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Sample records for 239pu 240pu 241pu

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

    PubMed

    Xu, Yihong; Qiao, Jixin; Hou, Xiaolin; Pan, Shaoming; Roos, Per

    2014-02-01

    This paper reports an analytical method for the determination of plutonium isotopes ((238)Pu, (239)Pu, (240)Pu, (241)Pu) 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 × 10(5) 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 values, revealing that the developed method for plutonium determination in environmental samples is reliable. The measurement results of (239+240)Pu by alpha spectrometry agreed very well with the sum of (239)Pu and (240)Pu measured by ICP-MS. ICP-MS can not only measure (239)Pu and (240)Pu separately but also (241)Pu. However, it is impossible to measure (238)Pu using ICP-MS in environmental samples even a decontamination factor as high as 10(6) for uranium was obtained by chemical separation. PMID:24401459

  2. Nevada test site fallout atom ratios: /sup 240/Pu//sup 239/Pu and /sup 241/Pu//sup 239/Pu

    SciTech Connect

    Hicks, H.G.; Barr, D.W.

    1984-02-01

    The exposure of the population in Utah to external gamma radiation from the fallout from nuclear weapons tests carried out between 1951 and 1958 at the Nevada Test Site (NTS) has been reconstructed from recent measurements of /sup 137/Cs and plutonium in soil. The fraction of /sup 137/Cs in the fallout from NTS events was calculated from the total plutonium and the /sup 240/Pu//sup 239/Pu ratios measured in the soil, using the values of 0.180 +- 0.006 and 0.032 +- 0.003 for that ratio in global fallout and NTS fallout, respectively. The total population exposure from NTS events was then calculated on the basis of exposure rates resulting from short-lived radionuclides associated with the /sup 137/Cs at the time of deposition. While the /sup 240/Pu//sup 239/Pu ratio is constant in global fallout, this ratio varies greatly in the fallout from individual events. While the composition of fallout on Utah from NTS events is rather uniform, the Off-Site Radiation Exposure Review Project is currently reconstructing radiation exposures for locations close to NTS where the fallout may be predominantly from one event. Therefore, the authors compiled the pertinent ratios in order to provide information concerning the exposure resulting from any individual event. The plutonium ratios measured at 30 days postshot were compiled from unpublished values in the archives of the Nuclear Chemistry Division of LLNL and INC-11 of LANL. These ratios are pertinent to fallout data. Dates for each event were taken from a publication by the Nevada Operations Office of the Department of Energy. 3 references.

  3. A method of measurement of (239)Pu, (240)Pu, (241)Pu in high U content marine sediments by sector field ICP-MS and its application to Fukushima sediment samples.

    PubMed

    Bu, Wenting; Zheng, Jian; Guo, Qiuju; Aono, Tatsuo; Tazoe, Hirofumi; Tagami, Keiko; Uchida, Shigeo; Yamada, Masatoshi

    2014-01-01

    An accurate and precise analytical method is highly needed for the determination of Pu isotopes in marine sediments for the long-term marine environment monitoring that is being done since the Fukushima Dai-ichi Nuclear Power Plant accident. The elimination of uranium from the sediment samples needs to be carefully checked. We established an analytical method based on anion-exchange chromatography and SF-ICP-MS in this work. A uranium decontamination factor of 2 × 10(6) was achieved, and the U concentrations in the final sample solutions were typically below 4 pg mL(-1), thus no extra correction of (238)U interferences from the Pu spectra was needed. The method was suitable for the analysis of (241)Pu in marine sediments using large sample amounts (>10 g). We validated the method by measuring marine sediment reference materials and our results agreed well with the certified and the literature values. Surface sediments and one sediment core sample collected after the nuclear accident were analyzed. The characterization of (241)Pu/(239)Pu atom ratios in the surface sediments and the vertical distribution of Pu isotopes showed that there was no detectable Pu contamination from the nuclear accident in the marine sediments collected 30 km off the plant site. PMID:24328266

  4. Room-temperature electron spectroscopy of 239Pu and 240Pu

    NASA Astrophysics Data System (ADS)

    Ahmad, I.; Kondev, F. G.; Greene, J. P.; Zhu, S.

    2015-06-01

    Passivated, implanted, planar silicon (PIPS) detectors have been used for the measurement of electron spectra. The commercially available PIPS detectors, available in thicknesses of 100 μm, 300 μm, and 500 μm, have an energy resolution (FWHM) of ~ 2.2 keV, which is essentially the same as that of PIN diodes. Alpha and electron spectra of mass-separated 239Pu and 240Pu sources have been measured with a 300-μm thick PIPS detector and the electron to alpha ratios for the conversion lines of the 51.62- and 45.24-keV transitions have been determined. A procedure has been developed to determine the amount of 239Pu and 240Pu in a mixed source. The α-particle emission rate of the mixed source is measured, which is the sum of individual rates. From the electron spectrum of the mixed source, measured with the same setup as the alpha spectrum, the rates of 239Pu electron lines are determined. Using the electron rate of the 239Pu line and the electron to alpha ratio measured for the pure source, the α-particle emission rate of 239Pu is determined. The difference from the total α-particle emission rate gives the α-particle emission rate of 240Pu. In addition, electron intensities and conversion coefficients of the 239Pu and 240Pu transitions have been measured.

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

    NASA Astrophysics Data System (ADS)

    Chamizo, E.; García-León, M.; Peruchena, J. I.; Cereceda, F.; Vidal, V.; Pinilla, E.; Miró, C.

    2011-12-01

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

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

    PubMed

    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

  7. Performance of Cladding on MOX Fuel with Low 240Pu/239Pu Ratio

    SciTech Connect

    McCoy, Kevin; Blanpain, Patrick; Morris, Robert Noel

    2014-01-01

    The U.S. Department of Energy has decided to dispose of a portion of its surplus plutonium by reconstituting it into mixed oxide (MOX) fuel and irradiating it in commercial power reactors. As part of fuel qualification, four lead assemblies were manufactured and irradiated to a maximum fuel rod average burnup of 47.3 MWd/kg heavy metal. This was the world s first commercial irradiation of MOX fuel with a 240Pu/239Pu ratio less than 0.10. Five fuel rods with varying burnups and plutonium contents were selected from one of the assemblies and shipped to Oak Ridge National Laboratory for hot cell examination. This paper discusses the results of those examinations with emphasis on cladding performance. Exams relevant to the cladding included visual and eddy current exams, profilometry, microscopy, hydrogen analysis, gallium analysis, and mechanical testing. There was no discernible effect of the type of MOX fuel on the performance of the cladding.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Determination of Plutonium Activity Concentrations and 240Pu/239Pu Atom Ratios in Brown Algae (Fucus distichus) Collected from Amchitka Island, Alaska.

    SciTech Connect

    Hamilton, T F; Brown, T A; Marchetti, A A; Martinelli, R E; Kehl, S R

    2005-05-02

    Plutonium-239 ({sup 239}Pu) and plutonium-240 ({sup 240}Pu) activity concentrations and {sup 240}Pu/{sup 239}Pu atom ratios are reported for Brown Algae (Fucus distichus) collected from the littoral zone of Amchitka Island (Alaska) and at a control site on the Alaskan peninsula. Plutonium isotope measurements were performed in replicate using Accelerator Mass Spectrometry (AMS). The average {sup 240}Pu/{sup 239}Pu atom ratio observed in dried Fucus d. collected from Amchitka Island was 0.227 {+-} 0.007 (n=5) and compares with the expected {sup 240}Pu/{sup 239}Pu atom ratio in integrated worldwide fallout deposition in the Northern Hemisphere of 0.1805 {+-} 0.0057 (Cooper et al., 2000). In general, the characteristically high {sup 240}Pu/{sup 239}Pu content of Fucus d. analyzed in this study appear to indicate the presence of a discernible basin-wide secondary source of plutonium entering the marine environment. Of interest to the study of plutonium source terms within the Pacific basin are reports of elevated {sup 240}Pu/{sup 239}Pu atom ratios in fallout debris from high-yield atmospheric nuclear tests conducted in the Marshall Islands during the 1950s (Diamond et al., 1960), the wide range of {sup 240}Pu/{sup 239}Pu atom ratio values (0.19 to 0.34) observed in sea water, sediments, coral and other environmental media from the North Pacific Ocean (Hirose et al., 1992; Buesseler, 1997) and updated estimates of the relative contributions of close-in and intermediate fallout deposition on oceanic inventories of radionuclidies, especially in the Northern Pacific Ocean (Hamilton, 2004).

  10. Accelerator Mass Spectrometric (AMS) Measurements of Plutonium Activity Concentrations and 240Pu/239Pu Atom Ratios In Soil Extracts Supplied by the Carlsbad Environmental Monitoring & Research Center

    SciTech Connect

    Hamilton, T F; Brown, T A; Marchetti, A A; Martinelli, R E; Kehl, S R

    2005-02-28

    Plutonium-239 ({sup 239}Pu) and plutonium-239+240 ({sup 239+240}Pu) activities concentrations and {sup 240}Pu/{sup 239}Pu atom ratios are reported for a series of chemically purified soil extracts received from the Carlsbad Environmental Monitoring & Research Center (CEMRC) in New Mexico. Samples were analyzed without further purification at the Lawrence Livermore National Laboratory (LLNL) using accelerator mass spectrometry (AMS). This report also includes a brief description of the AMS system and internal laboratory procedures used to ensure the quality and reliability of the measurement data.

  11. Measurement of 240Pu/239Pu isotopic ratios in soils from the Marshall Islands using ICP-MS.

    PubMed

    Muramatsu, Y; Hamilton, T; Uchida, S; Tagami, K; Yoshida, S; Robison, W

    2001-10-20

    Nuclear weapons tests conducted by the United States in the Marshall Islands produced significant quantities of regional or tropospheric fallout contamination. Here we report on some preliminary inductively coupled plasma-mass spectrometry (ICP-MS) measurements of plutonium isolated from seven composite soil samples collected from Bikini, Enewetak and Rongelap Atolls in the northern Marshall Islands. These data show that 240Pu/239Pu isotopic signatures in surface soils from the Marshall Island vary significantly and could potentially be used to help quantify the range and extent of fallout deposition (and associated impacts) from specific weapons tests. 137Cs and 60Co were also determined on the same set of soil samples for comparative purposes. PMID:11669263

  12. Determination of {sup 230}Th, {sup 234}U, {sup 239}Pu, and {sup 240}Pu in soils by ICP-MS using flow-injection preconcentration

    SciTech Connect

    Hollenbach, M.; Grohs, J.; Mamich, S.; Kroft, M.

    1995-12-31

    The US Department of Energy needs improved analytical methods for alpha-emitting radionuclides to support environmental restoration and waste management projects. Inductively coupled plasma-mass spectrometry (ICP-MS) has been used successfully to measure radionuclides with relatively long half-lives; however, ICP-MS used with conventional sample introduction techniques lacks the sensitivity or selectivity to measure shorter-lived radionuclides at levels important for environmental monitoring. New methods were developed for measuring {sup 230}Th, {sup 234}U, {sup 239}Pu, and {sup 240}Pu in soils. Samples are dried, ground, and dissolved by fusion. A flow injection (FI) analysis system is used to separate and concentrate the analytes by solid-phase extraction. The FI eluent is pumped directly into the nebulizer of the ICP-MS. The use of FI resulted in greater sensitivity and freedom from interferences when compared with direct aspiration. Detection limits are improved by approximately a factor of 20. The detection limits are approximately 3 Bq/kg (4 ng/kg) for {sup 230}Th, 0.6 Bq/kg (3 ng/kg) for {sup 234}U, 0.4 Bq/kg (0.2 ng/kg) for {sup 239}Pu, and 2 Bq/kg (0.3 ng/kg) for {sup 240}Pu. The FI-ICP-MS methods are faster, less labor intensive, and generate less laboratory waste than traditional radiochemical methods. The FI-ICP-MS gives individual results for {sup 239}Pu and {sup 240}Pu which cannot be resolved by the usual radiochemical method. The accuracy of the methods was verified by analyzing reference soils.

  13. Determination of 240Pu/239Pu isotopic ratios in human tissues collected from areas around the Semipalatinsk Nuclear Test Site by sector-field high resolution ICP-MS.

    PubMed

    Yamamoto, M; Oikawa, S; Sakaguchi, A; Tomita, J; Hoshi, M; Apsalikov, K N

    2008-09-01

    Information on the 240Pu/239Pu isotope ratios in human tissues for people living around the Semipalatinsk Nuclear Test Site (SNTS) was deduced from 9 sets of soft tissues and bones, and 23 other bone samples obtained by autopsy. Plutonium was radiochemically separated and purified, and plutonium isotopes (239Pu and 240Pu) were determined by sector-field high resolution inductively coupled plasma-mass spectrometry. For most of the tissue samples from the former nine subjects, low 240Pu/239Pu isotope ratios were determined: bone, 0.125 +/- 0.018 (0.113-0.145, n = 4); lungs, 0.063 +/- 0.010 (0.051-0.078, n = 5); and liver, 0.148 +/- 0.026 (0.104-0.189, n = 9). Only 239Pu was detected in the kidney samples; the amount of 240Pu was too small to be measured, probably due to the small size of samples analyzed. The mean 240Pu/239Pu isotope ratio for bone samples from the latter 23 subjects was 0.152 +/- 0.034, ranging from 0.088 to 0.207. A significant difference (a two-tailed Student's t test; 95% significant level, alpha = 0.05) between mean 240Pu/239Pu isotope ratios for the tissue samples and for the global fallout value (0.178 +/- 0.014) indicated that weapons-grade plutonium from the atomic bombs has been incorporated into the human tissues, especially lungs, in the residents living around the SNTS. The present 239,240Pu concentrations in bone, lung, and liver samples were, however, not much different from ranges found for human tissues from other countries that were due solely to global fallout during the 1970's-1980's. PMID:18695410

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

    DOE PAGESBeta

    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.; et al

    2015-02-27

    In this study, we have developed a new category of sensor for measurement of the 240Pu/239Pu 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 foundmore » 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 240Pu/239Pu 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.« less

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

    PubMed

    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

  16. 137Cs, 239+240Pu and 240Pu/239Pu atom ratios in the surface waters of the western North Pacific Ocean, eastern Indian Ocean and their adjacent seas.

    PubMed

    Yamada, Masatoshi; Zheng, Jian; Wang, Zhong-Liang

    2006-07-31

    Surface seawater samples were collected along the track of the R/V Hakuho-Maru cruise (KH-96-5) from Tokyo to the Southern Ocean. The (137)Cs activities were determined for the surface waters in the western North Pacific Ocean, the Sulu and Indonesian Seas, the eastern Indian Ocean, the Bay of Bengal, the Andaman Sea, and the South China Sea. The (137)Cs activities showed a wide variation with values ranging from 1.1 Bq m(-3) in the Antarctic Circumpolar Region of the Southern Ocean to 3 Bq m(-3) in the western North Pacific Ocean and the South China Sea. The latitudinal distributions of (137)Cs activity were not reflective of that of the integrated deposition density of atmospheric global fallout. The removal rates of (137)Cs from the surface waters were roughly estimated from the two data sets of Miyake et al. [Miyake Y, Saruhashi K, Sugimura Y, Kanazawa T, Hirose K. Contents of (137)Cs, plutonium and americium isotopes in the Southern Ocean waters. Pap Meteorol Geophys 1988;39:95-113] and this study to be 0.016 yr(-1) in the Sulu and Indonesian Seas, 0.033 yr(-1) in the Bay of Bengal and Andaman Sea, and 0.029 yr(-1) in the South China Sea. These values were much lower than that in the coastal surface water of the western Northwest Pacific Ocean. This was likely due to less horizontal and vertical mixing of water masses and less scavenging. (239+240)Pu activities and (240)Pu/(239)Pu atom ratios were also determined for the surface waters in the western North Pacific Ocean, the Sulu and Indonesian Seas and the South China Sea. The (240)Pu/(239)Pu atom ratios ranged from 0.199+/-0.026 to 0.248+/-0.027 on average, and were significantly higher than the global stratospheric fallout ratio of 0.18. The contributions of the North Pacific Proving Grounds close-in fallout Pu were estimated to be 20% for the western North Pacific Ocean, 39% for the Sulu and Indonesian Seas and 42% for the South China Sea by using the two end-member mixing model. The higher (240)Pu/(239)Pu

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

    SciTech Connect

    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.

  18. Determination of 239Pu and 240Pu isotope ratio for a nuclear bomb particle using X-ray spectrometry in conjunction with γ-ray spectrometry and non-destructive α-particle spectrometry

    NASA Astrophysics Data System (ADS)

    Pöllänen, R.; Ruotsalainen, K.; Toivonen, H.

    2009-11-01

    A nuclear bomb particle from Thule containing Pu and U was analyzed using X-ray spectrometry in combination with γ-ray spectrometry and non-destructive α-spectrometry. The main objective was to investigate the possibility to determine the 239Pu and 240Pu isotope ratios. Previously, X-ray spectrometry together with the above-mentioned methods has been successfully applied for radiochemically processed samples, but not for individual particles. In the present paper we demonstrate the power of non-destructive analysis. The 239Pu/( 239Pu+ 240Pu) atom ratio for the Thule particle was determined, using two different approaches, to be 0.93±0.07 and 0.91±0.05. These results are consistent with weapons-grade material and the results obtained by other investigators.

  19. Ultra-trace determination of (90)Sr, (137)Cs, (238)Pu, (239)Pu, and (240)Pu by triple quadruple collision/reaction cell-ICP-MS/MS: Establishing a baseline for global fallout in Qatar soil and sediments.

    PubMed

    Amr, Mohamed A; Helal, Abdul-Fattah I; Al-Kinani, Athab T; Balakrishnan, Perumal

    2016-03-01

    The development of practical, fast, and reliable methods for the ultra-trace determination of anthropogenic radionuclides (90)Sr, (137)Cs, (238)Pu, (239)Pu, and (240)Pu by triple quadruple collision/reaction cell inductively coupled plasma mass spectrometry (CRC-ICP-MS/MS) were investigated in term of its accuracy and precision for producing reliable results. The radionuclides were extracted from 1 kg of the environmental soil samples by concentrated nitric and hydrochloric acids. The leachate solutions were measured directly by triple quadrupole CRC-ICP-MS/MS. For quality assurance, a chemical separation of the concerned radionuclides was conducted and then measured by single quadrupole-ICP-MS. The developed methods were next applied to measure the anthropogenic radionuclides (90)Sr, (137)Cs, (238)Pu, (239)Pu, and (240)Pu in soil samples collected throughout the State of Qatar. The average concentrations of (90)Sr, (137)Cs, (238)Pu, (239)Pu, and (240)Pu were 0.606 fg/g (3.364 Bq/kg), 0.619 fg/g (2.038 Bq/kg), 0.034 fg/g (0.0195 Bq/kg), 65.59 fg/g (0.150 Bq/kg), and 12.06 fg/g (0.103 Bq/kg), respectively. PMID:26736181

  20. 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.

    PubMed

    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

  1. Vertical distribution of (241)Pu in the southern Baltic Sea sediments.

    PubMed

    Strumińska-Parulska, Dagmara I

    2014-12-15

    The vertical distribution of plutonium (241)Pu in marine sediments can assist in determining the deposition history and sedimentation process of analyzed regions. In addition, (241)Pu/(239+240)Pu activity ratio could be used as a sensitive fingerprint for radioactive source identification. The present preliminary studies on vertical distribution of (241)Pu in sediments from four regions of the southern Baltic Sea are presented. The distribution of (241)Pu was not uniform and depended on sediment geomorphology and depth as well as location. The highest concentrations of plutonium were found in the surface layers of all analyzed sediments and originated from the Chernobyl accident. PMID:25455816

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

    PubMed

    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

  3. Neutron Capture Cross Section of 239Pu

    NASA Astrophysics Data System (ADS)

    Mosby, S.; Arnold, C.; Bredeweg, T. A.; Couture, A.; Jandel, M.; O'Donnell, J. M.; Rusev, G.; Ullmann, J. L.; Chyzh, A.; Henderson, R.; Kwan, E.; Wu, C. Y.

    2014-09-01

    The 239Pu(n,γ) cross section has been measured over the energy range 10 eV - 10 keV using the Detector for Advanced Neutron Capture Experiments (DANCE) as part of a campaign to produce precision (n,γ) measurements on 239Pu in the keV region. Fission coincidences were measured with a PPAC and used to characterize the prompt fission γ-ray spectrum in this region. The resulting spectra will be used to better characterize the fission component of another experiment with a thicker target to extend the (n,γ) cross section measurement well into the keV region.

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

    PubMed

    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

  5. Resolving Chernobyl vs. global fallout contributions in soils from Poland using Plutonium atom ratios measured by inductively coupled plasma mass spectrometry.

    PubMed

    Ketterer, Michael E; Hafer, Kevin M; Mietelski, Jerzy W

    2004-01-01

    Plutonium in Polish forest soils and the Bór za Lasem peat bog is resolved between Chernobyl and global fallout contributions via inductively coupled plasma mass spectrometric measurements of 240Pu/230Pu and 241Pu/239Pu atom ratios in previously prepared NdF3 alpha spectrometric sources. Compared to global fallout, Chernobyl Pu exhibits higher abundances of 240Pu and 241Pu. The ratios 240Pu/230Pu and 241Pu/239Pu co-vary and range from 0.186 to 0.348 and 0.0029 to 0.0412, respectively, in forest soils (241Pu/239Pu = 0.2407 x [240Pu/239Pu] - 0.0413; r2 = 0.9924). Two-component mixing models are developed to apportion 239+240Pu and 241Pu activities; various estimates of the percentage of Chernobyl-derived 239+240Pu activity in forest soils range from < 10% to > 90% for the sample set. The 240Pu/230Pu - 241Pu/239Pu atom ratio mixing line extrapolates to estimate 241Pu/239Pu and the 241Pu/239+240Pu activity ratio for the Chernobyl source term (0.123 +/- 0.0007; 83 +/- 5; 1 May 1986). Sample 241Pu activities, calculated using existing alpha spectrometric 239+240Pu activities, and the 240Pu/230Pu and 241Pu/239Pu atom ratios, agree relatively well with previous liquid scintillation spectrometry measurements. Chernobyl Pu is most evident in locations from northeastern Poland. The 241Pu activities and/or the 241Pu/239Pu atom ratios are more sensitive than 240Pu/239Pu or 238Pu/239+240Pu activity ratios at detecting small Chernobyl 239+240Pu inputs, found in southern Poland. The mass spectrometric data show that the 241Pu activity is 40-62% Chernobyl-derived in southern Poland, and 58-96% Chernobyl in northeastern Poland. The Bór za Lasem peat bog (49.42 degrees N, 19.75 degrees E), located in the Orawsko-Nowotarska valley of southern Poland, consists of global fallout Pu. PMID:15023447

  6. Transport of 137Cs and 239,240Pu with ice-rafted debris in the Arctic Ocean

    USGS Publications Warehouse

    Landa, E.R.; Reimnitz, E.; Beals, D.M.; Pochkowski, J.M.; Winn, W.G.; Rigor, I.

    1998-01-01

    Ice rafting is the dominant mechanism responsible for the transport of fine-grained sediments from coastal zones to the deep Arctic Basin. Therefore, the drift of ice-rafted debris (IRD) could be a significant transport mechanism from the shelf to the deep basin for radionuclides originating from nuclear fuel cycle activities and released to coastal Arctic regions of the former Soviet Union. In this study, 28 samples of IRD collected from the Arctic ice pack during expeditions in 1989-95 were analyzed for 137Cs by gamma spectrometry and for 239Pu and 240Pu by thermal ionization mass spectrometry. 137Cs concentrations in the IRD ranged from less than 0.2 to 78 Bq??kg-1 (dry weight basis). The two samples with the highest 137Cs concentrations were collected in the vicinity of Franz Josef Land, and their backward trajectories suggest origins in the Kara Sea. Among the lowest 137Cs values are seven measured on sediments entrained on the North American shelf in 1989 and 1995, and sampled on the shelf less than six months later. Concentrations of 239Pu + 240Pu ranged from about 0.02 to 1.8 Bq??kg-1. The two highest values came from samples collected in the central Canada Basin and near Spitsbergen; calculated backward trajectories suggest at least 14 years of circulation in the Canada Basin in the former case, and an origin near Severnaya Zemlya (at the Kara Sea/Laptev Sea boundary) in the latter case. While most of the IRD samples showed 240Pu/239Pu ratios near the mean global fallout value of 0.185, five of the samples had lower ratios, in the 0.119 to 0.166 range, indicative of mixtures of Pu from fallout and from the reprocessing of weapons-grade Pu. The backward trajectories of these five samples suggest origins in the Kara Sea or near Severnaya Zemlya.

  7. Concordant 241Pu-241Am Dating of Environmental Samples: Results from Forest Fire Ash

    NASA Astrophysics Data System (ADS)

    Goldstein, S. J.; Oldham, W. J.; Murrell, M. T.; Katzman, D.

    2010-12-01

    We have measured the Pu, 237Np, 241Am, and 151Sm isotopic systematics for a set of forest fire ash samples from various locations in the western U.S. including Montana, Wyoming, Idaho, and New Mexico. The goal of this study is to develop a concordant 241Pu (t1/2 = 14.4 y)-241Am dating method for environmental collections. Environmental samples often contain mixtures of components including global fallout. There are a number of approaches for subtracting the global fallout component for such samples. One approach is to use 242Pu/239Pu as a normalizing isotope ratio in a three-isotope plot, where this ratio for the non-global fallout component can be estimated or assumed to be small. This study investigates a new, complementary method of normalization using the long-lived fission product, 151Sm (t1/2 = 90 y). We find that forest fire ash concentrates actinides and fission products with ~1E10 atoms 239Pu/g and ~1E8 atoms 151Sm/g, allowing us to measure these nuclides by mass spectrometric (MIC-TIMS) and radiometric (liquid scintillation counting) methods. The forest fire ash samples are characterized by a western U.S. regional isotopic signature representing varying mixtures of global fallout with a local component from atmospheric testing of nuclear weapons at the Nevada Test Site (NTS). Our results also show that 151Sm is well correlated with the Pu nuclides in the forest fire ash, suggesting that these nuclides have similar geochemical behavior in the environment. Results of this correlation indicate that the 151Sm/239Pu atom ratio for global fallout is ~0.164, in agreement with an independent estimate of 0.165 based on 137Cs fission yields for atmospheric weapons tests at the NTS. 241Pu-241Am dating of the non-global fallout component in the forest fire ash samples yield ages in the late 1950’s-early 1960’s, consistent with a peak in NTS weapons testing at that time. The age results for this component are in agreement using both 242Pu and 151Sm normalizations

  8. European roe deer antlers as an environmental archive for fallout (236)U and (239)Pu.

    PubMed

    Froehlich, M B; Steier, P; Wallner, G; Fifield, L K

    2016-01-01

    Anthropogenic (236)U and (239)Pu were measured in European roe deer antlers hunted between 1955 and 1977 which covers and extends beyond the period of intensive nuclear weapons testing (1954-1962). The antlers were hunting trophies, and hence the hunting area, the year of shooting and the approximate age of each animal is given. Uranium and plutonium are known to deposit in skeletal tissue. Since antler histology is similar to bone, both elements were expected in antlers. Furthermore, roe deer shed their antlers annually, and hence antlers may provide a time-resolved environmental archive for fallout radionuclides. The radiochemical procedure is based on a Pu separation step by anion exchange (Dowex 1 × 8) and a subsequent U purification by extraction chromatography using UTEVA(®). The samples were measured by Accelerator Mass Spectrometry at the VERA facility (University of Vienna). In addition to the (236)U and (239)Pu concentrations, the (240)Pu/(239)Pu isotopic ratios were determined with a mean value of 0.172 ± 0.023 which is in agreement with the ratio of global fallout (∼0.18). Rather high (236)U/(238)U ratios of the order of 10(-6) were observed. These measured ratios, where the (236)U arises only from global fallout, have implications for the use of the (236)U/(238)U ratio as a fingerprint for nuclear accidents or releases from nuclear facilities. Our investigations have shown the potential to use antlers as a temporally resolved archive for the uptake of actinides from the environment. PMID:26119579

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

    NASA Astrophysics Data System (ADS)

    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 ).

  10. Use of plutonium isotope activity ratios in dating recent sediments. [/sup 238/Pu//sup 239/Pu + /sup 240/Pu

    SciTech Connect

    Beasley, T. M.

    1982-01-01

    The majority of plutonium presently in the biosphere has come from the testing of nuclear devices. In the early 1950s, the Pu-238/239+240 activity ratio of fallout debris was > 0.04; in the more extensive test series of 1961 to 1962, the Pu-238/239+240 activity ratios were quite consistent at 0.02 to 0.03 and maximum fallout delivery occurred in mid-1963. A significant perturbation in Pu isotope activity ratios occurred in mid-1966 with the deposition of Pu-238 from the SNAP-9A reentry and burn-up. Recently deposited sediments have recorded these events and where accumulation rates are rapid (> 1 cm/y), changes in Pu isotope activity ratios can be used as a geochronological tool.

  11. Plutonium-239, /sup 240/Pu and /sup 210/Po contents of tobacco and cigarette smoke

    SciTech Connect

    Mussalo-Rauhamaa, H.; Jaakkola, T.

    1985-08-01

    The /sup 239/Pu and /sup 240/Pu found in the environment has mainly been produced by atmospheric nuclear tests. The accumulation of fallout Pu in man from inhalation and ingestion and its distribution in the body has previously been studied. Information about the accumulation is needed because of the expanding production of this highly radiotoxic substance. In the present work the Pu content of tobacco and cigarette smoke was determined to evaluate the contribution of smoking to total Pu intake by man. For comparison the /sup 210/Po content of tobacco and smoke were analyzed. The release of /sup 210/Po in tobacco smoke and the radiation dose for man have been widely studied because of the high incidence of lung cancer among smokers.

  12. Use of anthropogenic radioisotopes to estimate rates of soil redistribution by wind II: The potential for future use of 239+240Pu

    NASA Astrophysics Data System (ADS)

    Van Pelt, R. Scott; Ketterer, Michael E.

    2013-06-01

    In the previous paper, the use of soilborne 137Cs from atmospheric fallout to estimate rates of soil redistribution, particularly by wind, was reviewed. This method relies on the assumption that the source of 137Cs in the soil profile is from atmospheric fallout following the period of atmospheric weapons testing so that the temporal and, to a certain extent, the spatial patterns of 137Cs deposition are known. One of the major limitations occurs when local or regional sources of 137Cs contamination mask the pulse from global fallout, making temporal estimates of redistribution difficult or impossible. Like 137Cs, Pu exhibits strong affinity for binding to soil particle surfaces, and therefore, re-distribution of Pu inventory indicates inferred soil re-distribution. Compared to 137Cs, 239Pu and 240Pu offer several important advantages: (a) the two major Pu isotopes have much longer half-lives than 137Cs and (b) the ratio 240Pu/239Pu is used to examine whether the Pu is from stratospheric fallout. In this paper, we review the literature concerning Pu in soil and of current attempts to use this tracer to estimate rates of soil redistribution. We also present preliminary, unpublished data from a pilot study designed to test whether or not 239+240Pu can be used to estimate rates of soil redistribution by wind. Based on similarities of profile distribution and relative inventories between 137Cs measurements and 239+240Pu measurements of split samples from a series of fields with documented wind erosion histories, we conclude that 239+240Pu may well be the anthropogenic radioisotope of choice for future soil redistribution investigations.

  13. Second interlaboratory comparison study for the analysis of 239Pu in synthetic urine at the microBq (-100 aCi) level by mass spectrometry

    SciTech Connect

    McCurdy, D; Lin, Z; Inn, K W; Bell III, R; Wagner, S; Efurd, D W; Steiner, R; Duffy, C; Hamilton, T F; Brown, T A; Marchetti, A A

    2005-01-28

    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 {sup 239}Pu 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 {sup 239}Pu in urine at the {micro}Bq/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 {micro}Bq of {sup 239}Pu per liter of synthetic urine. Each test sample also contained {sup 240}Pu at a {sup 240}Pu/{sup 239}Pu atom ratio of {approx}0.15 and natural uranium at a concentration of 50 {micro}Bq/ml. From the results of the two studies, it can be inferred that the best performance at the {micro}Bq 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.

  14. 239Pu Resonance Evaluation for Thermal Benchmark System Calculations

    NASA Astrophysics Data System (ADS)

    Leal, L. C.; Noguere, G.; de Saint Jean, C.; Kahler, A. C.

    2014-04-01

    Analyses of thermal plutonium solution critical benchmark systems have indicated a deficiency in the 239Pu resonance evaluation. To investigate possible solutions to this issue, the Organisation for Economic Co-operation and Development (OECD) Nuclear Energy Agency (NEA) Working Party for Evaluation Cooperation (WPEC) established Subgroup 34 to focus on the reevaluation of the 239Pu resolved resonance parameters. In addition, the impacts of the prompt neutron multiplicity (νbar) and the prompt neutron fission spectrum (PFNS) have been investigated. The objective of this paper is to present the results of the 239Pu resolved resonance evaluation effort.

  15. [ECG indices in dogs after inhalation of 239Pu].

    PubMed

    Karpova, V N

    1985-11-01

    Dogs of both sexes aged 2 to 4 were subjected to inhalation inoculation with polymer 239Pu or submicron 239PuO2 aerosols in amounts close to acute, subacute and chronically effective ones. ECG was recorded in standard, amplified and single leads (V3). All calculations were done by lead II. Signs of the right heart overburdening were noted in the presence of the P-pulmonale complex, deep S1 wave or cardiac electrical axis of SI-SII-SIII type. Signs of the right heart overburdening were revealed after inhalation of polimer 239Pu (70%). The absence of similar changes in damage caused by 239Pu could be attributed to its fast resorption from the lungs resulting in more moderate lesion of the respiratory organs. PMID:4068946

  16. Microscopic Calculations of 240Pu Fission

    SciTech Connect

    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.

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

    PubMed

    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

  18. Tissue, cellular, and subcellular distribution of /sup 241/Pu in the rat testes

    SciTech Connect

    Miller, S.C.; Bowman, B.M.

    1983-05-01

    The distribution and localization of /sup 241/Pu in rat testes were determined by quantitative autoradiography. Rats were given intravenous injection of /sup 241/Pu citrate and tissues were collected 1 week later. The tissue distribution of /sup 241/Pu was determined by light microscope autoradiography. Significant concentrations of /sup 241/Pu were observed in the interstitial tissue but not in seminiferous tubules. The cellular distribution and subcellular localization of /sup 241/Pu were determined by electron microscope autoradiography. Within the interstitial tissue, /sup 241/Pu was concentrated in microphages. There was no preferential localization of /sup 241/Pu in any other interstitial tissue components. Within interstitial tissue macrophages, /sup 241/Pu was concentrated in the lysosomal system of the cell. Other organellar compartments of the cell did not preferentially incorporate /sup 241/Pu. The association of /sup 241/Pu with the macrophage lysosomal system may explain the long retention times of Pu in testes as observed in experimental studies.

  19. Neutron Resonance Parameters and Covariance Matrix of 239Pu

    SciTech Connect

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

    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.

  20. Normalization of the [sup 239]Pu fission cross section

    SciTech Connect

    Wagemans, C.; Van Uffelen, P.; Deruytter, A.; Barthelemy, R.; Van Gils, J. . Joint Research Centre)

    1993-10-01

    Measurements have been performed at the Geel Linear Accelerator from 0.01 eV up to 1,000 eV in order to investigate the normalization of [sup 239]Pu fission cross-section measurements. Two different experiments were performed using surface barrier detectors and a double ionization chamber, respectively. In both cases, the [sup 10]B(n, [alpha]) reaction was used as a flux monitor. The results indicate that the Weston and Todd data should be renormalized by [approximately]3%, resulting in a satisfactory agreement with ENDF/B-VI.

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

    USGS Publications Warehouse

    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.

  2. Resolving global versus local/regional Pu sources in the environment using sector ICP-MS

    USGS Publications Warehouse

    Ketterer, M.E.; Hafer, K.M.; Link, C.L.; Kolwaite, D.; Wilson, Jim; Mietelski, J.W.

    2004-01-01

    Sector inductively coupled plasma mass spectrometry is a versatile method for the determination of plutonium activities and isotopic compositions in samples containing this element at fallout levels. Typical detection limits for 239+240Pu are 0.1, 0.02 and 0.002 Bq kg -1Pu for samples sizes of 0.5 g, 3 g, and 50 g of soil, respectively. The application of sector ICP-MS-based Pu determinations is demonstrated in studies in sediment chronology, soil Pu inventory and depth distribution, and the provenance of global fallout versus local or regional Pu sources. A sediment core collected from Sloans Lake (Denver, Colorado, USA) exhibits very similar 137Cs and 239+240Pu activity profiles; 240Pu/239Pu atom ratios indicate possible small influences from the Nevada Test Site and/or the Rocky Flats Environmental Technology Site. An undisturbed soil profile from Lockett Meadow (Flagstaff, Arizona, USA) exhibits an exponential decrease in 239+240Pu activity versus depth; 240Pu/239Pu in the top 3 cm is slightly lower than the global fallout range of 0.180 ?? 0.014 due to possible regional influence of Nevada Test Site fallout. The 239??240Pu inventory at Lockett Meadow is 56 ?? 4 Bq m-2, consistent with Northern Hemisphere mid-latitude fallout. Archived NdF3 sources, prepared from Polish soils, demonstrate that substantial 239+240Pu from the 1986 Chernobyl disaster has been deposited in north eastern regions of Poland; compared to global fallout, Chernobyl Pu exhibits higher abundances of 240Pu and 241Pu. The ratios 240Pu/239pu and 241Pu/239Pu co-vary and range from 0.186-0.348 and 0.0029-0.0412, respectively, in forest soils (241Pu/239Pu = 0.2407??[240Pu/239Pu] - 0.0413; r2 = 0.9924). ?? The Royal Society of Chemistry 2004.

  3. Gamma-ray Output Spectra from 239 Pu Fission

    DOE PAGESBeta

    Ullmann, John

    2015-05-25

    Gamma-ray multiplicities, individual gamma-ray energy spectra, and total gamma energy spectra following neutron-induced fission of 239Pu were measured using the DANCE detector at Los Alamos. Corrections for detector response were made using a forward-modeling technique based on propagating sets of gamma rays generated from a paramaterized model through a GEANT model of the DANCE array and adjusting the parameters for best fit to the measured spectra. The results for the gamma-ray spectrum and multiplicity are in general agreement with previous results, but the measured total gamma-ray energy is about 10% higher. A dependence of the gamma-ray spectrum on the gamma-raymore » multplicity was also observed. Global model calculations of the multiplicity and gamma energy distributions are in good agreement with the data, but predict a slightly softer total-energy distribution.« less

  4. Gamma-ray Output Spectra from 239Pu Fission

    NASA Astrophysics Data System (ADS)

    Ullmann, John

    2015-05-01

    Gamma-ray multiplicities, individual gamma-ray energy spectra, and total gamma energy spectra following neutron-induced fission of 239Pu were measured using the DANCE detector at Los Alamos. Corrections for detector response were made using a forward-modeling technique based on propagating sets of gamma rays generated from a paramaterized model through a GEANT model of the DANCE array and adjusting the parameters for best fit to the measured spectra. The results for the gamma-ray spectrum and multiplicity are in general agreement with previous results, but the measured total gamma-ray energy is about 10% higher. A dependence of the gamma-ray spectrum on the gamma-ray multplicity was also observed. Global model calculations of the multiplicity and gamma energy distributions are in good agreement with the data, but predict a slightly softer total-energy distribution.

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

    NASA Astrophysics Data System (ADS)

    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.

  6. Chronic cigarette smoke exposure increases the pulmonary retention and radiation dose of {sup 239}Pu inhaled as {sup 239}PuO{sub 2} by F344 rats

    SciTech Connect

    Finch, G.L.; Lundgren, D.L.; Barr, E.B.; Chen, B.T.; Griffith, W.C.; Hobbs, C.H.; Hoover, M.D.; Nikula, K.J.; Mauderly, J.L.

    1998-12-01

    As a portion of a study to examine how chronic cigarette smoke exposure might alter the risk of lung tumors from inhaled {sup 239}PuO{sub 2} in rats, the effects of smoke exposure on alpha-particle lung dosimetry over the life-span of exposed rats were determined. Male and female rats were exposed to inhaled {sup 239}PuO{sub 2} alone or in combination with cigarette smoke. Animals exposed to filtered air along served as controls for the smoke exposure. Whole-body exposure to mainstream smoke diluted to concentrations of either 100 or 250 mg total particulate matter m{sup {minus}3} began at 6 wk of age and continued for 6 h d{sup {minus}1}, 5 d wk{sup {minus}1}, for 30 mo. A single, pernasal, acute exposure to {sup 239}PuO{sub 2} was given to all rats at 12 wk of age. Exposure to cigarette smoke caused decreased body weight gains in a concentration dependent manner. Lung-to-body weight ratios were increased in smoke-exposed rats. Rats exposed to cigarette smoke before the {sup 239}PuO{sub 2} exposure deposited less {sup 239}Pu in the lung than did controls. Except for male rats exposed to LCS, exposure to smoke retarded the clearance of {sup 239}Pu from the lung compared to control rats through study termination at 870 d after {sup 239}PuO{sub 2} exposure. Radiation doses to lungs were calculated by sex and by exposure group for rats on study for at least 360 d using modeled body weight changes, lung-to-body weight ratios, and standard dosimetric calculations. For both sexes, estimated lifetime radiation doses from the time of {sup 239}PuO{sub 2} exposure to death were 3.8 Gy, 4.4 Gy, or 6.7 Gy for the control, LCS, or HCS exposure groups, respectively. Assuming an approximately linear dose-response relationship between radiation dose and lung neoplasm incidence, approximate increases of 20% or 80% in tumor incidence over controls would be expected in rats exposed to {sup 239}PuO{sub 2} and LCS or {sup 239}PuO{sub 2} and HCS, respectively.

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

    PubMed

    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. A Method for Continuous (239)Pu Determinations in Arctic and Antarctic Ice Cores.

    PubMed

    Arienzo, M M; McConnell, J R; Chellman, N; Criscitiello, A S; Curran, M; Fritzsche, D; Kipfstuhl, S; Mulvaney, R; Nolan, M; Opel, T; Sigl, M; Steffensen, J P

    2016-07-01

    Atmospheric nuclear weapons testing (NWT) resulted in the injection of plutonium (Pu) into the atmosphere and subsequent global deposition. We present a new method for continuous semiquantitative measurement of (239)Pu in ice cores, which was used to develop annual records of fallout from NWT in ten ice cores from Greenland and Antarctica. The (239)Pu was measured directly using an inductively coupled plasma-sector field mass spectrometer, thereby reducing analysis time and increasing depth-resolution with respect to previous methods. To validate this method, we compared our one year averaged results to published (239)Pu records and other records of NWT. The (239)Pu profiles from the Arctic ice cores reflected global trends in NWT and were in agreement with discrete Pu profiles from lower latitude ice cores. The (239)Pu measurements in the Antarctic ice cores tracked low latitude NWT, consistent with previously published discrete records from Antarctica. Advantages of the continuous (239)Pu measurement method are (1) reduced sample preparation and analysis time; (2) no requirement for additional ice samples for NWT fallout determinations; (3) measurements are exactly coregistered with all other chemical, elemental, isotopic, and gas measurements from the continuous analytical system; and (4) the long half-life means the (239)Pu record is stable through time. PMID:27244483

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

    NASA Astrophysics Data System (ADS)

    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.

  10. Osteosarcomas among beagles exposed to /sup 239/Pu

    SciTech Connect

    Whittemore, A.S.; McMillan, A.

    1982-04-01

    A Weibull distribution was fit to the osteosarcoma death times of beagles given single intravenous injections of /sup 239/Pu. For injected doses in the range 0-1..mu..Ci/kg the osteosarcoma incidence rate h(t) at t days after injection can be fit by a quadratic function of injected dose d: h(t) = 2.61 X 10/sup -18/ d/sup 2/t/sup 4.91/. The best-fitting linear function was rejected by the data (P < 0.001). A different formula for h(t), derived from a multistage theory for osteosarcoma induction, was also fit to these data. For this purpose microdosimetry calculations were used to estimate the dose to the cells at risk in the endosteal layer (endosteal dose). According to the best fit, h(t) is a quadratic function of endosteal dose at low doses. A linear dose-response relationship was again rejected. The absence of a linear component at low doses might be explained by the fact that 108 of the 185 animals injected at the lowest doses (<0.02 ..mu..Ci/kg) were still alive at the time these data were collected.

  11. A comparison of fallout (236)U and (239)Pu uptake by Australian vegetation.

    PubMed

    Froehlich, M B; Dietze, M M A; Tims, S G; Fifield, L K

    2016-01-01

    The isotopes (236)U and (239)Pu, both produced during nuclear weapons tests carried out in the 1950s and 1960s, are present in the environment and may be used as tracers for soil erosion studies. Although these radionuclides occur only at ultra-trace levels in nature, they can be readily measured by accelerator mass spectrometry with the 14UD heavy ion accelerator at the Australian National University. We have analysed a series of vegetation samples for their (236)U and (239)Pu concentration and compared the results with those found in the surrounding soil. (236)U could be measured in all collected samples whereas (239)Pu could not be detected in several vegetation samples due to its very low concentration, although it was readily detectable in the soil. We find that, relative to plutonium, (236)U is preferentially taken up by plants with enrichment factors ((236)U/(239)Pu)veg/((236)U/(239)Pu)soil that range between 7 and 52 in the present study. PMID:26141188

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  14. Evaluation of the 239Pu(n,2n) Integrated Cross Section

    SciTech Connect

    McNabb, D P; Anderson, J D; Bauer, R W; Becker, J A; Dietrich, F; Navratil, P; Chadwick, M B; Young, P G

    2001-01-25

    Recently, new cross section measurements by the GEANIE collaboration have been published for {sup 239}Pu(n, 2n{gamma}) [Ber00] and {sup 235}U(n, 2n{gamma}) [You00] from threshold to 20 MeV. When combined with nuclear reaction calculations [Che00, Cha99, Cha01], these measurements provide the most accurate information available on the shape and magnitude of the {sup 239}Pu(n, 2n) cross section for incident neutron energies, E{sub n} {approx}< 14 MeV. This new data has prompted a re-evaluation of the {sup 239}Pu(n, 2n) {sup 238}Pu reaction cross section considering all available experimental data. The data prior to the measurement of Bernstein et al. [Ber00] is illustrated in Figure 1a. These data sets were considered by previous evaluations [ENDL] of the {sup 239}Pu(n, 2n) cross section. The most precise experiment was an activation measurement done by Lougheed et al. [Lou00] for incident neutron energies, E{sub n}, between 13-15 MeV. In addition, there were two neutron-counting experiments, one by Mather et al. [Mat72] and one by Frehaut et al. [Fre85]. These two measurements cover a wide incident neutron range, with data points from threshold to E{sub n} {approx} 14 MeV. The available data sets are in poor agreement with each other and in some cases do not meet basic expectations. These experiments will be reviewed in detail. The new contributions to this evaluation are (1) the GEANIE data coupled with reaction modeling, illustrated in Figure 1b, and (2) the systematic use of other nuclear data in order to put constraints on the shape and magnitude of the {sup 239}Pu(n, 2n) cross section. The approach of this evaluation has been to use consistency arguments supported by nuclear data to resolve the measurement differences, with the goal of providing: (1) A comprehensive picture of our knowledge on the {sup 239}Pu(n, 2n) cross section; and (2) A new evaluation including the best possible estimate of the cross section and a one-sigma estimate the uncertainties. This

  15. Cluster approach to the structure of 240Pu

    NASA Astrophysics Data System (ADS)

    Shneidman, T. M.; Adamian, G. G.; Antonenko, N. V.; Jolos, R. V.; Zhou, Shan-Gui

    2015-09-01

    The cluster approach, which allows us to take into account both shape deformation parameters and cluster degrees of freedom, is developed to describe alternating-parity rotational bands. The important ingredient of the model is the dinuclear system concept in which the wave function of the nucleus is treated as a superposition of a mononucleus and two-cluster configurations. The model is applied to describe the multiple positive and negative parity rotational bands in 240Pu . The observed excitation spectrum and the angular momentum dependences of the parity splitting and of the electric E 1 and E 2 transition moments are explained. Special emphasis is made on the investigation of the recently measured positive parity 02+ rotational band of reflection-asymmetric nature. The results suggest that this band might be understood as being built on the lowest excited state in the mass asymmetry degree of freedom. The B (E 1 )/B (E 2 ) branching ratios between the reduced transition probabilities of decay from the states of the 02+ band to the first negative parity band and to the groundstate band, respectively, are calculated and compared with experimental data.

  16. Analysis of 236U and plutonium isotopes, 239,240Pu, on the 1 MV AMS system at the Centro Nacional de Aceleradores, as a potential tool in oceanography

    NASA Astrophysics Data System (ADS)

    Chamizo, Elena; López-Lora, Mercedes; Villa, María; Casacuberta, Núria; López-Gutiérrez, José María; Pham, Mai Khanh

    2015-10-01

    The performance of the 1 MV AMS system at the CNA (Centro Nacional de Aceleradores, Seville, Spain) for 236U and 239,240Pu measurements has been extensively investigated. A very promising 236U/238U abundance sensitivity of about 3 × 10-11 has been recently achieved, and background figures for 239Pu of about 106 atoms were reported in the past. These promising results lead to the use of conventional low energy AMS systems for the analysis of 236U and 239Pu and its further application in environmental studies. First 236U results obtained on our AMS system for marine samples (sediments and water) are presented here. Results of two new IAEA reference materials (IAEA-410 and IAEA-412, marine sediments from Pacific Ocean) are reported. The obtained 236U/239Pu atom ratios, of 0.12 and 0.022, respectively, show a dependency with the contamination source (i.e. local fallout from the US tests performed at the Bikini Atoll and general fallout). The results obtained for a third IAEA reference material (IAEA-381, seawater from the Irish Sea), are also presented. In the following, the uranium and plutonium isotopic compositions obtained on a set of 5 intercomparison seawater samples from the Arctic Ocean provided by the ETH Zürich are discussed. By comparing them with the obtained results on the 600 kV AMS facility Tandy at the ETH Zürich, we demonstrate the solidity of the CNA technique for 236U/238U determinations at, at least, 7 × 10-10 level. Finally, these results are discussed in their environmental context.

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

    PubMed

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

    2016-10-01

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

  18. Resource Note on Photofission of Nuclei for {sup 235}U and {sup 239}Pu Detection

    SciTech Connect

    Nieto, Michael Martin

    2004-11-15

    Open-source data exist, in widely scattered places, on photofission of the important nuclear isotopes {sup 235}U and {sup 239}Pu. These data are useful for studies aimed at detecting these materials at ports of entry. An introductory survey is given to access that data.

  19. Plutonium concentration and isotopic ratio in soil samples from central-eastern Japan collected around the 1970s

    PubMed Central

    Zheng, Jian; Tagami, Keiko; Uchida, Shigeo

    2015-01-01

    Obtaining Pu background data in the environment is essential for contamination source identification and assessment of environmental impact of Pu released from the Fukushima Daiichi nuclear power plant (FDNPP) accident. However, no baseline information on Pu isotopes in Fukushima Prefecture has been reported. Here we analyzed 80 surface soil samples collected from the central-eastern Japan during 1969–1977 for 239+240Pu activity concentration and 240Pu/239Pu atom ratio to establish the baseline before the FDNPP accident. We found that 239+240Pu activity concentrations ranged from 0.004 –1.46 mBq g−1, and 240Pu/239Pu atom ratios varied narrowly from 0.148 to 0.229 with a mean of 0.186 ± 0.015. We also reconstructed the surface deposition density of 241Pu using the 241Pu/239Pu atom ratio in the Japanese fallout reference material. The obtained results indicated that, for the FDNPP-accident released 241Pu, a similar radiation impact can be estimated as was seen for the global fallout deposited 241Pu in the last decades. PMID:25881009

  20. Plutonium concentration and isotopic ratio in soil samples from central-eastern Japan collected around the 1970s

    NASA Astrophysics Data System (ADS)

    Yang, Guosheng; Zheng, Jian; Tagami, Keiko; Uchida, Shigeo

    2015-04-01

    Obtaining Pu background data in the environment is essential for contamination source identification and assessment of environmental impact of Pu released from the Fukushima Daiichi nuclear power plant (FDNPP) accident. However, no baseline information on Pu isotopes in Fukushima Prefecture has been reported. Here we analyzed 80 surface soil samples collected from the central-eastern Japan during 1969-1977 for 239+240Pu activity concentration and 240Pu/239Pu atom ratio to establish the baseline before the FDNPP accident. We found that 239+240Pu activity concentrations ranged from 0.004 -1.46 mBq g-1, and 240Pu/239Pu atom ratios varied narrowly from 0.148 to 0.229 with a mean of 0.186 +/- 0.015. We also reconstructed the surface deposition density of 241Pu using the 241Pu/239Pu atom ratio in the Japanese fallout reference material. The obtained results indicated that, for the FDNPP-accident released 241Pu, a similar radiation impact can be estimated as was seen for the global fallout deposited 241Pu in the last decades.

  1. Plutonium concentration and isotopic ratio in soil samples from central-eastern Japan collected around the 1970s.

    PubMed

    Yang, Guosheng; Zheng, Jian; Tagami, Keiko; Uchida, Shigeo

    2015-01-01

    Obtaining Pu background data in the environment is essential for contamination source identification and assessment of environmental impact of Pu released from the Fukushima Daiichi nuclear power plant (FDNPP) accident. However, no baseline information on Pu isotopes in Fukushima Prefecture has been reported. Here we analyzed 80 surface soil samples collected from the central-eastern Japan during 1969-1977 for (239+240)Pu activity concentration and (240)Pu/(239)Pu atom ratio to establish the baseline before the FDNPP accident. We found that (239+240)Pu activity concentrations ranged from 0.004 -1.46 mBq g(-1), and (240)Pu/(239)Pu atom ratios varied narrowly from 0.148 to 0.229 with a mean of 0.186 ± 0.015. We also reconstructed the surface deposition density of (241)Pu using the (241)Pu/(239)Pu atom ratio in the Japanese fallout reference material. The obtained results indicated that, for the FDNPP-accident released (241)Pu, a similar radiation impact can be estimated as was seen for the global fallout deposited (241)Pu in the last decades. PMID:25881009

  2. Determination of /sup 239,240/Pu in bottom sediments of the Baltic Sea

    SciTech Connect

    Kuznetsov, Yu.V.; Legin, V.K.; Pospelov, Yu.N.; Simonyak, Z.N.

    1988-11-01

    We present a technique for determining the /sup 239,240/Pu content, using /sup 236/Pu as the monitor of chemical yield, in samples of soils and bottom sediments - objects of the external environment. Plutonium is extracted from the matrix material by leaching with a mixture of concentrated acids HCl-HNO/sub 3/, after which it is separated by ion-exchange methods. After electrodeposition onto stainless steel discs the activity of the nuclides of plutonium is measured by the method of alpha-spectrometry. The average chemical yields during the analysis of the samples was 40-60%, the relative standard deviation was 10%, and the lower limit of detectability was 0.3 Bq. We present results of the determination of the /sup 239,240/Pu content in surface samples of bottom sediments from the Gulf of Finland and that past of the Baltic Sea which adjoins the territory of the USSR. It is found that the unit activity of /sup 239,240/Pu in the bottom sediments varies within the limits of 0.4-1.2 Bq/kg and lies at the global level. Global genesis of /sup 239,240/Pu in the bottom sediments of the Gulf of Finland and the open parts of the Baltic Sea is also confirmed by the values which are found for the ratios /sup 238/Pu//sup 239,240/Pu and /sup 239,240/Pu//sup 137/Cs.

  3. Neutron and gamma-ray spectra of 239PuBe and 241AmBe.

    PubMed

    Vega-Carrillo, Héctor René; Manzanares-Acuña, Eduardo; Becerra-Ferreiro, Ana María; Carrillo-Nuñez, Aureliano

    2002-08-01

    Neutron and gamma-ray spectra of 239PuBe and 241AmBe were measured and their dosimetric features were calculated. Neutron spectra were measured using a multisphere neutron spectrometer with a 6LiI(Eu) scintillator. The 239PuBe neutron spectrum was measured in an open environment, while the 241AmBe neutron spectrum was measured in a closed environment. Gamma-ray spectra were measured using a NaI(Tl) scintillator using the same experimental conditions for both sources. The effect of measuring conditions for the 241AmBe neutron spectrum indicates the presence of epithermal and thermal neutrons. The low-resolution neutron spectra obtained with the multisphere spectrometer allows one to calculate the dosimetric features of neutron sources. At 100 cm both sources produce approximately the same count rate as that of the 4.4 MeV gamma-ray per unit of alpha emitter activity. PMID:12150274

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

    NASA Astrophysics Data System (ADS)

    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.

  5. Measurement of fallout {sup 239}Pu levels in urine samples by fission track analysis

    SciTech Connect

    Moorthy, A.R.; Doty, R.M.

    1996-11-01

    A Fission Track Analysis (FTA) method for assessing 239Pu in urine samples was first developed at Brookhaven National Laboratory (BNL) in 1988; it then had a detection limit of 100 aCi (3.7 {micro}Bq). Since that time, several steps were introduced that increased chemical recovery and lowered the detection limit to less than 1O aCi per sample. These improvements include a process of micro-column separation of plutonium in the final stages. The improved FTA method was applied to 22 urine samples from male staff at BNL. The results showed that 239Pu from fallout excreted in urine was 33 +/- 11 aCi (1.2 {micro}Bq) per day.

  6. Alveolar deposition of sized particles of /sup 239/Pu0/sub 2/ in the mouse

    SciTech Connect

    Morgan, A.; Black, A; Moores, S.R.; Pritchard, J.N.; Walsh, M.; Lambert, B.E.

    1983-01-01

    Data on the alveolar deposition of /sup 239/PuO/sub 2/ particles in the mouse are presented. It is shown that alveolar deposition falls with increasing activity median aerodynamic diameter (AMAD) over the range 0.6 to 2.4 ..mu..m. In the mouse, any peak in alveolar deposition must occur at an AMAD of less than 1 ..mu..m. Information is also provided on the relative lobar concentrations (RLCs) of /sup 239/PuO/sub 2/. The RLC is greatest in the right apical lobe and increases quite sharply with AMAD. The RLCs of the other lobes of the right lung decline with AMAD. The RLC in the left lobe is relatively unaffected by AMAD.

  7. Alveolar deposition of sized particles of /sup 239/PuO/sub 2/ in the mouse

    SciTech Connect

    Morgan, A.; Black, A.; Moores, S.R.; Pritchard, J.N.; Walsh, M.; Lambert, B.E.

    1983-01-01

    Data on the alveolar deposition of /sup 239/PuO/sub 2/ particles in the mouse are presented. It is shown that alveolar deposition falls with increasing activity median aerodynamic diameter (AMAD) over the range 0.6 to 2.4 microns. In the mouse, any peak in alveolar deposition must occur at an AMAD of less than 1 micron. Information is also provided on the relative lobar concentrations (RLCs) of /sup 239/PuO/sub 2/. The RLC is greatest in the right apical lobe and increases quite sharply with AMAD. The RLCs of the other lobes of the right lung decline with AMAD. The RLC in the left lobe is relatively unaffected by AMAD.

  8. A Time Projection Chamber for precision 239Pu(n,f) cross section measurement

    SciTech Connect

    Heffner, M

    2008-01-14

    High precision measurements of the {sup 239}Pu(n,f) cross section have been identified as important for the Global Nuclear Energy Partnership (GNEP) and other programs. Currently the uncertainty on this cross section is of the order 2-3% for neutron energies below 14 MeV and the goal is to reduce this to less than 1%. The Time Projection Chamber (TPC) has been identified as a possible tool to make this high precision measurement.

  9. Determination of 241Pu in nuclear waste slurries: a comparative study using LSC and ICP-MS.

    PubMed

    Jäggi, M; Röllin, S; Alvarado, J A Corcho; Eikenberg, J

    2012-02-01

    (241)Pu was determined in slurry samples from a nuclear reactor decommissioning project at the Paul Scherrer Institute (Switzerland). To validate the results, the (241)Pu activities of five samples were determined by LSC (TriCarb and Quantulus) and ICP-MS, with each instrument at a different laboratory. In lack of certified reference materials for (241)Pu, the methods were further validated using the (241)Pu information values of two reference sediments (IAEA-300 and IAEA-384). Excellent agreement with the results was found between LSC and ICP-MS in the nuclear waste slurries and the reference sediments. PMID:22079960

  10. Carcinogenic interactions between a single inhalation of 239PuO2 and chronic exposure to cigarette smoke in rats.

    PubMed

    Mauderly, Joe L; Seilkop, Steven K; Barr, Edward B; Gigliotti, Andrew P; Hahn, Fletcher F; Hobbs, Charles H; Finch, Gregory L

    2010-05-01

    Rats were exposed once by inhalation to plutonium-239 dioxide ((239)PuO(2)), resulting in chronic alpha-particle irradiation of the lung, and exposed chronically to cigarette smoke to examine carcinogenic interactions between the two exposures. F344 rats were exposed to (239)PuO(2) to achieve an initial lung burden of 0.5 kBq and then exposed 6 h/day, 5 days/week to cigarette smoke at 100 or 250 mg particulate matter/m(3) for up to 30 months. Exposure to cigarette smoke increased the cumulative radiation dose to lung by slowing the clearance of (239)PuO(2). (239)PuO(2) alone did not affect survival, but the higher cigarette smoke exposure shortened survival in females. Combined exposure to (239)PuO(2) and cigarette smoke acted synergistically to shorten survival in both genders. The combined effects of cigarette smoke and (239)PuO(2) were approximately additive for lung hyperplasia and adenomas but were strongly synergistic for carcinomas. Differences between observed incidences and incidences predicted by survival-adjusted models accounting for increased radiation dose revealed a substantial component of synergy for carcinomas above that attributable to the radiation dose effect. The synergy for malignant lung tumors is consistent with findings from uranium miners and nuclear weapons production workers. These results bolster confidence in the epidemiological findings and have implications for risk assessment. PMID:20426667

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

    NASA Astrophysics Data System (ADS)

    Finn, Erin C.; McNamara, Bruce; Greenwood, Larry; Wittman, Richard; Soderquist, Charles; Woods, Vincent; VanDevender, Brent; Metz, Lori; Friese, Judah

    2015-04-01

    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.

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

    SciTech Connect

    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.

  13. Comprehensive appraisal of {sup 239+240}Pu in soils around Rocky Flats, Colorado

    SciTech Connect

    Litaor, M.I.; Allen, L.; Ellerbroek, D.

    1995-12-01

    Plutonium contamination of soils around Rocky Flats Environmental & Technology Site, near Golden, Colorado, resulted from past outdoor storage practices and subsequent remobilization due to inadequate cleanup practices. Until now human-health risk assessment has not been performed because of a lack of sufficient information regarding the spatial extent of {sup 239+240}Pu in soils. The purpose of this work was to elucidate the extent of plutonium contamination in surface soils, and to assess the uncertainty associated with the spatial distribution of {sup 239+240}Pu around Rocky Flats Environmental & Technology Site.

  14. 137Cs and (239+240)Pu levels in the Asia-Pacific regional seas.

    PubMed

    Duran, E B; Povinec, P P; Fowler, S W; Airey, P L; Hong, G H

    2004-01-01

    137Cs and (239+240)Pu data in seawater, sediment and biota from the regional seas of Asia-Pacific extending from 50 degrees N to 60 degrees S latitude and 60 degrees E to 180 degrees E longitude based on the Asia-Pacific Marine Radioactivity Database (ASPAMARD) are presented and discussed. 137Cs levels in surface seawater have been declining to its present median value of about 3 Bq/m3 due mainly to radioactive decay, transport processes, and the absence of new significant inputs. (239+240)Pu levels in surface seawater are much lower, with a median of about 6 mBq/m3. (239+240)Pu appears to be partly scavenged by particles and is therefore more readily transported down the water column. As with seawater, (239+240)Pu concentrations are lower than 137Cs in surface sediment. The median 137Cs concentration in surface sediment is 1.4 Bq/kg dry, while that of (239+240)Pu is only 0.2 Bq/kg dry. The vertical profiles of both 137Cs and (239+240)Pu in the sediment column of coastal areas are different from deep seas which can be attributed to the higher sedimentation rates and additional contribution of run-offs from terrestrial catchment areas in the coastal zone. Comparable data for biota are far less extensive than those for seawater and sediment. The median 137Cs concentration in fish (0.2 Bq/kg wet) is higher than in crustaceans (0.1 Bq/kg wet) or mollusks (0.1 Bq/kg wet). Benchmark values (as of 2001) for 137Cs and (239+240)Pu concentrations in seawater, sediment and biota are established to serve as reference values against which the impact of future anthropogenic inputs can be assessed. ASPAMARD represents one of the most comprehensive compilations of available data on 137Cs and (239+240)Pu in particular, and other anthropogenic as well as natural radionuclides in seawater, sediment and biota from the Asia-Pacific regional seas. PMID:15245845

  15. 239PU(N, f) at Resonance Energies and its Multi-Modal Interpretation

    NASA Astrophysics Data System (ADS)

    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.

  16. Commentary on Inhaled 239PuO2 in Dogs — A Prophylaxis against Lung Cancer?

    DOE PAGESBeta

    Cuttler, Jerry M.; Feinendegen, Ludwig E.

    2015-01-01

    Several studies on the effect of inhaled plutonium-dioxide particulates and the incidence of lung tumors in dogs reveal beneficial effects when the cumulative alpha-radiation dose is low. There is a threshold at an exposure level of about 100 cGy for excess tumor incidence and reduced lifespan. The observations conform to the expectations of the radiation hormesis dose-response model and contradict the predictions of the LNT hypothesis. These studies suggest investigating the possibility of employing low-dose alpha-radiation, such as from 239PuO2 inhalation, as a prophylaxis against lung cancer.

  17. Improving the Assay of 239Pu in Spent and Melted Fuel Using the Nuclear Resonance Fluorescence Integral Resonance Transmission Method

    NASA Astrophysics Data System (ADS)

    Angell, C. T.; Hayakawa, T.; Shizuma, T.; Hajima, R.; Quiter, B. J.; Ludewigt, B. A.; Karwowski, H.; Rich, G.

    2015-10-01

    Non-destructive assay (NDA) of 239Pu in spent nuclear fuel is possible using the isotope-specific nuclear resonance fluorescence (NRF) integral resonance transmission (IRT) method. The IRT method measures the absorption of photons from a quasi-monoenergetic γ-ray beam due to all resonances in the energy width of the beam. According to calculations the IRT method could greatly improve assay times for 239Pu in nuclear fuel. To demonstrate and verify the IRT method, the IRT signature was first measured in 181Ta, whose nuclear resonant properties are similar to those of 239Pu, and then measured in 239Pu. These measurements were done using the quasi-monoenergetic beam at the High Intensity γ-ray Source (HIγS) in Durham, NC, USA. The IRT signature was observed as a decrease in scattering strength when the same isotope material was placed upstream of the scattering target. The results confirm the validity of the IRT method in both 181Ta and 239Pu.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    G. Palmiottti; H. Hiruta; M. Salvatores

    2011-09-01

    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 {sup 235}U, {sup 238}U, and {sup 239}Pu. 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: {sup 235}U and {sup 239}Pu. 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 K{sub eff} 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.

  20. Partial (gamma)-Ray Cross Sections for the Reaction 239Pu(n,2n(gamma)i) and the 239Pu(n,2n) Cross Section

    SciTech Connect

    Beacker, J.A.; Bernstein, L.A.; Younes, W.; McNabb, D.P.; Garrett, P.E.; Archer, D.; McGrath, C.A.; Stoyer, M.A.; Chen, H.; Ormand, W.E.; Nelson, R.O.; Chadwick, M.B.; Johns, G.D.; Drake, D.; Young, P.G.; Devlin, M.; Fotiades, N.; Wilburn, W.S.

    2001-09-14

    Absolute partial {gamma}-ray cross sections for production of discrete {gamma} rays in the {sup 239}Pu(n,2n{gamma}i){sup 238}Pu reaction have been measured. The experiments were performed at LANSCE/WNR on the 60R flight line. Reaction {gamma}-rays were measured using the large-scale Compton-suppressed array of Ge detectors, GEANIE. The motivation for this experiment, an overview of the partial {gamma}-ray cross-section measurement, and an introduction to the main experimental issues will be presented. The energy resolution of the Ge detectors allowed identification of reaction {gamma} rays above the background of sample radioactivity and fission {gamma} rays. The use of planar Ge detectors with their reduced sensitivity to neutron interactions and improved line shape was also important to the success of this experiment. Absolute partial {gamma}-ray cross sections are presented for the 6{sub 1}{sup +} {yields} 4{sub 1}{sup +} member of the ground state rotational band in {sup 238}Pu, together with miscellaneous other {gamma}-ray partial cross sections. The n,2n reaction cross section shape and magnitude as a function of neutron energy was extracted from these partial cross sections using nuclear modeling (enhanced Hauser-Feshbach) to relate partial {gamma}-ray cross sections to the n,2n cross section. The critical nuclear modeling issue is the ratio of a partial cross section to the reaction channel cross section, and not the prediction of the absolute magnitude.

  1. 239Pu(n,2n) 238Pu cross section inferred from IDA calculations and GEANIE measurements

    SciTech Connect

    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.

  2. Exposure of F344 rats to aerosols of {sup 239}PuO{sub 2} and chronically inhaled cigarette smoke

    SciTech Connect

    Finch, G.L.; Nikula, K.J.; Barr, E.B.; Bechtold, W.E.; Chen, B.T.; Griffith, W.C.; Hobbs, C.H.; Hoover, M.D.; Mauderly, J.L.

    1994-11-01

    Nuclear workers may be accidently exposed to radioactive materials such as {sup 239}PuO{sub 2} by inhalation, and thus have increased risk for lung cancer compared to the general population. Of additional concern is the possibility that interactions between radionuclides and other carcinogens may increase the risk of cancer induction. An important and common lung carcinogen is cigarette smoke. This study is being conducted to better determine the combined effects of inhaled {sup 239}PuO{sub 2} and cigarette smoke on the induction of lung cancer in rats.

  3. Microdistribution and retention of injected /sup 239/Pu on trabecular bone surfaces of the beagle: implications for the induction of osteosarcoma

    SciTech Connect

    Wronski, T.J.; Smith, J.M.; Jee, W.S.S.

    1980-07-01

    A study was initiated to investigate the relationship between skeletal remodeling and the microdistribution and retention of /sup 239/Pu on trabecular bone surfaces of the beagle, and the contribution of these parameters to the nonuniform skeletal distribution of /sup 239/Pu-induced osteosarcomas. Young adult beagles were administered single iv injections of approx. 0.016 ..mu..Ci/kg monomeric /sup 239/Pu citrate and sacrificed at various times to 1 year after injection. The /sup 239/Pu concentration on trabecular bone surfaces was determined by counting fission fragment tracks in neutron-induced autoradiographs produced from thick (approx. 400 ..mu..m) bone sections. The rate of trabecular bone formation was calculated from an ultraviolet microscopic analysis of fluorescent tetracycline labels. The lumbar vertebra, pelvis, and proximal humerus, each of which exhibits a high incidence of /sup 239/Pu-induced osteosarcoma, were found to have a high intial concentration of /sup 239/Pu on their trabecular surfaces (approx. 7-8 pCi/cm/sup 2/) and a relatively high rate of trabecular bone formation. The /sup 239/Pu concentration at these sites decreased to approx. 2-3 pCi/cm/sup 2/ at the end of the first year. On the other hand, the proximal ulna and distal humerus, skeletal sites with a low tumor incidence, had a low intial concentration of /sup 239/Pu on their trabecular surfaces(approx. 1-2 pCi/cm/sup 2/) and a significantly lower rate of trabecular bone formation (P < 0.01). The /sup 239/Pu concentration at these sites remained nearly constant throughout the experimental period. These data suggest that the degree of the initial deposition of /sup 239/Pu on trabecular bone surfaces and the rate of trabecular bone turnover may play a role in the genesis of /sup 239/Pu-induced osteosarcomas.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  6. Quantitative scanning electron microscopic autoradiography of inhaled /sup 239/PuO/sub 2/

    SciTech Connect

    Sanders, C.L.; Lauhala, K.E.; McDonald, K.E.

    1989-03-01

    We have applied the scanning electron microscope (SEM) to obtain autoradiographs of particles of /sup 239/PuO/sub 2/ 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.

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

    SciTech Connect

    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.

  8. Correlation of /sup 239/Pu thermal and fast reactor fission yields with neutron energy

    SciTech Connect

    Maeck, W.J.

    1981-10-01

    The relative isotopic abundances and the fisson yields for over 40 stable and long-lived fission products from /sup 239/Pu fast fission were evaluated to determine if the data could be correlated with neutron energy. Only mass spectrometric data were used in this study. For some nuclides changes of only a few percent in the relative isotopic abundance or the fission yields over the energy range of thermal to 1 MeV are easily discernable and significant; for others the data are too sparse and scattered to obtain a good correlation. The neutron energy index usedin this study is the /sup 150/Nd//sup 143/Nd isotopic ratio. The results of this correlation study compared to the US Evaluated Nuclear Data File (ENDF) fast fission yield compilation. Several discrepancies are noted and suggestions for future work are presented.

  9. Release of Pu isotopes from the Fukushima Daiichi Nuclear Power Plant accident to the marine environment was negligible.

    PubMed

    Bu, Wenting; Fukuda, Miho; Zheng, Jian; Aono, Tatsuo; Ishimaru, Takashi; Kanda, Jota; Yang, Guosheng; Tagami, Keiko; Uchida, Shigeo; Guo, Qiuju; Yamada, Masatoshi

    2014-08-19

    Atmospheric deposition of Pu isotopes from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident has been observed in the terrestrial environment around the FDNPP site; however, their deposition in the marine environment has not been studied. The possible contamination of Pu in the marine environment has attracted great scientific and public concern. To fully understand this possible contamination of Pu isotopes from the FDNPP accident to the marine environment, we collected marine sediment core samples within the 30 km zone around the FDNPP site in the western North Pacific about two years after the accident. Pu isotopes ((239)Pu, (240)Pu, and (241)Pu) and radiocesium isotopes ((134)Cs and (137)Cs) in the samples were determined. The high activities of radiocesium and the (134)Cs/(137)Cs activity ratios with values around 1 (decay corrected to 15 March 2011) suggested that these samples were contaminated by the FDNPP accident-released radionuclides. However, the activities of (239+240)Pu and (241)Pu were low compared with the background level before the FDNPP accident. The Pu atom ratios ((240)Pu/(239)Pu and (241)Pu/(239)Pu) suggested that global fallout and the pacific proving ground (PPG) close-in fallout are the main sources for Pu contamination in the marine sediments. As Pu isotopes are particle-reactive and they can be easily incorporated with the marine sediments, we concluded that the release of Pu isotopes from the FDNPP accident to the marine environment was negligible. PMID:25050458

  10. 239Pu Prompt Fission Neutron Spectra Impact on a Set of Criticality and Experimental Reactor Benchmarks

    NASA Astrophysics Data System (ADS)

    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

  11. Prompt Gamma Emission in Resonance Neutron Induced Fission of 239Pu

    NASA Astrophysics Data System (ADS)

    Ruskov, I.; Kopatch, Yu. N.; Panteleev, Ts.; Skoy, V. R.; Shvetsov, V. N.; Dermendjiev, E.; Janeva, N.; Pikelner, L. B.; Grigoriev, Yu. V.; Mezentseva, Zh. V.; Ivanov, I.

    The scientific interest in the resonance neutron induced capture and fission reactions on 239Pu is continuously rising during the last decade. From a practical point of view, this is because more precise data on capture and fission cross sections, fission fragment mass and kinetic energy distributions, variation of prompt fission neutron and gamma yields in the resonance neutron region, are needed for the modelling of new generation nuclear power plants and for nuclear spent fuel and waste transmutation. From a heuristic and fundamental point of view, such a research improves our knowledge and understanding of the fission phenomena itself. To achieve these goals more powerful neutron sources and more precise fission product detectors have to be used. At the Joint Institute for Nuclear Research (JINR) Frank Laboratory of Neutron Physics (FLNP), where already half a century the thermal and resonance neutron induced nuclear reactions are studied, a new electron accelerator driven white spectrum pulsed neutron source IREN has been built and successfully tested. The improved characteristics of this facility, in comparison with those of the former pulse neutron fast reactor IBR-30, will allow measuring some of the neutron-nuclear reaction data with better precision and accuracy. A new experimental setup for detecting gamma rays (and neutrons) has been designed and is under construction. It will consist of 2 rings (arrays) of 12 NaI(Tl) detectors each (or 1 array of 24 detectors) with variable ring diameter and distance between both rings. Such a setup will make possible not only to measure the multiplicity, energy and angular anisotropy of prompt fission gammas, but also to separate the contribution of prompt fission neutrons by their longer time-of-flight from the fissile target to the detectors. The signals from all the 24 detectors will be recorded simultaneously in digitized form and will be stored on the hard disk of the personal computer for further off

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

    NASA Astrophysics Data System (ADS)

    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.

  13. Comprehensive appraisal of 239 + 240Pu in soils around Rocky Flats, Colorado.

    PubMed

    Litaor, M I; Ellerbroek, D; Allen, L; Dovala, E

    1995-12-01

    Plutonium contamination of soils around Rocky Flats Environmental & Technology Site, near Golden, Colorado, resulted from past outdoor storage practices and subsequent remobilization due to inadequate cleanup practices. Until now human-health risk assessment has not been performed because of a lack of sufficient information regarding the spatial extent of 239 + 240Pu in soils. The purpose of this work was to elucidate the extent of plutonium contamination in surface soils, and to assess the uncertainty associated with the spatial distribution of 239 + 240Pu around Rocky Flats Environmental & Technology Site. Four data sets were collected or compiled for this investigation: (1) samples collected from 240 plots of 1.01- or 4.05-hectare by compositing 25 evenly-spaced samples from the upper 0.64 cm in each plot; (2) samples collected from the upper 5 cm of soil in 167 of the same 240 plots by compositing 10 samples from the center of each plot; (3) historical data compiled from samples collected between 1969 and 1973, considered to be the most indicative of the original release; and (4) the exhaustive data set that contains the samples from 1, 2, and 3 and other published data sets collected between 1974 and 1994. These latter samples varied in depth and method of sampling. Plutonium activity reported in the exhaustive data set ranged from 0.03 Bq kg-1 to 407,000 Bq kg-1 with a mean of 1,443 Bq kg-1, median of 6.6 Bq kg-1, standard deviation of 18,463 Bq kg-1, and a coefficient of variation of 12.6. The technique of nonparametric indicator kriging was used to model four conditional cumulative distribution functions of 239 + 240Pu in soils around Rocky Flats Environmental & Technology Site. Each of the conditional cumulative distribution functions was used to generate an E-type (mean of the conditional cumulative distribution functions) surface. The resulted surfaces were consistent with the hypothesis that the westerly winds were the dominant mechanism of plutonium

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

    NASA Astrophysics Data System (ADS)

    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.

  15. Distribution of /sup 239/Pu and /sup 241/Am in the human skeleton

    SciTech Connect

    McInroy, J.F.; Swint, M.J.

    1984-01-01

    The /sup 241/Am and /sup 239/Pu 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.

  16. Isotopic yield measurement in the heavy mass region for 239Pu thermal neutron induced fission

    NASA Astrophysics Data System (ADS)

    Bail, A.; Serot, O.; Mathieu, L.; Litaize, O.; Materna, T.; Köster, U.; Faust, H.; Letourneau, A.; Panebianco, S.

    2011-09-01

    Despite the huge number of fission yield data available in the different evaluated nuclear data libraries, such as JEFF-3.1.1, ENDF/B-VII.0, and JENDL-4.0, more accurate data are still needed both for nuclear energy applications and for our understanding of the fission process itself. It is within the framework of this that measurements on the recoil mass spectrometer Lohengrin (at the Institut Laue-Langevin, Grenoble, France) was undertaken, to determine isotopic yields for the heavy fission products from the 239Pu(nth,f) reaction. In order to do this, a new experimental method based on γ-ray spectrometry was developed and validated by comparing our results with those performed in the light mass region with completely different setups. Hence, about 65 fission product yields were measured with an uncertainty that has been reduced on average by a factor of 2 compared to that previously available in the nuclear data libraries. In addition, for some fission products, a strongly deformed ionic charge distribution compared to a normal Gaussian shape was found, which was interpreted as being caused by the presence of a nanosecond isomeric state. Finally, a nuclear charge polarization has been observed in agreement, with the one described on other close fissioning systems.

  17. [Acceleration of the excretion of monomeric 239Pu-citrate from the body as effected by pentacyne encapsulated in liposomes].

    PubMed

    Il'in, L A; Smirnov, A A; Ivannikov, A T; Parfenova, I M

    1983-01-01

    Liposomes, obtained by a modified procedure involving reverse phases, contained 2-3-times more 14C-pentacyne than the multilayer Banchem;s liposomes. Efficiency of pentacyne encapsulated in liposomes was higher, as compared with a non-encapsulated preparation in studies of urinary excretion of monomeric 239Pu-citrate in rats. Liposomal pentacyne increased most effectively the rate of the radionuclide excretion from liver tissue and skeleton as compared with the action of non-encapsulated complex-forming agent; as a result of which the radionuclide was excreted from liver tissue at a 1.6-2-times and from skeleton--with the 1.4-times higher rates. The both preparations increased the 239Pu excretion with urine and feces. The liposomal pentacyne accelerated an additional excretion of the nuclide with urine. PMID:6353751

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

    NASA Astrophysics Data System (ADS)

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    We compare the suitability of the anthropogenic FRNs, 137Cs and 239+240Pu as soil erosion tracers in two alpine valleys of Switzerland (Ursern 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 done 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 1950's-1960's 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 0.9 to 6.4 t ha1yr1 and erosion of 2.3 to 14.1 t ha1yr1 in the Ursern Valley and sedimentation of 0.7 to 77 t ha1yr1 and erosion of 1 to 5.3 t ha1yr1at Val Piora). Our study represents a novel, successful application of 239+240Pu as a tracer of soil erosion in a mountain environment.

  20. Activity ratios of 137Cs, 90Sr and 239+240Pu in environmental samples.

    PubMed

    Bossew, P; Lettner, H; Hubmer, A; Erlinger, C; Gastberger, M

    2007-01-01

    Both global and Chernobyl fallout have resulted in environmental contamination with radionuclides such as 137Cs, 90Sr and 239+240Pu. In environmental samples, 137Cs and 239+240Pu can be divided into the contributions of either source, if also the isotopes 134Cs and 238Pu are measurable, based on the known isotopic ratios in global and Chernobyl fallout. No analogous method is available for 90Sr. The activity ratios of Sr to Cs and Pu, respectively, are known for the actual fallout mainly from air filter measurements; but due to the high mobility of Sr in the environment, compared to Cs and Pu, these ratios generally do not hold for the inventory many years after deposition. In this paper we suggest a method to identify the mean contributions of global and Chernobyl fallout to total Sr in soil, sediment and cryoconite samples from Alpine and pre-Alpine regions of Austria, based on a statistical evaluation of Sr/Cs/Pu radionuclide activity ratios. Results are given for Sr:Cs, Sr:Pu and Cs:Pu ratios. Comparison with fallout data shows a strong depletion of Sr against Cs and Pu. PMID:17407799

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

    PubMed

    Sibbens, G; Pommé, S; Altzitzoglou, T; García-Toraño, E; Janssen, H; Dersch, R; Ott, O; Sánchez, A Martín; Montero, M P Rubio; Loidl, M; Coron, N; de Marcillac, P; Semkow, T M

    2010-01-01

    Sources of enriched (240)Pu were prepared by vacuum evaporation on quartz substrates. High-resolution alpha-particle spectrometry of (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. PMID:20106670

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

    NASA Astrophysics Data System (ADS)

    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. Activities of Pu and Am isotopes and isotopic ratios in a soil contaminated by weapons-grade plutonium.

    PubMed

    Lee, M H; Clark, S B

    2005-08-01

    An accident and fire at the former McGuire Air Force Base and Boeing Michigan Aeronautical Research Center (BOMARC) site in New Jersey resulted in dispersion of weapons-grade plutonium in particulate form to the local environment. Soil samples collected at the BOMARC site were measured for their activities and isotopic ratios of Pu and Am isotopes by radioanalytical techniques. The activities of the Pu and Am isotopes in the BOMARC soil were markedly higher than fallout levels, and they decreased nearly exponentially with increasing particle size of the soil. The measured (241)Am activity was compared to calculated values based on decay of (241)Pu. The activity ratios of (238)Pu/(239,240)Pu, (241)Pu/(239,240)Pu, and (241)Am/(239,240)Pu observed in the BOMARC soil were much lower than those attributed to nuclear reprocessing plants and Chernobyl fallout. From the activity ratios of (241)Pu/(239,240)Pu and (241)Am/(239,240)Pu, the origin of the Pu isotopes was identified as weapons-grade and the time since production of the material was estimated. Furthermore, the atomic ratio of (240)Pu/(239)Pu in the BOMARC soil was remarkably lower than the fallout value influenced by nuclear weapons testing and the Chernobyl accident. The atomic ratio of (240)Pu/(239)Pu was very close to the value of the weapons-grade Pu detected from the Thule accident in Greenland. This work demonstrates the utility of radioanalytical measurements and decay calculations for defining characteristics of the source term and discriminating multiple processes that contribute to a source. Such an approach would also be needed to respond to a terrorist event involving an improvised nuclear device or radiological dispersal device. PMID:16124281

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  7. Induced Fission of ^{240}Pu within a Real-Time Microscopic Framework.

    PubMed

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

    2016-03-25

    We describe the fissioning dynamics of ^{240}Pu 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). PMID:27058076

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

    DOE PAGESBeta

    Sandhukhan, Jhilam; Nazarewicz, Witold; Schunck, Nicolas

    2016-01-20

    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. As a result, 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 tomore » the dissipation in collective motion and to adiabatic fission characteristics.« less

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

    NASA Astrophysics Data System (ADS)

    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).

  10. Microscopic Calculation of 240Pu Scission with a Finite-Range Effective Force

    SciTech Connect

    Younes, W; Gogny, D

    2009-05-04

    Hartree-Fock-Bogoliubov calculations of hot fission in {sup 240}Pu have been performed with a newly-implemented code that uses the D1S finite-range effective interaction. The hot-scission line is identified in the quadrupole-octupole-moment coordinate space. Fission-fragment shapes are extracted from the calculations. A benchmark calculation for {sup 226}Th is obtained and compared to results in the literature. In addition, technical aspects of the use of HFB calculations for fission studies are examined in detail. In particular, the identification of scission configurations, the sensitivity of near-scission calculations to the choice of collective coordinates in the HFB iterations, and the formalism for the adjustment of collective-variable constraints are discussed. The power of the constraint-adjustment algorithm is illustrated with calculations near the critical scission configurations with up to seven simultaneous constraints.

  11. Analysis of actinides in an ombrotrophic peat core - evidence of post-depositional migration of fallout radionuclides

    NASA Astrophysics Data System (ADS)

    Quinto, Francesca; Hrnecek, Erich; Krachler, Michael; Shotyk, William; Steier, Peter; Winkler, Stephan R.

    2013-04-01

    Plutonium (239Pu, 240Pu, 241Pu, 242Pu) and uranium (236U, 238U) isotopes were analyzed in an ombrotrophic peat core from the Black Forest, Germany, representing the last 80 years of atmospheric deposition. The reliable determination of these isotopes at ultra-trace levels was possible using ultra-clean laboratory procedures and accelerator mass spectrometry. The 240Pu/239Pu isotopic ratios are constant along the core with a mean value of 0.19 ±0.02 (N = 32). This result is consistent with the acknowledged average 240Pu/239Pu isotopic ratio from global fallout in the Northern Hemisphere. The global fallout origin of Pu is confirmed by the corresponding 241Pu/239Pu (0.0012 ±0.0005) and 242Pu/239Pu (0.004 ± 0.001) isotopic ratios. The identification of the Pu isotopic composition characteristic for global fallout in peat layers pre-dating the period of atmospheric atom bomb testing (AD 1956 - AD 1980) is a clear evidence of the migration of Pu downwards the peat profile. The maximum of global fallout derived 236U is detected in correspondence to the age/depth layer of maximum stratospheric fallout (AD 1963). This finding demonstrates that the 236U bomb peak can be successfully used as an independent chronological marker complementing the 210Pb dating of peat cores. The profiles of the global fallout derived 236U and 239Pu are compared with those of 137Cs and 241Am. As typical of ombrothrophic peat, the temporal fallout pattern of 137Cs is poorly retained. Similarly like for Pu, post-depositional migration of 241Am in peat layers preceding the era of atmospheric nuclear tests is observed.

  12. 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.

    SciTech Connect

    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

  13. 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.

    SciTech Connect

    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 demonstration

  14. Analysis of 137Cs and 239,240Pu concentrations in surface waters of the Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Hirose, Katsumi; Aoyama, Michio

    2003-09-01

    Geographical and temporal variations of anthropogenic radionuclides, 137Cs and 239,240Pu, in surface waters of the North Pacific Ocean were studied using the HAM database, which is a comprehensive data set on 137Cs, 239,240Pu, and other anthropogenic radionuclides. The geographical distributions suggest that 137Cs and 239,240Pu concentrations in surface waters of the Pacific Ocean in the 1960s were controlled by global fallout from the 1961-1962 US and former USSR atmospheric nuclear weapons tests. The changes in surface 137Cs concentrations in the Pacific that occurred after 1970 were caused by physical processes. In the 1990s, surface 137Cs showed a homogeneous distribution throughout the Pacific. Biogeochemical and physical processes are important factors controlling surface 239,240Pu concentrations. The time-series data on anthropogenic radionuclides suggest that wind-driven circulation, subduction, and upwelling of Pacific surface and subsurface waters control the geographic distributions of anthropogenic radionuclides and their fates.

  15. Comparative distribution of 241 Am and 239,240 Pu in soils around the Rocky Flats Environmental Technology Site.

    PubMed

    Ibrahim, S A; Schierman, M J; Whicker, F W

    1996-04-01

    The distribution and behavior of 241 Am and 239,240 Pu in soils from the buffer zone of the Rocky Flats Environmental Technology Site have been investigated. Concentrations of both radionuclides decreased at similar rates with soil depth. More than 80% of the total inventory of both contaminants was found in the upper 9 cm of the soils with over 50% of the inventory residing in the top 3 cm. Comparison with earlier studies indicate that the plutonium depth profile has not changed significantly over the last 25 y. The inventories of 241 Am and 239,240 Pu decreased with distance from the 903 Pad (a former waste storage site) according to a power function, and the plume extended mainly toward the east. The lateral movement of the two contaminants away from the 903 Pad was not significantly different. The median activity ratio of 241 Am: 239,240 Pu ranged from 17 to 19% and was independent of sampling location and soil depth. This observation provided further evidence that the movement of both contaminants is indistinguishable in the study area. Because of the strong correlation between the two radionuclides, 241 Am concentrations can then be used to infer 239,240 Pu by counting the 241 Am via gamma spectroscopy. PMID:8617592

  16. Reactor Decay Heat in {sup 239}Pu: Solving the {gamma} Discrepancy in the 4-3000-s Cooling Period

    SciTech Connect

    Algora, A.; Jordan, D.; Tain, J. L.; Rubio, B.; Agramunt, J.; Perez-Cerdan, A. B.; Molina, F.; Caballero, L.; Nacher, E.; Krasznahorkay, A.; Hunyadi, M. D.; Gulyas, J.; Vitez, A.; Csatlos, M.; Csige, L.; Aeysto, J.; Penttilae, H.; Moore, I. D.; Eronen, T.; Jokinen, A.

    2010-11-12

    The {beta} feeding probability of {sup 102,104,105,106,107}Tc, {sup 105}Mo, and {sup 101}Nb 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 {gamma} component of the decay heat for {sup 239}Pu in the 4-3000 s range.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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

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

    PubMed

    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

  20. 239,240Pu and inorganic substances in aerosols from the vicinity of a waste isolation pilot plant: the importance of resuspension.

    PubMed

    Arimoto, R; Kirchner, T; Webb, J; Conley, M; Stewart, B; Schoep, D; Walthall, M

    2002-10-01

    Aerosol samples were collected and analyzed to characterize the spatial and temporal variations in the concentrations of plutonium and selected inorganic substances in the atmosphere around the Waste Isolation Pilot Plant (WIPP). High-volume aerosol sampling was conducted at three sites: (1) On Site, (2) Near Field, and (3) Cactus Flats. 239,240Pu was determined by alpha spectrometry following chemical separations; mass loadings were determined gravimetrically. A separate set of low-volume aerosol samples was analyzed for major ions using ion chromatography and for trace elements by inductively-coupled plasma emission spectrometry and mass spectrometry. The average 239,240Pu activity concentrations in total suspended particle (TSP) samples (12 to 16 nBq m(-3)) were consistent with those previously reported, but they varied strongly with season, with the highest values generally in spring. Further, the 239,240Pu activity concentrations were comparable among the three sites, and therefore there was no evidence for elevated 239,240Pu activities due to WIPP operations. The fraction of the 239,240Pu activity concentrations in the PM10, samples (particles less than 10 microm diameter) relative to TSP was lower than the corresponding PM10/TSP ratios of either high-volume mass or several inorganics (sulfate, aluminum or lead), indicating that 239,240Pu tends to be on large particles. Aerosol mass loadings (microg m(-3)) and 239,240Pu activity concentrations were correlated for all sets of samples, but at On Site, the TSP samples showed higher mass to 239,240Pu ratios than the other sites. Thus activities or processes occurring at or near the WIPP site evidently produced aerosols that contributed to the mass loadings but contained less 239,244Pu than ambient aerosols. About 63% of the variability in 239,240Pu activity concentrations was explained by wind travel, sampling location, length of the sampling interval, and aerosol mass. 239,240Pu activity concentrations also were

  1. A generalized method for characterization of 235U and 239Pu content using short-lived fission product gamma spectroscopy

    DOE PAGESBeta

    Knowles, Justin R.; Skutnik, Steven E.; Glasgow, David C.; Kapsimalis, Roger J.

    2016-06-23

    Rapid non-destructive assay methods for trace fissile material analysis are needed in both nuclear forensics and safeguards communities. To address these needs, research at the High Flux Isotope Reactor Neutron Activation Analysis laboratory has developed a generalized non-destructive assay method to characterize materials containing fissile isotopes. This method relies on gamma-ray emissions from short-lived fission products and capitalizes off of differences in fission product yields to identify fissile compositions of trace material samples. Although prior work has explored the use of short-lived fission product gamma-ray measurements, the proposed method is the first to provide a holistic characterization of isotopic identification,more » mass ratios, and absolute mass determination. Successful single fissile isotope mass recoveries of less than 6% error have been conducted on standards of 235U and 239Pu as low as 12 nanograms in less than 10 minutes. Additionally, mixtures of fissile isotope standards containing 235U and 239Pu have been characterized as low as 229 nanograms of fissile mass with less than 12% error. The generalizability of this method is illustrated by evaluating different fissile isotopes, mixtures of fissile isotopes, and two different irradiation positions in the reactor. Furthermore, it is anticipated that this method will be expanded to characterize additional fissile nuclides, utilize various irradiation sources, and account for increasingly complex sample matrices.« less

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    Hernández-Mendoza, H.; Chamizo, E.; Yllera, A.; García-León, M.; Delgado, A.

    2010-04-01

    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.

  4. Comparison of early mortality in baboons and dogs after inhalation of /sup 239/PuO/sub 2/

    SciTech Connect

    Bair, W.J.; Metivier, H.; Park, J.F.; Masse, R.; Stevens, D.L.; Lafuma, J.; Watson, C.R.; Nolibe, D.

    1980-06-01

    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 /sup 239/PuO/sub 2/. 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 /sup 239/PuO/sub 2/. 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.

  5. Pulmonary retention and tissue distribution of {sup 239}Pu nitrate in F344 rats and syrian hamsters inhaling carbon tetrachloride

    SciTech Connect

    Benson, J.M.; Barr, E.B.; Lundgren, D.L.; Nikula, K.J.

    1994-11-01

    Carbon tetrachloride (CCl{sub 4}) has been used extensively in the nuclear weapons industry, so it is possible that nuclear plant workers have been exposed to CCl{sub 4} and plutonium compounds. Potential for future exposure exists during {open_quotes}cleanup{close_quotes} operations at weapon production sites such as the Hanford, Washington, and Rocky Flats, Colorado, facilities. The current Threshold Limit Value for CCl{sub 4} is 5 ppm; however, concentrations of CCl{sub 4} 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 CCl{sub 4} by CDF{sup register}(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 {sup 239}Pu nitrate {sup 239}Pu(NO{sub 3}){sub 4}.

  6. A GENERALIZED METHOD FOR CHARACTERIZATION OF 235U AND 239PU CONTENT USING SHORT-LIVED FISSION PRODUCT GAMMA SPECTROSCOPY

    SciTech Connect

    Knowles, Justin R; Skutnik, Steven E; Glasgow, David C; Kapsimalis, Roger J

    2016-01-01

    Rapid non-destructive assay methods for trace fissile material analysis are needed in both nuclear forensics and safeguards communities. To address these needs, research at the High Flux Isotope Reactor Neutron Activation Analysis laboratory has developed a generalized non-destructive assay method to characterize materials containing fissile isotopes. This method relies on gamma-ray emissions from short-lived fission products and capitalizes off of differences in fission product yields to identify fissile compositions of trace material samples. Although prior work has explored the use of short-lived fission product gamma-ray measurements, the proposed method is the first to provide a holistic characterization of isotopic identification, mass ratios, and absolute mass determination. Successful single fissile isotope mass recoveries of less than 6% error have been conducted on standards of 235U and 239Pu as low as 12 nanograms in less than 10 minutes. Additionally, mixtures of fissile isotope standards containing 235U and 239Pu have been characterized as low as 229 nanograms of fissile mass with less than 12% error. The generalizability of this method is illustrated by evaluating different fissile isotopes, mixtures of fissile isotopes, and two different irradiation positions in the reactor. It is anticipated that this method will be expanded to characterize additional fissile nuclides, utilize various irradiation sources, and account for increasingly complex sample matrices.

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

    SciTech Connect

    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.

  8. Experimental values for 241Am and 239+240Pu Kd's in French agricultural soils.

    PubMed

    Roussel-Debet, Sylvie

    2005-01-01

    Experiments resulted in determination of K(d) values for (241)Am and (239+240)Pu in 6 soils whose characteristics are representative of agricultural soils found around French nuclear power plant sites. These experiments were conducted in stirred batch reactors and the sorption isotherms were plotted. For americium, the experimental K(d) values varied from 60 to 4000 Lkg(-1) (d.w.) and correlated well with soil pH, K(d) increased with increasing pH. As regards plutonium, the experimental K(d) values varied between 300 and 9600 Lkg(-1) and decreased with increasing total sand content. The estimation of the total residence time determined by using a particular and experimentally refined value for K(d)-with a model similar to those currently used for impact assessments-illustrates the importance of establishing values that are better suited to specific soils than generic values. Lastly, depending on the type of evaluation envisioned, it might be important to look for a specific value of K(d)-and even modelling-more suited to the specificity of the scenario studied, by performing more complex, or even in situ, experiments. PMID:15603906

  9. 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

    SciTech Connect

    Suseno, Heny; Wisnubroto, Djarot S.

    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}.

  10. The depth distribution of sup 90 Sr, sup 137 Cs, and sup 239,240 Pu in soil profile samples

    SciTech Connect

    Price, K.R.

    1989-04-01

    A special study was conducted at the Hanford Site and vicinity to investigate the depth distribution of {sup 90}Sr, {sup 137}Cs, and {sup 239,240}Pu in soil at two locations. Duplicate sets of samples were collected at each location from the soil surface to a depth of 30 cm in increments of 2.5 cm. Results from an onsite location near a retired nuclear fuel reprocessing facility were compared to results from a background location upwind and distant from the Site. The study showed that, regardless of location, the top 5 cm of soil contained 51 to 74% of the {sup 90}Sr, 99% of the {sup 137}Cs, and 96% of the {sup 239,240}Pu. Soil at the background location received radionuclides only from deposition of worldwide fallout, and averaged 1.6 pCi/cm{sup 2} of {sup 90}Sr, 3.0 pCi/cm{sup 2} of {sup 137}Cs, and 0.071 pCi/cm{sup 2} of {sup 239,240}Pu. Soil at the onsite location received radionuclides from deposition of both worldwide fallout and past operations of the retired fuel reprocessing facility and contained 4 times as much {sup 90}Sr, 5 times as much {sup 137}Cs, and 44 times as much {sup 239,240}Pu as the background location. (Pacific Northwest Laboratory is operated for the US Department of Energy by Battelle Memorial Institute under Contract AC06-76RLO1830.) 8 refs., 2 figs.

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

    PubMed

    Tsumune, Daisuke; Aoyama, Michio; Hirose, Katsumi

    2003-01-01

    We simulated the spatial distributions and the temporal variations of 137Cs and (239,240)Pu 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 (239,240)Pu 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 (239,240)Pu 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 (239,240)Pu concentrations in surface water could be simulated by considering the scavenging effect. PMID:12860090

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

    NASA Astrophysics Data System (ADS)

    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. Feasibility study of plutonium isotopic analysis of resin beads by nondestructive gamma-ray spectroscopy

    SciTech Connect

    Li, T.K.

    1985-01-01

    We have initiated a feasibility study on the use of nondestructive low-energy gamma-ray spectroscopy for plutonium isotopic analysis on resin beads. Seven resin bead samples were measured, with each sample containing an average of 9 ..mu..g of plutonium; the isotopic compositions of the samples varied over a wide range. The gamma-ray spectroscopy results, obtained from 4-h counting-time measurements, were compared with mass spectrometry results. The average ratios of gamma-ray spectroscopy to mass spectrometry were 1.014 +- 0.025 for /sup 238/Pu//sup 239/Pu, 0.996 +- 0.018 for /sup 240/Pu//sup 239/Pu, and 0.980 +- 0.038 for /sup 241/Pu//sup 239/Pu. The rapid, automated, and accurate nondestructive isotopic analysis of resin beads may be very useful to process technicians and International Atomic Energy Agency inspectors. 3 refs., 1 fig., 3 tabs.

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

    NASA Astrophysics Data System (ADS)

    Neudecker, D.; Talou, P.; Kawano, T.; Kahler, A. C.; Rising, M. E.; White, M. C.

    2016-03-01

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

  15. Event-by-event evaluation of the prompt fission neutron spectrum from 239Pu(n,f)

    NASA Astrophysics Data System (ADS)

    Vogt, R.; Randrup, J.; Brown, D. A.; Descalle, M. A.; Ormand, W. E.

    2012-02-01

    Earlier studies of 239Pu(n,f) have been extended to incident neutron energies up to 20 MeV within the framework of the event-by-event fission model FREYA, into which we have incorporated multichance fission and pre-equilibrium neutron emission. The main parameters controlling prompt fission neutron evaporation have been identified and the prompt fission neutron spectrum has been analyzed by fitting those parameters to the average neutron multiplicity ν¯ from ENDF-B/VII.0, including the energy-energy correlations in the covariance of ν¯(E) obtained by fitting to the experimental ν¯ data used in the ENDF-B/VII.0 evaluation. We present our results, discuss relevant tests of this new evaluation, and describe possible further improvements.

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

    NASA Astrophysics Data System (ADS)

    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

  17. Characterization of ^{239,240}Pu Radionuclide Adsorption to Soil Particles and Mineral Dust Aerosols

    NASA Astrophysics Data System (ADS)

    Tatro, D. P.; Arimoto, R.; McMillan, N. J.; Barnes, M.

    2006-12-01

    The release of ^{239,240}Pu into the environment by nuclear weapons testing 50 years ago initiated the cyclic mobilization of Pu-contaminated soil particles via the resuspension of dust resulting in a widespread distribution of Pu and other radionuclides. It is unclear what enables the aeolian transport of Pu in the environment; plausible hypotheses of Pu binding to dust and soil particles include Pu adsorption to iron oxides/hydroxides, organic acids, or silicate minerals such as clays. To investigate the connections between surface soils, dust and radionuclides, samples of soil and/or dust were collected from the Project Gnome Site in Eddy County, NM, the Jemez Mountains near Los Alamos, NM, and two 50-year old attics and wind-blown dust in Big Spring, TX. This study tests the hypothesis that Pu is adsorbed onto Fe oxides and hydroxides that coat dust/soil particles. The samples are generally low in organic carbon (0.2 - 4.8%, except for the unburned Los Alamos sample at 9.4%), as measured by LOI (Loss On Ignition) at 360 °C. The citrate-bicarbonate-dithionite method (CDB) of Fe oxide removal, first proposed by Mehra and Jackson in 1960, was used to selectively extract Fe oxides from the samples while leaving silicate Fe intact. Chemical digestion of each sample creates two fractions, the extracted supernatant and a solid pellet residue. If the Pu were associated with Fe oxides, then Fe and Pu should both be selectively removed from the bulk sample during the CBD process, leaving the pellet depleted in Fe and Pu and the supernatant enriched. For Fe, this was confirmed by scanning electron microscope and petrographic analyses. Preliminary radiochemical analyses of Pu activity also verify this hypothesis. Pu activity is significantly lower in pellets than bulk samples (Pu activitypellet/Pu activitybulk average = 0.07, range 0.02-0.12); Pu activity in supernatants is significantly higher than in bulk samples (Pu activitysupernatant/Pu activitybulk average = 4

  18. Comparison of 241Am, (239,240)Pu and 137Cs concentrations in soil around rocky flats.

    PubMed

    Hulse, S E; Ibrahim, S A; Whicker, F W; Chapman, P L

    1999-03-01

    Gamma spectroscopy measurements were used to estimate concentrations of 241Am and 137Cs in soil profiles to depths of 21 cm at on-site and off-site locations around the Rocky Flats Environmental Technology Site and at regional background locations east of the Front Range between Colorado's borders with New Mexico and Wyoming. Concentrations of these radionuclides were compared with concentrations of (239,240)Pu in the same samples. Concentrations of 241Am in soil from depths of 0 to 3 cm decreased in an easterly direction from more than 5.3 kBq kg(-1) near the 903 pad to background levels of 1.3 Bq kg(-1) 5 to 7 km away at a rate that was nearly proportional to the inverse square of distance. Deposits of 137Cs were ubiquitous, averaging 0.12 kBq kg(-1) in soil from depths of 0 to 3 cm, but were unevenly distributed around Rocky Flats and the regional background locations. Deviations from the uniform exponential rate at which soil concentrations of 137Cs typically decreased with depth, -0.25 cm(-1) at undisturbed sites, enabled us to determine that about 10% of our sampling sites had been disturbed by erosion, tillage, or other factors. The mean rate at which (239,240)Pu decreased with depth was about the same, -0.23 cm(-1), throughout the study area. Soil concentrations of 241Am decreased with depth at a similar mean rate of -0.22 cm(-1) at locations close to the 903 pad where measurements were robust. Ratios between 241Am or (239,240)Pu and 137Cs proved more useful for delineating the extent and pattern of contamination from Rocky Flats than did activity concentrations in soil. PMID:10025653

  19. Comparison of {sup 241}Am, {sup 239,240}Pu, and {sup 137}Cs concentrations in soil around Rocky Flats

    SciTech Connect

    Hulse, S.E.; Ibrahim, S.A.; Whicker, F.W.; Chapman, P.L.

    1999-03-01

    Gamma spectroscopy measurements were used to estimate concentrations of {sup 241}Am and {sup 137}Cs in soil profiles to depths of 21 cm at on-site and off-site locations around the Rocky Flats Environmental Technology Site and at regional background locations east of the Front Range between Colorado`s borders with New Mexico and Wyoming. Concentrations of these radionuclides were compared with concentrations of {sup 239,240}Pu in the same samples. Concentrations of {sup 241}Am in soil from depths of 0 to 3 cm decreased in an easterly direction from more than 5.3 kBq kg{sup {minus}1} 5 to 7 km away at a rate that was nearly proportional to the inverse square of distance. Deposits of {sup 137}Cs were ubiquitous, averaging 0.12 kBq kg{sup {minus}1} in soil from depths of 0 to 3 cm, but were unevenly distributed around Rocky Flats and the regional background locations. Deviations from the uniform exponential rate at which soil concentrations of {sup 137}Cs typically decreased with depth, {minus}0.25 cm{sup {minus}1} at undisturbed sites, enabled the authors to determine that about 10% of their sampling sites had been disturbed by erosion, tillage, or other factors. The mean rate at which {sup 239,240}Pu decreased with depth was about the same, {minus}0.23 cm{sup {minus}1}, throughout the study area. Soil concentrations of {sup 241}Am decreased with depth at a similar mean rate of {minus}0.22 cm{sup {minus}1} at locations close to the 903 pad where measurements were robust. Ratios between {sup 241}Am or {sup 239,240}Pu and {sup 137}Cs proved more useful for delineating the extent and pattern of contamination from Rocky Flats than did activity concentrations in soil.

  20. AMS of the Minor Plutonium Isotopes.

    PubMed

    Steier, P; Hrnecek, E; Priller, A; Quinto, F; Srncik, M; Wallner, A; Wallner, G; Winkler, S

    2013-01-01

    VERA, the Vienna Environmental Research Accelerator, is especially equipped for the measurement of actinides, and performs a growing number of measurements on environmental samples. While AMS is not the optimum method for each particular plutonium isotope, the possibility to measure (239)Pu, (240)Pu, (241)Pu, (242)Pu and (244)Pu on the same AMS sputter target is a great simplification. We have obtained a first result on the global fallout value of (244)Pu/(239)Pu = (5.7 ± 1.0) × 10(-5) based on soil samples from Salzburg prefecture, Austria. Furthermore, we suggest using the (242)Pu/(240)Pu ratio as an estimate of the initial (241)Pu/(239)Pu ratio, which allows dating of the time of irradiation based solely on Pu isotopes. We have checked the validity of this estimate using literature data, simulations, and environmental samples from soil from the Salzburg prefecture (Austria), from the shut down Garigliano Nuclear Power Plant (Sessa Aurunca, Italy) and from the Irish Sea near the Sellafield nuclear facility. The maximum deviation of the estimated dates from the expected ages is 6 years, while relative dating of material from the same source seems to be possible with a precision of less than 2 years. Additional information carried by the minor plutonium isotopes may allow further improvements of the precision of the method. PMID:23565016

  1. AMS of the Minor Plutonium Isotopes

    PubMed Central

    Steier, P.; Hrnecek, E.; Priller, A.; Quinto, F.; Srncik, M.; Wallner, A.; Wallner, G.; Winkler, S.

    2013-01-01

    VERA, the Vienna Environmental Research Accelerator, is especially equipped for the measurement of actinides, and performs a growing number of measurements on environmental samples. While AMS is not the optimum method for each particular plutonium isotope, the possibility to measure 239Pu, 240Pu, 241Pu, 242Pu and 244Pu on the same AMS sputter target is a great simplification. We have obtained a first result on the global fallout value of 244Pu/239Pu = (5.7 ± 1.0) × 10−5 based on soil samples from Salzburg prefecture, Austria. Furthermore, we suggest using the 242Pu/240Pu ratio as an estimate of the initial 241Pu/239Pu ratio, which allows dating of the time of irradiation based solely on Pu isotopes. We have checked the validity of this estimate using literature data, simulations, and environmental samples from soil from the Salzburg prefecture (Austria), from the shut down Garigliano Nuclear Power Plant (Sessa Aurunca, Italy) and from the Irish Sea near the Sellafield nuclear facility. The maximum deviation of the estimated dates from the expected ages is 6 years, while relative dating of material from the same source seems to be possible with a precision of less than 2 years. Additional information carried by the minor plutonium isotopes may allow further improvements of the precision of the method. PMID:23565016

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Relative effectiveness of {sup 239}Pu and some other internal emitters for bone cancer induction in beagles

    SciTech Connect

    Lloyd, R.D.; Miller, S.C.; Taylor, G.N.; Bruenger, F.W.; Jee, W.S.S.; Angus, W.

    1994-10-01

    The toxicity ratio (relative effectiveness per gray of average skeletal dose) has been estimated for bone cancer induction in beagles injected as young adults with a number of bone-seeking internal emitters. These experiments yielded calculated toxicity ratios ({+-} SD) relative to {sup 226}Ra = 1.0 of {sup 239}Pu = 16 {+-} 5 (single exposure to monomeric Pu) and 32 {+-} 10 (continuous exposure from an extraskeletal deposit in the body), {sup 224}Ra = 16 {+-} 5 (chronic exposure) and approximately 6 {+-} 2 (single exposure), {sup 228}Th = 8.5 {+-} 2.3, {sup 241}Am = 6 {+-} 0.8, {sup 228}Ra = 2.0 {+-} 0.5, {sup 249}Cf = 6 {+-} 3, {sup 252}Cf = 4 {+-}2, {sup 90}Sr = 1.0 {+-} 0.5 (for high doses) and 0.05 {+-} 0.03 (for low doses) and 0.01 {+-} 0.01 (for extremely low doses). Because no skeletal malignancies were observed among beagles given only {sup 253}Es, the toxicity ratio is undefined. 43 refs., 2 tabs.

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

    NASA Astrophysics Data System (ADS)

    Zavorka, L.; Adam, J.; Baldin, A. A.; Caloun, P.; Chilap, V. V.; Furman, W. I.; Kadykov, M. G.; Khushvaktov, J.; Pronskikh, V. S.; Solnyshkin, A. A.; Sotnikov, V.; Stegailov, V. I.; Suchopar, M.; Tsoupko-Sitnikov, V. M.; Tyutyunnikov, S. I.; Voronko, V.; Vrzalova, J.

    2015-04-01

    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.

  6. The CIELO Collaboration: Neutron Reactions on 1H, 16O, 56Fe, 235,238U, and 239Pu

    NASA Astrophysics Data System (ADS)

    Chadwick, M. B.; Dupont, E.; Bauge, E.; Blokhin, A.; Bouland, O.; Brown, D. A.; Capote, R.; Carlson, A.; Danon, Y.; De Saint Jean, C.; Dunn, M.; Fischer, U.; Forrest, R. A.; Frankle, S. C.; Fukahori, T.; Ge, Z.; Grimes, S. M.; Hale, G. M.; Herman, M.; Ignatyuk, A.; Ishikawa, M.; Iwamoto, N.; Iwamoto, O.; Jandel, M.; Jacqmin, R.; Kawano, T.; Kunieda, S.; Kahler, A.; Kiedrowski, B.; Kodeli, I.; Koning, A. J.; Leal, L.; Lee, Y. O.; Lestone, J. P.; Lubitz, C.; MacInnes, M.; McNabb, D.; McKnight, R.; Moxon, M.; Mughabghab, S.; Noguere, G.; Palmiotti, G.; Plompen, A.; Pritychenko, B.; Pronyaev, V.; Rochman, D.; Romain, P.; Roubtsov, D.; Schillebeeckx, P.; Salvatores, M.; Simakov, S.; Soukhovitskiı˜, E. Sh.; Sublet, J. C.; Talou, P.; Thompson, I.; Trkov, A.; Vogt, R.; van der Marck, S.

    2014-04-01

    CIELO (Collaborative International Evaluated Library Organization) provides a new working paradigm to facilitate evaluated nuclear reaction data advances. It brings together experts from across the international nuclear reaction data community to identify and document discrepancies among existing evaluated data libraries, measured data, and model calculation interpretations, and aims to make progress in reconciling these discrepancies to create more accurate ENDF-formatted files. The focus will initially be on a small number of the highest-priority isotopes, namely 1H, 16O, 56Fe, 235,238U, and 239Pu. This paper identifies discrepancies between various evaluations of the highest priority isotopes, and was commissioned by the OECD's Nuclear Energy Agency WPEC (Working Party on International Nuclear Data Evaluation Co-operation) during a meeting held in May 2012. The evaluated data for these materials in the existing nuclear data libraries - ENDF/B-VII.1, JEFF-3.1, JENDL-4.0, CENDL-3.1, ROSFOND, IRDFF 1.0 - are reviewed, discrepancies are identified, and some integral properties are given. The paper summarizes a program of nuclear science and computational work needed to create the new CIELO nuclear data evaluations.

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

    PubMed

    Guillén, J; Baeza, A; Corbacho, J A; Muñoz-Muñoz, J G

    2015-06-01

    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 (137)Cs, (90)Sr, and (239+240)Pu. Using auxiliary modeling (diffusion-convection equation and compartmental model), it followed from field observations that the migration velocities of (90)Sr and (239+240)Pu were similar and higher than that of (137)Cs. The downward migration of radionuclides can be considered a consequence of their association with soil particles. A sequential speciation procedure also confirmed that (90)Sr was the most bioavailable radionuclide followed by (239+240)Pu and (137)Cs. Although this can explain the different velocity of (90)Sr and (137)Cs, bioavailability could not explain by itself the similar velocities of (239+240)Pu and (90)Sr. The presence of organic acids in the soil can also influence the migration of radionuclides attached to them, which decreased in the order: (239+240)Pu > (90)Sr > (137)Cs. Thus, the joint consideration of bioavailable and humic + fulvic acid fractions can explain the observed differences in the downward velocities. PMID:25827576

  8. U, Pu, and Am nuclear signatures of the Thule hydrogen bomb debris.

    PubMed

    Eriksson, Mats; Lindahl, Patric; Roos, Per; Dahlgaard, Henning; Holm, Elis

    2008-07-01

    This study concerns an arctic marine environment that was contaminated by actinide elements after a nuclear accident in 1968, the so-called Thule accident In this study we have analyzed five isolated hot particles as well as sediment samples containing particles from the weapon material for the determination of the nuclear fingerprint of the accident. We report that the fissile material in the hydrogen weapons involved in the Thule accident was a mixture of highly enriched uranium and weapon-grade plutonium and that the main fissile material was 235U (about 4 times more than the mass of 239Pu). In the five hot particles examined, the measured uranium atomic ratio was 235U/238U = 1.02 +/- 0.16 and the Pu-isotopic ratios were as follows: 24Pu/239Pu = 0.0551 +/- 0.0008 (atom ratio), 238Pu/239+240Pu = 0.0161 +/- 0.0005 (activity ratio), 241Pu/239+240Pu = 0.87 +/- 0.12 (activity ratio), and 241Am/ 239+240Pu = 0.169 +/- 0.005 (activity ratio) (reference date 2001-10-01). From the activity ratios of 241Pu/241Am, we estimated the time of production of this weapon material to be from the late 1950s to the early 1960s. The results from reanalyzed bulk sediment samples showed the presence of more than one Pu source involved in the accident, confirming earlier studies. The 238Pu/239+240PU activity ratio and the 240Pu/ 239Pu atomic ratio were divided into at least two Pu-isotopic ratio groups. For both Pu-isotopic ratios, one ratio group had identical ratios as the five hot particles described above and for the other groups the Pu isotopic ratios were lower (238Pu/ 239+240PU activity ratio approximately 0.01 and the 240Pu/P239Pu atomic ratio 0.03). On the studied particles we observed that the U/Pu ratio decreased as a function of the time these particles were present in the sediment. We hypothesis that the decrease in the ratio is due to a preferential leaching of U relative to Pu from the particle matrix. PMID:18677996

  9. The Investigation of the Doppler-Effect of the α-Value of 235U and 239Pu for Different Temperatures

    NASA Astrophysics Data System (ADS)

    Grigoriev, Yu. V.; Kitaev, V. Ya.; Sinitsa, V. V.; Mezentseva, Zh. V.; Faikov-Stanczyk, H.; Janeva, N. B.

    2005-05-01

    The time-of-flight spectra for γ -ray multiplicities from 1 to 15 were measured on the 122-m flight path of the IBR-30 pulsed neutron booster using the 16-section liquid scintillation detector for thin metallic radiator-samples of 235U (0.25 mm) and 239Pu (0.3 mm) at the presence of 235U and 239Pu filter-samples with a thickness of 0.5 mm at two temperatures (100 K and 293 K). Multiplicity spectra, Doppler-coefficients of the capture, fission cross-sections, and alpha values (their ratio) were determined from the time-of-flight spectra for above-mentioned temperatures.

  10. Effects of combined exposure of F344 rats to inhaled {sup 239}PuO{sub 2} and a chemical carcinogen (NNK)

    SciTech Connect

    Lundgren, D.L.; Belinsky, S.A.; Nikula, K.J.; Griffith, W.C.; Hoover, M.D.

    1994-11-01

    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 {sup 239}Pu. Although the carcinogenic effects of inhaled {sup 239}Pu 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.

  11. Comparison of the effects of inhaled {sup 239}PuO{sub 2} and {beta}- emitting radionuclides on the incidence of lung carcinomas in laboratory animals

    SciTech Connect

    Hahn, F.F.; Griffith, W.C.; Boecker, B.B.; Muggenburg, B.A.; Lundgren, D.L.

    1991-12-31

    The health effects of inhaling radioactive particles when the lung is the primary organ irradiated were studied in rats and Beagle dogs. The animals were exposed to aerosols of {sup 239}PuO{sub 2} or fission-product radionuclides in insoluble forms and observed for their life span. Lung carcinomas were the primary late-occuring effect. The incidence rate for lung carcinomas was modeled using a proportional hazard rate model. Linear functions predominated below 5 Gy to the lung. The life-time risk for lung carcinomas per 10{sup 4} Gy for beta emitters was 60 for rats and 65 for dogs, and for {sup 239}PuO{sub 2} it was 1500 for rats and 2300 for dogs.

  12. [Quantitative evaluation of 90Sr, 137Cs, 239Pu, 241Am transfer from polluted soil to gastric and intestine juice of cows].

    PubMed

    Chizhevskiĭ, I V

    2001-01-01

    Quantitative parameters of 90Sr, 137Cs, 239Pu and 241Am transfer from solid phase of soil to gastric, intestine juice of cows as well as to imitating solutions have been estimated on the base 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. PMID:11605246

  13. /sup 237/Np and /sup 239/Pu solution behavior during hydrothermal testing of simulated nuclear waste glass with basalt and steel

    SciTech Connect

    Schramke, J.A.; Simonson, S.A.; Coles, D.G.

    1984-09-01

    A series of hydrothermal experiments were carried out on /sup 237/Np- and /sup 239/Pu-doped PNL 76-68 glass, synthetic basalt groundwater, basalt, and cast steel. Experiments of duration were conducted in Dickson-type rocking autoclaves at 200/sup 0/C and 30 MPa, with an initial fluid to solid weight ratio of 10:1. The tests carried out were: glass and groundwater; glass, basalt, and groundwater; glass, steel, and groundwater; and glass, steel, basalt, and groundwater. Unfiltered, 4000 A filtered, and 18 A filtered solutions were analyzed to determine the concentrations of radionuclides in solution and those associated with colloids. In all four experiments, /sup 237/Np and /sup 239/Pu were present in solution in quantities at or below the analytical detection limits. The only detectable differences in radionuclide concentrations between the four experiments were brought about by changes in the amounts of colloidally associated radionuclides. Besalt added to the glass and groundwater system increased the quantities of the colloidally associated /sup 237/Np and /sup 239/Pu by an order of magnitude. The addition of steel to the glass and groundwater system reduced the colloidally associated radionuclides to levels below detection limits. The effects of both steel and basalt on the glass and groundwater system seemed to cancel out, and the colloidally associated radionuclide concentrations were similar to the observed levels in the glass plus groundwater system. These variations in the quantities of the colloidally associated radionuclides did not appear to be correlated with other changes in the quantities or composition of the colloidal material in solution. Other than /sup 237/Np and /sup 239/Pu, silica was the only constituent of the colloids in these experiments. The amounts of colloidal silica did not vary significantly between the four experiments. 7 references, 7 figures.

  14. Energy measurement of prompt fission neutrons in 239Pu(n,f) for incident neutron energies from 1 to 200 MeV

    SciTech Connect

    Haight, Robert C; Devlin, Matthew J; Nelson, Ronald O; O' Donnell, John M; Chatillon, Audrey; Granier, Thierry; Taieb, Julien; Belier, Gilbert; Laurent, Benoit; Noda, Shusaku

    2010-01-01

    An experimental campaign was started in 2002 in the framework of a collaboration belween CEA-DAM and the Los Alamos National Laboratory to measure the prompt fission neutron spectra (PFNS) for incident neutron energies from 1 to 200 MeV with consistent error uncertainties over the whole energy range. The prompt neutron spectra in {sup 235,238}U(n,f) and {sup 237}Np(n,f) have been already studied successfully. A first attempt to characterize the prompt neutrons emitted during the fission of the {sup 239}Pu was done in 2007. This contribution will focus on the results obtained during the final experiment to measure the PFNS in {sup 239}Pu(n,f) performed in 2008. Prompt fission neutron spectra in the neutron-induced fission of {sup 239}Pu have been measured for incident neutron energies from 1 to 200 MeV at the Los Alamos Neutron Science Center. Mean energies obtained from the spectra are discussed and compared to theoretical model calculation.

  15. Long-term changes in mouse lung following inhalation of a fibrosis-inducing dose of 239PuO2: changes in collagen synthesis and degradation rates.

    PubMed

    McAnulty, R J; Moores, S R; Talbot, R J; Bishop, J E; Mays, P K; Laurent, G J

    1991-01-01

    Mice were exposed by nose-only inhalation to 239PuO2, which resulted in an IAD of 1110 +/- 29 Bq. At various times after exposure, rates of collagen metabolism were measured using validated in vivo methods based on the administration of radiolabelled proline, together with a large flooding dose of unlabelled proline and measurement of its incorporation into lung collagen as hydroxyproline. Dramatic increases in both synthesis and degradation rates of collagen were observed. At 54 days after exposure the fractional synthesis rates in experimental mice were almost five times those in controls (control: 3.2 +/- 0.6%/day, 239PuO2-exposed: 14.5 +/- 0.4%/day) and by 300 days synthesis rates, although declining, were still more than double the control values. A similar pattern of change was observed for collagen degradation. The combination of changes in synthesis and degradation rates led to a 60% increase in lung collagen content by 300 days (control: 3.05 +/- 0.24 mg/lung, 239PuO2-exposed: 4.88 +/- 0.42 mg/lung). The data suggest that extensive remodelling of the lung connective tissue matrix occurs during development of fibrosis and that, over long periods of time, small imbalances between synthesis and degradation may result in quite large increases in protein content. PMID:1671069

  16. Determination of fission neutron transmission through waste matrix material using neutron signal correlation from active assay of {sup 239}Pu

    SciTech Connect

    Hollas, C.L.; Arnone, G.; Brunson, G.; Coop, K.

    1996-09-01

    The accuracy of TRU (transuranic) waste assay using the differential die-away technique depends upon significant corrections to compensate for the effects of the matrix material in which the TRU waste is located. The authors have used a new instrument, the Combined Thermal/Epithermal Neutron (CTEN) instrument for the assay of TRU waste, to develop methods to improve the accuracy of these corrections. Neutrons from a pulsed 14-MeV neutron generator are moderated in the walls of the CTEN cavity and induce fission in the TRU material. The prompt neutrons from these fission events are detected in cadmium-wrapped {sup 3}He neutron detectors. They report new methods of data acquisition and analysis to extract correlation in the neutron signals resulting form fission during active interrogation. They use the correlation information in conjunction with the total number of neutrons to determine the fraction of fission neutrons transmitted through the matrix material into the {sup 3}He detectors. This determination allows them to cleanly separate the matrix effects into two processes: matrix modification upon the neutron interrogating flux and matrix modification upon the fraction of fission neutrons transmitted to the neutron detectors. This transmission information is also directly applied in a neutron multiplicity analysis in the passive assay of {sup 240}Pu.

  17. Determination of plutonium and other transuranic elements by inductively coupled plasma mass spectrometry: A historical perspective and new frontiers in the environmental sciences

    NASA Astrophysics Data System (ADS)

    Ketterer, Michael E.; Szechenyi, Scott C.

    2008-07-01

    Inductively coupled plasma mass spectrometry (ICPMS), particularly with sector field mass analyzers (SF-ICPMS), has emerged in the past several years as an excellent analytical technique for rapid, highly sensitive determination of transuranic elements (TRU) in environmental samples. SF-ICPMS has advantages of simplicity of sample preparation, high sample throughput, widespread availability in laboratories worldwide, and relatively straightforward operation when compared to other competing mass spectrometric techniques. Arguably, SF-ICPMS is the preferred technique for routine, high-throughput determination of 237Np and the Pu isotopes, excepting 238Pu, at fg-pg levels in environmental samples. Many research groups have now demonstrated the SF-ICPMS determination of 239 + 240 Pu activities, 240Pu/ 239Pu and other Pu atom ratios in several different application areas. Many studies have examined the relative contribution of global fallout vs. local/regional Pu sources in the environment through measurement of 240Pu/ 239Pu and, in some cases, 241Pu/ 239Pu and 242Pu/ 239Pu. "Stratospheric fallout", which was deposited from thermonuclear tests, conducted largely during the 1952-1964 time period, is characterized by a well-defined 240Pu/ 239Pu of ~ 0.18, while most other sources have different ratios. Examples of local/regional Pu sources are the Nevada Test Site, the Chernobyl plume, and accidents at Palomares, Spain and Thule, Greenland. The determination of Pu activities and atom ratios has stimulated much interest in the use of Pu as a marine tracer; several studies have shown that Pu is transported over long distances by ocean currents. 240Pu/ 239Pu ratios > 0.20 in sediments and seawater of the North Pacific are ascribed to ocean current transport of fallout from the Pacific Proving Ground. In nuclear forensics, much effort is focused on detection and fingerprinting of small amounts of TRU in environmental samples consisting of bulk material or individual isolated

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

    SciTech Connect

    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.

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

    PubMed

    Margulies, Todd D; Schonbeck, Niels D; Morin-Voillequé, Normie C; James, Katherine A; LaVelle, James M

    2004-01-01

    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 (239,240)Pu) in soil was consistent with past sampling conducted by DOE, the Colorado Department of Public Health and Environment, and others. Elevated levels of (239,240)Pu 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. PMID:15172724

  20. Determination of (241)Pu by the method of disturbed radioactive equilibrium using 2πα-counting and precision gamma-spectrometry.

    PubMed

    Alekseev, I; Kuzmina, T

    2016-04-01

    A simple technique is proposed for the determination of the content of (241)Pu, which is based on disturbance of radioactive equilibrium in the genetically related (237)U←(241)Pu→(241)Am decay chain of radionuclides, with the subsequent use of 2πα-counting and precision gamma-spectroscopy for monitoring the process of restoration of that equilibrium. It has been shown that the data on dynamics of accumulation of the daughter (241)Am, which were obtained from the results of measurements of α- and γ-spectra of the samples, correspond to the estimates calculated for the chain of two genetically related radionuclides, the differences in the estimates of (241)Pu radioactivity not exceeding 2%. Combining the different methods of registration (2πα-counting, semiconductor alpha- and gamma-spectrometry) enables the proposed method to be efficiently applied both for calibration of (241)Pu-sources (from several hundreds of kBq and higher) and for radioisotopic analysis of plutonium mixtures. In doing so, there is a deep purification of (241)Pu from its daughter decay products required due to unavailability of commercial detectors that could make it possible, based only on analysis of alpha-spectra, to conduct quantitative analysis of the content of (238)Pu and (241)Am. PMID:26868275

  1. Study of Photon Strength Function of Actinides: the Case of (235)U, (238)Np and (241)Pu

    SciTech Connect

    Guerrero, C.; Koehler, Paul Edward; N_TOF collaboration,

    2011-01-01

    The decay from excited levels in medium and heavy nuclei can be described in a statistical approach by means of Photon Strength Functions and Level Density distributions. The study of electromagnetic cascades following neutron capture based on the use of high efficiency detectors has been shown to be well suited for probing the properties of the Photon Strength Function of heavy (high level density) and/or radioactive (high background) nuclei. In this work we have investigated for the first time the validity of the recommended PSF of actinides, in particular {sup 235}U, {sup 238}Np and {sup 241}Pu. Our study includes the search for resonance structures in the PSF below Sn and draws conclusions regarding their existence and their characteristics in terms of energy, width and electromagnetic nature.

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

  3. Fission Product Data Measured at Los Alamos for Fission Spectrum and Thermal Neutrons on 239Pu, 235U, 238U

    NASA Astrophysics Data System (ADS)

    Selby, H. D.; Mac Innes, M. R.; Barr, D. W.; Keksis, A. L.; Meade, R. A.; Burns, C. J.; Chadwick, M. B.; Wallstrom, T. C.

    2010-12-01

    where the present results are about 4%-relative higher for neutrons incident on 239Pu and 235U. Additionally, our results illustrate the importance of representing the incident energy dependence of fission product yields over the fast neutron energy range for high-accuracy work, for example the 147Nd from neutron reactions on plutonium. An upgrade to the ENDF library, for ENDF/B-VII.1, based on these and other data, is described in a companion paper to this work.

  4. Event-by-event evaluation of the prompt fission neutron spectrum from 239Pu(n,f)

    SciTech Connect

    Vogt, R; Randrup, J; Brown, D A; Descalle, M A; Ormand, W E

    2011-11-28

    We have developed an improved evaluation method for the spectrum of neutrons emitted in fission of {sup 239}Pu induced by incident neutrons with energies up to 20 MeV. The covariance data, including incident energy correlations introduced by the evaluation method, were used to fix the input parameters in our event-by-event model of fission, FREYA, by applying formal statistical methods. Formal estimates of uncertainties in the evaluation were developed by randomly sampling model inputs and calculating likelihood functions based on agreement with the evaluated . Our approach is able to employ a greater variety of fission measurements than the relatively coarse spectral data alone. It also allows the study of numerous fission observables for more accurate model validation. The combination of an event-by-event Monte Carlo fission model with a statistical-likelihood analysis is thus a powerful tool for evaluation of fission-neutron data. Our empirical model FREYA follows the complete fission event from birth of the excited fragments through their decay via neutron emission until the fragment excitation energy is below the neutron separation energy when neutron emission can no longer occur. The most recent version of FREYA incorporates pre-equilibrium neutron emission, the emission of the first neutron before equilibrium is reached in the compound nucleus, and multi-chance fission, neutron evaporation prior to fission when the incident neutron energy is above the neutron separation energy. Energy, momentum, charge and mass number are conserved throughout the fission process. The best available values of fragment masses and total kinetic energies are used as inputs to FREYA. We fit three parameters that are not well under control from previous measurements: the shift in the total fragment kinetic energy; the energy scale of the asymptotic level density parameter, controlling the fragment 'temperature' for neutron evaporation; and the relative excitation of the

  5. Transfer of aged 239+240Pu, 238Pu, 241Am, and 137Cs to cattle grazing a contaminated arid environment.

    PubMed

    Gilbert, R O; Engel, D W; Anspaugh, L R

    1989-09-01

    In this paper, estimates are obtained of the fraction of ingested 239+240Pu, 238Pu, 241Am and 137Cs transferred to blood, muscle, liver, kidney, femur, vertebra, and gonads of a reproducing herd of 17 beef cattle, individuals of which grazed within fenced enclosures for up to 1064 days under natural conditions with no supplemental feeding at an arid site contaminated 16 years previously with transuranic radionuclides. The estimated geometric mean (GM) GI-to-blood fractional transfer of 238Pu (0.0001) was about 20 times larger than the estimated transfer of 239+240Pu (0.000005), while the estimated transfer of 241Am (0.00001) was about 2 times larger than that of 239+240Pu. These GM GI-to-blood transfers were smaller than the GI-to-blood transfer value of 0.001 recommended by the International Commission on Radiological Protection (ICRP) for humans exposed via food chains or occupationally from unknown mixtures or compounds of plutonium and americium. Statistical tests indicated significantly (p less than 0.05) larger GI-to-tissue transfers of (1) 238Pu as compared to 239+240Pu for all tissues examined, (2) of 238Pu as compared to 241Am for muscle, liver, femur, and vertebra, and (3) of 241Am as compared to 239+240Pu for blood serum, femur, and kidney. The estimated GM fractional transfers of 137Cs from GI to muscle and liver were 0.03 (n = 8) and 0.001 (n = 3), respectively, assuming a 50-day biological half-time of 137Cs in cattle tissue. PMID:2814465

  6. Product yields of sup 235 U, sup 238 U, sup 237 Np, and sup 239 Pu by photofission reactions with 20-, 30-, and 60-MeV Bremsstrahlung

    SciTech Connect

    Kase, T.; Yamadera, A.; Nakamura, T. ); Shibata, S. ); Fujiwara, I. )

    1992-08-01

    This paper reports that as a basic study of photonuclear transmutation of actinides in high-level radioactive wastes using electron-produced bremsstrahlung, the absolute yields of cumulative mass distributions and the transmutation rate of {sup 235}U, {sup 238}U, {sup 237}Np, and {sup 239}Pu by photofission reactions induced by 20-, 30-, and 60-MeV bremsstrahlung were measured. The results of mass yield distributions and transmutation yields agree well with other experimental results and those calculated using photofission cross sections, respectively. The transmutation efficiency per electron increases about one order of magnitude with electron energy from 20 to 60 MeV.

  7. Report on the effectiveness of flocculation for removal of {sup 239}Pu at concentrations of 1 pCi/L and 0.1 pCi/L. RFP Pond Water Characterization and Treatment (LATO-EG&G-91-022): Task C deliverables: 5.1.2 and 5.2.2

    SciTech Connect

    Triay, I.R.; Bayhurst, G.K.; Mitchell, A.J.; Cisneros, M.R.; Efurd, D.W.; Roensch, F.R.; Rokop, D.J.; Aguilar, R.D.; Attrep, M.; Nuttall, H.E.

    1993-08-01

    The objective of this work is to assess the effectiveness of flocculation for the removal of Pu from Rocky Flats Plant (RFP) pond waters spiked with {sup 239}Pu at the 1.0 and 0.1 pCi/L level. The flocculation treatment procedure is described in detail. Results are presented for treatment studies for the removal of Pu from C-2 pond water spiked with {sup 239}Pu and from distilled water spiked with {sup 239}Pu.

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

    SciTech Connect

    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 of

  9. Relative radiosensitivity of bone tumor induction among beagles as a function of age at injection of {sup 239}Pu or {sup 226}Ra

    SciTech Connect

    Lloyd, R.D.; Taylor, G.N.; Jee, W.S.S.; Miller, S.C.

    1999-01-01

    A comparison was made of the response to induction of skeletal malignancy from exposure of beagles to monomeric {sup 239}Pu or to {sup 226}Ra as juveniles (3 mo of age), young adults (1.5 y of age), or mature adults (5 y of age). This indicated that of these age groups, animals injected as young adults are most sensitive per Gy of average skeletal dose evaluated at 1 y before death. Dogs exposed either as juveniles or as mature adults appeared to be less sensitive. Relative radiosensitivities (RRS) of juvenile and mature beagles ranged between about 0.3 and 0.7 that of dogs injected as young adults. Mean values of RRS for both radionuclides were about 0.5, but RRS values derived from dogs given monomeric {sup 239}Pu appeared to be most reliable and were 0.27 {+-} 0.09 for dogs injected as juveniles and 0.41 {+-} 0.13 for animals exposed as mature adults.

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

    NASA Astrophysics Data System (ADS)

    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.

  11. The Need for Precise and Well-documented Experimental Data on Prompt Fission Neutron Spectra from Neutron-induced Fission of 239Pu

    NASA Astrophysics Data System (ADS)

    Neudecker, D.; Taddeucci, T. N.; Haight, R. C.; Lee, H. Y.; White, M. C.; Rising, M. E.

    2016-01-01

    The spectrum of neutrons emitted promptly after 239Pu(n,f)-a so-called prompt fission neutron spectrum (PFNS)-is a quantity of high interest, for instance, for reactor physics and global security. However, there are only few experimental data sets available that are suitable for evaluations. In addition, some of those data sets differ by more than their 1-σ uncertainty boundaries. We present the results of MCNP studies indicating that these differences are partly caused by underestimated multiple scattering contributions, over-corrected background, and inconsistent deconvolution methods. A detailed uncertainty quantification for suitable experimental data was undertaken including these effects, and test-evaluations were performed with the improved uncertainty information. The test-evaluations illustrate that the inadequately estimated effects and detailed uncertainty quantification have an impact on the evaluated PFNS and associated uncertainties as well as the neutron multiplicity of selected critical assemblies. A summary of data and documentation needs to improve the quality of the experimental database is provided based on the results of simulations and test-evaluations. Given the possibly substantial distortion of the PFNS by multiple scattering and background effects, special care should be taken to reduce these effects in future measurements, e.g., by measuring the 239Pu PFNS as a ratio to either the 235U or 252Cf PFNS.

  12. The gender-specific chest wall thickness prediction equations for routine measurements of 239Pu and 241Am within the lungs using HPGe detectors.

    PubMed

    Vickers, L R

    1996-03-01

    The current chest wall thickness prediction equation is not applicable to use in routine lung counting measurements for detection of low energy photons (17--60 keV) within the lungs of male and female subjects. The current chest wall thickness prediction equation was derived for the NaI-CsI "phoswich" detection system, which is not the routine detection system in use; the subject position was supine, which is not the routine position; the equation did not account for the intercostal tissue thicknesses of muscle and adipose which significantly attenuate low energy photons (17--60keV); it was derived from male subjects only and is used to predict the chest wall thickness of female subjects for whom it is not applicable. The current chest wall thickness prediction equation yields unacceptable percent errors in the HPGe detection efficiency calibration for 239Pu and 241Am (17- and 59.5-keV photons, respectively) relative to the gender-specific HPGe chest wall thickness prediction equations of this paper (+284% to --73% for 239Pu; (+)42% to --39% for 241Am). As a result, use of the current chest wall thickness prediction equation yields unacceptable percent errors (proportional in magnitude to the percent errors in the detection efficiency calibration) in the calculation of the minimum detectable activity (Bq) or in an initial assessment of a radioactive contamination exposure detected by a routine lung count measurement. PMID:8609026

  13. The need for precise and well-documented experimental data on prompt fission neutron spectra from neutron-induced fission of 239Pu

    DOE PAGESBeta

    Neudecker, Denise; Taddeucci, Terry Nicholas; Haight, Robert Cameron; Lee, Hye Young; White, Morgan Curtis; Rising, Michael Evans

    2016-01-06

    The spectrum of neutrons emitted promptly after 239Pu(n,f)—a so-called prompt fission neutron spectrum (PFNS)—is a quantity of high interest, for instance, for reactor physics and global security. However, there are only few experimental data sets available that are suitable for evaluations. In addition, some of those data sets differ by more than their 1-σ uncertainty boundaries. We present the results of MCNP studies indicating that these differences are partly caused by underestimated multiple scattering contributions, over-corrected background, and inconsistent deconvolution methods. A detailed uncertainty quantification for suitable experimental data was undertaken including these effects, and test-evaluations were performed with themore » improved uncertainty information. The test-evaluations illustrate that the inadequately estimated effects and detailed uncertainty quantification have an impact on the evaluated PFNS and associated uncertainties as well as the neutron multiplicity of selected critical assemblies. A summary of data and documentation needs to improve the quality of the experimental database is provided based on the results of simulations and test-evaluations. Furthermore, given the possibly substantial distortion of the PFNS by multiple scattering and background effects, special care should be taken to reduce these effects in future measurements, e.g., by measuring the 239Pu PFNS as a ratio to either the 235U or 252Cf PFNS.« less

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    Bruenger, F W; Miller, S C; Lloyd, R D

    1991-06-01

    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). Bone tumor induction was clearly elevated in dogs injected with 239Pu and 228Th. When the effect of these bone tumors on survival

  16. Minimum Critical Values Study

    SciTech Connect

    Fox, P.B.

    2005-07-11

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

  17. A new Certified Reference Material for radionuclides in Irish sea sediment (IAEA-385).

    PubMed

    Pham, M K; Sanchez-Cabeza, J A; Povinec, P P; Andor, K; Arnold, D; Benmansour, M; Bikit, I; Carvalho, F P; Dimitrova, K; Edrev, Z H; Engeler, C; Fouche, F J; Garcia-Orellana, J; Gascó, C; Gastaud, J; Gudelis, A; Hancock, G; Holm, E; Legarda, F; Ikäheimonen, T K; Ilchmann, C; Jenkinson, A V; Kanisch, G; Kis-Benedek, G; Kleinschmidt, R; Koukouliou, V; Kuhar, B; Larosa, J; Lee, S-H; Lepetit, G; Levy-Palomo, I; Liong Wee Kwong, L; Llauradó, M; Maringer, F J; Meyer, M; Michalik, B; Michel, H; Nies, H; Nour, S; Oh, J-S; Oregioni, B; Palomares, J; Pantelic, G; Pfitzner, J; Pilvio, R; Puskeiler, L; Satake, H; Schikowski, J; Vitorovic, G; Woodhead, D; Wyse, E

    2008-11-01

    A new Certified Reference Material (CRM) for radionuclides in sediment (IAEA-385) is described and the results of the certification process are presented. Eleven radionuclides ((40)K, (137)Cs, (226)Ra, (228)Ra, (230)Th, (232)Th, (234)U, (238)U, (238)Pu, (239+240)Pu and (241)Am) have been certified and information mass activities with 95% confidence intervals are given for seven other radionuclides ((90)Sr, (210)Pb((210)Po), (235)U, (239)Pu, (240)Pu and (241)Pu). Results for less frequently reported radionuclides ((60)Co, (99)Tc, (134)Cs, (155)Eu, (224)Ra and (239)Np) and information on some activity and mass ratios are also reported. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in sediment samples, for the development and validation of analytical methods and for training purposes. PMID:18513984

  18. Certified reference material for radionuclides in fish flesh sample IAEA-414 (mixed fish from the Irish Sea and North Sea).

    PubMed

    Pham, M K; Sanchez-Cabeza, J A; Povinec, P P; Arnold, D; Benmansour, M; Bojanowski, R; Carvalho, F P; Kim, C K; Esposito, M; Gastaud, J; Gascó, C L; Ham, G J; Hegde, A G; Holm, E; Jaskierowicz, D; Kanisch, G; Llaurado, M; La Rosa, J; Lee, S-H; Liong Wee Kwong, L; Le Petit, G; Maruo, Y; Nielsen, S P; Oh, J-S; Oregioni, B; Palomares, J; Pettersson, H B L; Rulik, P; Ryan, T P; Sato, K; Schikowski, J; Skwarzec, B; Smedley, P A; Tarján, S; Vajda, N; Wyse, E

    2006-01-01

    A certified reference material (CRM) for radionuclides in fish sample IAEA-414 (mixed fish from the Irish Sea and North Seas) is described and the results of the certification process are presented. Nine radionuclides (40K, 137Cs, 232Th, 234U, 235U, 238U, 238Pu, 239+240Pu and 241Am) were certified for this material. Information on massic activities with 95% confidence intervals is given for six other radionuclides (90Sr, 210Pb(210Po), 226Ra, 239Pu, 240Pu 241Pu). Less frequently reported radionuclides (99Tc, 129I, 228Th, 230Th and 237Np) and information on some activity and mass ratios are also included. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in fish sample, for the development and validation of analytical methods and for training purposes. The material is available from IAEA, Vienna, in 100 g units. PMID:16549351

  19. Comparative studies on the lysosomal association of monomeric /sup 239/Pu and /sup 241/Am in rat and Chinese hamster liver: analysis with sucrose, metrizamide, and Percoll density gradients of subcellular binding as dependent on time

    SciTech Connect

    Suetterlin, U.; Thies, W.G.; Haffner, H.; Seidel, A.

    1984-05-01

    The binding of /sup 239/Pu and /sup 241/Am in the livers of Chinese hamsters and rats was analyzed by centrifugation of a mitochondrial-lysosomal fraction in sucrose, metrizamide, and Percoll density gradients at intervals between 4 and 70 days after nuclide injection. The behavior of /sup 239/Pu and /sup 241/Am during the centrifugation experiments was very similar. In contrast to the results for rats, the median densities of the nuclide fraction liberated by addition of Triton X-100, and the nuclide profiles do not respond typically to Triton WR 1339 treatment of the animals. It was concluded from the results that the major fraction of /sup 239/Pu and /sup 241/Am remained bound to typical lysosomes in rat liver, whereas those in hamster liver may be transformed into telolysosomes. Possibly, a vesicular biliary transport system for certain heavy metals, for which evidence exists in rat liver, does not occur in Chinese hamster liver.

  20. [Accumulation of 238, 239 + 240Pu and 241Am in Boar Organs and Tissues on the Territory of the Belarusian Part of the ChNPP Exclusion Zone].

    PubMed

    Bondar, Yu I; Zabrotski, V N; Sadchikov, V I; Kalinin, V N

    2015-01-01

    The paper is devoted to determination of α-emitting radionuclides of 238, 239 + 240Pu and 241Am in liver, lungs, muscular and bone tissues of the boars on the territory of the Belarusian part of the ChNPP exclusion zone. It is shown that the content of Pu and Am isotopes in boar organs and tissues decreases in the following order: liver > bone tissues > lungs ≥ muscular tissues. The results received allow evaluation of penetration of 238, 239 + 240Pu and 241Am through the biological chain "soil-ration-organs and tissues". It is calculated that 1.7% of a boar's ration falls on the soil getting into the stomach with food. Translocation and accumulation coefficients characterizing the transfer of radionuclides through the chain "soil-vegetation-organs and tissues" were calculated. The conclusion about accumulation of Pu in the boar's body is made. PMID:26964350

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

    NASA Astrophysics Data System (ADS)

    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).

  2. Fission track analysis of plutonium in small specimens of biological material: Ultrasensitive analysis for sup 239 Pu in 50 urine samples from the Marshall Islands furnished by Brookhaven National Laboratory

    SciTech Connect

    Wrenn, M.E.; Singh, N.P.; Xue, Ying-Hua.

    1990-11-20

    A neutron induced fission track method was successfully developed for assaying {sup 239}Pu in human urine. The technique involves means to remove potentially interfering natural uranium from the sample and reagents. The method was applied to 50 urine samples including an unknown number of spikes and controls from the Marshall Islands. 49 samples were successfully analyzed. The mean activity for the 47 samples which were not positive for {sup 239}Pu did not differ significantly from the mean for our control samples, which consisted of urines collected from six young adult Utah residents. 2 figs., 12 tabs.

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

    PubMed

    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

  4. Age determination of single plutonium particles after chemical separation

    NASA Astrophysics Data System (ADS)

    Shinonaga, T.; Donohue, D.; Ciurapinski, A.; Klose, D.

    2009-01-01

    Age determination of single plutonium particles was demonstrated using five particles of the standard reference material, NBS 947 (Plutonium Isotopic Standard. National Bureau of Standards, Washington, D.C. 20234, August 19, 1982, currently distributed as NBL CRM-137) and the radioactive decay of 241Pu into 241Am. The elemental ratio of Am/Pu in Pu particles found on a carbon planchet was measured by wavelength dispersive X-ray spectrometry (WDX) coupled to a scanning electron microscope (SEM). After the WDX measurement, each plutonium particle, with an average size of a few μm, was picked up and relocated to a silicon wafer inside the SEM chamber using a micromanipulator. The silicon wafer was then transferred to a quartz tube for dissolution in an acid solution prior to chemical separation. After the Pu was chemically separated from Am and U, the isotopic ratios of Pu ( 240Pu/ 239Pu, 241Pu/ 239Pu and 242Pu/ 239Pu) were measured with a thermal ionization mass spectrometer (TIMS) for the calculation of Pu age. The age of particles determined in this study was in good agreement with the expected age (35.9 a) of NBS 947 within the measurement uncertainty.

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

    SciTech Connect

    Younes, W

    2002-11-18

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

  6. 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)

    SciTech Connect

    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.

  7. Can 239 + 240Pu replace 137Cs as an erosion tracer in agricultural landscapes contaminated with Chernobyl fallout?

    PubMed

    Schimmack, W; Auerswald, K; Bunzl, K

    2001-01-01

    Erosion studies often use 137Cs from the global fallout (main period: 1953-1964) as a tracer in the soil. In many European countries, where 137Cs was deposited in considerable amounts also by the Chernobyl fallout in 1986, the global fallout fraction (GF-Cs) has to be separated from the Chernobyl fraction by means of the isotope 134Cs. In a few years, this will no longer be possible due to the short half-life of 134Cs (2 yr). Because GF-Cs in the soil can then no longer be determined, the potential of using 239 + 240Pu as a tracer is evaluated. This radionuclide originates in most European countries essentially only from the global fallout. The activities and spatial distributions of Pu and GF-Cs were compared in the soil of a steep field (inclination about 20%, area ca. 3 ha, main soil type Dystric Eutrochrept), sampled at 48 nodes of a 25 x 25 m2 grid. The reference values were determined at 12 points adjacent to the field. Their validity was assured by an inventory study of radiocaesium in a 70 ha area surrounding the field sampling 275 nodes of a 50 x 50 m2 grid. In the field studied, the activity concentrations of GF-Cs and Pu in the Ap horizon were not correlated (Spearman correlation coefficient R = 0.20, p > 0.05), and the activity balance of Pu differed from that of GF-Cs. Whereas no net loss of GF-Cs from the field was observed as compared to the reference site, Pu was more mobile with an average loss of ca. 11% per unit area. In addition, the spatial pattern of GF-Cs and Pu in the field differed significantly. The reason may be that due to their different associations with soil constituents, Pu and Cs represent different fractions of the soil, exhibiting different properties with respect to erosion/deposition processes. This indicates that both radionuclides or one of them may not be appropriate to quantity past erosion. When tracer losses are used to calibrate or verify erosion prediction models, systematic deviations may not only stem from model

  8. 210Pb, 137Cs and 239,240Pu in East China Sea Sediments: Sources, Pathways and Budgets of Sediments and Radionuclides

    NASA Astrophysics Data System (ADS)

    Su, C.; Huh, C.

    2001-05-01

    Profiles of 210Pb, 137Cs and 239,240Pu measured in eighty-three sediment cores collected from various sedimentary regimes in the East China Sea were analyzed to elucidate the sources, routes and budgets of sediments as well as these radionuclides. Distributions of sedimentation rates and nuclide inventories reveal alongshore transport of sediments, 137Cs and 239,240Pu from the mouth of the Yangtze River toward the south, and it is largely confined to the inner-shelf area (water depth <70 m). Mass balance calculations of the budgets of nuclides suggest that the East China Sea is a sink for the particle-reactive 210Pb and 239,240Pu, with up to 20% of their sedimentary budgets supplied via boundary scavenging. In contrast, due to lower affinity of 137Cs for particles and rapid turnover of the shelf water, the East China Sea serves as a source for 137Cs. About two-thirds of the cumulative inputs of 137Cs have been transported out of the East China Sea, leaving the remaining one-third in sediments and the overlying water column. As for the sediment budget, mass balance can not be established due to a shortfall in sediment supply of more than 30% based on a comparison between input terms documented thus far and the sedimentation flux derived from this study. It could be that our sedimentation rates are overestimated, and/or that long-distance transport from the Yellow River's dispersal system to the ECS is underestimated previously. Alternatively, there is no reason to expect the attainment of equilibrium between sediment input and output in the East China Sea on decadal time scales.

  9. Parity splitting and E1/E2 branching in the alternating parity band of {sup 240}Pu from two-center octupole wave functions using supersymmetric quantum mechanics

    SciTech Connect

    Jolos, R. V.; Brentano, P. von

    2011-08-15

    An interpretation is suggested of the recently published experimental data on the alternating parity bands in {sup 240}Pu. The interpretation is based on the assumption that the main role in the description of the properties of the alternating parity bands plays the octupole mode which preserves the axial symmetry. The mathematical technique of the supersymmetric quantum mechanics is used for the realization of the model with the two-center octupole wave functions. A good description of the parity splitting and of the ratio of the dipole and quadrupole transitional moments is obtained for the first two bands.

  10. Application of ICP-QMS for the determination of plutonium in environmental samples for safeguards purposes.

    PubMed

    Godoy, Maria Luiza D P; Godoy, José Marcus; Roldão, Luiz Alfredo

    2007-01-01

    Aiming to determine the plutonium amount as well as its isotopic composition, in particular, in swipe samples for safeguards purposes, an analytical method was developed with a plutonium separation step based on extraction chromatography using 2 cm TEVA columns and detection with quadrupole ICP-MS applying an ultra-sonic nebulizer coupled with membrane desolvation system. The method was successfully applied to New Brunswick plutonium certified reference materials as well as to Lawrence Livermore National Laboratory round robin samples, based on the round robin samples provided by the Institute for Reference Materials and Measurements (Belgium), as part of the Regular European Interlaboratory Measurement Evaluation Programme (REIMEP), campaign 16 (isotopic abundances of plutonium in plutonium nitrate samples), with a total plutonium amount between 1 and 0.25 ng per sample. After the introduction of an additional separation step, it was also possible to carry out precise and accurate total plutonium, (240)Pu/(239)Pu, (241)Pu/(239)Pu and (242)Pu/(239)Pu atom ratios determination in sediment sample showing its applicability to environmental samples in general, reaching a detection limit equivalent to 5 mBq(239)Pu kg(-1). PMID:17543430

  11. Calculated gamma-ray spectra for keV neutron capture in /sup 240/Pu, /sup 242/Pu, and /sup 238/U

    SciTech Connect

    Reffo, G.; Fabbri, F.; Kappeler, F.; Wisshak, K.

    1983-03-01

    Capture gamma-ray spectra of /sup 240/Pu, /sup 242/Pu, and /sup 238/U were calculated in the framework of the spherical optical model and the statistical model. A consistent set of input parameters was determined from available experimental information or from model-guided systematics. The complete gamma-ray cascades were calculated considering all possible transitions up to multiplicity seven. All experimental information on level schemes and gamma-ray transition probabilities of the compound nuclei was explicitly included as input. The capture gamma-ray spectra were used to correct experimental data for the capture cross sections of /sup 240/Pu and /sup 242/Pu from a relative measurement using a Moxon-Rae detector with a graphite converter and with /sup 197/Au and /sup 238/U as standards. This correction is required to take into account that the detector efficiency is not exactly proportional to the gamma-ray energy. The resulting correction factors proved to be negligible for measurements relative to /sup 238/U; whereas, they are about 3% if gold is used as a standard.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  15. Improved evaluation of [sup 239]Pu (n,f) between 0.1 and 20 MeV incident neutrons energies

    SciTech Connect

    Talou, P.; Young, P. G. ,; Chadwick, M. B.

    2001-01-01

    Accurate cross sections lie at the heart of successful neutronics simulations. The advent of innovative nuclear designs such as Accelerator Driven Systems (ADS) have recently emphasized the need for accurate measurements, evaluations, and calculations of neutron-induced fission cross sections over a wide range of nuclei and energies. As a first step, we have performed a thorough covariance analysis of the neutron induced fission cross section of {sup 239}Pu between 0.1 and 20 MeV. The choice of this first study has been driven by the importcame of this Pu isotope in the US nuclear waste stream. Newly available experimental data (both absolute and in ratio to the standard {sup 235}U) have been included in this new evaluation. A Bayesian statistical approach has been used to infer posterior knowledge on the cross sections and on the associated errors (standard deviations + correlations). Significant reductions of these errors are observed, compared to the previous ENDF/B-VI evaluation. Large changes (up to 4% in places) appear above 14 MeV incident neutron energies, mainly due to a recent revised {sup 235}U (n,f) evaluation. Overall very good agreement is observed elsewhere. Finally, a comparison between this new evaluation and other existing evaluations is discussed.

  16. Photofission and photoneutron cross sections and photofission neutron multiplicities for /sup 233/U, /sup 234/U, /sup 237/Np, and /sup 239/Pu

    SciTech Connect

    Berman, B.L.; Caldwell, J.T.; Dowdy, E.J.; Dietrich, S.S.; Meyer, P.; Alvarez, R.A.

    1986-12-01

    The photonuclear cross sections for /sup 233/U, /sup 234/U, /sup 237/Np, and /sup 239/Pu have been measured from threshold up to 18 MeV. The source of radiation was the monoenergetic photon beam from the annihilation in flight of fast positrons. The branching among the neutron-producing reaction channels was determined by measuring the photofission prompt neutron multiplicities nu-bar/sub p/. One interesting result is the complete absence of any (..gamma..,2n) cross section for /sup 233/U and /sup 234/U. The values of nu-bar/sub p/(E) for /sup 234/U agree with those measured with neutrons incident on /sup 233/U. The parameters of the giant dipole resonance deduced from the total photonuclear cross sections show that these nuclei have large static deformations, as expected. The integrated photofission cross sections are large (as are the absolute fission probabilities), and account for 60% to 80% of the total photonuclear absorption strength.

  17. Microdistribution and long-term retention of 239Pu (NO3)4 in the respiratory tracts of an acutely exposed plutonium worker and experimental beagle dogs.

    PubMed

    Nielsen, Christopher E; Wilson, Dulaney A; Brooks, Antone L; McCord, Stacey L; 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 [(239)Pu (NO(3))(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 histologic lung, lymph node, trachea, and nasal turbinate tissue sections. These studies showed that both the human and dogs had a nonuniform 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 subpleural 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 to increase cancer risk. PMID:22962267

  18. Novel insights into Fukushima nuclear accident from isotopic evidence of plutonium spread along coastal rivers.

    PubMed

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

    2014-08-19

    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, measurements of Pu isotopic atom and activity ratios are required to differentiate between the contributions of global nuclear test fallout and FDNPP emissions. In this study, we used a double-focusing sector field ICP-MS to measure Pu atom and activity ratios in recently deposited sediment along rivers draining the most contaminated part of the inland radioactive plume. Results showed that plutonium isotopes (i.e., (239)Pu, (240)Pu, (241)Pu, and (242)Pu) were detected in all samples, although in extremely low concentrations. The (241)Pu/(239)Pu 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 for the Northern Hemisphere between 31°-71° N: Kelley, J. M.; Bond, L. A.; Beasley, T. M. Global distribution of Pu isotopes and (237)Np. Sci. Total. Env. 1999, 237/238, 483-500). The results indicated the presence of Pu from FDNPP, in slight excess compared to the Pu background from global fallout that represented 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 been deposited in rivers representing a potential source of Pu to the ocean. In future, the high (241)Pu/(239)Pu atom ratio of the Fukushima accident sourced-Pu should be measured to quantify the supply of continental-originating material from Fukushima Prefecture to the Pacific Ocean. PMID:25014620

  19. Investigations of the Space Parity Violation and Interference Effects in the Fragment Angular Distributions of 235U, 233U, and 239Pu Fission by Resonance Neutrons

    NASA Astrophysics Data System (ADS)

    Sokolov, V. E.; Gagarski, A. M.; Guseva, I. S.; Golosovskaya, S. P.; Krasnoshchokova, I. S.; Petrov, G. A.; Petrova, V. I.; Petukhov, A. K.; Pleva, Yu. S.; Alfimenkov, V. P.; Chernikov, A. N.; Lason, L.; Mareev, Yu. D.; Novitski, V. V.; Pikelner, L. B.; Pikelner, T. L.; Tsulaya, M. I.

    2005-05-01

    Investigations of the space parity nonconserving (PNC) asymmetry of 233U, 235U, and 239Pu fission fragment emission and parity conserving (PC) interference effects of left-right and forward-backward asymmetries were carried out on the neutron beams of the reactor IBR-30 (JINR, Dubna) over the range of neutron energies from 0.02 eV to about 100 eV. All experimental results obtained have been found to be in a good mutual accordance within the frames of modern theoretical conceptions about the mechanisms of PNC and PC effects forming in fission process induced by slow neutrons. In case of the P-even interference effects of asymmetry the evident mutual well-marked irregularities in their neutron energy dependencies up to about 100 eV were observed. It is connected with the interference of s, p-resonances at fission compound stage according to modern theory. As a remarkable result of the PNC effect measurements the resonance behavior of the PNC asymmetry coefficients in the low neutron energy region (En < 2 eV) was observed. Unfortunately, the statistical accuracy of the PNC effect measurements is not enough for observation of these resonance effects in other cases of more high energies. Results of simultaneous analysis of all three asymmetry effects for all three nuclei are presented. The satisfactory combined description of the experimental points is received. As a result of theoretical evaluation of these data main parameters and the estimates of nuclear matrix elements of the weak interaction for some p-resonances in the low energy range were extracted.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

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

  2. Conversion electron spectrometry of Pu isotopes with a silicon drift detector.

    PubMed

    Pommé, S; Paepen, J; Peräjärvi, K; Turunen, J; Pöllänen, R

    2016-03-01

    An electron spectrometry set-up was built at IRMM consisting of a vacuum chamber with a moveable source holder and windowless Peltier-cooled silicon drift detector (SDD). The SDD is well suited for measuring low-energy x rays and electrons emitted from thin radioactive sources with low self-absorption. The attainable energy resolution is better than 0.5keV for electrons of 30keV. It has been used to measure the conversion electron spectra of three plutonium isotopes, i.e. (238)Pu, (239)Pu, (240)Pu, as well as (241)Am (being a decay product of (241)Pu). The obtained mixed x-ray and electron spectra are compared with spectra obtained with a close-geometry set-up using another SDD in STUK and spectra measured with a Si(Li) detector at IRMM. The potential of conversion electron spectrometry for isotopic analysis of mixed plutonium samples is investigated. With respect to the (240)Pu/(239)Pu isotopic ratio, the conversion electron peaks of both isotopes are more clearly separated than their largely overlapping peaks in alpha spectra. PMID:26651177

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Fission Product Data Measured at Los Alamos for Fission Spectrum and Thermal Neutrons on {sup 239}Pu, {sup 235}U, {sup 238}U

    SciTech Connect

    Selby, H.D.; Mac Innes, M.R.; Barr, D.W.; Keksis, A.L.; Meade, R.A.; Burns, C.J.; Chadwick, M.B.; Wallstrom, T.C.

    2010-12-15

    over to the ENDF/B-VII.0 library, except for {sup 99}Mo where the present results are about 4%-relative higher for neutrons incident on {sup 239}Pu and {sup 235}U. Additionally, our results illustrate the importance of representing the incident energy dependence of fission product yields over the fast neutron energy range for high-accuracy work, for example the {sup 147}Nd from neutron reactions on plutonium. An upgrade to the ENDF library, for ENDF/B-VII.1, based on these and other data, is described in a companion paper to this work.

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

    PubMed

    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 (<4 cm) stable (127)I concentrations was coniferous 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

  6. AN INTEGRAL REACTOR PHYSICS EXPERIMENT TO INFER ACTINIDE CAPTURE CROSS-SECTIONS FROM THORIUM TO CALIFORNIUM WITH ACCELERATOR MASS SPECTROMETRY

    SciTech Connect

    G. Youinou; M. Salvatores; M. Paul; R. Pardo; G. Palmiotti; F. Kondev; G. Imel

    2010-04-01

    The principle of the proposed experiment is to irradiate very pure actinide samples in the Advanced Test Reactor (ATR) at INL and, after a given time, determine the amount of the different transmutation products. The determination of the nuclide densities before and after neutron irradiation will allow inference of effective neutron capture cross-sections. This approach has been used in the past and the novelty of this experiment is that the atom densities of the different transmutation products will be determined using the Accelerator Mass Spectroscopy (AMS) technique at the ATLAS facility located at ANL. It is currently planned to irradiate the following isotopes: 232Th, 235U, 236U, 238U, 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 243Am and 248Cm.

  7. MANTRA: An Integral Reactor Physics Experiment to Infer Actinide Capture Cross-sections from Thorium to Californium with Accelerator Mass Spectrometry

    SciTech Connect

    G. Youinou; C. McGrath; G. Imel; M. Paul; R. Pardo; F. Kondev; M. Salvatores; G. Palmiotti

    2011-08-01

    The principle of the proposed experiment is to irradiate very pure actinide samples in the Advanced Test Reactor at INL and, after a given time, determine the amount of the different transmutation products. The determination of the nuclide densities before and after neutron irradiation will allow inference of effective neutron capture cross-sections. This approach has been used in the past and the novelty of this experiment is that the atom densities of the different transmutation products will be determined using the Accelerator Mass Spectrometry technique at the ATLAS facility located at ANL. It is currently planned to irradiate the following isotopes: 232Th, 235U, 236U, 238U, 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 243Am, 244Cm and 248Cm.

  8. Fragment mass and kinetic energy distributions for /sup 242/Pu(sf), /sup 241/Pu(n/sub th/,f), and /sup 242/Pu(. gamma. ,f)

    SciTech Connect

    Thierens, H.; Jacobs, E.; D'hondt, P.; De Clercq, A.; Piessens, M.; De Frenne, D.

    1984-02-01

    Energy correlation measurements were performed for the spontaneous fission of /sup 242/Pu, the thermal-neutron-induced fission of /sup 241/Pu, and the photofission of /sup 242/Pu with 12-, 15-, 20-, and 30-MeV bremsstrahlung. The photofission cross section for /sup 242/Pu was determined up to 30 MeV. For /sup 242/Pu(sf) the overall kinetic energy distribution is strongly asymmetric and the overall mass distribution has a very high peak yield (9%). Important deviations of the average total kinetic energy release and the average light and heavy fragment masses and from the systematics of Unik et al. are also observed for this fissioning system. These effects can be explained in the framework of the static scission point model by the strong preferential formation of a shell-stabilized scission configuration with the neutron number of the heavy and light fragments in the vicinity of the spherical N = 82 neutron shell and the deformed N = 66 neutron shell, respectively. A decrease of with the average excitation energy , d/d = -0.30 +- 0.04, is observed in the photofission of /sup 242/Pu.

  9. Influences of parameter uncertainties within the ICRP-66 respiratory tract model: regional tissue doses for 239PuO2 and 238UO2/238U3O8.

    PubMed

    Farfán, Eduardo B; Huston, Thomas E; Bolch, W Emmett; Vernetson, William G; Bolch, Wesley E

    2003-04-01

    This paper extends an examination of the influence of parameter uncertainties on regional doses to respiratory tract tissues for short-ranged alpha particles using the ICRP-66 respiratory tract model. Previous papers examined uncertainties in the deposition and clearance aspects of the model. The critical parameters examined in this study included target tissue depths, thicknesses, and masses, particularly within the thoracic or lung regions of the respiratory tract. Probability density functions were assigned for the parameters based on published data. The probabilistic computer code LUDUC (Lung Dose Uncertainty Code) was used to assess regional and total lung doses from inhaled aerosols of 239PuO2 and 238UO2/238U3O8. Dose uncertainty was noted to depend on the particle aerodynamic diameter. Additionally, dose distributions were found to follow a lognormal distribution pattern. For 239PuO2 and 238UO2/238U3O8, this study showed that the uncertainty in lung dose increases by factors of approximately 50 and approximately 70 for plutonium and uranium oxides, respectively, over the particle size range from 0.1 to 20 microm. For typical exposure scenarios involving both radionuclides, the ratio of the 95% dose fractile to the 5% dose fractile ranged from approximately 8-10 (corresponding to a geometric standard deviation, or GSD, of about 1.7-2) for particle diameters of 0.1 to 1 microm. This ratio increased to about 370 for plutonium oxide (GSD approximately 4.5) and to about 600 for uranium oxide (GSD approximately 5) as the particle diameter approached 20 microm. However, thoracic tissue doses were quite low at larger particle sizes because most of the deposition occurred in the extrathoracic airways. For 239PuO2, median doses from LUDUC were found be in general agreement with those for Reference Man (via deterministic LUDEP 2.0 calculations) in the particle range of 0.1 to 5 microm. However, median doses to the basal cell nuclei of the bronchial airways (BB

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

    SciTech Connect

    Bruenger, F.W.; Miller, S.C.; Lloyd, R.D. )

    1991-06-01

    The natural survival, relative to properly chosen controls, of 26 beagle dogs injected once intravenously with an average of 0.58 +/- 0.04 kBq {sup 239}Pu/kg, 23 dogs injected with 2.31 +/- 0.43 kBq {sup 226}Ra/kg, 13 dogs injected with 1.84 +/- 0.26 kBq {sup 228}Ra/kg, 12 dogs injected with 0.56 +/- 0.030 kBq {sup 228}Th/kg, and 12 dogs injected with 21.13 +/- 1.74 kBq {sup 90}Sr/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 {sup 239}Pu (P = 0.033), 1.0(4) for {sup 226}Ra (P = 0.86), 1.9 for {sup 228}Ra (P = 0.035), 2.5 for {sup 228}Th (P less than 0.001), and 0.52 for {sup 90}Sr (P = 0.041).

  11. Neutronic Benchmarks for the Utilization of Mixed-Oxide Fuel: Joint U.S./Russian Progress Report for Fiscal Year 1997 - Volume 4, Part 2--Saxton Plutonium Program Critical Experiments

    SciTech Connect

    Abdurrahman, NM

    2000-10-12

    Critical experiments with water-moderated, single-region PuO{sub 2}-UO{sub 2} or UO{sub 2}, and multiple-region PuO{sub 2}-UO{sub 2}- and UO{sub 2}-fueled cores were performed at the CRX reactor critical facility at the Westinghouse Reactor Evaluation Center (WREC) at Waltz Mill, Pennsylvania in 1965 [1]. These critical experiments were part of the Saxton Plutonium Program. The mixed oxide (MOX) fuel used in these critical experiments and then loaded in the Saxton reactor contained 6.6 wt% PuO{sub 2} in a mixture of PuO{sub 2} and natural UO{sub 2}. The Pu metal had the following isotopic mass percentages: 90.50% {sup 239}Pu; 8.57% {sup 239}Pu; 0.89% {sup 240}Pu; and 0.04% {sup 241}Pu. The purpose of these critical experiments was to verify the nuclear design of Saxton partial plutonium cores while obtaining parameters of fundamental significance such as buckling, control rod worth, soluble poison worth, flux, power peaking, relative pin power, and power sharing factors of MOX and UO{sub 2} lattices. For comparison purposes, the core was also loaded with uranium dioxide fuel rods only. This series is covered by experiments beginning with the designation SX.

  12. Determination of plutonium isotopic composition by gamma-ray spectroscopy

    SciTech Connect

    Sampson, T.E.; Hsue, S.T.; Parker, J.L.; Johnson, S.S.; Bowersox, D.F.

    1981-01-01

    We discuss the general approach, computerized data analysis methods, and results of measurements used 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, age, chemical, and isotopic composition. 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 plutonium mass with a precision of 0.6% for 1000-g samples of PuO/sub 2/ with 12% /sup 240/Pu content. The precision of isotopic measurements depends upon many factors, including sample size, sample geometry, and isotopic content. Typical ranges are found to be /sup 238/Pu, 1 to 10%; /sup 239/Pu, 0.1 to 0.5%; /sup 240/Pu, 2 to 5%; /sup 241/Pu, 0.3 to 0.7%; /sup 242/Pu (determined by isotopic correlation); and /sup 241/Am, 0.2 to 10%.

  13. Northern Marshall Islands radiological survey: sampling and analysis summary

    SciTech Connect

    Robison, W.L.; Conrado, C.L.; Eagle, R.J.; Stuart, M.L.

    1981-07-23

    A radiological survey was conducted in the Northern Marshall Islands to document reamining external gamma exposures from nuclear tests conducted at Enewetak and Bikini Atolls. An additional program was later included to obtain terrestrial and marine samples for radiological dose assessment for current or potential atoll inhabitants. This report is the first of a series summarizing the results from the terrestrial and marine surveys. The sample collection and processing procedures and the general survey methodology are discussed; a summary of the collected samples and radionuclide analyses is presented. Over 5400 samples were collected from the 12 atolls and 2 islands and prepared for analysis including 3093 soil, 961 vegetation, 153 animal, 965 fish composite samples (average of 30 fish per sample), 101 clam, 50 lagoon water, 15 cistern water, 17 groundwater, and 85 lagoon sediment samples. A complete breakdown by sample type, atoll, and island is given here. The total number of analyses by radionuclide are 8840 for /sup 241/Am, 6569 for /sup 137/Cs, 4535 for /sup 239 +240/Pu, 4431 for /sup 90/Sr, 1146 for /sup 238/Pu, 269 for /sup 241/Pu, and 114 each for /sup 239/Pu and /sup 240/Pu. A complete breakdown by sample category, atoll or island, and radionuclide is also included.

  14. Plutonium measurements by accelerator mass spectrometry at LLNL

    SciTech Connect

    McAninch, J E; Hamilton, T F; Broan, T A; Jokela, T A; Knezovich, T J; Ognibene, T J; Proctor, I D; Roberts, M L; Southon, J R; Vogel, J S; Sideras-Haddad, E

    1999-10-26

    Mass spectrometric methods provide sensitive, routine, and cost-effective analyses of long-lived radionuclides. Here the authors report on the status of work at Lawrence Livermore National Laboratory (LLNL) to develop a capability for actinide measurements by accelerator mass spectrometry (AMS) to take advantage of the high potential of AMS for rejection of interferences. This work demonstrates that the LLNL AMS spectrometer is well-suited for providing high sensitivity, robust, high throughput measurements of plutonium concentrations and isotope ratios. Present backgrounds are {approximately}2 x 10{sup 7}atoms per sample for environmental samples prepared using standard alpha spectrometry protocols. Recent measurements of {sup 239+240}Pu and {sup 241}Pu activities and {sup 240}Pu/{sup 239}Pu isotope ratios in IAEA reference materials agree well with IAEA reference values and with alpha spectrometry and recently published ICP-MS results. Ongoing upgrades of the AMS spectrometer are expected to reduce backgrounds below 1 x 10{sup 6} atoms per sample while allowing simplifications of the sample preparation chemistry. These simplifications will lead to lower per-sample costs, higher throughput, faster turn around and, ultimately, to larger and more robust data sets.

  15. Mechanical environmental transport of actinides and ¹³⁷Cs from an arid radioactive waste disposal site.

    PubMed

    Snow, Mathew S; Clark, Sue B; Morrison, Samuel S; Watrous, Matthew G; Olson, John E; Snyder, Darin C

    2015-10-01

    Aeolian and pluvial processes represent important mechanisms for the movement of actinides and fission products at the Earth's surface. Soil samples taken in the early 1970's near a Department of Energy radioactive waste disposal site (the Subsurface Disposal Area, SDA, located in southeastern Idaho) provide a case study for studying the mechanisms and characteristics of environmental actinide and (137)Cs transport in an arid environment. Multi-component mixing models suggest actinide contamination within 2.5 km of the SDA can be described by mixing between 2 distinct SDA end members and regional nuclear weapons fallout. The absence of chemical fractionation between (241)Am and (239+240)Pu with depth for samples beyond the northeastern corner and lack of (241)Am in-growth over time (due to (241)Pu decay) suggest mechanical transport and mixing of discrete contaminated particles under arid conditions. Occasional samples northeast of the SDA (the direction of the prevailing winds) contain anomalously high concentrations of Pu with (240)Pu/(239)Pu isotopic ratios statistically identical to those in the northeastern corner. Taken together, these data suggest flooding resulted in mechanical transport of contaminated particles into the area between the SDA and a flood containment dike in the northeastern corner, following which subsequent contamination spreading in the northeastern direction resulted from wind transport of discrete particles. PMID:26107287

  16. Sources of plutonium to the tropical Northwest Pacific Ocean (1943-1999) identified using a natural coral archive

    NASA Astrophysics Data System (ADS)

    Lindahl, Patric; Asami, Ryuji; Iryu, Yasufumi; Worsfold, Paul; Keith-Roach, Miranda; Choi, Min-Seok

    2011-03-01

    The Pu isotopes, 239Pu and 240Pu, were determined in annually-banded skeletons of an accurately dated (1943-1999) modern coral ( Porites lobata) from Guam Island to identify historical Pu sources to the tropical Northwest Pacific Ocean. Activity concentrations of 239+240Pu and 240Pu/ 239Pu atom ratios were determined in the dated coral bands using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). Close-in fallout from the former US Pacific Proving Grounds (PPG) in the Marshall Islands and global fallout were identified as the two main sources. The Guam site was dominated by PPG close-in fallout in the 1950s, with an average 240Pu/ 239Pu atom ratio of 0.315 ± 0.005. In addition, a higher 240Pu/ 239Pu atom ratio (0.456 ± 0.020) was observed that could be attributed to fallout from the "Ivy Mike" thermonuclear detonation in 1952. The atom ratio decreased in the 1960s and 1970s due to increase in the global fallout with a low 240Pu/ 239Pu atom ratio (˜0.18). Recent coral bands (1981-1999) are dominated by the transport of remobilised Pu, with high 240Pu/ 239Pu atom ratios, from the Marshall Islands to Guam Island along the North Equatorial Current (NEC). This remobilised Pu was estimated to comprise 69% of the total Pu in the recent coral bands, although its contribution was variable over time.

  17. Beta and gamma decay heat measurements between 0.1s - 50,000s for neturon fission of {sup 235}U, {sup 238}U and {sup 239}Pu. Progress report, June 1, 1992--December 31, 1994

    SciTech Connect

    Schier, W.A.; Couchell, G.P.

    1997-05-01

    In the investigations reported here, a helium-jet/tape-transport system was used for the rapid transfer of fission products to a low-background environment where their aggregate beta and gamma-ray spectra were measured as a function of delay time after neutron induced fission of {sup 235}U, {sup 238}U and {sup 239}Pu. Beta and gamma-ray energy distributions have been deduced for delay times as short as 0.2 s and extending out to 100,000s. Instrumentation development during the initial phase of the project included: (1) assembly and characterization of a NaI(Tl) spectrometer for determining aggregate gamma-ray energy distributions, (2) development and characterization of a beta spectrometer (having excellent gamma-ray rejection) for measuring aggregate beta-particle energy distributions, (3) assembly and characterization of a Compton-suppressed HPGe spectrometer for determining gamma-ray intensities of individual fission products to deduce fission-product yields. Spectral decomposition and analysis codes were developed for deducing energy distributions from measured aggregate beta and gamma spectra. The aggregate measurements in the time interval 0.2 - 20s after fission are of special importance since in this region data from many short-lived nuclei are missing and summation calculations in this region rely on model calculations for a large fraction of their predicted beta and gamma decay heat energy spectra. Comparison with ENDF/B-VI fission product data was performed in parallel with the measurements through a close collaboration with Dr. T. England at LANL, assisted by one of our graduate students. Such aggregate measurements provide tests of the Gross Theory of beta decay used to calculated missing contributions to this data base. Fission-product yields deduced from the HPGe studies will check the accuracy of the semi-empirical Gaussian dispersion model used presently by evaluators in the absence of measured yields.

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

    NASA Astrophysics Data System (ADS)

    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

  19. Energy dependence of fission product yields from 235U, 238U and 239Pu for incident neutron energies between 0.5 and 14.8 MeV

    DOE PAGESBeta

    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.; et al

    2016-01-06

    In this study, 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 varyingmore » 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

  20. Plutonium isotope ratio variations in North America

    SciTech Connect

    Steiner, Robert E; La Mont, Stephen P; Eisele, William F; Fresquez, Philip R; Mc Naughton, Michael; Whicker, Jeffrey J

    2010-12-14

    Historically, approximately 12,000 TBq of plutonium was distributed throughout the global biosphere by thermo nuclear weapons testing. The resultant global plutonium fallout is a complex mixture whose {sup 240}Pu/{sup 239}Pu atom ratio is a function of the design and yield of the devices tested. The average {sup 240}Pu/{sup 239}Pu atom ratio in global fallout is 0.176 + 014. However, the {sup 240}Pu/{sup 239}Pu atom ratio at any location may differ significantly from 0.176. Plutonium has also been released by discharges and accidents associated with the commercial and weapons related nuclear industries. At many locations contributions from this plutonium significantly alters the {sup 240}Pu/{sup 239}Pu atom ratios from those observed in global fallout. We have measured the {sup 240}Pu/{sup 239}Pu atom ratios in environmental samples collected from many locations in North America. This presentation will summarize the analytical results from these measurements. Special emphasis will be placed on interpretation of the significance of the {sup 240}Pu/{sup 239}Pu atom ratios measured in environmental samples collected in the Arctic and in the western portions of the United States.

  1. Measurement of Absolute Fission Yields in the Fast Neutron-Induced Fission of Actinides: {sup 238}U, {sup 237}Np, {sup 238}Pu, {sup 240}Pu, {sup 243}Am, and {sup 244}Cm by Track-Etch-cum-Gamma Spectrometry

    SciTech Connect

    Iyer, R.H.; Naik, H.; Pandey, A.K.; Kalsi, P.C.; Singh, R.J.; Ramaswami, A.; Nair, A.G.C.

    2000-07-15

    The absolute fission yields of 46 fission products in {sup 238}U (99.9997 at.%), 46 fission products in {sup 237}Np, 27 fission products in {sup 238}Pu (99.21 at.%), 30 fission products in {sup 240}Pu (99.48 at.%), 30 fission products in {sup 243}Am (99.998 at.%), and 32 fission products in {sup 244}Cm (99.43 at.%) induced by fast neutrons were determined using a fission track-etch-cum-gamma spectrometric technique. In the case of highly alpha-active and sparingly available actinides - e.g., {sup 238}Pu, {sup 240}Pu, {sup 243}Am, and {sup 244}Cm - a novel recoil catcher technique to collect the fission products on a Lexan polycarbonate foil followed by gamma-ray spectrometry was developed during the course of this work. This completely removed interferences from (a) gamma rays of daughter products in secular equilibrium with the target nuclide (e.g., {sup 243}Am-{sup 239}Np), (b) activation products of the catcher foil [e.g., {sup 24}Na from Al(n,{alpha})], and (c) activation products of the target [e.g., {sup 238}Np from {sup 237}Np(n,{gamma}) and {sup 239}Np from {sup 238}U(n,{gamma})] reactions, making the gamma spectrometric analysis very simple and accurate. The high-yield asymmetric fission products were analyzed by direct gamma spectrometry, whereas the low-yield symmetric products (e.g., Ag, Cd, and Sb) as well as some of the asymmetric fission products (e.g., Br) and rare earths (in the case of {sup 238}U and {sup 237}Np) were radiochemically separated and then analyzed by gamma-ray spectrometry. The neutron spectra in the irradiation positions of the reactors were measured and delineated in the thermal to 10-MeV region using threshold activation detectors. The present data were compared with the ENDF/VI and UKFY2 evaluated data files. From the measured cumulative yields, the mass-chain yields have been deduced using charge distribution systematics. The mass yields, along with similar data for other fast neutron-induced fissioning systems, show several

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

    DOE PAGESBeta

    Oldham, Jr., Warren J.; Hanson, Susan K.; Lavelle, Kevin B.; Miller, Jeffrey L.

    2015-08-30

    In this study, 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.

  3. Association of Chernobyl-derived 239+240Pu, 241Am, 90Sr and 137Cs with different molecular size fractions of organic matter in the soil solution of two grassland soils.

    PubMed

    Bunzl, K; Kracke, W; Agapkina, G I; Tikhomirov, A; Shcheglov, A I

    1998-10-01

    Radiocesium is normally bound only rather weakly and unspecifically by humic substances, in contrast to the actinides Pu and Am. Recently, however, it was observed that fallout 137Cs in the soil solution from an Of-horizon of a podzol forest soil (slightly decomposed plant material) was associated essentially only with one single size fraction of the humic substances. In deeper soil layers with well humified material (AOh-horizon), radiocesium was associated with all size fractions of the dissolved organic matter (DOM). To examine whether this unexpected behaviour is also observable for DOM isolated from other soils, we determined the association of fallout 137Cs, 90Sr, 238Pu, 239+240Pu and 241Am with various size fractions of DOM from in situ soil solutions isolated from two layers (0-2 cm and 2-5 cm) of two grassland soils (a soddy podzolic soil and a peat soil) within the 10 km zone of the nuclear reactor at Chernobyl (Ukraine). The four size fractions of DOM as obtained by gel filtration of the soil solution were (mean nominal molecular weight in daltons): fraction I: > or = 2000, fraction II: 1300; fraction III: 560, fraction IV: inorganic compounds. The results for the well humified DOM (humus accumulation horizon of podzol, deeper layer of peat soil) showed that Pu and Am are essentially associated with the high molecular weight fractions, while Sr is present only in the 'inorganic' fraction. Radiocesium is found in all the size fractions separated. A quite similar pattern was also found for Pu, Am, and Sr in the soil solution from only slightly decomposed plant material (0-2 cm of peat soil), but not for radiocesium. This radionuclide was again essentially only observable in one single low molecular weight fraction of DOM. The above results thus support our recent observations in the different horizons of a forest podzol mentioned above, even though no reason for the different binding of radiocesium by well humified soil organic matter and by only slightly

  4. Contributions of Rocky Flats releases to the total plutonium in regional soils.

    PubMed

    Ibrahim, S A; Webb, S B; Whicker, F W

    1997-01-01

    Total 239,240Pu and the 240Pu:239Pu atom ratio were measured in soil samples from around the Rocky Flats Environmental Technology Site (RFETS) during 1992-1994. Mass isotopic data provided a sensitive technique to resolve low levels of RFETS 239,240Pu superimposed on plutonium from global fallout. Concentrations of 239,240Pu within this sample set ranged from 1.1 Bq kg(-1) offsite to 57 Bq kg(-1) onsite, and the 240Pu:239Pu atom ratio increased from 0.055 onsite to 0.123 at approximately 19 km east of the RFETS boundary. The relationship between 24OPu:239Pu atom ratios and distance indicated that a measurable RFETS contribution may have extended to > or = 19 km offsite in the easterly direction. Although the RFETS contribution to total plutonium at the offsite locations ranged from 24-90%, the overall inventory was relatively small. Total inventory estimates, for one transect, based on 239,240Pu and from 240Pu:239Pu atom ratio measurements were not significantly different. PMID:8972825

  5. TRU Waste Assay Methodology with the Combined Thermal Epithermal Neutron (CTEN) System

    SciTech Connect

    Veilleux, J. M.; Enter, J. A.

    2003-02-27

    The CTEN assay system is designed to measure plutonium bearing 208-L waste drums and make the transuranic versus low-level waste determination. The system was certified for Waste Isolation Pilot Plant operations and the Environmental Protection Agency approved the CTEN in 2002. It is the only system capable of making the transuranic/low-level waste (TRU/LLW) determination since it can routinely assay below 100 nCi/g. The system conducts a measurement by using either (or both) an active 14 MeV neutron pulse to induce fission in 239Pu and 241Pu or measures the spontaneous fission properties of 238Pu, 240Pu and 242Pu. When the coincidence neutron signal is combined with mass fraction data from a gamma system, the result is the total plutonium mass. The system's lower limit of detection is as low as 2 mg of weapons grade plutonium, making it an ideal platform to make the TRU/LLW determination. Analysis of an assay is made with visual basic application driven subroutines and Micros oft Excel spreadsheets. Input values and calculations include: the raw neutron scaler and coincidence counts; mass fraction information; plutonium mass; alpha, total and TRU activity; thermal power, 239Pu Equivalent Curies; fissile gram equivalent mass; decay heat; and uncertainties associated with each parameter. A general diagnostic analysis is performed for each assay to facilitate a technical review of the results. The results of analysis from 372 waste drums are summarized. The results indicate that modifying current operating procedures involving the use of acceptable knowledge isotope data and use of the lower detection limit could increase the number of certifiable assays from 38% to 66%.

  6. Airborne Plutonium and non-natural Uranium from the Fukushima DNPP found at 120 km distance a few days after reactor hydrogen explosions.

    PubMed

    Shinonaga, Taeko; Steier, Peter; Lagos, Markus; Ohkura, Takehisa

    2014-04-01

    Plutonium (Pu) and non-natural uranium (U) originating from the Fukushima Daiichi Nuclear Power Plant (FDNPP) were identified in the atmosphere at 120 km distance from the FDNPP analyzing the ratio of number of atoms, following written as n(isotope)/n(isotope), of Pu and U. The n((240)Pu)/n((239)Pu), n((241)Pu)/n((239)Pu), n((234)U)/n((238)U), n((235)U)/n((238)U) and n((236)U)/n((238)U) in aerosol samples collected before and after the FDNPP incident were analyzed by accelerator mass spectrometry (AMS) and inductively coupled plasma mass spectrometry (ICPMS). The activity concentrations of (137)Cs and (134)Cs in the same samples were also analyzed by gamma spectrometry before the destructive analysis. Comparing the time series of analytical data on Pu and U obtained in this study with previously reported data on Pu, U, and radioactive Cs, we concluded that Pu and non-natural U from the FDNPP were transported in the atmosphere directly over a 120 km distance by aerosol and wind within a few days after the reactor hydrogen explosions. Effective dose of Pu were calculated using the data of Pu: (130 ± 21) nBq/m(3), obtained in this study. We found that the airborne Pu contributes only negligibly to the total dose at the time of the incident. However the analytical results show that the amount of Pu and non-natural U certainly increased in the environment after the incident. PMID:24621142

  7. Plutonium isotopic determination from gamma-ray spectra

    SciTech Connect

    Skourikhine, A.N.; Strittmatter, R.B.; Zardecki, A.

    1998-12-31

    The use of low- and medium-resolution room-temperature detectors for the nondestructive assay of nuclear materials has widespread applications to the safeguarding of nuclear materials. The challenge to using these detectors is the inherent difficulty of the spectral analysis to determine the amount of specific nuclear materials in the measured samples. This is especially true for extracting plutonium isotopic content from low- and medium-resolution spectral lines that are not well resolved. In this paper, neural networks trained by stochastic and singular value decomposition algorithms are applied to retrieve the plutonium isotopic content from a simulated NaI spectra. The simulated sample consists of isotopes {sup 238}Pu, {sup 239}Pu, {sup 240}Pu, {sup 241}Pu, {sup 242}Pu, and {sup 241}Am. It is demonstrated that the neutral network optimized by singular value decomposition (SVD) and stochastic training algorithms is capable of estimating plutonium content consistently resulting in an average error much smaller than the error previously reported.

  8. Spent fuel temperature and age determination from the analysis of uranium and plutonium isotopics

    SciTech Connect

    Scott, Mark R; Eccleston, George W; Bedell, Jeffrey J; Lockard, Chanelle M

    2009-01-01

    The capability to determine the age (time since irradiation) of spent fuel can be useful for verification and safeguards. While the age of spent fuel can be determined based on measurements of short-lived fission products, these measurements are not routinely done nor generally reported. As an alternative, age can also be determined if the uranium (U) and plutonium (Pu) isotopic values are available. Uranium isotopics are not strongly affected by fuel temperature, and bumup is determined from the {sup 235}U and {sup 236}U isotopic values. Age is calculated after estimating the {sup 241}Pu at the end of irradiation while accounting for the fuel temperature, which is determined from {sup 239}Pu or {sup 240}Pu. Burnup and age determinations are calibrated to reactor models that provide uranium and plutonium isotopics over the range of fuel irradiation. The reactor model must contain sufficient fidelity on details of the reactor type, fuel burnup, irradiation history, initial fuel enrichment and fuel temperature to obtain accurate isotopic calculations. If the latter four are unknown, they can be derived from the uranium and plutonium isotopics. Fuel temperature has a significant affect on the production of plutonium isotopics; therefore, one group cross section reactor models, such as ORIGEN, cannot be used for these calculations. Multi-group cross section set codes, such as Oak Ridge National Laboratory's TRITON code, must be used.

  9. Verification of a Depletion Method in SCALE for the Advanced High Temperature Reactor

    SciTech Connect

    KELLY, RYAN; Ilas, Dan

    2012-01-01

    This study describes a new method utilizing the Dancoff factor to model a non-standard TRISO fuel form characteristic of the AHTR reactor design concept for depletion analysis using the TRITON sequence of SCALE and the validation of this method by code-to-code comparisons. The fuel used in AHTR has the TRISO particles concentrated along the edges of a slab fuel element. This particular geometry prevented the use of a standard DOUBLEHET treatment, previously developed in SCALE to handle NGNP-designed fuel. The new method permits fuel depletion on complicated geometries that traditionally can be handled only by continuous energy based depletion code systems. The method was initially tested on a fuel design typical of the NGNP, where the DOUBLEHET treatment is available. A more comprehensive study was performed using the VESTA code that uses the continuous energy MCNP5 code as a transport solver and ORIGEN2.2 code for depletion calculations. Comparisons of the results indicate good agreement of whole core characteristics, such as the multiplication factor, and the isotopics, including their spatial distribution. Key isotopes analyzed included 235U, 239Pu, 240Pu and 241Pu. The results from this study indicate that the Dancoff factor method can generate estimates of core characteristics with reasonable precision for scoping studies of configurations where the DOUBLEHET treatment is unavailable.

  10. Verification of a Depletion Method in SCALE for the Advanced High Temperature Reactor

    SciTech Connect

    KELLY, RYAN; Ilas, Dan

    2013-01-01

    This study describes a new approach employing the Dancoff correction method to model the TRISO-based fuel form used by the Advanced High-Temperature Reactor (AHTR) reactor design concept. The Dancoff correction method is used to perform isotope depletion analysis using the TRITON sequence of SCALE and is verified by code-to-code comparisons. The current AHTR fuel design has TRISO particles concentrated along the edges of a slab fuel element. This geometry prevented the use of the DOUBLEHET treatment, previously developed in SCALE to model spherical and cylindrical fuel. The new method permits fuel depletion on complicated geometries that traditionally can be handled only by continuous energy based depletion code systems. The method was initially tested on a fuel configuration typical of the Next Generation Nuclear Plant (NGNP), where DOUBLEHET treatment is possible. A confirmatory study was performed on the AHTR reference core geometry using the VESTA code, which uses the continuous energy MCNP5 code as a transport solver and ORIGEN2.2 code for depletion calculations. Comparisons of the results indicate good agreement of whole core characteristics, such as the multiplication factor and the isotopics, including their spatial distribution. Key isotopes analyzed included 235U, 239Pu, 240Pu, and 241Pu. The results from this study indicate that the Dancoff factor method can generate estimates of core characteristics with reasonable precision for scoping studies of configurations where DOUBLEHET treatment cannot be performed.

  11. In-plant measurements of gamma-ray transmissions for precise K-edge and passive assay of plutonium concentration and isotopic fractions in product solutions. Final report on TASTEX Task G

    SciTech Connect

    Russo, P.A.; Hsue, S.T.; Sprinkle, J.K. Jr.; Johnson, S.S.; Asakura, Y.; Kondo, I.; Masui, J.; Shoji, K.

    1982-08-01

    An instrument based upon high-resolution gamma-ray measurements has been tested for more than 1 year at the Tokai Reprocessing Facility for determination of plutonium concentration by K-edge absorption densitometry and for determination of plutonium isotopic fractions by transmission-corrected passive gamma-ray spectrometry. The nondestructive assay instrument was designed and built at Los Alamos National Laboratory for the Tokai Advanced Safeguards Technology Exercise (TASTEX). It was used at Tokai for the timely assay of more than 100 product solution samples during the TASTEX evaluations. The results were compared to reference values obtained by conventional destructive analysis of these samples. The precision and accuracy of plutonium concentrations measured by the K-edge technique are shown to be within 0.6% (1delta) in these applications. The precisions and accuracies of the isotopic fractions determined by these passive gamma-ray methods are shown to be within 0.4% for /sup 239/Pu, 1% for /sup 240/Pu and /sup 241/Pu, and 10% for /sup 242/Pu.

  12. Compilation of fission product yields Vallecitos Nuclear Center

    SciTech Connect

    Rider, B.F.

    1980-01-01

    This document is the ninth in a series of compilations of fission yield data made at Vallecitos Nuclear Center in which fission yield measurements reported in the open literature and calculated charge distributions have been utilized to produce a recommended set of yields for the known fission products. The original data with reference sources, as well as the recommended yields are presented in tabular form for the fissionable nuclides U-235, Pu-239, Pu-241, and U-233 at thermal neutron energies; for U-235, U-238, Pu-239, and Th-232 at fission spectrum energies; and U-235 and U-238 at 14 MeV. In addition, U-233, U-236, Pu-240, Pu-241, Pu-242, Np-237 at fission spectrum energies; U-233, Pu-239, Th-232 at 14 MeV and Cf-252 spontaneous fission are similarly treated. For 1979 U234F, U237F, Pu249H, U234He, U236He, Pu238F, Am241F, Am243F, Np238F, and Cm242F yields were evaluated. In 1980, Th227T, Th229T, Pa231F, Am241T, Am241H, Am242Mt, Cm245T, Cf249T, Cf251T, and Es254T are also evaluated.

  13. Radioactinide Additions to the Electronic Gamma-ray Spectrum Catalogue

    SciTech Connect

    R.J. Gehrke; J.R. Davidson; P.J. Taylor; R.G. Helmer; J.W. Mandler

    2001-05-01

    With the completion of a CD ROM version of the original R. L. HEATH''s Gamma-ray Spectrum Catalogue, it became obvious that a number of radionuclides are missing which are important to various fields of nuclear science and technology. With a large amount of transuranic waste awaiting permanent disposal across the Department of Energy (DOE) complex and the need for its assay in order to dispose of it, it was decided that the addition of the radioactinides encountered in transuranic waste should be the first priority. In response to this need, the spectra of 233U, 235U, 238U, 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am and 243Am have been acquired with modern Ge detectors, and prepared for graphics presentation along with the parent and progeny decay chains and decay schemes. The associated tables of -ray energies and emission probabilities have been downloaded from the Evaluated Nuclear Structure Data file (ENSDF) database. This information is being incorporated into the Gamma-Ray Spectrometry Center Web Site at http://id.inel.gov/gamma

  14. A priori precision estimation for neutron triples counting

    SciTech Connect

    Croft, S.; Swinhoe, M. T.; Henzl, V.

    2011-07-01

    The nondestructive assay of Plutonium bearing items for criticality, safety, security, safeguards, inventory balance, process control, waste management and compliance is often undertaken using correlated neutron counting. In particular Multiplicity Shift Register analysis allows one to extract autocorrelation parameters from the pulse train which can, within the framework of a simple interpretational model, be related to the effective {sup 240}Pu spontaneous fission mass present. The effective {sup 240}Pu mass is a weighted sum of the {sup 238}Pu, {sup 240}Pu and {sup 242}Pu masses so if the relative isotopic composition of the Pu can be established from the measured {sup 240}Pu effective mass one can estimate the total Pu mass and also the masses of the individual isotopes, example the fissile species {sup 239}Pu and {sup 241}Pu. In multiplicity counting three counting rates are obtained. These are the Singles, Doubles and Triples rates. The Singles rate is just the gross, totals or trigger rate. The Doubles and Triples rates are calculated from factorial moments of the observed signal triggered neutron multiplicity distributions following spontaneous fission in the item and can be thought of as the rate of observed coincident pairs and coincident triplets on the pulse train. Coincident events come about because the spontaneous fission and induced fission chains taking place in the item result in bursts of neutrons. These remain time correlated during the detection process and so retain information, through the burst size distribution, about the Pu content. In designing and assessing the performance of a detector system to meet a given goal it is necessary to make a priori estimates of the counting precision for all three kinds of rates. This is non-trivial because the counting does not obey the familiar rules of a Poissonian counting experiment because the pulse train has time correlated events on it and the train is sampled by event triggered gates that may

  15. Lead Slowing-Down Spectrometry Time Spectral Analysis for Spent Fuel Assay: FY11 Status Report

    SciTech Connect

    Kulisek, Jonathan A.; Anderson, Kevin K.; Bowyer, Sonya M.; Casella, Andrew M.; Gesh, Christopher J.; Warren, Glen A.

    2011-09-30

    Developing a method for the accurate, direct, and independent assay of the fissile isotopes in bulk materials (such as used fuel) from next-generation domestic nuclear fuel cycles is a goal of the Office of Nuclear Energy, Fuel Cycle R&D, Material Protection and Control Technology (MPACT) Campaign. To meet this goal, MPACT supports a multi-institutional collaboration, of which PNNL is a part, to study the feasibility of Lead Slowing Down Spectroscopy (LSDS). This technique is an active nondestructive assay method that has the potential to provide independent, direct measurement of Pu and U isotopic masses in used fuel with an uncertainty considerably lower than the approximately 10% typical of today's confirmatory assay methods. This document is a progress report for FY2011 PNNL analysis and algorithm development. Progress made by PNNL in FY2011 continues to indicate the promise of LSDS analysis and algorithms applied to used fuel. PNNL developed an empirical model based on calibration of the LSDS to responses generated from well-characterized used fuel. The empirical model, which accounts for self-shielding effects using empirical basis vectors calculated from the singular value decomposition (SVD) of a matrix containing the true self-shielding functions of the used fuel assembly models. The potential for the direct and independent assay of the sum of the masses of 239Pu and 241Pu to within approximately 3% over a wide used fuel parameter space was demonstrated. Also, in FY2011, PNNL continued to develop an analytical model. Such efforts included the addition of six more non-fissile absorbers in the analytical shielding function and the non-uniformity of the neutron flux across the LSDS assay chamber. A hybrid analytical-empirical approach was developed to determine the mass of total Pu (sum of the masses of 239Pu, 240Pu, and 241Pu), which is an important quantity in safeguards. Results using this hybrid method were of approximately the same accuracy as the pure

  16. Characterization of Pu concentration and its isotopic composition in soils of Gansu in northwestern China.

    PubMed

    Zheng, Jian; Yamada, Masatoshi; Wu, Fengchang; Liao, Haiqing

    2009-01-01

    The total 239+240Pu activities and 240Pu/239Pu atom ratios in surface soil samples (0-5cm) in the Kumtag Desert in western Gansu Province, and in a soil core sample in Lanzhou were investigated using a sector-field ICP-MS. In the surface soil samples, 239+240Pu activities in fine particles (<150microm) were 1.3-2.1 times of those in coarse particles (150microm-1mm) which ranged from 0.005 to 0.157mBq/g. Atom ratios of 240Pu/239Pu in the surface soils ranged from 0.168 to 0.192 with a mean of 0.182+/-0.008. The mean ratio was similar to the typical global fallout value although the Kumtag Desert was believed to have received close-in fallout derived from Chinese nuclear weapons tests mainly conducted in the 1970s. Furthermore, the mean 240Pu/239Pu atom ratio observed in the soil core sample in Lanzhou was similar to the typical global fallout value. In the soil core sample, 239+240Pu activities in the various layers ranged from 0.012 to 0.23mBq/g, and the inventory of 239+240Pu (32.4Bq/m2, 0-23cm) was slightly lower than that expected from global fallout (42Bq/m2) at the same latitude. Rapid downward migration of Pu isotopes was observed in Lanzhou soil core sample layers. The contribution of the 10-cm deep top layers of surface soils to total inventory was only 17%, while the contribution of deeper layers (10-23cm) was as high as 83%. The 239+240Pu activity levels and 240Pu/239Pu atom ratios in soils in Gansu Province, China are similar to those in atmospheric deposition samples collected in the spring in recent years in Japan. PMID:19058885

  17. Plutonium age dating reloaded

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    Although the age determination of plutonium is and has been a pillar of nuclear forensic investigations for many years, additional research in the field of plutonium age dating is still needed and leads to new insights as the present work shows: Plutonium is commonly dated with the help of the 241Pu/241Am chronometer using gamma spectrometry; in fewer cases the 240Pu/236U chronometer has been used. The age dating results of the 239Pu/235U chronometer and the 238Pu/234U chronometer are scarcely applied in addition to the 240Pu/236U chronometer, although their results can be obtained simultaneously from the same mass spectrometric experiments as the age dating result of latter. The reliability of the result can be tested when the results of different chronometers are compared. The 242Pu/238U chronometer is normally not evaluated at all due to its sensitivity to contamination with natural uranium. This apparent 'weakness' that renders the age dating results of the 242Pu/238U chronometer almost useless for nuclear forensic investigations, however turns out to be an advantage looked at from another perspective: the 242Pu/238U chronometer can be utilized as an indicator for uranium contamination of plutonium samples and even help to identify the nature of this contamination. To illustrate this the age dating results of all four Pu/U clocks mentioned above are discussed for one plutonium sample (NBS 946) that shows no signs of uranium contamination and for three additional plutonium samples. In case the 242Pu/238U chronometer results in an older 'age' than the other Pu/U chronometers, contamination with either a small amount of enriched or with natural or depleted uranium is for example possible. If the age dating result of the 239Pu/235U chronometer is also influenced the nature of the contamination can be identified; enriched uranium is in this latter case a likely cause for the missmatch of the age dating results of the Pu/U chronometers.

  18. Self-regulating neutron coincidence counter

    DOEpatents

    Baron, N.

    1980-06-16

    A device for accurately measuring the mass of /sup 240/Pu and /sup 239/Pu in a sample having arbitrary moderation and mixed with various contaminants. The device utilizes a thermal neutron well counter which has two concentric rings of neutron detectors separated by a moderating material surrounding the well. Neutron spectroscopic information derived by the two rings of detectors is used to measure the quantity of /sup 239/Pu and /sup 240/Pu in device which corrects for background radiation, deadtime losses of the detector and electronics and various other constants of the system.

  19. Artificial radionuclides in the atmosphere over Lithuania.

    PubMed

    Lujaniene, G; Aninkevicius, V; Lujanas, V

    2009-02-01

    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 (137)Cs, (238)Pu, (239,240)Pu and (241)Am in the atmosphere in Vilnius at the end of April 1986. The (240)Pu/(239)Pu atom ratio showed clear evidence of non-global plutonium originating from the Chernobyl accident in the atmosphere over Lithuania. The (240)Pu/(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 (137)Cs by a factor of 100 (up to 300 microBq/m(3)) was found following forest fires in the Ukraine and Belarus. However, no transport of the Chernobyl plutonium was observed and the (240)Pu/(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 (240)Pu/(239)Pu atom ratio from 0.30 to 0.19 (mean values) was observed in 1995-2003. PMID:17884261

  20. Toxicological versus Radiological Hazards of {sup 239}Pu

    SciTech Connect

    Tansky, R.R.

    2001-07-26

    Plutonium is frequently referred to as ''the most toxic substance known to man''. While there are other chemicals that cause more immediately serious health consequences, plutonium does have the lowest permissible levels for any of the radioactive elements. Concentration limits for plutonium and its compounds are based on its radiotoxicity, specifically carcinogenicity, not on its chemical toxicity.

  1. Ultra-trace plutonium determination in small volume seawater by sector field inductively coupled plasma mass spectrometry with application to Fukushima seawater samples.

    PubMed

    Bu, Wenting; Zheng, Jian; Guo, Qiuju; Aono, Tatsuo; Tagami, Keiko; Uchida, Shigeo; Tazoe, Hirofumi; Yamada, Masatoshi

    2014-04-11

    Long-term monitoring of Pu isotopes in seawater is required for assessing Pu contamination in the marine environment from the Fukushima Dai-ichi Nuclear Power Plant accident. In this study, we established an accurate and precise analytical method based on anion-exchange chromatography and SF-ICP-MS. This method was able to determine Pu isotopes in seawater samples with small volumes (20-60L). The U decontamination factor was 3×10(7)-1×10(8), which provided sufficient removal of interfering U from the seawater samples. The estimated limits of detection for (239)Pu and (240)Pu were 0.11fgmL(-1) and 0.08fgmL(-1), respectively, which corresponded to 0.01mBqm(-3) for (239)Pu and 0.03mBqm(-3) for (240)Pu when a 20L volume of seawater was measured. We achieved good precision (2.9%) and accuracy (0.8%) for measurement of the (240)Pu/(239)Pu atom ratio in the standard Pu solution with a (239)Pu concentration of 11fgmL(-1) and (240)Pu concentration of 2.7fgmL(-1). Seawater reference materials were used for the method validation and both the (239+240)Pu activities and (240)Pu/(239)Pu atom ratios agreed well with the expected values. Surface and bottom seawater samples collected off Fukushima in the western North Pacific since March 2011 were analyzed. Our results suggested that there was no significant variation of the Pu distribution in seawater in the investigated areas compared to the distribution before the accident. PMID:24636561

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

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

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

  3. Temporal record of Pu isotopes in inter-tidal sediments from the northeastern Irish Sea.

    PubMed

    Lindahl, Patric; Worsfold, Paul; Keith-Roach, Miranda; Andersen, Morten B; Kershaw, Peter; Leonard, Kins; Choi, Min-Seok; Boust, Dominique; Lesueur, Patrick

    2011-11-01

    A depth profile of (239)Pu and (240)Pu specific activities and isotope ratios was determined in an inter-tidal sediment core from the Esk Estuary in the northeastern Irish Sea. The study site has been impacted with plutonium through routine radionuclide discharges from the Sellafield nuclear reprocessing plant in Cumbria, NW England. A pronounced sub-surface maximum of ~10 k Bq kg(-1) was observed for (239+240)Pu, corresponding to the peak in Pu discharge from Sellafield in 1973, with a decreasing trend with depth down to ~0.04 k Bq kg(-1) in the deeper layers. The depth profile of (239+240)Pu specific activities together with results from gamma-ray spectrometry for (137)Cs and (241)Am was compared with reported releases from the Sellafield plant in order to estimate a reliable sediment chronology. The upper layers (1992 onwards) showed higher (239+240)Pu specific activities than would be expected from the direct input of annual Sellafield discharges, indicating that the main input of Pu is from the time-integrated contaminated mud patch of the northeastern Irish Sea. The (240)Pu/(239)Pu atom ratios ranged from ~0.03 in the deepest layers to >0.20 in the sub-surface layers with an activity-weighted average of 0.181. The decreasing (240)Pu/(239)Pu atom ratio with depth reflects the changing nature of operations at the Sellafield plant from weapons-grade Pu production to reprocessing spent nuclear fuel with higher burn-up times in the late 1950s. In addition, recent annual (240)Pu/(239)Pu atom ratios in winkles collected during 2003-2008 from three stations along the Cumbrian coastline showed no significant spatial or temporal differences with an overall average of 0.204, which supports the hypothesis of diluted Pu input from the contaminated mud patch. PMID:21911246

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

    PubMed

    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

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

    PubMed Central

    Srncik, M.; Steier, P.; 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 using Dowex 1x2 (Dow Chemical Co.). Furthermore a new chemical procedure with tandem columns to separate Pu and U from the matrix was tested. For the determination of the uranium and plutonium isotopes by alpha spectrometry thin sources were prepared by microprecipitation techniques. Additionally these fractions separated from the soil samples were measured by Accelerator Mass Spectrometry (AMS) to get information on the isotopic ratios 236U/238U, 240Pu/239Pu and 236U/239Pu, respectively. The 236U concentrations [atoms/g] in each surface layer (∼2 cm) were surprisingly high compared to deeper layers where values around two orders of magnitude smaller were found. Since the isotopic ratio 240Pu/239Pu indicated a global fallout signature we assume the same origin as the probable source for 236U. Our measured 236U/239Pu value of around 0.2 is within the expected range for this contamination source. PMID:21481502

  6. Performance assessment requirements for the identification and tracking of transuranic waste intended for disposal at the Waste Isolation Pilot Plant

    SciTech Connect

    Snider, C.A.; Weston, W.W.

    1997-11-01

    To demonstrate compliance with environmental radiation protection standards for management and disposal of transuranic (TRU) radioactive wastes, a performance assessment (PA) of the Waste Isolation Pilot Plant (WIPP) was made of waste-waste and waste-repository interactions and impacts on disposal system performance. An estimate of waste components and accumulated quantities was derived from a roll-up of the generator/storage sites` TRU waste inventories. Waste components of significance, and some of negligible effect, were fixed input parameters in the model. The results identified several waste components that require identification and tracking of quantities to ensure that repository limits are not exceeded. The rationale used to establish waste component limits based on input estimates is discussed. The distinction between repository limits and waste container limits is explained. Controls used to ensure that no limits are exceeded are identified. For waste components with no explicit repository based limits, other applicable limits are contained in the WIPP Waste Acceptance Criteria (WAC). The 10 radionuclides targeted for identification and tracking on either a waste container or a waste stream basis include Am-241, Pu-238, Pu-239, Pu-240, Pu-242, U-233, U-234, U-238, Sr-90, and Cs-137. The accumulative activities of these radionuclides are to be inventoried at the time of emplacement in the WIPP. Changes in inventory curie content as a function of radionuclide decay and ingrowth over time will be calculated and tracked. Due to the large margin of compliance demonstrated by PA with the 10,000 year release limits specified, the quality assurance objective for radioassay of the 10 radionuclides need to be no more restrictive than those already identified for addressing the requirements imposed by transportation and WIPP disposal operations in Section 9 of the TRU Waste Characterization Quality Assurance Program Plan. 6 refs.

  7. Plutonium in surface soil near the southwestern boundary of the Hanford project

    SciTech Connect

    Price, K.R.; Dirkes, R.L.

    1981-05-01

    Samples of airborne particles collected near the Prosser Barricade in another study showed low /sup 240/Pu//sup 239/Pu ratios that are indicative of Hanford-produced plutonium. In an effort to locate evidence of a trail or the remains of a large short-term release of plutonium that may have occurred during past Hanford operations, surface soil samples were collected along the southweastern boundary of the Hanford Site in December 1979. Results indicated the possibility of slightly elevated levels of /sup 239/ /sup 240/Pu (0.016 pCi/g) occurring in the general vicinity of the Arid Land Ecology Field lab extending to the junction of Highway 240 and Horn Rapids Road as compared to lower levels (0.006 pCi/g) in a northwesterly direction along the base of Rattlesnake Mountain and the eastern slope of Yakima Ridge. Assuming the worldwide average /sup 240/Pu//sup 239/Pu ratio of 0.18 for soil of the Pacific Northwest, the plutonium in these soil samples may be slightly less enriched with /sup 240/Pu (/sup 240/Pu//sup 239/Pu = 0.16). No evidence was discovered of an acute release remaining intact and crossing the southwestern boundary during the operating history of plutonium facilities in the 200 Areas.

  8. Characterisation of the plutonium isotopic composition of a sediment core from Palomares, Spain, by low-energy AMS and alpha-spectrometry

    NASA Astrophysics Data System (ADS)

    Chamizo, E.; Jiménez-Ramos, M. C.; Enamorado, S. M.; García-León, M.; García-Tenorio, R.; Mas, J. L.; Masqué, P.; Merino, J.; Sanchez-Cabeza, J. A.

    2010-04-01

    The measurement of plutonium isotopes, 239Pu and 240Pu, at 670 kV on the compact accelerator mass spectrometry (AMS) system at the Centro Nacional de Aceleradores (CNA) in Seville, Spain, is now a reality. In this work, we present first Pu AMS results for environmental samples: a sediment core collected in a submarine canyon in the Mediterranean coast of the Spanish region of Palomares, affected by a nuclear accident in 1966. From the study of the 240Pu/ 239Pu atomic ratio profile, showing on average levels lower than 11%, we confirm that the weapon-grade plutonium released on land during the accident, with a characteristic 240Pu/ 239Pu atomic ratio of 5.8%, has found its way into the marine environment. A two-plutonium sources mixture model (Palomares and fallout) is used to elucidate the percentage of the plutonium coming from the accident. As a validation exercise of the Pu AMS measuring technique and in order to obtain the 238Pu/ (239+240)Pu activity ratios, samples were also studied by alpha-spectrometry (AS). The obtained AS 239+240Pu activity concentration results fit in with the AMS ones in a wide dynamic range, thus validating the AMS technique.

  9. Certified reference materials for radionuclides in Bikini Atoll sediment (IAEA-410) and Pacific Ocean sediment (IAEA-412).

    PubMed

    Pham, M K; van Beek, P; Carvalho, F P; Chamizo, E; Degering, D; Engeler, C; Gascó, C; Gurriaran, R; Hanley, O; Harms, A V; Herrmann, J; Hult, M; Ikeuchi, Y; Ilchmann, C; Kanisch, G; Kis-Benedek, G; Kloster, M; Laubenstein, M; Llaurado, M; Mas, J L; Nakano, M; Nielsen, S P; Osvath, I; Povinec, P P; Rieth, U; Schikowski, J; Smedley, P A; Suplinska, M; Sýkora, I; Tarjan, S; Varga, B; Vasileva, E; Zalewska, T; Zhou, W

    2016-03-01

    The preparation and characterization of certified reference materials (CRMs) for radionuclide content in sediments collected offshore of Bikini Atoll (IAEA-410) and in the open northwest Pacific Ocean (IAEA-412) are described and the results of the certification process are presented. The certified radionuclides include: (40)K, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (234)U, (238)U, (239)Pu, (239+240)Pu and (241)Am for IAEA-410 and (40)K, (137)Cs, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (235)U, (238)U, (239)Pu, (240)Pu and (239+240)Pu for IAEA-412. The CRMs can be used for quality assurance and quality control purposes in the analysis of radionuclides in sediments, for development and validation of analytical methods and for staff training. PMID:26631455

  10. Radionuclide uptake by trees at a radwaste pond in Washington State.

    PubMed

    Landeen, D S; Mitchell, R M

    1986-06-01

    This paper presents work conducted in the summer of 1980 by Rockwell Hanford Operations, Hanford, WA, in support of a proposed effort to decommission and decontaminate a Hanford radwaste pond (216-U-10 Pond). The radionuclide values presented here are in addition to the U-Pond work that was recently published (La83) and are below any levels of environmental concern and within state and federal guidelines. U-Pond was constructed in 1944 for the surface disposal of industrial waste waters from nuclear separation processes and is one of the longest used aquatic, low-level, radioactive waste-disposal sites in the world. Tree leaf/twig, root, core and soil samples were collected and analyzed for 137Cs, 90Sr and 239Pu/240Pu. Strontium-90 was more readily taken up by trees than 137Cs or 239Pu/240Pu. Soil concentration values for 137Cs and 239Pu/240Pu were significantly greater (p less than or equal to 0.05) than all tree component parts. Radionuclide concentration ratios were higher for 90Sr (0.01-1355.0) than for 137Cs and 239Pu/240Pu for all tree components examined. Concentration ratios for 239Pu/240Pu ranged from 10(-6) to 10(-2) and are comparable to other studies conducted at the U.S. Department of Energy's Oak Ridge and Savannah River laboratories. These data represent the first quantitative information with respect to radionuclide uptake by trees on the Hanford Site. PMID:3710785

  11. 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.

    PubMed

    Oikawa, Shinji; Watabe, Teruhisa; Takata, Hyoe

    2015-04-01

    A radioactivity measurement survey was carried out from 24 April 2008 to 3 June 2011 to determine the levels of plutonium isotopes and (240)Pu/(239)Pu 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 (241)Am 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+240)Pu 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+240)Pu concentrations in surface waters. Higher (239+240)Pu concentrations were found in bottom waters at deeper sampling locations, but the (240)Pu/(239)Pu atom ratios were nearly constant regardless of the water depth. Higher (239+240)Pu concentrations were also found in bottom sediments at deeper sampling locations, but vice versa for (240)Pu/(239)Pu 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. PMID:25659922

  12. Determination of 90Sr and Pu isotopes in contaminated groundwater samples by inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    Zoriy, Miroslav V.; Ostapczuk, Peter; Halicz, Ludwik; Hille, Ralf; Becker, J. Sabine

    2005-04-01

    A sensitive analytical method for determining the artificial radionuclides 90Sr, 239Pu and 240Pu at the ultratrace level in groundwater samples from the Semipalatinsk Test Site area in Kazakhstan by double-focusing sector field inductively coupled plasma mass spectrometry (ICP-SFMS) was developed. In order to avoid possible isobaric interferences at m/z 90 for 90Sr determination (e.g. 90Zr+, 40Ar50Cr+, 36Ar54Fe+, 58Ni16O2+, 180Hf2+, etc.), the measurements were performed at medium mass resolution under cold plasma conditions. Pu was separated from uranium by means of extraction chromatography using Eichrom TEVA resin with a recovery of 83%. The limits of detection for 90Sr, 239Pu and 240Pu in water samples were determined as 11, 0.12 and 0.1 fg ml-1, respectively. Concentrations of 90Sr and 239Pu in contaminated groundwater samples ranged from 18 to 32 and from 28 to 856 fg ml-1, respectively. The 240Pu/239Pu isotopic ratio in groundwater samples was measured as 0.17. This isotope ratio indicates that the most probable source of contamination of the investigated groundwater samples was the nuclear weapons tests at the Semipalatinsk Test Site conducted by the USSR in the 1960s.

  13. Spatial and temporal distribution of Pu in the Northwest Pacific Ocean using modern coral archives.

    PubMed

    Lindahl, Patric; Andersen, Morten B; Keith-Roach, Miranda; Worsfold, Paul; Hyeong, Kiseong; Choi, Min-Seok; Lee, Sang-Hoon

    2012-04-01

    Historical (239)Pu activity concentrations and (240)Pu/(239)Pu atom ratios were determined in skeletons of dated modern corals collected from three locations (Chuuk Lagoon, Ishigaki Island and Iki Island) to identify spatial and temporal variations in Pu inputs to the Northwest Pacific Ocean. The main Pu source in the Northwest Pacific is fallout from atmospheric nuclear weapons testing which consists of global fallout and close-in fallout from the former US Pacific Proving Grounds (PPG) in the Marshall Islands. PPG close-in fallout dominated the Pu input in the 1950s, as was observed with higher (240)Pu/(239)Pu atom ratios (>0.30) at the Ishigaki site. Specific fallout Pu contamination from the Nagasaki atomic bomb and the Ivy Mike thermonuclear detonation at the PPG were identified at Ishigaki Island from the (240)Pu/(239)Pu atom ratios of 0.07 and 0.46, respectively. During the 1960s and 1970s, global fallout was the major Pu source to the Northwest Pacific with over 60% contribution to the total Pu. After the cessation of the atmospheric nuclear tests, the PPG again dominated the Pu input due to the continuous transport of remobilised Pu from the Marshall Islands along the North Equatorial Current and the subsequent Kuroshio Current. The Pu contributions from the PPG in recent coral bands (1984 onwards) varied over time with average estimated PPG contributions between 54% and 72% depending on location. PMID:21890207

  14. Transport of (137)Cs, (241)Am and Pu isotopes in the Curonian Lagoon and the Baltic Sea.

    PubMed

    Lujanienė, G; Remeikaitė-Nikienė, N; Garnaga, G; Jokšas, K; Šilobritienė, B; Stankevičius, A; Šemčuk, S; Kulakauskaitė, I

    2014-01-01

    Activities of (137)Cs, (241)Am and (239,240)Pu were analyzed with special emphasis on better understanding of radionuclide transport from land via the Neman River estuaries to the Baltic Sea and behavior in the marine environment. Although activity concentrations of (137)Cs in water samples collected the Baltic Sea were almost 100 times higher as compared to the Curonian Lagoon, its activities in the bottom sediments were found to be comparable. Activity (238)Pu/(239,240)Pu and atom (240)Pu/(239)Pu ratios indicated a different contribution of the Chernobyl-originated Pu to the suspended particulate matter (SPM) and bottom sediments. The largest amount of the Chernobyl-derived Pu was found in the smallest suspended matter particles of 0.2-1 μm in size collected in the Klaipeda Strait in 2011-2012. The decrease of characteristic activity (238)Pu/(239,240)Pu and atom (240)Pu/(239)Pu ratios towards the global fallout ones in surface soil and the corresponding increase of plutonium (Pu) ratios in the suspended particulate matter and bottom sediments have indicated that the Chernobyl-derived Pu, primarily deposited on the soil surface, was washed out and transported to the Baltic Sea. Behavior of (241)Am was found to be similar to that of Pu isotopes. PMID:24144889

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

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

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

  16. A method to determine the time since last purification of weapons grade plutonium.

    PubMed

    Keegan, R P; Gehrke, R J

    2003-01-01

    A non-destructive technique to determine the time since last purification of weapons grade plutonium based on the 241Pu decay series has been developed and demonstrated to provide results that are consistent with our historical and process knowledge. This method is based on the use of the Bateman equations and the decay chain 241Pu-->237U & 241Am-->237Np-->233Pa. Secular equilibrium is assumed between the (2.1 x 10(6) year) 237Np and the (27 day) 233Pa. The proposed method is dependent upon the efficiency of the plutonium separation process but makes no assumption about the relative abundance of 241Pu in 239Pu. Even though the technique was developed for weapons grade plutonium, it is expected to apply to almost any material that contains plutonium. PMID:12941503

  17. Experiments on the synthesis of superheavy nuclei 284Fl and 285Fl in the Pu,240239+48Ca reactions

    NASA Astrophysics Data System (ADS)

    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.; Voinov, A. A.; Subbotin, V. G.; Sukhov, A. M.; Sabel'nikov, A. V.; Vostokin, G. K.; Hamilton, J. H.; Stoyer, M. A.; Strauss, S. Y.

    2015-09-01

    Irradiations of 239Pu and 240Pu targets with 48Ca beams aimed at the synthesis of Z =114 flerovium isotopes were performed at the Dubna Gas Filled Recoil Separator. A new spontaneously fissioning (SF) isotope 284Fl was produced for the first time in the 240Pu+48Ca (250 MeV) and 239Pu+48Ca (245 MeV) reactions. The cross section of the 239Pu(48Ca,3 n )284Fl reaction channel was about 20 times lower than predicted by theoretical models and about 50 times lower than the maximum fusion-evaporation cross section for the 3 n and 4 n channels measured in the 244Pu+48Ca reaction. In the 240Pu+48Ca experiment, performed at 245 MeV in order to maximize the 3 n -evaporation channel, three decay chains of 285Fl were detected. 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 with higher accuracy. The assignment of SF events observed during the irradiation of the 240Pu target with a 250 MeV 48Ca beam to 284Fl decay is presented and discussed. The cross sections at both 48Ca energies are similar and exceed that observed in the reaction with the lighter isotope 239Pu by a factor of 10. The decay properties of the synthesized nuclei and their production cross sections indicate a rapid decrease of stability of superheavy nuclei as the neutron number decreases from the predicted magic neutron number N =184 .

  18. LA-ICP-MS for Pu source identification at Mayak PA, the Urals, Russia.

    PubMed

    Cagno, S; Hellemans, K; Lind, O C; Skipperud, L; Janssens, K; Salbu, B

    2014-02-01

    Information on Pu in environmental samples is traditionally based on the determination of the (240+239)Pu activity via Alpha Spectrometry (AS). A large number of alpha spectrometry sources (planchettes) containing radiochemically separated Pu are therefore stored worldwide and are available for further analyses. These archive samples represent a resource from which valuable information on isotopic composition of alpha emitters including Pu can be obtained. The relative abundances of Pu isotopes can be used to trace specific Pu sources and characterize the relative contributions of different Pu sources in a sample. Thus, in addition to the total (239+240)Pu activity, determination of the (240)Pu/(239)Pu ratio can provide valuable information on the nature of the Pu emitting sources. The Pu isotopic ratios can be determined by mass spectrometry techniques such as Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICPMS) or Accelerator Mass Spectrometry (AMS) that require dissolution and complete destruction of the material deposited on the planchettes. In this study Laser Ablation (LA)-quadrupole-ICP-MS has been employed for the analysis of (239)Pu/(240)Pu ratios from alpha-planchettes prepared from samples originating from the Mayak PA nuclear facility, Russia. The results are compared with data from AMS and show that the (240)Pu/(239)Pu ratios obtained by LA-ICP-MS can be utilized to distinguish weapons-grade Pu from civil reprocessing sources. Moreover, isotope ratio mapping can also be performed across the planchettes, allowing e.g. the visualization of possible inhomogeneities in the Pu-isotope distribution on their surface. Thus, this solid sample technique can be applied to extract additional information from existing archives of samples. PMID:24424783

  19. Anomalous plutonium isotopic ratios in sediments of Lake Qinghai from the Qinghai-Tibetan Plateau, China.

    PubMed

    Wu, Fengchang; Zheng, Jian; Liao, Haiqing; Yamada, Masatoshi; Wan, Guojiang

    2011-11-01

    The vertical profiles of (239+240)Pu and (137)Cs activities and (240)Pu/(239)Pu isotopic ratios are determined for three sediment cores of Lake Qinghai from the Qinghai-Tibetan Plateau, China, and compared with those in sediments of another three lakes (Lakes Bosten, Sugan, and Shuangta), the only existing ones closest to Lop Nor area, China's nuclear weapons test site in the northwestern part of the country. The mean inventory of 47.7 ± 18.7 MBq km(-2) for (239+240)Pu activity in Lake Qinghai is comparable to the average value of global fallout expected at the same latitude, yet the mean inventory of 1112.0 ± 78.0 MBq km(-2) for (137)Cs is slightly lower than that of global fallout. Anomalously low (240)Pu/(239)Pu isotopic ratios (0.038-0.125) were found in the 3-6.5 cm deep sediment layers, indicating the trace Pu input from early nuclear weapons research activities at Atomic City in the lake's watershed during the 1950-60s. Model calculation indicated that the Pu input accounted for approximately 5-16% of the total Pu inventory. The observation of low (240)Pu/(239)Pu ratio in the deep sediment layer provided a new time marker for recent sediment dating in the lake and around the area. The results are of great significance to the further understanding of sources, records, and environmental impacts of global and regional nuclear activities in the environment and provide important chronological information for further studies on the water eutrophication process and climatic change, and reconstruction of pollution history of organic contaminants and heavy metals in the watershed of Lake Qinghai. PMID:21950768

  20. Topical report on actinide-only burnup credit for PWR spent nuclear fuel packages. Revision 1

    SciTech Connect

    None, None

    1997-04-01

    A methodology for performing and applying nuclear criticality safety calculations, for PWR spent nuclear fuel (SNF) packages with actinide-only burnup credit, is described. The changes in the U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, and Am-241 concentration with burnup are used in burnup credit criticality analyses. No credit for fission product neutron absorbers is taken. The methodology consists of five major steps. (1) Validate a computer code system to calculate isotopic concentrations of SNF created during burnup in the reactor core and subsequent decay. A set of chemical assay benchmarks is presented for this purpose as well as a method for assessing the calculational bias and uncertainty, and conservative correction factors for each isotope. (2) Validate a computer code system to predict the subcritical multiplication factor, k{sub eff}, of a spent nuclear fuel package. Fifty-seven UO{sub 2}, UO{sub 2}/Gd{sub 2}O{sub 3}, and UO{sub 2}/PuO{sub 2} critical experiments have been selected to cover anticipated conditions of SNF. The method uses an upper safety limit on k{sub eff} (which can be a function of the trending parameters) such that the biased k{sub eff}, when increased for the uncertainty is less than 0.95. (3) Establish bounding conditions for the isotopic concentration and criticality calculations. Three bounding axial profiles have been established to assure the ''end effect'' is accounted for conservatively. (4) Use the validated codes and bounding conditions to generate package loading criteria (burnup credit loading curves). Burnup credit loading curves show the minimum burnup required for a given initial enrichment. The utility burnup record is compared to this requirement after the utility accounts for the uncertainty in its record. Separate curves may be generated for each assembly design, various minimum cooling times and burnable absorber histories. (5) Verify that SNF assemblies meet the package loading criteria

  1. Very High Temperature Reactor (VHTR) Deep Burn Core and Fuel Analysis -- Complete Design Selection for the Pebble Bed Reactor

    SciTech Connect

    B. Boer; A. M. Ougouag

    2010-09-01

    The Deep-Burn (DB) concept focuses on the destruction of transuranic nuclides from used light water reactor fuel. These transuranic nuclides are incorporated into TRISO coated fuel particles and used in gas-cooled reactors with the aim of a fractional fuel burnup of 60 to 70% in fissions per initial metal atom (FIMA). This high performance is expected through the use of multiple recirculation passes of the fuel in pebble form without any physical or chemical changes between passes. In particular, the concept does not call for reprocessing of the fuel between passes. In principle, the DB pebble bed concept employs the same reactor designs as the presently envisioned low-enriched uranium core designs, such as the 400 MWth Pebble Bed Modular Reactor (PBMR-400). Although it has been shown in the previous Fiscal Year (2009) that a PuO2 fueled pebble bed reactor concept is viable, achieving a high fuel burnup, while remaining within safety-imposed prescribed operational limits for fuel temperature, power peaking and temperature reactivity feedback coefficients for the entire temperature range, is challenging. The presence of the isotopes 239-Pu, 240-Pu and 241-Pu that have resonances in the thermal energy range significantly modifies the neutron thermal energy spectrum as compared to a ”standard,” UO2-fueled core. Therefore, the DB pebble bed core exhibits a relatively hard neutron energy spectrum. However, regions within the pebble bed that are near the graphite reflectors experience a locally softer spectrum. This can lead to power and temperature peaking in these regions. Furthermore, a shift of the thermal energy spectrum with increasing temperature can lead to increased absorption in the resonances of the fissile Pu isotopes. This can lead to a positive temperature reactivity coefficient for the graphite moderator under certain operating conditions. The effort of this task in FY 2010 has focused on the optimization of the core to maximize the pebble discharge

  2. Combined use of medium mass resolution and desolvation introduction system for accurate plutonium determination in the femtogram range by inductively coupled plasma-sector-field mass spectrometry

    NASA Astrophysics Data System (ADS)

    Pointurier, Fabien; Pottin, Anne-Claire; Hémet, Philippe; Hubert, Amélie

    2011-03-01

    Formation of a polyatomic species made of an atom of a heavy element like lead, mercury or iridium, and atoms abundant in plasma (argon, nitrogen, oxygen, and hydrogen) when using an inductively coupled plasma-sector-field mass spectrometer (ICP-SFMS) may lead to false detection of femtograms (fg) of plutonium or bias in the measured concentrations. Mathematical corrections, based on the measurement of heavy element concentrations in the sample solutions and determination of the extents of formation of the polyatomic interferences, are efficient but time-consuming and degrade detection limits. We describe and discuss a new method based on the combination of, on the one hand, medium mass resolution (MR) of the ICP-SFMS to separate plutonium isotopes physically from interfering polyatomic species, and, on the other, use of a desolvation introduction system (DIS) to enhance sensitivity, thus partly compensating for the loss of transmission due to use of a higher resolution. Plutonium peaks are perfectly separated from the major interfering species (PbO 2, HgAr, and IrO 3) with a mass resolution of ~ 4000. The resulting nine-fold transmission loss is partly compensated by a five-fold increase in sensitivity obtained with the DIS and a lower background. The instrumental detection limits for plutonium isotopes, calculated for measurements of pure synthetic solutions, of the new method (known as MR-DIS method) and of the one currently used in the laboratory (LR method), based on a low mass resolution equal to 360, a microconcentric nebulizer and two in-line cooled spray chambers, are roughly equivalent, at around 0.2 fg ml - 1 . Regarding the measurement of real-life samples, the results obtained with both methods agree and the corresponding analytical detection limits for plutonium isotopes 239Pu, 240Pu and 241Pu are of a few fg·ml - 1 of sample solution, slightly lower with the MR-DIS method than with the current LR method. Although less sensitive than other plutonium

  3. Plutonium isotopes in settling particles: transport and scavenging of Pu in the western Northwest Pacific.

    PubMed

    Zheng, Jian; Yamada, Masatoshi

    2006-07-01

    We examined the vertical distributions of 239+240Pu activity and 240Pu/239Pu atom ratio in settling particles and quantified the particulate 239+240Pu fluxes in the water column in the western Northwest Pacific. Settling particle samples were collected using sediment traps. Plutonium isotopes were analyzed using a sector field high-resolution ICP-MS. To the best of our knowledge, this is the first time that both Pu activity and Pu isotope ratio data have been obtained for settling particles in the Pacific Ocean. The high (>0.18) 240Pu/239Pu atom ratios in settling particles indicate that plutonium from the Pacific Proving Grounds (PPG) source in the central Pacific is transported toward the western Northwest Pacific. Evidence indicates that Pu scavenging onto the settling particles is strongly dependent upon the bulk mass flux. The results suggest that advective lateral transport of dissolved Pu from the open ocean to the ocean margin and removal of Pu into the margin sediments by particle scavenging is a common phenomenon in the Pacific Ocean. Plutonium can be considered as a useful tracer to study the transport and fate of other contaminants that readily adsorb to particles in marine environments. PMID:16856723

  4. Modelling the distribution of plutonium in the Pacific Ocean.

    PubMed

    Nakano, Masanao; Povinec, Pavel P

    2003-01-01

    An Oceanic General Circulation Model (OGCM) including a plutonium scavenging model as well as an advection-diffusion model has been developed for modelling the distribution of plutonium in the Pacific Ocean. Calculated 239, 240Pu water profile concentrations and 239, 240Pu inventories in water and sediment of the Pacific Ocean have showed a reasonable agreement with the experimental results. The presence of local fallout plutonium in central North Pacific waters has been confirmed. The observed 240Pu/239Pu mass ratios confirm that plutonium originating from local fallout from nuclear weapons tests carried out at Bikini and Enewetak Atolls is more rapidly removed from surface waters to deeper waters than plutonium originating from global fallout. The developed OGCM can be used for modelling the dispersion of other non-conservative tracers in the ocean as well. PMID:12860091

  5. Combining Differential and Integral Experiments on 239PU for Reducing Uncertainties in Nuclear Data Applications

    NASA Astrophysics Data System (ADS)

    Kawano, T.; Hanson, K. M.; Frankle, S. C.; Talou, P.; Chadwick, M. B.; Little, R. C.

    2006-04-01

    We present an approach to uncertainty quantification for nuclear applications, which combines the covariance evaluation of differential cross-sections data and the error propagation from matching a criticality experiment using a neutron transport calculation. We have studied the effect on Pu-239 fission cross sections of using a one-dimensional neutron transport calculation with the PARTISN code. The evaluation of Pu-239 differential cross-section data is combined with a criticality measurement (Jezebel) using a Bayesian method. To perform the uncertainty quantification for such calculations, we generate a set of random samples of cross sections, which is representative of the covariance matrix, and estimate the distribution of calculated quantities, such as criticality. We show that inclusion of the Jezebel data reduces uncertainties in estimating neutron multiplicity.

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    We describe a new cumulated fission product yield (FPY) evaluation for fission spectrum neutrons on plutonium that updates the ENDF/B-VI evaluation by England and Rider, for the forthcoming ENDF/B-VII.1 database release. We focus on FPs that are needed for high accuracy burnup assessments; that is, for inferring the number of fissions in a neutron environment. Los Alamos conducted an experiment in the 1970s in the Bigten fast critical assembly to determine fission product yields as part of the Interlaboratory Reaction Rate (ILRR) collaboration, and this has defined the Laboratory's fission standard to this day. Our evaluation includes use of the LANL-ILRR measurements (not previously available to evaluators) as well as other Laboratory FPY measurements published in the literature, especially the high-accuracy mass spectrometry data from Maeck and others. Because the measurement database for some of the FPs is small — especially for 99Mo — we use a meta-analysis that incorporates insights from other accurately-measured benchmark FP data, using R-value ratio measurements. The meta-analysis supports the FP measurements from the LANL-ILRR experiment. Differences between our new evaluations and ENDF/B-VI are small for some FPs (less than 1-2%-relative for 95Zr, 140Ba, 144Ce), but are larger for 99Mo (4%-relative) and 147Nd (5%-relative, at 1.5 MeV) respectively. We present evidence for an incident neutron energy dependence to the 147Nd fission product yield that accounts for observed differences in the FPY at a few-hundred keV average energy in fast reactors versus measurements made at higher average neutron energies in Los Alamos' fast critical assemblies. Accounting for such FPY neutron energy dependencies is important if one wants to reach a goal of determining the number of fissions to accuracies of 1-2%. An evaluation of the energy-dependence of fission product yields is given for all A values based on systematical trends in the measured data, with a focus on the energy dependence over the fast neutron energy range from 0.2-2 MeV. Based on these trends, we present an evaluation of the FPY data at 0.5 and 2.0 MeV average incident neutron energies. This new set of ENDF/B-VII data will enable users to linearly interpolate between the pooled FPY data at ˜0.5 MeV and our new data at 2 MeV to obtain FPYs at other energies. We intend to release the ENDF/B-VII.1 database in December 2011, and all released data are subject to CSEWG approval. It is possible that the released evaluated data will differ from those presented in this paper; the evaluated date presented here can be referred to as ENDF/B-VII.1 beta 0.

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

    SciTech Connect

    Hollas, C.L.; Arnone, G.; Brunson, G.; Coop, K.

    1997-11-01

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

  8. Chronology of Pu isotopes and 236U in an Arctic ice core.

    PubMed

    Wendel, C C; Oughton, D H; Lind, O C; Skipperud, L; Fifield, L K; Isaksson, E; Tims, S G; Salbu, B

    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 (236)U, (239)Pu, and (240)Pu concentrations, and atom ratios, measured by accelerator mass spectrometry in a 28.6m 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 (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 (239+240)Pu ranged from 0.008 to 0.254 mBq cm(-2) and (236)U from 0.0039 to 0.053 μBq cm(-2). Concentrations varied in concordance with (137)Cs concentrations in the same ice core. In contrast to previous published results, the concentrations of Pu and (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 (240)Pu/(239)Pu ratio ranged from 0.15 to 0.19, and (236)U/(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 (236)U concentrations and (236)U/(239)Pu atom ratios in the Arctic and in ice cores. PMID:23770554

  9. Sources and migration of plutonium in groundwater at the Savannah River site.

    PubMed

    Dai, Minhan; Kelley, James M; Buesseler, Ken O

    2002-09-01

    The isotopic composition, size distribution, and redox speciation of plutonium (Pu) in the groundwater in the vicinity of the F-area seepage basins at the U.S. Department of Energy Savannah River Site (SRS) were examined. A low 240Pu/239Pu ratio in the upstream control well signifies a Pu source otherthan global fallout and indicates reactor-produced Pu. Elevated 240Pu/239Pu atom ratios downstream from the seepage basins are due to the decay of transplutonium isotopes, mainly 244Cm to 240Pu, which were generated at the SRS. Evidence suggests that the migration of basin-released Pu isotopes is minor. Rather, it is the transplutonium isotopes that migrate preferentially downstream and in the process decay to yield progeny Pu isotopes. Size fractionation studies with cross-flow ultrafiltration show that <4% of the 239Pu or 240Pu is found in the colloidal fraction, a finding that is consistent with the higher Pu oxidation states observed in the SRS groundwater. The observation of a low abundance of colloid-associated Pu in SRS groundwater cannot be extrapolated to all sites, but is in contrast to the conclusions of prior groundwater Pu studies at the SRS and elsewhere. This work is unique in its application of a novel combination of sampling and processing protocols as well as its use of thermal ionization mass spectrometry for the detection of Pu isotopes. This allows quantification of the Pu source terms and better determination of the ambient Pu size and redox speciation representative of in situ conditions. PMID:12322739

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

    PubMed

    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

  11. Bioreduction amenability testing of actinide contaminated soils. The systems: Am{sup 241}-Pu{sup 238}, Am{sup 241}-Pu{sup 239/40}, U

    SciTech Connect

    Korich, D.G.; Sharp, J.E.

    1995-01-01

    Bioreductive processing of actinide contaminated soils can achieve extraction levels in excess of 97% for both plutonium and uranium contaminants. Reasonable reaction rates of 4 to 6 day resident times for Pu-Am have been demonstrated on 4 gram sample charges. Longer reaction times of 17 days required for uranium extraction can be improved by soil sample preconditioning and/or an increase in process reagent concentrations. The environmentally benign treatment process operates at pH 6--7, preserves the original soil matrix, and utilizes standard processing equipment. The process reagent component (inoculum SD-1 and biological growth medium PX100{trademark}) are available for utilization in an integrated system. Process techniques developed by MBX, involving graduated volume bioreactors have been proven to alleviate biological toxicity problems in treatment leachates. Bioreduction processing of actinide contaminated soils, preconditioning of soil charges, and recycling or vegetation of unacceptable tailings can be combined to provide an effective and environmentally attractive method of remediation. The soil test program was designed to determine the applicability of the MBX bioreductive technology to solubilize Pu and Am from RFP, Mound and LANL soils and uranium from Hanford and Fernald soils.

  12. Determination of plutonium in environmental samples by AMS and alpha spectrometry.

    PubMed

    Hrnecek, E; Steier, P; Wallner, A

    2005-01-01

    Environmental samples from nuclear weapons test sites at the atolls of Mururoa and Fangataufa (French Polynesia, south Pacific) have been analyzed for their content of plutonium isotopes by applying the independent techniques of decay counting (Alpha Spectrometry) and accelerator mass spectrometry (AMS). Here, we propose the combination of both techniques which results in a maximum of information on the isotopic signature of Pu in environmental samples. Plutonium was chemically separated from the bulk material by anion exchange. (242)Pu was used as an internal standard for both AMS and alpha spectrometry. The samples for alpha spectrometry were prepared by micro-precipitation with NdF(3). After alpha spectrometry, the samples were reprocessed for AMS. Pu was co-precipitated with Fe(OH)(3) and finally, solid samples were prepared. At the VERA (Vienna Environmental Research Accelerator) facility, the various Pu isotopes were separated by their isotopic masses and quantified by the AMS technique. A good agreement of the results obtained from the AMS measurements was found with those obtained from Alpha Spectrometry. Overall, the data agree on average within 10% of each other. Isotope ratios for (238)Pu, (239)Pu and (240)Pu can be extracted from our investigations. Alpha spectrometry delivers data for the (238)Pu and the combination of ((239+240))Pu concentrations in those samples. In addition, the AMS technique provides information on the individual concentrations of (240)Pu and (239)Pu. PMID:15982894

  13. /sup 239/ /sup 240/Pu and /sup 238/Pu in sediments of the Hudson River estuary

    SciTech Connect

    Linsalata, P.; Wrenn, M.E.; Cohen, N.; Singh, N.P.

    1980-12-01

    Plutonium-239,240 and plutonium-238 were determined in 59 Hudson River sediment dredge samples collected during 1973-77 in the vicinity of the Indian Point Nuclear Power Station. Acid leaching followed by solvent extraction, electrodeposition, and alpha-spectrometry were used to extract, purify, and quantitate plutonium isotopes present in these samples. Annual median plutonium-238/plutonium-239,240 isotopic activity ratios in surficial sediments were 0.032 (1973-74), 0.035 (1975), 0.042 (1976), and 0.040 (1977). The source of these nuclides in the estuary was identified by analysis of the sample isotopic activity ratios. On the basis of the sampling regimen and the methods used, it is concluded that no input, other than that of fallout, has contributed significantly to the plutonium burden in Hudson sediments. (1 map, 9 references, 9 tables)

  14. Nuclear and dosimetric features of an isotopic neutron source

    NASA Astrophysics Data System (ADS)

    Vega-Carrillo, H. R.; Hernández-Dávila, V. M.; Rivera, T.; Sánchez, A.

    2014-02-01

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

  15. Plutonium in Colorado residents: results of autopsy bone samples collected during 1975-1979.

    PubMed

    Ibrahim, S A; Warren, G M; Whicker, F W; Efurd, D W

    2002-08-01

    Concentrations of (239,240)Pu and the 240Pu/239Pu atom ratios were measured in rib samples from 55 non-occupationally exposed Colorado residents. Samples were collected at autopsy during 1975-1979 under an earlier study intended to compare plutonium levels in liver and lung of people who lived at various proximities to the Rocky Flats Environmental Technology Site (RFETS) near Denver. Overall, median (239,240)Pu concentrations from rib samples were 100, 80, and 57 microBq g(-1) ash weight for area locations A, B, and C, respectively. Area A encompassed subjects who lived within 25 km of RFETS, area B was between 25 and 50 km from RFETS, and area C included all of Colorado outside 50 km from the site and east of the continental divide. The corresponding median plutonium skeletal burdens estimated for these area locations were 146, 93, and 71 mBq, respectively. A statistically significant difference was noted only between plutonium concentrations in male rib samples and their skeletal burdens from area A compared to area C. However, based on a regression analysis of all study subjects, distance from RFETS was not statistically correlated to plutonium rib concentrations or skeletal burdens in this sample. Overall, median 240Pu/239Pu atom ratios were 0.20, 0.18, and 0.17 for areas A, B, and C, respectively. Although higher (239,240)Pu concentrations and skeletal burdens were indicated in area A males than area C males, we cannot conclude that RFETS releases may have caused this difference. The decreasing trends in the 240Pu/239Pu ratios with distance from RFETS are contrary with such a conclusion and strongly indicate that the material was primarily global fallout rather than weapons-grade plutonium that was processed at RFETS. Furthermore, there are other plausible explanations for the differences observed between area A and C residents. These include a decreasing trend in global fallout from the Rocky Mountain foothills eastward, smoking history differences, sample

  16. Present Status of Nuclear Data for Nuclear Nonproliferation

    NASA Astrophysics Data System (ADS)

    Igashira, M.

    2015-10-01

    The present status of nuclear data was reviewed from the viewpoint of the research and development of non-destructive inspection methods for international controlled materials such as 235U, 239Pu, 241Pu, D2O, 6LiD, and 9Be. The nuclear characteristics of these materials were discussed, and neutron- and photon-reaction cross section data were reviewed. It was found that the accuracy of neutron data was enough for the research and development but that of photon data was not enough.

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

    SciTech Connect

    Garten, C.T. Jr.; Trabalka, J.R.; Bogle, M.A.

    1981-01-01

    The bioaccumulation of /sup 233/ /sup 234/U, /sup 238/U, /sup 238/Pu, /sup 239/ /sup 240/Pu, /sup 241/Am, and /sup 244/Cm in both native and introduced biota was studied at Pond 3513, a former low-level radioactive waste settling basin at Oak Ridge National Laboratory. This system, which was decommissioned in 1976 after more than 30 years use, contains approximately 5 Ci of /sup 239/ /sup 240/Pu; inventories of other actinide isotopes are considerably less. Significantly higher concentrations of actinides in fish that were allowed access to sediments indicated that sedimentary particulates may be the primary source of transuranics to biota in shallow fresh-water ecosystems. Our study determined habitat, in particular the degree of association of an organism with the sediment-water interface, to be the primary factor in controlling transuranic concentrations in aquatic biota. In most of the biological samples analyzed, excluding samples suspected of being contaminated by sediment, /sup 241/Am//sup 239/Pu, /sup 244/Cm//sup 239/Pu, and /sup 238/U//sup 239/Pu ratios were greater than the respective ratio in sediment while /sup 233/ /sup 234/U//sup 238/U, and /sup 239/ /sup 240/Pu//sup 238/Pu ratios were not different from the respective ratios in sediment. The relative uptake of actinides from contaminated sediment by aquatic and terrestrial biota at this site was U > Cm greater than or equal to Am > Pu. The relative extractability of actinides from shoreline sediment was U > Cm approx. = Am > Pu; we also observed the same relative ranking for sediment-water exchange in situ. Concentrations of transuranics in water, terrestrial vegetation, and vertebrate carcasses were less than 10% of the recommended public exposure maximum permissible concentration (MPC) of the ICRP.

  18. Isotopic evidence of plutonium release into the environment from the Fukushima DNPP accident

    PubMed Central

    Zheng, Jian; Tagami, Keiko; Watanabe, Yoshito; Uchida, Shigeo; Aono, Tatsuo; Ishii, Nobuyoshi; Yoshida, Satoshi; Kubota, Yoshihisa; Fuma, Shoichi; Ihara, Sadao

    2012-01-01

    The Fukushima Daiichi nuclear power plant (DNPP) accident caused massive releases of radioactivity into the environment. The released highly volatile fission products, such as 129mTe, 131I, 134Cs, 136Cs and 137Cs were found to be widely distributed in Fukushima and its adjacent prefectures in eastern Japan. However, the release of non-volatile actinides, in particular, Pu isotopes remains uncertain almost one year after the accident. Here we report the isotopic evidence for the release of Pu into the atmosphere and deposition on the ground in northwest and south of the Fukushima DNPP in the 20–30 km zones. The high activity ratio of 241Pu/239+240Pu (> 100) from the Fukushima DNPP accident highlights the need for long-term 241Pu dose assessment, and the ingrowth of 241Am. The results are important for the estimation of reactor damage and have significant implication in the strategy of decontamination. PMID:22403743

  19. Isotopic evidence of plutonium release into the environment from the Fukushima DNPP accident.

    PubMed

    Zheng, Jian; Tagami, Keiko; Watanabe, Yoshito; Uchida, Shigeo; Aono, Tatsuo; Ishii, Nobuyoshi; Yoshida, Satoshi; Kubota, Yoshihisa; Fuma, Shoichi; Ihara, Sadao

    2012-01-01

    The Fukushima Daiichi nuclear power plant (DNPP) accident caused massive releases of radioactivity into the environment. The released highly volatile fission products, such as (129m)Te, (131)I, (134)Cs, (136)Cs and (137)Cs were found to be widely distributed in Fukushima and its adjacent prefectures in eastern Japan. However, the release of non-volatile actinides, in particular, Pu isotopes remains uncertain almost one year after the accident. Here we report the isotopic evidence for the release of Pu into the atmosphere and deposition on the ground in northwest and south of the Fukushima DNPP in the 20-30 km zones. The high activity ratio of (241)Pu/(239+240)Pu (> 100) from the Fukushima DNPP accident highlights the need for long-term (241)Pu dose assessment, and the ingrowth of (241)Am. The results are important for the estimation of reactor damage and have significant implication in the strategy of decontamination. PMID:22403743

  20. Spatially resolved analysis of plutonium isotopic signatures in environmental particle samples by laser ablation-MC-ICP-MS.

    PubMed

    Konegger-Kappel, Stefanie; Prohaska, Thomas

    2016-01-01

    Laser ablation-multi-collector-inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) was optimized and investigated with respect to its performance for determining spatially resolved Pu isotopic signatures within radioactive fuel particle clusters. Fuel particles had been emitted from the Chernobyl nuclear power plant (ChNPP) where the 1986 accident occurred and were deposited in the surrounding soil, where weathering processes caused their transformation into radioactive clusters, so-called micro-samples. The size of the investigated micro-samples, which showed surface alpha activities below 40 mBq, ranged from about 200 to 1000 μm. Direct single static point ablations allowed to identify variations of Pu isotopic signatures not only between distinct fuel particle clusters but also within individual clusters. The resolution was limited to 100 to 120 μm as a result of the applied laser ablation spot sizes and the resolving power of the nuclear track radiography methodology that was applied for particle pre-selection. The determined (242)Pu/(239)Pu and (240)Pu/(239)Pu isotope ratios showed a variation from low to high Pu isotope ratios, ranging from 0.007(2) to 0.047(8) for (242)Pu/(239)Pu and from 0.183(13) to 0.577(40) for (240)Pu/(239)Pu. In contrast to other studies, the applied methodology allowed for the first time to display the Pu isotopic distribution in the Chernobyl fallout, which reflects the differences in the spent fuel composition over the reactor core. The measured Pu isotopic signatures are in good agreement with the expected Pu isotopic composition distribution that is typical for a RBMK-1000 reactor, indicating that the analyzed samples are originating from the ill-fated Chernobyl reactor. The average Pu isotope ratios [(240)Pu/(239)Pu = 0.388(86), (242)Pu/(239)Pu = 0.028(11)] that were calculated from all investigated samples (n = 48) correspond well to previously published results of Pu analyses in contaminated samples from

  1. Event-by-Event Fission Modeling of Prompt Neutrons and Photons from Neutron-Induced and Spontaneous Fission with FREYA

    NASA Astrophysics Data System (ADS)

    Vogt, Ramona; Randrup, Jorgen

    2013-04-01

    The event-by-event fission Monte Carlo code FREYA (Fission Reaction Event Yield Algorithm) generates large samples of complete fission events. Using FREYA, it is possible to obtain the fission products as well as the prompt neutrons and photons emitted during the fission process, all with complete kinematic information. We can therefore extract any desired correlation observables. Concentrating on ^239Pu(n,f), ^240Pu(sf) and ^252Cf(sf), we compare our FREYA results with available data on prompt neutron and photon emission and present predictions for novel fission observables that could be measured with modern detectors.

  2. Fission cross sections of some thorium, uranium, neptunium and plutonium isotopes relative to /sup 235/U

    SciTech Connect

    Meadows, J W

    1983-10-01

    Earlier results from the measurements, at this Laboratory, of the fission cross sections of /sup 230/Th, /sup 232/Th, /sup 233/U, /sup 234/U, /sup 236/U, /sup 238/U, /sup 237/Np, /sup 239/Pu, /sup 240/Pu, and /sup 242/Pu relative to /sup 235/U are reviewed with revisions to include changes in data processing procedures, alpha half lives and thermal fission cross sections. Some new data have also been included. The current experimental methods and procedures and the sample assay methods are described in detail and the sources of error are presented in a systematic manner. 38 references.

  3. Superconducting calorimetric alpha particle sensors for nuclear nonproliferation applications

    SciTech Connect

    Horansky, Robert D.; Ullom, Joel N.; Beall, James A.; Hilton, Gene C.; Irwin, Kent D.; Dry, Donald E.; Hastings, Elizabeth P.; Lamont, Stephen P.; Rudy, Clifford R.; Rabin, Michael W.

    2008-09-22

    Identification of trace nuclear materials is usually accomplished by alpha spectrometry. Current detectors cannot distinguish critical elements and isotopes. We have developed a detector called a microcalorimeter, which achieves a resolution of 1.06 keV for 5.3 MeV alphas, the highest resolving power of any energy dispersive measurement. With this exquisite resolution, we can unambiguously identify the {sup 240}Pu/{sup 239}Pu ratio in Pu, a critical measurement for ascertaining the intended use of nuclear material. Furthermore, we have made a direct measurement of the {sup 209}Po ground state decay.

  4. Comparative skeletal distribution of Am and Pu in man, monkey, and baboon

    SciTech Connect

    Lynch, T.P.; Kathren, R.L.; Dagle, G.E.; McInroy, J.F. )

    1989-01-01

    The skeletal distribution of Am and Pu in four human cases was compared with the skeletal distributions of these radioelements in baboons and monkeys. Excellent agreement was noted among the four human cases; data were available for Am in all four and Pu in three. A statistically significant correlation was found between the {sup 241}Am and {sup 239}Pu + {sup 240}Pu skeletal distributions in the humans and those in nonhuman primates. Trabecular bone had the highest concentrations of {sup 241}Am and {sup 239+240}Pu in humans, baboons, and monkeys. Scaling factors are proposed to convert the percentages of skeletal activity in animal bones to the corresponding percentages in the bones of the human skeleton.

  5. Global fallout Pu recorded in lacustrine sediments in Lake Hongfeng, SW China.

    PubMed

    Zheng, Jian; Wu, Fengchang; Yamada, Masatoshi; Liao, Haiqing; Liu, Congqiang; Wan, Guojiang

    2008-03-01

    Studies on the distribution and isotope compositions of fallout Pu are important for source characterization of possible future non-fallout Pu contamination in aquatic environments, and useful for dating of recent sediments to understand the pollution history of environmental contaminants. We present the historical record of atmospheric Pu fallout reconstructed from a sediment core from Lake Hongfeng, China. The Pu activity profile was in agreement with the 137Cs profile. Inventories were 50.7 Bq m(-2) for 239+240Pu and 1586 Bq m(-2) for 137Cs. The average 240Pu/239Pu atom ratio was 0.185+/-0.009, indicating that Pu originated from global stratospheric fallout rather than from direct tropospheric or close-in fallout from the Chinese nuclear testing conducted in the 1970s. Our data suggested that Lake Hongfeng would be an ideal setting for monitoring atmospheric fallout and environmental changes in this region. PMID:17651874

  6. Certified Reference Material IAEA-446 for radionuclides in Baltic Sea seaweed.

    PubMed

    Pham, M K; Benmansour, M; Carvalho, F P; Chamizo, E; Degering, D; Engeler, C; Gascó, C; Gwynn, J P; Harms, A V; Hrnecek, E; Ibanez, F L; Ilchmann, C; Ikaheimonen, T; Kanisch, G; Kloster, M; Llaurado, M; Mauring, A; Møller, B; Morimoto, T; Nielsen, S P; Nies, H; Norrlid, L D R; Pettersson, H B L; Povinec, P P; Rieth, U; Samuelsson, C; Schikowski, J; Silobritiene, B V; Smedley, P A; Suplinska, M; Vartti, V-P; Vasileva, E; Wong, J; Zalewska, T; Zhou, W

    2014-05-01

    A Certified Reference Material (CRM) for radionuclides in seaweed (Fucus vesiculosus) from the Baltic Sea (IAEA-446) is described and the results of the certification process are presented. The (40)K, (137)Cs, (234)U and (239+240)Pu radionuclides were certified for this material, and information values for 12 other radionuclides ((90)Sr, (99)Tc, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (230)Th, (232)Th, (235)U, (238)U, (239)Pu and (240)Pu) are presented. The CRM can be used for Quality Assurance/Quality Control of analysis of radionuclides in seaweed and other biota samples, as well as for development and validation of analytical methods, and for training purposes. PMID:24291528

  7. Plutonium in the WIPP environment: its detection, distribution and behavior.

    PubMed

    Thakur, P; Ballard, S; Nelson, R

    2012-05-01

    The Waste Isolation Pilot Plant (WIPP) is the only operating deep underground geologic nuclear repository in the United States. It is located in southeastern New Mexico, approximately 655 m (2150 ft) below the surface of the Earth in a bedded Permian evaporite salt formation. This mined geologic repository is designed for the safe disposal of transuranic (TRU) wastes generated from the US defense program. Aerosol and soil samples have been collected near the WIPP site to investigate the sources of plutonium in the WIPP environment since the late 1990s, well before WIPP received its first shipment. Activities of (238)Pu, (239+240)Pu and (241)Am were determined by alpha spectrometry following a series of chemical separations. The concentrations of Al and U were determined in a separate set of samples by inductively coupled plasma mass spectrometry. The annual airborne concentrations of (239+240)Pu during the period from 1998 to 2010 show no systematic interannual variations. However, monthly (239+240)Pu particulate concentrations show a typical seasonal variation with a maximum in spring, the time when strong and gusty winds frequently give rise to blowing dust. Resuspension of soil particles containing weapons fallout is considered to be the predominant source of plutonium in the WIPP area. Further, this work characterizes the source, temporal variation and its distribution with depth in a soil profile to evaluate the importance of transport mechanisms affecting the fate of these radionuclides in the WIPP environment. The mean (137)Cs/(239+240)Pu, (241)Am/(239+240)Pu activity ratio and (240)Pu/(239)Pu atom ratio observed in the WIPP samples are consistent with the source being largely global fallout. There is no evidence of any release from the WIPP contributing to radionuclide concentrations in the environment. PMID:22549140

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

    PubMed Central

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

    2013-01-01

    Surface and soil core samples from northeast China were analyzed for Pu isotopes. The measured 240Pu/239Pu atomic ratios and 239 + 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 and human activities resulted in different distribution of Pu in surface soils. A sub-surface maximum followed by exponential decline of 239 + 240Pu concentrations was observed in an undisturbed soil core, with a total 239 + 240Pu inventory of 86.9 Bq/m2 and more than 85% accumulated in 0 ~ 20 cm layers. While only half inventory of Pu was obtained in another soil core and no sub-surface maximum value occurred. Erosion of topsoil in the site should be the most possible reason for the significantly lower Pu inventory, which is also supported by the reported 137Cs profiles. These results demonstrated that Pu could be applied as an ideal substitute of 137Cs for soil erosion study in the future. PMID:24336360

  9. Cesium, americium and plutonium isotopes in ground level air of vilnius

    NASA Astrophysics Data System (ADS)

    Lujaniene, G.; Šapolaite, J.; Remeikis, V.; Lujanas, V.; Jermolajev, A.; Aninkevičius, V.

    2006-01-01

    Systematic observations of radionuclide composition and concentration in the atmosphere have been carried out at the Institute of Physics in Vilnius since 1963. Increases in activity concentration of radionuclides in the atmosphere were observed after nuclear weapon tests and the Chernobyl NPP accident. At present the radiation situation in Lithuania is determined by two main sources of radionuclides, forest fire and resuspension products transferred from highly polluted region of the Ukraine and Belarus. The activity concentrations of 137Cs were measured in two to three days samples while plutonium and americium in monthly samples. The extremely high activity concentrations of 238Pu, 239,240Pu, 241Am determined in the atmosphere during the Chernobyl accident can be explained by transport of “hot particles” of different composition. Activity concentration in 1995 2003 of 241Am and 239,240Pu isotopes ranged from 0.3 to 500 and from 1 to 500 nBq/m3, respectively. 238Pu/239,240Pu activity ratio in measured samples differs from 0.03 to 0.45. A decrease in 240Pu/239Pu atomic ratio from 0.30 to 0.19 was observed in 1995 2003.

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

    SciTech Connect

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

    2008-05-30

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

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

    SciTech Connect

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

    2010-02-04

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

  12. Fission Product Yields from Fission Spectrum n+{sup 239}Pu for ENDF/B-VII.1

    SciTech Connect

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

    2010-12-15

    We describe a new cumulated fission product yield (FPY) evaluation for fission spectrum neutrons on plutonium that updates the ENDF/B-VI evaluation by England and Rider, for the forthcoming ENDF/B-VII.1 database release. We focus on FPs that are needed for high accuracy burnup assessments; that is, for inferring the number of fissions in a neutron environment. Los Alamos conducted an experiment in the 1970s in the Bigten fast critical assembly to determine fission product yields as part of the Interlaboratory Reaction Rate (ILRR) collaboration, and this has defined the Laboratory's fission standard to this day. Our evaluation includes use of the LANL-ILRR measurements (not previously available to evaluators) as well as other Laboratory FPY measurements published in the literature, especially the high-accuracy mass spectrometry data from Maeck and others. Because the measurement database for some of the FPs is small - especially for {sup 99}Mo - we use a meta-analysis that incorporates insights from other accurately-measured benchmark FP data, using R-value ratio measurements. The meta-analysis supports the FP measurements from the LANL-ILRR experiment. Differences between our new evaluations and ENDF/B-VI are small for some FPs (less than 1-2%-relative for {sup 95}Zr, {sup 140}Ba, {sup 144}Ce), but are larger for {sup 99}Mo (4%-relative) and {sup 147}Nd (5%-relative, at 1.5 MeV) respectively. We present evidence for an incident neutron energy dependence to the {sup 147}Nd fission product yield that accounts for observed differences in the FPY at a few-hundred keV average energy in fast reactors versus measurements made at higher average neutron energies in Los Alamos' fast critical assemblies. Accounting for such FPY neutron energy dependencies is important if one wants to reach a goal of determining the number of fissions to accuracies of 1-2%. An evaluation of the energy-dependence of fission product yields is given for all A values based on systematical trends in the measured data, with a focus on the energy dependence over the fast neutron energy range from 0.2-2 MeV. Based on these trends, we present an evaluation of the FPY data at 0.5 and 2.0 MeV average incident neutron energies. This new set of ENDF/B-VII data will enable users to linearly interpolate between the pooled FPY data at {approx}0.5 MeV and our new data at 2 MeV to obtain FPYs at other energies.

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

    SciTech Connect

    Johnson, M S; McNabb, D P

    2009-01-07

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

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

    DOE PAGESBeta

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

    2016-05-13

    Here, 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.

  15. Final Report on Utilization of TRU TRISO Fuel as Applied to HTR Systems Part I: Pebble Bed Reactors

    SciTech Connect

    Brian Boer; Abderrafi M. Ougouag

    2011-03-01

    The Deep-Burn (DB) concept [ ] focuses on the destruction of transuranic nuclides from used light water reactor (LWR) fuel. These transuranic nuclides are incorporated into tri-isotopic (TRISO) coated fuel particles and used in gas-cooled reactors with the aim of a fractional fuel burnup of 60 to 70% in fissions per initial metal atom (FIMA). This high performance is expected through the use of multiple recirculation passes of the fuel in pebble form without any physical or chemical changes between passes. In particular, the concept does not call for reprocessing of the fuel between passes. In principle, the DB pebble bed concept employs the same reactor designs as the presently envisioned low-enriched uranium core designs, such as the 400 MWth Pebble Bed Modular Reactor (PBMR-400) [ ]. Although it has been shown in the previous Fiscal Year (FY) (2009) that a PuO2 fueled pebble bed reactor concept is viable, achieving a high fuel burnup while remaining within safety-imposed prescribed operational limits for fuel temperature, power peaking, and temperature reactivity feedback coefficients for the entire temperature range, is challenging. The presence of the isotopes 239Pu, 240Pu, and 241Pu that have resonances in the thermal energy range significantly modifies the neutron thermal energy spectrum as compared to a standard, UO2-fueled core. Therefore, the DB pebble bed core exhibits a relatively hard neutron energy spectrum. However, regions within the pebble bed that are near the graphite reflectors experience a locally softer spectrum. This can lead to power and temperature peaking in these regions. Furthermore, a shift of the thermal energy spectrum with increasing temperature can lead to increased absorption in the resonances of the fissile Pu isotopes. This can lead to a positive temperature reactivity coefficient for the graphite moderator under certain operating conditions. Regarding the coated particle performance, the FY 2009 investigations showed that no

  16. Results of the Excreta Bioassay Quality Control Program for April 1, 2009 through March 31, 2010

    SciTech Connect

    Antonio, Cheryl L.

    2012-07-19

    A total of 58 urine samples and 10 fecal samples were submitted during the report period (April 1, 2009 through March 31, 2010) to General Engineering Laboratories, South Carolina by the Hanford Internal Dosimetry Program (IDP) to check the accuracy, precision, and detection levels of their analyses. Urine analyses for Sr, 238Pu, 239Pu, 241Am, 243Am 235U, 238U, elemental uranium and fecal analyses for 241Am, 238Pu and 239Pu were tested this year as well as four tissue samples for 238Pu, 239Pu, 241Am and 241Pu. The number of QC urine samples submitted during the report period represented 1.3% of the total samples submitted. In addition to the samples provided by IDP, GEL was also required to conduct their own QC program, and submit the results of analyses to IDP. About 33% of the analyses processed by GEL during the third year of this contract were quality control samples. GEL tested the performance of 21 radioisotopes, all of which met or exceeded the specifications in the Statement of Work within statistical uncertainty (Table 4).

  17. Characterization and source term assessments of radioactive particles from Marshall Islands using non-destructive analytical techniques

    NASA Astrophysics Data System (ADS)

    Jernström, J.; Eriksson, M.; Simon, R.; Tamborini, G.; Bildstein, O.; Marquez, R. Carlos; Kehl, S. R.; Hamilton, T. F.; Ranebo, Y.; Betti, M.

    2006-08-01

    Six plutonium-containing particles stemming from Runit Island soil (Marshall Islands) were characterized by non-destructive analytical and microanalytical methods. Composition and elemental distribution in the particles were studied with synchrotron radiation based micro X-ray fluorescence spectrometry. Scanning electron microscope equipped with energy dispersive X-ray detector and with wavelength dispersive system as well as a secondary ion mass spectrometer were used to examine particle surfaces. Based on the elemental composition the particles were divided into two groups: particles with pure Pu matrix, and particles where the plutonium is included in Si/O-rich matrix being more heterogenously distributed. All of the particles were identified as nuclear fuel fragments of exploded weapon components. As containing plutonium with low 240Pu/ 239Pu atomic ratio, less than 0.065, which corresponds to weapons-grade plutonium or a detonation with low fission yield, the particles were identified to originate from the safety test and low-yield tests conducted in the history of Runit Island. The Si/O-rich particles contained traces of 137Cs ( 239 + 240 Pu/ 137Cs activity ratio higher than 2500), which indicated that a minor fission process occurred during the explosion. The average 241Am/ 239Pu atomic ratio in the six particles was 3.7 × 10 - 3 ± 0.2 × 10 - 3 (February 2006), which indicated that plutonium in the different particles had similar age.

  18. ANALYSIS AND EXAMINATION OF MOX FUEL FROM NONPROLIFERATION PROGRAMS

    SciTech Connect

    McCoy, Kevin; Machut, Dr McLean; Morris, Robert Noel; Blanpain, Patrick; Hemrick, James Gordon

    2013-01-01

    The U.S. Department of Energy has decided to dispose of a portion of the nation s surplus plutonium by reconstituting it into mixed oxide (MOX) fuel and irradiating it in commercial power reactors. Four lead assemblies were manufactured and irradiated to a maximum fuel rod burnup of 47.3 MWd/kg heavy metal. This was the first commercial irradiation of MOX fuel with a 240Pu/239Pu ratio of less than 0.10. Five fuel rods with varying burnups and plutonium contents were selected from one of the assemblies and shipped to Oak Ridge National Laboratory for hot cell examination. The performance of the rods was analyzed with AREVA s next-generation GALILEO code. The results of the analysis confirmed that the fuel rods had performed safely and predictably, and that GALILEO is applicable to MOX fuel with a low 240Pu/239Pu ratio as well as to standard MOX. The results are presented and compared to the GALILEO database. In addition, the fuel cladding was tested to confirm that traces of gallium in the fuel pellets had not affected the mechanical properties of the cladding. The irradiated cladding was found to remain ductile at both room temperature and 350 C for both the axial and circumferential directions.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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

  1. MATERIAL PROPERTIES OF PLUTONIUM-BEARING OXIDES STORED IN STAINLESS STEEL CONTAINERS

    SciTech Connect

    Kessinger, G.; Almond, P.; Bridges, N.; Bronikowski, M.; Crowder, M.; Duffey, J.; Livingston, R.; Mcelwee, M.; Missimer, D.; Scogin, J.; Summer, M.; Jurgensen, A.

    2010-02-01

    The destructive examination (DE) of 3013 containers after storage is part of the Surveillance and Monitoring Program based on the Department of Energy's standard for long-term storage of Pu (DOE-STD-3013). The stored, Pu-bearing materials may contain alkali halide contamination that varies from trace amounts of salt to about 50 weight percent, with smaller fractions of other compounds and oxides. These materials were characterized prior to packaging, and surveillance characterizations are conducted to determine the behavior of the materials during long term storage. The surveillance characterization results are generally in agreement with the pre-surveillance data. The predominant phases identified by X-ray diffraction are in agreement with the expected phase assemblages of the as-received materials. The measured densities are in reasonable agreement with the expected densities of materials containing the fraction of salts and actinide oxide specified by the pre-surveillance data. The radiochemical results are generally in good agreement with the pre-surveillance data for mixtures containing 'weapons grade' Pu (nominally 94% {sup 239}Pu and 6% {sup 240}Pu); however, the ICP-MS results from the present investigation generally produce lower concentrations of Pu than the pre-surveillance analyses. For mixtures containing 'fuel grade' Pu (nominally 81-93% {sup 239}Pu and 7-19% {sup 240}Pu), the ICP-MS results from the present investigation appear to be in better agreement with the pre-surveillance data than the radiochemistry results.

  2. Plutonium Isotopes in the Terrestrial Environment at the Savannah River Site, USA. A Long-Term Study

    DOE PAGESBeta

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

    2015-01-16

    This work presents the findings of a long term plutonium study at Savannah River Site (SRS) conducted between 2003 and 2013. Terrestrial environmental samples were obtained at Savannah River National Laboratory (SRNL) in A-area. Plutonium content and isotopic abundances were measured over this time period by alpha spectrometry and three stage thermal ionization mass spectrometry (3STIMS). Here we detail the complete 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 238Pu/239+240Pu activity ratios attributed to SRS are abovemore » atmospheric global fallout ranges. The 240Pu/239Pu atom ratios are reasonably consistent from year to year and are lower than fallout, while the 242Pu/239Pu atom ratios are higher than fallout values. Overall, the plutonium signatures obtained in this study reflect a mixture of weapons-grade, higher burn-up, and fallout material. This study provides a blue print for long term low level monitoring of plutonium in the environment.« less

  3. Polonium, uranium and plutonium radionuclides in aquatic and land ecosystem of Poland.

    PubMed

    Skwarzec, Bogdan; Strumińska-Parulska, Dagmara I; Boryło, Alicja; Kabat, Krzysztof

    2012-01-01

    This article presents the results of study about distribution, inflow and accumulation of polonium, uranium and plutonium in aquatic and land environment of Poland and the southern Baltic Sea. Radionuclides of (210)Po, (234)U and (238)U as well as (239+240)Pu and (241)Pu are strongly accumulated in Baltic organisms and plants and transferred through the trophic chain. The values of bioconcentration factor (BCF) in Baltic plants and animals are higher for polonium and plutonium in comparison with uranium. The principal source of radionuclides in the southern Baltic Sea is their inflow with rivers. Total annual runoff of polonium, uranium and plutonium from the Vistula and the Odra as well as the Pomeranian rivers were calculated at 95 GBq of (210)Po, 750 GBq of (234+238)U and 160 MBq of (238+239+240)Pu. Seasonal and spatial variability of (210)Po, (238)U and (239+240)Pu levels in the Vistula and the Odra drainage basins were assessed by application of neural-network based classification, especially cluster analysis (CA), principal component analysis (PCA) and self-organizing maps (SOM). The result for the Vistula river indicated correlation between polonium and plutonium as well as polonium and uranium. In the Odra drainage basin, the biggest differences were observed in the case of (238)U. To assess if there are statistically significant differences in mean concentration values of (210)Po, (238)U and (239+240)Pu for the Vistula and the Odra rivers drainage basins were obtained by used of the non-parametric tests. Comparing to the Vistula catchment area, statistically differences concentration of (210)Po and (239+240)Pu in all year was observed for river samples collected on the Odra drainage basin. PMID:22320701

  4. Initial Report for the Aquifer Background Study: Summary of Uranium and Plutonium Data from INEEL Groundwater Samples

    SciTech Connect

    Robert C. Roback; Don L. Koeppen

    2003-06-01

    As part of the “Aquifer Background Study,” Los Alamos National Laboratory (LANL) under contract with the Idaho National Engineering and Environmental Laboratory (INEEL) has undertaken a study to determine uranium and plutonium abundances and isotopic composition in groundwater samples collected at the INEEL. To date, four samples have been analyzed for uranium and plutonium and an additional nine samples have been analyzed for uranium. It is expected that several more samples will be analyzed for this study. This report summarizes the results from this initial set of samples. Of the 13 samples analyzed for uranium, four samples have 238U/235U ratios that differ from the natural value of 137.88. These four samples and two additional samples also contain 236U at 3-sigma level above detection limits. The presence of 236U and the non-natural 238U/235U ratios unequivocally indicate the presence of anthropic uranium in four of the samples. A small component of anthropic uranium is also present in two additional samples with positive 236U detection but natural 238U/235U isotope ratios. Two of the samples with anthropic uranium, as well as two samples with no detectable anthropic uranium were analyzed for plutonium. No plutonium was detected in these four samples at detection limits of approximately 5E7 239Pu atoms for three of the samples and approximately 1E8 239Pu atoms for the forth sample. These detection limits correspond to (239+240)Pu activity ratios (assuming a 240Pu/239Pu atom ratio of 0.18) of 0.002 and 0.004 pCi/L respectively.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  7. Plutonium gamma-ray measurements for mutual reciprocal inspections of dismantled nuclear weapons

    SciTech Connect

    Koenig, Z.M.; Carlson, J.B.; Clark, D.; Gosnell, T.B.

    1995-07-01

    The O`Leary-Mikhailov agreement of March 1994 stated that the U.S. and the Russian Federation would engage in mutual reciprocal inspections (MRI) of fissile materials removed from dismantled nuclear weapons. It was decided to begin with the plutonium (Pu) removed from dismantled weapons and held in storage containers. Later discussions between U.S. and Russian technical experts led to the conclusion that, to achieve the O`Leary-Mikhailov objectives, Pu MRI would need to determine that the material in the containers has properties consistent with a nuclear-weapon component. Such a property is a {sup 240}Pu/{sup 239}Pu ratio consistent with weapons-grade material. One of the candidate inspection techniques under consideration for Pu MRI is to use a narrow region (630-670 keV) of the plutonium gamma-ray spectrum, taken with a high-purity germanium detector, to determine that it is weapons-grade plutonium as well as to estimate the minimum mass necessary to produce the observed gamma-ray intensity. We developed software (the Pu600 code) for instrument control and analysis especially for this purpose. In November 1994, U.S. and Russian scientists met at the Lawrence Livermore National Laboratory for joint experiments to evaluate candidate Pu MRI inspection techniques. In one of these experiments, gamma-ray intensities were measured from three unclassified weapons-grade plutonium source standards and one reactor-grade standard (21% {sup 240}pu). Using our software, we determined the {sup 240}Pu/{sup 239}Pu ratio of these standards to accuracies within {+-}10%, which is adequate for Pu MRI. The minimum mass estimates varied, as expected, directly with the exposed surface area of the standards.

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

    SciTech Connect

    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 into multiple containers. A single item from that batch is then selected for both neutron and calorimetric measurements; all remaining items undergo a neutron measurement only. Using the technique mentioned above, the 'true' {alpha} value determined from the first (calorimeter and passive neutron measured) item is used in multiplicity analysis for all other items in the batch. The justification for using this {alpha} value in subsequent calculations is the assumption that the chemical composition and isotopic distribution of all batch items are the same, giving a constant ({alpha},n):spontaneous fission ratio. This analysis method has been successfully applied to the KIS Facility, significantly improving measurement uncertainties and reducing processing times for numerous items. Comprehensive plans were later developed to extend the use of this method to other applications, including the K-Area Shuffler and the H-Area Pu-Blending Project. While only the feasibility study for the Shuffler has been completed, implementation of the method in the H-Area Pu-Blending Project is currently in progress and has been successfully applied to multiple items. This report serves to document the details of this method in order to serve as a reference for future applications. Also contained herein are specific examples of the application of known-{alpha} multiplicity analysis.

  9. Pu and 137Cs in the Yangtze River estuary sediments: distribution and source identification.

    PubMed

    Liu, Zhiyong; Zheng, Jian; Pan, Shaoming; Dong, Wei; Yamada, Masatoshi; Aono, Tatsuo; Guo, Qiuju

    2011-03-01

    Pu isotopes and (137)Cs were analyzed using sector field ICP-MS and γ spectrometry, respectively, in surface sediment and core sediment samples from the Yangtze River estuary. (239+240)Pu activity and (240)Pu/(239)Pu atom ratios (>0.18) shows a generally increasing trend from land to sea and from north to south in the estuary. This spatial distribution pattern indicates that the Pacific Proving Grounds (PPG) source Pu transported by ocean currents was intensively scavenged into the suspended sediment under favorable conditions, and mixed with riverine sediment as the water circulated in the estuary. This process is the main control for the distribution of Pu in the estuary. Moreover, Pu is also an important indicator for monitoring the changes of environmental radioactivity in the estuary as the river basin is currently the site of extensive human activities and the sea level is rising because of global climate changes. For core sediment samples the maximum peak of (239+240)Pu activity was observed at a depth of 172 cm. The sedimentation rate was estimated on the basis of the Pu maximum deposition peak in 1963-1964 to be 4.1 cm/a. The contributions of the PPG close-in fallout Pu (44%) and the riverine Pu (45%) in Yangtze River estuary sediments are equally important for the total Pu deposition in the estuary, which challenges the current hypothesis that the riverine Pu input was the major source of Pu budget in this area. PMID:21306104

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

    NASA Astrophysics Data System (ADS)

    De Cesare, M.; Tims, S. G.; Fifield, L. K.

    2015-04-01

    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.

  11. Concordant plutonium-241-americium-241 dating of environmental samples: results from forest fire ash

    SciTech Connect

    Goldstein, Steven J; Oldham, Warren J; Murrell, Michael T; Katzman, Danny

    2010-12-07

    We have measured the Pu, {sup 237}Np, {sup 241}Am, and {sup 151}Sm isotopic systematics for a set of forest fire ash samples from various locations in the western U.S. including Montana, Wyoming, Idaho, and New Mexico. The goal of this study is to develop a concordant {sup 241}Pu (t{sub 1/2} = 14.4 y)-{sup 241}Am dating method for environmental collections. Environmental samples often contain mixtures of components including global fallout. There are a number of approaches for subtracting the global fallout component for such samples. One approach is to use {sup 242}/{sup 239}Pu as a normalizing isotope ratio in a three-isotope plot, where this ratio for the nonglobal fallout component can be estimated or assumed to be small. This study investigates a new, complementary method of normalization using the long-lived fission product, {sup 151}Sm (t{sub 1/2} = 90 y). We find that forest fire ash concentrates actinides and fission products with {approx}1E10 atoms {sup 239}Pu/g and {approx}1E8 atoms {sup 151}Sm/g, allowing us to measure these nuclides by mass spectrometric (MIC-TIMS) and radiometric (liquid scintillation counting) methods. The forest fire ash samples are characterized by a western U.S. regional isotopic signature representing varying mixtures of global fallout with a local component from atmospheric testing of nuclear weapons at the Nevada Test Site (NTS). Our results also show that {sup 151}Sm is well correlated with the Pu nuclides in the forest fire ash, suggesting that these nuclides have similar geochemical behavior in the environment. Results of this correlation indicate that the {sup 151}Sm/{sup 239}Pu atom ratio for global fallout is {approx}0.164, in agreement with an independent estimate of 0.165 based on {sup 137}Cs fission yields for atmospheric weapons tests at the NTS. {sup 241}Pu-{sup 241}Am dating of the non-global fallout component in the forest fire ash samples yield ages in the late 1950's-early 1960's, consistent with a peak in NTS

  12. Source-dependent and source-independent controls on plutonium oxidation state and colloid associations in groundwater.

    PubMed

    Buesseler, Ken O; Kaplan, Daniel I; Dai, Minhan; Pike, Steven

    2009-03-01

    Plutonium (Pu) was characterized for its isotopic composition, oxidation states, and association with colloids in groundwater samples near disposal basins in F-Area of the Savannah River Site and compared to similar samples collected six years earlier. Two sources of Pu were identified, the disposal basins, which contained a 24Pu/l39Pu isotopic signature consistent with weapons grade Pu, and 244Cm, a cocontaminant that is a progenitor radionuclide of 24Pu. 24Pu that originated primarily from 244Cm tended to be appreciably more oxidized (Pu(V/VI)), less associated with colloids (approximately 1 kDa - 0.2 microm), and more mobile than 239Pu, as suggested by our prior studies at this site. This is not evidence of isotope fractionation but rather "source-dependent" controls on 240Pu speciation which are processes that are not at equilibrium, i.e., processes that appear kinetically hindered. There were also "source-independent" controls on 239Pu speciation, which are those processes that follow thermodynamic equilibrium with their surroundings. For example, a groundwater pH increase in one well from 4.1 in 1998 to 6.1 in 2004 resulted in an order of magnitude decrease in groundwater 239Pu concentrations. Similarly, the fraction of 239Pu in the reduced Pu(III/IV) and colloidal forms increased systematically with decreases in redox condition in 2004 vs 1998. This research demonstrates the importance of source-dependent and source-independent controls on Pu speciation which would impact Pu mobility during changes in hydrological, chemical, or biological conditions on both seasonal and decadal time scales, and over short spatial scales. This implies more dynamic shifts in Pu speciation, colloids association, and transport in groundwater than commonly believed. PMID:19350898

  13. A compact gas-filled avalanche counter for DANCE

    DOE PAGESBeta

    Wu, C. Y.; Chyzh, A.; Kwan, E.; Henderson, R. A.; Gostic, J. M.; Carter, D.; Bredeweg, T. A.; Couture, A.; Jandel, M.; Ullmann, J. L.

    2012-08-04

    A compact gas-filled avalanche counter for the detection of fission fragments was developed for a highly segmented 4π γ-ray calorimeter, namely the Detector for Advanced Neutron Capture Experiments located at the Lujan Center of the Los Alamos Neutron Science Center. It has been used successfully for experiments with 235U, 238Pu,239Pu, and 241Pu isotopes to provide a unique signature to differentiate the fission from the competing neutron-capture reaction channel. We also used it to study the spontaneous fission in 252Cf. The design and performance of this avalanche counter for targets with extreme α-decay rate up to ~2.4×108/s are described.

  14. Precision spectroscopy with reactor antineutrinos

    NASA Astrophysics Data System (ADS)

    Huber, Patrick; Schwetz, Thomas

    2004-09-01

    In this work we present an accurate parameterization of the antineutrino flux produced by the isotopes 235U, 239Pu, and 241Pu in nuclear reactors. We determine the coefficients of this parameterization, as well as their covariance matrix, by performing a fit to spectra inferred from experimentally measured beta spectra. Subsequently we show that flux shape uncertainties play only a minor role in the KamLAND experiment, however, we find that future reactor-neutrino experiments to measure the mixing angle θ13 are sensitive to the fine details of the reactor-neutrino spectra. Finally, we investigate the possibility to determine the isotopic composition in nuclear reactors through an antineutrino measurement. We find that with a three month exposure of a 1ton detector the isotope fractions and the thermal reactor power can be determined at a few percent accuracy, which may open the possibility of an application for safeguard or nonproliferation objectives.

  15. National Low-Level Waste Management Program Radionuclide Report Series

    SciTech Connect

    J.P. Adams; M.L. Carboneau; W.E. Allred

    1999-02-01

    The National Low Level Waste Management Program at the Idaho National Engineering and Environmental Laboratory has published a report containing key information about selected radionuclides that are most likely to contribute significantly to the radiation exposures estimated from a performance assessment of a low-level radioactive waste (LLW) disposal facility. The information includes physical and chemical characteristics, production means, waste forms, behavior of the radionuclide in soils, plants, groundwater, and air, and biological effects in animals and humans. The radionuclides included in this study comprise all of the nuclides specifically listed in 10CFR61.55, Tables 1 and 2, 3 H, 14 C, 59 Ni, 60 Co, 63 Ni, 90 Sr, 94 Nb, 99 Tc, 129 I, 137 Cs, 241 Pu, and 242 Cm. Other key radionuclides addressed in the report include 237 Np, 238 U, 239 Pu, and 241 Am. This paper summarizes key information contained within this report.

  16. National Low-Level Waste Management Program Radionuclide Report Series

    SciTech Connect

    Adams, James Paul; Carboneau, Michael Leonard; Allred, William Edgar

    1999-03-01

    The National Low Level Waste Management Program at the Idaho National Engineering and Environmental Laboratory has published a report containing key information about selected radionuclides that are most likely to contribute significantly to the radiation exposures estimated from a performance assessment of a low-level radioactive waste (LLW) disposal facility. The information includes physical and chemical characteristics, production means, waste forms, behavior of the radionuclide in soils, plants, groundwater, and air, and biological effects in animals and humans. The radionuclides included in this study comprise all of the nuclides specifically listed in 10CFR61.55, Tables 1 and 2, 3 H, 14 C, 59 Ni, 60 Co, 63 Ni, 90 Sr, 94 Nb, 99 Tc, 129 I, 137 Cs, 241 Pu, and 242 Cm. Other key radionuclides addressed in the report include 237 Np, 238 U, 239 Pu, and 241 Am. This paper summarizes key information contained within this report.

  17. Americium

    NASA Astrophysics Data System (ADS)

    Runde, Wolfgang H.; Schulz, Wallace W.

    Americium, element 95, was discovered in 1944-45 by Seaborg et al. (1950) at the Metallurgical Laboratory of the University of Chicago as a product of the irradiation of plutonium with neutrons: 239{Pu}( n,γ )^{240} Put( n,γ )^{241} Pu → - β ^-}^{241}{Am} This reaction is still the best method for the production of pure 241Am. In post-World War II work at the University of Chicago, Cunningham isolated Am(OH)3 and measured the first absorption spectrum of the Am3+ aquo ion (Cunningham, 1948). By the 1950s, the major center for americium chemistry research in the world was at Los Alamos. Since the 1970s, the majority of publications on americium have come from researchers in the former USSR and West Germany. Extensive reviews of americium chemistry can be found in Freeman and Keller (1985), Gmelin (1979), Penneman and Asprey (1955), and Schulz (1976).

  18. Application of Neutron-Absorbing Structural-Amorphous Metal (SAM) Coatings for Spent Nuclear Fuel (SNF) Container to Enhance Criticality Safety Controls

    SciTech Connect

    Choi, Jor-Shan; Lee, Chuck; Farmer, Joseph; Day, Dan; Wall, Mark; Saw, Cheng; Boussoufi, Moe; Liu, Ben; Egbert, Harold; Branagan, Dan; D'Amato, Andy

    2007-07-01

    Spent nuclear fuel contains fissionable materials ({sup 235}U, {sup 239}Pu, {sup 241}Pu, etc.). To prevent nuclear criticality in spent fuel storage, transportation, and during disposal, neutron-absorbing materials (or neutron poisons, such as borated stainless steel, Boral{sup TM}, Metamic{sup TM}, Ni-Gd, and others) would have to be applied. The success in demonstrating that the High-Performance Corrosion- Resistant Material (HPCRM){sup [1]} can be thermally applied as coating onto base metal to provide for corrosion resistance for many naval applications raises the interest in applying the HPCRM to USDOE/OCRWM spent fuel management program. The fact that the HPCRM relies on the high content of boron to make the material amorphous - an essential property for corrosion resistance - and that the boron has to be homogeneously distributed in the HPCRM qualify the material to be a neutron poison. (authors)

  19. Analysis of spent fuel assay with a lead slowing down spectrometer

    SciTech Connect

    Gavron, Victor I; Smith, L Eric; Ressler, Jennifer J

    2008-01-01

    Assay of fissile materials in spent fuel that are produced or depleted during the operation of a reactor, is of paramount importance to nuclear materials accounting, verification of the reactor operation history, as well as for criticality considerations for storage. In order to prevent future proliferation following the spread of nuclear energy, we must develop accurate methods to assay large quantities of nuclear fuels. We analyze the potential of using a Lead Slowing Down Spectrometer for assaying spent fuel. We conclude that it is possible to design a system that will provide around 1% statistical precision in the determination of the {sup 239}Pu, {sup 241}Pu and {sup 235}U concentrations in a PWR spent-fuel assembly, for intermediate-to-high burnup levels, using commercial neutron sources, and a system of {sup 238}U threshold fission detectors. Pending further analysis of systematic errors, it is possible that missing pins can be detected, as can asymmetry in the fuel bundle.

  20. Analysis of spent fuel assay with a lead slowing down spectrometer

    SciTech Connect

    Gavron, Victor I; Smith, L. Eric; Ressler, Jennifer J

    2010-10-29

    Assay of fissile materials in spent fuel that are produced or depleted during the operation of a reactor, is of paramount importance to nuclear materials accounting, verification of the reactor operation history, as well as for criticality considerations for storage. In order to prevent future proliferation following the spread of nuclear energy, we must develop accurate methods to assay large quantities of nuclear fuels. We analyze the potential of using a Lead Slowing Down Spectrometer for assaying spent fuel. We conclude that it is possible to design a system that will provide around 1% statistical precision in the determination of the {sup 239}Pu, {sup 241}Pu and {sup 235}U concentrations in a PWR spent-fuel assembly, for intermediate-to-high burnup levels, using commercial neutron sources, and a system of {sup 238}U threshold fission detectors. Pending further analysis of systematic errors, it is possible that missing pins can be detected, as can asymmetry in the fuel bundle.

  1. Spectrum tailoring of the neutron energy spectrum in the context of delayed neutron detection

    SciTech Connect

    Koehler, William E; Tobin, Steve J; Sandoval, Nathan P; Fensin, Mike L

    2010-01-01

    For the purpose of measuring plutonium mass in spent fuel, a delayed neutron instrument is of particular interest since, if properly designed, the delayed neutron signal from {sup 235}U is significantly stronger than the signature from {sup 239}Pu or {sup 241}Pu. A key factor in properly designing a delayed neutron instrument is to minimize the fission of {sup 238}U. This minimization is achieved by keeping the interrogating neutron spectrum below {approx} 1 MeV. In the context of spent fuel measurements it is desirable to use a 14 MeV (deuterium and tritium) neutron generator for economic reasons. Spectrum tailoring is the term used to describe the inclusion of material between the 14 MeV neutrons and the interrogated object that lower the neutron energy through nuclear reactions and moderation. This report quantifies the utility of different material combination for spectrum tailoring.

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

    PubMed

    Xu, Yihong; Qiao, Jixin; Pan, Shaoming; Hou, Xiaolin; Roos, Per; Cao, Liguo

    2015-04-01

    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. PMID:25544336

  3. Using radiosilver and plutonium isotopes to trace the dispersion of contaminated sediment in Fukushima coastal catchments

    NASA Astrophysics Data System (ADS)

    Evrard, O.; Ayrault, S.; Pointurier, F.; Onda, Y.; Laceby, J. P.; Lepage, H.; Chartin, C.; Cirella, M.; Pottin, A. C.; Hubert, A.; Lefèvre, I.

    2015-12-01

    The Fukushima Dai-ichi nuclear power plant (FDNPP) accident in March 2011 resulted in a 3000-km² radioactive pollution plume consisting predominantly of radiocesium (137Cs and 134Cs). This plume is drained by several rivers to the Pacific Ocean after flowing through less contaminated, but densely inhabited coastal plains. As the redistribution of radionuclide contaminated sediment could expose the local population to higher radiation rates, novel fingerprinting methods were developed to trace the downstream dispersion of contaminated sediment. First, the heterogeneous deposition of metastable silver-110 (110mAg) across these coastal catchments was used to investigate sediment migration. In particular, the 110mAg/137Cs activity ratio was measured in soils and river sediment demonstrating the occurrence of a seasonal cycle of soil erosion during typhoons and spring snowmelt in 2011 and 2012. However, due to the rapid decay of 110mAg (half-life of 250 days), alternative methods were required to continue tracking sediment from 2013 onwards. One promising method includes the analyses of plutonium isotopes to further understand sediment migration in the Fukushima region. For example, 241Pu/239Pu atom ratios measured in sediment collected in Fukushima coastal rivers shortly after the accident were shown to be significantly higher (0.0017 - 0.0884) than corresponding values attributed to the global fallout (0.00113 ± 0.00008). Additional analyses were conducted on sediment sampled in 2013 and 2014 after the start of decontamination works. These analyses show that the 241Pu/239Pu atom ratios decreased towards the global fallout values in rivers draining decontaminated paddy fields, demonstrating the effectiveness of remediation works.

  4. Improved predictions of reactor antineutrino spectra

    SciTech Connect

    Mueller, Th. A.; Lhuillier, D.; Letourneau, A.

    2011-05-15

    Precise predictions of the antineutrino spectra emitted by nuclear reactors is a key ingredient in measurements of reactor neutrino oscillations as well as in recent applications to the surveillance of power plants in the context of nonproliferation of nuclear weapons. We report new calculations including the latest information from nuclear databases and a detailed error budget. The first part of this work is the so-called ab initio approach where the total antineutrino spectrum is built from the sum of all {beta} branches of all fission products predicted by an evolution code. Systematic effects and missing information in nuclear databases lead to final relative uncertainties in the 10-20% range. A prediction of the antineutrino spectrum associated with the fission of {sup 238}U is given based on this ab initio method. For the dominant isotopes we developed a more accurate approach combining information from nuclear databases and reference electron spectra associated with the fission of {sup 235}U, {sup 239}Pu, and {sup 241}Pu, measured at Institut Laue-Langevin (ILL) in the 1980s. We show how the anchor point of the measured total {beta} spectra can be used to suppress the uncertainty in nuclear databases while taking advantage of all the information they contain. We provide new reference antineutrino spectra for {sup 235}U, {sup 239}Pu, and {sup 241}Pu isotopes in the 2-8 MeV range. While the shapes of the spectra and their uncertainties are comparable to those of the previous analysis of the ILL data, the normalization is shifted by about +3% on average. In the perspective of the reanalysis of past experiments and direct use of these results by upcoming oscillation experiments, we discuss the various sources of errors and their correlations as well as the corrections induced by off-equilibrium effects.

  5. Measurements of fission yields in the heavy region at the recoil ass spectrometer lohengrin

    NASA Astrophysics Data System (ADS)

    Bail, A.; Serot, O.; Mathieu, L.; Litaize, O.; Materna, T.; Köster, U.; Faust, H.; Letourneau, A.; Panebianco, S.; Dupont, E.; Michel-Sendis, F.

    2009-10-01

    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 in the light mass region. Almost all fission yields of isotopes from Th to Cf have been measured at Lohengrin with this method. It has 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 γ spectrometry. The results are presented in this paper.

  6. Multi-collector Isotope Ratio Mass Spectrometer -- Operational Performance Report

    SciTech Connect

    Appelhans, Anthony D; Olson, John E; Watrous, Matthew G; Ward, Michael B.; Dahl, David A.

    2010-12-01

    This report describes the operational testing of a new magnetic sector mass spectrometer that utilizes seven full-sized discrete dynode electron multipliers operating simultaneously. The instrument includes a newly developed ion dispersion lens that enables the mass dispersed individual isotope beams to be separated sufficiently to allow a full-sized discrete dynode pulse counting multiplier to be used to measure each isotope beam. The performance of the instrument was measured using SRM 996 (244Pu spike) at loadings of 2.4 and 12 fg on resin beads and with SRM 4350B Columbia River Sediment samples. The measured limit of detection (3s) for 240Pu was 3.4 attograms for SRM 996. The limit of quantitation (LOQ), defined as 10 s, was 11.2 attograms. The measured concentration of 239Pu in the CRS standard was 152 ± 6 fg/g.

  7. Advanced alpha spectrum analysis based on the fitting and covariance analysis of dependent variables

    NASA Astrophysics Data System (ADS)

    Ihantola, S.; Pelikan, A.; Pöllänen, R.; Toivonen, H.

    2011-11-01

    The correct handling of statistical uncertainties is crucial especially when unfolding alpha spectra that contain a low number of counts or overlapping peaks from different nuclides. For this purpose, we have developed a new spectrum analysis software package called ADAM, which performs a full covariance calculus for alpha-particle emitting radionuclides. By analyzing a large number of simulated and measured spectra, the program was proved to give unbiased peak areas and statistically correct uncertainty limits. This applies regardless of the peak areas and the number of unknown parameters during the fitting. In addition, ADAM performs reliable deconvolution for multiplets, which opens the way for the determination of isotope ratios, such as 239Pu/240Pu.

  8. Concepts for Alpha Coincidence Detection

    SciTech Connect

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

    2015-03-01

    The effectiveness of conventional measurement techniques for environmental monitoring is limited by background and other interferences. We are exploring a new measurement approach involving the detection of α particles in coincidence with conversion electrons as a means to simultaneously assay environmental samples for actinides without chemical separation. The initial target isotopes studied in this work are 238Pu, 239Pu, 240Pu and 241Am. We explore various aspects of the design, such as impact of the mounting of the source material, resolution requirements and impact of a background on isotopic uncertainties. We conclude that a dual gas proportional counter and a dual-sided, large-area silicon detector could provide similar performance for the measurement scenario examined.

  9. SUBSURFACE MOBILE PLUTONIUM SPECIATION: SAMPLING ARTIFACTS FOR GROUNDWATER COLLOIDS

    SciTech Connect

    Kaplan, D.; Buesseler, K.

    2010-06-29

    A recent review found several conflicting conclusions regarding colloid-facilitated transport of radionuclides in groundwater and noted that colloids can both facilitate and retard transport. Given these contrasting conclusions and the profound implications even trace concentrations of plutonium (Pu) have on the calculated risk posed to human health, it is important that the methodology used to sample groundwater colloids be free of artifacts. The objective of this study was: (1) to conduct a field study and measure Pu speciation, ({sup 239}Pu and {sup 240}Pu for reduced-Pu{sub aq}, oxidized-Pu{sub aq}, reduced-Pu{sub colloid}, and oxidized-Pu{sub colloid}), in a Savannah River Site (SRS) aquifer along a pH gradient in F-Area, (2) to determine the impact of pumping rate on Pu concentration, Pu speciation, and Pu isotopic ratios, (3) determine the impact of delayed sample processing (as opposed to processing directly from the well).

  10. Applications of Event-by-Event Fission Modeling with FREYA

    SciTech Connect

    Vogt, R; Randrup, J

    2011-09-16

    The recently developed code FREYA (Fission Reaction Event Yield Algorithm) generates large samples of complete fission events, consisting of two receding product nuclei as well as a number of neutrons and photons, all with complete kinematic information. Thus it is possible to calculate arbitrary correlation observables whose behavior may provide unique insight into the fission process. We first discuss the present status of FREYA, which has now been extended to include spontaneous fission. Concentrating on {sup 239}Pu(n{sub th},f), {sup 240}Pu(sf) and {sup 252}Cf(sf), we discuss the neutron multiplicity correlations, the dependence of the neutron energy spectrum on the neutron multiplicity, and the relationship between the fragment kinetic energy and the number of neutrons and their energies. We also suggest novel fission observables that could be measured with modern detectors.

  11. Atmospheric transport of radionuclides emitted due to wildfires near the Chernobyl Nuclear Power Plant in 2015

    NASA Astrophysics Data System (ADS)

    Evangeliou, Nikolaos; Zibtsev, Sergey; Myroniuk, Viktor; Zhurba, Marina; Hamburger, Thomas; Stohl, Andreas; Balkanski, Yves; Paugam, Ronan; Mousseau, Timothy A.; Møller, Anders P.; Kireev, Sergey I.

    2016-04-01

    In 2015, two major fires in the Chernobyl Exclusion Zone (CEZ) have caused concerns about the secondary radioactive contamination that might have spread over Europe. The total active burned area was estimated to be about 15,000 hectares, of which 9000 hectares burned in April and 6000 hectares in August. The present paper aims to assess, for the first time, the transport and impact of these fires over Europe. For this reason, direct observations of the prevailing deposition levels of 137Cs and 90Sr, 238Pu, 239Pu, 240Pu and 241Am in the CEZ were processed together with burned area estimates. Based on literature reports, we made the conservative assumption that 20% of the deposited labile radionuclides 137Cs and 90Sr, and 10% of the more refractory 238Pu, 239Pu, 240Pu and 241Am, were resuspended by the fires. We estimate that about 10.9 TBq of 137Cs, 1.5 TBq of 90Sr, 7.8 GBq of 238Pu, 6.3 GBq of 239Pu, 9.4 GBq of 240Pu and 29.7 GBq of 241Am were released from both fire events. These releases could be classified as of "Level 3" on the relative INES (International Nuclear Events Scale) scale, which corresponds to a serious incident, in which non-lethal deterministic effects are expected from radiation. To simulate the dispersion of the resuspended radionuclides in the atmosphere and their deposition onto the terrestrial environment, we used a Lagrangian dispersion model. Spring fires redistributed radionuclides over the northern and eastern parts of Europe, while the summer fires also affected Central and Southern Europe. The more labile elements escaped more easily from the CEZ and then reached and deposited in areas far from the source, whereas the larger refractory particles were removed more efficiently from the atmosphere and thus did mainly affect the CEZ and its vicinity. For the spring 2015 fires, we estimate that about 80% of 137Cs and 90Sr and about 69% of 238Pu, 239Pu, 240Pu and 241Am were deposited over areas outside the CEZ. 93% of the labile and 97% of

  12. The design and implementation of the AVNG measurement system

    SciTech Connect

    Macarthur, Duncan W; Thron, Jonathan; Razinkov, Sergey; Livke, Alexander; Kondratov, Sergey

    2010-01-01

    An attribute measurement system (AMS) measures a number of unclassified attributes of potentially classified material. By displaying these unclassified results only as red or green lights, the AMS protects potentially classified information while still generating confidence in the measurement result. The AVNG that we describe is an AMS built by RFNC-VNIIEF in Sarov, Russia. The AVNG detects neutron and gamma radiation signatures and displays the three unclassified attributes of 'plutonium presence,' 'plutonium mass >2 kg,' and 'plutonium isotopic ratio ({sup 240}Pu to {sup 239}Pu) < 0.1.' In this presentation, we will describe the design of the AVNG neutron and gamma detector subsystems, as well as the design of the entire AMS incorporating these detectors. We will also describe the construction of the AVNG and the final design that was demonstrated in June 2009.

  13. Recent advances in modeling fission cross sections over intermediate structures

    SciTech Connect

    Bouland, Olivier; Lynn, J. Eric; Talou, Patrick

    2009-01-01

    More accurate fission cross section calculations in presence of underlying intermediate structure are strongly desired. This paper recalls the common approximations used below the fission threshold and quantifies their impact. In particular, an exact expanded R-matrix Monte Carlo calculation of the intermediate structure, deeply mixed with the fluctuations of the class-I and II decay amplitudes, is shown. This paper also insists on the microscopic structure of the level densities as a function of the nucleus deformation and show preliminary neutron induced fission cross section calculations for {sup 239}Pu and {sup 240}Pu using newly calculated combinatorial level densities. Comparisons with recent evaluated and measured fission cross sections are made.

  14. LITERATURE REVIEW ON MAXIMUM LOADING OF RADIONUCLIDES ON CRYSTALLINE SILICOTITANATE

    SciTech Connect

    Adu-Wusu, K.; Pennebaker, F.

    2010-10-13

    Plans are underway to use small column ion exchange (SCIX) units installed in high-level waste tanks to remove Cs-137 from highly alkaline salt solutions at Savannah River Site. The ion exchange material slated for the SCIX project is engineered or granular crystalline silicotitanate (CST). Information on the maximum loading of radionuclides on CST is needed by Savannah River Remediation for safety evaluations. A literature review has been conducted that culminated in the estimation of the maximum loading of all but one of the radionuclides of interest (Cs-137, Sr-90, Ba-137m, Pu-238, Pu-239, Pu-240, Pu-241, Am-241, and Cm-244). No data was found for Cm-244.

  15. Improved precision and accuracy in quantifying plutonium isotope ratios by RIMS

    DOE PAGESBeta

    Isselhardt, B. H.; Savina, M. R.; Kucher, A.; Gates, S. D.; Knight, K. B.; Hutcheon, I. D.

    2015-09-01

    Resonance ionization mass spectrometry (RIMS) holds the promise of rapid, isobar-free quantification of actinide isotope ratios in as-received materials (i.e. not chemically purified). Recent progress in achieving this potential using two Pu test materials is presented. RIMS measurements were conducted multiple times over a period of two months on two different Pu solutions deposited on metal surfaces. Measurements were bracketed with a Pu isotopic standard, and yielded absolute accuracies of the measured 240Pu/239Pu ratios of 0.7% and 0.58%, with precisions (95% confidence intervals) of 1.49% and 0.91%. In conclusion, the minor isotope 238Pu was also quantified despite the presence ofmore » a significant quantity of 238U in the samples.« less

  16. New antineutrino energy spectra predictions from the summation of beta decay branches of the fission products.

    PubMed

    Fallot, M; Cormon, S; Estienne, M; Algora, A; Bui, V M; Cucoanes, A; Elnimr, M; Giot, L; Jordan, D; Martino, J; Onillon, A; Porta, A; Pronost, G; Remoto, A; Taín, J L; Yermia, F; Zakari-Issoufou, A-A

    2012-11-16

    In this Letter, we study the impact of the inclusion of the recently measured beta decay properties of the (102;104;105;106;107)Tc, (105)Mo, and (101)Nb nuclei in an updated calculation of the antineutrino energy spectra of the four fissible isotopes (235,238)U and (239,241)Pu. These actinides are the main contributors to the fission processes in pressurized water reactors. The beta feeding probabilities of the above-mentioned Tc, Mo, and Nb isotopes have been found to play a major role in the γ component of the decay heat of (239)Pu, solving a large part of the γ discrepancy in the 4-3000 s range. They have been measured by using the total absorption technique, insensitive to the pandemonium effect. The calculations are performed by using the information available nowadays in the nuclear databases, summing all the contributions of the beta decay branches of the fission products. Our results provide a new prediction of the antineutrino energy spectra of (235)U, (239,241)Pu, and, in particular, (238)U for which no measurement has been published yet. We conclude that new total absorption technique measurements are mandatory to improve the reliability of the predicted spectra. PMID:23215477

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

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2010-03-01

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

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

    SciTech Connect

    Whicker, F.W. ); Pinder, J.E. III; Bowling, J.W. ); Alberts, J.J. . Marine Inst.); Brisbin, I.L. Jr. )

    1989-05-01

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

  20. Natural and man-made radioactivity in soils and plants around the research reactor of Inshass.

    PubMed

    Higgy, R H; Pimpl, M

    1998-12-01

    The specific radioactivities of the U-series, 232Th, 137Cs and 40K were measured in soil samples around the Inshass reactor in Cairo, using a gamma-ray spectrometer with a HpGe detector. The alpha activity of 238U, 234U and 235U was measured in the same soil samples by surface barrier detectors after radiochemical separation and the obtained results were compared with the specific activities determined by gamma-measurements. The alpha-activity of 238Pu, 239+240Pu, 241Am, 242Cm and 244Cm was measured after radiochemical separation by surface barrier detectors for both soil and plant samples. Then beta-activity of 241Pu was measured using liquid scintillation spectrometry. PMID:9776618

  1. Monte Carlo simulation of transfer reactions using extended R-matrix theory picturing surrogate-type WFCF features

    NASA Astrophysics Data System (ADS)

    Bouland, Olivier H.

    2016-03-01

    This article supplies an overview of issues related to the interpretation of surrogate measurement results for neutron-incident cross section predictions; difficulties that are somehow masked by the historical conversion route based on Weisskopf-Ewing approximation. Our proposal is to handle the various difficulties by using a more rigorous approach relying on Monte Carlo simulation of transfer reactions with extended R-matrix theory. The multiple deficiencies of the historical surrogate treatment are recalled but only one is examined in some details here; meaning the calculation of in-out-going channel Width Fluctuation Correction Factors (WFCF) which behavior witness partly the failure of Niels Bohr's compound nucleus theoretical landmark. Relevant WFCF calculations according to neutron-induced surrogate- and cross section-types as a function of neutron-induced fluctuating energy range [0 - 2.1 MeV] are presented and commented in the case of the 240Pu* and 241Pu* compound nucleus isotopes.

  2. Radioactive substances in tap water.

    PubMed

    Atsuumi, Ryo; Endo, Yoshihiko; Suzuki, Akihiko; Kannotou, Yasumitu; Nakada, Masahiro; Yabuuchi, Reiko

    2014-01-01

    A 9.0 magnitude (M) earthquake with an epicenter off the Sanriku coast occurred at 14: 46 on March 11, 2011. TEPCO Fukushima Daiichi Nuclear Power Plant (F-1 NPP) was struck by the earthquake and its resulting tsunami. Consequently a critical nuclear disaster developed, as a large quantity of radioactive materials was released due to a hydrogen blast. On March 16(th), 2011, radioiodine and radioactive cesium were detected at levels of 177 Bq/kg and 58 Bq/kg, respectively, in tap water in Fukushima city (about 62km northwest of TEPCO F-1 NPP). On March 20th, radioiodine was detected in tap water at a level of 965 Bq/kg, which is over the value-index of restrictions on food and drink intake (radioiodine 300 Bq/kg (infant intake 100 Bq/kg)) designated by the Nuclear Safety Commission. Therefore, intake restriction measures were taken regarding drinking water. After that, although the all intake restrictions were lifted, in order to confirm the safety of tap water, an inspection system was established to monitor all tap water in the prefecture. This system has confirmed that there has been no detection of radioiodine or radioactive cesium in tap water in the prefecture since May 5(th), 2011. Furthermore, radioactive strontium ((89) Sr, (90)Sr) and plutonium ((238)Pu, (239)Pu+(240)Pu) in tap water and the raw water supply were measured. As a result, (89) Sr, (238)Pu, (239)Pu+(240)Pu were undetectable and although (90)Sr was detected, its committed effective dose of 0.00017 mSv was much lower than the yearly 0.1 mSv of the World Health Organization guidelines for drinking water quality. In addition, the results did not show any deviations from past inspection results. PMID:25030724

  3. Isotopic fingerprinting of the world's first nuclear device using post-detonation materials.

    PubMed

    Bellucci, Jeremy J; Simonetti, Antonio; Wallace, Christine; Koeman, Elizabeth C; Burns, Peter C

    2013-04-16

    In the event of a rogue nuclear attack or interception of illicit nuclear materials, timely forensic investigations are critical for accurate source attribution. Uranium (U) and plutonium (Pu) isotopic ratios of intercepted materials or postdetonation samples are, perhaps, the most valuable evidence in modern nuclear forensics. These ratios simultaneously provide information regarding the material's ''age'' (i.e., time elapsed since last purification), actinide concentrations, and relevant isotopic ratios/enrichment values. Consequently, these isotope signatures are invaluable in determining the origin, processing history, and intended purpose of any nuclear material. Here we show, for the first time, that it is feasible to determine the U and Pu isotopic compositions of historic nuclear devices from their postdetonation materials utilizing in situ U isotopic measurements. The U isotopic compositions of trinitite glass, produced subsequent to the world's first atomic explosion, indicate two sources: the device's tamper, composed of natural U that underwent fission during detonation, and natural U from the geological background. Enrichments in (234,235,236)U reflect the in situ decay of (238,239,240)Pu, the fuel used in the device. Time-integrated U isotopic modeling yields "supergrade" compositions, where (240)Pu/(239)Pu ≈ 0.01-0.03 and (238)Pu/(239)Pu ≈ 0.00011-0.00017, which are consistent with the Pu originating from the Hanford reactor. Spatially resolved U isotopic data of postdetonation debris reveal important details of the device in a relatively short time frame (hours). This capacity serves as an important deterrent to future nuclear threats and/or terrorist activities and is critical for source attribution and international security. PMID:23517046

  4. The Dynamic Movement of Plutonium in an Underground Nuclear Test with Implications for the Contamination of Groundwater

    SciTech Connect

    Smith, D K; Williams, R W

    2003-03-25

    The recent discovery of the migration of plutonium in groundwater away from underground nuclear tests at the Nevada Test Site has spawned considerable interest in the mechanisms by which plutonium may be released to the environment by a nuclear test. A suite of solid debris samples was collected during drilling through an expended test cavity and the overlying collapse chimney. Uranium and plutonium were analyzed for isotope ratios and concentration using high precision magnetic sector inductively coupled mass spectrometry. The data unequivocally shows that plutonium may be dispersed throughout the cavity and chimney environment at the time of the detonation. The {sup 239}Pu/{sup 240}Pu ratios are also fractionated relative to initial plutonium isotope ratio for the test device. Fractionation is the result of the volatilization of uranium and production of {sup 239}Pu by the reaction {sup 238}U (n,{gamma}). We conclude that for the test under consideration plutonium was deposited outside of the confines of the cavity by dynamic processes in early-time and it is this plutonium that is most likely first transferred to the groundwater regime.

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

    SciTech Connect

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

    2010-01-25

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

  6. Actinide Targets for Neutron Cross Section Measurements

    SciTech Connect

    John D. Baker; Christopher A. McGrath

    2006-10-01

    The Advanced Fuel Cycle Initiative (AFCI) and the Generation IV Reactor Initiative have demonstrated a lack of detailed neutron cross-sections for certain "minor" actinides, those other than the most common (235U, 238U, and 239Pu). For some closed-fuel-cycle reactor designs more than 50% of reactivity will, at some point, be derived from "minor" actinides that currently have poorly known or in some cases not measured (n,?) and (n,f) cross sections. A program of measurements under AFCI has begun to correct this. One of the initial hurdles has been to produce well-characterized, highly isotopically enriched, and chemically pure actinide targets on thin backings. Using a combination of resurrected techniques and new developments, we have made a series of targets including highly enriched 239Pu, 240Pu, and 242Pu. Thus far, we have electrodeposited these actinide targets. In the future, we plan to study reductive distillation to achieve homogeneous, adherent targets on thin metal foils and polymer backings. As we move forward, separated isotopes become scarcer, and safety concerns become greater. The chemical purification and electodeposition techniques will be described.

  7. 237Np in hemp-palm leaves of Bontenchiku for fishing gear used by the Fifth Fukuryu-Maru: 40 years after "Bravo".

    PubMed

    Yamamoto, M; Ishiguro, T; Tazaki, K; Komura, K; Ueno, K

    1996-05-01

    The alpha radioactive components in the Hemp-palm of Bontenchiku were determined with emphasis on the measurement low-level 237Np by alpha-ray spectrometry after chemical separation. Bontenchiku is a kind of fishing gear for long-line fishing used by the Fifth Fukuryu-Maru (Lucky Dragon). This gear was exposed to fallout from the second thermonuclear test explosion (Bravo) at Bikini Atoll in March 1954. The 237Np content in the Bontenchiku sample was determined to be 11.5 +/- 0.8 mBq g(-1), with an activity ratio of 237Np:239,240Pu and an atom ratio of 237Np:239Pu estimated to be (2.2 +/- 0.2) x 10(-3) and 0.42 +/- 0.04, respectively. The data showed the existence of a chain reaction of 238U and its ratio to be 237Np:239Pu, as well as the presence of 237U at the time of fallout from Bravo event in March 1954. PMID:8690589

  8. Upward movement of plutonium to surface sediments during an 11-year field study.

    PubMed

    Kaplan, D I; Demirkanli, D I; Molz, F J; Beals, D M; Cadieux, J R; Halverson, J E

    2010-05-01

    An 11-year lysimeter study was established to monitor the movement of Pu through vadose zone sediments. Sediment Pu concentrations as a function of depth indicated that some Pu moved upward from the buried source material. Subsequent numerical modeling suggested that the upward movement was largely the result of invading grasses taking up the Pu and translocating it upward. The objective of this study was to determine if the Pu of surface sediments originated from atmosphere fallout or from the buried lysimeter source material (weapons-grade Pu), providing additional evidence that plants were involved in the upward migration of Pu. The (240)Pu/(239)Pu and (242)Pu/(239)Pu atomic fraction ratios of the lysimeter surface sediments, as determined by Thermal Ionization Mass Spectroscopy (TIMS), were 0.063 and 0.00045, respectively; consistent with the signatures of the weapons-grade Pu. Our numerical simulations indicate that because plants create a large water flux, small concentrations over multiple years may result in a measurable accumulation of Pu on the ground surface. These results may have implications on the conceptual model for calculating risk associated with long-term stewardship and monitored natural attenuation management of Pu contaminated subsurface and surface sediments. PMID:20227801

  9. Radionuclide transfer to marine biota species: review of Russian language studies.

    PubMed

    Fesenko, S; Fesenko, E; Titov, I; Karpenko, E; Sanzharova, N; Fonseca, A Gondin; Brown, J

    2010-11-01

    An extensive programme of experiments on transfer of radionuclides to aquatic species was conducted in the former USSR starting from the early 1950s. Only a few of these studies were made available in the English language literature or taken into account in international reviews of radionuclide behaviour in marine ecosystems. Therefore, an overview of original information on radionuclide transfer to marine biota species available from Russian language literature sources is presented here. The concentration ratio (CR) values for many radionuclides and for marine species such as: (239)Pu, (106)Ru and (95)Zr (crustacean), (54)Mn, (90)Sr, (95)Nb, (106)Ru, (137)Cs (239)Pu, (241)Am and natural U (molluscs), and (54)Mn, (90)Sr, (137)Cs and (144)Ce (fish) are in good agreement with those previously published, whilst for some of them, in particular, for (32)P and (110)Ag (crustaceans), (35)S (molluscs), (32)P, (35)S, (95)Nb, and (106)Ru (macroalgae) and (60)Co and (239,240)Pu (fish) the data presented here suggest that changes in the default CR reference values presented in recent marine reviews may be required. The data presented here are intended to supplement substantially the CR values being collated within the handbook on Wildlife Transfer Coefficients, coordinated under the IAEA EMRAS II programme. PMID:20798950

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

    PubMed Central

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

    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 mass spectrometry, we clearly demonstrated the release of Pu from the Fukushima Daiichi power plant: While most samples contained only the radionuclide signature of fallout plutonium, there is at least one vegetation sample whose isotope ratio (0.381 ± 0.046) evidences that the Pu originates from a nuclear reactor (239+240Pu activity concentration 0.49 Bq/kg). Plutonium content and isotope ratios differ considerably even for very close sampling locations, e.g. the soil and the plants growing on it. This strong localization indicates a particulate Pu release, which is of high radiological risk if incorporated. PMID:24136192

  11. Comparative skeletal distribution of americium and plutonium in man, monkey and baboon

    SciTech Connect

    Lynch, T.P.; Dagle, G.E.; Kathren, R.L.; McInroy, J.F.

    1988-10-01

    The skeletal distributions of americium and plutonium in four humans were compared with the skeletal distributions of these radioelements in baboons and monkeys. With respect to the skeletal distribution of these elements, excellent agreement was noted among the four human cases; americium data was available for all four cases and plutonium for three. The human case database was thus adequate for comparison with those of other primates. A statistically significant correlation was found between the /sup 241/Am and /sup 239/Pu + /sup 240/Pu skeletal distributions in the humans and those in non-human primates. Trabecular bone had the highest concentrations of /sup 241/Am and /sup 239 +240/Pu in man, baboon, and monkey. Scaling factors are proposed to convert the percentages of skeletal activity in animal bones to the corresponding percentages in the bones of the human skeleton. However, considerable variation was found between the humans and animals in the percentages of the skeletal activity found in the same bone. 12 refs., 7 tabs.

  12. Main results of the 2012 joint Norwegian-Russian expedition to the dumping sites of the nuclear submarine K-27 and solid radioactive waste in Stepovogo Fjord, Novaya Zemlya.

    PubMed

    Gwynn, Justin P; Nikitin, Aleksander; Shershakov, Viacheslav; Heldal, Hilde Elise; Lind, Bjørn; Teien, Hans-Christian; Lind, Ole Christian; Sidhu, Rajdeep Singh; Bakke, Gunnar; Kazennov, Alexey; Grishin, Denis; Fedorova, Anastasia; Blinova, Oxana; Sværen, Ingrid; Lee Liebig, Penny; Salbu, Brit; Wendell, Cato Christian; Strålberg, Elisabeth; Valetova, Nailja; Petrenko, Galina; Katrich, Ivan; Logoyda, Igor; Osvath, Iolanda; Levy, Isabelle; Bartocci, Jean; Pham, Mai Khanh; Sam, Adam; Nies, Hartmut; Rudjord, Anne Liv

    2016-01-01

    This paper reports the main results of the 2012 joint Norwegian-Russian expedition to investigate the radioecological situation of the Stepovogo Fjord on the eastern coast of Novaya Zemlya, where the nuclear submarine K-27 and solid radioactive waste was dumped. Based on in situ gamma measurements and the analysis of seawater and sediment samples taken around the submarine, there was no indication of any leakage from the reactor units of K-27. With regard to the radioecological status of Stepovogo Fjord, activity concentrations of all radionuclides in seawater, sediment and biota in 2012 were in general lower than reported from the previous investigations in the 1990s. However in 2012, the activity concentrations of (137)Cs and, to a lesser extent, those of (90)Sr remained elevated in bottom water from the inner part of Stepovogo Fjord compared with surface water and the outer part of Stepovogo Fjord. Deviations from expected (238)Pu/(239,240)Pu activity ratios and (240)Pu/(239)Pu atom ratios in some sediment samples from the inner part of Stepovogo Fjord observed in this study and earlier studies may indicate the possibility of leakages from dumped waste from different nuclear sources. Although the current environmental levels of radionuclides in Stepovogo Fjord are not of immediate cause for concern, further monitoring of the situation is warranted. PMID:25716076

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

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    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 mass spectrometry, we clearly demonstrated the release of Pu from the Fukushima Daiichi power plant: While most samples contained only the radionuclide signature of fallout plutonium, there is at least one vegetation sample whose isotope ratio (0.381 +/- 0.046) evidences that the Pu originates from a nuclear reactor (239+240Pu activity concentration 0.49 Bq/kg). Plutonium content and isotope ratios differ considerably even for very close sampling locations, e.g. the soil and the plants growing on it. This strong localization indicates a particulate Pu release, which is of high radiological risk if incorporated.

  14. Burnup estimation of fuel sourcing radioactive material based on monitored Cs and Pu isotopic activity ratios in Fukushima N. P. S. accident

    SciTech Connect

    Yamamoto, T.; Suzuki, M.; Ando, Y.

    2012-07-01

    After the severe core damage of Fukushima Dai-Ichi Nuclear Power Station, radioactive material leaked from the reactor buildings. As part of monitoring of radioactivity in the site, measurements of radioactivity in soils at three fixed points have been performed for {sup 134}Cs and {sup 137}Cs with gamma-ray spectrometry and for Pu, Pu, and {sup 240}Pu with {alpha}-ray spectrometry. Correlations of radioactivity ratios of {sup 134}Cs to {sup 137}Cs, and {sup 238}Pu to the sum of {sup 239}Pu and {sup 240}Pu with fuel burnup were studied by using theoretical burnup calculations and measurements on isotopic inventories, and compared with the Cs and Pu radioactivity rations in the soils. The comparison indicated that the burnup of the fuel sourcing the radioactivity was from 18 to 38 GWd/t, which corresponded to that of the fuel in the highest power and, therefore, the highest decay heat in operating high-burnup fueled BWR cores. (authors)

  15. Plutonium Detection with Straw Neutron Detectors

    SciTech Connect

    Mukhopadhyay, Sanjoy; Maurer, Richard; Guss, Paul

    2014-03-27

    A kilogram of weapons grade plutonium gives off about 56,000 neutrons per second of which 55,000 neutrons come from spontaneous fission of 240Pu (~6% by weight of the total plutonium). Actually, all even numbered isotopes (238Pu, 240Pu, and 242Pu) produce copious spontaneous fission neutrons. These neutrons induce fission in the surrounding fissile 239Pu with an approximate multiplication of a factor of ~1.9. This multiplication depends on the shape of the fissile materials and the surrounding material. These neutrons (typically of energy 2 MeV and air scattering mean free path >100 meters) can be detected 100 meters away from the source by vehicle-portable neutron detectors. [1] In our current studies on neutron detection techniques, without using 3He gas proportional counters, we designed and developed a portable high-efficiency neutron multiplicity counter using 10B-coated thin tubes called straws. The detector was designed to perform like commercially available fission meters (manufactured by Ortec Corp.) except instead of using 3He gas as a neutron conversion material, we used a thin coating of 10B.

  16. Transuranic isotopes and 90Sr in attic dust in the vicinity of two nuclear establishments in northern Germany.

    PubMed

    Schmitz-Feuerhake, I; Mietelski, J W; Gaca, P

    2003-05-01

    Attic dust was chosen as the test medium in order to search for traces of man-made bone seeking alpha and beta emitters. The samples were taken from 5 houses in the community of Elbmarsch situated at the river Elbe, adjacent to the Krümmel nuclear power plant and the nuclear research center of Geesthacht. Five houses in other regions of northern Germany were taken as a control. 238Pu, (239,240)Pu, 241Am, and 244Cm were measured by alpha spectrometry after chemical separation. Additionally, 241Pu was measured by liquid scintillation spectrometry, and the fission product 90Sr was measured in a separate investigation. All nuclides except 244Cm showed activities above the detection limit in the Elbmarsch samples and an elevated mean concentration compared to the control. It can be concluded from the activity ratio 241Am/(239,240)Pu that the Elbmarsch contamination cannot be accounted for by the background levels of transuranic nuclides resulting from weapons fallout. The derived release of alpha emitters is assumed to have contributed to the induction of a leukemia cluster in children, which was observed in Elbmarsch between 1990 and 1996. PMID:12747479

  17. Short term soil erosion dynamics in alpine grasslands - Results from a Fallout Radionuclide repeated-sampling approach

    NASA Astrophysics Data System (ADS)

    Arata, Laura; Meusburger, Katrin; Zehringer, Markus; Ketterer, Michael E.; Mabit, Lionel; Alewell, Christine

    2016-04-01

    Improper land management and climate change has resulted in accelerated soil erosion rates in Alpine grasslands. To efficiently mitigate and control soil erosion and reduce its environmental impact in Alpine grasslands, reliable and validated methods for comprehensive data generation on its magnitude and spatial extent are mandatory. The use of conventional techniques (e.g. sediment traps, erosion pins or rainfall simulations) may be hindered by the extreme topographic and climatic conditions of the Alps. However, the application of the Fallout Radionuclides (FRNs) as soil tracers has already showed promising results in these specific agro-ecosystems. Once deposited on the ground, FRNs strongly bind to fine particles at the surface soil and move across the landscape primarily through physical processes. As such, they provide an effective track of soil and sediment redistribution. So far, applications of FRN in the Alps include 137Cs (half-life: 30.2 years) and 239+240Pu (239Pu [half-life = 24110 years] and 240Pu [half-life = 6561 years]). To investigate short term (4-5 years) erosion dynamics in the Swiss Alps, the authors applied a FRNs repeated sampling approach. Two study areas in the central Swiss Alps have been investigated: the Urseren Valley (Canton Uri), where significant land use changes occurred in the last centuries, and the Piora Valley (Canton Ticino), where land use change plays a minor role. Soil samples have been collected at potentially erosive sites along the valleys over a period of 4-5 years and measured for 137Cs and 239+240Pu activity. The inventory change between the sampling years indicates high erosion and deposition dynamics at both valleys. High spatial variability of 137Cs activities at all sites has been observed, reflecting the heterogeneous distribution of 137Cs fallout after the Chernobyl power plant accident in 1986. Finally, a new modelling technique to convert the inventory changes to quantitative estimates of soil erosion has

  18. Evaluating global atmospheric transport of plutonium with dust aerosols

    NASA Astrophysics Data System (ADS)

    Velarde, R.; Arimoto, R.; Gill, T. E.; Kang, C.; Goodell, P.

    2009-12-01

    The resuspension of soils contaminated with radionuclides from nuclear weapons tests is a mechanism by which plutonium can be re-distributed throughout the environment. To better understand the global atmospheric transport of plutonium, we measured the activity of Pu in aerosol samples from four widely separated sites that receive dust from distant sources in both Asia and Africa. High-volume aerosol samples were collected from Barbados (2005 - 2006); Gosan, South Korea (2005 - 2006); Izaña, Canary Islands (1989 - 1996); and Mauna Loa Observatory, Hawaii (2005 - 2006) to evaluate the relationship between Pu activity and mineral dust concentrations (using crustal elements such as aluminum as a dust proxy). The activity of 239,240Pu (239Pu + 240Pu) in the aerosol samples was determined by alpha spectrometry following a series of chemical separations. Concentrations of other elements were determined by a variety of techniques. Pu activity was below the detection limit in many samples. In those samples where it was detected, the Gosan site had the highest dust concentrations and highest total plutonium activity, while Mauna Loa Observatory had the lowest dust concentrations and lowest 239,240Pu activity. The Izaña samples had the second highest concentrations of dust and plutonium activity, while Barbados had the third highest levels of both crustal aerosols and plutonium activity. The dust concentrations are consistent with previous observations at these remote sites, and we propose that the plutonium (primarily from past atmospheric nuclear weapons testing, much of which took place in arid lands) was deposited on erodible soil surfaces and subsequently transported as part of the overall mineral dust load. The results of this study have implications for the global transport and fate of Pu through its association with dust, the biogeochemical and environmental impacts of other substances associated with dust, and the workings of the dust cycle itself.

  19. PLANTS AS BIO-MONITORS FOR 137CS, 238PU, 239, 240PU AND 40K AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Caldwell, E.; Duff, M.; Ferguson, C.

    2010-12-16

    The nuclear fuel cycle generates a considerable amount of radioactive waste, which often includes nuclear fission products, such as strontium-90 ({sup 90}Sr) and cesium-137 ({sup 137}Cs), and actinides such as uranium (U) and plutonium (Pu). When released into the environment, large quantities of these radionuclides can present considerable problems to man and biota due to their radioactive nature and, in some cases as with the actinides, their chemical toxicity. Radionuclides are expected to decay at a known rate. Yet, research has shown the rate of elimination from an ecosystem to differ from the decay rate due to physical, chemical and biological processes that remove the contaminant or reduce its biological availability. Knowledge regarding the rate by which a contaminant is eliminated from an ecosystem (ecological half-life) is important for evaluating the duration and potential severity of risk. To better understand a contaminants impact on an environment, consideration should be given to plants. As primary producers, they represent an important mode of contamination transfer from sediments and soils into the food chain. Contaminants that are chemically and/or physically sequestered in a media are less likely to be bio-available to plants and therefore an ecosystem.

  20. Evidence for Hydroxamate Siderophores and Other N-Containing Organic Compounds Controlling (239,240)Pu Immobilization and Remobilization in a Wetland Sediment.

    PubMed

    Xu, Chen; Zhang, Saijin; Kaplan, Daniel I; Ho, Yi-Fang; Schwehr, Kathleen A; Roberts, Kimberly A; Chen, Hongmei; DiDonato, Nicole; Athon, Matthew; Hatcher, Patrick G; Santschi, Peter H

    2015-10-01

    Pu concentrations in wetland surface sediments collected downstream of a former nuclear processing facility in F-Area of the Savannah River Site (SRS), USA, were ∼2.5 times greater than those measured in the associated upland aquifer sediments; similarly, the Pu concentration solid/water ratios were orders of magnitude greater in the wetland than in the low-organic matter content aquifer soils. Sediment Pu concentrations were correlated to total organic carbon and total nitrogen contents and even more strongly to hydroxamate siderophore (HS) concentrations. The HS were detected in the particulate or colloidal phases of the sediments but not in the low molecular weight fractions (<1000 Da). Macromolecules which scavenged the majority of the potentially mobile Pu were further separated from the bulk mobile organic matter fraction ("water extract") via an isoelectric focusing experiment (IEF). An electrospray ionization Fourier-transform ion cyclotron resonance ultrahigh resolution mass spectrometry (ESI FTICR-MS) spectral comparison of the IEF extract and a siderophore standard (desferrioxamine; DFO) suggested the presence of HS functionalities in the IEF extract. This study suggests that while HS are a very minor component in the sediment particulate/colloidal fractions, their concentrations greatly exceed those of ambient Pu, and HS may play an especially important role in Pu immobilization/remobilization in wetland sediments. PMID:26313339

  1. R-matrix analysis of the {sup 240}Pu neutron cross sections in the thermal to 5700 eV energy range

    SciTech Connect

    Derrien, H.; Bouland, O.; Larson, N.M.; Leal, L.C.

    1997-08-01

    Resonance analysis of high resolution neutron transmission data and of fission cross sections were performed in the neutron energy range from the thermal regions to 5,700 eV by using the Reich-Moore Bayesian code SAMMY. The experimental data base is described and the method of analysis is given. The experimental data were carefully examined in order to identify more resonances than those found in the current evaluated data files. The statistical properties of the resonance parameters are given. A new set of the average values of the parameters is proposed, which could be used for calculation of the average cross sections in the unresolved resonance region. The resonance parameters are available IN ENDF-6 format at the national or international data centers.

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

    PubMed

    Sayles, F L; Livingston, H D; Panteleyev, G P

    1997-08-25

    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. PMID:9241876

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

    NASA Astrophysics Data System (ADS)

    Ketterer, Michael; Moan, Matthew; Gremillion, Paul

    2010-05-01

    Pu activities, and hence contain most or all of the cumulative deposition inventory of smelter pollutants, while soils with low 239+240Pu activities can be regarded as 'disturbed', and cannot contain the entire deposition inventory. 240Pu/239Pu atom ratio measurements reveal that the Pu is from stratospheric fallout, precluding other local or regional sources. Our results indicate that 239+240Pu activities are closely correlated with concentrations of smelter pollutants within a specific distance grouping; hence, the soil concentrations of contaminant metals are described by a 'distance' factor and a 'disturbance' factor, the latter being probed using 239+240Pu as an effective proxy measure. Linear correlations (r2 > 0.95) are observed for metal concentrations vs. 239+240Pu activity for a given distance grouping; lines of varying slope are observed for different distance groupings. In desert soils remote from the smelter, the metal constituents are present from other anthropogenic and geogenic sources, and their concentrations are uncorrelated with 239+240Pu activity.

  4. Radionuclides in Arctic sea ice: Tracers of sources, fates and ice transit time scales

    NASA Astrophysics Data System (ADS)

    Masqué, P.; Cochran, J. K.; Hirschberg, D. J.; Dethleff, D.; Hebbeln, D.; Winkler, A.; Pfirman, S.

    2007-08-01

    Arctic sea ice can incorporate sediment and associated chemical species during its formation in shallow shelf environments and can also intercept atmospherically transported material during transit. Release of this material in ice ablation areas (e.g. the Fram Strait) enhances fluxes of both sediments and associated species in such areas. We have used a suite of natural ( 7Be, 210Pb) and anthropogenic ( 137Cs, 239Pu, 240Pu) radionuclides in sea ice, sea-ice sediments (SIS), sediment trap material and bottom sediments from the Fram Strait to estimate transit times of sea ice from source to ablation areas, calculate radionuclide fluxes to the Fram Strait and investigate the role of sea-ice entrained sediments in sedimentation processes. Sea ice intercepts and transports the atmospherically supplied radionuclides 7Be and 210Pb, which are carried in the ice and are scavenged by any entrained SIS. All of the 7Be and most of the excess 210Pb measured in SIS collected in the Fram Strait are added to the ice during transit through the Arctic Ocean, and we use these radionuclides as chronometers to calculate ice transit times for individual ice floes. Transit times estimated from the 210Pb inventories in two ice cores are 1-3 years. Values estimated from the 7Be/ 210Pb excess activity ratio of SIS are about 3-5 years. Finally, equilibrium values of the activity ratio of 210Pb to its granddaughter 210Po in the ice cores indicate transit times of at least 2 years. These transit times are consistent with back-trajectory analyses of the ice floes. The latter, as well as the clay-mineral assemblage of the SIS (low smectite and high illite content), suggest that the sampled sea-ice floes originated from the eastern Siberian Arctic shelf seas such as the eastern Laptev Sea and the East Siberian Sea. This result is in agreement with the relatively low activities of 239,240Pu and 137Cs and the 240Pu/ 239Pu atom ratios (˜0.18, equivalent to that in global fallout) in SIS, indicating

  5. Cleanup levels for Am-241, Pu-239, U-234, U-235 & U-238 in soils at the Rocky Flats Environmental Technology Site

    SciTech Connect

    Roberts, R.; Colby, B.; Brooks, L.; Slaten, S.

    1997-07-03

    This presentation briefly outlines a cleanup program at a Rocky Flats site through viewgraphs and an executive summary. Exposure pathway analyses to be performed are identified, and decontamination levels are listed for open space and office worker exposure areas. The executive summary very briefly describes the technical approach, RESRAD computer code to be used for analyses, recommendations for exposure levels, and application of action levels to multiple radionuclide contamination. Determination of action levels for surface and subsurface soils, based on radiation doses, is discussed. 1 tab.

  6. Delayed neutron detection with an integrated differential die-away and delayed neutron instrument

    SciTech Connect

    Blanc, Pauline; Tobin, Stephen J; Lee, Taehoon; Hu, Jianwei S; Hendricks, John; Croft, Stephen

    2010-01-01

    The Next Generation Safeguards Initiative (NGSI) of the U.S. Department of Energy (DOE) has funded a multilab/university collaboration to quantify the plutonium (Pu) mass and detect the diversion of pins from spent nuclear fuel. The first two years of this NGSI effort was focused on quantifying the capability of a range of nondestructive assay (NDA) techniques with Monte Carlo (MCNPX) modeling and the second current phase involves measuring Spent Fuel. One of the techniques of interest in this paper involves measuring delayed neutrons. A delayed neutron instrument using 36 fission chambers and a 14 MeV neutron generator so called DT generator (Deuterium + Tritium) surrounding the fuel was previously studied as part of the NGSI effort. This paper will quantify the capability of a standalone delayed neutron instrument using 4 {sup 3}He gas filled tubes and a DT generator with significant spectrum tailoring, located far from the fuel. So that future research can assess how well a delayed neutron instrument will function as part of an integrated NDA system. A new design is going to be used to respond to the need of the techniques. This design has been modeled for a water media and is currently being optimized for borated water and air media as part of ongoing research. This new design was selected in order to minimize the fission of {sup 238}U, to use a more realistic neutron generator design in the model, to reduce cost and facilitate the integration of a delayed neutron (DN) with a differential die-away (DDA) instrument. Since this paper will focus on delayed neutron detection, the goal is to quantify the signal from {sup 235}U, {sup 239}Pu and {sup 241}Pu, which are the isotopes present in Spent Fuel that respond significantly to a neutron interrogation. This report will quantify the capability of this new delayed neutron design to measure the combined mass of {sup 235}U, {sup 239}Pu and {sup 241}Pu for 16 of the 64 assemblies of the NGSI Spent Fuel library in one

  7. Low-Level Plutonium Bioassay Measurements at the Lawrence Livermore National Laboratory

    SciTech Connect

    Hamilton, T; Brown, T; Hickman, D; Marchetti, A; Williams, R; Kehl, S

    2007-06-18

    Plutonium-239 ({sup 239}Pu) and plutonium-240 ({sup 240}Pu) are important alpha emitting radionuclides contained in radioactive debris from nuclear weapons testing. {sup 239}Pu and {sup 240}Pu are long-lived radionuclides with half-lives of 24,400 years and 6580 years, respectively. Concerns over human exposure to plutonium stem from knowledge about the persistence of plutonium isotopes in the environment and the high relative effectiveness of alpha-radiation to cause potential harm to cells once incorporated into the human body. In vitro bioassay tests have been developed to assess uptakes of plutonium based on measured urinary excretion patterns and modeled metabolic behaviors of the absorbed radionuclides. Systemic plutonium absorbed by the deep lung or from the gastrointestinal tract after ingestion is either excreted or distributed to other organs, primarily to the liver and skeleton, where it is retained for biological half-times of around 20 and 50 years, respectively. Dose assessment and atoll rehabilitation programs in the Marshall Islands have historically given special consideration to residual concentrations of plutonium in the environment even though the predicted dose from inhalation and/or ingestion of plutonium accounts for less than 5% of the annual effective dose from exposure to fallout contamination. Scientists from the Lawrence Livermore National Laboratory (LLNL) have developed a state-of-the-art bioassay test to assess urinary excretion rates of plutonium from Marshallese populations. This new heavy-isotope measurement system is based on Accelerator Mass Spectrometry (AMS). The AMS system at LLNL far exceeds the standard measurement requirements established under the latest United States Department of Energy (DOE) regulation, 10CFR 835, for occupational monitoring of plutonium, and offers several advantages over classical as well as competing new technologies for low-level detection and measurement of plutonium isotopes. The United States

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

    PubMed

    Lind, O C; Salbu, B; Janssens, K; Proost, K; García-León, M; García-Tenorio, R

    2007-04-15

    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 ratios in individual particles from both sites obtained by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) show that the particles contain highly enriched U and weapon-grade Pu. Furthermore, results from electron microscopy with Energy Dispersive X-ray analysis (EDX) and synchrotron radiation (SR) based micrometer-scale X-ray fluorescence (micro-XRF) 2D mapping demonstrated that U and Pu coexist throughout the 1-50 microm sized particles, while surface heterogeneities were observed in EDX line scans. SR-based micrometer-scale X-ray Absorption Near Edge Structure Spectroscopy (micro-XANES) showed that the particles consisted of an oxide mixture of U (predominately UO(2) with the presence of U(3)O(8)) and Pu ((III)/(IV), (IV)/(V) or (III), (IV) and (V)). Neither metallic U or Pu nor uranyl or Pu(VI) could be observed. Characteristics such as elemental distributions, morphology and oxidation states are remarkably similar for the Palomares and Thule particles, reflecting that they originate from similar source and release scenarios. Thus, these particle characteristics are more dependent on the original material from which the particles are derived (source) and the formation of particles (release scenario) than the environmental conditions to which the particles have been exposed since the late 1960s. PMID:17336369

  9. Determination of Pu in urine at ultratrace level by sector field inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    Zoriy, M. V.; Pickhardt, C.; Ostapczuk, P.; Hille, R.; Becker, J. S.

    2004-04-01

    A new analytical procedure has been developed for the determination of Pu in urine at the low ag ml-1 concentration level by double-focusing sector field inductively coupled plasma mass spectrometry (ICP-SFMS). One liter of urine doped with 4 pg 242Pu was analyzed after co-precipitation with Ca3(PO4)2 followed by extraction chromatography on TEVA resin in order to enrich the Pu and remove uranium and matrix elements. Figures of merit of ICP-SFMS for the determination of Pu were studied using two nebulizers, PFA-100 and direct injection high-efficiency nebulizer (DIHEN), for solution introduction with uptake rates of 0.58 and 0.06 ml min-1, respectively. The sensitivity for Pu in ICP-SFMS was determined to be 2000 and 1380 MHz ppm-1 for the PFA-100 and DIHEN nebulizers, respectively. Due to the low solution uptake rate of DIHEN the absolute sensitivity was about seven times better and yielded 1380 counts fg-1 in comparison to 207 counts fg-1 measured with the PFA-100 nebulizer. Recovery using 242Pu tracer was about 70%. The limits of detection for 239Pu in 1 l of urine, based on an enrichment factor of 100 for PFA-100 nebulizer and 1000 for DIHEN, were 9×10-18 and 1.02×10-18 g ml-1, respectively. Measurements of 240Pu/239Pu isotopic ratio in synthetically prepared urine standard solution yielded a precision of 1.8 and 1.9% and accuracy of 1.5 and 1.8% for the PFA-100 and DIHEN nebulizers, respectively.

  10. Field test of New TASTEX system for plutonium product verification at the Tokai Reprocessing Plant

    SciTech Connect

    Kuno, Y.; Shigeoka, K.; Nishida, K.; Ikeda, H.; Hayashi, N.; Wachi, I.; Hsue, S.T.; Sprinkle, J.K.; Gunnink, R.; Ruhter, W.D.

    1988-01-01

    This report describes the field test results of the New TASTEX system. This system consisting of the high resolution gamma spectrometer and the k-edge densitometer can measure both isotopic abundances and concentration of plutonium simultaneously. Entire system is controlled by the multichannel analyzer and a multi-user computer. The system was designed and built under the Japan Support Program for Agency Safeguards (JASPAS). The software of this system developed at LANL and LLNL has been installed in the system assembled at the Tokai reprocessing plant (TRP) in July 1985. In the course of campaigns from 1985 until 1988, field tests have been carried out on plutonium product solutions of TRP. The results of plutonium concentration and isotopic abundances obtained by the k-edge densitometer and the high resolution gamma spectrometer (HRGS) have been compared with those by controlled potential coulometer and mass spectrometer respectively. Precision of plutonium determination with k-edge densitometer is estimated approximately 0.7% and 1.0% for the freshly processed plutonium and the aged plutonium respectively. The scatters in the relative differences between HRGS and the destructive analysis (DA) detected on the results of freshly processed plutonium sample were 1.6%, 0.4%, 0.5%, 1.1%, 8.0% for Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242 respectively, whereas those on the results of aged sample were 1.4%, 0.5%, 1.1%, 1.1% for Pu-238, Pu-239, Pu-240, and Pu-241 respectively. 9 refs., 15 figs., 7 tabs.

  11. Characterization of U/Pu Particles Originating From the Nuclear Weapon Accidents at Palomares, Spain, 1966 And Thule, Greenland, 1968

    SciTech Connect

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

    2007-07-10

    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 ratios in individual particles from both sites obtained by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) show that the particles contain highly enriched U and weapon-grade Pu. Furthermore, results from electron microscopy with Energy Dispersive X-ray analysis (EDX) and synchrotron radiation (SR) based micrometer-scale X-ray fluorescence ({micro}-XRF) 2D mapping demonstrated that U and Pu coexist throughout the 1-50 {micro}m sized particles, while surface heterogeneities were observed in EDX line scans. SR-based micrometer-scale X-ray Absorption Near Edge Structure Spectroscopy ({micro}-XANES) showed that the particles consisted of an oxide mixture of U (predominately UO[2] with the presence ofU[3][8]) and Pu ((III)/(IV), (V)/(V) or (III), (IV) and (V)). Neither metallic U or Pu nor uranyl or Pu(VI) could be observed. Characteristics such as elemental distributions, morphology and oxidation states are remarkably similar for the Palomares and Thule particles, reflecting that they originate from similar source and release scenarios. Thus, these particle characteristics are more dependent on the original material from which the particles are derived (source) and the formation of particles (release scenario) than the environmental conditions to which the particles have been exposed since the late 1960s.

  12. Plutonium and Uranium Atom Ratios and Activity Levels in Cochiti Lake Bottom Sediments Provided by Pueblo de Cochiti

    SciTech Connect

    Gallaher, B.M.; Efurd, D.W.; Rokop, D.J.; Benjamin, T.M.

    1999-05-01

    Historical operations at the Los Alamos National Laboratory have contaminated stream sediments with plutonium and other radionuclides. A small portion of these contaminated sediments has been carried by floods into the Rio Grande drainage system, eventually to be trapped by Cochiti Lake located on Pueblo de Cochiti lands approximately 8 km downstream of the Laboratory. In this study, lake bottom sediment samples provided by the Pueblo de Cochiti were analyzed by thermal ionization mass spectrometry to determine plutonium and uranium activity levels and isotopic atom ratios. This specialized analytical method allows us to take isotopic fingerprints of radionuclides found in the sediment and to determine how much plutonium and uranium came from the Laboratory and how much was deposited by worldwide fallout or is natural. Two distinct types of samples were processed: segments of a continuous vertical core of the entire accumulated sediment sequence and other samples from across the lake bottom at the water/sediment interface. Based on measurement of the {sup 240}Pu/{sup 239}Pu atom ratio, Laboratory-derived plutonium is present in eight of nine samples at the core site. On a depth-weighted basis, approximately one-half of the {sup 239}Pu and {sup 240}Pu came from early operations at the Laboratory; the remaining plutonium came from fallout dispersed by above-ground nuclear tests. In contrast to the core site, the samples from the other locations showed little or no evidence of Laboratory-derived plutonium, with more than 90 percent of the plutonium attributable to fallout. The overall amount of plutonium in all the samples is of the same magnitude as other reservoirs in the region. The net increase in plutonium over upstream reservoirs unaffected by Laboratory activities is a maximum of 0.014 pCi/g or 3.5 times. All of the samples reflect natural uranium compositions. Laboratory-derived uranium is not identifiable, presumably because the sediment contains abundant

  13. Long-term development of the radionuclide exposure of murine rodent populations in Belarus after the Chernobyl accident.

    PubMed

    Ryabokon, N I; Smolich, I I; Kudryashov, V P; Goncharova, R I

    2005-12-01

    As a determinant of the associated health risks, the behavior of radionuclides in natural ecosystems needs to be better understood. Therefore, the activity concentration of various long-lived radionuclides released due to the Chernobyl accident, and the corresponding contributions to the whole-body dose rate, was studied as a function of time in mammalian indicator species inhabiting the natural forest ecosystems of Belarus, the bank vole (Clethrionomys glareolus) and the yellow-necked mouse (Apodemus flavicollus). The activity concentrations of 137Cs, 134Cs, 90Sr, 238Pu, 239,240Pu, 241Pu and 241Am in soil and in animals were measured at five monitoring sites with different ground deposition of radionuclides at different distances from the destroyed reactor. The observed temporal pattern of the radionuclide activity concentration in the studied animal populations reflects the changes in biological availability of these isotopes for biota, mostly due to fuel particle destruction and appearance of dissolved and exchangeable forms of radionuclides. The time course of 134+137Cs activity concentrations in animal populations appeared as a sequence of increase, peak and decrease. Maximal levels of radiocesium occurred 1-2 years after deposition, followed by an exponential decrease. Concentrations of incorporated 90Sr increased up to the tenth year after deposition. The activity concentrations of transuranic elements (238Pu, 239,240Pu, 241Pu and 241Am) were much lower than those of the other radionuclides, in the studied animals. A considerable activity of 241Am in animals from areas with high levels of contamination was firstly detected 5 years after deposition, it increased up to the tenth year and is expected to increase further in the future. Maximal values of the whole-body absorbed dose rates occurred during the year of deposition, followed by a decrease in the subsequent period. Generally, this decrease was monotonic, mainly determined by the decrease of the

  14. Risk assessment of soil-based exposures to plutonium at experimental sites located on the Nevada Test Site and adjoining areas

    SciTech Connect

    Layton, D.W.; Anspaugh, L.R.; Bogen, K.T.; Straume, T.

    1993-06-01

    In the late 1950s and early 1960s, a series of tests was conducted at or near the Nevada Test Site to study issues involving plutonium-bearing devices. These tests resulted in the dispersal of about 5 TBq of {sup 239,240}Pu on the surficial soils at the test locations. Access to the sites is strictly controlled; therefore, it does not constitute a threat to human health at the present time. However, because the residual {sup 239} Pu decays slowly (half-life of 24,110 y), the sites could indeed represent a long-term hazard if they are not remediated and if institutional controls are lost. To investigate the magnitude of the potential health risks for this no-remediation case, we defined three basic exposure scenarios that could bring individuals in contact with {sup 239,240}Pu at the sites: (1) a resident living in a subdivision located at a test site, (2) a resident farmer, and (3) a worker at a commercial facility. Our screening analyses indicated that doses to organs are dominated by the intemal deposition of Pu via the inhalation pathway, and thus our risk assessment focused on those factors that affect inhalation exposures and associated doses, including inhalation rates, activity patterns, tenure at a residence or occupation, indoor/outdoor air relationships, and resuspension outdoors. Cancer risks were calculated as a function of lifetime cumulative doses to the key target organs (i.e., bone surface, liver, and lungs) and risk factors for those organs. Uncertainties in the predicted cancer risks were analyzed using Monte-Carlo simulations of the probability distributions used to represent assessment parameters. The principal sources of uncertainty in the estimated risks were population mobility, the relationship between indoor and outdoor contaminant levels, and the dose and risk factors for bone, liver, and lung.

  15. Characterization and Source Term Assessments of Radioactive Particles from Marshall Islands Using Non-Destructive Analytical Techniques

    SciTech Connect

    Jernstrom, J; Eriksson, M; Simon, R; Tamborini, G; Bildstein, O; Carlos-Marquez, R; Kehl, S R; Betti, M; Hamilton, T

    2005-06-11

    A considerable fraction of radioactivity entering the environment from different nuclear events is associated with particles. The impact of these events can only be fully assessed where there is some knowledge about the mobility of particle bound radionuclides entering the environment. The behavior of particulate radionuclides is dependent on several factors, including the physical, chemical and redox state of the environment, the characteristics of the particles (e.g., the chemical composition, crystallinity and particle size) and on the oxidative state of radionuclides contained in the particles. Six plutonium-containing particles stemming from Runit Island soil (Marshall Islands) were characterized using non-destructive analytical and microanalytical methods. By determining the activity of {sup 239,240}Pu and {sup 241}Am isotopes from their gamma peaks structural information related to Pu matrix was obtained, and the source term was revealed. Composition and elemental distribution in the particles were studied with synchrotron radiation based micro X-ray fluorescence (SR-{mu}-XRF) spectrometry. Scanning electron microscope equipped with energy dispersive X-ray detector (SEMEDX) and secondary ion mass spectrometer (SIMS) were used to examine particle surfaces. Based on the elemental composition the particles were divided into two groups; particles with plain Pu matrix, and particles where the plutonium is included in Si/O-rich matrix being more heterogeneously distributed. All of the particles were identified as fragments of initial weapons material. As containing plutonium with low {sup 240}Pu/{sup 239}Pu atomic ratio, {approx}2-6%, which corresponds to weapons grade plutonium, the source term was identified to be among the safety tests conducted in the history of Runit Island.

  16. Sensitivity of the Antineutrino Emission from Reactors to the Fuel Content

    SciTech Connect

    Hayes-Sterbenz, Anna C

    2012-06-25

    We investigated the antineutrino signals for several reactor core designs. In all cases we found that the antineutrino signals are distinct. The signals are distinguishable by the combination of their magnitudes and their rate of change with fuel burn-up. If the thermal power of the reactor is known, the overall uncertainty in the antineutrino flux emitted from the reactor is about 5%. The quoted uncertainty in the number of antineutrinos per fission for {sup 235}U, {sup 239}Pu, and {sup 241}Pu is less than 3% and for {sup 238}U is 8%. When folded with the uncertainty in the thermal power measurement and the uncertainty in converting the thermal power to a fission rate, the total antineutrino flux is typically quoted with an accuracy of 3-5%. This overall uncertainty in the antineutrino flux, together with the calculations presented here, suggests that the differences in fuels for the class of reactor designed considered would be detectable using antineutrino monitoring.

  17. Reactor vessel fluence evaluation and dosimetry

    SciTech Connect

    Lois, L. )

    1992-01-01

    The methodology currently in use for the estimation of the fast neutron fluence to the pressure vessel (inside surface and reactor cavity) is based on discrete ordinates two-dimensional codes such as DOT or its updated version DORT. This methodology assumes a P[sub 3] scattering, an S[sub 8] quadrature approximation, and cross sections based on the ENDF/B-IV file. Associated one-dimensional codes are often used for the cross-section collapsing portion of the calculation. The neutron spectrum at the pressure vessel location of interest is estimated assuming a [sup 235]U, [sup 239]Pu, or [sup 241]Pu source spectrum or an appropriate combination thereof. The two-dimensional codes and associated methodologies were benchmarked in the early eighties using the results of the PCA and PSF Oak Ridge National Laboratory reactor experiments. The benchmarking experiments were estimated to provide an uncertainty of [approx]10%. The results of the calculations applied to a reactor were estimated to have an uncertainty of [approx]20%. This level of uncertainty was assumed in the estimation of the margin term defined in 10CFR50.61

  18. Plutonium process control using an advanced on-line gamma monitor for uranium, plutonium, and americium

    SciTech Connect

    Marsh, S.F.; Miller, M.C.

    1987-05-01

    An on-line gamma monitor has been developed to profile uranium, plutonium, and americium in waste and product streams of the anion exchange process used to recover and purify plutonium at the Los Alamos Plutonium Facility. The gamma monitor employs passive gamma spectrometry to measure /sup 241/Am and /sup 239/Pu, based on their 59.5-keV and 129-keV gamma rays, respectively. Because natural and depleted uranium present in typical process streams have no gamma rays suitable for measurement by such passive methods, uranium measurement requires a novel and less direct technique. Plutonium-241, which is always present in plutonium processed at Los Alamos, decays primarily by beta emission to form /sup 241/Am. However, a small fraction of /sup 241/Pu decays by alpha emission to 6.8-day /sup 237/U. The short half-life and 208-keV gamma energy of /sup 237/U make it an ideal radiotracer to mark the position of macro amounts of uranium impurity in the separation process. The real-time data obtained from an operating process allow operators to optimize many process parameters. The gamma monitor also provides a permanent record of the daily performance of each ion exchange system. 2 refs., 12 figs.

  19. Biokinetics of sup 237 Pu citrate and nitrate in the rat: Implications for Pu studies in man

    SciTech Connect

    Talbot, R.J.; Knight, D.A.; Morgan, A. )

    1990-08-01

    Plutonium-237 decays mainly by electron capture with a half-life of 45 d. Alpha particles are emitted in only 5 x 10(-3)% of its disintegrations. This nuclide can now be produced with relatively small amounts of alpha-emitting contaminants so that, in principle, {sup 237}Pu can be used for studies of Pu biokinetics in man. However, because of its high specific activity, there was some doubt that its metabolism would be the same as that of the alpha- and beta-emitting isotopes of Pu normally encountered in the nuclear industry. In this study, the biokinetics of nearly pure, high specific activity {sup 237}Pu are compared with those of lower specific activity, impure {sup 237}Pu containing significant amounts of alpha-emitting Pu, following administration to rats by intravenous injection as the citrate. Both the distribution and excretion of the pure and impure {sup 237}Pu used in the two studies were similar and also in good agreement with the results of previously reported studies using {sup 239}Pu and {sup 241}Pu citrate, thus validating the use of {sup 237}Pu for studies of Pu metabolism in man. Data on the biokinetics of {sup 237}Pu nitrate are also included.

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

    SciTech Connect

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

    1998-12-04

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

  1. Distributions of cell populations within. cap alpha. -particle range of plutonium deposits in the rat and beagle testis

    SciTech Connect

    Miller, S.C.; Rowland, H.G.; Bowman, B.M.

    1985-01-01

    Plutonium is not uniformly distributed in testicular tissues; thus some cell populations may receive larger or smaller radiation exposures than would be expected if the nuclide were uniformly distributed. The distributions of cell populations within ..cap alpha..-particle range of Pu deposits in rat and beagle testes were determined. The data were collected from autoradiographs of testicular tissues containing /sup 241/Pu. A cell distribution factor (CDF) was determined for each cell population and is defined as the average number of each cell type within ..cap alpha..-particle range of each observed Pu deposit relative to the number of each cell type that would be expected within ..cap alpha..-particle range of each Pu deposit, if the deposits were distributed uniformly. In addition, the percentage of the spermatogonial stem cell population within ..cap alpha..-particle range of Pu deposits was determined. The largest CDFs seen in both species were in the interstitial tissues, particulary for Leydig cells. Because the organization of testicular tissues in the beagle is quite different from rodents but more similar to human, the results from this study suggest that extrapolations from rodents to humans may tend to overestimate the potential for radiation exposure to spermatogonial stem cells as well as the fraction of the spermatogonial stem cell population at risk to exposure from internally deposited /sup 239/Pu.

  2. Application of Neutron-Absorbing Structural-Amorphous Metal (SAM) Coatings for Spent Nuclear Fuel (SNF) Container to Enhance Criticality Safety Controls

    SciTech Connect

    Choi, J; Lee, C; Day, D; Wall, M; Saw, C; MoberlyChan, W; Farmer, J; Boussoufl, M; Liu, B; Egbert, H; Branagan, D; D'Amato, A

    2006-11-13

    Spent nuclear fuel contains fissionable materials ({sup 235}U, {sup 239}Pu, {sup 241}Pu, etc.). Neutron multiplication and the potential for criticality are enhanced by the presence of a moderator during cask loading in water, water incursion in accidents conditions during spent fuel storage or transport. To prevent nuclear criticality in spent fuel storage, transportation, and during disposal, neutron-absorbing materials (or neutron poisons, such as borated stainless steel, Boral{trademark}, Metamic{trademark}, Ni-Gd, and others) would have to be applied. The success in demonstrating that the High-Performance Corrosion-Resistant material (HPCRM) can be thermally applied as coating onto base metal to provide for corrosion resistance for many naval applications raises the interest in applying the HPCRM to USDOE/OCRWM spent fuel management program. The fact that the HPCRM relies on the high content of boron to make the material amorphous--an essential property for corrosion resistance--and that the boron has to be homogeneously distributed in the HPCRM qualify the material to be a neutron poison.

  3. Determination of the Sensitivity of the Antineutrino Probe for Reactor Core Monitoring

    SciTech Connect

    Cormon, S.; Fallot, M. Bui, V.-M.; Cucoanes, A.; Estienne, M.; Lenoir, M.; Onillon, A.; Shiba, T.; Yermia, F.; Zakari-Issoufou, A.-A.

    2014-06-15

    This paper presents a feasibility study of the use of the detection of reactor-antineutrinos (ν{sup ¯}{sub e}) for non proliferation purpose. To proceed, we have started to study different reactor designs with our simulation tools. We use a package called MCNP Utility for Reactor Evolution (MURE), initially developed by CNRS/IN2P3 labs to study Generation IV reactors. The MURE package has been coupled to fission product beta decay nuclear databases for studying reactor antineutrino emission. This method is the only one able to predict the antineutrino emission from future reactor cores, which don't use the thermal fission of {sup 235}U, {sup 239}Pu and {sup 241}Pu. It is also the only way to include off-equilibrium effects, due to neutron captures and time evolution of the fission product concentrations during a reactor cycle. We will present here the first predictions of antineutrino energy spectra from innovative reactor designs (Generation IV reactors). We will then discuss a summary of our results of non-proliferation scenarios involving the latter reactor designs, taking into account reactor physics constraints.

  4. Contribution of Recently Measured Nuclear Data to Reactor Antineutrino Energy Spectra Predictions

    SciTech Connect

    Estienne, M.; Bui, V.M.; Cucoanes, A.; Elnimr, M.; Giot, L.; Martino, J.; Onillon, A.; Porta, A.; Pronost, G.; Remoto, A.; Yermia, F.; Zakari-Issoufou, A.-A.

    2014-06-15

    The aim of this work is to study the impact of the inclusion of the recently measured β decay properties of the {sup 102,104,105,106,107}Tc, {sup 105}Mo, and {sup 101}Nb nuclei in the calculation of the antineutrino (anti-ν) energy spectra arising after the fissions of the four main fissile isotopes {sup 235,238}U, and {sup 239,241}Pu in PWRs. These β feeding probabilities, measured using the Total Absorption Technique (TAS) at the JYFL facility of Jyväskylä, have been found to play a major role in the γ component of the decay heat for {sup 239}Pu in the 4-3000 s range. Following the fission product summation method, the calculation was performed using the MCNP Utility Reactor Evolution code (MURE) coupled to the experimental spectra built from β decay properties of the fission products taken from evaluated databases. These latest TAS data are found to have a significant effect on the Pu isotope energy spectra and on the spectrum of {sup 238}U showing the importance of their measurement for a better assessment of the reactor anti-ν energy spectrum, as well as importance for fundamental neutrino physics experiments and neutrino applied physics.

  5. Determination of antineutrino spectra from nuclear reactors

    SciTech Connect

    Huber, Patrick

    2011-08-15

    In this paper we study the effect of well-known higher-order corrections to the allowed {beta}-decay spectrum on the determination of antineutrino spectra resulting from the decays of fission fragments. In particular, we try to estimate the associated theory errors and find that induced currents like weak magnetism may ultimately limit our ability to improve the current accuracy and under certain circumstance could even greatly increase the theoretical errors. We also perform a critical evaluation of the errors associated with our method to extract the antineutrino spectrum using synthetic {beta} spectra. It turns out that a fit using only virtual {beta} branches with a judicious choice of the effective nuclear charge provides results with a minimal bias. We apply this method to actual data for {sup 235}U, {sup 239}Pu, and {sup 241}Pu and confirm, within errors, recent results, which indicate a net 3% upward shift in energy-averaged antineutrino fluxes. However, we also find significant shape differences which can, in principle, be tested by high-statistics antineutrino data samples.

  6. Contribution of Recently Measured Nuclear Data to Reactor Antineutrino Energy Spectra Predictions

    NASA Astrophysics Data System (ADS)

    Estienne, M.; Fallot, M.; Cormon, S.; Algora, A.; Bui, V. M.; Cucoanes, A.; Elnimr, M.; Giot, L.; Jordan, D.; Martino, J.; Onillon, A.; Porta, A.; Pronost, G.; Remoto, A.; Taín, J. L.; Yermia, F.; Zakari-Issoufou, A.-A.

    2014-06-01

    The aim of this work is to study the impact of the inclusion of the recently measured β decay properties of the 102,104,105,106,107Tc, 105Mo, and 101Nb nuclei in the calculation of the antineutrino (anti-ν) energy spectra arising after the fissions of the four main fissile isotopes 235,238U, and 239,241Pu in PWRs. These β feeding probabilities, measured using the Total Absorption Technique (TAS) at the JYFL facility of Jyväskylä, have been found to play a major role in the γ component of the decay heat for 239Pu in the 4-3000 s range. Following the fission product summation method, the calculation was performed using the MCNP Utility Reactor Evolution code (MURE) coupled to the experimental spectra built from β decay properties of the fission products taken from evaluated databases. These latest TAS data are found to have a significant effect on the Pu isotope energy spectra and on the spectrum of 238U showing the importance of their measurement for a better assessment of the reactor anti-ν energy spectrum, as well as importance for fundamental neutrino physics experiments and neutrino applied physics.

  7. Estimation of Radiation Doses in the Marshall Islands Based on Whole Body Counting of Cesium-137 (137Cs) and Plutonium Urinalysis

    SciTech Connect

    Daniels, J; Hickman, D; Kehl, S; Hamilton, T

    2007-06-11

    measurement. The amount of {sup 137}Cs detected is often reported in activity units of kilo-Becquerel (kBq), where 1 kBq equals 1000 Bq and 1 Bq = 1 nuclear transformation per second (t s{sup -1}). [However, in the United States the Curie (Ci) continues to be used as the unit of radioactivity; where 1 Ci = 3.7 x 10{sup 10} Bq.] The detection of {sup 239}Pu and {sup 240}Pu in bioassay (urine) samples indicates the presence of internally deposited (systemic) plutonium in the body. Urine samples that are collected in the Marshall Islands from volunteers participating in the RSMP are transported to LLNL, where measurements for {sup 239+240}Pu are performed using a state-of-the-art technology based on Accelerator Mass Spectrometry (AMS) (Hamilton et al., 2004, 2007; Brown et al., 2004). The urinary excretion of plutonium by RSMP volunteers is usually described in activity units, expressed as micro-Becquerel ({micro}Bq) of {sup 239+240}Pu (i.e., representing the sum of the {sup 239}Pu and {sup 240}Pu activity) excreted (lost) per day (d{sup -1}), where 1 {micro}Bq d{sup -1} = 10{sup -6} Bq d{sup -1} and 1 Bq = 1 t s{sup -1}. The systemic burden of plutonium is then estimated from biokinetic relationships as described by the International Commission on Radiological Protection (e.g., see ICRP, 1990). In general, nuclear transformations are accompanied by the emission of energy and/or particles in the form of gamma rays ({gamma}), beta particles ({beta}), and/or alpha particles ({alpha}). Tissues in the human body may adsorb these emissions, where there is a potential for any deposited energy to cause biological damage. The general term used to quantify the extent of any radiation exposure is referred to as the dose. The equivalent dose is defined by the average absorbed dose in an organ or tissue weighted by the average quality factor for the type and energy of the emission causing the dose. The effective dose equivalent (EDE; as applied to the whole body), is the sum of the average

  8. Automated monitoring of in-process plutonium concentration

    SciTech Connect

    Rebagay, T.V.; Huff, G.A.; Hofstetter, K.J.

    1982-01-01

    An automated low-level plutonium monitor capable of measuring total and isotopic plutonium abundances in solutions is described. To demonstrate near real-time assay of in-process plutonium, we installed a monitor on a flowing stream of a laboratory experimental facility. The stream was composed of uranium and plutonium in nitric acid at concentrations typical of a plant using a Purex flowsheet modified to permit coprocessing of spent nuclear fuel. The plutonium isotopic abundances were typical of those found in light water reactor grade fuel. The plutonium isotopic concentrations in the stream with the exception of /sup 242/Pu were determined by direct lambda-ray spectrometry. The /sup 242/Pu abundance was calculated by isotope correlation techniques. Additional data were obtained on coprocessed uranium-plutonium solutions denatured with fission products (/sup 103/Ru, /sup 144/Ce//sup 144/Pr, and /sup 95/Zr//sup 95/Nb). /sup 239/Pu and /sup 240/Pu concentrations can be determined to within 2% and 5%, respectively, of the concentrations determined by mass spectrometry.

  9. Chemical resolution of Pu+ from U+ and Am+ using a band-pass reaction cell inductively coupled plasma mass spectrometer.

    PubMed

    Tanner, Scott D; Li, Chunsheng; Vais, Vladimir; Baranov, Vladimir I; Bandura, Dmitry R

    2004-06-01

    Determination of the concentration and distribution of the Pu and Am isotopes is hindered by the isobaric overlaps between the elements themselves and U, generally requiring time-consuming chemical separation of the elements. A method is described in which chemical resolution of the elemental ions is obtained through ion-molecule reactions in a reaction cell of an ICPMS instrument. The reactions of "natural" U(+), (242)Pu(+), and (243)Am(+) with ethylene, carbon dioxide, and nitric oxide are reported. Since the net sensitivities to the isotopes of an element are similar, chemical resolution is inferred when one isobaric element reacts rapidly with a given gas and the isobar (or in this instance surrogate isotope) is unreactive or slowly reactive. Chemical resolution of the m/z 238 isotopes of U and Pu can be obtained using ethylene as a reaction gas, but little improvement in the resolution of the m/z 239 isobars is obtained. However, high efficiency of reaction of U(+) and UH(+) with CO(2), and nonreaction of Pu(+), allows the sub-ppt determination of (239)Pu, (240)Pu, and (242)Pu (single ppt for (238)Pu) in the presence of 7 orders of magnitude excess U matrix without prior chemical separation. Similarly, oxidation of Pu(+) by NO, and nonreaction of Am(+), permit chemical resolution of the isobars of Pu and Am over 2-3 orders of magnitude relative concentration. The method provides the potential for analysis of the actinides with reduced sample matrix separation. PMID:15167781

  10. Apparatus and method for quantitative assay of generic transuranic wastes from nuclear reactors

    DOEpatents

    Caldwell, John T.; Kunz, Walter E.; Atencio, James D.

    1984-01-01

    A combination of passive and active neutron measurements which yields quantitative information about the isotopic composition of transuranic wastes from nuclear power or weapons material manufacture reactors is described. From the measurement of prompt and delayed neutron emission and the incidence of two coincidentally emitted neutrons from induced fission of fissile material in the sample, one can quantify .sup.233 U, .sup.235 U and .sup.239 Pu isotopes in waste samples. Passive coincidence counting, including neutron multiplicity measurement and determination of the overall passive neutron flux additionally enables the separate quantitative evaluation of spontaneous fission isotopes such as .sup.240 Pu, .sup.244 Cm and .sup.252 Cf, and the spontaneous alpha particle emitter .sup.241 Am. These seven isotopes are the most important constituents of wastes from nuclear power reactors and once the mass of each isotope present is determined by the apparatus and method of the instant invention, the overall alpha particle activity can be determined to better than 1 nCi/g from known radioactivity data. Therefore, in addition to the quantitative analysis of the waste sample useful for later reclamation purposes, the alpha particle activity can be determined to decide whether "permanent" low-level burial is appropriate for the waste sample.

  11. Pu isotopes in soils collected downwind from Lop Nor: regional fallout vs. global fallout

    PubMed Central

    Bu, Wenting; Ni, Youyi; Guo, Qiuju; Zheng, Jian; Uchida, Shigeo

    2015-01-01

    For the first time, soil core samples from the Jiuquan region have been analyzed for Pu isotopes for radioactive source identification and radiological assessment. The Jiuquan region is in downwind from the Lop Nor Chinese nuclear test (CNT) site. The high Pu inventories (13 to 546 Bq/m2) in most of the sampling locations revealed that this region was heterogeneously contaminated by the regional fallout Pu from the CNTs. The contributions of the CNTs to the total Pu in soils were estimated to be more than 40% in most cases. The 240Pu/239Pu atom ratios in the soils ranged from 0.059 to 0.186 with an inventory-weighted average of 0.158, slightly lower than that of global fallout. This atom ratio could be considered as a mixed fingerprint of Pu from the CNTs. In addition, Pu in soils of Jiuquan region had a faster downward migration rate compared with other investigated places in China. PMID:26184740

  12. Resuspension and atmospheric transport of radionuclides due to wildfires near the Chernobyl Nuclear Power Plant in 2015: An impact assessment

    NASA Astrophysics Data System (ADS)

    Evangeliou, N.; Zibtsev, S.; Myroniuk, V.; Zhurba, M.; Hamburger, T.; Stohl, A.; Balkanski, Y.; Paugam, R.; Mousseau, T. A.; Møller, A. P.; Kireev, S. I.

    2016-05-01

    In April and August 2015, two major fires in the Chernobyl Exclusion Zone (CEZ) caused concerns about the secondary radioactive contamination that might have spread over Europe. The present paper assessed, for the first time, the impact of these fires over Europe. About 10.9 TBq of 137Cs, 1.5 TBq of 90Sr, 7.8 GBq of 238Pu, 6.3 GBq of 239Pu, 9.4 GBq of 240Pu and 29.7 GBq of 241Am were released from both fire events corresponding to a serious event. The more labile elements escaped easier from the CEZ, whereas the larger refractory particles were removed more efficiently from the atmosphere mainly affecting the CEZ and its vicinity. During the spring 2015 fires, about 93% of the labile and 97% of the refractory particles ended in Eastern European countries. Similarly, during the summer 2015 fires, about 75% of the labile and 59% of the refractory radionuclides were exported from the CEZ with the majority depositing in Belarus and Russia. Effective doses were above 1 mSv y‑1 in the CEZ, but much lower in the rest of Europe contributing an additional dose to the Eastern European population, which is far below a dose from a medical X-ray.

  13. Using anisotropies in prompt fission neutron coincidences to assess the neutron multiplication of highly multiplying subcritical plutonium assemblies

    NASA Astrophysics Data System (ADS)

    Mueller, J. M.; Mattingly, J.

    2016-07-01

    There is a significant and well-known anisotropy between the prompt neutrons emitted from a single fission event; these neutrons are most likely to be observed at angles near 0° or 180° relative to each other. However, the propagation of this anisotropy through different generations of a fission chain reaction has not been previously studied. We have measured this anisotropy in neutron-neutron coincidences from a subcritical highly-multiplying assembly of plutonium metal. The assembly was a 4.5 kg α-phase plutonium metal sphere composed of 94% 239Pu and 6% 240Pu by mass. Data were collected using two EJ-309 liquid scintillators and two EJ-299 plastic scintillators. The angular distribution of neutron-neutron coincidences was measured at 90° and 180° and found to be largely isotropic. Simulations were performed using MCNPX-PoliMi of similar plutonium metal spheres of varying sizes and a correlation between the neutron multiplication of the assembly and the anisotropy of neutron-neutron coincidences was observed. In principle, this correlation could be used to assess the neutron multiplication of an unknown assembly.

  14. Plutonium and uranium contamination in soils from former nuclear weapon test sites in Australia

    NASA Astrophysics Data System (ADS)

    Child, D. P.; Hotchkis, M. A. C.

    2013-01-01

    The British government performed a number of nuclear weapon tests on Australian territory from 1952 through to 1963 with the cooperation of the Australian government. Nine fission bombs were detonated in South Australia at Emu Junction and Maralinga, and a further three fission weapons were detonated in the Monte Bello Islands off the coast of Western Australia. A number of soil samples were collected by the Australian Radiation Laboratories in 1972 and 1978 during field surveys at these nuclear weapon test sites. They were analysed by gamma spectrometry and, for a select few samples, by alpha spectrometry to measure the remaining activities of fission products, activation products and weapon materials. We have remeasured a number of these Montebello Islands and Emu Junction soil samples using the ANTARES AMS facility, ANSTO. These samples were analysed for plutonium and uranium isotopic ratios and isotopic concentrations. Very low 240Pu/239Pu ratios were measured at both sites (∼0.05 for Alpha Island and ∼0.02 for Emu Field), substantially below global fallout averages. Well correlated but widely varying 236U and plutonium concentrations were measured across both sites, but 233U did not correlate with these other isotopes and instead showed correlation with distance from ground zero, indicating in situ production in the soils.

  15. Resuspension and atmospheric transport of radionuclides due to wildfires near the Chernobyl Nuclear Power Plant in 2015: An impact assessment

    PubMed Central

    Evangeliou, N.; Zibtsev, S.; Myroniuk, V.; Zhurba, M.; Hamburger, T.; Stohl, A.; Balkanski, Y.; Paugam, R.; Mousseau, T. A.; Møller, A. P.; Kireev, S. I.

    2016-01-01

    In April and August 2015, two major fires in the Chernobyl Exclusion Zone (CEZ) caused concerns about the secondary radioactive contamination that might have spread over Europe. The present paper assessed, for the first time, the impact of these fires over Europe. About 10.9 TBq of 137Cs, 1.5 TBq of 90Sr, 7.8 GBq of 238Pu, 6.3 GBq of 239Pu, 9.4 GBq of 240Pu and 29.7 GBq of 241Am were released from both fire events corresponding to a serious event. The more labile elements escaped easier from the CEZ, whereas the larger refractory particles were removed more efficiently from the atmosphere mainly affecting the CEZ and its vicinity. During the spring 2015 fires, about 93% of the labile and 97% of the refractory particles ended in Eastern European countries. Similarly, during the summer 2015 fires, about 75% of the labile and 59% of the refractory radionuclides were exported from the CEZ with the majority depositing in Belarus and Russia. Effective doses were above 1 mSv y−1 in the CEZ, but much lower in the rest of Europe contributing an additional dose to the Eastern European population, which is far below a dose from a medical X-ray. PMID:27184191

  16. Survey of plutonium and uranium atom ratios and activity levels in Mortandad Canyon

    SciTech Connect

    Gallaher, B.M.; Efurd, D.W.; Rokop, D.J.; Benjamin, T.M.; Stoker, A.K.

    1997-10-01

    For more than three decades, Mortandad Canyon has been the primary release area of treated liquid radioactive waste from the Los Alamos National Laboratory (Laboratory). In this survey, six water samples and seven stream sediment samples collected in Mortandad Canyon were analyzed by thermal ionization mass spectrometry to determine the plutonium and uranium activity levels and atom ratios. By measuring the {sup 240}Pu/{sup 239}Pu atom ratios, the Laboratory plutonium component was evaluated relative to that from global fallout. Measurements of the relative abundance of {sup 235}U and {sup 236}U were also used to identify non-natural components. The survey results indicate that the Laboratory plutonium and uranium concentrations in waters and sediments decrease relatively rapidly with distance downstream from the major industrial sources. Plutonium concentrations in shallow alluvial groundwater decrease by approximately 1,000-fold along a 3,000-ft distance. At the Laboratory downstream boundary, total plutonium and uranium concentrations were generally within regional background ranges previously reported. Laboratory-derived plutonium is readily distinguished from global fallout in on-site waters and sediments. The isotopic ratio data indicate off-site migration of trace levels of Laboratory plutonium in stream sediments to distances approximately two miles downstream of the Laboratory boundary.

  17. Survey of plutonium and uranium atom ratios and activity levels in Mortandad Canyon

    SciTech Connect

    Gallaher, B.M.; Benjamin, T.M.; Rokop, D.J.; Stoker, A.K.

    1997-09-22

    For more than three decades Mortandad Canyon has been the primary release area of treated liquid radioactive waste from the Los Alamos National Laboratory (Laboratory). In this survey, six water samples and seven stream sediment samples collected in Mortandad Canyon were analyzed by thermal ionization mass spectrometry (TIMS) to determine the plutonium and uranium activity levels and atom ratios. Be measuring the {sup 240}Pu/{sup 239}Pu atom ratios, the Laboratory plutonium component was evaluated relative to that from global fallout. Measurements of the relative abundance of {sup 235}U and {sup 236}U were also used to identify non-natural components. The survey results indicate the Laboratory plutonium and uranium concentrations in waters and sediments decrease relatively rapidly with distance downstream from the major industrial sources. Plutonium concentrations in shallow alluvial groundwater decrease by approximately 1000 fold along a 3000 ft distance. At the Laboratory downstream boundary, total plutonium and uranium concentrations were generally within regional background ranges previously reported. Laboratory derived plutonium is readily distinguished from global fallout in on-site waters and sediments. The isotopic ratio data indicates off-site migration of trace levels of Laboratory plutonium in stream sediments to distances approximately two miles downstream of the Laboratory boundary.

  18. The new extended HVE 1 MV multi-element AMS system for low background installed at the Aarhus AMS Dating Centre

    NASA Astrophysics Data System (ADS)

    Heinemeier, Jan; Olsen, Jesper; Klein, Matthias; Mous, Dirk

    2015-10-01

    Aarhus University, Department of Physics and Astronomy has installed a new multi-element AMS system at its AMS 14C Dating Centre. It is manufactured by High Voltage Engineering Europa B.V. and based on a 1 MV Tandetron accelerator with a dual gas system (Ar and He) for the terminal stripper. The injector is equipped with two independently operating ion sources and a 120 degree bouncer magnet with high resolution and a bending power of 340 amu at 35 keV, supporting the measurements of actinides. The high-energy (HE) spectrometer features a degrader foil for isobar suppression and a second HE magnet for suppression of ions scattered in the HE ESA, which ensures very low detection limits. The control system supports different methods for isotope switching: "traditional" fast bouncing, adjusting the Hall-probe controlled magnet fields (for, e.g., 3H), or changing the complete set of operation parameters (e.g., for actinides). During the on-site acceptance tests, the following background levels were measured: <10-16 for tritium, <10-15 for 14C, <10-15 for 10Be (down to <10-16 in a later 3 h run), 2 × 10-15 for 26Al, 2 × 10-13 for 129I and 9 × 10-12 for 41Ca and for 239Pu (240Pu) a 1.5 (0.5) pg per mg iron, which demonstrates the multi-element capability of the system.

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

    PubMed

    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. Actinide Targets for Neutron Cross Section Measurements (C)

    SciTech Connect

    J. D. Baker; C. A. McGrath

    2006-04-01

    The Advanced Fuel Cycle Initiative (AFCI) and the Generation IV Reactor Initiative have demonstrated a lack of detailed neutron cross-sections for certain "minor" actinides, those other than the most common (235U, 238U, and 239Pu). For some closed-fuel-cycle reactor designs more than 50% of reactivity will, at some point, be derived from “minor” actinides that currently have poorly known (n,g) and (n,f) cross sections. A program of measurements under AFCI has begun to correct this. One of the initial hurdles has been to produce well-characterized, highly isotopically enriched, and chemically pure actinide targets on thin backings. Using a combination of resurrected techniques and new developments, we have made a series of targets including highly enriched 240Pu, and 242Pu. Thus far, we have electrodeposited these actinide targets. In the future, we plan to study reductive distillation to achieve homogeneous, adherent targets on thin metal foils and polymer backings. As we move forward, separated isotopes become scarcer, and safety concerns become greater. The chemical purification and electodeposition techniques will be described.

  1. Concurrent determination of 237Np and Pu isotopes using ICP-MS: analysis of NIST environmental matrix standard reference materials 4357, 1646a, and 2702.

    PubMed

    Matteson, Brent S; Hanson, Susan K; Miller, Jeffrey L; Oldham, Warren J

    2015-04-01

    An optimized method was developed to analyze environmental soil and sediment samples for (237)Np, (239)Pu, and (240)Pu by ICP-MS using a (242)Pu isotope dilution standard. The high yield, short time frame required for analysis, and the commercial availability of the (242)Pu tracer are significant advantages of the method. Control experiments designed to assess method uncertainty, including variation in inter-element fractionation that occurs during the purification protocol, suggest that the overall precision for measurements of (237)Np is typically on the order of ± 5%. Measurements of the (237)Np concentration in a Peruvian Soil blank (NIST SRM 4355) spiked with a known concentration of (237)Np tracer confirmed the accuracy of the method, agreeing well with the expected value. The method has been used to determine neptunium and plutonium concentrations in several environmental matrix standard reference materials available from NIST: SRM 4357 (Radioactivity Standard), SRM 1646a (Estuarine Sediment) and SRM 2702 (Inorganics in Marine Sediment). PMID:25644752

  2. Sequential injection method for rapid and simultaneous determination of 236U, 237Np, and Pu isotopes in seawater.

    PubMed

    Qiao, Jixin; Hou, Xiaolin; Steier, Peter; Golser, Robin

    2013-11-19

    An automated analytical method implemented in a novel dual-column tandem sequential injection (SI) system was developed for simultaneous determination of (236)U, (237)Np, (239)Pu, and (240)Pu in seawater samples. A combination of TEVA and UTEVA extraction chromatography was exploited to separate and purify target analytes, whereupon plutonium and neptunium were simultaneously isolated and purified on TEVA, while uranium was collected on UTEVA. The separation behavior of U, Np, and Pu on TEVA-UTEVA columns was investigated in detail in order to achieve high chemical yields and complete purification for the radionuclides of interest. (242)Pu was used as a chemical yield tracer for both plutonium and neptunium. (238)U was quantified in the sample before the separation for deducing the (236)U concentration from the measured (236)U/(238)U atomic ratio in the separated uranium target using accelerator mass spectrometry. Plutonium isotopes and (237)Np were measured using inductively coupled plasma mass spectrometry after separation. The analytical results indicate that the developed method is robust and efficient, providing satisfactory chemical yields (70-100%) of target analytes and relatively short analytical time (8 h/sample). PMID:24134480

  3. The Influence of Hydrothermal Plumes on the Distribution of Anthropogenic Radionuclides Between the Particulate and Dissolved Phases: Results from U.S. Geotraces Equatorial Pacific Zonal Transect GP16

    NASA Astrophysics Data System (ADS)

    Kenna, T. C.; Villa Alfageme, M.; Casacuberta Arola, N.; Masque, P.

    2014-12-01

    Here we present and discuss the results from the analysis of samples from selected stations collected on the US GEOTRACES Equatorial Pacific Zonal Transect (GP16) completed in 2013. The section, between Peru and Tahiti, encompasses a range of processes that influence the supply, removal, and internal cycling of trace metals and offers the opportunity to gain a better understanding of the drivers of the transport and fate of contaminants in the ocean. The capability to analyze water and filtered particulate samples in the quantities available, allows us to determine the partitioning of selected radionuclides among dissolved and particulate forms (Kd) and estimate Pu-particulate fluxes. The overarching objective of our work is to determine the concentrations of several anthropogenic radionuclides, including 239Pu, 240Pu, 237Np, and 137Cs with sufficient resolution to define their basin-wide distributions in the Pacific Ocean. Data collected in the East Pacific Rise hydrothermal plume allows a discussion on the partitioning behavior of plutonium and neptunium.

  4. Mercuric iodide room-temperature array detectors for gamma-ray imaging

    SciTech Connect

    Patt, B.

    1994-11-15

    Significant progress has been made recently in the development of mercuric iodide detector arrays for gamma-ray imaging, making real the possibility of constructing high-performance small, light-weight, portable gamma-ray imaging systems. New techniques have been applied in detector fabrication and then low noise electronics which have produced pixel arrays with high-energy resolution, high spatial resolution, high gamma stopping efficiency. Measurements of the energy resolution capability have been made on a 19-element protypical array. Pixel energy resolutions of 2.98% fwhm and 3.88% fwhm were obtained at 59 keV (241-Am) and 140-keV (99m-Tc), respectively. The pixel spectra for a 14-element section of the data is shown together with the composition of the overlapped individual pixel spectra. These techniques are now being applied to fabricate much larger arrays with thousands of pixels. Extension of these principles to imaging scenarios involving gamma-ray energies up to several hundred keV is also possible. This would enable imaging of the 208 keV and 375-414 keV 239-Pu and 240-Pu structures, as well as the 186 keV line of 235-U.

  5. Results of Gamma-Ray Measurements from a Recent Demonstration for Russian Technical Experts

    SciTech Connect

    Luke, S J; Archer, D E; Gosnell, T B; Lochner, R T; Morgan, J F; White, G K; Weitz, R

    2001-06-01

    In August 2001, a group of U.S. technical experts demonstrated an Attribute Measurement System with an Information Barrier (AMSIB) for a delegation of Russian technical experts. The purpose of the demonstration was to show that attributes of a classified plutonium item of potential interest to arms control and nonproliferation transparency regimes could be ascertained without releasing any sensitive information. For this demonstration, both gamma-ray and neutron attributes were determined. We consider only the gamma-ray attributes here. The specific plutonium attributes measured were the isotopic ratio of {sup 240}Pu to {sup 239}Pu, the ''age'' of the plutonium (time elapsed since the most recent chemical purification of the plutonium), and the absence of plutonium oxide in the item's storage container. In this paper, we briefly review the technologies employed for the attribute measurements used in the gamma-ray portion of the demonstration, concentrating on the results of the test measurements of the isotopic and age attributes made on unclassified items.

  6. Determination of plutonium in seawater using co-precipitation and inductively coupled plasma mass spectrometry with ultrasonic nebulisation

    NASA Astrophysics Data System (ADS)

    Eroglu, Ahmet E.; McLeod, Cameron W.; Leonard, Kinson S.; McCubbin, David

    1998-08-01

    A flow injection-inductively coupled plasma-mass spectrometric (FI-ICP-MS) procedure, utilising ultrasonic nebulisation with membrane desolvation (USN/MD), has been developed for the determination of plutonium (Pu) in seawater at fg l -1 concentration levels. Seawater samples (1 l), after filtration, were subjected to co-precipitation with NdF 3, followed by ion exchange to enrich Pu and to reject seawater matrix ions and co-existing uranium. The seawater concentrate (1.0 ml) was then analysed by FI-ICP-MS. The limit of detection for 239Pu in seawater based on an enrichment factor of 1000 was 5 fg l -1, and precision at the 0.80 pg l -1 level was 12% RSD. Accuracy was verified via recovery experiments, and by comparing survey data for the Irish Sea with that derived by standard methodology based on co-precipitation and α-spectrometry. Concentrations for dissolved 239Puand240Pu in the Irish Sea were in the range of 0.267-0.941 pg l -1 (0.614-2.164 mBq l -1) and 0.051-0.196 pg l -1 (0.428-1.646 mBq l -1), respectively.

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

    PubMed

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

    2011-01-31

    This paper reports an automated analytical method for rapid determination of plutonium isotopes ((239)Pu and (240)Pu) in environmental solid extracts. Anion exchange chromatographic columns were incorporated in a sequential injection (SI) system to undertake the automated separation of plutonium from matrix and interfering elements. The analytical results most distinctly demonstrated that the crosslinkage of the anion exchanger is a key parameter controlling the separation efficiency. AG 1-×4 type resin was selected as the most suitable sorbent material for analyte separation. Investigation of column 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 10(3) to 10(4). 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 is straightforward and less labor intensive as compared with batch-wise anion exchange chromatographic procedures. Besides, the automated method features low consumption of ion-exchanger and reagents for column washing and elution, with the consequent decrease in the generation of acidic waste, thus bearing green chemical credentials. PMID:21168558

  8. Resuspension and atmospheric transport of radionuclides due to wildfires near the Chernobyl Nuclear Power Plant in 2015: An impact assessment.

    PubMed

    Evangeliou, N; Zibtsev, S; Myroniuk, V; Zhurba, M; Hamburger, T; Stohl, A; Balkanski, Y; Paugam, R; Mousseau, T A; Møller, A P; Kireev, S I

    2016-01-01

    In April and August 2015, two major fires in the Chernobyl Exclusion Zone (CEZ) caused concerns about the secondary radioactive contamination that might have spread over Europe. The present paper assessed, for the first time, the impact of these fires over Europe. About 10.9 TBq of (137)Cs, 1.5 TBq of (90)Sr, 7.8 GBq of (238)Pu, 6.3 GBq of (239)Pu, 9.4 GBq of (240)Pu and 29.7 GBq of (241)Am were released from both fire events corresponding to a serious event. The more labile elements escaped easier from the CEZ, whereas the larger refractory particles were removed more efficiently from the atmosphere mainly affecting the CEZ and its vicinity. During the spring 2015 fires, about 93% of the labile and 97% of the refractory particles ended in Eastern European countries. Similarly, during the summer 2015 fires, about 75% of the labile and 59% of the refractory radionuclides were exported from the CEZ with the majority depositing in Belarus and Russia. Effective doses were above 1 mSv y(-1) in the CEZ, but much lower in the rest of Europe contributing an additional dose to the Eastern European population, which is far below a dose from a medical X-ray. PMID:27184191

  9. DEVELOPMENT OF AN IMPROVED TITANATE-BASED SORBENT FOR STRONTIUM AND ACTINIDE SEPARATIONS UNDER STRONGLY ALKALINE CONDITIONS

    SciTech Connect

    Hobbs, D.; Peters, T.; Taylor-Pashow, K.; Fink, S.

    2010-02-18

    High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove {sup 134,137}Cs, {sup 90}Sr, and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. Separation processes at SRS include the sorption of {sup 90}Sr and alpha-emitting radionuclides onto monosodium titanate (MST) and caustic side solvent extraction of {sup 137}Cs. The MST and separated {sup 137}Cs is encapsulated along with the sludge fraction of high-level waste (HLW) into a borosilicate glass waste form for eventual entombment at a federal repository. The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes {sup 238}Pu, {sup 239}Pu, and {sup 240}Pu; {sup 237}Np; and uranium isotopes, {sup 235}U and {sup 238}U. This paper describes recent results evaluating the performance of an improved sodium titanate material that exhibits increased removal kinetics and capacity for {sup 90}Sr and alpha-emitting radionuclides compared to the current baseline material, MST.

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

    PubMed

    Qiao, Jixin; Hansen, Violeta; Hou, Xiaolin; Aldahan, Ala; Possnert, Göran

    2012-08-01

    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 (129)I (also (127)I), (137)Cs, (232)Th, (238)U and plutonium isotopes ((239)Pu and (240)Pu) 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. PMID:22750199

  11. Apparatus and method for quantitative assay of generic transuranic wastes from nuclear reactors

    DOEpatents

    Caldwell, J.T.; Kunz, W.E.; Atencio, J.D.

    1982-03-31

    A combination of passive and active neutron measurements which yields quantitative information about the isotopic composition of transuranic wastes from nuclear power or weapons material manufacture reactors is described. From the measurement of prompt and delayed neutron emission and the incidence of two coincidentally emitted neutrons from induced fission of fissile material in the sample, one can quantify /sup 233/U, /sup 235/U and /sup 239/Pu isotopes in waste samples. Passive coincidence counting, including neutron multiplicity measurement and determination of the overall passive neutron flux additionally enables the separate quantitative evaluation of spontaneous fission isotopes such as /sup 240/Pu, /sup 244/Cm and /sup 252/Cf, and the spontaneous alpha particle emitter /sup 241/Am. These seven isotopes are the most important constituents of wastes from nuclear power reactors and once the mass of each isotope present is determined by the apparatus and method of the instant invention, the overall alpha particle activity can be determined to better than 1 nCi/g from known radioactivity data. Therefore, in addition to the quantitative analysis of the waste sample useful for later reclamation purposes, the alpha particle activity can be determined to decide whether permanent low-level burial is appropriate for the waste sample.

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

    SciTech Connect

    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.

  13. Pu isotopes in soils collected downwind from Lop Nor: regional fallout vs. global fallout

    NASA Astrophysics Data System (ADS)

    Bu, Wenting; Ni, Youyi; Guo, Qiuju; Zheng, Jian; Uchida, Shigeo

    2015-07-01

    For the first time, soil core samples from the Jiuquan region have been analyzed for Pu isotopes for radioactive source identification and radiological assessment. The Jiuquan region is in downwind from the Lop Nor Chinese nuclear test (CNT) site. The high Pu inventories (13 to 546 Bq/m2) in most of the sampling locations revealed that this region was heterogeneously contaminated by the regional fallout Pu from the CNTs. The contributions of the CNTs to the total Pu in soils were estimated to be more than 40% in most cases. The 240Pu/239Pu atom ratios in the soils ranged from 0.059 to 0.186 with an inventory-weighted average of 0.158, slightly lower than that of global fallout. This atom ratio could be considered as a mixed fingerprint of Pu from the CNTs. In addition, Pu in soils of Jiuquan region had a faster downward migration rate compared with other investigated places in China.

  14. Plutonium isotopes and 241Am in the atmosphere of Lithuania: A comparison of different source terms

    NASA Astrophysics Data System (ADS)

    Lujanienė, G.; Valiulis, D.; Byčenkienė, S.; Šakalys, J.; Povinec, P. P.

    2012-12-01

    137Cs, 241Am and Pu isotopes collected in aerosol samples during 1994-2011 were analyzed with special emphasis on better understanding of Pu and Am behavior in the atmosphere. The results from long-term measurements of 240Pu/239Pu atom ratios showed a bimodal frequency distribution with median values of 0.195 and 0.253, indicating two main sources contributing to the Pu activities at the Vilnius sampling station. The low Pu atom ratio of 0.141 could be attributed to the weapon-grade plutonium derived from the nuclear weapon test sites. The frequency of air masses arriving from the North-West and North-East correlated with the Pu atom ratio indicating the input from the sources located in these regions (the Novaya Zemlya test site, Siberian nuclear plants), while no correlation with the Chernobyl region was observed. Measurements carried out during the Fukushima accident showed a negligible impact of this source with Pu activities by four orders of magnitude lower as compared to the Chernobyl accident. The activity concentration of actinides measured in the integrated sample collected in March-April, 2011 showed a small contribution of Pu with unusual activity and atom ratios indicating the presence of the spent fuel of different origin than that of the Chernobyl accident.

  15. Testing the AVNG

    SciTech Connect

    Thron, Jonathan Louis; Mac Arthur, Duncan W; Kondratov, Sergey; Livke, Alexander; Razinkov, Sergey

    2010-01-01

    An attribute measurement system (AMS) measures a number of unclassified attributes of potentially classified material. By only displaying these unclassified results as red or green lights, the AMS protects potentially classified information while still generating confidence in the measurement result. The A VNG implementation that we describe is an AMS built by RFNC - VNIIEF in Sarov, Russia. The AVNG detects neutron and gamma radiation signatures and displays the three unclassified attributes of 'plutonium presence,' 'plutonium mass > 2 kg,' and 'plutonium isotopic ratio ({sup 240}Pu to {sup 239}Pu) < 0.1.' Prior to demonstration to a joint US/Russian audience, the overall operation and thresholds of the AVNG were tested using a number of multi-kg plutonium reference material (RM) sources manufactured for this purpose. As the AVNG was designed to incorporate an open mode (where all radiation data was displayed) as well as a secure mode (where only the red/green attribute lights were visible), the AVNG was tested in both modes. We will present data from these tests using unclassified plutonium RM sources as well as detector test results obtained using smaller calibration sources.

  16. Reference material manufacture and certification for the AVNG

    SciTech Connect

    Hauck, Danielle K; Mac Arthur, Duncan; Thron, Jonathan L; Livke, Alexander; Kondratov, Sergey; Razinkov, Sergey

    2010-01-01

    Testing and demonstration of any radiation measurement system requires the use of appropriate radioactive sources. The AVNG implementation that we describe is an attribute measurement system built by RFNC - VNIIEF in Sarov, Russia. The AVNG detects neutron and gamma radiation signatures and displays the three unclassified attributes of 'plutonium presence,' 'plutonium mass > 2 kg,' and 'plutonium isotopic ratio ({sup 240}Pu to {sup 239}Pu) < 0.1.' The AVNG was tested using a number of reference material (RM) sources with masses and isotopic ratios above and below these thresholds. The AVNG was demonstrated in June 2009 using several of these sources in addition to detector calibration sources. Since the AVNG was designed to measure multi-kg plutonium sources, the RM was manufactured specifically for use with this system. In addition, the RM was used to test the thresholds in the AVNG, so the size and composition of each RM was certified prior to use. In this presentation, we will describe the various steps in the manufacture and certification of these RM sources.

  17. AVNG system objectives and concept

    SciTech Connect

    Macarthur, Duncan W; Thron, Jonathan; Razinkov, Sergey; Livke, Alexander; Kondratov, Sergey

    2010-01-01

    Any verification measurement performed on potentially classified nuclear material must satisfy two constraints. First and foremost, no classified information can be released to the monitoring party. At the same time, the monitoring party must gain sufficient confidence from the measurement to believe that the material being measured is consistent with the host's declarations concerning that material. The attribute measurement technique addresses both concerns by measuring several attributes of the nuclear material and displaying unclassified results through green (indicating that the material does possess the specified attribute) and red (indicating that the material does not possess the specified attribute) lights. The AVNG that we describe is an attribute measurement system built by RFNC-VNIIEF in Sarov, Russia. The AVNG measures the three attributes of 'plutonium presence,' 'plutonium mass >2 kg,' and 'plutonium isotopic ratio ({sup 240}Pu to {sup 239}Pu) <0.1' and was demonstrated in Sarov for a joint US/Russian audience in June 2009. In this presentation, we will outline the goals and objectives of the AVNG measurement system. These goals are driven by the two, sometimes conflicting, requirements mentioned above. We will describe the conceptual design of the AVNG and show how this conceptual design grew out of these goals and objectives.

  18. MONTE-CARLO BURNUP CALCULATION UNCERTAINTY QUANTIFICATION AND PROPAGATION DETERMINATION

    SciTech Connect

    Sternat, M.; Nichols, T.

    2011-06-09

    Reactor burnup or depletion codes are used thoroughly in the fields of nuclear forensics and nuclear safeguards. Two common codes include MONTEBURNS and MCNPX/CINDER. These are Monte-Carlo depletion routines utilizing MCNP for neutron transport calculations and either ORIGEN or CINDER for burnup calculations. Uncertainties exist in the MCNP steps, but this information is not passed to the depletion calculations or saved. To quantify this transport uncertainty and determine how it propagates between burnup steps, a statistical analysis of multiple repeated depletion runs is performed. The reactor model chosen is the Oak Ridge Research Reactor (ORR) in a single assembly, infinite lattice configuration. This model was burned for a 150 day cycle broken down into three steps. The output isotopics as well as effective multiplication factor (k-effective) were tabulated and histograms were created at each burnup step using the Scott Method to determine the bin width. The distributions for each code are a statistical benchmark and comparisons made. It was expected that the gram quantities and k-effective histograms would produce normally distributed results since they were produced from a Monte-Carlo routine, but some of the results appear to not. Statistical analyses are performed using the {chi}{sup 2} test against a normal distribution for the k-effective results and several isotopes including {sup 134}Cs, {sup 137}Cs, {sup 235}U, {sup 238}U, {sup 237}Np, {sup 238}Pu, {sup 239}Pu, and {sup 240}Pu.

  19. Elemental bio-imaging of thorium, uranium, and plutonium in tissues from occupationally exposed former nuclear workers.

    PubMed

    Hare, Dominic; Tolmachev, Sergei; James, Anthony; Bishop, David; Austin, Christine; Fryer, Fred; Doble, Philip

    2010-04-15

    Internal exposure from naturally occurring radionuclides (including the inhaled long-lived actinides (232)Th and (238)U) is a component of the ubiquitous background radiation dose (National Council on Radiation Protection and Measurements. Ionizing radiation exposure of the population of the United States; NCRP Report No. 160; NCRP: Bethesda, MD, 2009). It is of interest to compare the concentration distribution of these natural alpha-emitters in the lungs and respiratory lymph nodes with those resulting from occupational exposure, including exposure to anthropogenic plutonium and depleted and enriched uranium. This study examines the application of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICPMS) to quantifying and visualizing the mass distribution of uranium and thorium isotopes from both occupational and natural background exposure in human respiratory tissues and, for the first time, extends this application to the direct imaging of plutonium isotopes. Sections of lymphatic and lung tissues taken from deceased former nuclear workers with a known history of occupational exposure to specific actinide elements (uranium, plutonium, or americium) were analyzed by LA-ICPMS. Using a previously developed LA-ICPMS protocol for elemental bio-imaging of trace elements in human tissue and a new software tool, we generated images of thorium ((232)Th), uranium ((235)U and (238)U), and plutonium ((239)Pu and (240)Pu) mass distributions in sections of tissue. We used a laboratory-produced matrix-matched standard to quantify the (232)Th, (235)U, and (238)U concentrations. The plutonium isotopes (239)Pu and (240)Pu were detected by LA-ICPMS in 65 mum diameter localized regions of both a paratracheal lymph node and a sample of lung tissue from a person who was occupationally exposed to refractory plutonium (plutonium dioxide). The average (overall) (239)Pu concentration in the lymph node was 39.2 ng/g, measured by high purity germanium (HPGe) gamma

  20. Recoil Based Fuel Breeding Fuel Structure

    SciTech Connect

    Popa-Simil, Liviu

    2008-07-01

    Nuclear transmutation reactions are based on the absorption of a smaller particle as neutron, proton, deuteron, alpha, etc. The resulting compound nucleus gets out of its initial lattice mainly by taking the recoil, also with help from its sudden change in chemical properties. The recoil implantation is used in correlation with thin and ultra thin materials mainly for producing radiopharmaceuticals and ultra-thin layer radioactive tracers. In nuclear reactors, the use of nano-particulate pellets could facilitate the recoil implantation for breeding, transmutation and partitioning purposes. Using enriched {sup 238}U or {sup 232}Th leads to {sup 239}Pu and {sup 233}U production while using other actinides as {sup 240}Pu, {sup 241}Am etc. leads to actinide burning. When such a lattice is immersed into a radiation resistant fluid (water, methanol, etc.), the recoiled product is transferred into the flowing fluid and removed from the hot area using a concentrator/purifier, preventing the occurrence of secondary transmutation reactions. The simulation of nuclear collision and energy transfer shows that the impacted nucleus recoils in the interstitial space creating a defect or lives small lattices. The defect diffuses, and if no recombination occurs it stops at the lattices boundaries. The nano-grains are coated in thin layer to get a hydrophilic shell to be washed by the collection liquid the particle is immersed in. The efficiency of collection depends on particle magnitude and nuclear reaction channel parameters. For {sup 239}Pu the direct recoil extraction rate is about 70% for {sup 238}UO{sub 2} grains of 5 nm diameters and is brought up to 95% by diffusion due to {sup 239}Neptunium incompatibility with Uranium dioxide lattice. Particles of 5 nm are hard to produce so a structure using particles of 100 nm have been tested. The particles were obtained by plasma sputtering in oxygen atmosphere. A novel effect as nano-cluster radiation damage robustness and cluster

  1. Measurement of Actinides in Environmental Samples at Micro-Becquerel Levels by Accelerator Mass Spectrometry

    SciTech Connect

    Brown, T A; Knezovich, J P; Marchetti, A A; Hamilton, T F

    2002-09-03

    The need for ultra-sensitive actinide measurements continues to expand in the fields of environmental stewardship, nuclear isotope forensics, radiobioassay and environmental research. We have developed a heavy isotope accelerator mass spectrometry (AMS) system at Lawrence Livermore National Laboratory's Center for Accelerator Mass Spectrometry (CAMS). The system was designed particularly for the measurement of actinide concentrations and isotopic ratios. A fast isotope switching capability has been incorporated in the system, allowing flexibility in isotope selection and for the quasi-continuous normalization to a reference isotope spike. Initially, our utilization of the system has concentrated on the measurement of Pu isotopes. Under current operating conditions, background levels equivalent to <10{sup 6} atoms are observed during routine {sup 239}Pu and {sup 240}Pu measurements. Measurements of samples containing 10{sup 13} {sup 238}U atoms demonstrate that the system provides a {sup 238}U rejection factor of >10{sup 7}. Recently, we have utilized the high dynamic range of the AMS system in measuring samples whose Pu contents ranged from <10{sup 6} (background) to >10{sup 11} Pu atoms. Measurements of known materials, combined with results from an externally organized intercomparison program, indicate that our {sup 239}Pu measurements are accurate and precise down to the {mu}Bq level ({approx}10{sup 6} atoms). The development of the heavy isotope system was undertaken with particular interest in the measurement of environmental samples, including soils, sediments, waters, air filters, tissue samples, and human urine. The high rejection of interferences, including molecular interferences, and low susceptibility to matrix components, provided by the AMS technique are of particular relevance for such complex samples. These two factors significantly reduce demands on sample preparation chemistry for Pu analyses, allowing relatively simple, cost-effective procedures

  2. Characterization of the C1 and C2 waste tanks located in the BVEST system at ORNL

    SciTech Connect

    Keller, J.M.; Giaquinto, J.M.

    1998-02-01

    There was a major effort to sample and analyze the Active Liquid Low-Level Waste (LLLW) tanks at ORNL which include the Melton Valley Storage Tanks (MVST) and the Bethel Valley Evaporator Service Tanks (BVEST). The characterization data summarized in this report was needed to address waste processing options, address concerns dealing with the performance assessment (PA) data for the Waste Isolation Pilot Plant (WIPP), evaluate the waste characteristics with respect to the waste acceptance criteria (WAC) for WIPP and Nevada Test Site (NTS), address criticality concerns, and meet DOT requirements for transporting the waste. This report discusses the analytical characterization data for the supernatant and sludge in the BVEST waste tanks C-1 and C-2. The isotopic data presented in this report supports the position that fissile isotopes of uranium ({sup 233}U and {sup 235}U) and plutonium ({sup 239}Pu and {sup 241}Pu) were denatured as required by the administrative controls stated in the ORNL LLLW waste acceptance criteria (WAC). In general, the sludge in tanks C1 and C2 was found to be hazardous based on RCRA characteristics and the transuranic alpha activity was well above the 100 nCi/g limit for TRU waste. Additional characteristics of the C1 and C2 sludge inventory relative to the WIPP WAC limits for fissile gram equivalent, plutonium equivalent activity, and thermal power from decay heat were estimated from the data in this report and found to be far below the upper boundary for any of the remote-handled transuranic waste (RH-TRU) requirements for disposal of the waste in WIPP.

  3. Characterization of the ORNL MVST Waste Tanks After Transfer of Sludge from BVEST, GAAT, and OHF Tanks

    SciTech Connect

    Keller, J.M.

    2001-03-23

    Over the last several years most of the sludge and liquid from the Liquid Low-Level Waste (LLLW) tanks at ORNL has been transferred and consolidated in the Melton Valley Storage Tanks (MVST). The contents of the MVST tanks at the time the sludge samples were collected for this report included the original inventory in the MVSTs along with the sludge and liquid from the Bethel Valley Evaporator Service Tanks (BVEST), Old Hydrofracture (OHF) tanks, and most of the Gunite and Associated Tanks (GAAT). During the spring and summer of 2000 the MVST composite sludge was sampled and characterized to validate the radiochemical content and to ensure regulatory compliance. This report only discusses the analytical characterization of the sludge from the MVST waste tanks (except for W-29 and W-30). The isotopic data presented in this report supports the position that fissile isotopes of uranium ({sup 233}U and {sup 235}U) and plutonium ({sup 239}Pu and {sup 241}Pu) were ''denatured'' as required by the administrative controls stated in the ORNL LLLW waste acceptance criteria (WAC). In general, the MVST sludge was found to be hazardous by RCRA characteristics based on total analysis of chromium, mercury, and lead. Also, the alpha activity due to transuranic isotopes was well above the 100 nCi/g limit for TRU waste. The characteristics of the MVST sludge relative to the WIPP WAC limits for fissile gram equivalent, plutonium equivalent activity, and thermal power from decay heat, were estimated from the data in this report and found to be far below the upper boundary for any of the remote-handled transuranic waste (RH-TRU) requirements for disposal of the waste in WIPP.

  4. Sensitivity analysis of Monju using ERANOS with JENDL-4.0

    SciTech Connect

    Tamagno, P.; Van Rooijen, W. F. G.; Takeda, T.; Konomura, M.

    2012-07-01

    This paper deals with sensitivity analysis using JENDL-4.0 nuclear data applied to the Monju reactor. In 2010 the Japan Atomic Energy Agency - JAEA - released a new set of nuclear data: JENDL-4.0. This new evaluation is expected to contain improved data on actinides and covariance matrices. Covariance matrices are a key point in quantification of uncertainties due to basic nuclear data. For sensitivity analysis, the well-established ERANOS [1] code was chosen because of its integrated modules that allow users to perform a sensitivity analysis of complex reactor geometries. A JENDL-4.0 cross-section library is not available for ERANOS. Therefore a cross-section library had to be made from the original nuclear data set, available as ENDF formatted files. This is achieved by using the following codes: NJOY, CALENDF, MERGE and GECCO in order to create a library for the ECCO cell code (part of ERANOS). In order to make sure of the accuracy of the new ECCO library, two benchmark experiments have been analyzed: the MZA and MZB cores of the MOZART program measured at the ZEBRA facility in the UK. These were chosen due to their similarity to the Monju core. Using the JENDL-4.0 ECCO library we have analyzed the criticality of Monju during the restart in 2010. We have obtained good agreement with the measured criticality. Perturbation calculations have been performed between JENDL-3.3 and JENDL-4.0 based models. The isotopes {sup 239}Pu, {sup 238}U, {sup 241}Am and {sup 241}Pu account for a major part of observed differences. (authors)

  5. Characterization of the Radioactive Sludge from the ORNL MVST Waste Tanks

    SciTech Connect

    Keller, J.M.

    2001-10-24

    Over the last several years most of the sludge and liquid from the Liquid Low-Level Waste (LLLW) tanks at ORNL has been transferred and consolidated in the Melton Valley Storage Tanks (MVST). The contents of the MVST tanks at the time the sludge samples were collected for this report included the original inventory in the MVSTs along with the sludge and liquid from the Bethel Valley Evaporator Service Tanks (BVEST), Old Hydrofracture (OHF) tanks, and the Gunite and Associated Tanks (GAAT). During the summer of 2001 full core samples of sludge were collected from the MVST tanks. The purpose of this sampling campaign was to characterize and validate that the current radiochemical and chemical contents of the MVST sludge, which was needed to meet the contract agreements prior to the transfer of the waste to another DOE contractor for processing. This report only discusses the analytical characterization of the sludge from the MVST waste tanks. The isotopic data presented in this report supports the position that fissile isotopes of uranium ({sup 233}U and {sup 235}U) and plutonium ({sup 239}Pu and {sup 241}Pu) were ''denatured'' as required by the administrative controls stated in the ORNL LLLW waste acceptance criteria (WAC). In general, the MVST sludge was found to be hazardous by RCRA characteristics based on total analysis of chromium, mercury, and lead. Also, the alpha activity due to transuranic isotopes was well above the 100 nCi/g limit for TRU waste. The characteristics of the MVST sludge relative to the WIPP WAC limits for fissile gram equivalent, plutonium equivalent activity, and thermal power from decay heat, were estimated from the data in previous reports and found to be far below the upper boundary for any of the remote-handled transuranic waste (RH-TRU) requirements for disposal of the waste in WIPP. Therefore, the WIPP WAC limits were not evaluated for this set of samples.

  6. Characterization of the Old Hydrofracture Facility (OHF) waste tanks located at ORNL

    SciTech Connect

    Keller, J.M.; Giaquinto, J.M.; Meeks, A.M.

    1997-04-01

    The Old Hydrofracture Facility (OHF) is located in Melton Valley within Waste Area Grouping (WAG) 5 and includes five underground storage tanks (T1, T2, T3, T4, and T9) ranging from 13,000 to 25,000 gal. capacity. During the period of 1996--97 there was a major effort to re-sample and characterize the contents of these inactive waste tanks. The characterization data summarized in this report was needed to address waste processing options, examine concerns dealing with the performance assessment (PA) data for the Waste Isolation Pilot Plant (WIPP), evaluate the waste characteristics with respect to the waste acceptance criteria (WAC) for WIPP and Nevada Test Site (NTS), address criticality concerns, and to provide the data needed to meet DOT requirements for transporting the waste. This report discusses the analytical characterization data collected on both the supernatant and sludge samples taken from three different locations in each of the OHF tanks. The isotopic data presented in this report supports the position that fissile isotopes of uranium ({sup 233}U and {sup 235}U) do not satisfy the denature ratios required by the administrative controls stated in the ORNL LLLW waste acceptance criteria (WAC). The fissile isotope of plutonium ({sup 239}Pu and {sup 241}Pu) are diluted with thorium far above the WAC requirements. In general, the OHF sludge was found to be hazardous (RCRA) based on total metal content and the transuranic alpha activity was well above the 100 nCi/g limit for TRU waste. The characteristics of the OHF sludge relative to the WIPP WAC limits for fissile gram equivalent, plutonium equivalent activity, and thermal power from decay heat were estimated from the data in this report and found to be far below the upper boundary for any of the remote-handled transuranic waste (RH-TRU) requirements for disposal of the waste in WIPP.

  7. Inorganic, radioisotopic and organic analysis of 241-AP-101 tank waste

    SciTech Connect

    SK Fiskum; PR Bredt; JA Campbell; LR Greenwood; OT Farmer; GJ Lumetta; GM Mong; RT Ratner; CZ Soderquist; RG Swoboda; MW Urie; JJ Wagner

    2000-06-28

    Battelle received five samples from Hanford waste tank 241-AP-101, taken at five different depths within the tank. No visible solids or organic layer were observed in the individual samples. Individual sample densities were measured, then the five samples were mixed together to provide a single composite. The composite was homogenized and representative sub-samples taken for inorganic, radioisotopic, and organic analysis. All analyses were performed on triplicate sub-samples of the composite material. The sample composite did not contain visible solids or an organic layer. A subsample held at 10 C for seven days formed no visible solids. The characterization of the 241-AP-101 composite samples included: (1) Inductively-coupled plasma spectrometry for Ag, Al, Ba, Bi, Ca, Cd, Cr, Cu, Fe, K, La, Mg, Mn, Na, Nd, Ni, P, Pb, Pd, Ru, Rh, Si, Sr, Ti, U, Zn, and Zr (Note: Although not specified in the test plan, As, B, Be, Co, Li, Mo, Sb, Se, Sn, Tl, V, W, and Y were also measured and reported for information only) (2) Radioisotopic analyses for total alpha and total beta activities, {sup 3}H, {sup 14}C, {sup 60}Co, {sup 79}Se, {sup 90}Sr, {sup 99}Tc as pertechnetate, {sup 106}Ru/Rh, {sup 125}Sb, {sup 134}Cs, {sup 137}Cs, {sup 152}Eu, {sup 154}Eu, {sup 155}Eu, {sup 238}Pu, {sup 239+240}Pu, {sup 241}Am, {sup 242}Cm, and {sup 243+244}Cm; (3) Inductively-coupled plasma mass spectrometry for {sup 237}Np, {sup 239}Pu, {sup 240}Pu, {sup 99}Tc, {sup 126}Sn, {sup 129}I, {sup 231}Pa, {sup 233}U, {sup 234}U, {sup 235}U, {sup 236}U, {sup 238}U, {sup 241}AMU, {sup 242}AMU, {sup 243}AMU, As, B, Be, Ce, Co, Cs, Eu, I, Li, Mo, Pr, Rb, Sb, Se, Ta, Te, Th, Tl, V, and W; (4) total U by kinetic phosphorescence analysis; (5) Ion chromatography for Cl, F, NO{sub 2}, NO{sub 3}, PO{sub 4}, SO{sub 4}, acetate, formate, oxalate, and citrate; (6) Density, inorganic carbon and organic carbon by two different methods, mercury, free hydroxide, ammonia, and cyanide. The 241-AP-101 composite met all

  8. Report on INL Activities for Uncertainty Reduction Analysis of FY11

    SciTech Connect

    G. Plamiotti; H. Hiruta; M. Salvatores

    2011-09-01

    This report presents the status of activities performed at INL under the ARC Work Package on 'Uncertainty Reduction Analyses' that has a main goal the reduction of uncertainties associated with nuclear data on neutronic integral parameters of interest for the design of advanced fast reactors under consideration by the ARC program. First, an analysis of experiments was carried out. For both JOYO (the first Japanese fast reactor) and ZPPR-9 (a large size zero power plutonium fueled experiment performed at ANL-W in Idaho) the performance of ENDF/B-VII.0 is quite satisfying except for the sodium void configurations of ZPPR-9, but for which one has to take into account the approximation of the modeling. In fact, when one uses a more detailed model (calculations performed at ANL in a companion WP) more reasonable results are obtained. A large effort was devoted to the analysis of the irradiation experiments, PROFIL-1 and -2 and TRAPU, performed at the French fast reactor PHENIX. For these experiments a pre-release of the ENDF/B-VII.1 cross section files was also used, in order to provide validation feedback to the CSWEG nuclear data evaluation community. In the PROFIL experiments improvements can be observed for the ENDF/B-VII.1 capture data in 238Pu, 241Am, 244Cm, 97Mo, 151Sm, 153Eu, and for 240Pu(n,2n). On the other hand, 240,242Pu, 95Mo, 133Cs and 145Nd capture C/E results are worse. For the major actinides 235U and especially 239Pu capture C/E's are underestimated. For fission products, 105,106Pd, 143,144Nd and 147,149Sm are significantly underestimated, while 101Ru and 151Sm are overestimated. Other C/E deviations from unity are within the combined experimental and calculated statistical uncertainty. From the TRAPU analysis, the major improvement is in the predicted 243Cm build-up, presumably due to an improved 242Cm capture evaluation. The COSMO experiment was also analyzed in order to provide useful feedback on fission cross sections. It was found out that ENDF

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

    NASA Astrophysics Data System (ADS)

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

    2000-03-01

    129I ( t1/2 = 1.56 × 10 7 yr) has both natural as well as anthropogenic sources. 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. These low 240Pu/ 239Pu values are attributed to low yield, close-in, tropospherically transported bomb fallout produced from the Nevada test site in the early 1950s, which had a value of about 0.035, and strongly suggest a terrestrial source for Pu isotopes. 129I/ 127I ratios increased from 2 × 10 -10 at 3 cm to 4 × 10 -10 at 20 cm, and from there decreased monotonously to pre-anthropogenic values at 53 cm and below. 129I concentrations ranged from 8-13 × 10 6 atoms/g in the top 20 cm, and decreased to values of less than 1 × 10 6 atoms/g below 50 cm. Atom ratios of 129I/ 137Cs, 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

  10. Plutonium contamination in soils and sediments at Mayak PA, Russia.

    PubMed

    Skipperud, Lindis; Salbu, Brit; Oughton, Deborah H; Drozcho, Eugeny; Mokrov, Yuri; Strand, Per

    2005-09-01

    The Mayak Production Association (Mayak PA) was established in the late 1940's to produce plutonium for the Soviet Nuclear Weapons Programme. In total, seven reactors and two reprocessing plants have been in operation. Today, the area comprises both military and civilian reactors as well as reprocessing and metallurgical plants. Authorized and accidental releases of radioactive waste have caused severe contamination to the surrounding areas. In the present study, [alpha]-spectrometry and inductively coupled plasma-mass spectrometry (ICP-MS) have been used to determine plutonium activities and isotope ratios in soil and sediment samples collected from reservoirs of the Techa River at the Mayak area and downstream Techa River. The objective of the study was to determine the total inventory of plutonium in the reservoirs and to identify the different sources contributing to the plutonium contamination. Results based on [alpha]-spectrometry and ICP-MS measurements show the presence of different sources and confirmed recent reports of civilian reprocessing at Mayak. Determination of activity levels and isotope ratios in soil and sediment samples from the Techa River support the hypothesis that most of the plutonium, like other radionuclides in the Techa River, originated from the very early waste discharges to the Techa River between 1949 and 1951. Analysis of reservoir sediment samples suggest that about 75% of the plutonium isotopes could have been released to Reservoir 10 during the early weapons production operation of the plant, and that the majority of plutonium in Reservoir 10 originates from discharges from power production or reprocessing. Enhanced 240Pu/239Pu atom ratios in river sediment upper layers (0-2 cm) between 50 and 250 km downstream from the plant indicate a contribution from other, non-fallout sources. PMID:16096501

  11. A new ground-level fallout record of uranium and plutonium isotopes for northern temperate latitudes

    NASA Astrophysics Data System (ADS)

    Warneke, Thorsten; Croudace, Ian W.; Warwick, Phillip E.; Taylor, Rex N.

    2002-11-01

    Plutonium and uranium isotope ratios can be used to differentiate the sources of nuclear contamination from nuclear weapon establishments (Environ. Sci. Technol. 34 (2000) 4496; Internal Report for AWRE Aldermaston, UK (1961)), weapon fallout (Geochim. Cosmochim. Acta 51 (1987) 2623; Earth Planet. Sci. Lett. 63 (1983) 202; Earth Planet. Sci. Lett. 22 (1974) 111; Geochim. Cosmochim. Acta 64 (2000) 989), reprocessing plants, reactor or satellite accidents (Science 105 (1979) 583; Science 238 (1987) 512) and in addition they provide markers for post-1952 geochronology of environmental systems. A good record of plutonium and uranium isotope ratios of the background resulting from atmospheric nuclear testing is essential for source characterisation studies. Using recently developed mass spectrometric techniques (J. Anal. At. Spectrom. 16 (2001) 279) we present here the first complete records between 1952 and the present day of northern temperate latitude 240Pu/ 239Pu and 238U/ 235U atom ratios for atmospheric deposition. Such information was not derived directly during the period of atmospheric testing because suitable mass spectrometric capability was not available. The currently derived records are based on an annual herbage archive and a core from an Alpine glacier. These studies reveal hitherto unseen fluctuations in the 238U/ 235U atmospheric fallout record, some of which are directly related to nuclear testing. In addition, they also provide the first evidence that plutonium contamination originating from Nevada Desert atmospheric weapon tests in 1952 and 1953 extended eastwards as far as northwestern Europe. The results presented here demonstrate that we now have the capability to detect and precisely identify sources of plutonium in the environment with implications for the development of atmospheric transport models, recent geochronology and environmental studies.

  12. Critical experiments on single-unit spherical plutonium geometries reflected and moderated by oil

    SciTech Connect

    Rothe, R.E.

    1997-05-01

    Experimental critical configurations are reported for several dozen spherical and hemispherical single-unit assemblies of plutonium metal. Most were solid but many were hollow-centered, thick, shell-like geometries. All were constructed of nested plutonium (mostly {sup 2139}Pu) metal hemispherical shells. Three kinds of critical configurations are reported. Two required interpolation and/or extrapolation of data to obtain the critical mass because reflector conditions were essentially infinite. The first finds the plutonium essentially fully reflected by a hydrogen-rich oil; the second is essentially unreflected. The third kind reports the critical oil reflector height above a large plutonium metal assembly of accurately known mass (no interpolation required) when that mass was too great to permit full oil reflection. Some configurations had thicknesses of mild steel just outside the plutonium metal, separating it from the oil. These experiments were performed at the Rocky Flats Critical Mass Laboratory in the late 1960s. They have not been published in a form suitable for benchmark-quality comparisons against state-of-the-art computational techniques until this paper. The age of the data and other factors lead to some difficulty in reconstructing aspects of the program and may, in turn, decrease confidence in certain details. Whenever this is true, the point is acknowledged. The plutonium metal was alpha-phase {sup 239}Pu containing 5.9 wt-% {sup 240}Pu. All assemblies were formed by nesting 1.667-mm-thick (nominal) bare plutonium metal hemispherical shells, also called hemishells, until the desired configuration was achieved. Very small tolerance gaps machined into radial dimensions reduced the effective density a small amount in all cases. Steel components were also nested hemispherical shells; but these were nominally 3.333-mm thick. Oil was used as the reflector because of its chemical compatibility with plutonium metal.

  13. Rapid multisample analysis for simultaneous determination of anthropogenic radionuclides in marine environment.

    PubMed

    Qiao, Jixin; Shi, Keliang; Hou, Xiaolin; Nielsen, Sven; Roos, Per

    2014-04-01

    An automated multisample processing flow injection (FI) system was developed for simultaneous determination of technetium, neptunium, plutonium, and uranium in large volume (200 L) seawater. Ferrous hydroxide coprecipitation was used for the preliminary sample treatment providing the merit of simultaneous preconcentration of all target radionuclides. Technetium was separated from the actinides via valence control of technetium (as Tc(VII)) in a ferric hydroxide coprecipitation. A novel preseparation protocol between uranium and neptunium/plutonium fractions was developed based on the observation of nearly quantitative dissolution of uranium in 6 mol/L sodium hydroxide solution. Automated extraction (TEVA for technetium and UTEVA for uranium) and anion exchange (AGMP-1 M for plutonium and neptunium) chromatographic separations were performed for further purification of each analyte within the FI system where four samples were processed in parallel. Analytical results indicate that the proposed method is robust and straightforward, providing chemical yields of 50-70% and improved sample throughput (3-4 d/sample). Detection limits were 8 mBq/m(3) (0.013 pg/L), 0.26 μBq/m(3) (0.010 fg/L), 23 μBq/m(3) (0.010 fg/L), 84 μBq/m(3) (0.010 fg/L) and 0.6 mBq/m(3) (0.048 ng/L) for (99)Tc, (237)Np, (239)Pu, (240)Pu and (238)U for 200 L seawater, respectively. The unique feature of multiradionuclide and multisample simultaneous processing vitalizes the developed method as a powerful tool in obtaining reliable data with reduced analytical cost in both radioecology studies and nuclear emergency preparedness. PMID:24617716

  14. Plutonium contamination in soils in open space and residential areas near Rocky Flats, Colorado

    SciTech Connect

    Litaor, M.I.

    1999-02-01

    Spatial analysis of the {sup 240}Pu:{sup 239}Pu isotopic ratio of 42 soil samples collected around Rocky Flats Plant near Golden, Colorado, was conducted to assess the effect of Rocky Flats Plant activity on the soil environment. Two probability maps that quantified the uncertainty of the spatial distribution of plutonium isotopic ratios were constructed using the sequential Gaussian simulation technique (sGs). Assuming a plutonium isotopic ratio range of 0.152 {+-} 0.003 to 0.169 {+-} 0.009 is characteristic to global fallout in Colorado, and a mean value of 0.155 is representative for the Rocky Flats Plant area, the main findings of the current work were (1) the areas northwest and southwest of Rocky Flats Plant exhibited a plutonium ratio {ge}0.155, this were minimally impacted by the plant activity; (2) he study area east of Rocky Flats Plant exhibited a plutonium isotopic ratio {le}0.155, which is a definitive indicator of Rocky Flats Plant-derived plutonium; and (3) inventory calculations across the study area exhibited large standard error of estimates. These errors were originated from the high variability in plutonium activity over a small sampling scale and the uncertainty in the global fallout isotopic ratio. Using the mean simulated estimates of plutonium isotopic ratio, coupled with plutonium activity measured at 11 soil pits and additional plutonium information published elsewhere, the plutonium loading on the open space and residential areas amounted to 111.2 GBq, with a standard error of estimate of 50.8 GBq.

  15. Plutonium contamination in soils in open space and residential areas near Rocky Flats, Colorado.

    PubMed

    Litaor, M I

    1999-02-01

    Spatial analysis of the 240Pu:239Pu isotopic ratio of 42 soil samples collected around Rocky Flats Plant near Golden, Colorado, was conducted to assess the effect of Rocky Flats Plant activity on the soil environment. Two probability maps that quantified the uncertainty of the spatial distribution of plutonium isotopic ratios were constructed using the sequential Gaussian simulation technique (sGs). Assuming a plutonium isotopic ratio range of 0.152+/-0.003 to 0.169+/-0.009 is characteristic to global fallout in Colorado, and a mean value of 0.155 is representative for the Rocky Flats Plant area, the main findings of the current work were (1) the areas northwest and southwest of Rocky Flats Plant exhibited a plutonium ratio > or = 0.155, thus were minimally impacted by the plant activity; (2) the study area east of Rocky Flats Plant (approximately 120 km2) exhibited a plutonium isotopic ratio < or = 0.155, which is a definitive indicator of Rocky Flats Plant-derived plutonium; and (3) inventory calculations across the study area exhibited large standard error of estimates. These errors were originated from the high variability in plutonium activity over a small sampling scale and the uncertainty in the global fallout isotopic ratio. Using the mean simulated estimates of plutonium isotopic ratio, coupled with plutonium activity measured at 11 soil pits and additional plutonium information published elsewhere, the plutonium loading on the open space and residential areas amounted to 111.2 GBq, with a standard error of estimate of 50.8 GBq. PMID:9929128

  16. SCALED ELECTRON MODEL OF A DOGBONE MUON RLA WITH MULTI-PASS ARCS

    SciTech Connect

    Kevin Beard, Rolland Johnson, Vasiliy Morozov, Yves Roblin, Andrew Hutton, Geoffrey Krafft, Slawomir Bogacz

    2012-07-01

    The design of a dogbone RLA with linear-field multi-pass arcs was earlier developed for accelerating muons in a Neutrino Factory and a Muon Collider. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over separate-arc or pulsed-arc designs. Such an RLA may have applications going beyond muon acceleration. This paper describes a possible straightforward test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme, in which a 4.5 MeV electron beam is injected at the middle of a 3 MeV/pass linac with two double-pass return arcs and is accelerated to 18 MeV in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to a readily available at CEBAF 1.5 GHz. The footprint of a complete RLA fits in an area of 25 by 7 m. The scheme utilizes only fixed magnetic fields including injection and extraction. The hardware requirements are not very demanding, making it straightforward to implement. In this report, we have shown first of all that measuring the energy spectrum of the fast neutrons in the liquid scintillators allows one to distinguish the two chemical forms of plutonium. In addition, combining this information with the Feynman 2-neutron and 3-neutron correlations allows one to extract the {alpha}-ratio without explicitly knowing the multiplication. Given the {alpha}-ratio one can then extract the multiplication as well as the {sup 239}Pu and {sup 240}Pu masses directly from the moment equations.

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

    PubMed

    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

  18. Investigating Pu and U isotopic compositions in sediments: a case study in Lake Obuchi, Rokkasho Village, Japan using sector-field ICP-MS and ICP-QMS.

    PubMed

    Zheng, Jian; Yamada, Masatoshi

    2005-08-01

    The objectives of the present work were to study isotope ratios and the inventory of plutonium and uranium isotope compositions in sediments from Lake Obuchi, which is in the vicinity of several nuclear fuel facilities in Rokkasho, Japan. Pu and its isotopes were determined using sector-field ICP-MS and U and its isotopes were determined with ICP-QMS after separation and purification with a combination of ion-exchange and extraction chromatography. The observed (240)Pu/(239)Pu atom ratio (0.186 +/- 0.016) was similar to that of global fallout, indicating that the possible early tropospheric fallout Pu did not deliver Pu from the Pacific Proving Ground to areas above 40 degrees N. The previously reported higher Pu inventory in the deep water area of Lake Obuchi could be attributed to the lateral transportation of Pu deposited in the shallow area which resulted from the migration of deposited global fallout Pu from the land into the lake by river runoff and from the Pacific Ocean by tide movement and sea water scavenging, as well as from direct soil input by winds. The (235)U/(238)U atom ratios ranged from 0.00723 to 0.00732, indicating the natural origin of U in the sediments. The average (234)U/(238)U activity ratio of 1.11 in a sediment core indicated a significant sea water U contribution. No evidence was found for the release of U containing wastes from the nearby nuclear facilities. These results will serve as a reference baseline on the levels of Pu and U in the studied site so that any further contamination from the spent nuclear fuel reprocessing plants, the radioactive waste disposal and storage facilities, and the uranium enrichment plant can be identified, and the impact of future release can be rapidly assessed. PMID:16049580

  19. Biomedical aspects of natural and manufactured environmental radioactivity

    SciTech Connect

    Hodge, V.

    1996-12-31

    While weapons testing has altered natural radioactivity background, manufactured radioactivity in most parts of the world constitutes but a very small fraction of the total alpha, beta, and gamma radioactivity in soil, air, water, and the biota. For example, in the early 1970s, we found what appeared to be the highest natural concentration of radioactivity ever reported in fish while attempting to measure the manufactured plutonium ({sup 239}Pu and {sup 240}Pu) in organs of oceanic tuna. The natural alpha emitter polonium ({sup 210}Po) was discovered in the same organs at orders of magnitude higher concentrations. In particular, the caecum, which is a digestive organ composed of many small closed-ended sacs, contained concentrations of polonium as high as 79 pCi/g of wet tissue and lesser amounts of two manufactured isotopes: 0.0001 pCi/g of plutonium and 0.01 pCi/g of radiocesium ({sup 137}Cs). This equates to {approximately}80 rem/yr of radiation dose to this organ, overwhelmingly from the natural polonium, or {approximately}5000 times higher than is found in the human liver, the highest polonium concentration in man. The average background radiation for humans, for comparison, is {approximately}0.2 rem/yr, but the dose for Japanese, whose diet is high in seafood, is {approximately}15 rem/yr. The question arose: {open_quotes}Are these high concentrations of natural polonium limited to oceanic fish?{close_quotes} To answer this question, polonium was determined in the organs of striped bass and catfish from Lake Mead. In a related study, the plutonium and radiocesium ({sup 137}Cs) distributions in soils were determined to ascertain the impact of weapons testing on the natural background radioactivity of soils.

  20. Evaluation of the anthropogenic radionuclide concentrations in sediments and fauna collected in the Beaufort Sea and northern Alaska

    SciTech Connect

    Efurd, D.W.; Miller, G.G.; Rokop, D.J.

    1997-07-01

    This study was performed to establish a quality controlled data set about the levels of radio nuclide activity in the environment and in selected biota in the U.S. Arctic. Sediment and biota samples were collected by the National Oceanic and Atmospheric Administration (NOAA), the National Biological Service, and the North Slope Borough`s Department of Wildlife Management to determine the impact of anthropogenic radionuclides in the Arctic. The results summarized in this report are derived from samples collected in northwest Alaska with emphasis on species harvested for subsistence in Barrow, Alaska. Samples were analyzed for the anthropogenic radionuclides {sup 90}Sr, {sup 137}Cs, {sup 238}Pu, {sup 239}Pu, {sup 240}Pu and {sup 241}Am. The naturally occurring radionuclides {sup 40}K, {sup 212}Pb and {sup 214}Pb were also measured. One goal of this study was to determine the amounts of anthropogenic radionuclides present in the Beaufort Sea. Sediment samples were isotopically fingerprinted to determine the sources of radio nuclide activities. Biota samples of subsistence and ecological value were analyzed to search for evidence of bio-accumulation of radionuclides and to determine the radiation exposures associated with subsistence living in northern Alaska. The anthropogenic radio nuclide content of sediments collected in the Beaufort Sea was predominantly the result of the deposition of global fallout. No other sources of anthropogenic radionuclides could be conclusively identified in the sediments. The anthropogenic radio nuclide concentrations in fish, birds and mammals were very low. Assuming that ingestion of food is an important pathway leading to human contact with radioactive contaminants and given the dietary patterns in coastal Arctic communities, it can be surmised that marine food chains are presently not significantly affected.

  1. Sensitivity Analysis of Neutron Cross-Sections Considered for Design and Safety Studies of Lfr and SFR Generation IV Systems

    NASA Astrophysics Data System (ADS)

    Tucek, Kamil; Carlsson, Johan; Wider, Hartmut

    2006-04-01

    We evaluated the sensitivity of several design and safety parameters with regard to five different nuclear data libraries, JEF2.2, JEFF3.0, ENDF/B-VI.8, JENDL3.2, and JENDL3.3. More specifically, the effective multiplication factor, burn-up reactivity swing and decay heat generation in available LFR and SFR designs were estimated. Monte Carlo codes MCNP and MCB were used in the analyses of the neutronic and burn-up performance of the systems. Thermo-hydraulic safety calculations were performed by the STAR-CD CFD code. For the LFR, ENDF/B-VI.8 and JEF2.2 showed to give a harder neutron spectrum than JEFF3.0, JENDL3.2, and JENDL3.3 data due to the lower inelastic scattering cross-section of lead in these libraries. Hence, the neutron economy of the system becomes more favourable and keff is higher when calculated with ENDF/B-VI.8 and JEF2.2 data. As for actinide cross-section data, the uncertainties in the keff values appeared to be mainly due to 239Pu, 240Pu and 241Am. Differences in the estimated burn-up reactivity swings proved to be significant, for an SFR as large as a factor of three (when comparing ENDF/B-VI.8 results to those of JENDL3.2). Uncertainties in the evaluation of short-term decay heat generation showed to be of the order of several per cent. Significant differences were, understandably, observed between decay heat generation data quoted in literature for LWR-UOX and those calculated for an LFR (U,TRU)O2 spent fuel. A corresponding difference in calculated core parameters (outlet coolant temperature) during protected total Loss-of-Power was evaluated.

  2. A comprehensive appraisal of 241Am in soils around Rocky Flats, Colorado.

    PubMed

    Litaor, M I; Allen, L

    1996-09-01

    Soils east of Rocky Flats Plant (RFETS) near Golden, Colorado, were contaminated with actinides because of accidental release of oils laden with plutonium isotopes. Consequently, these soils were contaminated by 241Am due to radioactive decay of 241Pu (t1/2 = 14.4 y). A spatial analysis of 241Am activity in soils east of RFETS was conducted to elucidate the magnitude and the mode of 241Am dispersion in the soil environment. 241Am activity of 178 soil samples ranged from 0.037 Bq kg-1 to 10,004 Bq kg-1 with a mean of 214 Bq kg-1, median of 7.28 Bq kg-1, standard deviation of 942 Bq kg-1, and a coefficient of variation of 4.3. Spatial analysis of 241Am in soils around RFETS was conducted using indicator kriging, which is a nonparametric technique especially suitable to model a conditional cumulative distribution function (ccdf) of highly skewed environmental data such as 241Am. The ccdf was used to generate an E-type (mean of the conditional cdf) surface. The resulted surfaces were consistent with the hypothesis that the westerly winds were the dominant mechanism of americium dispersal. The spatial distribution and dispersal mechanisms of 241Am were similar to those of 239+240Pu. The ccdf was also used to construct probability of exceedence maps of 241Am in soils. For the purpose of this report two threshold values for the probability maps were selected: (1) the mean measured background activity of 241Am (0.4 Bq kg-1), and (2) the programmatic preliminary remediation goal for residential occupancy scenario (87.7 Bq kg-1). The probability-of-exceedance maps provide estimates of spatial uncertainty associated with each threshold. The E-type maps in conjunction with the probability-of-exceedance maps provide a robust framework for future cleanup options and land use decisions. PMID:8698577

  3. Determining Sources and Transport of Nuclear Contamination in Hudson River Sediments with Plutonium, Neptunium, and Cesium isotope ratios

    NASA Astrophysics Data System (ADS)

    Kenna, T. C.; Chillrud, S. N.; Chaky, D. A.; Simpson, H. J.; McHugh, C. M.; Shuster, E. L.; Bopp, R. F.

    2004-12-01

    Different sources of radioactive contamination contain characteristic and identifiable isotopic signatures, which can be used to study sediment transport. We focus on Pu-239, Pu-240, Np-237 and Cs-137, which are strongly bound to fine grained sediments. The Hudson River drainage basin has received contamination from at least three separate sources: 1) global fallout from atmospheric testing of nuclear weapons, which contributed Pu, Np and Cs; 2) contamination resulting from reactor releases at the Indian Point Nuclear Power Plant (IPNPP) located on the Hudson River Estuary ˜70km north of New York Harbor, where records document releases of Cs-137; 3) contamination resulting from activities at the Knolls Atomic Power Laboratory (KAPL) located on the Mohawk River, where incomplete records document releases of Cs-137 but no mention is made of Pu or Np. Here we report measurements of Pu isotopes, Np-237 and Cs-137 for a series of sediment cores collected from various locations within the drainage basin: 1) Mohawk River downstream of KAPL, 2) Hudson River upstream of its confluence with the Mohawk River, and 3) lower Hudson River at a location in close proximity to IPNPP. In addition, we present data from selected samples from two other lower Hudson River locations: One site located ˜30km downstream of IPNPP and another ˜30km upstream of IPNPP. By comparing the isotopic ratios Pu-240/Pu-239, Np-237/Pu-239, and Cs-137/Pu-239, measured in fluvial sediments to mean global fallout values, it is possible to identify and resolve different sources of non-fallout contamination. To date, isotopic data for sediments indicate non-fallout sources of Pu-239, Pu-240, and Cs-137; Np-237, however, appears to originate from global fallout only. Mohawk River sediments downstream of KAPL exhibit enrichments in Pu-239, Pu-240, and Cs-137 that are 7 to 20 times higher than levels expected from global fallout as indicated from Np-237. The elevated levels, non-fallout isotopic signatures

  4. Tables of Neutron-Induced Fission Cross Section for Various Pu, U, and Th Isotopes, Deduced from Measured Fission Probabilites

    SciTech Connect

    Younes, W; Britt, H C

    2003-03-31

    Cross sections for neutron-induced fission of {sup 231,233}Th, {sup 234,235,236,237,239}U, and {sup 240,241,243}Pu are presented in tabular form for incident neutron energies of 0.1 {le} E{sub n}(MeV) {le} 2.5. The cross sections were obtained by converting measured fission probabilities from (t,pf) reactions on mass-A targets to (n,f) cross sections on mass-A + 1 neutron targets, by using modeling to compensate for the differences in the reaction mechanisms. Data from Britt et al. were used for the {sup 234}U(t,pf) reaction, from Cramer et al. for the {sup 230,232}Th(t,pf), {sup 236,238}U(t,pf), and {sup 240,242}Pu(t,pf) reactions, and from Britt et al. for the {sup 233,235}U(t,pf) and {sup 239}Pu(t,pf) reactions. The fission probabilities P{sub (t,pf)}(E{sub x}), measured as a function of excitation energy E{sub x} of the compound system formed by the (t,p) reaction, are listed in the tables with the corresponding deduced cross sections as a function of incident neutron energy E{sub n}, {sigma}{sub (n,f)}(E{sub n}). The excitation energy and incident neutron energy are related by E{sub x} = E{sub n} + B{sub n}, where B{sub n}, where B{sub n} is the neutron binding energy. Comparison with ENDF/B-VI evaluations of the well-measured {sup 234,235,236}U(n,f) and {sup 240,241}Pu(n,f) cross sections confirms the accuracy of the present results within a 10% standard deviation above E{sub n} = 1 MeV. Below E{sub n} = 1 MeV, localized deviations of at most {+-} 20% are observed.

  5. Doubles counting of highly multiplying items in reflective surroundings

    SciTech Connect

    Croft, Stephen; Evans, Louise G; Schear, Melissa A; Tobin, Stephen J

    2010-11-18

    When a neutrons are counted from a spontaneously fissile multiplying item in a reflecting environment the temporal behavior of the correlated signal following neutron birth is complex. At early times the signal is dominated by prompt fission events coming from spontaneous fission bursts and also from prompt fast-neutron induced fission events. At later times neutrons 'returning' from the surroundings induce fission and give rise to an additional chain of correlated events. The prompt and returning components probe the fissile and fertile constituents of the item in different ways and it is potentially beneficial to exploit this fact. In this work we look at how the two components can be represented using a linear combination of two simple functions. Fitting of the composite function to the capture time distribution represents one way of quantifying the proportion of each contribution. Another approach however is to use a dual shift register analysis where after each triggering event two coincidence gates are opened, one close to the trigger that responds preferentially to the prompt dynamics and one later in time which is more sensitive to the returning neutron induced events. To decide on the best gate positions and gate widths and also to estimate the counting precision we can use the analytical fit to work out the necessary gate utilization factors which are required in both these calculations. In this work, we develop the approach. Illustrative examples are given using spent Low Enriched Uranium (LEU) Pressurized light Water Reactor (LWR) fuel assemblies submersed in borated water and counted in a ring of {sup 3}He gas-filled proportional counters. In this case the prompt component is dominated by {sup 244}Cm spontaneous fission and induced fast neutron fission in for example {sup 238}U while the returning low energy neutrons induce fission mainly in the fissile nuclides such as {sup 239}Pu, {sup 241}Pu and {sup 235}U. One requirement is to calculate the Random

  6. HOLDUP MEASUREMENTS FOR THREE VISUAL EXAMINATION AND TRU REMEDIATION GLOVEBOX FACILITIES AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Dewberry, R; Donald Pak, D

    2007-05-04

    Visual Examination (VE) gloveboxes are used to remediate transuranic waste (TRU) drums at three separate facilities at the Savannah River Site. Noncompliant items are removed before the drums undergo further characterization in preparation for shipment to the Waste Isolation Pilot Plant (WIPP). Maintaining the flow of drums through the remediation process is critical to the program's seven-days-per-week operation. Conservative assumptions are used to ensure that glovebox contamination from this continual operation is below acceptable limits. Holdup measurements using cooled HPGe spectrometers are performed in order to confirm that these assumptions are conservative. {sup 239}Pu is the main nuclide of interest; however, {sup 241}Pu, equilibrium {sup 237}Np/{sup 233}Pa and {sup 238}Pu (if detected) are typically assayed. At the Savannah River National Laboratory (SRNL) facility {sup 243,244,245}Cm are also generally observed and are always reported at either finite levels or at limits of detection. A complete assay at each of the three facilities includes a measure of TRU content in the gloveboxes and HEPA filters in the glovebox exhaust. This paper includes a description of the {gamma}-PHA acquisitions, of the modeling, and of the calculations of nuclide content. Because each of the remediation facilities is unique and ergonomically unfavorable to {gamma}-ray acquisitions, we have constructed custom detector support devices specific to each set of acquisitions. This paper includes a description and photographs of these custom devices. The description of modeling and calculations include determination and application of container and matrix photon energy dependent absorption factors and also determination and application of geometry factors relative to our detector calibration geometry. The paper also includes a discussion of our measurements accuracy using off-line assays of two SRNL HEPA filters. The comparison includes assay of the filters inside of 55-gallon

  7. Lead Slowing-Down Spectrometry for Spent Fuel Assay: FY11 Status Report

    SciTech Connect

    Warren, Glen A.; Casella, Andrew M.; Haight, R. C.; Anderson, Kevin K.; Danon, Yaron; Hatchett, D.; Becker, Bjorn; Devlin, M.; Imel, G. R.; Beller, D.; Gavron, A.; Kulisek, Jonathan A.; Bowyer, Sonya M.; Gesh, Christopher J.; O'Donnell, J. M.

    2011-08-01

    Executive Summary Developing a method for the accurate, direct, and independent assay of the fissile isotopes in bulk materials (such as used fuel) from next-generation domestic nuclear fuel cycles is a goal of the Office of Nuclear Energy, Fuel Cycle R&D, Material Protection and Control Technology (MPACT) Campaign. To meet this goal, MPACT supports a multi-institutional collaboration to study the feasibility of Lead Slowing Down Spectroscopy (LSDS). This technique is an active nondestructive assay method that has the potential to provide independent, direct measurement of Pu and U isotopic masses in used fuel with an uncertainty considerably lower than the approximately 10% typical of today’s confirmatory assay methods. This document is a progress report for FY2011 collaboration activities. Progress made by the collaboration in FY2011 continues to indicate the promise of LSDS techniques applied to used fuel. PNNL developed an empirical model based on calibration of the LSDS to responses generated from well-characterized used fuel. The empirical model demonstrated the potential for the direct and independent assay of the sum of the masses of 239Pu and 241Pu to within approximately 3% over a wide used fuel parameter space. Similar results were obtained using a perturbation approach developed by LANL. Benchmark measurements have been successfully conducted at LANL and at RPI using their respective LSDS instruments. The ISU and UNLV collaborative effort is focused on the fabrication and testing of prototype fission chambers lined with ultra-depleted 238U and 232Th, and uranium deposition on a stainless steel disc using spiked U3O8 from room temperature ionic liquid was successful, with improving thickness obtained. In FY2012, the collaboration plans a broad array of activities. PNNL will focus on optimizing its empirical model and minimizing its reliance on calibration data, as well continuing efforts on developing an analytical model. Additional measurements are

  8. Nuclear Fuel Reprocessing

    SciTech Connect

    Harold F. McFarlane; Terry Todd

    2013-11-01

    Reprocessing is essential to closing nuclear fuel cycle. Natural uranium contains only 0.7 percent 235U, the fissile (see glossary for technical terms) isotope that produces most of the fission energy in a nuclear power plant. Prior to being used in commercial nuclear fuel, uranium is typically enriched to 3–5% in 235U. If the enrichment process discards depleted uranium at 0.2 percent 235U, it takes more than seven tonnes of uranium feed to produce one tonne of 4%-enriched uranium. Nuclear fuel discharged at the end of its economic lifetime contains less one percent 235U, but still more than the natural ore. Less than one percent of the uranium that enters the fuel cycle is actually used in a single pass through the reactor. The other naturally occurring isotope, 238U, directly contributes in a minor way to power generation. However, its main role is to transmute into plutoniumby neutron capture and subsequent radioactive decay of unstable uraniumand neptuniumisotopes. 239Pu and 241Pu are fissile isotopes that produce more than 40% of the fission energy in commercially deployed reactors. It is recovery of the plutonium (and to a lesser extent the uranium) for use in recycled nuclear fuel that has been the primary focus of commercial reprocessing. Uraniumtargets irradiated in special purpose reactors are also reprocessed to obtain the fission product 99Mo, the parent isotope of technetium, which is widely used inmedical procedures. Among the fission products, recovery of such expensive metals as platinum and rhodium is technically achievable, but not economically viable in current market and regulatory conditions. During the past 60 years, many different techniques for reprocessing used nuclear fuel have been proposed and tested in the laboratory. However, commercial reprocessing has been implemented along a single line of aqueous solvent extraction technology called plutonium uranium reduction extraction process (PUREX). Similarly, hundreds of types of reactor

  9. Predicting Reactor Antineutrino Emissions Using New Precision Beta Spectroscopy

    SciTech Connect

    Asner, David M.; Burns, Kimberly A.; Greenfield, Bryce A.; Kos, Marek S.; Orrell, John L.; Schram, Malachi; VanDevender, Brent A.; Wootan, David W.

    2013-05-01

    Neutrino experiments at nuclear reactors are currently vital to the study of neutrino oscillations. The observed antineutrino rates at reactors are typically lower than model expectations. This observed deficit is called the “reactor neutrino anomaly”. A new understanding of neutrino physics may be required to explain this deficit, though model estimation uncertainties may also play a role in the apparent discrepancy. PNNL is currently investigating an experimental technique that promises reduced uncertainties for measured data to support these hypotheses and interpret reactor antineutrino measurements. The experimental approach is to 1) direct a proton accelerator beam on a metal target to produce a source of neutrons, 2) use spectral tailoring to modify the neutron spectrum to closely simulate the energy distribution of a power reactor neutron spectrum, 3) irradiate isotopic fission foils (235U, 238U, 239Pu, 241Pu) in this neutron spectrum so that fissions occur at energies representative of a reactor, 4) transport the beta particles released by the fission products in the foils to a beta spectrometer, 5) measure the beta energy spectrum, and 6) invert the measured beta energy spectrum to an antineutrino energy spectrum. A similar technique using a beta spectrometer and isotopic fission foils was pioneered in the 1980’s at the ILL thermal reactor. Those measurements have been the basis for interpreting all subsequent antineutrino measurements at reactors. A basic constraint in efforts to reduce uncertainties in predicting the antineutrino emission from reactor cores is any underlying limitation of the original measurements. This may include beta spectrum energy resolution, the absolute normalization of beta emission to number of fission, statistical counting uncertainties, lack of 238U data, the purely thermal nature of the IIL reactor neutrons used, etc. An accelerator-based neutron source that can be tailored to match various reactor neutron spectra

  10. Criticality Benchmark Results Using Various MCNP Data Libraries

    SciTech Connect

    Stephanie C. Frankle

    1999-07-01

    A suite of 86 criticality benchmarks has been recently implemented in MCNP{trademark} as part of the nuclear data validation effort. These benchmarks have been run using two sets of MCNP continuous-energy neutron data: ENDF/B-VI based data through Release 2 (ENDF60) and the ENDF/B-V based data. New evaluations were completed for ENDF/B-VI for a number of the important nuclides such as the isotopes of H, Be, C, N, O, Fe, Ni, {sup 235,238}U, {sup 237}Np, and {sup 239,240}Pu. When examining the results of these calculations for the five manor categories of {sup 233}U, intermediate-enriched {sup 235}U (IEU), highly enriched {sup 235}U (HEU), {sup 239}Pu, and mixed metal assembles, we find the following: (1) The new evaluations for {sup 9}Be, {sup 12}C, and {sup 14}N show no net effect on k{sub eff}; (2) There is a consistent decrease in k{sub eff} for all of the solution assemblies for ENDF/B-VI due to {sup 1}H and {sup 16}O, moving k{sub eff} further from the benchmark value for uranium solutions and closer to the benchmark value for plutonium solutions; (3) k{sub eff} decreased for the ENDF/B-VI Fe isotopic data, moving the calculated k{sub eff} further from the benchmark value; (4) k{sub eff} decreased for the ENDF/B-VI Ni isotopic data, moving the calculated k{sub eff} closer to the benchmark value; (5) The W data remained unchanged and tended to calculate slightly higher than the benchmark values; (6) For metal uranium systems, the ENDF/B-VI data for {sup 235}U tends to decrease k{sub eff} while the {sup 238}U data tends to increase k{sub eff}. The net result depends on the energy spectrum and material specifications for the particular assembly; (7) For more intermediate-energy systems, the changes in the {sup 235,238}U evaluations tend to increase k{sub eff}. For the mixed graphite and normal uranium-reflected assembly, a large increase in k{sub eff} due to changes in the {sup 238}U evaluation moved the calculated k{sub eff} much closer to the benchmark value. (8

  11. LLD Determination for PFP Residues Using the ANTECH Calorimeters

    SciTech Connect

    WESTSIK, G.A.

    2003-07-07

    The Plutonium Finishing Plant (PFP) facility performs waste characterization measurements for disposal of transuranic waste (TRU) at the Waste Isolation Pilot Plant (WIPP). The WIPP's performance assessment requires monitoring and tracking of the following ten radionuclides in the waste that is accepted and disposed of at the WIPP facility. Activities and mass values must be reported for: {sup 241}Am, {sup 238}Pu, {sup 239}Pu, {sup 240}Pu, {sup 242}Pu, {sup 233}U, {sup 234}U, {sup 238}U, {sup 90}Sr and {sup 137}Cs on a payload container basis. In addition the system must be able to report other nuclides, which contribute to the FGE, decay heat or contribute to more than 95% of the total radiological hazard. PFP reports the activity and mass of these radionuclides when positively identified in any waste container. In situations where one of the 10 WIPP tracked radionuclides is not positively identified on a PFP assay, PFP either reports a ''zero'', indicating the nuclide was not positively identified in the waste assay and is not identified by the acceptable knowledge (AK), or ''

  12. Certified reference materials and reference methods for nuclear safeguards and security.

    PubMed

    Jakopič, R; Sturm, M; Kraiem, M; Richter, S; Aregbe, Y

    2013-11-01

    Confidence in comparability and reliability of measurement results in nuclear material and environmental sample analysis are established via certified reference materials (CRMs), reference measurements, and inter-laboratory comparisons (ILCs). Increased needs for quality control tools in proliferation resistance, environmental sample analysis, development of measurement capabilities over the years and progress in modern analytical techniques are the main reasons for the development of new reference materials and reference methods for nuclear safeguards and security. The Institute for Reference Materials and Measurements (IRMM) prepares and certifices large quantities of the so-called "large-sized dried" (LSD) spikes for accurate measurement of the uranium and plutonium content in dissolved nuclear fuel solutions by isotope dilution mass spectrometry (IDMS) and also develops particle reference materials applied for the detection of nuclear signatures in environmental samples. IRMM is currently replacing some of its exhausted stocks of CRMs with new ones whose specifications are up-to-date and tailored for the demands of modern analytical techniques. Some of the existing materials will be re-measured to improve the uncertainties associated with their certified values, and to enable laboratories to reduce their combined measurement uncertainty. Safeguards involve the quantitative verification by independent measurements so that no nuclear material is diverted from its intended peaceful use. Safeguards authorities pay particular attention to plutonium and the uranium isotope (235)U, indicating the so-called 'enrichment', in nuclear material and in environmental samples. In addition to the verification of the major ratios, n((235)U)/n((238)U) and n((240)Pu)/n((239)Pu), the minor ratios of the less abundant uranium and plutonium isotopes contain valuable information about the origin and the 'history' of material used for commercial or possibly clandestine purposes, and

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

    PubMed

    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

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

    SciTech Connect

    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

  15. Measurements of actinides in soil, sediments, water and vegetation in Northern New Mexico

    SciTech Connect

    Gallaher, B. M.; Efurd, D. W.

    2002-01-01

    This study was undertaken during 1991 - 1998 to identify the origin of plutonium uranium in northern New Mexico Rio Grande and tributary stream sediments. Isotopic fingerprinting techniques help distinguish radioactivity from Los Alamos National Laboratory (LANL) and from global fallout or natural sources. The geographic area covered by the study extended from the headwaters of the Rio Grande in southern Colorado to Elephant Butte Reservoir in southern New Mexico. Over 100 samples of stream channel and reservoir bottom sediments were analyzed for the atom ratios of plutonium and uranium isotopes using thermal ionization mass spectrometry (TIMS). Comparison of these ratios against those for fallout or natural sources allowed for quantification of the Laboratory impact. Of the seven major drainages crossing LANL, movement of LANL plutonium into the Rio Grande can only be traced via Los Alamos Canyon. The majority of sampled locations within and adjacent to LANL have little or no input of plutonium from the Laboratory. Samples collected upstream and distant to L A N show an average (+ s.d.) fallout 240Pu/239Pauto m ratio of 0.169 + 0.012, consistent with published worldwide global fallout values. These regional background ratios differ significantly from the 240Pu/239Pu atom ratio of 0.015 that is representative of LANL-derived plutonium entering the Rio Grande at Los Alamos Canyon. Mixing calculations of these sources indicate that the largest proportion (60% to 90%) of the plutonium in the Rio Grande sediments is from global atmospheric fallout, with an average of about 25% from the Laboratory. The LANL plutonium is identifiable intermittently along the 35-km reach of the Rio Grande to Cochiti Reservoir. The source of the LANL-derived plutonium in the Rio Grande was traced primarily to pre-1960 discharges of liquid effluents into a canyon bottom at a distance approximately 20 km upstream of the river. Plutonium levels decline exponentially with distance downstream

  16. Neutron scattering studies in the actinide region. Progress report, August 1, 1992--July 31, 1993

    SciTech Connect

    Kegel, G.H.R.; Egan, J.J.

    1993-09-01

    This report discusses the following topics: Prompt fission neutron energy spectra for {sup 235}U and {sup 239}Pu; Two-parameter measurement of nuclear lifetimes; ``Black`` neutron detector; Data reduction techniques for neutron scattering experiments; Inelastic neutron scattering studies in {sup 197}Au; Elastic and inelastic scattering studies in {sup 239}Pu; and neutron induced defects in silicon dioxide MOS structures.

  17. Plutonium in human urine: Normal levels in the US public. 1991 Annual report, Volume 2

    SciTech Connect

    Wrenn, M.E.; Singh, N.P.; Xue, Ying-Hua

    1997-03-01

    A neutron induced fission track method was successfully developed for assaying {sup 239}Pu in human urine with a detection limit below 20 aCi/sample. The technique involves the co-precipitation of {sup 239}Pu with rhodizonic acid, separation of {sup 239}Pu from potentially interfering natural uranium and other inorganic materials by ion-exchange techniques, collection of the sample onto lexan detectors, irradiation of sample in MIT reactor at a fluence of 1.1 x 10{sup 17} n/cm{sup 2}, etching of the lexan slide and counting the track either manually or by some automated counting system.

  18. Corrections for Exchange and Screening Effects in Low-energy Beta Decays

    SciTech Connect

    Mougeot, X. Bé, M.-M.; Bisch, C.; Loidl, M.

    2014-06-15

    The beta spectra of {sup 241}Pu and {sup 63}Ni have been recently measured using metallic magnetic calorimeters. This powerful experimental technique allows theoretical beta spectra calculations to be tested at low energy with an accuracy never before achievable. Their comparison with classical beta calculations exhibits a significant deviation below 4 keV for {sup 241}Pu and 8 keV for {sup 63}Ni. The atomic exchange effect explains the main part of this deviation in the {sup 63}Ni beta spectrum. This effect has a significant contribution, equivalent to the magnitude of the screening, in the {sup 241}Pu beta spectrum.

  19. Improved methods of measurement and analysis of conversion electron and beta-particle spectra

    PubMed

    Dragoun; Spalek; Rysavy; Kovalik; Yakushev; Brabec; Frana; Venos

    2000-03-01

    A general statistical test of the stability of measurement conditions was demonstrated on the beta-spectra of 241Pu cumulated during four years. The alpha- and gamma-ray spectroscopy indicated stability of the 241Pu source. Monte Carlo modelling of individual collision events clarified the role of electron scattering and energy losses within a radioactive source down to energies of several hundreds of eV. The impact ionization by beta-particles of carbon and oxygen atoms in a surface contamination layer on the 241Pu and 63Ni sources was observed. PMID:10724379

  20. Seaborg's plutonium? A case study in nuclear forensics

    NASA Astrophysics Data System (ADS)

    Norman, Eric B.; Thomas, Keenan J.; Telhami, Kristina E.

    2015-10-01

    Passive X-ray and gamma-ray analysis was performed on a curious sample from UC Berkeley's Hazardous Material Facility inventory, and the object was found to contain 239Pu. No other radioactive isotopes were observed. The mass of 239Pu contained in this object was determined to be 2.0 ± 0.3 μg. These observations are consistent with the identification of this object as containing the 2.77-μg PuO2 (2.44 μg 239Pu) sample produced in 1942 and described by Seaborg and his collaborators as the first sample of 239Pu that was large enough to be weighed.

  1. Seaborg's Plutonium? A Case Study in Nuclear Forensics

    NASA Astrophysics Data System (ADS)

    Norman, Eric B.; Thomas, Keenan J.; Telhami, Kristina E.

    2015-10-01

    Passive X-ray and gamma-ray analysis was performed on UC Berkeley's EH&S Sample S338. The object was found to contain 239Pu. No other radioactive isotopes were observed. The mass of 239Pu contained in this object was determined to be 2.0 +- 0.3 μg. These observations are consistent with the identification of this object as containing the 2.77- μg PuO2 (2.44 μg 239Pu) sample produced in 1942 and described by Glenn Seaborg and his collaborators as the first sample of 239Pu that was large enough to be weighed. This work was supported in part by the U.S. Dept. of Energy National Nuclear Security Administration under Award No. DE-NA0000979.

  2. Fabrication of a 238Pu target

    SciTech Connect

    Wu, C Y; Chyzh, A; Kwan, E; Henderson, R; Gostic, J; Carter, D

    2010-11-16

    higher neutron incident energy. However, it indicates that a cross section of less than one barn can be measured. The second phase of this experiment will be carried out in 2011 by assembling a PPAC with the {sup 238}Pu target to extend the measurement to higher neutron incident energies by distinguishing the capture from fission events. The fission cross section becomes dominant for neutron incident energies above 30 keV. This PPAC was developed in FY2010 under the NA22 funding and performed very well for the {sup 239}Pu and {sup 241}Pu measurements. A new {sup 238}Pu target will be fabricated for the phase II measurement using the same electroplating technique.

  3. Neutron scattering studies in the actinide region. Progress report, August 1, 1988--July 31, 1991

    SciTech Connect

    Beghian, L.E.; Kegel, G.H.R.

    1991-08-01

    During the report period we have investigated the following areas: Neutron elastic and inelastic scattering measurements on {sup 14}N, {sup 181}Ta, {sup 232}Th, {sup 238}U and {sup 239}Pu; Prompt fission spectra for {sup 232}Th, {sup 235}U, {sup 238}U and {sup 239}Pu; Theoretical studies of neutron scattering; Neutron filters; New detector systems; and Upgrading of neutron target assembly, data acquisition system, and accelerator/beam-line apparatus.

  4. Neutron scattering studies in the actinide region

    SciTech Connect

    Beghian, L.E.; Kegel, G.H.R.

    1991-08-01

    During the report period we have investigated the following areas: Neutron elastic and inelastic scattering measurements on {sup 14}N, {sup 181}Ta, {sup 232}Th, {sup 238}U and {sup 239}Pu; Prompt fission spectra for {sup 232}Th, {sup 235}U, {sup 238}U and {sup 239}Pu; Theoretical studies of neutron scattering; Neutron filters; New detector systems; and Upgrading of neutron target assembly, data acquisition system, and accelerator/beam-line apparatus.

  5. Evaluating criticality safety of TRU waste with NDA measurements and risk analyses

    SciTech Connect

    Hochel, R.C.; Hofstetter, K.J.; Sigg, R.A.; Winn, W.G.; Chay, S.C.

    1994-09-01

    The criticality safety of {sup 239}Pu in 55-gal. drums stored in TRU waste containers (concrete culverts) was evaluated using NDA neutron and gamma measurements and risk analyses. The neutron measurements yielded a {sup 239}Pu mass and k{sub eff} for a culvert, which contains up to 14 drums. The gamma measurements helped reveal and correct for any interfering neutron sources in the waste. Conservation probabilistic risk analyses were developed for both drums and culverts.

  6. Plutonium excretion in urine of residents living near the Rocky Flats Environmental Technology Site.

    PubMed

    Ibrahim, S A; Whicker, F W; Reuss, S K; Whicker, R D; Chapman, P L; Krahenbuhl, M P

    1999-04-01

    An assessment of current levels of 239Pu in individuals living near the Rocky Flats Environmental Technology Site was conducted. Long-term residents of areas adjacent to the Site, as well as people living well beyond any expected influence of the site, provided urine samples, which were analyzed by fission track analysis for the levels of 239Pu. The Rocky Flats Environmental Technology Site vicinity participants were selected for maximum possible exposure to environmental plutonium by virtue of residence location, length of residence, age, and outdoor lifestyle. The mean 239Pu excretion rate in urine estimated for the entire Rocky Flats group was 1.1 microBq d(-1), in contrast to that estimated for the background group (0.85 microBq d(-1)). The estimated median 239Pu excretion rate for the Rocky Flats group was 1.1 microBq d(-1), compared to 0.54 microBq d(-1) for the background group. Both parametric and non-parametric tests indicated that these differences were not statistically significant (alpha = 0.05). Measured levels of 239Pu in urine from the Rocky Flats group were low and well within the range of reported "background" values, indicating small doses and low health risks. The fission track analysis technique may not be sufficiently accurate or precise to allow definitive comparisons between two groups of subjects with near-background levels of 239Pu in urine. PMID:10086597

  7. Plutonium and americium behavior in coral atoll environments

    SciTech Connect

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

    1984-02-01

    Inventories of /sup 239 +240/Pu and /sup 241/Am greatly in excess of global fallout levels persist in the benthic environments of Bikini and Enewetak Atolls. Quantities of /sup 239 +240/Pu and lesser amounts of /sup 241/Am are continuously mobilizing from these sedimentary reservoirs. The amount of /sup 239 +240/Pu mobilized to solution at any time represents 0.08 to 0.09% of the sediment inventories to a depth of 16 cm. The mobilized /sup 239 +240/Pu has solute-like characteristics and different valence states coexist in solution - the largest fraction of the soluble plutonium is in an oxidized form (+V,VI). The adsorption of plutonium to sediments is not completely reversible because of changes that occur in the relative amounts of the mixed oxidation states in solution with time. Further, any characteristics of /sup 239 +240/Pu described at one location may not necessarily be relevant in describing its behavior elsewhere following mobilization and migration. The relative amounts of /sup 241/Am to /sup 239 +240/Pu in the sedimentary deposits at Enewetak and Bikini may be altered in future years because of mobilization and radiological decay. Mobilization of /sup 239 +240/Pu is not a process unique to these atolls, and quantities in solution derived from sedimentary deposits can be found at other global sites. These studies in the equatorial Pacific have significance in assessing the long-term behavior of the transuranics in any marine environment. 22 references, 1 figure, 13 tables.

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

    SciTech Connect

    Bannochie, C

    2005-05-01

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

  9. REPORTABLE RADIONUCLIDES IN DWPF SLUDGE BATCH 7A (MACROBATCH 8)

    SciTech Connect

    Reboul, S.; Diprete, D.; Click, D.; Bannochie, C.

    2011-12-20

    The Waste Acceptance Product Specifications (WAPS) 1.2 require that the waste producer 'shall report the curie inventory of radionuclides that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115.' As part of the strategy to meet WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type all radionuclides that have half-lives longer than 10 years and contribute greater than 0.01 percent of the total curie inventory from the time of production through the 1100 year period from 2015 through 3115. The initial list of radionuclides to be reported is based on the design-basis glass identified in the Waste Form Compliance Plan (WCP) and Waste Form Qualification Report. However, it is required that the list be expanded if other radionuclides with half-lives greater than 10 years are identified that meet the 'greater than 0.01% of the curie inventory' criterion. Specification 1.6 of the WAPS, International Atomic Energy Agency Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, and U-238; and Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242. Therefore, the complete list of reportable radionuclides must also include these sets of U and Pu isotopes - and the U and Pu isotopic mass distributions must be identified. The DWPF receives HLW sludge slurry from Savannah River Site (SRS) Tank 40. For Sludge Batch 7a (SB7a), the waste in Tank 40 contained a blend of the heel from Sludge Batch 6 (SB6) and the Sludge Batch 7 (SB7) material transferred to Tank 40 from Tank 51. This sludge blend is also referred to as Macrobatch 8. Laboratory analyses of a Tank 40 sludge sample were performed to quantify the concentrations of pertinent radionuclides in the SB7a waste. Subsequently, radiological decay and in

  10. A preliminary study for the development of reference material using oyster for determination of (137)Cs, (90)Sr and plutonium isotopes.

    PubMed

    Lee, Sang-Han; Oh, Jung-Suk; Lee, Jong-Man; Lee, Kyung-Bum; Park, Tae-Soon; Lee, Min-Kie; Kim, Seung-Hwan; Choi, Jong-Ki

    2016-03-01

    A new reference material for the determination of (137)Cs, (90)Sr and Pu isotopes ((238)Pu and (239,240)Pu) is being developed using dried oyster matrix by Korea Research Institute of Standards and Science (KRISS). The oyster was collected from Tongyoung harbour, southern part of Korea and the artificial radionuclides ((137)Cs, (90)Sr, (238)Pu and (239,240)Pu) were spiked into the material. After pretreatment and processing, the material was tested for homogeneity and massic activities were determined by measuring (137)Cs, (90)Sr, (238)Pu and (239,240)Pu. The reference value and extended uncertainty for those isotopes will be reported later. PMID:26688367

  11. SALTSTONE VAULT CLASSIFICATION SAMPLES MODULAR CAUSTIC SIDE SOLVENT EXTRACTION UNIT/ACTINIDE REMOVAL PROCESS WASTE STREAM APRIL 2011

    SciTech Connect

    Eibling, R.

    2011-09-28

    Savannah River National Laboratory (SRNL) was asked to prepare saltstone from samples of Tank 50H obtained by SRNL on April 5, 2011 (Tank 50H sampling occurred on April 4, 2011) during 2QCY11 to determine the non-hazardous nature of the grout and for additional vault classification analyses. The samples were cured and shipped to Babcock & Wilcox Technical Services Group-Radioisotope and Analytical Chemistry Laboratory (B&W TSG-RACL) to perform the Toxic Characteristic Leaching Procedure (TCLP) and subsequent extract analysis on saltstone samples for the analytes required for the quarterly analysis saltstone sample. In addition to the eight toxic metals - arsenic, barium, cadmium, chromium, mercury, lead, selenium and silver - analytes included the underlying hazardous constituents (UHC) antimony, beryllium, nickel, and thallium which could not be eliminated from analysis by process knowledge. Additional inorganic species determined by B&W TSG-RACL include aluminum, boron, chloride, cobalt, copper, fluoride, iron, lithium, manganese, molybdenum, nitrate/nitrite as Nitrogen, strontium, sulfate, uranium, and zinc and the following radionuclides: gross alpha, gross beta/gamma, 3H, 60Co, 90Sr, 99Tc, 106Ru, 106Rh, 125Sb, 137Cs, 137mBa, 154Eu, 238Pu, 239/240Pu, 241Pu, 241Am, 242Cm, and 243/244Cm. B&W TSG-RACL provided subsamples to GEL Laboratories, LLC for analysis for the VOCs benzene, toluene, and 1-butanol. GEL also determines phenol (total) and the following radionuclides: 147Pm, 226Ra and 228Ra. Preparation of the 2QCY11 saltstone samples for the quarterly analysis and for vault classification purposes and the subsequent TCLP analyses of these samples showed that: (1) The saltstone waste form disposed of in the Saltstone Disposal Facility in 2QCY11 was not characteristically hazardous for toxicity. (2) The concentrations of the eight RCRA metals and UHCs identified as possible in the saltstone waste form were present at levels below the UTS. (3) Most of the

  12. Methods for the assessment of long-lived radionuclides in humans resulting from nuclear activities or accidents: Fission track analysis of trace amounts plutonium-239 and a copper hexacyanoferrate kit for monitoring radiocaesium

    NASA Astrophysics Data System (ADS)

    Johansson, Lena Camilla

    Fission track analysis (FTA) was developed to be applied to ultra-low levels of 239Pu in bioassay samples. An analytical protocol was established for the FTA processing. The detection limit was determined to 1.5 μBq and the calibration constant was 24 fission fragments per μBq 239Pu. Naturally occurring nuclides of thorium and uranium, present in biological and environmental samples, did not interfere in the determination of 239Pu. Self-absorption of fission fragments was shown to be insignificant. The study included the determination of 239Pu in urine samples from twenty Chernobyl clean-up workers. All urine samples contained activities below the detection limit for radioanalytical analysis using alpha spectrometry (0.5 mBq). Seven of the samples were further investigated using a thermal ionization mass spectrometer with a sensitivity of 106 atoms 239Pu. The content of 239Pu in the samples showed to be below 1μBq (106 atoms), with only one exception. It was not possible to draw any major conclusions from the 239Pu results, regarding the clean-up workers' exposure from radionuclides released by the Chernobyl accident. A kit was designed for selective adsorption of radiocaesium in urine samples to be used in situ by contaminated subjects. The kit consisted of copper hexacyanoferrate impregnated cotton filters held by filter holders for sample flow-through. After use, the adsorbed fraction of caesium was >=90% in urine samples. The kit facilitates the screening of a population exposed to radiocaesium. Parameters influencing the adsorption efficiency, such as potassium, sodium and calcium concentration of the sample and the sample pH, were investigated and shown to be insignificant for urine samples.

  13. Multimedia contaminant environmental exposure assessment methodology as applied to Los Alamos, New Mexico

    SciTech Connect

    Whelan, G.; Thompson, F.L.; Yabusaki, S.B.

    1983-02-01

    The MCEA (Multimedia Contaminant Environmental Exposure Assessment) methodology assesses exposures to air, water, soil, and plants from contaminants released into the environment by simulating dominant mechanisms of contaminant migration and fate. The methodology encompasses five different pathways (i.e., atmospheric, terrestrial, overland, subsurface, and surface water) and combines them into a highly flexible tool. The flexibility of the MCEA methodology is demonstrated by encompassing two of the pathways (i.e., overland and surface water) into an effective tool for simulating the migration and fate of radionuclides released into the Los Alamos, New Mexico region. The study revealed that: (a) the /sup 239/Pu inventory in lower Los Alamos Canyon increased by approximately 1.1 times for the 50-y flood event; (b) the average contaminant /sup 239/Pu concentrations (i.e., weighted according to the depth of the respective bed layer) in lower Los Alamos Canyon for the 50-y flood event decreased by 5.4%; (c) approx. 27% of the total /sup 239/Pu contamination resuspended from the entire bed (based on the assumed cross sections) for the 50-y flood event originated from lower Pueblo Canyon; (d) an increase in the /sup 239/Pu contamination of the bed followed the general deposition patterns experienced by the sediment in Pueblo-lower Los Alamos Canyon; likewise, a decrease in the /sup 239/Pu contamination of the bed followed general sediment resuspension patterns in the canyon; (e) 55% of the /sup 239/Pu reaching the San Ildefonso Pueblo in lower Los Alamos Canyon originated from lower Los Alamos Canyon; and (f) 56% of the /sup 239/Pu contamination reaching the San Ildefonso Pueblo in lower Los Alamos Canyon was carried through towards the Rio Grande. 47 references, 41 figures, 29 tables.

  14. [Influence of Professional Contact with Plutonium-239 on Indicators of the Immune Status of the Personnel at Siberian Chemical Plant].

    PubMed<