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Sample records for 239pu actinides combined

  1. Effects of combined exposure of rats to 239PuO2 and whole-body X irradiation. II

    Using F344/N rats, we are studying the biological effects of inhalation exposure to 239PuO2 aerosols combined with whole-body exposure to X rays. Data from this study will provide an improved estimate of the cancer risk from combined exposures in people. A total of 2136 (66%) of the 3232 rats to be entered into this study have been exposed. We have achieved lung burdens of 239Pu and X-ray exposures within the ranges desired. Life shortening has occurred among rats receiving whole-body exposure to X rays, but not among those exposed only to 239PuO2. (author)

  2. Consistent Data Assimilation of Actinide Isotopes: 235U and 239Pu

    In this annual report we illustrate the methodology of the consistent data assimilation that allows to use the information coming from integral experiments for improving the basic nuclear parameters used in cross section evaluation. A series of integral experiments were analyzed using the EMPIRE evaluated files for 235U, 238U, and 239Pu. Inmost cases the results have shown quite large worse results with respect to the corresponding existing evaluations available for ENDF/B-VII. The observed discrepancies between calculated and experimental results were used in conjunction with the computed sensitivity coefficients and covariance matrix for nuclear parameters in a consistent data assimilation. Only the GODIVA and JEZEBEL experimental results were used, in order to exploit information relative to the isotope of interest that are, in this particular case: 235U and 239Pu. The results obtained by the consistent data assimilation indicate that with reasonable modifications (mostly within the initial standard deviation) it is possible to eliminate the original large discrepancies on the Keff of the two critical configurations. However, some residual discrepancy remains for a few fission spectral indices that are, most likely, to be attributed to the detector cross sections.

  3. Effects of combined inhalation exposure of rats to 239PuO2 and beryllium metal

    We exposed rats acutely to achieve one of two initial lung burdens (ILBs) of 239PuO2 alone or in combination with one of three ILBs of beryllium metal. Additional control groups of rats were sham exposed to air. Currently, approximately 58% of all rats planned for inclusion have been exposed. This report describes procedures used for the exposure, maintenance, and evaluation of rats in this study. Most of the animals are to be held for their life span in order to quantitate cancer incidence, with other animals assigned to serial sacrifice groups for quantitation of Pu and Be retention and determination of translocation patterns. Exposure to beryllium at any of the three doses tested retarded clearance of plutonium from the lung by a factor of approximately six. Acute inflammatory responses were studied in a separate group of rats exposed to Be. Except for rats receiving the highest ILB of beryllium metal, no differences between exposed and sham-exposed control groups have yet been noted in terms of mortality, weight changes, and clinical signs. (author)

  4. Effects of combined exposure of F344 rats to inhaled 239PuO2 and a chemical carcinogen (NNK)

    Workers in nuclear weapons facilitates have a significant potential for exposure to chemical carcinogens and to radiation from external sources or from internally deposited radionuclides such as 239Pu. Although the carcinogenic effects of inhaled 239Pu and many chemicals have been studied individually, very little information is available on their combined effects. One chemical carcinogen that workers could be exposed to, via tobacco smoke, is the tobacco-specific nitrosamine 4-(N-Methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a product of the curing of tobacco and pyrolysis of nicotine in tobacco. NNK causes lung tumors in rats, regardless of the route of administration and to a lesser extent tumors in the liver, nasal passages, and pancreas. The purpose of this study is to characterize the effects of combined exposure of rats to NNK and internally deposited plutonium, as well as to these agents alone

  5. Status of 239Pu evaluations

    This paper summarises the current status of nuclear data evaluations for n+239Pu. The nuclear data we address include fission, capture, scattering cross-sections, as well as the prompt fission neutron energy spectrum, which has large sensitivities to the criticality benchmark testing. The evaluated nuclear data files currently available for 239Pu are compared, and the source of differences in the cross-sections are discussed. Some open questions on the statistical model calculations for deformed systems are also given. (authors)

  6. Quantitative estimation of the combined effect of external γ-radiation and incorporated α-radiation (239Pu) by the biochemical indices of rat immune system

    The combined effect of external γ-radiation (137Cs, 103-26 mC/kg) and incorporated α-radiation (239Pu nitrate, 93-9.3 kBq/kg body mass) was estimated by changes in the nucleic acid metabolism and the number of cells in rat thymus, spleen and bone marrow. The data obtained were processed using a model of multiplicate action of the factors which is equivalent, in the case of low effects, to a traditional model of additive effects. The results of the combined action of the two factors may be estimated by the coefficient of the interaction and the coefficient of the enhancement of the effects

  7. Determination of plutonium isotopes (238Pu, 239Pu, 240Pu, 241Pu) in environmental samples using radiochemical separation combined with radiometric and mass spectrometric measurements

    Xu, Yihong; Qiao, Jixin; Hou, Xiaolin;

    2014-01-01

    This paper reports an analytical method for the determination of plutonium isotopes (238Pu, 239Pu, 240Pu, 241Pu) in environmental samples using anion exchange chromatography in combination with extraction chromatography for chemical separation of Pu. Both radiometric methods (liquid scintillation...... counting and alpha spectrometry) and inductively coupled plasma mass spectrometry (ICP-MS) were applied for the measurement of plutonium isotopes. The decontamination factors for uranium were significantly improved up to 7.5×105 for 20 g soil compared to the level reported in the literature......, this is critical for the measurement of plutonium isotopes using mass spectrometric technique. Although the chemical yield of Pu in the entire procedure is about 55%, the analytical results of IAEA soil 6 and IAEA-367 in this work are in a good agreement with the values reported in the literature or reference...

  8. Transmutation of 239Pu with spallation neutrons

    Incineration studies of plutonium were carried out at the Synchrophasotron of the Joint Institute for Nuclear Research (JINR), Dubna, using proton beams with energies of 0.53 GeV and 1.0 GeV. Solid lead targets (8 cm in diameter and 20 cm long) were surrounded with 6 cm thick paraffin as neutron moderator and then irradiated. The transmutation of 239Pu and the associated production of fission products 91Sr, 92Sr, 97Zr, 99Mo, 103Ru, 105Ru, 129Sb, 132Te, 133I, 135I and 143Ce were studied in the present work. The plutonium samples (each 449 mg) were placed on the outer surface of moderator. For 1.0 GeV proton beam, the fission rate of 239Pu is 0.0032 atoms per proton in one gram plutonium samples, for 0.53 GeV proton this value is 0.0022. The experimental uncertainty is about 15%. The experiments are compared to two theoretical model calculations with moderate success, using the Dubna Cascade Model (CEM) and the LAHET code. The practical incineration rate of 239Pu is very high. For example: if one uses 10 mA, 1 GeV proton beams under the same (fictive) experimental conditions, the incineration rate of 239Pu via fission is 3 mg out of the 449 mg sample per day. For 0.53 GeV protons the corresponding rate is 2 mg per day. (author)

  9. Gamma-ray intensities of 239Pu

    Relative intensities of 239Pu γ-rays were precisely measured with a Ge(Li) detector which was accurately calibrated and corrections were made for self-absorption of γ-rays. Accuracies of 1-2% were obtained for strong γrays. Detector efficiences were calibrated with a standard source of 133Ba and γ-ray sources of 152Eu, 154Eu and 182Ta. Intensities per decay were determined by the measured γ-ray intensities, weight and isotopic abundance of plutonium in the source. (author)

  10. Adsorption behavior of 239Pu by Gaomiaozi bentonite

    Adsorption behavior of 239Pu by Gaomiaozi bentonite as a function of the factors of aqueous phase pH value, 239Pu initial concentration and ionic species is studied by static adsorption experiments in this paper. The following results are obtained. Adsorption equilibrium time of 239Pu by Gaomiaozi bentonite samples is about 24 h, and the adsorption distribution ratio Kd value of 239Pu increases with the pH value, but decreases with increasing initial concentration of 239Pu. And adsorption of 239Pu by bentonite samples with different ionic species show that anions affect the most on adsorption of bentonite is CO32-, followed by HCO3- and SO42-, whereas Cl- and NO3- hardly have any influence on the adsorption of bentonite. (authors)

  11. In vitro dose-response of macrophages to 239PuO2 and 241AmO2

    As part of a study designed to examine various means of solubilizing actinide particles within macrophages, we have measured the in vitro effects of 241AmO2 and 239PuO2 on these cells. Dose distribution within the cell population was estimated by autoradiography and compared to cell detachment as a function of time. The 241AmO2 and 239PuO2 were toxic in proportion to their radioactivity rather than their mass. Approximately 385 intracellular disintegrations are required from either radionuclide to cause cells to detach from the flask surface

  12. Fission of 239Pu with resonance neutrons

    A measurement of fission fragment energy and mass distributions in the 239Pu(n,f) resolved resonance region has been performed applying the twin Frisch-gridded ionization chamber technique. An improved pile-up rejection system has been developed to cope with the strong α background. The results for the mass and mean total kinetic energy (TKE-bar) distributions for resolved resonances do not show any strong 'pattern' of fluctuations, unlike it was the case for 235U(n,f) in the same neutron energy region. This can be explained in the frame of existing theoretical models, according to which the only possible low-energy spin states available (Jπ=0+, 1+) belong to two well separated (∼1.25 MeV) transition state bands with given fission fragment properties. An anti-correlation between TKE-bar and ν-barp was found to be not significant. The obtained small spin dependence of TKE-bar of about 70 keV is in agreement with literature values. A slight correlation was found between TKE-bar versus 1/Γf. But also this was considered not to be significant. (author)

  13. Prompt Fission Neutron Emission in Resonance Fission of 239Pu

    Hambsch, Franz-Josef; Varapai, Natallia; Zeinalov, Shakir; Oberstedt, Stephan; Serot, Olivier

    2005-05-01

    The prompt neutron emission probability from neutron-induced fission in the resonance region is being investigated at the time-of-flight facility GELINA of the IRMM. A double Frisch-gridded ionization chamber is used as a fission-fragment detector. For the data acquisition of both the fission-fragment signals as well as the neutron detector signals the fast digitization technique has been applied. For the neutron detection, large-volume liquid scintillation detectors from the DEMON collaboration are used. A specialized data analysis program taking advantage of the digital filtering technique has been developed to treat the acquired data. Neutron multiplicity investigations for actinides, especially in resonance neutron-induced fission, are rather scarce. They are, however, important for reactor control and safety issues as well as for understanding the basic physics of the fission process. Fission yield measurements on both 235U and 239Pu without prompt neutron emission coincidence have shown that fluctuation of the fission-fragment mass distribution exists from resonance to resonance, larger in the case of 235U. To possibly explain these observations, the question now is whether the prompt neutron multiplicity shows similar fluctuations with resonance energy.

  14. Biosorption of 239Pu by immobilized sargassum fusiforme

    Sargassum fusiforme was immobilized with calcium alginates and its biosorption property to 239Pu was studied by batch and column methods. Biosorption equilibrium time of immobilized Sargassum fusiforme biosorbent to 239Pu is 120 min and biosorption efficiency is over 99.2% when the initial concentration of 239Pu is 21.5 kBq/L and pH is 2.5-5.0. After five times repetition biosorption-desorption cycles biosorption efficiency is still over 98.0% when the velocity of flow is 2 ml/min in column experiment. Immobilized Sargassum fusiforme biosorbent is better to 239Pu due to its better chemical stability, mechanical strength, lower cost, high biosorption efficiency and repeated biosorption-desorption cycles. (authors)

  15. Effects of monomeric 239Pu on the pregnant rabbit

    The effects of 239Pu treatment (0, 10 or 40 μCi/kg) on hematological measurements in pregnant rabbits were studied at 29 days of gestation. Mean clotting times were significantly increased in all plutonium-treated rabbits. There was also a significant increase in clotting time with increasing time between plutonium dosing and sample collection in rabbits injected with 10 μCi/kg. Platelet counts were significantly decreased in all rabbits exposed to 239Pu for 14 days or greater. Hematocrits were significantly depressed in rabbits exposed to 239Pu for 20 days. It is speculated that monomeric 239Pu accumulates at a hematopoietic site close to that affected in X-irradiated animals. (U.K.)

  16. Decreased pulmonary clearance of 239PuO2 and lung toxicity induced by inhaled beryllium metal in rats

    Workers in nuclear industries may be accidentally exposed to both beryllium and plutonium. To characterized the effects of combined exposures to these agents on their pulmonary clearance, groups of F344/N rats inhaled aerosols of beryllium metal and 239PuO2 to result in initial lung burdens for beryllium metal of 0, 50, 150, and 450 μg, and for 239PuO2 of 0, 56, and 170 Bq. Rats were exposed to each possible beryllium/plutonium combination. The whole-body clearance half time of 239Pu in the absence of beryllium metal was approximately 50 days. For rats exposed to both materials, however, 239Pu clearance half-times ranged from 280 to 410 days, with no apparent dose-dependent effect of beryllium metal. Analysis of the lungs for both agents confirmed this pattern of retention. The lungs of beryllium metal-exposed rats displayed a hemorrhagic, exudative pneumonitis, with an influx of neutrophils, and later, progressive fibrosis accompanied by macrophage and epithelial cell hyperplasia. Enhanced 239PuO2 retention will increase the radiation dose to the lung and may result in an eventual synergistic neoplastic response in rats exposed to the two agents

  17. Calculation of 239Pu neutron inelastic cross sections

    We have calculated cross sections for neutron-induced reactions on 239Pu between 0.001 and 5 MeV, with particular emphasis on inelastic scattering. Coupled-channel and Hauser-Feshbach statistical models were used. Within the coupled-channel calculations we employed neutron optical parameters derived from simultaneous fits to total, elastic, inelastic, and resonance data. The resulting transmission coefficients were used in Hauser-Feshbach statistical calculations having a fission channel based on a double-humped barrier representation. Barrier parameters and transition state enhancements needed to reproduce well the (n,f) cross sections between 0.001 and 5 MeV were in general agreement with those from other published analyses. Calculated compound-nucleus and direct-reaction components for inelastic scattering were combined incoherently, and the resultant cross sections agreed well with the Bruyeres-le-Chatel measurements for scattering from levels occupying the ground state rotational band. Our results are in substantial disagreement with ENDF/B-V values for these levels. We are presently performing DWBA calculations to determine direct-reaction components for states occupying higher-lying vibrational bands

  18. Biological effects in intramuscular 239Pu administration during chelatotherapy

    Durable (up to 64 days) application of complexones (Ca and Zn DTPA) in the case of intramuscular administration of 239Pu large amounts in rats is studied. The results of studying the biological effect proving considerable decrease of the average lifespan of rats are given

  19. Strain differences in the embryotoxicity of 239Pu

    Comparison of the embryolethality of monomeric 239Pu injected at 9 days of gestation demonstrated that the sensitivity of Charles River CD strain was greater than that of Hilltop Wistar rats. Subsequent comparisons showed that rats derived from the Hilltop Fischer strain were more sensitive than the Wistar and, although not directly compared, more sensitive than the CD

  20. Subcellular binding of 239Pu in the liver of selected species of rodents

    The subcellular distribution of 239Pu in the liver of selected rodent species was investigated as well as the relation between 239Pu and the iron metabolism. The goal of the investigation was to find out why the liver discharge of 239Pu from the liver varies so much between species. (orig.)

  1. Preliminary Study on the Determination of ~(235)U and ~(239)Pu Using Delayed Neutron Counting Method

    2011-01-01

    The preliminary study on the fast measurements of 235U and 239Pu in samples containing 235U, 239Pu and 235U-239Pu mixture using delayed neutron counting method is introduced. All samples were irradiated for 30 s using the 30 kW Miniature Neutron

  2. Role of protracted exposure on the toxicology of inhaled 239PuO2

    Studies were initiated to examine in rats the effects of a protracted exposure to inhaled 239PuO2. Graphs are presented to show effect of multiple exposures to 239PuO2 on the deposition and clearance of 239Pu in the alveoli

  3. Surrogate Reaction Measurement of Angular Dependent 239Pu (n , f) Probabilities

    Koglin, Johnathon; Burke, Jason; Casperson, Robert; Jovanovic, Igor

    2015-10-01

    The surrogate method has previously been used to measure (n , f) cross sections of difficult to produce actinide isotopes. These measurements have inaccuracies at excitation energies below 1.5 MeV where the distribution of angular momentum states populated in the compound nucleus created by neutron absorption significantly differs from that arising from direct reactions. A method to measure the fission probability of individual angular momentum states arising from 239Pu (d , pf) and 239Pu (α ,α' f) reactions has been developed. This experimental apparatus consists of charged particle detectors with 40 keV FWHM resolution at 13 angles up and downstream of the particle beam. A segmented array of photovoltaic (solar) cells is used to measure the angular distribution of fission fragments. This distribution uniquely identifies the populated angular momentum states. These are fit to expected distributions to determine the contribution of each state. The charged particle and fission rates matrix obtained from this analysis determines fission probabilities of specific angular momentum states in the transition nucleus. Development of this scheme and first results will be discussed.

  4. Evaluation of covariances for resolved resonance parameters of 235U, 238U, and 239Pu in JENDL-3.2

    Evaluation of covariances for resolved resonance parameters of 235U, 238U, and 239Pu was carried out. Although a large number of resolved resonances are observed for major actinides, uncertainties in averaged cross sections are more important than those in resonance parameters in reactor calculations. We developed a simple method which derives a covariance matrix for the resolved resonance parameters from uncertainties in the averaged cross sections. The method was adopted to evaluate the covariance data for some important actinides, and the results were compiled in the JENDL-3.2 covariance file. (author)

  5. Inhaled 239PuO2 in rats with pulmonary emphysema

    The modifying effects of a pre-existing lung disease (emphysema) on the deposition, distribution, retention, and effects of inhaled 239PuO2 in the rat are being investigated. Preliminary observations indicated that the deposition and retention patterns for 239Pu particles inhaled by rats with emphysema and control rats were similar, but the distribution of inhaled 239Pu immediately after exposure was different. Respiratory function measured through one year after exposure to 239Pu was consistent with emphysema and was not altered by the 239Pu lung burden. Long-term observations are continuing. 4 references, 2 tables

  6. Metabolic pathways of 239Pu immediately after administration

    239Pu chloride was given to male rats intravenously or by the oral route. The early stages of the Pu metabolism are characterized by a fast distribution in liver and skeleton and a high concentration in the intestine and the muscle tissue. The rate of elimination from the liver and muscles was the same for both types of application. With injection into different parts of the vascular system, the binding to protein and other tissue components was identical. 239Pu is practically not absorbed from the gastrointestinal tract if given perorally. The absorbed fraction had an osteotropic character, i.e. the plutonium was bound to the organic as well as to the mineral fraction. When Pu chloride is injected intravenously, there is a slow redistribution from the characteristic hepatotropic to the osteotropic type. The function of the liver as a barrier against the plutonium is not very prominent and seems to depend on the type of compound given. (MG/AK)

  7. Neutron Resonance Parameters and Covariance Matrix of 239Pu

    Derrien, Herve [ORNL; Leal, Luiz C [ORNL; Larson, Nancy M [ORNL

    2008-08-01

    In order to obtain the resonance parameters in a single energy range and the corresponding covariance matrix, a reevaluation of 239Pu was performed with the code SAMMY. The most recent experimental data were analyzed or reanalyzed in the energy range thermal to 2.5 keV. The normalization of the fission cross section data was reconsidered by taking into account the most recent measurements of Weston et al. and Wagemans et al. A full resonance parameter covariance matrix was generated. The method used to obtain realistic uncertainties on the average cross section calculated by SAMMY or other processing codes was examined.

  8. Low level 239PuO2 life-span studies

    The purpose of this projet is to determine the dose-response curve for lung-tumor incidence in rats following inhalation of 239PuO2 at levels producing a lifespan radiation dose of 2 to 100 rad. In preliminary studies, rats were intratracheally instilled with, or inhaled 169Yb-239PuO2 or 169Yb-Yb2O3 particles. Whole-body, excreta and tissue levels of 169Yb were determined by external gamma counting; 239Pu levels were determined radiochemically by scintillation counting. It was found that 169Yb dissociated from 239PuO2 and was cleared more rapidly from the lung and the whole body. Despite this fact, however, whole-body counts performed at 7 days after exposure to 169Yb-239PuO2 gave a reproducible measure of the 239Pu lung burden

  9. Characterization of a neutron source of 239PuBe

    The spectrum equivalent dose and environmental equivalent dose f a 239PuBe source have been determined. The appropriate handling of a neutron source depends on the knowledge of its characteristics, such as its energy distribution, total rate of flowing and dosimetric magnitudes. In many facilities have not spectrometer that allows to determine the spectrum and then area monitors are used that give a dosimetric magnitude starting from measuring the flowing rate and the use of conversion factors, however this procedure has many limitations and it is preferable to measure the spectra and starting from this information the interest dosimetric magnitudes are calculated. In this work a Bonner sphere spectrometer has been used with a 6LiI(Eu) scintillator obtaining the count rates that produce, to a distance of 100 cm, a 239PuBe source of 1.85E(11) Bq. The spectrum was reconstructed starting from the count rates using BUNKIUT code and response matrix UTA4. With the spectrum information was calculated the source intensity, total flow, energy average, equivalent dose rate, environmental equivalent dose rate, equivalent dose coefficient and environmental equivalent dose coefficient. By means of two area monitors for neutrons, Eberline ASP-1 and LB 6411 of Berthold the equivalent dose and environmental equivalent dose were measured. The determinate values were compared with those reported in literature and it found that are coincident inside 17%. (Author)

  10. Decommissioning of a 239Pu contaminated incinerator facility

    In early 1978, a plutonium contaminated incinerator facility at the Los Alamos Scientific Laboratory (LASL), Los Alamos, New Mexico, was decommissioned. The project involved dismantling the facility and disposal by burial or by retrievable storage of the debri at an on-site waste disposal area. Contaminated soil from the 0.5 hectare area was buried. The facility was constructed in 1951 to incinerate plutonium contaminated wastes. It was later used as a decontamination facility. The major features included a 185 m2 control building, incinerator, cyclone dust collector, spray cooler, venturi scrubber, air filter bank, ash separator, and two 140,000 litres ash storage tanks. Preliminary soil contamination surveys were performed by a LASL developed portable phoswich detector system. Final soil contamination levels were measured with a zinc sulphide gross alpha scintillation system. Six hundred cubic metres of debris and 1200 m3 of soil contaminated with less than 10 nCi 239 Pu/g were buried at the LASL disposal area. Five cubic metres of 239 Pu contaminated ash residues were packed and stored to meet the Department of Energy's 20 year retrievable storage criteria. (author)

  11. Multilevel analysis of the low energy 239Pu cross sections

    It is well known that the ENDF/B-V representation of the 239Pu resonance region is not satisfactory: below 1 eV the cross sections are given by smooth files (file 3) rather than by resonance parameters. Above 1 eV the single-level formalism used in ENDF/B-V necessitates a structured file 3 contribution. The present paper presents the results of an R-matrix multilevel analysis of several recent data sets as well as of the older data. The analysis is concerned with the region up to 30 eV, an energy region that is important for thermal reactors and for which no recent multilevel analyses had previously been available

  12. R-matrix analyses of the 235U and 239Pu neutron cross sections

    The resonance parameter analysis code SAMMY was used to perform consistent resonance analyses of several 235U and 239Pu fission and capture cross section and transmission measurements up to 110 eV for 235U and up to 1 keV for 239Pu. The method of analysis, the measurement selection and the results are briefly outlined in this paper

  13. Random Probability Analysis of 48Ca +239Pu Experimental Data

    Strauss, S. Y.; Henderson, R. A.; Stoyer, M. A.; Abdullin, A. F. Sh.; Brewer, N. T.; Dmitriev, S. N.; Grzywacz, R. K.; Hamilton, J. H.; Itkis, M. G.; Miernik, K.; Oganessian, Yu. Ts.; Polyakov, A. N.; Roberto, J. B.; Rykaczewski, K. P.; Sabelnikov, A. V.; Sagaidak, R. N.; Shirokovsky, I. V.; Shumeyko, M. V.; Subbotin, V. G.; Sukhov, A. M.; Tsyganov, Yu. S.; Utyonkov, V. K.; Voinov, A. A.; Vostokin, G. K.

    2014-09-01

    Element 114 (Fl), was discovered at the Flerov Laboratory of Nuclear Reactions (FLNR) using the 48Ca +244Pu reaction and the Dubna Gas-Filled Recoil Separator (DGFRS). The structural properties of the super heavy elements are still largely unknown. The extent of the region of enhanced stability near Z = 114 and N = 184 is not completely known. To examine these properties, a new experimental data set has been taken using the 48Ca +239Pu reaction at the DGFRS, in an effort to look for lighter isotopes of Fl. Progress on the production of lighter isotopes of Fl, cross-section measurements, and any nuclear decay properties will be discussed. Comparisons with reactions using heavier 242,244Pu targets and Monte Carlo random probability analysis will be highlighted. Element 114 (Fl), was discovered at the Flerov Laboratory of Nuclear Reactions (FLNR) using the 48Ca +244Pu reaction and the Dubna Gas-Filled Recoil Separator (DGFRS). The structural properties of the super heavy elements are still largely unknown. The extent of the region of enhanced stability near Z = 114 and N = 184 is not completely known. To examine these properties, a new experimental data set has been taken using the 48Ca +239Pu reaction at the DGFRS, in an effort to look for lighter isotopes of Fl. Progress on the production of lighter isotopes of Fl, cross-section measurements, and any nuclear decay properties will be discussed. Comparisons with reactions using heavier 242,244Pu targets and Monte Carlo random probability analysis will be highlighted. This work was performed under Contract DE-AC52-07NA27344 and Grant DE-NA0002135.

  14. Inhaled 239PuO2 in rats with pulmonary emphysema. II

    The modifying effects of pre-existing pulmonary emphysema on deposition, distribution, retention, and effects of inhaled 239PuO2 in the rat were investigated. The presence of emphysema in the rats tested was indicated by respiratory function measurements and confirmed microscopically. Initial lung burdens of 239Pu per kg body weight were less in rats with emphysema than in control rats; however, the retention of 239Pu was similar in emphysematous and control rats. Survival and lung tumor occurrence were similar in emphysematous and control rats exposed to 239PuO2. We concluded that rats with pre-existing pulmonary emphysema were not more sensitive to the effects of inhaled 239PuO2 than control rats. (author)

  15. The removal of inhaled 239Pu from beagle dogs by bronchopulmonary lavage and chelation therapy

    The efficacy of bronchopulmonary lavage and chelatan therapy for removing 239Pu from beagle dogs after inhalation of 239Pu aerosols having different solubilities has been investigated. The four aerosols used were nebulized from a solution of 239PuCl4 and heat treated at temperatures of 325, 600, 900 and 11500C. Groups of six beagle dogs were exposed to each of the aerosols. Subsequently, three dogs in each group were treated by lavage and intravenous injections of DTPA. The remaining three dogs in each group served as untreated controls. It was found that bronchopulmonary lavage treatment was effective in removing nearly half of the 239Pu activity from the lung regardless of the aerosol production temperature. This early removal of 239Pu activity resulted in a significant reduction in daily dose rate and therefore cumulative α dose to lung. The effectiveness of DTPA treatment depended on aerosol production temperature, and was effective in reducing accumulation of 239Pu in liver and skeleton of the dogs that inhaled aerosols produced at 3250 and 6000C by enhancing urinary excretion of 239Pu. (U.K.)

  16. Numerical prediction of 239Pu migration in unsaturated porous media under infiltration scenario

    In terms of the study on site selection of a radioactive waste disposal repository in northwest China, a numerical prediction of 239Pu migration for potential groundwater pollution in the unsaturated zone was conducted with the HYDRUS-1D model. The results showed that the groundwater will not be contaminated by the migration of soluble 239Pu. And there is little possibility that 239Pu migration through groundwater path might have an unacceptable impact on exosphere. Measurements of the distribution coefficient, Kd, are critical in the determination of sorption-induced retardation of radionuclide transport. (authors)

  17. Distribution of 239Pu and 241Am in the human skeleton

    The 241Am and 239Pu distribution in the skeletons of two former nuclear workers has been measured. The skeletons of both individuals appear to be within normal limits for Caucasian men about 50 y old. Both had lower limb bones that were heavier than the age controls and Case I had upper-body bones that were lighter than the age control group. The distribution of americium in the skeleton of Case I, 25 years post exposure, indicated that a more rapid turnover of initially deposited americium on the bone surfaces of cancellous bone, as compared to that deposited on the bone surfaces of compact bone, had occurred. This resulted in a larger proportion of americium located in the compact bone of the extremities and a lesser quantity in the more cancellous bones of the vertebral column, pelvis and rib cage. A similar shift in the distribution of plutonium occurred in Case II in the 35 y since initial deposition, but at a slower rate than that for americium. The ratio of each actinide in the liver to that in the systemic system (liver content/systemic system content) was 0.065 and 0.436, for americium and plutonium, respectively, suggesting that a much more rapid turnover of americium in the liver, compared to plutonium, provided a much larger fraction of that nuclide for circulatory feedback to the remodeling skeletal system. 8 references, 3 tables

  18. Toxicity of 239PuO2 inhaled by aged Beagle dogs. X

    The influence of age at exposure on the metabolism, dosimetry, and biological effects of inhaled 239PuO2 particles is being studied in aged Beagle dogs (8.0-10.5 yr of age at exposure). Forty-eight dogs inhaled 239PuO2 particles with an activity median aerodynamic diameter of 1.5 mm to achieve graded levels of initial pulmonary burdens (IPB) ranging from 0.02-0.66 μCi 239Pu/kg body weight (0.75-24 kBq/kg). Twelve other dogs were exposed to the aerosol diluent only. All forty-eight exposed dogs have died, including two in the past year. The twelve control dogs have also died, including one in the past year. Radiation pneumonitis and pulmonary fibrosis have been the primary causes of death in these aged dogs exposed to 239PuO2. (author)

  19. Malignancy of transplanted hamster lung lesions induced by inhaled 239PuO2

    Selected sites from the lungs of hamsters that had inhaled 239PuO2 aerosol were serially transplanted into the cheek pouches of recipient hamsters. Up to 13 mo postexposure, no evidence of malignancy has appeared

  20. Low-level inhaled-239PuO2 life-span studies in rats

    This study determined the dose-response curve for lung tumor incidence in rats after inhalation of high-fired 239PuO2, which gave radiation doses to the lung of from ∼5 to >1000 rads. Exposed rats were given a single, nose-only, inhalation exposure to 169Yb-239PuO2 aerosol (AMAD, 1.6 +- 0.11 μm). The effective half-time for 169Yb in the lung was 14 days, whereas ∼76% of 239Pu was cleared with a half-time of 20 days and 24%, with a half-time of 180 days. Whole-body counting for 169Yb at 14 days after exposure was an accurate method for determining 239Pu IAD in individual rats, even at IAD's as low as 0.60 nCi of 239Pu. The 239Pu lung-clearance curve and an equation describing changes in lung weight with body weight and age were used to determine lung radiation doses. The IAD's of exposure groups were 0.60 +- 0.15 nCi of 239Pu (1000 rats), 0.98 +- 0.25 (531 rats), 2.4 +- 0.69 (209 rats), 5.7 +- 1.2 (98 rats), and 7.5 +- 2.0 to 150 +- 37 nCi (300 rats); corresponding radiation doses to the lung estimated at 3 years after exposure were 8.3, 14, 33, 79, and 100 to 2100 rads, respectively. 71 refs., 5 figs., 4 tabs

  1. Repeated inhalation exposure of rats to aerosols of 239PuO2. V

    The biological responses following protracted alpha irradiation of rat lungs are being studied. Groups of rats have been exposed once, or repeatedly, to aerosols of 239PuO2 to achieve, or to re-establish, lung burdens of 239Pu that will result in projected lifetime alpha-radiation doses to the lungs of 20, 60, 200, or 600 rad. There were dose related increases in the incidence of primary lung tumors In the rats exposed once or repeatedly to 239PuO2. Repeated inhalation exposure of rats to 239PuO2 did not increase the incidence of lung tumors, their time of occurrence nor the risk of death with a lung tumor per unit of absorbed alpha dose to the lung compared to doses received following single exposures. These findings are consistent with those in Beagle dogs repeatedly exposed to 239PuO2 in other studies, but are not consistent with previous observations In mice. The findings in mice indicated protraction of the alpha dose to the lung by repeated inhalation exposure was more carcinogenic than similar doses after a single inhalation exposure. (author)

  2. Migration of 239Pu in soluble and insoluble forms in soil

    A field experiment study was performed at the rural site of South-East Lithuania. The main tasks of the study included an evaluation of the peculiarities of partition of 239Pu in soluble (239Pu(NO3)4, 239PuCl3) and insoluble (239PuO2) forms in soddy and forest soil horizons. The results of durable experiments (418 and 326 days) have shown that from 44.1% to 92.2% of 239Pu of investigated chemical forms were accumulated in the top (0-5 cm) soil layer. Some share (5.7-39.2%) of plutonium from studied chemical forms was found in the 5-20 cm layers of studied soil samples (columns). Obtained distribution of plutonium in soil layers may be attributed to the consideration that the migration rate to the soil depth for plutonium is 0.1-1.0 cm x y-1 but for some part of plutonium 10 times higher migration rate is characteristic as well. Plutonium transfer factor (TF) to the grassland plants was calculated, the values ranged from 10-2 to 10-1. (author)

  3. Sensitivities of five alpha continuous air monitors for detection of airborne {sup 239}Pu

    McIsaac, C.V.; Amaro, C.R.

    1992-07-01

    Results of measurements of the sensitivities of five alpha continuous air monitors (CAMs) for detection of airborne {sup 239}Pu are presented. Four commercially available alpha CAMs (Kurz model 8311, Merlin Gerin Edgar, RADeCO model 452, and Victoreen model 758) and a prototype alpha CAM currently in use at Argonne National Laboratory- West (ANL-W) were tested sampling natural ambient air and laboratory-generated atmospheres laden with either blank dust or dust containing nCi/g concentrations of {sup 239}Pu. Cumulative alpha spectra were stored at 30 or 60 minute intervals during each sampling and were subsequently analyzed using three different commonly used alpha spectrum analysis algorithms. The effect of airborne dust concentration and sample filter porosity on detector resolution and sensitivity for airborne {sup 239}Pu are described.

  4. Sensitivities of five alpha continuous air monitors for detection of airborne sup 239 Pu

    McIsaac, C.V.; Amaro, C.R.

    1992-07-01

    Results of measurements of the sensitivities of five alpha continuous air monitors (CAMs) for detection of airborne {sup 239}Pu are presented. Four commercially available alpha CAMs (Kurz model 8311, Merlin Gerin Edgar, RADeCO model 452, and Victoreen model 758) and a prototype alpha CAM currently in use at Argonne National Laboratory- West (ANL-W) were tested sampling natural ambient air and laboratory-generated atmospheres laden with either blank dust or dust containing nCi/g concentrations of {sup 239}Pu. Cumulative alpha spectra were stored at 30 or 60 minute intervals during each sampling and were subsequently analyzed using three different commonly used alpha spectrum analysis algorithms. The effect of airborne dust concentration and sample filter porosity on detector resolution and sensitivity for airborne {sup 239}Pu are described.

  5. Sensitivities of five alpha continuous air monitors for detection of airborne 239Pu

    Results of measurements of the sensitivities of five alpha continuous air monitors (CAMs) for detection of airborne 239Pu are presented. Four commercially available alpha CAMs (Kurz model 8311, Merlin Gerin Edgar, RADeCO model 452, and Victoreen model 758) and a prototype alpha CAM currently in use at Argonne National Laboratory- West (ANL-W) were tested sampling natural ambient air and laboratory-generated atmospheres laden with either blank dust or dust containing nCi/g concentrations of 239Pu. Cumulative alpha spectra were stored at 30 or 60 minute intervals during each sampling and were subsequently analyzed using three different commonly used alpha spectrum analysis algorithms. The effect of airborne dust concentration and sample filter porosity on detector resolution and sensitivity for airborne 239Pu are described

  6. Biochemical effects of inhaled 239PuO2 on lung lipids

    Results of experiments carried out to assess the effect of 239Pu α irradiation on lung lipid biosynthesis and to determine the lungs ability to incorporate palmitate into lavage lecithin and its turnover are reported. The experiments were carried out on rats which had inhaled 239PuO2 particles. The study of palmitate incorporation into lipids shows conclusively that for medium (23 to 42 nCi) or high (more than 100 nCi) lung depositions the incorporation by isolated mitochondria is significantly (P 239PuO2 were positive, with respect to controls in 8 of 10 instances, when measured following the label of palmitate in lung lavage lecithin. The interpretation of the significant result (P < 0.05) is that: (1) initial and/or final lecithin pool sizes were different, (2) transfer rates were affected between blood and lung, or (3) rates of degradation of lung lavage lecithin were affected. (U.K.)

  7. Covariances for 239Pu induced cross section in the resonance range using the CONRAD code

    This paper will present the evaluation of neutron induced cross sections covariances for the 239Pu in the resonance range. The methodology used is based on marginalization and retroactive technique to allow the treatment of experimental systematic uncertainties such as normalization. In addition, as sensitivity studies performed on iso-thermal temperature moderator analysis have demonstrated the need for improving the description of the 239Pu neutron cross sections in the sub-thermal energy range and knowing the poor accuracy of the EXFOR data below the thermal energy range, integral trends have to be taken into account in this evaluation work. The focus of the presentation is to show results obtained on the 239Pu capture and fission neutron cross sections in the resonance range with an exhaustive integral validation. (authors)

  8. Medical Care for Accidental Deposition of Plutonium (239Pu) Within the Body

    With expanding uses of plutonium chances for accidental deposition within the body are increasing. Metabolism of plutonium within the body is variable, depending on chemical composition, particle size and shape, monomeric or polymeric physical state, route of entry (inhalation,or through wounds) and many other factors. A notable exception is the negligible absorption from the gastrointestinal tract. It is difficult to determine lung deposition of poorly soluble plutonium by either bioassay or in vivo counting. The intravenous administration of the chelating agent tri-sodium calcium salt of diethylenetriamine- pentaacetic acid (DTPA), soon after an accident, is quite effective in removing soluble plutonium which has been inhaled or deposited in wounds. Conditions requiring prolonged therapy are described. Effectiveness of treatment of 239Pu body depositions is greatly influenced by the solubility of the plutonium at the site of deposition. Size, frequency and duration of dose of DTPA is recommended. Mice developed fibrosarcomas following subcutaneous injections of 0.064 μCi of 239Pu, while an employee apparently developed a pre-cancerous condition after subcutaneous deposition of only 0.005 μCi. It is our policy to recommend excision of any measurable quantity of 239Pu in a superficial wound when this may be accomplished with little hazard. The maximum permissible deposition in skin or subcutaneous tissue may be much lower than that for depositions in bone liver, lung or tracheo-bronchial lymph nodes. No limiting value has been set for depositions in wounds by any official body; The surgeon must balance the benefits to be secured against the risk of the operation. A wound bearing 239Pu should be immediately washed with DTPA, normal saline, or water, in that order of preference. Methods of removal of 239Pu from the intact skin are briefly discussed. A U.S. Plutonium Registry will assist in evaluating depositions of 239Pu and effectiveness of therapy by reconciling

  9. Exploratory study of fission product yields of neutron-induced fission of 235U , 238U , and 239Pu at 8.9 MeV

    Bhatia, C.; Fallin, B. F.; Gooden, M. E.; Howell, C. R.; Kelley, J. H.; Tornow, W.; Arnold, C. W.; Bond, E.; Bredeweg, T. A.; Fowler, M. M.; Moody, W.; Rundberg, R. S.; Rusev, G. Y.; Vieira, D. J.; Wilhelmy, J. B.; Becker, J. A.; Macri, R.; Ryan, C.; Sheets, S. A.; Stoyer, M. A.; Tonchev, A. P.

    2015-06-01

    Using dual-fission chambers each loaded with a thick (200 -400 -mg /c m2) actinide target of 235 ,238U or 239Pu and two thin (˜10 -100 -μ g /c m2) reference foils of the same actinide, the cumulative yields of fission products ranging from 92Sr to 147Nd have been measured at En= 8.9 MeV . The 2H(d ,n ) 3He reaction provided the quasimonoenergetic neutron beam. The experimental setup and methods used to determine the fission product yield (FPY) are described, and results for typically eight high-yield fission products are presented. Our FPYs for 235U(n ,f ) , 238U(n ,f ) , and 239Pu(n ,f ) at 8.9 MeV are compared with the existing data below 8 MeV from Glendenin et al. [Phys. Rev. C 24, 2600 (1981), 10.1103/PhysRevC.24.2600], Nagy et al. [Phys. Rev. C 17, 163 (1978), 10.1103/PhysRevC.17.163], Gindler et al. [Phys. Rev. C 27, 2058 (1983), 10.1103/PhysRevC.27.2058], and those of Mac Innes et al. [Nucl. Data Sheets 112, 3135 (2011), 10.1016/j.nds.2011.11.009] and Laurec et al. [Nucl. Data Sheets 111, 2965 (2010), 10.1016/j.nds.2010.11.004] at 14.5 and 14.7 MeV, respectively. This comparison indicates a negative slope for the energy dependence of most fission product yields obtained from 235U and 239Pu , whereas for 238U the slope issue remains unsettled.

  10. Effects of inhalation of 239PuO2 on immune responses following lung immunization

    Results of this study indicated that the number of antibody-forming cells in lung-associated lymph nodes after intratracheal immunization was significantly lower in animals exposed to 239PuO2. Only a few antibody-forming cells were found in spleen and cervical lymph nodes. Thus, 239PuO2 exposure suppressed immune responses in lung-associated lymph nodes, although their filtering capacity was unaffected and antigen did not translocate to the spleen. Changes in immunologic responses were observed as the animals aged and the number of antibody-forming cells gradually decreased in the lung-associated lymph nodes and increased in the spleen

  11. Effects of 239Pu administered at 9 days of gestation on hematologic development of the rat

    Injection of pregnant rats with monomeric 239Pu after 9 days of gestation decreased their leukocyte and reticulocyte counts at 5 and 10 days postexposure. Most of the fetal hematologic enumerative values were unaffected by injection of monomeric 239Pu. There was, however, a major change in the maturation of the cells of the erythroid series, as indicated by a difference in the distribution between cell types. The weight of the yolk sac and fetal liver, and the cellularity of the fetal spleen were decreased

  12. Response of CR-39 plastic track detector to 239Pu and 252Cf sources

    CR-39 plastic track detectors have been irradiated with 239Pu and 252Cf sources separately at nuclear physics laboratory B.H.U., Varanasi to investigate track recording properties of detector material. All detectors etched in 6.25N NaOH solution at different temperatures for different hours. The bulk and track etch rates are calculated for both detectors (irradiated by 239Pu and 252Cf sources separately). The diameter and sensitivity along the trajectory of the track have been determined at different temperatures. (author)

  13. Pulmonary immune response of dogs after exposure to 239PuO2

    This study evaluated the cell-mediated (CMI) and humoral immune responses in four Beagle dogs five to six years after single inhalation exposures to different monodisperse 239PuO2 aerosols (0.72-1.4μm activity median aerodynamic diameter). These exposures resulted in initial lung burdens ranging from 19 to 35kBq. The immune responses induced by lung immunization of dogs that had inhaled 239PuO2 were not suppressed by large doses of chronic alpha irradiation of the lungs and tracheobronchial lymph nodes, indicating that local pulmonary immune responses are preserved despite severe radiation-induced alteration of these tissues. (author)

  14. Effect of inhaled 239PuO2 on alveolar Type II cells

    Morphological changes of rat alveolar type II (AT-II) cells were studied at 8 and 10 months following inhalation of 239PuO2 to elucidate the biological role of AT-II cells in the induction of lung tumours. TEM micrographs of random sections of lung were analysed qualitatively and quantitatively using an automatic image analyser. Eighteen morphometric parameters were obtained according to stereological principles. The results showed that, following the inhalation of 239PuO2, AT-II cells became less differentiated and the metabolism of the pulmonary surfactant in AT-II cells was disturbed. (author)

  15. Effect of inhaled 239PuO2 on alveolar type II cells

    Morphological changes of rat alveolar type II (AT-II) cells were studied at 8 and 10 months following inhalation of 239PuO2 to elucidate the biological role of At-II cells in the induction of lung tumours. TEM micrographs of random sections of lung were analysed qualitatively and quantitatively using an automatic image analyser. Eighteen morphometric parameters were obtained according to stereo logical principles. The results showed that, following the inhalation of 239PuO2, AT-II cells became less differentiated and the metabolism of the pulmonary surfactant in AT-II cells was disturbed

  16. Effects of pregnancy and lactation on the toxicity of 239Pu

    Nulliparous, pregnant, or lactating Wistar rats were injected intravenously with 0, 0.5 or 2.0 μCi of 239Pu per kilogram of body weight. Half of each group were repeatedly bred while the others were held for observation without further treatment. Treatment with either dose of 239Pu decreased the median time to appearance of mammary tumors. Repeated breeding tended to increase the mean time to appearance. Longevity was decreased in a dose-related fashion by Pu administration. Repeated breeding did not influence survival in a major way

  17. Potential of Vetiveria zizanoides L. Nash for phytoremediation of plutonium ((239)Pu): Chelate assisted uptake and translocation.

    Singh, Shraddha; Fulzele, D P; Kaushik, C P

    2016-10-01

    Plants have demonstrated a great potential to remove toxic elements from soils and solutions and been successfully used for phytoremediation of important radionuclides. Uptake potential of vetiver plants (V. zizanoides) for the remediation of (239)Pu in hydroponic and soil conditions was studied in the present work. High efficiency of V. zizanoides for the removal of (239)Pu was recorded with 66.2% being removed from the hydroponic solution after 30 days. However, remediation of (239)Pu from soil was limited. Remediation of (239)Pu from soil was increased with the addition of chelating agents citric acid (CA) and diethylenetriaminepentaacetic acid (DTPA). Accumulation of (239)Pu was recorded higher in roots than shoots, however its translocation from roots to shoots increased in the presence of chelators in hydroponic as well as soil conditions. DTPA was found more effective than CA showing higher translocation index (TI). Increase in TI was observed 8 and 6 times in the solution and soil respectively when plants were exposed to (239)Pu-DTPA in comparison to only (239)Pu. The present study demonstrates that V. zizanoides plant is a potential plant for phytoremediation of (239)Pu. PMID:27318195

  18. Modifying effects of pre-existing fibrosis in rats exposed to aerosols of 239PuO2. II

    We have initiated a study using rats to determine the modifying effects of pre-existing pulmonary fibrosis on the retention and biological effects of inhaled 239PuO2. Pulmonary fibrosis was induced by intratracheal instillation of 8.5 IU/kg body weight of bleomycin at 45 to 49 days before inhalation exposure to an aerosol of 239PuO2. The clearance of 239Pu from the lungs of rats was decreased significantly (p 239Pu, apparently by entrapping the particles in fibrotic areas of the lung. The life span of the rats with pulmonary fibrosis was decreased by up to 25% compared with control rats having similar initial lung burdens of 239Pu. (author)

  19. Biological effects of 239PuO2 inhalation in the Rhesus monkey

    Rhesus monkeys were exposed to polydisperse, high-fired 239PuO2 aerosols and have been studied for 3 yr to determine the biological effects associated with this inhalation exposure. Initial lung burdens in 16 monkeys exposed to aerosols of 239PuO2 ranged from 7 to 1800 nCi. Two monkeys are serving as controls. The inhaled 239 PuO2 was retained with a long effective half-life in the lung with some translocation from the lung to the pulmonary lymph nodes. In animals exposed to high levels of 239PuO2, there was a depression in the number of lymphocytes in the peripheral blood. However, blood lymphocytes cultured at time periods up to 30 mo after inhalation showed no increase in chromosome aberration frequency. An animal with an estimated initial lung burden of 1000 nCi showed marked alterations in respiratory function. Only slight respiratory changes were detected in the other animals evaluated. To date, three monkeys have died, two of radiation pneumonitis and the third of gastric torsion. Comparing these data from Rhesus monkeys with those obtained from baboons and Beagle dogs indicate that Rhesus monkeys are similar to dogs in their early radiation response

  20. Pulmonary distribution of inhaled 239PuO2 in dogs

    Dogs exposed to 239PuO2 by inhalation were killed from 1 to 69 mo postexposure. The distribution of plutonium in the lungs, which was studied by analyzing autoradiographs, changed relative to time postexposure. This study investigates methods of measuring these changes

  1. R-matrix analysis of the 239Pu cross sections up to 1 keV

    The results are reported of an R-matrix resonance analysis of the 239Pu neutron cross sections up to 1 keV. After a description of the method of analysis the nearly 1600 resonance parameters obtained are listed and extensive graphical and numerical comparisons between calculated and measured cross-section and transmission date are presented. 47 refs., 47 figs., 8 tabs

  2. Isotope ratios of 240Pu/239Pu in soil samples from different areas

    Plutonium concentrations and 240Pu/239Pu atom ratios in soil samples from Japan and other areas in the world (including IAEA standard reference materials) were determined by ICP-MS. The range of 240Pu/239Pu atom ratios observed in 21 Japanese soil samples was 0.155 - 0.194 and the average was 0.180 ± 0.011, which is comparable to the global fallout value. A low ratio of about 0.05, which is derived from Pu-bomb, was found in samples from Nishiyama (Nagasaki) and Mururoa Atoll (IAEA-368), while a high ratio of about 0.31 was found in a sample from Bikini Atoll (Marshall Islands). The ratio for Irish Sea sediment (IAEA-135) was 0.21, which was higher than the global fallout value, suggesting the influence by the contamination from the Sellafield facility. The 240Pu/239Pu atom ratios in soils from the Chernobyl area were determined, and the ratio was found to be very high (about 0.4), indicating the high burn-up grade of the reactor fuel. These results show that the 240Pu/239Pu ratio can be used as a finger print to identify the source of the contamination. (author)

  3. Yield-Energy Evaluation of 85Kr of 239Pu+n Fission

    2008-01-01

    <正>The yields of 85Kr, the important production of the 239Pu fission, were re-evaluated over the incident neutron energy 1-15 MeV, based upon all the experimental data. The yields as function of energ

  4. Effects of inhaled 239PuO2 on the primary immune response of beagle dogs

    Effects of inhaled 239PuO2 on the humoral component of the immune system were measured by intravenous immunizations of beagle dogs with keyhole limpet hemocyanin (KLH). With this T-cell-dependent antigen, a significant decrease in primary antibody response was observed in exposed versus unexposed dogs

  5. Chromosome aberration frequency in blood lymphocytes of animals with 239Pu lung burdens

    Other investigators have suggested a causal relationship between accidental 239Pu exposures in man and the presence of chromosome aberrations in blood lymphocytes. To assess this relationship experimimentally, 16 Rhesus monkeys and 171 Chinese hamsters were exposed by inhalation to 239PuO2 aerosols and an additional five hamsters were injected with 239Pu citrate and the frequency of aberrations in blood lymphocytes determined. After an initial rapid clearance phase, the 239Pu was retained in the monkey lung with a long effective half-life (greater than 500 days). At 30 days after inhalation, 99 percent of the sacrifice body burden was in the lungs of both species. The ranges of cumulative radiation dose to the hamster lungs 30 days after inhalation were calculated to be 80 to 170, 220 to 540, and 830 to 2120 rads for initial lung burden levels of 10 to 30, 30 to 70, and 180 to 260 nCi/g, respectively. By 120 days, these doses were calculated to be 40 to 350, 500 to 710, and 1440 to 2170 rads. Hamsters with the highest lung burdens had a median survival time of about 80 days. No deaths occurred in any of the other treated hamsters or monkeys by 250 days after 239Pu inhalation. Hamsters sacrificed at 30 days showed an increase in chromosome aberration frequency with increasing dose to lung. By 120 days after inhalation, the aberration frequency in the controls was 0.012. The frequency in animals with doses that produced significant life shortening (1440 to 2170 rads) had decreased to 0.018 and to 0.032 aberrations/cell in animals with lung doses of 500 to 710 rads. At 380 days after injection of 60 nCi 239Pu citrate/gm, hamster lymphocytes had an aberration frequency of 0.048 aberrations/cell. The level of chromosome damage in the 239PuO2 exposed monkeys at 30 and 90 days after inhalation was not different than observed in controls. (U.S.)

  6. Radiation effect of 239PuO2 on human cells in vitro

    In this paper, the in vitro short and long term effects of 239PuO2 on human embryo lung fibroblast are reported. The short term effect observed is the changes in proliferation and survival of the cell line which were exposed to 239PuO2 with concentration of 0.0006 μCi/mL for a week. On 7th day, the proliferation was only 4.88 PDN (population doubling number), while the control was 10.5 PDN. On the 6th day the surviving fraction of the treated cells was 56.3% and that of the control was 96%. For the long term effect studies, the follow-up observation for 12 groups of cell culture exposed to 239PuO2 of 0.0015 and 0.003 μCi/mL was made. In the cultures exposed to 239PuO2 of 0.003 μCi/mL, the shape of the cells became shorter and their life-span shortened with a higher mortality and death appears early. In 7 cultures exposed to 239PuO2 of 0.0015 μCi/mL, the change in cell morphology was the same as above and their life span was shortened by 58.7% averagely in comparison with control. On other two cultures of them not only was no life-span shortening found, but it was longer than that in the control and their inherent characteristics of regionol arrangment disappeared. At last epithelium-like shape of transformed cells were appeared. In the electron microscope siking of the nuclear membranes into nucleus and hypertrophy of the nucleolus with netted structure can be observed. The nuclear volume increased largely and the ratio between nucleus and cytoplasm increased

  7. Applicability of 239Pu as a tracer for soil erosion in the wet-dry tropics of northern Australia

    The technique of accelerator mass spectroscopy (AMS) has been employed to determine modern soil loss rates through the analysis of 239Pu profiles in soil cores from the Daly basin in Northern Territory, Australia. In areas in which soil conservation banks were not present or were only added recently (−1 a−1. The measured rates are up to 5 times higher compared to agricultural and uncultivated areas within soil conservation banks in other parts of the catchment. High intensity seasonal rainfall combined with reduction in land cover due to grazing and episodic bush fires are primary factors influencing erosion although other impacts on the landscape such as tillage generated runoff and land clearing seem to be responsible for accelerated sediment production.

  8. Applicability of {sup 239}Pu as a tracer for soil erosion in the wet-dry tropics of northern Australia

    Lal, R., E-mail: rajeev.lal@anu.edu.au [Department of Nuclear Physics, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Tims, S.G.; Fifield, L.K. [Department of Nuclear Physics, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Wasson, R.J.; Howe, D. [Charles Darwin University, Darwin, NT 0810 (Australia)

    2013-01-15

    The technique of accelerator mass spectroscopy (AMS) has been employed to determine modern soil loss rates through the analysis of {sup 239}Pu profiles in soil cores from the Daly basin in Northern Territory, Australia. In areas in which soil conservation banks were not present or were only added recently (<25a) and which had a history of grazing and cultivation the measured soil loss rates over the past {approx}50 years were 7.5-19.5 t ha{sup -1} a{sup -1}. The measured rates are up to 5 times higher compared to agricultural and uncultivated areas within soil conservation banks in other parts of the catchment. High intensity seasonal rainfall combined with reduction in land cover due to grazing and episodic bush fires are primary factors influencing erosion although other impacts on the landscape such as tillage generated runoff and land clearing seem to be responsible for accelerated sediment production.

  9. Evaluating and adjusting 239Pu, 56Fe, 28Si and 95Mo nuclear data with a Monte Carlo technique

    In this paper, Monte Carlo optimization and nuclear data evaluation are combined to produce optimal adjusted nuclear data files. The methodology is based on the so-called 'Total Monte Carlo' and the TALYS system. Not only a single nuclear data file is produced for a given isotope, but virtually an infinite number, defining probability distributions for each nuclear quantity. Then each of these random nuclear data libraries is used in a series of benchmark calculations. With a goodness-of-fit estimator, best 239Pu, 56Fe, 28Si and 95Mo evaluations for that benchmark set can be selected. A few thousands of random files are used and each of them is tested with a large number of fast, thermal and intermediate energy criticality benchmarks. From this, the best performing random file is chosen and proposed as the optimum choice among the studied random set. (authors)

  10. 240Pu/239Pu atom ratios in seawater from the western North Pacific and its marginal sea

    Full text: The atom ratio of 240Pu/239Pu is known to be a useful tracer to identify the sources of plutonium in the ocean. The objectives of this study are to measure the 239+240Pu activities and 240Pu/239Pu atom ratios in seawater from the western North Pacific and its marginal sea and to discuss the transport processes of plutonium. The 240Pu/239Pu atom ratios were measured with sector-field ICPMS. The atom ratios were significantly higher than the mean global fallout ratio. These high atom ratios proved the existence of close-in fallout plutonium originating from the Pacific proving grounds. (author)

  11. Characterization of a neutron source of {sup 239}PuBe; Caracterizacion de una fuente de neutrones de {sup 239}PuBe

    Hernandez V, R.; Chacon R, A.; Hernandez D, V. M.; Mercado, G. A.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Ramirez G, J. [Instituto Nacional de Estadistica Geografia e Informatica, Direccion General de Innovacion y Tecnologia de Informacion, Av. Heroes de Nacozari Sur 2301, Fracc. Jardines del Parque, 20276 Aguascalientes (Mexico)], e-mail: ruben_zac@yahoo.com

    2009-10-15

    The spectrum equivalent dose and environmental equivalent dose f a {sup 239}PuBe source have been determined. The appropriate handling of a neutron source depends on the knowledge of its characteristics, such as its energy distribution, total rate of flowing and dosimetric magnitudes. In many facilities have not spectrometer that allows to determine the spectrum and then area monitors are used that give a dosimetric magnitude starting from measuring the flowing rate and the use of conversion factors, however this procedure has many limitations and it is preferable to measure the spectra and starting from this information the interest dosimetric magnitudes are calculated. In this work a Bonner sphere spectrometer has been used with a {sup 6}LiI(Eu) scintillator obtaining the count rates that produce, to a distance of 100 cm, a {sup 239}PuBe source of 1.85E(11) Bq. The spectrum was reconstructed starting from the count rates using BUNKIUT code and response matrix UTA4. With the spectrum information was calculated the source intensity, total flow, energy average, equivalent dose rate, environmental equivalent dose rate, equivalent dose coefficient and environmental equivalent dose coefficient. By means of two area monitors for neutrons, Eberline ASP-1 and LB 6411 of Berthold the equivalent dose and environmental equivalent dose were measured. The determinate values were compared with those reported in literature and it found that are coincident inside 17%. (Author)

  12. Investigation of the resonance self-shielding effect in the α-value of 239Pu

    Gamma-spectra from 1 to 15 multiplicities were measured on 122 m flight path of the IBR-30 pulsed neutron booster using a 16-section liquid scintillation detector of a total volume of 80 l for two thin metallic radiator-samples of 239Pu in the presence of a filter-samples with four thickness: 0.3, 0.5, 1 and 2.3 mm in the neutron beam and without them. The multiplicity distribution spectra, the average multiplicities and the alpha value α = σγ/σf for 27 resonances in the energy region 7-170 eV and for the energy group in the region 4.65-2150 eV with and without filter-samples of 239Pu in the beam were obtained. The self-shielding effect in the alpha value and the average multiplicity in limits 5-40% of experimental value is observed

  13. Studies of Neutron-Induced Fission of 235U, 238U, and 239Pu

    Duke, Dana; TKE Team

    2014-09-01

    A Frisch-gridded ionization chamber and the double energy (2E) analysis method were used to study mass yield distributions and average total kinetic energy (TKE) release from neutron-induced fission of 235U, 238U, and 239Pu. Despite decades of fission research, little or no TKE data exist for high incident neutron energies. Additional average TKE information at incident neutron energies relevant to defense- and energy-related applications will provide a valuable observable for benchmarking simulations. The data can also be used as inputs in theoretical fission models. The Los Alamos Neutron Science Center-Weapons Neutron Research (LANSCE - WNR) provides a neutron beam from thermal to hundreds of MeV, well-suited for filling in the gaps in existing data and exploring fission behavior in the fast neutron region. The results of the studies on 238U, 235U, and 239Pu will be presented. LA-UR-14-24921.

  14. R matrix analysis of the 239Pu cross sections up to 600 eV

    The ENDF/B-V representation of the 239Pu neutron cross sections in the resonance region is unsatisfactory: the single-level formalism is used, necessitating a structured file 3 contribution. Furthermore, Salvatores et al. have stressed the need to extend the resolved resonance region above the present ENDF/B limit of 300 eV for the calculation of Doppler effect and self-shielded group cross sections. The purpose of our work is to improve the representation of the 239Pu cross sections by using a multilevel formalism (which avoids the need for the file 3 contributions) and by extending the resolved resonance range from 300 up to 600 eV. The present resonance analysis is based on the Reich-Moore multilevel formalism and was performed with the Bayesian code SAMMY. The resonance parameters published in 1974 by Derrien were used as prior information. More than 200 levels and 1000 resonance parameters are included in the analysis

  15. Toxicity of 239PuO2 in immature Beagle dogs. X

    Immature beagles have been exposed by inhalation to a monodisperse aerosol of 239PuO2 (1.5 μm AMAD) to compare the biological effects with those being observed in dogs exposed to a similar aerosol when they were young or aged adults. The study includes 96 dogs exposed to 239PuO2 and 12 controls. A total of 66 experimental and 11 control dogs are still alive. Six dogs died during the past year, all of radiation-related causes. Five dogs died from lung carcinomas and the sixth dog died of pneumonia/fibrosis, but with a lung tumor. With the large number of dogs still alive in this study, it is still premature to compare the cancer dose-response relationships for the immature and adult dogs. (author)

  16. Fission Mode Influence on Prompt Neutrons and γ-rays Emitted in the Reaction 239Pu(nth,f)

    Serot, O.; Litaize, O.; Regnier, D.

    Recently, a Monte-Carlo code, which simulates the fission fragment de-excitation process, has been developed at CEA- Cadarache. Our aim is to get a tool capable to predict spectra and multiplicities of prompt particles (neutron and gamma) and to investigate possible correlations between fission observables. One of the main challenges is to define properly the share of the available excitation energy at scission between the two nascent fission fragments. Initially, after the full acceleration of the fission fragments, these excitation energies were treated within a Fermi-gas approximation in aT2 (where a and T stand for the level density parameter and the nuclear temperature) and a mass dependent law of the temperature ratio (RT=TL/TH, with TL and TH the temperature of the light and heavy fragment) has been proposed. With this RT-law, the main fission observables of the 252Cf(sf) could be reproduced. Here, in order to take into account the fission modes by which the fissioning nucleus undergoes to fission, we have adopted a specific RT-law for each fission mode. For actinides, the main fission modes are called Standard I, Standard II and Super Long (following Brosa's terminology). This new procedure has been applied in the case of the thermal neutron induced fission of 239Pu, reaction for which fission modes are rather well known.

  17. Alpha and conversion electron spectroscopy of 238,239Pu and 241Am and alpha-conversion electron coincidence measurements

    Dion, Michael P.; Miller, Brian W.; Warren, Glen A.

    2016-09-01

    A technique to determine the isotopic constituents of a mixed actinide sample has been proposed by a coincident alpha-conversion electron measurement. This presents a unique signature to allow the unfolding of isotopes that possess overlapping alpha particle energy and reduce backgrounds of an unseparated sample. The work presented here are results of conversion electron spectroscopy of 241Am, 238Pu and 239Pu using a dual-stage peltier-cooled 25 mm2 silicon drift detector and alpha spectroscopy with a passivated ion implanted planar silicon detector. The conversion electron spectra were evaluated from 20-55 keV based on fits to the dominant conversion electron emissions, which allowed the relative conversion electron emission intensities to be determined. These measurements provide crucial singles spectral information and calibration to aid in the coincident measurement approach. Furthermore, an alpha-conversion electron spectrometer was assembled using the silicon based detectors described and results of a coincident spectrum analysis is reported for 241Am.

  18. Neutron-induced transmutation reactions in 237Np, 238Pu, and 239Pu at the massive natural uranium spallation target

    Transmutation reactions in the 237Np, 238Pu, and 239Pu samples were investigated in the neutron field generated inside a massive (m = 512 kg) natural uranium spallation target. The uranium target assembly QUINTA was irradiated with the deuteron beams of kinetic energy 2, 4, and 8 GeV provided by the Nuclotron accelerator at the Joint Institute for Nuclear Research (JINR) in Dubna. The neutron-induced transmutation of the actinide samples was measured off-line by implementing methods of gamma-ray spectrometry with HPGe detectors. Results of measurement are expressed in the form of both the individual reaction rates and average fission transmutation rates. For the purpose of validation of radiation transport programs, the experimental results were compared with simulations of neutron production and distribution performed by the MCNPX 2.7 and MARS15 codes employing the INCL4-ABLA physics models and LAQGSM event generator, respectively. In general, a good agreement between the experimental and calculated reaction rates was found in the whole interval of provided beam energies

  19. Early effects of inhaled 239Pu(NO3)4 aerosols in beagle dogs

    Beagle dogs given a single inhalation exposure to 239Pu(NO3)4, and observed for life-span dose-effect relationship, died from radiation pneumonitis (4 of 5) at the highest dosage level, 14 to 25 mo postexposure. There were also indications in these dogs of radiation osteosis, characterized by peritrabecular fibrosis. Leukopenia, lymphopenia, neutropenia and decreased numbers of circulating monocytes and eosinophils occurred at the two highest dosage levels, as previously reported

  20. Analysis of the 239Pu neutron cross sections from 300 to 2000 eV

    A recent high-resolution measurement of the neutron fission cross section of 239Pu has allowed the extension from 1 to 2 keV of a previously reported resonance analysis of the neutron cross sections, and an improvement of the previous analysis in the range 0.3 to 1 keV. This report analyzes this region. 8 refs., 1 fig., 2 tabs

  1. 235 U consumption and 239 Pu formation on IPR-R1 reactor

    On the present world conjuncture it is necessary a rigorous storage and utilization control of nuclear materials under safeguard, specially those considered as strategic and those that could be used on the nuclear armaments fabrications as 235U and 239Pu. Brazil have signed and ratified many international pacts related to the peaceful utilization of the nuclear materials, making the compromise to attend nuclear safeguard procedures accorded with international regulatory organizations. The main goal of this work is the development of a simplified method for the estimation of the 239Pu productivity during the operation of the IPR-R1, TRIGA Mark-1 type, nuclear research reactor, that can achieve the maximum power of 100 KWt. A computational algorithm have been made to calculate the consumption of 235U on the fuel elements used on the reactor and the subsequent 239Pu formation (by the neutronic capture process), using the power generated by the reactor since the first criticality. The particular geometry of this kind of reactor allowed the calculation of the burn factors of the fuel elements discriminated by nuclear concentric rings, based on the thermal neutrons field distribution observed on experiments accomplished during a time period in similar reactors and on the IPR-R1. The simplified block diagram of the process, based on the calculation described above, is presented

  2. Presence of plutonium isotopes, {sup 239}Pu and {sup 240}Pu, in soils from Chile

    Chamizo, E., E-mail: echamizo@us.es [Centro Nacional de Aceleradores, Avda. Thomas Alba Edison, 7, 41092 Sevilla (Spain); Garcia-Leon, M., E-mail: manugar@us.es [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, Avda. Reina Mercedes sn, 41012 Seville (Spain); Peruchena, J.I., E-mail: jiperuchena@gmail.com [Centro Nacional de Aceleradores, Avda. Thomas Alba Edison, 7, 41092 Sevilla (Spain); Cereceda, F., E-mail: francisco.cereceda@usm.cl [Laboratorio de Quimica Ambiental, Centro de Tecnologias Ambientales (CETAM), Universidad Tecnica Federico Santa Maria, Casilla 110-V, Valparaiso (Chile); Vidal, V., E-mail: victor.vidal@usm.cl [Laboratorio de Quimica Ambiental, Centro de Tecnologias Ambientales (CETAM), Universidad Tecnica Federico Santa Maria, Casilla 110-V, Valparaiso (Chile); Pinilla, E., E-mail: epinilla@unex.es [Departamento de Quimica Analitica, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas sn, 06071 Badajoz (Spain); Miro, C., E-mail: cmiro@unex.es [Departamento de Fisica Aplicada, Universidad de Extremadura, Avda. de la Universidad sn, 10071 Caceres (Spain)

    2011-12-15

    Plutonium is present in every environmental compartment, due to a variety of nuclear activities. The Southern Hemisphere has received about 20% of the global {sup 239}Pu and {sup 240}Pu environmental inventory, with an important contribution of the so-called tropospheric fallout from both the atmospheric nuclear tests performed in the French Polynesia and in Australia by France and United Kingdom, respectively. In this work we provide new data on the impact of these tests to South America through the study of {sup 239}Pu and {sup 240}Pu in soils from different areas of Northern, Central and Southern Chile. The obtained results point out to the presence of debris from the French tests in the 20-40 Degree-Sign Southern latitude range, with {sup 240}Pu/{sup 239}Pu atomic ratios quite heterogeneous and ranging from 0.02 to 0.23. They are significantly different from the expected one for the global fallout in the Southern Hemisphere for the 30-53 Degree-Sign S latitude range (0.185 {+-} 0.047), but they follow the same trend as the reported values by the Department of Energy of United States for other points with similar latitudes. The {sup 239+240}Pu activity inventories show as well a wider variability range in that latitude range, in agreement with the expected heterogeneity of the contamination.

  3. Presence of plutonium isotopes, 239Pu and 240Pu, in soils from Chile

    Plutonium is present in every environmental compartment, due to a variety of nuclear activities. The Southern Hemisphere has received about 20% of the global 239Pu and 240Pu environmental inventory, with an important contribution of the so-called tropospheric fallout from both the atmospheric nuclear tests performed in the French Polynesia and in Australia by France and United Kingdom, respectively. In this work we provide new data on the impact of these tests to South America through the study of 239Pu and 240Pu in soils from different areas of Northern, Central and Southern Chile. The obtained results point out to the presence of debris from the French tests in the 20–40° Southern latitude range, with 240Pu/239Pu atomic ratios quite heterogeneous and ranging from 0.02 to 0.23. They are significantly different from the expected one for the global fallout in the Southern Hemisphere for the 30–53°S latitude range (0.185 ± 0.047), but they follow the same trend as the reported values by the Department of Energy of United States for other points with similar latitudes. The 239+240Pu activity inventories show as well a wider variability range in that latitude range, in agreement with the expected heterogeneity of the contamination.

  4. Investigations of the chemical forms of 239Pu and 241Am in estuarine sediments and a salt marsh soil

    Estuarine sediments and a salt marsh soil have been fractionated by non-destructive procedures. The distribution of 239Pu and 241Am in these fractions has been determined by gel permeation chromatography and extraction with complexing agents. (author)

  5. Neutron inelastic-scattering cross sections of 232Th, 233U, 235U, 238U, 239Pu and 240Pu

    Differential-neutron-emission cross sections of 232Th, 233U, 235U, 238U, 239Pu and 240Pu are measured between approx. = 1.0 and 3.5 MeV with the angle and magnitude detail needed to provide angle-integrated emission cross sections to approx. 232Th, 233U, 235U and 238U inelastic-scattering values, poor agreement is observed for 240Pu, and a serious discrepancy exists in the case of 239Pu

  6. Group cross-sections and resonance self-shielding factors for 239Pu in the unresolved resonance region

    The authors analyse experimental data on the transmission and fission self-indication functions for 239Pu in the unresolved resonance region. Use is made of the method of generating a cross-section structure based on the multi-level R-matrix formalism (stochastic K-matrix method). Evaluations of the average resonance parameters and group constants for 239Pu are made. (author)

  7. Modification of 239Pu metabolism in the blood in various modes of iron preparation administration in the body

    A study was made of the intravenous, intraperitoneal and oral routes of iron administration. It was shown that the oral route of the entry of appropriate amounts of iron in the body made it possible to saturate the transferrin spare capacity and hence to influence 239Pu metabolism in the blood. The results obtained can be employed for improving sensitivity of indirect dosimetry methods of 239Pu in the body using chelates

  8. Cytogenetic and other biological effects of 239PuO2 inhaled by the rhesus monkey

    Sixteen immature rhesus monkeys were exposed via inhalation to an insoluble, polydisperse 239PuO2 aerosol labeled with 169Yb which had an activity median aerodynamic diameter of 1.6 μm and a sigma/sub g/ of 1.6. Four groups with three monkeys per group were exposed to achieve initial 239Pu lung burdens of 1000 to 2000, 200 to 300, 20 to 65, and 2 to 10 nCi, respectively. To determine early retention and distribution of the aerosol, four additional monkeys were exposed with initial lung burdens of 200 to 600 nCi and were sacrificed 4 hr and 30 days after inhalation exposure. Two monkeys were sham exposed and served as controls. Using data derived from external whole-body counting of the 169Yb label, it was estimated that the inhaled 239PuO2 was retained in the body with an average effective half-life of 1000 days with some translocation from the lung to the pulmonary lymph nodes. Chromosome aberrations were scored in blood lymphocytes cultured 1, 3, 7, 19, 31, and 43 months after inhalation. Only in animals with cumulative lung doses greater than 1000 rad was there a significant increase in the frequency of rings and dicentrics when compared to the controls. An animal with an estimated initial lung burden of 1000 nCi showed marked alterations in respiratory function 30 days prior to his death from pulmonary fibrosis 990 days after inhalation exposure. Only slight respiratory changes were detected in the other animals evaluated. To date, three monkeys have died, two with initial lung burdens of 1800 and 1000 nCi 239Pu which died from radiation pneumonitis and the third with an initial lung burden of 20 nCi which died of gastric torsion presumably not related to Pu exposure. Comparison of survival data from rhesus monkeys with those obtained from baboons and beagles indicates that rhesus monkeys, baboons, and dogs are similar in their early response to inhaled 239PuO2

  9. 239PU(N, f) at Resonance Energies and its Multi-Modal Interpretation

    Hambsch, F.-J.; Bax, H.; Ruskov, I.; Demattè, L.

    2003-10-01

    A measurement of fission fragment total kinetic energy (TKE) and mass yield distributions Y (A,TKE) in the 239Pu(n,f) resolved resonance region has been performed applying the twin Frisch gridded ionization chamber technique. Special emphasis was devoted to cope with the strong α-activity of this isotope by an improved pile-up rejection system. Up to about 200 eV all fission resonances could be resolved and their two-dimensional mass yield and TKE distribution, Y(A,TKE), measured. Compared to the results on 235U(n,f), much smaller fluctuations of the fission fragment mass and TKE have been observed in the case of 239Pu. From a physical point of view such fluctuations have been expected for the fission fragment properties, because the only possible lowenergy spin states (Jπ=0+,1+) belong to well separated (about 1.25 MeV) transition state bands. Hence, it was expected to observe differences in the fission fragment mass and TKE distributions between spin 0+ and 1+ resonances. However, no spin dependence and only a slight anti-correlation of the TKE with the prompt neutron multiplicity, νp. has been found in the resolved resonance energy region above 1 eV. Within the multi-modal random neck-rupture (MM-RNR) model the Y(A,TKE) distributions have been fitted assuming three fission modes, two asymmetric and one symmetric one. The branching ratio of the two asymmetric modes shows similar fluctuations as the experimental TKE. Recently, a new theoretical approach has given a solution to the absence of pronounced fluctuations of the fission properties in the case of 239Pu. Since only one transition state is involved in the fission of 0+ and 1+ resonances with a given fission fragment distribution, no fluctuations are expected.

  10. In vitro studies of actinides and alveolar macrophages

    The toxicity of 239PuO2, 239Pu(NO3)4, and 241AmO2 to rabbit alveolar macrophages in culture was assessed. Comparison of toxicity of 239Pu(NO3)4 and 241AmO2 at the same radiation dose level indicates toxicity is due to radiation and not the chemical form of the actinide. Investigations were begun to determine the effect of serum macrophages and DTPA on 241AmO2 solubility

  11. Determination of isobar composition and yields of 239Pu fission-products by thermal neutrons

    On the research nuclear reactor WWR-SM of INP Uz AS by means of mass-spectrometer the heavy fission-products of 239Pu nuclei induced by thermal neutrons are measured in ranges of mass Ai = 125 -157, kinetic energies Ek = 45 - 87 MeV and effective ionic charges z* = 18 - 30. 102 isobar nuclei in composition of the measured fission-products, also the partial yields of the each element giving the contribution to formation of a total yield of heavy fission-product with mass Ai are defined. (authors)

  12. On the ENDF/B unresolved resonance region formalism representation for 239Pu

    The purpose of this work is to compare the performance of several cross-section evaluation files for the calculation of average cross sections in the unresolved resonance region and to test the validity of the ENDF/B methodology for the calculation of self-shielding factors in this region. The 239Pu neutron cross sections were used for this comparison since a multilevel R-matrix analysis was available, which extended the resolved resonance region from its present ENDF/B limit of 300 eV up to 1 keV. 12 refs., 2 tabs

  13. Status of 239Pu cross-section evaluation in the resonance region at Cadarache

    Some aspects of the evaluations of 239 Pu cross-sections in the resonance region have been presented in this report. A set of resonance parameters assembling the results of a multilevel analysis in the energy range thermal to 200 eV and the result of a single analysis in the energy range 200 eV - 660eV is proposed for the calculation of the cross-sections in the energy range thermal-600eV. These parameters provide a quite good representation of the most recent measured fission cross-sections

  14. Repeated inhalation exposure of Beagle dogs to aerosols of 239PuO2. XII

    Beagle dogs were exposed once or semi-annually for 10 yr by inhalation to aerosols of 239PuO2 to study the relative doses and effects of these two types of exposures. All exposures have been completed. Dogs exposed at high levels died predominantly of radiation pneumonitis and pulmonary fibrosis. Dogs exposed at lower levels, either once or repeatedly, are dying of a variety of causes including lung cancer. Dogs have survived up to 11 yr after their first exposure. Preliminary results suggest that single and repeated exposures cause similar health effects for equal accumulated radiation doses. (author)

  15. Effects of cigarette smoke exposure on pulmonary clearance of 239PuO2 in rats

    Groups of rats were exposed or sham exposed to cigarette smoke for 7 mo, at which time they were exposed to an aerosol of 239PuO2. Rats were then subjected to whole-body counting (17-keV X-rays) periodically, beginning at day 4 after plutonium exposure, and smoke exposures or sham exposures were resumed on day 7. Clearance of plutonium from the lungs of cigarette-smoke-exposed rats was significantly slower than that from the sham-exposed rats' lungs. The difference between the two groups became significant 7 days after the resumption of cigarette-smoke exposures

  16. Direct reduction of 238PuO2 and 239PuO2 to metal

    The process for reducing 700 g 239PuO2 to metal is a standard procedure at Los Alamos National Laboratory. This process is based on research for reducing 200 g 238PuO2 to metal. This report describes in detail the experiments and development of the 200-g process. The procedure uses calcium metal as the reducing agent in a molten CaCl2 solvent system. The process to convert impure plutonia to high-purity metal by oxide reduction followed by electrorefining is also described

  17. Distribution and retention of 239Pu in the tree shrew (Tupaia belangeri) following intramuscular injection

    The retention of intramuscularly injected monomeric 239Pu has been studied in the tree shrew (Tupaia belangeri), a primitive prosimian species. Resorption from the injection site is rapid, and the main depository organs are skeleton and liver with approximately 50 and 20% of the absorbed dose, respectively. The half life of retention in skeleton is approximately 500-600 days and in liver approximately 150 days, these half lives are compared to data for the retention of transuranium elements in other animal species. Indications of liver lesions were found in 5 animals and 1 animal died at day 790 with an osteosarcoma. (author)

  18. The evaluation of the mass distribution data for 238U, 239Pu and 242Pu fission

    The mass distribution data for 238U at En=1.5, 5.5, 8.3, 11.3, 14.9, 22.0, 27.5, 50.0, 99.5, 160.0 MeV, Ep=20.0, 60.0 MeV 239Pu at En=0.17, 7.9, 14.5 MeV and 242Pu at En=15.1 MeV were evaluated and recommended based on the main available experimental data up to now. The experimental data were make necessary corrections and their errors were also made necessary adjustments. The problems concerned were discussed

  19. R-matrix analysis of the 239Pu neutron cross sections

    239Pu neutron cross-section data in the resolved resonance region were analyzed with the R-Matrix Bayesian Program SAMMY. Below 30 eV the cross sections computed with the multilevel parameters are consistent with recent fission and transmission measurements as well as with older capture and alpha measurements. Above 30 eV no suitable transmission data were available and only fission cross-section measurements were analyzed. However, since the analysis conserves the complete covariance matrix, the analysis can be updated by the Bayes method as transmission measurements become available. To date, the analysis of the fission measurements has been completed up to 300 eV. (author)

  20. Dominant lethal tests of male mice given 239Pu salt injections

    To study the possible genetic effects of 239Pu manifesting in dominant lethals, five test series (E1-E5) were performed. Males from an inbred CBA strain were given 239Pu salt injections intravenously and mated weekly to 3 CBA females each for 12 to 24 weeks. Some interruptions in the mating scheme were made. For the first two test series (E1, E2) 239Pu nitrate solution and 239Pu citrate, used in E3-E5, were prepared. The solution was millipore filtered just prior to injection. Among a total of 10255 implants sired by males given Pu-nitrate in E1 and E2 no significant excess of intra-uterine death relative to 7216 control implants occurred. Test series E3-E5 with 60 males each, used three groups of 20, with one control group. In E3, 0.5 μCi and 0.1 μCi were given per male/group, respectively; in E4 and E5, 0.25 μCi and 0.05 μCi, respectively. The males given 0.5 μCi in E3 became successively sterile from the 7th week. The results in E3-E5 point in the same direction with significant excess of intra-uterine death in E3 and E5. In E4 the females from matings from the 9th, 14th and 16th week, and in E5 females from the 9th week, were allowed to litter to give F1 offspring. Dominant lethal tests of F1 males gave concordant results in all four samples, showing significantly excessive death in offspring to F1 males whose fathers had received Pu. The excessive death was evenly distributed and did not indicate the presence of semisterile F1 males. In tests of Pu-injected males and of F1 males a remarkable excess of death in late stages of foetal development was observed. Such effects had never before been observed in this CBA strain in tests of extrinsic and intrinsic exposure to ionizing irradiation

  1. Radiosensitivity of vertebral bone marrow CFU-S surviving in mice internally contaminated with 239Pu or 241Am

    The radiosensitivity of pluripotent hemopoietic stem cells was studied in ICR ''Swiss'' mice (28 g/mouse) given i.v. 198.6 kBq 239Pu/kg as citrate complex or 208.6 kBq 241Am/kg as nitrate at the age of 10 weeks. The bone marrow cells were examined at the early and late phases of radionuclide contamination. To obtain data for survival curves and D0 of stem cells the CFU-S assay was used and the donor vertebral marrow cells were exposed to the complementary X-irradiation either early after injection to the heavily irradiated recipients or to the ''in vitro'' irradiation given before the transplantation. To determine the iron uptake in splenic erythroid progeny the recipients given marrow cells unexposed to the X-rays received 37 kBq 59Fe 6 h before they were killed and the relative activity per colony was calculated. The radiation effect of the used actinides on the bone marrow cells resulted in decreased cellularity and seriously altered both relative and absolute CFU-S numbers. The radiosensitivity of CFU-S increased in all intervals examined (D0 from 0.60 to 0.86 Gy, in controls 0.97 to 1.06 Gy) and was more expressed when the CFU-S were exposed to the X-rays immediately after the bone marrow cell transplantation to the heavily irradiated hosts. The stem cell pool appeared, especially at older age, to be affected also in its ability to produce erythrocytic progeny. (orig.)

  2. Effect of physical exercise on the state of the heart and central hemodynamics in dogs exposed to external (60Co) and internal (239PuO2) irradiation

    Experiments were conducted on mongrel dogs aged 2 to 4 with the body mass of 15.1 ± 0.9 kg. The animals were exposed to combined and isolated γ-irradiation at a dose of 51.6 mC/kg and submicron 239PuO2 in the amount not less than 7 kBq/kg. Single circular irradiation was provided from 60Co γ-sources at a dose rate of 1.03-1.3 mA/kg. 239PuO2 was inhaled 6 days after irradiation. 20 min. running on a tredbahn with the speed of 4.7 km/h served as a physical exercise model. The dogs were examined 0.5, 1, 1.5 and 4 yrs. after the initiation of the experiment at rest and within 1 h after physical exercise. Methods of tetrapolar chest rheography and electrocardiography were employed. It was shown that in the combined effect of two radiation factors the rates of increase in the cardiac index were inhibited at the expense of physical exercise influence as compared to those in the isolated radionuclide effect and resulted from less ''economical'' heart action

  3. Artificial neural networks applied in the spectrometry of a 239Pu-Be source

    To explore the potential use of a neutron source and to define the procedure to handle it under safety conditions, features like neutron spectrum and the ambient dose equivalent of the source must be known. The aim of this work was to determine the spectrum, the total fluence rate and the ambient dose equivalent of a 185 GBq 239Pu-Be neutron source. Using Monte Carlo methods the spectrum, the total fluence rate, and the ambient dose equivalent of a 239Pu-Be were calculated. The spectrum was calculated at 50, 100, 200 and 300 cm from the source in air using MCNP X and MCNP 4C codes. The neutron spectrum was also obtained, at 100 cm, using a Bonner sphere spectrometer whose count rates were used to unfold the neutron spectrum, the unfolding was carried out using an Artificial Neural Network for neutron spectrometry. With the spectrum, the total neutron fluence and the ambient dose equivalent were determined. Calculated results were compared with measured values where Monte Carlo results were smaller than those measured. These differences were attributed to the presence of 241Pu during the source manufacturing. In order to match calculated and measured quantities a 0.102 w/o of 241Pu was estimated. After corrections the differences between calculated and experimental results were 1%. This result shows the advantages of using Artificial Neural Networks technology in the unfolding of neutron spectrum using as a single piece of information the count rates of a Bonner sphere spectrometer. (author)

  4. Alligator Rivers Analogue project. Geochemistry of 239Pu, 129I, 99Tc and 36Cl

    One objective of this research programme has been to evaluate the applicability of uranium orebodies as natural analogues for testing radionuclide release-rate models used in performance assessment activities. The investigated nuclides included three of the most persistent radioactive constituents of high-level wastes from nuclear fission power reactors: plutonium-239, iodine-129, and technetium-99. The feasibility of uranium minerals as analogues for the behavior of these nuclear reaction products (NRP) in spent fuel relies upon a capability to characterise NRP concentrations in the source minerals. Measured abundances of natural 239Pu, 99Tc and 129I in uranium ores are compared to calculated abundances in order to evaluate the degree to retention of these radionuclides by the ore. This modelling study also shows the extent to which various NRP are correlated, such that one provides a constraint on the production rates of others. Under most conditions, 36Cl, another long-lived neutron-capture product found in uranium ores, is shown to be an ideal in-situ monitor of the 235U fission rate, which is the dominant source term for 129I and possibly a significant one for 99Tc. Similarly, 239Pu/U ratios can be used to establish limits on the 238U neutron-induced fission rate; the ratios measured in this study suggest that 238U induced fission comprises 129I and 99Tc. 79 refs., 21 tabs., 18 figs

  5. Comparison of early mortality in baboons and dogs after inhalation of 239PuO2

    Results from experiments with baboons were compared with those from experiments with dogs to determine the relative sensitivity of the two species to early mortality from inhaled 239PuO2. To ensure a valid comparison of data developed at two laboratories, methodology differences were minimized by establishing a common pool of raw data, using the same computer programs to analyze the data, and standardizing assumptions regarding the calculation of plutonium concentration in lungs. Several comparison methods were used involving variations in estimating different parameters used in these calculations. Although nearly all comparisons suggested baboons were slightly more sensitive, none of the methods for comparing the relationship between dose and survival time showed consistently significant differences between baboons and dogs. Although the baboons were physiologically and morphologically immature when exposed to plutonium, whereas the dogs were mature, we concluded that adult baboons and dogs are similarly sensitive to the early effects of inhaled 239PuO2. Since only early mortality was considered in this comparison, the results do not apply to possible late effects caused by much lower levels of plutonium than were used in these experiments

  6. Preliminary evaluation of lung doses for dogs exposed to 239PuO2

    A group of beagle dogs exposed to inhaled 239PuO2 is being followed for life-span effects. This paper reports preliminary lung dose estimates and dose-response relationships for incidence of lung tumors and radiation pneumonitis which have been observed to date. Doses were estimated by using both conventional dose-averaging and microdosimetric techniques. Cascade impactor sampling data were used to reconstruct the original plutonium aerosol size distributions unique to each of about 120 individual dogs exposed to 239PuO2. Data providing the initial plutonium lung burden and lifetime lung retention-clearance functions of plutonium for each dog were used for calculating average dose rates, cumulative absorbed doses, and specific energy distributions. A linear dose-response relationship for lung tumor induction was estimated on the basis of cumulative lung dose. Average time to death was estimated as a function of average dose rate. Conclusions regarding the potential value of microdosimetry in the interpretation of such dose-response relationships are discussed. 8 refs., 5 figs., 1 tab

  7. Lymphocytopenia induced in beagle dogs by inhalation of 239PuO2

    To determine the life-span dose-effect relationships of inhaled plutonium, we gave 124 beagle dogs a single exposure of 239PuO2 2 to 3 years ago at six different levels, i.e., 4, 20, 80, 300, 1100, or 5800 nCi mean initial alveolar depositions. Another group (20 dogs) served as controls. All dogs were about 18 months old. At the four highest exposure levels, a chronic lymphocytopenia developed which correlated with the initial alveolar plutonium burden in regard to magnitude of depression and time of development after exposure. The nadir occurred near 10 months after exposure in dogs receiving 5800, 1100, and 300 nCi, with corresponding lymphocyte levels 40, 55, and 75 percent, respectively, of those observed in control dogs. In the 80-nCi level the nadir occurred about 2 years after exposure at approximately 80 percent of control values. At the two lowest doses, i.e., 4 and 20 nCi, no effect on lymphocyte concentrations was noted 3 years after exposure. The persistent lymphocytopenia related to plutonium inhalation may be of significance in the subsequent development of pulmonary neoplasms previously observed in beagles at this laboratory 8 to 11 years after initial lung depositions of 200 to 1000 nCi of 239Pu

  8. Comparison of acute mortality in baboons and dogs after inhalation of 239PuO2

    Results from experiments with baboons were compared with those from experiments with dogs to determine the relative sensitivity of the two species to acute mortality from inhaled 239PuO2. To assure a valid comparison of data developed at two laboratories, methodology differences were minimized by establishing a common pool of raw data, using the same computer programs to analyze the data, and standardizing assumptions regarding the calculation of radiation doses to lungs. Several comparison methods were used involving variations in estimating different parameters such as the concentration of plutonium in the lungs. Although nearly all comparisons suggested baboons were slightly more sensitive, none of the methods for comparing the relationship between dose and survival time showed consistently significant differences between baboons and dogs. Although the baboons were physiologically and morphologically immature when exposed to plutonium, whereas the dogs were mature, it was concluded that adult baboons and dogs are similarly sensitive to the acute effects of inhaled 239PuO2. Since only acute mortality was considered in this comparison, the results do not apply to possible late effects caused by much lower levels of plutonium than were used in these experiments

  9. Occurrence of bone cancer among young adult Beagles given 239Pu

    Two hundred thirty-five young adult Beagles of both sexes were each given a single intravenous injection of 239Pu-citrate at graded dose-levels averaging about 0.026 to 106 kBq/kg when they were about 1 1/2 years of age and were maintained for lifespan observation. An additional 133 young adult Beagles of both sexes were entered into the experiment as control animals. All of these animals have now died or have been removed from the colony, and the occurrence of skeletal malignancies has been determined from histological examination. There were a total of 85 radiographically apparent malignant bone tumors in 77 dogs given 239Pu, and there was one control animal that developed a skeletal malignancy. Most of these were osteosarcomas, but there were seven chondrosarcomas of bone, one liposarcoma of bone, and in addition, there was one plasma cell myeloma and one ameloblastoma (admantinoma). Only those dogs that survived to at least the minimum latent period for death with radiation-induced bone sarcoma are included in the tabulation. There appeared to be a linear relationship between the percent of dogs with bone tumor and the average skeletal dose up to a dose of about 1 Gy. All dose-levels with skeletal doses of about 2 Gy and greater exhibited close to 100% occurrence

  10. New data on the toxicity and translocation of inhaled 239PuO2 in baboons

    In 1973-1974, baboons were exposed to a polydispersed aerosol of 239PuO2, prepared at 10000C, at the Commissariat a l'Energie Atomique in France. The data published in 1978 for these baboons were used by Bair et al (1980), for comparison with those obtained in beagles exposed to 239PuO2 at the Pacific Northwest Laboratory, USA. Since our 1978 publication, 8 baboons have died or were killed by euthanasia when moribund, and 11 were still alive when the present report was drafted. Two of the eight baboons died of lung squamous cell carcinoma at 2171 and 2528 days respectively. The remaining 6 died of fibrosis, interstitial pneumonia or diseases unrelated to Pu toxicity. The relationship observed in the eight baboons between initial lung burden and survival time shows that their lifespan was longer than expected from the data curve based on the findings for the first 1000 days. However, this increased survival time was not observed if the lifespan was expressed as a function of the average lung burden. (author)

  11. Role of 239Pu-induced chromosome alterations and mutated Ki-v-ras oncogene during liver-cancer induction in Chinese hamsters and mice

    Chromosome aberrations and mutated oncogenes can cause important changes during carcinogenesis. Model systems are being studied in which defined cellular and molecular changes can be quantitated and altered, and tumor frequency, type, and time of appearance can be evaluated. Dose-response relationships for Pu Citrate-induced chromosome aberrations and liver cancer were measured in Chinese hamsters. Chromosome aberrations increased linearly according to dose, with a slope of 4.8 x 10-1 aberrations/cell/Gy; liver-tumor incidence was 1.1 x 10-1 tumors/animal/Gy. The dose was calculated at the 50% survival time. The interaction between Pu and Ki-v-ras, an altered, dominant-acting oncogene, on the induction of liver cancer was measured in B6C3F1 mice. The neo oncogene was used as a negative control in these studies. The Ki-v-ras oncogene was inserted into a viral vector and incorporated into the livers of mice either 30 days before or after the incorporation of 239Pu. Compared with both the controls and the mice injected with a single insult, mortality increased in groups of animals that received combined exposure to oncogenes, CCl4, and 239Pu. The relationships between molecular and cellular damage and the induction of cancer is being defined in both mice and Chinese hamsters

  12. Microlocalization of 239Pu in structural elements of the interalveolar septa after inhalation of its various compounds and pentacin

    A quantitative and qualitative evaluation of 239 Pu mictodistribution in the structural elements of the interalveolar septa after inhalation of three plutonium compounds different in solubility is made. Thirty minutes after the inhalation 55.3-85.3% of plutonium (dioxide>nitrate>=citrate) was revealed in rhe cells, predominantly in the microphages. More than half of the isotope found in the noncellular elements, lies in the surface layer of the alveoli and the intercellular matter. First 239Pu is seen as ''stars'' of tracks (dioxide), mainly (nitrate) or exclusively (citrate) as individual tracks. The different extent of plutonium elimination from the interalveolar septa (dioxide239Pu from the cells is mainly determined by its escape from the macrophages (dioxide) or from all cellular elements (nitrate, citrate). Pentacin accelates elimination of plutonium from the most of the structural elements of the interalveolar septa (citrate>nitrate)

  13. 239Pu(n,2n) 238Pu cross section inferred from IDA calculations and GEANIE measurements

    Chen, H; Ormand, W E; Dietrich, F S

    2000-09-01

    This report presents the latest {sup 239}Pu(n,2n){sup 238}Pu cross sections inferred from calculations performed with the nuclear reaction-modeling code system, IDA, coupled with experimental measurements of partial {gamma}-ray cross sections for incident neutron energies ranging from 5.68 to 17.18 MeV. It is found that the inferred {sup 239}Pu(n,2n){sup 238}Pu cross section peaks at E{sub inc} {approx} 11.4 MeV with a peak value of approximately 326 mb. At E{sub inc} {approx} 14 MeV, the inferred {sup 239}Pu(n,2n){sup 238}Pu cross section is found to be in good agreement with previous radio-chemical measurements by Lockheed. However, the shape of the inferred {sup 239}Pu(n,2n){sup 238}Pu cross section differs significantly from previous evaluations of ENDL, ENDF/B-V and ENDF/B-VI. In our calculations, direct, preequilibrium, and compound reactions are included. Also considered in the modeling are fission and {gamma}-cascade processes in addition to particle emission. The main components of physics adopted and the parameters used in our calculations are discussed. Good agreement of the inferred {sup 239}Pu(n,2n){sup 238}Pu cross sections derived separately from IDA and GNASH calculations is shown. The two inferences provide an estimate of variations in the deduced {sup 239}Pu(n,2n){sup 238}Pu cross section originating from modeling.

  14. Investigation of forming mechanism of instantaneous neutron spectrum of 235U, 239Pu, 252Cf nuclei fission

    Formation mechanism of prompt neutrons spectrum during the fission of the 235U, 239Pu nuclei by thermal and fast neutrons and spontaneous fission of 252Cf is investigated. The formation procedure for prompt neutrons spectrum during the fission of nuclei as superposition of three partial evaporation Weisskopf spectra with the mean energy of neutrons 0.4, 2.06 and 2.8 MeV is proposed. Formation mechanism of the spectrum just as during the fission of the 235U, 239Pu nuclei by thermal and fast neutrons, so spontaneous fission of the 252Cf nuclei is identical

  15. Calculation of 239Pu fission observables in an event-by-event simulation

    Vogt, R; Randrup, J; Pruet, J; Younes, W

    2010-03-31

    The increased interest in more exclusive fission observables has demanded more detailed models. We describe a new computational model, FREYA, that aims to meet this need by producing large samples of complete fission events from which any observable of interest can then be extracted consistently, including any interesting correlations. The various model assumptions are described and the potential utility of the model is illustrated. As a concrete example, we use formal statistical methods, experimental data on neutron production in neutron-induced fission of {sup 239}Pu, along with FREYA, to develop quantitative insights into the relation between reaction observables and detailed microscopic aspects of fission. Current measurements of the mean number of prompt neutrons emitted in fission taken together with less accurate current measurements for the prompt post-fission neutron energy spectrum, up to the threshold for multi-chance fission, place remarkably fine constraints on microscopic theories.

  16. Pulmonary distribution of inhaled 239PuO2 in dogs

    The distribution of plutonium in the lungs was studied by analyzing autoradiographs from dogs killed up to 69 months after single, nose-only exposures to 239PuO2 aerosols. Within 5 months of exposure, the pattern of alpha-star distribution was relatively dispersed and uniform throughout the lung section, changing by 12 months to a less uniform distribution that exhibited focal concentration, subpleural concentration, and alpha-star aggregation. Increased subpleural concentrations were demonstrated infve of six dogs killed 12 or more months after exposure. The percentage of alpha stars found in localized regions of relatively high concentration and the portion found in aggregation (define here as two or more alpha stars with overlapping tracks) increased with tie postexposure. The data demonstrate that an initial relatively uniform dispersion of plutonium particles changed with time to a focally concentrated distribution with relatively small tissue volume containing most of the pulmonary plutonium burden

  17. The self-absorption effect of gamma rays in 239Pu

    Nuclear materials assay with gamma-ray spectrum measurement is a well-established method for safeguards. However, for a thick source, the self-absorption of characteristic low-energy gamma rays has been a handicap to accurate assay. The author has carried out Monte Carlo simulations to study this effect using the 239Pu α-decay gamma-ray spectrum as an example. The thickness of a plutonium metal source can be considered a function of gamma-ray intensity ratios. In a practical application, gamma-ray intensity ratios can be obtained from a measured spectrum. With the help of calculated curves, scientists can find the source thickness and make corrections to gamma-ray intensities, which then lead to an accurate quantitative determination of radioactive isotopes in the material

  18. Toxicity of inhaled 239PuO2 in immature beagle dogs

    Immature beagle dogs have been exposed by inhalation to a 1.5 μm aerodynamic diameter monodisperse aerosol of 239PuO2 to compare the biological effects with those seen in young adult and aged dogs exposed to a similar aerosol. To date, 18 dogs have been exposed to the aerosol, resulting in graded initial lung burdens ranging from 0.003 to 0.38 μCi/kg body weight. Two dogs have been exposed to the aerosol diluent and serve as controls. Two of the 18 exposed animals were sacrificed 8 days after exposure to provide information on initial deposition and distribution. All other exposed animals are alive 400 days after exposure. No dogs were exposed during the past year because of an outbreak of canine parvovirus enteritis which caused death in 8 to 10 week-old dogs

  19. Comparison of rats and dogs exposed to 239PuO2

    Rats and dogs inhaled aerosols of 239PuO2 at comparable ages relative to their lifespan. Both received a single exposure. The estimated lung doses at death in dogs were between 1100 and 11,000 rad. From two inhalation experiments, rats receiving doses in this range were chosen from the high-level exposed animals for comparison. Based on this data base, several comparisons were investigated. Metabolism of the material was compared for all animals and for animals which developed lung tumors. The differences in histopathology and tumor incidence in the lung were also reviewed. Although there were several differences between species, there were also many similarities. On-going research in dogs should produce data which will allow clarification of these relationships

  20. Quantitative scanning electron microscopic autoradiography of inhaled 239PuO2

    We have applied the scanning electron microscope (SEM) to obtain autoradiographs of particles of 239PuO2 deposited in rat lung. The technique was used to obtain quantitative information on the clearance rates of particles from the alveoli, bronchioles and trachea up to 240 d after exposure. At all times, the concentration of particles on the surface of the bronchioles was an order of magnitude greater than on the tracheal surface. The clearance of Pu from both regions followed a biphasic pattern, similar to that obtained by radiometric analysis of the whole lung. Most of the radiation dose to the bronchiolar epithelium originated from Pu particles in peribronchiolar alveoli in which they were preferentially retained, compared to other alveolar regions. The prolonged retention of particles in the peribronchiolar alveoli may be a significant factor in the induction of lung carcinomas

  1. Aerosols generated by 239PU and 233U droplets burning in air

    The inhalation hazards of radioactive aerosols produced by the explosive disruption and subsequent combustion of metallic plutonium in air are not adequately understood. Results of a study to determine whether uranium can be substituted for plutonium in such a situation in which experiments were performed under identical conditions with laser-ignited, single, freely falling droplets of 239Pu and 233U are reported. The total amounts of aerosol produced were studied quantitatively as a function of time during the combustion. Also, particle size distributions of selected aerosols were studied with aerodynamic particle separation techniques. Results showed that the ultimate quantity of aerosols, their final particle size distributions, and depositions as a function of time are not identical mainly because of the different vapor pressures of the metals, and the unlike degrees of violence of the explosions of the droplets

  2. The simultaneous determination of 235U and 239Pu using delayed neutron activation analysis

    Delayed neutron activation analysis (DNAA) remains one of the most sensitive methods of nondestructively determining fissile materials in a variety of sample matrices, provided that the samples contain only a single fissile component. This has historically been the limiting factor in many applications of DNAA, and often chemically destructive methods of analysis have needed to be utilized for many real-world samples. This work seeks to develop a method that will allow for DNAA to be utilized on samples containing multiple fissile components. Initial efforts, presented here, show that using a multivariate linear regression model to describe the delayed neutron emission profile of an irradiated sample allows for the concurrent determination of fissile nuclides in samples containing both 235U and 239Pu, without chemical separations and using only a single counting step. (author)

  3. A comparative study of the carcinogenetic effects of 241Am, 239Pu and 237Np

    In this experiment, 420 wistar rats were used to study the comparative carcinogenetic effects of 241Am, 239Pu and 237Np. These nuclides were injected to animals intravenously, subcutaneously or directly into the lung (Stansen's lung puncture method) in doses of 1.0, 5.0 and 8.5 μCi/kg, respectively. As soluble nitrate, the nuclides were rapidly transfered from the site of injection into the bone and the liver. Osteosarcomas were found in some animals 8 months to one year after intoxication. Diagnosis of osteosarcoma is based on the histopatological examination and X-ray photography. In the Am-poisoned rats the incidence of osteosarcoma is about 31-74%, varied with different doses and different routes of intoxication; in Pu-poisoned rats, the incidence of osteosarcoma is about 55-66%. while in Np-poisoned rats, it is about 36-53%. Primary lung cancers were also found in those animals poisoned by means of Stansen's lung puncture method with the above three nuclides. The incidence of primary lung cancers is about 6% in Am-and Pu-poisoned rats and 13% in Np-poisoned rats. The incidence of metastasis of osteosarcoma in lung is about 25-65% for Am-poisoned rats, 45-55% for Pu-poisoned rats and 41-80% for Np-poisoned rats. The life-span of above poisoned rats was significantly shorter than that of the normal control animals. The chemical weight for 241Am, 239Pu and 237Np in same unit of radioactivity (1.0 μCi) equals to 0.308 μg, 15.9 μg and 1418.7 μg, respectively. For this reason, we have to pay more attention to the chemical mass effect in carcinogenesis of the above three nuclides

  4. Dosimetry and response in rat pulmonary epithelium following inhalation of 239PuO2

    The distribution of inhaled 239PuO2 and pathologic changes have been studied in the lung of rats. The clearance of inhaled 237239PuO2 from the lung is a function of the amount of deposited Pu with a decrease in early alveolar clearance with increasing lung burden. With increasing time post-exposure there is a greater concentration of PuO2 and an increased aggregation of PuO2 particles in subpleural regions of the lung. Fibrotic and metaplastic lesions in the lung were usually focal, being found in subpleural regions associated with aggregates of PuO2. An average of 12 +- 6 percent of the lung volume was fibrotic at 530 days after an initial alveolar deposition of 180 nCi 239Pu. Lung tumors occupied 4 +- 6 percent and epithelial metaplasias less than 1 percent of the lung volume at this time. Cell proliferation as assayed by tritiated thymidine autoradiography was greater in fibrotic, metaplastic and neoplastic regions than in areas of normal alveolar-bronchiolar epithelium. Turnover times ranged from about 6 days for fibrotic lesions to 1 to 3 days for metaplastic and neoplastic lesions. The lung tumor doubling times were 57 to 116 days due to tumor cell necrosis and other factors that limit tumor cell survival. Cell proliferation rates for adenomatous metaplasia were similar to those for adenocarcinoma while those for squamous cell metaplasia were similar to those for squamous cell carcinoma. Squamous lesions exhibited a more rapid growth than did adenomatous lesions

  5. Comparison of metabolism and late effects in dogs and rats exposed to 239PuO2

    Lung tumors were observed proportionally earlier in relation to expected life span in dogs than in rats after inhalation of 239PuO2. Dogs appear to translocate a higher percentage of initial lung burden to liver, skeleton and thoracic lymph nodes than rats

  6. Initial deposition and early clearance of inhaled 239Pu(NO3)4 aerosols in beagle dogs

    Data from exposures of 113 beagle dogs to 239Pu(NO3)4 aerosols were analyzed for effects of aerosol properties on deposition and early clearance. The percent of inhaled aerosols deposited was not significantly dependent on particle size or aerosol concentration. The early clearance rate was significantly slower at the highest exposure levels than at medium and low levels

  7. Experimental determination of residual nuclei formation cross sections in 660 MeV proton reactions with 239Pu and natU

    Experimental cross sections for proton induced reactions of an energy of 660 MeV with various fission products, minor actinides, and 'major' actinides (plutonium, uranium, thorium) are studied. The paper describes 239Pu and natural U experiments; other experiments have already been published or are planned. Cross section determination consist of three parts: experiment, data processing, and mathematical codes simulation of the problem. This paper deals only with experiment description and data processing methodology. 4 irradiation experiments have been performed: 2 with natural uranium targets and 2 with plutonium targets. Each two experiments were identical, differences were only in irradiation time (and of course another sample was used). Uranium samples were in the thin foil form while plutonium was in dioxide form in a duralumin container. Shorter irradiation time experiments were used to observe isotopes with half-lives in the range of minutes and hours while the longer ones were used to observe long-lived isotopes. The irradiated samples were submitted to γ spectroscopy about 5 minutes after the end of irradiation. A total number of 105 uranium spectra and 156 plutonium spectra were acquired. Measured data were processed using standard γ spectrometry methods and standard software packages as well as home-made programs were used to determine cross-sections. Neither final results of processing, nor simulation of plutonium experiment are paper-ready at the moment. Uranium data have partially already been presented, final complete results are planned to be published with plutonium results together in reviewed journal

  8. Effect of alpha irradiation of the lungs from inhaled 239PuO2 on the immunity of mice to Listeria monocytogenes

    The pulmonary clearance of inhaled Listeria monocytogenes from the lungs of nonimmunized and immunized mice was observed 3 to 4 or 26 wks after prior exposure to 239PuO2 to achieve initial lung burdens of 2.6, 5.0 and 11.9 nanocuries (nCi). Mice from 239PuO2 and sham-exposed groups were immunized against L. monocytogenes and 1 wk later challenged via the respiratory route. Pulmonary clearance was suppressed in mice with an 11.9 nCi initial lung burden of 239Pu 26 wk after 239PuO2 inhalation but not in the mice with initial lung burdens of 2.6 and 5.0 nCi at 4 to 5 or 27 wk after 239PuO2 exposure. Mice with a mean initial lung burden of 11.9 nCi of 239Pu, which were immunized against L. monocytogenes 26 wk after 239PuO2 inhalation, had a decreased survival after respiratory challenge with L. monocytogenes when compared to immunized control animals. Body weight gain and hematological differences did not correlate with suppressed pulmonary clearance or decreased survival. Pulmonary lavage studies indicated that fewer alveolar macrophages were recoverable from mice with a mean initial lung burden of 11.9 nCi of 239Pu 26 wk after 239PuO2 inhalation. It was concluded that an initial lung burden of 11.9 nCi of 239Pu which delivered approximately 700 rads of alpha radiation to the lungs of mice resulted in decreased pulmonary clearance and decreased survival of mice which had been immunized against L. monocytogenes

  9. 239Pu Prompt Fission Neutron Spectra Impact on a Set of Criticality and Experimental Reactor Benchmarks

    Peneliau, Y.; Litaize, O.; Archier, P.; De Saint Jean, C.

    2014-04-01

    A large set of nuclear data are investigated to improve the calculation predictions of the new neutron transport simulation codes. With the next generation of nuclear power plants (GEN IV projects), one expects to reduce the calculated uncertainties which are mainly coming from nuclear data and are still very important, before taking into account integral information in the adjustment process. In France, future nuclear power plant concepts will probably use MOX fuel, either in Sodium Fast Reactors or in Gas Cooled Fast Reactors. Consequently, the knowledge of 239Pu cross sections and other nuclear data is crucial issue in order to reduce these sources of uncertainty. The Prompt Fission Neutron Spectra (PFNS) for 239Pu are part of these relevant data (an IAEA working group is even dedicated to PFNS) and the work presented here deals with this particular topic. The main international data files (i.e. JEFF-3.1.1, ENDF/B-VII.0, JENDL-4.0, BRC-2009) have been considered and compared with two different spectra, coming from the works of Maslov and Kornilov respectively. The spectra are first compared by calculating their mathematical moments in order to characterize them. Then, a reference calculation using the whole JEFF-3.1.1 evaluation file is performed and compared with another calculation performed with a new evaluation file, in which the data block containing the fission spectra (MF=5, MT=18) is replaced by the investigated spectra (one for each evaluation). A set of benchmarks is used to analyze the effects of PFNS, covering criticality cases and mock-up cases in various neutron flux spectra (thermal, intermediate, and fast flux spectra). Data coming from many ICSBEP experiments are used (PU-SOL-THERM, PU-MET-FAST, PU-MET-INTER and PU-MET-MIXED) and French mock-up experiments are also investigated (EOLE for thermal neutron flux spectrum and MASURCA for fast neutron flux spectrum). This study shows that many experiments and neutron parameters are very sensitive to

  10. Incidence of liver tumors in beagles with body burdens of 239Pu or 241Am

    Tetravalent 239Pu or trivalent 241Am in a citrate buffer, given via a single intravenous injection to beagles, induced very pronounced liver changes, usually at relatively long postinjection times. The lesions consisted of cell injury or cell necrosis which was followed by nodular hyperplasia and a significant incidence of primary liver tumors. The most frequent neoplasm was the bile duct adenoma, followed by the bile duct carcinoma. A lesser number of sarcomas were also induced, especially fibrosarcomas. The number of hepatic cell tumors was low. An abnormally high incidence of both hyperplastic nodules and primary liver tumors occurred at long postinjection times and at average doses extending down to ∼10 rads. The various nodular lesions and liver tumors frequently occurred as incidental findings in dogs dying from other causes, especially bone cancer. In comparison to bone neoplasia, the liver was a much less important target organ in the high-dose level groups, but in some of the low-dose groups, especially in the 241Am groups, the risk of radiation-induced liver cancer was approximately equal to or exceeded the risk of skeletal tumors. However, in any projection of the risks observed in this animal model to man, one should be mindful that the beagle skeleton is approximately 25 times more sensitive to radiation-induced bone neoplasia than is the human skeleton (Mays et al., 1976) and that the radiosensitivity difference for the beagle and human liver is unknown. 41 refs., 8 figs., 5 tabs

  11. Effects of the herbicide glyphosate on the uptake of 239Pu and 241Am to vegetation

    Glyphosate (n-phosphonomethyl glycine) is a broad spectrum herbicide widely used in lowland agriculture, forestry and improved upland pastures. Although its metal chelating properties are well established, its interaction with radionuclides remains unknown. A pot experiment was conducted to determine the effect of soil applications of glyphosate on the uptake of 239Pu and 241Am to peas and carrots grown in loam, peat and sand soils. Soil-to-plant transfer factors were calculated for treated and untreated soils at harvest. The most marked effect was an increase in 241Am uptake to crops grown in loam soil. Supplementary laboratory batch experiments were conducted by shaking radiolabelled soil and its associated soil solution with glyphosate. The activity concentration of 241Am increased ten fold in the liquid phase of loam soils treated with glyphosate. It is postulated that this 241Am desorption could have been mediated by the formation of a stable Am-glyphosate complex which was subsequently more available for crop uptake than Am alone. (author)

  12. Photofission product yields of 238U and 239Pu with 22-MeV bremsstrahlung

    Wen, Xianfei; Yang, Haori

    2016-06-01

    In homeland security and nuclear safeguards applications, non-destructive techniques to identify and quantify special nuclear materials are in great demand. Although nuclear materials naturally emit characteristic radiation (e.g. neutrons, γ-rays), their intensity and energy are normally low. Furthermore, such radiation could be intentionally shielded with ease or buried in high-level background. Active interrogation techniques based on photofission have been identified as effective assay approaches to address this issue. In designing such assay systems, nuclear data, like photofission product yields, plays a crucial role. Although fission yields for neutron-induced reactions have been well studied and readily available in various nuclear databases, data on photofission product yields is rather scarce. This poses a great challenge to the application of photofission techniques. In this work, short-lived high-energy delayed γ-rays from photofission of 238U were measured in between linac pulses. In addition, a list-mode system was developed to measure relatively long-lived delayed γ-rays from photofission of 238U and 239Pu after the irradiation. Time and energy information of each γ-ray event were simultaneously recorded by this system. Cumulative photofission product yields were then determined using the measured delayed γ-ray spectra.

  13. Evaluation of the thermal cross sections of 239Pu and 241Pu

    The thermal neutron cross sections of the isotopes 239Pu and 241Pu have been evaluated in the thermal neutron energy region below 1.0 eV. The method of evaluation fitted energy-dependent data constrained by a modified Adler-Adler multilevel resonance fission and capture formalism and multilevel Breit-Wigner scattering theory. The energy dependence of the number of neutrons per fission was prescribed in the theory by introducing nu as fitted resonance spin-dependent values. The data were fitted in a resonance parameter fitting code, RPFC, using the method of maximum likelihood. The code fits simultaneously the total and partial energy-dependent cross section data to the theory. The types of data explicitly fitted are total, fission, capture, total scattering, coherent scattering, and absorption cross sections plus the quantities alpha, total nu and eta. Relative energy-dependent data with precision errors are fitted along with absolute values and errors at chosen energies. RPFC also allows energy-scale adjustment and Doppler broadening of selected data sets, and fits correlated data of two isotopes simultaneously. Reference experimental data bases of original data plus condensed and modified data were assembled for the evaluation for each isotope. 19 figures, 9 tables

  14. Evaluation of chelation concentration and cation separation of actinides at ultra-trace levels in urine matrix

    The feasibility of measuring picogram levels of actinides in a urine matrix using ion chromatography coupled on-line to an inductively coupled plasma quadrupole mass spectrometer (IC-Q-ICPMS) was investigated. A chelation column for separation of matrix ions and preconcentration of the actinides was combined with a cation-exchange column for separation of the actinides. Sample preparation required simple addition of ammonium acetate to adjust the pH of the urine matrix. Spike solutions containing 232Th, 237Np, 238U, 239Pu, and 241Am were added to undiluted urine, diluted urine (1 : 9) and water. This approach enhanced the signal sensitivities of all the tested actinides over two orders of magnitude in the water matrix, while certain elements (especially Am) can still be effectively concentrated in undiluted urine. (author)

  15. Pulmonary retention and tissue distribution of 239Pu nitrate in F344 rats and syrian hamsters inhaling carbon tetrachloride

    Carbon tetrachloride (CCl4) has been used extensively in the nuclear weapons industry, so it is possible that nuclear plant workers have been exposed to CCl4 and plutonium compounds. Potential for future exposure exists during open-quotes cleanupclose quotes operations at weapon production sites such as the Hanford, Washington, and Rocky Flats, Colorado, facilities. The current Threshold Limit Value for CCl4 is 5 ppm; however, concentrations of CCl4 occurring in the nuclear weapons facilities over the past 40-50 y are unknown and may have exceeded this value. The pilot study described in this report is designed to determine whether subchronic inhalation of CCl4 by CDFregister(F-344)/CrlBR rats and Syrian golden hamsters, at concentrations expected to produce some histologic changes in liver, alters the hepatic retention and toxic effects of inhaled 239Pu nitrate 239Pu(NO3)4

  16. Probing energy dissipation, γ-ray and neutron multiplicity in the thermal neutron-induced fission of 239Pu

    Pahlavani, M. R.; Mirfathi, S. M.

    2016-04-01

    The incorporation of the four-dimensional Langevin equations led to an integrative description of fission cross-section, fragment mass distribution and the multiplicity and energy distribution of prompt neutrons and γ-rays in the thermal neutron-induced fission of 239Pu. The dynamical approach presented in this paper thoroughly reproduces several experimental observables of the fission process at low excitation energy.

  17. Study of neutron-deficient isotopes of Fl in the 239Pu, 240Pu + 48Ca reactions

    Voinov, A. A.; Utyonkov, V. K.; Brewer, N. T.; Oganessian, Yu Ts; Rykaczewski, K. P.; Abdullin, F. Sh; Dmitriev, S. N.; Grzywacz, R. K.; Itkis, M. G.; Miernik, K.; Polyakov, A. N.; Roberto, J. B.; Sagaidak, R. N.; Shirokovsky, I. V.; Shumeiko, M. V.; Tsyganov, Yu S.; Subbotin, V. G.; Sukhov, A. M.; Sabelnikov, A. V.; Vostokin, G. K.; Hamilton, J. H.; Stoyer, M. A.; Strauss, S. Y.

    2016-07-01

    The results of the experiments aimed at the synthesis of Fl isotopes in the 239Pu + 48Ca and 240Pu + 48Ca reactions are presented. The experiment was performed using the Dubna gas-filled recoil separator at the U400 cyclotron. In the 239Pu+48Ca experiment one decay of spontaneously fissioning 284Fl was detected at 245-MeV beam energy. In the 240Pu+48Ca experiment three decay chains of 285Fl were detected at 245 MeV and four decays were assigned to 284Fl at the higher 48Ca beam energy of 250 MeV. The α-decay energy of 285Fl was measured for the first time and decay properties of its descendants 281Cn, 277Ds, 273Hs, 269Sg, and 265Rf were determined more precisely. The cross section of the 239Pu(48Ca,3n)284Fl reaction was observed to be about 20 times lower than those predicted by theoretical models and 50 times less than the value measured in the 244Pu+48Ca reaction. The cross sections of the 240Pu(48Ca,4-3n)284,285Fl at both 48Ca energies are similar and exceed that observed in the reaction with lighter isotope 239Pu by a factor of 10. The decay properties of the synthesized nuclei and their production cross sections indicate rapid decrease of stability of superheavy nuclei with departing from the neutron number N=184 predicted to be the next magic number.

  18. Comparison of evaluations for 235U, 239Pu, 240Pu, 241Pu and 242Pu with integral measurements

    The evaluations for 235U, 239Pu, 240Pu, 241Pu and 242Pu are considered. Intercomparison is made of the neutron cross section data from INDL/A, ENDL-84, ENDF/B-5 and ENDF/B-6 (where applicable). Integral measurements of the spectrum averaged cross sections are compared to the values derived from evaluated data libraries. (author). 40 refs, 49 figs, 11 tabs

  19. Estimation of uncertainties in resonance parameters of {sup 56}Fe, {sup 239}Pu, {sup 240}Pu and {sup 238}U

    Nakagawa, Tsuneo; Shibata, Keiichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-05-01

    Uncertainties have been estimated for the resonance parameters of {sup 56}Fe, {sup 239}Pu, {sup 240}Pu and {sup 238}U contained in JENDL-3.2. Errors of the parameters were determined from the measurements which the evaluation was based on. The estimated errors have been compiled in the MF32 of the ENDF format. The numerical results are given in tables. (author)

  20. Extrapolation to man of the relation between activity and damage to organism of laboratory animals internally contaminated with 239Pu

    The relations were analyzed between the initial amount of the radionuclide deposited and mortality. The mortality curves were analyzed using the Gompaertz relation and the exponential relation was found between the rate of the mortality changes and 239Pu activity. Using comparative analysis the results of the model were approximated to man and compared with data published in the literature on human contamination. The comparison did not exclude the validity of the applied model. (author)

  1. Determination of 240Pu/239Pu isotope ratios in Kara Sea and Novaya Zemlya sediments using accelerator mass spectrometry

    Accelerator mass spectrometry (AMS) has been used to determine Pu activity concentrations and 240Pu/239Pu isotope ratios in sediments from the Kara Sea and radioactive waste dumping sites at Novaya Zemlya. Measured 239,240Pu activities ranged from 0.06 - 9.8 Bq/kg dry weight, 240Pu/239Pu atom ratios ranged from 0.13 to 0.28, and 238Pu/239,240Pu activity ratios from 0.02 to 0.6. Perturbations from global fallout isotope ratios were evident at three sites: the Yenisey Estuary and Abrosimov Fjords where 240Pu/239Pu ratios were lower (0.13-0.14); and Stepovogo Fjord sediments where ratios were higher (up to 0.28) than fallout ratios. Based on procedural blanks, detection limits for AMS were below 1 fg Pu and the method showed good precision for isotope ratio measurements, minimal matrix, interference and memory effects. For high level samples, comparison between alpha spectrometry and AMS gave good agreement for measurement of 239,240Pu activity concentrations. (author)

  2. Fission Product Yields for 14 MeV Neutrons on 235U, 238U and 239Pu

    Mac Innes, M.; Chadwick, M. B.; Kawano, T.

    2011-12-01

    We report cumulative fission product yields (FPY) measured at Los Alamos for 14 MeV neutrons on 235U, 238U and 239Pu. The results are from historical measurements made in the 1950s-1970s, not previously available in the peer reviewed literature, although an early version of the data was reported in the Ford and Norris review. The results are compared with other measurements and with the ENDF/B-VI England and Rider evaluation. Compared to the Laurec (CEA) data and to ENDF/B-VI evaluation, good agreement is seen for 235U and 238U, but our FPYs are generally higher for 239Pu. The reason for the higher plutonium FPYs compared to earlier Los Alamos assessments reported by Ford and Norris is that we update the measured values to use modern nuclear data, and in particular the 14 MeV 239Pu fission cross section is now known to be 15-20% lower than the value assumed in the 1950s, and therefore our assessed number of fissions in the plutonium sample is correspondingly lower. Our results are in excellent agreement with absolute FPY measurements by Nethaway (1971), although Nethaway later renormalized his data down by 9% having hypothesized that he had a normalization error. The new ENDF/B-VII.1 14 MeV FPY evaluation is in good agreement with our data.

  3. Fission Product Yields for 14 MeV Neutrons on 235U, 238U and 239Pu

    We report cumulative fission product yields (FPY) measured at Los Alamos for 14 MeV neutrons on 235U, 238U and 239Pu. The results are from historical measurements made in the 1950s–1970s, not previously available in the peer reviewed literature, although an early version of the data was reported in the Ford and Norris review. The results are compared with other measurements and with the ENDF/B-VI England and Rider evaluation. Compared to the Laurec (CEA) data and to ENDF/B-VI evaluation, good agreement is seen for 235U and 238U, but our FPYs are generally higher for 239Pu. The reason for the higher plutonium FPYs compared to earlier Los Alamos assessments reported by Ford and Norris is that we update the measured values to use modern nuclear data, and in particular the 14 MeV 239Pu fission cross section is now known to be 15–20% lower than the value assumed in the 1950s, and therefore our assessed number of fissions in the plutonium sample is correspondingly lower. Our results are in excellent agreement with absolute FPY measurements by Nethaway (1971), although Nethaway later renormalized his data down by 9% having hypothesized that he had a normalization error. The new ENDF/B-VII.1 14 MeV FPY evaluation is in good agreement with our data.

  4. First measurements of 236U concentrations and 236U/239Pu isotopic ratios in a Southern Hemisphere soil far from nuclear test or reactor sites

    The variation of the 236U and 239Pu concentrations as a function of depth has been studied in a soil profile at a site in the Southern Hemisphere well removed from nuclear weapon test sites. Total inventories of 236U and 239Pu as well as the 236U/239Pu isotopic ratio were derived. For this investigation a soil core from an undisturbed forest area in the Herbert River catchment (17°30′ – 19°S) which is located in north-eastern Queensland (Australia) was chosen. The chemical separation of U and Pu was carried out with a double column which has the advantage of the extraction of both elements from a relatively large soil sample (∼20 g) within a day. The samples were measured by Accelerator Mass Spectrometry using the 14UD pelletron accelerator at the Australian National University. The highest atom concentrations of both 236U and 239Pu were found at a depth of 2–3 cm. The 236U/239Pu isotopic ratio in fallout at this site, as deduced from the ratio of the 236U and 239Pu inventories, is 0.085 ± 0.003 which is clearly lower than the Northern Hemisphere value of ∼0.2. The 236U inventory of (8.4 ± 0.3) × 1011 at/m2 was more than an order of magnitude lower than values reported for the Northern Hemisphere. The 239Pu activity concentrations are in excellent agreement with a previous study and the 239+240Pu inventory was (13.85 ± 0.29) Bq/m2. The weighted mean 240Pu/239Pu isotopic ratio of 0.142 ± 0.005 is slightly lower than the value for global fallout, but our results are consistent with the average ratio of 0.173 ± 0.027 for the southern equatorial region (0–30°S). - Highlights: • Exploration of uranium-236 (236U) and plutonium-239 (239Pu) in the Southern Hemisphere by accelerator mass spectrometry. • We report the depth profile for both isotopes from a forest site well removed from nuclear test or reactor sites. • 236U and 239Pu were deposited at the same time due to nuclear weapons tests but show a slightly different depth dependence. • The

  5. Simultaneous evaluation for (n,f) cross section of 235U, 239Pu, 238U and (n,γ) cross sections of 238U

    The fission cross sections for 235U, 238U, 239Pu, the capture cross sections for 238U and the ratios for 239Pu(n,f)/235U(n,f), 238U(m,f)/235U(n,f), 238U(n,γ)/235U(n,f) were firstly evaluated respectively. The experimental data were collected, analysed, selected and corrected. The data were fitted with spline fit program

  6. The absolute total delayed neutron yields, relative abundances and half-lives of delayed neutron groups in 6- and 8-group model format from neutron induced fission of 232Th, 233U, 236U, 239Pu, and 241Am in the energy range from 0.35 MeV (or threshold energy) to 5 MeV

    The latest evaluation of delayed neutron constants was made for main fuel nuclides (235U, 238U, 239Pu) within an working group under the auspices of the Nuclear Energy Agency’s (NEA) Working Party on International Evaluation Cooperation (WPEC), Subgroup 6 (SG6) in 1999 [1]. As a result of this work the total delayed yields for the above nuclides were essentially corrected as compared with Tuttle’s recommended data set [2]. For the total delayed yields from 238U correction is +5.6%, for thermal induced fission of 239Pu - +3.4% and for fast neutron induced fission of 239Pu - +3.2%. This is a direct indication that there is a need for a continuing effort on delayed neutron data improving. From now, this will be mainly directed at satisfying new requirements emerging from the current trends in reactor technology, such as: the use of high burn-up fuel, the burning of plutonium stocks, the general growing interest in fuel recycling strategies, and new concept of actinide burners

  7. Reactor Decay Heat in 239Pu: Solving the γ Discrepancy in the 4-3000-s Cooling Period

    The β feeding probability of 102,104,105,106,107Tc, 105Mo, and 101Nb nuclei, which are important contributors to the decay heat in nuclear reactors, has been measured using the total absorption technique. We have coupled for the first time a total absorption spectrometer to a Penning trap in order to obtain sources of very high isobaric purity. Our results solve a significant part of a long-standing discrepancy in the γ component of the decay heat for 239Pu in the 4-3000 s range.

  8. Study of delayed neutron decay curves from thermal neutron induced fission of 235U and 239Pu

    The results of measurements of decay curves for delayed neutrons, obtained in the thermal neutron induced fission of 235U and 239Pu, are presented. The data were obtained by the periodical irradiation method on the IBR-2 pulsed reactor in the time interval from 5 to 730 msec after the end of irradiation. The comparison of the measured curves with the curves calculated with using several known from literature parameter sets (relative weights and half-lives of 6 or 8 exponents) was carried out. The new 7-group parameter set, which describes experimental data better, is proposed. (author)

  9. Reactor decay heat in 239Pu: solving the γ discrepancy in the 4-3000-s cooling period.

    Algora, A; Jordan, D; Taín, J L; Rubio, B; Agramunt, J; Perez-Cerdan, A B; Molina, F; Caballero, L; Nácher, E; Krasznahorkay, A; Hunyadi, M D; Gulyás, J; Vitéz, A; Csatlós, M; Csige, L; Aysto, J; Penttilä, H; Moore, I D; Eronen, T; Jokinen, A; Nieminen, A; Hakala, J; Karvonen, P; Kankainen, A; Saastamoinen, A; Rissanen, J; Kessler, T; Weber, C; Ronkainen, J; Rahaman, S; Elomaa, V; Rinta-Antila, S; Hager, U; Sonoda, T; Burkard, K; Hüller, W; Batist, L; Gelletly, W; Nichols, A L; Yoshida, T; Sonzogni, A A; Peräjärvi, K

    2010-11-12

    The β feeding probability of (102,104,105,106,107)Tc, 105Mo, and 101Nb nuclei, which are important contributors to the decay heat in nuclear reactors, has been measured using the total absorption technique. We have coupled for the first time a total absorption spectrometer to a Penning trap in order to obtain sources of very high isobaric purity. Our results solve a significant part of a long-standing discrepancy in the γ component of the decay heat for 239Pu in the 4-3000 s range. PMID:21231223

  10. Energy dependence of mass, charge, isotopic, and energy distributions in neutron-induced fission of 235U and 239Pu

    Pasca, H.; Andreev, A. V.; Adamian, G. G.; Antonenko, N. V.; Kim, Y.

    2016-05-01

    The mass, charge, isotopic, and kinetic-energy distributions of fission fragments are studied within an improved scission-point statistical model in the reactions 235U+n and 239Pu+n at different energies of the incident neutron. The charge and mass distributions of the electromagnetic- and neutron-induced fission of 214,218Ra, 230,232,238U are also shown. The available experimental data are well reproduced and the energy-dependencies of the observable characteristics of fission are predicted for future experiments.

  11. Retention, distribution, and excretion of 239PuO2 particles labeled with 169Yb in the Rhesus monkey after a single acute inhalation exposure

    Sixteen Rhesus monkeys were exposed to a high fired 239PuO2 aerosol labeled with 169Yb, and retention, distribution, and excretion patterns were determined. After an early rapid clearance phase, which had a half-life of less than one day, the remaining plutonium was retained in the lungs with a half-life that appeared to be greater than 500 days. By 30 days after exposure, 99 percent of the 239Pu in the body was in the lungs. At this time, 6 to 10 percent of the 169Yb burden was in the carcass and skeleton suggesting that there was dissociation of some 169Yb from the particles. The remaining 169Yb activity was in the lungs. There was little 239Pu in the liver, bone, or lymph nodes. The particulate material was cleared rapidly from the gastrointestinal and upper respiratory tracts and appeared in feces over the first four days. The level of 239Pu in feces returned to background by six days. Urinary excretion of 239Pu reached a peak by 8 to 10 days and then remained at a constant rate throughout the remainder of the experiment. These data are useful in calculating radiation dose to a variety of organs and relating this dose to the appearance of late effects from inhaled alpha-emitting particles. (U.S.)

  12. Synthesis and study of 239Pu-doped ceramics based on zircon, (Zr,Pu)Sio4, and hafnon, (Hf,Pu)SiO4

    Zircon, ZrSiO4, as well as its Hf-analogue hafnon, HfSiO4, have been proposed for use as durable Pu host phases for the immobilization of weapons grade Pu and other actinides. Four samples of Pu-doped ceramics based on the zircon and hafnon structures were synthesized through sintering in air using precursors containing 5-6 and 10 wt% 239Pu. Synthesized ceramic samples were studied by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), microprobe method, MCC-1 leach test at 25 and 90 deg C. Inclusions of separated a PuO2 phase in the matrix of zircon-based ceramic and presumably, (Pu,Hf)O2 phase in the hafnon-based ceramic were observed for samples obtained from precursors doped with 10 wt% Pu. No separated Pu-phases in significant amounts were identified in the matrices of both ceramics obtained from the precursors doped with 5-6 wt% Pu. It was found that normalized Pu mass losses (without correction on ceramic porosity) for samples doped with 10 wt% Pu which contain separated inclusions of PuO2 or (Pu1Hf)O2 after 14/28 days were approximately (in g/m2) - for zircon: 0.2/0.2 - at 90 deg C and 0.03/0.04 - at 25 deg C and for hafnon: 0.02/0.04 - at 90 deg C and 0.01/0.01 - at 25 deg C. The losses of Pu from samples doped with 5-6 wt% are 1-2 order of magnitude less. It was suggested that optimal amount of Pu which could be incorporated by zircon and hafnon lattices does not exceed 7 wt%. An important additional conclusion is that Pu-doped ceramic based on zircon or hafnon can be successfully fabricated excluding hot pressing method. Copyright (2001) Material Research Society

  13. Determination of long-lived actinides in soil leachates by inductively coupled plasma: Mass spectrometry

    Inductively coupled plasma -- mass spectrometry (ICP-MS) was used to concurrently determine multiple long-lived (t1/2 > 104 y) actinide isotopes in soil samples. Ultrasonic nebulization was found to maximize instrument sensitivity. Instrument detection limits for actinides in solution ranged from 50 mBq L-1 (239Pu) to 2 μBq L-1 (235U) Hydride adducts of 232Th and 238U interfered with the determinations of 233U and 239 Pu; thus, extraction chromatography was, used to eliminate the sample matrix, concentrate the analytes, and separate uranium from the other actinides. Alpha spectrometric determinations of 230Th, 239Pu, and the 234U/238U activity ratio in soil leachates compared well with ICP-MS determinations; however, there were some small systematic differences (ca. 10%) between ICP-MS and a-spectrometric determinations of 234U and 238U activities

  14. Mass Yields and Average Total Kinetic Energy Release in Fission for 235U, 238U, and 239Pu

    Duke, Dana

    2015-10-01

    Mass yield distributions and average total kinetic energy (TKE) in neutron induced fission of 235U, 238U, and 239Pu targets were measured with a gridded ionization chamber. Despite decades of fission research, our understanding of how fragment mass yields and TKE depend on incident neutron energy is limited, especially at higher energies (above 5-10 MeV). Improved accuracy in these quantities is important for nuclear technology as it enhances our simulation capabilities and increases the confidence in diagnostic tools. The data can also guide and validate theoretical fission models where the correlation between the fragment mass and TKE is of particular value for constraining models. The Los Alamos Neutron Science Center - Weapons Neutron Research (LANSCE - WNR) provides a neutron beam with energies from thermal to hundreds of MeV, well-suited for filling in the gaps in existing data and exploring fission behavior in the fast neutron region. The results of the studies on target nuclei 235U, 238U, and 239Pu will be presented with a focus on exploring data trends as a function of neutron energy from thermal through 30 MeV. Results indicate clear evidence of structure due to multi-chance fission in the TKE . LA-UR-15-24761.

  15. Investigation of resonance structure and Doppler-effect of cross sections for 232 Th, 235 U and 239 Pu

    The results of measuring the neutron transmissions for 232 Th, 235 U and 239 Pu metal samples carried out at the 60 m, 123 m and 1006 m flight paths of the Dubna IBR-30 booster in the neutron energy range of 2 eV - 200 keV are given and discussed. The measurements were made at the room and liquid nitrogen temperatures. The batteries of 3 boron and 26 helium counters were used as detectors. The results of the calculations of analogous transmissions realized on the base of the evaluated data libraries BROND-2, ENDF/B-6 and JENDL-3 by means of the GRUCON computer program package are also given. It is concluded that the 235 U Doppler coefficients and effective total cross sections taken from measured transmissions are in a good agreement with calculation results based on the ENDF/B-6 library at energies of 2.15 eV - 200 keV. The BROND-2 and JENDL-3 parameters give the Doppler coefficients and effective cross sections which are 10-30% higher than the experimental and ENDF/B-6 ones at the resonance energies of 46.5 - 465 eV. For 239 Pu there is agreement of the experimental and calculational results within the experimental error limits. For 232 Th experimental values for the Doppler coefficients and effective cross sections are 10-15% higher than the calculated ones with all libraries in resonance energy region. 9 refs., 2 tabs., 1 fig

  16. Toxicity of inhaled 239PuO2 in immature, young adult and aged Syrian hamsters. V

    Human populations that might be exposed in the event of a catastrophic nuclear accident would include individuals with widely differing ages. To obtain better information on the possible effects of age on observed dose-response relationships for inhaled 239PuO2, groups of Syrian hamsters were exposed via inhalation at either 28 (immature), 84 (young adults) or 340 (aged) days of age to polydisperse aerosols of 239PuO2. The projected graded levels of initial lung burden were 240, 60, 15, 3.8, 0.95, 0.25 and 0.029 nCi for the immature and young adult animals and 240, 60, 15 and 3.8 nCi for the aged animals. Additional animals were included in the 60 nCi initial lung burden level for serial sacrifice to determine the radiation dose pattern. All other animals were maintained for life span observation. For all age groups, less than 1% of the sacrifice body burden was found in all tissues other than lung. Mortality data analysis indicated significant life shortening only in animals that received the highest level inital lung burden. These early deaths were related to radiation pneumonitis and pulmonary fibrosis. No pulmonary neoplasms were observed

  17. The induction of nuclear abnormalities in the alveolar macrophages of mouse lung after inhalation of 239PuO2

    Effects of inhaled 239PuO2 on the free-cell population of the lungs of CBA/H mice have been studied using broncho-alveolar lavage following initial alveolar depositions (IADs) of 209 to 2800 Bq. The numbers of pulmonary alveolar macrophages (PAM) were quantified using a radioactive tracer technique. The number of PAM declined soon after exposure; the extent of the depression and the time taken to reach the nadir were both dose-dependent. Numbers eventually returned to normal but, with high IADs, only after 3 months. The number of binucleate PAM and those with micronuclei increased following relatively low IADs in a dose-dependent manner. Micronucleate PAM were the most sensitive indicator of cellular damage as a result of 239PuO2 inhalation, providing a short-term assessment of radiation damage to lung cells at doses known to produce lung tumors. The results also provide further evidence that mitosis in PAM, or in their precursor cells, does occur within the lung. (author)

  18. Measurement of 239Pu in urine samples at ultra-trace levels using a 1 MV compact AMS system

    Routine bioassay monitoring of Pu intake in exposed workers of research and nuclear industry is usually performed by alpha spectrometry. This technique involves large sample volumes of urine and time-consuming preparative and counting protocols. Compact accelerator mass spectrometry (AMS) facilities make feasible the determination of ultra low-level Pu activity concentrations and Pu isotopic ratios in biological samples (blood, urine and feces), being a rapid and cost-effective measurement technique. The plutonium results in urine samples presented here have been obtained on the 1 MV compact AMS system sited at the Centro Nacional de Aceleradores (CNA), in Seville, Spain. In this work, a different methodological approach has been developed alternative to the 'classical' preparation of urine samples for alpha spectrometry. The procedure avoids the Pu precipitation step, and involves acid sample evaporation and acid digestion in a microwave oven. Finally, purification of plutonium was achieved by using chromatography columns filled up with BioRad AG1X2 anion exchange resin (Bio-Rad Laboratories Inc.). The total time needed for analysis is about 10 h, unlike the 'classical' methods based on alpha spectrometry which need about 1 week. At present, it has been demonstrated that this method allows quantifying 239Pu activity concentrations in urine of, at least, 30 μBq (13 fg 239Pu). We can conclude that the procedure would be suitable to perform in vitro routine bioassay measurements. Moreover, the innovative application of AMS opens new and interesting analytical alternatives in this field.

  19. Nuclear data evaluation for 239Pu in the energy region 100 075. ev - 15 MeV

    The present work incorporates the results of the new nuclear data evaluation for 239Pu. The complete file compiled by the authors in 1974 was practically completely re-examined. The most substantial changes were made above 0.5 keV. In the region of unresolved resonances (0.3-100 keV), the channel contribution to the process widths for a given state and some other aspects were taken into account. The fission cross section and the α-value were evaluated with regard for the correlation of experimental errors. The non-spherical potential with optimized parameters was used to make calculations by the optical and statistical models. The contribution of pre-equilibrium emission was taken into account in calculations of secondary neutron spectra. The new standard anti nusub(sp)(252Csub(f)) was used to calculate anti nusub(p). The 26-group constants and g-Westcott factors were obtained from the evaluated data. The complete file of the evaluated data for 239Pu is presented in the ENDF/B format and conveyed to the Nuclear Data Section of the IAEA. (author)

  20. Inhaled 239PuO2 and/or total-body gamma radiation: Early mortality and morbidity in rats and dogs

    Rats and beagle dogs were given doses of 60Co gamma radiation and/or body burdens of 239PuO2 within lethal ranges in an experiment to determine and compare morbidity and mortality responses of both species within 1 year after exposure. Radiation-induced morbidity was assessed by measuring changes in body weights, hematologic parameters, and pulmonary-function parameters. Gamma radiation caused transient morbidity, reflected by immediately depressed blood cell concentrations and by long-term loss of body weight and diminished pulmonary function in animals of both species that survived the acute gamma radiation syndrome. Inhaled plutonium caused a loss of body weight and diminished pulmonary function in both species, but its only effect on blood cell concentrations was lymphocytopenia in dogs. Combined gamma irradiation and plutonium lung burdens were synergistic, in that animals receiving both radiation insults had higher morbidity and mortality rates than would be predicted based on the effect of either kind of radiation alone. Plutonium lung burdens enhanced the effect of gamma radiation in rats within the first 30 days of exposure, and gamma radiation enhanced the long-term effect of plutonium lung burdens in both species. Rats were less sensitive to both kinds of radiation, whether administered alone or in combination. 71 refs., 105 figs., 48 tabs

  1. Inhaled /sup 239/PuO/sub 2/ and/or total-body gamma radiation: Early mortality and morbidity in rats and dogs

    Filipy, R.E.; Decker, J.R.; Lai, Y.L.; Lauhala, K.E.; Buschbom, R.L.; Hiastala, M.P.; McGee, D.R.; Park, J.F.; Kuffel, E.G.; Ragan, H.A.; Cannon, W.C.; Yaniv, S.S.; Scott, B.R.

    1988-08-01

    Rats and beagle dogs were given doses of /sup 60/Co gamma radiation and/or body burdens of /sup 239/PuO/sub 2/ within lethal ranges in an experiment to determine and compare morbidity and mortality responses of both species within 1 year after exposure. Radiation-induced morbidity was assessed by measuring changes in body weights, hematologic parameters, and pulmonary-function parameters. Gamma radiation caused transient morbidity, reflected by immediately depressed blood cell concentrations and by long-term loss of body weight and diminished pulmonary function in animals of both species that survived the acute gamma radiation syndrome. Inhaled plutonium caused a loss of body weight and diminished pulmonary function in both species, but its only effect on blood cell concentrations was lymphocytopenia in dogs. Combined gamma irradiation and plutonium lung burdens were synergistic, in that animals receiving both radiation insults had higher morbidity and mortality rates than would be predicted based on the effect of either kind of radiation alone. Plutonium lung burdens enhanced the effect of gamma radiation in rats within the first 30 days of exposure, and gamma radiation enhanced the long-term effect of plutonium lung burdens in both species. Rats were less sensitive to both kinds of radiation, whether administered alone or in combination. 71 refs., 105 figs., 48 tabs.

  2. Plutonium concentration and 240Pu/239Pu atom ratio in biota collected from Amchitka Island, Alaska: recent measurements using ICP-SFMS

    Three underground nuclear tests, including the Unites States' largest, were conducted on Amchitka Island, Alaska. Monitoring of the radiological environment around the island is challenging because of its remote location. In 2008, the Department of Energy (DOE) Office of Legacy Management (LM) became responsible for the long term maintenance and surveillance of the Amchitka site. The first DOE LM environmental survey occurred in 2011 and is part of a cycle of activities that will occur every 5 years. The University of Alaska Fairbanks, a participant in the 2011 study, provided the lichen (Cladonia spp.), freshwater moss (Fontinalis neomexicanus), kelp (Eualaria fistulosa) and horse mussel (Modiolus modiolus) samples from Amchitka Island and Adak Island (a control site). These samples were analyzed for 239Pu and 240Pu concentration and 240Pu/239Pu atom ratio using inductively coupled plasma sector field mass spectrometry (ICP-SFMS). Plutonium concentrations and 240Pu/239Pu atom ratios were generally consistent with previous terrestrial and marine studies in the region. The 239+240Pu levels (mBq kg−1, dry weight) ranged from 3.79 to 57.1 for lichen, 167–700 for kelp, 27.9–148 for horse mussel, and 560–573 for moss. Lichen from Adak Island had higher Pu concentrations than Amchitka Island, the difference was likely the result of the higher precipitation at Adak compared to Amchitka. The 240Pu/239Pu atom ratios were significantly higher in marine samples compared to terrestrial and freshwater samples (t-test, p 240Pu/239Pu ratios in terrestrial samples are within the range of global fallout. • Elevated 240Pu/239Pu in marine samples was characteristic of North Pacific Ocean. • Potential sources of enriched Pu to the marine environment regionally are suggested. • Pu ratios cannot by themselves explain the enriched Pu in seawater around Amchitka

  3. Statistical Tests for the Detection of Intermediate Structures in the Fission Cross-Sections of 235U and 239Pu

    The existence of intermediate structures in the neutron-induced fission cross sections of 235U and 239Pu was pointed out in 1957 by Egelstaff. An interpretation, recently proposed by Cao et al. and Blons et al., was based on the Strutinsky calculations of the deformation energies of the compound nucleus when shell effects are included in the liquid-drop model. The theoretical interpretation in terms of current reaction theories has been given by Weigmann and Lynn. The purpose of this paper is to develop and evaluate various statistical tests intended for the detection and interpretation of these narrow intermediate fission structures. A fission cross-section was computed in the interval 0-5 keV using randomly generated parameters with distributions chosen to mock up the 235U nucleus. The Jπ = 4- state fission width was ''modulated'' in the manner suggested by Weigmann's work. Auto-correlation and cumulative average tests were done on these mock-up cross-sections to determine if the correct average spacing of the shape isomer levels could be obtained by such tests. It is shown that the usual correlation tests tend to overestimate the spacing between structures. A proposed technique is based on the direct analysis of the averaged cross-section which affords a method of correcting for peaks of the intermediate structure below the detectability limit of the usual statistical tests. The techniques developed on the basis of the mock-up cross-sections were used to analyse the fission cross-sections of 235U and 239Pu. Average spacings of 227 and 312 eV were found for those two nuclei, respectively. These values are somewhat lower than the ones reported by Cao and Blons, which were based only on the auto-correlation analysis. The energy of the second minimum in the fission barrier was found to be 3.1 MeV for 235U and 2.9 for 239Pu. Both values are in close agreement with the values of 3 MeV predicted by Strutinsky. (author)

  4. Transfer and translocation of {sup 241}Am, {sup 239}Pu, {sup 137}Cs and {sup 85}Sr after partial foliar contamination of bean plants

    Henner, P.; Colle, C.; Morello, M. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

    2004-07-01

    Bean plants at the flowering development stage were contaminated by soaking their two first leaves for 3 hours in a solution containing one of the actinides {sup 241}Am or {sup 239}Pu, or both {sup 137}Cs and {sup 85}Sr. The aim of the study was to assess the adequacy of using the values of Cs/Sr for the foliar transfer parameters of transuranic actinides, as used for example in the ASTRAL code to calculate the contamination of agricultural products after a nuclear accident. Secondly, these experiments were launched to tentatively determine specific values for the foliar transfer parameters for Am and Pu, despite technical limitations due to high radiotoxicity of these isotopes which prevented the contamination of the whole foliage of bean plants. Cs and Sr were used to compare the results with those obtained with other modes of contamination, by dry deposition of aerosols for example. Results showed that the soaking protocol was adequate to compare the foliar transfer of various radionuclides, although it should be difficult to provide specific values because of partial contamination of the foliage. Foliar transfer factors, expressed as Bq.kg{sup -1}{sub dw} {sub pods}/Bq.L{sup -1}{sub solution} (2.5x10{sup -2}) and translocation factors, dimensionless, (2.3x10{sup -3}) for Am and for Pu (1.5x10{sup -3} and 7.5x10{sup -5} respectively), compared to those for Sr (respectively 3.6x10{sup -3} and 5.9x10{sup -4}) and for Cs (respectively 2.9x10{sup -1} and 1.3x10{sup -1}), were studied using this procedure. Transfer and translocation factors for Am were significantly higher than those for Sr, but were smaller than those for Cs. Therefore, Am can be classified as a medium mobile radionuclide in plant. Transfer and translocation of Pu were significantly lower than these for Sr and for Am. Besides, the transfer and translocation factors of Am and Pu only differed from one order of magnitude or less from the one of Sr, which could be in the usual range of variation

  5. Role of self-irradiation defects on the ageing of 239PuCoGa5

    Low-temperature accumulation and annealing experiments, in conjunction with electrical resistivity and critical current density measurements, were used to study the ageing of the actinide superconductor PuCoGa5. These measurements reveal that 2-nm-sized non-superconducting point-like regions are the main damages formed during room temperature ageing; smaller point-like defects are irrelevant to transport properties. Defect sizes and densities deduced from experiment agree with Transmission Electron Microscopy observations. (authors)

  6. Fission fragment charge and mass distributions in 239Pu(n,f) in the adiabatic nuclear energy density functional theory

    Regnier, D; Schunck, N; Verriere, M

    2016-01-01

    Accurate knowledge of fission fragment yields is an essential ingredient of numerous applications ranging from the formation of elements in the r-process to fuel cycle optimization for nuclear energy. The need for a predictive theory applicable where no data is available is an incentive to develop a fully microscopic approach to fission dynamics. In this work, we calculate the pre-neutron emission charge and mass distributions of the fission fragments formed in the neutron-induced fission of 239Pu using a microscopic method based on nuclear energy density functional (EDF) method, where large amplitude collective motion is treated adiabatically using the time dependent generator coordinate method (TDGCM) under the Gaussian overlap approximation (GOA). Fission fragment distributions are extracted from the flux of the collective wave packet through the scission line. We find that the main characteristics of the fission charge and mass distributions can be well reproduced by existing energy functionals even in tw...

  7. The deposition, distribution and retention of inhaled 239PuO2 in the lungs of rats with pulmonary emphysema

    Individuals with chronic obstructive lung disease, such as emphysema, may be more susceptible to injury from other inhaled pollutants. However, dose-response studies of inhaled radionuclides conducted to aid in estimating the biological effects of inhaled radionuclides in man have typically used healthy laboratory animals. Changes in radionuclide deposition, distribution and retention in the lungs as the result of pre-existing lung diseases could alter the radiation dose or the resulting biological effects. An experimental animal model for human emphysema, in which emphysema is induced by the intratracheal instillation of either elastase or papain, has been reviewed. This model was used to study the effects of pulmonary emphysema on the deposition, distribution and retention of inhaled 239PuO2 in rats. (author)

  8. Uncertainty Budget and Efficiency Analysis for the 239Pu (n,2ny) Partial Reaction Cross-Section Measurements

    The 239Pu(n,2nγ)238Pu partial reaction cross-section, σ(n,2nγ), has been measured as a function of neutron energy for several transitions in 238Pu. Partial γ-ray cross sections for yrast, ''collector'' transitions, can provide especially valuable constraints on the magnitude and shape of the total (n,2n) reaction cross-section. In essence, nuclear reaction models will be used to infer the shape and magnitude of the total (n,2n) reaction cross-section from the measured partial γ-ray cross-sections. The reason for undertaking this somewhat indirect approach is that previous measurements of the 239Pu(n,2nγ) have been hampered by a variety of constraints. Activation measurements have several hurdles: (1) intense flux and long counting times are required to overcome the relatively long half-life of 238Pu (87 years) and (2) isotopically pure samples of 239Pu in an environment free of 238Pu contamination are difficult to come by. Neutron counting experiments are subject to significant uncertainties because (1) large background statistics from fission neutrons and (2) the experimental fission neutron multiplicity spectrum is subject to systematic errors because the flux of low-energy neutrons which induce fissions in thermally-fissile 239Pu is very difficult to characterize. In this measurement, spallation neutrons are provided by the LANSCE/WNR facility, and reaction neutron energies are determined via time-of-flight. Neutron flux is monitored in-beam with one 235U fission chamber and one 238U fission chamber. The 238U is not sensitive to background from low-energy neutrons, whereas the 235U fission chamber has better statistics. Hence, in essence the partial γ-ray cross sections are normalized to the evaluated fission cross sections of 235U and 238U. As a check of our normalization to provide additional constraints to the nuclear reaction modeling, benchmark measurements of natFe(n, n(prime)γ) and 235U(n,2nγ) have also been undertaken. The secondary γ-rays are

  9. Evaluating the 239Pu Prompt Fission Neutron Spectrum Induced by Thermal to 30 MeV Neutrons

    Neudecker D.

    2016-01-01

    Full Text Available We present a new evaluation of the 239Pu prompt fission neutron spectrum (PFNS induced by thermal to 30 MeV neutrons. Compared to the ENDF/B-VII.1 evaluation, this one includes recently published experimental data as well as an improved and extended model description to predict PFNS. For instance, the pre-equilibrium neutron emission component to the PFNS is considered and the incident energy dependence of model parameters is parametrized more realistically. Experimental and model parameter uncertainties and covariances are estimated in detail. Also, evaluated covariances are provided between all PFNS at different incident neutron energies. Selected evaluation results and first benchmark calculations using this evaluation are briefly discussed.

  10. Development of a rapid radiochemical procedure for the separation of /sup 235m/U from 239Pu

    We have developed a rapid radiochemical procedure for the isolation and purification of /sup 235m/U (t/sub 1/2/ = 26 minutes) from 239Pu samples up to 250 mg. Purpose of developing the procedure was to measure the thermal neutron fission cross section of the isomeric meta state of 235U. We used rapid small-scale anion exchange columns that absorbed uranium in concentrated HBr but did not absorb plutonium. Uranium was easily eluted with very dilute HF. The separation time required 25 to 35 minutes. We were able to attain a separation factor of uranium from plutonium of approximately 1 x 1010 with samples ranging from 1 x 1010 to 3 x 1011. The ratio of the fission cross sections for the meta to ground state was measured to be 1.42. 4 figs., 1 tab

  11. Estimation of 239Pu independent and cumulative fission product yields from the chain yield data using a Bayesian technique

    The independent and cumulative fission product yields (FPYs) are obtained by using the Bayesian technique based on the evaluated mass chain yield, where required constraints such as the normalization can be straightforwardly included. We apply this technique to the 239Pu FPY data at neutron incident energies of 0.5, 2.0, and 14 MeV, where the most updated mass chain yield ENDF/B-VII.1 data are available. The obtained yield data are compared with the evaluated values by England and Rider in ENDF/B-VI, and differences from their values are investigated. We show that the modern decay data used, such as branching ratios to ground and metastable states, cause differences in the evaluated individual and cumulative fission yields. (author)

  12. Determination of the 240Pu/239Pu atom ratio in low activity environmental samples by alpha spectrometry and spectral deconvolution

    In this paper, a simple technique, based on commercially-available software developed for gamma spectra analysis (MicroSAMPO trademark), is described by which this complex multiplet can be resolved at the much lower activities typical of many environmental samples. In our approach, it is not necessary to make any alterations to the normal alpha spectrometric set-up (including energy dispersion), other than to improve collimation. The instrumental function is defined for each spectrum by fitting a modified gaussian with exponential tails to the comparatively well-resolved 242Pu ''doublet'' (used as tracer) and, if present, the 238Pu ''doublet''. The fitted peaks are used to create an energy calibration file with which, using published energy data, the positions (in channels) of the component peaks of the multiplet are predicted. These positions are not altered subsequently when MicroSAMPO's interactive multiplet analysis facility is used to quantify the relative spectral intensities of the components. Before calculating the 240Pu/239Pu ratio, it is advisable to correct for coincidence summing of alpha particles and conversion electrons. The technique has been applied to the determination of the 240Pu/239Pu ratio in a set of environmental samples, most of which were supplied by IAEA-MEL under their laboratory intercomparison programme. Subsequently, replicate samples were analysed independently using thermal ionisation mass spectrometry. The agreement between the two sets of data was most satisfactory. Further validation of this deconvolution technique was provided by the good agreement between the measured alpha-emission probabilities for the component peaks in the 239,240Pu multiplet and published values. (orig.)

  13. Intercomparison study of inductively coupled plasma mass spectrometry, thermal ionization mass spectrometry and fission track analysis of μBq quantities of 239Pu in synthetic urine

    Even today, some Marshall Islanders are looking forward to permanently resettling their islands after five decades. The U.S. Department of Energy and the resettled residents require reasonable but cost-prudent assurance that the doses to resident from residual 239Pu will not exceed recognized international standards or recommendations, as estimated from the excretion of 239Pu in urine. The goal of this study was to evaluate the bias, uncertainty and sensitivity of analytical techniques that measure 3-56 μBq 239Pu in synthetic urine. The analytical techniques studied in this work included inductively coupled plasma mass spectrometry, thermal ionization mass spectrometry and fission track analysis. The results of the intercomparison demonstrated that all three techniques were capable of marking the measurements, although not with equal degree of bias and uncertainty. The estimated minimum detectable activity was 1 μBq of 239Pu per synthetic urine sample. This exercise is also the first effort to certify test materials of plutonium in the nBqxg-1 range. (author)

  14. Perturbation in the 240Pu/239Pu global fallout ratio in local sediment following the nuclear accidents at Thule (Greenland) and Palomares (Spain)

    It is well established that the main source of the plutonium found in marine sediments throughout the Northern Hemisphere is global stratospheric fallout, characterized by a typical 240Pu/239Pu atom ratio of ∼0.18. Measurements of perturbations in this ratio at various sites which had been subjected to close-in fallout, mainly from surface-based testing, has confirmed the feasibility of using this ratio to distinguish plutonium from different fallout sources. In the present study, the 240Pu/239Pu ratio has been examined in samples of sediment collected at Thule (Greenland) and Palomares (Spain), where accidents involving the release and dispersion of plutonium from fractured nuclear weapons occurred in 1968 and 1966, respectively. The 240Pu/239Pu ratio was measured by high-resolution alpha spectrometry and spectral deconvolution. The analytical results showed that at Thule the mean 240Pu/239Pu atom ratio was 0.033±0.004, while at Palomares the equivalent ratio appeared to be significantly higher at 0.056±0.003. Both ratios are consistent with those reported for soils samples at the Nevada site and Nagasaki, and are clearly indicative of weapons-grade plutonium. 27 refs., 1 fig., 2 tabs

  15. The biokinetics of four 239Pu/241Am dioxide bearing dusts in the rat after inhalation: the implications for occupational exposure

    The aims of the work described here were to provide an experimental basis for evaluating the committed effective dose equivalent per unit intake together with the ALI for four industrial oxide bearing dusts, and to assess the extent to which 241Am could be used for estimating the 239Pu content of the lung after an accidental intake of these materials. (author)

  16. Analytical Method for Pu-239, Pu-240, Np-237 and Tc-99 using Inductively Coupled Plasma Mass Spectrometry

    Kim, Cheol Su

    2007-02-15

    An efficient analytical method for Pu isotopes (Pu-239 and Pu-240), Np-237 and Tc-99 in environmental samples has been developed using sector field inductively coupled plasma mass spectrometry (SF-ICPMS) detection. The chemical separation of Pu in terrestrial samples, soil, and sediment was carried out on two extraction resins, Sr-Spec and TEVA, which were sequentially combined in PrepLab, an integrated liquid handing device. By reducing the final eluent volume to 2.4 mL, directly injecting it to SF-ICPMS, and employing MCN-6000, a membrane desolvating sample introduction system, the analysis of Pu isotopes was found to be feasible in 1 g of soil. The detection limits of Pu-239, Pu-240, and Pu-242 were approximately 4 fg mL-1 (9.2 Bq mL-1), 3 fg mL-1 (25 Bq mL-1), and 6 fg mL-1 (0.87 Bq mL-1), which represent total amounts of 9.6, 7.2, and 14 fg, respectively, in the final eluent. Chemical separation and measurement were fully automated by a sequential injection (SI) program in an on-line system, and the analysis could thereby be completed within roughly 5 hours. The reliability of this method was confirmed by a validity test with several certified standard reference materials (NIST-4350b, IAEA-6, IAEA-300, IAEA-367, IAEA-368, IAEA-375). The analytical method for Pu in environmental seawater is different from that of terrestrial samples owing to the strong interference effect of U as well as ultra-low level Pu. Although the principle of chemical separation is nearly the same as in soil, seawater was co-precipitated with Fe(OH)2 in the pre-treatment step and a micro TEVA column (50 L) was used in the on-line system to improve precision and the lower detection limit. With this method, it was possible to analyze ultra-trace level Pu isotopes in only 5 L of surface seawater within 1 day, and the precision for Pu-239 and Pu-240 was less than 3.4% (n=7) and 5% (n=7), respectively. The accuracy of this method was verified by analysis of reference seawater (IAEA-381) as

  17. Analytical Method for Pu-239, Pu-240, Np-237 and Tc-99 using Inductively Coupled Plasma Mass Spectrometry

    An efficient analytical method for Pu isotopes (Pu-239 and Pu-240), Np-237 and Tc-99 in environmental samples has been developed using sector field inductively coupled plasma mass spectrometry (SF-ICPMS) detection. The chemical separation of Pu in terrestrial samples, soil, and sediment was carried out on two extraction resins, Sr-Spec and TEVA, which were sequentially combined in PrepLab, an integrated liquid handing device. By reducing the final eluent volume to 2.4 mL, directly injecting it to SF-ICPMS, and employing MCN-6000, a membrane desolvating sample introduction system, the analysis of Pu isotopes was found to be feasible in 1 g of soil. The detection limits of Pu-239, Pu-240, and Pu-242 were approximately 4 fg mL-1 (9.2 Bq mL-1), 3 fg mL-1 (25 Bq mL-1), and 6 fg mL-1 (0.87 Bq mL-1), which represent total amounts of 9.6, 7.2, and 14 fg, respectively, in the final eluent. Chemical separation and measurement were fully automated by a sequential injection (SI) program in an on-line system, and the analysis could thereby be completed within roughly 5 hours. The reliability of this method was confirmed by a validity test with several certified standard reference materials (NIST-4350b, IAEA-6, IAEA-300, IAEA-367, IAEA-368, IAEA-375). The analytical method for Pu in environmental seawater is different from that of terrestrial samples owing to the strong interference effect of U as well as ultra-low level Pu. Although the principle of chemical separation is nearly the same as in soil, seawater was co-precipitated with Fe(OH)2 in the pre-treatment step and a micro TEVA column (50 L) was used in the on-line system to improve precision and the lower detection limit. With this method, it was possible to analyze ultra-trace level Pu isotopes in only 5 L of surface seawater within 1 day, and the precision for Pu-239 and Pu-240 was less than 3.4% (n=7) and 5% (n=7), respectively. The accuracy of this method was verified by analysis of reference seawater (IAEA-381) as

  18. Perturbation in the 240Pu/239Pu global fallout ratio in local sediments following the nuclear accidents at Thule (Greenland) and Palomares (Spain).

    Mitchell, P I; León Vintró, L; Dahlgaard, H; Gascó, C; Sánchez-Cabeza, J A

    1997-08-25

    It is well established that the main source of the plutonium found in marine sediments throughout the Northern Hemisphere is global stratospheric fallout, characterized by a typical 240Pu/239Pu atom ratio of approximately 0.18. Measurement of perturbations in this ratio at various sites which had been subjected to close-in fallout, mainly from surface-based testing (e.g. Bikini Atoll, Nevada test site, Mururoa Atoll), has confirmed the feasibility of using this ratio to distinguish plutonium from different fallout sources. In the present study, the 240Pu/239Pu ratio has been examined in samples of sediment (and soil) collected at Thule (Greenland) and Palomares (Spain), where accidents involving the release and dispersion of plutonium from fractured nuclear weapons occurred in 1968 and 1966, respectively. The 240Pu/239Pu ratio was measured by high-resolution alpha spectrometry and spectral deconvolution, and confirmed in the case of the most active samples by high-resolution X-ray spectrometry. Only samples which displayed plutonium heterogeneities, i.e. hot particles or concentrations well in excess (at least two orders of magnitude) of those expected from global fallout, were selected for analysis. The analytical results showed that at Thule the mean 240Pu/239Pu atom ratio was 0.033 +/- 0.004 (n = 4), while at Palomares the equivalent ratio appeared to be significantly higher at 0.056 +/- 0.003 (n = 4). Both ratios are indicative of low burn-up plutonium and are consistent with those reported for weapons-grade plutonium. It is noteworthy that the mean 238Pu/239Pu activity ratio in the Thule samples, at 0.0150 +/- 0.0017 (n = 4), was also lower than that measured in the Palomares samples, namely, 0.0275 +/- 0.0012 (n = 4). The 241Pu/239Pu ratios were similarly different. Finally, the data show, in contrast to Palomares, that not all of the samples from the Thule accident site were contaminated with plutonium of identical isotopic composition. PMID:9241884

  19. Phenyl trifluoromethyl sulfone as diluent in a grouped actinide extraction process. Extraction properties of the solvent components TBP and CyMe4-BTBP

    The grouped actinide extraction (GANEX) process combines two extractants CyMe4-BTBP and TBP in a diluent, in this study phenyl trifluoromethyl sulfone (FS-13). The extraction of U-235, Np-239, Pu-238, Am-241, Cm-244 and Eu-152 has been investigated in four different systems. System 1: 70 %vol FS-13, 30 %vol TBP and 10 mM CyMe4-BTBP, system 2: 70 %vol FS-13 and 30 %vol TBP, system 3: 100 %vol FS-13 and 10 mM CyMe4-BTBP and system 4: pure FS-13. In all cases 4 M HNO3 was used as aqueous phase. In system 1 all actinides were extracted and separated from the lanthanides. In both system 2 and 3 mainly U and Pu were extracted. In system 4 none of the metals were extracted. (author)

  20. A Study of the Resonance Interaction Effect between 238U and 239Pu in Lower Energy Region

    An investigation has been made of the statistical frequency function for the distances between the 238U and the 239Pu resonances in the region 4-244 eV. It is concluded that the frequency function is probably constant but that the distances diverge appreciably from a constant function in the actual case, and that the divergence is such that the interaction effect on the resonance integral is smaller than would be expected from statistical considerations. This is also confirmed by calculations on the interaction effect. These have been performed using three different methods, namely: a) considering the actual positions and widths of the resonances, b) assuming a constant frequency function for the resonance. spacing and applying a theory developed by Rowlands and E A Fischer. c) applying a simplified, approximate method for calculations based on the statistical theory. The calculations are made for two temperatures and two values of the plutonium enrichment. It is shown that the average cross sections are considerably larger than the statistical calculations indicate

  1. Radionuclide distribution dynamics in skeletons of beagles fed 90Sr: Correlation with injected 226Ra and 239Pu

    Data for the bone-by-bone redistribution of 90Sr in the beagle skeleton are reported for a period of 4000 d following a midgestation-to-540-d-exposure by ingestion. The partitioned clearance model (PCM) that was originally developed to describe bone-by-bone radionuclide redistribution of 226Ra after eight semimonthly injections at ages 435-535 d has been fitted to the 90Sr data. The parameter estimates for the PCM that describe the distribution and clearance of 226Ra after deposition on surfaces following injection and analogous parameter estimates for 90Sr after uniform deposition in the skeleton as a function of Ca mass are given. Fractional compact bone masses per bone group (mi,COM) are also predicted by the model and compared to measured values; a high degree of correlation (r = 0.84) is found. Bone groups for which the agreement between the model and experimental values of mi,COM was poor had tissue-to-calcium weight ratios about 1.5 times those for bones that agreed well. Metabolically defined surface in PCM is initial activity fraction per Ca fraction in a given skeletal component for intravenously injected alkaline earth (Sae) radionuclides; comparisons are made to similarly defined surface (Sact) values from 239Pu injection studies. The patterns of Sae and Sact distribution throughout the skeleton are similar

  2. Neutron emission effects on fragment mass and kinetic energy distribution from fission of 239Pu induced by thermal neutrons

    The average of fragment kinetic energy () and the multiplicity of prompt neutrons (ν(bar sign)) as a function of fragment mass (m*), as well as the fragment mass yield (Y (m*)) from thermal neutron induced fission of 239Pu, have been measured by Tsuchiya et al.. In that work the mass and kinetic energy are calculated from the measured kinetic energy of one fragment and the difference of time of flight of the two complementary fragments. However they do not present their results about the standard deviation σE*(m*). In this work we have made a numerical simulation of that experiment, assuming an initial distribution of the primary fragment kinetic energy (E(A)) with a constant value of the standard deviation as function of fragment mass σE(A)). As a result of that simulation we obtain the dependence σE*(m*) which presents an enhancement between m* = 92 and m* 110, and a peak at m* = 121. (orig.)

  3. Neutron emission effects on fragment mass and kinetic energy distribution from fission of 239Pu induced by thermal neutrons

    The average of fragment kinetic energy (E-bar sign*) and the multiplicity of prompt neutrons (ν(bar sign)) as a function of fragment mass (m*), as well as the fragment mass yield (Y(m*)) from thermal neutron-induced fission of 239Pu have been measured by Tsuchiya et al.. In that work the mass and kinetic energy are calculated from the measured kinetic energy of one fragment and the difference of time of flight of the two complementary fragments. However they do not present their results about the standard deviation σE*(m*). In this work we have made a numerical simulation of that experiment which reproduces its results, assuming an initial distribution of the primary fragment kinetic energy (E(A)) with a constant value of the standard deviation as function of fragment mass (σE(A)). As a result of the simulation we obtain the dependence σE*(m*) which presents an enhancement between m* = 92 and m* = 110, and a peak at m* = 121.

  4. Re-entrainment of {sup 239}PuO{sub 2} Particles Captured on HEPA Filter Fibres

    Yamada, Y.; Koizumi, A.; Miyamoto, K

    1999-07-01

    Filter performance is very important not only before use but also in use. In addition to particle collection, particle retention or dispersion rate should be evaluated. Re-entrainment of {sup 239}PuO{sub 2} particles collected on HEPA filter fibres was investigated under various conditions of air flow direction, air flow rate, air flow pattern and dust loading. Plutonium aerosols with an activity median aerodynamic diameter of 0.45 {mu}m and a geometric standard deviation of 2.0 were used. Dispersion rate per hour, which is defined as activity ratio on the sampling filter downstream to that on the source filter, under forward flow, was measured as less than 2.3 x 10{sup -7} h{sup -1}. Under reverse flow, higher dispersion rates were observed, but the dispersion decreased with repeated sample runs. A high air flow rate increased the dispersion rate. There was no significant differences among air flow patterns. Dispersion rate depended strongly on the dust loading level. For example, at 2.9 times the loading of atmospheric aerosols compared with the initial pressure drop the dispersion rate was increased by approximately 100 times to 10{sup -2} h{sup -1}. (author)

  5. Evaluation of the thermal-neutron constants for 233U, 235U, 239Pu and 241Pu

    A consistent set of best values of the 2200 meter/second neutron cross sections, Westcott g-factors, and fission neutron yields for 233U, 235U, 239Pu and 241Pu are presented. A least squares fitting program, LSF, is used to obtain the best fit and to estimate the sensitivity of these fissile parameters to the quoted uncertainties in experimental data. The half-lives of the uranium and plutonium nuclides have been evaluated and these have been used to reassess the significant experimental data. The latest revision of the spontaneous fission neutron yield anti nu, of 252Cf and the foil thickness corrections to the fission neutron yield ratios of fissile nuclei to 252Cf are included. These lead to greater consistency in the data used for anti nu (252Cf). Similarly, the 234U half-life as revised leads to improved consistency in the 235U fission cross section. Comparison is made with the values from ENDF/B-V and other evaluations

  6. Reciprocal translocations in ageing mice and mice with long-term low-level 239Pu contamination

    Single intravenous injections of 185 Bq monomeric 239Pu were given to male mice, and the frequency of primary spermatocytes with reciprocal translocations, determined 724 days after treatment, was not significantly different from that of age-matched untreated controls. These old animals showed significantly higher aberration frequencies than young adults. The data therefore show that for low initial activity and very long retention time the possible cytogenetic effects of incorporated nuclide does not change the age-related pattern of increase of spontaneous chromosome aberrations. Considerations of the main variables involved in the induction of cytogenetic effects of incorporated plutonium, based on literature data, indicate that the initial injected activity, the estimated total accumulated average organ dose, and the retention time interact in a complex way; as far as can be seen at present, the effects seem to be dependent mainly on the initial activity at short times after contamination, while the retention time appears to be predominant in the case of long-term observations. (author)

  7. Coulomb effects in isobaric cold fission from reactions 233U(nth,f), 235U(nth,f), 239Pu(nth,f) and 252Cf(sf)

    Montoya, Modesto

    2014-01-01

    The Coulomb effect hypothesis, formerly used to interpret fluctuations in the curve of maximal total kinetic energy as a function of light fragment mass in reactions 233U(nth,f), 235U(nth,f) and 239Pu(nth,f), is confirmed in high kinetic energy as well as in low excitation energy windows, respectively. Data from reactions 233U(nth,f), 235U(nth,f), 239Pu(nth,f) and 252Cf(sf) show that, between two isobaric fragmentations with similar Q-values, the more asymmetric charge split reaches the higher value of total kinetic energy. Moreover, in isobaric charge splits with different Q-values, similar preference for asymmetrical fragmentations is observed in low excitation energy windows.

  8. Evaluation of quantitative factors of 90Sr, 137Cs, 239Pu, 241Am transfer from contaminated soil with gastric and intestine juices of cows

    The biological availability and parameters of transuranium elements metabolism in an organism of cows pasturing in the Chernobyl NPP alienation zone are evaluated. The values of the radioactivity of 90Sr, 137Cs, 239Pu and 241Am are presented in samples of gastric and intestine juices of cows as well as in simulative solutions after soil processing by them. Quantitative parameters of 90Sr, 137Cs, 239Pu and 241Am transfer from solid phase of soil to gastric, intestine juice of cows as well as to simulative solutions have been estimated on the basis of results of laboratory incubation experiments. A prevailing role of enzyme complex and microflora of gastrointestinal tract in radionuclides transfer from solid phase of soil to solution has been shown

  9. Assinatura da deposição atmosférica de testes nucleares em sedimentos da costa brasileira (240+239Pu e 137Cs

    Christian J. Sanders

    2012-01-01

    Full Text Available The aim of this review is to take a look at Cold War era nuclear tests signatures found in Brazilian coastal sediments. Both137Cs and 240+239Pu signatures have been documented in mangrove, coastal mudflats and continental shelf sediments, associated with above ground nuclear tests beginning in the 1950's. The dates associated to the anthropogenic radionuclide signatures 137Cs and 240+239Pu along sediment columns are confirmed by 210Pb geochronology in many of the studies highlighted in this review. The results outlined in this review characterize the extent to which nuclear fallout products reach the Brazilian coast in quantities sufficient for detection, allowing the use of these radioisotopes as geochronometers.

  10. XAS and XRD study of annealed 238Pu- and 239Pu-substituted zircons (Zr0.92Pu0.08SiO4)

    An annealing study has been completed on two compositionally identical Pu-substituted zircons (Zr0.92Pu0.08SiO4) prepared 18 yr ago with different 238Pu/239Pu isotopic ratios. The activity and accumulated dose for each material varies greatly due to the very different half-lives of 238Pu (87.7 yr) and 239Pu (24 100 yr). The predominantly 238Pu-substituted zircon is in a highly amorphous state after accumulating a dose of 2.8x1019 α-decays/g, which is a factor of two higher than the dose previously determined necessary to amorphize this material. The 239Pu-substituted zircon has remained highly crystalline after an accumulated dose of 1.2x1017 α-decays/g. The Pu in both samples is trivalent due to sintering under reducing conditions. The short-range and long-range structures of each sample have been characterized by detailed X-ray absorption spectroscopy and X-ray diffraction (XRD) methods. The oxidation of Pu3+ to Pu4+ in the crystalline 239Pu-substituted zircon during annealing in air resulted in a decrease in lattice distortion due to the decrease in ionic radius of Pu3+ to Pu4+ on the Zr4+ site. A significant amount of PuO2 exsolved from the zircon structure after annealing at 1200 deg. C in air. Detailed characterization of the amorphous 238Pu-substituted zircon demonstrated that while devoid of long-range order it still retained a distorted zircon structure and composition over a length scale of 0.5 nm. The recrystallization of the amorphous 238Pu-substituted zircon could be achieved directly at temperatures as low as 1200 deg. C when annealed for 12 h in air; however, annealing at 1000 deg. C resulted in decomposition into constituent oxides

  11. Comparison of the ENDF/B-V and SOKRATOR evaluations of 235U, 239Pu, 240Pu and 241Pu at low neutron energies

    The US and USSR's most recent evaluationsof 235U, 239Pu, 240Pu and 241Pu are compared over the thermal region and over the first few resonances. The two evaluations rest on essentially the same experimental data base and the differences reflect different approaches to the representation of the cross sections or different weightings of the experimental results. It is found that over the thermal and resolved ranges the two evaluations are very similar. Some differences in approaches are briefly discussed

  12. Long-term effects of inhaled Ca-DTPA in rats previously exposed to 239Pu(NO3)4 aerosols

    Inhaled Ca-DTPA given 20 days after 239Pu(NO3)4 inhalation was marginally effective (p = 0.10) in reducing the amount of Pu in rat lung. This reduction in Pu lung burden did not, however, affect the later induction of lung tumors. An increased osteosarcoma incidence was noted in control rats exposed only to nitric acid aerosols. Complete tumor incidence data are not yet available. (U.S.)

  13. The subcellular distribution of 239Pu, 241Am and 59Fe in the liver of rat and Chinese hamster as dependent on time

    The subcellular distribution of monomeric 239Pu, 241Am and iron in rat and Chinese hamster liver has been investigated by sucrose-, metrizamide- and Percoll-density gradients. In rat liver, the transuranium elements become and remain bound to typical lysosomes primary storage organelle in Chinese hamster liver. However, their apparent density in sucrose decreases with time, which possible indicates transition into telolysomes. The transuranium nuclides show a subcellular distribution which is quite different from that of iron. (orig.)

  14. Some pathophysiological and biochemical changes in dogs with different forms of lesions induced by inhalation of /sup 239/Pu and /sup 241/Am nitrates

    Kalmykova, Z.I.; Tokarskaya, Z.B.; Buldakov, L.A.; Nifatov, A.P.; Vedeneev, V.S.

    Dogs were acutely, subacutely and chronically inhaled with polymeric /sup 239/Pu and monomeric /sup 241/Am nitrates. Distinctly directed changes were observed in the protein fraction and glycoproteins, as well as in transaminases and sorbitoldehydrogenase of the blood serum, which were attributed to unequal radiation loads to the lungs and the organs of the secondary deposition of nuclides, and also to different degree of the respiratory distress.

  15. Suppression of the pulmonary clearance of Staphylococcus aureus in mice that had inhaled either 144CeO2 or 239PuO2

    The rate of pulmonary clearance of inhaled Staphylococcus aureus in mice was determined at intervals after inhalation exposure to either 144CeO2 or 239PuO2. In mice with mean initial lung burdens between 0.6 and 4.7 μCi 144Ce the pulmonary clearance of S. aureus was suppressed up to 12 weeks after inhalation of 144CeO2. In mice with mean initial lung burdens between 1.3 and 29.0 μCi 239Pu the pulmonary clearance of S. aureus was suppressed up to 26 weeks after inhalation of 239PuO2. The suppressed pulmonary clearance of S. aureus appeared to correlate with the radiation dose rate to the lungs at the time of exposure to bacteria but not with the cumulative radiation dose to the lungs. The changes in bacterial clearance did not appear to be correlated with changes in body weight, hematological parameters, or radiation-induced histopathological changes. Altered bacterial clearance may be related to radiation damage to pulmonary macrophages. It was concluded that irradiation of the lung from radionuclides inhaled in relatively insoluble forms may result in increased bacterial invasion of the lungs

  16. Radiosensitivity and proliferative activity of vertebral CFU-s surviving in mice injected with oncogenic activities of 239Pu or 241Am

    Survival, radiosensitivity and capability to produce differentiated progeny were studied in CFU-S from lumbar vertebrae of mice injected with 198.6 kBq 239Pu/kg or 208.6 kBq 241Am/kg. The CFU-S assay and 59Fe uptake by spleen colonies were used. The number of CFU-S from treated mice was significantly lower than in the controls. Higher radiosensitivity of CFU-S from 239Pu- or 241Am-treated mice was demonstrated using additional exposure to 0.5 Gy X-rays 1, 24, 48, 72 hrs after cell transplant and expressed more accurately by survival curves obtained 1 hr after the marrow cell injection. The effect of 239Pu on CFU-S was characterized by D0 0.58 Gy (n=0.91) and that of 241Am by D0 0.64 Gy (n=0.91); corresponding control values were D0 0.89 Gy, n=1.11. Lower iron utilization due not only to the decreased CFU-S numbers, but also to the defective production of erythrocytes per one CFU-S was found. The complexity of radiation effect on hematopoietic stem cells was demonstrated by the present study. (author)

  17. Calculation of prompt fission product average cross sections for neutron-induced fission of 235U and 239Pu

    Yield-weighted average cross sections of neutron radiative capture, (n,2n), and (n,3n) reactions over prompt fission products (FPs) from 235U and 239Pu are calculated. The prompt fission production yields are taken from the ENDF/B-VII.0 library. The FPs for each fissile material exist over a range of approximately 1000 neutron-rich nuclides. Several nuclear reaction codes are utilized for calculating the cross sections on each individual fission product - EMPIRE-2.19, TALYS-1.0, GNASH, and CoH. The influence of the FP isomers on the average cross sections is examined with TALYS. We investigate the dependence of the average cross sections on the number of FPs taken for averaging. It is shown that the average capture cross section is much more sensitive to the number of FPs included, compared with the (n,2n) and (n,3n) reactions. An intercomparison of the calculated cross sections with the different reaction codes is carried out. In the capture reaction, EMPIRE predicted lower cross section than TALYS and CoH owing to different default assumptions used in the γ-ray strength function modeling. Moreover, the pre-equilibrium models implemented in each code give different predictions for the neutron-emission reactions, although the differences are relatively small. We also discuss a difference between the macroscopic and microscopic calculation options in TALYS for the pre-equilibrium model, optical potential model, and γ-ray strength function. The predictive capability of the reaction codes for the capture reaction is examined by comparing their calculations with the ENDF data, which are based on measurements. Compared with the historic Foster and Arthur's evaluation, our new (n,2n) predictions are similar, although our capture predictions are almost an order of magnitude higher. Recommended cross sections for use in applications have been tabulated in ENDF-formatted files. (author)

  18. Feedback on 239Pu and 240Pu nuclear data and associated covariances through the CERES integral experiments

    Benchmark measurements of irradiated and un-irradiated fuel samples were performed in the framework of the CERES collaborative program between AEA (UK Atomic Energy Agency) and CEA (French Atomic Energy Commission). These experiments provide relevant data for the validation of fuel burn-up and criticality-safety calculations for the whole fuel cycle. As part of this program, pile-oscillation measurements were carried out on a range of mixed-oxide samples with plutonium of various mass and isotopic contents, both in the MINERVE and DIMPLE reactors. Four core configurations, two over-thermalized situations and two pressurized water reactor (PWR)-type situations, were constituted with different forward and adjoint flux spectra, emphasizing fission and/or capture contributions. The experiments were analyzed using reference TRIPOLI4 calculations with the JEFF-3.1.1 library, using exact three-dimensional models of the core configurations. In a first step, calculations of each DIMPLE configuration were performed and compared with the experiment, showing very good agreements with a maximum C-E of -230 pcm. In the second step, reactivity worth experiments were analyzed, using recently developed exact-perturbation capabilities in TRIPOLI4. A consistent assimilation of calculation over experiment discrepancies was performed with the CONRAD code, using the integral data assimilation method. Covariance matrix on multigroup neutron cross sections and multiplicities were generated and significant trends were identified, especially on the 239Pu and 240Pu capture cross sections in the thermal energy range (E < 0.1 eV). Further investigations should be required to confirm these conclusions, due to the strong dependence of these trends and of posterior covariances to prior covariances. (author)

  19. Event-by-event study of prompt neutrons from 239Pu(n,f)

    Vogt, R; Randrup, J; Pruet, J; Younes, W

    2009-07-23

    Employing a recently developed Monte-Carlo model, we study the fission of {sup 240}Pu induced by neutrons with energies from thermal to just below the threshold for second chance fission. Current measurements of the mean number of prompt neutrons emitted in fission, together with less accurate measurements of the neutron energy spectra, place remarkably fine constraints on predictions of microscopic calculations. In particular, the total excitation energy of the nascent fragments must be specified to within 1MeV to avoid disagreement with measurements of the mean neutron multiplicity. The combination of the Monte-Carlo fission model with a statistical likelihood analysis also presents a powerful tool for the evaluation of fission neutron data. Of particular importance is the fission spectrum, which plays a key role in determining reactor criticality. We show that our approach can be used to develop an estimate of the fission spectrum with uncertainties several times smaller than current experimental uncertainties for outgoing neutron energies of less than 2 MeV.

  20. Event-by-Event Study of Prompt Neutrons from 239Pu

    Vogt, R; Randrup, J; Pruet, J; Younes, W

    2010-01-15

    Employing a recently developed Monte Carlo model, we study the fission of {sup 240}Pu induced by neutrons with energies from thermal to just below the threshold for second chance fission. Current measurements of the mean number of prompt neutrons emitted in fission, together with less accurate measurements of the neutron energy spectra, place remarkably fine constraints on predictions of microscopic calculations. In particular, the total excitation energy of the nascent fragments must be specified to within 1 MeV to avoid disagreement with measurements of the mean neutron multiplicity. The combination of the Monte Carlo fission model with a statistical likelihood analysis also presents a powerful tool for the evaluation of fission neutron data. Of particular importance is the fission spectrum, which plays a key role in determining reactor criticality. We show that our approach can be used to develop an estimate of the fission spectrum with uncertainties several times smaller than current experimental uncertainties for outgoing neutron energies of less than 2 MeV.

  1. Matrix effects corrections in DDT assay of {sup 239}Pu with the CTEN instrument

    Hollas, C.L.; Arnone, G.; Brunson, G.; Coop, K. [Los Alamos National Lab., NM (United States)

    1997-11-01

    The accuracy of transuranic (TRU) waste assay using the differential die-away technique depends upon significant corrections to compensate for the effects of the matrix material in which the TRU waste is located. We have used a new instrument, the combined thermal/epithermal neutron (CTEN) instrument for the assay of TRU waste, to develop methods to improve the accuracy of these corrections. Neutrons from a pulsed 14-MeV neutron generator are moderated in the walls of the CTEN cavity and induce fission in the TRU material. The prompt neutrons from these fission events are detected in cadmium-wrapped {sup 3}He neutron detectors. We have developed methods of data acquisition and analysis to extract correlation in the neutron signals resulting from fission during active interrogation. This correlation information, in conjunction with the total number of neutrons detected, is used to determine the fraction of fission neutrons transmitted through the matrix material into the {sup 3}He detectors. This determination allows us to cleanly separate the matrix effects into two processes: matrix modification upon the neutron interrogating flux and matrix modification upon the fraction of fission neutrons transmitted to the neutron detectors. Recent results indicate that for some matrix systems, corrections for position dependent effects within the matrix are possible. 7 refs., 7 figs., 1 tab.

  2. Fission fragment charge and mass distributions in 239Pu(n ,f ) in the adiabatic nuclear energy density functional theory

    Regnier, D.; Dubray, N.; Schunck, N.; Verrière, M.

    2016-05-01

    Background: Accurate knowledge of fission fragment yields is an essential ingredient of numerous applications ranging from the formation of elements in the r process to fuel cycle optimization for nuclear energy. The need for a predictive theory applicable where no data are available, together with the variety of potential applications, is an incentive to develop a fully microscopic approach to fission dynamics. Purpose: In this work, we calculate the pre-neutron emission charge and mass distributions of the fission fragments formed in the neutron-induced fission of 239Pu using a microscopic method based on nuclear density functional theory (DFT). Methods: Our theoretical framework is the nuclear energy density functional (EDF) method, where large-amplitude collective motion is treated adiabatically by using the time-dependent generator coordinate method (TDGCM) under the Gaussian overlap approximation (GOA). In practice, the TDGCM is implemented in two steps. First, a series of constrained EDF calculations map the configuration and potential-energy landscape of the fissioning system for a small set of collective variables (in this work, the axial quadrupole and octupole moments of the nucleus). Then, nuclear dynamics is modeled by propagating a collective wave packet on the potential-energy surface. Fission fragment distributions are extracted from the flux of the collective wave packet through the scission line. Results: We find that the main characteristics of the fission charge and mass distributions can be well reproduced by existing energy functionals even in two-dimensional collective spaces. Theory and experiment agree typically within two mass units for the position of the asymmetric peak. As expected, calculations are sensitive to the structure of the initial state and the prescription for the collective inertia. We emphasize that results are also sensitive to the continuity of the collective landscape near scission. Conclusions: Our analysis confirms

  3. Evaluation of fission cross sections and covariances for {sup 233}U, {sup 235}U, {sup 238}U, {sup 239}Pu, {sup 240}Pu, and {sup 241}Pu

    Kawano, Toshihiko [Kyushu Univ., Fukuoka (Japan); Matsunobu, Hiroyuki [Data Engineering, Inc. (Japan); Murata, Toru [AITEL Corporation, Tokyo (JP)] [and others

    2000-02-01

    A simultaneous evaluation code SOK (Simultaneous evaluation on KALMAN) has been developed, which is a least-squares fitting program to absolute and relative measurements. The SOK code was employed to evaluate the fission cross sections of {sup 233}U, {sup 235}U, {sup 238}U, {sup 239}Pu, {sup 240}Pu, and {sup 241}Pu for the evaluated nuclear data library JENDL-3.3. Procedures of the simultaneous evaluation and the experimental database of the fission cross sections are described. The fission cross sections obtained were compared with evaluated values given in JENDL-3.2 and ENDF/B-VI. (author)

  4. Beta-decay half-lives of neutron rich Cu and Ni isotopes produced by thermal fission of 235U and 239Pu

    The half-lives of very neutron rich isotopes of Ni and Cu have been measured. The isotopes are produced in very asymmetric thermal fission of 235U and 239Pu at the I.L.L. high flux reactor. They are separated by means of the Lohengrin spectrometer. They are identified with a ΔE-E ionization chamber and implanted in one of the 8 Si planar detectors where the β- particles are also detected. The time correlations between the implantation and the detection of β- particles provide the half-life. The values obtained are compared to current theoretical predictions

  5. The subcellular distribution of 239Pu, 241Am and 59Fe in the liver of rat and Chinese hamster as dependent on time

    The subcellular distribution of monomeric 239Pu, 241Am and iron in rat and Chinese hamster liver has been investigated by sucrose-, metrizamide- and Percoll-density gradients. In rat liver, the transuranium elements become and remain bound to typical lysosomes up to several months after incorporation. Lysosomes are also the primary storage organelle in Chinese hamster liver. However, their apparent density in sucrose decreases with time, which possibly indicates transition into telolysomes. The transuranium nuclides show a subcellular distribution which is quite different from that of iron. (orig.)

  6. Simultaneous multi-level analysis of the total and fission cross-sections of 239Pu up to 160 eV

    In order to describe cross-sections a multi-level scheme based on S-matrix theory was used taking the Doppler effect and the resolution into account. A multi-level analysis of the total cross-section and fission cross-section of 239Pu was made by the least-squares method in the energy region up to 160 eV. The experimental cross-section data used have a good resolution. The multi-level parameters can be used to represent all the features of the detailed energy structure of experimental cross-sections where the regions of interference minima are of the greatest interest. (author)

  7. Measurement/Evaluation Techniques and Nuclear Data Associated with Fission of 239Pu by Fission Spectrum Neutrons

    Baisden, P; Bauge, E; Ferguson, J; Gilliam, D; Granier, T; Jeanloz, R; McMillan, C; Robertson, D; Thompson, P; Verdon, C; Wilkerson, C; Young, P

    2010-03-16

    This Panel was chartered to review and assess new evaluations of work on fission product data, as well as the evaluation process used by the two U.S. nuclear weapons physics laboratories. The work focuses on fission product yields resulting from fission spectrum neutrons incident on plutonium, and includes data from measurements that had not been previously published as well as new or revised fission product cumulative yield data, and related quantities such as Q values and R values. This report documents the Panel's assessment of the work presented by Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL). Based on the work presented we have seven key observations: (1) Experiments conducted in the 1970s at LANL, some of which were performed in association with a larger, NIST-led, program, have recently been documented. A preliminary assessment of this work, which will be referred to in this document as ILRR-LANL, shows it to be technically sound. (2) LLNL has done a thorough, unbiased review and evaluation of the available literature and is in the process of incorporating the previously unavailable LANL data into its evaluation of key fission product yields. The results of the LLNL effort, which includes a preliminary evaluation of the ILRR-LANL data, have been documented. (3) LANL has also conducted an evaluation of fission product yields for fission spectrum neutrons on plutonium including a meta-analysis of benchmark data as part of a planned upgrade to the ENDF/B compilation. We found that the approach of using meta-analysis provides valuable additional insight for evaluating the sparse data sets involved in this assessment. (4) Both laboratories have provided convincing evidence for energy dependence in the fission product yield of {sup 147}Nd produced from the bombardment of {sup 239}Pu with fission spectrum neutrons over an incident neutron energy range of 0.2 to 1.9 MeV. (5) Consistent, complete, and explicit treatment

  8. Precision and accuracy in the determination of sup(238)Pu/(sup(239)Pu + sup(240)Pu) alpha activity ratio by alpha spectrometry

    Investigations were carried out for the evaluation of precision and accuracy in determining sup(238)Pu/(sup(239)Pu + sup(240)Pu) activity ratio by α spectrometry from the point of view of determining sup(238)Pu accurately in plutonium samples and in exploiting Isotope Dilution Alpha Spectrometry (IDAS) for determining the concentration of plutonium in the irradiated fuel dissolver solutions. Synthetic mixtures with α activity ratios ranging from 0.01 to 10 were prepared using sup(238)Pu and sup(239)Pu isotopes. Different methods which can be routinely used were tried to calculate the α activity ratio from the α spectrum taken on electrodeposited sources prepared from these mixtures. An accuracy of better than 0.5% and a precision of +- 0.2% (1 sigma) is demonstrated in the determination of α activity ratios ranging from 0.01 to 10 using electrodeposited sources and the evaluation method based on the geometric progression decrease (G.P.) for the far tail of the spectrum. (auth.)

  9. Long-term effects of low-level 239Pu contamination on murine bone-marrow stem cells and their progeny

    The effects of long-term internal contamination with 13.3 kBq kg-1239Pu injected intravenously were studied in 10-week-old ICR (SPF) female mice. Radiosensitivity of spleen colony-forming units (CFU-S) and 125IUdR incorporation into proliferating cells of vertebral bone marrow and spleens were determined in plutonium-treated and control animals one year after nuclide injection. The CFU-S in 239Pu-treated mice were more sensitive to X-rays (D0 = 0.52 +- 0.01 Gy) than in controls (D0 = 0.84 +- 0.02 Gy). 125IUdR incorporation into bone marrow and spleen cells was reduced after plutonium contamination. At one year following plutonium injection, the occurrence of chromosome aberrations was evaluated in metaphase figures of femoral bone marrow cells. The frequency of aberrations increased early after plutonium treatment, at later intervals it tended to decrease but not below the control level. While the relative numbers of vertebral marrow CFU-S decreased significantly, but only to 86% of normal, cellularity of vertebral bone marrow, peripheral blood counts and survival of 239Pu-treated mice did not differ from the control data. (author)

  10. Plutonium isotopes 238Pu, 239+240Pu, 241Pu and 240Pu/239Pu atomic ratios in the southern Baltic Sea ecosystem

    Dagmara I. Strumińska-Parulska

    2010-09-01

    Full Text Available The paper summarizes the results of plutonium findings in atmospheric fallout samples and marine samples from the southern Baltic Sea during our research in 1986-2007. The activities of 238Pu and 239+240Pu isotopes were measured with an alpha spectrometer. The activities of 241Pu were calculated indirectly by 241Am activity measurements 16-18 years after the Chernobyl accident. The 240Pu/239Pu atomic ratios were measured using accelerator mass spectrometry (AMS. The 241Pu activities indicate that the main impact of the Chernobyl accident was on the plutonium concentration in the components of the Baltic Sea ecosystem examined in this work. The highest 241Pu/239+240Pu activity ratio was found in sea water (140 ± 33. The AMS measurements of atmospheric fallout samples collected during 1986 showed a significant increase in the 240Pu/239Pu atomic ratio from 0.29 ± 0.04 in March 1986 to 0.47 ± 0.02 in April 1986.

  11. Measurements of the ratio fo 239Pu and 235U fission cross sections in the 0.024-7.4 MeV neutron energy range

    Aimed at improving the accuracy of available nuclear data 239Pu-to-235U fission cross section ratios were measured in a broad range of neutron energies. The measurements were taken in electrostatic accelerators with the Li(p,n)-,T(p,n)- and D(d,n) reactions used as neutron sources. The fission fragments were registered by a twin ionization chamber. The measured energy dependence curve of the fission cross section ratios was calibrated by means of an auxiliary technique employing glass detectors. The quantity ratio of the fissioning nuclei in 239Pu- and 235U layers was determined by two independent methods: from the alpha-activity in the layers and by taking measurements in the reactor thermal column. The total errors in the measured results makes up 1.4 to 1.5% for the most portion of the investigated neutron energy range, while rowing up to 1.7 to 2% in the range below 100 keV

  12. A study of 239Pu production rate in a water cooled natural uranium blanket mock-up of a fusion-fission hybrid reactor

    Feng, Song; Liu, Rong; Lu, Xinxin; Yang, Yiwei; Xu, Kun; Wang, Mei; Zhu, Tonghua; Jiang, Li; Qin, Jianguo; Jiang, Jieqiong; Han, Zijie; Lai, Caifeng; Wen, Zhongwei

    2016-03-01

    The 239Pu production rate is important data in neutronics design for a natural uranium blanket of a fusion-fission hybrid reactor, and the accuracy and reliability should be validated by integral experiments. The distribution of 239Pu production rates in a subcritical natural uranium blanket mock-up was obtained for the first time with a D-T neutron generator by using an activation technique. Natural uranium foils were placed in different spatial locations of the mock-up, the counts of 277.6 keV γ-rays emitted from 239Np generated by 238U capture reaction were measured by an HPGe γ spectrometer, and the self-absorption of natural uranium foils was corrected. The experiment was analyzed using the Super Monte Carlo neutron transport code SuperMC2.0 with recent nuclear data of 238U from the ENDF/B-VII.0, ENDF/B-VII.1, JENDL-4.0u2, JEFF-3.2 and CENDL-3.1 libraries. Calculation results with the JEFF-3.2 library agree with the experimental ones best, and they agree within the experimental uncertainty in general with the average ratios of calculation results to experimental results (C/E) in the range of 0.93 to 1.01.

  13. Measurement of the 240Pu/239Pu mass ratio using a transition-edge-sensor microcalorimeter for total decay energy spectroscopy.

    Hoover, Andrew S; Bond, Evelyn M; Croce, Mark P; Holesinger, Terry G; Kunde, Gerd J; Rabin, Michael W; Wolfsberg, Laura E; Bennett, Douglas A; Hays-Wehle, James P; Schmidt, Dan R; Swetz, Daniel; Ullom, Joel N

    2015-04-01

    We have developed a new category of sensor for measurement of the (240)Pu/(239)Pu mass ratio from aqueous solution samples with advantages over existing methods. Aqueous solution plutonium samples were evaporated and encapsulated inside of a gold foil absorber, and a superconducting transition-edge-sensor microcalorimeter detector was used to measure the total reaction energy (Q-value) of nuclear decays via heat generated when the energy is thermalized. Since all of the decay energy is contained in the absorber, we measure a single spectral peak for each isotope, resulting in a simple spectral analysis problem with minimal peak overlap. We found that mechanical kneading of the absorber dramatically improves spectral quality by reducing the size of radioactive inclusions within the absorber to scales below 50 nm such that decay products primarily interact with atoms of the host material. Due to the low noise performance of the microcalorimeter detector, energy resolution values of 1 keV fwhm (full width at half-maximum) at 5.5 MeV have been achieved, an order of magnitude improvement over α-spectroscopy with conventional silicon detectors. We measured the (240)Pu/(239)Pu mass ratio of two samples and confirmed the results by comparison to mass spectrometry values. These results have implications for future measurements of trace samples of nuclear material. PMID:25723106

  14. Early retention and distribution of monomeric 237Pu(IV) and 239Pu(IV) in C57BL/Do mice

    The early metabolism of monomeric Pu may depend upon its in vivo concentration, since in higher concentrations it may polymerize forming radiocolloids and be subject to phagocytosis. In this study the early biological behavior of 237Pu(IV) and 239Pu(IV), administered by intraperitoneal injection in citrate solution into C57BL/Do mice, is compared with the in vivo concentrations of these two nuclides differing by a factor of 105. 237Pu is also used as a γ-ray tracer of the α-emitting 239Pu in order to determine the latter's biological retention and tissue distribution. The results show no significant difference in the metabolism of the two nuclides throughout a 91 day serial sacrifice schedule. However, there is a significant sex dependence in the total body retention of Pu primarily due to a factor of 2.7 greater quantity of Pu excreted by the female during the first 24 hours post-injection. Furthermore, the half-time for removal of Pu from the livers of males is 42.7 +- 5.5 days and from livers of females 29.0 +- 2.7 days

  15. Alveolar macrophage kinetics after inhalation of 239PuO2 by CBA/Ca mice: Changes in synthesis of DNA

    For workers in the nuclear industry, the primary route for the entry of radioactive materials into the body is by inhalation, and the rate of clearance of particles from the pulmonary region of the lung is an important factor in determining radiation dose. It is the function of alveolar macrophages (AM) to maintain the sterility of the lung and to remove insoluble particles from the respiratory surfaces and airways. The AM population is not static, and under normal conditions the loss of macrophages from the alvoli via the conducting airways is balanced by renewal. In this investigation the effects of inhaled 239PuO2 (plutonium dioxide) particles on the synthesis of DNA by AM were studied at times up to 77 days after exposure. We also measured the number of cells recovered by bronchoalveolar lavage and the incidence of AM with nuclear aberrations. The latter provides a sensitive indicator of the effects of radiation. One of the earliest effects observed after exposure to 239PuO2 is a reduction in the number of AM recovered by lavage. This reduction is associated with a 3-fold reduction in the proportion of AM undergoing DNA synthesis at early times after exposure. The overall mean pulse labeling index of AM recovered from sham-exposed mice is 1.68%, and no trends is observed with time. At later times after exposure there is a concurrent increase both in the number of AM recovered by lavage and the proportion of AM in the S-phase of the cell cycle. This repopulation of the AM pool is associated with an increase in the incidence of AM with nuclear aberrations. The results of this study are consistent with the theory of an intrapulmonary pool of proliferating macrophages. The depletion of the AM pool and the latency in the induction of nuclear aberrations after exposure to 239PuO2 can be attributed to a radiation-induced inhibition of cell division in addition to interphase death of AM. 57 refs., 4 figs

  16. Migration Simulation of 239 Pu in Groundwater From Melt Glass%熔岩玻璃体239Pu在地下水中的迁移模拟研究

    包敏; 王群书

    2014-01-01

    针对内华达核试验场CHESHIRE地下核试验状况和近场水文地质参数,建立了熔岩玻璃体239 Pu的溶解释放和迁移模型。估算了熔岩玻璃体释放产生239 Pu的速率,将释放出的239 Pu分为溶解态和胶体态,以软件FEFLOW作为建模工具,数值模拟了10万年内溶解态239 Pu和胶体态239 Pu在地下水中的污染羽分布。模拟结果表明,溶解态239 Pu不能发生远距离迁移,影响迁移的关键参数是分配系数,当分配系数大于10 mL/g后,可忽略溶解态239 Pu的远距离迁移;胶体态239 Pu在爆心下游形成较固定的污染晕,距爆心1.3 km处的胶体态239 Pu的模拟活度浓度长期处于10-2 Bq/L ;影响胶体态239 Pu迁移的主要因素包括熔岩玻璃体的溶解速度、熔岩玻璃体释放239 Pu形成胶体态239 Pu的比例、岩层渗透系数。由模拟结果可见,只有当239 Pu形成胶体粒子后才可能发生远距离迁移。%According to the circumstances of an underground nuclear test CHESHIRE at the Nevada Test Site ,a model was developed to simulate the dissolution and migration of 239 Pu from melt glass in groundwater .The release rate of 239 Pu was calculated and the released 239 Pu was divided into dissolved fraction and colloid fraction . The pollution plumes for dissolved 239 Pu and colloid 239 Pu were simulated in 100 000 years by software FEFLOW .The results show that the dissolved 239 Pu can’t migration far away from the melt glass and sorption coefficient is the key parameter .If sorption coefficient is more than 10 mL/g ,the long distance migration of dissolved 239 Pu can be ignored .The colloid 239 Pu plume will be long-standing in the downstream of the melt glass .The 239 Pu con-centration at 1.3 km away from the melt glass would be 10-2 Bq/L for a long time .The parameters effecting colloid 239 Pu migration are the melt glass release rate ,the colloid fraction ratio and aquifer conductivity .It can be concluded

  17. Role of self-irradiation defects on the ageing of {sup 239}PuCoGa{sub 5}

    Jutier, F.; Griveau, J.C.; Colineau, E.; Wastin, F.; Rebizant, J.; Boulet, P.; Wiss, T.; Thiele, H. [European Commiss, Joint Res Ctr, Inst Transuranium Elements, D-76125 Karlsruhe, (Germany); Van der Beek, C.J. [CEA Saclay, DSM/DRECAM/LSI, CEA-CNRS-Ecole Polytechnique, UMR 7642, Lab Solides Irradies, F-91191 Gif-sur-Yvette, (France); Simoni, E. [Institut de Physique Nucleaire, F-91406 Orsay Cedex, (France)

    2007-06-15

    Low-temperature accumulation and annealing experiments, in conjunction with electrical resistivity and critical current density measurements, were used to study the ageing of the actinide superconductor PuCoGa{sub 5}. These measurements reveal that 2-nm-sized non-superconducting point-like regions are the main damages formed during room temperature ageing; smaller point-like defects are irrelevant to transport properties. Defect sizes and densities deduced from experiment agree with Transmission Electron Microscopy observations. (authors)

  18. Transmutation of 129I, 237Np, 238Pu, 239Pu, and 241Am using neutrons produced in target-blanket system `Energy plus Transmutation' by relativistic protons

    J Adam; K Katovsky; A Balabekyan; V G Kalinnikov; M I Krivopustov; H Kumawat; A A Solnyshkin; V I Stegailov; S G Stetsenko; V M Tsoupko-Sitnikov; W Westmeier

    2007-02-01

    Target-blanket facility `Energy + Transmutation' was irradiated by proton beam extracted from the Nuclotron Accelerator in Laboratory of High Energies of Joint Institute for Nuclear Research in Dubna, Russia. Neutrons generated by the spallation reactions of 0.7, 1.0, 1.5 and 2 GeV protons and lead target interact with subcritical uranium blanket. In the neutron field outside the blanket, radioactive iodine, neptunium, plutonium and americium samples were irradiated and transmutation reaction yields (residual nuclei production yields) have been determined using -spectroscopy. Neutron field's energy distribution has also been studied using a set of threshold detectors. Results of transmutation studies of 129I, 237Np, 238Pu, 239Pu and 241Am are presented.

  19. Estimating Reaction Cross Sections from Measured (Gamma)-Ray Yields: The 238U(n,2n) and 239Pu(n,2n) Cross Sections

    Younes, W

    2002-11-18

    A procedure is presented to deduce the reaction-channel cross section from measured partial {gamma}-ray cross sections. In its simplest form, the procedure consists in adding complementary measured and calculated contributions to produce the channel cross section. A matrix formalism is introduced to provide a rigorous framework for this approach. The formalism is illustrated using a fictitious product nucleus with a simple level scheme, and a general algorithm is presented to process any level scheme. In order to circumvent the cumbersome algebra that can arise in the matrix formalism, a more intuitive graphical procedure is introduced to obtain the same reaction cross-section estimate. The features and limitations of the method are discussed, and the technique is applied to extract the {sup 235}U (n,2n) and {sup 239}Pu(n,2n) cross sections from experimental partial {gamma}-ray cross sections, coupled with (enhanced) Hauser-Feshbach calculations.

  20. Neutron induced fission cross section ratios for 232Th, /sup 235,238/U, 237Np, and 239Pu from 1 to 400 MeV

    Time-of-flight measurements of neutron induced fission cross section ratios for 232Th, /sup 235,238/U, 237Np, and 239Pu, were performed using the WNR high intensity spallation neutron source located at Los Alamos National Laboratory. A multiple-plate gas ionization chamber located at a 20-m flight path was used to simultaneously measure the fission rate for all samples over the energy range from 1 to 400 MeV. Because the measurements were made with nearly identical neutron fluxes, we were able to cancel many systematic uncertainties present in previous measurements. This allows us to resolve discrepancies among different data sets. In addition, these are the first neutron-induced fission cross section values for most of the nuclei at energies above 30 MeV. 8 refs., 3 figs

  1. Aerosol sampling and characterization for hazard evaluation. Progress report, October 1, 1977-September 30, 1978. [/sup 239/Pu aerosol monitor performance in work area

    Scripsick, R.C.; Tillery, M.I.; Stafford, R.G.; Romero, P.O.

    1979-11-01

    Measurements of the dilution of air contaminants between worker breathing zone and area air samplers were made by releasing a test fluorescent aerosol in workrooms equipped with aerosol surveillance systems. These data were used to evaluate performance and suggest improvements in design of alarming air monitor systems. In one workroom studied, average half-hour breathing zone air concentration needed to trigger alarm was found to be 960 times the maximum permissible air concentration for occupational exposure to soluble /sup 239/Pu (MPC/sub a/). It was shown that alternative monitor placement in this room could result in decreasing average triggering concentration to 354 times the MPC/sub a/. Analysis of data from impaction-autoradiographic sizing comparison studies showed average disintegration to track ratio called track efficiency factor, to be 2.7 +- 0.4.

  2. Simultaneous measurement of 239Pu, 240Pu, 241Pu, and 242Pu by high resolution inductively coupled plasma mass spectrometer (HR ICP-MS) in marine sediments

    Transuranics elements are of particular interest in radioecological studies because of their radiotoxicity and their potential use to decipher source fingerprints and transport processes. The simultaneous measurement of 239Pu, 240Pu, 241Pu, and 242Pu in environmental samples requires a specific chemical procedure. This work deals with an analytical procedure which yields a very high grade of purification of Pu suitable for ultra low level detection by HR ICP-MS, from marine sediments. After the elimination of major elements (Fe, Al, Mg...) by a first chromatographic separation, a new device of purification by solvent extraction and concentration by a second chromatographic separation is used to obtain a concentrated and high purified solution of plutonium. The chemical procedure have been validated on IAEA certified sediment samples and on sediment samples collected in the roads of Cherbourg which had been previously analysed by other techniques (a spectrometry and thermo-ionisation mass spectrometer). (author)

  3. 133Ba as a gamma-ray surrogate source for 1kg HEU and 10g 239Pu and 252Cf as a Neutron Surrogate for Pu

    Monte Carlo was performed for the purpose of relating gamma-ray signal strength from 1kg of HEU and 10g of 239Pu (as described in the ASTM standards) to the radiation emitted from an amount of 133Ba. A determination was made on the amount of 133Ba that could act as a surrogate for the specified amounts of HEU and Pu. 133Ba is not the ideal source to use as a surrogate for HEU because of its higher energies. 133Ba was chosen as the surrogate since it has a half-life of 10.54 years, rather then the more ideal surrogate of 57Co which has a half-life of 271 days. A similar Monte Carlo was performed for the purpose of relating neutron signal strength from 200g of Pu (as described in the ASTM standards) to the radiation emitted from an amount of shielded 252Cf. A determination was made on the amount of 252Cf necessary to act as a surrogate for the 200g of Pu. An ASTM standard source is a metallic sphere, cube, or right cylinder of SNM having maximum self-attenuation of its emitted radiation. For plutonium, the source should be at least 93% 239Pu, less than 6.5% 240Pu, and less than 0.5% impurities. A cadmium filter of at least 0.08cm thick should be used to reduce the impact of 241Am. For uranium, the source should contain at least 95% 235U and less than 0.25% impurities. For neutron detector testing, the neutron source shall be placed in a lead shielding container that reduces the gamma radiation from the source to 1% of its unshielded value

  4. In vivo measurement of actinides in the human lung

    The problems associated with the in vivo detection and measurement of actinides in the human lung are discussed together with various measurement systems currently in use. In particular, the methods and calibration procedures employed at the Lawrence Livermore Laboratory, namely, the use of twin Phoswich detectors and a new, more realistic, tissue-equivalent phantom, are described. Methods for the measurement of chest-wall thickness, fat content, and normal human background counts are also discussed. Detection-efficiency values and minimum detectable activity estimates are given for three common actinides, 238Pu, 239Pu, and 241Am

  5. Radionuclide concentrations in soils and vegetation at Low-Level Radioactive Waste Disposal Area G during the 1998 growing season (with a cumulative summary of {sup 3}H and {sup 239}Pu over time)

    P. R. Fresquez; M. H. Ebinger; R. J. Wechsler; L. Naranjo, Jr.

    1999-11-01

    Soils and unwashed overstory and understory vegetation were collected at eight locations within and around Area G, a disposal facility for low-level, radioactive solid waste at Los Alamos National Laboratory. The samples were analyzed for {sup 3}H, {sup 238}Pu, {sup 239}Pu, {sup 90}Sr, {sup 241}Am, {sup 137}Cs, {sup tot}U. Most of the radionuclide concentrations in soils and vegetation were within the upper 95% level of background concentrations except for {sup 3}H and {sup 239}Pu. Tritium concentrations in vegetation from most sites were greater than background concentrations of about 2 pCi mL{sup {minus}1}. The concentrations of {sup 239}Pu in soils and understory vegetation were largest in samples collected several meters north of the transuranic waste pad area and were consistent with previous results. Based on {sup 3}H and {sup 239}Pu data through 1998, it was shown that concentrations were (1) significantly greater than background concentrations (p < 0.05) in soils and vegetation collected from most locations at Area G, and (2) there was no systematic increase or decrease in concentrations with time apparent in the data.

  6. Radionuclide concentrations in soils and vegetation at Low-Level Radioactive Waste Disposal Area G during the 1998 growing season (with a cumulative summary of 3H and 239Pu over time)

    Soils and unwashed overstory and understory vegetation were collected at eight locations within and around Area G, a disposal facility for low-level, radioactive solid waste at Los Alamos National Laboratory. The samples were analyzed for 3H, 238Pu, 239Pu, 90Sr, 241Am, 137Cs, totU. Most of the radionuclide concentrations in soils and vegetation were within the upper 95% level of background concentrations except for 3H and 239Pu. Tritium concentrations in vegetation from most sites were greater than background concentrations of about 2 pCi mL-1. The concentrations of 239Pu in soils and understory vegetation were largest in samples collected several meters north of the transuranic waste pad area and were consistent with previous results. Based on 3H and 239Pu data through 1998, it was shown that concentrations were (1) significantly greater than background concentrations (p < 0.05) in soils and vegetation collected from most locations at Area G, and (2) there was no systematic increase or decrease in concentrations with time apparent in the data

  7. Minior Actinide Doppler Coefficient Measurement Assessment

    Nolan E. Hertel; Dwayne Blaylock

    2008-04-10

    The "Minor Actinide Doppler Coefficient Measurement Assessment" was a Department of Energy (DOE) U-NERI funded project intended to assess the viability of using either the FLATTOP or the COMET critical assembly to measure high temperature Doppler coefficients. The goal of the project was to calculate using the MCNP5 code the gram amounts of Np-237, Pu-238, Pu-239, Pu-241, AM-241, AM-242m, Am-243, and CM-244 needed to produce a 1E-5 in reactivity for a change in operating temperature 800C to 1000C. After determining the viability of using the assemblies and calculating the amounts of each actinide an experiment will be designed to verify the calculated results. The calculations and any doncuted experiments are designed to support the Advanced Fuel Cycle Initiative in conducting safety analysis of advanced fast reactor or acceoerator-driven transmutation systems with fuel containing high minor actinide content.

  8. Actinides AMS at CIRCE and 236U and Pu measurements of structural and environmental samples from in and around a mothballed nuclear power plant

    De Cesare, M.; Fifield, L. K.; Sabbarese, C.; Tims, S. G.; De Cesare, N.; D'Onofrio, A.; D'Arco, A.; Esposito, A. M.; Petraglia, A.; Roca, V.; Terrasi, F.

    2013-01-01

    Accelerator mass spectrometry (AMS) is presently the most sensitive technique for the measurement of long-lived actinides, e.g. 236U and 239Pu. A new actinide line is in operation at the Center for Isotopic Research on Cultural and Environmental heritage (CIRCE) in Caserta, Italy. Using the actinide line a uranium mass sensitivity of around 4 μg has been reached measuring with a 16-strip silicon detector, and a 239Pu background level of below 0.1 fg has been obtained. In this work we also discuss preliminary results for environmental and structural samples from in and around the Garigliano nuclear power plant (GNPP), presently in the decommissioning phase. Measurements on environmental samples from the vicinity of the plant allow the assessment of contamination, if any, over the years. Measurements of structural samples from the plant are relevant to the optimization of the decommissioning program for the GNPP.

  9. Actinides AMS at CIRCE and 236U and Pu measurements of structural and environmental samples from in and around a mothballed nuclear power plant

    Accelerator mass spectrometry (AMS) is presently the most sensitive technique for the measurement of long-lived actinides, e.g. 236U and 239Pu. A new actinide line is in operation at the Center for Isotopic Research on Cultural and Environmental heritage (CIRCE) in Caserta, Italy. Using the actinide line a uranium mass sensitivity of around 4 μg has been reached measuring with a 16-strip silicon detector, and a 239Pu background level of below 0.1 fg has been obtained. In this work we also discuss preliminary results for environmental and structural samples from in and around the Garigliano nuclear power plant (GNPP), presently in the decommissioning phase. Measurements on environmental samples from the vicinity of the plant allow the assessment of contamination, if any, over the years. Measurements of structural samples from the plant are relevant to the optimization of the decommissioning program for the GNPP.

  10. Decay Heat Analyses after Thermal-Neutron Fission of 235U and 239Pu by SCALE-6.1.3 with Recently Available Fission Product Yield Data

    The heat reaches about 1.5% after one hour and falls to 0.4% after a day. After a week it will be about 0.2%. The reactor, however, still requires further cooling for several years to keep the fuel rods safe. In general, the decay heat in the reactors can be calculated using a summation calculation method, which is simply the sum of the activities of the fission products produced during the fission process and after the reactor shutdown weighted by the mean decay energies. Consequently, the method is strongly dependent on the available nuclear structure data. Nowadays, the method has been implemented in various burnup and depletion programs such as ORIGEN and CINDER. In this study, the decay heat measurements after thermal-neutron fission of 235U and 239Pu have been evaluated by the ORIGEN-S with the decay data and fission product yield libraries included in the SCALE-6.1.3 software package. The new libraries were applied to the decay heat calculations, and the results were compared with those by the ORIGEN reference calculation. The decay heat measurements for very short cooling times after thermal-neutron fission of 235U and 239Pu have been evaluated by the ORIGEN-S summation calculation. The reference calculation results by the latest ORIGEN data libraries of the SCALE-6.1.3 have been validated with the measurements by ORNL and Studsvik. In addition, the generation of the new ORIGEN yield libraries has been completed based on the ENDF/B-VII.1, JEFF-3.1.1, JENDL/FPY-2011, and JENDL-4.0. The new libraries have been successfully applied to the decay heat calculations and comparative analyses have been devoted to verifying the importance of the fission product yield data when estimating the decay heat values for each isotope in a very short time. The decay data library occupies an important position in the ORIGEN summation calculation along with the fission product yield library

  11. A comparison of the natural survival of beagle dogs injected intravenously with low levels of 239Pu, 226Ra, 228Ra, 228Th, or 90Sr

    The natural survival, relative to properly chosen controls, of 26 beagle dogs injected once intravenously with an average of 0.58 +/- 0.04 kBq 239Pu/kg, 23 dogs injected with 2.31 +/- 0.43 kBq 226Ra/kg, 13 dogs injected with 1.84 +/- 0.26 kBq 228Ra/kg, 12 dogs injected with 0.56 +/- 0.030 kBq 228Th/kg, and 12 dogs injected with 21.13 +/- 1.74 kBq 90Sr/kg was evaluated statistically. The amounts of these radionuclides are related directly to the estimated maximum permissible body burdens for humans suggested in ICRP II (1959). They constitute a level of exposure that initially was assumed to cause no deleterious effects in dogs. This study had two objectives: (1) identification of homogeneous control groups against which to evaluate the survival of the irradiated groups and (2) comparison of the survival characteristics and estimation of mortality or hazard rate ratios for control dogs vs dogs injected with the baseline dosages given above. It was shown, by goodness-of-fit plots, that the Cox proportional hazards model was an appropriate method of analysis. Therefore, covariates that possibly could influence survival were tested for significance. Only the effects of grand mal seizure, which is caused in epileptic dogs by an external stimulus and can be fatal if untreated, were significant (P less than 0.0001). Consequently, in the final model, death from grand mal seizure was considered as accidental. After censoring the dogs dying from grand mal seizure, it was established that the data for the control groups from previous and contemporary experiments could be pooled. The change in hazard rates relative to controls resulting from exposure to the baseline radionuclide level was modest, 1.6 times for 239Pu (P = 0.033), 1.0(4) for 226Ra (P = 0.86), 1.9 for 228Ra (P = 0.035), 2.5 for 228Th (P less than 0.001), and 0.52 for 90Sr (P = 0.041)

  12. Estimation of multi-group cross section covariances for 235,238U, 239Pu, 241Am, 56Fe, 23Na and 27Al

    This paper presents the methodology used to estimate multi-group covariances for some major isotopes used in reactor physics. The starting point of this evaluation is the modelling of the neutron induced reactions based on nuclear reaction models with parameters. These latest are the vectors of uncertainties as they are absorbing uncertainties and correlation arising from the confrontation of nuclear reaction model to microscopic experiment. These uncertainties are then propagated towards multi-group cross sections. As major breakthroughs were then asked by nuclear reactor physicists to assess proper uncertainties to be used in applications, a solution is proposed by the use of integral experiment information at two different stages in the covariance estimation. In this paper, we will explain briefly the treatment of all type of uncertainties, including experimental ones (statistical and systematic) as well as those coming from validation of nuclear data on dedicated integral experiment (nuclear data oriented). We will illustrate the use of this methodology with various isotopes such as 235,238U, 239Pu, 241Am, 56Fe, 23Na and 27Al. (authors)

  13. The Association of Inbreeding With Lung Fibrosis Incidence in Beagle Dogs That Inhaled 238PuO2 or 239PuO2.

    Wilson, Dulaney A.; Brigantic, Andrea M.; Morgan, William F.

    2011-09-12

    Studies of health effects in animals after exposure to internally deposited radionuclides were intended to supplement observational studies in humans. Both nuclear workers and Beagle dogs have exhibited plutonium associated lung fibrosis; however, the dogs smaller gene pool may limit the applicability of findings to humans. Data on Beagles that inhaled either plutonium-238 dioxide (238PuO2) or plutonium-239 dioxide (239PuO2) were analyzed. Wright's Coefficient of Inbreeding was used to measure genetic or familial susceptibility and was assessed as an explanatory variable when modeling the association between lung fibrosis incidence and plutonium exposure. Lung fibrosis was diagnosed in approximately 80% of the exposed dogs compared with 23.7% of the control dogs. The maximum degree of inbreeding was 9.4%. Regardless of isotope, the addition of inbreeding significantly improved the model in female dogs but not in males. In female dogs an increased inbreeding coefficient predicted decreased hazard of a lung fibrosis diagnosis. Lung fibrosis was common in these dogs with inbreeding affecting models of lung fibrosis incidence in females but not in males. The apparent protective effect in females predicted by these models of lung fibrosis incidence is likely to be minimal given the small degree of inbreeding in these groups.

  14. Speciation analysis of 129I, 137Cs, 232Th, 238U, 239Pu and 240Pu in environmental soil and sediment

    The environmental mobility and bioavailability of radionuclides are related to their physicochemical forms, namely species. We here present a speciation analysis of important radionuclides including 129I (also 127I), 137Cs, 232Th, 238U and plutonium isotopes (239Pu and 240Pu) in soil (IAEA-375) and sediment (NIST-4354) standard reference materials and two fresh sediment samples from Øvre Heimdalsvatnet Lake, Norway. A modified sequential extraction protocol was used for the speciation analysis of these samples to obtain fractionation information of target radionuclides. Analytical results reveal that the partitioning behaviour, and thus the potential mobility and bioavailability, are exclusively featured for the individual radionuclide. Iodine is relatively mobile and readily binds to organic matter, while plutonium is mainly bound to both organic matter and nitric acid leachable fractions. Thorium is predominated in nitric acid leachable fraction and caesium is primarily observed in nitric acid and aqua regia leachable fractions and residue. Our analytical results reveal that around 50% of uranium might still remain in the residue which could not be extracted with aggressive acid, namely, aqua regia.

  15. Comparative effects of protracted exposures to 60Co γ-radiation and 239Pu α-radiation on breeding performance in female mice

    Breeding performances are compared of hybrid female mice given 239Pu(5 or 10μCikg-1 body mass in 1 per cent trisodium citrate via the tail-vein), or kept in a 10rad/day or 20rad/day 60Co γ-irradiation field (but mated in the control area), or unirradiated. Ovarian dose-rates from the injected plutonium were initially 0.8 and 1.7 rad/day, changing little thereafter; actual γ-ray dose-rates to breeding females averaged around 8 and 16 rad/day respectively. Both γ-ray treatments affected reproductive performance more than the plutonium injections, with respect to duration of fertility and to offspring per litter in successive 4-weekly periods, though overall mean litter-sizes were not significantly less than controls. The r.b.e. for these effects on reproduction, attributed to germ-cell killing, is about 2.5 for the α particles vs. γ-rays, lower than for testis mass reduction in males. This low r.b.e. may be connected with inhomogeneity of α-particle dose within the ovary, but it is known that fission neutron versus gamma r.b.e.'s for impairment of female fertility are also lower than those for impairment of male fertility. (Author)

  16. Study of High-Resolution Spectroscopy of Plutonium. Part I. Contribution to the Classification of the Arc Spectrum. Part II. Determination of the Magnetic Moment of 239Pu

    The study of the hyperfine structure and isotope shift enabled the positions of the first five levels of the multiplet 7F0-6 belonging to the fundamental configuration 5f67s2 to be determined. The classification of the arc spectrum begun in this way led to 25 odd levels, the number of classified lines (70) representing about 30 p. 100 of the light emitted by this hollow cathode in the visible. In addition, the isotope shifts of many lines and the data given by the King furnace show that the first levels of the configuration 5f56d7s2 are also low less than 8000 cm-1 above the fundamental level 7F0. The proximity of the configuration f6s2 and f5ds2 shows that the bonding energies of the 5f and 6d electrons are of the same order of magnitude and this fact must be responsible for the multiple valences belonging to plutonium. From the hyperfine structure of spark lines (Pu II) the interval factor a7 for the electron was deduced giving for the calculated nuclear moment of 239Pu a value of +0.21 ±0.06 μN. The position of the hyperfine components show that the nuclear moment is positive, although the theoretical value given by B. R. Mottelson and S. Nillson is negative and equal to -0.1 μN. (author)

  17. Use of faecal excretion function for quick estimation of initial and existing lung burden for occupational exposure control due to 239Pu for S-class of intake

    Two functions namely initial lung deposition and lung retention per unit faecal excretion rate are constructed primarily based on the excretion pattern of four subjects exposed to 239Pu. In the absence of initial clear knowledge about the class of compound inhaled, faecal to urine excretion ratio was used to infer the type of inhaled class. Trends in the urine and faecal data had suggested that the intake was due to mixed class of plutonium compound for each case. With the assumption of 1:1 mixture of plutonium M and S class inhaled compound, faecal excretion rates for only S-class intake were worked out. Uptake inferred based on their urinary data had suggested it to be of similar level within 40% of uncertainty for 5 μm particle size distribution. Data, all the four cases, were pooled for analysis citing the similar level of intake, particle size distribution, nature and pattern of work. The function obtained was tested for S-class lung retention and faecal excretion rate value. These functions are handy tool for estimating initial lung burden and lung retention value for low level of S-class plutonium intake based on subject faecal analysis data. (authors)

  18. Microdistribution and Long-Term Retention of 239Pu (NO3)4 in the Respiratory Tracts of an Acutely Exposed Plutonium Worker and Experimental Beagle Dogs

    Nielsen, Christopher E.; Wilson, Dulaney A.; Brooks, Antone L.; McCord, Stacey; Dagle, Gerald E.; James, Anthony C.; Tolmachev, Sergei Y.; Thrall, Brian D.; Morgan, William F.

    2012-11-01

    The long-term retention of inhaled soluble forms of plutonium raises concerns as to the potential health effects in persons working in nuclear energy or the nuclear weapons program. The distributions of long-term retained inhaled plutonium-nitrate [239Pu (NO3)4] deposited in the lungs of an accidentally exposed nuclear worker (Human Case 0269) and in the lungs of experimentally exposed beagle dogs with varying initial lung depositions were determined via autoradiographs of selected histological lung, lymph node, trachea, and nasal turbinate tissue sections. These studies showed that both the human and dogs had a non-uniform distribution of plutonium throughout the lung tissue. Fibrotic scar tissue effectively encapsulated a portion of the plutonium and prevented its clearance from the body or translocation to other tissues and diminished dose to organ parenchyma. Alpha radiation activity from deposited plutonium in Human Case 0269 was observed primarily along the sub-pleural regions while no alpha activity was seen in the tracheobronchial lymph nodes of this individual. However, relatively high activity levels in the tracheobronchial lymph nodes of the beagles indicated the lymphatic system was effective in clearing deposited plutonium from the lung tissues. In both the human case and beagle dogs, the appearance of retained plutonium within the respiratory tract was inconsistent with current biokinetic models of clearance for soluble forms of plutonium. Bound plutonium can have a marked effect on the dose to the lungs and subsequent radiation exposure has the potential increase in cancer risk.

  19. Capture and Fission rate of 232-Th, 238-U, 237-Np and 239-Pu from spallation neutrons in a huge block of lead.

    Vlachoudis, Vasilis

    2000-01-01

    The study is centered on the research of the incineration possibility of nuclear waste, by the association of a particle accelerator with a multiplying medium of neutrons, in the project "Energy Amplifier" of C. Rubbia. It consists of the experimental determination of the rates of capture and fission of certain elements (232-Th, 238-U, 237-Np and 239-Pu) subjected to a fluence of fast spallation neutrons. These neutrons are produced by the interaction of high kinetic energy protons (several GeV) provided by the CERN-PS accelerator, on a large lead solid volume. The measurement techniques used in this work, are based on the activation of elements in the lead volume and the subsequent gamma spectroscopy of the activated elements, and also by the detection of fission fragment traces. The development, of a Monte Carlo code makes it possible, on one hand, to better understand the relevant processes, and on the other hand, to validate the code, by comparison with measurements, for the design and the construction of...

  20. Ultra-sensitive Mass Spectrometric and Other Advanced Methods Applied to Biological Samples. Second interlaboratory comparison study for the analysis of 239Pu in synthetic urine at the μBq (∼100 aCi) level by mass spectrometry

    As a follow up to the initial 1998 intercomparison study, a second study was initiated in 2001 as part of the ongoing evaluation of the capabilities of various ultra-sensitive methods to analyze 239Pu in urine samples. The initial study was sponsored by the Department of Energy, Office of International Health Programs to evaluate and validate new technologies that may supersede the existing fission tract analysis (FTA) method for the analysis of 239Pu in urine at the μBq/l level. The ultra-sensitive techniques evaluated in the second study included accelerator mass spectrometry (AMS) by LLNL, thermal ionization mass spectrometry (TIMS) by LANL and FTA by the University of Utah. Only the results for the mass spectrometric methods will be presented. For the second study, the testing levels were approximately 4, 9, 29 and 56 μBq of 239Pu per liter of synthetic urine. Each test sample also contained 240Pu at a 240Pu/239Pu atom ratio of ∼0.15 and natural uranium at a concentration of 50 μBq/ml. From the results of the two studies, it can be inferred that the best performance at the μBq level is more laboratory specific than method specific. The second study demonstrated that LANL-TIMS and LLNL-AMS had essentially the same quantification level for both isotopes. Study results for bias and precision and acceptable performance compared to ANSI N13.30 and ANSI N42.22 have been compiled. (author)

  1. Statistical evaluation of lung, bone, and liver tumors in rats exposed to aerosols of 238PuO2, 239PuO2, and 244CmO2

    The Mantel--Haenszel procedure was applied to the evaluation of tumor data from exposures to aerosols of 238PuO2, 239PuO2, and 244CmO2. Significance was evident for lung tumors for all three transuranics, for osteosarcomas in animals exposed to 244CmO2, and was suggested for liver tumors in animals exposed to 244CmO2

  2. Procedures for the use of Lexan and Makrofol SSNTDs in the detection of environmental concentrations of 235U and 239Pu

    Solid State Nuclear Track Detectors are used to study a variety of atomic particles. Polycarbonate SSNTD is used to study environmental concentrations of 235U and 239Pu in human urine and feces through fission track analysis. The samples of interest are deposited upon a Lexan slide, covered with a piece of Makrofol and exposed to a neutron fluence of 1.1 X 1017. The fissile isotopes in the sample fission and the resulting fission fragments pass through either the surface of the Lexan or the surface of the Makrofol. The positive Coulombic attraction of the ionized fission fragments causes the electrons of the polycarbonate lattice to move towards the path of these particles, resulting in the breakage of chemical bonds in the lattice. The detector is then chemically etched in 6.5 N KOH that preferentially dissolves the damaged polycarbonate left in the path of the fission fragment. The chemically etched fission tracks are permanent records of the path of the fission fragment. The etched fission tracks in Lexan are optically counted using a microscope and the fission tracks in Makrofol are counted using a Spark Chamber. The amount of fissile material in the original sample can be calculated from the number of fission tracks. This paper presents further details of procedures for etching fission tracks in Lexan and Makrofol and for operating a Spark Chamber to count etched fission tracks in Makrofol. The physics of fission track formation in dielectric detectors is also discussed, as well as the physics of the Spark Chamber

  3. Evaluation of the {sup 239}Pu prompt fission neutron spectrum induced by neutrons of 500 keV and associated covariances

    Neudecker, D., E-mail: dneudecker@lanl.gov [Theoretical Division, Los Alamos National Laboratory, P.O. Box 1663, MS-B283, NM 87545 (United States); Talou, P., E-mail: talou@lanl.gov [Theoretical Division, Los Alamos National Laboratory, P.O. Box 1663, MS-B283, NM 87545 (United States); Kawano, T., E-mail: kawano@lanl.gov [Theoretical Division, Los Alamos National Laboratory, P.O. Box 1663, MS-B283, NM 87545 (United States); Smith, D.L., E-mail: donaldlarnedsmith@gmail.com [Nuclear Engineering Division, Argonne National Laboratory, 1710 Avenida del Mundo #1506, Coronado, CA 92118 (United States); Capote, R., E-mail: r.capotenoy@iaea.org [Nuclear Data Section, International Atomic Energy Agency Vienna, Vienna International Centre, P.O. Box 100, A-1400 Vienna (Austria); Rising, M.E., E-mail: mrising@lanl.gov [X-Division, Los Alamos National Laboratory, P.O. Box 1663, MS-F663, NM 87545 (United States); Kahler, A.C., E-mail: akahler@lanl.gov [Theoretical Division, Los Alamos National Laboratory, P.O. Box 1663, MS-B283, NM 87545 (United States)

    2015-08-11

    We present evaluations of the prompt fission neutron spectrum (PFNS) of {sup 239}Pu induced by 500 keV neutrons, and associated covariances. In a previous evaluation by Talou et al. (2010), surprisingly low evaluated uncertainties were obtained, partly due to simplifying assumptions in the quantification of uncertainties from experiment and model. Therefore, special emphasis is placed here on a thorough uncertainty quantification of experimental data and of the Los Alamos model predicted values entering the evaluation. In addition, the Los Alamos model was extended and an evaluation technique was employed that takes into account the qualitative differences between normalized model predicted values and experimental shape data. These improvements lead to changes in the evaluated PFNS and overall larger evaluated uncertainties than in the previous work. However, these evaluated uncertainties are still smaller than those obtained in a statistical analysis using experimental information only, due to strong model correlations. Hence, suggestions to estimate model defect uncertainties are presented, which lead to more reasonable evaluated uncertainties. The calculated k{sub eff} of selected criticality benchmarks obtained with these new evaluations agree with each other within their uncertainties despite the different approaches to estimate model defect uncertainties. The k{sub eff} one standard deviations overlap with some of those obtained using ENDF/B-VII.1, albeit their mean values are further away from unity. Spectral indexes for the Jezebel critical assembly calculated with the newly evaluated PFNS agree with the experimental data for selected (n,γ) and (n,f) reactions, and show improvements for high-energy threshold (n,2n) reactions compared to ENDF/B-VII.1.

  4. Sensitivity of ICP-MS, PERALS and alpha spectrometry for the determination of actinides

    The purpose of this study was to compare the sensitivity of the three most popular techniques for the determination of minor actinides at environmental levels: ICP-MS, PERALS and solid state alpha spectrometry. For each method the limit of detection and the resolution were estimated in order to study the content and isotopic composition of the actinides. The sensitivities of the three determination techniques were compared. Two international reference materials, IAEA-135 (Irish Sea sediment) and IAEA-300 (Baltic Sea sediment) were analyzed for activity concentrations of 238Pu, 239Pu, 240Pu, 241Pu and 241Am. (authors)

  5. Study on Prompt Fission Neutron Spectra and Associated Covariances for 235U(nth,f) and 239Pu(nth,f)

    Berge, L.; Litaize, O.; Serot, O.; Jean, C. De Saint; Archier, P.; Peneliau, Y.

    normalization of experimental spectra, and the uncertainty on the energy-dependent neutron detection efficiency. We show the resulting PFNS and associated covariance matrix in the case of thermal neutron-induced fission of 235U and 239Pu.

  6. Anthropogenic Actinides in the Environment

    The use of nuclear energy and the testing of nuclear weapons have led to significant releases of anthropogenic isotopes, in particular a number of actinide isotopes generally not abundant in nature. Most prominent amongst these are 239Pu, 240Pu, and 236U. The study of these actinides in nature has been an active field of study ever since. Measurements of actinides are applied to nuclear safeguards, investigating the sources of contamination, and as a tracer for a number of erosion and hydrology studies. Accelerator Mass Spectrometry (AMS) is ideally suited for these studies and generally offers higher sensitivities than competing techniques, like ICP-MS or decay counting. Recent advances in AMS allow the study of “minor” plutonium isotopes (241Pu, 242Pu, and 244Pu). Furthermore, 236U can now be measured at the levels expected from the global stratospheric fall-out of the atmospheric nuclear weapon tests in the 1950s and 1960s. Even the pre-anthropogenic isotope ratios could be within reach. However, the distribution and abundance levels of these isotopes are not well known yet. I will present an overview of the field, and in detail two recent studies on minor plutonium isotopes and 236U, respectively.(author)

  7. ANSI/ANS-8.15-1981(R87): Nuclear criticality control of special actinide elements

    The American National Standard, open-quotes Nuclear Criticality Safety in Operations with Fissionable Materials Outside Reactotorsclose quotes American National Standards Institute/American Nuclear Society (ANSI/ANS)-8.1-1983(R88) provides guidance for the nuclides 233U, 235U, and 239Pu. These three nuclides are of primary interest in out-of-reactor criticality safety since they are the most commonly encountered in the vast majority of operations. However, some operations can involve nuclides other than 233U, 235U, and 239Pu in sufficient quantities that their effect on criticality safety could be of concern. ANSI/ANS-8.15-1981(R87) open-quotes Nuclear Criticality Control of Special Actinide Elements,close quotes provides guidance for 15 such nuclides. The standard was approved for use on November 9, 1981. When it received its first 5-yr review, no changes were made, and it was reaffirmed effective October 30, 1987. The standard was again reviewed and reaffirmed without changes in December 1995. The next 5-yr review of the standard is due in December 2000. The affected nuclides are 237Np, 238Pu, 240Pu, 242Pu, 241Am, 243Am, 244Cm, 239Pu, 241Pu, 242mAm, 243Cm, 245Cm, 247Cm, 249Cf, and 251Cf

  8. Detection of internally deposited actinides. Part II. Statistical techniques and risk analysis

    Since a considerable number of workers at Oak Ridge National Laboratory work with compounds of the transuranic elements, computer techniques have been developed to evaluate phoswich spectra in order to determine lung burdens following accidental inhalation of 239Pu, 241Am, 244Cm or other isotopes. Two unfolding methods which have been found useful in the analysis of such cases are presented and discussed. These techniques have been used successfully to detect low levels of 239Pu, 241Am, 244Cm, 233U, 90Sr, and 153Gd in contaminated workers; but because of the current importance of 239Pu, emphasis is placed on detection of that isotope in the presence of 241Am and natural human background. In the health physics tradition of emphasizing benefit vs. risk, we also analyze uncertainties inherent in external counting of the actinides from the viewpoint of statistical risk analysis and derive decision criteria which are useful in determining whether various radioactive species have, in fact, been detected. These criteria are somewhat different from those encountered using traditional counting statistics and derive from the realization that some errors will always be made in scanning large numbers of radiation workers. The optimum decision strategy for the determination of lung burden is, therefore, one which minimizes the long-term risk of error. The usefulness of this approach to whole body counting will be discussed and analyzed

  9. Simultaneous determination of radiocesium ((135)Cs, (137)Cs) and plutonium ((239)Pu, (240)Pu) isotopes in river suspended particles by ICP-MS/MS and SF-ICP-MS.

    Cao, Liguo; Zheng, Jian; Tsukada, Hirofumi; Pan, Shaoming; Wang, Zhongtang; Tagami, Keiko; Uchida, Shigeo

    2016-10-01

    Due to radioisotope releases in the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, long-term monitoring of radiocesium ((135)Cs and (137)Cs) and Pu isotopes ((239)Pu and (240)Pu) in river suspended particles is necessary to study the transport and fate of these long-lived radioisotopes in the land-ocean system. However, it is expensive and technically difficult to collect samples of suspended particles from river and ocean. Thus, simultaneous determination of multi-radionuclides remains as a challenging topic. In this study, for the first time, we report an analytical method for simultaneous determination of radiocesium and Pu isotopes in suspended particles with small sample size (1-2g). Radiocesium and Pu were sequentially pre-concentrated using ammonium molybdophosphate and ferric hydroxide co-precipitation, respectively. After the two-stage ion-exchange chromatography separation from the matrix elements, radiocesium and Pu isotopes were finally determined by ICP-MS/MS and SF-ICP-MS, respectively. The interfering elements of U ((238)U(1)H(+) and (238)U(2)H(+) for (239)Pu and (240)Pu, respectively) and Ba ((135)Ba(+) and (137)Ba(+) for (135)Cs and (137)Cs, respectively) were sufficiently removed with the decontamination factors of 1-8×10(6) and 1×10(4), respectively, with the developed method. Soil reference materials were utilized for method validation, and the obtained (135)Cs/(137)Cs and (240)Pu/(239)Pu atom ratios, and (239+240)Pu activities showed a good agreement with the certified/information values. In addition, the developed method was applied to analyze radiocesium and Pu in the suspended particles of land water samples collected from Fukushima Prefecture after the FDNPP accident. The (135)Cs/(137)Cs atom ratios (0.329-0.391) and (137)Cs activities (23.4-152Bq/g) suggested radiocesium contamination of the suspended particles mainly originated from the accident-released radioactive contaminates, while similar Pu contamination of suspended

  10. Field studies on the terrestrial behavior of actinide elements in East Tennessee

    Field studies on the comparative uptake of various actinide elements (232Th, 233U, 238U, 239Pu, 241Am, and 244Cm) by plants and animals inhabiting historically contaminated environments on the Oak Ridge National Laboratory (ORNL) reservation in East Tennessee are summarized. The present-day pattern of actinide element bioaccumulation from a flood plain site contaminated with Pu in 1944 is U > Th approx. Pu. Thus the environmentally dispersed 239Pu exhibits a transfer from floodplain soil to biota comparable to that of indigenous 232Th and less than that of the indigenous 238U. This ranking agrees with the chemical extractability of U, Th, and Pu from soil, using either weak acids or strongly basic reagents. The pattern of actinide element uptake from the shoreline of a historically contaminated pond is Pu 238U = 233U. This ranking also agrees with the chemical extractability of Pu, Am, Cm, and U from shoreline sediment, using weak acids. Results from field studies at ORNL agree with what has been generally inferred about the relative food chain transfer of the actinides, based on laboratory studies and field studies at other sites in the United States. Because they share the same valence state, there are apparent strong similarities in soil sorption, plant uptake, and animal uptake between trivalent Am and Cm and between tetravalent Pu and Th. Available evidence suggests that knowledge of the behavior of naturally occurring 232Th in the terrestrial food chain can be useful for predicting the long-term fate of environmentally dispersed 239Pu, while data on 238U might be used to place an upper limit on the expected long-term food chain transfer of all transuranic elements except Np. 33 references, 5 figures, 1 table