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Sample records for 239pu 240pu isotope

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

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

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

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

  3. 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. 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.

  5. 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.

  6. 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.

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

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

    2014-01-01

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

  8. 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

  9. 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)

  10. 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

  11. 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

  12. 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)

  13. 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

  14. 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

  15. 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

  16. 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)

  17. 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.)

  18. 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

  19. 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.)

  20. 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

  1. 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.

  2. 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)

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

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

    2000-02-01

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

  4. 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. 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)

  6. 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

  7. 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).

  8. 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.

  9. 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.

  10. A multi-radionuclide approach to evaluate the suitability of (239+240)Pu as soil erosion tracer.

    Meusburger, Katrin; Mabit, Lionel; Ketterer, Michael; Park, Ji-Hyung; Sandor, Tarjan; Porto, Paolo; Alewell, Christine

    2016-10-01

    Fallout radionuclides have been used successfully worldwide as tracers for soil erosion, but relatively few studies exploit the full potential of plutonium (Pu) isotopes. Hence, this study aims to explore the suitability of the plutonium isotopes (239)Pu and (240)Pu as a method to assess soil erosion magnitude by comparison to more established fallout radionuclides such as (137)Cs and (210)Pbex. As test area an erosion affected headwater catchment of the Lake Soyang (South Korea) was selected. All three fallout radionuclides confirmed high erosion rates for agricultural sites (>25tha(-1)yr(-1)). Pu isotopes further allowed determining the origin of the fallout. Both (240)Pu/(239)Pu atomic ratios and (239+240)Pu/(137)Cs activity ratios were close to the global fallout ratio. However, the depth profile of the (239+240)Pu/(137)Cs activity ratios in undisturbed sites showed lower ratios in the top soil increments, which might be due to higher migration rates of (239+240)Pu. The activity ratios further indicated preferential transport of (137)Cs from eroded sites (higher ratio compared to the global fallout) to the depositional sites (smaller ratio). As such the (239+240)Pu/(137)Cs activity ratio offered a new approach to parameterize a particle size correction factor that can be applied when both (137)Cs and (239+240)Pu have the same fallout source. Implementing this particle size correction factor in the conversion of (137)Cs inventories resulted in comparable estimates of soil loss for (137)Cs and (239+240)Pu. The comparison among the different fallout radionuclides highlights the suitability of (239+240)Pu through less preferential transport compared to (137)Cs and the possibility to gain information regarding the origin of the fallout. In conclusion, (239+240)Pu is a promising soil erosion tracer, however, since the behaviour i.e. vertical migration in the soil and lateral transport during water erosion was shown to differ from that of (137)Cs, there is a clear

  11. Measurement of fallout radionuclides, (239)(,240)Pu and (137)Cs, in soil and creek sediment: Sydney Basin, Australia.

    Smith, B S; Child, D P; Fierro, D; Harrison, J J; Heijnis, H; Hotchkis, M A C; Johansen, M P; Marx, S; Payne, T E; Zawadzki, A

    2016-01-01

    Soil and sediment samples from the Sydney basin were measured to ascertain fallout radionuclide activity concentrations and atom ratios. Caesium-137 ((137)Cs) was measured using gamma spectroscopy, and plutonium isotopes ((239)Pu and (240)Pu) were quantified using accelerator mass spectrometry (AMS). Fallout radionuclide activity concentrations were variable ranging from 0.6 to 26.1 Bq/kg for (137)Cs and 0.02-0.52 Bq/kg for (239+240)Pu. Radionuclides in creek sediment samples were an order of magnitude lower than in soils. (137)Cs and (239+240)Pu activity concentration in soils were well correlated (r(2) = 0.80) although some deviation was observed in samples collected at higher elevations. Soil ratios of (137)Cs/(239+240)Pu (decay corrected to 1/1/2014) ranged from 11.5 to 52.1 (average = 37.0 ± 12.4) and showed more variability than previous studies. (240)Pu/(239)Pu atom ratios ranged from 0.117 to 0.165 with an average of 0.146 (±0.013) and an error weighted mean of 0.138 (±0.001). These ratios are lower than a previously reported ratio for Sydney, and lower than the global average. However, these ratios are similar to those reported for other sites within Australia that are located away from former weapons testing sites and indicate that atom ratio measurements from other parts of the world are unlikely to be applicable to the Australian context. PMID:26344369

  12. 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

  13. 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)

  14. 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)

  15. 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.

  16. Analysis Method of 241Pu Radioactivity by Isotope Dilution-Extraction Liquid Scintillation Spectrometer

    2008-01-01

    <正>241Pu is the only pure β emitter with the maximum energy of 20.81 keV in plutonium isotopes of 238Pu, 239Pu, 240Pu and 242Pu, in which 241Pu is mostly specific radioactivity because its half-life is 14.29 a.

  17. Sector field inductively coupled plasma mass spectrometry in the elemental and isotopic analysis of lanthanides and actinides

    Plutonium is one element which is indispensable in identifying the source and for estimating the hazardous effects of rad. The isotopic ratios of plutonium (240Pu/239Pu) and its total concentration in environmental samples were also precisely estimated by high resolution inductively coupled plasma mass spectrometry

  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. 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...

  20. 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)

  1. Distribution and source of (129)I, (239)(,240)Pu, (137)Cs in the environment of Lithuania.

    Ežerinskis, Ž; Hou, X L; Druteikienė, R; Puzas, A; Šapolaitė, J; Gvozdaitė, R; Gudelis, A; Buivydas, Š; Remeikis, V

    2016-01-01

    Fifty five soil samples collected in the Lithuania teritory in 2011 and 2012 were analyzed for (129)I, (137)Cs and Pu isotopes in order to investigate the level and distribution of artificial radioactivity in Lithuania. The activity and atomic ratio of (238)Pu/((239,24)0)Pu, (129)I/(127)I and (131)I/(137)Cs were used to identify the origin of these radionuclides. The (238)Pu/(239+240)Pu and (240)Pu/(239)Pu ratios in the soil samples analyzed varied in the range of 0.02-0.18 and 0.18-0.24, respectively, suggesting the global fallout as the major source of Pu in Lithuania. The values of 10(-9) to 10(-6) for (129)I/(127)I atomic ratio revealed that the source of (129)I in Lithuania is global fallout in most cases though several sampling sites shows a possible impact of reprocessing releases. Estimated (129)I/(131)I ratio in soil samples from the southern part of Lithuania shows negligible input of the Chernobyl fallout. No correlation of the (137)Cs and Pu isotopes with (129)I was observed, indicating their different sources terms. Results demonstrate uneven distribution of these radionuclides in the Lithuanian territory and several sources of contamination i.e. Chernobyl accident, reprocessing releases and global fallout. PMID:26476410

  2. Estimation of 240Pu Mass in a Waste Tank Using Ultra-Sensitive Detection of Radioactive Xenon Isotopes from Spontaneous Fission

    We report on a technique to detect and quantify the amount of 240Pu in a large tank used to store nuclear waste from plutonium production at the Hanford nuclear site. While the contents of this waste tank are known from previous grab sample measurements, our technique could allow for determination of the amount of 240Pu in the tank without costly sample retrieval and analysis of this highly radioactive material. This technique makes an assumption, which was confirmed, that 240Pu dominates the spontaneous fissions occurring in the tank.

  3. Transport process of Pu isotope in marginal seas of the western North Pacific Ocean

    Significant quantities of Pu isotopes have been released into the marine environment as the result of atmospheric nuclear weapons testing. Most radionuclides globally dispersed in atmospheric nuclear weapons testing were released into the environment during the 1950's and 1960's. In the western North Pacific Ocean, the principal source can be further distinguished as two distinct sources of Pu: close-in tropospheric fallout from nuclear weapons testing at the Pacific Proving Grounds (PPG) in the Marshall Islands and global stratospheric fallout. Since the 240Pu/239Pu atom ratio is characteristic for the Pu emission source, information on Pu isotopic signature is very useful to better understand the transport process in the oceans and to identify the sources of Pu. The mean atom ratio of 240Pu/239Pu from the global stratospheric fallout is 0.180 ±0.014 based on soil sample data, whereas that from close-in tropospheric fallout from the PPG is 0.33 - 0.36. The 240Pu/239Pu atom ratios in seawater samples collected in marginal seas of the western North Pacific Ocean will provide important and useful data for understanding the process controlling Pu transport and for distinguishing future Pu sources. The objectives of this study were to measure the 239+240Pu concentrations and 240Pu/239Pu atom ratios in seawater from the Sea of Okhotsk, Japan Sea, South China Sea and Sulu Sea and to discuss the transport process of Pu. Large-volume seawater samples (250 L each) were collected from the surface to the bottom in marginal seas of the western North Pacific Ocean with acoustically triggered quadruple PVC sampling bottles during the R/V Hakuho-Maru cruise. The 239Pu and 240Pu concentrations and 240Pu/239Pu atom ratios were measured with a double-focusing SF-ICP-MS, which was equipped with a guard electrode to eliminate secondary discharge in the plasma and to enhance overall sensitivity. In the Sea of Okhotsk, the 239+240Pu concentration was 2.8 mBq m-3 in the surface water

  4. Fabrication of 12% {sup 240}Pu calorimetry standards

    Long, S.M.; Hildner, S.; Gutierrez, D.; Mills, C.; Garcia, W.; Gurule, C.

    1995-08-01

    Throughout the DOE complex, laboratories are performing calorimetric assays on items containing high burnup plutonium. These materials contain higher isotopic range and higher wattages than materials previously encountered in vault holdings. Currently, measurement control standards have been limited to utilizing 6% {sup 240}Pu standards. The lower isotopic and wattage value standards do not complement the measurement of the higher burnup material. Participants of the Calorimetry Exchange (CALEX) Program have identified the need for new calorimetric assay standards with a higher wattage and isotopic range. This paper describes the fabrication and verification measurements of the new CALEX standard containing 12% {sup 240}Pu oxide with a wattage of about 6 to 8 watts.

  5. 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

  6. 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.)

  7. (236)U and (239,)(240)Pu ratios from soils around an Australian nuclear weapons test site.

    Tims, S G; Froehlich, M B; Fifield, L K; Wallner, A; De Cesare, M

    2016-01-01

    The isotopes (236)U, (239)Pu and (240)Pu are present in surface soils as a result of global fallout from nuclear weapons tests carried out in the 1950's and 1960's. These isotopes potentially constitute artificial tracers of recent soil erosion and sediment movement. Only Accelerator Mass Spectrometry has the requisite sensitivity to measure all three isotopes at these environmental levels. Coupled with its relatively high throughput capabilities, this makes it feasible to conduct studies of erosion across the geographical extent of the Australian continent. In the Australian context, however, global fallout is not the only source of these isotopes. As part of its weapons development program the United Kingdom carried out a series of atmospheric and surface nuclear weapons tests at Maralinga, South Australia in 1956 and 1957. The tests have made a significant contribution to the Pu isotopic abundances present in the region around Maralinga and out to distances ∼1000 km, and impact on the assessment techniques used in the soil and sediment tracer studies. Quantification of the relative fallout contribution derived from detonations at Maralinga is complicated owing to significant contamination around the test site from numerous nuclear weapons safety trials that were also carried out around the site. We show that (236)U can provide new information on the component of the fallout that is derived from the local nuclear weapons tests, and highlight the potential of (236)U as a new fallout tracer. PMID:26141189

  8. 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)

  9. 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.)

  10. 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.)

  11. 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)

  12. 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

    In an effort to identify and characterize nuclear contaminants released from sources contained within the Hudson River drainage basin, Pu isotopes and 237Np have been measured in a series of sediment cores collected from various locations within the region. During the last several decades, the Hudson River has received input of radioactive contamination from several sources. The first and most significant, has been global fallout, which was a result of atmospheric testing of nuclear weapons primarily by governments of the United States and Former Soviet Union in the 1950s and 1960s. The second, is contamination resulting from reactor releases at the Indian Point Nuclear Power Plant (IPNPP) located on the Hudson River about 35 miles north of New York City. This facility began operation in 1962. A third source of radioactive contamination to the region is contamination resulting from activities at the Knolls Atomic Power Laboratory (KAPL) located on the Mohawk River, which began operation in 1946. Our research entails identifying different sources of nuclear contamination by measurement of plutonium and neptunium isotopic ratios by inductively coupled plasma mass spectrometry (ICP-MS). The isotopic composition of a nuclear contaminant is a sensitive indicator of its origin. By comparing the isotopic composition measured in fluvial sediments to mean values reported for global fallout (i.e. 240Pu/239Pu = 0.18 ñ 0.014, 237Np/239Pu = 0.48 ñ 0.07, and 241Pu/239Pu = .00194 ñ 00028) it is possible to identify contaminants as non-fallout in origin. To date, we have analyzed selected samples from 3 sediment cores collected from the following locations: 1) the Mohawk River downstream of KAPL, 2) the Hudson River above its confluence with the Mohawk River, and 3) the lower Hudson River at a location in close proximity to IPNPP. Isotopic analysis of sediments from the Mohawk River indicates contamination that is clearly non-fallout in origin (240Pu/239Pu ranges between 0

  13. Using 239+240Pu atmospheric deposition and a simplified mass-balance model to re-estimate the soil erosion rate. A case study of Liaodong Bay in China

    By using the mass balance model of 137Cs and introducing 239+240Pu atmospheric deposition, a simplified mass balance model of 239+240Pu was developed and the soil erosion rate was re-estimated. The results indicated that the reference inventory of 239+240Pu was estimated to be 88.4 Bq/m2 in Liaodong Bay. In addition, the atomic ratios of 240Pu/239Pu in all core samples were approximately 0.18, which indicated that the major source of Pu was the global fallout. Statistical analysis of the erosion rates derived from the model demonstrates that the 239+240Pu atmospheric deposition is a feasible way to estimate the soil erosion rate and further improve tracer technique to assess the soil erosion rate. (author)

  14. 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.)

  15. Evaluation of 239+240Pu, 137Cs and natural 210Pb fallout in agricultural upland fields in Rokkasho, Japan

    The background distributions of 239+240Pu and 137Cs fallout in agricultural soil were investigated in Rokkasho where Japan's first commercial nuclear fuel reprocessing plant is now being constructed. The mean inventories of 239+240Pu and 137Cs in three fields with non-yam-cultivation history were 116 Bq x m-2 and 3.4 kBq x m-2, respectively. The mean atomic ratio of 240Pu/239Pu for all studied fields was 0.18±0.04, and was similar to that of global fallout. The 239+240Pu concentrations correlated very well with 137Cs (r = 0.97) in spite of heavy disturbance of the soil, and the activity ratio of 239+240Pu/137Cs was 0.037 ± 0.007, which is a typical value for global fallout. These results showed that the nuclides had similar behavior in agricultural upland fields in Rokkasho. Since 210Pb is steadily deposited from the atmosphere to the land, this nuclide could be an index for the degree of disturbance of a field and of soil lost from the field. The ratio of excess 210Pb inventory in the soil to the equivalent inventory of atmospheric 210Pb deposition was 96%, and indicated that soil was not lost from the cultivated fields. (author)

  16. 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

  17. Background distributions of 239+240Pu and 137Cs of upland soil in Rokkasho, Japan

    The background distributions of Pu and 137Cs in soil were investigated in Rokkasho, Aomori Prefecture, where the first commercial nuclear fuel reprocessing plant in Japan is now being constructed. Soil core samples to 1 m depth were collected at 13 upland fields in Rokkasho and control sites in Hachinohe and Hirosaki. Since fields under yam (Dioscorea babatus) cultivation, which is a common crop in Rokkasho, were dug to approximately 1 m depth at harvesting, depth profiles of fallout radionuclides are heavily disturbed for most fields in Rokkasho. The mean inventories of 239+240Pu and 137Cs in three fields with no yam cultivation history were 116 Bq m-2 and 3.4 kBq m-2, respectively and similar to values in Hachinohe. However, the inventories were approximately a half of those in Hirosaki. The mean ratio of 239Pu/240Pu for all studied fields was 0.18±0.04, and similar to that of global fallout. The Pu concentrations correlate very well with 137Cs (r=0.97) in spite of heavy disturbance of soil, and the ratio of 239+240Pu/137Cs was 0.037±0.007, which is a typical value for global fallout. (author)

  18. Impact of environmental curium on plutonium migration and isotopic signatures.

    Kurosaki, Hiromu; Kaplan, Daniel I; Clark, Sue B

    2014-12-01

    Plutonium (Pu), americium (Am), and curium (Cm) activities were measured in sediments from a former radioactive waste disposal basin located on the Savannah River Site, South Carolina, and in subsurface aquifer sediments collected downgradient from the basin. In situ Kd values (Pu concentration ratio of sediment/groundwater) derived from this field data and previously reported groundwater concentration data compared well to laboratory Kd values reported in the literature. Pu isotopic signatures confirmed multiple sources of Pu contamination. The ratio of (240)Pu/(239)Pu was appreciably lower for sediment samples compared to the associated groundwater. This isotopic ratio difference may be explained by the following: (1) (240)Pu produced by decay of (244)Cm may exist predominantly in high oxidation states (Pu(V)O2(+) and Pu(VI)O2(2+)) compared to Pu derived from the disposed waste effluents, and (2) oxidized forms of Pu sorb less to sediments than reduced forms of Pu. Isotope-specific Kd values calculated from measured Pu activities in the sediments and groundwater indicated that (240)Pu, which is derived primarily from the decay of (244)Cm, had a value of 10 ± 2 mL g(-1), whereas (239)Pu originating from the waste effluents discharged at the site had a value of 101 ± 8 mL g(-1). One possible explanation for the isotope-specific sorption behavior is that (240)Pu likely existed in the weaker sorbing oxidation states, +5 or +6, than (239)Pu, which likely existed in the +3 or +4 oxidation states. Consequently, remediation strategies for radioactively contaminated systems must consider not only the discharged contaminants but also their decay products. In this case, mitigation of Cm as well as Pu will be required to completely address Pu migration from the source term. PMID:25350948

  19. 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)

  20. 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)

  1. 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.

  2. 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

  3. 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)

  4. Evaluation both level and 239+240Pu spatial contamination of the Lira object and the neighbouring areas

    In the work the generalization of considerable data collection for revealing of 239+240Pu content range discriminative for Lira object and neighbouring areas is carried out. 239+240Pu mean specific activity in the soil cover surface and in the Berezovka River bottom sedimentations are determined. The correlation dependence between 239+240Pu artificial radionuclides and 137Cs is revealed. The general source of artificial radionuclide origination for examined isotopes is shown up, and it is related with global radioactive fallout

  5. 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)

  6. 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.)

  7. Comparative analysis of spent fuel isotope composition for VVER-440 compare to VVER-1000 reactors

    Calculations were made for reactor cell of fuel assemblies for VVER-440 and VVER-1000 depending on their manufactory and operation conditions. These cells were composed of the fuel assemblies with the maximum multiplying purpose (enrichment of 4.4% for both reactor types). Concentration as function of burnup of ten most usable isotopes, such as main fuel isotopes U235, U236, U238, Pu239, Pu240, Pu241, as well as some actinides, and fission products, such as Pu242, Am241, Sm149, Sm151 was analyzed

  8. Modeling and production of 240Am by deuteron-induced activation of a 240Pu target

    Finn, Erin C.; McNamara, Bruce K.; Greenwood, Lawrence R.; Wittman, Richard S.; Soderquist, Chuck Z.; Woods, Vincent T.; VanDevender, Brent A.; Metz, Lori A.; Friese, Judah I.

    2015-02-01

    A novel reaction pathway for production of 240Am is reported. Models of reaction cross-sections in EMPIRE II suggests that deuteron-induced activation of a 240Pu target produces maximum yields of 240Am from 11.5 MeV incident deuterons. This activation had not been previously reported in the literature. A 240Pu target was activated under the modeled optimum conditions to produce 240Am. The modeled cross-section for the 240Pu(d, 2n)240Am reaction is on the order of 20-30 mbarn, but the experimentally estimated value is 5.3 ± 0.2 mbarn. We discuss reasons for the discrepancy as well as production of other Am isotopes that contaminate the final product.

  9. Modeling and production of 240Am by deuteron-induced activation of a 240Pu target

    A novel reaction pathway for production of 240Am is reported. Models of reaction cross-sections in EMPIRE II suggest that deuteron-induced activation of a 240Pu target produces maximum yields of 240Am from 11.5 MeV incident deuterons. This activation had not been previously reported in the literature. A 240Pu target was activated under the modeled optimum conditions to produce 240Am. The modeled cross-section for the 240Pu(d, 2n)240Am reaction is on the order of 20–30 mbarn, but the experimentally estimated value is 5.6 ± 0.2 mbarn. We discuss reasons for the discrepancy as well as production of other Am isotopes that contaminate the final product

  10. 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)

  11. Microscopic Calculations of 240Pu Fission

    Younes, W; Gogny, D

    2007-09-11

    Hartree-Fock-Bogoliubov calculations have been performed with the Gogny finite-range effective interaction for {sup 240}Pu out to scission, using a new code developed at LLNL. A first set of calculations was performed with constrained quadrupole moment along the path of most probable fission, assuming axial symmetry but allowing for the spontaneous breaking of reflection symmetry of the nucleus. At a quadrupole moment of 345 b, the nucleus was found to spontaneously scission into two fragments. A second set of calculations, with all nuclear moments up to hexadecapole constrained, was performed to approach the scission configuration in a controlled manner. Calculated energies, moments, and representative plots of the total nuclear density are shown. The present calculations serve as a proof-of-principle, a blueprint, and starting-point solutions for a planned series of more comprehensive calculations to map out a large set of scission configurations, and the associated fission-fragment properties.

  12. 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.

  13. 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

  14. 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

  15. Preparation of a multi-isotope plutonium AMS standard and preliminary results of a first inter-lab comparison

    Dittmann, B.-A.; Dunai, T. J.; Dewald, A.; Heinze, S.; Feuerstein, C.; Strub, E.; Fifield, L. K.; Froehlich, M. B.; Tims, S. G.; Wallner, A.; Christl, M.

    2015-10-01

    The motivation of this work is to establish a new multi-isotope plutonium standard for isotopic ratio measurements with accelerator mass spectrometry (AMS), since stocks of existing solutions are declining. To this end, certified reference materials (CRMs) of each of the individual isotopes 239Pu, 240Pu, 242Pu and 244Pu were obtained from JRC IRMM (Joint Research Center Institute for Reference Materials and Measurements). These certified reference materials (IRMM-081a, IRMM-083, IRMM-043 and IRMM-042a) were diluted with nitric acid and mixed to obtain a stock standard solution with an isotopic ratio of approximately 1.0:1.0:1.0:0.1 (239Pu:240Pu:242Pu:244Pu). From this stock solution, samples were prepared for measurement of the plutonium isotopic composition by AMS. These samples have been measured in a round-robin exercise between the AMS facilities at CologneAMS, at the ANU Canberra and ETH Zurich to verify the isotopic ratio and to demonstrate the reproducibility of the measurements. The results show good agreement both between the different AMS measurements and with the gravimetrically determined nominal ratios.

  16. 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

  17. 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

  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. 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

  1. 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)

  2. Distribution of Pu isotopes and 137Cs in and around the former soviet union's Semipalatinsk nuclear test site

    This paper is a report on our survey of residual radioactivity, Pu isotopes and 137Cs, within and without the territory of the Semipalatinsk nuclear test site. Soil samples within the test site were collected at approximately 30 sites along the roads connecting Kurchatov City, ground zero for the first USSR nuclear test, Balapan, Degelen Mountain and Salzhal settlement. Furthermore, outside the test site, the soil was sampled at about 20 sites, including some settlements (Mostik, Dolon, Tchagan, etc.), forest and pasture areas, along the roads from Semipalatinsk City to Kurchatov City and north Korosteli settlement. The contamination levels of long-lived radionuclides, 137Cs, 238Pu and 239,240Pu as well as 240Pu/239Pu atomic ratio in the soil were determined by non-destructive γ-spectrometric method and radiochemical separation followed by α-spectrometric and/or ICP-MS methods, respectively. The results showed that although 137Cs was within typical environmental levels except for an areas near ground zero and Balapan, 239,240Pu was elevated levels contaminated with weapons-grade plutonium in all area we visited. From the stepwise leaching of Pu from the soil, 50-80% of total 239,240Pu in most samples was found to be tightly incorporated into the soil components which might have been melted at time of detonation. (author)

  3. Further development of IDGS: Isotope dilution gamma-ray spectrometry

    The isotope dilution gamma-ray spectrometry (IDGS) technique for determining the plutonium concentration and isotopic composition of highly radioactive spent-fuel dissolver solutions has been further developed. Both the sample preparation and the analysis have been improved. The plutonium isotopic analysis is based on high-resolution, low-energy gamma-ray spectrometry. The plutonium concentration in the dissolver solutions then is calculated from the measured isotopic differences among the spike, the dissolver solution, and the spiked dissolver solution. Plutonium concentrations and isotopic compositions of dissolver solutions analyzed from this study agree well with those obtained by traditional isotope dilution mass spectrometry (IDMS) and are consistent with the first IDGS experimental result. With the current detector efficiency, sample size, and a 100-min count time, the estimated precision is ∼0.5% for 239Pu and 240Pu isotopic analyses and ∼1% for the plutonium concentration analysis. 5 refs., 2 figs., 7 tabs

  4. Latitudinal distribution and sedimentation of 90Sr, 137Cs, 241Am and 239,240Pu in bottom sediment of the Northwest Pacific Ocean

    As a part of the Worldwide Marine Radioactivity Studies (WOMARS) of the International Atomic Energy Agency's Marine Environment Laboratory (IAEA-MEL) in Monaco, bottom sediment samples were collected along with water column samples in 1997 from the Northwest Pacific Ocean, and were analysed for 90Sr, 137Cs, 239,240Pu and 241Am contents in order to identify current distribution patterns and inventories, and to elucidate sources of these radionuclides in the region where the past US nuclear weapons tests were carried out. This study complements a previous reports on bottom sediments and water column. All the reported sediment data including data from 1997 cruise revealed that sedimentary 239+240Pu and 241Am concentrations peaked both in the latitudinal bands between 10-20 deg. N and 30-40 deg. N, and 137Cs and 90Sr in the latitudinal band between 30-40 deg. N. The latitudinal bands between 10-20 deg. N and 30-40 deg. N correspond to the major areas affected by close-in fallout and global fallout, respectively. Sediment inventories of 239,240Pu and 241Am exceeded or nearly equalled their overlying water inventories near the Bikini Atoll, however, in mid latitudes, more than 70% of 239,240Pu still remains in the water column. Sediment inventories of 137Cs and 90Sr account for about ten and less than five percent of the water column inventories, respectively. 241Am inventories in sediments exceeded those of the water column. The activity ratios of 137Cs/90Sr and 241Am/239,240Pu in sediments were higher than of the global fallout ratios. 90Sr content in the bottom sediments also appears to be controlled by the carbonate contents of the sea floor. The relative contribution of global and close-in fallouts to the total 239,240Pu was estimated using a two end-member mixing model based on the atom ratios of 240Pu/239Pu. The contribution of close-in fallout in sediment appears to be about 56 % for the latitudinal belt 10-20 deg. N. It is not unexpected that close-in fallout Pu

  5. Latitudinal distribution and sedimentation of 90Sr, 137Cs, 241Am and 239,240Pu in bottom sediment of the Northwest Pacific Ocean

    As a part of the Worldwide Marine Radioactivity Studies (WOMARS) of the International Atomic Energy Agency's Marine Environment Laboratory (IAEA-MEL) in Monaco, bottom sediment samples were collected along with water column samples in 1997 from the Northwest Pacific Ocean, and were analysed for 90Sr, 137Cs, 239,240Pu and 241Am contents in order to identify current distribution patterns and inventories, and to elucidate sources of these radionuclides in the region where the past US nuclear weapons tests were carried out. This study complements a previous reports on bottom sediments and water column. All the reported sediment data including data from 1997 cruise revealed that sedimentary 239+240Pu and 241Am concentrations peaked both in the latitudinal bands between 10-20 deg. N and 30-40 deg. N, and 137Cs and 90Sr in the latitudinal band between 30-40 deg. N. The latitudinal bands between 10-20 deg N and 30-40 deg. N correspond to the major areas affected by close-in fallout and global fallout, respectively. Sediment inventories of 239+240Pu and 241Am exceeded or nearly equalled their overlying water inventories near the Bikini Atoll, however, in mid latitudes, more than 70% of 239+240Pu still remains in the water column. Sediment inventories of 137Cs and 90Sr account for about ten and less than five percent of the water column inventories, respectively. 241Am inventories in sediments exceeded those of the water column. The activity ratios of 137Cs/90Sr and 241Am/239,240Pu in sediments were higher than of the global fallout ratios. 90Sr content in the bottom sediments also appears to be controlled by the carbonate contents of the sea floor. The relative contribution of global and close-in fallouts to the total 239,240Pu was estimated using a two end-member mixing model based on the atom ratios of 240Pu/239Pu. The contribution of close-in fallout in sediment appears to be about 56 % for the latitudinal belt 10-20 deg. N. It is not unexpected that close-in fallout Pu

  6. 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.

  7. Modeling and production of {sup 240}Am by deuteron-induced activation of a {sup 240}Pu target

    Finn, Erin C., E-mail: Erin.Finn@pnnl.gov; McNamara, Bruce, E-mail: Bruce.McNamara@pnnl.gov; Greenwood, Larry, E-mail: Larry.Greenwood@pnnl.gov; Wittman, Richard, E-mail: Richard.Wittman@pnnl.gov; Soderquist, Charles, E-mail: Chuck.Soderquist@pnnl.gov; Woods, Vincent, E-mail: Vincent.Woods@pnnl.gov; VanDevender, Brent, E-mail: Brent.Vandevender@pnnl.gov; Metz, Lori, E-mail: Lori.Metz@pnnl.gov; Friese, Judah, E-mail: Judah.Friese@pnnl.gov

    2015-04-15

    A novel reaction pathway for production of {sup 240}Am is reported. Models of reaction cross-sections in EMPIRE II suggest that deuteron-induced activation of a {sup 240}Pu target produces maximum yields of {sup 240}Am from 11.5 MeV incident deuterons. This activation had not been previously reported in the literature. A {sup 240}Pu target was activated under the modeled optimum conditions to produce {sup 240}Am. The modeled cross-section for the {sup 240}Pu(d, 2n){sup 240}Am reaction is on the order of 20–30 mbarn, but the experimentally estimated value is 5.6 ± 0.2 mbarn. We discuss reasons for the discrepancy as well as production of other Am isotopes that contaminate the final product.

  8. Distribution of Pu isotopes and {sup 137}Cs in and around the former soviet union`s Semipalatinsk nuclear test site

    Yamamoto, Masayoshi [Kanazawa Univ., Tatsunokuchi, Ishikawa (Japan). Low Level Radioactivity Laboratory; Hoshi, Masaharu; Takada, Jun; Tsukatani, Tsuneo; Sekerbaev, A.Kh.; Busev, B.I.

    1999-03-01

    This paper is a report on our survey of residual radioactivity, Pu isotopes and {sup 137}Cs, within and without the territory of the Semipalatinsk nuclear test site. Soil samples within the test site were collected at approximately 30 sites along the roads connecting Kurchatov City, ground zero for the first USSR nuclear test, Balapan, Degelen Mountain and Salzhal settlement. Furthermore, outside the test site, the soil was sampled at about 20 sites, including some settlements (Mostik, Dolon, Tchagan, etc.), forest and pasture areas, along the roads from Semipalatinsk City to Kurchatov City and north Korosteli settlement. The contamination levels of long-lived radionuclides, {sup 137}Cs, {sup 238}Pu and {sup 239,240}Pu as well as {sup 240}Pu/{sup 239}Pu atomic ratio in the soil were determined by non-destructive {gamma}-spectrometric method and radiochemical separation followed by {alpha}-spectrometric and/or ICP-MS methods, respectively. The results showed that although {sup 137}Cs was within typical environmental levels except for an areas near ground zero and Balapan, {sup 239,240}Pu was elevated levels contaminated with weapons-grade plutonium in all area we visited. From the stepwise leaching of Pu from the soil, 50-80% of total {sup 239,240}Pu in most samples was found to be tightly incorporated into the soil components which might have been melted at time of detonation. (author)

  9. Precision of gamma-ray measurements of the effective specific power and effective {sup 240}Pu fraction of plutonium

    Sampson, T.E.

    1992-05-01

    This paper uses gamma-ray spectrometry data from replicate measurements on 40 plutonium-bearing samples to examine the repeatability of the effective {sup 240}Pu fraction ({sup 240}Pu{sub eff}) and the effective specific power (P{sub eff}) calculated from the isotopic distribution analyzed with gamma-ray spectrometry codes. The measurements were used to identify the error component arising from repeatability in the determination of the isotopic composition of plutonium in the sample and the contribution of the error component to the uncertainty in total plutonium mass measurements from neutron coincidence counting ({sup 240}Pu{sub eff}) and calorimetry (P{sub eff}). The 40 samples had {sup 240}Pu{sub eff} percentages ranging from 2 to 39% and P{sub eff} values ranging from 2 to 16 mW/g Pu. Four different gamma-ray spectrometry codes (FRAM, MGA, Blue Box, and PUJRC) were used to analyze the data (not all samples were analyzed with each code). All analyses showed that the % relative standard deviation of P{sub eff} was smaller than that of {sup 240}Pu{sub eff}. This result coupled with a cursory examination of uncertainties in coincidence counting of well-characterized samples and water-bath calorimetry errors for the same types of samples lead to the conclusion that smaller uncertainties will be present in the total plutonium mass determined by the combination of calorimetry/gamma-ray spectrometry than in the mass determined by coincidence counting/gamma-ray spectrometry. An additional examination of the biases arising from the {sup 240}Pu correlation used in the gamma-ray spectrometry codes also supported this conclusion. 17 refs.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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)

  15. 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)

  16. Evaluation of neutron nuclear data for 240Pu

    Based on the experimental data evaluation and theoretical calculation, a complete set of neutron nuclear data for 240Pu has been recommended in the incident neutron energy range from 10-5 eV to 20 MeV for CENDL-2. The comparison of present evaluation with ENDF/B-6 and JENDL-3 has been carried out

  17. Plutonium isotopes in the terrestrial environment at the Savannah River Site, USA: a long-term study.

    Armstrong, Christopher R; Nuessle, Patterson R; Brant, Heather A; Hall, Gregory; Halverson, Justin E; Cadieux, James R

    2015-02-01

    This work presents the findings of a long-term plutonium (Pu) study at Savannah River Site (SRS) conducted between 2003 and 2013. Terrestrial environmental samples were obtained at the Savannah River National Laboratory (SRNL) in the A-Area. Plutonium content and isotopic abundances were measured over this time period by α particle and thermal ionization mass spectrometry (3STIMS). We detail the complete process of the sample collection, radiochemical separation, and measurement procedure specifically targeted to trace plutonium in bulk environmental samples. Total plutonium activities were determined to be not significantly above atmospheric global fallout. However, the (238)Pu/(239+240)Pu activity ratios attributed to SRS are substantially different than fallout due to past (238)Pu production on the site. The (240)Pu/(239)Pu atom ratios are reasonably consistent from year to year and are lower than fallout indicating an admixture of weapons-grade material, while the (242)Pu/(239)Pu atom ratios are higher than fallout values, again due to actinide production activities. Overall, the plutonium signatures obtained in this study reflect a distinctive mixture of weapons-grade, heat source, and higher burn-up plutonium with fallout material. This study provides a unique opportunity for developing and demonstrating a blue print for long-term low-level monitoring of trace plutonium in the environment. PMID:25535652

  18. Bioturbation depths, rates and processes in Massachusetts Bay sediments inferred from modeling of 210Pb and 239 + 240Pu profiles

    Crusius, John; Bothner, Michael H.; Sommerfield, Christopher K.

    2004-01-01

    Profiles of 210Pb and 239 + Pu from sediment cores collected throughout Massachusetts Bay (water depths of 36-192 m) are interpreted with the aid of a numerical sediment-mixing model to infer bioturbation depths, rates and processes. The nuclide data suggest extensive bioturbation to depths of 25-35 cm. Roughly half the cores have 210Pb and 239 + 240Pu profiles that decrease monotonically from the surface and are consistent with biodiffusive mixing. Bioturbation rates are reasonably well constrained by these profiles and vary from ~0.7 to ~40 cm2 yr-1. As a result of this extensive reworking, however, sediment ages cannot be accurately determined from these radionuclides and only upper limits on sedimentation rates (of ~0.3 cm yr-1) can be inferred. The other half of the radionuclide profiles are characterized by subsurface maxima in each nuclide, which cannot be reproduced by biodiffusive mixing models. A numerical model is used to demonstrate that mixing caused by organisms that feed at the sediment surface and defecate below the surface can cause the subsurface maxima, as suggested by previous work. The deep penetration depths of excess 210Pb and 239 + 240Pu suggest either that the organisms release material over a range of >15 cm depth or that biodiffusive mixing mediated by other organisms is occurring at depth. Additional constraints from surficial sediment 234Th data suggest that in this half of the cores, the vast majority of the present-day flux of recent, nuclide-bearing material to these core sites is transported over a timescale of a month or more to a depth of a few centimeters below the sediment surface. As a consequence of the complex mixing processes, surface sediments include material spanning a range of ages and will not accurately record recent changes in contaminant deposition.

  19. 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

  20. 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

  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. 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

  3. 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

  4. 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)

  5. Assessment of 238Pu and 239+240Pu, in marine sediments of the oceans Atlantic and Pacific of Guatemala

    In this investigation samples of marine sediments were taken from 14 places representatives of the oceans coast of Guatemala. For the assesment of 238Pu and 239+240Pu in sediments a radiochemical method was used to mineralize sediments and by ionic interchange it was separated from other elements, after that an electrodeposition of plutonium was made in metallic discs. The radioactivity of plutonium was measured by alpha spectrometry system and the alpha spectrums were obtained. The levels of plutonium are not higher than other countries that shown contamination. The contamination of isotope of 239+240Pu is higher than 238Pu and the contamination by two isotopes of plutonium is higher in the Atlantic than the Pacific ocean

  6. Measurement of plutonium isotopic composition by gamma-ray spectroscopy

    The technology of the analysis of plutonium isotopic ratio is independent of the measurement geometry and applicable to samples of physical and chemical composition. Three standard plutonium samples were measured in the HPGe system. The results showed that CRM 136 and CRM 137 containing 238Pu(0.223%) and 238Pu(0.268%) were 18.4% and 14.2% error and CRM 138 of 238Pu(0.01%) was 76% error. However the analysis represented less than 1.6% and 9% error in the three standard samples of highly involved 239Pu and 240Pu. Therefore, gamma-ray spectroscopy is very effective in the plutonium isotope analysis, having greater than 10% in content

  7. 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.)

  8. Plutonium isotopic composition by gamma-ray spectroscopy

    We discuss the general approach, computerized data analysis methods, and results of measurements to determine the isotopic composition of plutonium by gamma-ray spectroscopy. The simple techniques are designed to be applicable to samples of arbitrary size, geometry, chemical and isotopic composition that have attained 241Pu-237U equilibrium. The combination of the gamma spectroscopic measurement of isotopic composition coupled with calorimetric measurement of total sample power is shown to give a totally nondestructive determination of sample Pu mass with a precision of 0.6% for 1000-g samples of PuO2 with 12% 240Pu content. The precision of isotopic measurements depends upon many factors including sample size, sample geometry, and isotopic content. Typical ranges are found to be 238Pu, 239Pu, 0.1 to 0.5%; 240Pu, 2 to 5%; 241Pu, 0.3 to 0.7%; 242Pu (determined by isotopic correlation); and 241Am, 0.2 to 10%

  9. 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)

  10. 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.

  11. 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

  12. 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)

  13. 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

  14. 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

  15. 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

  16. Behaviors and transfers of anthropogenic radionuclides (137Cs, 239+240Pu and 241Am) in a protected alpine wetland (France)

    The aim of this study is to confirm and increase the knowledge on anthropogenic radionuclide (RN) behavior (137Cs, 239+240Pu, 241Am) in natural compartments (artificial pool in a protected upland area). The novelty lies on comparisons of the three main compartments (pool water, soil, sediments) of this original mountainous site. Migration processes and transfers were particularly detailed in the light of two processes: lixiviation and leaching. Regarding 238U, anthropogenic RNs, lithology, organic matter contents, sedimentation rates (210Pb) and isotopic mass balances, RNs are mainly transported by leaching processes with higher 241Am in-depth mobility compared to 137Cs (intermediate for 239+240Pu). (author)

  17. Radioecologycal study of {sup 239/240}Pu in Bangka Island and Muria Peninsula: Determination of {sup 239/240}Pu in marine sediment and seawater as part of baseline data collecting for sitting of candidates of first Indonesia NPP

    Suseno, Heny, E-mail: henis@batan.go.id [Radioactive Waste Technology Center - The Indonesian National Nuclear Energy Agency (Indonesia); Wisnubroto, Djarot S. [The Indonesian National Nuclear Energy Agency (Indonesia)

    2014-03-24

    Radioisotope Pu-239/240 are alpha emitting nuclides important indicators of radioactive contamination of the marine environment. Global fallout is the main source of plutonium in the marine environment. There are very limited study on {sup 239/240}Pu in Indonesia coastal environments. The data of this radioisotopes is needed for baseline data of nuclear power plant (NPP) site candidates both in Bangka Island and Muria Peninsula. Bottom sediments play an important role in radioecological studies of the marine environment because a large proportion of radioactive substances entering the sea is adsorbed over time onto suspended particulate matter and deposited in sediments. Plutonium is particle reactive and deposited in marine sediment. Radioisotope {sup 239/240}Pu was determinated by alpha spectrometry after radiochemical procedure that was performed in both water and marine sediment from Bangka Island and Muria Peninsula. The sediment baseline of concentration {sup 239/240}Pu in Bangka Island and Muria Peninsula were range from 0.013 to 0.021 Bq.kg{sup −1} and 0.018 to 0.024 Bq.kg{sup −1} respectively. The water baseline concentration this isotope were range from 2.73 to 4.05 mBq.m{sup −3} and 2.98 to 4.50 mBq.m{sup −3}.

  18. Tracing the dispersion of contaminated sediment with plutonium isotope measurements in coastal catchments of Fukushima Prefecture

    Evrard, Olivier; Pointurier, Fabien; Onda, Yuichi; Chartin, Caroline; Hubert, Amélie; Lepage, Hugo; Pottin, Anne-Claire; Lefèvre, Irène; Bonté, Philippe; Laceby, J. Patrick; Ayrault, Sophie

    2015-04-01

    The Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident led to important releases of radionuclides into the environment, and trace levels of plutonium (Pu) were detected in northeastern Japan. However, measurement of Pu isotopic atom and activity ratios is required to differentiate between the contributions of global nuclear test fallout and FDNPP emissions. In this study, we measured Pu isotopic ratios in recently deposited sediments along rivers draining the most contaminated part of the inland radioactive plume. To this end, we carried out a thorough chemical purification and concentration of Pu from sediment samples (5 g dry material) and precise isotopic measurements using a double-focusing sector field ICP-MS. Results showed that the entire range of measured Pu isotopes (i.e., 239Pu, 240Pu, 241Pu, and 242Pu) were detected in all samples, although in extremely low concentrations. The 241Pu/239Pu atom ratios measured in sediment deposits (0.0017-0.0884) were significantly higher than the corresponding values attributed to the global fallout (0.00113±0.00008 on average in the Northern Hemisphere between 31°-71°N). The results indicated the presence of Pu from FDNPP, in slight excess compared to the Pu background from global fallout, representing up to ca. 60% of Pu in the analyzed samples. These results demonstrate that this radionuclide has been transported relatively long distances (45 km) from FDNPP and deposited in rivers representing a potential source of Pu to the ocean.

  19. Calculated activities of some isotopes in the RA reactor highly enriched fuel significant for possible environmental contamination - Operational report

    This report contains calculation basis and obtained results of activities for three groups of isotopes in the RA reactor 80% enriched fuel element. The following isotopes are included: 1) 85mKr, 87Kr, 88Kr, 131J, 132J, 133J, 134J, 135J, 133Xe, 138Xe i 138Cs, 2) 89Sr, 90Sr, 91Sr, 92Sr, 95Zr, 97Zr, 103Ru, 105Ru, 106Ru, 129mTe, 134Cs, 137Cs, 140Ba, 144Ce, kao i 3) 238Pu, 239Pu i 240Pu. It was estimated that the fuel is exposed to mean neutron flux. The periodicity of reactor operation is taken into account. Calculation results are given dependent on the time of exposure. These results are to be used as source data for Ra reactor safety analyses

  20. 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.

  1. 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

  2. Pu-239 and Pu-240 inventories and Pu-240/ Pu-239 atom ratios in the water column off Sanriku, Japan.

    Yamada, Masatoshi; Zheng, Jian; Aono, Tatsuo

    2013-04-01

    A magnitude 9.0 earthquake and subsequent tsunami occurred in the Pacific Ocean off northern Honshu, Japan, on 11 March 2011 which caused severe damage to the Fukushima Dai-ichi Nuclear Power Plant. This accident has resulted in a substantial release of radioactive materials to the atmosphere and ocean, and has caused extensive contamination of the environment. However, no information is available on the amounts of radionuclides such as Pu isotopes released into the ocean at this time. Investigating the background baseline concentration and atom ratio of Pu isotopes in seawater is important for assessment of the possible contamination in the marine environment. Pu-239 (half-life: 24,100 years), Pu-240 (half-life: 6,560 years) and Pu-241 (half-life: 14.325 years) mainly have been released into the environment as the result of atmospheric nuclear weapons testing. The atom ratio of Pu-240/Pu-239 is a powerful fingerprint to identify the sources of Pu in the ocean. The Pu-239 and Pu-240 inventories and Pu-240/Pu-239 atom ratios in seawater samples collected in the western North Pacific off Sanriku before the accident at Fukushima Dai-ichi Nuclear Power Plant will provide useful background baseline data for understanding the process controlling Pu transport and for distinguishing additional Pu sources. Seawater samples were collected with acoustically triggered quadruple PVC sampling bottles during the KH-98-3 cruise of the R/V Hakuho-Maru. The Pu-240/Pu-239 atom ratios were measured with a double-focusing SF-ICP-MS, which was equipped with a guard electrode to eliminate secondary discharge in the plasma and to enhance overall sensitivity. The Pu-239 and Pu-240 concentrations were 2.07 and 1.67 mBq/m3 in the surface water, respectively, and increased with depth; a subsurface maximum was identified at 750 m depth, and the concentrations decreased with depth, then increased at the bottom layer. The total Pu-239+240 inventory in the entire water column (depth interval 0

  3. 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)

  4. 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)

  5. Generation of an actinide isotopes cross section set for fast reactor calculations using data from ENDL and ENDF/B-IV

    A Bondarenko format 25-group cross section set of actinide isotopes was generated for the fuel cycle evaluation and the incineration study in fast reactor systems. Evaluated Nuclear Data Library of Lawrence Livermore Laboratory (U.S.) was used as the source data. The actinide isotopes treated are the following 28: Th-232, U-233, U-234, U-235, U-236, U-237, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, Pu-243, Am-241, Am-242, Am-243, Cm-242, Cm-243, Cm-245, Cm-246, Cm-247, Cm-248, Bk-249, Cf-249, Cf-250, Cf-251, Cf-252 and a pseudo-fission product. ENDF/B-IV was used for U-238. The set was then collapsed to one energy group using a large LMFBR core spectrum for the comparison with other one-group sets. (author)

  6. 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

  7. 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.

  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 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

  10. 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.)

  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. 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

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

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

  14. 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

  15. 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

  16. 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)

  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 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

  18. 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)

  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. Concentrations of sup(239,240)Pu and 241Am in drinking water and organic fertilizer

    As part of an investigation of the chemistry and aquatic distribution of fallout-derived sup(239,240)Pu and 241Am in the aquatic environment a study has been made of the concentration of these nuclides in the drinking water and organic fertilizer, distributed to the populace of the Chicago area. The results clearly indicate that the concentration of sup(239,240)Pu is always lower in the water which has been treated at the Chicago Central Water Filtration Plant than in the raw water before treatment. Raw water levels are consistent with normal levels of sup(239,240)PU found in Lake Michigan waters which are approx 6 orders of magnitude below the maximum permissible concentration standard for drinking water. An additional possible source of sup(239,240)Pu and 241Am to humans can be through the distribution of the organic fertilizer, 'Nu Earth', by the Metropolitan Sanitary District, free of charge, for the use in home gardens. 'Nu Earth' consists primarily of sediment from an Imhoff Process which has been air-dried and aged in large, open-air piles. Samples of this organic fertilizer were analysed for sup(239,240)Pu and 241Am. The results indicate that there is little evidence to indicate that sup(239,240)Pu in drinking water or sup(239,240)Pu and 241Am from organic sludge will be health hazards in the Chicago area under current conditions. (U.K.)

  1. 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)

  2. 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

  3. 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)

  4. 239+240Pu and 90Sr deposition densities in undisturbed surface soil in Vietnam

    The study's goal is determination of 239+240Pu and 90Sr deposition densities from known distribution of 137Cs deposition density. The tasks done include: simultaneous determination of 239+240Pu, 90Sr and 137Cs deposition densities in undisturbed surface soil layer having depth to 20 cm and use it as basis for determining the ratios of deposition densities 239+240Pu/137Cs and 90Sr/137Cs; studying the impact of soil parameters such as soil texture, content of organic matter, Humic, Fulvic as well as of geography parameters such as latitude, longitude, annual rainfall to the variation of these ratios. (NHA)

  5. 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...

  6. On the substantion of permissible concentrations of plutonium isotopes in the water of fresh water and sea water NPP cooling reservoirs

    Substantiation of maximum permissible concentration (PC) of plutonium isotopes (238Pu, 239Pu, 240Pu) in fresh and sea water cooling reservoirs of NPP with fast neutron reactors is given. The main criterion when calculating permissible plutonium content in water of surface reservoirs is the requirement not to exceed the established limits for radiation doses to persons resulted from water use. Data on coefficients of plutonium concentration in sea and fresh water hydrobionts are presented as well as on plutonium PC in water of fresh and sea water cooling reservoirs and bottom sediments of sea water cooling reservoirs. It is shown that doses to critical groups of population doesn't exceed potentially hazardous levels due to plutonium intake through food chains. But the calculation being carried out further should be corrected

  7. 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)

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. ZZ AMZ, 70-Group 40 Isotope Multigroup Library for Fast Reactor Calculation

    1 - Description of program or function: format: EXPANDA; number of groups: 70-group library of multigroup constants; nuclides: H-1, Be-9, B-10, B-11, C-12, O-16, N-23, Mg, Al-27, Si, Ti, V, Cr, Mn-55, Fe, Ni, Cu, Ga, Zr, Nb-93, Mo, In-115, Sn, Pb, Th-232, Pa-233, U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, Am-241, and lumped fission products of U-233, U-235, Pu-239. origin: ENDF/B-IV and ENDF/B-V; weighting spectrum: Fission products inventories for BBR reactor at 360 and 600 days of irradiation were calculated and used as weighting function. AMZ is a 70-group library of multigroup constants for the fast reactor nuclear design code EXPANDA. Data is stored for three temperatures (300 K, 900 K, 2100 K) and for seven background cross sections. The following isotopes are available: H1, Be9, B10, B11, C12, O16, N23, Mg, Al27, Si, Ti, V, Cr, Mn55, Fe, Ni, Cu, Ga, Zr, Nb93, Mo, In115, Sn, Pb, Th232, Pa233, U233, U234, U235, U236, U238, Pu238, Pu239, Pu240, Pu241, Pu242, Am241, and lumped fission products of U233, U235, Pu239. 2 - Method of solution: Nuclear cross sections, transfer matrices, and self-shielding factors were generated from ENDF/B-IV data using the codes NJOY (PSR-0171) and RGENDF

  14. 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.)

  15. 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

  16. Worldwide data on fluxes of 239,240Pu, 238Pu to the oceans

    According to measurements (GEOSECS) the world's oceans contain approximately 16 PBq 239,240Pu, of which one-fourth is in the Atlantic and three-fourths in the Pacific Ocean. The expected inventory (from nuclear weapons testing) in the world's oceans is 12 PBq 239,240Pu including local fallout at the test sites. In the Irish Sea a local contamination of 0.3 PBq 239,240Pu from the Sellafield reprocessing plant resides in the sediments. No other sources than fallout and reprocessing add significantly to the 239,240Pu inventories in the oceans. The discrepancy between measurements and expectations are assumed to be due to an underestimate of the rainfall and dry fallout (seaspray) and thus of the Pu-deposition over the oceans, but may also to some degree be due to inadequate sampling

  17. Precision of gamma-ray measurements of the effective specific power and effective 240Pu fraction of plutonium

    This paper uses gamma-ray spectrometry data from replicate measurements on 40 plutonium-bearing samples to examine the repeatability of the effective 240Pu fraction (240Pueff) and the effective specific power (Peff) calculated from the isotopic distribution analyzed with gamma-ray spectrometry codes. The measurements were used to identify the error component arising from repeatability in the determination of the isotopic composition of plutonium in the sample and the contribution of the error component to the uncertainty in total plutonium mass measurements from neutron coincidence counting (240Pueff) and calorimetry (Peff). The 40 samples had 240Pueff percentages ranging from 2 to 39% and Peff values ranging from 2 to 16 mW/g Pu. Four different gamma-ray spectrometry codes (FRAM, MGA, Blue Box, and PUJRC) were used to analyze the data (not all samples were analyzed with each code). All analyses showed that the % relative standard deviation of Peff was smaller than that of 240Pueff. This result coupled with a cursory examination of uncertainties in coincidence counting of well-characterized samples and water-bath calorimetry errors for the same types of samples lead to the conclusion that smaller uncertainties will be present in the total plutonium mass determined by the combination of calorimetry/gamma-ray spectrometry than in the mass determined by coincidence counting/gamma-ray spectrometry. An additional examination of the biases arising from the 240Pu correlation used in the gamma-ray spectrometry codes also supported this conclusion. 17 refs

  18. 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

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

    The lack of a gamma-ray signature from 242 Pu 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 242 Pu 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 with the recommended coefficients for PWR and BWR fuels. This type of correlation was adopted 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 with different sets of coefficients 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 238 Pu/239 Pu versus 240 Pu/239 Pu 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 242 Pu estimate is substantially improving in most cases. Performance data for 242 Pu in particular, and for plutonium isotope abundance measurements by HRGS in general, as derived from a larger set of measurement data are presented and discussed in terms of their impact on the interpretation of passive neutron

  20. 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)

  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. 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.

  3. 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

  4. 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)

  5. 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

  6. 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

  7. 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

  8. 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

  9. Neutron-induced fission cross section of 240Pu from 0.5 MeV to 3 MeV

    Salvador-Castiñeira, P.; Bryś, T.; Eykens, R.; Hambsch, F.-J.; Göök, A.; Moens, A.; Oberstedt, S.; Sibbens, G.; Vanleeuw, D.; Vidali, M.; Pretel, C.

    2015-07-01

    240Pu has recently been pointed out by a sensitivity study of the Organization for Economic Cooperation and Development (OECD) Nuclear Energy Agency (NEA) to be one of the isotopes whose fission cross section lacks accuracy to meet the upcoming needs for the future generation of nuclear power plants (GEN-IV). In the High Priority Request List (HPRL) of the OECD, it is suggested that the knowledge of the 240Pu(n ,f ) cross section should be improved to an accuracy within 1-3 %, compared to the present 5%. A measurement of the 240Pu cross section has been performed at the Van de Graaff accelerator of the Joint Research Center (JRC) Institute for Reference Materials and Measurements (IRMM) using quasi-monoenergetic neutrons in the energy range from 0.5 MeV to 3 MeV. A twin Frisch-grid ionization chamber (TFGIC) has been used in a back-to-back configuration as fission fragment detector. The 240Pu(n ,f ) cross section has been normalized to three different isotopes: 237Np(n ,f ) , 235U (n ,f ) , and 238U (n ,f ) . Additionally, the secondary standard reactions were benchmarked through measurements against the primary standard reaction 235U (n ,f ) in the same geometry. A comprehensive study of the corrections applied to the data and the associated uncertainties is given. The results obtained are in agreement with previous experimental data at the threshold region. For neutron energies higher than 1 MeV, the results of this experiment are slightly lower than the ENDF/B-VII.1 evaluation, but in agreement with the experiments of Laptev et al. (2004) as well as Staples and Morley (1998).

  10. 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)

  11. Measurement of the fission cross-section of $^{240}$Pu and $^{242}$Pu at CERN's n_TOF Facility

    Pavlik, A F; Gonzalez romero, E M

    The n_TOF Collaboration proposes to continue the fission program, already started in 2002-2004, taking advantage of the newly constructed Work Sector Type A, with the measurement of the two isotopes : $^{240}$ Pu and $^{242}$ Pu. They are both of major importance for reactor physics applications and are included in the Nuclear Energy Agency (NEA) High Priority List [1], in the NEA WPEC Subgroup 26 Report on the accuracy of nuclear data for advanced reactor designe [2] and in the EU 6$^{th}$ Framework Programme IP-EUROTRANS/NUDATRA reports [3]. Based on those requests, the measurement of the fission cross-section of the two Pu isotopes is one of the objectives of the project ANDES of the FP7 EURATOM program [4].

  12. 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

  13. 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)

  14. 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

  15. 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.

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

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

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

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

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

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

  19. 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

  20. 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)

  1. 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

  2. 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)

  3. 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

  4. 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)

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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)

  11. 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

  12. 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)

  13. 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

  14. 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

  15. Sources and Spatial Distribution of Metal Pollutants in Soils near the El Paso Smelter: A Forensic Study with Pb and Pu Isotopes.

    Ketterer, Michael; Moan, Matthew; Gremillion, Paul

    2010-05-01

    Lead and copper smelting has been conducted at El Paso since the late 1800's, and as a result, environmental media near the smelter have become contaminated. A study has been conducted to investigate the sources and spatial distribution of metal pollutants (Pb, Cd, Zn, Hg, As, Cu) and concomitant tracers (Ag, In, Sb, Bi) in soils from the smelter vicinity. Sampled locations were residential and non-residential locations in El Paso (Texas, USA), Anapra (New Mexico, USA) and Ciudad Juarez (Chihuahua, Mexico). Lead isotope studies indicate that the soil Pb is derived from smelting, and is consistent with two-component mixing between lead ores from Chihuahua (northern Mexico) having 206Pb/204Pb of 18.6 - 18.8 and ores from the Hanover, New Mexico (USA) mining district with 206Pb/204Pb of ~ 17.6. The Pb isotope results also exclude other common anthropogenic Pb sources such as paint and gasoline emissions as being major contributors. Concentrations of Hg and Pb of up to 10 and 11,000 ppm were found in surface soils within 1 km of the smelter. The metal concentration results clearly indicate that soils near the smelter ( 10 km distant). A general trend of decreasing concentrations vs. distance from the smelter was also observed. However, the results indicate that metal concentrations vary widely even at a fixed distance from the smelter point source. This phenomenon results from a combination of natural and anthropogenic processes that disturb and re-distribute soils in the surface environment. The site conditions consist of a very arid environment with little vegetation cover that is frequently disturbed by high winds and severe episodic rainfall. To study these effects, we have investigated stratospheric fallout plutonium (239+240Pu) as a proxy measure of disturbed vs. undisturbed soil conditions. The premise is that 'undisturbed' locations will have high 239+240Pu activities, and hence contain most or all of the cumulative deposition inventory of smelter pollutants

  16. Study on plutonium isotopic analysis in environmental samples

    A method for determination of plutonium isotope ratio in environmental samples was investigated in our laboratory. Plutonium was separated with complex matrix and purified by using TEVA extraction chromatography resin, and determined by MC-ICP-MS. The elution of Pu from TEVA column was tested. Plutonium could be eluted from TEVA column effectively by 0.025mol·l-1 H2C2O4-0.15mol·l-1HNO3 or 10-2 mol·l-1 ascorbic acid- 0.2 mol·l-1HNO3. For one TEVA column, the decontamination factors of main environmental matrix , such as Na, K, Ca, Al, Fe, Mg, were between 104-105, and the concentration of total cation ions in the final elution was less than 10 μg·g-1, which could be determined by MC-ICP-MS directly. The decontamination of U, Th and Am was also examined, DFU/Pu=1.97x103, DFTh/Pu=7.19 x 104, DFAm/Pu=1.52x104 were obtained. The chemical recovery of plutonium during the whole process was ∼ 30%. Because of the tailing of 238U and the formation of 238UH+ while the determination of plutonium isotope by MS, it was not enough for the decontamination of uranium by using one TEVA column. A UTEVA column was needed before the solution loading in the TEVA resin. The decontamination factor of uranium could reach 1.33x106. The detection limit of Pu by MC-ICP-MS was about 2.5 fg·ml-1. The influence of U on the determination of plutonium isotope ratio was also examined. For the solution containing less than 1 ng·g-1 uranium, Aridus sample introduction system was adopted to improve the sensitivity. Meinhard PFA nebulizer was used for solutions of high uranium concentration (1- 500 ng·g-1). The results show that, the 238UH+/U+ is about 8.9x10-5 for the high content of uranium, and about 3.6x10-4 for the low content. According to the method mentioned above, two IAEA reference materials, IAEA-368 and SOIL-6 were analyzed. Purified Pu fractions were obtained by using UTEVA+TEVA extraction chromatography; 240Pu/239Pu were determined by MC-ICP-MS. The results were shown. Ocean

  17. Study on plutonium isotopic analysis in environmental samples

    A method for determination of plutonium isotope ratio in environmental samples was investigated in our laboratory. Plutonium was separated with complex matrix and purified by using TEVA extraction chromatography resin, and determined by MC-ICP-MS. The elution of Pu from TEVA column was tested. Plutonium could be eluted from TEVA column effectively by 0.025mol·l-1 H2C2O4-0.15mol·l-1HNO3 or 10-2 mol·l-1 ascorbic acid-0.2mol·l-1HNO3. For one TEVA column, the decontamination factors of main environmental matrix , such as Na, K, Ca, Al, Fe, Mg, were between 104-105, and the concentration of total cation ions in the final elution was less than 10 μg·g-1, which could be determined by MC-ICP-MS directly. The decontamination of U, Th and Am was also examined, DFU/Pu=1.97x103,DFTh/Pu=7.19x104,DFAm/Pu=1.52x104 were obtained. The chemical recovery of plutonium during the whole process was ∼30%. Because of the tailing of 238U and the formation of 238UH+ while the determination of plutonium isotope by MS, it was not enough for the decontamination of uranium by using one TEVA column. A UTEVA column was needed before the solution loading in the TEVA resin. The decontamination factor of uranium could reach 1.33x106. The detection limit of Pu by MC-ICP-MS was about 2.5 fg·ml-1. The influence of U on the determination of plutonium isotope ratio was also examined. For the solution containing less than 1 ng·g-1 uranium, Aridus sample introduction system was adopted to improve the sensitivity. Meinhard PFA nebulizer was used for solutions of high uranium concentration(1-500 ng·g-1). The results show that, the 238UH+/U+ is about 8.9x10-5 for the high content of uranium, and about 3.6x10-4 for the low content. According to the method mentioned above, two IAEA reference materials, IAEA-368 and SOIL-6 were analyzed. Purified Pu fractions were obtained by using UTEVA+TEVA extraction chromatography; 240Pu/239Pu were determined by MC-ICP-MS. The results were showed in table 1. Ocean

  18. 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.

  19. The isotopic signature of fallout plutonium in the North Pacific

    Plutonium analyses of a dated coral record from the French Frigate Shoals in the central North Pacific indicate that there are two major sources of Pu in this basin: close-in (tropospheric) fallout from nuclear weapons testing at the Pacific Proving Grounds in the Marshall Islands in the 1950s and global (stratospheric) fallout which peaked in 1962. Furthermore, the 240Pu/239Pu atom ratio of fallout from the Pacific Proving Grounds is characteristically higher (0.24) than that of global fallout Pu (0.18-0.19). Seawater and sediment samples from the North Pacific exhibit a wide range of 240Pu/239Pu values (0.19-0.34), with a trend towards higher ratios in the subsurface waters and sediment. Deep water 240Pu/239Pu ratios are higher in the vicinity of the Marshall Islands relative to stations further from this close-in fallout source. These preliminary data suggest that fallout Pu from the Pacific Proving Grounds is more rapidly removed from the surface waters than is global fallout Pu. Plutonium geochemistry appears to be related to the physical/chemical form of Pu-bearing particles generated by different fallout sources. (author)

  20. ZZ JFS-1, Cross-Sections Library 25-Groups ABBN and 70-Group JFS for Fast Reactor Calculation. ZZ JFS-2, 25 Group (ABBN) and 70 Group JFS Cross Sections Library for Fast Reactors. ZZ JFS-3/J2, 70 Group 30 Isotopes Cross Section Library for Fast Reactors

    1 - Description of problem or function: - JFS-V2-1: Format: ABBN energy structure; Number of groups: 25 group constants; Nuclides: Be, B-10, B-11, C, O, Na, Al, Si, Cr, Mn, Fe, Ni, Cu, Mo, Th-232, U-233, U-234, U-235, U-236, U-238, Pu-239, Pu-240, Pu-241, Pu-242, Am-241, fission products of U-235, and fission products of Pu-239. Origin: ENDF/B-IV; Weighting spectrum: The cross-section adjustment has been made by using an auxiliary equation for simultaneous evaluations for U-235, U-238, and Pu-239. - JFS-V2-2: Format: JFS energy structure; Number of groups: 70 group constants; Nuclides: Be, B-10, B-11, C, O, Na, Al, Si, Cr, Mn, Fe, Ni, Cu, Mo, Th-232, U-233, U-234, U-235, U-236, U-238, Pu-239, Pu-240, Pu-241, Pu-242, Am-241, fission products of U-235, and fission products of Pu-239. Origin: ENDF/B-IV; Weighting spectrum: The cross-section adjustment has been made by using an auxiliary equation for simultaneous evaluations for U-235, U-238, and Pu-239. - JFS-3/J2: Number of groups: 70 group constants with quarter-lethargy width; Nuclides: H-1, He-4, Be-9, B-10, B-11, C-12, N-14, O-16, Na-23, Al-27, Si, Ar, Ti, V, Cr, Mn-55, Fe, Ni, Cu, Zr, Nb-93, Mo, Eu-151, Eu-153, Gd, Gd-155, Gd-156, Gd-157, Gd-158, Gd-160, Ta-181, W, Th-228, Th-230, Th-232, Th-233, Th-234, Pa-233, U-233, U-234, U-235, U-236, U-238, Np-237, Np-239, Pu-236, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, Am-241, Am-242m, Am-242g, Am-243, Cm-242, Cm-243, Cm-244, Cm-245 and 12 LFPs for 4 mother nuclides (U-235, U-238, Pu-239 and Pu-241) and 3 burnup days (180, 1080 and 1800). Origin: JENDL-2 and ENDF/B-V; Weighting spectrum: the collision density spectrum for a typical large LMFBR core spectrum is used as the weighting function. ZZ-JFS-3/J2: To improve fast reactor group constant set JFS-3-J2 to be applicable for high burnup reactor calculation, burnup depending lumped FP group cross sections for mother fission isotopes of U-235, U-238, Pu-239 and Pu-241 have been generated by using 155 FP nuclides of JENDL-2

  1. 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

  2. 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

  3. The Pöschl Teller model for total cross section of neutron scattering from 240Pu

    Neutron scattering cross-section of 240Pu have been investigated using an attractive potential. On applying the modified Pöschl-Teller model, the total cross-section of the n+240Pu in the energy range of 5-20 MeV have been calculated. It was compared with the available experimental data and evaluated data of JENDL-4.0, ENDF/B-VII.0 and CENDL-3.1 as well as with the theoretical values from TALYS-1.2 Nuclear Reaction Program, EMPIRE: 2.19 Nuclear Reaction Model Code and are found to be in reasonably good agreement. This supports the validity of the present calculation. (author)

  4. Prompt fission γ -ray spectrum characteristics from 240Pu(sf ) and 242Pu(sf )

    Oberstedt, S.; Oberstedt, A.; Gatera, A.; Göök, A.; Hambsch, F.-J.; Moens, A.; Sibbens, G.; Vanleeuw, D.; Vidali, M.

    2016-05-01

    In this paper we present first results for prompt fission γ -ray spectra (PFGS) characteristics from the spontaneous fission (sf) of 240Pu and 242Pu. For 242Pu(sf ) we obtained, after proper unfolding of the detector response, an average energy per photon ɛ¯γ=(0.843 ±0.012 ) MeV, an average multiplicity M¯γ=(6.72 ±0.07 ) , and an average total γ -ray energy release per fission E¯γ ,tot = (5.66 ± 0.06) MeV. The 240Pu(sf ) emission spectrum was obtained by applying a so-called detector-response transformation function determined from the 242Pu spectrum measured in exactly the same geometry. The results are an average energy per photon ɛ¯γ=(0.80 ±0.07 ) MeV, the average multiplicity M¯γ = (8.2 ± 0.4), and an average total γ -ray energy release per fission E¯γ ,tot = (6.6 ± 0.5) MeV. The PFGS characteristics for 242Pu(sf ) are in very good agreement with those from thermal-neutron-induced fission on 241Pu and scales well with the corresponding prompt neutron multiplicity. Our results in the case of 240Pu(sf ), although drawn from a limited number of events, show a significantly enhanced average multiplicity and average total energy, but may be understood from a different fragment yield distribution in 240Pu(sf ) compared to that of 242Pu(sf ).

  5. 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.

  6. 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

  7. 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

  8. 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

  9. 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)

  10. 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

  11. 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

  12. Measurement of the ${240}$Pu(n,f) reaction cross-section

    Following proposal CERN-INTC-2010-042 / INTC-P-280 (“Measurement of the fission cross-section of $^{240}$Pu and $^{242}$Pu at CERN’s n_TOF Facility”), the parallel measurement of the $^{240}$Pu(n,f) and $^{242}$Pu(n,f) reaction cross-sections was carried out at n_TOF EAR-1. While the $^{242}$Pu measurement was successful, unexpected sample-induced damage to the detectors caused by the high α-activity of the 240Pu samples resulted in a deterioration of the detector performance over the data taking period of several months, which compromised the measurement. This obstacle can be eliminated by performing the measurement in EAR-2, where the higher neutron flux will allow collecting data in a much shorter time, thus preventing the degradation of the detectors. In addition to this obvious advantage, the measurement would also benefit from the stronger suppression of the sample-induced α-background, due to the shorter times-of-flight involved.

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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)

  18. 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

  19. Association of fallout-derived 137Cs,90Sr and 239,240Pu with natural organic substances in soils

    Activity concentrations and associations of fallout-derived Cs, Sr and Pu in soils were investigated. The activity concentrations of 137Cs, 90Sr and 239,240Pu in volcanic ash soil were much higher than those in granite soil. They decreased with increasing depth in the soil. The activity ratios of 239,240Pu/137Cs and 90Sr/137Cs tended to increase slightly with increasing soil depth. Alkali extraction experiments with 0.1 M NaOH solution showed that the percentage activities of the fallout radionuclides found in the organic acid fractions were in the order 239,240Pu>90Sr>137Cs. The concentrations of 137Cs and 239,240Pu reacted with humic fractions were higher than those with fulvic fractions. In contrast to 137Cs and 239,240Pu,90Sr reacted more with fulvic fractions than with humic fractions. These results provide information about the effects of organic substances on the retention and migration of 137Cs,90Sr and 239,240Pu in soils under natural conditions

  20. The coagulation of dissolved sup(239,240)Pu in estuaries as determined from a mixing experiment

    A mixing experiment, using large volumes (100 l) of filtered (240Pu during estuarine mixing. An organic-rich freshwater with a relatively high concentration (0.8 dpm/100 l) of dissolved sup(239,) 240Pu was used as one end-member; Buzzards Bay seawater (dissolved sup(239,) 240Pu=0.04 dpm/100 l) was the other. The results demonstrate that dissolved sup(239,) 240Pu in the freshwater undergoes extensive and rapid coagulation under simulated estuarine conditions. There is a strong correlation between the amount of coagulation of dissolved sup(239,) 240Pu, humic acids (HA), and Fe. The extent of coagulation of all three constituents increases with increasing salinity and the net extent of their removal is 53%, 57%, and 100% for Pu, HA, and Fe respectively. As has been domented for Fe in freshwater, dissolved sup(239,) 240Pu appears to be stabilized by naturally occurring humic substances to form negatively charged colloids which are then coagulated by seawater cations. The extrapolation of these experimental results to real estuaries will require additonal research. (orig.)

  1. Separation Of Uranium And Plutonium Isotopes For Measurement By Multi Collector Inductively Coupled Plasma Mass Spectroscopy

    Martinelli, R E; Hamilton, T F; Williams, R W; Kehl, S R

    2009-03-29

    Uranium (U) and plutonium (Pu) isotopes in coral soils, contaminated by nuclear weapons testing in the northern Marshall Islands, were isolated by ion-exchange chromatography and analyzed by mass spectrometry. The soil samples were spiked with {sup 233}U and {sup 242}Pu tracers, dissolved in minerals acids, and U and Pu isotopes isolated and purified on commercially available ion-exchange columns. The ion-exchange technique employed a TEVA{reg_sign} column coupled to a UTEVA{reg_sign} column. U and Pu isotope fractions were then further isolated using separate elution schemes, and the purified fractions containing U and Pu isotopes analyzed sequentially using multi-collector inductively coupled plasma mass spectrometer (MCICP-MS). High precision measurements of {sup 234}U/{sup 235}U, {sup 238}U/{sup 235}U, {sup 236}U/{sup 235}U, and {sup 240}Pu/{sup 239}Pu in soil samples were attained using the described methodology and instrumentation, and provide a basis for conducting more detailed assessments of the behavior and transfer of uranium and plutonium in the environment.

  2. A study of in-line plutonium isotopic analysis for gaseous plutonium hexafluoride

    In-line plutonium isotopic analysis of gaseous plutonium hexafluoride (PuF6) is very important for process control and special nuclear material accountability in any plutonium-isotope-separation process that requires a gaseous phase. Although much effort had been devoted to analyze arbitrary plutonium samples, no isotopic analysis had been done on gaseous PuF6 samples. We have initiated a study on the use of a high-resolution, gamma-ray spectroscopy technique to analyze gaseous plutonium hexafluoride. For the first time, PuF6 gas samples with pressures varying from 0.15 to 31 torr, which were directly fed into a gas cell from a process flow loop, were measured. The isotopic results of these measurements agree very well with those of mass spectrometry measurements of solid PuF4. The precision of a 10-min measurement of a 10-torr reactor-grade PuF6 is 1.5% for 238Pu, 0.22% for 239Pu, 0.87% for 240Pu, and 17.5% for 241Pu

  3. 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

  4. A 233U/236U/242Pu/244Pu spike for isotopic and isotope dilution analysis by mass spectrometry with internal calibration

    The Khlopin Radium Institute prepared on behalf of the IAEA a synthetic mixture of 233U, 236U, 242Pu and 244Pu isotopes. The isotopic composition and elemental concentration of uranium and plutonium were certified on the basis of analyses done by four laboratories of the IAEA Network, using mass spectrometry with internal standardization. The certified values for 233U/236U ratio and the 236U chemical concentration have a coefficient of variation of 0.05%. The latter is fixed by the uncertainty in the 235U/238U ratio of NBS500 used as internal standard. The coefficients of variation of the 244Pu/242Pu ratio and the 242Pu chemical concentration are respectively 0.10% and 0.16% and limited by the uncertainty in the 240Pu/239Pu ratio of NBS947. This four isotope mixture was used as an internal standard as well as a spike, to analyze 30 batches of LWR spent fuel solutions. The repeatability of the mass spectrometric measurements have a coefficient of variation of 0.025% for the uranium concentration, and of 0.039% for the plutonium concentration. The spiking and treatment errors had a coefficient of variation of 0.048%. (author). Refs, figs and tabs

  5. {sup 239+240}Pu in the Barents Sea Regions. Sources and radioecological assessment

    Iosjpe, Mikhail [Norwegian Radiation Protection Authority, P.O. Box 55, N-1332 Oesteraas (Norway)

    2014-07-01

    The radioecological assessment for {sup 239+240}Pu in the Barents sea regions was made using the compartment modelling approach. The following sources of radioactive contamination were under consideration: global fallout from atmospheric testing of nuclear weapons, transport of {sup 239+240}Pu from the Sellafield and La Hauge nuclear plants and underwater testing of nuclear weapons in Chernaya Bay, Novaya Zemlya. The box model developed at NRPA uses a modified approach for compartmental modeling, which takes into account the dispersion of radionuclides over time. The box structures for surface, mid-depth and deep water layers have been developed based on the description of polar, Atlantic and deep waters in the Arctic Ocean and the Northern Seas, as well as site-specific information for the boxes. The volume of the three water layers in each box has been calculated using detailed bathymetry together with Geographical Information Systems. The box model includes the processes of advection of radioactivity between compartments, sedimentation, diffusion of radioactivity through pore water in sediments, resuspension, mixing due to bioturbation, particle mixing and a burial process for radionuclides in deep sediment layers. Radioactive decay is calculated for all compartments. The contamination of biota is further calculated from the known radionuclide concentrations in filtered seawater in the different water regions. Doses to man are calculated on the basis of seafood consumptions, in accordance with available data for seafood catches and assumptions about human diet in the respective areas. Dose to biota are determined on the basis of calculated radionuclide concentrations in marine organisms, water and sediment, using dose conversion factors. Results of the calculations show that atmospheric deposition is the dominant source for the Barents Sea, except for the Chernaya Bay region. It is also demonstrated that the impact of the Sellafield nuclear facilities has

  6. Microscopic modeling of mass and charge distributions in the spontaneous fission of 240Pu

    Sadhukhan, Jhilam; Schunck, Nicolas

    2016-01-01

    In this letter, we outline a methodology to calculate microscopically mass and charge distributions of spontaneous fission yields. We combine the multi-dimensional minimization of collective action for fission with stochastic Langevin dynamics to track the relevant fission paths from the ground-state configuration up to scission. The nuclear potential energy and collective inertia governing the tunneling motion are obtained with nuclear density functional theory in the collective space of shape deformations and pairing. We obtain a quantitative agreement with experimental data and find that both the charge and mass distributions in the spontaneous fission of 240Pu are sensitive both to the dissipation in collective motion and to adiabatic characteristics.

  7. Microscopic modeling of mass and charge distributions in the spontaneous fission of 240Pu

    Sadhukhan, Jhilam; Nazarewicz, Witold; Schunck, Nicolas

    2016-01-01

    We propose a methodology to calculate microscopically the mass and charge distributions of spontaneous fission yields. We combine the multidimensional minimization of collective action for fission with stochastic Langevin dynamics to track the relevant fission paths from the ground-state configuration up to scission. The nuclear potential energy and collective inertia governing the tunneling motion are obtained with nuclear density functional theory in the collective space of shape deformations and pairing. We obtain a quantitative agreement with experimental data and find that both the charge and mass distributions in the spontaneous fission of 240Pu are sensitive both to the dissipation in collective motion and to adiabatic fission characteristics.

  8. Annular cylinders experimental programme containing plutonium solutions at different 240Pu contents

    From 1963 to 1976, 730 critical experiments dealing with annular cylinders containing plutonium nitrate solutions were conducted on Valduc critical facility, called 'Apparatus B'. They aimed at validating critical configurations encountered in the fuel cycle, especially in storage and also at validating the 240Pu cross-sections in thermal neutron spectrum. It is to be noticed that these experiments validate criticality codes either in configurations with reactor-grade plutonium coming from the reprocessing cycle or with weapon-grade plutonium coming from the decommissioning of nuclear weapons. (authors)

  9. 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

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

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

  11. Effects of 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)

  12. 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)

  13. 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.

  14. Plutonium in Soils from Northeast China and Its Potential Application for Evaluation of Soil Erosion

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

    2013-01-01

    Surface and soil core samples from northeast China were analyzed for Pu isotopes. The measured 240Pu/239Pu atomic ratios and 239 1 240Pu/137Cs activity ratios revealed that the global fallout is the dominant source of Pu and 137Cs at these sites. Migration behavior of Pu varying with land type an...

  15. Intercalibration of selected anthropogenic radionuclides for the GEOTRACES Program

    Kenna, Timothy C.; Masqué, Pere; Mas, Jose Luis;

    2012-01-01

    As part of the GEOTRACES Program, six laboratories participated in an intercalibration exercise on several anthropogenic radionuclides of interest. The effort was successful for 239,240Pu activity, 240Pu/239Pu isotope ratio, and 137Cs activity measured in filtered seawater samples from the Bermuda...

  16. 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

  17. 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

  18. 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.

  19. 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)

  20. The pore water chemistry of sup(239,240)Pu and 137Cs on sediments of Buzzards Bay, Massachusetts

    The collection of large volumes of pore water and low level radiochemical measurements of sup(239,240)Pu and 137Cs have been combined to produce the first study of these fallout artificial radionuclides in marine pore waters. Profiles from box cores taken in June and September 1982 from Buzzards Bay, Mass., are reported along with profiles of many diagenetic constituents (i.e. SO42-, alkalinity, Fe, Mn, DOC, and nutrients). The sup(239,240)Pu pore water profile is characterized by a subsurface maximum of about 0.28 dpm/100 kg lying between 3 to 11 cm. Overlying seawater, in contrast, has an activity of 0.01 +- 0.02 dpm/100 kg. Below about 11 cm, the pore water sup(239,240)Pu distribution follows that of the solid phase which decreases rapidly with depth. The pore water profiles of 137Cs are characterized by a broad and deeply penetrating maximum where activities of about 35 to 40 dpm/100 kg extend from 3 to 20 cm. Overlying seawater, in contrast, has an activity of 17 to 24 dpm/100 kg. The 137Cs and sup(239,240)Pu pore water data show that there is preferential downward transport of 137Cs and that sup(239,240)Pu does not have an active diagenetic chemistry and is not significantly mobile in these coastal sediments. (author)

  1. Alpha-particle emission probabilities in the decay of {sup 240}Pu

    Sibbens, G., E-mail: goedele.sibbens@ec.europa.e [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Pomme, S.; Altzitzoglou, T. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Garcia-Torano, E. [Laboratorio de Metrologia de Radiaciones Ionizantes, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain); Janssen, H.; Dersch, R.; Ott, O. [Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig (Germany); Martin Sanchez, A. [Departamento de Fisica, Universidad de Extremadura, Badajoz, E-06071 (Spain); Rubio Montero, M.P. [Departamento de Fisica Aplicada, Universidad de Extremadura, Merida, Badajoz, E-06800 (Spain); Loidl, M. [Laboratoire National Henri Becquerel, LNE/CEA-LIST, 91191 Gif-sur-Yvette (France); Coron, N.; Marcillac, P. de [Institut d' Astrophysique Spatiale, CNRS, 91405 Orsay Campus (France); Semkow, T.M. [Wadsworth Center, New York State Department of Health, Albany, NY 12201 (United States)

    2010-07-15

    Sources of enriched {sup 240}Pu were prepared by vacuum evaporation on quartz substrates. High-resolution alpha-particle spectrometry of {sup 240}Pu was performed with high statistical accuracy using silicon detectors and with low statistical accuracy using a bolometer. The alpha-particle emission probabilities of six transitions were derived from the spectra and compared with literature values. Additionally, some alpha-particle emission probabilities were derived from {gamma}-ray intensity measurements with a high-purity germanium detector. The alpha-particle emission probabilities of the three main transitions at 5168.1, 5123.6 and 5021.2 keV were derived from seven aggregate spectra analysed with five different fit functions and the results were compatible with evaluated data. Two additional weak peaks at 4863.5 and 4492.0 keV were fitted separately, using the exponential of a polynomial function to represent the underlying tailing of the larger peaks. The peak at 4655 keV could not be detected by alpha-particle spectrometry, while {gamma}-ray spectrometry confirms that its intensity is much lower than expected from literature.

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

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

    2011-12-01

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

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

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

  4. 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)

  5. Separation and activity determination of 239+240Pu, 241Am and Curium (242and244Cm) in evaporator concentrate by Alpha Spectrometry

    Alpha spectrometry analysis was used for activity determinations of Pu, Am and Cm isotopes in evaporator concentrate samples from nuclear power plants. Using a sequential procedure the first step was Pu isolation by an anion exchange column followed by an Am and Cm separation of U and Fe by a co-precipitation with oxalic acid. The precipitate was used for americium and curium separation of strontium by using a TRU resin extraction chromatography column. Due to their chemical similarities and energy difference it was seen that the simultaneous determination of 241Am, 242Cm and 243,244Cm isotopes is possible using the 243Am as tracer, once they have peaks in different region of interest (ROI) in the alpha spectrum. In this work it was used tracers, 238Pu, 243Am, 244Cm and 232U, for determination and quantification of theirs isotopes, respectively. The standard deviations for replicate analysis were calculated and for 241Am it was (1,040 ± 160 mBqKg-1), relative standard deviation 15.38%, and for 239+240Pu it was (551 +- 44 mBqKg-1), relative standard deviation 7.98%. In addition, for the 242Cm isotope the standard deviation for determinations was(75 ± 23 mBqKg-1), with the relative standard deviation 30.67% higher than for 241Am and 239+240Pu. The radiometric yields ranged from 90% to 105% and the lower limit of detection was estimated as being 2.05 mBqKg-1. (author)

  6. 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.

  7. 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.

  8. 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

  9. Current levels of Pu isotopes and {sup 137}Cs at the former Soviet Union`s Semipalantisk nuclear test site

    Yamamoto, M. [Kanazawa Univ., Ishikawa (Japan). Low Level Radioactivity Laboratory; Tsumura, A. [National Inst. of Agro-Environmental Sciences, Ibaraki (Japan); Tsukatani, T. [Kyoto Univ. (Japan). Kyoto Institute of Economic Research

    1998-10-01

    This paper is a report on our survey of residual radioactivity in the soil of the Semipalatinsk nuclear test site in the former USSR. The soil was sampled at approximately 30 sites along the roads connecting Kurchatov City, ground zero for the first USSR nuclear test, Balapan, Degelen Mountain and Salzhal settlement. The radioactivity levels of {sup 137}Cs, {sup 238}Pu and {sup 239,240}Pu as well as the {sup 240}Pu/{sup 239}Pu atomic ratios in the soil were determined. Although {sup 137}Cs was within typical environmental levels except for an area near ground zero, {sup 239,240}Pu was at elevated levels contaminated with weapons-grade plutonium in all areas we visited. (orig.)

  10. 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)

  11. 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)

  12. 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

  13. Spatial distribution of 241Am, 137Cs, 238Pu, 239,240Pu and 241Pu over 17 year periods in the Ravenglass saltmarsh, Cumbria, UK

    Ninety five surface scrape samples were collected at the Ravenglass saltmarsh and analysed for radionuclides by alpha spectrometry (238Pu and 239,240Pu), gamma spectrometry (241Am and 137Cs) and liquid scintillation counting (241Pu). Both 241Am and 137Cs activities are compared with those reported by Horrill [1983. Concentrations and spatial distribution of radioactivity in an ungrazed saltmarsh. In: Coughtrey, P.J. (Ed.), Ecological Aspects of Radionuclide Release. British Ecological Society Special Publication No. 3. Blackwell, Oxford, pp. 119-215.] Significant decreases in activities for both radionuclides were observed which is caused by the declining levels of discharges from the Sellafield nuclear reprocessing plant since the 1980s. It has been concluded that the spatial distribution of these radionuclides are controlled by the tidal currents and the clay contents in the sediments. There is evidence of surface erosion of the saltmarsh and redistribution of radionuclides in the saltmarsh using isotopic ratios of measured Pu.

  14. 238Pu and 239+240Pu activities in lower Rhone valley in cultivated soils

    Measured 238Pu and 239+240Pu activities in French soils can be explained by the fallout from atmospheric nuclear tests and the disintegration of a US nuclear reactor satellite in 1964. However, some soil samples from the lower Rhone valley show higher mass activities, due to the Marcoule nuclear fuel reprocessing plant discharges. Soil samples from the Camargue, flooded in 1993 and 1994, where Rhone River sediments have been deposited, contain Pu from liquid effluents released by the nuclear plant. Seven samples taken near the nuclear facility show a direct influence by its atmospheric releases. Samples from soils irrigated with Rhone River water for 30 years do not show any activity significantly higher than regional means. (authors)

  15. Induced Fission of 240Pu within a Real-Time Microscopic Framework

    Bulgac, Aurel; Magierski, Piotr; Roche, Kenneth J.; Stetcu, Ionel

    2016-03-01

    We describe the fissioning dynamics of 240Pu from a configuration in the proximity of the outer fission barrier to full scission and the formation of the fragments within an implementation of density functional theory extended to superfluid systems and real-time dynamics. The fission fragments emerge with properties similar to those determined experimentally, while the fission dynamics appears to be quite complex, with many excited shape and pairing modes. The evolution is found to be much slower than previously expected, and the ultimate role of the collective inertia is found to be negligible in this fully nonadiabatic treatment of nuclear dynamics, where all collective degrees of freedom (CDOF) are included (unlike adiabatic treatments with a small number of CDOF).

  16. ZPR-6 assembly 7 high {sup 240}Pu core experiments : a fast reactor core with mixed (Pu,U)-oxide fuel and a centeral high{sup 240}Pu zone.

    Lell, R. M.; Morman, J. A.; Schaefer, R.W.; McKnight, R.D.; Nuclear Engineering Division

    2009-02-23

    ZPR-6 Assembly 7 (ZPR-6/7) encompasses a series of experiments performed at the ZPR-6 facility at Argonne National Laboratory in 1970 and 1971 as part of the Demonstration Reactor Benchmark Program (Reference 1). Assembly 7 simulated a large sodium-cooled LMFBR with mixed oxide fuel, depleted uranium radial and axial blankets, and a core H/D near unity. ZPR-6/7 was designed to test fast reactor physics data and methods, so configurations in the Assembly 7 program were as simple as possible in terms of geometry and composition. ZPR-6/7 had a very uniform core assembled from small plates of depleted uranium, sodium, iron oxide, U{sub 3}O{sub 8} and Pu-U-Mo alloy loaded into stainless steel drawers. The steel drawers were placed in square stainless steel tubes in the two halves of a split table machine. ZPR-6/7 had a simple, symmetric core unit cell whose neutronic characteristics were dominated by plutonium and {sup 238}U. The core was surrounded by thick radial and axial regions of depleted uranium to simulate radial and axial blankets and to isolate the core from the surrounding room. The ZPR-6/7 program encompassed 139 separate core loadings which include the initial approach to critical and all subsequent core loading changes required to perform specific experiments and measurements. In this context a loading refers to a particular configuration of fueled drawers, radial blanket drawers and experimental equipment (if present) in the matrix of steel tubes. Two principal core configurations were established. The uniform core (Loadings 1-84) had a relatively uniform core composition. The high {sup 240}Pu core (Loadings 85-139) was a variant on the uniform core. The plutonium in the Pu-U-Mo fuel plates in the uniform core contains 11% {sup 240}Pu. In the high {sup 240}Pu core, all Pu-U-Mo plates in the inner core region (central 61 matrix locations per half of the split table machine) were replaced by Pu-U-Mo plates containing 27% {sup 240}Pu in the plutonium

  17. ZPR-6 assembly 7 high {sup 240} PU core : a cylindrical assemby with mixed (PU, U)-oxide fuel and a central high {sup 240} PU zone.

    Lell, R. M.; Schaefer, R. W.; McKnight, R. D.; Tsiboulia, A.; Rozhikhin, Y.; Nuclear Engineering Division; Inst. of Physics and Power Engineering

    2007-10-01

    Over a period of 30 years more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited to form the basis for criticality safety benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more complex nature, a small number of assemblies from the other two classes would make useful criticality safety benchmarks because they have features related to criticality safety issues, such as reflection by soil-like material. The term 'benchmark' in a ZPR program connotes a particularly simple loading aimed at gaining basic reactor physics insight, as opposed to studying a reactor design. In fact, the ZPR-6/7 Benchmark Assembly (Reference 1) had a very simple core unit cell assembled from plates of depleted uranium, sodium, iron oxide, U3O8, and plutonium. The ZPR-6/7 core cell-average composition is typical of the interior region of liquid-metal fast breeder reactors (LMFBRs) of the era. It was one part of the Demonstration Reactor Benchmark Program,a which provided integral experiments characterizing the important features of

  18. 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

  19. Optimized Chemical Separation and Measurement by TE TIMS Using Carburized Filaments for Uranium Isotope Ratio Measurements Applied to Plutonium Chronometry.

    Sturm, Monika; Richter, Stephan; Aregbe, Yetunde; Wellum, Roger; Prohaska, Thomas

    2016-06-21

    An optimized method is described for U/Pu separation and subsequent measurement of the amount contents of uranium isotopes by total evaporation (TE) TIMS with a double filament setup combined with filament carburization for age determination of plutonium samples. The use of carburized filaments improved the signal behavior for total evaporation TIMS measurements of uranium. Elevated uranium ion formation by passive heating during rhenium signal optimization at the start of the total evaporation measurement procedure was found to be a result from byproducts of the separation procedure deposited on the filament. This was avoided using carburized filaments. Hence, loss of sample before the actual TE data acquisition was prevented, and automated measurement sequences could be accomplished. Furthermore, separation of residual plutonium in the separated uranium fraction was achieved directly on the filament by use of the carburized filaments. Although the analytical approach was originally tailored to achieve reliable results only for the (238)Pu/(234)U, (239)Pu/(235)U, and (240)Pu/(236)U chronometers, the optimization of the procedure additionally allowed the use of the (242)Pu/(238)U isotope amount ratio as a highly sensitive indicator for residual uranium present in the sample, which is not of radiogenic origin. The sample preparation method described in this article has been successfully applied for the age determination of CRM NBS 947 and other sulfate and oxide plutonium samples. PMID:27240571

  20. The inflow of 238Pu and 239+240Pu from the Vistula River catchment area to the Baltic Sea

    The aim of the work was to estimate plutonium inflow from the Vistula River's catchments area to the Baltic Sea. There were differences in plutonium activities depending on season and sampling site. The highest activities of 238Pu and 239+240Pu were transported from the Vistula River watershed to the Baltic Sea in spring and the lowest in summer. Annually, the southern Baltic Sea is enriched via the Vistula River with 10.3 MBq of 238Pu and 89.0 MBq of 239+240Pu. The enhanced concentration of plutonium in water from the Vistula River is the result of its runoff from the Vistula drainage area, mostly from snowmelt, enhanced rainfalls and leached materials from river bed. - Highlights: → We estimated plutonium inflow from the Vistula River catchment area to the Baltic Sea. → We found differences in Pu activities depending on season and sampling site. → The highest amount of 239 + 240Pu was transported in spring and the lowest in summer. → Annually, the southern Baltic Sea is enriched with 89.0 MBq of 239 + 240Pu. → Enhanced Pu amount in water came from snowmelt, rainfalls and leached materials.

  1. 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)

  2. 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)

  3. 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.

  4. 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

  5. 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.

  6. Suitability of 239+240Pu and 137Cs as tracers for soil erosion assessment in mountain grasslands.

    Alewell, Christine; Meusburger, Katrin; Juretzko, Gregor; Mabit, Lionel; Ketterer, Michael E

    2014-05-01

    Anthropogenic radionuclides have been distributed globally due to nuclear weapons testing, nuclear accidents, nuclear weapons fabrication, and nuclear fuel reprocessing. While the negative consequences of this radioactive contamination are self-evident, the ubiquitous fallout radionuclides (FRNs) distribution form the basis for the use as tracers in ecological studies, namely for soil erosion assessment. Soil erosion is a major threat to mountain ecosystems worldwide. We compare the suitability of the anthropogenic FRNs, 137Cs and 239+240Pu as soil erosion tracers in two alpine valleys of Switzerland (Urseren Valley, Canton Uri, Central Swiss Alps and Val Piora, Ticino, Southern Alps). We sampled reference and potentially erosive sites in transects along both valleys. 137Cs measurements of soil samples were performed with a Li-drifted Germanium detector and 239+240Pu with ICP-MS. Our data indicates a heterogeneous deposition of the 137Cs, since most of the fallout origins from the Chernobyl April/May 1986 accident, when large parts of the European Alps were still snow-covered. In contrast, 239+240Pu fallout originated mainly from 1950s to 1960s atmospheric nuclear weapons tests, resulting in a more homogenous distribution and thus seems to be a more suitable tracer in mountainous grasslands. Soil erosion assessment using 239+240Pu as a tracer pointed to a huge dynamic and high heterogeneity of erosive processes (between sedimentation of 1.9 and 7 t ha(-1) yr(-1) and erosion of 0.2-16.4 t ha(-1) yr(-1) in the Urseren Valley and sedimentation of 0.4-20.3 t ha(-1) yr(-1) and erosion of 0.1-16.4 t ha(-1) yr(-1) at Val Piora). Our study represents a novel and successful application of 239+240Pu as a tracer of soil erosion in a mountain environment. PMID:24374184

  7. 40K, 137Cs, 90Sr, 238,239+240Pu and 241Am in mammals' skulls from owls' pellets and owl skeletons in Poland

    Skulls of small mammals belonging to two species of rodents and three species of insectivores collected in Eastern Poland were the subject of the present investigation. The skulls were separated from owl pellets. Activities of 40K, 137Cs, 90Sr, 238,239+240Pu and 241Am were determined by means of gamma spectrometry as well as liquid scintillation spectrometry or alpha spectrometry along with relevant radiochemical procedures. A detailed description of the procedures is provided. The research was supplied with the analysis of three skeletons of owls. No measurable difference between the skulls of rodents and insectivorous animals with regard to activity of any of the examined radionuclides was found. No accumulation effect in the owl skeletons was detected. Though measured activities of 137Cs and 40K for the skulls were of the same magnitude as those found previously for large wild herbivorous animals from typical locations in Poland, those for 90Sr were even lower than previously determined. A big difference was found for activities of plutonium and americium isotopes. Their mean activities were higher by an order of magnitude when compared to the examined previously values. The maximum 239+240Pu activity was equal to 97.5±7.7 mBq/kg, with 65% of it originating from global fallout. Relatively high content of transuranic elements found for rodents and insectivorous mammals seems to be unrelated to their feeding habits and should rather be attributed to the living conditions. It is suggested that small mammals, together with tiny soil particles present in mid-soil living tunnels, can inhale the transuranic elements

  8. Application of isotopic fingerprinting in nuclear forensic investigations: A case study

    -amounts of the sample were carried out to investigate relative differences under experimental conditions mimicking leaching through exposure to rainwater or washing-machine conditions. Such 'treatments' may not have been performed intentionally on the stolen items; thus great care was necessary in the interpretation of these results. In contrast to that, isotope ratios (e.g. 235U/238U, 240Pu/239Pu) do not change through such chemical treatments. Consistent results were found for most of the samples, indicating that the observed contaminations were related to the two stolen items. However, one sample showed a significantly different 238Pu/239Pu isotope abundance ratio. (author)

  9. 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.)

  10. 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

  11. 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

  12. 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)

  13. 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.

  14. 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

  15. 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)

  16. 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

  17. 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

  18. Evaluation of the fission and capture cross sections of 240Pu and 241Pu for ENDF/B-V

    Since there were appreciable new data which were not available for ENDF/B-IV, new evaluations for 240Pu and 241Pu were carried out for ENDF/B-V. The evaluation of the fission and capture cross sections is reviewed and problem areas are discussed. The neutron energy range of concern was from 10-5 eV to 20 MeV. Significant changes were made over the entire neutron energy region because of the new experimental data available. The problems in the evaluations due to discrepancies in the nuclear data are emphasized, particularly the 1-eV resonance in 240Pu and the 0.3-eV resonance in 241Pu. The evaluation of the fission and capture cross sections for ENDF/B-V represents an improvement over the previous evaluation; however, there continues to be a need for accurate experimental data. 7 figures

  19. Numerical simulation of 137Cs and 239,240Pu concentrations by an ocean general circulation model

    We simulated the spatial distributions and the temporal variations of 137Cs and 239,240Pu concentrations in the ocean by using the ocean general circulation model which was developed by National Center of Atmospheric Research. These nuclides are introduced into seawaters from global fallout due to atmospheric nuclear weapons tests. The distribution of radioactive deposition on the world ocean is estimated from global precipitation data and observed values of annual deposition of radionuclides at the Meteorological Research Institute in Japan and several observed points in New Zealand. Radionuclides from global fallout have been transported by advection, diffusion and scavenging, and this concentration reduces by radioactive decay in the ocean. We verified the results of the model calculations by comparing simulated values of 137Cs and 239,240Pu in seawater with the observed values included in the Historical Artificial Radionuclides in the HAM database, which has been constructed by the Meteorological Research Institute. The vertical distributions of the calculated 137Cs concentrations were in good agreement and are in good agreement with the observed profiles in the 1960s up to 250 m, in the 1970s up to 500 m, in the 1980s up to 750 m and in the 1990s up to 750 m. However, the calculated 137Cs concentrations were underestimated compared with the observed 137Cs at the deeper layer. This may suggest other transport processes of 137Cs to deep waters. The horizontal distributions of 137Cs concentrations in surface water could be simulated. A numerical tracer release experiment was performed to explain the horizontal distribution pattern. A maximum 239,240Pu concentration layer occurs at an intermediate depth for both observed and calculated values, which is formed by particle scavenging. The horizontal distributions of the calculated 239,240Pu concentrations in surface water could be simulated by considering the scavenging effect

  20. 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)

  1. 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.

  2. 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.

  3. 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...

  4. 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.

  5. 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)

  6. 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

  7. 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)

  8. 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

  9. 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)

  10. 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)

  11. Impact of soil humus material on the behaviour of 239+240Pu in the terrestrial environment in tropical conditions

    When long-lived radionuclides deposited by fallout come in contact with soil, most are bound so tightly to soil particles that they are nearly immobile. Many fallout radionuclides are held either by adsorption on reactive sites on clay mineral soil particles, or by ion exchange and precipitation as hydroxide or sulfide. Thus, the radionuclides are distributed in organic and inorganic constituents of soil. Natural organic matter of soil consists of the dead plant and animal material and partially decomposed and resynthesized organic compounds present in soils and sediments. The purpose of this study was to determine the association of 239,240Pu with natural organic substances in soils

  12. Model testing of radioactive contamination by 90Sr, 137Cs and 239,240Pu of water and bottom sediments in the Techa River (Southern Urals, Russia)

    This paper presents results of testing models for the radioactive contamination of river water and bottom sediments by 90Sr, 137Cs and 239,240Pu. The scenario for the model testing was based on data from the Techa River (Southern Urals, Russia), which was contaminated as a result of discharges of liquid radioactive waste into the river. The endpoints of the scenario were model predictions of the activity concentrations of 90Sr, 137Cs and 239,240Pu in water and bottom sediments along the Techa River in 1996. Calculations for the Techa scenario were performed by six participant teams from France (model CASTEAUR), Italy (model MARTE), Russia (models TRANSFER-2, CASSANDRA, GIDRO-W) and Ukraine (model RIVTOX), all using different models. As a whole, the radionuclide predictions for 90Sr in water for all considered models, 137Cs for MARTE and TRANSFER-2, and 239,240Pu for TRANSFER-2 and CASSANDRA can be considered sufficiently reliable, whereas the prediction for sediments should be considered cautiously. At the same time the CASTEAUR and RIVTOX models estimate the activity concentrations of 137Cs and 239,240Pu in water more reliably than in bottom sediments. The models MARTE (239,240Pu) and CASSANDRA (137Cs) evaluated the activity concentrations of radionuclides in sediments with about the same agreement with observations as for water. For 90Sr and 137Cs the agreement between empirical data and model predictions was good, but not for all the observations of 239,240Pu in the river water-bottom sediment system. The modelling of 239,240Pu distribution proved difficult because, in contrast to 137Cs and 90Sr, most of models have not been previously tested or validated for plutonium

  13. Precise isotope ratio measurements for uranium, thorium and plutonium by quadrupole-based inductively coupled plasma mass spectrometry

    Precise long-term measurements of uranium and thorium isotope ratios was carried out in 1 μg/L solutions using a quadrupole inductively coupled plasma mass spectrometer (ICP-QMS). The isotopic ratios of uranium (235U/ 238U = 1, 0.02 and 0.00725) were determined using a cross-flow nebulizer (CFN, at solution uptake rate of 1 mL/min) and a low-flow microconcentric nebulizer (MCN, at solution uptake rate of 0.2 mL/min) over 20 h. For 1 μg/L uranium solution (235U/238U = 1) relative external standard deviations (RESDs) of 0.05% and 0.044% using CFN and MCN, respectively, can be achieved. Additional short term isotope ratio measurements using a direct injection high-efficiency nebulizer (DIHEN) of 1 μg/L uranium solution (235U/238U = 1) at a solution uptake rate of 0.1 mL/min yielded an RSD of 0.06-0.08%. The sensitivity of solution introduction by DIHEN for uranium, thorium and plutonium (145 MHz/ppm, 150 MHz/ppm and 177 MHz/ppm, respectively) increased significantly compared to CFN and MCN and the solution uptake rate can be reduced to 1 μL/ min in DIHEN-ICP-MS. Isotope ratio measurements at an ultralow concentration level (e.g. determination of 240Pu/ 239Pu isotope ratio in a 10 ng/L Pu waste solution) were carried out for the characterization of radioactive waste and environmental samples. (orig.)

  14. Distribution of the Pu and Am isotopes in the BOMARC missile site soil

    reserved for subsequent separation of the Am and U isotopes. Pu was eluted with 0.36 M HCl / 0.01 M HF. The Am and U residue was dissolved in 2 M HNO3. Samples were loaded onto TRU Spec columns, after the TRU columns were conditioned with 2 M HNO3. The columns were washed with 2 M HNO3 and 9 M HCl. The Am fraction was eluted with 4 M HCl U was eluted with 0.1 M ammonium oxalate solution. The Am fraction was purified with anion exchange resin that had been previously conditioned with 1 M HNO3 - 93% CH3OH. The purified Pu, Am and U isotopes were electroplated on stainless steel platelets and measured by an alpha spectrometer. For measuring the 241Pu, Pu isotopes electrodeposited onto the stainless steel planchet were dissolved in 8 M HNO3 and purified with an anion exchange column. The purified Pu isotopes were subjected to the 241Pu measurement by a low background liquid scintillation counter. Also, the atomic ratios of 240Pu/239Pu were measured by a high resolution inductively coupled plasma mass spectrometry. The activities of 239,240Pu and 241Am were apparently increased with a decreasing particle size of soil due to an increasing surface area, and the fitted values for these isotopes were correlated well with actual measured values (239,240Pu; 0.994, 241Am; 0.992). This result suggests that most of the Pu and Am isotopes are fixed to the soil as a surface coating. The fitted values of 238U did not correlated well with the measured activities of 238U (R2 ; 0.588), which implies that a significant fraction of the U may be partitioned into the soil matrix rather than sorbed onto the particle surfaces. The activity ratios of 238Pu/239,240Pu in different particle sizes of the BOMARC soil were found to be in the range of 0.018 to 0.033 with a mean value of 0.024, which is lower than the reported value (0.04) influenced by the SNAP-9A satellite accident in 1964. The activity ratios of 241Pu/239,240Pu and 241Am/239,240Pu were measured in the range of 2.87 to 3.52 and 0.15 to 0

  15. Distribution of Pu and Am isotopes in BOMARC missile site soil

    reserved for subsequent separation of the Am and U isotopes. Pu was eluted with 0.36 M HCl/0.01 M HF. The Am and U residue was dissolved in 2 M HNO3. Samples were loaded onto TRU Spec columns, after the TRU columns were conditioned with 2 M HNO3. The columns were washed with 2 M HNO3 and 9 M HCl. The Am fraction was eluted with 4 M HCl. U was eluted with 0.1 M ammonium oxalate solution. The Am fraction was purified with anion exchange resin that had been previously conditioned with 1 M HNO3 - 93% CH3OH. The purified Pu, Am and U isotopes were electroplated on stainless steel platelets and measured by an alpha spectrometer. For measuring the 241Pu, Pu isotopes electrodeposited onto the stainless steel planchet were dissolved in 8 M HNO3 and purified with an anion exchange column. The purified Pu isotopes were subjected to the 241Pu measurement by a low background liquid scintillation counter. Also, the atomic ratios of 240Pu/239Pu were measured by a high resolution inductively coupled plasma mass spectrometry. The activities of 239,240Pu and 241Am were apparently increased with a decreasing particle size of soil due to an increasing surface area, and the fitted values for these isotopes were correlated well with actual measured values (239,240Pu; 0.994, 241Am; 0.992). This result suggests that most of the Pu and Am isotopes are fixed to the soil as a surface coating. The fitted values of 238U did not correlated well with the measured activities of 238U (R2 ; 0.588), which implies that a significant fraction of the U may be partitioned into the soil matrix rather than sorbed onto the particle surfaces. The activity ratios of 238Pu/239,240Pu in different particle sizes of the BOMARC soil were found to be in the range of 0.018 to 0.033 with a mean value of 0.024, which is lower than the reported value (0.04) influenced by the SNAP-9A satellite accident in 1964. The activity ratios of 241Pu/239,240Pu and 241Am/239,240Pu were measured in the range of 2.87 to 3.52 an d 0.15 to 0

  16. Migration of 137Cs, 90Sr, and 239+240Pu in Mediterranean forests: influence of bioavailability and association with organic acids in soil

    The understanding of downward migration of anthropogenic radionuclides in soil is a key factor in the assessment of their environmental behavior. There are several factors that can affect this process, such as the radionuclide source, their chemical form, soil and environmental characteristics, etc. Two Mediterranean pinewood ecosystems in Spain, which were affected mainly by global fallout, were selected to assess the migration of 137Cs, 90Sr, and 239+240Pu. Using auxiliary modeling (diffusion–convection equation and compartmental model), it followed from field observations that the migration velocities of 90Sr and 239+240Pu were similar and higher than that of 137Cs. The downward migration of radionuclides can be considered a consequence of their association with soil particles. A sequential speciation procedure also confirmed that 90Sr was the most bioavailable radionuclide followed by 239+240Pu and 137Cs. Although this can explain the different velocity of 90Sr and 137Cs, bioavailability could not explain by itself the similar velocities of 239+240Pu and 90Sr. The presence of organic acids in the soil can also influence the migration of radionuclides attached to them, which decreased in the order: 239+240Pu > 90Sr > 137Cs. Thus, the joint consideration of bioavailable and humic + fulvic acid fractions can explain the observed differences in the downward velocities. - Highlights: • Downward migration velocities of 137Cs, 90Sr and 239+240Pu in two Mediterranean forests were determined. • Downward migration velocities: 90Sr ≈ 239+240Pu > 137Cs. • Bioavailability by itself (90Sr > 239+240Pu > 137Cs) does not explain differences in migration velocities. • Humic + Fulvic acids: 239+240Pu > 90Sr > 137Cs. • Humic + Fulvic acids and bioavailable fraction can explain the downward migration velocities

  17. 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.)

  18. 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.

  19. 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

  20. 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.

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

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

  2. 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)

  3. 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

  4. 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

  5. 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)

  6. A modelling study on {sup 137}Cs and {sup 239,240}Pu behaviour in the Alboran Sea, western Mediterranean

    Perianez, R. [Departamento Fisica Aplicada I, E.U. Ingenieria Tecnica Agricola, Universidad de Sevilla, Ctra., Utrera km 1, 41013 Sevilla (Spain)], E-mail: rperianez@us.es

    2008-04-15

    A model for simulating the dispersion processes of {sup 137}Cs and {sup 239,240}Pu in the Alboran Sea is described. The model consists of two hydrodynamic models: a 2D depth-averaged model and a two-layer model which provide tidal and geostrophic currents, respectively; a sediment transport model which provides suspended particle concentrations and sedimentation rates over the domain; and the radionuclide dispersion model including interactions of dissolved radionuclides with suspended particles and bed sediments. These processes are formulated using kinetic transfer coefficients. The hydrodynamic and sediment models are run and validated in advance, and their results are then used to simulate the dispersion of {sup 137}Cs and {sup 239,240}Pu, which are introduced from atmospheric fallout. Radionuclide concentrations in the water column and distributions in bed sediments have been compared with measurements in the sea. Both set of data are, in general, in agreement. The model has also been applied to calculate radionuclide fluxes through the Strait of Gibraltar. These computed fluxes have been compared with previous estimations as well.

  7. Laboratory studies of the diagenesis and mobility of sup(239,240)Pu and 137Cs in nearshore sediments

    Controlled laboratory experiments have been used to study the diagenetic chemistry of sup(239,240)Pu, 137Cs and 55Fe. Experiments using Buzzards Bay sediments in small tanks show that sulfate reduction is accompanied by the production of large pore water concentration gradients of alkalinity, phosphate, ammonia and dissolved organic carbon and the formation of subsurface maxima in Fe and Mn. These pore water profiles demonstrate that bacterially-mediated processes of organic matter degradation and redox reactions can be simulated in the laboratory. A vertical profile of 55Fe in pore waters is reported for the first time: it follows the profile of stable Fe and as such has a large subsurface maximum between 2 to 4 cm depth. Comparison of 55Fe/Fe ratios in sediments and pore waters shows that there is preferential solubilization of 55Fe over stable Fe. The pore water activities of sup(239,240)Pu show no gradients within the large uncertainties of the counting statistics, but are two to four times higher than Buzzards Bay seawater. The activity of 137Cs in the pore water profile is constant within the large counting uncertainties and is twice that of Buzzards Bay seawater. Cs-137 does not appear to be involved in diagenetic chemistry but may increase in pore waters as a result of ion exchange reactions. (author)

  8. 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.

  9. 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

  10. 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.

  11. 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.)

  12. 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.)

  13. 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.

  14. 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

  15. 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)

  16. 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

  17. Coupled study of radionuclides and stable lead isotopes in Western Mediterranean; Etude couplee des radionucleides et des isotopes stables du plomb en Mediterranee occidentale

    Miralles, J

    2004-05-15

    The aim of this work is to identified an environmental deposit able to have stored the atmospheric signal over large time-scale leaning our investigations on lead stable isotopes ({sup 206}Pb, {sup 207}Pb, {sup 208}Pb) and radionuclide ({sup 210}Pb, {sup 137}Cs, {sup 239}Pu, {sup 240}Pu) analysis. Owing to prior studies on anthropogenic lead sources, emission intensity and sedimentary accumulation, we choose to investigate the marine sediments of the Western Mediterranean. In the Gulf of Lions, the sedimentary accumulation is 110 {+-} 7 {mu}g.cm{sup -2} high in good agreement with the atmospheric inventory estimate we made from salt marshes of Camargue (99 {mu}g.cm{sup -2}). The reconstructed lead accumulation through a modelling step coupling {sup 210}Pb and stable isotopes corroborates the regional anthropogenic emissions (Ferrand, 1996). Briefly, in this context of the marine sediments are a relevant proxy to study past lead atmospheric concentration over the last hundred years. In the Alboran Sea, the study area is less constrained and more complex in terms of climatic, meteorological and hydrological conditions. The sedimentary inventory is of 153 {+-} 47 {mu}g.cm{sup -2}, 1,5 higher than in the margin sediments of the Gulf of Lions. The analysis of aerosols, sediments and settling particles evidences a continuity between the atmospheric signal and the sedimentary record. In spite of this encouraging results, the knowledge of the Alboran system is still too restricted in order to unambiguously conclude on accuracy of deep marine sediments of this area to study past atmospheric fallouts. (author)

  18. 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)

  19. 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.)

  20. 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

  1. Coupled study of radionuclides and stable lead isotopes in Western Mediterranean

    The aim of this work is to identified an environmental deposit able to have stored the atmospheric signal over large time-scale leaning our investigations on lead stable isotopes (206Pb, 207Pb, 208Pb) and radionuclide (210Pb, 137Cs, 239Pu, 240Pu) analysis. Owing to prior studies on anthropogenic lead sources, emission intensity and sedimentary accumulation, we choose to investigate the marine sediments of the Western Mediterranean. In the Gulf of Lions, the sedimentary accumulation is 110 ± 7 μg.cm-2 high in good agreement with the atmospheric inventory estimate we made from salt marshes of Camargue (99 μg.cm-2). The reconstructed lead accumulation through a modelling step coupling 210Pb and stable isotopes corroborates the regional anthropogenic emissions (Ferrand, 1996). Briefly, in this context of the marine sediments are a relevant proxy to study past lead atmospheric concentration over the last hundred years. In the Alboran Sea, the study area is less constrained and more complex in terms of climatic, meteorological and hydrological conditions. The sedimentary inventory is of 153 ± 47 μg.cm-2, 1,5 higher than in the margin sediments of the Gulf of Lions. The analysis of aerosols, sediments and settling particles evidences a continuity between the atmospheric signal and the sedimentary record. In spite of this encouraging results, the knowledge of the Alboran system is still too restricted in order to unambiguously conclude on accuracy of deep marine sediments of this area to study past atmospheric fallouts. (author)

  2. Polonium 210Po, uranium (234U, 238U and plutonium (238Pu, 239+240Pu bioaccumulation in marine birds

    Strumińska-Parulska D. I.

    2013-04-01

    Full Text Available The aim of this work was the determination of 210Po, 234U, 238U, 238Pu and 239+240Pu concentration in marine birds which permanently or temporally live in the southern Baltic Sea coast. We chose 11 species of seabirds: three species permanently residing at southern Baltic Sea, four species of wintering birds and three species of migrating birds. The results show that analyzed radionuclides are non-uniformly distributed in the marine birds. The highest activities of 210Po were observed in feathers, muscles and liver. The highest uranium content was found in liver, rest of viscera and feathers, while plutonium in the digestion organs and feathers. Omnivore seabirds accumulated more polonium, plutonium than species that feed on fish, while herbivore seabirds accumulated more uranium than carnivore.

  3. sup(239/240)Pu, 137Cs, 90Sr, and 40K in different types of honey

    Information on the concentration of radionuclides in honey is of interest because this foodstuff consumed worldwide could be a source of radionuclides to man. Besides that, honey is used as a bioindicator for several radionuclides because the bees forage for nectar, pollen or honeydew over a large area of landscape. In this connection, it is of special interest to know when, and, if so, to what extent the concentrations of radionuclides in the honey depend on the type of honey sampled by the bees. For this reason, we determined sup(239/240)Pu, 137Cs, 90Sr and 40K in three important types of honey produced in the F.R.G., namely in honey from flowers, from honeydew and from heather. The data obtained in this way was used also to investigate whether significant correlations exist between these radionuclides in the various honey samples. (author)

  4. References to Studies of 137Cs, 90Sr and 239+240Pu in the Pacific Ocean a Bibliography

    Noshkin, V.E.

    2001-02-01

    This report contains a listing of publications known to this author on reported concentrations, reviews and discussions of {sup 137}Cs, {sup 90}Sr and {sup 239+240}Pu in seawater, sediment and the biota from parts of the North and South Pacific Ocean. Each reference has been assigned an accession number consisting of the first three letters of the first author's last name followed by the first letter of the first name, the year of the publication and an assigned number. Studies in both the coastal areas and the open ocean are included as well as those providing data within lagoons of coral atolls. Some references to the radionuclides in the Indian Ocean are also provided.

  5. Studies on the Precise Measurement of Isotope of Trace Plutonium in Uranium by MC-ICP-MS%多接收电感耦合等离子体质谱法精确测量铀中痕量钚同位素方法研究

    李力力; 李金英; 赵永刚; 常志远; 张继龙; 王同兴

    2009-01-01

    The infinitesimal plutonium impurity was contained in the uranium product obtained by reprocessing. The precise measurement of the isotope ratio of plutonium was beneficial to the identification of the corresponding source of uranium product. Basing on the separation of trace plutonium from uranium matrix, the operating parameters of MC-ICP-MS were studied and optimized for determining the isotope ratio of trace plutonium, such as the adjustment of resolution, selection of mode of ion extraction, elimination of background and interference, etc. The correction method of the mass discrimination was explored for MCICP-MS measuring isotope ratio. The isotope ratio of ~(239)pu/~(240)Pu in two selected uranium products obtained by reprocessing, which was measured and corrected by measuring plutonium reference material. The ratio of uranium and plutonium is more than 10~(10), and the sum of relative uncertainty for plutonium measurement is better than 5%. The measuring method of isotope ratiois establishes for ng · L~(-1) level of plutonium.%经过核燃料后处理得到的铀产品中含有极微量钚杂质,对其同位素组成进行分析有利于对应铀材料的溯源.本工作在铀钚化学分离的基础上,对影响MC-ICP-MS法精确测量痕量钚同位素丰度比值的仪器条件进行了优化,研究了仪器分辨率、离子提取模式的选择、"背景和干扰"等参数的影响,探索研究了MC-ICP-MS上质量偏倚的校正方法.对选择的两个后处理铀产品中痕量钚同位素比进行了测量,当铀钚比例达10~(10)时,测得的~(239)Pu/~(240)Pu相对不确定度优于5%.并且建立了在MC-ICP-MS上测量ng·L~(-1)量级钚同位素丰度比值的方法.

  6. A comparative study of 239,240Pu in soil near the former Rocky Flats Nuclear Weapons Facility, Golden, CO

    The Rocky Flats Nuclear Weapons Plant near Golden, CO released plutonium into the environment during almost 40 years of operation. Continuing concern over possible health impacts of these releases has been heightened by lack of public disclosure of the US Department of Energy (DOE) activities. A dose reconstruction study for the Rocky Flats facilities, begun in 1990, provided a unique opportunity for concerned citizens to design and implement field studies without participation of the DOE, its contractors, or other government agencies. The Citizens Environmental Sampling Committee was formed in late 1992 and conducted a field sampling program in 1994. Over 60 soil samples, including both surface and core samples, were collected from 28 locations where past human activities would have minimal influence on contaminant distributions in soil. Cesium-137 activity was used as a means to assess whether samples were collected in undisturbed locations. The distribution of plutonium (as 239,240Pu) in soil was consistent with past sampling conducted by DOE, the Colorado Department of Public Health and Environment, and others. Elevated levels of 239,240Pu were found immediately east of the Rocky Flats Plant, with concentrations falling rapidly with distance from the plant to levels consistent with background from fallout. Samples collected in areas south, west, and north of the plant were generally consistent with background from fallout. No biases in past sampling due to choice of sampling locations or sampling methodology were evident. The study shows that local citizens, when provided sufficient resources, can design and implement technical studies that directly address community concerns where trust in the regulated community and/or regulators is low

  7. 240Pu(n,f), 242Pu(n,f), 237Np(n,f), neutron fission cross sections, Esub(n) = 2.5 MeV

    Measurements of the absolute neutron fission cross section of 240Pu, 242Pu and 237Np have been made at 2.5 MeV using a hybrid detector. The fission events were detected in an ionization chamber (2π) and the neutron flux was determined by a proton recoil telescope and a directional long counter. Our values are compared to previous data

  8. Deposition of [sup 210]Pb, [sup 137]Cs, [sup 239+240]Pu, [sup 238]Pu, and [sup 241]Am in the Antarctic peninsula area

    Roos, P.; Holm, E.; Persson, R.B.R. (Lund Univ. (Sweden). Dept. of Radiation Physics); Aarkrog, A.; Nielsen, S.P. (Risoe National Lab., Roskilde (Denmark))

    1994-01-01

    [sup 210]Pb, [sup 137]Cs, [sup 239+240]Pu, [sup 238]Pu, and [sup 241]Am were analysed in lichen, moss, grass and soil samples, as well as in lake sediments, from the South Shetland Islands, the Antarctic, in order to evaluate the flux and deposition of these elements. Average inventories of the analysed radionuclides in 1988 are given. The ratios [sup 238]Pu/[sup 239+240]Pu and [sup 241]Am/[sup 239+240]Pu of 0.21 [+-] 0.04 and 0.35 [+-] 0.08 respectively agree well with expected values in this area. A significant difference in [sup 137]Cs/[sup 239+240]Pu ratios between lichens and moss/grass/soil is observed which may be an effect of submerging and melt water altering radionuclide ratios. From one of three lakes studied it is possible to perform [sup 210]Pb dating with reasonable accuracy showing an average annual sediment accumulation in this lake of about 45 g m[sup -2]. (author).

  9. 239+240Pu and 137Cs concentrations in fish, cephalopods, crustaceans, shellfish, and algae collected around the Japanese coast in the early 1990s

    Marine organisms, i.e. fish, cephalopods, crustaceans, shellfish, and algae, were collected in the early 1990s along the Sea of Japan coast and the Japanese Pacific coast and analyzed for their 239+240Pu and 137Cs concentrations. The 239+240Pu concentrations in muscle of fish were below 0.4 mBq/kg wet wt. and the lowest among the analyzed marine organisms. Most 137Cs concentrations in muscle of fish ranged from 100 to 300 mBq/kg wet wt. Higher concentrations of 239+240Pu, ranging from 1.6 to 5.7 mBq/kg wet wt., were observed in viscera of cephalopods than in their muscle. The 239+240Pu concentrations in whole soft tissues of bivalves varied approximately one order of magnitude from 0.8 to 6.1 mBq/kg wet wt., while 137Cs concentrations had little variation, being approximately 60 mBq/kg wet wt. The 239+240Pu concentrations in algae had a wide variation, ranging from 1.7 to 42.3 mBq/kg wet wt., and were higher than those of the other marine organisms. No statistically significant difference in mean concentrations of 239+240Pu was detected among the whole soft tissues of bivalves, viscera of cephalopods and crustaceans, and whole bodies of cephalopods and crustaceans within the 95% confidence limit. The mean concentrations of 137Cs became higher in the order, cephalopods and crustaceans and bivalves, algae, viscera of fish, muscles of fish. The mean concentrations of 239+240Pu were comparable for algae collected along the Japan Sea coast and the Pacific coast. Furthermore, the difference in mean concentrations of 137Cs in algae between the Japan Sea coast and the Pacific coast was not statistically significant within the 95% confidence limit. These results can be considered to indicate no definite influence from radioactive dumping into the Japan Sea by the former USSR and Russia with respect to radioactive pollution of marine organisms collected along the Japanese coast

  10. 137Cs, 239,240Pu and 241Am in boreal forest soil and their transfer into wild mushrooms and berries

    Profiles of podzolic soil from boreal forests were sampled from eight sites in Finland and the distribution of 137Cs in the soil layers was determined. In addition, 239,240Pu and 241Am were determined from two soil profiles taken at one sampling site. Inventories of 137Cs in the soil profiles varied between 1.7 kBq/m2 and 42 kBq/m2, reflecting known variation in 137Cs fallout from the Chernobyl accident. The highest proportions of the radionuclides were found in the organic layer at a depth of less than 5 cm, which on average contained 47% of 137Cs, 76% of 239,240Pu and 79% of 241Am. In the litter, clearly higher proportions of 137Cs were found compared to 239,240Pu and 241Am, probably indicating its more effective recycling from the organic layer back to the surface. Only very minor proportions of 137Cs were recorded below 20 cm. The concentration of 137Cs in the soil profiles could be approximated with a declining logarithmic trend. The activity concentrations of 137Cs were determined for six wild mushroom species and three wild berry species at two sites, as well as the aggregated transfer factors and the distribution of 137Cs between their various parts. In addition, 239,240Pu and 241Am were determined in one mushroom and three berry species at one site. Very high concentrations of 137Cs, up to 20 kBq/kg (d.w.), were found in mushrooms, and their transfer factors were between 0.1 m2/kg and 1.0 m2/kg. In berries, the transfer factors were an order of magnitude lower. 137Cs accumulated more in the caps of mushrooms and in the fruits of berries than in other parts. Transfer factors for 239,240Pu and 241Am were two to three orders of magnitude lower than those of 137Cs. - Highlights: ► 137Cs, 239,240Pu and 241Am mainly concentrated in organic layer in podzolic soil. ► Distribution of 137Cs in the upper 20 cm soil follows exponential declining trend. ► 137Cs concentrates into mushrooms but varies considerably between species. ► 137Cs concentrates in mushroom

  11. 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

  12. 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.

  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. 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)

  15. 福岛核事故向环境释放的 Pu研究进展%Plutonium Isotopes Released f rom Fukushima Daiichi Nuclear Power Plant Accident into Environment

    倪有意; 卜文庭; 郭秋菊; 胡丹; 许宏

    2015-01-01

    On March 11 , 2011 , a catastrophic tsunami induced by a magnitude 9.0 earthquake caused the terrible Fukushima Daiichi Nuclear Power Plant (FDNPP) acci‐dent ,leading to the release of a large amount of radionuclides into the environment .T he published studies on plutonium isotopes in the environment after the FDNPP accident were reviewed in this paper .The total atmospheric released amounts of Pu from the FDNPP accident were estimated to be 109 Bq ,that is only 1/10 000 of that released from the Chernobyl accident .The Pu isotopes were released from the damaged reactors ,not from the spent fuel pools in the FDNPP .The Pu isotopic ratios (240 Pu/239 Pu ,241 Pu/239 Pu) and activity ratios of A(238 Pu)/A(239+ 240 Pu) were significantly different from that of global fallout ,serving as powerful fingerprints for Pu source identification .To date , the plutonium isotopes from the accident in the terrestrial environment within the 30 km zone around the FDNPP site have been widely observed and there are no strong positive correlations between the Pu isotopes contamination levels and the distances from the FDNPP site .The influence of the FDNPP accident on Pu distributions in the marine environment is limited .No detectable Pu contamination from the accident is observed even in the near coastal (5 km off the FDNPP site) marine sediments .%福岛核事故向环境释放的放射性核素中包含了锕系元素Pu ,其中以极毒组的239 Pu、240 Pu和高毒组的241 Pu为主。本文总结并分析了针对福岛核事故向环境释放的 Pu的相关研究。据估计,福岛核事故向环境中排放的239+240 Pu总量约为109 Bq ,是切尔诺贝利核事故排放量的万分之一。此次事故排放的Pu同位素原子比(240 Pu/239 Pu和241 Pu/239 Pu)及活度比(A (238 Pu)/A (239+240 Pu))明显异于全球沉降值,可作为事故中Pu溯源的判定依据。事故所排放的Pu全部来源于核电站1~3号反应堆堆芯

  16. 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

  17. 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

  18. 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

  19. 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)

  20. 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

  1. 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

  2. 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.

  3. Distribution of 90Sr, 137Cs and 239,240Pu in Caspian Sea water and biota

    Povinec, Pavel P.; Froehlich, Klaus; Gastaud, Janine; Oregioni, Beniamino; Pagava, Samson V.; Pham, Mai K.; Rusetski, Vladimir

    2003-09-01

    Two sampling expeditions were carried out in the Caspian Sea in 1995 and 1996. The aim was to investigate oceanographic conditions, water dynamics of the Sea and to measure radionuclide concentrations using 90Sr, 137Cs and 239,240Pu as tracers in the water column. Of the three basins comprising the Caspian Sea, the two deep basins (the central and southern basins) appear to be rapidly ventilated on a time scale of about 30 years, as shown by the penetration of radionuclides to bottom waters. The main source of radionuclides in the Sea has been global fallout and subsequent river run-off from catchment areas. At the stations visited, there were no signs of radioactive waste dumping, although the 90Sr levels found were higher than expected from global fallout, which may be due to remobilization of 90Sr from soil and its transport by rivers to the Sea. Radionuclide concentrations in fish and caviar are within the expected ranges and are not of radiological importance for consumption of fish and caviar from the Caspian Sea.

  4. Determination of 90Sr, 137Cs and (239+240)Pu in waters with use of preliminary concentration

    A method for the simultaneous determination of artificial radionuclides (90Sr, 137Cs and (239+240)Pu) in water samples is described. The following preconcentration steps are used: co-precipitation of cesium on copper ferrocyanide; co-precipitation of plutonium on iron hydroxide; and precipitation of strontium in the carbonate form. The chemical yield is determined by using the tracers: 88Y, 85Sr, 134Cs and 236Pu or 242Pu. The method was applied to the determination of artificial radionuclides in water sources at nuclear test sites - the former Semipalatinsk nuclear test site and the 'Azgir' and 'Lira' test sites. The volume of water samples was 0.5 - 30.0 l, and the mineralization ranged from 0.1g/l to 100 g/l. The determination limits were: < 1 mBq/l for cesium-137; 0.02 mBq/l for plutonium-(239+240); and 1.5 mBq/l for strontium-90. The chemical yield was 60 - 90%

  5. Using uncertainty analyses to test for differences in fractional transfers of 238Pu and 239+240Pu to cattle grazing a contaminated arid environment

    This paper reports the results of Monte Carlo uncertainty and sensitivity analyses of the modeled fractional transfers of 238Pu and 239+240Pu from the gastrointestinal tract to the tissues of cattle that grazed a plutonium contaminated arid site near the Nevada Test Site. The analyses were conducted to assess the uncertainty in model parameters for the purpose of testing if the fractional transfer of 238Pu was greater than that of 239+240Pu to the tissues of the cattle. A sensitivity analysis of the fractional transfer model indicated that the Pu tissue concentration was the model parameter that had the highest correlation with computed fractional transfers. It was shown that accurate information on the variability of tissue concentrations is needed to obtain accurate estimates of the uncertainty of modeled fractional transfers. 34 refs., 3 figs., 5 tabs

  6. The concentration of 90Sr, 239,240Pu and 238Pu in the surface air of Prague in 1989 and 1990

    In 1989, positive values were found twice for 90Sr, namely in monitoring periods January-February (0.6 μBq.m-3) and September-October (0.8 μBq.m-3). In other monitoring periods, the concentrations of 90Sr in the surface air in Prague were below 0.3 μBq.m-3. Presence of 239,240Pu was not proved in Prague surface air in 1989. In the individual monitoring periods the concentrations of 239,240Pu were less than 0.13 μBq.m-3. In 1990, 90Sr concentrations in January-February and September-October were 2.1 and 1.2 μBq.m-3, respectively. In other monitoring periods, the concentrations of 90Sr were less than 0.3 μBq.m-3. The presence of 239,240Pu was not proved in Prague surface air in 1990 either. In the individual monitoring periods the concentrations were below 0.04 μBq.m-3. (Z.S.) 2 tabs., 8 refs

  7. Gamma-emitters 90Sr, 238,239+240Pu and 241Am in bones and liver of eagles from Poland

    The present study focused on analyzing samples of bones, livers and kidneys of European white-tailed eagles (Haliaetus albicilla) and lesserspotted eagle (Aquila pomarina). Bone samples were collected for both species, from 7 and 2 individuals, respectively, whereas liver and kidney samples for white-tailed eagle species only, 2 and 1 individuals, respectively. The samples were analyzed for the presence of gamma-emitters and then for 90Sr, 238Pu, 239+240Pu and 241Am. The applied radiochemical method is presented. Activity concentration in ashen bones (600 deg C) for 90Sr ranged from 4.6±1.2 to 31.0±2.5 Bq/kg, for 239+240Pu from 238Pu from 241Am from 239+240Pu activity concentration of 78±9 mBq/kg (for fresh weight) was recorded in a single kidney sample. The liver samples showed activities of magnitude at least one order lower. No clear correlations were found between the activities of different radionuclides. (author)

  8. Spatial distributions of {sup 137}Cs and {sup 239+240}Pu in surface seawater within the Exclusive Economic Zone of East Coast Peninsular Malaysia

    Ahmad, Zaharudin, E-mail: zahar@nuclearmalaysia.gov.m [Radiochemistry and Environmental Group, Malaysian Nuclear Agency (Nuclear Malaysia), Bangi, 43000 Kajang (Malaysia); Mei-Wo, Yii; Abu Bakar, Ahmad Sanadi; Shahar, Hidayah [Radiochemistry and Environmental Group, Malaysian Nuclear Agency (Nuclear Malaysia), Bangi, 43000 Kajang (Malaysia)

    2010-09-15

    The studies of {sup 137}Cs and {sup 239+240}Pu distributions in surface seawater at South China Sea within the Exclusive Economic Zone (EEZ) of Peninsular Malaysia were carried out in June 2008. The analysis results will serve as additional information to the expanded baseline data for Malaysia's marine environment. Thirty locations from extended study area were identified in the EEZ from which large volumes of surface seawater samples were collected. Different co-precipitation techniques were employed to concentrate cesium and plutonium separately. A known amount of {sup 134}Cs and {sup 242}Pu tracers were used as yield determinant. The precipitate slurry was collected and oven dried at 60 {sup o}C for 1-2 days. Cesium precipitate was fine-ground and counted using gamma-ray spectrometry system at 661.62 keV, while plutonium was separated from other radionuclides using anion exchange, electrodeposited and counted using alpha spectrometry. The activity concentrations of {sup 137}Cs and {sup 239+240}Pu were in the range of 3.40-5.89 Bq/m{sup 3} and 2.3-7.9 mBq/m{sup 3}, respectively. The {sup 239+240}Pu/{sup 137}Cs ratios indicate that there are no new inputs of these radionuclides into the area.

  9. Estimates of /sup 239-240/Pu + 241Am inventory, spatial pattern, and soil tonnage for removal at nuclear site-201, NTS

    Estimates of /sup 239-240/Pu + 241Am inventory and spatial pattern in surface soil are given for Nuclear Site (NS)-201 in Area 18 on the Nevada Test Site (NTS). These estimates were obtained using Kriging techniques and the estimated average /sup 239-240/Pu to 241Am ratio of 7.5. (Henceforth, Pu and Am refer to /sup 239-240/Pu and 241Am.) Estimated concentration contours, 68% confidence bands on contours, and estimated average concentrations in 100- x 100-foot blocks are given. The total Pu + Am inventory estimated to be in the top 5 cm of soil over the defined area is approximately 9.4 curies. Lower and upper limits on this inventory estimate are 4 and 30 curies. It is estimated that about 33 acres (approx. = 13 hectares) of land are contaminated at levels greater than 160 pCi/g and about 51 acres (approx. = 21 hectares) to levels greater than 40 pCi/g. Approximately 23,000 tons of soil would need to be removed (to 15-cm depth) to clean up all areas with estimated concentrations greater than or equal to 160 pCi/g. About 36,000 tons would require removal at the 40- pCi/g level. The above estimates will be updated when additional data become available early in Calender Year 1980. 10 references, 7 figures, 1 table

  10. Spatial distributions of 137Cs and 239+240Pu in surface seawater within the Exclusive Economic Zone of East Coast Peninsular Malaysia

    The studies of 137Cs and 239+240Pu distributions in surface seawater at South China Sea within the Exclusive Economic Zone (EEZ) of Peninsular Malaysia were carried out in June 2008. The analysis results will serve as additional information to the expanded baseline data for Malaysia's marine environment. Thirty locations from extended study area were identified in the EEZ from which large volumes of surface seawater samples were collected. Different co-precipitation techniques were employed to concentrate cesium and plutonium separately. A known amount of 134Cs and 242Pu tracers were used as yield determinant. The precipitate slurry was collected and oven dried at 60 oC for 1-2 days. Cesium precipitate was fine-ground and counted using gamma-ray spectrometry system at 661.62 keV, while plutonium was separated from other radionuclides using anion exchange, electrodeposited and counted using alpha spectrometry. The activity concentrations of 137Cs and 239+240Pu were in the range of 3.40-5.89 Bq/m3 and 2.3-7.9 mBq/m3, respectively. The 239+240Pu/137Cs ratios indicate that there are no new inputs of these radionuclides into the area.

  11. Bioaccumulation of 239+240Pu in benthic organisms crab (Scylla serrata) and arca (Anadara granosa) : a case study from Trombay

    The study presents the concentration of (239+240)Pu in various size groups of crab (SCYLLA SERRATA) and arca (ANADARA GRANOSA). Around 96 crabs and 650 arcas were harvested from the Mumbai Harbour Bay. Crabs and arcas were grouped in different size groups as per their widths. The maximum concentration 239+240Pu is observed in case of crab for the lowest size group whereas for arca the same is observed in the highest size group. This difference in the uptake of (239+240)Pu is attributed to the difference in metabolic functions of the two species. Bio-accumulation factor (Bp) values in case of crab flesh ranged between 70 to 1140 kg-1 with a GM value of 180 and in arca the value ranged between 6 to 60 l kg-1 with a GM of 20. The values for shell were higher by factors of 2 to 9 in case of crab and 3 to 22 in case of arca. The smallest size group of crab shows maximum Bp value whereas for arca maximum Bp is observed for maximum size group. (author)

  12. Examining (239+240)Pu, (210)Pb and historical events to determine carbon, nitrogen and phosphorus burial in mangrove sediments of Moreton Bay, Australia.

    Sanders, Christian J; Santos, Isaac R; Maher, Damien T; Breithaupt, Joshua L; Smoak, Joseph M; Ketterer, Michael; Call, Mitchell; Sanders, Luciana; Eyre, Bradley D

    2016-01-01

    Two sediment cores were collected in a mangrove forest to construct geochronologies for the previous century using natural and anthropogenic radionuclide tracers. Both sediment cores were dated using (239+240)Pu global fallout signatures as well as (210)Pb, applying both the Constant Initial Concentration (CIC) and the Constant Rate of Supply (CRS) models. The (239+240)Pu and CIC model are interpreted as having comparable sediment accretion rates (SAR) below an apparent mixed region in the upper ∼5 to 10 cm. In contrast, the CRS dating method shows high sediment accretion rates in the uppermost intervals, which is substantially reduced over the lower intervals of the 100-year record. A local anthropogenic nutrient signal is reflected in the high total phosphorus (TP) concentration in younger sediments. The carbon/nitrogen molar ratios and δ(15)N values further support a local anthropogenic nutrient enrichment signal. The origin of these signals is likely the treated sewage discharge to Moreton Bay which began in the early 1970s. While the (239+240)Pu and CIC models can only produce rates averaged over the intervals of interest within the profile, the (210)Pb CRS model identifies elevated rates of sediment accretion, organic carbon (OC), nitrogen (N), and TP burial from 2000 to 2013. From 1920 to 2000, the three dating methods provide similar OC, N and TP burial rates, ∼150, 10 and 2 g m(-2) year(-1), respectively, which are comparable to global averages. PMID:26004816

  13. 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

  14. 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

  15. Application of isotopic fingerprinting in nuclear forensic investigations - A case study

    constant. This observation can only be explained by differences in the sample treatment (e.g. weathering, rinsing or washing). Solubility tests using micro-amounts of the sample were carried out to investigate the relative difference of solubility under experimental conditions mimicking leaching through rainwater or washing-machine conditions. Such 'treatments' may not have been performed intentionally on the stolen items; thus great care needs to be taken in the interpretation of these results. In contrast to that, the isotope ratios (e.g. 235U/238U, 240Pu/239Pu) do not change through such chemical treatments. Consistent results were found for most of the samples, indicating that the observed contaminations can be related to the two stolen items One sample however showed a significantly different 238Pu/239Pu isotope abundance ratio. The paper will show how isotopic fingerprinting was used to establish a picture on the origin of contaminations and their interrelations. (author)

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. Application of 210Pb geochronology by the reconstruction of historical radionuclides concentrations ( 137Cs et 239+240Pu ) in the columns of the Alboran Sea

    Full text: The marine sediments are considered as a final reservoir of radioactive contaminants. The 210Pb from atmospheric fallouts deposits is stored in sediments with those from 226Ra original lithogenic. The activity of 210Pb excess in the accumulated sediment is an important tool to study the chronological process of sedimentation on recent time scales at over 100 years. However, this method should be validated using at least one independent tracer which provides an unequivocal temporal marker as 137Cs from nuclear testing. This work presents a method to rebuild historic concentrations of 137Cs and 230+240Pu in the water column Alboran Sea and their corresponding stream sediment. This is achieved by coupling the radiometric dating of the sediment column profiles using three independent levels: the excess 210Pb, 137Cs and 239 +240Pu. On the other hand, a simple model of the water column has been adapted to this end by making use of atmospheric flow, the measured values of distribution coefficient (Kd) and a first approximation of the rate of sedimentation. The timing model CM-CSR (diffusion coefficient of sedimentation rate constant) has been successfully applied to the three independent profiles, and was able to determine the parameters of diffusion and mass sedimentation rate. The results obtained give some ideas on the fate of atmospheric inputs to the marine environment and, particularly, that of the Chernobyl accident. The results of the models showed that direct and deferred contributions of Chernobyl accident are negligible in the Alboran Sea. The annual input of 210Pb to the sediment was estimated at 720±150 Bq.m-2. by year, while the rate of sedimentation is about 0092±0.003 g.cm-2 by year. On the other hand, the model could successfully reconstruct historic concentrations of 137Cs and 239+240Pu in the water column, and was able to reproduce the work of the same elements in the sediment column

  4. Measurement at n-TOF of the 237Np(n, γ) and 240Pu(n, γ) cross sections for the transmutation of nuclear waste

    The final design, safety assessment and precise performance analysis of transmutation devices such as Accelerator Driven Systems (ADS) or Fast Critical Reactors, need accurate and reliable nuclear data. The cross sections of 237Np and 240Pu have been measured in 2004 at n-TOF with good accuracy due to a combination of features unique in the world: high instantaneous neutron fluence and excellent energy resolution of the n-TOF facility [1], innovative Data Acquisition System based on flash ADCs and the use of a high performance BaF2 Total Absorption Calorimeter as a detection device. (authors)

  5. Radiotoxicological analyses of 239+240Pu and 241Am in biological samples by anion-exchange and extraction chromatography: a preliminary study for internal contamination evaluations

    Many biological samples (urines and faeces) have been analysed by means of chromatographic extraction columns, utilising two different resins (AG 1-X2 resin chloride and T.R.U.), in order to detect the possible internal contamination of 239+240Pu and 241Am, for some workers of a reprocessing nuclear plant in the decommissioning phase. The results obtained show on one hand the great suitability of the first resin for the determination of plutonium, and on the other the great selectivity of the second one for the determination of americium

  6. Model testing of radioactive contamination by {sup 90}Sr, {sup 137}Cs and {sup 239,240}Pu of water and bottom sediments in the Techa River (Southern Urals, Russia)

    Kryshev, I.I. [Scientific and Production Association ' Typhoon' , 82 Lenin Ave., Obninsk, Kaluga Region, 249038 (Russian Federation)], E-mail: ecomod@obninsk.com; Boyer, P.; Monte, L.; Brittain, J.E.; Dzyuba, N.N.; Krylov, A.L.; Kryshev, A.I.; Nosov, A.V.; Sanina, K.D.; Zheleznyak, M.I. [Scientific and Production Association ' Typhoon' , 82 Lenin Ave., Obninsk, Kaluga Region, 249038 (Russian Federation)

    2009-03-15

    This paper presents results of testing models for the radioactive contamination of river water and bottom sediments by {sup 90}Sr, {sup 137}Cs and {sup 239,240}Pu. The scenario for the model testing was based on data from the Techa River (Southern Urals, Russia), which was contaminated as a result of discharges of liquid radioactive waste into the river. The endpoints of the scenario were model predictions of the activity concentrations of {sup 90}Sr, {sup 137}Cs and {sup 239,240}Pu in water and bottom sediments along the Techa River in 1996. Calculations for the Techa scenario were performed by six participant teams from France (model CASTEAUR), Italy (model MARTE), Russia (models TRANSFER-2, CASSANDRA, GIDRO-W) and Ukraine (model RIVTOX), all using different models. As a whole, the radionuclide predictions for {sup 90}Sr in water for all considered models, {sup 137}Cs for MARTE and TRANSFER-2, and {sup 239,240}Pu for TRANSFER-2 and CASSANDRA can be considered sufficiently reliable, whereas the prediction for sediments should be considered cautiously. At the same time the CASTEAUR and RIVTOX models estimate the activity concentrations of {sup 137}Cs and {sup 239,240}Pu in water more reliably than in bottom sediments. The models MARTE ({sup 239,240}Pu) and CASSANDRA ({sup 137}Cs) evaluated the activity concentrations of radionuclides in sediments with about the same agreement with observations as for water. For {sup 90}Sr and {sup 137}Cs the agreement between empirical data and model predictions was good, but not for all the observations of {sup 239,240}Pu in the river water-bottom sediment system. The modelling of {sup 239,240}Pu distribution proved difficult because, in contrast to {sup 137}Cs and {sup 90}Sr, most of models have not been previously tested or validated for plutonium.

  7. 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)

  8. The neutron capture cross sections of 237Np(n,γ) and 240Pu(n,γ) and its relevance in the transmutation of nuclear waste

    Neutron capture cross sections of actinides are of great relevance for the Transmutation of Nuclear Waste in Accelerator Driven Systems (ADS) and Generation-IV reactors. The neutron capture cross sections of 237Np and 240Pu in the range of 1 eV to 2 keV were measured at the n-TOF facility with a Total Absorption Calorimeter. The data have been analyzed with the SAMMY code. The corresponding covariance matrices have been generated. The final cross sections are presented and compared to the previously existing ones.The n-TOF 237Np σ(n,γ) is in agreement with the evaluated data files below 300 eV and its is lower by 10 to 15% up to 2 keV. This discrepancy with the evaluated data files is also observed in the capture cross section derived from the transmission measurements of Gressier et al. In the case of the 240Pu σ(n,γ), the n-TOF σ(n,γ) agrees within uncertainties with JENDL-3.3 and JEFF-3.1, except for a group of resonances around 800 eV. Endf/B-VII data are lower than n-TOF and the mentioned evaluations, with differences that increase with neutron energy up to 15-20 per cent

  9. The neutron capture cross sections of {sup 237}Np(n,{gamma}) and {sup 240}Pu(n,{gamma}) and its relevance in the transmutation of nuclear waste

    Guerrero, C.; Abbondanno, U.; Aerts, G.; Alvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Baumann, P.; Becvar, F.; Berthoumieux, E.; Calvino, F.; Calviani, M.; Cano-Ott, D.; Capote, R.; Carrapico, C.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillmann, I.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Fujii, K.; Furman, W.; Goncalves, I.; Gonzalez-Romero, E.; Gramegna, F.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Jericha, E.; Kappeler, F.; Kadi, Y.; Karadimos, D.; Karamanis, D.; Kerveno, M.; Koehler, P.; Kossionides, E.; Krticka, M.; Lampoudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marrone, S.; Martinez, T.; Massimi, C.; Mastinu, P.; Mengoni, A.; Milazzo, P.M.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; O' Brien, S.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Pigni, M.T.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Praena, J.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Santos, C.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J.L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M.C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wiescher, M.; Wisshak, K

    2008-07-01

    Neutron capture cross sections of actinides are of great relevance for the Transmutation of Nuclear Waste in Accelerator Driven Systems (ADS) and Generation-IV reactors. The neutron capture cross sections of {sup 237}Np and {sup 240}Pu in the range of 1 eV to 2 keV were measured at the n-TOF facility with a Total Absorption Calorimeter. The data have been analyzed with the SAMMY code. The corresponding covariance matrices have been generated. The final cross sections are presented and compared to the previously existing ones.The n-TOF {sup 237}Np {sigma}(n,{gamma}) is in agreement with the evaluated data files below 300 eV and its is lower by 10 to 15% up to 2 keV. This discrepancy with the evaluated data files is also observed in the capture cross section derived from the transmission measurements of Gressier et al. In the case of the {sup 240}Pu {sigma}(n,{gamma}), the n-TOF {sigma}(n,{gamma}) agrees within uncertainties with JENDL-3.3 and JEFF-3.1, except for a group of resonances around 800 eV. Endf/B-VII data are lower than n-TOF and the mentioned evaluations, with differences that increase with neutron energy up to 15-20 per cent.

  10. Plutonium isotopes in sediments from the Sudanese coast of the Red Sea

    Activity concentrations of Pu isotopes in surface marine sediments collected from the Sudanese coast of the Red Sea is presented. The following concentration ranges were determined: 238Pu, 4.7-28.6 mBq/kg; 239+240Pu, 53-343 mBq/kg dry weight. The average activity ratios of 238Pu/239+240Pu (0.075 ± 0.045 mBqk/kg) and 239+240Pu/137Cs (0.026 ± 0.025 mBq/kg) are appropriately comparable to the literature values that are characteristic of the global fallout from the atmospheric nuclear weapon tests. However, 239/240Pu/137Cs ratio in sediments collected from the biologically rich fringing reef is an order of magnitude higher compared to other sampling locations. (author)

  11. {\\alpha}-accompanied cold ternary fission of $^{238-244}$Pu isotopes in equatorial and collinear configuration

    Santhosh, K P; Krishnan, Sreejith; Priyanka, B.

    2015-01-01

    The cold ternary fission of $^{238}$Pu, $^{240}$Pu, $^{242}$Pu and $^{244}$Pu isotopes, with $^{4}$He as light charged particle, in equatorial and collinear configuration has been studied within the Unified ternary fission model (UTFM). The fragment combination $^{100}$Zr+$^{4}$He+$^{134}$Te possessing the near doubly magic nuclei $^{134}$Te (N=82, Z=52) gives the highest yield in the alpha accompanied ternary fission of $^{238}$Pu. For the alpha accompanied ternary fission of $^{240}$Pu, $^{...

  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. 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

  15. 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.

  16. 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.

  17. 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...

  18. Distribution of 137Cs, 90Sr, 239+240Pu, 241Am and 230,232Th on the fractions of natural organic species soils of ChNPP alienation zone

    The experimental data determination of distribution 137Cs, 90Sr, 239+240Pu, 241Am 'Chernobyl' releases and 230,232Th on the fraction of humic and fulvic acids sandy- podsolic, meadow and peaty soils taken in the exclusive zone ChNPP are presents. Soils organic matter was isolated by conventional alkali extraction (Turin's method). It was shown that, with depending of soils types 15-45 % 241Am associate with fulvic acids. In all investigated types of soils 30 - 40 % 239+240Pu connects with humic acids, as strong complexes. The distribution of environmental 230,232Th and artificial 239+240Pu on the fraction natural organic species is the same

  19. Possible differences in biological availability of isotopes of plutonium: Report of a workshop

    Kercher, J.R.; Gallegos, G.M. [eds.

    1993-09-01

    This paper presents the results of a workshop conducted on the apparent different bioavailability of isotopes {sup 238}Pu and {sup 239}Pu. There is a substantial body of evidence that {sup 238}Pu as commonly found in the environment is more biologically available than {sup 239}Pu. Studies of the Trinity Site, Nevada Test Site from nonnuclear and nuclear events, Rocky Flats, Enewetak and Bikini, and the arctic tundra support this conclusion and indicate that the bioavailability of {sup 238}Pu is more than an order of magnitude greater than that of {sup 239}Pu. Plant and soil studies from controlled environments and from Savannah River indicate no isotopic difference in availability of Pu to plants; whereas studies at the Trinity Site do suggest a difference. While it is possible that these observations can be explained by problems in the experimental procedure and analytical techniques, this possibility is remote given the ubiquitous nature of the observations. Studies of solubility of Pu in the stomach contents of cattle grazing at the Nevada Test Site and from fish from Bikini Atoll both found that {sup 238}Pu was more soluble than {sup 239}Pu. Studies of the Los Alamos effluent stream indicate that as particle size decreases, the content of {sup 238}Pu relative to {sup 239}Pu increases.

  20. 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

  1. Role of natural organic matter on iodine and (239)(,240)Pu distribution and mobility in environmental samples from the northwestern Fukushima Prefecture, Japan.

    Xu, Chen; Zhang, Saijin; Sugiyama, Yuko; Ohte, Nobuhito; Ho, Yi-Fang; Fujitake, Nobuhide; Kaplan, Daniel I; Yeager, Chris M; Schwehr, Kathleen; Santschi, Peter H

    2016-03-01

    In order to assess how environmental factors are affecting the distribution and migration of radioiodine and plutonium that were emitted from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, we quantified iodine and (239,240)Pu concentration changes in soil samples with different land uses (urban, paddy, deciduous forest and coniferous forest), as well as iodine speciation in surface water and rainwater. Sampling locations were 53-63 km northwest of the FDNPP within a 75-km radius, in close proximity of each other. A ranking of the land uses by their surface soil (forest > deciduous forest > urban > paddy, and (239,240)Pu concentrations ranked as deciduous forest > coniferous forest > paddy ≥ urban. Both were quite distinct from that of (134)Cs and (137)Cs: urban > coniferous forest > deciduous forest > paddy, indicating differences in their sources, deposition phases, and biogeochemical behavior in these soil systems. Although stable (127)I might not have fully equilibrated with Fukushima-derived (129)I, it likely still works as a proxy for the long-term fate of (129)I. Surficial soil (127)I content was well correlated to soil organic matter (SOM) content, regardless of land use type, suggesting that SOM might be an important factor affecting iodine biogeochemistry. Other soil chemical properties, such as Eh and pH, had strong correlations to soil (127)I content, but only within a given land use (e.g., within urban soils). Organic carbon (OC) concentrations and Eh were positively, and pH was negatively correlated to (127)I concentrations in surface water and rain samples. It is also noticeable that (127)I in the wet deposition was concentrated in both the deciduous and coniferous forest throughfall and stemfall water, respectively, comparing to the bulk rainwater. Further, both forest throughfall and stemflow water consisted exclusively of organo-iodine, suggesting all inorganic iodine in the original bulk deposition (∼ 28.6% of total iodine) have

  2. Distributions of long-lived anthropogenic radionuclides (14C, 129I and 239+240Pu) in coastal water columns off Sanriku, Japan

    The first commercial facility for reprocessing nuclear spent fuel in Japan is going to run in July 2006 and routine release of radionuclides to marine environment off Rokkasho will begin. Off Rokkasho area is located in the boundary where subarctic (Oyashio) and subtropical (Kuroshio) gyre mixes. And the Tsugaru Warm Current (TWC) flows into this region through the Tsugaru Strait and originates in the Kuroshio flowing in the Sea of Japan/the East Sea. Those three water masses of different origins and coastal water mass coexist in the surface layer of this domain. So it is important to clarify the distribution of anthropogenic radionuclides and their behaviors in the coastal seawater. Seawater samples were collected by use of CTD/Multi-Bottle Samplers (MBS) and large volume samplers (LVS) in October 2001 and June 2002. Carbon-14 and 129I were analyzed by accelerator mass spectrometry (AMS) and 239,240Pu was determined by the method of radiochemical separation and alpha spectrometry. Th long- lived radionuclide concentrations for all samples were in the range -233 - 75 per mille for Δ14C, not detected (N.D.) - 2.5x107 atoms/l for 129I, and N.D. - 0.025 mBq/l for 239,240Pu, respectively. The other anthropogenic radionuclides have the same concentration as those reported by the other organization. The vertical profiles of 14C and 129I decreased monotonically with depths. On the other hand, 239,240Pu profile have maximum at a depth of 500 - 700 m. The plots of potential density versus the concentrations designate that 14C and 129I virtually occurred in the water column lighter than the density of 26.6 - 26.8 and slightly penetrate into dense deeper layer. The maximum of Pu concentration existed at a density of 26.8 - 27.2. There is no difference of 129I concentration between two water masses (Oyashio and TWC) classified according to water temperature and salinity. Δ14C concentrations in TWC are higher than those in Oyashio, because TWC flows in sea surface over

  3. The effect of isotope on the dosimetry of inhaled plutonium oxide

    Results of experimental studies in which animals inhaled 238PuO2 or 239PuO2 aerosols have shown that the biokinetics and associated radiation dose patterns for these two isotopes differ significantly due to differences in in-vivo solubility caused by the 260-fold difference in specific activity between 238PuO2 and 239PuO2. We have adapted a biokinetics and dosimetry model derived from results of the ITRI dog studies to humans and have calculated dose commitments and annual limits on intake (ALI) for both Pu isotopes. Our results show that the ALI calculated in this study is one-third that for class Y 238Pu from ICRP 30, and one-half or equal to that for class Y 239Pu, depending on how activity in the thoracic lymph nodes is treated dosimetrically

  4. Results of 90Sr and 239+240Pu, 238Pu, 241Am measurements in some samples of mushrooms and forest soil from Poland

    Strontium-90, plutonium and americium activity concentrations in a few samples of forest soils, some species of mushrooms and fern leaves were determined. These results are compared with caesium activity concentrations in the same materials obtained in a previous work. Radiochemical procedures are described. The origin of the contamination (Chernobyl accident or nuclear test explosion release) is discussed. The 90Sr activity concentration ranges from 0.6 Bq/kg (mushroom samples) to 48.4 Bq/kg (fern leaves). For 239+240Pu, it ranges from not detected above background (mushrooms, fern) to 10.8 Bq/kg (humus layer of forest soil). The maximum concentration of 241Am is found to be 2.4 Bq/kg (humus sample) and for 238Pu it is 0.85 Bq/kg (also in the humus sample). (author). 12 refs, 9 figs, 7 tabs

  5. Studying of distribution of 137Cs, 90Sr, 239+240Pu, 241Am and 244Cm according to the organic acids fractions of the alienation zone soils

    The paper deals with data of research on the distribution of the radionuclides 137Cs, 90Sr, 239+240Pu, 241Am and 244Cm of ''the Chornobyl rains'' by the fractions of the organic matters of derno-podzolic sandy, derno-meadow and peat soils sampled in the alienation zone of the Chornobyl NPP. Functioning of organic matters was carried according to Tyurin's method. It is stressed that, independently on soil type, 137Cs is connected with the mineral contituent by 80-95%. It is found out that, independently on the soil type, 50-70% 137Sr and 15-45% 241Am are associated with fulvic acid fractions. The 241Am and 244Cm distribution according to organic acids taking into account deviations while carrying out determinations is unambiguous. It is found out that in all the soils tested the main quality of 239+24Pu is connected with humic acids

  6. 90Sr and 239+240Pu 238Pu 241Am in some samples of mushrooms and forest soil from Poland

    Strontium-90, plutonium and americium activity concentrations in a few samples of forest soils, some species of mushrooms and fern leaves have been determined. These results are compared with cesium activity concentrations in the same materials obtained in a previous work. Radiochemical procedures are described. The origin of the contamination (Chernobyl accident or nuclear test explosion release) is discussed. The 90Sr activity concentration ranges from 0.6 Bq/kg (mushroom samples) to 48.4 Bq/kg (fern leaves). For 239+240Pu, it ranges from not detected above background (mushrooms, fern) to 10.8 Bq/kg (humus layer of forest soil). The maximum concentration of 241Am is found to be 2.4 Bq/kg (humus sample) and for 238Pu it is 0.85 Bq/kg (also in the humus sample). (author) 16 refs.; 7 figs.; 3 tabs

  7. 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.

  8. 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

  9. Dissolved forms of 90Sr, 239+240Pu and 241Am in the Sahan river waters from the Chernobyl area

    The dissolved forms of 90Sr, 239+240Pu and 241Am were studied for river water samples from the Chernobyl area in Ukraine on the basis of molecular size distribution. The river waters were collected at a station from Sahan River, which is a tributary of Pripyat River and located in the so-called Exclusion Zone (30-km zone), near the Chernobyl Nuclear Power Plant, in April and August 1996. The water samples had a pH of 7, conductivity of 190-210 mS m-1 and DOC concentration of 8-11 mg l-1. An ultrafiltration technique was used for the size-fractionation of the radionuclides in the river waters. Percentage of 90Sr, 239+240Pu and 241Am in the size fraction over 10,000 daltons was 2-20%, 68-79% and 57-62%, respectively. On the other hand, percentage of DOC and Si was 25-36% and 3%, respectively, for the size fraction over 10,000 daltons. These results indicate that 90Sr is present as cationic ions, but Pu and Am may be associated with organics of high molecular size and not with inorganic colloids such as aluminosilicate. In order to understand the association properties, laboratory experiments were performed for Am using humic substances isolated from the Sahan River water in April 1999 because of a significant fraction of dissolved organic materials and high complexation ability for actinides. The molecular size of 241Am in the presence of humic substances were studied for 0.01M NaClO4 solution at pH7 and the humic concentration of 10 mg l-1. The size patterns of 241Am were in good agreement with those of the river water samples. These results suggest that the dissolved forms of actinides in the Sahan River water are controlled by the presence of aquatic humic substances. (author)

  10. Even–odd effects in prompt emission of spontaneously fissioning even–even Pu isotopes

    Tudora, A., E-mail: anabellatudora@hotmail.com [University of Bucharest, Faculty of Physics, Bucharest Magurele, POB MG-11, R-76900 (Romania); Hambsch, F.-J. [EC-JRC Institute for Reference Materials and Measurements (IRMM), Retieseweg 111, B-2440, Geel (Belgium); Giubega, G.; Visan, I. [University of Bucharest, Faculty of Physics, Bucharest Magurele, POB MG-11, R-76900 (Romania)

    2015-01-15

    The available experimental Y(A,TKE) data for {sup 236,238,240,242,244}Pu(SF) together with the Zp model prescription with appropriate parameters allows the investigation of even–odd effects in fragment distributions. The size of the global even–odd effect in Y(Z) is decreasing from {sup 244}Pu(SF) to {sup 236}Pu(SF) confirming the general observation of a decrease of the even–odd effect with the fissility parameter. Charge polarizations (ΔZ) and root-mean squares (rms) as a function of A of {sup 236–244}Pu(SF) were obtained for the first time. In the asymmetric fission region both ΔZ(A) and rms(A) exhibit oscillations with a periodicity of about 5 mass units due to the even–odd effects. The total average charge deviations 〈ΔZ〉 (obtained by averaging ΔZ(A) over the experimental Y(A) distribution) are of about |0.5| for all studied Pu(SF) systems. The comparison of the calculated ΔZ(A) and rms(A) of {sup 240}Pu(SF) with those of {sup 239}Pu(n{sub th},f) reported by Wahl shows an in-phase oscillation with a higher amplitude in the case of {sup 240}Pu(SF), confirming the higher even–odd effect in the case of SF. As in the previously studied cases ({sup 233,235}U(n{sub th},f), {sup 239}Pu(n{sub th},f), {sup 252}Cf(SF)) the even–odd effects in the prompt emission of {sup 236–244}Pu(SF) are mainly due to the Z even–odd effects in fragment distributions and charge polarizations and the N even–odd effects in the average neutron separation energies from fragments 〈Sn〉. The size of the global N even–odd effect in 〈Sn〉 is decreasing with the fissility parameter, being higher for the Pu(SF) systems compared to the previously studied systems. The prompt neutron multiplicities as a function of Z, ν(Z), exhibit sawtooth shapes with a visible staggering for asymmetric fragmentations. The size of the global Z even–odd effect in ν(Z) exhibits a decreasing trend with increasing fissility. The average prompt neutron multiplicities as a

  11. Refinement of Pu parent-daughter isotopic and concentration analysis for forensic (dating) purposes

    Plutonium (Pu) metal samples from an interlaboratory exchange exercise and simulated swipe samples were dated using plutonium-uranium (Pu-U) and plutonium-americium (Pu-Am). Metal data were evaluated for consistency and the swipe data against its source material. Metal ages based on 239Pu versus 235U and 240Pu versus 236U agreed to within a few percent, while the 238Pu-234U and 241Pu-241Am measurements had larger uncertainties. Swipe ages compared favorably with the material's known history. Neptunium (237Np) analyses were examined in the context of the 241Pu-241Am-237Np system to estimate whether Np can provide insights on material from which Am, Np, and U were removed. (author)

  12. 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

  13. Production and certification of an equal atom plutonium isotopic standard - the New Brunswick Laboratory certified reference material (CRM) No. 128

    The US Department of Energy (DOE), New Brunswick Laboratory (NBL) has produced an equal atom 239Pu/242Pu isotopic standard, NBL CRM No. 128. Provisional certification of this standard relative to uranium was completed in 1984 and the material made available for distribution to the nuclear community. Certification of the 239Pu/242Pu ratio on an absolute basis has now been accomplished using highly accurate and precise chemical and mass spectrometric measurement techniques. The absolute certification of NBL CRM No. 128 has established it as the primary reference for calibrating the measurement of plutonium isotopic ratios

  14. 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.

  15. 137Cs, 90Sr, 241Am and 239+240Pu radionuclides speciation in soils of the former Semipalatinsk test site

    The paper presents results of studies into 137Cs and 90Sr, 241Am and 239+240Pu techno-genic radionuclides speciation in soils of ecosystems at different topography of the Semipalatinsk Test Site (STS), exposed to different nuclear testing. The data were obtained for radionuclides speciation in soils of the following STS ecosystems: - grassland ecosystems within near-portal areas of tunnels - horizontal adits constructed for nuclear testing, affected by radioactive-contaminated water flows from the tunnels of Degelen Site; - steppe ecosystems, exposed to ground radioactive contamination resulted from above-ground and aerial nuclear testing of different yield, as well as simulation (hydrodynamic and hydro-nuclear) experiments at 'Experimental Field' testing site. - steppe ecosystems, exposed to ground radioactive contamination caused by testing of liquid and powdery radiological warfare weapon (RWW) at Site '4 a'; - 'Northern' and 'Western' areas of STS, where concentration level of artificial radionuclides in soil is comparable with the level of global fall-outs ('background' areas). To study the radionuclides speciation, method of sequential extraction was applied, and water-soluble, exchange, organic mobile and tightly bound forms were separated. Feature of the studied grassland ecosystems is that they are developed solely along the bed of water streams flowing from tunnels and are located at small area of 1-2 m2. Radioactive contamination of soil is caused by radioactive contaminant sorption by sediments. Despite the significant space limitation of the ecosystems content of radionuclides speciation in soil greatly varies, particularly readily-soluble and mobile forms. The variation may be explained by high humidity which makes possible both sorption and desorption processes. If basic radionuclides contributing to radioactive contamination of grassland soils at Degelen Site are 137Cs and 90Sr, then at Experimental Field site these are transuranic radionuclides

  16. {sup 137}Cs, {sup 90}Sr, {sup 241}Am and {sup 239+240}Pu radionuclides speciation in soils of the former Semipalatinsk test site

    Kabdyrakova, A.M.; Kunduzbaeva, A.Y.; Lukashenko, S.N.; Magasheva, R.Y. [Institute of radiation safety and ecology (Kazakhstan)

    2014-07-01

    The paper presents results of studies into {sup 137}Cs and {sup 90}Sr, {sup 241}Am and {sup 239+240}Pu techno-genic radionuclides speciation in soils of ecosystems at different topography of the Semipalatinsk Test Site (STS), exposed to different nuclear testing. The data were obtained for radionuclides speciation in soils of the following STS ecosystems: - grassland ecosystems within near-portal areas of tunnels - horizontal adits constructed for nuclear testing, affected by radioactive-contaminated water flows from the tunnels of Degelen Site; - steppe ecosystems, exposed to ground radioactive contamination resulted from above-ground and aerial nuclear testing of different yield, as well as simulation (hydrodynamic and hydro-nuclear) experiments at 'Experimental Field' testing site. - steppe ecosystems, exposed to ground radioactive contamination caused by testing of liquid and powdery radiological warfare weapon (RWW) at Site '4 a'; - 'Northern' and 'Western' areas of STS, where concentration level of artificial radionuclides in soil is comparable with the level of global fall-outs ('background' areas). To study the radionuclides speciation, method of sequential extraction was applied, and water-soluble, exchange, organic mobile and tightly bound forms were separated. Feature of the studied grassland ecosystems is that they are developed solely along the bed of water streams flowing from tunnels and are located at small area of 1-2 m{sup 2}. Radioactive contamination of soil is caused by radioactive contaminant sorption by sediments. Despite the significant space limitation of the ecosystems content of radionuclides speciation in soil greatly varies, particularly readily-soluble and mobile forms. The variation may be explained by high humidity which makes possible both sorption and desorption processes. If basic radionuclides contributing to radioactive contamination of grassland soils at Degelen Site are {sup

  17. Radionuclides 137Cs, 90Sr, 241Am and 239+240Pu in vegetation cover of the former Semipalatinsk test site

    The Semipalatinsk Test Site (STS) is one of the largest testing grounds for nuclear weapons. Diverse nuclear explosions were carried out on its territory: 340 underground tests (sites 'Degelen', 'Balapan' and 'Sary-Uzen'), 30 surface and 86 nuclear air explosions (site for radioactive warfare agent (RWA) and 'Experimental Field'). Since the STS was shutdown a large amount of information about current radiological situation in its territory has been collected. In recent years, one of the main problems is gradual transfer of its lands for national economy. Under these conditions, an essential element for prediction of radioactive contamination levels of food products is radionuclides redistribution parameters in soil-plant system used in calculation of doses to the population living within STS territory. Until recently, matter of radionuclides migration from soil to plants has been poorly studied. Individual researches, more or less devoted to this issue occurred in the past, but have virtually no information about accumulation of transuranic radionuclides in plants. More regular studies in this direction have been initiated recently. Between 2007 and 2013 features of artificial radionuclides accumulation in certain plant species under radioactive tunnel watercourses at 'Degelen' site were studied. We've obtained statistically reliable data characterizing accumulation of radionuclides, including 239+240Pu and 241Am, in steppe plants at 'Experimental field' site. The content of radionuclides in plants was researched at the RWA site. Comprehensive ecological survey in order to release the lands to the national economic turnover investigated parameters of radionuclides accumulation in steppe grasses at conditionally 'background' areas of STS and some parts of radioactive trace plume caused by the explosion in 1953. To date, all the findings have been generalized. We present an integrated picture about accumulation of artificial radionuclides 137Cs, 90Sr, 239+240Pu and

  18. The AS-76 interlaboratory experiment on the alpha spectrometric determinaion of Pu-238. Part 3: Preparation and characterization of samples

    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

  19. Plutonium release from Fukushima Daiichi fosters the need for more detailed investigations

    Stephanie Schneider; Clemens Walther; Stefan Bister; Viktoria Schauer; Marcus Christl; Hans-Arno Synal; Katsumi Shozugawa; Georg Steinhauser

    2013-01-01

    The contamination of Japan after the Fukushima accident has been investigated mainly for volatile fission products, but only sparsely for actinides such as plutonium. Only small releases of actinides were estimated in Fukushima. Plutonium is still omnipresent in the environment from previous atmospheric nuclear weapons tests. We investigated soil and plants sampled at different hot spots in Japan, searching for reactor-borne plutonium using its isotopic ratio 240Pu/239Pu. By using accelerator...

  20. 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 ...

  1. 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.

  2. 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.

  3. 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

  4. Updated estimates of /sup 239-240/Pu + 241Am inventory, spatial pattern, and soil tonnage for removal at nuclear site-201, NTS

    These new estimates are based on 712 241Am soil concentrations including 185 data values not previously available. Estimates were obtained using essentially the same kriging techniques and the estimated average /sup 239-240/Pu to 241Am ratio of 7.5 used to obtain previous results. The total Pu + Am inventory estimated to be in the top 5 cm of soil over the 109 hectare study is approximately 16.3 curies. Lower and upper limits on this inventory estimate are about 6.7 and 45.6 curies, respectively. It is estimated that about 58 acres (approx. = 23 hectares) of land in the study are contaminated at levels greater than 40 pCi/g which includes about 40 acres (approx. = 16 hectares) at levels greater than 160 pCi/g. Approximately 28,000 tons of soil would need to be removed (to 15-cm depth) to clean up all areas with estimated concentrates greater than or equal to 160 pCi/g. About 41,000 tons would require removal at the 40 pCi/g level. 5 references, 6 figures, 2 tables

  5. Sequential leaching extraction of 239,240Pu, 238Pu, 241Pu and 241Am from a mud sample: An intercomparison study

    Full text: The determination of the association percentages of transuranics to different sediment phases could define their fate once they have been deposited onto the marine floor and their possible reactivity at the sediment/sea water interphase. Nowadays, there is a wide variety of leaching methods to extract transuranics from the different geochemical compounds conforming the sediments. Nevertheless, a general controversy is extended in the scientific world due to the extreme difficulty in testing their reliability, since the standards of transuranics linked to a certain sedimentary phase are not commercially available. Two mud subsamples taken from a storage container were analysed employing the same sequential extraction method, but with small handling differences.The following fractions were isolated: (1) Readily available (2) Carbonate bound and specifically adsorbed (3) Organically bound (4) Oxide and hydroxides bound and (5) residual. The 239,240Pu, 238Pu and 241Am extracted in each phase were analysed using standard radiochemical procedures. 241Pu was determined by both direct scintillation counting and through the 241Am in-growth up on the old disks containing Plutonium. The procedure for uncertainty calculations has been also included. (author)

  6. Sequential leaching extraction of 239,240Pu, 238Pu, 241Pu, 237Np and 241Am from a mud sample: An intercomparison study

    The transuranics content of a mud sample taken from a nuclear waste storage container was analysed employing two different sequential extraction methods. The following fractions were isolated: (1)Water soluble (2) Readily available (3) Carbonate bound and specifically adsorbed (4) Organically bound (5) Oxide and hydroxides bound and (6) residual. Both methods differ in the reagents employed, the extraction sequence applied as well as the temperature and means of extraction. The 239,240Pu, 238Pu, 237Np and 241Am extracted in each phase were determined using standard radiochemical procedures. 241Pu was analysed through the 241Am in-growth on just one old disk of the residual fraction containing plutonium. Plutonium was mainly associated to organic-oxides fractions (89-92 %). The percentage extracted in each fraction depended on the method and the extraction sequence used. The soluble fraction of plutonium was less than 13%. Neptunium seemed to be the more soluble than the other transuranics (27%) and the americium showed a tendency to be associated to carbonates (30%). (author)

  7. Estimation of covariances of 10B, 11B, 55Mn, 240Pu and 241Pu neutron nuclear data in JENDL-3.2

    Covariances of nuclear data have been estimated for 5 nuclides contained in JENDL-3.2. The nuclides considered are 10B, 11B, 55Mn, 240Pu, and 241Pu, which are regarded as important for the nuclear design study of fast reactors. The physical quantities for which covariances are deduced are cross sections, resolved and unresolved resonance parameters, and the first order Legendre-polynomial coefficient for the angular distribution of elastically scattered neutrons. The covariances were estimated by using the same methodology that had been used in the JENDL-3.2 evaluation in order to keep a consistency between mean values and their covariances. The least-squares fitting code GMA was used in estimating covariances for reactions of which JENDL-3.2 cross sections had been evaluated by taking account of measurements. Covariances of nuclear model calculations were deduced by the KALMAN system. The covariance data obtained were compiled in the ENDF-6 format, and will be put into the JENDL-3.2 Covariance File which is one of JENDL special purpose files. (author)

  8. Estimation of covariances of {sup 10}B, {sup 11}B, {sup 55}Mn, {sup 240}Pu and {sup 241}Pu neutron nuclear data in JENDL-3.2

    Shibata, Keiichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Nakajima, Yutaka; Murata, Toru

    1998-08-01

    Covariances of nuclear data have been estimated for 5 nuclides contained in JENDL-3.2. The nuclides considered are {sup 10}B, {sup 11}B, {sup 55}Mn, {sup 240}Pu, and {sup 241}Pu, which are regarded as important for the nuclear design study of fast reactors. The physical quantities for which covariances are deduced are cross sections, resolved and unresolved resonance parameters, and the first order Legendre-polynomial coefficient for the angular distribution of elastically scattered neutrons. The covariances were estimated by using the same methodology that had been used in the JENDL-3.2 evaluation in order to keep a consistency between mean values and their covariances. The least-squares fitting code GMA was used in estimating covariances for reactions of which JENDL-3.2 cross sections had been evaluated by taking account of measurements. Covariances of nuclear model calculations were deduced by the KALMAN system. The covariance data obtained were compiled in the ENDF-6 format, and will be put into the JENDL-3.2 Covariance File which is one of JENDL special purpose files. (author)

  9. The 129Iodine bomb pulse recorded in Mississippi River Delta sediments: Results from isotopes of I, Pu, Cs, Pb, and C

    Anthropogenic sources from nuclear reprocessing discharges and bomb test fallout have completely overwhelmed the natural signal on the surface of the earth in the last 50 years. However, the transfer functions in and out of environmental compartments are not well known due to temporal variations in the sources of 129I and to a lack of knowledge regarding the forms of iodine. From a vertical profile of 129I/127I ratios in sediments located in the Mississippi Delta region in approximately 60 meters water depth, the 129I input function to this region was reconstructed. Dates in the core were assigned based on the plutonium peak at 20 cm depth (assumed to have been deposited in 1963) and the excess 210Pb profile in the same depth interval, and below that, based on the steadily decreasing 240Pu/239Pu ratios from a ratio of 0.18 at 22 cm to 0.05 at 57 cm depth, the 1953 horizon. Atom ratios of 129I/137I Cs, decay corrected to 1962, the year of maximum radionuclide production, are about 0.3, very close to the production ratios of about 0.2 during atomic bomb tests. This evidence, combined with other observations, strongly suggests that 129I in Mississippi River Delta sediments originates from atomic bomb fallout eroded from soils of the Mississippi River drainage basin, with little alteration of the isotopic ratios during transport from watershed to coastal deposits. Based on these observations and on laboratory evidence, the authors propose a conceptual model which explains this correspondence and the low 129I/127I ratios. Differences in mobilities of the different chemical forms of 129I and 127I, as well as the variances in chemical forms of 129I from nuclear bomb fallout versus nuclear fuel reprocessing, are proposed to have created such a correspondence between I-isotope ratios and bomb fallout nuclides, without revealing recent inputs from nuclear fuel reprocessing releases to the northern hemisphere observed in watersheds of the USA and Europe

  10. The {sup 129}Iodine bomb pulse recorded in Mississippi River Delta sediments: Results from isotopes of I, Pu, Cs, Pb, and C

    Oktay, S.D.; Santschi, P.H.; Moran, J.E.; Sharma, P.

    2000-03-01

    Anthropogenic sources from nuclear reprocessing discharges and bomb test fallout have completely overwhelmed the natural signal on the surface of the earth in the last 50 years. However, the transfer functions in and out of environmental compartments are not well known due to temporal variations in the sources of {sup 129}I and to a lack of knowledge regarding the forms of iodine. From a vertical profile of {sup 129}I/{sup 127}I ratios in sediments located in the Mississippi Delta region in approximately 60 meters water depth, the {sup 129}I input function to this region was reconstructed. Dates in the core were assigned based on the plutonium peak at 20 cm depth (assumed to have been deposited in 1963) and the excess {sup 210}Pb profile in the same depth interval, and below that, based on the steadily decreasing {sup 240}Pu/{sup 239}Pu ratios from a ratio of 0.18 at 22 cm to 0.05 at 57 cm depth, the 1953 horizon. Atom ratios of {sup 129}I/{sup 137}I Cs, decay corrected to 1962, the year of maximum radionuclide production, are about 0.3, very close to the production ratios of about 0.2 during atomic bomb tests. This evidence, combined with other observations, strongly suggests that {sup 129}I in Mississippi River Delta sediments originates from atomic bomb fallout eroded from soils of the Mississippi River drainage basin, with little alteration of the isotopic ratios during transport from watershed to coastal deposits. Based on these observations and on laboratory evidence, the authors propose a conceptual model which explains this correspondence and the low {sup 129}I/{sup 127}I ratios. Differences in mobilities of the different chemical forms of {sup 129}I and {sup 127}I, as well as the variances in chemical forms of {sup 129}I from nuclear bomb fallout versus nuclear fuel reprocessing, are proposed to have created such a correspondence between I-isotope ratios and bomb fallout nuclides, without revealing recent inputs from nuclear fuel reprocessing releases to

  11. 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)

  12. 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)

  13. CALORIMETER-BASED ADJUSTMENT OF MULTIPLICITY DETERMINED 240PU EFF KNOWN-A ANALYSIS FOR THE ASSAY OF PLUTONIUM

    Dubose, F.

    2012-02-21

    In nuclear material processing facilities, it is often necessary to balance the competing demands of accuracy and throughput. While passive neutron multiplicity counting is the preferred method for relatively fast assays of plutonium, the presence of low-Z impurities (fluorine, beryllium, etc.) rapidly erodes the assay precision of passive neutron counting techniques, frequently resulting in unacceptably large total measurement uncertainties. Conversely, while calorimeters are immune to these impurity effects, the long count times required for high accuracy can be a hindrance to efficiency. The higher uncertainties in passive neutron measurements of impure material are driven by the resulting large (>>2) {alpha}-values, defined as the ({alpha},n):spontaneous fission neutron emission ratio. To counter impurity impacts for high-{alpha} materials, a known-{alpha} approach may be adopted. In this method, {alpha} is determined for a single item using a combination of gamma-ray and calorimetric measurements. Because calorimetry is based on heat output, rather than a statistical distribution of emitted neutrons, an {alpha}-value determined in this way is far more accurate than one determined from passive neutron counts. This fixed {alpha} value can be used in conventional multiplicity analysis for any plutonium-bearing item having the same chemical composition and isotopic distribution as the original. With the results of single calorimeter/passive neutron/gamma-ray measurement, these subsequent items can then be assayed with high precision and accuracy in a relatively short time, despite the presence of impurities. A calorimeter-based known-{alpha} multiplicity analysis technique is especially useful when requiring rapid, high accuracy, high precision measurements of multiple plutonium bearing items having a common source. The technique has therefore found numerous applications at the Savannah River Site. In each case, a plutonium (or mixed U/Pu) bearing item is divided

  14. Radiation damage on the first wall of an IFE type fusion reactor using weapon grade plutonium isotopes

    Full text: Eliminating the frequent replacement of the first wall structure of a fusion reactor during reactor's lifetime would provide a significant improvement in the cost efficiency. The most promising method to make this is to use a protective flowing wall between plasma and solid first wall. HYLIFE-II is a molten salt inertial fusion energy (IFE) reactor where heavy ion beams are focused onto a target to initiate micro-explosions with a frequency of approx. 6 Hz. In HYLIFE-II, a molten salt wall of Li2BeF4 (Flibe) is used between the solid first wall and the explosions to keep the radiation damage of the first wall below limits. This fusion reactor uses deuterium-tritium (DT) fusion neutrons so that self-sufficient tritium production should be maintained in the fusion blanket to remove an investment on external tritium production unit. In this paper, radiation damage study on the first wall structure made of W-5Re, V-4Cr-4Ti, 9Cr2WVTa or SiC/SiC composite in the HYLIFE-II reactor using a molten salt containing Li2BeF4 (Flibe) with weapon grade (WG) plutonium as a flowing liquid wall was carried out. Significant amount of WG plutonium consisting of 94% 239Pu and 6% 240Pu isotopes have been deposited in the nuclear warheads during the Cold War. Its destruction by peaceful ways is very important to keep security and environment. For this reason WG plutonium was considered in this work both for its reduction by a peaceful route and improve the performance of the fusion reactor. Neutron transport calculations were made with the aid of SCALE4.3 by solving the Boltzmann transport equation with XSDRNPM code in 238 energy groups and S8-P3 approximation. Radiation damage at the first wall structure and tritium production were obtained with respect to the protective wall thickness. Numerical results pointed out that the best performance was attained in the reactor using W-5Re alloy which would require a liquid wall thickness of approx. 30 cm to supply radiation damage

  15. Plutonium isotopes in the surface air in Japan

    Plutonium isotope concentrations in the surface air at Tsukuba, Japan are reported during the period from 1981 to the end of 1986. The 239,240Pu concentration in the surface air, which showed a marked seasonal variation with a spring maximum and fall minimum, decreased until the end of 1985 according to the stratospheric residence time of 1.15 years. In May 1986, elevated 239,240Pu concentrations with high 238Pu/239,240Pu activity ratios were observed. The serial trend of plutonium concentration in the surface air is similar to the concentrations of the Chernobyl-released radionuclides. These findings suggest that a significant part of the plutonium in the surface air in May 1986 was due to the Chernobyl fallout. (author) 15 refs.; 2 figs.; 3 tabs

  16. 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.

  17. 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)

  18. Retention and translocation of foliar applied {sup 239,240}Pu and {sup 241}Am, as compared to {sup 137}Cs and {sup 85}Sr, into bean plants (Phaseolus vulgaris)

    Henner, P. [Institute for Radioprotection and Nuclear Safety, Environment and Emergency Operations Division, Department for the Study of Radionuclides Behaviour in Ecosystems, Laboratory of Radioecology and Ecotoxicology, IRSN/DPRE/SECRE/LRE, Cadarache Centre, Building 186, BP 3, 13115 Saint-Paul-lez-Durance (France)]. E-mail: pascale.henner@irsn.fr; Colle, C. [Institute for Radioprotection and Nuclear Safety, Environment and Emergency Operations Division, Department for the Study of Radionuclides Behaviour in Ecosystems, Laboratory of Radioecology and Ecotoxicology, IRSN/DPRE/SECRE/LRE, Cadarache Centre, Building 186, BP 3, 13115 Saint-Paul-lez-Durance (France); Morello, M. [Institute for Radioprotection and Nuclear Safety, Environment and Emergency Operations Division, Department for the Study of Radionuclides Behaviour in Ecosystems, Laboratory of Radioecology and Ecotoxicology, IRSN/DPRE/SECRE/LRE, Cadarache Centre, Building 186, BP 3, 13115 Saint-Paul-lez-Durance (France)

    2005-07-01

    Foliar transfer of {sup 241}Am, {sup 239,240}Pu, {sup 137}Cs and {sup 85}Sr was evaluated after contamination of bean plants (Phaseolus vulgaris) at the flowering development stage, by soaking their first two trifoliate leaves into contaminated solutions. Initial retentions of {sup 241}Am (27%) and {sup 239,240}Pu (37%) were higher than those of {sup 137}Cs and {sup 85}Sr (10-15%). Mean fraction of retained activity redistributed among bean organs was higher for {sup 137}Cs (20.3%) than for {sup 239,240}Pu (2.2%), {sup 241}Am (1%) or {sup 85}Sr (0.1%). Mean leaf-to-pod translocation factors (Bq kg{sup -1}dry weight pod/Bq kg{sup -1}dry weight contaminated leaves) were 5.0 x 10{sup -4} for {sup 241}Am, 2.7 x 10{sup -6} for {sup 239,240}Pu, 5.4 x 10{sup -2} for {sup 137}Cs and 3.6 x 10{sup -4} for {sup 85}Sr. Caesium was mainly recovered in pods (12.8%). Americium and strontium were uniformly redistributed among leaves, stems and pods. Plutonium showed preferential redistribution in oldest bean organs, leaves and stems, and very little redistribution in forming pods. Results for americium and plutonium were compared to those of strontium and caesium to evaluate the consistency of the attribution of behaviour of strontium to transuranium elements towards foliar transfer, based on translocation factors, as stated in two radioecological models, ECOSYS-87 and ASTRAL.

  19. Retrospective determination of 238Pu, 239,240Pu and 90Sr activities in the outer bark of Norway spruce (Picea abies (L.) Karst.) collected at various sites in the Czech Republic

    The activity concentrations of 238Pu, 239,240Pu and 90Sr were determined in 25 archived spruce outer bark samples collected in coniferous forests across the Czech Republic in 1995. At three sampling sites the radionuclide activity concentrations were determined in forest soil. Data was provided on the cumulative deposition and vertical distribution of 238Pu, 239,240Pu and 90Sr in forest soil. The median activity concentration of 238Pu in the spruce bark samples was 0.009 Bq kg-1. The median activity concentration of 239,240Pu was 0.212 Bq kg-1, and the median activity concentration of 90Sr was 10.6 Bq kg-1. The radionuclide activity concentration distribution was not significantly explained by the local long-term (1961-2000) mean annual precipitation totals, by site elevation, by bark acidity, by soil moisture and soil texture. The activity concentrations of the radionuclides in bark were found to be higher than or comparable with the published and measured figures for radionuclide activity concentrations in cultivated and uncultivated soils (0-20 cm layer) in the Czech Republic and abroad. The activity concentration ratio of 90Sr/239,240Pu in the investigated spruce bark samples was higher than in the relevant soil samples. We assume that the crucial radioactive contamination loads in bark occurred in the first half of the 1960s, when the concentration of the investigated radionuclides in the air was highest. Spruce trunk bark has preserved relatively high activity concentrations of these radionuclides. The mechanism governing the long-term radionuclide activity concentrations in outer bark proportional to the local radioactive fallout rates is not correctly known. Our results indicate the suitability of spruce bark for use as an effective monitor of radioactive plume fallout loads even several decades after the contamination episode. (author)

  20. Behavior of plutonium isotopes in the marine environment of Enewetak atoll

    There continue to be reports in the literature that suggest a difference in the behavior of 239+240Pu and 238Pu in some aquatic environments. Plutonium isotopes have been measured in marine samples collected over 3 decades form Enewetak atoll, one of the sites in the Marshall Islands used by the United States between 1946 and 1958 to test nuclear devices. The plutonium isotopes originated from a variety of complex sources and could possibly coexist in this environment as different physical-chemical species. However results indicate little difference in the mobility and biological availability of 239+240Pu and 238Pu. (author)

  1. Rapid analytical technique to identify alpha emitting isotopes in water, air-filters, urine, and solid matrices using a Frisch Grid detector.

    Scarpitta, Salvatore C; Miltenberger, Robert P; Gaschott, Robert; Carte, Nina

    2003-04-01

    A 5-inch-diameter Frisch Grid gas-proportional ionization chamber was utilized at Brookhaven National Laboratory (BNL) to rapidly characterize and quantify alpha-emitting actinides in unprocessed water, soil, air-filter, urine, and solid matrices. Instrument calibrations for the various matrices were performed by spiking representative samples with National Institute of Standards and Technology traceable isotopes of 230Th, 232U, 236Pu, and 243Am. Detection efficiencies were typically 15-20% for solid matrices (soil, concrete, filters, dry urine) and 45% for mass-less water samples. Instrument background over a 512-channel alpha-energy range of 3-8 MeV is very low at 0.01 cps. At optimum efficiency, minimum detectable levels of 0.56 mBq Kg(-1), 74 mBq L(-1) and 14.8 mBq filter(-1) were achievable for 40 x 10(-6) Kg soil, 1 x 10(-3) L tap water (or urine), and 4.5 cm diameter air-filter samples, respectively, each counted for 60 min. Data and spectra are presented showing the quality of results obtained using untreated samples obtained from the BNL Graphite Research Reactor Decommissioning Project. These samples contained Bq to MBq per gram amounts of (239,240)Pu, 241Am, and/or (234,235/238)U (as well as other beta/gamma emitters). Data and spectra are also presented for a very finely pulverized and homogeneous U.S. DOE/RESL soil reference standard (spiked with 239Pu, 241Am, and 233U) that was used to assess precision, accuracy, and reproducibility. Although this technique has its limitations, the advantages are (1) minimal sample preparation, (2) no separation chemistry required, (3) no chemical or hazardous waste generated, and (4) ability to immediately characterize and quantify alpha-emitting nuclides in most matrices. The benefits of this technique to the BNL/DOE Project Managers were rapid (1-2 d) turn-around times coupled with significant cost savings, as compared to commercial off-site analyses. PMID:12705448

  2. 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.

  3. 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.)

  4. 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).

  5. 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

  6. 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

  7. Sequential determination of 239,240Pu, 238 Pu, 241 Am and 90Sr in radioactive wastes using SPE sorbents Analig Pu02, AnaLig Sr01 and TRU Resin

    A simple and rapid method of the sequential determination of radionuclides 239,240Pu, 238 Pu, 241 Am and 90Sr in radioactive sludge from the NPP Bohunice A1 with high radiochemical yields and efficient removal of interfering components from a matrix was developed. Separation method combines SPE sorbents Analig Pu02, AnaLig Sr01 made by IBC Advanced Technologies and TRU Resin (Eichrom Technologies) placed in tandem. Advantage of a single-stage column located on the vacuum box with a rapid flow is an effective pre-concentration and separation of radionuclides and minimization of sample separation time. (authors)

  8. 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

  9. 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)

  10. 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

  11. 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)

  12. Removal of low level of 239+240Pu in aqueous solution between pH 2-6 by calcium alginate and its variation with aquatic humic substance

    During this work laboratory simulated experiments were carried out for the removal of low level of 239+240Pu from the aqueous solution. Water samples after filtering through 0.22 mm filter paper were spiked with 250 Bq/1 of 239+240Pu as Pu(NO3)4. The pH of the solutions were controlled between 2-6 by using 0.01M NaOH/HNO3. Spiked samples were kept in the argon atmosphere for a week. The spiked water is passed separately through 20 cm column having about 4 gm of calcium alginate beads. Calcium-alginate beads were prepared by immobilising 2% sodium alginate in 0.2 M calcium chloride solution. At different pH about 95-98% Pu was retained in the beads and significant variation was not observed at pH range studied. To understand the impact of dissolved organic substance on the absorption characteristics of Pu(IV) on calcium-alginate beads, about 0.01% (weight/volume) humic acid solution was mixed in the ratio of 1-4/100 (V/V) experimental solutions. It was observed that the presence of organic matter decreased the absorption by 40% which clearly indicate the complexation of Pu(IV) with humic acid, which was not further forming complex within the alginate beads. The various physicochemical characteristics were measured before and after passing the solution. About 40% of Pu is recovered from sodium alginate beads by using 0.1 M HNO3. (author)

  13. Seasonal variations in activity concentrations of 137Cs, 40K, 7Be, 228Ac, 99Tc, 90Sr, and 239/240Pu in Fucus vesiculosus and Ascophyllum nodosum from the South-Eastern coast of Norway

    Brown algae have been proven to be useful indicator organisms for heavy metals and radionuclides in the marine environments due to their ability to concentrate elements from the ambient water. There is quite a lot of data available on 137Cs in brown algae, especially for Fucus Vesiculosus. Fucus Vesiculosus is also commonly used to monitor the impact of the releases of 99Tc from the reprocessing plant in Sellafield. There is however a lack of data for other long-lived anthropogenic nuclides as 90Sr and Pu, and for natural occurring radionuclides. There is also a need for more knowledge about the mechanisms for uptake and accumulation of the different elements, and about different factors influencing the uptake. In this study activity concentrations of 137Cs, 40K, 7Be, 228Ac, 99Tc, 90Sr and 239/240Pu are measured in whole plants of Fucus vesiculosus and Ascophyllum nodosum collected over a period of one year from the south-eastern coast of Norway. Significant differences between the two species have been found. For 137Cs, 40K, 7Be, 228Ra and 239/240Pu, the activity concentrations were significantly higher in Fucus vesiculosus than in Ascophyllum nodosum, whereas for 99Tc the activity concentrations were higher in Ascophyllum nodosum than in Fucus vesiculosus. There were great seasonal variations in the concentrations of the measured radionuclides. For 99Tc there was also a difference in the temporal pattern for the two species. Possible uptake mechanisms will be discussed based on the results and on the known physiological differences between the two species. (author)

  14. Measurements of low-level anthropogenic radionuclides from soils around Maralinga

    Tims Stephen G.; Tsifakis Dimitrios; Srncik Michaela; Keith Fifield L.; Hancock Gary J.; De Cesare Mario

    2013-01-01

    The isotopes 239Pu and 240Pu are present in surface soils as a result of global fallout from nuclear weapons tests carried out in the 1950’s and 1960’s. These isotopes constitute artificial tracers of recent soil erosion and sediment movement. In practice the high throughput capabilities and high sensitivity of the AMS technique makes the study of Australia’s geographically large areas viable using Pu isotopes. As part of its weapons development program the United Kingdom carried out a series...

  15. 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.

  16. Determination of {sup 238}Pu, {sup 239+240}Pu, {sup 241}Pu and {sup 241}Am in radioactive waste from IPEN reactor

    Geraldo, Bianca; Taddei, Maria Helena T.; Cheberle, Sandra M.; Ferreira, Marcelo T., E-mail: bgeraldo@cnen.gov.b, E-mail: mhtaddei@cnen.gov.b, E-mail: scsantos@cnen.gov.b, E-mail: ferreira@cnen.gov.b [Brazilian Nuclear Energy Commission (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Lab. of Pocos de Caldas; Marumo, Julio T., E-mail: jtmarumo@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Ion exchange resin is a common type of radioactive waste arising from treatment of coolant water of the main circuit of research and nuclear power reactors. This waste contains high concentrations of fission and activation products. The management of this waste includes its characterization in order to determine and quantify specific radionuclides including those known as difficult-to-measure radionuclides (RDM). The analysis of RDMs generally involves expensive and time-consuming complex radiochemical analysis for purification and separation of the radionuclides. The objective of this work is to show an easy methodology for quantifying plutonium and americium isotopes in spent ion exchange resin, used for purification of the cooling water of the IEA-R1 reactor located at the Nuclear and Energy Research Institute, IPEN-CNEN/SP. The resins were destroyed by acid digestion, followed by purification and separation of the Pu and Am isotopes with anionic and chromatographic resins. {sup 238}Pu, {sup 239}+{sup 24}'0Pu, and {sup 24}'1Am isotopes were analyzed in an alpha spectrometer equipped with surface barrier detectors. {sup 241}Pu isotope was analyzed by liquid scintillation counting. Chemical recovery yield ranged from 73 to 98% for Pu and 77 to 98% for Am, demonstrating that the methodology is suitable for identification and quantification of the isotopes studied in spent resins. (author)

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

    The use of 237Pu as a tracer for 238Pu and 239Pu was studied in a plant--soil system. Sandy clay--loam soil was spiked with approx. 240 pCi/g of 237Pu, 14.3 pCi/g of 238Pu, and 33 pCi/g of 239Pu in the form of Pu(NO3)4. The uptake of these three isotopes of plutonium was measured in the standing vegetation of sweet corn (Zea mays L. var. Silver Queen) after 30 and 50 days of growth. The mean concentrations in the standing crop and the concentration ratios of each isotope decreased from 30 to 50 days. There was an apparent differential availability of the three isotopes: 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 for both sampling times. Factors influencing these results are discussed

  18. Rapid fuel drawer scanner for fast critical assembly safeguards

    An integrated scanning system incorporating highly efficient collimated neutron and high purity germanium gamma detectors with an on-line microprocessor has been developed to perform rapid inventorying of uranium and plutonium fuel drawers from fast critical assemblies. On-line least-squares fit procedures provide quantitative comparisons at a rate exceeding two drawers per minute. For plutonium-containing fuel, the neutron scan data can be related to the included 240Pu isotopic mass; individual 239Pu, 241Pu, and 241Am isotopic contents are obtained from simultaneous scans of the appropriate isolated gamma lines

  19. 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

  20. 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

  1. The history and source of particulate 137Cs and 239,240Pu deposition in sediments of the Ob River Delta, Siberia

    This paper presents the first results of a project designed to examine the transfer of particle-associated artificial radionuclides down the Ob River in Siberia to its delta over the past 5 decades. The main sources include fallout from atmospheric nuclear weapons tests and weapons complexes and test sites of the Former Soviet Union in or near the Ob watershed. The approach is to measure the accumulation of the radionuclides in undisturbed delta sediments - obtaining a record of their deposition over time. These records were found in sediments of shallow lakes apart from, and connected to, the main channel. Sediment cores were collected in the summer of 1994 using a shallow draft catamaran to reach these lakes from a support ship in the main channel. Measurements are presented on the depth distributions of 137Cs and Pu isotopes and their inventories in a series of dated sediment cores - including one from a location in the Taz Estuary (which does not receive Ob River sediments). Sediment dating was carried out using the excess 210Pb technique. The results obtained are compared with known information on the temporal history of releases from the various sources and characteristics of the isotopic composition of the sources. The results show that good records of radionuclide deposition indicate that the major fraction of 137Cs and Pu isotopes deposited in these delta sediments comes from atmospheric nuclear weapons test fallout - both delivered directly from the atmosphere and from downstream transport of watershed sediments. No more than 25% of the observed inventories could be derived from other sources

  2. 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

  3. Uptake of three plutonium isotopes in a plant-soil system

    This study, conducted on the Savannah River Plant (SRP), was concerned with uptake of 237Pu, 238Pu, and 239Pu by sweet corn from a southeastern soil. Concentrations of Pu associated with roots and standing vegetation were evaluated with the following variables: source of contamination; time of harvest; soil concentrations; and Pu isotope. Comparisons between concentrations of plutonium in the standing vegetation on the basis of source of contamination at harvest times of 30 and 50 days showed no statistically significant difference in the 239Pu standing vegetation concentration for either harvest time whether 239Pu was applied to soil in a nitrate form or was found in soil as a result of reprocessing plant releases. There was also no statistically significant difference between 238Pu standing vegetation concentrations for the two sources at 30 days, however, the vegetation concentration of 238Pu at 50 days from spiked soil was significantly greater than that grown on Savannah Reprocessing Plant soil. The standing vegetation concentration of 237Pu decreased significantly for a harvest time of 30 to 50 days with a resultant significant decrease in the concentration ratio. A similar decreasing trend was indicated in the data for 238Pu and 239Pu, however, these were not statistically significant. The concentration ratios for each isotope were inversely correlated with soil concentration resulting in from 1 to 2 orders of magnitude differences in the concentration ratios. Findings indicated that 237Pu may not be a suitable tracer for 238Pu. Additional studies were suggested to further delineate the influence of mass concentrations on Pu uptake

  4. Accumulation of polonium 210Po, uranium (234U and 238U and plutonium (238Pu and 239+240Pu in tissues and organs of deer Carvidae from northern Poland

    Strumińska-Parulska D. I.

    2013-04-01

    Full Text Available Livers, kidneys and muscles of large herbivorous animals: roe deer (Capreolus capreolus, red deer (Cervus elaphus and fallow deer (Dama dama, collected in northern Poland, were the subject of the investigation. Polonium, uranium and plutonium activities were measured using alpha spectrometry along with relevant radiochemical procedures. The average concentrations of 210Po ranged between 0.02±0.01 Bq kg−1 ww in muscles and 7.15±0.12 Bq kg−1 ww in kidneys. The concentration of 238U ranged widely between 2.49±0.18 and 69.37±5.45 mBq kg−1 ww. The average concentrations of 239+240Pu ranged between 0.18±0.04 mBq kg−1 ww in muscle and 2.77±0.60 mBq kg−1 ww in kidneys. Statistical analysis showed that the sampling location, sex, age and species did not influence on the radioisotope activities in the analyzed samples.

  5. Sequential determination of natural (232Th, 238U) and anthropogenic (137Cs, 90Sr, 241Am, 239+240Pu) radionuclides in environmental matrix

    A new sequential method for the determination of both natural (U, Th) and anthropogenic (Sr, Cs, Pu, Am) radionuclides has been developed for application to soil and sediment samples. The procedure was optimised using a reference sediment (IAEA-368) and reference soils (IAEA-375 and IAEA-326). Reference materials were first digested using acids (leaching), 'total' acids on hot plate, and acids in microwave in order to compare the different digestion technique. Then, the separation and purification were made by anion exchange resin and selective extraction chromatography: Transuranic (TRU) and Strontium (SR) resins. Natural and anthropogenic alpha radionuclides were separated by Uranium and Tetravalent Actinide (UTEVA) resin, considering different acid elution medium. Finally, alpha and gamma semiconductor spectrometer and liquid scintillation spectrometer were used to measure radionuclide activities. The results obtained for strontium-90, cesium-137, thorium-232, uranium- 238, plutonium-239+240 and americium-241 isotopes by the proposed method for the reference materials provided excellent agreement with the recommended values and good chemical recoveries. (authors)

  6. 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

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

    Qiao, Jixin; Hansen, Violeta; Hou, Xiaolin;

    2012-01-01

    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...... 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...

  8. Communication of nuclear data progress: No.6 Supplement (1992)

    This is a supplement to No.6 of Communication of Nuclear Data Progress (CNDP), in which the second and final part of the papers of CENDL-2 (Chinese Evaluated Nuclear Data Library, Version 2.0) is published. It includes the evaluation reports of 17 elements and isotopes with incident neutron energy from 10-5 eV to 20 MeV, they are 16O, 23Na, 31P, Ca, Zn, Mn, 59Co, Cd, In, Hf, 232Th, 235U, 239Pu, 240Pu, 241Am, 249Bk, 249Cf

  9. 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)

  10. Behaviour of long-lived radionuclides associated with deep-sea disposal of radioactive wastes

    The IAEA sponsored this Coordinated Research Programme to improve knowledge of various long-lived radionuclides likely to be dumped in the deep sea. During the three years of this programme the state of knowledge has advanced significantly in this area, and this document provides a review of the progress. The isotopes studied were mainly 238Pu, 239Pu, 240Pu, 241Am, 226Ra, 210Po, 90Sr, 137Cs, 60Co, and 99Tc. A separate abstract was prepared for each of the 15 papers

  11. 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.

  12. Comparative concentrations of 137Cs, 90Sr, /sup 239,240/Pu, and 241Am in tissues of fish from the Marshall Islands and calculated dose commitments from their consumption

    Body burdens of 90Sr, 137Cs, and the transuranics in bottom-feeding fish from Marshall Island atolls are derived, in part, from the quantities of the radionuclides irreversibly fixed to ingested carbonate material. Radionuclide concentration factors for different species of fish are characterized by relating tissue concentrations to those in filtered seawater. For bottom-feeding fish, the values are lower at the lesser contaminated atolls than those values determined for the same species at the more contaminated atolls. These fish have the ability to lower their gut pH during feeding. When this occurs, there is a dissolution of a fraction of the ingested calcium carbonate containing radionuclides that were fixed or fused internally to the material during nuclear testing. Fractions of the radionuclides released during solution in carbonate matrix are available for passage across the gut wall. Amounts released to solution in the gut are proportional to the levels of contamination at the different atolls. Concentration factors for higher trophic level species, which do not rely on sediments or coral for their source of food, show no such trends between differentially contaminated atolls. A two-source model used to compute the internal concentrations is described. Americium-241 seems to be more biologically available than /sup 239,240/Pu to higher trophic level species from the lagoons, whereas at lower trophic levels the opposite seems to be the case. Cesium-137 is now the largest contributor of the small radiological dose to man from the marine fish pathway, with the transuranics contributing from 2 to 30% of the total dose. 22 references, 1 figure, 19 tables

  13. Measurements of low-level anthropogenic radionuclides from soils around Maralinga

    Tims Stephen G.

    2013-12-01

    Full Text Available The isotopes 239Pu and 240Pu are present in surface soils as a result of global fallout from nuclear weapons tests carried out in the 1950’s and 1960’s. These isotopes constitute artificial tracers of recent soil erosion and sediment movement. In practice the high throughput capabilities and high sensitivity of the AMS technique makes the study of Australia’s geographically large areas viable using Pu isotopes. As part of its weapons development program the United Kingdom carried out a series of atmospheric and surface nuclear weapons tests at Maralinga, South Australia in 1956 and 1957. The contribution from the Maralinga tests to the Pu isotopic abundances present in the region around Maralinga is largely unknown. In global fallout, for example, the 240Pu/239Pu ratio is typically in the range 0.17 - 0.19, but the influence of the regional tests could lead to values outside this range. This would impact on the assessment techniques used in the soil and sediment tracer studies. We report recent measurements on soil samples collected from across the Maralinga Test site.

  14. 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

  15. 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)

  16. 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)

  17. Radioecological studies at the National Center of Accelerators based on the use of the accelerator mass spectrometry; Estudios radioecologicos en el Centro Nacional de Aceleradores basados en el uso de la Espectrometria de Masas con Acelerador (AMS)

    Chamizo, E.; Lopez-Gutierrez, J. M.; Gomez-Guzman, J. M.; Santos, F. J.; Garcia-Leon, M.; Garcia-Tenorio, R.

    2013-03-01

    Since mid-2006 a compact Accelerator Mass Spectrometry (AMS) of 1 MV, Tandetron type, named SARA (Spanish Accelerator for Radionuclide Analysis) is installed at the National Accelerator Centre in Seville. After an initial period, to set-up the equipment and to study its capability to detect the long-lived radionuclides {sup 1}4C, {sup 1}0B, {sup 2}6Al, {sup 1}29I and plutonium isotopes ({sup 2}39Pu and {sup 2}40Pu) compared to other techniques of mass spectrometry (MS), numerous research lines in fields as diverse as archaeology, geology, palaeontology, oceanography, internal dosimetry, astrophysics and characterization of radioactive waste, among others, have been opened. In particular, since 2008 numerous contributions in the field of Radioecology have been done, based in the measurements of {sup 1}29I and Pu isotopes ({sup 2}39Pu and {sup 2}40Pu). In this article, some of these radioecological researches are summarized and presented, with special emphasis on showing that its accomplishment requires the application of the AMS technique, to be able to achieve sensitivities and detection limits which are impossible to reach when radiometric and mass spectrometry conventional techniques are applied. (Author) 13 refs.

  18. Status of the compact 1 MV AMS facility at the Centro Nacional de Aceleradores (Spain)

    Since February 2006, the new 1 MV multielement compact AMS facility SARA (Spanish Accelerator for Radionuclides Analyses) at the Centro Nacional de Aceleradores (CNA) in Sevilla (Spain) is fully operative. During the first one and a half year of operation, the viability of the system for the measurement of 10Be, 14C, 129I and plutonium isotopes, 239Pu and 240Pu, has been evaluated. First results have demonstrated that, in terms of precision and detection limits, the performance of the device compares to other compact AMS facilities, although some progress can still be done in order to optimize its capacities. At this moment, background levels are in the order of 10-14 for 10Be/9Be, 10-13 for 129I/127I, 10-15 for 14C/12C (processed and unprocessed blank) and about 106 atoms for plutonium isotopes: 239Pu, 240Pu and 242Pu. In this work, the current status of the AMS measurements at CNA for the above mentioned radionuclides is described

  19. Quantitative Analysis of Plutonium Content in Particles Collected from a Certified Reference Material by Total Nuclear Reaction Energy (Q Value) Spectroscopy

    Croce, M. P.; Hoover, A. S.; Rabin, M. W.; Bond, E. M.; Wolfsberg, L. E.; Schmidt, D. R.; Ullom, J. N.

    2016-08-01

    Microcalorimeters with embedded radioisotopes are an emerging category of sensor with advantages over existing methods for isotopic analysis of trace-level nuclear materials. For each nuclear decay, the energy of all decay products captured by the absorber (alpha particles, gamma rays, X-rays, electrons, daughter nuclei, etc.) is measured in one pulse. For alpha-decaying isotopes, this gives a measurement of the total nuclear reaction energy (Q value) and the spectra consist of well-separated, narrow peaks. We have demonstrated a simple mechanical alloying process to create an absorber structure consisting of a gold matrix with small inclusions of a radioactive sample. This absorber structure provides an optimized energy thermalization environment, resulting in high-resolution spectra with minimal tailing. We have applied this process to the analysis of particles collected from the surface of a plutonium metal certified reference material (CRM-126A from New Brunswick Laboratory) and demonstrated isotopic analysis by microcalorimeter Q value spectroscopy. Energy resolution from the Gaussian component of a Bortels function fit was 1.3 keV FWHM at 5244 keV. The collected particles were integrated directly into the detector absorber without any chemical processing. The ^{238}Pu/^{239}Pu and ^{240}Pu/^{239}Pu mass ratios were measured and the results confirmed against the certificate of analysis for the reference material. We also demonstrated inter-element analysis capability by measuring the ^{241}Am/^{239}Pu mass ratio.

  20. Quantitative Analysis of Plutonium Content in Particles Collected from a Certified Reference Material by Total Nuclear Reaction Energy (Q Value) Spectroscopy

    Croce, M. P.; Hoover, A. S.; Rabin, M. W.; Bond, E. M.; Wolfsberg, L. E.; Schmidt, D. R.; Ullom, J. N.

    2016-03-01

    Microcalorimeters with embedded radioisotopes are an emerging category of sensor with advantages over existing methods for isotopic analysis of trace-level nuclear materials. For each nuclear decay, the energy of all decay products captured by the absorber (alpha particles, gamma rays, X-rays, electrons, daughter nuclei, etc.) is measured in one pulse. For alpha-decaying isotopes, this gives a measurement of the total nuclear reaction energy (Q value) and the spectra consist of well-separated, narrow peaks. We have demonstrated a simple mechanical alloying process to create an absorber structure consisting of a gold matrix with small inclusions of a radioactive sample. This absorber structure provides an optimized energy thermalization environment, resulting in high-resolution spectra with minimal tailing. We have applied this process to the analysis of particles collected from the surface of a plutonium metal certified reference material (CRM-126A from New Brunswick Laboratory) and demonstrated isotopic analysis by microcalorimeter Q value spectroscopy. Energy resolution from the Gaussian component of a Bortels function fit was 1.3 keV FWHM at 5244 keV. The collected particles were integrated directly into the detector absorber without any chemical processing. The ^{238} Pu/^{239} Pu and ^{240} Pu/^{239} Pu mass ratios were measured and the results confirmed against the certificate of analysis for the reference material. We also demonstrated inter-element analysis capability by measuring the ^{241} Am/^{239} Pu mass ratio.

  1. Isotopic composition and origin of uranium and plutonium in selected soil samples collected in Kosovo

    Soil samples collected from locations in Kosovo where depleted uranium (DU) ammunition was expended during the 1999 Balkan conflict were analysed for uranium and plutonium isotopes content (234U, 235U, 236U, 238U, 238Pu, 239+240Pu). The analyses were conducted using gamma spectrometry (235U, 238U), alpha spectrometry (238Pu, 239+240Pu), inductively coupled plasma-mass spectrometry (ICP-MS) (234U, 235U, 236U, 238U) and accelerator mass spectrometry (AMS) (236U). The results indicated that whenever the U concentration exceeded the normal environmental values (∼2 to 3 mg/kg) the increase was due to DU contamination. 236U was also present in the released DU at a constant ratio of 236U (mg/kg)/238U (mg/kg)=2.6x10-5, indicating that the DU used in the ammunition was from a batch that had been irradiated and then reprocessed. The plutonium concentration in the soil (undisturbed) was about 1 Bq/kg and, on the basis of the measured 238Pu/239+240Pu, could be entirely attributed to the fallout of the nuclear weapon tests of the 1960s (no appreciable contribution from DU)

  2. Isotopic composition and origin of uranium and plutonium in selected soil samples collected in Kosovo

    Danesi, P.R. E-mail: P.R.Danesi@iaea.org; Bleise, A.; Burkart, W.; Cabianca, T.; Campbell, M.J.; Makarewicz, M.; Moreno, J.; Tuniz, C.; Hotchkis, M

    2003-07-01

    Soil samples collected from locations in Kosovo where depleted uranium (DU) ammunition was expended during the 1999 Balkan conflict were analysed for uranium and plutonium isotopes content ({sup 234}U, {sup 235}U, {sup 236}U, {sup 238}U, {sup 238}Pu, {sup 239+240}Pu). The analyses were conducted using gamma spectrometry ({sup 235}U, {sup 238}U), alpha spectrometry ({sup 238}Pu, {sup 239+240}Pu), inductively coupled plasma-mass spectrometry (ICP-MS) ({sup 234}U, {sup 235}U, {sup 236}U, {sup 238}U) and accelerator mass spectrometry (AMS) ({sup 236}U). The results indicated that whenever the U concentration exceeded the normal environmental values ({approx}2 to 3 mg/kg) the increase was due to DU contamination. {sup 236}U was also present in the released DU at a constant ratio of {sup 236}U (mg/kg)/{sup 238}U (mg/kg)=2.6x10{sup -5}, indicating that the DU used in the ammunition was from a batch that had been irradiated and then reprocessed. The plutonium concentration in the soil (undisturbed) was about 1 Bq/kg and, on the basis of the measured {sup 238}Pu/{sup 239+240}Pu, could be entirely attributed to the fallout of the nuclear weapon tests of the 1960s (no appreciable contribution from DU)

  3. Plutonium isotopes in marine sediments and some biota from the Sudanese coast of the Red Sea

    Measurements of 239+240Pu and 238Pu were carried out on marine biota as well as on sediments from the fringing reefs area extending towards north and south (Flamingo Bay) of Port Sudan harbour. The analyses were performed using radiochemical separation and alpha spectrometry. The range of the activity concentrations in marine sediments, in mBq kg-1 dry weight, was found to be from 5.10 to 82.00 for 239+240Pu and from 0.89 to 8.63 for 238Pu. Corresponding activity concentrations of 239+240Pu and 238Pu in sediments from the harbours at Port Sudan and Sawakin were 53-301 and 8.29-28.6 (Port Sudan) and 163-343 and 4.7 (Sawakin), respectively. The higher values for plutonium in marine algae suggest their suitability as an indicator species for monitoring purposes. The results obtained are generally lower than those found by other studies and show that the Red Sea environment is mildly affected by plutonium contamination. Activity ratios of plutonium isotopes confirm that the existence of plutonium in the Red Sea is mainly due to atmospheric global fallout. (authors)

  4. Plutonium and cesium radionuclides in the Hudson River estuary. Annual technical progress report, December 1, 1976--November 30, 1977

    We have obtained a large set of sediment cores from the Hudson estuary through much of the ambient salinity range. A number of core sections and samples of suspended particles have been analyzed for 137Cs, 134Cs and 60Co by direct gamma counting, and 239Pu, 240Pu, and 238Pu by alpha spectrometry. The distribution of both 137Cs and 239Pu, 240Pu indicates rapid accumulation in marginal cover areas, and especially in the harbor region adjacent to New York City. The distributions of both 137Cs and 239Pu, 240Pu are similar in surface sediments and with depth in cores, but there are deviations from the fallout ratio due to addition of reactor 137Cs and loss of 137Cs from the particle phases at higher salinities. Measureable amounts of reactor-derived 134Cs and 60Co are found in nearly all sediment samples containing appreciable 137Cs, between 15 km upstream of Indian Point and the downstream extent of our sampling, 70 km south of the reactor. Accumulations of 239Pu, 240Pu in New York harbor sediments are more than an order of magnitude greater than the fallout delivery rate. The most likely explanation is accumulation of fine particles in the harbor which have been transported from upstream areas of the Hudson. Our evidence so far indicates that Indian Point is probably not a significant source of 239Pu, 240Pu or 238Pu compared with the fallout burden of these nuclides already in the sediments

  5. Measurement of mass and isotopic fission yields for heavy fission products with the LOHENGRIN mass spectrometer

    In spite of the huge amount of fission yield data available in different libraries, more accurate values are still needed for nuclear energy applications and to improve our understanding of the fission process. Thus measurements of fission yields were performed at the mass spectrometer Lohengrin at the Institut Laue-Langevin in Grenoble, France. The mass separator Lohengrin is situated at the research reactor of the institute and permits the placement of an actinide layer in a high thermal neutron flux. It separates fragments according to their atomic mass, kinetic energy and ionic charge state by the action of magnetic and electric fields. Coupled to a high resolution ionization chamber the experiment was used to investigate the mass and isotopic yields of the light mass region. Almost all fission yields of isotopes from Th to Cf have been measured at Lohengrin with this method. To complete and improve the nuclear data libraries, these measurements have been extended in this work to the heavy mass region for the reactions 235U(nth,f), 239Pu(nth,f) and 241Pu(nth,f). For these higher masses an isotopic separation is no longer possible. So, a new method was undertaken with the reaction 239Pu(nth,f) to determine the isotopic yields by spectrometry. These experiments have allowed to reduce considerably the uncertainties. Moreover the ionic charge state and kinetic energy distributions were specifically studied and have shown, among others, nanosecond isomers for some masses. (author)

  6. Plutonium source isotopic analysis with up to 25 mm Pb shielding using the FRAM Isotopic Analysis Code.

    Hypes, Philip A.

    2000-01-01

    The FRAM Isotopics Analysis Code has been used to analyze plutonium spectra taken through very thick shielding. Three plutonium sources with 240Pu content of 6.6%, 9.7%, and 16.3% were measured with lead shielding thicknesses ranging from zero to 25.3 mm, in nominal increments of 1.6mm. Multiple spectra were taken for each sample at each shielding level, and the spectra were analyzed using FRAM V3.2. A new parameter set was developed to analyze spectra from zero to 25 mm lead. We will report on the accuracy capabilities of this parameter set.

  7. Plutonium isotopes and 137Cs in Dolon settlement near the Semipalatinsk Nuclear Test Site. About 50 years after the first nuclear weapon testing

    Recent controversies concerning the radiation doses for populations living in the village of Dolon due to the nuclear explosions carried out at the Semipalatinsk Nuclear Test Site (SNTS) have encouraged us to evaluate in more detail the levels and distributions of residual long-lived radionuclides 137Cs and Pu isotopes (238Pu, 239,240Pu) in soils within the village. Soil core samples up to a depth of about 30 cm and/or 100 cm were collected at 25 sites and subjected to analysis of 137Cs and Pu isotopes. The inventories of 137Cs and 239,240Pu were found to be in the wide range of 790-10,310 and 530-14,320 Bq/m2, respectively. Sequential leaching of Pu from the soil showed that more than ca. 80% of the 239,240Pu was not leached by hot digestion with conc. HNO3 + H2O2, indicating the presence of Pu associated with fused silicates. Further, the presence of hot-particles from the Pu contaminants by a-track radiography technique using CR-39 polycarbonate was confirmed in the soil, even at present, after about 50 years from the first nuclear weapon testing. (author)

  8. Calculation of Plutonium content in RSG-GAS spent fuel using IAFUEL computer code

    It has been calculated the contain of isotopes Pu-239, Pu-240, Pu-241, and isotope Pu-242 in MTR reactor fuel types which have U-235 contain about 250 gram. The calculation was performed in three steps. The first step is to determine the library of calculation output of BOC (Beginning of Cycle). The second step is to determine the core isotope density, the weight of plutonium for one core, and one fuel isotope density. The third step is to calculate weight of plutonium in gram. All calculation is performed by IAFUEL computer code. The calculation was produced content of each Pu isotopes were Pu-239 is 6.7666 gr, Pu-240 is 1.4628 gr, Pu-241 is 0.52951 gr, and Pu-242 is 0.068952 gr

  9. Comparison of Pu and 137Cs as tracers of soil and sediment transport in a terrestrial environment

    Following atmospheric nuclear weapons testing in the 1950s and 1960s significant quantities of 137Cs and 239+240Pu were deposited worldwide. In recent decades, 137Cs has been commonly used as a tracer of soil erosion and sedimentation, particularly in the Northern Hemisphere where atomic deposition was three times as great as in the Southern Hemisphere. The relatively short 30-year half-life of this isotope means that its sensitivity as a tracer is rapidly decreasing. In contrast, with half-lives of 24,110 and 6561 years, the sensitivity of the two plutonium isotopes remains essentially the same as when it was deposited. Here we use the technique of Accelerator Mass Spectrometry to demonstrate the potential of anthropogenic Pu as an alternative to 137Cs as a tracer of soil transport in Australia. We measure an average 137Cs/239+240Pu activity ratio of 27.3 ± 1.5 and an average 240Pu/239Pu atom ratio of 0.149 ± 0.003, both slightly lower than the global average

  10. Development of isotope dilution gamma-ray spectrometry for plutonium analysis

    Li, T.K.; Parker, J.L. (Los Alamos National Lab., NM (United States)); Kuno, Y.; Sato, S.; Kurosawa, A.; Akiyama, T. (Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan))

    1991-01-01

    We are studying the feasibility of determining the plutonium concentration and isotopic distribution of highly radioactive, spent-fuel dissolver solutions by employing high-resolution gamma-ray spectrometry. The study involves gamma-ray plutonium isotopic analysis for both dissolver and spiked dissolver solution samples, after plutonium is eluted through an ion-exchange column and absorbed in a small resin bead bag. The spike is well characterized, dry plutonium containing {approximately}98% of {sup 239}Pu. By using measured isotopic information, the concentration of elemental plutonium in the dissolver solution can be determined. Both the plutonium concentration and the isotopic composition of the dissolver solution obtained from this study agree well with values obtained by traditional isotope dilution mass spectrometry (IDMS). Because it is rapid, easy to operate and maintain, and costs less, this new technique could be an alternative method to IDMS for input accountability and verification measurements in reprocessing plants. 7 refs., 4 figs., 4 tabs.

  11. Design concepts for an analytical chemistry laboratory to support plutonium processing

    The Idaho National Engineering Laboratory was chosen as the preferred site for the location of the special isotope separation (SIS) production plant. The SIS plant will use the atomic vapor laser isotope separation process to ionize the undesirable isotopes of plutonium (238Pu, 240Pu, and 241Pu) in the metal vapor and separate them electrostatically from the desirable isotope 239Pu. Feed to the plant will be reactor-grade plutonium oxide, and the product will be weapons-grade plutonium metal. The SIS plant uses both pyrochemical and aqueous processes. An analytical laboratory, the Material and Process Control Laboratory (MPCL), was designed for making chemical measurements for process control, material control and accountability, and criticality safety

  12. Design concepts for an analytical chemistry laboratory to support plutonium processing

    Wade, M.A.; Treibs, H.A.; Hartenstein, S.D.

    1990-01-01

    The Idaho National Engineering Laboratory was chosen as the preferred site for the location of the special isotope separation (SIS) production plant. The SIS plant will use the atomic vapor laser isotope separation process to ionize the undesirable isotopes of plutonium ([sup 238]Pu, [sup 240]Pu, and [sup 241]Pu) in the metal vapor and separate them electrostatically from the desirable isotope [sup 239]Pu. Feed to the plant will be reactor-grade plutonium oxide, and the product will be weapons-grade plutonium metal. The SIS plant uses both pyrochemical and aqueous processes. An analytical laboratory, the Material and Process Control Laboratory (MPCL), was designed for making chemical measurements for process control, material control and accountability, and criticality safety.

  13. Dating of a sediment core from Lake Biel (Switzerland) and source characterization of fallout Pu; {sup 210}Pb- und {sup 137}Cs-Datierung eines Sedimentbohrkerns aus dem Bieler See (CH) und Ursprungsbestimmung von Pu-Fallout

    Pregler, Anja

    2016-08-01

    A sediment core from Lake Biel was dated by means of the naturally occurring radioactive isotope {sup 210}Pb as well as by the anthropogenic isotope {sup 137}Cs. The latter one can be detected as radioactive fallout of certain events in the sediment layers and accordingly be correlated with a distinct date. A verification of the correlated events is accomplished by particular isotope ratios of the anthropogenic isotopes {sup 238}Pu, {sup 239}Pu and {sup 240}Pu as well as {sup 241}Am as a decay product of the short-lived {sup 241}Pu. Furthermore, the percentage of the total {sup 137}Cs fallout was calculated corresponding to the specific events.

  14. Uranium comparison by means of AMS and ICP-MS and Pu and 137Cs results around an Italian Nuclear Power Plant

    De Cesare M.

    2015-01-01

    Full Text Available Italy built and commissioned 4 nuclear power plants between 1958-1978, which delivered a total of 1500 MW. All four were closed down after the Chernobyl accident following a referendum in 1987. One of the plants was Garigliano, commissioned in 1959. This plant used a 160 MW BWR1 (SEU of 2.3 % and was operational from 1964 to 1979, when it was switched off for maintenance. It was definitively stopped in 1982, and is presently being decommissioned. We report here details on the chemistry procedure and on the measurements for soil samples, collected up to 4.5 km from the Nuclear Plant. A comparison between uranium (238U concentration as determined by means of AMS (Accelerator Mass Spectrometry and by ICP-MS (Inductively Coupled Plasma-Mass Spectrometry techniques respectively at the ANU (Australian National University and at the Ecowise company in Canberra, Australia, is reported, as well as 236U and 239;240Pu concentration results detected by AMS. 236U/238U and 240Pu/239Pu isotopic ratios by means of AMS are also provided. A contamination from Chernobyl is visible in the 137Cs/239+240Pu activity ratio measurements.

  15. Characterization of U/Pu particles originating from the nuclear weapons accidents at Palomares, Spain, 1966 and Thule, Greenland, 1968

    Lind, O. C.; Salbu, B.; Janssens, K.; Proost, K.; Garcia-Leon, M.; R. Garcia-Tenorio

    2007-01-01

    Following the USAF B-52 bomber accidents at Palomares, Spain in 1966 and at Thule, Greenland in 1968, radioactive particles containing uranium (U) and plutonium (Pu) were dispersed into the environment. To improve long-term environmental impact assessments for the contaminated ecosystems, particles from the two sites have been isolated and characterized with respect to properties influencing particle weathering rates. Low (239)Pu/(235)U (0.62-0.78) and (240)Pu/(239)Pu (0.055-0.061) atom ratio...

  16. Lagoon sediment radioactivity in Polynesian French nuclear test sites

    In 1996, at the request of the French government, IAEA conducted an international study to assess the radiological situation of the atolls of Mururoa and Fangataufa. Results obtained by French scientists in the previous years were provided for the study. In this paper, some new results, such as 240Pu/239Pu activity ratio, are reported. 27 top-layer sediments were sampled in 1993 and 1995 in Mururoa and Fangataufa lagoons. Radioactivity measurements of the major man-made γ-emitters (60Co, 125Sb, 137Cs and 155Eu), of 90Sr, 99Tc and 239Pu, together with activity ratios (238Pu/239Pu, 240Pu/239Pu, 241Am/239Pu and 237Np/241Am) are given. These results are compared with previous measurements, in particular the radiological situations established in years 1984-90. Radiological maps, 155Eu concentration , 239,240Pu concentration and 238Pu/239,240Pu activity ratio, for sediment radioactivity in Mururoa and Fangataufa lagoons are shown. Results of two cores sampled in 1996 during the IAEA study are also reported. An assessment of total inventories is given for both atolls. (author)

  17. Nuclear forensic applications involving high spatial resolution analysis of Trinitite cross-sections

    This study reports a comprehensive cross-sectional analysis of major and trace element abundances and 240Pu/239Pu ratios within vertically oriented Trinitite thin sections. The upper glassy layer (∼2 mm thick) represents fused desert sand combined with devolatilized fallout from the debris cloud. The vertical distribution of 240Pu/239Pu ratios indicates that residual fuel was incorporated deeper (up to ∼10 mm depth) into Trinitite than previously reported. This requires thorough mixing and disturbance of the upper cm of the blast site prior to or during the initial melting of the desert sand resulting from the nuclear explosion. (author)

  18. Study on determination of plutonium isotopes in soils from Lublin region (Poland)

    Plutonium isotopes were introduced to the environment mainly as a fallout from nuclear weapons tests carried out intensively in 1954 - 1963 and occasionally later. It was estimated that about 1.2·1016 Bq of 239,240Pu and about 8·10l4Bq of 238Pu was spread in the atmosphere. Another source of plutonium isotopes, which caused local contamination were liquid releases from nuclear facilities, fallout from nuclear-powered satellites burnt up in the atmosphere, accidents of airplanes carrying nuclear missiles or accidental releases such as from Chernobyl in 1986. The latter, which caused the most extensive contamination, especially in Europe, introduced to the atmosphere about 2·1014 Bq of 239,240Pu. Most of plutonium isotopes was spread in the stratosphere, from where it falls down continuously on the Earth surface. Region of Lublin (in eastern part of Poland) has not come yet within monitoring of soil contamination by alpha emitting isotopes like plutonium, while the large contaminations with Chernobyl originated radioisotopes were observed. In our Department we have taken up a study on determination of contamination level of soil by alpha emitting nuclides and, as a result of a cooperation with J. Stefan Institute in Ljubljana (Slovenia), we have developed methods for plutonium isotopes separation

  19. Development and evaluation of an alpha spectrometer for precise measurement of activity ratio of plutonium

    In reprocessing plants, alpha spectrometry is used for the determination of plutonium concentration by isotope dilution alpha spectrometry. 238Pu content and for isotope correlations to calculate the specific activity and isotope composition of plutonium. All these studies involve the use of an alpha spectrometer to measure the activity ratio of 238Pu/(239Pu+240Pu) precisely. Technical Physics and Prototype Engineering Division (TPPED) of Bhabha Atomic Research Centre (BARC), Trombay, India has recently developed an alpha spectrometer, performance evaluation of which has been carried out by employing it to determine the activity ratio measurements of plutonium. Comparison of its performance with a commercially available system demonstrates that the indigenously developed instrument does provide acceptable levels of precision and accuracy for the activity ratio measurements of plutonium. (author)

  20. Manmade radionuclide vector in Austrian soil and vegetation near Temelin nuclear power plant

    Sinojmeri, M.; Ringer, V. [Oesterreichische Agentur fuer Gesundheit und Ernaehrungssicherheit - AGES (Austria)

    2014-07-01

    Since Chernobyl NPP accident an environmental monitoring program concerning the Upper Austrian region near Czech Republic Nuclear Power Plant, NPP Temelin, is in progress between AGES and BMLFUV, the Austrian Federal Ministry of Agriculture, Forestry, Environment, Water and Food, in Austria. This paper presents the results obtained during the sampling campaign over biennial period of 2010-2011. Soil samples, grass and different cereal species were collected. Beside Cs-134, Cs-137 and Sr-89, Sr-90 isotopes, at this phase the number of isotopes determined was extended with plutonium isotopes Pu-238, Pu-239, Pu-240, Pu-241 and Am-241. A comparison of these results with the existing data so far is presented. New knowledge was obtained related the bio-kinetic parameters of these elements in the environment. Document available in abstract form only. (authors)

  1. WWER-1000 spent fuel nuclide inventory at the Kozloduy NPP

    This paper contains a presentation and discussion of selected isotope inventory results for different types of WWER-1000 spent fuel assemblies. Nuclide inventory calculations of spent fuel assemblies at the Kozloduy NPP are routinely performed using the SCALE 4.4a computer code system. Besides the standard 17x17 ORIGEN-S library, a specific library developed at the Kozloduy NPP for each different fuel type at typical irradiation conditions is used. The evaluated concentrations of the most important isotopes - 235U, 236U, 238U, 239Pu, 240Pu, 241Pu, 242Pu - depending on burnup, are compared with fuel supplier data and with data calculated using the HELIOS-1.5 lattice code. The buildup of some other isotopes (237Np, 241Am, 243Am) is presented, too. (authors)

  2. WWER-1000 spent fuel nuclide inventory at the Kozloduy NPP

    This paper contains a presentation and discussion of selected isotope inventory results for different types of WWER-1000 spent fuel assemblies. Nuclide inventory calculations of spent fuel assemblies at Kozloduy NPP are routinely performed using the SCALE 4.4a computer code system. Besides the standard 17x17 ORIGEN-S library, a specific library developed at the Kozloduy NPP for each different fuel type at typical irradiation conditions is used. The evaluated concentrations of the most important isotopes-235U, 236U, 238U, 239Pu, 240Pu, 241Pu, 242Pu-depending on burnup, are compared with fuel supplier data and with data calculated using the HELIOS-1.5 lattice code. The buildup of some other isotopes (237Np, 241Am, 243Am) is presented, too (Authors)

  3. 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.

  4. Artificial radionuclides in the atmosphere over Lithuania

    Lujaniene, G. [Institute of Physics, Nuclear and Environmental Radioactivity Research Laboratory, Savanoriu 231, LT-02300 Vilnius (Lithuania)], E-mail: lujaniene@ar.fi.lt; Aninkevicius, V. [Semiconductor Physics Institute, A. Gostauto 11, LT-01108 Vilnius (Lithuania); Lujanas, V. [Institute of Physics, Nuclear and Environmental Radioactivity Research Laboratory, Savanoriu 231, LT-02300 Vilnius (Lithuania)

    2009-02-15

    Measurements of airborne radioactive aerosol concentration were carried out on the basis of 1-3 days samples after the Chernobyl disaster and during the period of 1992-2003. Transport of 'hot' particles of different composition resulted in the high activity concentrations of {sup 137}Cs, {sup 238}Pu, {sup 239,240}Pu and {sup 241}Am in the atmosphere in Vilnius at the end of April 1986. The {sup 240}Pu/{sup 239}Pu atom ratio showed clear evidence of non-global plutonium originating from the Chernobyl accident in the atmosphere over Lithuania. The {sup 240}Pu/{sup 239}Pu atom ratio ranged from 0.14 to 0.40 in monthly samples in Vilnius in 1995-2003. An increase in activity concentration of {sup 137}Cs by a factor of 100 (up to 300 {mu}Bq/m{sup 3}) was found following forest fires in the Ukraine and Belarus. However, no transport of the Chernobyl plutonium was observed and the {sup 240}Pu/{sup 239}Pu atom ratio in samples collected during the forest fires was found to be 0.229 and 0.185, respectively. The exponential decrease in the {sup 240}Pu/{sup 239}Pu atom ratio from 0.30 to 0.19 (mean values) was observed in 1995-2003.

  5. Preparation of isotopes and sources of actinide elements

    As the C.E.A. possesses no isotopic separation facility, the productions of isotopes of actinide elements are performed: a) by neutron irradiation and chemical treatment of special targets, b) by milking decay products from stocks of aged actinide elements, c) by chemical treatment of alpha active wastes. These productions concern the following isotopes: 233U, 238Pu, 242Pu, 243Cm, 242Cm, 244Cm (a); 228Th, 229Th, 234U, 237U, 239Np, 240Pu, 241Am, 248Cm (b); 237Np, 241Am (c). These isotopes are produced to satisfy French and international needs and are sent to users in various forms: solutions, metals, oxides, fluorides, or in different sources forms. The preparation of the sources represents an important field of activities divided into two parts: 1/Industrial sources: production of large series of different sources, 2/ Scientific sources: production of sources suitable for a specific scientific problem. A large overview of these activities is given

  6. 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

  7. Migration of plutonium isotopes in forest soil profiles in Lublin region (Eastern Poland)

    The distribution of Pu isotopes in three profiles of forest soil in Lublin region was determined. The retention half-time and migration velocity of 239,240Pu originated from global and Chernobyl fallouts was calculated. The average rate of migration of the global fallout plutonium was 0.4 cm/year and that of the Chernobyl one 0.7 cm/year. Good correlation between Pu concentration and organic matter contents was found only in the case of podzolic soil profile. In two profiles a good negative correlation between Pu activity and exchangeable pH of the soil layer was determined. (author)

  8. Equivalence test for sample data of isotopic compositions in PWR spent fuel

    Statistical combination method for previous and JAERI data of isotopic compositions in PWR spent fuel has been investigated. Using the F and T statistical test method, tests for the normality, the homogeneous variance and equivalent mean at a 5 % significance level have been carried out for twenty two isotopes which consist of spent fuel over 30 GWd/tU in burnup. All isotopes except U-238 and Nd-148 seem to be satisfied with the normality. 16 isotopes including U-234 seem to be satisfied with the homogeneous variance. 9 isotopes including U-235 seem to have a equivalent mean. 6 isotopes of U-235, Pu-240, Pu-241, Cs-134, Nd-144 and Sm-148 are appeared to be satisfied simultaneously with 3 alternative test results

  9. Comparative analysis between measured and calculated concentrations of major actinides using destructive assay data from Ohi-2 PWR

    Oettingen Mikołaj

    2015-09-01

    Full Text Available In the paper, we assess the accuracy of the Monte Carlo continuous energy burnup code (MCB in predicting final concentrations of major actinides in the spent nuclear fuel from commercial PWR. The Ohi-2 PWR irradiation experiment was chosen for the numerical reconstruction due to the availability of the final concentrations for eleven major actinides including five uranium isotopes (U-232, U-234, U-235, U-236, U-238 and six plutonium isotopes (Pu-236, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242. The main results were presented as a calculated-to-experimental ratio (C/E for measured and calculated final actinide concentrations. The good agreement in the range of ±5% was obtained for 78% C/E factors (43 out of 55. The MCB modeling shows significant improvement compared with the results of previous studies conducted on the Ohi-2 experiment, which proves the reliability and accuracy of the developed methodology.

  10. Rapid isolation of plutonium in environmental solid samples using sequential injection anion exchange chromatography followed by detection with inductively coupled plasma mass spectrometry

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

    2011-01-01

    This paper reports an automated analytical method for rapid determination of plutonium isotopes (239Pu and 240Pu) in environmental solid extracts. Anion exchange chromatographic columns were incorporated in a sequential injection (SI) system to undertake the automated separation of plutonium from...... size effect upon the separation efficiency revealed that small-sized (2 mL) columns sufficed to handle up to 50 g of environmental soil samples. Under the optimum conditions, chemical yields of plutonium exceeded 90% and the decontamination factors for uranium, thorium and lead ranged from 103 to 104....... The determination of plutonium isotopes in three standard/certified reference materials (IAEA-375 soil, IAEA-135 sediment and NIST-4359 seaweed) and two reference samples (Irish Sea sediment and Danish soil) revealed a good agreement with reference/certified values. The SI column-separation method...

  11. Actinide-only burnup credit for spent fuel transport

    A conservative methodology is described that would allow taking credit for burn up in the criticality safety analysis of spent nuclear fuel packages. Requirements for its implementation include isotopic and criticality validation, generation of package loading criteria using limiting parameters, and assembly burn up verification by measurement. The method allows credit for the changes in the 234U, 235U, 236U, 238U, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, and 241Am concentrations with burnup. No credit for fission product neutron absorbers is taken. Analyses are included regarding the methodology's financial benefits and conservative margin. It is estimated that the proposed actinide-only burnup credit methodology would save 20% of the transport costs. Nevertheless, the methodology includes a substantial margin. Conservatism due to the isotopic correction factors, limiting modelling parameters, limiting axial profiles and exclusion of the fission products ranges from 10 to 25% k. (author)

  12. 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

  13. 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)

  14. 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

  15. 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

  16. Current status of the multi-isotopic transuranic-waste-assay system

    We have designed, constructed, tested, and are scheduled to field a 208-l barrel-sized working version of our multi-isotopic transuranic assay system. This system uses both passive neutron multiplicity and pulsed active measurements to identify and quantify spontaneous neutron emitters and fissile TRU isotopes. Using the system we can separately quantify up to seven individual transuranic isotopes under favorable conditions with the intrinsic sensitivity to screen or assay barrels at or below the 10 nCi/g transuranic level. Our measured 3 sigma sensitivity for 239Pu is about 0.5 mg. A large range of waste matrix materials can be accommodated by the system, as well as extremes in both gamma-ray and neutron backgrounds

  17. Plutonium as a tracer for soil erosion assessment in northeast China

    Soil erosion is one of the most serious environmental and agricultural problems faced by human society. Assessing intensity is an important issue for controlling soil erosion and improving eco-environmental quality. The suitability of the application of plutonium (Pu) as a tracer for soil erosion assessment in northeast China was investigated by comparing with that of 137Cs. Here we build on preliminary work, in which we investigated the potential of Pu as a soil erosion tracer by sampling additional reference sites and potential erosive sites, along the Liaodong Bay region in northeast China, for Pu isotopes and 137Cs. 240Pu/239Pu atomic ratios in all samples were approximately 0.18, which indicated that the dominant source of Pu was the global fallout. Pu showed very similar distribution patterns to those of 137Cs at both uncultivated and cultivated sites. 239+240Pu concentrations in all uncultivated soil cores followed an exponential decline with soil depth, whereas at cultivated sites, Pu was homogenously distributed in plow horizons. Factors such as planted crop types, as well as methods and frequencies of irrigation and tillage were suggested to influence the distribution of radionuclides in cultivated land. The baseline inventories of 239+240Pu and 137Cs were 88.4 and 1688 Bq m−2 respectively. Soil erosion rates estimated by 239+240Pu tracing method were consistent with those obtained by the 137Cs method, confirming that Pu is an effective tracer with a similar tracing behavior to that of 137Cs for soil erosion assessment. - Highlights: • The potential for the use of Pu as a soil erosion tracer was investigated. • Pu would be a good tracer given its long half-life. • Depth profiles of Pu in soils were systematically studied and compared to 137Cs. • Pu is an effective soil erosion tracer with behavior similar to that of 137Cs. • Thus, Pu provides a means of investigating soil erosion

  18. {\\alpha}-accompanied cold ternary fission of $^{238-244}$Pu isotopes in equatorial and collinear configuration

    Santhosh, K P; Priyanka, B

    2015-01-01

    The cold ternary fission of $^{238}$Pu, $^{240}$Pu, $^{242}$Pu and $^{244}$Pu isotopes, with $^{4}$He as light charged particle, in equatorial and collinear configuration has been studied within the Unified ternary fission model (UTFM). The fragment combination $^{100}$Zr+$^{4}$He+$^{134}$Te possessing the near doubly magic nuclei $^{134}$Te (N=82, Z=52) gives the highest yield in the alpha accompanied ternary fission of $^{238}$Pu. For the alpha accompanied ternary fission of $^{240}$Pu, $^{242}$Pu and $^{244}$Pu isotopes, the highest yield was found for the fragment combination with doubly magic nuclei $^{132}$Sn (N=82, Z=50) as the heavier fragment. The deformation and orientation of fragments have also been taken into account for the alpha accompanied ternary fission of $^{238-244}$Pu isotopes, and it has been found that in addition to closed shell effect, ground state deformation also plays an important role in determining the isotopic yield in the ternary fission process. The emission probability and ki...

  19. Sediment core record of global fallout and Bikini close-in fallout Pu in Sagami Bay, Western Northwest Pacific margin.

    Zheng, Jian; Yamada, Masatoshi

    2004-07-01

    The total 239-240Pu activity and 240Pu/239Pu atom ratio in the sediments in Sagami Bay of the western Northwest Pacific margin were investigated using ICP-MS with a shield torch system. 239+240Pu inventories in the examined sediment cores were found to be much higher than those predicted from atmospheric global fallout (42 MBq/km2) at the same latitude. In addition, elevated 240Pu/239Pu atom ratios ranging from 0.22 to 0.28 were observed in the sediment samples. On the basis of the vertical profiles of 239+240Pu and characterized 240Pu/239Pu atom ratios in a sediment core collected in the center of Sagami Bay, we identified two distinct sources of fallout Pu in the bay: the global stratospheric fallout with characteristic 240Pu/239Pu ratio of 0.18 and the transported close-in fallout derived from Bikini and Enewetak surface nuclear weapon test series in the 1950s. We propose that the Pu transportation was mainly due to oceanic processes (for example, through the North Equatorial Current and the Kuroshio Current). Using a two fallout end-member model, we find that the contribution of Bikini close-in fallout Pu ranged from 44 to 59% in Sagami Bay sediments. To the best of our knowledge, this is the first report that Pu contamination, which originated from Bikini and Enewetak nuclear weapon test series in the 1950s, has extended westwards as far as the Japanese coast. PMID:15296298

  20. Neutron spectra produced by moderating an isotopic neutron source

    A Monte Carlo study has been carried out to determine the neutron spectra produced by an isotopic neutron source inserted in moderating media. Most devices used for radiation protection have a response strongly dependent on neutron energy. ISO recommends several neutron sources and monoenergetic neutron radiations, but actual working situations have broad spectral neutron distributions extending from thermal to MeV energies, for instance, near nuclear power plants, medical applications accelerators and cosmic neutrons. To improve the evaluation of the dosimetric quantities, is recommended to calibrate the radiation protection devices in neutron spectra which are nearly like those met in practice. In order to complete the range of neutron calibrating sources, it seems useful to develop several wide spectral distributions representative of typical spectra down to thermal energies. The aim of this investigation was to use an isotopic neutron source in different moderating media to reproduce some of the neutron fields found in practice. MCNP code has been used during calculations, in these a 239PuBe neutron source was inserted in H2O, D2O and polyethylene moderators. Moderators were modeled as spheres and cylinders of different sizes. In the case of cylindrical geometry the anisotropy of resulting neutron spectra was calculated from 0 to 2. From neutron spectra dosimetric features were calculated. MCNP calculations were validated by measuring the neutron spectra of a 239PuBe neutron source inserted in a H2O cylindrical moderator. The measurements were carried out with a multisphere neutron spectrometer with a 6LiI(Eu) scintillator. From the measurements the neutron spectrum was unfolded using the BUNKIUT code and the UTA4 response matrix. Some of the moderators with the source produce a neutron spectrum close to spectra found in actual applications, then can be used during the calibration of radiation protection devices