustaining level and the mass of uranium oxidised will likely to be small in relation to mass of uranium hydride oxidised. (authors)

  12. Australia's uranium export potential

    International Nuclear Information System (INIS)

    Mosher, D.V.

    1981-01-01

    During the period 1954-71 in Australia approximately 9000 MT of U 3 O 8 was produced from five separate localities. Of this, 7000 MT was exported to the United Kingdom and United States and the balance stockpiled by the Australian Atomic Energy Commission (AAEC). Australia's uranium ore reserves occur in eight deposits in three states and the Northern Territory. However, 83% of Australia's reserves are contained in four deposits in lower Proterozoic rocks in the East Alligator River region of the Northern Territory. The AAEC has calculated Australia's recoverable uranium reserves by eliminating estimated losses during the mining and milling of the ores. AAEC has estimated reasonably assured resources of 289,000 MT of uranium at a recovery cost of less than US$80 per kilogram uranium. The companies have collectively announced a larger ore reserve than the Australian Atomic Energy Commission. This difference is a result of the companies adopting different ore reserve categories. On August 25, 1977, the federal government announced that Australia would develop its uranium resources subject to stringent environmental controls, recognition of Aboriginal Land Rights, and international safeguards. Australian uranium production should gradually increase from 1981 onward, growing to 10,000 to 15,000 MT by 1985-86. Further increases in capacity may emerge during the second half of the 1980s when expansion plans are implemented. Exploration for uranium has not been intensive due to delays in developing the existing deposits. It is likely that present reserves can be substantially upgraded if more exploration is carried out. 6 figures, 3 tables

  13. Pyrophoric behaviour of uranium hydride and uranium powders

    Science.gov (United States)

    Le Guyadec, F.; Génin, X.; Bayle, J. P.; Dugne, O.; Duhart-Barone, A.; Ablitzer, C.

    2010-01-01

    Thermal stability and spontaneous ignition conditions of uranium hydride and uranium metal fine powders have been studied and observed in an original and dedicated experimental device placed inside a glove box under flowing pure argon. Pure uranium hydride powder with low amount of oxide (Oxidation mechanisms are proposed.

  14. Uranium Supply Strategy of China

    International Nuclear Information System (INIS)

    Gao Shangxiong; Zhang Decun; Zhang Yi

    2014-01-01

    Conclusion: With the rapid development of nuclear power in the next few years, uranium demand will increase accordingly. Overseas uranium development will be the major channel to meet the future requirement of NPP demand in China.

  15. Collect method of uranium hexafluoride

    International Nuclear Information System (INIS)

    Moura, S.C.; Bustillos, O.W.V.

    1991-01-01

    A collect method of uranium hexafluoride was designed, constructed and assembled in Analytical Laboratory from Instituto de Energia Atomica, Sao Paulo, Brazil. This method of collect is main for quality control of uranium hexafluoride. (author)

  16. The case against uranium mining

    International Nuclear Information System (INIS)

    Robotham, F.P.

    1980-01-01

    Australia is a potential uranium supplier. The case against uranium mining is presented. Biological effects of radiation, risks involved in reactor operation and the problems of waste disposal are discussed

  17. Electron Impact Ionization of C60

    International Nuclear Information System (INIS)

    Duenser, B.; Lezius, M.; Scheier, P.; Deutsch, H.; Maerk, T.D.

    1995-01-01

    Absolute partial and total cross sections for the electron impact ionization of C 60 have been measured using a novel approach for the absolute calibration. The results obtained reveal not only an anomalous large parent ion cross section (as compared to the other ionization channels), but also anomalies for the production of multiply charged parent and fragment ions. This special behavior has its origin in the specific electronic and geometric structure of C 60 . Semiclassical calculations for singly charged ions support the measured data

  18. International uranium market

    International Nuclear Information System (INIS)

    Neff, T.L.; Jacoby, H.D.

    1980-12-01

    Discussed in this report are 1) how one might think about uranium demand, resources and supply, 2) how producers and consumers see the market and are likely to behave, including specifics about export and import commitments, and 3) how these actors are brought together in the international market. The general conclusion is that much of current anxiety about future uranium supply results primarily from a brief but difficult period in the mid- to late-1970's; and that current conditions and trends are favorable (at least to consumers) that there is now little basis for concern. Inventories contractual positions and producer commitments--when compared with realistic (or even unrealistic) demand estimates--imply a buyer's market for at least the next decade. The result will be considerable increases in market flexibility and resilience to shock, and real prices that are low relative to those of the past few years. There is a need to reconsider assumptions about desired directions of technological development, for many current programs were planned in an era of pessimism about uranium supply and process. Similar questions must be raided about nonproliferation policies that depend on some level of control of fuel supplies by the industrial nations. With a soft and more diversified uranium market, leverage that may have existed in the past is rapidly being eroded. Finally, as world prices turn soft, there may be significant problems created for U.S. uranium producers, who have relatively high costs in relation to several large-scale foreign suppliers

  19. Uranium hexafluoride handling

    International Nuclear Information System (INIS)

    1991-01-01

    The United States Department of Energy, Oak Ridge Field Office, and Martin Marietta Energy Systems, Inc., are co-sponsoring this Second International Conference on Uranium Hexafluoride Handling. The conference is offered as a forum for the exchange of information and concepts regarding the technical and regulatory issues and the safety aspects which relate to the handling of uranium hexafluoride. Through the papers presented here, we attempt not only to share technological advances and lessons learned, but also to demonstrate that we are concerned about the health and safety of our workers and the public, and are good stewards of the environment in which we all work and live. These proceedings are a compilation of the work of many experts in that phase of world-wide industry which comprises the nuclear fuel cycle. Their experience spans the entire range over which uranium hexafluoride is involved in the fuel cycle, from the production of UF 6 from the naturally-occurring oxide to its re-conversion to oxide for reactor fuels. The papers furnish insights into the chemical, physical, and nuclear properties of uranium hexafluoride as they influence its transport, storage, and the design and operation of plant-scale facilities for production, processing, and conversion to oxide. The papers demonstrate, in an industry often cited for its excellent safety record, continuing efforts to further improve safety in all areas of handling uranium hexafluoride

  20. Uranium tailings sampling manual

    International Nuclear Information System (INIS)

    Feenstra, S.; Reades, D.W.; Cherry, J.A.; Chambers, D.B.; Case, G.G.; Ibbotson, B.G.

    1985-01-01

    The purpose of this manual is to describe the requisite sampling procedures for the application of uniform high-quality standards to detailed geotechnical, hydrogeological, geochemical and air quality measurements at Canadian uranium tailings disposal sites. The selection and implementation of applicable sampling procedures for such measurements at uranium tailings disposal sites are complicated by two primary factors. Firstly, the physical and chemical nature of uranium mine tailings and effluent is considerably different from natural soil materials and natural waters. Consequently, many conventional methods for the collection and analysis of natural soils and waters are not directly applicable to tailings. Secondly, there is a wide range in the physical and chemical nature of uranium tailings. The composition of the ore, the milling process, the nature of tailings depositon, and effluent treatment vary considerably and are highly site-specific. Therefore, the definition and implementation of sampling programs for uranium tailings disposal sites require considerable evaluation, and often innovation, to ensure that appropriate sampling and analysis methods are used which provide the flexibility to take into account site-specific considerations. The following chapters describe the objective and scope of a sampling program, preliminary data collection, and the procedures for sampling of tailings solids, surface water and seepage, tailings pore-water, and wind-blown dust and radon

  1. Oxidants for uranium leaching

    International Nuclear Information System (INIS)

    Ho, E.; Ring, B.

    2007-01-01

    Most uranium ores are leached with sulfuric acid under oxidising conditions. This paper reviews the oxidants that have been traditionally used in uranium leaching and discusses their merits in the context of overall flow sheet considerations. Options for alternative oxidants are also discussed. In acid leaching, ferric ion in solution oxidises insoluble uranium(IV) to soluble uranium (VI). Though ferric ion may be added directly, usually an oxidant is added to the circuit to convert ferrous ion to ferric ion in the liquor so that leaching can continue. The most common oxidants are pyrolusite and sodium chlorate. Pyrolusite is relatively cheap but introduces manganese ions into the liquor and consumes twice as much acid as sodium chlorate. Sodium chlorate is a slow reacting oxidant at low temperatures and acidities, and introduces chloride into the leach liquor. Caro's acid, is a non-polluting reagent that was used successfully at the Nabarlek uranium mine, and provided very good control of oxidising conditions. Other oxidants that are now being considered to overcome the disadvantages of pyrolusite and sodium chlorate are oxygen, hydrogen peroxide and SO 2 /O 2 . Some performance data for these oxidants are presented

  2. Uranium hexafluoride handling. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-31

    The United States Department of Energy, Oak Ridge Field Office, and Martin Marietta Energy Systems, Inc., are co-sponsoring this Second International Conference on Uranium Hexafluoride Handling. The conference is offered as a forum for the exchange of information and concepts regarding the technical and regulatory issues and the safety aspects which relate to the handling of uranium hexafluoride. Through the papers presented here, we attempt not only to share technological advances and lessons learned, but also to demonstrate that we are concerned about the health and safety of our workers and the public, and are good stewards of the environment in which we all work and live. These proceedings are a compilation of the work of many experts in that phase of world-wide industry which comprises the nuclear fuel cycle. Their experience spans the entire range over which uranium hexafluoride is involved in the fuel cycle, from the production of UF{sub 6} from the naturally-occurring oxide to its re-conversion to oxide for reactor fuels. The papers furnish insights into the chemical, physical, and nuclear properties of uranium hexafluoride as they influence its transport, storage, and the design and operation of plant-scale facilities for production, processing, and conversion to oxide. The papers demonstrate, in an industry often cited for its excellent safety record, continuing efforts to further improve safety in all areas of handling uranium hexafluoride. Selected papers were processed separately for inclusion in the Energy Science and Technology Database.

  3. Uranium resources, production and demand

    International Nuclear Information System (INIS)

    1988-01-01

    Nuclear power-generating capacity will continue to expand, albeit at a slower pace than during the past fifteen years. This expansion must be matched by an adequately increasing supply of uranium. This report compares uranium supply and demand data in free market countries with the nuclear industry's natural uranium requirements up to the year 2000. It also reviews the status of uranium exploration, resources and production in 46 countries

  4. The Toxicity of Depleted Uranium

    OpenAIRE

    Briner, Wayne

    2010-01-01

    Depleted uranium (DU) is an emerging environmental pollutant that is introduced into the environment primarily by military activity. While depleted uranium is less radioactive than natural uranium, it still retains all the chemical toxicity associated with the original element. In large doses the kidney is the target organ for the acute chemical toxicity of this metal, producing potentially lethal tubular necrosis. In contrast, chronic low dose exposure to depleted uranium may not produce a c...

  5. Uranium Age Determination by Measuring the 230Th / 234U Ratio

    International Nuclear Information System (INIS)

    LAMONT, STEPHEN P.

    2004-01-01

    A radiochemical isotope dilution mass spectrometry method has been developed to determine the age of uranium materials. The amount of 230Th activity, the first progeny of 234U, that had grown into a small uranium metal sample was used to determine the elapsed time since the material was last radiochemically purified. To preserve the sample, only a small amount of oxidized uranium was removed from the surface of the sample and dissolved. Aliquots of the dissolved sample were spiked with 233U tracer and radiochemically purified by anion-exchange chromatography. The 234U isotopic concentration was then determined by thermal ionization mass spectrometry. Additional aliquots of the sample were spiked with 229Th tracer, and the thorium was purified using two sequential anion-exchange chromatography separations. The isotopic concentrations of 230Th and 232Th were determined by TIMS. The lack of any 232Th confirmed the assumption that all thorium was removed from the uranium sample at the time of purification. The 230Th and 234U mass concentrations were converted to activities and the 230Th/234U ratio for the sample was calculated. The experimental 230Th/234U ratio showed the uranium in this sample was radiochemically purified in about 1945. Isotope dilution thermal ionization mass spectrometry has sufficient sensitivity to determine the age of 100 samples of uranium. This method could certainly be employed as a nuclear forensic method to determine the age of small quantities of uranium metal or salts. Accurate determination of the ultra-trace 230Th radiochemically separated from the uranium is possible due to the use of 229Th as an isotope dilution tracer. The precision in the experimental age of the uranium could be improved by making additional replicate measurements of the 230Th/234U isotopic ratio or using a larger initial sample

  6. Uranium. Resources, production and demand

    International Nuclear Information System (INIS)

    1997-01-01

    The events characterising the world uranium market in the last several years illustrate the persistent uncertainly faced by uranium producers and consumers worldwide. With world nuclear capacity expanding and uranium production satisfying only about 60 per cent of demand, uranium stockpiles continue to be depleted at a high rate. The uncertainty related to the remaining levels of world uranium stockpiles and to the amount of surplus defence material that will be entering the market makes it difficult to determine when a closer balance between uranium supply and demand will be reached. Information in this report provides insights into changes expected in uranium supply and demand until well into the next century. The 'Red Book', jointly prepared by the OECD Nuclear Energy Agency and the International Atomic Energy Agency, is the foremost reference on uranium. This world report is based on official information from 59 countries and includes compilations of statistics on resources, exploration, production and demand as of 1 January 1997. It provides substantial new information from all of the major uranium producing centres in Africa, Australia, Eastern Europe, North America and the New Independent States, including the first-ever official reports on uranium production in Estonia, Mongolia, the Russian Federation and Uzbekistan. It also contains an international expert analysis of industry statistics and worldwide projections of nuclear energy growth, uranium requirements and uranium supply

  7. Sandstone-type uranium deposits

    International Nuclear Information System (INIS)

    Finch, W.I.; Davis, J.F.

    1985-01-01

    World-class sandstone-type uranium deposits are defined as epigenetic concentrations of uranium minerals occurring as uneven impregnations and minor massive replacements primarily in fluvial, lacustrine, and deltaic sandstone formations. The main purpose of this introductory paper is to define, classify, and introduce to the general geologic setting for sandstone-type uranium deposits

  8. Yeguang granite and uranium metallogeny

    International Nuclear Information System (INIS)

    Gong Wenshu

    1988-03-01

    The geological, petrologic and geochemical characteristics of rock body of yeguang granite are discussed with emphasis on clarification of occurrence of uranium in rock body and uranium deposit characteristics related to rock body, based on extensive field observations and laboratory test. View points are presented that granite refers to genetic series of terrestial crust transformation tye and uranium deposit is hot water deposit

  9. Uranium immobilization and nuclear waste

    International Nuclear Information System (INIS)

    Duffy, C.J.; Ogard, A.E.

    1982-02-01

    Considerable information useful in nuclear waste storage can be gained by studying the conditions of uranium ore deposit formation. Further information can be gained by comparing the chemistry of uranium to nuclear fission products and other radionuclides of concern to nuclear waste disposal. Redox state appears to be the most important variable in controlling uranium solubility, especially at near neutral pH, which is characteristic of most ground water. This is probably also true of neptunium, plutonium, and technetium. Further, redox conditions that immobilize uranium should immobilize these elements. The mechanisms that have produced uranium ore bodies in the Earth's crust are somewhat less clear. At the temperatures of hydrothermal uranium deposits, equilibrium models are probably adequate, aqueous uranium (VI) being reduced and precipitated by interaction with ferrous-iron-bearing oxides and silicates. In lower temperature roll-type uranium deposits, overall equilibrium may not have been achieved. The involvement of sulfate-reducing bacteria in ore-body formation has been postulated, but is uncertain. Reduced sulfur species do, however, appear to be involved in much of the low temperature uranium precipitation. Assessment of the possibility of uranium transport in natural ground water is complicated because the system is generally not in overall equilibrium. For this reason, Eh measurements are of limited value. If a ground water is to be capable of reducing uranium, it must contain ions capable of reducing uranium both thermodynamically and kinetically. At present, the best candidates are reduced sulfur species

  10. Uranium industry in the USSR

    International Nuclear Information System (INIS)

    Nikipelov, B.V.; Chernov, A.G.

    1990-01-01

    A brief historical account of the Soviet production of natural and enriched uranium is given. The geological and geographical location of major uranium deposits are mentioned. The processing of natural ores including in-situ leaching (ISL) is also briefly described. Gas centrifuges play a large part in uranium enrichment. The role of Techsnabexport for the export of nuclear materials is explained

  11. Uranium content of Philippine coals

    International Nuclear Information System (INIS)

    De la Rosa, A.M.; Sombrito, E.Z.; Nuguid, Z.S.; Bulos, A.M.; Bucoy, B.M.; De la Cruz, M.

    1984-01-01

    Uranium content of coal samples from seven areas in the Philippines, i.e. Cebu, Semirara, Bislig, Albay, Samar, Malangas and Polilio Is. was found to contain trace quantities of uranium. The mean value of 0.401 ppm U is lower than reported mean uranium contents for coal from other countries. (ELC)

  12. Uranium extraction from underground deposits

    International Nuclear Information System (INIS)

    Wolfe, C.R.

    1982-01-01

    Uranium is extracted from underground deposits by passing an aqueous oxidizing solution of carbon dioxide over the ore in the presence of calcium ions. Complex uranium carbonate or bicarbonate ions are formed which enter the solution. The solution is forced to the surface and the uranium removed from it

  13. Activities of Protection against Ionizing Radiation in Niger

    International Nuclear Information System (INIS)

    Kando Hamadou, M.

    2008-01-01

    Niger, sahelian country of Western Africa, is limited to North by Libya and Algeria, to the South by Nigeria and the Benin, to the East by Chad and the West by Mali and Burkina Faso. It covers a surface of 1 267 000 km2 and has a population of approximately 12 000 000 inhabitants. Niger is a large uranium producer with two extraction and treatment development companies of uranium ore which are the company of the mines of Air (SOMAIR) created in 1971 and the mining company of Akouta (COMINAK) created in 1978. Beyond the mining sector, ionizing radiation sources are used in the fields of industry, health, teaching and research. The first lawful text of protection against ionizing radiation was signed on December 5, 1979 and specifically related to the mining activities of uranium. With the multiform assistance of International Atomic Energy Agency (IAEA) protection against radiation knew a significant evolution. A national centre of protection against radiation was created in 1998, two laws relating to the field were adopted in June 2006 and three lawful texts of application of these laws are in the process of finalization

  14. Uranium prices continue their upward climb

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    This article is the uranium market overview for the month of February 1996. Prices were up in the spot market for U3O8, while conversion market prices and SWU prices remained steady. There were six trades in the U3O8 spot market, ten deals in the long-term U3O8 market, three deals in the conversion market, and a single deal in the SWU market

  15. Uranium deposits of Zaire

    International Nuclear Information System (INIS)

    Kitmut, D.; Malu wa Kalenga

    1979-01-01

    Since April 1960, following the closing of the Shinkolobwe mine, the Republic of Zaire has ceased to be a producer of uranium. Nevertheless, Gecamines (Generale des carrieres et mines du Zaire), a wholly state-owned company, is continuing its research on uranium occurrences which have been discovered in its concession in the course of aerial radiometric prospecting. The most recent campaign was the one carried out in 1969 and 1972 by Hunting Company. On-the-ground verification of these shows has not yet resulted in the discovery of a workable deposit. There are other sectors cutting across Zaire which might well contain uranium deposits: this is true of the sedimentary phosphates of the region of Lower Zaire as well as of the frontier region between Zaire and the Central African Empire. However, no detailed exploration work has yet been carried out. (author)

  16. Process for recovering uranium

    Science.gov (United States)

    MacWood, G. E.; Wilder, C. D.; Altman, D.

    1959-03-24

    A process useful in recovering uranium from deposits on stainless steel liner surfaces of calutrons is presented. The deposit is removed from the stainless steel surface by washing with aqueous nitric acid. The solution obtained containing uranium, chromium, nickel, copper, and iron is treated with an excess of ammonium hydroxide to precipitnte the uranium, iron, and chromium and convert the nickel and copper to soluble ammonio complexions. The precipitated material is removed, dried and treated with carbon tetrachloride at an elevated temperature of about 500 to 600 deg C to form a vapor mixture of UCl/ sub 4/, UCl/sub 5/, FeCl/sub 3/, and CrCl/sub 4/. The UCl/sub 4/ is separated from this vapor mixture by selective fractional condensation at a temperature of about 500 to 400 deg C.

  17. The Kintyre uranium project

    International Nuclear Information System (INIS)

    Larson, B.

    1997-01-01

    The Kintyre Uranium Project is being developed by Canning Resources Pty Ltd, a subsidiary of Rio Tinto (formerly CRA). The work on the project includes the planning and management of a number of background environmental studies. The company has also commissioned studies by external consultants into process technologies, mining strategies and techniques for extracting the uranium ore from the waste rock. In addition, Canning Resources has made a detailed assessment of the worldwide market potential for Australian uranium in the late 1990s and into the 21st century. The most significant factor affecting the future of this project is the current product price. This price is insufficient to justify the necessary investment to bring this project into production

  18. Uranium market and resources

    International Nuclear Information System (INIS)

    Capus, G.; Arnold, T.

    2005-01-01

    Under the combined effect of various factors, such as interrogations related to facing the climatic changes, the increasing prices of oil versus announced decrease of its resources, the major geopolitical evolution and the remarkable development of Asia, we live nowadays a revival of nuclear power in the very front of stage. In tis context, the following question is posed: could the nuclear fission be a sustainable source of energy when taking into consideration the availability of uranium resources? The article aims at pinpointing the knowledge we have about the world uranium resources, their limits of uncertainty and the relation between knowledge resources and market evolution. To conclude, some susceptible tracks are proposed to improve the using process of uranium resources particularly in softening the impact of high prices

  19. Australian uranium resources

    International Nuclear Information System (INIS)

    Battey, G.C.; Miezitis, Y.; McKay, A.D.

    1987-01-01

    Australia's uranium resources amount to 29% of the WOCA countries (world outside centrally-planned-economies areas) low-cost Reasonably Assured Resources and 28% of the WOCA countries low-cost Estimated Additional Resources. As at 1 January 1986, the Bureau of Mineral Resources estimated Australia's uranium resources as: (1) Cost range to US$80/kg U -Reasonably Assured Resources, 465 000 t U; Estimated Additional Resources, 256 000 t U; (2) Cost range US$80-130/kg U -Reasonably Assured Resources, 56 000 t U; Estimated Additional Resources, 127 000 t U. Most resources are contained in Proterozoic unconformity-related deposits in the Alligator Rivers uranium field in the Northern Territory (Jabiluka, Ranger, Koongarra, Nabarlek deposits) and the Proterozoic stratabound deposit at Olympic Dam on the Stuart Shelf in South Australia

  20. Uranium exploration in Ecuador

    International Nuclear Information System (INIS)

    Severne, B.; Penaherrera, P.F.; Fiallos, V.S.

    1981-01-01

    The 600-km segment of the Andean Cordillera in Ecuador includes zones that can be correlated, geologically, with uranium districts elsewhere in the Andes. It is believed that these essentially unexplored zones have the potential for economic uranium mineralization. Exploration activity to date has been limited, although it has involved both geochemical and radiometric techniques to evaluate geological concepts. Minor uranium occurrences (with chemical analyses up to 100 ppm) have been encountered, which provide further incentive to commence large-scale systematic exploration. It is recognized that a very large exploration budget and considerable technical expertise will be required to ensure exploration success. Consequently, participation by groups of proven capability from other countries will be sought for Ecuador's national exploration programme. (author)

  1. Uranium Enrichment, an overview

    International Nuclear Information System (INIS)

    Coates, J.H.

    1994-01-01

    This general presentation on uranium enrichment will be followed by lectures on more specific topics including descriptions of enrichment processes and assessments of the prevailing commercial and industrial situations. I shall therefore avoid as much as possible duplications with these other lectures, and rather dwell on: some theoretical aspects of enrichment in general, underlying the differences between statistical and selective processes, a review and comparison between enrichment processes, remarks of general order regarding applications, the proliferation potential of enrichment. It is noteworthy that enrichment: may occur twice in the LWR fuel cycle: first by enriching natural uranium, second by reenriching uranium recovered from reprocessing, must meet LWR requirements, and in particular higher assays required by high burn up fuel elements, bears on the structure of the entire front part of the fuel cycle, namely in the conversion/reconversion steps only involving UF 6 for the moment. (author). tabs., figs., 4 refs

  2. Uranium extraction technology

    International Nuclear Information System (INIS)

    1993-01-01

    In 1983 the Nuclear Energy Agency of the Organisation for Economic Co-operation and Development (OECD/NEA) and the IAEA jointly published a book on Uranium Extraction Technology. A primary objective of this report was to document the significant technological developments that took place during the 1970s. The purpose of this present publication is to update and expand the original book. It includes background information about the principle of the unit operations used in uranium ore processing and summarizes the current state of the art. The publication also seeks to preserve the technology and the operating 'know-how' developed over the past ten years. This publication is one of a series of Technical Reports on uranium ore processing that have been prepared by the Division of Nuclear Fuel Cycle and Waste Management at the IAEA. A complete list of these reports is included as an addendum. Refs, figs and tabs

  3. Uranium ore processing

    International Nuclear Information System (INIS)

    Ritcey, G.M.; Haque, K.E.; Lucas, B.H.; Skeaff, J.M.

    1983-01-01

    The authors have developed a complete method of recovering separately uranium, thorium and radium from impure solids such as ores, concentrates, calcines or tailings containing these metals. The technique involves leaching, in at least one stage. The impure solids in finely divided form with an aqueous leachant containing HCl and/or Cl 2 until acceptable amounts of uranium, thorium and radium are dissolved. Uranium is recovered from the solution by solvent extraction and precipitation. Thorium may also be recovered in the same manner. Radium may be recovered by at least one ion exchange, absorption and precipitation. This amount of iron in the solution must be controlled before the acid solution may be recycled for the leaching process. The calcine leached in the first step is prepared in a two stage roast in the presence of both Cl 2 and a metal sulfide. The first stage is at 350-450 0 and the second at 550-700 0

  4. Piezomagnetism and magnetoelastic memory in uranium dioxide.

    Science.gov (United States)

    Jaime, M; Saul, A; Salamon, M; Zapf, V S; Harrison, N; Durakiewicz, T; Lashley, J C; Andersson, D A; Stanek, C R; Smith, J L; Gofryk, K

    2017-07-24

    The thermal and magnetic properties of uranium dioxide, a prime nuclear fuel and thoroughly studied actinide material, remain a long standing puzzle, a result of strong coupling between magnetism and lattice vibrations. The magnetic state of this cubic material is characterized by a 3-k non-collinear antiferromagnetic structure and multidomain Jahn-Teller distortions, likely related to its anisotropic thermal properties. Here we show that single crystals of uranium dioxide subjected to strong magnetic fields along threefold axes in the magnetic state exhibit the abrupt appearance of positive linear magnetostriction, leading to a trigonal distortion. Upon reversal of the field the linear term also reverses sign, a hallmark of piezomagnetism. A switching phenomenon occurs at ±18 T, which persists during subsequent field reversals, demonstrating a robust magneto-elastic memory that makes uranium dioxide the hardest piezomagnet known. A model including a strong magnetic anisotropy, elastic, Zeeman, Heisenberg exchange, and magnetoelastic contributions to the total energy is proposed.The nuclear fuel uranium dioxide is of intrinsic interest due to its industrial applications but it also exhibits intriguing electronic and magnetic properties. Here, the authors demonstrate how its complex magnetic structure and interactions give rise to a strong piezomagnetic effect.

  5. The uranium International trade

    International Nuclear Information System (INIS)

    Gonzalez U, L.A.

    1993-01-01

    The aim of this thesis is the understanding of how the present dynamic of uranium International trade is developed, the variables which fall into, the factors that are affecting and conditioning it, in order to clarify which are going to be the outlook in the future of this important resource in front of the present ecological situation and the energetic panorama of XXI Century. For this purpose, as starting point, the uranium is considered as a strategic material which importance take root in its energetic potential as alternate energy source, and for this reason in Chapter I, the general problem of raw materials, its classification and present situation in the global market is presented. In Chapter II, by means of a historical review, is explain what uranium is, how it was discovered, and how since the end of the past Century and during the last three decades of present, uranium pass of practically unknown element, to the position of a strategic raw material, which by degrees, generate an International market, owing to its utilization as a basic resource in the generation of energy. Chapter III, introduce us in the roll played by uranium, since its warlike applications until its utilization in nuclear reactors for the generation of electricity. Also is explain the reason for this change in the perception at global level. Finally, in Chapter IV we enter upon specifically in the present conditions of the International market of this mineral throughout the trends of supply and demand, the main producers, users, price dynamics, and the correlation among these economical variables and other factors of political, social and ecological nature. All of these with the purpose to found out, if there exist, a meaning of the puzzle that seems to be the uranium International trade

  6. Uranium 2000 : International symposium on the process metallurgy of uranium

    International Nuclear Information System (INIS)

    Ozberk, E.; Oliver, A.J.

    2000-01-01

    The International Symposium on the Process Metallurgy of Uranium has been organized as the thirtieth annual meeting of the Hydrometallurgy Section of the Metallurgical Society of the Canadian Institute of Mining, Metallurgy and Petroleum (CIM). This meeting is jointly organized with the Canadian Mineral Processors Division of CIM. The proceedings are a collection of papers from fifteen countries covering the latest research, development, industrial practices and regulatory issues in uranium processing, providing a concise description of the state of this industry. Topics include: uranium industry overview; current milling operations; in-situ uranium mines and processing plants; uranium recovery and further processing; uranium leaching; uranium operations effluent water treatment; tailings disposal, water treatment and decommissioning; mine decommissioning; and international regulations and decommissioning. (author)

  7. Production of sized particles of uranium oxides and uranium oxyfluorides

    International Nuclear Information System (INIS)

    Knudsen, I.E.; Randall, C.C.

    1976-01-01

    A process is claimed for converting uranium hexafluoride (UF 6 ) to uranium dioxide (UO 2 ) of a relatively large particle size in a fluidized bed reactor by mixing uranium hexafluoride with a mixture of steam and hydrogen and by preliminary reacting in an ejector gaseous uranium hexafluoride with steam and hydrogen to form a mixture of uranium and oxide and uranium oxyfluoride seed particles of varying sizes, separating the larger particles from the smaller particles in a cyclone separator, recycling the smaller seed particles through the ejector to increase their size, and introducing the larger seed particles from the cyclone separator into a fluidized bed reactor where the seed particles serve as nuclei on which coarser particles of uranium dioxide are formed. 9 claims, 2 drawing figures

  8. Corrosion-resistant uranium

    Science.gov (United States)

    Hovis, Jr., Victor M.; Pullen, William C.; Kollie, Thomas G.; Bell, Richard T.

    1983-01-01

    The present invention is directed to the protecting of uranium and uranium alloy articles from corrosion by providing the surfaces of the articles with a layer of an ion-plated metal selected from aluminum and zinc to a thickness of at least 60 microinches and then converting at least the outer surface of the ion-plated layer of aluminum or zinc to aluminum chromate or zinc chromate. This conversion of the aluminum or zinc to the chromate form considerably enhances the corrosion resistance of the ion plating so as to effectively protect the coated article from corrosion.

  9. Uranium Conversion & Enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-06

    The isotopes of uranium that are found in nature, and hence in ‘fresh’ Yellowcake’, are not in relative proportions that are suitable for power or weapons applications. The goal of conversion then is to transform the U3O8 yellowcake into UF6. Conversion and enrichment of uranium is usually required to obtain material with enough 235U to be usable as fuel in a reactor or weapon. The cost, size, and complexity of practical conversion and enrichment facilities aid in nonproliferation by design.

  10. Uranium Transport Modeling

    International Nuclear Information System (INIS)

    Bostick, William D.

    2008-01-01

    Uranium contamination is prevalent at many of the U.S. DOE facilities and at several civilian sites that have supported the nuclear fuel cycle. The potential off-site mobility of uranium depends on the partitioning of uranium between aqueous and solid (soil and sediment) phases. Hexavalent U (as uranyl, UO 2 2+ ) is relatively mobile, forming strong complexes with ubiquitous carbonate ion which renders it appreciably soluble even under mild reducing conditions. In the presence of carbonate, partition of uranyl to ferri-hydrate and select other mineral phases is usually maximum in the near-neutral pH range ∼ 5-8. The surface complexation reaction of uranyl with iron-containing minerals has been used as one means to model subsurface migration, used in conjunction with information on the site water chemistry and hydrology. Partitioning of uranium is often studied by short-term batch 'equilibrium' or long-term soil column testing ; MCLinc has performed both of these methodologies, with selection of method depending upon the requirements of the client or regulatory authority. Speciation of uranium in soil may be determined directly by instrumental techniques (e.g., x-ray photoelectron spectroscopy, XPS; x-ray diffraction, XRD; etc.) or by inference drawn from operational estimates. Often, the technique of choice for evaluating low-level radionuclide partitioning in soils and sediments is the sequential extraction approach. This methodology applies operationally-defined chemical treatments to selectively dissolve specific classes of macro-scale soil or sediment components. These methods recognize that total soil metal inventory is of limited use in understanding bioavailability or metal mobility, and that it is useful to estimate the amount of metal present in different solid-phase forms. Despite some drawbacks, the sequential extraction method can provide a valuable tool to distinguish among trace element fractions of different solubility related to mineral phases

  11. Uranium ore dressing process

    International Nuclear Information System (INIS)

    Floter, W.; Schoning, G.; Landsiedel, K.

    1982-01-01

    A process for dressing uranium ore containing water-soluble substances is claimed. In a mixture of crushed ore and water the solid material and water are partly separated. The first fraction, which contains the smaller grain-size portion of the solid material and the major part of the water is passed through a water softening means for removal of undesired ions. The second fraction, which contains the coarser grain-size portion of the solid material and most of the solids of the first fraction from which undesired ions have been at least partly removed is leached. The liquid is processed to obtain the dissolved uranium compounds

  12. Uranium ore deposits

    International Nuclear Information System (INIS)

    Angelelli, Victorio.

    1984-01-01

    The main uranium deposits and occurrences in the Argentine Republic are described, considering, in principle, their geologic setting, the kind of 'model' of the mineralization and its possible origin, and describing the ore species present in each case. The main uraniferous accumulations of the country include the models of 'sandstong type', veintype and impregnation type. There are also other kinds of accumulations, as in calcrete, etc. The main uranium production has been registered in the provinces of Mendoza, Salta, La Rioja, Chubut, Cordoba and San Luis. In each case, the minerals present are mentioned, having been recognized 37 different species all over the country (M.E.L.) [es

  13. Uranium exploration techniques

    International Nuclear Information System (INIS)

    Nichols, C.E.

    1984-01-01

    The subject is discussed under the headings: introduction (genetic description of some uranium deposits; typical concentrations of uranium in the natural environment); sedimentary host rocks (sandstones; tabular deposits; roll-front deposits; black shales); metamorphic host rocks (exploration techniques); geologic techniques (alteration features in sandstones; favourable features in metamorphic rocks); geophysical techniques (radiometric surveys; surface vehicle methods; airborne methods; input surveys); geochemical techniques (hydrogeochemistry; petrogeochemistry; stream sediment geochemistry; pedogeochemistry; emanometry; biogeochemistry); geochemical model for roll-front deposits; geologic model for vein-like deposits. (U.K.)

  14. Uranium conversion wastes

    International Nuclear Information System (INIS)

    Vicente, R.; Dellamano, J.C.

    1989-12-01

    A set of mathematical equations was developed and used to estimate the radiological significance of each radionuclide potentially present in the uranium refining industry effluents. The equations described the evolution in time of the radionuclides activities in the uranium fuel cycle, from mining and milling, through the yellowcake, till the conversion effluents. Some radionuclides that are not usually monitored in conversion effluents (e.g. Pa-231 and Ac-227) were found to be potentially relevant from the radiological point of view in conversion facilities, and are certainly relevant in mining and milling industry, at least in a few waste streams. (author) [pt

  15. Joining uranium to steel

    International Nuclear Information System (INIS)

    Perkins, M.A.

    1976-05-01

    A method has been devised which will allow the joining of uranium to steel by fusion welding through the use of an intermediate material. Uranium-0.5 titanium was joined to AISI 304L stainless steel by using a vanadium insert. Also, a method is now available for selecting possible filler metals when two entirely dissimilar metals need to be joined. This method allows a quantitative ranking to be made of the possible filler metals and thus the most likely candidate can be selected

  16. The critical ionization velocity

    International Nuclear Information System (INIS)

    Raadu, M.A.

    1980-06-01

    The critical ionization velocity effect was first proposed in the context of space plasmas. This effect occurs for a neutral gas moving through a magnetized plasma and leads to rapid ionization and braking of the relative motion when a marginal velocity, 'the critical velocity', is exceeded. Laboratory experiments have clearly established the significance of the critical velocity and have provided evidence for an underlying mechanism which relies on the combined action of electron impact ionization and a collective plasma interaction heating electrons. There is experimental support for such a mechanism based on the heating of electrons by the modified two-stream instability as part of a feedback process. Several applications to space plasmas have been proposed and the possibility of space experiments has been discussed. (author)

  17. Surface ionization theory

    International Nuclear Information System (INIS)

    Bonnal, J.-F.; Pelissier, Andre

    1974-01-01

    After a brief theoretical review, the relationship existing between the ionization rate in the vicinity of a metallic plate in thermodynamic equilibrium with a cesium plasma and the density of electron current issued from the same plate is presented. The evolution of this density of current is represented by the Langmuir S-curves. It is shown that knowledge of the S-curves leads to that of the critical temperatures and of the ionization rates when the generated ions are extracted by an electric field. The influence of the principal parameters (the nature and temperature of the plate and the cesium flow supplying it) is analyzed using the Rasor theory. The theoretical results obtained using a model of the flat plate represent fairly closely the operations observed experimentally on porous tungstem ionizers [fr

  18. The ionizing treatment of food

    International Nuclear Information System (INIS)

    1998-01-01

    This book of proceedings contains the talks given by the members of the Society of chemical experts of France (SECF) and by various specialists of the ionizing treatment during the scientific days of September 25-26, 1997. The aim of this meeting was to reconsider the effects of ionization from a scientific point of view and apart from the polemics generated by this domain. The following topics were discussed successively: source and characterization of a ionizing treatment, biological effects of ionization on food and the expected consequences, the ionizing treatment and the reduction of the vitamin C content of fruits and vegetables, is it safe to eat irradiated food?, the organoleptic modifications of food after ionization, quality assurance of dosimetry measurements in an industrial installation of food ionization, the French and European regulations in food ionization, the detection of irradiated foodstuffs, processed food and complex lipid matrices, sterilization of dishes for immuno-depressed patients using ionization. (J.S.)

  19. Physical properties of uranium dipnictides

    International Nuclear Information System (INIS)

    Blaise, A.; Fournier, J.-M.; Lagnier, R.; Schenkel, R.; Mortimer, M.J.; Henkie, Z.; Wajakowski, A.

    1978-01-01

    The results of measurements of the magnetic susceptibility, specific heat and electrical resistivity at low temperatures of a series of uranium dipnictides (UX 2 , X=P, As, Sb, Bi) are reported. In all experiments very sharp transitions were observed from which the Neel temperatures were derived. Susceptibility measurements performed on single crystals in the a plane and c direction confirmed the collinear magnetic structure. From precise resistivity measurements in the a plane, drho/dT was calculated. Specific-heat data served to determine the magnetic entropies and the electronic specific-heat coefficients. The behaviour of the 5f electrons can be treated within a virtual bound-state model. (author)

  20. Contact ionization ion source

    International Nuclear Information System (INIS)

    Hashmi, N.; Van Der Houven Van Oordt, A.J.

    1975-01-01

    An ion source in which an apertured or foraminous electrode having a multiplicity of openings is spaced from one or more active surfaces of an ionisation electrode, the active surfaces comprising a material capable of ionising by contact ionization a substance to be ionized supplied during operation to the active surface or surfaces comprises means for producing during operation a magnetic field which enables a stable plasma to be formed in the space between the active surface or surfaces and the apertured electrode, the field strength of the magnetic field being preferably in the range between 2 and 8 kilogauss. (U.S.)

  1. Ionizing Radiation Processing Technology

    International Nuclear Information System (INIS)

    Rida Tajau; Kamarudin Hashim; Jamaliah Sharif; Ratnam, C.T.; Keong, C.C.

    2017-01-01

    This book completely brief on the basic concept and theory of ionizing radiation in polymers material processing. Besides of that the basic concept of polymerization addition, cross-linking and radiation degradation also highlighted in this informative book. All of the information is from scientific writing based on comprehensive scientific research in polymerization industry which using the radiation ionizing. It is very useful to other researcher whose study in Nuclear Sciencea and Science of Chemical and Material to use this book as a guideline for them in future scientific esearch.

  2. Liquid ionizing radiaion detector

    International Nuclear Information System (INIS)

    deGaston, A.N.

    1979-01-01

    A normally nonconducting liquid such as liquid hydrocarbon is encased between a pair of electrodes in an enclosure so that when the liquid is subjected to ionizing radiation, the ion pairs so created measurably increase the conductivity of the fluid. The reduced impedance between the electrodes is detectable with a sensitive ohm-meter and indicates the amount of ionizing radiation. The enclosure, the electrodes and the fluid can be constructed of materials that make the response of the detector suitable for calibrating a large range of radiation energy levels. The detector is especially useful in medical applications where tissue equivalent X ray detectors are desired

  3. The uranium market 1980 - 1990

    International Nuclear Information System (INIS)

    Darmayan, Philippe

    1980-01-01

    The Supply and Demand Committee of the Uranium Institute was established to monitor continuously information and developments bearing on the uranium market and to publish from time to time reports giving its views on the supply and demand outlook. The last Uranium institute supply and demand report was published in July 1979 and a summary was given by Mr. Erkes at the last Uranium Institute symposium. Its main conclusions were that from 1979 to 1990 the flexibilities of the market were such as to offer adequate scope to producers and consumers of uranium to ensure a balance between supply and demand. Is that conclusion still valid one and a half years later [fr

  4. Uranium enriched granites in Sweden

    International Nuclear Information System (INIS)

    Wilson, M.R.; Aakerblom, G.

    1980-01-01

    Granites with uranium contents higher than normal occur in a variety of geological settings in the Swedish Precambrian, and represent a variety of granite types and ages. They may have been generated by (1) the anatexis of continental crust (2) processes occurring at a much greater depth. They commonly show enrichement in F, Sn, W and/or Mo. Only in one case is an important uranium mineralization thought to be directly related to a uranium-enriched granite, while the majority of epigenetic uranium mineralizations with economic potential are related to hydrothermal processes in areas where the bedrock is regionally uranium-enhanced. (Authors)

  5. Uranium sorption by tannin resins

    International Nuclear Information System (INIS)

    Olivares Rieumont, S.; Martinez Luzardo, J.; Torres Hernandez, J.; Lima Cazorla, D. de la Rosa.

    1998-01-01

    The sorption of uranium by immobilised Eucalyptus Saligna Sm. and Lysiloma latisiliqua L tannins was investigated. Immobilization condition were analyzed. These resins resulted suitable adsorbent for the concentration of uranium from aqueous systems. The sorption of uranium is pH dependent. At pH 5.5 maximum in sorption capacity is registered. The presence of appreciable amount of sodium chloride do not have any effect on uranium removal. Carbonate and calcium ions in concentrations similar to these that could be found in sea water and other natural water do not decrease the uranium uptake. Tannin resins can be used several times without an appreciable decay of their sorption capacity

  6. Fault rocks and uranium mineralization

    International Nuclear Information System (INIS)

    Tong Hangshou.

    1991-01-01

    The types of fault rocks, microstructural characteristics of fault tectonite and their relationship with uranium mineralization in the uranium-productive granite area are discussed. According to the synthetic analysis on nature of stress, extent of crack and microstructural characteristics of fault rocks, they can be classified into five groups and sixteen subgroups. The author especially emphasizes the control of cataclasite group and fault breccia group over uranium mineralization in the uranium-productive granite area. It is considered that more effective study should be made on the macrostructure and microstructure of fault rocks. It is of an important practical significance in uranium exploration

  7. Uranium oxidation: characterization of oxides formed by reaction with water

    International Nuclear Information System (INIS)

    Fuller, E.L. Jr.; Smyrl, N.R.; Condon, J.B.; Eager, M.H.

    1983-01-01

    Three different uranium oxide samples have been characterized with respect to the different preparation techniques. Results show that the water reaction with uranium metal occurs cyclically forming laminar layers of oxide which spall off due to the strain at the oxide/metal interface. Single laminae are released if liquid water is present due to the prizing penetration at the reaction zone. The rate of reaction of water with uranium is directly proportional to the amount of adsorbed water on the oxide product. Rapid transport is effected through the open hydrous oxide product. Dehydration of the hydrous oxide irreversibly forms a more inert oxide which cannot be rehydrated to the degree that prevails in the original hydrous product of uranium oxidation with water. 27 figures

  8. Uranium oxidation: characterization of oxides formed by reaction with water

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, E.L. Jr.; Smyrl, N.R.; Condon, J.B.; Eager, M.H.

    1983-04-27

    Three different uranium oxide samples have been characterized with respect to the different preparation techniques. Results show that the water reaction with uranium metal occurs cyclically forming laminar layers of oxide which spall off due to the strain at the oxide/metal interface. Single laminae are released if liquid water is present due to the prizing penetration at the reaction zone. The rate of reaction of water with uranium is directly proportional to the amount of adsorbed water on the oxide product. Rapid transport is effected through the open hydrous oxide product. Dehydration of the hydrous oxide irreversibly forms a more inert oxide which cannot be rehydrated to the degree that prevails in the original hydrous product of uranium oxidation with water. 27 figures.

  9. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Gisone, Pablo; Perez, Maria R.

    2001-01-01

    It has been emphasised the importance of DNA as the main target for ionizing radiation, that can induce damage by its direct action on this molecule or by an indirect effect mediated by free-radicals generated by water radiolysis. Biological effects of ionizing radiation are influenced not only by the dose but also by the dose-rate and the radiation quality. Radiation induced damage, mainly DNA single and double strand breaks, is detected by molecular sensors which in turn trigger signalling cascades leading to cell cycle arrest to allow DNA repair or programmed cell death (apoptosis). Those effects related with cell death, named deterministic, exhibits a dose-threshold below which they are not observed. Acute radiation syndrome and radiological burns are examples of this kind of effects. Other radiation induced effects, called stochastic, are the consequence of cell transformation and do not exhibit a dose-threshold. This is the case of cancer induction and hereditary effects. The aim of this presentation is briefly describe the main aspects of deterministic and stochastic effects from the point of view of radiobiology and radio pathology. (author)

  10. NMR Metabolomics in Ionizing Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jian Z.; Xiao, Xiongjie; Hu, Mary Y.

    2016-09-08

    Ionizing radiation is an invisible threat that cannot be seen, touched or smelled and exist either as particles or waves. Particle radiation can take the form of alpha, beta or neutrons, as well as high energy space particle radiation such as high energy iron, carbon and proton radiation, etc. (1) Non-particle radiation includes gamma- and x-rays. Publically, there is a growing concern about the adverse health effects due to ionizing radiation mainly because of the following facts. (a) The X-ray diagnostic images are taken routinely on patients. Even though the overall dosage from a single X-ray image such as a chest X-ray scan or a CT scan, also called X-ray computed tomography (X-ray CT), is low, repeated usage can cause serious health consequences, in particular with the possibility of developing cancer (2, 3). (b) Human space exploration has gone beyond moon and is planning to send human to the orbit of Mars by the mid-2030s. And a landing on Mars will follow.

  11. Recovery of uranium from seawater

    International Nuclear Information System (INIS)

    Hirotsu, Takahiro; Takagi, Norio; Katoh, Shunsaku

    1995-01-01

    Present status of the development of chelating adsorbents for the recovery of uranium from seawater is outlined with emphasis on the research by the author. Uranium is estimated to exist as stable tri (carbonate) uranylate (6) ion in seawater in a very low concentration. The adsorbent for uranium from seawater in a very low concentration. The adsorbent for uranium from seawater should have high selectivity and affinity for uranium around pH 8. The required characteristics for uranium adsorbent are examined. Various chelating adsorbents have been proposed for the uranium adsorbent and their structures are discussed. Amidoxime type adsorbents have the highest adsorbing power for uranium among the adsorbents hitherto developed and fibrous amidoxime adsorbents are most promising for the practical application. Synthesis, structure and suitable shape of the amidoxime adsorbents are discussed. Uranium adsorption behavior and the amount of saturated adsorption are examined theoretically based on the complexation of an amidoxime monomer and the formula for the adsorption equiliburium is derived. The adsorption and recovery process for uranium from seawater is composed of adsorption, desorption, separation and concentration and finally, uranium is recovered as the yellow cake. A floating body mooring system is proposed by Nobukawa. (T.H.)

  12. Types of hydrogenic uranium deposits

    International Nuclear Information System (INIS)

    Kondrat'eva, I.A.; Lisitsin, A.K.; Komarova, G.V.

    1980-01-01

    Principles of uranium deposit systematics are considered. Systematization, presented in this paper, is based on a regularity that the main industrial exogenic epigenetic uranium concentrations are formed in zones of reduction geochemical barriers. Types of uranium-bearing ground waters and nature of uranium reducing agents were taken into account during systematization. Hydrogenic uranium deposits are related to 3 types: formed by ground (1 type), stratal (2 type) and vein (3 type) waters. By the nature of uranium reducing agents 2 deposit subtypes are marked out: A - in rocks with syngenetic reducing agents, B - in rocks with epigenetic reducing agents. Uranium deposits are also differentiated by nature of reducing agents distribution in ore-containing rocks [ru

  13. Uranium deposits in granitic rocks

    International Nuclear Information System (INIS)

    Nishimori, R.K.; Ragland, P.C.; Rogers, J.J.W.; Greenberg, J.K.

    1977-01-01

    This report is a review of published data bearing on the geology and origin of uranium deposits in granitic, pegmatitic and migmatitic rocks with the aim of assisting in the development of predictive criteria for the search for similar deposits in the U.S. Efforts were concentrated on the so-called ''porphyry'' uranium deposits. Two types of uranium deposits are primarily considered: deposits in pegmatites and alaskites in gneiss terrains, and disseminations of uranium in high-level granites. In Chapter 1 of this report, the general data on the distribution of uranium in igneous and metamorphic rocks are reviewed. Chapter 2 contains some comments on the classification of uranium deposits associated with igneous rocks and a summary of the main features of the geology of uranium deposits in granites. General concepts of the behavior of uranium in granites during crustal evolution are reviewed in Chapter 3. Also included is a discussion of the relationship of uranium mineralization in granites to the general evolution of mobile belts, plus the influence of magmatic and post-magmatic processes on the distribution of uranium in igneous rocks and related ore deposits. Chapter 4 relates the results of experimental studies on the crystallization of granites to some of the geologic features of uranium deposits in pegmatites and alaskites in high-grade metamorphic terrains. Potential or favorable areas for igneous uranium deposits in the U.S.A. are delineated in Chapter 5. Data on the geology of specific uranium deposits in granitic rocks are contained in Appendix 1. A compilation of igneous rock formations containing greater than 10 ppM uranium is included in Appendix 2. Appendix 3 is a report on the results of a visit to the Roessing area. Appendix 4 is a report on a field excursion to eastern Canada

  14. Uranium mineralizations in Niger

    International Nuclear Information System (INIS)

    Duchemin, Ch.; Gerbeaud, O.; James, O.; Le Goux, F.; Pouradier, A.; Salabert, J.; Wagani, I.; Breton, G.; Feybesse, J.L.; Parize, O.; Wattinne, A.; Flotte, N.; Brouand, M.

    2009-01-01

    The authors report the analysis of mineralizations located in the Tim Mersoi basin in Niger where sediments deposited between the Paleozoic and the Cretaceous era. They analyse and describe the tectonic evolution of this area during different periods, and focus on some specific uranium mineralisation sites

  15. Method to extract uranium

    International Nuclear Information System (INIS)

    Barreiro, A.J.; Hollemann, R.A.; Lyon, W.L.; Randell, C.C.

    1978-01-01

    The invented method to clean the commercial wet-method phosphoric acid - as pretreatment stage in the recovery of uranium - can be carried out at low capital and operational costs and requires little maintenance. In order to recover 0.2 g uranium which are contained in 1 litre of phosphoric acid solution obtained from the wet process, the solution is firstly largely cleared and cleaned. A cleaning agent, essentially of hydrocarbon with a boiling point between 150 and 300 0 C, reacts with the remaining slurry-forming impurities in the acid and enables these to be separated off in a solvent-extraction mixer separator with the slurry. Kerosine is used as cleaning agent in wet-process phosphoric acid with humus impurities. The same process can also be used with oxidation or reduction extraction separation methods to obtain uranium from industrial crude wet phosphoric acid solutions. Comparing a flow sheet each of a known method of separating uranium and the new one as according to the invention, one can see the attained simplification and probable cost reduction. (RW) [de

  16. Ranger uranium project

    International Nuclear Information System (INIS)

    1979-01-01

    This agreement between the Commonwealth of Australia, Peko-Wallsend Operations Ltd., Electrolytic Zinc Company of Australasia Limited, and the Australian Atomic Energy Commission sets out articles under which the Ranger uranium project in the Northern Territory of Australia is to be operated

  17. Ranger uranium project

    International Nuclear Information System (INIS)

    1979-01-01

    Details of alterations to the Atomic Energy Act 1953 are described which authorize the Australian Atomic Energy Commission, Peko-Wallsend Operations Ltd., and Electrolytic Zinc Company of Australasia Limited to carry out uranium mining operations in the Alligator Rivers region of the Northern Territory of Australia

  18. Uranium extraction from seawater

    International Nuclear Information System (INIS)

    Koske, P.H.; Ohlrogge, K.; Denzinger, H.

    1982-01-01

    Besides basic considerations about the problem of Uranium extraction from seawater system studies on process engineering and marine technology approaches are presented. In addition the present and future developments in the Federal Republic of Germany are discussed in somewhat more detail. (orig.) [de

  19. Uranium and nuclear issues

    International Nuclear Information System (INIS)

    1983-01-01

    This seminar focussed on the major issues affecting the future of the entire nuclear fuel cycle. In particular it covered issues bearing on the formation of public policy in relation to the use of uranium as an energy source: economic risk, industrial risks, health effects, site selection, environmental issues, and public acceptance

  20. Geophysics in uranium exploration

    International Nuclear Information System (INIS)

    Darnley, A.G.

    1975-01-01

    There are no revolutionary new methods of uranium exploration on the horizon. Continuing improvements in existing methods and types of instrumentation are to be expected, but the main scope of improvement will hinge upon using the best of the available methods more meticulously and systematically, and paying more attention to the analysis of data. (author)

  1. Following the electroreduction of uranium dioxide to uranium in LiCl-KCl eutectic in situ using synchrotron radiation

    Science.gov (United States)

    Brown, L. D.; Abdulaziz, R.; Jervis, R.; Bharath, V. J.; Atwood, R. C.; Reinhard, C.; Connor, L. D.; Simons, S. J. R.; Inman, D.; Brett, D. J. L.; Shearing, P. R.

    2015-09-01

    The electrochemical reduction of uranium dioxide to metallic uranium has been investigated in lithium chloride-potassium chloride eutectic molten salt. Laboratory based electrochemical studies have been coupled with in situ energy dispersive X-ray diffraction, for the first time, to deduce the reduction pathway. No intermediate phases were identified using the X-ray diffraction before, during or after electroreduction to form α-uranium. This suggests that the electrochemical reduction occurs via a single, 4-electron-step, process. The rate of formation of α-uranium is seen to decrease during electrolysis and could be a result of a build-up of oxygen anions in the molten salt. Slow transport of O2- ions away from the UO2 working electrode could impede the electrochemical reduction.

  2. Ionizing radiation in hospitals

    International Nuclear Information System (INIS)

    This booklet is concerned with radiation safety of radiologist and other hospital personnel. Part 1 deals with properties of radiation in general (especially of ionizing radiation). In part 2, different applications of radiation in hospitals are discussed. Part 3 indicates what to do to make improvements to not totally safe situations in hospitals. (Auth./G.J.P.)

  3. Ionization beam scanner

    CERN Multimedia

    CERN PhotoLab

    1973-01-01

    Inner structure of an ionization beam scanner, a rather intricate piece of apparatus which permits one to measure the density distribution of the proton beam passing through it. On the outside of the tank wall there is the coil for the longitudinal magnetic field, on the inside, one can see the arrangement of electrodes creating a highly homogeneous transverse electric field.

  4. Detection of ionized foods

    International Nuclear Information System (INIS)

    Beerens, H.

    1986-01-01

    Irradiated foods and feed might be identified with two kinds of tests: 1. biochemical: detection of specific products are not yet available 2. microbiological: when a microbial species dissapears from a sample of food i.e. it is not detectable after enrichment (for instance Coliforms in hamburgers) it is likely that the sample has been ionized [fr

  5. Ionization chamber smoke detectors

    International Nuclear Information System (INIS)

    1988-03-01

    One kind of smoke detector, the ionization-type, is regulated by the Atomic Energy Control Board (AECB) because it uses a radioactive substance in its mechanism. Radioactivity and radiation are natural phenomena, but they are not very familiar to the average householder. This has led to a number of questions being asked of the AECB. These questions and AECB responses are outlined

  6. Ionization loss in BGO

    International Nuclear Information System (INIS)

    Bakken, J.A.; Denes, P.; Piroue, P.A.; Stickland, D.P.; Sumner, R.L.; Taylor, C.; Barone, L.; Borgia, B.; Diemoz, M.; Dionisi, C.; Falciano, S.; Ferroni, F.; Gratta, G.; Longo, E.; Luminari, L.; Morganti, S.; Valente, E.; Blaising, J.J.; Boutigny, D.; Coignet, G.; Karyotakis, Y.; Sauvage, G.; Schneegans, M.; Vivargent, M.; Extermann, P.; Morand, G.; Ossmann, J.; Ruckstuhl, W.; Schaad, T.P.; Lecoq, P.; Walk, W.; Li, P.J.; Micke, M.; Micke, U.; Schmitz, D.

    1988-01-01

    We report on a precise measurement of the energy loss through ionization by pions in bismuth germanate performed at several values of the incident particles momentum with a prototype of the L3 electromagnetic calorimeter. The experimental results are in good agreement with theoretical predictions showing the relativistic rise modified by density effect. (orig.)

  7. Kvanefjeld uranium project

    International Nuclear Information System (INIS)

    Erlendsson, G.; Jensen, J.; Kofoed, S.; Paulsen, J.L.

    1983-11-01

    The draft uranium project ''Kvanefjeld'' describes the establishment and operation of an industrial plant for exploiting the uranium deposit at Kvanefjeld. The draft project is part of the overall pre-feasibility project and is based on its results. The draft project includes two alternative locations for the processing plant and the tailings deposit plant. The ore reserve is estimated at 56 million tons with an average content of 365 PPM. The mine will be established as an open pit, with a slope angle of 55deg. Conventional techniques are used in drilling, blasting and handling the ore. Waste rock with no uranium content will be disposed of in two ponds near the mine. The waste rock volume is estimated at 80 million tons. A processing plant for extracting uranium from the ore will be established. The technical layout of the plant is based on the extraction experiments performed at Risoe from 1981-83. Yearly capacity is 4.2 million tons of ore. Electrical energy will be supplied from a hydroelectric station to be built at Johan Dahl Land. Thermal energy (steam/heat) will be supplied from a coal-fired district heating plant to be built in connection with the processing plant. Expected power consumption is estimated at 225 GWh/year. Heat consumption is of the same order. In the third year the plant is expected to operate at full capacity. Operating costs will be Dkr. 121/ton of ore from years 1 through 7. Consumption of chemicals will be reduced from the 7th year, and operating costs will consequently drop to Dkr. 115/ton of ore. Calculations show that industrial extraction of the uranium deposit in Kvanefjeld is economically advantageous. In addition, the economy of the project is expected to improve by extracting byproducts from the ore. (EG)

  8. Uranium from seawater

    Energy Technology Data Exchange (ETDEWEB)

    Gregg, D.; Folkendt, M.

    1982-09-21

    A novel process for recovering uranium from seawater is proposed and some of the critical technical parameters are evaluated. The process, in summary, consists of two different options for contacting adsorbant pellets with seawater without pumping the seawater. It is expected that this will reduce the mass handling requirements, compared to pumped seawater systems, by a factor of approximately 10/sup 5/, which should also result in a large reduction in initial capital investment. Activated carbon, possibly in combination with a small amount of dissolved titanium hydroxide, is expected to be the preferred adsorbant material instead of the commonly assumed titanium hydroxide alone. The activated carbon, after exposure to seawater, can be stripped of uranium with an appropriate eluant (probably an acid) or can be burned for its heating value (possible in a power plant) leaving the uranium further enriched in its ash. The uranium, representing about 1% of the ash, is then a rich ore and would be recovered in a conventional manner. Experimental results have indicated that activated carbon, acting alone, is not adequately effective in adsorbing the uranium from seawater. We measured partition coefficients (concentration ratios) of approximately 10/sup 3/ in seawater instead of the reported values of 10/sup 5/. However, preliminary tests carried out in fresh water show considerable promise for an extraction system that uses a combination of dissolved titanium hydroxide (in minute amounts) which forms an insoluble compound with the uranyl ion, and the insoluble compound then being sorbed out on activated carbon. Such a system showed partition coefficients in excess of 10/sup 5/ in fresh water. However, the system was not tested in seawater.

  9. PRODUCTION OF URANIUM METAL BY CARBON REDUCTION

    Science.gov (United States)

    Holden, R.B.; Powers, R.M.; Blaber, O.J.

    1959-09-22

    The preparation of uranium metal by the carbon reduction of an oxide of uranium is described. In a preferred embodiment of the invention a charge composed of carbon and uranium oxide is heated to a solid mass after which it is further heated under vacuum to a temperature of about 2000 deg C to produce a fused uranium metal. Slowly ccoling the fused mass produces a dendritic structure of uranium carbide in uranium metal. Reacting the solidified charge with deionized water hydrolyzes the uranium carbide to finely divide uranium dioxide which can be separated from the coarser uranium metal by ordinary filtration methods.

  10. Precise coulometric titration of uranium in a high-purity uranium metal and in uranium compounds

    International Nuclear Information System (INIS)

    Tanaka, Tatsuhiko; Yoshimori, Takayoshi

    1975-01-01

    Uranium in uranyl nitrate, uranium trioxide and a high-purity uranium metal was assayed by the coulometric titration with biamperometric end-point detection. Uranium (VI) was reduced to uranium (IV) by solid bismuth amalgam in 5M sulfuric acid solution. The reduced uranium was reoxidized to uranium (VI) with a large excess of ferric ion at a room temperature, and the ferrous ion produced was titrated with the electrogenerated manganese(III) fluoride. In the analyses of uranium nitrate and uranium trioxide, the results were precise enough when the error from uncertainty in water content in the samples was considered. The standard sample of pure uranium metal (JAERI-U4) was assayed by the proposed method. The sample was cut into small chips of about 0.2g. Oxides on the metal surface were removed by the procedure shown by National Bureau of Standards just before weighing. The mean assay value of eleven determinations corrected for 3ppm of iron was (99.998+-0.012) % (the 95% confidence interval for the mean), with a standard deviation of 0.018%. The proposed coulometric method is simple and permits accurate and precise determination of uranium which is matrix constituent in a sample. (auth.)

  11. Numerical simulations of single and double ionization of H{sub 2} in short intense laser pulses; Numerische Simulation zur Einfach- und Doppelionisation von H{sub 2} in kurzen intensiven Laserpulsen

    Energy Technology Data Exchange (ETDEWEB)

    Baier, Silvio

    2008-07-01

    Rescattering is the dominant process leading to double ionization in atoms and molecules interacting with linearly polarized laser pulses with wavelengths around 800 nm and in an intensity regime of 10{sup 14} to 10{sup 15} W/cm{sup 2}. Using numerical integrations of the two-electron Schroedinger equation of the Hydrogen molecule in appropriate reduced dimensions two mechanisms, namely correlated emission of the electrons and excitation followed by field ionization after rescattering, could be identified and characterized. With the help of a planar model in reduced dimensions these mechanisms were quantitatively compared by their dependence on the molecular alignment with respect to the polarization axis. Two additional mechanisms, which are also related to rescattering, could be identified as well. (orig.)

  12. Review of the uranium miner experience in the United States

    International Nuclear Information System (INIS)

    Hilberg, A.W.

    1973-01-01

    Mining of uranium ores on a very small scale began in the United States in 1898. In 1948 mining of uranium ores increased significantly as a result of the increasing demands of the atomic energy program, particularly, the weapons program. It was well-known that radioactivity was associated with uranium ore and potential health hazards had been identified as early as 1921. It was then suggested that the large number of lung cancers found in the Schneeberg miners could possibly be caused by ionizing radiation. Radiation exposure to the lungs of uranium ore miners comes about because of varying concentrations of radon decay products in the mine atmosphere. Measurements of the amount of radioactivity in mine atmospheres began in the United States in 1950 and between 1951 and through 1968, approximately 43,000 measurements were made in about 2,500 uranium mines. Periodic medical surveys were made starting in 1950, but it was not until 1954, that a concerted effort was made to examine all miners. At this time an epidemiological study was begun by the U.S. Public Health Service to determine the effects of uranium mining with particular emphasis on the problem of lung cancer induction. The study of the miners, the results of which have been published, revealed a distinct and somewhat dramatic increase in lung cancer. This increase has been ascribed to the radiation exposure to radon-daughters. Because of the presence of a number of other potential occupational carcinogens in the dust of underground mines, there has been some question as to whether radon and radon-daughters constitute the principal cause of increased lung cancer risk among these miners

  13. Syntheses of the Uranium Complexes [U{N(SiMe(3))(2)}(2){N(SiMe(3))(SiMe(2)CH(2)B(C(6)F(5))(3))}] and [U{C(Ph)(NSiMe(3))(2)}(2){&mgr;(3)-BH(4)}(2)]. Determination of Hydrogen Positions by Single-Crystal X-ray and Neutron Diffraction.

    Science.gov (United States)

    Müller, Matthias; Williams, V. Cliff; Doerrer, Linda H.; Leech, Michael A.; Mason, Sax A.; Green, Malcolm L. H.; Prout, Keith

    1998-03-23

    The complex [U{N(SiMe(3))(2)}(2){N(SiMe(3))(SiMe(2)CH(2)B(C(6)F(5))(3))}] (1) is formed in the reaction between the hydride complex [U{N(SiMe(3))(2)}(3)(H)] and B(C(6)F(5))(3), and H(2) is evolved. The X-ray [C(36)H(53)BF(15)N(3)Si(6)U.3.5C(6)D(6), triclinic, space group P&onemacr;, Z = 2, 90 K, a = 14.065(1) Å, b = 14.496(1) Å, c = 18.759(1) Å, alpha = 82.898(1) degrees, beta = 74.415(1) degrees, gamma = 62.919(1) degrees ] and neutron structure [C(36)H(53)BF(15)N(3)Si(6)U.3.5C(6)D(6), triclinic, space group P&onemacr;, Z = 2, 20 K, a = 13.993(1) Å, b = 14.484(1) Å, c = 18.720(1) Å, alpha = 82.810(1) degrees, beta = 74.200(1) degrees, gamma = 63.054(1)E] of compound 1, which crystallizes with 3.5 molecules of C(6)D(6) per asymmetric unit, show the electron deficiency of the uranium atom to be effectively compensated by the formation of multicenter bonds between U and three Si-CH(2) units of the amido ligands. The reaction of the uranium complex [U{C(Ph)(NSiMe(3))(2)}(2)(Cl)(2)] with [Na(BH(4))] gives the complex [U{C(Ph)(NSiMe(3))(2)}(2){&mgr;(3)-BH(4)}(2)] (2). The X-ray structure of 2 [C(26)H(54)B(2)N(4)Si(4)U, monoclinic, space group C2/c, Z = 4, 90 K, a = 21.613(1) Å, b = 9.233(1) Å, c = 18.132(1) Å, beta = 98.804(1) degrees ] proves unequivocally the &mgr;(3) coordination of the BH(4) moieties. In both single-crystal X-ray structure determinations, all hydrogen and deuterium atoms could be located and isotropically refined, including those which are directly coordinated to the uranium. The reliability of the refined hydrogen and deuterium positions for compound 1 is confirmed by comparison of the X-ray and neutron structure determinations. The ability to locate the hydrogen and deuterium positions in these uranium compounds by single-crystal X-ray diffraction is due to good crystal quality, the measurement of data at low temperature, and the use of image plate technology for data collection.

  14. Recovery of uranium from uranium bearing black shale

    International Nuclear Information System (INIS)

    Das, Amrita; Yadav, Manoj; Singh, Ajay K.

    2016-01-01

    Black shale is the unconventional resource of uranium. Recovery of uranium from black shale has been carried out by the following steps: i) size reduction, ii) leaching of uranium in the aqueous medium, iii) fluoride ion removal, iv) solvent extraction of uranium from the aqueous leach solution, v) scrubbing of the loaded solvent after extraction to remove impurities as much as possible and vi) stripping of uranium from the loaded organic into the aqueous phase. Leaching of black shale has been carried out in hydrochloric acid. Free acidity of the leach solution has been determined by potentiometric titration method. Removal of fluoride ions has been done using sodium chloride. Solvent extraction has been carried out by both tributyl phosphate and alamine-336 as extractants. Scrubbing has been tried with oxalic acid and sulphuric acid. Stripping with sodium carbonate solution has been carried out. Overall recovery of uranium is 95%. (author)

  15. Optical Imaging of Ionizing Radiation from Clinical Sources.

    Science.gov (United States)

    Shaffer, Travis M; Drain, Charles Michael; Grimm, Jan

    2016-11-01

    Nuclear medicine uses ionizing radiation for both in vivo diagnosis and therapy. Ionizing radiation comes from a variety of sources, including x-rays, beam therapy, brachytherapy, and various injected radionuclides. Although PET and SPECT remain clinical mainstays, optical readouts of ionizing radiation offer numerous benefits and complement these standard techniques. Furthermore, for ionizing radiation sources that cannot be imaged using these standard techniques, optical imaging offers a unique imaging alternative. This article reviews optical imaging of both radionuclide- and beam-based ionizing radiation from high-energy photons and charged particles through mechanisms including radioluminescence, Cerenkov luminescence, and scintillation. Therapeutically, these visible photons have been combined with photodynamic therapeutic agents preclinically for increasing therapeutic response at depths difficult to reach with external light sources. Last, new microscopy methods that allow single-cell optical imaging of radionuclides are reviewed. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  16. Uranium leaching from phosphatic sandstone and shale of Qatrani using citrate as a new leaching reagent

    International Nuclear Information System (INIS)

    Hussein, E.M.

    1997-01-01

    Uranium is found in Qatrani area (Southwest of Cairo and North of lake Qarun) in various forms in sedimentary rocks. Two important ore materials have been chosen for studying the recovery of their uranium contents namely; the phosphatic sandstone and the carbonaceous shale. The main emphasis in this thesis is the choice of an acid that would selectively leach uranium from thesis ores while leaving calcium phosphate and carbonate minerals minerals almost completely intact. Citric acid was indeed found advantageous due primarily to its strong ability to form stable complexes with uranium over a wide range of PH values beside the possibility of controlling thr solubility of calcium-bearing compounds by adding calcium citrate. The latter is actually characterized by its ability to exist in an unionized or associated from in citric acid solutions. From the general leaching characteristics of both uranium and P 2 O 5 from Qatrani phosphatic sandstone by citric acid, it was found that uranium could be completely leached beside the possibility of realizing a differential leaching percent values vs P 2 O 5 which is generally of limited solubility. Such a low solubility of P 2 O 5 has even been completely inhibited by providing calcium citrate to the citric acid solutions in amounts sufficient to exist in an optimum ionized non-associated state. Such a provision would render the solution unable to carry any further calcium ions thus the breakdown of the phosphate mineral was hindered while uranium has completely been selectively

  17. Ternary fission of spontaneously fissile uranium isomers excited by neutrons

    International Nuclear Information System (INIS)

    Makarenko, V.E.; Molchanov, Y.D.; Otroshchenko, G.A.; Yan'kov, G.B.

    1989-01-01

    Spontaneously fissile isomers (SFI) of uranium were excited in the reactions 236,238 U(n,n') at an average neutron energy 4.5 MeV. A pulsed electrostatic accelerator and time analysis of the fission events were used. Fission fragments were detected by the scintillation method, and long-range particles from fission were detected by an ionization method. The relative probability of fission of nuclei through a spontaneously fissile isomeric state was measured: (1.30±0.01)·10 -4 ( 236 U) and (1.48±0.02)·10 -4 ( 238 U). Half-lives of the isomers were determined: 121±2 nsec (the SFI 236 U) and 267±13 nsec (the SFI 238 U). In study of the ternary fission of spontaneously fissile isotopes of uranium it was established that the probability of the process amounts to one ternary fission per 163±44 binary fissions of the SFI 236 U and one ternary fission per 49±14 binary fissions of the SFI 238 U. The substantial increase of the probability of ternary fission of SFI of uranium in comparison with the case of ternary fission of nuclei which are not in an isomeric state may be related to a special nucleon configuration of the fissile isomers of uranium

  18. RECOVERY OF URANIUM FROM ZIRCONIUM-URANIUM NUCLEAR FUELS

    Science.gov (United States)

    Gens, T.A.

    1962-07-10

    An improvement was made in a process of recovering uranium from a uranium-zirconium composition which was hydrochlorinated with gsseous hydrogen chloride at a temperature of from 350 to 800 deg C resulting in volatilization of the zirconium, as zirconium tetrachloride, and the formation of a uranium containing nitric acid insoluble residue. The improvement consists of reacting the nitric acid insoluble hydrochlorination residue with gaseous carbon tetrachloride at a temperature in the range 550 to 600 deg C, and thereafter recovering the resulting uranium chloride vapors. (AEC)

  19. Epidemiology and ionizing radiations

    International Nuclear Information System (INIS)

    Bourguignon, M.; Masse, R.; Slama, R.; Spira, A.; Timarche, M.; Laurier, D.; Billon, S.; Rogel, A.; Telle Lamberton, M.; Catelinois, O.; Thierry, I.; Grosche, B.; Ron, E.; Vathaire, F. de; Cherie Challine, L.; Donadieu, J.; Pirard, Ph.; Bloch, J.; Setbon, M.

    2004-01-01

    The ionizing radiations have effects on living being. The determinist effects appear since a threshold of absorbed dose of radiation is reached. In return, the stochastic effects of ionizing radiations are these ones whom apparition cannot be described except in terms of probabilities. They are in one hand, cancers and leukemia, on the other hand, lesions of the genome potentially transmissible to the descendants. That is why epidemiology, defined by specialists as the science that studies the frequency and distribution of illness in time and space, the contribution of factors that determine this frequency and this distribution among human populations. This issue gathers and synthesizes the knowledge and examines the difficulties of methodologies. It allows to give its true place to epidemiology. (N.C.)

  20. Ionizing radiation and neoplasia

    International Nuclear Information System (INIS)

    Fajardo, L.F.

    1986-01-01

    Among the well accepted causes of neoplasia, ionizing radiation is quite prominent. Its oncogenic role was suspected by a few pioneers in the field of radiation biology, and some evidence for its oncogenicity has been available for almost 80 years. Since then unquestionable and abundant proof, statistical and experimental, has linked radiation with multiple tumors in mammals. Other forms of radiation (e.g., ultraviolet) are also causally related to neoplasia. This review, however, refers only to the tumors associated with ionizing radiation, either electromagnetic (i.e., gamma and x-rays) or particulate (alpha particles, neutrons, etc.). The field of radiation oncogenesis can be compared to a sea of hypotheses, with a few solid islands of facts. This paper considers the facts (specific radiation-induced neoplasms, risk data, etc.) and then considers some of the hypotheses (possible mechanisms of radiation oncogenesis)

  1. ELECTROLYSIS OF THORIUM AND URANIUM

    Science.gov (United States)

    Hansen, W.N.

    1960-09-01

    An electrolytic method is given for obtaining pure thorium, uranium, and thorium-uranium alloys. The electrolytic cell comprises a cathode composed of a metal selected from the class consisting of zinc, cadmium, tin, lead, antimony, and bismuth, an anode composed of at least one of the metals selected from the group consisting of thorium and uranium in an impure state, and an electrolyte composed of a fused salt containing at least one of the salts of the metals selected from the class consisting of thorium, uranium. zinc, cadmium, tin, lead, antimony, and bismuth. Electrolysis of the fused salt while the cathode is maintained in the molten condition deposits thorium, uranium, or thorium-uranium alloys in pure form in the molten cathode which thereafter may be separated from the molten cathode product by distillation.

  2. Optimization of uranium leach mining

    International Nuclear Information System (INIS)

    Schecter, R.S.; Bommer, P.M.

    1982-01-01

    The effects of well pattern and well spacing on uranium recovery and oxidant utilization are considered. As expected, formation permeability heterogeneities and anisotropies are found to be important issues requiring careful consideration; however, it also is shown that the oxidant efficiency and the produced uranium solution concentrations are sensitive to the presence of other minerals competing with uranium for oxidant. If the Damkohler number for competing minerals, which measures the speed of the reaction, exceeds that for uranium, the competing mineral will have to be oxidized completely to recover a large proportion of the uranium. If the Damkohler number is smaller, it may be possible to achieve considerable selectivity for uranium by adjusting the well spacing. 9 refs

  3. Yellowcake: the international uranium cartel

    International Nuclear Information System (INIS)

    Taylor, J.H.; Yokell, M.D.

    1979-01-01

    The dramatic events that occurred in the uranium market between 1972 and 1976, and their repercussions is discussed. In particular, the book concentrates on the international uranium cartel's attempt to fix yellowcake prices. The background of the yellowcake industry is discussed in Part I of the book, and the demand for uranium and the nuclear fuel cycle isdiscussed, along with a brief anecdotal history of the uranium industry. Part II describes the political conflicts in Australia which led to the public exposure of the uranium cartel and the situation in the world uranium market that led to the cartel's formation. The legal repercussions of the cartel's exposure are discussed in Part III, and in Part IV, the authors reflect on the ramifications of the events described in the book and some of the issues they raise

  4. World uranium production in 1995

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    For the first time since the political and economic opening of the former Soviet Union and Eastern Europe, world uranium production actually increased in 1995. Preliminary estimates for 1996 continue this trend, indicating additional (if slight) production increases over 1995 levels. Natural uranium production increased by about 5% in 1995 to 34,218 tons uranium or 89 Mlbs U3O8. This is an increase of approximately 1700 tons of uranium or 4.3 Mlbs of U3O8 over the updated 1994 quantities. Data is presented for each of the major uranium producing countries, for each of the world's largest uranium mines, for each of the world's largest corporate producers, and for major regions of the world

  5. Promotion of uranium enrichment business

    International Nuclear Information System (INIS)

    Kurushima, Morihiro

    1981-01-01

    The Committee on Nuclear Power has studied on the basic nuclear power policy, establishing its five subcommittees, entrusted by the Ministry of Nternational Trade and Industry. The results of examination by the subcommittee on uranium enrichment business are given along with a report in this connection by the Committee. In order to establish the nuclear fuel cycle, the aspect of uranium enrichment is essential. The uranium enrichment by centrifugal process has proceeded steadily in Power Reactor and Nuclear Fuel Development Corporation. The following matters are described: the need for domestic uranium enrichment, the outlook for overseas enrichment services and the schedule for establishing domestic enrichment business, the current state of technology development, the position of the prototype enrichment plant, the course to be taken to establish enrichment business the main organization operating the prototype and commercial plants, the system of supplying centrifuges, the domestic conversion of natural uranium the subsidies for uranium enrichment business. (J.P.N.)

  6. Recovery of uranium from lignites

    International Nuclear Information System (INIS)

    Hurst, F.J.

    1980-01-01

    Uranium in raw lignite is associated with the organic matter and is readily soluble in acid (and carbonate) solutions. However, beneficiation techniques were not successful for concentrating the uranium or removing part of the reagent-consuming materials. Once the lignite was heated, the uranium became much less soluble in both acid and carbonate solutions, and complete removal of carbon was required to convert it back to a soluble form. Proper burning improves acid-leaching efficiency; that is, it reduces the reagent consumption and concentrates the uranium, thereby reducing plant size for comparable uranium throughput, and it eliminates organic fouling of leach liquors. Restrictions are necessary during burning to prevent the uranium from becoming refractory. The most encouraging results were obtained by flash-burning lignite at 1200 to 1300 0 C and utilizing the released SO 2 to supplement the acid requirement. The major acid consumers were aluminum and iron

  7. Aluminum titanate crucible for molten uranium

    International Nuclear Information System (INIS)

    Asbury, J.J.

    1975-01-01

    An improved crucible for molten uranium is described. The crucible or crucible liner is formed of aluminum titanate which essentially eliminates contamination of uranium and uranium alloys during molten states thereof. (U.S.)

  8. Isotopic analysis of uranium by thermoionic mass spectrometry

    International Nuclear Information System (INIS)

    Moraes, N.M.P. de.

    1979-01-01

    Uranium isotopic ratio measurements by thermoionic spectrometry are presented. Emphasis is given upon the investigation of the parameters that directly affect the precision and accuracy of the results. Optimized procedures, namely, chemical processing, sample loading on the filaments, vaporization, ionization and measurements of ionic currents, are established. Adequate statistical analysis of the data for the calculation of the internal and external variances and mean standard deviation are presented. These procedures are applied to natural and NBS isotopic standard uranium samples. The results obtained agree with the certified values within specified limits. 235 U/ 238 U isotopic ratios values determined for NBS-U500, and a series of standard samples with variable isotopic compositon, are used to calculate mass discrimination factor [pt

  9. Ionization by nuclear transitions

    International Nuclear Information System (INIS)

    Freedman, M.S.

    1975-01-01

    A phenomenological description of ionization events is given that applies to both shaking transitions of the composite nucleus-atom system and the process in which the charged particles emitted in a nuclear decay transfer energy by a relatively slow ''direct collision'' final state interaction with atomic electrons. Specific areas covered include shakeoff in internal conversion, shakeoff in electron capture, shakeoff in beta decay, and inner electron ejection in alpha decay. (5 figs., 1 table)

  10. Gridded Ionization Chamber

    International Nuclear Information System (INIS)

    Manero Amoros, F.

    1962-01-01

    In the present paper the working principles of a gridded ionization chamber are given, and all the different factors that determine its resolution power are analyzed in detail. One of these devices, built in the Physics Division of the JEN and designed specially for use in measurements of alpha spectroscopy, is described. finally the main applications, in which the chamber can be used, are shown. (Author) 17 refs

  11. Topical and working papers on uranium resources and availability

    International Nuclear Information System (INIS)

    Basic topics relative to world-wide resources and availability of uranium resources; potential for recovery of uranium from mill tailings in Canada; uranium from seawater; depleted uranium as an energy source; world uranium requirements in perspective

  12. Production of uranium dioxide

    International Nuclear Information System (INIS)

    Knudsen, I.E.

    1977-01-01

    A three stage fluidized bed process is described for converting uranium hexafluoride (UF 6 ) to a ceramic-grade uranium dioxide (UO 2 ) powder by first, reacting hydrogen and steam with UF 6 in a first fluidized bed in a temperature range of from about 475 to 600 0 C to form solid intermediate products UO 2 F 2 and U 3 O 8 ; second, reacting hydrogen and steam with the intermediate products in a second fluidized bed at a temperature ranging from about 575 to about 675 0 C to produce a second group of intermediate products including UO 2 F 2 , U 3 O 8 , and UO 2 ; and, third, reacting hydrogen and steam with the second group of intermediate products in a third fluidized bed as a temperature of 575 to 675 0 C to produce ceramic grade UO 2 powder having low residual content of fluorides and other foreign materials. 9 claims, 1 figure

  13. South Australia, uranium enrichment

    International Nuclear Information System (INIS)

    1976-02-01

    The Report sets out the salient data relating to the establishment of a uranium processing centre at Redcliff in South Australia. It is conceived as a major development project for the Commonwealth, the South Australian Government and Australian Industry comprising the refining and enrichment of uranium produced from Australian mines. Using the data currently available in respect of markets, demand, technology and possible financial return from overseas sales, the project could be initiated immediately with hexafluoride production, followed rapidly in stages by enrichment production using the centrifuge process. A conceptual development plan is presented, involving a growth pattern that would be closely synchronised with the mining and production of yellowcake. The proposed development is presented in the form of an eight-and-half-year programme. Costs in this Report are based on 1975 values, unless otherwise stated. (Author)

  14. Uranium resources and requirements

    International Nuclear Information System (INIS)

    Silver, J.M.; Wright, W.J.

    1976-01-01

    Australia has about 19% of the reasonably assured resources of uranium in the Western World recoverable at costs of less than $A20/kgU, or about 9% of the resources (reasonably assured and estimated additional) recoverable at costs of less than $A30/kgU. Australia's potential for further discoveries of uranium is good. Nevertheless, if Australia did not export any of these resources it would probably have only a marginal effect on the development of nuclear power. Other resources would be exploited earlier and prices would rise, but not sufficiently to make the costs of nuclear power unattractive. On the other hand, this policy could deny to Australia real benefits in foreign earnings, employment and national development. (author)

  15. Uranium resources and requirements

    International Nuclear Information System (INIS)

    Silver, J.M.; Wright, W.J.

    1975-08-01

    Australia has about 19% of the reasonably assured resources of uranium in the Western World recoverable at costs of less than $A20 per kilogram, or about 9% of the resources (reasonably assured and estimated additional) recoverable at costs of less than $A30 per kilogram. Australia's potential for further discoveries of uranium is good. Nevertheless, if Australia did not export any of these resources it would probably have only a marginal effect on the development of nuclear power; other resources would be exploited earlier and prices would rise, but not sufficiently to make the costs of nuclear power unattractive. On the other hand, this policy could deny to Australia real benefits in foreign currency earnings, employment and national development. (author)

  16. Spot market for uranium

    International Nuclear Information System (INIS)

    Colhoun, C.

    1982-01-01

    The spot market is always quoted for the price of uranium because little information is available about long-term contracts. A review of the development of spot market prices shows the same price curve swings that occur with all raw materials. Future long-term contracts will probably be lower to reflect spot market prices, which are currently in the real-value range of $30-$35. An upswing in the price of uranium could come in the next few months as utilities begin making purchases and trading from stockpiles. The US, unlike Europe and Japan, has already reached a supply and demand point where the spot market share is increasing. Forecasters cannot project the market price, they can only predict the presence of an oscillating spot or a secondary market. 5 figures

  17. Riddle of depleted uranium

    International Nuclear Information System (INIS)

    Hussein, A.S.

    2005-01-01

    Depleted Uranium (DU) is the waste product of uranium enrichment from the manufacturing of fuel rods for nuclear reactors in nuclear power plants and nuclear power ships. DU may also results from the reprocessing of spent nuclear reactor fuel. Potentially DU has both chemical and radiological toxicity with two important targets organs being the kidney and the lungs. DU is made into a metal and, due to its availability, low price, high specific weight, density and melting point as well as its pyrophoricity; it has a wide range of civilian and military applications. Due to the use of DU over the recent years, there appeared in some press on health hazards that are alleged to be due to DU. In these paper properties, applications, potential environmental and health effects of DU are briefly reviewed

  18. Uranium industry update

    International Nuclear Information System (INIS)

    Poissonnet, M.

    1994-01-01

    Canada is the world's largest producer of uranium. With stockpiles becoming depleted, new sources of production will soon be needed. Production in Ontario was expected to cease in 1996, leaving decommissioning as the main activity there. Present production in Canada is almost entirely from the Athabasca basin in Saskatchewan, and mainly from three mines, Key Lake and Rabbit Lake (both owned by Cameco and Uranerz), and Cluff Lake (owned by Cogema). Following hearings in 1993, extensions to Cluff Lake and Rabbit Lake, and a new project at McClean Lake (by Minatco) received environmental approval, while the Midwest project as presented by Denison was rejected, but Cogema was revising it (at the time of the conference). An environmental impact statement for Cigar Lake was due to be submitted to the Assessment panel in October 1994. The author regrets that discussion of 'natural analogues' has created confusion between uranium mining and nuclear waste disposal in the public mind. 2 ills

  19. Uranium dioxide preparation

    International Nuclear Information System (INIS)

    Watt, G.W.; Baugh, D.W. Jr.

    1977-01-01

    An actinide dioxide, e.g., uranium dioxide, is prepared by reacting an actinide nitrate or hydrate or tetrahydrofuranate thereof, e.g., uranyl nitrate, a hydrate of uranyl nitrate, or a tetrahydrofuranate of uranyl nitrate with an alkali or alkaline earth metal adduct of a monocyclic or polycyclic hydrocarbon in the presence of an inert organic solvent. Typically, the starting material may be uranyl nitrate dihydrate or uranyl nitrate ditetrahydrofuranate (the latter material is a novel composition of matter) with a reactant such as the sodium adduct of naphthalene in the presence of a solvent such as tetrahydrofuran. The resultant uranium dioxide may be further purified by heating it in the presence of hydrogen. 15 claims

  20. Western Canada uranium perspective

    International Nuclear Information System (INIS)

    Lloyd, R.E.

    1984-01-01

    The current situation in the exploration for uranium in British Columbia, the Yukon, the Northwest Territories, and Saskatchewan is reviewed. A moratorium on exploration has been in effect in British Columbia since 1980; it is due to expire in 1987. Only the Blizzard deposit appears to have any economic potential. The Lone Gull discovery in the Thelon Basin of the Northwest Territories has proven reserves of more than 35 million pounds U 3 O 8 grading 0.4%. Potentially prospective areas of the northern Thelon Basin lie within a game sanctuary and cannot be explored. Exploration activity in Saskatchewan continues to decline from the peak in 1980. Three major deposits - Cluff Lake, Rabbit Lake and Key Lake - are in production. By 1985 Saskatchewan will produce 58% of Canada's uranium, and over 13% of the western world's output. (L.L.) (3 figs, 2 tabs.)