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Sample records for 239pu semi-experimental determination

  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. 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. 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)

  4. 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)

  5. 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.)

  6. 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)

  7. 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.)

  8. 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...

  9. 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

  10. 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)

  11. 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

  12. 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)

  13. 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

  14. 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)

  15. 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)

  16. 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)

  17. 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

  18. 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)

  19. 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)

  20. 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.)

  1. 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)

  2. 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)

  3. 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

  4. 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)

  5. 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)

  6. 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

  7. 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)

  8. 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.)

  9. Development of 239Pu total cross section multilevel parameters determination technique by analysing experiments on neutron transmission in resolved resonance region

    The aim of this work is development of S-matrix multilevel resonance parameters determination technique with neutron transmission data used in resolved resonance region. Experimental transmission data values were obtained for the Pu-239 thickness range 0.00217-0.1234 nucl/barns on the time-of-flight spectrometer with 70 ns/m resolution. S-matrix Adler's formalism with least square method fit were used for experimental data description. The method developed enables to justify the resonance-resonance interference parameters H. Its possibilities are demonstrated by determination of these parameters for four resonances of the Pu-239 total cross section

  10. Determination of the transfer coefficients between oyster's mushrooms and their cultivation media by using of isotopes 239Pu and 241Am

    Mushrooms are unicellular or poly-cellular organisms, which are feed lateral or saprophytic. Mainly their cells have developed cellular sheet and definite form. Poly-cellular mushrooms generate the fibers, called hypes, which make twine, called mycelium, which side as feeding tissue. From mycelium grow fertile body, which have reproductive function. These fertile bodies with their speed and period of grow, as possible bio-indicators of contamination biosphere by heavy metals, present applicable matrix for analysis. In this work we try to find a way of using fungus to clean up soil contaminated with radioactive waste, especially plutonium and americium. The completely natural method, called myco-remediation or fungal remediation, which was successfully used for clean up soil contaminated with petroleum hydrocarbons and other toxic or hazardous waste, is expected to be faster and more cost-effective than other bioremediation techniques. The analyzed radionuclides were determined using by followed algorithm - the Pu was separated by liquid extraction with Aliquat-336 and for the determination of Am was used liquid extraction with TOPO. For the determination of chemical recovery was used tracer 242Pu with activity 5,0.10-2 Bq, respectively 243Am with activity 1.28.10-1 Bq. The samples after separation were precipitated, micro-filtrated and follow measured by α-spectrometer Ortec. (author)

  11. Radiochemical method for the simultaneous determination of 233U, 236U, 237Np, 236Pu, 238Pu, and 239Pu in biological materials

    A radiochemical method has been developed for the determination of multiple isotopes of uranium, neptunium, and plutonium in biological materials. The elements are separated from the other sample constituents and from each other by anion exchange in halide media. Their recoveries are monitored by isotopic diluents. The amounts of the analyte and diluent isotopes of each element are measured alpha spectrometrically. The interelemental separation factors are generally greater than 102, and the recovery of each element ranges from 60% to 90%. 4 references, 1 table

  12. 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.)

  13. Determination of Radionuclides (90Sr, 238Pu, 239Pu) and the Total Amount of Trace Elements in Food, Urine and Soil Samples from Kazakhstan

    Full text: From 1949 to 1989 the Semipalatinsk area was used for nuclear weapon testing experiments. After 467 tests been conducted the site was closed for experimentation in 1991. The region around the test site is inhabited and the Kazakh government still needs help in the comprehensive assessment of the radiological situation in this area. As a first step to meet this objective a pilot study in September 1995 has been carried out. These fieldmission was focussed on two villages of Moistik and Maisk. The pilot study was very successful and so far resulted in a review paper. Lessons learned in these study include: concerning the radiological situation life in Moistik and Maisk was safe at those time (ambient doses are comparable to global background); the Sr-content in soil samples as well as in urine samples was slightly enhanced; urinary excretion of Pu was below the detection limit. To control if some changes in the environmental situation appears a next fieldmission of German and Kazakh experts was started in August 2000. Analytical data for Pu and Sr determination in urine samples taken from selected cohort and pre-processed in a field laboratory will be presented. For selected soil and food samples ICP-MS measurements have been done after pressure digestion with different acids in a PTFE bomb. A comparison of the radioisotope and elemental concentrations found in samples collected in August 2000 and data from pilot study will be presented. (author)

  14. 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

  15. 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)

  16. 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

  17. 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

  18. 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.)

  19. 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

  20. 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

  1. 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)

  2. 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

  3. 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)

  4. 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.

  5. 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)

  6. 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.)

  7. 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.

  8. 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)

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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)

  14. 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

  15. 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

  16. 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

  17. 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.

  18. 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)

  19. 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.

  20. 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.)

  1. 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

  2. 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

  3. 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.

  4. 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)

  5. 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

  6. 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)

  7. 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)

  8. 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.

  9. 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.

  10. 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

  11. 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)

  12. 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

  13. 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.

  14. 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)

  15. 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

  16. 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

  17. 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)

  18. 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

  19. 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

  20. 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)

  1. 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)

  2. 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.

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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)

  12. 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.

  13. 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.

  14. 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)

  15. 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)

  16. 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.

  17. 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

  18. 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)

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. 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

  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. 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)

  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. 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.

  11. 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

  12. 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)

  13. 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

  14. 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

  15. 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)

  16. 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

  17. 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

  18. 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)

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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.

  4. 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)

  5. 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.

  6. 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.

  7. 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)

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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)

  13. 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.

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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.)

  6. 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.

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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.

  13. 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)

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. 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)

  20. 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)

  1. 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.

  2. 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

  3. 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.

  4. 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)

  5. 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.

  6. 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

  7. 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)

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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...

  14. 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.

  15. 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)

  16. 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...

  17. 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)

  18. 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

  19. 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)

  20. 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)

  1. 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

  2. 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)

  3. 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

  4. 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

  5. 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

  6. The fission cross sections of 230Th, 232Th, 233U, 234U, 236U, 238U, 237Np, 239Pu and 242Pu relative 235U at 14.74 MeV neutron energy

    The measurement of the fission cross section ratios of nine isotopes relative to 235U at an average neutron energy of 14.74 MeV is described with particular attention to the determination of corrections and to sources of error. The results are compared to ENDF/B-V and to other measurements of the past decade. The ratio of the neutron induced fission cross section for these isotopes to the fission cross section for 235U are: 230Th - 0.290 +- 1.9%; 232Th - 0.191 +- 1.9%; 233U - 1.132 +- 0.7%; 234U - 0.998 +- 1.0%; 236U - 0.791 +- 1.1%; 238U - 0.587 +- 1.1%; 237Np - 1.060 +- 1.4%; 239Pu - 1.152 +- 1.1%; 242Pu - 0.967 +- 1.0%. 40 refs., 11 tabs., 9 figs

  7. Synchronous Changes of the Shape of Histograms Constructed from the Results of Measurements of 90-Sr Beta-Decay and 239-Pu Alpha-Decay Observed in More than 3000 km Distant Laboratories

    Filin E. Y.

    2015-07-01

    Full Text Available It was discovered many years ago that histograms constructed from the results of mea- surements of various natural processes are not random. The histogram shape was demonstrated to be determined by the diurnal rotation and circumsolar movement of the Earth and to be independent of the nature of the process considered [1-17]. The results of those works change our basic views about stochasticity of natural processes. When the time series of physical measurements, which are traditionally considered stochastic, are transformed into the series of histograms constructed for an optimally small num- ber of the results (i.e., optimally short segment of the time series, one can see regular changes in the histogram shape. The paper illustrates the main manifestations of this phenomenon by comparing the results of 90 Sr -radioactivity and 239 Pu -decay mea- surements, with the distance between the laboratories in which the data were collected being about 3000 km.

  8. 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.)

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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

  15. 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)

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. 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.)

  1. 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.)

  2. 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.

  3. 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)

  4. 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)

  5. 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)

  6. 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.

  7. Fission Product Yields from Fission Spectrum n+239Pu for ENDF/B-VII.1

    We describe a new cumulated fission product yield (FPY) evaluation for fission spectrum neutrons on plutonium that updates the ENDF/B-VI evaluation by England and Rider, for the forthcoming ENDF/B-VII.1 database release. We focus on FPs that are needed for high accuracy burnup assessments; that is, for inferring the number of fissions in a neutron environment. Los Alamos conducted an experiment in the 1970s in the Bigten fast critical assembly to determine fission product yields as part of the Interlaboratory Reaction Rate (ILRR) collaboration, and this has defined the Laboratory's fission standard to this day. Our evaluation includes use of the LANL-ILRR measurements (not previously available to evaluators) as well as other Laboratory FPY measurements published in the literature, especially the high-accuracy mass spectrometry data from Maeck and others. Because the measurement database for some of the FPs is small - especially for 99Mo - we use a meta-analysis that incorporates insights from other accurately-measured benchmark FP data, using R-value ratio measurements. The meta-analysis supports the FP measurements from the LANL-ILRR experiment. Differences between our new evaluations and ENDF/B-VI are small for some FPs (less than 1-2%-relative for 95Zr, 140Ba, 144Ce), but are larger for 99Mo (4%-relative) and 147Nd (5%-relative, at 1.5 MeV) respectively. We present evidence for an incident neutron energy dependence to the 147Nd fission product yield that accounts for observed differences in the FPY at a few-hundred keV average energy in fast reactors versus measurements made at higher average neutron energies in Los Alamos' fast critical assemblies. Accounting for such FPY neutron energy dependencies is important if one wants to reach a goal of determining the number of fissions to accuracies of 1-2%. An evaluation of the energy-dependence of fission product yields is given for all A values based on systematical trends in the measured data, with a focus on the

  8. 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.

  9. 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.

  10. Fission Product Yields from Fission Spectrum n+ 239Pu for ENDF/B-VII.1

    Chadwick, M. B.; Kawano, T.; Barr, D. W.; Mac Innes, M. R.; Kahler, A. C.; Graves, T.; Selby, H.; Burns, C. J.; Inkret, W. C.; Keksis, A. L.; Lestone, J. P.; Sierk, A. J.; Talou, P.

    2010-12-01

    We describe a new cumulated fission product yield (FPY) evaluation for fission spectrum neutrons on plutonium that updates the ENDF/B-VI evaluation by England and Rider, for the forthcoming ENDF/B-VII.1 database release. We focus on FPs that are needed for high accuracy burnup assessments; that is, for inferring the number of fissions in a neutron environment. Los Alamos conducted an experiment in the 1970s in the Bigten fast critical assembly to determine fission product yields as part of the Interlaboratory Reaction Rate (ILRR) collaboration, and this has defined the Laboratory's fission standard to this day. Our evaluation includes use of the LANL-ILRR measurements (not previously available to evaluators) as well as other Laboratory FPY measurements published in the literature, especially the high-accuracy mass spectrometry data from Maeck and others. Because the measurement database for some of the FPs is small — especially for 99Mo — we use a meta-analysis that incorporates insights from other accurately-measured benchmark FP data, using R-value ratio measurements. The meta-analysis supports the FP measurements from the LANL-ILRR experiment. Differences between our new evaluations and ENDF/B-VI are small for some FPs (less than 1-2%-relative for 95Zr, 140Ba, 144Ce), but are larger for 99Mo (4%-relative) and 147Nd (5%-relative, at 1.5 MeV) respectively. We present evidence for an incident neutron energy dependence to the 147Nd fission product yield that accounts for observed differences in the FPY at a few-hundred keV average energy in fast reactors versus measurements made at higher average neutron energies in Los Alamos' fast critical assemblies. Accounting for such FPY neutron energy dependencies is important if one wants to reach a goal of determining the number of fissions to accuracies of 1-2%. An evaluation of the energy-dependence of fission product yields is given for all A values based on systematical trends in the measured data, with a focus on

  11. 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

  12. 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

  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 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.)

  14. 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)

  15. 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

  16. 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)

  17. 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.

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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)

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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.

  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. 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)

  13. 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)

  14. 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)

  15. 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.

  16. 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.

  17. Determining the age and history of plutonium using isotope correlations and experimentally determined data on isotopic abundances of plutonium and 241Am

    Linear correlations using a data set of nominally cooled samples of Pu formed in Indian PHWRs using experimentally determined 241Pu/239Pu versus 240Pu/239Pu and 241Am/239Pu versus 240Pu/239Pu isotope ratios have been developed which can be used for determining the age of Pu. By correlating both Pu and Am isotopic information, an understanding of how the material was processed, when chemical separations occurred to remove 241Am as well as the true age of the Pu in sample can be obtained. Two actual samples from a PHWR with unknown origin were analyzed as a part of case study for application of this new methodology. (author)

  18. 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)

  19. 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

  20. 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

  1. 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.

  2. 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

  3. Toxicity of inhaled 239PuO2 in immature, young adult and aged Syrian hamsters. IV

    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 in the possible effects of age on observed dose-response relationships for inhaled 238PuO2, 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 238PuO2. The 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, 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. Lung retention determined for each age group varied in the fraction of the initial burden undergoing rapid initial clearance; 63% cleared with a half-time of 1.2 days for the immature group and 22% cleared with a half-time of 2 days for the young adult group. No separate initial phase of clearance was evident for the aged animals. 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 which received the highest level initial lung burden. These early deaths were related to radiation pneumonitis and pulmonary fibrosis. No pulmonary neoplasms have been observed to date

  4. Transuranic concentrations in reef and pelagic fish from the Marshall Islands. [/sup 239/Pu, /sup 240/Pu

    Noshkin, V.E.; Eagle, R.J.; Wong, K.M.; Jokela, T.A.

    1980-09-01

    Concentrations of /sup 239 + 240/Pu are reported in tissues of several species of reef and pelagic fish caught at 14 different atolls in the northern Marshall Islands. Several regularities that are species dependent are evident in the distribution of /sup 239 + 240/Pu among different body tissues. Concentrations in liver always exceeded those in bone and concentrations were lowest in the muscle of all fish analyzed. A progressive discrimination against /sup 239 + 240/Pu was observed at successive trophic levels at all atolls except Bikini and Enewetak, where it was difficult to conclude if any real difference exists between the average concentration factor for /sup 239 + 240/Pu among all fish, which include bottom feeding and grazing herbivores, bottom feeding carnivores, and pelagic carnivores from different atoll locations. The average concentration of /sup 239 + 240/Pu in the muscle of surgeonfish from Bikini and Enewetak was not significantly different from the average concentrations determined in these fish at the other, lesser contaminated atolls. Concentrations among all 3rd, 4th, and 5th trophic level species are highest at Bikini where higher environmental concentrations are found. The reasons for the anomalously low concentrations in herbivores from Bikini and Enewetak are not known.

  5. Evaluation of fission product yields from fission spectrum n+239Pu using a meta analysis of benchmark data

    Chadwick, Mark B.

    2009-10-01

    Los Alamos conducted a dual fission-chamber experiment in the 1970s in the Bigten critical assembly to determine fission product data in a fast (fission neutron spectrum) environment, and this defined the Laboratory's fission basis today. We describe how the data from this experiment are consistent with other benchmark fission product yield measurements for 95,97Zr, 140Ba, 143,144Ce, 137Cs from the NIST-led ILRR fission chamber experiments, and from Maeck's mass-spectrometry data. We perform a new evaluation of the fission product yields that is planned for ENDF/B-VII.1. Because the measurement database for some of the FPs is small—especially for 147Nd and 99Mo—we use a meta-analysis that incorporates insights from other accurately-measured benchmark FP data. The %-relative changes compared to ENDF/B-VI are small for some FPs (less than 1% for 95Zr, 140Ba, 144Ce), but are larger for 99Mo (3%) and 147Nd (5%). We suggest an incident neutron energy dependence to the 147Nd fission product yield that accounts for observed differences in the FPY at a few-hundred keV average energy in fast reactors versus measurements made at higher average energies.

  6. Energy Dependence of Fission Product Yields from 235U, 238U and 239Pu for Incident Neutron Energies Between 0.5 and 14.8 MeV

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

    2016-01-01

    Fission Product Yields (FPY) have historically been one of the most observable features of the fission process. They are known to have strong variations that are dependent on the fissioning species, the excitation energy, and the angular momentum of the compound system. However, consistent and systematic studies of the variation of these FPY with energy have proved challenging. This is caused primarily by the nature of the experiments that have traditionally relied on radiochemical procedures to isolate specific fission products. Although radiochemical procedures exist that can isolate all products, each element presents specific challenges and introduces varying degrees of systematic errors that can make inter-comparison of FPY uncertain. Although of high importance in fields such as nuclear forensics and Stockpile Stewardship, accurate information about the energy dependence of neutron induced FPY are sparse, due primarily to the lack of suitable monoenergetic neutron sources. There is a clear need for improved data, and to address this issue, a collaboration was formed between Los Alamos National Laboratory (LANL), Lawrence Livermore National Laboratory (LLNL) and the Triangle Universities Nuclear Laboratory (TUNL) to measure the energy dependence of FPY for 235U, 238U and 239Pu. The measurements have been performed at TUNL, using a 10 MV Tandem Van de Graaff accelerator to produce monoenergetic neutrons at energies between 0.6 MeV to 14.8 MeV through a variety of reactions. The measurements have utilized a dual-fission chamber, with thin (10-100 μg/cm2) reference foils of similar material to a thick (100-400 mg) activation target held in the center between the chambers. This method allows for the accurate determination of the number of fissions that occurred in the thick target without requiring knowledge of the fission cross section or neutron fluence on target. Following activation, the thick target was removed from the dual-fission chamber and gamma

  7. Identification of the contamination source of plutonium in environmental samples with isotopic ratios determined by inductively coupled plasma mass spectrometry and alpha-spectrometry

    Concentrations of 239+249Pu in environmental samples were determined by ICP-MS and α spectrometry, showing consistent results, which suggests an applicability of ICP-MS to 239Pu and 240Pu measurement. The activity ratios of 238Pu/239+240Pu and 240Pu/239Pu were significantly different in samples from the general environment and near Sellafield reprocessing plants, indicating the usefulness of these ratios for identification of the Pu contamination source. (author)

  8. 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.

  9. Intensified proliferative activity of the CFU-S in vertebral bone marrow of 239Pu-treated mice as one of the factors involved in the induction of granulocytic leukemia

    Using the exocolonizing test, 59Fe utilization technique and classical cytology, 210 days after i.v. injection of 166.7 kBq of 239Pu/kg in about 30% of contaminated mice a proliferative activity was observed in vertebral bone marrow, characterized by high relative numbers of pluripotent hemopoietic stem cells, significantly higher than in the seriously damaged vertebral bone marrow of other 239Pu-treated mice and even higher than in untreated controls. Also the amount of cells in the granulocytic series increased. After transplantation to the heavily irradiated syngeneic hosts the stem cells differentiated into splenic colonies with higher iron utilization than in corresponding controls. Higher numbers of mature granulocytes were also found in the peripheral blood and the spleen. It is assumed that this activity was an inadequate reparative response of the hemopoietic stem cell compartment to the damaging effect and it is considered to be the critical phase which not only preceded the induction of granulocytic leukemia but also created conditions favorable for leukemic transformation of the hemopoietic stem cells. (author)

  10. Beta and gamma decay heat measurements between 0.1s--50,000s for neutron fission of 235U, 238U and 239Pu. Final report, June 1, 1992--December 31, 1996

    This is a final reporting on the composition of separate beta and gamma decay heat measurements following neutron fission of 235U and 238U and 239Pu and on cumulative and independent yield measurements of fission products of 235U and 238U. What made these studies unique was the very short time of 0.1 s after fission that could be achieved by incorporating the helium jet and tape transport system as the technique for transporting fission fragments from the neutron environment of the fission chamber to the low-background environment of the counting area. This capability allowed for the first time decay heat measurements to extend nearly two decades lower on the logarithmic delay time scale, a region where no comprehensive aggregate decay heat measurements had extended to. This short delay time capability also allowed the measurement of individual fission products with half lives as short as 0.2s. The purpose of such studies was to provide tests both at the aggregate level and at the individual nuclide level of the nation's evaluated nuclear data file associated with fission, ENDF/B-VI. The results of these tests are in general quite encouraging indicating this data base generally predicts correctly the aggregate beta and aggregate gamma decay heat as a function of delay time for 235U, 238U and 239Pu. Agreement with the measured individual nuclide cumulative and independent yields for fission products of 235U and 238U was also quite good although the present measurements suggest needed improvements in several individual cases

  11. 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

  12. An intercomparison experiment on isotope dilution thermal ionisation mass spectrometry using plutonium-239 spike for the determination of plutonium concentration in dissolver solution of irradiated fuel

    Determination of plutonium concentration in the dissolver solution of irradiated fuel is one of the key measurements in the nuclear fuel cycle. This report presents the results of an intercomparison experiment performed between Fuel Chemistry Division (FCD) at BARC and PREFRE, Tarapur for determining plutonium concentration in dissolver solution of irradiated fuel using 239Pu spike in isotope dilution thermal ionisation mass spectrometry (ID-TIMS). The 239Pu spike method was previously established at FCD as viable alternative to the imported enriched 242Pu or 244Pu; the spike used internationally for plutonium concentration determination by IDMS in dissolver solution of irradiated fuel. Precision and accuracy achievable for determining plutonium concentration are compared under the laboratory and the plant conditions using 239Pu spike in IDMS. For this purpose, two different dissolver solutions with 240Pu/239Pu atom ratios of about 0.3 and 0.07 corresponding, respectively, to high and low burn-up fuels, were used. The results of the intercomparison experiment demonstrate that there is no difference in the precision values obtained under the laboratory and the plant conditions; with mean precision values of better than 0.2%. Further, the plutonium concentration values determined by the two laboratories agreed within 0.3%. This exercise, therefore, demonstrates that ID-TIMS method using 239Pu spike can be used for determining plutonium concentration in dissolver solution of irradiated fuel, under the plant conditions. 7 refs., 8 tabs

  13. About the first experiment on investigation of 129I, 237Np, 238Pu and 239Pu transmutation at the nuclotron 2.52 GeV deuteron beam in neutron field generated in U/Pb-assembly 'Energy plus transmutation'

    Preliminary results of the first experiment with energy 2.52 GeV at the electronuclear setup which consists of Pb-target (diameter 8.4 cm, length 45.6 cm) and natU-blanket (206.4 kg), transmutation samples of 129I, 237Np, 238Pu and 239Pu (radioecological aspect) are described. Hermetically sealed samples in notable amounts are gathered in atomic reactors and setups of industries which use nuclear materials and nuclear technologies were irradiated in the field of neutrons produced in the Pb-target and propagated in the natU-blanket. Estimates of transmutations were obtained as a result of measurements of gamma activities of the samples. The information about the space and energy distribution of neutrons in the volume of the lead target and the uranium blanket was obtained with the help of sets of activation threshold detectors (Al, Co, Y, I, Au, Bi and others), solid-state nuclear track detectors, 3He neutron detectors and nuclear emulsion. Comparison of the experimental data with the results of simulation with the MCNPX program was performed

  14. Energy dependence of relative abundances and periods of separate groups of delayed neutrons at neutron induced fission of 239Pu in a range of neutrons energies 0.37 - 5 MeV

    The fundamental role of delayed neutrons in behavior, control and safety of reactors is well known today. Delayed neutron data are of great interest not only for reactor physics but also for nuclear fission physics and astrophysics. The purpose of the present work was the measurement of energy dependence of delayed neutrons (DN) group parameters at fission of nuclei 239Pu in a range of energies of primary neutrons from 0.37 up to 5 MeV. The measurements were executed on installation designed on the basis of the electrostatic accelerator of KG - 2.5 SSC RF IPPE. The data are obtained in 6-group representation. It is shown, that there is a significant energy dependence of DN group parameters in a range of primary neutrons energies from thermal meanings up to 5 MeV, which is expressed in reduction of the average half-life of nuclei of the DN precursors on 10 %. The data, received in the present work, can be used at creation of a set of group constants for reactors with an intermediate spectrum of neutrons. (authors)

  15. 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

  16. Toxicity of inhaled 239PuO2 in Beagle dogs: A. Monodisperse 0.75-μm AMAD particles. B. Monodisperse 1.5-μm AMAD particles. C. Monodisperse 3.0--μm AMAD particles. XI

    Beagle dogs were exposed to monodisperse aerosols of 239PuO2 of 0.75, 1.5, or 30 μm activity median aerodynamic diameter (AMAD) to obtain information on the relative importance of homogeneity of alpha irradiation doses to the lung in producing biological effects. The dogs' initial pulmonary burdens (IPB) ranged from 0.0002-2.0 μCi (0.0074 to 74 kBq) 239Pu/kg of body mass. Thirty-six dogs were exposed to the aerosol diluent as controls. Forty-two of 48 dogs exposed to 0.75 μm AMAD particles have died; 67 of 96 have died in the study involving 1.5 μm AMAD particles; and 62 of 72 have died in the study involving the 3.0 μm AMAD particles. Seven of 36 control dogs have died. Most dogs exposed to 239Pu that have failed to survive have died with radiation pneumonitis and fibrosis and/or lung cancer. Surviving dogs have lived up to 4300 days after exposure. The data obtained to date indicate that the degree of uniformity of dose to the lung does not significantly modify the risk of lung cancer. (author)

  17. On the similarity of 239Pu α-activity histograms when the angular velocities of the Earth diurnal rotation, orbital movement and rotation of collimators are equalized

    Shnoll, S. E.; Rubinstein, I. A.; Shapovalov, S. N.; Tolokonnikova, A. A.; Shlektaryov, V. A.; Kolombet, V. A.; Kondrashova, M. N.

    2016-01-01

    It was shown earlier that the persistent "scatter" of results of measurements of any nature is determined by the diurnal and orbital movement of the Earth. The movement is accompanied by "macroscopic fluctuations" (MF)—regular, periodic changes in the shape of histograms, spectra of fluctuation amplitudes of the measured parameters. There are two near-daily periods ("sidereal", 1436 min; and "solar", 1440 min) and three yearly ones ("calendar", 365 average solar days; "tropical", 365 days 5 h and 48 min; and "sidereal", 365 days 6 h and 9 min). This periodicity was explained by the objects whose parameters are measured passing through the same spatial-temporal heterogeneities as the Earth rotates and shifts along its orbit.

  18. Artificial radioactivity and marine environment. Study of 238Pu, 239Pu+240Pu, 241Pu and 241Am in the Mediterranean sea

    This paper is in two parts. Part one is about the methods for analyzing transuranium elements particularly the development of an analytical process for plutonium and for perfecting an Americium analyzing method, capable of treating samples of 200 litres of sea water, 100 grams of sediment and 100 grams of biological matter. Part two concerns the in situ determinations carried out within the scope of the study on the distribution and behaviour of transuranium elements in the Mediterranean sea. The high sea studies concerned the effects of atmospheric fall out and the vertical distribution of Pu and Am. Studies along the coasts enabled a quantitative study to be made of the contribution of rivers to the Mediterranean and to study the distribution of Pu along the French Mediterranean coast line

  19. Leaching of UO2 pellets doped with alpha-emitters (238/239Pu) in synthetic deep Callovian-Oxfordian groundwater

    The reactivity of a polycrystalline UO2 surface under alpha irradiation in contact with groundwater is investigated, in the hypothesis of direct disposal of spent fuel in a deep geological repository. Two series of plutonium-doped UO2 samples (specific alpha activity of 18 and 385 MBq·g-1UO2) were leached in a synthetic Callovian-Oxfordian deep groundwater under anoxic conditions (Ar/CO2 3000 ppm, 3.5 bar relative pressure) to assess both the impact of alpha radiolysis of water and the complexing capacity of the groundwater ions on the dissolution of UO2. This study follows a prior one performed in pure and carbonated waters. Firstly, technical developments were necessary for the analyses in the groundwater solution because of its high salt concentrations: quantification limits were determined for the measurement of uranium and radiolytic H2O2 traces in this medium. Secondly, given the very high reactivity of these samples in the presence of air and in order to minimize any prior surface oxidation, a strict experimental protocol was followed, based on high-temperature annealing in Ar + 4% H2 with preleaching cycles. Each type of UO2 pellet was then leached under static conditions for 30 days (anoxic conditions, deep groundwater solutions). Results on the evolution of uranium releases are presented. For the lowest alpha activity (18 MBq·g-1UO2), uranium releases in groundwater were below the quantification limit of 2 x 10-8 mol·L-1 with a kinetic phosphorescence analyzer, even after 30 days. However, for higher alpha activity (385 MBq·g-1UO2) the uranium releases begin to exceed the quantification limit after 14 days of leaching and then increase exponentially. This increase is comparable to results previously obtained in carbonated solutions.

  20. Leaching of UO2 pellets doped with alpha-emitters (238/239Pu) in synthetic deep Callovian-Oxfordian groundwater

    Tribet, M.; Jégou, C.; Broudic, V.; Marques, C.; Rigaux, P.; Gavazzi, A.

    2010-03-01

    The reactivity of a polycrystalline UO2 surface under alpha irradiation in contact with groundwater is investigated, in the hypothesis of direct disposal of spent fuel in a deep geological repository. Two series of plutonium-doped UO2 samples (specific alpha activity of 18 and 385 MBq·g-1UO2) were leached in a synthetic Callovian-Oxfordian deep groundwater under anoxic conditions (Ar/CO2 3000 ppm, 3.5 bar relative pressure) to assess both the impact of alpha radiolysis of water and the complexing capacity of the groundwater ions on the dissolution of UO2. This study follows a prior one performed in pure and carbonated waters. Firstly, technical developments were necessary for the analyses in the groundwater solution because of its high salt concentrations: quantification limits were determined for the measurement of uranium and radiolytic H2O2 traces in this medium. Secondly, given the very high reactivity of these samples in the presence of air and in order to minimize any prior surface oxidation, a strict experimental protocol was followed, based on high-temperature annealing in Ar + 4% H2 with preleaching cycles. Each type of UO2 pellet was then leached under static conditions for 30 days (anoxic conditions, deep groundwater solutions). Results on the evolution of uranium releases are presented. For the lowest alpha activity (18 MBq·g-1UO2), uranium releases in groundwater were below the quantification limit of 2 × 10-8 mol·L-1 with a kinetic phosphorescence analyzer, even after 30 days. However, for higher alpha activity (385 MBq·g-1UO2) the uranium releases begin to exceed the quantification limit after 14 days of leaching and then increase exponentially. This increase is comparable to results previously obtained in carbonated solutions.

  1. Isotope dilution alpha spectrometry for the determination of plutonium concentration in irradiated fuel dissolver solution : IDAS and R-IDAS

    The report presents a new technique, Isotope Dilution Alpha Spectrometry (IDAS) and Reverse Isotope Dilution Alpha Spectrometry (R-IDAS) for determining the concentration of plutonium in the irradiated fuel dissolver solution. The method exploits sup(238)Pu in IDAS and sup(239)Pu in R-IDAS as a spike and provides an alternative method to Isotope Dilution Mass Spectrometry (IDMS) which requires enriched sup(242)Pu as a spike. Depending upon the burn-up of the fuel, sup(238)Pu or sup(239)Pu is used as a spike to change the sup(238)Pu/(sup(239)Pu+sup(240)Pu)α activity ratio in the sample by a factor of 10. This change is determined by α-spectrometry on electrodeposited sources using a solid state silicon surface barrier detector coupled to a multichannel analyser. The validity of a simple method based on the geometric progression (G.P.) decrease for the far tail of the spectrum to correct for the tail contribution of sup(238)Pu peak (5.50 MeV) to the low energy sup(239)Pu + sup(240)Pu peak (5.17 MeV) is established. Results for the plutonium concentration on different irradiated fuel dissolver solutions with burn-uo ranging from J,000 to 100,000 MWD/TU are presented and compared with those obtained by IDMS. The values obtained by IDAS or R-IDAS and IDMS agree within 0.5%. (auth.)

  2. Rapid Determination of Plutonium Isotopes in Environmental Samples Using Sequential Injection Extraction Chromatography and Detection by Inductively Coupled Plasma Mass Spectrometry

    Qiao, Jixin; Hou, Xiaolin; Roos, Per;

    2009-01-01

    This article presents an automated method for the rapid determination of 239Pu and 240Pu in various environmental samples. The analytical method involves the in-line separation of Pu isotopes using extraction chromatography (TEVA) implemented in a sequential injection (SI) network followed by det...

  3. Los Alamos National Laboratory thermal ionization mass spectrometry results from intercomparison study of inductively coupled plasma mass spectrometry, thermal ionization mass spectrometry, and fission track analysis of μBq quantities of 239Pu in synthetic urine (LA-UR-001698)

    In 1997, the Department of Energy, Office of International Health Programs (EH-63) contracted the National Institute of Standards and Technology (NIST) to perform an intercomparison to evaluate state-of-the-art analysis techniques for 239Pu in synthetic urine in μBq quantities. Sample preparation was performed by Yankee Atomic Environmental Laboratory. Five replicate samples at spike amounts of 3.7, 9.26, 29.6, and 55.6 μBq and a black amount were distributed to the participating laboratories in 200 g synthetic urine. Los Alamos National Laboratory (LANL) participated in the intercomparison using thermal ionization mass spectrometry (TIMS). LANL results, system improvements, and future intercomparisons are discussed. (author)

  4. Simultaneous measurement of {sup 239}Pu, {sup 240}Pu, {sup 241}Pu, and {sup 242}Pu by high resolution inductively coupled plasma mass spectrometer (HR ICP-MS) in marine sediments; Mesure des isotopes du plutonium des sediments marins par spectrometrie de masse a plasma couple inductivement haute resolution (HR ICP-MS)

    Bruneau, F

    1999-07-01

    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 {sup 239}Pu, {sup 240}Pu, {sup 241}Pu, and {sup 242}Pu 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)

  5. Determination of heavy elements in humans

    The uncertainties associated with the determined measurement of lung burdens of transuranium elements become important when positive results are obtained. A lung burden of 16 nCi of 239Pu with no uncertainty was reported for one individual on each of three different counts. Because the uncertainty was not reported it was impossible to evaluate the exposure with any degree of confidence. The result could mean that one lung burden of activity has been determined or it could mean that the detection limit for the method has not been exceeded and so the person has no measurable activity. An alternate method of measuring 239Pu in the body is to separate and count the 239Pu excreted in the feces or the urine. An assumption must be made about how the eliminations from the body represent the material deposited inside the body. Although uncertainties do exist in this assumption the advantage over chest counting is that the detection limit is only 0.002 of a maximum permissible lung burden instead of being a one permissible burden

  6. Determination of the rates of clearance of insoluble compounds of plutonium from the lung

    There are indications that the process of clearance of inhaled insoluble plutonium compounds from the lung may be represented by a model consisting of three exponential phases. A survey of published data on 'in vivo' and bioassay measurements made after 239PuO2 inhalation by men and dogs has been carried out, and the half times of the three exponential phases determined as approximately 1 day, 30 days and 500 days. (author)

  7. The study on determination of trace α-nuclide contents in aqueous solution with TRPO solvent extraction-liquid scintillation count method

    The solvent extraction-liquid scintillation count method has been studied, TRPO has been used as the extractant, dimethylbenzol as the diluent, 2,5-diphenyloxazole as the scintillator. The quenching effects caused by TRPO or other impurity elements have been studied. The results appear that this method can determine trace α-nuclide contents (233U, 239Pu, 241Am) with a large quantity of impurity elements and amino-polycarboxylic acid. The determination can be done simply, quickly and sensitively

  8. Histograms Constructed from the Data of 239-Pu Alpha-Activity Manifest a Tendency for Change in the Similar Way as at the Moments when the Sun, the Moon, Venus, Mars and Mercury Intersect the Celestial Equator

    Kharakoz D. P.

    2011-04-01

    Full Text Available Earlier, the shape of histograms of the results of measurements obtained in processes of different physical nature had been shown to be determined by cosmophysical factors. Appearance of histograms of a similar shape is repeated periodically: these are the near-a-day, near-27-days and annual periods of increased probability of the similar shapes. There are two distinctly distinguished near-a-day periods: the sidereal-day (1,436 minutes and solar-day (1,440 minutes ones. The annual periods are represented by three sub-periods: the "calendar" (365 average solar days, "tropical" (365 days 5 hours and 48 minutes and "sidereal" (365 days 6 hours and 9 minutes ones. The tropical year period indicates that fact that histogram shape depends on the time elapsed since the spring equinox.The latter dependence is studied in more details in this work. We demonstrate that the appearance of similar histograms is highly probable at the same time count off from the moments of equinoxes, independent from the geographic location where the measurements had been performed: in Pushchino, Moscow Region (54 deg NL, 37 deg EL, and in Novolazarevskaya, Antarctic (70 deg SL, 11 deg EL. The sequence of the changed histogram shapes observed at the spring equinoxes was found to be opposite to that observed at the autumnal equinoxes. As the moments of equinoxes are defined by the cross of the celestial equator by Sun, we also studied that weather is not the same as observed at the moments when the celestial equator was crossed by other celestial bodies - the Moon, Venus, Mars and Mercury. Let us, for simplicity, refer to these moments as a similar term "planetary equinoxes". The regularities observed at these "planetary equinoxes" had been found to be the same as in the case of true solar equinoxes. In this article, we confine ourselves to considering the phenomenological observations only; their theoretical interpretation is supposed to be subject of further studies.

  9. Prompt fission neutron emission in resonance fission of 239Pu

    The prompt fission neutron emission probability was investigated at the time-of-flight facility GELINA at the IRMM. A double Frisch-gridded ionization chamber was used as a fission fragment detector. For the data acquisition of both 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 were used. A specialized data analysis program taking advantage of the digital filtering technique has been developed to treat the acquired data

  10. 239Pu metabolism in the blood after its intratracheal administration

    The kinetics of the resorbed from the lungs plutonium metabolism and the forms of its presence in the blood as well as the dynamics of its deposit in the organs of secondary deposition (liver, skeleton) were studied in experiment with female rats. It was shown (gel-filtration method) that plutonium is present in blood serum in various physico-chemical forms: bound with macroglobulin, γ-globulin and albumin-transferrin fractions of proteins and not bound with proteins; this or that form of plutonium may dominate in time (4 min-64 days)

  11. Some comments on the toxicity of 239Pu

    There is no simple method of expressing a concept such as toxicity. The toxicity of a material depends upon its form (solid, liquid, or gas), the method of entry into the body (ingestion, inhalation, or abrasion), and the individual it enters (young, old, sick, well, heavy cigarette smoker, or consumer of alcohol). Thus, statements such as ''plutonium is the most toxic material known to man'' are not only incorrect; they are meaningless. By taking the one aspect of plutonium which can be quantitated in a meaningful manner, the induction of malignant bone sarcomas in humans, the incremental risk presented to those who have been exposed to this radioelement has been shown to be quite small. By means of a hypothetical exposure of radium dial workers to plutonium instead of radium, an industry-wide exposure to plutonium would have been less harmful than the actual exposure to radium, in spite of the fact that plutonium appears to be far more toxic than radium. Further, the observation that, after radium was recognized as a toxic material, it no longer was a hazard in the dial industry, clearly demonstrates that hazardous radioactive materials can be handled safely. This has been demonstrated again with plutonium, for even though much larger quantities have been handled by many more individuals, there are no demonstrable cases of malignancies induced by this hazardous material. The absence of clearly demonstrable excesses of lung cancer in the large group of long-term thorium workers is reassuring, for it may imply that low doses to the lung have a very low probability of inducing lung cancers. It is concluded that plutonium, a highly toxic material, can be handled safely, as are many other hazardous materials that play important roles in our daily lives

  12. Determination of 236U and transuranium elements in depleted uranium ammunition by α-spectrometry and ICP-MS

    It is well known that ammunition containing depleted uranium (DU) was used by NATO during the Balkan conflict. To evaluate the origin of DU (the enrichment of natural uranium or the reprocessing of spent nuclear fuel) it is necessary to directly detect the presence of activation products (236U, 239Pu, 240Pu, 241Am, and 237Np) in the ammunition. In this work the analysis of actinides by α-spectrometry was compared with that by inductively coupled plasma mass spectrometry (ICP-MS) after selective separation of ultratraces of transuranium elements from the uranium matrix. 242Pu and 243Am were added to calculate the chemical yield. Plutonium was separated from uranium by extraction chromatography, using tri-n-octylamine (TNOA), with a decontamination factor higher than 106; after elution plutonium was determined by ICP-MS (239Pu and 240Pu) and α-spectrometry (239+240Pu) after electroplating. The concentration of Pu in two DU penetrator samples was 7 x 10-12 g g-1 and 2 x 10-11 g g-1. The 240Pu/239Pu isotope ratio in one penetrator sample (0.12±0.04) was significantly lower than the 240Pu/239Pu ratios found in two soil samples from Kosovo (0.35±0.10 and 0.27±0.07). 241Am was separated by extraction chromatography, using di(2-ethylhexyl)phosphoric acid (HDEHP), with a decontamination factor as high as 107. The concentration of 241Am in the penetrator samples was 2.7 x 10-14 g g-1 and -15 g g-1. In addition 237Np was detected at ultratrace levels. In general, ICP-MS and α-spectrometry results were in good agreement.The presence of anthropogenic radionuclides (236U, 239Pu,240Pu, 241Am, and 237Np) in the penetrators indicates that at least part of the uranium originated from the reprocessing of nuclear fuel. Because the concentrations of radionuclides are very low, their radiotoxicological effect is negligible. (orig.)

  13. 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)

  14. Determination of 236Np(n,f) cross-section using surrogate ratio method

    Surrogate strategy is widely used to determine (n,f) cross-sections. Hybrid ratio approach is used to get 236Np(n,f) cross-section for which there is no experimental data available beyond 7 MeV till date. 237Np and 239Pu are produced over the similar excitation energy range (20.4-25.4 MeV) using 235U(6Li,α)237Np and 235U(6Li,d)239Pu reactions respectively. The ground state Q values for these two reactions are 7.707 MeV and - 6.718 respectively. Hence 237Np and 239Pu can be populated at overlapping excitation energies in 6Li + 235U transfer reactions for bombarding energies around 44.4 MeV. Fission probabilities of these two compound nuclei are measured and the desired cross-sections are determined using the following formula based on Weisskopf-Ewing approximation. Measurements were carried out using 44.4 MeV 6Li beam (from BARC-TIFR Pelletron) and 1.6 mg/cm2 thick 235U target (with 4.5 mg/cm2 thick Ni-Cu backing). Four telescopes (ΔE-E) made of silicon surface barrier detectors, used to detect light charged particles, were kept 100 apart covering 700-1000. A large area silicon detector (with a solid angle ∼ 33 msr and an angular coverage of 1540- 1660) was used to detect fission fragments. Two monitor detectors were placed at forward angles. Results for 236Np(n,f) cross sections using the yields from the forward most telescope are shown. Contributions from Ni-Cu backing in inclusive counts have been subtracted out. The experimental results are consistent with the EMPIRE3.1 calculations

  15. Rapid methods for determination of small amount of actinides in waste waters

    A rapid method of plutonium and actinide sum (Ac) (except uranium) determination in waste waters has been developed. For rapid isolation of 239Pu and Ac sum a method of extraction to iron hydroxide myomphate (IHM), consisting in Ac deposition on iron hydroxide, solvent extraction by monoisooctylmethylphosphinic acid and flotation of the disperse phase into solid extract of IHM, has been applied. The method permits to concentrate plutonium quantitatively from solutions in all of its forms, including colloid ones. For analysis of solid extracts α-spectroimetric instrumentation is used. The analysis sensitivity is 1 Bg/l, relative standard deviation - 0.3. 10 refs.; 1 fig.; 2 tabs

  16. Challenge in determination of long-lived radionuclides by ICP-MS

    The ultra-trace and isotope analysis of long-lived radionuclides in environmental materials (in biological or geological samples and waters) is relevant of increasing importance [1-5].E.g., the determination of long-lived radionuclides is for the detection of radionuclide contamination in environmental materials in which several radioactive nuclides (e.g.99Tc, 129I , 237Np, 239Pu, 240Pu, 241Am) are present from fallout due to nuclear weapons testing, nuclear power plants or nuclear accidents. Especially, isotope ratios of uranium and plutonium [6] can indicate the origin of contamination in the environmental samples

  17. Determination of 236Np(n,f) and 238Pu(n,f) cross-sections using surrogate reactions

    Cross sectional data for 236Np(n,f) reaction is not available for neutron energies beyond 4.32 MeV. In this work, we have determined the cross-section of the above reaction for the neutron energy range En=10-18 MeV using ‘Hybrid Surrogate Ratio’ method via 235U(6Li, α)237Np and 235U(6Li,d)239Pu reactions. The cross-sections for 238Pu(n,f) reaction available in literature have been used as a reference for the above surrogate method

  18. Determination of Pu content in a Spent Fuel Assembly by Measuring Passive Total Neutron count rate and Multiplication with the Differential Die-Away Instrument

    Henzl, Vladimir [Los Alamos National Laboratory; Croft, Stephen [Los Alamos National Laboratory; Swinhoe, Martyn T. [Los Alamos National Laboratory; Tobin, Stephen J. [Los Alamos National Laboratory

    2012-07-13

    Inspired by approach of Bignan and Martin-Didier (ESARDA 1991) we introduce novel (instrument independent) approach based on multiplication and passive neutron. Based on simulations of SFL-1 the accuracy of determination of {sup tot}Pu content with new approach is {approx}1.3-1.5%. Method applicable for DDA instrument, since it can measure both multiplication and passive neutron count rate. Comparison of pro's & con's of measuring/determining of {sup 239}Pu{sub eff} and {sup tot}Pu suggests a potential for enhanced diversion detection sensitivity.

  19. Determination of plutonium isotopes in freshwater lake sediments by sector-field ICP-MS after separation using ion-exchange chromatography

    The determination of Pu isotopes in lake sediments is important for many studies, such as Pu pollution source identification, sediment mixing estimation, erosion evaluation and establishment of deposition chronology in lakes. In this paper, a simple analytical method using sector field inductively coupled plasma mass spectrometry (ICP-MS) combined with two-stage chromatographic separation and purification of Pu was developed based on the optimization and adaptation of the previously published method for marine samples with an emphasis on the study of the elimination of interferences for the analysis of freshwater lake sediments. A strong base anion-exchange resin (AG MP-1M) was used to purify Pu isotopes with concentrated HBr as the final eluent for Pu elution. The chemical yields were ca. 64% and the decontamination factor for U was ca. 105. The developed method was validated using a freshwater lake sediment reference material (SRM-4354) and a marine sediment reference material (IAEA-368), and applied to the determination of Pu isotopes in sediment samples of Lake Poyang, East China. For the analysis of certified reference materials, both 239+240Pu activity of 31.6 mBq g-1 and 240Pu/239Pu atom ratio of 0.033 for IAEA-368 were comparable to the certified value and/or literature values. As for SRM-4354, 239+240Pu activity of 3.90 mBq g-1 agreed well with the certified value. However, the mean 240Pu/239Pu atom ratio of 0.144 was lower than those reported by other laboratories. This difference suggested that this material may be isotopically inhomogeneous. 240Pu/239Pu atom ratios of Poyang Lake sediment samples ranged from 0.185 to 0.192 with a mean value of 0.187±0.004, indicating that plutonium pollution originated from global fallout

  20. Analytical method for the determination of Np and Pu in sea water by AMS with respect to the Fukushima accident

    Hain, K.; Faestermann, T.; Famulok, N.; Fimiani, L.; Gómez-Guzmán, J. M.; Korschinek, G.; Kortmann, F.; Lierse v. Gostomski, Ch.; Ludwig, P.; Shinonaga, T.

    2015-10-01

    A chemical separation procedure for plutonium (Pu) and neptunium (Np) was developed using extraction chromatography, mass spectrometry and radiometric analysis to determine their concentrations and isotopic ratios in sea water. 241Am, which causes isobaric background to 241Pu in mass spectrometric measurements, was successfully separated from the Pu fraction by this method. Water samples which were spiked with 242Pu and 237Np or 239Np, respectively, were used for chemical yield determination. The chemical yields of Pu and Np, which were determined by alpha and gamma spectrometry at the Radiochemie München (RCM), of more than 85% were obtained. The developed method was applied to analyze the concentration of Pu and Np in the certified reference material, IAEA-443, by Accelerator Mass Spectrometry (AMS) at the Maier-Leibnitz-Laboratory (MLL) to check the applicability of the method to sea water samples. The concentrations of 240Pu, 241Pu and 237Np obtained in this study are in agreement with the certified and literature values within the uncertainties. Due to strong isotopic interference of 239Pu with 238U, it was not possible to analyze the concentration of 239Pu. Some modifications of the chemical separation method to suppress the uranium (U) fraction are under consideration. This method can be used for the analysis of Pu and Np in Pacific Ocean water samples collected after the Fukushima accident.

  1. DETERMINATION OF 237NP AND PU ISOTOPES IN LARGE SOIL SAMPLES BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY

    Maxwell, S.

    2010-07-26

    A new method for the determination of {sup 237}Np and Pu isotopes in large soil samples has been developed that provides enhanced uranium removal to facilitate assay by inductively coupled plasma mass spectrometry (ICP-MS). This method allows rapid preconcentration and separation of plutonium and neptunium in large soil samples for the measurement of {sup 237}Np and Pu isotopes by ICP-MS. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via {sup 238}U peak tailing. The method provides enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then transferring Pu to DGA resin for additional purification. The decontamination factor for removal of uranium from plutonium for this method is greater than 1 x 10{sup 6}. Alpha spectrometry can also be applied so that the shorter-lived {sup 238}Pu isotope can be measured successfully. {sup 239}Pu, {sup 242}Pu and {sup 237}Np were measured by ICP-MS, while {sup 236}Pu and {sup 238}Pu were measured by alpha spectrometry.

  2. Routine radiochemical method for the determination of 90Sr, 238Pu, 239+240Pu, 241Am and 244Cm in environmental samples

    Routine analytical procedures have been developed for the reliable simultaneous determination of 90Sr, 238Pu, 239+240Pu, 241Am and 242-244Cm, Chernobyl derived radioisotopes and fallout after nuclear weapon tests in a wide range of environmental samples: soil (100-200 g), sediments, aerosols, water and vegetation. This procedure has been applied to thousands of soil and sediment samples and hundreds of biological and water samples taken in the exclusive zone of Chernobyl NPP and different regions of Ukraine from 1989 to the present. After the sample has been properly prepared and isotopic tracers added, plutonium, americium and curium are precipitated with calcium oxalate and then lanthanum fluoride. Plutonium is separated from americium and curium by anion-exchange. Americium and curium are separated from rare earths by cation-exchange with gradient elute α-hydroxy-iso-butyric acid. During projects by AQCS IAEA 'Evaluation of Methods for 90Sr in a Mineral Matrix' and 'Proficiency Test for 239Pu, 241Pu and 241Am Measurement in a Mineral Matrix' accuracy and precision for 90Sr, 239Pu and 241Am by present procedure was evaluated. Advantages, difficulties and limitations of the method are discussed. (author)

  3. Determination of actinides in environmental and biological samples using high-performance chelation ion chromatography coupled to sector-field inductively coupled plasma mass spectrometry.

    Truscott, J B; Jones, P; Fairman, B E; Evans, E H

    2001-08-31

    High-performance chelation ion chromatography, using a neutral polystyrene substrate dynamically loaded with 0.1 mM dipicolinic acid, coupled with sector-field inductively coupled plasma mass spectrometry has been successfully used for the separation of the actinides thorium, uranium, americium, neptunium and plutonium. Using this column it was possible to separate the various actinides from each other and from a complex sample matrix. In particular, it was possible to separate plutonium and uranium to facilitate the detection of the former free of spectral interference. The column also exhibited some selectivity for different oxidation states of Np, Pu and U. Two oxidation states each for plutonium and neptunium were found, tentatively identified as Np(V) and Pu(III) eluting at the solvent front, and Np(IV) and Pu(IV) eluting much later. Detection limits were 12, 8, and 4 fg for 237Np, 239Pu, and 241Am, respectively, for a 0.5 ml injection. The system was successfully used for the determination of 239Pu in NIST 4251 Human Lung and 4353 Rocky Flats Soil, with results of 570+/-29 and 2939+/-226 fg g(-1), respectively, compared with a certified range of 227-951 fg g(-1) for the former and a value of 3307+/-248 fg g(-1) for the latter. PMID:11589474

  4. Ionization potential of neutral atomic plutonium determined by laser spectroscopy

    The ionization potential of the neutral plutonium atom, Pu i, has been determined by two- and three-step resonance photoionization observation of the threshold of ionization and of the Rydberg series. The Rydberg series were observed by field ionization as series that converge to the first ionization limit and as autoionizing series the converge to the second and to several higher convergence limits. The threshold and Rydberg series were obtained through a number of two- and three-step pathways. The photoionization threshold value for the 239Pu i ionization potential is 48 582(30) cm-1, and the more accurate value from the Rydberg series is 48 604(1) cm-1 or 6.0262(1) eV

  5. Preliminary studies for the determination of alpha emitters using the gross alpha coprecipitation methods

    The radiological quality of drinking water in Spain is regulated by Nuclear Security Guideline No, 7.7 (Rev.1) of the Nuclear Security Council (NSC). this guideline establishes the protocol to follow when the radiological level exceeds 0,1 Bq.l''1. When this level is passed, the responsible alpha emitter must be identified; ''210 Po, ''226Ra, ''230Th, ''239Pu, ''224Ra, ''234 U and ''138 U. Activity due to these isotopes is usually determined using alpha spectrometry with semiconductor detectors. This method allows the activity of the alpha emitters to be determined with a good sensitivity. however, it requires long radiochemical isolations and long counting times, so the method is not suitable for rough estimate radiological analysis. In this preliminary work, we present the conditioning of the sample-precipitate that is essential for further radiochemical isolations. (Author) 9 refs

  6. Determination of actinide elements in environmental samples by ICP-MS

    Methods for the determination of the actinide elements in water, biological, soil and sediment samples have been developed using on-line solid phase extraction and high performance liquid chromatography (HPLC) coupled with inductively coupled plasma mass spectrometry (ICP-MS). Initial applications utilised a commercially available resin, namely TRU-Spec resin, for efficient removal of the matrix prior to elution of uranium and thorium analytes. Comparative analyses of reference materials and natural water samples from Plymouth and Dartmoor demonstrated significant improvement in precision and speed of analysis by using TRU-Spec coupled to ICP-MS compared with alpha spectrometry. Further applications of the TRU-Spec resin for the determination of the transuranic actinide elements neptunium, plutonium and americium, resulted in the successful determination of 239Pu and 217Np in biological reference materials. Detection limits were 700, 850, and 600 attograms (ag) for 237Np, 233Pu, and 241Am, respectively, for a 0.5 mI sample injection, and better than 200 ag g-1 with 50 ml pre-concentration when sector field (SF) ICP-MS was used. A method for the selective sequential elution of uranium and plutonium was also developed to facilitate the determination of 239Pu without interference due to the 238U1H+ polyatomic ion, caused by high concentrations of 238U in sediment samples. Investigations were performed into the use of a polymeric substrate, which was dynamically coated with chelating dyes such as xylenol orange and 4-(2-pyridylazo) resorcinol, and a silica substrate coated with permanently bonded iminodiacetic acid. The latter was used for the successful determination of uranium and thorium in certified reference material waters. However, the column was found to have a high affinity for iron, making it unsuitable for the determination of the actinides in soil and sediment samples. Subsequently, a polystyrene substrate which was dynamically coated with dipicolinic acid

  7. Characterisation and determination of the neutron transmission properties of sodium-calcium and sodium borates from different regions in Turkey

    In this study, ulexite, probertite found within sodium-calcium borates and borax, and tincalconite found within sodium borates retrieved from different regions in Turkey are evaluated for their neutron irradiation performances. Characterisations were performed using XRD, FT-IR, Raman spectroscopy. B2O3 contents were determined experimentally, structural water contents and surface morphologies were determined using DTA/TG and SEM. Neutron transmission values and total macroscopic cross-sections were determined using 239Pu-Be source moderated in a howitzer. Neutron transmission values from lowest to highest were found to be as follows: secondary ulexite (Kirka), tincalconite (Kirka), ulexite (Kestelek), ulexite (Kirka), borax (Kirka), probertite (Kestelek) and ulexite (Bigadic). (author)

  8. 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)

  9. Late effects of 239Pu injection in adult, weanling, newborn, and fetal rats

    Exposure to Pu decreased the latency of mammary tumor induction in all age groups; incidence varied with the age at injection, and with the dose. There were age-related differences in the effect of plutonium exposure on pituitary tumor incidence, as well as an association between the presence of both mammary and pituitary tumors. Prenatal exposure also increased the incidence of adrenal and pancreatic neoplasms in males

  10. Measurement and analysis of anti ν energy dependence for 233U, 238U, 239Pu

    The energy dependence of the average yield of prompt neutrons per fission (anti ν) for U233, U238 and Pu239 in the incident neutron energy range (Esub(n)) up to 5 MeV has been studied using an electrostatic accelerator. The recommended curves for anti ν (Esub(n)) has been obtained with the help of the polynomial least square method fitting. The resons of deviations from the linear dependence have been analysed

  11. Critical dimensions of systems containing 235U, 239Pu, and 233U: 1986 Revision

    This report is primarily a compilation of critical data obtained from experiments performed in a number of laboratories during the period of 1945 through 1985. It supplements the Nuclear Safety Guide [Report TID-7016 (Rev. 2)] in presenting critical data on which recommendations of the Guide are based. It must be emphasized that this report gives critical data without safety factors, so it is no substitute for the Guide or for the related document, The American National Standard for Nuclear Criticality Safety in Operations with Fissionable Materials Outside Reactors. Critical measurements with materials of interest in desired configurations yield information of greatest usefulness and accuracy. Where it is not feasible to obtain the desired critical data, for example, as a result of safety restrictions, subcritical data may be directly applicable, and in some cases may be extrapolated to approximate critical conditions. Critical conditions also may be approximated from the distribution of neutrons introduced into a subcritical assembly. These ''exponential experiments'' may be the only alternative where the quantity of material required is too great for a critical experiment. Calculated extensions of experimental data are included to show the nature of trends, not to substitute for results of experiments. They should be used with caution. A fundamental aim of this document is to illustrate relationships among critical data. The compilation and correlation of data for this purpose, from many measurements in a number of laboratories, require a certain amount of normalization or reduction to common terms. Frequently, for example, the effects of variations in geometry or density must be removed to show trends in data. The manner in which these alterations may be made is discussed in the early section Relations for Conversion to Standard Conditions. 195 refs

  12. Evaluation of Cross-Sections Uncertainties using Physical Constraints 238U, 239Pu and others..

    This presentation reports on nuclear data activities at CEA Cadarache, e.g. marginalization techniques to account for systematic uncertainties, use of Lagrange multipliers to impose simultaneous consistency constraints on several models, assimilation of integral data during the evaluation process, adjustment of nuclear reaction model parameters, evaluation of covariance matrices, etc. The CEA activities cover both differential and integral data and the possible synergies between SG39 and SG40-CIELO are highlighted. These two new subgroups have the potential to link evaluation and integral experiments beyond the traditional validation issues

  13. Characterization of peripheral-blood lymphocytes in lymphocytopenic dogs exposed to 239PuO2

    Mitogen stimulation assays of canine peripheral-blood lymphocytes in whole-blood and density-gradient-isolated lymphocyte cultures showed that a functional decrease had occurred in these lymphocyte populations from plutonium-exposed dogs, suggesting an alteration in immunocompetence

  14. Quantative autoradiography of inhaled 239PuO2 in the lung

    PuO2 particles behaved similarly in the lungs of rat and hamster. The relative concentrations of PuO2 up to 1-yr postexposure were 1.0 for lung parenchyma, 1.3 for subpleural areas, 0.5 for peribronchiolar regions and 0.2 for perivascular regions in the lungs

  15. Subcellular distribution of 239Pu in the liver of rat, mouse, Syrian and Chinese hamster

    An attempt was made to elucidate the biochemical mechanisms responsible for the species differences in the biological half life of plutonium-239 in the liver of rats, mice, Syrian hamsters and Chinese hamsters. Six days after intravenously administered Pu-239, the animals were given Triton i.p. which causes a shift of the density of the lysosomes and thus any lysosomally-associated material can be recognised by a parallel shift. On the tenth day, an MLP fraction was obtained by differential centrifugation of the liver homogenates; the distribution of radioactivity and marker enzymes was then examined after centrifugation of the MLP fraction in a sucrose density gradient. If the parallelism between the shift of Pu-239 and acid phosphatase is taken as a measure for the extent of lysosomal binding, there is clear evidence for association with these organelles for rats and mice, the species with rapid Pu elimination; however these organelles appear to become less important in the species with longer Pu retention, Syrian and especially Chinese hamster. (U.K.)

  16. Oncogene expression in primary lung tumors in dogs that inhaled 239PuO2

    Ten radiation-induced and three spontaneous lung tumors were analyzed for aberrant expression of known oncogenes. In 12 of 13 tumors tested, sequences hybridizing to the c-myc oncogene were expressed at levels 1.5 times higher than sequences hybridizing to β-actin. This level of oncogene expression was also observed in 9 of 13 tumors for 1 or more members of the ras family of oncogenes. Seven of thirteen tumors examined express sequences that hybridize with clones of v-ros or c-met. The ros and met clones both code for oncogenes whose normal homologues are transmembrane proteins related to the insulin receptor. (author)

  17. Distribution of 241Am in the human body as determined by external counting

    Methods for determining the distribution of 241Am within the body of a contaminated subject and their application to several cases under study at the Center for Human Radiobiology are described. In general, 241Am is found in the lungs even at long times after inhalation, and systemic 241Am is observed to deposit in the liver and to label the skeleton in a fairly uniform manner; similar findings have been reported in animal studies (L172). Further analysis of the skeletal distribution of 241Am indicates deposition on bone surfaces. In contrast, the distribution of injected 239Pu in an (abnormal) skeleton is rather non-uniform when compared to that of 241Am

  18. Development of NDA reactivity measurement method to determine the fissile contents for spent fuel

    NDA reactivity measurement method was developed and simulated for the possible use in determination of fissile content and its reactivity characteristics of spent fuel material. This is necessary and practical for the purpose of safeguards implementation and timely control of process line under the condition of very high radiation environment. The neutron detector response due to induced fission from fissile material in spent fuel is calculated by using the MCNP model. The effects of detector response on fissile content, burnup and initial enrichment of fuel are investigated. It shows that the detector response of spent fuel contained 239Pu and fission products is slightly higher than that of flesh fuel with coresponding 235U enrichment

  19. Determination of actinides by alpha spectrometric methods

    The submitted thesis in its first part concern with content determination of plutonium, americium, uranium, thorium radionuclides, like the most significant representatives of actinides in environmental patterns, where by the primary consideration is a focusing on content of these actinides in samples of superior mycotic organisms - mushrooms. Following the published studies the mushrooms were monitored as organisms that could verify most of attributes putted on bioindicators in term of observation of substantial radionuclides in living environment. There were analyzed two groups of samples that came from two chosen locations, one of them is situated in Eastern Slovakia and the second one in West Slovakia. Except for mushrooms samples the examined radionuclides volumes were determined even in specimens of soil sub-base and some plants from chosen localities. The liquid - liquid extraction methods were used for determination of mass activities of actinides in samples for radiochemical separation of monitored radionuclides. The obtained results of plutonium and americium mass activities determination's lead us to carry out experiments that proved abilities of superior mycotic organisms to absorb and accumulate alpha radionuclides in their textures. We choose the oyster mushroom (Pleurotus ostreatus) species as an experimental object. Sporocarps of this mushroom were cultivated on substratum which is commercially exploited to cultivate it whereby this substratum was purposely contaminated by known activities of 239Pu and 241Am. We prepared five autonomous samples together. The values of mass activities of 239Pu and 241Am obtained by following analysis of prepared samples showed the ability of mushrooms to absorb observed actinides in their texture structures. On the basis of obtained mass activities it was possible to evaluate and numerically determine a transmitting factor's attributes of monitored radionuclides in sporocarps and in sub-base. Accordingly we defined

  20. Improved radioanalytical method for the simultaneous determination of Th, U, Np, Pu and Am(Cm) on a single TRU column by alpha spectrometry and ICP-MS

    Macsik, Z.; Groska, J.; Vajda, N. [RadAnal Ltd., Budapest (Hungary); Vogt, S.; Kim, C.S.; Maddison, A.; Donohye, D. [IAEA, Seibersdorf (Austria). Environmental Sample Lab.; Kis-Benedek, G. [IAEA, Seibersdorf (Austria). Terrestrial Environment Lab.

    2013-05-01

    A radioanalytical method based on the use of a single TRU extraction chromatographic column and selective, on-column oxidation state adjustment of actinides was developed for the determination of Th, U, Np, Pu and Am(Cm) in environmental samples (such as sediment and swipe samples). The procedure of Vajda et al. was further investigated and optimized focusing on the separation of Th, U and Np. The improved method combines two measurement techniques - alpha spectrometry and inductively coupled plasma mass spectrometry (ICP-MS) - which allows to obtain more reliable information on a wider range of isotopes: {sup 228}Th, {sup 230}Th, {sup 232}Th, {sup 234}U, {sup 235}U, ({sup 236}U), {sup 238}U, {sup 237}Np, {sup 238}Pu, {sup 239}Pu, {sup 240}Pu, {sup 241}Pu, {sup 241}Am, {sup 242}Cm, {sup 243}Cm and {sup 244}Cm from one sample. (orig.)

  1. Rapid and simultaneous determination of neptunium and plutonium isotopes in environmental samples by extraction chromatography using sequential injection analysis and ICP-MS

    Qiao, Jixin; Hou, Xiaolin; Roos, Per;

    2010-01-01

    This paper reports an automated analytical method for rapid and simultaneous determination of plutonium isotopes (239Pu and 240Pu) and neptunium (237Np) in environmental samples. An extraction chromatographic column packed with TrisKem TEVA® resin was incorporated in a sequential injection (SI......) system for the isolation of plutonium and neptunium from matrix elements and interfering nuclides. Valence adjustment is a crucial step to ensure the same chemical behavior of plutonium and neptunium onto the TEVA column and consequently to accomplish their simultaneous separation and detection. Distinct...... procedures were investigated and compared for the adjustment of oxidation states of plutonium and neptunium to Pu(IV) and Np(IV), respectively. A two-step protocol using sulfite and concentrated nitric acid as redox reagents was proven to be the most effective method. The analytical results for both...

  2. Improved radioanalytical method for the simultaneous determination of Th, U, Np, Pu and Am(Cm) on a single TRU column by alpha spectrometry and ICP-MS

    A radioanalytical method based on the use of a single TRU extraction chromatographic column and selective, on-column oxidation state adjustment of actinides was developed for the determination of Th, U, Np, Pu and Am(Cm) in environmental samples (such as sediment and swipe samples). The procedure of Vajda et al. was further investigated and optimized focusing on the separation of Th, U and Np. The improved method combines two measurement techniques - alpha spectrometry and inductively coupled plasma mass spectrometry (ICP-MS) - which allows to obtain more reliable information on a wider range of isotopes: 228Th, 230Th, 232Th, 234U, 235U, (236U), 238U, 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 241Am, 242Cm, 243Cm and 244Cm from one sample. (orig.)

  3. Non-destructive assay of EBR-II blanket elements using resonance transmission analysis.

    Klann, R.T.; Poenitz, W.P.

    1998-09-11

    Resonance transmission analysis utilizing a faltered reactor beam was examined as a means of determining the {sup 239}Pu content in Experimental Breeder Reactor-II depleted uranium blanket elements. The technique uses cadmium and gadolinium falters along with a {sup 239}Pu fission chamber to isolate the 0.3 eV resonance in {sup 239}Pu. In the energy range of this resonance (0.1 eV to 0.5 ev), the total microscopic cross-section of {sup 239}Pu is significantly greater than the cross-sections of {sup 238}U and {sup 235}U. This large difference allows small changes in the {sup 239}Pu content of a sample to result in large changes in the mass signal response. Tests with small stacks of depleted uranium and {sup 239}Pu foils indicate a significant change in response based on the {sup 239}Pu content of the foil stack. In addition, the tests indicate good agreement between the measured and predicted values of {sup 239}Pu up to approximately two weight percent.

  4. Non-destructive assay of EBR-II blanket elements using resonance transmission analysis

    Resonance transmission analysis utilizing a faltered reactor beam was examined as a means of determining the 239Pu content in Experimental Breeder Reactor-II depleted uranium blanket elements. The technique uses cadmium and gadolinium falters along with a 239Pu fission chamber to isolate the 0.3 eV resonance in 239Pu. In the energy range of this resonance (0.1 eV to 0.5 ev), the total microscopic cross-section of 239Pu is significantly greater than the cross-sections of 238U and 235U. This large difference allows small changes in the 239Pu content of a sample to result in large changes in the mass signal response. Tests with small stacks of depleted uranium and 239Pu foils indicate a significant change in response based on the 239Pu content of the foil stack. In addition, the tests indicate good agreement between the measured and predicted values of 239Pu up to approximately two weight percent

  5. A semi-experimental nodal synthesis method for the on-line reconstruction of three-dimensional neutron flux-shapes and reactivity

    Jacqmin, R.P.

    1991-12-10

    The safety and optimal performance of large, commercial, light-water reactors require the knowledge at all time of the neutron-flux distribution in the core. In principle, this information can be obtained by solving the time-dependent neutron diffusion equations. However, this approach is complicated and very expensive. Sufficiently accurate, real-time calculations (time scale of approximately one second) are not yet possible on desktop computers, even with fast-running, nodal kinetics codes. A semi-experimental, nodal synthesis method which avoids the solution of the time-dependent, neutron diffusion equations is described. The essential idea of this method is to approximate instantaneous nodal group-fluxes by a linear combination of K, precomputed, three-dimensional, static expansion-functions. The time-dependent coefficients of the combination are found from the requirement that the reconstructed flux-distribution agree in a least-squares sense with the readings of J ({ge}K) fixed, prompt-responding neutron-detectors. Possible numerical difficulties with the least-squares solution of the ill-conditioned, J-by-K system of equations are brought under complete control by the use of a singular-value-decomposition technique. This procedure amounts to the rearrangement of the original, linear combination of K expansion functions into an equivalent more convenient, linear combination of R ({le}K) orthogonalized modes'' of decreasing magnitude. Exceedingly small modes are zeroed to eliminate any risk of roundoff-error amplification, and to assure consistency with the limited accuracy of the data. Additional modes are zeroed when it is desirable to limit the sensitivity of the results to measurement noise.

  6. A semi-experimental nodal synthesis method for the on-line reconstruction of three-dimensional neutron flux-shapes and reactivity. Final report

    Jacqmin, R.P.

    1991-12-10

    The safety and optimal performance of large, commercial, light-water reactors require the knowledge at all time of the neutron-flux distribution in the core. In principle, this information can be obtained by solving the time-dependent neutron diffusion equations. However, this approach is complicated and very expensive. Sufficiently accurate, real-time calculations (time scale of approximately one second) are not yet possible on desktop computers, even with fast-running, nodal kinetics codes. A semi-experimental, nodal synthesis method which avoids the solution of the time-dependent, neutron diffusion equations is described. The essential idea of this method is to approximate instantaneous nodal group-fluxes by a linear combination of K, precomputed, three-dimensional, static expansion-functions. The time-dependent coefficients of the combination are found from the requirement that the reconstructed flux-distribution agree in a least-squares sense with the readings of J ({ge}K) fixed, prompt-responding neutron-detectors. Possible numerical difficulties with the least-squares solution of the ill-conditioned, J-by-K system of equations are brought under complete control by the use of a singular-value-decomposition technique. This procedure amounts to the rearrangement of the original, linear combination of K expansion functions into an equivalent more convenient, linear combination of R ({le}K) orthogonalized ``modes`` of decreasing magnitude. Exceedingly small modes are zeroed to eliminate any risk of roundoff-error amplification, and to assure consistency with the limited accuracy of the data. Additional modes are zeroed when it is desirable to limit the sensitivity of the results to measurement noise.

  7. A semi-experimental nodal synthesis method for the on-line reconstruction of three-dimensional neutron flux-shapes and reactivity

    The safety and optimal performance of large, commercial, light-water reactors require the knowledge at all time of the neutron-flux distribution in the core. In principle, this information can be obtained by solving the time-dependent neutron diffusion equations. However, this approach is complicated and very expensive. Sufficiently accurate, real-time calculations (time scale of approximately one second) are not yet possible on desktop computers, even with fast-running, nodal kinetics codes. A semi-experimental, nodal synthesis method which avoids the solution of the time-dependent, neutron diffusion equations is described. The essential idea of this method is to approximate instantaneous nodal group-fluxes by a linear combination of K, precomputed, three-dimensional, static expansion-functions. The time-dependent coefficients of the combination are found from the requirement that the reconstructed flux-distribution agree in a least-squares sense with the readings of J (≥K) fixed, prompt-responding neutron-detectors. Possible numerical difficulties with the least-squares solution of the ill-conditioned, J-by-K system of equations are brought under complete control by the use of a singular-value-decomposition technique. This procedure amounts to the rearrangement of the original, linear combination of K expansion functions into an equivalent more convenient, linear combination of R (≤K) orthogonalized ''modes'' of decreasing magnitude. Exceedingly small modes are zeroed to eliminate any risk of roundoff-error amplification, and to assure consistency with the limited accuracy of the data. Additional modes are zeroed when it is desirable to limit the sensitivity of the results to measurement noise

  8. The SMORES capability for minimum critical mass determination

    The purpose of the present work is to illustrate the capability of SMORES - a new sequence incorporated in SCALE-5, for automated minimum critical mass (MCM) determination. The illustration is done by identifying the MCM of spherical systems of 233U, 235U or 239Pu moderated and reflected with either D2O or a combination of polyethylene and Be. The latter provide the lowest critical mass of, respectively, 151.7 g, 202.2 g and 119.0 g. These masses are close to a factor of 2 lower than the MCM of the corresponding fissile material with D2O and close to a factor of 4 for the MCM in H2O. The fissile material concentration exhibit a spike near the core outer boundary, at the interface between the polyethylene and Be. The SMORES sequence of SCALE 5 could be useful for determining margins of subcriticality and for other applications encountered by the criticality safety community. (author)

  9. Nondestructive NMR technique for moisture determination in radioactive materials

    This progress report focuses on experimental and computational studies used to evaluate nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) for detecting, quantifying, and monitoring hydrogen and other magnetically active nuclei (3H, 3He, 239Pu, 241Pu) in Spent nuclear fuels and packaging materials. The detection of moisture by using a toroid cavity NMR imager has been demonstrated in SiO2 and UO2 systems. The total moisture was quantified by means of 1H NMR detection of H2O with a sensitivity of 100 ppm. In addition, an MRI technique that was used to determine the moisture distribution also enabled investigators to discriminate between bulk and stationary water sorbed on the particles. This imaging feature is unavailable in any other nondestructive assay (NDA) technique. Following the initial success of this program, the NMR detector volume was scaled up from the original design by a factor of 2000. The capacity of this detector exceeds the size specified by DOE-STD-3013-96

  10. Nondestructive NMR technique for moisture determination in radioactive materials.

    Aumeier, S.; Gerald, R.E. II; Growney, E.; Nunez, L.; Kaminski, M.

    1998-12-04

    This progress report focuses on experimental and computational studies used to evaluate nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) for detecting, quantifying, and monitoring hydrogen and other magnetically active nuclei ({sup 3}H, {sup 3}He, {sup 239}Pu, {sup 241}Pu) in Spent nuclear fuels and packaging materials. The detection of moisture by using a toroid cavity NMR imager has been demonstrated in SiO{sub 2} and UO{sub 2} systems. The total moisture was quantified by means of {sup 1}H NMR detection of H{sub 2}O with a sensitivity of 100 ppm. In addition, an MRI technique that was used to determine the moisture distribution also enabled investigators to discriminate between bulk and stationary water sorbed on the particles. This imaging feature is unavailable in any other nondestructive assay (NDA) technique. Following the initial success of this program, the NMR detector volume was scaled up from the original design by a factor of 2000. The capacity of this detector exceeds the size specified by DOE-STD-3013-96.

  11. Radiolytic oxidation of UO{sub 2} pellets doped with alpha-emitters ({sup 238/239}Pu)

    Muzeau, B. [Commissariat a l' Energie Atomique, Rhone Valley Research Center DTCD/SECM/LMPA, BP 17 171, 30207 Bagnols-sur-Ceze Cedex (France); Jegou, C. [Commissariat a l' Energie Atomique, Rhone Valley Research Center DTCD/SECM/LMPA, BP 17 171, 30207 Bagnols-sur-Ceze Cedex (France)], E-mail: christophe.jegou@cea.fr; Delaunay, F. [Commissariat a l' Energie Atomique, Valduc Research Center, 21120 Is-sur-Tille (France); Broudic, V. [Commissariat a l' Energie Atomique, Rhone Valley Research Center DTCD/SECM/LMPA, BP 17 171, 30207 Bagnols-sur-Ceze Cedex (France); Brevet, A. [Commissariat a l' Energie Atomique, Valduc Research Center, 21120 Is-sur-Tille (France); Catalette, H. [Electricite de France, Les Renardieres Research Center, Route de Sens Ecuelles, 77250 Moret-sur-Loing (France); Simoni, E. [Institut de Physique Nucleaire, Bat. 100, 91406 Orsay Cedex (France); Corbel, C. [Laboratoire des Solides Irradies, UMR 7642-CNRS-CEA-Ecole Polytechnique, Ecole Polytechnique, 91128 Palaiseau Cedex (France)

    2009-01-07

    To assess the impact of alpha radiolysis of water on the oxidative dissolution of UO{sub 2} under anoxic conditions, two series of plutonium-doped samples (specific alpha activity 385 and 18 MBqg{sub UO{sub 2}}{sup -1}) were fabricated, characterized and leached in water of varying complexity (pure water, carbonated water, dissolved hydrogen). Given the very high reactivity of these samples in the presence of air and in order to minimize any prior surface oxidation, a strict experimental protocol was developed based on high-temperature annealing in Ar + 4% H{sub 2} with preleaching cycles. Failure to follow this protocol prevents absolute quantification of oxidation of the UO{sub 2} surface by water radiolysis in solutions. Preoxidation of the pellet surface can lead to uranium release in solution that is dependent on the alpha particle flux, revealing initial oxidation by radiolysis in air including potential traces of water. This makes difficult the accurate quantification of the radiolytic oxidation in water solutions. Controlling the initial surface condition of the samples finally allowed us to demonstrate that radiolytic oxidation in water-saturated media is governed by several threshold effects for which the main parameters are the sample alpha activity and the hydrogen concentration.

  12. 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)

  13. Comparison and development of new extraction procedures for 239Pu, Ca, Fe and Cu organic complexes in soil

    Two new extraction methods - the silylation of the organic constituents of soil with trimethylchlorosilane (TMCS) and triethylchlorosilane (TECS) in the presence of dimethylformamide (DMF) -have been developed for mobilization of the organic complexes of Ca, Fe, Cu and Pu which might exist in some soils. By silylation of the carboxylic, phenolic, alcoholic and perhaps the amino moieties of humic and fulvic acids (the principal organic constituents of soils) the authors have modified the solubility of the humic substances with perhaps a minimum perturbation of the humate-metal ion complexes. These new extraction procedures, which used a non-aqueous solvent, have been compared with a variety of aqueous extraction procedures (sodium hydroxide, 1 M potassium chloride and diethylene triaminepentaacetic acid solution) and found to be superior in the release of the elements from soils. (author)

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

    Regnier, D.; Dubray, N.; 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 ...

  15. Final Report for Nuclear Resonance Fluorescence Measurements of 239Pu above 2.5 MeV

    Johnson, M S; McNabb, D P

    2009-01-07

    Nuclear Resonance Fluorescence measurements were performed at the free electron laser facility at UC Santa Barbara using a bremsstrahlung beam. Three endpoint energies were chosen for the bremsstrahlung to cover as much area above 2.5 MeV as possible. We were able to set an upper limit of NRF state strengths between 2.5 and 3.8 MeV at roughly 38(5) eV barns at the 4-sigma level and 9(2) eV barns at the 1-sigma level. Published results on states near 2.4 MeV indicate strengths about 10(2) eV barns. Details of the results are presented in this report.

  16. Spatial statistical analysis of contamination level of 241Am and 239Pu, Thule, North-West Greenland

    Strodl Andersen, J. (JSA EnviroStat (Denmark))

    2011-10-15

    A spatial analysis of data on radioactive pollution on land at Thule, North-West Greenland is presented. The data comprises levels of 241Am and 239,240Pu on land. Maximum observed level of 241Am is 2.8x105 Bq m-2. Highest levels were observed near Narsaarsuk. This area was also sampled most intensively. In Groennedal the maximum observed level of 241Am is 1.9-104 Bq m-2. Prediction of the overall amount of 241Am and 239,240Pu is based on grid points within the range from the nearest measurement location. The overall amount is therefore highly dependent on the model. Under the optimal spatial model for Narsaarsuk, within the area of prediction, the predicted total amount of 241Am is 45 GBq and the predicted total amount of 239,240Pu is 270 GBq. (Author)

  17. Neutron multiplicity for neutron induced fission of 235U, 238U, and 239Pu as a function of neutron energy

    Recent development in the theory and practice of neutron correlation (''coincidence'') counting require knowledge of the higher factorial moments of the P/sub ν/ distribution (the probability that (ν) neutrons are emitted in a fission) for the case where the fission is induced by bombarding neutrons of more than thermal energies. In contrast to the situation with spontaneous and thermal neutron induced fission, where with a few exceptions the P/sub ν/ is reasonably well known, in the fast neutron energy region, almost no information is available concerning the multiplicity beyond the average value, [ν], even for the most important nuclides. The reason for this is the difficulty of such experiments, with consequent statistically poor and physically inconsistent results

  18. Successful DTPA therapy in the case of 239Pu penetration via injured skin exposed to nitric acid

    This paper presents results of the radiological study and DTPA therapy for a worker exposed to a plutonium nitrate solution. Plutonium levels were measured in excreta, blood, plasma and wound for several weeks. Plutonium renal clearance ranged from 110-190 ml min-1 to 3-4 ml min-1 at different stages of chelation therapy. Plutonium absorption into blood from the injured skin amounted to 4.3%. As a result of intensive therapy, 96% of absorbed plutonium was successfully excreted. (author)

  19. A comparison of the distribution of 239-Pu and calcein in the ilium of the female CBA mouse

    It is well recognised that plutonium 239 and certain vital stains such as calcein behave similarly when injected i.v. into experimental animals. Both are rapidly cleared from blood, and concentrate on bone surfaces. Certain differences of behaviour are also known, such as the competitive concentration of plutonium in liver and other soft tissues; and differences in the distribution of site of location of the substances on bone surface. Plutonium tends to concentrate evenly on all bone surfaces in proportion to the blood supply to that region, leading to higher concentrations on endosteal than periosteal surfaces. Calcein deposits at sites of mineralisation, which occur on both endosteum and periosteum in response to the demands of growth and remodelling. Subsequent behaviour of both substances would appear to depend entirely on the growth and remodelling activities of the bone, the deposits remaining fixed in position until the containing bone is resorbed or buried by freshly formed bone. Many studies of the distribution and dosimetry of plutonium in experimental animals, mainly dogs, and mice have been recorded. There is however, a lack of information concerning the behaviour of the radionuclide in man. More information is available on the behaviour in man and experimental animals of the vital stains, some of which are well known anti-biotics. Consequently, there is much to be gained if a knowledge of the behaviour of vital stains such as calcein can be used to predict the distribution of plutonium in the human skeleton. (orig.)

  20. Rapid determination of long-lived artificial alpha radionuclides using time interval analysis

    It is important to monitor long lived alpha radionuclides as plutonium (238Pu, 239+240Pu) in the field of working area and environment of nuclear fuel cycle facilities, because it is well known that potential risks of cancer-causing from alpha radiation is higher than gamma radiations. Thus, these monitoring are required high sensitivity, high resolution and rapid determination in order to measure a very low-level concentration of plutonium isotopes. In such high sensitive monitoring, natural radionuclides, including radon (222Rn or 220Rn) and their progenies, should be eliminated as low as possible. In this situation, a sophisticated discrimination method between Pu and progenies of 222Rn or 220Rn using time interval analysis (TIA), which was able to subtract short-lived radionuclides using the time interval distributions calculation of successive alpha and beta decay events within millisecond or microsecond orders, was designed and developed. In this system, alpha rays from 214Po, 216Po and 212Po are extractable. TIA measuring system composes of Silicon Surface Barrier Detector (SSD), an amplifier, an Analog to Digital Converter (ADC), a Multi-Channel Analyzer (MCA), a high-resolution timer (TIMER), a multi-parameter collector and a personal computer. In ADC, incidental alpha and beta pulses are sent to the MCA and the TIMER simultaneously. Pulses from them are synthesized by the multi-parameter collector. After measurement, natural radionuclides are subtracted. Airborne particles were collected on membrane filter for 60 minutes at 100 L/min. Small Pu particles were added on the surface of it. Alpha and beta rays were measured and natural radionuclides were subtracted within 5 times of 145 msec. by TIA. As a result of it, the hidden Pu in natural background could be recognized clearly. The lower limit of determination of 239Pu is calculated as 6x10-9 Bq/cm3. This level is satisfied with the derived air concentration (DAC) of 239Pu (8x10-9 Bq/cm3) in Japan

  1. Analytical methods for fissionable material determinations in the nuclear fuel cycle. Progress report, October 1, 1978-September 30, 1979

    Work continues on the development of dissolution techniques for difficult-to-dissolve nuclear materials, the development of methods and automated instruments for plutonium, uranium, and thorium determinations, and the preparation of plutonium materials for the Safeguards Analytical Laboratory Evaluation (SALE) program and distribution by the National Bureau of Standards (NBS) as standard reference materials (SRMs). We are measuring the loner plutonium isotope half-lives, evaluating the isotope correlation techniques and the chemistry involved in the mass-spectrometric ion-bead techniques, and analyzing the SALE uranium materials. Completed subtasks include evaluations of various Teflon materials to recommend those acceptable for the dissolution apparatus developed at LASL, investigations of laser-enhanced dissolution of refractory materials, determinations of diverse ion effects on the microgram-sensitive method for determining uranium, fabrication of the first automated controlled-potential coulometric analyzer for determining plutonium, preparation of a 244Pu material for distribution by NBS as a SRM, and determination of the half-life of 239Pu. Work has been started on a spectrophotometric method for determining microgram quantities of plutonium, a microcomplexometric titration method for determining uranium, the use of new reagents for separations of plutonium, the preparation and packaging of a new lot of high-purity plutonium metal for distribution by NBS as a plutonium chemical SRM, and determination of half-lives of other plutonium isotopes

  2. Progress in determination of long-lived radionuclides by inductively coupled plasma mass spectrometry

    Mass spectrometric methods (such as inductively coupled plasma mass spectrometry - ICP-MS and laser ablation (LA)-ICP-MS) with their ability to provide a very sensitive multielemental and precise isotopic analysis have become established for the determination of radionuclides in quite different sample materials. The determination of long-lived radionuclides is of increasing interest for the characterization of radioactive waste materials and for the detection of radionuclide contamination in environmental materials in which several radioactive nuclides are present from fallout due to nuclear weapons testing, nuclear power plants or nuclear accidents. Due to its multielement capability, excellent sensitivity, low detection limits (up to sub pg I1 range), very good precision, easy sample preparation and measurement procedures ICP-MS of aqueous solutions has been increasingly applied for the ultrasensitive determination of long-lived radionuclides such as 99Tc, 129I, 230Th, 232Th, 234U, 235U, 236U, 239Pu, 240Pu and 241Am and precise isotope ratio measurements of U,Th and Pu. The application especially of microanalytical methods (analysis of some MU by flow injection and on-line coupling techniques as capillary electrophoresis (CE-ICP-MS) or HPLC-ICP-MS) for the precise determination nuclide abundances and concentration of long-lived radionuclides at ultra trace concentration levels in radioactive waste and also for controlling contamination from radioactive waste in the environment is a challenging task

  3. Determination of plutonium isotopes in low activity waste of NPP origin

    Nikiforova, A.; Taskaeva, I.; Veleva, B.; Valova, Tz.; Slavchev, B.; Dimitrova, D.

    2006-01-01

    The inventory analysis of the alkaline low level liquid radioactive waste collected during more than 30 years of NPP “Kozloduy” operation requires determination of eighteen radioactive isotopes with different decay properties. Plutonium isotopes of interest are Pu-238, Pu-239/Pu-240, and Pu-242. The preliminary investigations of the supernatant phase of model and authentic waste samples showed essential challenges for determination of plutonium due to its various oxidation states and low concentration in the complex matrix. Plutonium concentration was determined in precipitate and supernatant after the calcium phosphate precipitation and in the different fractions of the anion exchange steps. The separation by anion exchange and final purification of plutonium fraction by extraction chromatography on TEVA resin (EiChroM Industries) was studied by variation of plutonium oxidation states. The sources were prepared by micro precipitation with NdF3 and counted by alpha spectrometry. As a result from the performed experiments, plutonium determination procedure was optimized and applied to real waste samples.

  4. Rapid determination of gross alpha/beta activity in milk using liquid scintilation counter technique

    Sas Daniel

    2016-01-01

    Full Text Available Rapid determination of gross alpha and beta emitters in milk by liquid scintillation counter is discussed. This method is based on direct addition of different types of milk into scintillation cocktail and therefore it is very promising for fast determination of alpha/beta activity due to direct alpha and beta separation, measurement in close 4p geometry and without sample treatment. The selected group of radionuclides was chosen with the respect to military significance, radio-toxicity, and possibility of potential misuse. As model radionuclides 241Am, 239Pu, and 90Sr were selected. The Liquid Scintilation Counter Hidex 300 SL equipped with triple-double-coincidence-ratio technique was used for sample measurement. The aim of the work was focused on comparison of different cocktails produced by Hidex and Perkin Elmer, choosing the best cocktail based on our measurement results and adjustment of its appropriate volume. Furthermore, the optimization of ratio between the volume of scintillation cocktail and the volume of urine was investigated with the respect to the model radionuclides. According to the obtained results, the efficiency for alpha emitters was greater than 85% and for beta, greater than 95%. The obtained results allowed this method to be used for rapid determination of gross alpha/beta activity in cases where time is an essence, such as first responders or mass-scale samples, where ordinary means suffer from lack of capacity or simply collapse under the onslaught.

  5. Determination of the neutron mass; Determinacion de la masa del neutron

    Amador V, P.; Chacon R, A.; Arcos P, A.; Rodriguez N, S.; Pinedo S, A.; Vega C, H.R. [Unidad Academica de Estudios Nucleares, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)]. e-mail: paus2281@yahoo.com.mx

    2005-07-01

    The binding energy of the deuteron was measured and it was determined the neutron mass starting from the nuclear reaction, {sup 1}{sub 0} n + {sup 1}{sub 1} H {yields}{sup 2}{sub 1} D + {gamma}. The produced photon is soon a gamma ray that is emitted when the hydrogen captures a thermal neutron. The photon energy was measured using two spectrometric systems for gamma rays. A system with a detector of NaI(TI) of 3'' x 3'' and the other one with a High-purity Germanium detector. The first detector has a bigger efficiency and a smaller resolution in comparison with the second detector. The energy of the measured photon is the binding energy of the deuteron. With the measurement of the photon energy and the masses of the proton and of the deuterium it was determined the neutron mass. The value of the mass obtained with both systems it was compared with the value reported in the literature. The nuclear reaction was induced in a volume of paraffin that it was bombing with a source {sup 239} PuBe whose activity is of 3.7 x 10{sup 10} Bq. (Author)

  6. Experimental determination of the antineutrino spectrum of the fission products of U238

    Accurate predictions of the antineutrino spectrum emitted by a nuclear reactor are of paramount importance for current and future reactor neutrino experiments. The antineutrinos are produced in the β - decays of the fission daughters of the four main fuel isotopes 235U, 238U, 239Pu, and 241Pu. One way to calculate the total anti νe - spectrum emitted by a fuel assembly is to experimentally determine the cumulative β-spectra emitted after fission of these four main fuel isotopes and to convert these into the corresponding anti νe-spectra. Three of the four spectra could already be determined in the 1980's, but only recently an experiment at the scientific neutron source FRM II in Garching could be performed to measure the anti νe-spectrum of 238U which contributes 10 % to the total antineutrino output of a standard PWR. With this spectrum, it is now possible to predict the antineutrino output of a reactor without the use of theoretical calculations for the contributing spectra. This talk describes the results of the experiment and discusses the impact on the current analysis of reactor neutrino experiments and the reactor antineutrino anomaly, which may give a hint on the possible existence of light sterile neutrinos.

  7. 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

  8. Distribution of neptunium and plutonium in New Mexico lichen samples (Usnea arizonica) contaminated by atmospheric fallout

    The concentrations of 237Np, 239Pu and 240Pu were determined in lichen samples (Usnea arizonica) that were collected from ten locations in New Mexico between 2011 and 2013 using isotope dilution inductively-coupled plasma mass spectrometry (ID-ICP-MS). The observed isotopic ratios for 237Np/239Pu and 240Pu/239Pu indicate trace contamination from global and regional fallout (e.g. Trinity test and atmospheric testing at the Nevada Test Site). The fact that actinide contamination is detected in recent lichen collections suggests continuous re-suspension of fallout radionuclides even 50 years after ratification of the Limited Test Ban Treaty. (author)

  9. Implementation in laboratories of Latin America of procedures of harmonized essay for the determination of the radioactive contamination of food

    In Latin America, nowadays, it is not had harmonized essay procedures for the determination of radioactive contaminants in foods. Equally, the great diversity of institutions that in each country are devoted to carry out this control and the difference in the level that its possess the same ones in quality matter, its impose the necessity to implant a Quality Management System on the base of harmonized technical criteria that its help to obtain reliable analytical results. With this end, it was proposed and it was approved the ARCAL LXXIX regional project: 'Harmonization of the technical and specific requirements of quality for the control of the radioactive contamination of foods'. In this work the aspects more significant of the design and content of the Manual of technical procedures for the determination of radioactive contaminants in foods, elaborated in the marks of the one referred project are presented. The same one includes eight procedures for the previous treatment of the samples, the spectrometric determination of gamma emitters radionuclides, the determination of the alpha activity indexes and total beta, of 131 I, 89,90 Sr, 226 Ra, 238,239 Pu and 3 H, using different methodologies validated in the region. The actions carried out to implement this Manual are also exposed. (Author)

  10. Monte Carlo simulations of differential die-away instrument for determination of fissile content in spent fuel assemblies

    Lee, Tae-Hoon; Menlove, Howard O.; Swinhoe, Martyn T.; Tobin, Stephen J.

    2011-10-01

    The differential die-away (DDA) technique has been simulated by using the MCNPX code to quantify its capability of measuring the fissile content in spent fuel assemblies. For 64 different spent fuel cases of various initial enrichment, burnup and cooling time, the count rate and signal to background ratios of the DDA system were obtained, where neutron backgrounds are mainly coming from the 244Cm of the spent fuel. To quantify the total fissile mass of spent fuel, a concept of the effective 239Pu mass was introduced by weighing the relative contribution to the signal of 235U and 241Pu compared to 239Pu and the calibration curves of DDA count rate vs. 239Pu eff were obtained by using the MCNPX code. With a deuterium-tritium (DT) neutron generator of 10 9 n/s strength, signal to background ratios of sufficient magnitude are acquired for a DDA system with the spent fuel assembly in water.

  11. Burnup determination of silicide MTR fuel elements (20% 235U) in the LFR laboratory

    The LFR facility is a radiochemical laboratory designed and constructed with a hot-cells line, a glove-box and a fume hood, all of them suited to work radioactive materials. At the beginning of the LFR operation a series of dissolutions of MTR irradiated silicide fuel elements was performed, and determined its isotopic composition of 235U, 239Pu and 148Nd (the last one as burn up monitor), by the thermal ionization mass spectrometry (TIMS). These assays are linked to the IAEA RLA/4/018 Regional Project 'Management of Spent Fuel from Research Reactors'. It is concluded that this technique of burn up measurement is powerful and accurate when properly applied, and permit to validate the calculation codes when isotopic dilution is performed. It is worth noticed the LFR capacity to carry on different research and development programs in the nuclear fuel cycle field, such as the previously mentioned absolute burn up measurements, or the evaluation of radioactive waste immobilization processes and researches on burnable poisons. (author)

  12. Determination of Pu isotopic composition and 241Am by high resolution gamma spectrometry on solid samples

    The present report gives a detailed account of the development of non-destructive assay technique using high resolution gamma-ray spectrometry (HRGS) for determination of plutonium (Pu) isotopic composition and the 241Am content in solid Pu samples. Energy range 120-420 keV was used in this study. The methodology involves in situ relative efficiency calibration during the measurement process itself, to reduce the errors and increase the reliability of the method. Twenty solid Pu samples of power reactor and research reactor grade were analyzed by this method and the results were compared with those obtained by thermal ionization mass spectrometry. The accuracy of the final results depends strongly upon the accuracy of the available nuclear data (decay constant, gamma abundance etc.). MATLAB based programme was written to perform the analysis. A counting time of 4 hour was chosen for achieving good statistics on the results for samples having 100-200 mg of Pu. The attainable accuracy is found to be 0.5-1% for the fissile isotopes (239Pu + 241Pu) and 5-10% for 241Am content. (author)

  13. Hydride interference on the determination of minor actinide isotopes by inductively coupled plasma mass spectrometry

    Hydrogen adducts of the major naturally occurring actinide isotopes 232Th and 238U were studied using an inductively coupled plasma mass spectrometer. The hydride:atomic ion ratios for both elements varied as a function of the parameters that were studied, i.e., nebulizer flow rate, solution uptake rate and desolvation conditions. When the instrument sensitivity for U and Th was optimized, 232ThH+:232Th+ was found to be (3.9±0.2) x 10-5 with pneumatic nebulization and (2.10±0.07) x 10-5 with ultrasonic nebulization. Under the same conditions, 238UH+:238U+ was found to be (3.2±0.2) x 10-5 and (1.8±0.1) x 10-5 using pneumatic and ultrasonic nebulization, respectively. Conditions that reduced hydrogen number density and/or increased plasma temperature decreased the hydride:atomic ion ratio. Such conditions are best if 233U and 239Pu are to be determined in the presence of 232Th and 238U. (Author)

  14. Uranium concentrations in human bone

    The natural uranium content in the bone of one person has been determined by a new method. The results were obtained by quantitative analysis of fission track autoradiographs of bone from a person injected witn 239Pu

  15. Determination of Plutonium Contribution to the Total Burnup of a Spent Nuclear Fuel by Mass Spectrometric Measurements of Uranium and Ruthenium

    The U and Ru isotope patterns provide information on the real irradiation characteristics which are necessary for evaluating a fuel's performance in a reactor. A comparison of the Pu contribution values determined independently provides a promising way to check on the validity of the results. In order to check the consistency of the post-irradiation analysis results, correlations between the parameters of the irradiated nuclear fuels such as the concentration of the heavy elements and fission products, ratios of their isotopes and burnup were established. These correlations can be used to identify the reactor fuels and to estimate the burnup and Pu production. A new approach was carried out with Ru isotopic ratio for the determination of Pu contribution to the total burnup of a spent nuclear fuel from a power reactor. The principle of this approach was based on the use of the difference in the fission yield ratios of the Ru fission products involved for the three main fissionable nuclides such as 235U, 239Pu, and 241Pu. In this work, to determine the contribution of Pu to the total burnup of the fuel, the following two independent methods have been applied: by measuring the isotope ratios of the stable Ru fission products 101Ru/104Ru, and by determining the total burnup by Nd-148 method and subtracting partial burnup, which is determined form the measured values of U isotope ratios

  16. Report on intercomparison IAEA/SOIL-6 of the determination of Cs-137, Pu-239, Ra-226, and Sr-90 in soil

    The report presents results of a laboratory intercomparison of the determination of the activity level of cesium-137, plutonium-239, radium-226 and strontium-90 in a provided soil sample organized by the IAEA's Analytical Quality Control Service. Twenty-seven laboratories from 16 countries returned results based on 77 laboratory means (295 individual determinations). The aim of the interlaboratory comparison was to offer to the laboratories engaged in soil investigation an opportunity to control their analytical performance and to establish the concentration level of some radionuclides in a batch of analyzed soil for certification purposes. All radionuclides were determined by typical commonly used methods: cesium-137 by direct gamma spectroscopy, plutonium-239 by alpha spectroscopy after separation and electrodeposition, radium-226 by direct determination without or with separation or by determination of radon, and strontium-90 by measurement of its daughter yttrium-90. In general, the results can be accepted as satisfactory at such low level of activity (pCi/kg). The relative confidence intervals of the medians of 137Cs and 239Pu are below +-10% and of 226Ra and 90Sr below +-20%

  17. Report on two intercomparisons on the determination of selected radionuclides in simulated air filters [Air-1/1 and Air-2/1 (1978-1979)

    The public interest in atmospheric pollution by heavy metals and radioactive contaminants and the need for their reliable determination has convinced the International Atomic Energy Agency of the necessity to continue its programme of intercomparisons of air filter analyses. Several such intercomparison exercises have been organized by the Agency in the past years. The present report deals with a recent intercomparison of activity measurements of air filters spiked with radionuclides. This intercomparison exercise had the aims to provide laboratories dealing with the determination of radionuclides in air filters with an opportunity of checking their analytical performance and, in addition, it was hoped that these simulated air filters would become sufficiently well characterized to be considered later as reference samples with ''recommended'' values for the activities of several radionuclides. The values for 137Cs, 54Mn, 239Pu and 90Sr in Air-1/1 filters seem to be established with a reasonable degree of confidence. The issue of Air-1/1 filters as a reference material for the above radionuclides will follow soon. The comparison of the results of these intercomparison runs with those of the preceding exercises shows on the whole no significant improvement of the quality of analysis. The results of these intercomparison runs show again the difficulties encountered in the determination of radionuclides on air filters. Much effort is still needed to achieve better reliability

  18. Inhaled plutonium oxide in dogs

    This project is concerned with long-term experiments to determine the lifespan dose-effect relationships of inhaled 239PuO2 and 238PuO2 in beagles. Beagle dogs given a single exposure to 239PuO2 or 238PuO2 aerosols are being observed for lifespan dose-effect relationships. The 239Pu body burden of the nine dogs that died of pulmonary-fibrosis-induced respiratory insufficiency during the first 3 yr after exposure was 1 to 12μCi. Nineteen of the dogs exposed to 238Pu haved died during the first 7-1/2 yr after exposure due to bone and/or lung tumors; their body burdens at death ranged from 0.7 to 10μCi. Chronic lymphopenia was the earliest observed effect after inhalation of 239PuO2 or 238PuO2

  19. Determination of ultratrace amounts of plutonium-239 in bioassay samples for alpha dosimetry

    Potential alpha contamination in PHWRs is of concern when working with materials which may contain fuel debris, such as around fueling machines and feeders which are cut open. Traditional screening methods use alpha spectrometry of fecal samples. It is highly desirable to use less invasive methods. Screening of urine samples is well accepted in the industry for a variety of purposes. However, various solubility models and known biological throughputs indicate that it is only practical to measure 239Pu/240Pu in urine and that these must be measured at very low concentrations in order to be a practical screening tool. It is necessary to achieve a detection limit of about 5 uBq in a daily urine output to correspond to a dose of 0.1 mSv/annum. This corresponds to about 2 femtograms (10-15 g) of 239Pu and 0.5 fg 240Pu in daily urine output. If the daily urine output is concentrated to 1 g, then the desired detection limit is 2 fg/g or 2 pg/kg for 239Pu, for example. Although alpha spectrometry would provide information on multiple isotopes of interest, its practical detection limit is about 100 to 300 uBq. The currently available methods for measuring uBq amounts of 239Pu/240Pu (the only alpha emitters in urine suitable for screening measurements) are all mass spectrometry based and vary in the means by which the analyte is presented to the mass spectrometer

  20. Determination of ultra-trace amounts of radium, thorium and uranium in waste water by high-resolution ICP-MS after coprecipitation with the iron (III) hydroxide

    Inductively coupled plasma mass spectrometry with a quadrupole mass analyzer (ICP-MS) is now regarded as a powerful technique to determine almost every element in the periodic table with ppt (pg/ml) level. So far, this technique has been used to measure long half-life radionuclides in the open-quotes pollutedclose quotes environment. For example, 239Pu and 240Pu in the top-soil were measured precisely and relatively easily in the range of 0.2 to 2.6 mBq/g by using ICP-MS. Conventional radiometric methods which have very high sensitivity for short half-life radionuclides need, however, complex chemical pretreatment for isolation and concentration of focused isotopes, and are time consuming. Higher sensitivity and lower detection limits are still needed for monitoring low concentration of long half-life radionuclides in the environmental samples. Recently, high-resolution (M/ΔM ∼10000) and high sensitivity (ppq = fg/ml level). In this study, HR-ICP-MS was applied to the determination of ultra-trace amounts of Ra, Th, and U in waste water sampled including high concentration of alkaline, alkaline earth and transition metal elements

  1. Implementation in laboratories of Latin America of procedures of harmonized essay for the determination of the radioactive contamination of food; Implementacion en laboratorios de Latinoamerica de procedimientos de ensayo armonizados para la determinacion de la contaminacion radiactiva de alimentos

    Fernandez G, I.M. [CPHR (Cuba); Iglicki, F.A. [CNEA (Argentina); Aguirre G, J. [CNSNS, (Mexico); Melo F, A.C. de [Instituto de Radioprotecao e Dosimetria, (Brazil); Tomicic M, I.J. [Comision Chilena de Energia Nuclear, (Chile); Loria M, L.G. [Centro de Investigacion en Ciencias Atomicas Nucleares y Moleculares, (Costa Rica); Diodati, J.M. [ARN, Av. Del Libertador 8250, Buenos Aires (1429), (Argentina); Vasquez B, L.R. [Comision Ecuatoriana de Energia Atomica, (Ecuador); Alarcon S, F.A. [Centro de Investigaciones y Aplicaciones Nucleares, El Salvador (El Salvador); Civil, M. [Laboratoire Veterinaire et de Controle de Qualite des Aliments, (Haiti); Naut M, B.C. [Universidad Autonoma de Santo Domingo, Republica Dominicana (Dominican Republic); Odino M, M.R. [Direccion Nacional de Energia y Tecnologia Nuclear (Uruguay); Flores M, Y.R. [Direccion General de Energia Atomica, (Venezuela); Rossbach, M. [International Atomic Energy Agency, (Austria)]. e-mail: isis@cphr.edu.cu

    2006-07-01

    In Latin America, nowadays, it is not had harmonized essay procedures for the determination of radioactive contaminants in foods. Equally, the great diversity of institutions that in each country are devoted to carry out this control and the difference in the level that its possess the same ones in quality matter, its impose the necessity to implant a Quality Management System on the base of harmonized technical criteria that its help to obtain reliable analytical results. With this end, it was proposed and it was approved the ARCAL LXXIX regional project: 'Harmonization of the technical and specific requirements of quality for the control of the radioactive contamination of foods'. In this work the aspects more significant of the design and content of the Manual of technical procedures for the determination of radioactive contaminants in foods, elaborated in the marks of the one referred project are presented. The same one includes eight procedures for the previous treatment of the samples, the spectrometric determination of gamma emitters radionuclides, the determination of the alpha activity indexes and total beta, of {sup 131} I, {sup 89,90} Sr, {sup 226} Ra, {sup 238,} {sup 239} Pu and {sup 3} H, using different methodologies validated in the region. The actions carried out to implement this Manual are also exposed. (Author)

  2. Determination of Isotopic Composition of Uranium and Plutonium in Simulated 1AF Feed Solution by TIMS%TIMS测定模拟1AF料液中铀钚同位素组分

    蒋军清; 高月华; 汪南杰; 姜国杜

    2012-01-01

    The precise determination of the uranium and plutonium isotopic composition in the simulated 1AF feed solution by solvent extraction/ion exchange separation-thermal ioni-zation mass spectroscopy(TIMS) was studied in this paper. The precise determination of uranium and plutonium isotopic composition was realized by optimization of chemical separations, and minimization of possible interferences, and proper selection of instrument parameters. Under the selected conditions, the uranium and plutonium isotopic composition in the 1AF feed solution were accurately determined. The relative standard deviations of the main isotopes 235U and 239Pu are less than 0. 05%.%采用溶剂萃取/离子交换分离-热表面电离质谱法,对模拟1AF料液中铀钚同位素组分测定技术进行了研究.通过对化学分离条件、仪器测量参数、信号强度、各种干扰等测定条件的研究和选择,实现了铀、钚同位素组分的精密测定.在选定的条件下,测定了模拟1AF料液中的铀钚同位素,主要同位素235 U和239pu测定精密度(sr)均优于0.05%.

  3. A new method for the determination of plutonium and americium using high pressure microwave digestion and alpha-spectrometry or ICP-SMS

    Plutonium and americium are radionuclides particularly difficult to measure in environmental samples because they are a-emitters and therefore necessitate a careful separation before any measurement, either using radiometric methods or ICP-SMS. Recent developments in extraction chromatography resins such as EichromR TRU and TEVA have resolved many of the analytical problems but drawbacks such as low recovery and spectral interferences still occasionally occur. Here, we report on the use of the new EichromR DGA resin in association with TEVA resin and high pressure microwave acid leaching for the sequential determination of plutonium and americium in environmental samples. The method results in average recoveries of 83 ± 15% for plutonium and 73 ± 22% for americium (n = 60), and a less than 10% deviation from reference values of four IAEA reference materials and three samples from intercomparisons exercises. The method is also suitable for measuring 239Pu in water samples at the μBq/l level, if ICP-SMS is used for the measurement. (author)

  4. Plutonium determination in urine by techniques of mass spectrometry

    The objective of this study was to develop an analytic method for quantification and plutonium reappraisal in plane tables of alpha spectrometry be means of the mass spectrometry technique of high resolution with plasma source inductively coupled and desolvator Aridus (Aridus-Hr-Icp-Ms) and mass spectrometry with accelerator (AMS). The obtained results were, the recovery percentage of Pu in the plane table was of ∼ 90% and activity minimum detectable obtained with Aridus-Hr-Icp-Ms and AMS was of ∼ 3 and ∼ 0.4 f g of 239Pu, respectively. Conclusion, the results demonstrate the aptitude of the Aridus-Hr-Icp-Ms and AMS techniques in the Pu reappraisal in plane tables with bigger speed and precision, improving the values notably of the activity minimum detectable that can be obtained with the alpha spectrometry (∼ 50 f g of 239Pu). (author)

  5. Determination of new European biometric equations for the calibration of in vivo lung counting systems using Livermore phantom

    Full text: In vivo lung measurement is a widely used method for nuclear workers monitoring. This technique consists of assessing retained activity in lungs after an inhalation, by means of an external direct measurement of x- or gamma rays emitted during disintegration of incorporated nuclides. This estimation is always done by comparing the measurement of the subject to the measurement obtained using a physical calibration phantom. However, due to emissions by actinides of x and γ-rays with energies below 200 keV and low emission ratio, calibration of in vivo measurement systems is very delicate, leading to important systematic errors despite the improvements realized in the design of sophisticated phantoms. Moreover, in France, calibration factors for a given subject are generally corrected thanks to biometric equations determining chest wall thickness according to weight/height ratio of the measured person. Nevertheless these equations were determined for a 2, 3 or 6 detectors system in chair geometry and for American subjects, that doesn't represent the geometry encountered in French laboratories. The work presented here is dedicated to the determination of new biometric equations more adapted to the French measurement systems using 4 germanium detectors in bed geometry with a Livermore calibration phantom. These equations were determined on the basis of computed tomography (CT) images of 33 adult males and for energies of 17 and 60 keV (respectively full absorption peaks of 239Pu and 241Am). These biometric equations which can be directly converted into Livermore chest thicknesses, were calculated for all kinds of Livermore phantoms: 16 mm and 19 mm torso plate (100 % muscle equivalent) and for all composition of overlay plates (100 % muscle; 50 % muscle-50 % adipose; 13 % muscle-87 % adipose). The obtained results could directly be used in the different European radiobioassay laboratories to improve the calibration of in vivo lung counting systems. (author)

  6. Determination of natural radioactive elements in Abo Zaabal, Egypt by means of gamma spectroscopy

    Highlights: ► We examined the radioactivity of different type samples from Abo Zaabaal Lake. ► We evaluated the natural nuclide gamma-ray activities and their annual dose rates. ► We evaluated the concentrations of 226Ra and its hazard indices. ► We assessed the absorbed dose in human. ► All results are within normal ranges. - Abstract: The natural nuclide gamma-ray activities and their respective annual effective dose rates, produced by 238U, 232Th, 40K and 226Ra, are determined for 10 different natural samples (soil–plant–water) from Abo Zaabaal Lake. This lake is located very close to the Egyptian reactors. The gamma spectra analysis indicates that the photo-gamma lines represent ten radioactive nuclides 234Th, 239Pu, 228Ac, 226Ra, 212Pb, 214Pb, 208Tl, 212Bi, 214Bi and 40K. These nuclides represent the daughters of the natural radioactive series 238U and 232Th with 40K. The mean activity concentration of 238U was found to be 6.57, 10.16 and 5.44 Bq kg−1 for (soil–plant–water); 8.46, 8.33 and 6.04 Bq kg−1 of 232Th, and 136.3, 216.8 and 119.2 Bq kg−1 of 40K respectively. The mean activity concentrations of 226Ra were obtained which help to evaluate the radiation hazard indices as radium equivalent, internal and external hazard indices. In addition, to assess the radiation risk to a biosystem, the annual effective dose rate, the absorbed dose in human and the absorbed dose outdoor are also evaluated.

  7. Determination of fissile fraction in MOX (mixed U + Pu oxides) fuels for different burnup values

    Ozdemir, Levent, E-mail: levent.ozdemir@taek.gov.tr [Department of Nuclear Engineering, Hacettepe University, 06800 Beytepe, Ankara (Turkey); Acar, Banu Bulut; Zabunoglu, Okan H. [Department of Nuclear Engineering, Hacettepe University, 06800 Beytepe, Ankara (Turkey)

    2011-02-15

    When spent Light Water Reactor fuels are processed by the standard Purex method of reprocessing, plutonium (Pu) and uranium (U) in spent fuel are obtained as pure and separate streams. The recovered Pu has a fissile content (consisting of {sup 239}Pu and {sup 241}Pu) greater than 60% typically (although it mainly depends on discharge burnup of spent fuel). The recovered Pu can be recycled as mixed-oxide (MOX) fuel after being blended with a fertile U makeup in a MOX fabrication plant. The burnup that can be obtained from MOX fuel depends on: (1) isotopic composition of Pu, which is closely related to the discharge burnup of spent fuel from which Pu is recovered; (2) the type of fertile U makeup material used (depleted U, natural U, or recovered U); and (3) fraction of makeup material in the mix (blending ratio), which in turn determines the total fissile fraction of MOX. Using the Non-linear Reactivity Model and the code MONTEBURNS, a step-by-step procedure for computing the total fissile content of MOX is introduced. As was intended, the resulting expression is simple enough for quick/hand calculations of total fissile content of MOX required to reach a desired burnup for a given discharge burnup of spent fuel and for a specified fertile U makeup. In any case, due to non-fissile (parasitic) content of recovered Pu, a greater fissile fraction in MOX than that in fresh U is required to obtain the same burnup as can be obtained by the fresh U fuel.

  8. A model for determination of screening level for radioactive elements in soil

    At the present, decision about clean-up of Brazilian sites contaminated with radioactive isotopes is addressed on a case-by-case basis, since there is no general guidance or recommendation to support actions in early phases of the problem identification. For chemicals, CETESB - the governmental organization responsible for preventing and controlling environmental pollution in Sao Paulo State - established background values, prevention and intervention, as the first step to implement a remediation actions based on human health risk assessment. The aim of this study was to develop a methodology for the establishment of target values for radioactive soil contamination, as far as possible consistent and compatible with the approach adopted by CETESB for sites contaminated with chemicals. The following steps have been addressed in this study: conceptual scenario and model development; codification of the equations in an electronic spreadsheet; selection of proper range and statistical distribution of the input values; derivation of the intervention levels for selected radionuclides using Monte Carlo methods. The mathematical model developed was mainly based on the equations used by the U.S. Environmental Protection Agency (EPA) and by the National Council on Radiation Protection and Measurements (NCRP) for soil screening purposes. Intervention and prevention values are presented for adult and 10 years old child, for each 3 exposure scenarios: agricultural, residential and industrial; the following radionuclides were considered: 3H, 14C, 32P, 35S, 45Ca, 51Cr, 90Sr, 125I, 131I, 134Cs, 137Cs, 210Pb, 226Ra, 228Ra, 232Th, 238U, 239Pu and 241 Am. Quality reference values were determined for 40K, 137Cs, 210Pb, 226Ra, 228Ra, 228Th, Th-nat e U-nat. Results obtained in this study showed a good agreement with those reported by NCRP, considering that the equations and the input data used in both models are not the same ones.(author)

  9. Changes in the Shape of Histograms Constructed from the Results of 239-Pu Alpha-Activity Measurements Correlate with the Deviations of the Moon from the Keplerian Orbit

    Shapovalov S. N.

    2009-10-01

    Full Text Available We have found that the shape of the histograms, constructed on the basis of the results of radioactivity measurements, changes in correlation with the distortions of the lunar Keplerian orbit (due to the gravitational influence of the Sun. Taking into account that the phenomenon of “macroscopic fluctuations” (regular changes in the fine structure of histograms constructed from the results of measurements of natural processes does not depend on the nature of the process under study, one can consider the correlation of the histogram shape with the Moon’s deviations from the Keplerian orbit to be independent from the nature of the process the histograms were obtained on.

  10. Statistical activities during 1976 and the design and initial analysis of nuclear site studies. [/sup 241/Am, /sup 137/Cs, /sup 239/Pu, /sup 240/Pu

    Gilbert, R O; Essington, E H; Brady, D N; Doctor, P G; Eberhardt, L L

    1977-05-01

    Statistical design and analysis activities for the Nevada Applied Ecology Group (NAEG) during 1976 are briefly outlined. This is followed by a description of soil data collected thus far at nuclear study sites. Radionuclide concentrations in surface soil collected along a transect from ground zero (GZ) along the main fallout pattern are given for Nuclear Site (NS) 201. Concentrations in soil collected at 315 locations on a grid system at 200 foot spacings are also given for this site. The /sup 241/Am to /sup 137/Cs ratios change over NS 201 depending on location relative to GZ. They range from less than one where /sup 241/Am is at low levels, to more than fifty where /sup 241/Am levels are high (near GZ). The estimated median /sup 239/ /sup 240/Pu to /sup 241/Am ratio is 11 and appears to be relatively constant over the area (the 95 percent lower and upper limits on the true median ratio are about 8 and 14).

  11. On uncertainties and fluctuations of averaged neutron cross sections in unresolved resonance energy region for 235U, 238U, 239Pu

    This paper analyses the reasons for the differences which exist between group-averaged evaluated cross-section data from different evaluated data files for U235, U238 and Pu239 in the unresolved resonance energy region. (author)

  12. Physicochemical state of 239Pu in the rat blood after resorption thereof from the lungs, muscles, subcutaneous connective tissue, and abdominal cavity

    Depending on the route of uptake, original state of administered compound, concentration of the radionuclide in blood and time lapsed after the administration thereof, at least three plutonium forms bound with proteins (with macro- and gamma-glubulin and albumin-transferrin serum fractions) and the plutonium form non-bound with proteins can coexist in blood serum at varying ratios

  13. Fission Cross-Section Measurements on Pu239, Pu241 , U232, and a Search for Fission Components in Pu238 Resonances

    Fission cross-section measurements on Pu239 and Pu241 have been carried out from sub-thermal-neutron energy to the keV region; resonance parameters are given and errors in the average values of the cross-section are discussed. The discovery of large fission components in the U232 neutron resonances stimulated a search for fission components in Pu238. The results of these experiments are given. All the measurements were performed on the Harwell time-of-flight spectrometer. (author)

  14. Mechanical behavior of 238UO2, 238PuO2, and 239PuO2 as a function of strain rate and temperature

    The mechanical response of 238UO2 was measured as a function of strain rate and temperature. We evaluated material produced by two processing schedules: hot pressing followed by a grain stabilization; and cold pressing plus a sintering treatment. The response of these two materials was identical, within the scatter of our data. We complemented our data with that published in the literature, after having made the appropriate corrections for grain size, porosity, and stoichiometry. The entire collection of data was used to evaluate the Follansbee-Kocks mechanical threshold stress (MTS) model for the prediction of yield stress as a function of strain rate and temperature. We used this model to predict the yield stress of 238UO2 for strain rates between var-epsilon = 10-5 and 103 s-1 and temperatures from 800 to 1600C. These predictions provided the basis for constructing a deformation/fracture map for both urania and plutonia. Examination of the maps indicates that for compressive loading and impact strain rates, the 238UO2 will be an excellent mock material for 238PuO2. Under these conditions both the strength and deformation and the fracture modes are consistent between these two materials

  15. Beta and gamma decay heat measurements between 0.1s--50,000s for neutron fission of 235U, 238U and 239Pu

    A helium-jet/tape-transport system is employed in the study of beta-particle and gamma-ray energy spectra of aggregate fission products as a function of time after fission. During the initial nine months of this project we have investigated the following areas: Design, assembly and characterization of a beta-particle spectrometer; Measurement of 235U(nthff) beta spectra for delay times 0.2 s to 12,000 s; Assembly and characterization of a 5 x 5 Nal(Tl) gamma-ray spectrometer; Measurement of 235U(nthff) gamma-ray spectra for delay times 0.2s to 1 5,500s; Assembly and characterization of HPGe gamma-ray spectrometer with a Nal(Tl) Compton-and-background-suppression annulus; Measurement of 235U(n th,ff) high-resolution gamma-ray spectra for delay times 0.6 s to over 100,000 s; Comparison of individual gamma-line intensities with ENDF/B-VI; Adaptation to our computer of unfolding program FERDO for beta and gamma aggregate fission-product energy spectra and development of a spectrum-stripping program for analysis of HPGe gamma-ray spectra; Study of the helium-jet fission-fragment elemental transfer efficiency. This work has resulted in the publication of twelve BAPS abstracts of presentations at scientific meetings. There are currently four Ph.D. and two M.S. candidates working on dissertations associated with the project

  16. Energy dependence of the neutron multiplicity P/sub nu/ in fast neutron induced fission of /sup 235,238/U and 239Pu

    Certain applications require knowledge of the higher moments of the neutron multiplicity probability. It can be shown that the second factorial moment is proportional to the fission rate in the sample, and that the third factorial moment can be of use in disentangling spontaneous fission from induced fission. Using a source of unpublished work in which neutron multiplicities were derived for the fast neutron induced fission of U-235, U-238, and Pu-239, the multiplicity probability has been calculated as a function of neutron energy for the energy range 0 to 10 MeV

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

    Adam, Jindřich

    2007-01-01

    Roč. 68, č. 2 (2007), s. 201-212. ISSN 0304-4289 R&D Projects: GA MŠk 1P04LA213 Institutional research plan: CEZ:AV0Z10480505 Keywords : neutro production Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.383, year: 2007

  18. Distribution of sup 137 Cs, sup 90 Sr, sup 238 Pu, sup 239 Pu, sup 241 Am and sup 244 Cm in Pond B, Savannah River Site

    Whicker, F.W. (Colorado State Univ., Fort Collins, CO (USA)); Pinder, J.E. III; Bowling, J.W. (Savannah River Ecology Lab., Aiken, SC (USA)); Alberts, J.J. (Georgia Univ., Sapelo Island, GA (USA). Marine Inst.); Brisbin, I.L. Jr. (Savannah River Ecology Lab., Aiken, SC (USA))

    1989-05-01

    The gradual senescence of present-day operating nuclear facilities, and resultant contamination of aquatic and terrestrial ecosystems, emphasize the importance of understanding the behavior of radionuclides in the environment. Observations and deductions concerning mechanisms of radionuclide transport can contribute significantly to knowledge of fundamental ecological processes. This study emphasized the ecosystem-level distribution of several long-lived radionuclides in an abandoned reactor cooling impoundment after a twenty year period of chemical and biological equilibration. 90 refs., 14 figs., 5 tabs.

  19. Rapid determination of plutonium isotopes in environmental samples using sequential injection extraction chromatography and detection by inductively coupled plasma mass spectrometry.

    Qiao, Jixin; Hou, Xiaolin; Roos, Per; Miró, Manuel

    2009-10-01

    This article presents an automated method for the rapid determination of 239Pu and 240Pu in various environmental samples. The analytical method involves the in-line separation of Pu isotopes using extraction chromatography (TEVA) implemented in a sequential injection (SI) network followed by detection of isolated analytes with inductively coupled plasma mass spectrometry (ICP-MS). The method has been devised for the determination of Pu isotopes at environmentally relevant concentrations, whereby it has been successfully applied to the analyses of large volumes/amounts of samples, for example, 100-200 g of soil and sediment, 20 g of seaweed, and 200 L of seawater following analyte preconcentration. The investigation of the separation capability of the assembled SI system revealed that up to 200 g of soil or sediment can be treated using a column containing about 0.70 g of TEVA resin. The analytical results of Pu isotopes in the reference materials showed good agreement with the certified or reference values at the 0.05 significance level. Chemical yields of Pu ranged from 80 to 105%, and the decontamination factors for uranium, thorium, mercury and lead were all above 10(4). The duration of the in-line extraction chromatographic run was <1.5 h, and the proposed setup was able to handle up to 20 samples (14 mL each) in a fully automated mode using a single chromatographic column. The SI manifold is thus suitable for rapid and automated determination of Pu isotopes in environmental risk assessment and emergency preparedness scenarios. PMID:19722516

  20. NKS-Norcmass reference material for analysis of Pu-isotopes and 237Np by mass spectrometry

    The aim of the reference material in the Norcmass-project was to produce a low-level (239Pu) sample of sufficient amount to allow individual laboratories to perform several tests without risk of using up the material. Although there are several reference materials available (eg IAEA) few have 239Pu/240Pu data and almost none have 237Np/239Pu-data. Those who have (eg IAEA-384) have very high concentrations and are not useful for testing analytical methods designed for low-level measurements where a large sample mass may be required. The reference material consist of the top 10cm of 2mm sieved soil pooled together from 12 different Danish locations collected during 2003. The Soil was blended and sieved through 0.6 and finally through a 0.4 mm sieve. A total amount of 17 kg soil was produced. Several aliquots of the material was subject to analysis by alpha spectrometry and ICP-MS. The material contain 239+240Pu at a concentration of 0.24 ± 0.01 mBq/g and a 240Pu/239Pu atom ratio of 0.19 ± 0.006. The ratio 237Np/239Pu was determined to 0.32 ± 0.01. (au)

  1. Gamma ray spectrum of NaI(TI) for plutonium waste and comparison with MCNP simulated response function

    The spectroscopic analysis of 239Pu is a routine job for Plutonium handling lab. The radioactive waste packages are monitored to determine % of 239Pu present in waste in order to restrict it below disposal level set by Regulatory authority. The activity analysis is done using gamma spectrometry. The response function of NaI(Tl) detector for gamma ray bins emitted from 239Pu is needed to be compared with MCNP simulation results in order to determination of correction factors for lab environment and geometrical shape and constraint in measurements. For this purpose a study is initialized with comparison between the spectrum obtained with NaI(Tl) detector for standard waste package of lab and MCNP simulation spectrum generated for an identical environment

  2. Plutonium determination in urine by techniques of mass spectrometry; Determinacion de plutonio en orina por tecnicas de espectrometria de masas

    Hernandez M, H. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Yllera de Ll, A., E-mail: hector.hernandez520@gmail.com [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Departamento de Medio Ambiente, Av. Complutense 22, 28040 Madrid (Spain)

    2013-10-15

    The objective of this study was to develop an analytic method for quantification and plutonium reappraisal in plane tables of alpha spectrometry be means of the mass spectrometry technique of high resolution with plasma source inductively coupled and desolvator Aridus (Aridus-Hr-Icp-Ms) and mass spectrometry with accelerator (AMS). The obtained results were, the recovery percentage of Pu in the plane table was of ∼ 90% and activity minimum detectable obtained with Aridus-Hr-Icp-Ms and AMS was of ∼ 3 and ∼ 0.4 f g of {sup 239}Pu, respectively. Conclusion, the results demonstrate the aptitude of the Aridus-Hr-Icp-Ms and AMS techniques in the Pu reappraisal in plane tables with bigger speed and precision, improving the values notably of the activity minimum detectable that can be obtained with the alpha spectrometry (∼ 50 f g of {sup 239}Pu). (author)

  3. Development and implementation of methods for determination of the origin of nuclear materials

    The determination of the origin of seized nuclear material is important for authorities in the context of the criminal investigation, in order to return the material to its last legal owner and to help preventing any further diversion of material from this source. Origin determination is based on a complex pattern of parameters obtained through analytical measurements. The information required to determine the origin of nuclear materials may be divided into two categories: endogenous information (e.g. age or mode of production of the material) which is self-explanatory; whereas exogenous information (e.g. dimensions, surface roughness, impurities) requires a database to which the parameters can be compared. The Institute for Transuranium Elements has developed methods to determine characteristic parameters like impurities, surface roughness, or microstructural information. Furthermore, a database was set up containing relevant information on reactor fuels. Age determination of plutonium has been demonstrated successfully for both bulk and particle samples. It is based on several parent-daughter relations (238Pu/234U, 239Pu/235U, 240Pu/236U and 241Pu/241Am). These parent-daughter ratios are preferably determined by thermal ionisation mass spectrometry for bulk samples and by secondary ion mass spectrometry for particle samples. The age determination of enriched 235U fuel through the 234U/230Th ratio is being developed. The mode of Pu production can be identified by isotope correlation technique using accurately measured isotope ratios as input data. Using data on surface roughness of fuel pellets proved to be useful to distinguish between production facilities applying different fabrication methods (e.g. grinding). The determination of the geographical origin of uranium fuel can be supported by geolocation techniques. These techniques are based on natural isotopic variations of certain elements. The variation in isotope ratios correlates with geographical location

  4. First AID (Atom counting for Isotopic Determination).

    Roach, J. L. (Jeffrey L.); Israel, K. M. (Kimberly M.); Steiner, R. E. (Robert E.); Duffy, C. J. (Clarence J.); Roench, F. R. (Fred R.)

    2002-01-01

    Los Alamos National Laboratory (LANL) has established an in vitro bioassay monitoring program in compliance with the requirements in the Code of Federal Regulations, 10 CFR 835, Occupational Radiation Protection. One aspect of this program involves monitoring plutonium levels in at-risk workers. High-risk workers are monitored using the ultra-sensitive Therrnal Ionization Mass Spectrometry (TIMS) technique to ensure compliance with DOE standards. TIMS is used to measure atom ratios of 239Pua nd 240Puw ith respect to a tracer isotope ('Pu). These ratios are then used to calculate the amount of 239Pu and 240Pup resent. This low-level atom counting technique allows the calculation of the concentration levels of 239Pu and 240Pu in urine for at risk workers. From these concentration levels, dose assessments can be made and worker exposure levels can be monitored. Detection limits for TIMS analysis are on the order of millions of atoms, which translates to activity levels of 150 aCi 239Pua nd 500 aCi for 240Pu. pCi for Our poster presentation will discuss the ultra-sensitive, low-level analytical technique used to measure plutonium isotopes and the data verification methods used for validating isotopic measurements.

  5. Origin and release date assessment of environmental plutonium by isotopic composition

    Varga, Zsolt [Hungarian Academy of Sciences, Radiation Safety Department, Institute of Isotopes, Budapest (Hungary)

    2007-10-15

    The origin and release date of environmental plutonium have been assessed by the measurement of plutonium and americium isotopic composition. The applicability and sensitivity of different plutonium isotope ratios, {sup 240}Pu/{sup 239}Pu and {sup 241}Pu/{sup 239}Pu measured by inductively coupled plasma sector field mass spectrometry and {sup 238}Pu/{sup 239}Pu analysed by alpha spectrometry, have been evaluated for origin determination in several types of environmental samples. With use of mixing models the contribution of different sources (e.g. global fallout or Chernobyl) can be calculated. By the measurement of the {sup 241}Am/{sup 241}Pu isotope ratio, the release date (i.e. formation of {sup 241}Pu by irradiation) can be estimated in environmental samples, which is an important parameter to distinguish recent plutonium release from previous (e.g. Chernobyl) emissions. (orig.)

  6. Origin and release date assessment of environmental plutonium by isotopic composition

    The origin and release date of environmental plutonium have been assessed by the measurement of plutonium and americium isotopic composition. The applicability and sensitivity of different plutonium isotope ratios, 240Pu/239Pu and 241Pu/239Pu measured by inductively coupled plasma sector field mass spectrometry and 238Pu/239Pu analysed by alpha spectrometry, have been evaluated for origin determination in several types of environmental samples. With use of mixing models the contribution of different sources (e.g. global fallout or Chernobyl) can be calculated. By the measurement of the 241Am/241Pu isotope ratio, the release date (i.e. formation of 241Pu by irradiation) can be estimated in environmental samples, which is an important parameter to distinguish recent plutonium release from previous (e.g. Chernobyl) emissions. (orig.)

  7. Assessment of Degree of Applicability of Benchmarks for Gadolinium Using KENO V.a and the 238-Group SCALE Cross-Section Library

    Goluoglu, S.

    2003-12-01

    A review of the degree of applicability of benchmarks containing gadolinium using the computer code KENO V.a and the gadolinium cross sections from the 238-group SCALE cross-section library has been performed for a system that contains {sup 239}Pu, H{sub 2}O, and Gd{sub 2}O{sub 3}. The system (practical problem) is a water-reflected spherical mixture that represents a dry-out condition on the bottom of a sludge receipt and adjustment tank around steam coils. Due to variability of the mixture volume and the H/{sup 239}Pu ratio, approximations to the practical problem, referred to as applications, have been made to envelop possible ranges of mixture volumes and H/{sup 239}Pu ratios. A newly developed methodology has been applied to determine the degree of applicability of benchmarks as well as the penalty that should be added to the safety margin due to insufficient benchmarks.

  8. Isotopic signature of plutonium at Bikini atoll

    Atom ratios of the isotopes 239Pu, 240Pu, 241Pu and 244Pu were determined in sediments and soils from Bikini atoll using low energy Accelerator Mass Spectrometry. All samples had been contaminated by local fallout from nuclear weapon testing between 1946 and 1958 and show significant variations in the isotopic composition, which are ascribed to the different yields of single tests and to the mixture of material from various devices. Differences in the 244Pu/239Pu ratio (2.8-5.7x10-4) are more pronounced than in the 240Pu/239Pu ratio of the same samples and provide complementary information to distinguish the sources of contamination.

  9. Effects of combined exposure of F344 rats to radiation and chronically inhaled cigarette smoke

    Nuclear workers may be exposed to radiation in various forms, such as low-LET γ-irradiation or α-irradiation from inhaled 239PuO2 particles. These workers may then have increased risk for lung cancer compared to the general population. Of additional concern is the possibility that interactions between radiation and other carcinogens may increase the risk of cancer induction, compared to the risks from either type of agent alone. An important and common lung carcinogen is cigarette smoke. The purpose of this project is to better determine the combined effects of chronically inhaled cigarette smoke and either inhaled 239PuO2 or external, thoracic X-irradiation on the induction of lung cancer in rats. Histologic and dosimetric evaluations of rats in the CS + 239PuO2 study continue, and the study of CS + X rays is beginning

  10. Composite delayed neutron energy spectra of fissionable isotopes

    Delayed neutron (DN) energy spectra spanning a range of 0.01-4.00 MeV have been measured for 235U, 238U and 239Pu. DN equilibrium spectra were also measured for all three nuclides. A helium jet transfer system was used to transport fission products to a low-background counting area. Beta-neutron correlations were used for background suppression and for energy determination by the neutron time-of-flight method. The 235U and 239Pu spectra show marked similarity, while those from the fast fission of 238U are considerably more energetic. DN six-group spectra for 235U, 238U and 239Pu have been deduced from these measurements using a constrained least-squares iterative method

  11. Effects of combined exposure of F344 rats to radiation and chronically inhaled cigarette smoke

    Finch, G.L.; Nikula, K.J.; Barr, E.B. [and others

    1995-12-01

    Nuclear workers may be exposed to radiation in various forms, such as low-LET {gamma}-irradiation or {alpha}-irradiation from inhaled {sup 239}PuO{sub 2} particles. These workers may then have increased risk for lung cancer compared to the general population. Of additional concern is the possibility that interactions between radiation and other carcinogens may increase the risk of cancer induction, compared to the risks from either type of agent alone. An important and common lung carcinogen is cigarette smoke. The purpose of this project is to better determine the combined effects of chronically inhaled cigarette smoke and either inhaled {sup 239}PuO{sub 2} or external, thoracic X-irradiation on the induction of lung cancer in rats. Histologic and dosimetric evaluations of rats in the CS + {sup 239}PuO{sub 2} study continue, and the study of CS + X rays is beginning.

  12. Uncertainty analysis of delayed neutron fissile material assay using a genetic algorithm

    An uncertainty analysis of the delayed neutron non-destructive assay method was conducted to explicitly define the accuracy with which plutonium content in an uncharacterized sample can be assessed. Perturbing various parameters allowed for an investigation of the sensitivity of this method to various nuclear data, and it was determined that the relative delayed neutron group abundances had the largest effect on the genetic algorithm. Specifically, for a sample containing 235U, 238U, and 239Pu, irradiations in the thermal spectrum were shown to be more sensitive to 235U and 239Pu data, while irradiations in a fast spectrum were shown to be more sensitive to the 238U data. The overall uncertainties of the mass estimates were 15%, 5%, and 30% for 235U, 238U, and 239Pu, respectively. Finally, reducing the first delayed neutron group abundances by a factor of three as suggested by recent research reduced the overall uncertainties to 10%, 3%, and 20%. (author)

  13. Monte Carlo simulations of differential die-away instrument for determination of fissile content in spent fuel assemblies

    Lee, Tae-Hoon, E-mail: typhoon@kaeri.re.kr [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Korea Atomic Energy Research Institute, 150-1 Dukjin-dong, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Menlove, Howard O.; Swinhoe, Martyn T.; Tobin, Stephen J. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2011-10-01

    The differential die-away (DDA) technique has been simulated by using the MCNPX code to quantify its capability of measuring the fissile content in spent fuel assemblies. For 64 different spent fuel cases of various initial enrichment, burnup and cooling time, the count rate and signal to background ratios of the DDA system were obtained, where neutron backgrounds are mainly coming from the {sup 244}Cm of the spent fuel. To quantify the total fissile mass of spent fuel, a concept of the effective {sup 239}Pu mass was introduced by weighing the relative contribution to the signal of {sup 235}U and {sup 241}Pu compared to {sup 239}Pu and the calibration curves of DDA count rate vs. {sup 239}Pu{sub eff} were obtained by using the MCNPX code. With a deuterium-tritium (DT) neutron generator of 10{sup 9} n/s strength, signal to background ratios of sufficient magnitude are acquired for a DDA system with the spent fuel assembly in water.

  14. RAPID DETERMINATION OF 237 NP AND PU ISOTOPES IN WATER BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY

    Maxwell, S.; Jones, V.; Culligan, B.; Nichols, S.; Noyes, G.

    2010-06-23

    A new method that allows rapid preconcentration and separation of plutonium and neptunium in water samples was developed for the measurement of {sup 237}Np and Pu isotopes by inductively-coupled plasma mass spectrometry (ICP-MS) and alpha spectrometry; a hybrid approach. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via peak tailing. The method provide enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then moving Pu to DGA resin for additional removal of uranium. The decontamination factor for uranium from Pu is almost 100,000 and the decontamination factor for U from Np is greater than 10,000. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration is performed using a streamlined calcium phosphate precipitation method. Purified solutions are split between ICP-MS and alpha spectrometry so that long and short-lived Pu isotopes can be measured successfully. The method allows for simultaneous extraction of 20 samples (including QC samples) in 4 to 6 hours, and can also be used for emergency response. {sup 239}Pu, {sup 242}Pu and {sup 237}Np were measured by ICP-MS, while {sup 236}Pu, {sup 238}Pu, and {sup 239}Pu were measured by alpha spectrometry.

  15. Burnup determination in irradiated fuel by means of isotopic analysis and comparison to CASMO calculations

    One of the traditional methods for determining the burnup of irradiated Light Water Reactor (LWR) fuel is the 148Nd method according to ASTM E-321. Probably one of the largest sources for systematic errors in this method is the assumed fission yield, requiring knowledge of the fraction of fissions occurring in different fissile nuclides. Another traditional method for burnup determination is based on the uranium and plutonium isotopic composition; however, this method is rarely used for LWR fuel due to its rather simplified and rough assumptions regarding the neutron spectrum and fission fractions. However, modern physics codes like CASMO and HELIOS are instead able to calculate the amount of fission products and actinides formed or consumed during reactor operation in a much more sophisticated way. Isotopic Dilution Analysis with chemical separation of elements of interest, followed by isotopic analysis with a Thermal Ionization Mass Spectrometer (TIMS) is a well established method for determining the content of selected isotopes in samples of dissolved irradiated fuel. This method normally provides very accurate and precise results. High Performance Liquid Chromatography (HPLC) for elemental separations, combined with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) has become a much faster alternative. In general, this method is somewhat less precise. This disadvantage is at least partly compensated by the possibility of analyzing a larger number of nuclides and samples. The local pellet burnup of a well characterised fuel sample irradiated in the Swedish Boiling Water Reactor Forsmark 3 to about 60 MWd/kgU was determined. Weight ratios of neodymium isotopes relative to 238U, analysed by Isotope Dilution Analysis applying HPLC-ICP-MS as well as 235U and 239Pu abundance values were compared to corresponding values calculated by a single-assembly CASMO-4 simulation. Input data were generated by CASMO-4/POLCA7 core tracking calculations. The overall result

  16. Identifying Sources of Non-fallout Nuclear Contamination in Hudson River Sediments by Plutonium and Neptunium isotope ratios.

    Kenna, T. C.; Chillrud, S. N.

    2002-12-01

    .050 and 0.070, 237Np/239Pu ranges between 0.003 and 0.141, and 241Pu/239Pu ranges between 0.00037and 0.00074). Isotopic analysis of sediments from the lower Hudson River also indicates contamination that is non-fallout in origin (240Pu/239Pu ranges between 0.13 and 0.14, 237Np/239Pu ranges between 0.35 and 0.39, and 241Pu/239Pu ranges between 0.0013 and 0.0016). Isotopic analysis of sediments from the upper Hudson River, above its confluence with the Mohawk, indicates contamination that is largely derived from global fallout (240Pu/239Pu ranges between 0.15 and 0.18, 237Np/239Pu ranges between 0.42 and 0.53, and 241Pu/239Pu ranges between 0.0019 and 0.0023). Initial results clearly indicate contributions from at least one source of non-fallout contamination to Mohawk and Hudson River sediments. Given the geographic location of the Mohawk River sample site, the source is most likely KAPL. Additional work is necessary to determine the source of non-fallout contamination to the lower Hudson River coring site. Although the proximity of this site to IPNPP may suggest that this facility is a source, the isotopic compositions measured to date are consistent with a mixture of global fallout and material similar to that collected at the Mohawk River site. The data presented above, demonstrate the utility of using Pu and Np isotopic ratios to identify contamination originating form non-fallout sources located within the Hudson River drainage basin.

  17. Plutonium uptake by the green alga Scenedesmus obliquus (Turp) Kutz, as a function of isotope and oxidation state

    This study was designed to determine the effect of plutonium chemical valence state on the availability of small concentrations of 238Pu and 239Pu to algae. The uptake experiments involved the green alga Scenedesmus obliquus, grown in batch cultures. Plutonium concentrations accumulated by this alga were linearly related to plutonium concentrations. There was no significant difference (rho = 0.05) in algal plutonium accumulations, on a mass basis, of either 238Pu or 239Pu in either Pu+4 or Pu+6 oxidation state at the concentrations studied

  18. Fission product yields

    Data are summed up necessary for determining the yields of individual fission products from different fissionable nuclides. Fractional independent yields, cumulative and isobaric yields are presented here for the thermal fission of 235U, 239Pu, 241Pu and for fast fission (approximately 1 MeV) of 235U, 238U, 239Pu, 241Pu; these values are included into the 5th version of the YIELDS library, supplementing the BIBFP library. A comparison is made of experimental data and possible improvements of calculational methods are suggested. (author)

  19. Statistical model evaluation of (n,xn) and (n,xnf) cross sections for heavy nuclei

    A method for a statistical model evaluation of fission, (n,2n) and (n,3n) cross sections from 2MeV to 20MeV neutrons on 237U, 238U, 239U and 239Pu is presented. It consists of the determination of fission width parameters by a fit to known fission cross-sections. This method makes use of neutron transmission coefficients from an adapted coupled channel model. The neutron, fission and radiative widths are calculated by the statistical model including Fermi gas model level densities. Results are given for 237U, 238U, 239U and 239Pu nuclei

  20. Neutron absorbers and detector types for spent fuel verification using the self-interrogation neutron resonance densitometry

    The Self-Interrogation Neutron Resonance Densitometry (SINRD) is a passive non-destructive assay (NDA) technique that is proposed for the direct measurement of 239Pu in a spent fuel assembly. The insertion of neutron detectors wrapped with different neutron absorbing materials, or neutron filters, in the central guide tube of a PWR fuel assembly is envisaged to measure the neutron flux in the energy region close to the 0.3 eV resonance of 239Pu. In addition, the measurement of the fast neutron flux is foreseen. This paper is focused on the determination of the Gd and Cd neutron filters thickness to maximize the detection of neutrons within the resonance region. Moreover, several detector types are compared to identify the optimal condition and to assess the expected total neutron counts that can be obtained with the SINRD measurements. Results from Monte Carlo simulations showed that ranges between 0.1–0.3 mm and 0.5–1.0 mm ensure the optimal conditions for the Gd and Cd filters, respectively. Moreover, a 239Pu fission chamber is better suited to measure neutrons close to the 0.3 eV resonance and it has the highest sensitivity to 239Pu, in comparison with a 235U fission chamber, with a 3He proportional counter, and with a 10B proportional counter. The use of a thin Gd filter and a thick Cd filter is suggested for the 239Pu and 235U fission chambers to increase the total counts achieved in a measurement, while a thick Gd filter and a thin Cd filter are envisaged for the 3He and 10B proportional counters to increase the sensitivity to 239Pu. We concluded that an optimization process that takes into account measurement time, filters thickness, and detector size is needed to develop a SINRD detector that can meet the requirement for an efficient verification of spent fuel assemblies

  1. Investigation of plutonium chemical compounds sorption in soil

    Migration and accumulation of contaminants in soil and other environmental systems are related to the stability and change of chemical form of either pollutants themselves or their natural carrier. Therefore, the objectives of this study were to evaluate the possibility of sorption of different plutonium chemical forms (soluble and insoluble) in soil and to determine their ability to migrate into the depth as well. A field experiment was performed for this purpose. An outdoor soil surface was artificially contaminated with 239Pu in the form of 239Pu(NO3)4, 239PuCl3 and 239PuO2. The experiment lasted 326 and 418 days. The experiment showed that most of the released plutonium accumulated in the top layer. This process did not depend on the baseline chemical forms of 239Pu compounds. Result analysis showed that 44 % to 92 % of soluble and insoluble forms of plutonium remained in the top 0-5 cm of the soil. Plutonium chloride was more mobile in soil than plutonium nitrate, which was related to the valence form of the radionuclide that formed stable complex compounds. The content of organic matter in the upper soil layer played a significant role in this process. The insoluble plutonium compound 239PuO2 bound to a greater extent (92 %) with the top, 0-5 cm layer. The results of the field experiment suggest that the top soil layer is a new potential source of artificial radionuclides. From the radioecological point of view, the top layer of soil plays a critical role in the formation of human irradiation dose.(author)

  2. Determination of Pu and total alpha activity in spent TBP/kerosene

    after separation to the activity of 239+240Pu measured in the total alpha measurement as 239Pu was the main alpha-emitter in the spent TBP/kerosene sample. Additionally, it has been discovered that the radioelements in the spent TBP/kerosene was not distributed uniformly. (authors)

  3. Determination of the response of a NaI(Tl) detector

    By means of Monte Carlo calculations it was determined the response of a scintillator of NaI (Tl) of 7.62 Φ x 7.62 cm to monoenergetic gamma rays of 0.2 to 3.5 MeV. The response allows to determine the spectra of height of pulses of the monoenergetic photons. This type of calculations was also carried out for photons emitted by sources of Cs-137, Co-60, Na-22, Na-24 and 239 PuBe, with the purpose of reproducing the gamma spectra obtained with this type of detecting. In the calculations the detector was modelled as a NaI cylinder with Al cover and the base of lucite; due to the absence of reliable information on the quantity of thallium in the calculations this information was omitted: for photons whose energy is greater to 1.022 MeV the presence of the gamma peak of the simple escape and twice is observed. The source was modelled as punctual and was located to 5 cm along the axial axis of the detector. To verify the calculations its were carried out measurements with a spectrometer with a scintillator of 7.62 Φ x 7.62 cm. In the measured spectra the sum peak is observed, while in those calculated it doesn't appear; because the simultaneous detection of photons of different energy doesn't happen each photon since, in single form, it is followed until its complete absorption in the scintillator or when it escapes from the volume of the detector. To reproduce the sum peak and to obtain height spectra of pulses similar to those measured, the sum photons were introduced in the calculations. With the purpose of that Monte Carlo calculation it reproduces the scattering around the photopeak it was used a gaussian function in each photopeak whose characteristics were obtained starting from the experimental data. The calculation of the response of a scintillator allows to establish the capacity of the measurement of the gamma radiation as well as to distinguish the real events of those that appear by the limitations of the detection process. (Author)

  4. Determination of aqueous plutonium oxidation states by spectrophotometry and solvent extraction

    The oxidation states (III, IV, and VI) of aqueous plutonium ions were controlled in nitric acid media using oxidants or reductants and determined from the measurements of absorption spectra ranging from 400 to 1200 nm. Pu(III) was obtained from the oxidation-reduction reaction of Pu(IV) stock solution and hydroxylamine in 1 M nitric acid media. The observation of spectral changes with reaction time showed that Pu(IV) was completely reduced to Pu(III) within 4 hours and the oxidation state of Pu(III) remained unchanged at least for 30 days under the closed condition, and for 10 days under the open condition. The Pu(III) was completely oxidized to Pu(IV) within a few hours by an addition of NaNO2 in 1 M nitric acid media, and the Pu(IV) was stable all the way for 30 and 10 days under the closed and open conditions, respectively. Pu(IV) was oxidized very slowly to Pu(VI) by ozone gas in 1 M nitric acid media. When the flow rate of ozone gas was kept as low as possible in order to prevent the Pu solution from bubbling over, it took 12 hours to oxidize Pu(IV) to Pu(VI) completely. The resulting Pu(VI) was stable at least for 30 and 10 days under the closed and open conditions, respectively. The addition of H2O2 to the Pu(VI) in 8 M nitric acid media caused a complete reduction to Pu(IV) within a few minutes, and successively to Pu(III) in an hour. The Pu(III) was oxidized very slowly to Pu(IV) for 2 weeks. In this case, the heating of Pu(III) solution containing an excess of H2O2 at 90 .deg. C for 30 minutes leaded to a rapid oxidation of Pu(III) to Pu(IV). The oxidation states of 239Pu tracer were controlled in 0.5 M nitric acid media in essentially the same manner as before and determined by thenoyltrifluoroacetone(TTA) extraction

  5. Determination the total neutron yields of several semiconductor compounds using various alpha emitters

    Abdullah, Ramadhan Hayder; Sabr, Barzan Nehmat

    2016-03-01

    In the present work, the cross-sections of (α,n) reactions available in the literature as a function of α-particle energies for light and medium elements have been rearranged for α-particle energies from near threshold up to 10 MeV in steps of (0.050MeV) using the (Excel and Matlab) computer programs. The obtained data were used to calculate the neutron yields (n/106α) using the quick basic-computer program (Simpson Rules). The stopping powers of alpha particle energies from near threshold to 10 MeV for light and medium elements such as (nat.Be,10B,11B,13C,14N,nat.O,nat.F,nat.Mg,nat.Al,29Si,30Si, nat.P and 46.48Ti) have been calculated using the Zeigler formula. The kinetic energies (Tα) and the branching ratios of each α-emitters such as (211Bi, 210Po, 211Po, 215Po, 217At, 218Rn, 219Rn, 222Rn, 224Ra, 226Ra, 215Th, 228Th, 232U, 234U, 236U, 238U, 238Pu, 239Pu, 241Am, 245Es, 252Fm, 254Fm, 256Fm, 257Fm and 257Md) are taken into consideration to calculate the mean kinetic energy . The polynomial expressions were used to fitting the calculated weighted average of neutron yields (n/106α) for natural light and medium elements such as (Be, B, C, N, O, F, Mg, Al, Si, P and Ti) to determine the adopted neutron yields from the best fitting equation with minimum (CHISQ) at mean kinetic energies of various α-emitters. The total neutron yields (n/s/gx/ppmi) of the mentioned natural light and medium elements have been calculated using the adopted neutron yields (n/106α) from the fitting equations at mean kinetic energies of various α-emitters. The total neutron yields (n/s/gα-emitters/gcompounds) of semiconductor compounds such as (AlN, AlP, BN, BP, SiC, TiO2, BeSiN2, MgCN2, MgSiN2 and MgSiP2) have been calculated by mixing (1gram) of compounds with (1gram) of pure α-emitters using the quick basic computer program. The aim of the present work is to constructed and fabricate the neutron sources theoretically

  6. Modifying radionuclide effects

    The metabolism and effects of radionuclides may be influenced by a number of dietary, physiological, and environmental factors. Some factors are studied which have been identified as potentially important determinants of radionuclide behavior: the reproductive performance of female rats exposed to 239Pu during pregnancy or lactation, and the relative contribution of cross-placental and milk transfer to offspring

  7. Analysis of Sub-picogram Plutonium by Isotope Mass Spectrometry%亚皮克量级钚的质谱分析技术

    龙开明; 汤磊; 贾宝亭; 刘雪梅; 杨天丽; 刘钊

    2005-01-01

    By using active carbon powder as ionization enhance matter, the detect sensitivity of 239Pu ,which was 0.5 pg (1±0.15, 95% confidence level), was about 20 times that of the tradition method. The sub-picogram plutonium sample was determined quantitatively by isotope dilution mass spectrometry (IDMS).

  8. Plutonium flux into the Gulf of Mexico. Progress report

    Progress is reported on the following projects: expansion of equipment and facilities; sampling procedures; analysis of river samples for 238Pu, 239Pu, and 240Pu; analyses of river bottom sediments; factors determining the concentration of fallout nuclides in soil and sediment samples; analyses of river sediments for 234U, 238U, and 230Th; and geographic variation in sediments

  9. Biological behavior of mixed LMFBR-fuel-sodium aerosols in rodents

    Clearance of 239Pu from lung and other tissues was determined after nose-only exposure of rats to mixed aerosols of sodium-LMFBR fuel or to LMFBR fuels only. The rates of clearance from lung and from total body were both higher after exposure to the mixed sodium-fuel than after exposure to fuel-only aerosols

  10. Uptake of three isotopes of plutonium from soil by sweet corn grown in a growth chamber

    A gamma-emitting isotope of plutonium for simulating 238Pu and 239Pu behavior in the environment would eliminate the high cost of sample preparation necessary for detecting alpha particles. To date, selected tracers for this purpose have not been satisfactory; however, the availability of 237Pu has provided an additional candidate tracer. 237Pu has been used to trace 239Pu in metabolic studies of plutonium distribution in, and excretion by, dogs and rats and to determine the distribution coefficient of plutonium between sediment and sea water. The suitability of 237Pu as a tracer for 238Pu and 239Pu in environmental systems was determined using a plant-soil system. These three isotopes were compared by measuring their uptakes by sweet corn. A nitrate solution containing all three isotopes was added to the soil. The apparent availability of the three isotopes differed: 237Pu was more available than 238Pu, which was more available than 239Pu. The quantity of 237Pu in the standing crop, on a mass basis, closely approximated that of 238Pu

  11. DETERMINATION OF REPORTABLE RADIONUCLIDES FOR DWPF SLUDGE BATCH 5 (MACROBATCH 6)

    Bannochie, C.; Bibler, N.; Diprete, D.

    2010-02-04

    The Waste Acceptance Product Specifications (WAPS) 1.2 require that ''The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115''. As part of the strategy to comply with WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production through the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP) and Waste Form Qualification Report (WQR). However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that may meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, International Atomic Energy Agency (IAEA) Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The DWPF is receiving radioactive sludge slurry from HLW Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the heel from Tank 40 (Sludge Batch 4 (SB4)), Sludge Batch 5 (SB5) that was transferred to Tank 40 from Tank 51, and H-Canyon Np transfers completed after the start of processing. The blend of sludge in Tank 40 is also referred to as Macrobatch 6 (MB6). This report develops the list of reportable radionuclides and associated activities and determines the radionuclide activities as a function of time

  12. Inhaled plutonium oxide in dogs

    This project is concerned with long-term experiments to determine the lifespan dose-effect relationships of inhaled 239PuO2 and 238PuO2 in beagles. The data will be used to estimate the health effects of inhaled transuranics. Beagle dogs given a single exposure to 239PuO2 or 238PuO2 aerosols to obtain graded levels of initial lung burdens are being observed for lifespan dose-effect relationships. Mortality due to radiation pneumonitis and lung tumor increased in the four highest dose-level groups exposed to 239PuO2, during the 13-yr postexposure period. During the 10 1/2 years after exposure to 238PuO2, mortality due to lung and/or bone tumors increased in the three highest dose-level groups. Chronic lymphopenia, occurring 0.5 to 2 year after exposure, was the earliest observed effect after inhalation of either 239PuO2 or 238PuO2 in the four highest dose-level groups that had initial lung burdens greater than or equal to 80 nCi. 3 figures, 6 tables

  13. Inhaled plutonium oxide in dogs

    This project is concerned with long-term experiments to determine the lifespan dose-effect relationships of inhaled 239PuO2 or 238PuO2 in beagles. The data will be used to estimate the health effects of inhaled transuranics. Beagle dogs given a single exposure to 239PuO2 or 238PuO2 aerosols to obtain graded levels of initial lung burdens (ILB) are being observed for lifespan dose-effect relationships. Mortality due to radiation pneumonitis and lung tumor increased in the four highest dose-level groups exposed to 239PuO2 during the 15-year postexposure period. During the 12 1/2 years after exposure to 238PuO2, mortality due to lung and/or bone tumors increased in the three highest dose-level groups. Chronic lymphopenia, occurring 0.5 to 2 years after exposure, was the earliest observed effect after inhalation of either 239PuO2 or 238PuO2 in the four highest dose-level groups that had ILB of ≥ 80 nCi. Other plutonium-exposure-related effects include sclerosis of the tracheobronchial lymph nodes, focal radiation pneumonitis, adenomatous hyperplasia of the liver, and dystrophic osteolytic lesions in the skeleton. 4 figures, 7 tables

  14. Inhaled plutonium oxide in dogs

    This project is concerned with long-term experiments to determine the life span dose-effect relationships of inhaled 239PuO2 or 238PuO2 in beagles. The data will be used to estimate the health effects of inhaled transuranics. Beagle dogs given a single exposure to 239PuO2 or 238PuO2 aerosols to obtain graded levels of initial lung burdens (ILB) are being observed for life span dose-effect relationships. Mortality due to radiation pneumonitis and lung tumor increased in the four highest dose-level groups exposed to 239PuO2 during the 16-year post exposure period. During the 13 years after exposure to 238PuO2, mortality due to lung and/or bone tumors increased in the three highest dose-level groups. Chronic lymphopenia, occurring 0.5 to 2 years after exposure, was the earliest observed effect after inhalation of either 239PuO2 or 238PuO2 in the four highest dose-level groups that had ILB of ≥ 80 nCi. Other plutonium-exposure-related effects include sclerosis of the tracheobronchial lymph nodes, focal radiation pneumonitis, adenomatous hyperplasia of the liver, and dystrophic osteolytic lesions in the skeleton

  15. Inhaled plutonium oxide in dogs

    This project is concerned with long-term experiments to determine the lifespan dose-effect relationships of inhaled 239PuO2 and 238PuO2 in beagles. The data will be used to estimate the health effects of inhaled transuranics. Beagle dogs given a single exposure to 239PuO2 or 238PuO2 aerosols to obtain graded levels of initial lung burdens (ILB) are being observed for lifespan dose-effect relationships. Mortality due to radiation pnuemonitis and lung tumor increased in the four highest dose-level groups exposed to 239PuO2 during the 14-year postexposure period. During the 11 1/2 years after exposure to 238PuO2, mortality due to lung and/or bone tumors increased in the three highest dose-level groups. Chronic lymphopenia, occurring 0.5 to 2 years after exposure, was the earliest observed effect after inhalation of either 239PuO2 or 238PuO2 in the four highest dose-level groups that had ILB of greater than or equal to80 nCi. Other plutonium-exposure-related effects include sclerosis of the tracheobronchial lymph nodes, focal radiation pneumonitis, adenomatous hyperplasia of the liver, and dystrophic osteolytic lesions in the skeleton. 5 figures, 7 tables

  16. Experimental determination of contaminant metal mobility as a function of temperature, time and solution chemistry. 1997 annual progress report

    'Strontium is significantly more mobile than other hazardous radioactive metals. Its partitioning between aqueous and solid phases is controlled by reactions that occur at the interface between natural waters and minerals. At a groundwater site in Hanford (200-BP-5), the aerial extent of the 90Sr plume is 100 times larger than the aerial extent of the 137Cs and the 239Pu plumes. Similarly, contaminated, perched watertables at INEL have much higher aqueous concentrations of 90Sr than 137Cs, presumably because Cs is preferentially sorbed to solids (Duncan 1995). Under high physical flow conditions, such as those in the highly fractured rock at Hanford and INEL, 90Sr present in plumes may spread off-site and cause contamination of aquifers or other water sources. Geochemical factors that may contribute to the overall mobility of Sr in natural waters are the solubilities of phases such as strontianite (SrCO3) and formation of strong complexes with sulfate and nitrate. Although 90Sr is mobilized in natural waters in these examples, significant concentrations may also be present in solid phases. Sorption experiments using a wide variety of substrates at room temperature have shown that Sr is removed from solution under certain conditions. Additionally, strontianite (SrCO3) may precipitate at low Sr concentrations in the pH range of waters in contact with basaltic rocks, which varies between pH 8 and 10. Waters contain variable amounts of carbonate owing to atmospheric interactions; the partial pressure of CO2 is about 10 x 3.5 atm in air and commonly as high as 10 x 2.5 atm in soils. The objective of this work is to determine the fundamental data needed to predict the behavior of strontium at temperature and time scales appropriate to thermal remediation. The authors approach combines macroscopic sorption/precipitation and desorption/dissolution kinetic experiments, which track changes in solution composition, with direct molecular characterization of strontium in the

  17. The AS-76 interlaboratory experiment on the alpha spectrometric determination of Pu-238. Pt. 3

    Four plutonium samples containing 0.2, 0.8, 1.6 and 0.9 Atom% of 238Pu have been prepared for the Interlaboratory Experiment AS-76. Of these, three were input solutions from a reprocessing plant. The fourth sample was from a plutonium product solution. These samples have been characterized by two alpha spectrometry laboratories and two mass spectrometry laboratories to certify the ratio of alpha activities 238Pu/(239Pu + 240Pu) and the isotopic composition, respectively. (orig.) 891 HP/orig. 892 MKO

  18. DETERMINATION OF REPORTABLE RADIONUCLIDES FOR DWPF SLUDGE BATCH 4 MACROBATCH 5

    The Waste Acceptance Product Specifications (WAPS)1 1.2 require that 'The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115'. As part of the strategy to meet WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production through the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP)2 and Waste Form Qualification Report (WQR)3. However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that may meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, International Atomic Energy Agency (IAEA) Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The DWPF is receiving radioactive sludge slurry from HLW Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the previous contents of Tank 40 (Sludge Batch 3) and the sludge that was transferred to Tank 40 from Tank 51. The blend of sludge from Tank 51 and Tank 40 defines Sludge Batch 4 (also referred to as Macrobatch 5 (MB5)). This report develops the list of reportable radionuclides and associated activities and determines the radionuclide activities as a function of time. The DWPF will use this list and the activities as one of

  19. DETERMINATION OF REPORTABLE RADIONUCLIDES FOR DWPF SLUDGE BATCH 4 MACROBATCH 5

    Bannochie, C; Ned Bibler, N; David Diprete, D

    2008-05-30

    The Waste Acceptance Product Specifications (WAPS)1 1.2 require that 'The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115'. As part of the strategy to meet WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production through the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP)2 and Waste Form Qualification Report (WQR)3. However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that may meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, International Atomic Energy Agency (IAEA) Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The DWPF is receiving radioactive sludge slurry from HLW Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the previous contents of Tank 40 (Sludge Batch 3) and the sludge that was transferred to Tank 40 from Tank 51. The blend of sludge from Tank 51 and Tank 40 defines Sludge Batch 4 (also referred to as Macrobatch 5 (MB5)). This report develops the list of reportable radionuclides and associated activities and determines the radionuclide activities as a function of time. The DWPF will use this list and the activities

  20. Determination of the response of a NaI(Tl) detector; Determinacion de la respuesta de un detector de NaI(Tl)

    Vega C, H.R.; Manzanares A, E.; Hernandez D, V.M.; Chacon R, A. [Universidad Autonoma de Zacatecas, A.P. 336, 98000 Zacatecas (Mexico)]. e-mail: fermineutron@yahoo.com

    2006-07-01

    By means of Monte Carlo calculations it was determined the response of a scintillator of NaI (Tl) of 7.62 {phi} x 7.62 cm to monoenergetic gamma rays of 0.2 to 3.5 MeV. The response allows to determine the spectra of height of pulses of the monoenergetic photons. This type of calculations was also carried out for photons emitted by sources of Cs-137, Co-60, Na-22, Na-24 and {sup 239} PuBe, with the purpose of reproducing the gamma spectra obtained with this type of detecting. In the calculations the detector was modelled as a NaI cylinder with Al cover and the base of lucite; due to the absence of reliable information on the quantity of thallium in the calculations this information was omitted: for photons whose energy is greater to 1.022 MeV the presence of the gamma peak of the simple escape and twice is observed. The source was modelled as punctual and was located to 5 cm along the axial axis of the detector. To verify the calculations its were carried out measurements with a spectrometer with a scintillator of 7.62 {phi} x 7.62 cm. In the measured spectra the sum peak is observed, while in those calculated it doesn't appear; because the simultaneous detection of photons of different energy doesn't happen each photon since, in single form, it is followed until its complete absorption in the scintillator or when it escapes from the volume of the detector. To reproduce the sum peak and to obtain height spectra of pulses similar to those measured, the sum photons were introduced in the calculations. With the purpose of that Monte Carlo calculation it reproduces the scattering around the photopeak it was used a gaussian function in each photopeak whose characteristics were obtained starting from the experimental data. The calculation of the response of a scintillator allows to establish the capacity of the measurement of the gamma radiation as well as to distinguish the real events of those that appear by the limitations of the detection process. (Author)

  1. Deposition of 236U from atmospheric nuclear testing in Washington state (USA) and the Pechora region (Russian Arctic)

    Stratospheric fallout-derived 236U has been detected by sector field ICPMS at two field locations for which our laboratory possessed available archived samples: A) four soil cores from Washington state (northwestern USA) and B) sediment cores from three small lakes in the Pechora region (Russian Arctic). Four Washington state soil cores exhibit 236U inventories of 8.1 ± 1.3, 11.1 ± 0.9, 18 ± 2, and 30.2 ± 3.9 Tatoms/m2; the respective 239Pu contents are 52.9 ± 3.5, 67 ± 3, 71 ± 2, and 151 ± 2 Tatoms/m2. A 236U/239Pu atom ratio of 0.19 ± 0.04 (1 SD) has been determined from the Washington state soil cores. The three Pechora region lake cores each exhibit coincident maxima in their 236U and 239Pu atom concentration profiles. The 236U/238U atom ratios are controlled by two independent factors; 236U is from fallout deposition and 238U concentrations are a property of the geochemical distribution of naturally occurring U. A 236U/238U atom ratio as high as 8.9 × 10−6 has been observed for acid-leached soils containing Pu solely derived from bomb-test fallout. Accordingly, a non-zero 236U background from stratospheric fallout must be recognized and taken into account when detectable 236U is used to infer specific local or regional influences of reactor-irradiated U. -- Highlights: ► The isotope 236U, originating from atmospheric nuclear weapons tests, has been identified at two locations in the Northern Hemisphere. ► Peak 236U concentrations match peak 239Pu concentrations in sediment cores. ► The 236U/239Pu atom ratio is 0.19 ± 0.04

  2. First results studying the transmutation of 129I, 237Np, 238Pu, and 239Pu in the irradiation of an extended natU/Pb-assembly with 2.52 GeV deuterons

    Krivopustov, M. I.; Pavljuk, A. V.; Kovalenko, A.D.; Mariin, I.I.; Elishev, A.F.; Adam, Jindřich; Kovalík, Alojz; Batusov, Yu, A.; Kalinnikov, V. G.; Brudanin, V. B.; Čaloun, Pavel; Tsoupko-Sitnikov, V. M.; Solnyshkin, A. A.; Stegailov, V. I.; Gerbish, Sh.; Svoboda, Ondřej; Dubnická, Z.; Kala, M.; Kloc, M.; Krása, Antonín; Kugler, Andrej; Majerle, Mitja; Wagner, Vladimír; Brandt, R.; Westmeier, W.; Robotham, H.; Siemon, K.; Bielewicz, M.; Kilim, S.; Szuta, M.; Strugalska-Gola, E.; Wojeciechowski, A.; Hashemi-Nezhad, R. S.; Manolopoulou, M.; Fragopolou, M.; Stoulos, S.; Zamani-Valasiadou, M.; Jokic, S.; Katovsky, K.; Schastny, O.; Zhuk, I. V.; Potapenko, A.S.; Safronova, A.A.; Lukashevich, Zh.A.; Voronko, V.A.; Sotnikov, V.V.; Sidorenko, V.V.; Ensinger, W.; Severin, H.D.; Batsev, S.; Kostov, L.; Protokhristov, Kh.; Stoyanov, Ch,.; Yordanov, O.; Zhivkov, P.K.; Kumar, A.V.; Sharma, M.; Khilmanovich, A.M.; Marcinkevich, B.A.; Korneev, S.V.; Damdinsuren, Ts.; Togoo, Ts.; Kumawat, H.

    2009-01-01

    Roč. 279, č. 2 (2009), s. 567-584. ISSN 0236-5731 R&D Projects: GA AV ČR IAA100480803; GA MŠk LC07050 Institutional research plan: CEZ:AV0Z10480505 Keywords : MCNPX. * GeV Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.631, year: 2009

  3. Investigation of prompt fission neutron and gamma spectra with their covariance matrices - Application to 239Pu+nth, 238U+n1.8MeV,235U+nth

    Prompt fission neutron and gamma spectra as well as multiplicities are important for nuclear heating purpose. A recent tool, FIFRELIN, has been developed at Cadarache for simulating the de-excitation of the fission fragments (FF) in order to generate the quantities mentioned above within a single code. The input data required by the code are the pre-neutron mass and kinetic energy distributions. These distributions come from experiments. Additional models are used to sample the charge, spin and parity of the fragments. The excitation energy sharing between two complementary fragments has been detailed in previous works. When the FF characteristics are sampled (A, Z, KE, J, π) the de-excitation process can start. The first scheme is based on Weisskopf statistical theory for neutron emission and level density plus strength functions for gamma emission. The neutron emission is performed before the gamma emission (uncoupled scheme). The second one is a Hauser-Feshbach like scheme based on neutron and gamma transmission coefficients (neutron and gamma emissions are coupled). The whole simulation allows the estimation of fission observables such as prompt fission neutron and gamma spectra as well as multiplicities but also distributions of all fission-related quantities. Various thermal, fast and spontaneous fissioning systems have been studied. In addition, a coupling algorithm between FIFRELIN and the CONRAD nuclear data evaluation code has been initiated in order to generate covariance matrices related to prompt fission spectra. (authors)

  4. A model for determination of screening level for radioactive elements in soil; Modelo para o estabelecimento de valores orientadores para elementos radioativos no solo

    Peres, Ana Claudia

    2007-07-01

    At the present, decision about clean-up of Brazilian sites contaminated with radioactive isotopes is addressed on a case-by-case basis, since there is no general guidance or recommendation to support actions in early phases of the problem identification. For chemicals, CETESB - the governmental organization responsible for preventing and controlling environmental pollution in Sao Paulo State - established background values, prevention and intervention, as the first step to implement a remediation actions based on human health risk assessment. The aim of this study was to develop a methodology for the establishment of target values for radioactive soil contamination, as far as possible consistent and compatible with the approach adopted by CETESB for sites contaminated with chemicals. The following steps have been addressed in this study: conceptual scenario and model development; codification of the equations in an electronic spreadsheet; selection of proper range and statistical distribution of the input values; derivation of the intervention levels for selected radionuclides using Monte Carlo methods. The mathematical model developed was mainly based on the equations used by the U.S. Environmental Protection Agency (EPA) and by the National Council on Radiation Protection and Measurements (NCRP) for soil screening purposes. Intervention and prevention values are presented for adult and 10 years old child, for each 3 exposure scenarios: agricultural, residential and industrial; the following radionuclides were considered: {sup 3}H, {sup 14}C, {sup 32}P, {sup 35}S, {sup 45}Ca, {sup 51}Cr, {sup 90}Sr, {sup 125}I, {sup 131}I, {sup 134}Cs, {sup 137}Cs, {sup 210}Pb, {sup 226}Ra, {sup 228}Ra, {sup 232}Th, {sup 238}U, {sup 239}Pu and {sup 241} Am. Quality reference values were determined for {sup 40}K, {sup 137}Cs, {sup 210}Pb, {sup 226}Ra, {sup 228}Ra, {sup 228}Th, Th-nat e U-nat. Results obtained in this study showed a good agreement with those reported by NCRP

  5. Neutron capture radiography to determine the concentration of natural boron in leaves using the nuclear reaction 10B(n,α)7Li

    Neutron capture radiography (NCR) is a nuclear analytical imaging method. It is based on using thermal neutron induced nuclear reactions, such as (n,p), (n,α) or (n,f). Clearly NCR can be used for the detection of only those nuclides whose cross-section (σ) for one of these nuclear reactions is not too low. With σ being indicated in barns (1 barn 10-28m2) in brackets, this is the case especially with 14N (1.83), 35Cl (0.48), 40K (4.4) for (n,p) reactions; 6Li (941.4), 10B (3836), 17O (0.24), 35S (0.14), 40K (0.39) for (n,α) reactions; and 235U (583) and 239Pu (742) for neutron induced fissions (n,f). Some of these nuclear reactions are characteristic of stable isotopes (14N, 6Li, 10B, 17O) of chemical elements that are highly relevant for biology but have no radioactive isotope usable in practice. It is possible to use these stable isotopes for the labelling and analytical imaging of the corresponding elements almost as easily as with radioactive tracers when they exist. Some of these nuclear reactions are characteristic of stable isotopes (14N, 6Li, 10B, 17O) of chemical elements that are highly relevant for biology but have no radioactive isotope usable in practice. It is possible to use these stable isotopes for the labelling and analytical imaging of the corresponding elements almost as easily as with radioactive tracers when they exist. In conventional NCR studies, the biological specimen (a histological section in most cases) is laid against an appropriate detector (most often a film of cellulose nitrate or polycarbonate), and then this whole assembly is irradiated with thermal neutrons. The impact of the ionizing particles (p,α, fission fragments) emitted by the nuclear reactions creates latent tracks in the detecting film. Using an appropriate chemical treatment (most often by dipping the detectors in a strong alkaline solution), the latent tracks are enlarged to the size of tracks visible with an optical microscope. The features (especially the size

  6. A rapid and accurate method for the determination of plutonium in food using magnetic sector ICP-MS with an ultra-sonic nebuliser and ion chromatography.

    Evans, P; Elahi, S; Lee, K; Fairman, B

    2003-02-01

    In the event of a nuclear incident it is essential that analytical information on the distribution and level of contamination is available. An ICP-MS method is described which can provide data on plutonium contamination in food within 3 h of sample receipt without compromising detection limits or accuracy relative to traditional counting methods. The method can also provide simultaneous determinations of americium and neptunium. Samples were prepared by HNO3 closed-vessel microwave digestion, evaporated to dryness and diluted into a mobile phase comprising 1.5 M HNO3 and 0.1 mM 2,6-pyridinedicarboxylic acid. A commercially available polystyrene-divinylbenzene ion chromatography column provides on-line separation of 239Pu and 238U reducing the impact of the 238U1H interference. Oxidation of the sample using H2O2 ensures all Pu is in the Pu(+4) state. The oxidation also displaces Np away from the solvent front by changing the oxidation state from Np(+3) to Np(+4) and produces the insoluble Am(+4) ion. Simultaneous Pu, Am and Np analyses therefore require omission of the oxidation stage and some loss of Pu data quality. Analyses were performed using a magnetic sector ICP-MS (Finnigan MAT Element). The sample is introduced to the plasma via an ultrasonic nebuliser-desolvation unit (Cetac USN 6000AT+). This combination achieves an instrumental sensitivity of 238U > 2 x 10(7) cps/ppb and removes hydrogen from the sample gas, which also inhibits the formation of 238U1H. The net effect of the improved sample introduction conditions is to achieve detection levels for Pu of 0.020 pg g(-1) (4.6 x 10(-2) Bq kg(-1)) which is significantly below 1/10th of the most stringent EU (European Union) legislation, currently 0.436 pg g(-1) (1 Bq kg(-1)) set for baby food. The new method was evaluated with a range of biological samples ranging from cabbage to milk and meat. Recovery of Pu agrees with published values (100% +/- 20%). PMID:12619774

  7. A fast semi-quantitative method for Plutonium determination in an alpine firn/ice core

    Gabrieli, J.; Cozzi, G.; Vallelonga, P.; Schwikowski, M.; Sigl, M.; Boutron, C.; Barbante, C.

    2009-04-01

    Plutonium is present in the environment as a consequence of atmospheric nuclear tests carried out in the 1960s, nuclear weapons production and releases by the nuclear industry over the past 50 years. Plutonium, unlike uranium, is essentially anthropogenic and it was first produced and isolated in 1940 by deuteron bombardment of uranium in the cyclotron of Berkeley University. It exists in five main isotopes, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, derived from civilian and military sources (weapons production and detonation, nuclear reactors, nuclear accidents). In the environment, 239Pu is the most abundant isotope. Approximately 6 tons of 239Pu have been released into the environment as a result of 541 atmospheric weapon tests Nuclear Pu fallout has been studied in various environmental archives, such as sediments, soil and herbarium grass. Mid-latitude ice cores have been studied as well, on Mont Blanc, the Western Alps and on Belukha Glacier, Siberian Altai. We present a Pu record obtained by analyzing 52 discrete samples of an alpine firn/ice core from Colle Gnifetti (M. Rosa, 4450 m a.s.l.), dating from 1945 to 1991. The239Pu signal was recorded directly, without preliminary cleaning or preconcentration steps, using an ICP-SFMS (Thermo Element2) equipped with a desolvation system (APEX). 238UH+ interferences were negligible for U concentrations lower than 50 ppt as verified both in spiked fresh snow and pre-1940 ice samples. The shape of 239Pu profile reflects the three main periods of atmospheric nuclear weapons testing: the earliest peak starts in 1954/55 to 1958 and includes the first testing period which reached a maximum in 1958. Despite a temporary halt in testing in 1959/60, the Pu concentration decreased only by half with respect to the 1958 peak. In 1961/62 Pu concentrations rapidly increased reaching a maximum in 1963, which was about 40% more intense than the 1958 peak. After the sign of the "Limited Test Ban Treaty" between USA and URSS in 1964, Pu

  8. Dating of sediments from four Swiss prealpine lakes with 210Pb determined by gamma-spectrometry: progress and problems

    In this paper the most important problems in dating lake sediments with unsupported 210Pb are summarized and the progress in gamma-spectrometry of the unsupported 210Pb is discussed. The main topics of these studies concern sediment samples preparation for gamma-spectrometry, measurement techniques and data analysis, as well as understanding of accumulation and sedimentation processes in lakes. The vertical distributions of artificial (137Cs, 241Am, 239Pu) and natural radionuclides (40K, 210,214Pb, 214Bi) as well as stable trace elements (Fe, Mn, Pb) in sediment cores from four Swiss lakes were used as examples for the interpretation, inter-comparison and validation of depth–age relations established by three 210Pb-based models (CF-CSR, CRS and SIT). The identification of turbidite layers and the influence of the turbidity flows on the accuracy of sediment dating is demonstrated. Time-dependent mass sedimentation rates in lakes Brienz, Thun, Biel and Lucerne are discussed and compared with published data. - Highlights: • State-of-the-art aspects of gamma-spectrometry of unsupported 210Pb are summarized. • Reduction of 222Rn loss by sealing sediment samples was experimentally quantified. • 210Pb models (CF-CSR, CRS, SIT) are applied on long sediment cores from 4 lakes. • Results for profiles, depth–age relations and sedimentation rates are compared. • 210Pb dating is supported by independent time-markers (7Be, 137Cs, 241Am, 239Pu)

  9. Determination of Reportable Radionuclides for DWPF Sludge Batch 3 (Macrobatch 4)

    The Waste Acceptance Product Specifications (WAPS) 1.2 require that ''The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115''. As part of the strategy to meet WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production through the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP) and Waste Form Qualification Report (WQR). However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, IAEA Safeguards Reporting for HLW, requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The Defense Waste Processing Facility (DWPF) is receiving radioactive sludge slurry from High Level Waste Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the previous contents of Tank 40 (Sludge Batch 2) and the sludge that was transferred to Tank 40 from Tank 51. The blend of sludge from Tank 51 and Tank 40 defines Macrobatch 4 (also referred to as Sludge Batch 3). This report develops the list of reportable radionuclides and associated activities and determines the radionuclide activities as a function of time. The DWPF will use this list and the activities as one of the inputs for the

  10. Neutron absorbers and detector types for spent fuel verification using the self-interrogation neutron resonance densitometry

    Rossa, Riccardo, E-mail: rrossa@sckcen.be [SCK-CEN, Belgian Nuclear Research Centre, Boeretang, 200, B2400 Mol (Belgium); Université libre de Bruxelles, Ecole polytechnique de Bruxelles, Service de Métrologie Nucléaire (CP 165/84), Avenue F.D. Roosevelt, 50, B1050 Brussels (Belgium); Borella, Alessandro, E-mail: aborella@sckcen.be [SCK-CEN, Belgian Nuclear Research Centre, Boeretang, 200, B2400 Mol (Belgium); Labeau, Pierre-Etienne, E-mail: pelabeau@ulb.ac.be [Université libre de Bruxelles, Ecole polytechnique de Bruxelles, Service de Métrologie Nucléaire (CP 165/84), Avenue F.D. Roosevelt, 50, B1050 Brussels (Belgium); Pauly, Nicolas, E-mail: nipauly@ulb.ac.be [Université libre de Bruxelles, Ecole polytechnique de Bruxelles, Service de Métrologie Nucléaire (CP 165/84), Avenue F.D. Roosevelt, 50, B1050 Brussels (Belgium); Meer, Klaas van der, E-mail: kvdmeer@sckcen.be [SCK-CEN, Belgian Nuclear Research Centre, Boeretang, 200, B2400 Mol (Belgium)

    2015-08-11

    The Self-Interrogation Neutron Resonance Densitometry (SINRD) is a passive non-destructive assay (NDA) technique that is proposed for the direct measurement of {sup 239}Pu in a spent fuel assembly. The insertion of neutron detectors wrapped with different neutron absorbing materials, or neutron filters, in the central guide tube of a PWR fuel assembly is envisaged to measure the neutron flux in the energy region close to the 0.3 eV resonance of {sup 239}Pu. In addition, the measurement of the fast neutron flux is foreseen. This paper is focused on the determination of the Gd and Cd neutron filters thickness to maximize the detection of neutrons within the resonance region. Moreover, several detector types are compared to identify the optimal condition and to assess the expected total neutron counts that can be obtained with the SINRD measurements. Results from Monte Carlo simulations showed that ranges between 0.1–0.3 mm and 0.5–1.0 mm ensure the optimal conditions for the Gd and Cd filters, respectively. Moreover, a {sup 239}Pu fission chamber is better suited to measure neutrons close to the 0.3 eV resonance and it has the highest sensitivity to {sup 239}Pu, in comparison with a {sup 235}U fission chamber, with a {sup 3}He proportional counter, and with a {sup 10}B proportional counter. The use of a thin Gd filter and a thick Cd filter is suggested for the {sup 239}Pu and {sup 235}U fission chambers to increase the total counts achieved in a measurement, while a thick Gd filter and a thin Cd filter are envisaged for the {sup 3}He and {sup 10}B proportional counters to increase the sensitivity to {sup 239}Pu. We concluded that an optimization process that takes into account measurement time, filters thickness, and detector size is needed to develop a SINRD detector that can meet the requirement for an efficient verification of spent fuel assemblies.

  11. Off-Site Radiation Exposure Review Project: Phase 2 soils program

    McArthur, R.D.; Miller, F.L. Jr.

    1989-12-01

    To help estimate population doses of radiation from fallout originating at the Nevada Test Site, soil samples were collected throughout the western United States. Each sample was prepared by drying and ball-milling, then analyzed by gamma-spectrometry to determine the amount of {sup 137}Cs it contained. Most samples were also analyzed by chemical separation and alpha-spectrometry to determine {sup 239 + 240}Pu and by isotope mass spectroscopy to determine the ratios of {sup 240}Pu to {sup 239}Pu and {sup 241}Pu to {sup 239}Pu. The total inventories of cesium and plutonium at 171 sites were computed from the results. This report describes the sample collection, processing, and analysis, presents the analytical results, and assesses the quality of the data. 10 refs., 9 figs., 12 tabs.

  12. Fission yields in the thermal neutron fission of plutonium-239

    Fission yields for 27 mass numbers were determined in the thermal neutron fission of 239Pu using high resolution gamma ray spectrometry and radiochemical method. The results obtained using gamma ray spectrometry and from the investigations on the fission yield of 99Mo using radiochemical method were reported earlier. These data along with fission yields for 19 mass numbers determined using radiochemical method formed a part of Ph.D. thesis. The data given here are a compilation of all the results and are presented considering the neutron temperature correction to 239Pu fission cross-section which is used for calculating the total number of fissions in these studies. A comparison is made of the resulting fission yield values with the latest experimentally determined values and those given in two recent compilations. (author)

  13. Depth profile of 236U/238U in soil samples in La Palma, Canary Islands

    Srncik, M.; P. Steier; Wallner, G.

    2011-01-01

    The vertical distribution of the 236U/238U isotopic ratio was investigated in soil samples from three different locations on La Palma (one of the seven Canary Islands, Spain). Additionally the 240Pu/239Pu atomic ratio, as it is a well establish tool for the source identification, was determined. The radiochemical procedure consisted of a U separation step by extraction chromatography using UTEVA® Resin (Eichrom Technologies, Inc.). Afterwards Pu was separated from Th and Np by anion exchange ...

  14. Plutonium age dating (production date measurement) by inductively coupled plasma mass spectrometry

    Varga, Zsolt; Nicholl, Adrian; Wallenius, Maria; Mayer, Klaus

    2015-01-01

    This paper describes rapid methods for the determination of the production date (age dating) of plutonium (Pu) materials by inductively coupled plasma mass spectrometry (ICP-MS) for nuclear forensic and safeguards purposes. One of the presented methods is a rapid, direct measurement without chemical separation using 235U/239Pu and 236U/240Pu chronometers. The other method comprises a straightforward extraction chromatographic separation, followed by ICP-MS measurement for the 234U/238Pu, 235U...

  15. Calibration of a large hyperpure germanium array for in-vivo detection of the actinides with a tissue-equivalent torso phantom

    For calibration of the array for internally deposited 238Pu, 239Pu, and 241Am, a tissue-equivalent anthropomorphic phantom, was used for efficiency determinations at the ORNL facility. This phantom consists of a tissue-equivalent torso into which is imbedded an adult male skeleton, interchangeable organs containing a homogeneous distribution of various radionuclides, and two sets of chest overlay plates for simulation of progressively thicker tissue over the chest, as well as differing thoracic fat contents

  16. Individual economical value of plutonium isotopes and analysis of the reprocessing of irradiated fuel

    An economical analysis of plutonium recycle in a PWR reactor, without any modification, is done, supposing an open market for the plutonium. The individual value of the plutonium isotopes is determined solving a system with four equations, which the unknow factors are the Pu-239, Pu-240, pu-241 and Pu-242 values. The equations are obtained equalizing the cost of plutonium fuel cycle of four different isotope mixture to the cost of the uranium fuel cycle. (E.G.)

  17. Contribution to the chromatography of atmospheric gases (1963)

    In the first part, the author studies the gas-phase chromatographic separation of the atmospheric rare gases, of hydrogen, and of some gaseous compounds of carbon (CO, CO2, CH4) using inactive gases to obtain the most favourable operational conditions far this separation. In the second part, the optimum conditions for detecting non-active gases using an ionisation chamber and a 239Pu radioactive source emitting 5.15 MeV α particles are determined. (author)

  18. Inhaled plutonium oxide in dogs

    This project is concerned with long-term experiments to determine the life-span dose-effect relationships of inhaled 239PuO2 and 238PuO2 in beagles. The data will be used to estimate the health effects of inhaled transuranics. The tissue distribution of plutonium, radiation effects in the lung and hematologic changes in plutonium-exposed beagles with lung tumors were evaluated

  19. FFTF (FAST FLUX TEST FACILITY) REACTOR CHARACTERIZATION PROGRAM ABSOLUTE FISSION RATE MEASUREMENTS

    FULLER JL; GILLIAM DM; GRUNDL JA; RAWLINS JA; DAUGHTRY JW

    1981-05-01

    Absolute fission rate measurements using modified National Bureau of Standards fission chambers were performed in the Fast Flux Test Facility at two core locations for isotopic deposits of {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U, {sup 237}Np, {sup 239}Pu, {sup 240}Pu, and {sup 241}Pu. Monitor chamber results at a third location were analyzed to support other experiments involving passive dosimeter fission rate determinations.

  20. FFTF (Fast Flux Test Facility) Reactor Characterization Program: Absolute Fission-rate Measurements

    Fuller, J.L.; Gilliam, D.M.; Grundl, J.A.; Rawlins, J.A.; Daughtry, J.W.

    1981-05-01

    Absolute fission rate measurements using modified National Bureau of Standards fission chambers were performed in the Fast Flux Test Facility at two core locations for isotopic deposits of {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U, {sup 237}Np, {sup 239}Pu, {sup 240}Pu, and {sup 241}Pu. Monitor chamber results at a third location were analyzed to support other experiments involving passive dosimeter fission rate determinations.

  1. Neutron spectroscopy. Progress report, 1 October 1976--30 September 1977

    During 1977 a six week run was performed at ORELA using the new data acquisition system based on the PDP-11. Coincident double energy fission fragments were measured as a function of neutron time-of-flight for 229Th, 235U and 239Pu. Data was also obtained in the thermal energy region. Extensive results are reported on the 1976 229Th measurements with 2 families of widely differing fission widths determined. Earlier results on the variation of the ratio of symmetric to asymmetric mass division on 239Pu fission were confirmed. Variations in the total kinetic energies of 235U resonances have been seen. An experiment using 252Cf and measuring the energy of two coincident fission fragments and the time-of-flight of one of them was started. Work on the adaption of the code MULTI to the Columbia University computer was continued

  2. Plutonium age dating (production date measurement) by inductively coupled plasma mass spectrometry

    This paper describes rapid methods for the determination of the production date (age dating) of plutonium (Pu) materials by inductively coupled plasma mass spectrometry (ICP-MS) for nuclear forensic and safeguards purposes. One of the presented methods is a rapid, direct measurement without chemical separation using 235U/239Pu and 236U/240Pu chronometers. The other method comprises a straightforward extraction chromatographic separation, followed by ICP-MS measurement for the 234U/238Pu, 235U/239Pu, 236U/240Pu and 238U/242Pu chronometers. Age dating results of two plutonium certified reference materials (SRM 946 and 947, currently distributed as NBL CRM 136 and 137) are in good agreement with the archive purification dates. (author)

  3. Feasibility of a room temperature silicon system to perform low energy lung spectroscopy

    This study is part of a project aimed at developing a new monitoring system to improve measurements of lung retention for 239Pu. To cover the thoracic volume, the proposed system uses silicon detectors operating at room temperature. This report gives the first conclusions of this feasibility study. The results were obtained using a detection module composed of silicon strip detectors. Analogue electronics were specially designed to optimise signal-to-noise ratio and to investigate background by using anticoincidence between the silicon detectors. Overall counting efficiency determination was carried out by scanning the surface of a Livermore phantom. Combining these measurements, the detection limits are discussed for the complete modular system with emphasis on the competition between efficiency and background to demonstrate the innovative feature of such a system as an alternative to germanium detectors systems. The proposed new monitoring system may enable the detection limit for 239Pu to be lowered by a factor of 2. (author)

  4. Alpha-activities in environmental samples

    Determination of 239Pu(240Pu) in human lungs from autopsies show for the period 1961 - 1965 lung burdens between 150 - 600 fCi and about 50 fCi/organ for the years 1978/79. In some cases also 241Am and 234U/238U contents were analyzed. Air concentration measurements concerning 239Pu(240Pu) and uranium isotopes were carried out using air filters taken between 1962 - 1979 at a sampling station in Vienna. Additionally performed investigations about the α-activity of typical food stuffs allow a rough estimation of the intake for the general population. Based on statistical data and the results of activity measurements especially of 210Po, 226Ra, 232Th and U(nat) in coals and the ashes, emissions from coal fired stationary sources are discussed. (Author)

  5. Application of FORSS sensitivity and uncertainty methodology to fast reactor benchmark analysis

    Weisbin, C.R.; Marable, J.H.; Lucius, J.L.; Oblow, E.M.; Mynatt, F.R.; Peelle, R.W.; Perey, F.G.

    1976-12-01

    FORSS is a code system used to study relationships between nuclear reaction cross sections, integral experiments, reactor performance parameter predictions, and associated uncertainties. This paper presents the theory and code description as well as the first results of applying FORSS to fast reactor benchmarks. Specifically, for various assemblies and reactor performance parameters, the nuclear data sensitivities were computed by nuclide, reaction type, and energy. Comprehensive libraries of energy-dependent coefficients have been developed in a computer retrievable format and released for distribution by RSIC and NNCSC. Uncertainties induced by nuclear data were quantified using preliminary, energy-dependent relative covariance matrices evaluated with ENDF/B-IV expectation values and processed for /sup 238/U(n,f), /sup 238/U(n,..gamma..), /sup 239/Pu(n,f), and /sup 239/Pu(..nu..). Nuclear data accuracy requirements to meet specified performance criteria at minimum experimental cost were determined.

  6. Linear compartment model of plutonium dynamics in a deciduous forest ecosystem

    Systems ecology techniques have been useful in simulating the fate and dynamics of radionuclides in forest ecosystems. The applications of systems models in this context are twofold: projection of the time-dependent distribution of radioisotopes among various ecosystems components, and manipulation of the modeled system to determine the sensitivity of components to variation in transfer coefficients and, thereby, identify critical fluxes affecting system behavior. The present paper describes a systems model that projects the possible fate of plutonium in a deciduous forest ecosystem. The isotopes of interest are 239Pu and 240Pu which have physical half lives of 2.44 x 104 and 6540 years, respectively. These isotopes are indistinguishable by alpha spectrometry hence 239Pu is used to refer to both

  7. Different spectra with the same neutron source

    Using as source term the spectrum of a 239Pu-Be source several neutron spectra have been calculated using Monte Carlo methods. The source term was located in the centre of spherical moderators made of light water, heavy water and polyethylene of different diameters. Also a 239Pu-Be source was used to measure its neutron spectrum, bare and moderated by water. The neutron spectra were measured at 100 cm with a Bonner spheres spectrometer. Monte Carlo calculations were used to calculate the neutron spectra of bare and water-moderated spectra that were compared with those measured with the spectrometer. Resulting spectra are similar to those found in power plants with PWR, BWR and Candu nuclear reactors. Beside the spectra the dosimetric features were determined. Using moderators and a single neutron source can be produced neutron spectra alike those found in workplaces, this neutron fields can be utilized to calibrate neutron dosimeters and area monitors. (Author)

  8. Low temperature nuclear orientation of 239Np in gadolinium host

    The angular distribution of γ-radiation from the decay of 239Np oriented at low temperatures in gadolinium matrix was investigated. The orientation parameters B2 and B4 were determined. The attenuation factors for two long-living states in 239Pu at 391.5 keV and 285.4 keV were calculated. From the anisotropies measured the multipole mixing ratios for 11 γ-transitions in 239Pu were deduced. The results obtained support the assignment of spins of the levels at 492.2 keV and 391.6 keV as 3/2- and 7/2-, respectively. 18 refs.; 2 figs.; 3 tabs

  9. Concentration of plutonium in desert plants from contaminated area

    The investigation of plutonium in desert plants from contaminated sites contributes to the evaluation of its pollution situation and to the survey of plutonium hyper accumulator. The concentration of 239Pu in desert plants collected from a contaminated site was determined, and the influence factors were studied. The concentration of 239Pu in plants was (1.8±4.9) Bq/kg in dry weight, and it means that the plants were contaminated, moreover, the resuspension results in dramatic plutonium pollution of plant surface. The concentration of plutonium in plants depends on species, live stages and the content of plutonium in the rhizosphere soil. The concentration of plutonium in herbage is higher than that in woody plant, and for the seven species of desert plants investigated, it decreases in the order of Hexinia polydichotoma, Phragmites australis, Halostashys caspica, Halogeton arachnoideus, Lycium ruthenicum, Tamarix hispida and Calligonum aphyllum. (authors)

  10. Energy Dependence of Plutonium Fission-Product Yields

    A method is developed for interpolating between and/or extrapolating from two pre-neutron-emission first-chance mass-asymmetric fission-product yield curves. Measured 240Pu spontaneous fission and thermal-neutron-induced fission of 239Pu fission-product yields (FPY) are extrapolated to give predictions for the energy dependence of the n + 239Pu FPY for incident neutron energies from 0 to 16 MeV. After the inclusion of corrections associated with mass-symmetric fission, prompt-neutron emission, and multi-chance fission, model calculated FPY are compared to data and the ENDF/B-VII.1 evaluation. The ability of the model to reproduce the energy dependence of the ENDF/B-VII.1 evaluation suggests that plutonium fission mass distributions are not locked in near the fission barrier region, but are instead determined by the temperature and nuclear potential-energy surface at larger deformation.

  11. Energy Dependence of Plutonium Fission-Product Yields

    Lestone, J. P.

    2011-12-01

    A method is developed for interpolating between and/or extrapolating from two pre-neutron-emission first-chance mass-asymmetric fission-product yield curves. Measured 240Pu spontaneous fission and thermal-neutron-induced fission of 239Pu fission-product yields (FPY) are extrapolated to give predictions for the energy dependence of the n + 239Pu FPY for incident neutron energies from 0 to 16 MeV. After the inclusion of corrections associated with mass-symmetric fission, prompt-neutron emission, and multi-chance fission, model calculated FPY are compared to data and the ENDF/B-VII.1 evaluation. The ability of the model to reproduce the energy dependence of the ENDF/B-VII.1 evaluation suggests that plutonium fission mass distributions are not locked in near the fission barrier region, but are instead determined by the temperature and nuclear potential-energy surface at larger deformation.

  12. Use of triton-WR-1339 (TWR) for a quantitative determination of the lysosomal binding of transuranium elements in the rat liver

    The subcellular localisation of 239Pu and 241Am in the rat liver was investigated. A biochemical separation method with modified lysosomes was applied for the first time; the method permitted unique statements on the mitochondrial or lysosomal association of transuranium elements. Lysosomal association of 239Pu and 241Am between days 4 and 6 after radionuclide injection was most easily detected by follow-up treatment with TWR, i.e. the nonionic detergent was applied 2 days after injection of the radionuclide and 4 days before the onset of the analytical procedure. Extracellular transuranium depots could not be proved to exist neither by comparing absolute retention figures in perfused and nonperfused livers nor by subcellular distribution studies. A quantitative relation between the DTPA mobilisation efficiency in the total liver and the subcellular distribution patterns obtained for americium could be estimated for the period between the first and 18th day after radionuclide injection. It suggests on intracellular effect of DTPA. (orig./MG)

  13. Determination of a radioactive waste classification system

    Cohen, J.J.; King, W.C.

    1978-03-01

    Several classification systems for radioactive wastes are reviewed and a system is developed that provides guidance on disposition of the waste. The system has three classes: high-level waste (HLW), which requires complete isolation from the biosphere for extended time periods; low-level waste (LLW), which requires containment for shorter periods; and innocuous waste (essentially nonradioactive), which may be disposed of by conventional means. The LLW/innocuous waste interface was not defined in this study. Reasonably conservative analytical scenarios were used to calculate that HLW/LLW interface level which would ensure compliance with the radiological exposure guidelines of 0.5 rem/y maximum exposure for a few isolated individuals and 0.005 rem/y for large population groups. The recommended HLW/LLW interface level for /sup 239/Pu or mixed transuranic waste is 1.0 ..mu..Ci/cm/sup 3/ of waste. Levels for other radionuclides are based upon a risk equivalent to this level. A cost-benefit analysis in accordance with as low as reasonably achievable (ALARA) and National Environmental Protection Act (NEPA) guidance indicates that further reduction of this HLW/LLL interface level would entail marginal costs greater than $10/sup 8/ per man-rem of dose avoided. The environmental effects considered were limited to those involving human exposure to radioactivity.

  14. Determination of a radioactive waste classification system

    Several classification systems for radioactive wastes are reviewed and a system is developed that provides guidance on disposition of the waste. The system has three classes: high-level waste (HLW), which requires complete isolation from the biosphere for extended time periods; low-level waste (LLW), which requires containment for shorter periods; and innocuous waste (essentially nonradioactive), which may be disposed of by conventional means. The LLW/innocuous waste interface was not defined in this study. Reasonably conservative analytical scenarios were used to calculate that HLW/LLW interface level which would ensure compliance with the radiological exposure guidelines of 0.5 rem/y maximum exposure for a few isolated individuals and 0.005 rem/y for large population groups. The recommended HLW/LLW interface level for 239Pu or mixed transuranic waste is 1.0 μCi/cm3 of waste. Levels for other radionuclides are based upon a risk equivalent to this level. A cost-benefit analysis in accordance with as low as reasonably achievable (ALARA) and National Environmental Protection Act (NEPA) guidance indicates that further reduction of this HLW/LLL interface level would entail marginal costs greater than $108 per man-rem of dose avoided. The environmental effects considered were limited to those involving human exposure to radioactivity

  15. Neutron sources and its dosimetric characteristics

    By means of Monte Carlo methods the spectra of the produced neutrons 252 Cf, 252 Cf/D2O, 241 Am Be, 239 Pu Be, 140 La Be, 239 Pu18O2 and 226 Ra Be have been calculated. With the information of the spectrum it was calculated the average energy of the neutrons of each source. By means of the fluence coefficients to dose it was determined, for each one of the studied sources, the fluence factors to dose. The calculated doses were H, H*(10), Hp,sIab (10, 00), EAP and EISO. During the phase of the calculations the sources were modeled as punctual and their characteristics were determined to 100 cm in the hole. Also, for the case of the sources of 239 Pu Be and 241 Am Be, were carried out calculations modeling the sources with their respective characteristics and the dosimetric properties were determined in a space full with air. The results of this last phase of the calculations were compared with the experimental results obtained for both sources. (Author)

  16. 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

  17. The influence of plutonium exposure and lung cancer on the frequency of x-ray-induced micronuclei in dog blood lymphocytes

    This study determined if lung cancer or exposure to an inhaled alpha emitter, plutonium-239, increased the frequency of micronuclei in blood lymphocytes or altered the responsiveness of lymphocytes to induction of micronuclei by subsequent doses of X rays in vitro. Beagle dogs inhaled 1.5 mm ABAD monodisperse 239PuO2 aerosols. The exposure resulted in initial lung burdens of 1.8 KBq to 48 KBq and produced cumulative alpha radiation lung doses of 1.4 to 10.4 Gy at the time of this study. Blood lymphocytes were sampled and irradiated with either 0.0 or 2.0 Gy of X rays. The lymphocytes were stimulated to divide by phytohemagglutinin, cytokinesis was blocked with cytochalasin B, and the frequency of micronuclei was determined in binucleated cells. Plutonium inhalation alone produced no significant increase in the frequency of micronuclei in blood lymphocytes. When 2 Gy of X rays ws given to blood lymphocytes of dogs that had inhaled 239PuO2 , there was a linear increase in micronuclei frequency as a function of alpha dose to the lungs; micronuclei/binucleated cell = 0.15 +0.2 D, where D is the cumulative alpha-radiation dose to the lung in Gy. Dogs with 239PuO2- induced lung cancer did not have a significant increase in the frequency of X- ray-induced micronuclei relative to dogs exposed to plutonium that did not have lung cancer. These data suggest that inhaled 239PuO2 alters the responsiveness of blood lymphocytes to subsequent X-ray exposure. (author)

  18. Determination of relative plutonium isotopic abundances by gamma-ray spectrometry

    Plutonium, a fissionable material and, consequently, a special nuclear material (SNM), must be accurately accounted for and safeguarded. Accountability of plutonium usually requires a measurement of the isotopic abundances as well as the elemental weight or concentration. Although mass spectrometers are commonly used to measure isotopic abundances, they require extensive preparation of the sample and destroy the sample during the analysis. The authors have developed techniques and computer programs have been developed to measure plutonium isotopic abundances by gamma-ray spectrometry, they have developed a methodology that is substantially different. The methods have been programmed into a computerized multigroup analysis (MGA) code. They routinely use the MGA program at Lawrence Livermore National Laboratory for analyzing metals, oxides, and solutions that are high in 239Pu content for materials accountability purposes. The program has also been put into routine use by the Euratom Safeguards Directorate and the international Atomic Energy Agency

  19. An iterative approach for TRIGA fuel burn-up determination using nondestructive gamma-ray spectrometry

    Wang Tienko E-mail: tkw@faculty.nthu.edu.tw; Peir Jinnjer

    2000-01-01

    The purpose of this work is to establish a method for evaluating the burn-up values of the rod-type TRIGA spent fuel by using gamma-ray spectrometry of the short-lived fission products {sup 97}Zr/{sup 97}Nb, {sup 132}I, and {sup 140}La. Fuel irradiation history is not needed in this method. Short-lived fission-product activities were established by re irradiating the spent fuels in a nuclear reactor. Based on the measured activities, {sup 235}U burn-up values can be deduced by iterative calculations. The complication caused by {sup 239}Pu production and fission is also discussed in detail. The burn-up values obtained by this method are in good agreement with those deduced from the conventional method based on long-lived fission products {sup 137}Cs, {sup 134}Cs/{sup 137}Cs ratio and {sup 106}Ru/{sup 137}Cs ratio.

  20. An iterative approach for TRIGA fuel burn-up determination using nondestructive gamma-ray spectrometry

    The purpose of this work is to establish a method for evaluating the burn-up values of the rod-type TRIGA spent fuel by using gamma-ray spectrometry of the short-lived fission products 97Zr/97Nb, 132I, and 140La. Fuel irradiation history is not needed in this method. Short-lived fission-product activities were established by re irradiating the spent fuels in a nuclear reactor. Based on the measured activities, 235U burn-up values can be deduced by iterative calculations. The complication caused by 239Pu production and fission is also discussed in detail. The burn-up values obtained by this method are in good agreement with those deduced from the conventional method based on long-lived fission products 137Cs, 134Cs/137Cs ratio and 106Ru/137Cs ratio

  1. An iterative approach for TRIGA fuel burn-up determination using nondestructive gamma-ray spectrometry.

    Wang, T K; Peir, J J

    2000-01-01

    The purpose of this work is to establish a method for evaluating the burn-up values of the rod-type TRIGA spent fuel by using gamma-ray spectrometry of the short-lived fission products 97Zr/97Nb, 132I, and 140La. Fuel irradiation history is not needed in this method. Short-lived fission-product activities were established by reirradiating the spent fuels in a nuclear reactor. Based on the measured activities, 235U burn-up values can be deduced by iterative calculations. The complication caused by 239Pu production and fission is also discussed in detail. The burn-up values obtained by this method are in good agreement with those deduced from the conventional method based on long-lived fission products 137Cs, 134Cs/137Cs ratio and 106Ru/137Cs ratio. PMID:10670930

  2. Radionuclide concentrations in soils and vegetation at radioactive-waste disposal Area G during the 1996 growing season. Progress report

    Soil and overstory and understory vegetation (washed and unwashed) collected at eight locations within and around Area G--a low-level radioactive solid-waste disposal facility at Los Alamos National laboratory--were analyzed for 3H, 90Sr, 238Pu, 239Pu, 137Cs, 234U, 235U, 238U, totU, 228Ac, 214Bi, 60Co, 40K, 54Mn, 22Na, 214Pb, and 208Tl. Also, heavy metals (Ag, As, Ba, Be, Cd, Cr, Hg, Ni, Pb, Sb, Se, and Tl) in soil and vegetation were determined. In general, most radionuclide concentrations, with the exception of 3H and 239Pu, in soils and washed and unwashed overstory and understory vegetation collected from within and around Area G were within upper limit background concentrations. Tritium was detected as high as 14,744 pCi mL-1 in understory vegetation collected from transuranic (TRU) waste pad number-sign 4, and the TRU waste pad area contained the highest levels of 239Pu in soils and in understory vegetation as compared to other areas at Area G

  3. Radionuclide concentrations in/on vegetation at radioactive-waste disposal Area G during the 1995 growing season. Progress report

    Overstory (pinon pine) and understory (grass and forb) vegetation were collected within and around selected points at Area G--a low- level radioactive solid-waste disposal facility at Los Alamos National Laboratory--for the analysis of tritium (3H), strontium (90Sr), plutonium (238Pu and 239Pu), cesium (137Cs), and total uranium. Also, heavy metals (Ag, As, Ba, Be, Cd, Cr, Hg, Ni, Pb, Sb, Se, and Tl) in/on vegetation were determined. In general, most (unwashed) vegetation collected within and around Area G contained 3H, uranium, 238Pu, and 239Pu in higher concentrations than vegetation collected from background areas. Tritium, in particular, was detected as high as 7300 pCi mL-1 in understory vegetation collected from the west side of the transuranic (TRU) pads. The south and west ends of the tritium shaft field also contained elevated levels of 3H in overstory, and especially in understory vegetation, as compared to background; this suggests that 3H may be migrating from this waste repository through surface and subsurface pathways. Also, understory vegetation collected north of the TRU pads (adjacent to the fence line of Area G) contained the highest values of 238Pu and 239Pu as compared to background, and may be a result of surface holding, storage, and/or disposal activities

  4. A sensitivity study on neutronic properties of DUPIC fuel

    Choi, Hang Bok; Roh, Gyu Hong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    A sensitivity study has been done to determine the composition of DUPIC fuel from the viewpoint of neutronics fuel design. The spent PWR fuel compositions were generated and fissile contents adjusted by blending fresh uranium after mixing two spent PWR fuel assemblies. The {sup 239}Pu and {sup 235}U enrichments of DUPIC fuel were adjusted by controlling the amount of fresh uranium feed and the ratio of slightly enriched and depleted uranium in the feed uranium. Based on the material balance calculation, it is recommended that DUPIC fuel composition be such that spent PWR fuel utilization is more than 90%. A sensitivity study on the temperature reactivity coefficient of DUPIC fuel and shown that it is desirable to increase the {sup 239}Pu and {sup 235}U contents to reduce both the fuel and coolant temperature coefficients. On the other hand, refueling simulations of the DUPIC core have shown that the channel power peaking factor, which is a measure of the reactor trip margin, increases with the total fissile content. Considering these neutronic characteristics of the DUPIC fuel, it is recommended to have enrichments of 0.45 and 1.00 wt% for {sup 239}Pu and {sup 235}U, respectively. 3 refs., 2 tabs. (Author)

  5. Fetal and juvenile radiotoxicity

    This project is directed at obtaining detailed comparative information on the deposition, distribution, retention, and toxicity of radionuclides in the prenatal and juvenile mammal. Because quantitative data cannot necessarily be extrapolated to man, emphasis is also directed toward establishing patterns, phenomenologic interactions, and relationships which will be useful in determining appropriate exposure levels for rapidly growing infants or children and for pregnant women. Further dosimetry for an experiment to evaluate the effects of foster-rearing of newborn rats on the lifetime effects of 239Pu exposure has demonstrated that most of the lifetime burden is derived from prenatal exposure and that milk contributes little in addition. Other measurements have confirmed a tentative observation that the lifetime burden in offspring is greater with near-term exposure than with exposure earlier in gestation. Additional results from a comparison of the embryotoxicity of 239Pu and 241Am have confirmed that, on the basis of dose administered to the dam, the former has a greater effect on the conceptus. Pilot studies indicate that 233U is teratogenic, acting as a chemical rather than as a radiological teratogen. Studies with 239Pu-exposed pregnant rabbits have shown that maternal distribution differs from that in rodents; concentration patterns in the placenta and membranes also differed. 4 figures, 1 table

  6. Radionuclide concentrations in soils and vegetation at radioactive-waste disposal Area G during the 1996 growing season. Progress report

    Fresquez, P.R.; Vold, E.L.; Naranjo, L. Jr.

    1997-07-01

    Soil and overstory and understory vegetation (washed and unwashed) collected at eight locations within and around Area G--a low-level radioactive solid-waste disposal facility at Los Alamos National laboratory--were analyzed for {sup 3}H, {sup 90}Sr, {sup 238}Pu, {sup 239}Pu, {sup 137}Cs, {sup 234}U, {sup 235}U, {sup 238}U, {sup tot}U, {sup 228}Ac, {sup 214}Bi, {sup 60}Co, {sup 40}K, {sup 54}Mn, {sup 22}Na, {sup 214}Pb, and {sup 208}Tl. Also, heavy metals (Ag, As, Ba, Be, Cd, Cr, Hg, Ni, Pb, Sb, Se, and Tl) in soil and vegetation were determined. In general, most radionuclide concentrations, with the exception of {sup 3}H and {sup 239}Pu, in soils and washed and unwashed overstory and understory vegetation collected from within and around Area G were within upper limit background concentrations. Tritium was detected as high as 14,744 pCi mL{sup {minus}1} in understory vegetation collected from transuranic (TRU) waste pad {number_sign}4, and the TRU waste pad area contained the highest levels of {sup 239}Pu in soils and in understory vegetation as compared to other areas at Area G.

  7. Study on the evaluation method to determine the radioactivity concentration waste generated from post-irradiation examination facilities

    In order to dispose of the radioactive waste which is generated from post-irradiation examination (PIE) facilities, the common evaluation method of radioactivity in wastes from PIE should be established by the actual data such as radioactivity values and the theoretical calculation. In this study, the radioactivity concentrations of 17 nuclides (H-3, C-14, Co-60, Ni-63, Sr-90, Tc-99, Cs-137, Eu-154, U-234, U-235, U-238, Pu-238, Pu-239, Pu-240, Pu-241, Am-241, Cm-244) in combustible wastes stored in NUCLEAR DEVELOPMENT CORPORATION were measured from 3 samples and the radioactivity was calculated by ORIGEN-2 based on initial contents and operation record of the spent fuel. From the comparison of the obtained data by the radiological measurement with the calculated values, the subject to be solved for establishment of the radioactivity evaluation method for PIE was extracted. (author)

  8. Performance of isotope correlations for the estimate of 242Pu

    Full text: The lack of a gamma-ray signature from 242Pu represents an Achilles heel for many plutonium isotope abundance measurements made by high-resolution gamma spectrometry (HRGS). This holds in particular for plutonium materials containing a significant fraction of this isotope. The problem is partially solved through the application of isotope correlations estimating the relative abundance of 242Pu from relations to ratios of other plutonium isotopes measurable by HRGS. In the mid of the nineties a new type of isotope correlation had been proposed for LWR plutonium based on the following relation: 242Pu/239Pu = C0·[238Pu/239Pu]c1 · [240Pu/239Pu]c2 with recommended coefficients C0, C1 and C2 for PWR and BWR fuels, respectively. We have adopted this type of correlation for the routine analysis of safeguards samples in the Euratom On-Site Laboratories and in the Institute for Transuranium Elements. In order to cover the full range of plutonium materials received for analysis, the application of the above correlation has been also extended to AGR and Magnox-type of plutonium. The differing sets of coefficients C0, C1 and C2 approximating best the correlation for the additional types of materials were determined from a set of reference isotopic data. Since in many instances the origin and the type of the plutonium are not known a priori, criteria for categorization were established helping to select the appropriate isotope correlation. Parametric plots of the ratios 238Pu/239Pu versus 240Pu/239Pu generally allow to discern unambiguously Magnox, AGR and LWR plutonium, and to some extent also BWR and PWR plutonium, as long as a mixing of the respective plutonium materials has not occurred. With this kind of categorization implemented in the routine analysis the performance of the 242Pu estimate is substantially improving in most cases. Performance data for 242Pu in particular, and for plutonium isotope abundance measurements by HRGS in general, as derived from a

  9. Rapid determination of alpha emitters using Actinide resin.

    Navarro, N; Rodriguez, L; Alvarez, A; Sancho, C

    2004-01-01

    The European Commission has recently published the recommended radiological protection criteria for the clearance of building and building rubble from the dismantling of nuclear installations. Radionuclide specific clearance levels for actinides are very low (between 0.1 and 1 Bq g(-1)). The prevalence of natural radionuclides in rubble materials makes the verification of these levels by direct alpha counting impossible. The capability of Actinide resin (Eichrom Industries, Inc.) for extracting plutonium and americium from rubble samples has been tested in this work. Besides a strong affinity for actinides in the tri, tetra and hexavalent oxidation states, this extraction chromatographic resin presents an easy recovery of absorbed radionuclides. The retention capability was evaluated on rubble samples spiked with certified radionuclide standards (239Pu and 241Am). Samples were leached with nitric acid, passed through a chromatographic column containing the resin and the elution fraction was measured by LSC. Actinide retention varies from 60% to 80%. Based on these results, a rapid method for the verification of clearance levels for actinides in rubble samples is proposed. PMID:15177360

  10. Radiometric analysis: status of the effective-standard-value experiment

    Preliminary work on the effective-standard-value (ESV) experiment for two waste categories has been completed. Gamma (γ) spectroscopy has been employed on standards and stream materials to determine γ ratios of plutonium-239 (239Pu). The experimental results have been compared to theoretical calculations from a mathematical model. The experimental goal is to correct the ratios determined for the standards to match the ratios determined for the actual waste stream situations. When the appropriate correction values are determined, effective standard gram values can then be assigned

  11. Determination Of Reportable Radionuclides For DWPF Sludge Batch 6 (Macrobatch 7)

    The Waste Acceptance Product Specifications (WAPS) 1.2 require that 'The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115'. As part of the strategy to comply with WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production through the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP) and Waste Form Qualification Report (WQR). However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that may meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, International Atomic Energy Agency (IAEA) Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The DWPF is receiving radioactive sludge slurry from HLW Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the heel from Sludge Batch 5 (SB5) with H-Canyon Np transfers completed after the start of processing SB5, and Sludge Batch 6 (SB6) that was transferred to Tank 40 from Tank 51. The blend of sludge in Tank 40 is also referred to as Macrobatch 7 (MB7). This report develops the list of reportable radionuclides and associated activities as a function of time. The DWPF will use this list and the activities as one of the

  12. Determination Of Reportable Radionuclides For DWPF Sludge Batch 7B (Macrobatch 9)

    The Waste Acceptance Product Specifications (WAPS) 1.2 require that ''The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115''. As part of the strategy to comply with WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production through the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP) and Waste Form Qualification Report (WQR). However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that may meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, International Atomic Energy Agency (IAEA) Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The DWPF is receiving radioactive sludge slurry from HLW Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the heel from Sludge Batch 7a (SB7a) and Sludge Batch 7b (SB7b) that was transferred to Tank 40 from Tank 51. The blend of sludge in Tank 40 is also referred to as Macrobatch 9 (MB9). This report develops the list of reportable radionuclides and associated activities as a function of time. The DWPF will use this list and the activities as one of the inputs for the development of the Production Records that relate to

  13. Determination Of Reportable Radionuclides For DWPF Sludge Batch 7B (Macrobatch 9)

    Crawford, C. L.; DiPrete, D. P.

    2013-08-22

    The Waste Acceptance Product Specifications (WAPS) 1.2 require that “The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115”. As part of the strategy to comply with WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production through the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP) and Waste Form Qualification Report (WQR). However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that may meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, International Atomic Energy Agency (IAEA) Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The DWPF is receiving radioactive sludge slurry from HLW Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the heel from Sludge Batch 7a (SB7a) and Sludge Batch 7b (SB7b) that was transferred to Tank 40 from Tank 51. The blend of sludge in Tank 40 is also referred to as Macrobatch 9 (MB9). This report develops the list of reportable radionuclides and associated activities as a function of time. The DWPF will use this list and the activities as one of the inputs for the development of the Production Records that relate to

  14. DETERMINATION OF REPORTABLE RADIONUCLIDES FOR DWPF SLUDGE BATCH 6 (MACROBATCH 7)

    Bannochie, C.; Diprete, D.

    2011-06-01

    The Waste Acceptance Product Specifications (WAPS) 1.2 require that 'The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115'. As part of the strategy to comply with WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production through the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP) and Waste Form Qualification Report (WQR). However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that may meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, International Atomic Energy Agency (IAEA) Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The DWPF is receiving radioactive sludge slurry from HLW Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the heel from Sludge Batch 5 (SB5) with H-Canyon Np transfers completed after the start of processing SB5, and Sludge Batch 6 (SB6) that was transferred to Tank 40 from Tank 51. The blend of sludge in Tank 40 is also referred to as Macrobatch 7 (MB7). This report develops the list of reportable radionuclides and associated activities as a function of time. The DWPF will use this list and the activities as one of

  15. DETERMINATION OF REPORTABLE RADIONUCLIDES FOR DWPF SLUDGE BATCH 7B (MACROBATCH 9)

    Crawford, C. L.; Diprete, D. P.

    2014-05-01

    The Waste Acceptance Product Specifications (WAPS) 1.2 require that “The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115”. As part of the strategy to comply with WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production through the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP) and Waste Form Qualification Report (WQR). However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that may meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, International Atomic Energy Agency (IAEA) Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu- 242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The DWPF is receiving radioactive sludge slurry from HLW Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the heel from Sludge Batch 7a (SB7a) and Sludge Batch 7b (SB7b) that was transferred to Tank 40 from Tank 51. The blend of sludge in Tank 40 is also referred to as Macrobatch 9 (MB9). This report develops the list of reportable radionuclides and associated activities as a function of time. The DWPF will use this list and the activities as one of the inputs for the development of the Production Records that relate to

  16. Resonance ionization mass spectroscopy for trace analysis of plutonium

    Trace amounts of plutonium are determined by means of resonance ionization mass spectroscopy (RIMS). Plutonium atoms evaporated from a heated filament are ionized via a three-step excitation leading to an autoionizing state. The ions are mass-selectively detected with a time-of-flight (TOF) mass spectrometer. Several types of filaments have been tested with respect to atomic yield after evaporation and reproducibility. The best results have been obtained using tantalum as backing and titanium as covering. An overall detection efficiency of 1·10-5 could be determined with such filaments yielding a detection limit of 2·106 atoms of 239Pu

  17. Resonance ionization mass spectroscopy for trace analysis of plutonium

    Erdmann, N.; Albus, F.; Deiβenberger, R.; Eberhardt, K.; Funk, H.; Hasse, H.-U.; Herrmann, G.; Huber, G.; Kluge, H.-J.; Köhler, S.; Nunnemann, M.; Passler, G.; Trautmann, N.; Urban, F.-J.

    1995-04-01

    Trace amounts of plutonium are determined by means of resonance ionization mass spectroscopy (RIMS). Plutonium atoms evaporated from a heated filament are ionized via a three-step exciation leading to an autoionizing state. The ions are mass-selectively detected with a time-of-flight (TOF) mass spectrometer. Several types of filaments have been tested with respect to atomic yield after evaporation and reproducibility. The best results have been obtained using tantalum as backing and titanium as covering. An overall detection efficiency of 1ṡ10-5 could be determined with such filaments yielding a detection limit of 2ṡ106 atoms of 239Pu.

  18. Photonuclear measurements on fissionable isotopes using monoenergetic photons

    The LLL linac monochromatic photon facility is used for measurements, which to date have included at least some data on the eight isotopes: 232Th, 233U, 234U, 235U, 236U, 237Np, 238U, and 239Pu. Photofission events are determined from an analysis of the emitted neutron multiplicity distributions as determined with the LLL 4π neutron detector. A sampling of data taken to date is included and is organized as follows: low-energy photofission cross sections, neutrino and fission neutron multiplicity distribution width parameter data, ring-ratio multiplicity coincidence data, delayed-neutron fraction data, and photonuclear and photofission cross sections. 2 refs., 32 figs

  19. Leaching properties of solidified TRU waste forms

    Safety analysis of waste forms requires an estimate of the ability of these forms to retain activity in the disposal environment. This program of leaching tests will determine the leaching properties of TRU contaminated incinerator ash waste forms using hydraulic cement, urea--formaldehyde, bitumen, and vinyl ester--styrene as solidification agents. Three types of leaching tests will be conducted, including both static and flow rate. Five generic groundwaters will be used. Equipment and procedures are described. Experiments have been conducted to determine plate out of 239Pu, counter efficiency, and stability of counting samples

  20. Sensitivity and uncertainty analysis for the mixed-oxide thermal lattice U-L212

    The sensitivities of a mixed oxide (2Wt%PuO2 - 8% 240Pu) fueled, light water moderated critical lattice experiment carried out at Battelle Northwest Laboratories under EPRI sponsorship have been determined. A two-dimensional diffusion theory analysis was performed and the sensitivity of the eigenvalue (k) and four reaction rate ratios to changes in nuclear data have been determined. The sensitivity analysis capability was extended to include upscattering and multi-dimension ability. A covariance matrix has been developed for 239Pu, and the uncertainty associated with calculated performance parameters due to uncertainties in nuclear data has been obtained

  1. Thorium--uranium cycle ICF hybrid concept

    The results of preliminary studies of a laser-driven fusion-fission hybrid concept utilizing the 232Th-233U breeding cycle are reported. Neutron multiplication in the breeding blanket is provided by a region containing 238UO2 and the equilibrium concentration of 239PuO2. Established fission reactor technology is utilized to determine limits on operating conditions for high-temperature fuels and structures. The implications of nonproliferation policies for the operation of fusion-fission hybrid reactors are discussed

  2. Inhaled plutonium nitrate in dogs

    The major objective of this project is to determine dose-effect relationships of inhaled plutonium nitrate in dogs to aid in predicting health effects of accidental exposure in man. For lifespan dose-effect studies, beagle dogs were given a single inhalation exposure to 239Pu(NO3)4, in 1976 and 1977. The earliest biological effect was on the hematopoietic system; lymphopenia and neutropenia occurred at the two highest dose levels. The authors have also observed radiation pneumonitis, lung cancer, and bone cancer at the three highest dose levels. 1 figure, 4 tables

  3. Inhaled plutonium nitrate in dogs

    The major objective of this project is to determine dose-effect relationships of inhaled plutonium nitrate in dogs to aid in predicting health effects of accidental exposure in man. For lifespan dose-effect studies, beagle dogs were given a single inhalation exposure to 239Pu(NO3)4, in 1976 and 1977. The earliest biological effect was on the hematopoietic system; lymphopenia and neutropenia occurred at the two highest dose levels. They have also observed radiation pneumonitis, lung cancer, and bone cancer at the three highest dose levels. 1 figure, 3 tables

  4. Environmental radioactivity in Greenland in 1980

    Measurements of fallout radioactivity in Greenland in 1980 are reported. Strontium-90 (and Cesium-137 in most cases) was determined in samples of precipitation, sea water, vegetation, animals, and drinking water. Estimates are given of the mean contents of 90Sr and 137Cs in the human diet in Greenland in 1980. Provisional results of the 239Pu, 240Pu and 241Am measurements on samples from the expedition to Thule in August 1979 and from the Swedish YMER expedition in 1980 are presented. (author)

  5. On thorium and plutonium cocrystallization with calcium oxalate

    Study of possibility of 239Pu and 234Th concentration from bone ashe (calcium phosphate) hydrochloric acid solutions by coprecipitation with nonisotopic medium (CaC2O4) for their further radiometry or alpha-spectrometry is carried out. Thorium and plutonium distribution coefficients in calcium oxalate precipitate - solution system, as well as coefficients of Th and Pu cocrystallization with CaC2O4 and cocrystallization type are determined. Possibility of Pu and Th concentration from bone tissue solutions is demonstrated on small oxalate amount containing 25% of Ca total amount in bone tissue

  6. Evaluation of postmortem tissue samples

    Collection and radiochemical analysis of postmortem tissue samples (lung, liver, bone and tracheobronchial lymph nodes) from individuals formerly residing in the vicinity of the Hanford project continued during the past year. Postmortem tissue samples and blood samples were also analyzed for the U. S. Transuranium Registry (USTR). During the year commencing November 1, 1974, 85 analyses for plutonium-238 and plutonium-239+240 were performed on samples from the Hanford locality, and 41 analyses for plutonium-238 and plutonium-239+240 on samples obtained from the USTR. Plutonium-242 is the tracer of choice for yield determination in the alpha energy analysis of tissues for 238Pu and 239Pu

  7. Rapid analysis by X-ray fluorescence excitation

    The application of the energy dispersive X-ray fluorescence spectrometry for a quick multielement analysis of different samples (sedimented dust, motor oil, watery solutions) is discussed. Using a source of 30 mCi 239Pu for the X-ray excitation it is possible to determine the concentration of the elements Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Sr, and Pb in a single working operation with a detection efficiency between 1000 ppm for Ca and about 10 ppm for Zn, Br, Sr and Pb using a testing time of 1000 seconds. (author)

  8. Radionuclides and heavy metals in rainbow trout from Tsichomo, Nana Ka, Wen Povi, and Pin De Lakes in Santa Clara Canyon

    Fresquez, P.R.; Armstrong, D.R.; Naranjo, L. Jr.

    1998-04-01

    Radionuclide ({sup 3}H, {sup 90}Sr, {sup 137}Cs, {sup 238}Pu, {sup 239}Pu, and total uranium) and heavy metal (Ag, As, Ba, Be, Cd, Cr, Hg, Ni, Pb, Sb, Se, and TI) concentrations were determined in rainbow trout collected from Tsichomo, Nana Ka, Wen Povi, and Pin De lakes in Santa Clara Canyon in 1997. Most radionuclide and heavy metal concentrations in fish collected from these four lakes were within or just above upper limit background concentrations (Abiquiu reservoir), and as a group were statistically (p < 0.05) similar in most parameters to background.

  9. Neutron source for Neutron Capture Synovectomy

    Monte Carlo calculations were performed to obtain a thermal neutron field from a 239PuBe neutron source inside a cylindrical heterogeneous moderators for Neutron Capture Synovectomy. Studied moderators were light water and heavy water, graphite and heavy water, lucite and polyethylene and heavy water. The neutron spectrum of polyethylene and heavy water moderator was used to determine neutron spectra inside a knee model. In this model the elemental composition of synovium and synovial liquid was assumed like blood. Kerma factors for synovium and synovial liquid were calculated to compare with water Kerma factors, in this calculations the synovium was loaded with two different concentrations of Boron

  10. Intercomparison of radionuclide measurements in marine fish flesh sample MA-B-3

    This final report presents results of the laboratory intercomparison of the activity concentration determination of 40K, 90Sr, 137Cs, 210Pb, 210Po, 226Ra, 228Th, 230Th, 232Th, 238U, 239Pu, 240Pu and 241Am in the sample of garpike fish organized by the IAEA's Analytical Quality Control Service. The forty-three laboratories from twenty-three countries have reported results established by different analytical techniques. This sample is intended as a reference material for the measurement of 40K and 137Cs in marine biological samples and other similar matrices. 4 refs, 9 tabs

  11. Radionuclides and heavy metals in rainbow trout from Tsichomo, Nana Ka, Wen Povi, and Pin De Lakes in Santa Clara Canyon

    Radionuclide (3H, 90Sr, 137Cs, 238Pu, 239Pu, and total uranium) and heavy metal (Ag, As, Ba, Be, Cd, Cr, Hg, Ni, Pb, Sb, Se, and TI) concentrations were determined in rainbow trout collected from Tsichomo, Nana Ka, Wen Povi, and Pin De lakes in Santa Clara Canyon in 1997. Most radionuclide and heavy metal concentrations in fish collected from these four lakes were within or just above upper limit background concentrations (Abiquiu reservoir), and as a group were statistically (p < 0.05) similar in most parameters to background

  12. Geographical distribution of plutonium derived from the atomic bomb in the eastern area of Nagasaki

    The detonation of Nagasaki atomic bomb occurred on August 9, 1945. A large amount of unfissioned plutonium was dispersed into Nagasaki area. In our previous study, we measured 240Pu/239Pu ratios as well as 239+240Pu concentrations in sediment collected at Nishiyama reservoir in the center of Nishiyama area, where 'lack rain' was precipitated, and found that trace amount of the atomic-bomb plutonium has flown into the reservoir even now. A further study on soil samples collected within 10 km from the hypocenter including the basin of the reservoir elucidated the geological distribution of the atomic-bomb plutonium, which was locally deposited at Nishiyama area. In addition, the ratios of 0.13±0.01, which was lower than the value (0.176) of global fallout, were found in samples taken about 8 km east from the hypocenter, while the concentrations were comparable with back ground level. This means a possibility that the plutonium was deposited farther in eastern area. For this reason, we expanded the search area to the eastern area of Nagasaki for determining the deposition of the atomic-bomb plutonium from view point of 240Pu/239Pu ratio. Until now, we collected eight soil samples within 100 km north eastward of the hypocenter. As preliminary results of 2 samples collected at about 25 km east and 45 km from the hypocenter, the 240Pu/239Pu ratios were 0.154±0.017 and 0.111±0.004, which were lower than the value of global fallout indicating the existence of the atomic-bomb plutonium. In the presentation, we will report the details and other results in soils collected in farther area and discuss about deposit area of the atomic-bomb plutonium.

  13. Final report on ARPA fission yield project work at Battelle-Northwest, April 1970--April 1973

    The overall objective has been to measure the independent and cumulative fission yields of selected halogen and rare gas nuclides for application to characterization of underground nuclear detonations. The studies have included fission yield measurements for thermal, fission spectrum, and 15 MeV neutron-induced fission events. Target materials included 235U, 238U and 239Pu. The research effort was divided into two basic parts. In one part, the nuclides of interest were separated radiochemically and determined by gamma-ray spectrometry. This approach provides information on the independent and cumulative yields of nuclides with half-lives of a few seconds or greater. The second part of our effort involved the use of on-line mass separation techniques. This approach yields information on independent fission yields of nuclides with half-lives ranging down to fractions of a second and provides data on all significant isotopes of a given fission product element in one set of measurements. The main effort in the radiochemistry program was centered on measurements of the cumulative fission yield of 89Kr. Cumulative fission yields of 89Kr were measured for thermal-neutron fission of 239Pu and for fission-spectrum and 15-MeV neutron fission of 235U, 238U and 239Pu. In addition, cumulative fission yields of the other rare gas radionuclides, /sup 85m/Kr, 87Kr, 88Kr, 137Xe, 138Xe, were measured for the same fission type events. Fractional independent yields of 89Rb and 138Cs were also measured for a limited number of fission systems. On-line mass spectrometer facilities were established at a Van de Graaff accelerator and at a nuclear reactor. Measurements were made of relative independent fission yields of rubidium isotopes of masses 89 through 97 and of cesium isotopes of masses 139 through 145.(U.S.)

  14. Distribution of Np and Pu in Swedish lichen samples (Cladonia stellaris) contaminated by atmospheric fallout

    Lindahl, Patric E-mail: patric.lindahl@radfys.lu.se; Roos, Per; Eriksson, Mats; Holm, Elis

    2004-07-01

    The activity concentrations of {sup 237}Np and the two Pu isotopes, {sup 239}Pu and {sup 240}Pu, were determined in lichen samples (Cladonia stellaris) contaminated by fallout from atmospheric nuclear test explosions and the Chernobyl accident. The samples were collected at 18 locations in Sweden, from north to south, between 1986 and 1988 and analysed with high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) and alpha spectrometry. Data on the activity ratios {sup 238}Pu/{sup 239+240}Pu and {sup 134}Cs/{sup 137}Cs measured previously were also included in this study for comparison. The {sup 237}Np activity concentration ranged from 0.08{+-}0.01 to 2.08{+-}0.17 mBq kg{sup -1}, depending on the location of the sampling site and time of collection. The {sup 239+240}Pu activity concentration ranged from 0.09{+-}0.01 to 4.09{+-}0.15 Bq kg{sup -1}, with the {sup 240}Pu/{sup 239}Pu atomic ratio ranging between 0.16{+-}0.01 and 0.44{+-}0.03, the higher ratios indicating a combination of weapons test fallout and Chernobyl fallout. The {sup 237}Np/{sup 239}Pu atomic ratios ranged between 0.06{+-}0.01 and 0.42{+-}0.04, the lower ratios indicating combination of weapons test fallout and Chernobyl fallout. At a well-defined sampling site at Lake Rogen (62.32 deg. N, 12.38 deg. E), additional lichen samples were collected between 1987 and 1998 to study the distribution of Np and Pu in different layers. The concentrations of the two elements follow each other quite well in the profile.

  15. Comparative food-chain behavior and distribution of actinide elements in and around a contaminated fresh-water pond

    The bioaccumulation of 233234U, 238U, 238Pu, 239240Pu, 241Am, and 244Cm in both native and introduced biota was studied at Pond 3513, a former low-level radioactive waste settling basin at Oak Ridge National Laboratory. This system, which was decommissioned in 1976 after more than 30 years use, contains approximately 5 Ci of 239240Pu; inventories of other actinide isotopes are considerably less. Significantly higher concentrations of actinides in fish that were allowed access to sediments indicated that sedimentary particulates may be the primary source of transuranics to biota in shallow fresh-water ecosystems. Our study determined habitat, in particular the degree of association of an organism with the sediment-water interface, to be the primary factor in controlling transuranic concentrations in aquatic biota. In most of the biological samples analyzed, excluding samples suspected of being contaminated by sediment, 241Am/239Pu, 244Cm/239Pu, and 238U/239Pu ratios were greater than the respective ratio in sediment while 233234U/238U, and 239240Pu/238Pu ratios were not different from the respective ratios in sediment. The relative uptake of actinides from contaminated sediment by aquatic and terrestrial biota at this site was U > Cm greater than or equal to Am > Pu. The relative extractability of actinides from shoreline sediment was U > Cm approx. = Am > Pu; we also observed the same relative ranking for sediment-water exchange in situ. Concentrations of transuranics in water, terrestrial vegetation, and vertebrate carcasses were less than 10% of the recommended public exposure maximum permissible concentration (MPC) of the ICRP

  16. Determination of plutonium in environmental samples by controlled valence in anion exchange

    Chen, Q.J.; Aarkrog, A.; Nielsen, S.P.;

    1993-01-01

    The title method was successfully used for collecting Pu-239, Pu-249 from 200 litres of seawater by coprecipitation with 16 g FeSO4 . 7H2O under reducing conditions without filtering. The plutonium is leached by concentrated HNO3 + HCI from the coprecipitate and the solid particles. The precipitate...... is heated at 400-degrees-C and digested in aqua regia. Na2SO3 and NaNO2 have been applied to obtain the Pu4+ valence state in 0.571 N HN03 for different samples. Plutonium and thorium are coadsorbed on anionic resin from 8N HN03. The column is eluted with 8N HN03 containing fresh NaNO2 to keep the Pu4......+ state for uranium decontamination. The system of the column is changed from 8N HNO3 to concentrated HCl with 50 ml concentrated HCI containing a few milligrams of NaNO2. Further decontamination of thorium was achieved by elution with concentrated HCI instead of 9N HCl. The plutonium is successfully...

  17. RAPID DETERMINATION OF ACTINIDES IN URINE BY INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY: A HYBRID APPROACH

    Maxwell, S.; Jones, V.

    2009-05-27

    A new rapid separation method that allows separation and preconcentration of actinides in urine samples was developed for the measurement of longer lived actinides by inductively coupled plasma mass spectrometry (ICP-MS) and short-lived actinides by alpha spectrometry; a hybrid approach. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration, if required, is performed using a streamlined calcium phosphate precipitation. Similar technology has been applied to separate actinides prior to measurement by alpha spectrometry, but this new method has been developed with elution reagents now compatible with ICP-MS as well. Purified solutions are split between ICP-MS and alpha spectrometry so that long- and short-lived actinide isotopes can be measured successfully. The method allows for simultaneous extraction of 24 samples (including QC samples) in less than 3 h. Simultaneous sample preparation can offer significant time savings over sequential sample preparation. For example, sequential sample preparation of 24 samples taking just 15 min each requires 6 h to complete. The simplicity and speed of this new method makes it attractive for radiological emergency response. If preconcentration is applied, the method is applicable to larger sample aliquots for occupational exposures as well. The chemical recoveries are typically greater than 90%, in contrast to other reported methods using flow injection separation techniques for urine samples where plutonium yields were 70-80%. This method allows measurement of both long-lived and short-lived actinide isotopes. 239Pu, 242Pu, 237Np, 243Am, 234U, 235U and 238U were measured by ICP-MS, while 236Pu, 238Pu, 239Pu, 241Am, 243Am and 244Cm were measured by alpha spectrometry. The method can also be adapted so that the separation of uranium isotopes for assay is not required, if uranium assay by direct dilution of the urine sample is preferred instead

  18. Chronology of Pu isotopes and {sup 236}U in an Arctic ice core

    Wendel, C.C., E-mail: cato.wendel@umb.no [Isotope Laboratory, Department of Plant and Environmental Sciences, Agricultural University of Norway, P.O. Box 5003, N-1432 Aas (Norway); Oughton, D.H., E-mail: deborah.oughton@umb.no [Isotope Laboratory, Department of Plant and Environmental Sciences, Agricultural University of Norway, P.O. Box 5003, N-1432 Aas (Norway); Lind, O.C., E-mail: ole-christian.lind@umb.no [Isotope Laboratory, Department of Plant and Environmental Sciences, Agricultural University of Norway, P.O. Box 5003, N-1432 Aas (Norway); Skipperud, L., E-mail: lindis.skipperud@umb.no [Isotope Laboratory, Department of Plant and Environmental Sciences, Agricultural University of Norway, P.O. Box 5003, N-1432 Aas (Norway); Fifield, L.K., E-mail: keith.fifield@anu.edu.au [Department of Nuclear Physics, Australian National University, Canberra ACT 0200 (Australia); Isaksson, E., E-mail: elisabeth.isaksson@npolar.no [Norwegian Polar Institute, Fram Centre, Hjalmar Johansens Gate 14, N9296 Tromsø (Norway); Tims, S.G., E-mail: steve.tims@anu.edu.au [Department of Nuclear Physics, Australian National University, Canberra ACT 0200 (Australia); Salbu, B., E-mail: brit.salbu@umb.no [Isotope Laboratory, Department of Plant and Environmental Sciences, Agricultural University of Norway, P.O. Box 5003, N-1432 Aas (Norway)

    2013-09-01

    In the present work, state of the art isotopic fingerprinting techniques are applied to an Arctic ice core in order to quantify deposition of U and Pu, and to identify possible tropospheric transport of debris from former Soviet Union test sites Semipalatinsk (Central Asia) and Novaya Zemlya (Arctic Ocean). An ice core chronology of {sup 236}U, {sup 239}Pu, and {sup 240}Pu concentrations, and atom ratios, measured by accelerator mass spectrometry in a 28.6 m deep ice core from the Austfonna glacier at Nordaustlandet, Svalbard is presented. The ice core chronology corresponds to the period 1949 to 1999. The main sources of Pu and {sup 236}U contamination in the Arctic were the atmospheric nuclear detonations in the period 1945 to 1980, as global fallout, and tropospheric fallout from the former Soviet Union test sites Novaya Zemlya and Semipalatinsk. Activity concentrations of {sup 239+240}Pu ranged from 0.008 to 0.254 mBq cm{sup −2} and {sup 236}U from 0.0039 to 0.053 μBq cm{sup −2}. Concentrations varied in concordance with {sup 137}Cs concentrations in the same ice core. In contrast to previous published results, the concentrations of Pu and {sup 236}U were found to be higher at depths corresponding to the pre-moratorium period (1949 to 1959) than to the post-moratorium period (1961 and 1962). The {sup 240}Pu/{sup 239}Pu ratio ranged from 0.15 to 0.19, and {sup 236}U/{sup 239}Pu ranged from 0.18 to 1.4. The Pu atom ratios ranged within the limits of global fallout in the most intensive period of nuclear atmospheric testing (1952 to 1962). To the best knowledge of the authors the present work is the first publication on biogeochemical cycles with respect to {sup 236}U concentrations and {sup 236}U/{sup 239}Pu atom ratios in the Arctic and in ice cores. - Highlights: • Concentrations and atom ratios of Pu and {sup 236}U determined in an Arctic ice core. • Concentrations of U and Pu found to be higher pre- than post-moratorium. • U and Pu concentrations

  19. Distributions of Pu isotopes in seawater and bottom sediments in the coast of the Japanese archipelago before and soon after the Fukushima Dai-ichi Nuclear Power Station accident

    A radioactivity measurement survey was carried out from 24 April 2008 to 3 June 2011 to determine the levels of plutonium isotopes and 240Pu/239Pu atom ratios in the marine environments off the sites of commercial nuclear power stations around the Japanese islands; the sampling period extended to two months after the Fukushima Dai-ichi Nuclear Power Station accident. In our previous study (Oikawa et al., 2015), data on Pu isotopes and 241Am in sediments have already been reported. In this study, we report those on Pu isotopes in seawater as well as sediments, and the characteristics of sediments in addition (e.g., ignition loss and biogenic opals). Concentrations of 239+240Pu in seawater and bottom sediments remained nearly constant at all sampling locations during the survey period. In addition, no regional differences were observed in the 239+240Pu concentrations in surface waters. Higher 239+240Pu concentrations were found in bottom waters at deeper sampling locations, but the 240Pu/239Pu atom ratios were nearly constant regardless of the water depth. Higher 239+240Pu concentrations were also found in bottom sediments at deeper sampling locations, but vice versa for 240Pu/239Pu atom ratios as reported in the previous report. The sediments samples from deeper locations showed the higher percentage of ignition loss as well as the higher content of biogenic opal. There was likely to be some driving force participating in the transfer of Pu isotopes associated with biogenic substances to the deeper seabed. The present survey showed that the accident at the Fukushima Dai-ichi Nuclear Power Station did not contribute much to the inventory of Pu isotopes in the adjacent sea area. - Highlights: • Pu concentration off the Japan coast before and after FDNPS accident was measured. • No regional differences were observed in 239+240Pu concentrations in surface waters. • 240Pu/239Pu atom ratios were also nearly identical in seawaters. • There were no significant

  20. Speciation of plutonium and americium in the soils affected by Kraton-3 accidental underground nuclear explosion in Yakutia (Russia)

    In calcareous soils from Yakutia only 0.1 % or less 239Pu and 241Am exist in water-soluble form, i.e., the mobility of these radionuclides is relatively low. In the top humus-containing layer (0-4 cm) 239Pu and 241Am are distributed uniformly between organic and inorganic soil components. In the bottom soil layer (20-30 cm) the radionuclides are present mainly in inorganic soil components. The estimation of the radionuclide mobility demonstrates that 241Am is potentially a more mobile element than 239Pu. In the considered calcareous soils collected from the top layer 239Pu and 241Am exist both in humic and fulvic acids (FA). 241Am is much stronger bound to the group of mobile FA than 239Pu. In the bottom soil layer 239Pu and 241Am have been found mainly in FA. (author)

  1. Application of inductively coupled plasma mass spectrometry to the study of environmental radioactivity

    Applications of inductively coupled plasma mass spectrometry (ICP-MS) to the determination of long-lived radionuclides in environmental samples were summarized. In order to predict the long-term behavior of the radionuclides, related stable elements were also determined. Compared with radioactivity measurements, the ICP-MS method has advantages in terms of its simple analytical procedures, prompt measurement time, and capability of determining the isotope ratio such as 240Pu/239Pu, which can not be separated by radiation. Concentration of U and Th in Japanese surface soils were determined in order to determine the background level of the natural radionuclides. The 235U/238U ratio was successfully used to detect the release of enriched U from reconversion facilities to the environment and to understand the source term. The 240Pu/239Pu ratios in environmental samples varied widely depending on the Pu sources. Applications of ICP-MS to the measurement of I and Tc isotopes were also described. The ratio between radiocesium and stable Cs is useful for judging the equilibrium of deposited radiocesium in a forest ecosystem. (author)

  2. Nuclear and dosimetric features of an isotopic neutron source

    A multisphere neutron spectrometer was used to determine the features of a 239PuBe neutron source that is used to operate the ESFM-IPN Subcritical Reactor. To determine the source main features it was located a 100 cm from the spectrometer which was a 6LiI(Eu) scintillator and 2, 3, 5, 8, 10 and 12 in.-diameter polyethylene spheres. Count rates obtained with the spectrometer were unfolded using the NSDUAZ code and neutron spectrum, total fluence, and ambient dose equivalent were determined. A Monte Carlo calculation was carried out to estimate the spectrum and integral features being less than values obtained experimentally due to the presence of 241Pu in the Pu used to fabricate the source. Actual neutron yield and the mass fraction of 241Pu was estimated. - Highlights: • The neutron spectrum of a 239PuBe was measured. • With the spectrum integral features were determined. • It was estimated 0.23 w/o of 241Pu in the Pu used to make the source

  3. Effect of UV-radiation on track etch parameters of CR-39 plastic track detectors

    CR-39 track detectors have been irradiated with 239Pu source at nuclear physics laboratory B.H.U. Varanasi, to investigate the track recording properties of the detector. The bulk etch rate is determined by measuring the change in thickness before and after etching, and track etch rate is determined by measuring the change in track length. Other track parameters such as diameter and sensitivity of the plastic detector are also determined. Another set of CR-39 plastic detector is irradiated by 239Pu source and exposed by UV-radiation after irradiation to see the effect of UV-rays on track etches parameters. All detectors were etched in 6.25 N NaOH solution at different temperatures for different hours and all track parameters are measured by optical microscope (Olympus BH-2, magnification 600x). After etching in 6.25 N NaOH solution we see that bulk etch rate, track etch rate and track diameter increased in the case of UV-radiation exposed CR-39 plastics detectors. (author)

  4. Spent-fuel assay performance and Monte Carlo Analysis of the Rensselaer slowing-down-time spectrometer

    The slowing-down-time method for the nondestructive assay of light water reactor (LWR) spent fuel is under development at Rensselaer Polytechnic Institute. A series of assay measurements of an LWR fuel assembly replica were carried out at the Rensselaer lead slowing-down-time spectrometer facility by using 238U and 232Th threshold fission detectors and 235U and 239Pu probe chambers. An assay model relating the assay signal and the signals of the probe chambers to the unknown masses of the fissile isotopes in the fuel assembly was developed. The probe chamber data were used to provide individual fission counting spectra of 235U and 239Pu inside the fuel assembly and to simulate spent-fuel assay signals. The fissile isotopic contents of the fuel were determined to better than 1%. Monte Carlo analyses were performed to simulate the experimental measurements, determine certain parameters of the assay system, and investigate the effect of the fuel assembly and hydrogen impurities on the performance of the system. The broadened resolution of the system caused by the presence of the fuel was still found to be sufficient for the accurate and separate assay of the uranium and plutonium fissiles in spent fuel

  5. UPWARD MOVEMENT OF PLUTONIUM TO SURFACE SEDIMENTS DURING AN 11-YEAR FIELD STUDY

    Kaplan, D.; Beals, D.; Cadieux, J.; Halverson, J.

    2010-01-25

    An 11-y lysimeter study was established to monitor the movement of Pu through vadose zone sediments. Sediment Pu concentrations as a function of depth indicated that some Pu moved upward from the buried source material. Subsequent numerical modeling suggested that the upward movement was largely the result of invading grasses taking up the Pu and translocating it upward. The objective of this study was to determine if the Pu of surface sediments originated from atmosphere fallout or from the buried lysimeter source material (weapons-grade Pu), providing additional evidence that plants were involved in the upward migration of Pu. The {sup 240}Pu/{sup 239}Pu and {sup 242}Pu/{sup 239}Pu atomic fraction ratios of the lysimeter surface sediments, as determined by Thermal Ionization Mass Spectroscopy (TIMS), were 0.063 and 0.00045, respectively; consistent with the signatures of the weapons-grade Pu. Our numerical simulations indicate that because plants create a large water flux, small concentrations over multiple years may result in a measurable accumulation of Pu on the ground surface. These results may have implications on the conceptual model for calculating risk associated with long-term stewardship and monitored natural attenuation management of Pu contaminated subsurface and surface sediments.

  6. Separation Techniques for Quantification of Radionuclides in Environmental Samples

    Dusan Galanda

    2009-01-01

    Full Text Available The reliable and quantitative measurement of radionuclides is important in order to determine environmental quality and radiation safety, and to monitor regulatory compliance. We examined soil samples from Podunajske Biskupice, near the city of Bratislava in the Slovak Republic, for the presence of several natural (238U, 232Th, 40K and anthropogenic (137Cs, 90Sr, 239Pu, 240Pu, 241Am radionuclides. The area is adjacent to a refinery and hazardous waste processing center, as well as the municipal incinerator plant, and so might possess an unusually high level of ecotoxic metals. We found that the levels of both naturally occurring and anthropogenic radionuclides fell within the expected ranges, indicating that these facilities pose no radiological threat to the local environment. During the course of our analysis, we modified existing techniques in order to allow us to handle the unusually large and complex samples that were needed to determine the levels of 239Pu, 240Pu, and 241Am activity. We also rated three commercial techniques for the separation of 90Sr from aqueous solutions and found that two of them, AnaLig Sr-01 and Empore Extraction Disks, were suitable for the quantitative and reliable separation of 90Sr, while the third, Sr-Spec Resin, was less so. The main criterion in evaluating these methods was the chemical recovery of 90Sr, which was less than we had expected. We also considered speed of separation and additional steps needed to prepare the sample for separation.

  7. Direct isotope ratio analysis of individual uranium–plutonium mixed particles with various U/Pu ratios by thermal ionization mass spectrometry

    Uranium and plutonium isotope ratios in individual uranium–plutonium (U–Pu) mixed particles with various U/Pu atomic ratios were analyzed without prior chemical separation by thermal ionization mass spectrometry (TIMS). Prior to measurement, micron-sized particles with U/Pu ratios of 1, 5, 10, 18, and 70 were produced from uranium and plutonium certified reference materials. In the TIMS analysis, the peaks of americium, plutonium, and uranium ion signals were successfully separated by continuously increasing the evaporation filament current. Consequently, the uranium and plutonium isotope ratios, except the 238Pu/239Pu ratio, were successfully determined for the particles at all U/Pu ratios. This indicates that TIMS direct analysis allows for the measurement of individual U–Pu mixed particles without prior chemical separation. - Highlights: • U–Pu mixed particles with U/Pu ratios of 1, 5, 10, 18 and 70 were produced. • U and Pu isotope ratios were determined by TIMS for particles without prior chemical separation. • Accurate values were obtained for all isotope ratios, except the 238Pu/239Pu ratio

  8. Calibration of whole-body counters for transuranic radionuclides by using total-body donations to the United States Transuranium Registry

    One of the many benefits of the whole-body donation programme of the United States Transuranium Registry is the calibration of whole-body counters by measuring a donated body containing radioactivity before radiochemical analysis of the body occurs. These measurements have provided the best existing calibration factors for measuring 241Am and 239Pu in the skeleton of living people. In one case where the body contained an easily measurable quantity of 241Am, the 241Am content was found to be the same for identical bones on the right and left sides of the body. The bones from the right side of the body and every other vertebrae were radiochemically analysed and the bones from the left side were reserved. These latter have a known quantity of naturally distributed 241Am based on the analysis of bones from the right side. These reserved bones are being incorporated into tissue equivalent body parts for future calibrations and interlaboratory comparisons. The measurements on the total body and the reserved bones have already been very useful in determining the contribution of skeletal activity to that of lung measurements and determining a calibration factor for measuring 239Pu deposited in the skeleton. In the future it is planned to periodically make in vivo measurements on those people participating in the total-body donation programme so that calibration factors can be obtained for lung and liver content after subsequent analysis of these tissues. (author)

  9. Classification of hot particles from the Chernobyl accident and nuclear weapons detonations by non-destructive methods

    Both after the Chernobyl accident and nuclear weapon detonations, agglomerates of radioactive material, so-called hot particles, were released or formed which show a behaviour in the environment quite different from the activity released in gaseous or aerosol form. The differences in their characteristic properties, in the radionuclide composition and the uranium and actinide contents are described in detail for these particles. While nuclear bomb hot particles (both from fission and fusion bombs) incorporate well detectable trace amounts of 60Co and 152Eu, these radionuclides are absent in Chernobyl hot particles. In contrast, Chernobyl hot particles contain 125Sb and 144Ce which are absent in atomic bomb HPs. Obvious differences are also observable between fusion and fission bombs' hot particles (significant differences in 152Eu/155Eu, 154Eu/155Eu and 238Pu/239Pu ratios) which facilitate the identification of HPs of unknown provensence. The ratio of 239Pu/240Pu in Chernobyl hot particles could be determined by a non-destructive method at 1:1.5. A non-destructive method to determine the content of non-radioactive elements by Kα-emission measurements was developed by which inactive Zr, Nb, Fe and Ni could be verified in the particles

  10. Flicker-noise fluctuations in α-radioactive decay

    Counting statistics of α particles from three sources, one containing 241Am; one containing 239Pu, 241Am, and 244Cu; and a source containing 148Gd, were determined over periods of 1-4000 min. In particular, the two-sample variance or Allan variance was determined for many sample runs. According to a recent theorem, there is a unique relation between the particle-flux spectral noise density and the Allan variance. It was found that for small counting periods, the statistics were Poissonian, corresponding to shot noise of the particle flux. For long periods (> ≅ 200 min), the counting statistics were found to be non-Poissonian, indicating the presence of 1/f noise and (or) Lorentzian noise. The 1/f noise gave flicker floors of (0.5-0.7) x 10-7 for 239Pu, (1.0-1.3) x 10-7 for 241Am, and 3.0 x 10-7 for 244Cm. The Lorentzians were not reproducible in different runs and are probably associated with chemical oxidation-reduction rate processes in the source. The 1/f noise is likely inherent in the process of α-particle decay, indicating that the classical picture of alpha decay as a Poisson process is incomplete. Some forms of quantum 1/f noise associated with the tunnel-emission process are briefly discussed

  11. Determination of long-lived fission products and actinides in Savannah River Site HLW sludge and glass for waste acceptance

    Savannah River Site (SRS) is immobilizing the radioactive, high-level waste sludge in Tank 51 into a borosilicate glass for disposal in a geologic repository. A requirement for repository acceptance is that SRS report the concentrations of certain fission product and actinide radionuclides in the glass. This paper presents measurements of many of these concentrations in both Tank 51 sludge and the final glass. The radionuclides were measured by inductively coupled plasma mass spectrometry and α, β, and γ counting methods. Examples of the radionuclides are 90Sr, 137Cs, 238U and , 239Pu. Concentrations in the glass are 3.1 times lower due to dilution of the sludge with a nonradioactive glass forming frit in the vitrification process. Results also indicated that in both the sludge and glass the relative concentrations of the long lived fission products insoluble in caustic are in proportion to their yields from the fission of 235U waste in the SRS reactors. This allowed the calculation of a fission yield scaling factor. This factor in addition to the sludge dilution factor can be used to estimate concentrations of waste acceptance radionuclides that cannot be measured in the glass. Examples of these radionuclides are 79Se, 93Zr, and 107Pd. (author)

  12. Determining impurities

    A method of determining the content of impurities in organic-origin natural fibrous materials, in which a specimen of said material is compacted to a surface density of from 0.05 to 50 g/cm2, whereupon it is exposed to the effect of a soft gamma-radiation, the mass attenuation coefficient (μ) is determined and the percentage content (Csub(A)) of impurities is assessed. The method has applications in the textile industry. (author)

  13. Absolute measurement of the 242Pu neutron-capture cross section

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Chyzh, A.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Ullmann, J. L.; Dance Collaboration

    2016-04-01

    The absolute neutron-capture cross section of 242Pu was measured at the Los Alamos Neutron Science Center using the Detector for Advanced Neutron-Capture Experiments array along with a compact parallel-plate avalanche counter for fission-fragment detection. The first direct measurement of the 242Pu(n ,γ ) cross section was made over the incident neutron energy range from thermal to ≈6 keV, and the absolute scale of the (n ,γ ) cross section was set according to the known 239Pu(n ,f ) resonance at En ,R=7.83 eV. This was accomplished by adding a small quantity of 239Pu to the 242Pu sample. The relative scale of the cross section, with a range of four orders of magnitude, was determined for incident neutron energies from thermal to ≈40 keV. Our data, in general, are in agreement with previous measurements and those reported in ENDF/B-VII.1; the 242Pu(n ,γ ) cross section at the En ,R=2.68 eV resonance is within 2.4 % of the evaluated value. However, discrepancies exist at higher energies; our data are ≈30 % lower than the evaluated data at En≈1 keV and are approximately 2 σ away from the previous measurement at En≈20 keV.

  14. Fetal and juvenile radiotoxicity

    This project is directed at obtaining detailed comparative information on the deposition, distribution, retention, and toxicity of radionuclides in the prenatal and juvenile mammal. Because quantitative data cannot necessarily be extrapolated to man, our emphasis is directed toward establishing patterns, phenomenologic interactions, and relationships which will be useful in determining appropriate exposure levels for the rapidly growing infant or child, and for pregnant women. Recent results demonstrated that injection of pregnant rats with 23Pu had the greatest effect on longevity and bone-tumor incidence of the offspring when exposure occurred at 19 days of gestation (dg); less effect at 15 dg and the least effect at 9 dg. Ongoing distribution studies are providing data which confirm our tentative explanation that marked variations in the anatomic distributions of bone tumors, with age at the time of injection, were attributable to age-related differences in 239Pu microdosimetry and concentrations among skeletal components. Other studies, using a placental perfusion technique, have demonstrated that intravenous injection of 239Pu in pregnant guinea pigs leads to a marked decrease in maternal blood flow to the placenta

  15. Dissolution of low burnup Fast Flux Test reactor fuel

    The first Fast-Flux Test Facility reactor fuel [mixed (U,Pu)O2 composition] has been used in dissolution tests for fuel reprocessing. The fuel tested here had a peak burnup of 0.22 at. %, with peak centerline temperatures of 19970C. Linear dissolution rates of 0.99 to 1.57 mm/h were determined for dissolver solution and fresh acid, respectively. Insoluble residues from dissolution at 950C ranged from 0.18 to 0.28% of the original fuel. From 2 to 37 wt % of the residue was recoverable plutonium. Dissolution at 290C yielded residues of 0.56 to 0.64% of the original fuel. The major elements present in the HF leached residue included Ru, Mo, and Rh. The recovered cladding from the 950C dissolution contained the equivalent of 198 mg of 239Pu per 100 g of hulls, while the cladding from the 290c experiments contained only 0.21 mg of 239Pu per 100 g of hulls. 9 references, 5 figures

  16. Thermal/fluid modeling of the response of saturated marine red clays to emplacement of nuclear waste

    This report discusses the heat and mass transport in marine red clay sediments being considered as a nuclear waste isolation medium. Development of two computer codes, one to determine temperature and convective velocity fields, the other to analyze the nuclide migration problem, is discussed and preliminary results from the codes reviewed. The calculations indicate that for a maximum allowable sediment/canister temperature range of 200 to 2500C, the sediment can absorb about 1.5 kW initial power from waste in a 3 m long by 0.3 m diameter canister. The resulting fluid displacement due to convection is found to be small, less than 1 m. The migration of four nuclides, 239Pu, 137Cs, 129I, and 99Tc were computed for a canister buried 30 m deep in 60 m thick sediment. It was found that the 239Pu and 137Cs, which migrate as cations and have relatively high distribution coefficients, are essentially completely contained in the sediment. The anionic species, 129I and 99Tc, which have relatively low distribution coefficients, broke through the sediment in about 5000 years. The resultant peak injection rates which occur at about 15,000 years were extremely small

  17. Vertical distributions of plutonium isotopes in marine sediment cores off the Fukushima coast after the Fukushima Dai-ichi Nuclear Power Plant accident

    W. T. Bu

    2013-04-01

    Full Text Available The Fukushima Dai-ichi Nuclear Power Plant (FDNPP accident led to the release of large amounts of radionuclides into the atmosphere as well as direct discharges into the sea. In contrast to the intensive studies on the distribution of the released high volatility fission products, such as 131I, 134Cs and 137Cs, similar studies of the actinides, especially the Pu isotopes, are limited. To obtain the vertical distribution of Pu isotopes in marine sediments and to better assess the possible contamination of Pu from the FDNPP accident in the marine environment, we determined the activities of 239+240Pu and 241Pu as well as the atom ratios of 240Pu/239Pu and 241Pu/239Pu in sediment core samples collected in the western North Pacific off Fukushima from July 2011 to July 2012. We also measured surface sediment samples collected from seven Japanese estuaries before the FNDPP accident to establish the comprehensive background baseline data. The observed results of both the Pu activities and the Pu atom ratios for the sediments in the western North Pacific were comparable to the baseline data, suggesting that the FDNPP accident did not cause detectable Pu contamination to the studied regions prior to the sampling time. The Pu isotopes in the western North Pacific 30 km off the Fukushima coast originated from global fallout and Pacific Proving Ground close-in fallout.

  18. Minimum Critical Values Study

    Fox, P.B.

    2005-07-11

    This report provides minimum critical values for various 30-cm water-reflected uranium and plutonium oxide and nitrate aqueous mixtures as calculated by the SCALE CSAS1X sequence using the 238-group ENDF/B-V neutron cross-section library. The minimum values were determined through parametric searches in one-dimensional geometry. The calculations have been performed to obtain the minimum values: critical volume and mass for spheres, critical radius for cylinders, critical thickness for slabs, and minimum critical concentration (infinite geometry) for the following homogeneous mixtures: (1) UO{sub 2}-H{sub 2}O for 3, 4, 5, 20, and 100 wt % {sup 235}U; (2) UNH for 3, 4, 5, 20, and 100 wt % {sup 235}U; (3) PuO{sub 2}-H{sub 2}O for 100/0/0, 95/5/0, 90/5/5, 80/10/10, and 71/17/11/1 wt % of {sup 239}Pu/{sup 240}Pu/{sup 241}Pu(/{sup 242}Pu); and (4) PuNH for 100/0/0, 95/5/0, 90/5/5, 80/10/10, and 71/17/11/1 wt % of {sup 239}Pu/{sup 240}Pu/{sup 241}Pu(/{sup 242}Pu). All bounding surfaces were fully reflected by 30 cm of H{sub 2}O.

  19. CMR Shuffler System: Passive Mode Calibration and Certification Report

    Frame, Katherine C. [Los Alamos National Laboratory; Gomez, Cipriano D. [Retired CMR-OPS: OPERATIONS; Salazar, William R. [Los Alamos National Laboratory; Mayo, Douglas R. [Los Alamos National Laboratory; Vigil, Georgiana M. [Los Alamos National Laboratory; Crooks, William J. [Los Alamos National Laboratory; Stange, Sy [Los Alamos National Laboratory

    2012-07-20

    Los Alamos National Laboratory has a number of spherical confinement vessels (CVs) remaining from tests involving nuclear materials. These vessels have an inner diameter of 6 feet with 1 to 2 inch thick steel walls. The goal of the Confinement Vessel Disposition (CVD) project is to remove debris and reduce contamination inside the vessels. As debris is removed from the vessels, material will be placed in waste drums. Far-field gamma ray assay will be used to determine when a drum is nearing a {sup 239}Pu equivalent mass of less than 200 g. The drum will then be assayed using a waste drum shuffler operated in passive mode using a neutron coincidence counting method for accountability. This report focuses on the testing and calibration of the CMR waste drum shuffler in passive mode operation. Initial testing was performed to confirm previously accepted measurement parameters. The system was then calibrated using a set of weapons grade Pu (WGPu, {sup 239}Pu > 93%) oxide standards placed inside a 55 gallon drum. The calibration data ranges from Pu mass of 0.5 g to 188.9 g. The CMR waste drum shuffler has been tested and calibrated in passive mode in preparation for safeguards accountability measurements of waste drums containing material removed from CVs for the CVD project.

  20. Characterization and testing of a 238Pu loaded ceramic waste form

    This paper will describe the preparation and progress of the effort at Argonne National Laboratory-West to produce ceramic waste forms loaded with 238Pu. The purpose of this study is to determine the extent of damage, if any, that alpha decay events will play over time to the ceramic waste form under development at Argonne. The ceramic waste form is glass-bonded sodalite. The sodalite is utilized to encapsulate the fission products and transuranics which are present in a chloride salt matrix which results from a spent fuel conditioning process. 238Pu possesses approximately 250 times the specific activity of 239Pu and thus allows for a much shorter time frame to address the issue. In preparation for production of 238Pu loaded waste forms 239Pu loaded samples were produced. Data is presented for samples produced with typical reactor grade plutonium. X-ray diffraction, scanning electron micrographs and durability test results will be presented. The ramifications for the production of the 238Pu loaded samples will be discussed