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Sample records for 238pu 239pu 241am

  1. 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.

  2. 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

  3. 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.

  4. [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

  5. 238Pu, 239,240Pu, 241Am, 90Sr and 137Cs in soils around nuclear research centre Rez, near Prague.

    PubMed

    Hölgye, Z; Schlesingerová, E; Tecl, J; Filgas, R

    2004-01-01

    Forty-four soil samples were taken around the nuclear research centre Rez, near Prague. The mean activity concentrations of 238Pu, 239,240Pu, 241Am, 90Sr and 137Cs in uncultivated soil were 0.010, 0.26, 0.12, 2.7 and 23 Bq.kg(-1), respectively. Contents of radionuclides in cultivated soil were lower and in forest soil higher than in uncultivated soil. The mean activity ratios of 238Pu/239,240Pu, 241Am/239,240Pu, 90Sr/239,240Pu and 239,240Pu/137Cs in uncultivated soil were 0.041, 0.47, 10.9 and 0.013, respectively. The mean activity ratios in cultivated and forest soils were close to the values given above. It follows from the results that the source of 239,240Pu, 90Sr and 137Cs in the studied area is deposition from atmospheric nuclear tests, in the case of 137Cs also deposition from Chernobyl accident. The contribution of the research centre effluents was not proved for these radionuclides. Increased activity ratio of 241Am/239,240Pu indicates the presence of 241Am in the soils studied emanating from sources other than nuclear tests. Uniform distribution of the 241Am/239,240Pu activity ratio around the nuclear research centre and the absence of an area with evidently higher activity ratio, including at sites lying in the main wind direction, suggest that the additional activity of 241Am does not originate from the nuclear research centre. The additional source might be the deposition following the Chernobyl accident.

  6. 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.

  7. 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

  8. 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.

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

    PubMed

    Oh, J-S; Warwick, P E; Croudace, I W

    2009-01-01

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

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

    PubMed

    Oh, J-S; Warwick, P E; Croudace, I W

    2009-01-01

    Ninety five surface scrape samples were collected at the Ravenglass saltmarsh and analysed for radionuclides by alpha spectrometry ((238)Pu and (239,240)Pu), gamma spectrometry ((241)Am and (137)Cs) and liquid scintillation counting ((241)Pu). Both (241)Am and (137)Cs activities are compared with those reported by Horrill [1983. Concentrations and spatial distribution of radioactivity in an ungrazed saltmarsh. In: Coughtrey, P.J. (Ed.), Ecological Aspects of Radionuclide Release. British Ecological Society Special Publication No. 3. Blackwell, Oxford, pp. 119-215.] Significant decreases in activities for both radionuclides were observed which is caused by the declining levels of discharges from the Sellafield nuclear reprocessing plant since the 1980s. It has been concluded that the spatial distribution of these radionuclides are controlled by the tidal currents and the clay contents in the sediments. There is evidence of surface erosion of the saltmarsh and redistribution of radionuclides in the saltmarsh using isotopic ratios of measured Pu. PMID:19285416

  11. 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.

  12. Selectivity of 90Sr urine bioassay technique over 241Am, 238/239PU, 210PO, 137CS and 60CO.

    PubMed

    Sadi, Baki B; Li, Chunsheng; Bahraini, Negar; Lai, Edward P C; Kramer, Gary H

    2010-09-01

    The selectivity of a rapid (90)Sr bioassay technique over (241)Am, (238/239)Pu, (210)Po, (137)Cs and (60)Co has been investigated. Similar to (90)Sr, these radionuclides are likely to be used in radiological dispersive devices. The purpose of this study was to demonstrate the degree to which the (90)Sr bioassay technique is free from interference by these radionuclides if present in a urine matrix. The interfering radionuclides were removed (from (90)Sr) by their retention on an anion exchange column. While, recovery of the target radionuclide ((90)Sr) was found to be >or= 90 %, contributions from (241)Am, (242)Pu and (208)Po were found to be

  13. Comparative study of the fragments' mass and energy characteristics in the spontaneous fussion of 238Pu, 240Pu and 242Pu and in the thermal-neutron-induced fission of 239Pu

    NASA Astrophysics Data System (ADS)

    Schillebeeckx, P.; Wagemans, C.; Deruytter, A. J.; Barthélémy, R.

    1992-08-01

    The energy and mass distribution and their correlations have been studied for the spontaneous fission of 238, 240, 242Pu and for the thermal-neutron-induced fission of 239Pu. A comparison of 240Pu(s.f.) and 239Pu(nth,f) shows that the increase in excitation energy mainly results in an increase of the intrinsic excitation energy. A comparison of the results for 238Pu, 240Pu and 242Pu(s.f.) demonstrates the occurence of different fission modes with varying relative probability. These results are discussed in terms of the scission point model as well as in terms of the fission channel model with random neck-rupture.

  14. [90Sr, 137Cs, 238Pu, 239+240Pu, and 241Am radionuclides in macrophytes within the Krasnensky flood plain: species specificity of concentration and distribution in phytocenosis components].

    PubMed

    Gudkov, D I; Zub, L N; Derevets, V V; Kuz'menko, M I; Nazarov, A B; Kaglian, A E; Savitskiĭ, A L

    2002-01-01

    The analysis of the content of radionuclides 90Sr, 137Cs, 238Pu, 239 + 240Pu and 241Am in water vegetation of flood plain reservoirs has allowed studing features of radionuclide accumulation by various species of macrophytes and revealing bioindicators of radionuclide contamination. Thus species-specificity of radionuclide accumulation can essentially change the contribution of different species to a percentage ratio of the radionuclide content in phytomass of reservoirs in comparison with fund of higher aquatic plants.

  15. 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.

  16. Comparative toxicity of /sup 226/Ra, /sup 239/Pu, /sup 241/Am, /sup 249/Cf, and /sup 252/Cf in C57BL/Do black and albino mice

    SciTech Connect

    Taylor, G.N.; Mays, C.W.; Lloyd, R.D.; Gardner, P.A.; TAlbot, L.R.; McFarland, S.S.; Pollard, T.A.; Atherton, D.R.; vanMoorhem, D.; Brammer, D.

    1983-09-01

    Groups of C57BL/Do (black and albino) mice were injected with graded activities of /sup 226/Ra, /sup 239/Pu, /sup 241/Am, /sup 249/Cf, or /sup 252/Cf and were followed throughout life. Bone sarcoma was the principal radiation-induced end point, and the risks associated with average skeletal doses of the four transuranium radionuclides, relative to radium, were determined. The relative biological effectiveness (RBE) was calculated for each emitter by dividing its risk coefficient (bone sarcomas per 10/sup 6/ mouse-rad) by the risk coefficient for /sup 226/Ra. Combined data for males and females in both black and albino mice gave the following values +- SD for the RBE relative to /sup 226/Ra = 1.0: /sup 239/Pu = 15.3 +- 3.9, /sup 241/Am = 4.9 +- 1.4, /sup 249/Cf = 5.0 +- 1.4, and /sup 252/Cf = 2.6 +- 0.8. About 70% of the tumors occurred in the axial skeleton, and the risk coefficient for females averaged about four times higher than for males when all five nuclides were included. The RBE of fission fragment irradiation from /sup 252/Cf for cancer induction, relative to ..cap alpha.. irradiation, for the combined data in all of the animals given /sup 252/Cf and /sup 249/Cf, was 0.02 +- 0.28, in agreement with the calculated theoretical value of 0.03, based on the ratio of summed track lengths in tissue.

  17. Comparative toxicity of /sup 226/Ra, /sup 239/Pu, /sup 241/Am, /sup 249/Cf, and /sup 252/Cf in C57BL/Do black and albino mice

    SciTech Connect

    Taylor, G.N.; Mays, C.W.; Lloyd, R.D.; Gardner, P.A.; Talbot, L.R.; McFarland, S.S.; Pollard, I.A.; Atherton, D.R.; VanMoorhem, D.; Brammer, D.

    1983-09-01

    Groups of C57BL/Do (black and albino) mice were injected with graded activities of /sup 226/Ra, /sup 239/Pu, /sup 241/Am, /sup 249/Cf, or /sup 252/Cf and were followed throughout life. Bone sarcoma was the principal radiation-induced end point, and the risks associated with average skeletal doses of the four transuranium radionuclides, relative to radium, were determined. The relative biological effectiveness (RBE) was calculated for each emitter by dividing its risk coefficient (bone sarcomas per 10(/sup 6/) mouse-rad) by the risk coefficient for /sup 226/Ra. Combined data for males and females in both black and albino mice gave the following values +/- SD for the RBE relative to /sup 226/Ra . 1.0: /sup 239/Pu . 15.3 +/- 3.9, /sup 241/Am . 4.9 +/- 1.4, /sup 249/Cf . 5.0 +/- 1.4, and /sup 252/Cf . 2.6 +/- 0.8. About 70% of the tumors occurred in the axial skeleton, and the risk coefficient for females averaged about four times higher than for males when all five nuclides were included. The RBE of fission fragment irradiation from /sup 252/Cf for cancer induction, relative to alpha irradiation, for the combined data in all of the animals given /sup 252/Cf and /sup 249/Cf, was 0.02 +/- 0.28, in agreement with the calculated theoretical value of 0.03, based on the ratio of summed track lengths in tissue.

  18. Determination of (235)U, (239)Pu, (240)Pu, and (241)Am in a nuclear bomb particle using a position-sensitive α-γ coincidence technique.

    PubMed

    Peräjärvi, Kari A; Ihantola, Sakari; Pöllänen, Roy C; Toivonen, Harri I; Turunen, Jani A

    2011-02-15

    A nuclear bomb particle containing 1.6 ng of Pu was investigated nondestructively with a position-sensitive α detector and a broad-energy HPGe γ-ray detector. An event-mode data acquisition system was used to record the data. α-γ coincidence counting was shown to be well suited to nondestructive isotope ratio determination. Because of the very small background, the 51.6 keV γ rays of (239)Pu and the 45.2 keV γ rays of (240)Pu were identified, which enabled isotopic ratio calculations. In the present work, the (239)Pu/((239)Pu+(240)Pu) atom ratio was determined to be 0.950 ± 0.010. The uncertainties were much smaller than in the previous more conventional nondestructive studies on this particle. Obtained results are also in good agreement with the data from the destructive mass spectrometric studies obtained previously by other investigators.

  19. Evaluation of Measurements of 238Pu, 239Pu and 240Pu in Urine at the Microbecquerel Level Using Thermal Ionization Mass Spectrometry and Alpha Spectrometry at Los Alamos National Laboratory: Results of a Two Year Comparison Test (LA-UR-06-8055)

    SciTech Connect

    Bores, Norman; Schultz, Michael K

    2008-01-01

    The Intercomparison Studies Program (ISP) at the Oak Ridge National Laboratory (ORNL, Oak Ridge, TN, USA) provides natural-matrix urine quality-assurance/quality-control (QA/QC) samples to radiobioassay analysis laboratories. In 2003, a single laboratory (Los Alamos National Laboratory LANL, Los Alamos NM USA) requested a change in the test-samples provided previously by the ISP. The change was requested to evaluate measurement performance for analyses conducted using thermal-ionization mass spectrometry (TIMS). Radionuclides included {sup 239}Pu at two activity levels (75-150 {micro}Bq {sm_bullet} sample{sup -1} and 1200-1600 {micro}Bq {sm_bullet} sample{sup -1}) and {sup 238}Pu (3700-7400 {micro}Bq {sm_bullet} sample{sup -1}). In addition, {sup 240}Pu was added to the samples so that the {sup 239+240}Pu specific activity was 3700-7400 {micro}Bq {sm_bullet} sample{sup -1}. In this paper, the results of testing during the period May, 2003 through September, 2005 are presented and discussed.

  20. 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.

  1. Radionuclide concentrations in soils and vegetation at Low-Level Radioactive Waste Disposal Area G during the 1998 growing season (with a cumulative summary of {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.

  2. 238Pu: accumulation, tissue distribution, and excretion in Mayak workers after exposure to plutonium aerosols.

    PubMed

    Suslova, Klara G; Sokolova, Alexandra B; Khokhryakov, Viktor V; Miller, Scott C

    2012-03-01

    The alpha spectrometry measurements of specific activity of 238Pu and 239Pu in urine from bioassay examinations of 1,013 workers employed at the radiochemical and plutonium production facilities of the Mayak Production Association and in autopsy specimens of lung, liver, and skeleton from 85 former nuclear workers who died between 1974-2009, are summarized.The accumulation fraction of 238Pu in the body and excreta has not changed with time in workers involved in production of weapons-grade plutonium production (e.g., the plutonium production facility and the former radiochemical facility). The accumulation fraction of 238Pu in individuals exposed to plutonium isotopes at the newer Spent Nuclear Fuel Reprocessing Plant ranged from 0.13% up to 27.5% based on the autopsy data. No statistically significant differences between 238Pu and 239Pu in distribution by the main organs of plutonium deposition were found in the Mayak workers. Based on the bioassay data,the fraction of 238Pu activity in urine is on average 38-69% of the total activity of 238Pu and 239Pu, which correlates with the isotopic composition in workplace air sampled at the Spent Nuclear Fuel Reprocessing Plant. In view of the higher specific activity of 238Pu, the contribution of 238Pu to the total internal dose, particularly in the skeleton and liver, might be expected to continue to increase, and continued surveillance is recommended.

  3. Beneficial uses of /sup 241/Am

    SciTech Connect

    Mangeng, C.A.; Thayer, G.R.

    1984-05-01

    This report assesses the uses of /sup 241/Am and the associated costs and supply. The study shows that /sup 241/Am-fueled radioisotope thermoelectric generators in the range of 1 to 5 W electrical provide the most promising use of kilogram amounts of this isotope. For medical uses, where purity is essential, irradiation of /sup 241/Am can produce 97% pure /sup 238/Pu at $21,000/g. Using a pyro-metallurgical process, /sup 241/Am could be recovered from molten salt extraction (MSE) residues at an estimated incremental cost of $83/g adjusted to reflect the disposal costs of waste products. This cost of recovery is less than the $300/g cost for disposal of the /sup 241/Am contained in the MSE residues.

  4. Overview of advanced technologies for stabilization of 238Pu-contaminated waste

    NASA Astrophysics Data System (ADS)

    Ramsey, Kevin B.; Foltyn, Elizabeth M.; Heslop, J. Mark

    1998-01-01

    This paper presents an overview of potential technologies for stabilization of 238Pu-contaminated waste. Los Alamos National Laboratory (LANL) has processed 238PuO2 fuel into heat sources for space and terrestrial uses for the past several decades. The 88-year half-life of 238Pu and thermal power of approximately 0.6 watts/gram make this isotope ideal for missions requiring many years of dependable service in inaccessible locations. However, the same characteristic which makes 238Pu attractive for heat source applications, the high Curie content (17 Ci/gram versus 0.06 Ci/gram for 239Pu), makes disposal of 238Pu-contaminated waste difficult. Specifically, the thermal load limit on drums destined for transport to the Waste Isolation Pilot Plant (WIPP), 0.23 gram per drum for combustible waste, is impossible to meet for nearly all 238Pu-contaminated glovebox waste. Use of advanced waste treatment technologies including Molten Salt Oxidation (MSO) and aqueous chemical separation will eliminate the combustible matrix from 238Pu-contaminated waste and recover kilogram quantities of 238PuO2 from the waste stream. A conceptual design of these advanced waste treatment technologies will be presented.

  5. 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.

  6. Application of a canine {sup 238}Pu dosimetry model to human bioassay data

    SciTech Connect

    Hickman, A.W. Jr.

    1991-08-01

    Associated with the use of 2{sup 238}Pu in thermoelectric power sources for space probes and power supplies for cardiac devices is the potential for human exposure to {sup 238}Pu, primarily by inhalation. In the event of human internal exposure, a means is needed for assessing the level of intake and calculating radiation doses. Several bioassay/dosimetry models have been developed for {sup 239}Pu. However, results from studies with laboratory animals have indicated that the biokinetics, and therefore the descriptive models, of {sup 238}Pu are significantly different from those for {sup 239}Pu. A canine model accounting for these differences has been applied in this work to urinary excretion data from seven humans occupationally exposed to low levels of an insoluble {sup 238}Pu compound. The modified model provides a good description of the urinary excretion kinetics observed in the exposed humans. The modified model was also used to provide estimates of the initial intakes of {sup 238}Pu for the seven individuals; these estimates ranged from 4.5 nCi (170 Bq) to 87 nCi (3200 Bq). Autopsy data on the amount and distribution of {sup 238}Pu retained in the organs may be used in the future to validate or refute both these estimates and the assumptions used to formulate the human model. Modification of the human model to simulate an injection exposure to {sup 239}Pu gave patterns of retention in the organs and urinary excretion comparable to those seen previously in humans; further modification of the model using fecal data (unavailable for the subjects of this study) is indicated.

  7. 240Pu/239Pu mass ratio in environmental samples in Finland.

    PubMed

    Salminen-Paatero, S; Nygren, U; Paatero, J

    2012-11-01

    The (240)Pu/(239)Pu mass ratio was determined with SF-ICP-MS in lichen, peat, grass, air filter, and hot particle samples obtained in Finland. The main part of the air filters were sampled in northern Finland in 1963, whereas all the other samples were collected in southern and central Finland immediately after the Chernobyl accident in 1986. The (240)Pu/(239)Pu mass ratio varied between 0.13 ± 0.01 and 0.53 ± 0.03 in the environmental samples analyzed. The values for the (240)Pu/(239)Pu ratio confirm previous estimations, based on the (238)Pu/(239+240)Pu alpha activity ratio in the same samples, that global fallout from nuclear weapons testing and deposition from the Chernobyl accident have been the main Pu contamination sources in the environment in Finland. PMID:22776691

  8. Application of a canine {sup 238}Pu biokinetics/dosimetry model to human bioassay data

    SciTech Connect

    Hickman, A.W. |; Griffith, W.C.; Guilmette, R.A.

    1995-03-01

    Associated with the use of {sup 238}Pu in thermoelectric power sources for space probes is the potential for human exposure, primarily by inhalation and most likely as {sup 238}PuO{sub 2}. Several models have been developed for assessing the level of intake and predicting the resulting radiation dose following human exposure to {sup 239}Pu. However, there are indications that existing models do not adequately describe the disposition and dosimetry of {sup 239}Pu following human exposure. In this study, a canine model that accounts for these differences has been adapted for use with human excretion data. The model is based on existing knowledge about organ retention of plutonium. An analysis of the sensitivity of the model to changes in aerosol-associated properties indicated that predictions of urinary excretion are most sensitive to changes in particle solubility and diameter and in the ratio of fragment:particle surface area. Application of the model to urinary excretion data from seven workers exposed to a {sup 238}Pu ceramic aerosol gave estimated intakes of 390-8,200 Bq and associated initial pulmonary burdens of 80-1,700 Bq. The resulting 50-y dose commitments to critical organs per Bq of {sup 238}Pu intake were estimated to be 0.5 mSv for the thoracic region, 0.2 mSv for the liver, and 1 mSv for the bone surfaces. 29 refs., 8 figs., 7 tabs.

  9. The 239 Pu(n,2n)238Pu cross section: preliminary calculations

    SciTech Connect

    Chen, H; Reffo, G; Ross, M A; White, R M

    1999-03-12

    The primary motivation for the present work is to provide theoretical values for the ratio of the partial 239Pu(n,2nx{gamma})238Pu to total 239 Pu(n,2n)238Pu cross section for several discrete gamma transitions. Results and conclusions of preliminary calculations from threshold to 20 MeV are presented. Calculations are based on theoretical models with parameters obtained from the literature or from our ad hoc systematics. Optical model cross sections and transmission coefficients were determined using the coupled-channels method. The calculations included a preequilibrium component followed by multiple particle and gamma-ray emissions. Fission competition was included at all stages of de-excitation. Suggestions for further verifications and possible improvements are provided.

  10. Application of a canine 238Pu biokinetics/dosimetry model to human bioassay data.

    PubMed

    Hickman, A W; Griffith, W C; Roessler, G S; Guilmette, R A

    1995-03-01

    Associated with the use of 238Pu in thermoelectric power sources for space probes is the potential for human exposure, primarily by inhalation and most likely as 238PuO2. Several models have been developed for assessing the level of intake and predicting the resulting radiation dose following human exposure to 239Pu. However, there are indications that existing models do not adequately describe the disposition and dosimetry of 238Pu following human exposure. In this study, a canine model that accounts for these differences has been adapted for use with human excretion data. The model is based on existing knowledge about organ retention of plutonium. An analysis of the sensitivity of the model to changes in aerosol-associated properties indicated that predictions of urinary excretion are most sensitive to changes in particle solubility and diameter and in the ratio of fragment:particle surface area. Application of the model to urinary excretion data from seven workers exposed to a 238Pu ceramic aerosol gave estimated intakes of 390-8,200 Bq and associated initial pulmonary burdens of 80-1,700 Bq. The resulting 50-y dose commitments to critical organs per Bq of 238Pu intake were estimated to be 0.5 mSv for the thoracic region, 0.2 mSv for the liver, and 1 mSv for the bone surfaces. PMID:7860307

  11. Surrogate measurement of the {sup 238}Pu(n,f) cross section

    SciTech Connect

    Ressler, J. J.; Burke, J. T.; Escher, J. E.; Bernstein, L. A.; Bleuel, D. L.; Casperson, R. J.; Gostic, J.; Henderson, R.; Scielzo, N. D.; Thompson, I. J.; Wiedeking, M.; Angell, C. T.; Goldblum, B. L.; Munson, J.; Basunia, M. S.; Phair, L. W.; Beausang, C. W.; Hughes, R. O.; Hatarik, R.; Ross, T. J.

    2011-05-15

    The neutron-induced fission cross section of {sup 238}Pu was determined using the surrogate ratio method. The (n,f) cross section over an equivalent neutron energy range 5-20 MeV was deduced from inelastic {alpha}-induced fission reactions on {sup 239}Pu, with {sup 235}U({alpha},{alpha}{sup '}f) and {sup 236}U({alpha},{alpha}{sup '}f) used as references. These reference reactions reflect {sup 234}U(n,f) and {sup 235}U(n,f) yields, respectively. The deduced {sup 238}Pu(n,f) cross section agrees well with standard data libraries up to {approx}10 MeV, although larger values are seen at higher energies. The difference at higher energies is less than 20%.

  12. Report on 238Pu(n,x) surrogate cross section measurement

    SciTech Connect

    Burke, J T; Ressler, J J; Henderson, R A; Scielzo, N D; Escher, J E; Thompson, I J; Gostic, J; Bleuel, D; Weideking, M; Bernstein, L A

    2010-03-31

    The goal of this year's effort is to measure the {sup 238}Pu(n,f) and {sup 238}Pu(n,2n) cross section from 100 keV to 20 MeV. We designed a surrogate experiment that used the reaction {sup 239}Pu(a,a{prime}x) as a surrogate for {sup 238}Pu(n,x). The experiment was conducted using the STARS/LIBERACE experimental facility located at the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory in January 2010. A description of the experiment and status of the data analysis is given. In order to obtain a reliable {sup 238}Pu(n,x) cross section we designed the experiment using the surrogate ratio technique. This technique allows one to measure a desired, unknown, cross section relative to a known cross section. In the present example, the {sup 238}Pu(n,x) cross section of interest is determined relative to the known {sup 235}U(n,x) cross section. To increase confidence in the results, and to reduce overall uncertainties, we are also determining the {sup 238}Pu(n,x) cross section relative to the known {sup 234}U(n,x) cross section. The compound nuclei of interest for this experiment were produced using inelastic alpha scattering. For example, {sup 236}U(a,a{prime}x) served as a surrogate for {sup 235}U(n,x); analogous reactions were considered for the other cross sections. Surrogate experiments determine the probabilities for the decay of the compound nuclei into the various channels of interest (fission, gamma decay) by measuring particle-fission (p-f) or particle?gamma (p?g) reaction spectra. By comparing the decay probabilities associated with the unknown cross section to that of a known cross section it is possible to obtain the ratio of these cross sections and thus determine the unknown, desired cross section.

  13. 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.

  14. Preparation and characterization of {sup 238}Pu-ceramics for radiation damage experiments

    SciTech Connect

    DM Strachan; RD Scheele; WC Buchmiller; JD Vienna; RL Sell; RJ Elovich

    2000-06-15

    As a result of treaty agreements between Russia and the US, portions of their respective plutonium and nuclear weapons stockpiles have been declared excess. In support of the US Department of Energy's 1998 decision to pursue immobilization of a portion of the remaining Pu in a titanate-based ceramic, the authors prepared nearly 200 radiation-damage test specimens of five Pu- and {sup 238}Pu-ceramics containing 10 mass% Pu to determine the effects of irradiation from the contained Pu and U on the ceramic. The five Pu-ceramics were (1) phase-pure pyrochlore [ideally, Ca(U, Pu)Ti{sub 2}O{sub 7}], (2) pyrochlore-rich baseline, (3) pyrochlore-rich baseline with impurities, (4) phase-pure zirconolite [ideally Ca(U, Pu)Ti{sub 2}O{sub 7}], and (5) a zirconolite-rich baseline. These ceramics were prepared with either normal weapons-grade Pu, which is predominantly {sup 239}Pu, or {sup 238}Pu. The {sup 238}Pu accelerates the radiation damage relative to the {sup 239}Pu because of its much higher specific activity. The authors were unsuccessful in preparing phase-pure (Pu, U) brannerite, which is the third crystalline phase present in the baseline immobilization form. Since these materials will contain {approximately}10 mass% Pu and about 20 mass% U, radiation damage to the crystalline structure of these materials will occur overtime. As the material becomes damaged from the decay of the Pu and U, it is possible for the material to swell as both the alpha particles and recoiling atoms rupture chemical bonds within the solid. As the material changes density, cracking, perhaps in the form of microcracks, may occur. If cracking occurs in ceramic that has been placed in a repository, the calculated rate of radionuclide release if the can has corroded would increase proportionately to the increase in surface area. To investigate the effects of radiation damage on the five ceramics prepared, the authors are storing the specimens at 20, 125, and 250 C until the {sup 238}Pu specimens

  15. 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.

  16. Materials compatibility for 238Pu-HNO3/HF solution containment: 238Pu aqueous processing

    NASA Astrophysics Data System (ADS)

    Reimus, M. A.; Pansoy-Hjelvik, M. E.; Silver, G.; Brock, J.; Nixon, J.; Ramsey, K. B.; Moniz, P.

    2000-07-01

    The Power Source Technologies Group at Los Alamos National Laboratory is building a 238Pu Aqueous Scrap Recovery Line at the Plutonium Facility. The process line incorporates several unit operations including dissolution, filtration, ion exchange, and precipitation. During 1997-1999, studies were carried out to determine the chemistry used in the full-scale process. Other studies focussed on the engineering design of the operation. Part of the engineering design was to determine, in compatibility studies, the materials for reaction and storage vessels which will contain corrosive 238Pu-HNO3/HF solutions. The full-scale line is to be operational by the end of year 2000.

  17. Purification of 238Pu Oxide using the Pu Oxalate Process

    SciTech Connect

    Mew, D A; Krikorian, O H; Dodson, K E; Schmitz, J A

    2001-11-28

    The Pu oxalate process is used to remove {sup 234}U from aged {sup 238}Pu-enriched PuO{sub 2} ({sup 234}U grows into the PuO{sub 2} material with time from a-decay of {sup 238}Pu). The Pu oxalate process was first used on a mixture of weapons grade PuO{sub 2} with UO{sub 2} to work out the processing parameters. It was then applied to aged {sup 238}Pu-enriched PuO{sub 2} ({sup 238}PuO{sub 2}). The {sup 234}U content of the {sup 238}PuO{sub 2} was reduced from 13.2 wt% to 0.0254 wt%, and the Pu recovery yield was 78.5%. The process is complex and is complicated by radiolysis problems when working with {sup 238}Pu. Details of the experiments are described.

  18. 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.

  19. [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.

  20. 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

  1. Neutron Capture and Fission Measurement on ^238Pu at DANCE

    NASA Astrophysics Data System (ADS)

    Chyzh, Andrii; Wu, Ching-Yen; Kwan, Elaine; Henderson, Roger; Gostic, Jolie; Couture, Aaron; Young, Hye; Ullmann, John; O'Donnell, John; Jandel, Marian; Haight, Robert; Bredeweg, Todd

    2012-10-01

    Neutron capture and fission reactions on actinides are important in nuclear engineering and physics. DANCE (Detector for Advanced Neutron Capture Measurement, LANL) combined with PPAC (avalanche technique based fission tagging detector, LLNL) were used to study the neutron capture reactions in ^238Pu. Because of extreme spontaneous α-radioactivity in ^238Pu and associated safety issues, 3 separate experiments were performed in 2010-2012. The 1st measurement was done without fission tagging on a 396-μg thick target. The 2nd one was with PPAC on the same target. The 3rd final measurement was done on a thin target with a mass of 40 μg in order to reduce α-background load on PPAC. This was the first such measurement in a laboratory environment. The absolute ^238Pu(n,γ) cross section is presented together with the prompt γ-ray multiplicity in the ^238Pu(n,f) reaction.

  2. Photodisintegration Cross Section of 241Am

    NASA Astrophysics Data System (ADS)

    Tonchev, A. P.; Hammond, S.; Howell, C. R.; Huibregtse, C.; Hutcheson, A.; Karwowski, H. J.; Kelley, J. H.; Kwan, E.; Rusev, G.; Tornow, W.; Vieira, D. J.; Wilhelmy, J. B.

    2009-03-01

    The photodisintegration cross section of radioactive 241Am has been obtained for the first time using monoenergetic γ-ray beams from the HIγS facility. The induced activity of 240Am produced via the 241Am(γ,n) reaction in the γ-ray energy range from 9.5 to 16 MeV was measured by the activation technique utilizing high resolution HPGe detectors. The 241Am(γ,n) cross section was determined both by measuring the absolute γ-ray flux and by comparison to the 197Au(γ,n) and 58Ni(γ,n) cross section standards. The experimental data for the 241Am(γ,n) reaction in the giant dipole resonance energy region is compared with statistical nuclear-model calculations.

  3. Neutron Capture Cross Section Measurement on $^{238}$Pu at DANCE

    SciTech Connect

    Chyzh, A; Wu, C Y

    2011-02-14

    The proposed neutron capture measurement for {sup 238}Pu was carried out in Nov-Dec, 2010, using the DANCE array at LANSCE, LANL. The total beam-on-target time is about 14 days plus additional 5 days for the background measurement. The target was prepared at LLNL with the new electrplating cell capable of plating the {sup 238}Pu isotope simultaneously on both sides of the 3-{micro}m thick Ti backing foil. A total mass of 395 {micro}g with an activity of 6.8 mCi was deposited onto the area of 7 mm in diameter. The {sup 238}Pu sample was enriched to 99.35%. The target was covered by 1.4 {micro}m double-side aluminized mylar and then inserted into a specially designed vacuum-tight container, shown in Fig. 1, for the {sup 238}Pu containment. The container was tested for leaks in the vacuum chamber at LLNL. An identical container without {sup 238}Pu was made as well and used as a blank for the background measurement.

  4. A study of accelerated radiation damage effects in PuO2 and gadolinia-stabilized cubic zirconia, Zr0.79Gd0.14Pu0.07O1.93, doped with 238Pu

    NASA Astrophysics Data System (ADS)

    Burakov, B. E.; Yagovkina, M. A.

    2015-12-01

    Polycrystalline samples of cubic zirconia, Zr0.79Gd0.14Pu0.07O1.93, doped with approximately 9.9 wt.% 238Pu, and PuO2 containing 11.0 wt. % 238Pu (and main isotope is 239Pu) have been repeatedly studied during many years by X-ray diffraction analysis. At a temperature of 25 °C the unit-cell parameter of PuO2 increases depending on accumulated dose, and is accompanied by decrease of coherent scattering region (CSR). Self-irradiation of Zr0.79Gd0.14Pu0.07O1.93 is accompanied with repeated change of unit-cell parameter and CSR.

  5. Induction of liver tumors by /sup 239/Pu citrate of /sup 239/PuO/sub 2/ particles in the Chinese hamster

    SciTech Connect

    Brooks, A.L.; Benjamin, S.A.; Hahn, F.F.; Brownstein, D.G.; Griffith, W.C.; McClellan, R.O.

    1983-10-01

    The influence of radiation dose distribution on the frequency of /sup 239/Pu-induced liver tumors was evaluated in the Chinese hamster. Different concentrations of /sup 239/Pu citrate or /sup 239/PuO/sub 2/ particles of known sizes were injected intravenously via the jugular vein. About 60% of the injected /sup 23/Pu citrate was deposited in the liver and 40% in the bone. The /sup 239/Pu citrate was rather uniformly distributed throughout the liver parenchyma. Injected plutonium oxide particles were taken up by the reticuloendothelial system with 90% of the body burden deposited in the liver. The /sup 239/PuO/sub 2/ particles were localized in the Kupffer cells and produced nonuniform dose distributions that were dependent on particle size. There was an activity- and dose-dependent increase in the incidence of total liver parenchymal cell tumors following injection with either plutonium particles or citrate. Plutonium citrate also produced hemangiosarcomas of the liver and tumors in bone and bone marrow. The latent period for liver tumor appearance in animals exposed to /sup 239/Pu citrate or /sup 239/PuO/sub 2/ particles increased as the injected activity decreased. These data indicate that, in Chinese hamster liver, local radiation dose distribution is less important in altering tumor incidence than injected activity or average dose. However, the more uniform irradiation from /sup 239/Pu citrate administration was more effective in cancer production than the nonuniform irradiation from /sup 239/PuO/sub 2/ particle.

  6. /sup 238/Pu fuel form processes. Final report, January-September 1983

    SciTech Connect

    Mosley, W.C.; Taylor, D.H.

    1983-01-01

    Progress is reported on the following: analytical studies of weld-quench cracking in DOP-26 iridium alloy, iridium//sup 238/PuO/sub 2/ compatibility test, surface area measurements of /sup 238/PuO/sub 2/ using the Blaine air permeability apparatus, and helium release from /sup 238/PuO/sub 2/. (MHR)

  7. 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.

  8. /sup 238/Pu processing at the Savannah River Plant

    SciTech Connect

    Burney, G.A.

    1983-01-01

    /sup 238/Pu is produced by irradiating /sup 237/Np. The /sup 237/Np is produced as a byproduct when natural or enriched uranium is irradiated with neutrons. The /sup 237/Np is separated by solvent extraction and ion exchange. It is converted to NpO/sub 2/ and fabricated into targets for irradiation. The irradiated targets are cooled and dissolved in strong nitric acid. The /sup 238/Pu and /sup 237/Np are separated from fission products and other cationic impurities and from each other by three cycles of anion exchange. The /sup 237/Np is recycled to produce more targets for irradiation. The pure /sup 238/Pu solution is precipitated as Pu oxalate and calcined to PuO/sub 2/. After several powder-conditioning steps, the PuO/sub 2/ is hot pressed into fuel forms. Each form is encased in iridium for loading into a specially designed power unit for space application. 8 references, 9 figures, 1 table.

  9. Vertical distributions of radionuclides ((239+240)Pu, (240)Pu/(239)Pu, and (137)Cs) in sediment cores of Lake Bosten in Northwestern China.

    PubMed

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

    2014-04-01

    Artificial radionuclides ((137)Cs, (239+240)Pu, (241)Pu, (241)Am) deposited in lacustrine sediments have been used for dating as well as radionuclide source identification. In the present work, we investigated the vertical distributions of (239+240)Pu and (137)Cs activities, (240)Pu/(239)Pu atom ratios, and (239+240)Pu/(137)Cs activity ratios in sediment cores collected from Lake Bosten, which is the lake closest to the Lop Nor Chinese Nuclear Weapon Test site in northwestern China. Uniformly high concentrations of (239+240)Pu and (137)Cs were found in the upper layers deposited since 1964 in the sediment cores, and these were controlled by the resuspension of soil containing radionuclides from the nearby land surface. As the Chinese nuclear tests varied remarkably in yield, the mixing of the tropospheric deposition from these tests and the stratospheric deposition of global fallout has led to a (240)Pu/(239)Pu atom ratio that is similar to that of global fallout and to a (239+240)Pu/(137)Cs activity ratio that is slightly higher than that of global fallout. However, a low (240)Pu/(239)Pu atom ratio of 0.080 and high (239+240)Pu/(137)Cs activity ratio of 0.087, significantly different from the global fallout values, were observed in one sediment core (07BS10-2), indicating the inhomogenous tropospheric deposition from the Chinese nuclear tests in Lake Bosten during 1967-1973. These results are important to understand the influence of the CNTs on the radionuclide contamination in Lake Bosten.

  10. 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.

  11. Gamma-ray Output Spectra from 239 Pu Fission

    DOE PAGES

    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

  12. 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.

  13. Mechanical resuspension of /sup 239/Pu from unpaved roads

    SciTech Connect

    Hodgin, C.R.

    1982-01-01

    The impacts of resuspended plutonium from two unpaved roads at the Rocky Flats Plant on nearby air samplers were investigated. Because the sources were complex fugitive dust emitters and because of the small source-receptor distances, traditional dispersion modeling techniques could not be employed. Thus two specialized techniques, one for fugitive dust emissions and one for near distance dispersion, were developed and used to calculate atmospheric dust concentrations at the subject air samplers. Atmospheric /sup 239/Pu impacts were then determined from measurements of plutonium concentrations in the resuspendible dust on the road surfaces. As a final step in the process the calculated plutonium impacts were compared to the 1980 annual average /sup 239/Pu concentration at four samplers. The impact calculated for the Gunnery Range Road represented 2.1 percent of the observed annual concentration, with a 95 percent confidence interval of 1.1 to 7.9 percent. The Southeast Perimeter Road produced a more substantial effect with a point estimate of 3.8 percent. The 95 percent confidence interval for this source was 2.0 to 9.1 percent. The combined impact of the two roads on the subject samplers was 5.9 percent of the observed plutonium concentration, with a 95 percent confidence interval of 3.2 to 17.0 percent. Thus it was shown that fugitive plutonium emissions from the Gunnery Range Road and Southeast Perimeter Road are not substantial contributors to the plutonium concentrations observed at the subject samplers. Even an increase in dust control efficiency to 90 percent (as with paving) would result in only a four percent decrease in the overall atmosperic plutonium concentration at the site.

  14. 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.

  15. 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

  16. 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.

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

    SciTech Connect

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

    2005-05-24

    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.

  18. 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.

  19. Neutron transmission and capture of 241Am

    NASA Astrophysics Data System (ADS)

    Lampoudis, C.; Kopecky, S.; Plompen, A.; Schillebeeckx, P.; Wynants, R.; Gunsing, F.; Sage, C.; Bouland, O.; Noguere, G.

    2013-03-01

    A set of neutron transmission and capture experiments based on the Time Of Flight (TOF) technique, were performed in order to determine the 241Am capture cross section in the energy range from 0.01 eV to 1 keV. The GELINA facility of the Institute for Reference Materials and Measurements (IRMM) served as the neutron source. A pair of C6D6 liquid scintillators was used to register the prompt gamma rays emerging from the americium sample, while a Li-glass detector was used in the transmission setup. Results from the capture and transmission data acquired are consistent with each other, but appear to be inconsistent with the evaluated data files. Resonance parameters have been derived for the data up to the energy of 100 eV.

  20. Helium release from 238PuO2 fuel particles

    NASA Astrophysics Data System (ADS)

    El-Genk, Mohamed S.; Tournier, Jean-Michel

    2000-01-01

    Coated plutonia fuel particles have recently been proposed for potential use in future space exploration missions that employ radioisotope power systems and/or radioisotope heater units (RHUs). The design of this fuel form calls for full retention of the helium generated by the natural radioactive decay of 238Pu, with the aid of a strong zirconium carbide coating. This paper reviews the potential release mechanisms of helium in small-grain (7-40 μm) plutonia pellets currently being used in the General Purpose Heat Source (GPHS) modules and RHUs, during both steady-state and transient heating conditions. The applicability of these mechanisms to large-grain and polycrystalline 238PuO2 fuel kernels is examined and estimates of helium release during a re-entry heating pulse up to 1723 K are presented. These estimates are based on the reported data for fission gas release from granular and monocrystal UO2 fuel particles irradiated at isothermal conditions up to 6.4 at.% burnup and 2030 K. It is concluded that the helium release fraction from large-grain (>=300 μm) plutonia fuel kernels heated up to 1723 K could be less than 7%, compared to ~80% from small-grain (7-40 μm) fuel. The helium release fraction from polycrystalline plutonia kernels fabricated using Sol-Gel techniques could be even lower. Sol-Gel fabrication processes are favored over powder metallurgy, because of their high precision and excellent reproducibility and the absence of a radioactive dust waste stream, significantly reducing the fabrication and post-fabrication clean-up costs. .

  1. Overview of advanced technologies for stabilization of {sup 238}Pu-contaminated waste

    SciTech Connect

    Ramsey, K.B.; Foltyn, E.M.; Heslop, J.M.

    1998-02-01

    This paper presents an overview of potential technologies for stabilization of {sup 238}Pu-contaminated waste. Los Alamos National Laboratory (LANL) has processed {sup 238}PuO{sub 2} fuel into heat sources for space and terrestrial uses for the past several decades. The 88-year half-life of {sup 238}Pu and thermal power of approximately 0.6 watts/gram make this isotope ideal for missions requiring many years of dependable service in inaccessible locations. However, the same characteristic which makes {sup 238}Pu attractive for heat source applications, the high Curie content (17 Ci/gram versus 0.06 Ci/gram for 239{sup Pu}), makes disposal of {sup 238}Pu-contaminated waste difficult. Specifically, the thermal load limit on drums destined for transport to the Waste Isolation Pilot Plant (WIPP), 0.23 gram per drum for combustible waste, is impossible to meet for nearly all {sup 238}Pu-contaminated glovebox waste. Use of advanced waste treatment technologies including Molten Salt Oxidation (MSO) and aqueous chemical separation will eliminate the combustible matrix from {sup 238}Pu-contaminated waste and recover kilogram quantities of {sup 238}PuO{sub 2} from the waste stream. A conceptual design of these advanced waste treatment technologies will be presented.

  2. Plant uptake and transport of /sup 241/Am

    SciTech Connect

    Wallace, A.; Romney, E.M.; Mueller, R.T. Sr.; soufi, S.M.

    1981-07-01

    We conducted several experiments with /sup 241/Am to obtain a more complete understanding of how this transuranium element is absorbed and transported in plants. In a plant species (Tamarix pentandra Pall.) that has salt glands in the leaves excreting NaCl and other ions, /sup 241/Am was not pumped through these glands. Cyanide, which forms complexes with any metals, when applied to a calcareous soil, greatly increased the transport of /sup 241/Am into stems and leaves of bush bean plants. Radioactive cyanide (/sup 14/C) was also transported to leaves and stems. When radish was grown in both calcareous and noncalcareous soils, /sup 241/Am appeared to be fixed on the peel so firmly that it was resistant to removal by HNO/sub 3/ washing. The chelating agent DTPA induced increased transport of /sup 241/Am to leaves and into the fleshy roots of the radish.

  3. 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.

  4. Determining site-specific drum loading criteria for storing combustible {sup 238}Pu waste

    SciTech Connect

    Marshall, R.S.; Callis, E.L.; Cappis, J.H.; Espinoza, J.M.; Foltyn, E.M.; Reich, B.T.; Smith, M.C.

    1994-02-01

    Waste containing hydrogenous-combustible material contaminated with {sup 238}Pu can generate hydrogen gas at appreciable rates through alpha radiolysis. To ensure safe transportation of WIPP drums, the limit for {sup 238}Pu-combustible waste published in the WIPP TRUPACT-11 CONTENT (TRUCON) CODES is 21 milliwafts per 55 gallon drum. This corresponds to about 45 milligrams of {sup 238}PuO{sub 2} used for satellite heat source-electrical generators. The Los Alamos waste storage site adopted a {sup 238}Pu waste storage criteria based on these TRCUCON codes. However, reviews of the content in drums of combustible waste generated during heat source assembly at Los Alamos showed the amount of {sup 238}Pu is typically much greater than 45 milligrams. It is not feasible to appreciably reduce Los Alamos {sup 238}Pu waste drum loadings without significantly increasing waste volumes or introducing unsafe practices. To address this concern, a series of studies were implemented to evaluate the applicability of the TRUCON limits for storage of this specific waste. Addressed in these evaluations were determination of the hydrogen generation rate, hydrogen diffusion rates through confinement layers and vent filters, and packaging requirements specific to Los Alamos generated {sup 238}Pu contaminated combustible waste. These studies also showed that the multiple-layer packaging practices in use at Los Alamos could be relaxed without significantly increasing the risk of contamination. Based on a model developed to predict H{sub 2} concentrations in packages and drum headspace, the site specific effective hydrogen generation rate, and hydrogen-diffusion values, and revising the waste packaging practices, we were able to raise the safe loading limit for {sup 238}Pu waste drums for on site storage to the gram levels typical of currently generated {sup 238}Pu waste.

  5. 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

  6. 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.

  7. Determination of (239)Pu, (240)Pu, (241)Pu and (242)Pu at femtogram and attogram levels - evidence for the migration of fallout plutonium in an ombrotrophic peat bog profile.

    PubMed

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

    2013-04-01

    The isotopic composition of plutonium ((239)Pu, (240)Pu, (241)Pu and (242)Pu) was investigated in a ∼0.5 m long peat core from an ombrotrophic bog (Black Forest, Germany) using clean room procedures and accelerator mass spectrometry (AMS). This sophisticated analytical approach was ultimately needed to detect reliably the Pu concentrations present in the peat samples at femtogram (fg) and attogram (ag) levels. The mean (240)Pu/(239)Pu isotopic ratio of 0.19 ± 0.02 (N = 32) in the peat layers, representing approximately the last 80 years, was in good agreement with the accepted value of 0.18 for the global fallout in the Northern Hemisphere. This finding is largely supported by the corresponding and rather constant (241)Pu/(239)Pu (0.0012 ± 0.0005) and (242)Pu/(239)Pu (0.004 ± 0.001) ratios. Since the Pu isotopic composition characteristic of the global fallout was also identified in peat samples pre-dating the period of atmospheric atom bomb testing (AD 1956-AD 1980), migration of Pu within the peat profile is clearly indicated. These results highlight, for the first time, the mobility of Pu in a peat bog with implications for the migration of Pu in other acidic, organic rich environments such as forest soils and other wetland types. These findings constitute a direct observation of the behaviour of Pu at fg and ag levels in the environment. The AMS measurements of Pu concentrations (referring to a corresponding activity of (240+239)Pu from 0.07 mBq g(-1) to 5 mBq g(-1)) essentially confirm our a priori estimates based on existing (241)Am and (137)Cs data in the investigated peat core and agree well with the global fallout levels from the literature. Exclusively employing the Pu isotope ratios established for the peat samples, the date of the Pu irradiation (AD 1956, correctable to AD 1964) was calculated and subsequently compared to the (210)Pb age of the peat layers; this comparison provided an additional hint that global fallout derived Pu is not fixed in

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. Influence of thermal and resonance neutron on fast neutron flux measurement by 239Pu fission chamber

    NASA Astrophysics Data System (ADS)

    Zeng, Li-Na; Wang, Qiang; Song, Ling-Li; Zheng, Chun

    2015-01-01

    The 239Pu fission chambers are widely used to measure fission spectrum neutron flux due to a flat response to fast neutrons. However, in the meantime the resonance and thermal neutrons can cause a significant influence on the measurement if they are moderated, which could be eliminated by using 10B and Cd covers. At a column enriched uranium fast neutron critical assembly, the fission reaction rates of 239Pu are measured as 1.791×10-16, 2.350×10-16 and 1.385×10-15 per second for 15 mm thick 10B cover, 0.5 mm thick Cd cover, and no cover respectively, while the fission reaction rate of 239Pu is rapidly increased to 2.569×10-14 for a 20 mm thick polythene covering fission chamber. The average 239Pu fission cross-section of thermal and resonance neutrons is calculated to be 500 b and 24.95 b with the assumption of 1/v and 1/E spectra respectively, then thermal, resonance and fast neutron flux are achieved to be 2.30×106, 2.24×106 and 1.04×108 cm-2·s-1.

  13. Method comparison for 241Am emergency urine bioassay.

    PubMed

    Li, Chunsheng; Sadi, Baki; Benkhedda, Karima; St-Amant, Nadereh; Moodie, Gerry; Ko, Raymond; Dinardo, Anthony; Kramer, Gary

    2010-10-01

    241Am is one of the high-risk radionuclides that might be used in a terrorist attack. 241Am in urine bioassay can identify the contaminated individuals who need immediate medical intervention and decontamination. This paper compares three methods for the measurement of 241Am in urine, namely liquid scintillation counting (LSC), inductively coupled plasma mass spectrometry (ICP-MS) and gamma spectrometry (GS), at two levels, 20 and 2 Bq l(-1). All three methods satisfied the ANSI N13.30 radio-bioassay criteria for accuracy and repeatability. ICP-MS offered the best sensitivity and fastest sample turnaround; however, the ICP-MS system used in this work may not be available in many bioassay laboratories. LSC and GS are more commonly available instruments. GS requires minimal or no sample preparation, which makes it a good candidate method. Moreover, the sample throughput can be significantly improved if the GS and LSC methods are automated.

  14. 241Am (n,gamma) isomer ratio measurement

    SciTech Connect

    Bond, Evelyn M; Vieira, David J; Moody, Walter A; Slemmons, Alice K

    2011-01-05

    The objective of this project is to improve the accuracy of the {sup 242}Cm/{sup 241}Am radiochemistry ratio. We have performed an activation experiment to measure the {sup 241}Am(n,{gamma}) cross section leading to either the ground state of {sup 242g}Am (t{sub 1/2} = 16 hr) which decays to {sup 242}Cm (t{sub 1/2} = 163 d) or the long-lived isomer {sup 242m}Am (t{sub 1/2} = 141 yr). This experiment will develop a new set of americium cross section evaluations that can be used with a measured {sup 242}Cm/{sup 241}Am radiochemical measurement for nuclear forensic purposes. This measurement is necessary to interpret the {sup 242}Cm/{sup 241}Am ratio because a good measurement of this neutron capture isomer ratio for {sup 241}Am does not exist. The targets were prepared in 2007 from {sup 241}Am purified from LANL stocks. Gold was added to the purified {sup 241}Am as an internal neutron fluence monitor. These targets were placed into a holder, packaged, and shipped to Forschungszentrum Karlsruhe, where they were irradiated at their Van de Graff facility in February 2008. One target was irradiated with {approx}25 keV quasimonoenergetic neutrons produced by the {sup 7}Li(p,n) reaction for 3 days and a second target was also irradiated for 3 days with {approx}500 keV neutrons. Because it will be necessary to separate the {sup 242}Cm from the {sup 241}Am in order to measure the amount of {sup 242}Cm by alpha spectrometry, research into methods for americium/curium separations were conducted concurrently. We found that anion exchange chromatography in methanol/nitric acid solutions produced good separations that could be completed in one day resulting in a sample with no residue. The samples were returned from Germany in July 2009 and were counted by gamma spectrometry. Chemical separations have commenced on the blank sample. Each sample will be spiked with {sup 244}Cm, dissolved and digested in nitric acid solutions. One third of each sample will be processed at a time

  15. Transuranic sealed source recovery project.

    PubMed

    Tompkins, J A; Pearson, M W

    2001-11-01

    If you have transuranic sealed sources (239Pu, 238Pu, or 241Am) that have no potential for recycle or commercial disposal, the Off Site Source Recovery Project at LANL can assist in recovering the sealed sources from your facility to a DOE storage site. PMID:11669192

  16. The interception and retention of 238Pu deposition by orange trees.

    PubMed

    Pinder, J E; Adriano, D C; Ciravolo, T G; Doswell, A C; Yehling, D M

    1987-06-01

    Radioisotope thermoelectric generators (RTG) transform the heat produced during the alpha decay of 238Pu into electrical energy for use by deep-space probes, such as the Voyager spacecraft, which have returned images and other data from Jupiter, Saturn and Uranus. Future missions involving RTGs may be launched aboard the space shuttle, and there is a remote possibility that an explosion of liquid-hydrogen and liquid-oxygen fuel could rupture the RTGs and disperse 238Pu into the atmosphere over central Florida. Research was performed to determine the potential transport to man of atmospherically dispersed Pu via contaminated orange fruits. The results indicate that the major contamination of oranges would result from the interception and retention of 238Pu deposition by fruits. The resulting surface contamination could enter human food chains through transfer to internal tissues during peeling or in the reconstituted juices and flavorings made from orange skins. The interception of 238Pu deposition by fruits is especially important because the results indicate no measurable loss of Pu from fruit surfaces through time or with washing. Approximately 1% of the 238Pu deposited onto an orange grove would be harvested in the year following deposition.

  17. Interception and retention of /sup 238/Pu deposition by orange trees

    SciTech Connect

    Pinder, J.E. III; Adriano, D.C.; Ciravolo, T.G.; Doswell, A.C.; Yehling, D.M.

    1987-06-01

    Radioisotope thermoelectric generators (RTG) transform the heat produced during the alpha decay of /sup 238/Pu into electrical energy for use by deep-space probes, such as the Voyager spacecraft, which have returned images and other data from Jupiter, Saturn and Uranus. Future missions involving RTGs may be launched aboard the space shuttle, and there is a remote possibility that an explosion of liquid-hydrogen and liquid-oxygen fuel could rupture the RTGs and disperse /sup 238/Pu into the atmosphere over central Florida. Research was performed to determine the potential transport to man of atmospherically dispersed Pu via contaminated orange fruits. The results indicate that the major contamination of oranges would result from the interception and retention of /sup 238/Pu deposition by fruits. The resulting surface contamination could enter human food chains through transfer to internal tissues during peeling or in the reconstituted juices and flavorings made from orange skins. The interception of /sup 238/Pu deposition by fruits is especially important because the results indicate no measurable loss of Pu from fruit surfaces through time or with washing. Approximately 1% of the /sup 238/Pu deposited onto an orange grove would be harvested in the year following deposition.

  18. /sup 238/Pu fuel form processes. Quarterly report, October-December 1980

    SciTech Connect

    Not Available

    1981-08-01

    Goals of the Savannah River Laboratory (SRL) program include providing technical support for the production of /sup 238/PuO/sub 2/ fuel forms in the Savannah River Plant's (SRP) Plutonium Fuel Form (PuFF) Facility. Progress is reported including studies on the impact response of SRP MHW /sup 238/PuO/sub 2/ fuel spheres. The iridium containment shell of an encapsulated SRP fuel sphere, Multi-hundred Watt Fuel Test (MHFT) 65 split open during a Safety Verification Impact Test (SVT), and about 2 g of /sup 238/PuO/sub 2/ was released. (Typical oxide releases in previous tests were 1 to 10 mg). The cause of the impact failure was investigated. Also, the feasibility of using a direct fabrication process to produce full-scale GPHS fuel pellets has been demonstrated. (WHK)

  19. Tagging fast neutrons from an (241)Am/(9)Be source.

    PubMed

    Scherzinger, J; Annand, J R M; Davatz, G; Fissum, K G; Gendotti, U; Hall-Wilton, R; Håkansson, E; Jebali, R; Kanaki, K; Lundin, M; Nilsson, B; Rosborge, A; Svensson, H

    2015-04-01

    Shielding, coincidence, and time-of-flight measurement techniques are employed to tag fast neutrons emitted from an (241)Am/(9)Be source resulting in a continuous polychromatic energy-tagged beam of neutrons with energies up to 7MeV. The measured energy structure of the beam agrees qualitatively with both previous measurements and theoretical calculations. PMID:25644080

  20. Tagging fast neutrons from an (241)Am/(9)Be source.

    PubMed

    Scherzinger, J; Annand, J R M; Davatz, G; Fissum, K G; Gendotti, U; Hall-Wilton, R; Håkansson, E; Jebali, R; Kanaki, K; Lundin, M; Nilsson, B; Rosborge, A; Svensson, H

    2015-04-01

    Shielding, coincidence, and time-of-flight measurement techniques are employed to tag fast neutrons emitted from an (241)Am/(9)Be source resulting in a continuous polychromatic energy-tagged beam of neutrons with energies up to 7MeV. The measured energy structure of the beam agrees qualitatively with both previous measurements and theoretical calculations.

  1. 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.

  2. Determination of 240Pu/239Pu atom ratio in seawaters from the East China Sea.

    PubMed

    Yamada, Masatoshi; Zheng, Jian

    2011-07-01

    The (240)Pu/(239)Pu atom ratios in seawater samples on the East China Sea continental shelf were measured. These ratios for surface and bottom waters had no significant difference. They were significantly higher than the average global fallout ratio of 0.18. It was proposed that the oceanic currents are accounted for delivery of close-in Pu from the Pacific Proving Grounds (PPG) to the studied areas. The contribution of the PPG close-in fallout was calculated to be 40 % on average. The (240)Pu/(239)Pu atom ratios should provide useful background data before the expected expansion of nuclear power capacity in East and South Asian countries and for distinguishing future sources of Pu.

  3. Prompt γ-ray production in neutron-induced fission of 239Pu

    NASA Astrophysics Data System (ADS)

    Ullmann, J. L.; Bond, E. M.; Bredeweg, T. A.; Couture, A.; Haight, R. C.; Jandel, M.; Kawano, T.; Lee, H. Y.; O'Donnell, J. M.; Hayes, A. C.; Stetcu, I.; Taddeucci, T. N.; Talou, P.; Vieira, D. J.; Wilhelmy, J. B.; Becker, J. A.; Chyzh, A.; Gostic, J.; Henderson, R.; Kwan, E.; Wu, C. Y.

    2013-04-01

    Background: The prompt gamma-ray spectrum from fission is important for understanding the physics of nuclear fission, and also in applications involving fission. Relatively few measurements of the prompt gamma spectrum from 239Pu(n,f) have been published.Purpose: This experiment measured the multiplicity, individual gamma energy spectrum, and total gamma energy spectrum of prompt fission gamma rays from 239Pu(n,f) in the neutron energy range from thermal to 30 keV, to test models of fission and to provide information for applications.Method: Gamma rays from neutron-induced fission of 239Pu were measured using the DANCE gamma-ray calorimeter. Fission events were tagged by detecting fission products in a parallel-plate avalanche counter in the center of DANCE. The measurements were corrected for detector response using a geant4 model of DANCE. A detailed analysis for the gamma rays from the 1+ resonance complex at 10.93 eV is presented.Results: A six-parameter analytical parametrization of the fission gamma-ray spectrum was obtained. A Monte Carlo Hauser-Feshbach calculation provided good general agreement with the data, but some differences remain to be resolved.Conclusions: An analytic parametrization can be made of the gamma-ray multiplicity, energy distribution, and total-energy distribution for the prompt gamma rays following neutron-induced fission of 239Pu. This parametrization may be useful for applications. Modern Monte Carlo Hauser-Feshbach calculations can do a good job of calculating the fission gamma-ray emission spectrum, although some details remain to be understood.

  4. [State of cellular immunity effectors of the lung after inhalation of 239Pu polymer nitrate].

    PubMed

    Sokol'nikov, M E

    1992-01-01

    Wistar rats, who inhaled 239Pu (IV) at a dose that did not reduce the average life expectancy (the initial level in the lung was 0.77 kBq) did not exhibit any essential changes in the quality and functional activity of the alveolar macrophages. Revealed were the injuries to cells of bifurcation lymph nodes, the severity of which was a function of dose absorbed in the lung.

  5. 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.

  6. Radionuclide concentrations in bed sediment and fish tissue within the Rio Grande drainage basin

    SciTech Connect

    Booher, J.L.; Fresquez, P.R.; Carter, L.F.; Gallaher, B.M.; Mullen, M.A.

    1998-02-01

    In 1992-93, Los Alamos National Laboratory collaborated with the U.S. Geological Survey in an effort to characterize radionuclide concentrations in bed sediment and fish tissue within the Rio Grande drainage basin from Colorado to Texas. Bed sediment was sampled from 18 locations for cesium ({sup 137}Cs), tritium ({sup 3}H), strontium ({sup 90}Sr), plutonium ({sup 238}Pu and {sup 239}Pu), americium ({sup 241}Am), total uranium ({sup tot}U) and alpha, beta, and gamma activity. Fish tissue was sampled from 12 locations for {sup 137}Cs, {sup 90}Sr, {sup 238}Pu, {sup 239}Pu and {sup tot}U.

  7. Conceptual designs for a long term {sup 238}PuO{sub 2} storage vessel

    SciTech Connect

    Kwon, D.M.; Replogle, W.C.

    1996-08-01

    This is a report on conceptual designs for a long term, 250 years, storage container for plutonium oxide ([sup 238]PuO[sub 2]). These conceptual designs are based on the use of a quartz filter to release the helium generated during the plutonium decay. In this report a review of filter material selection, design concepts, thermal modeling, and filter performance are discussed.

  8. The toxicity of inhaled particles of sup 238 PuO sub 2 in dogs

    SciTech Connect

    Muggenburg, B.A.; Guilmette, R.A.; Griffith, W.C. Jr.; Hahn, F.F.; Boecker, B.B. . Inhalation Toxicology Research Inst.); Gillett, N.A. )

    1991-01-01

    This study was conducted to determine the toxicity of inhaled {sup 238}PuO{sub 2} in the dog. Inhalation was selected because it is the mostly likely route of human exposure in the event of an accidental airborne release. Of 166 dog in the study, 72 inhaled 1.5{mu}m and 72 inhaled 3.0 {mu}m activity median aerodynamic diameter particles of {sup 238}PuO{sub 2}. Another 24 dogs inhaled the aerosol vector without plutonium. The aerosol exposures resulted in initial pulmonary burdens ranging from 37 to 0.11 and 55.5 to 0.37 kBq of {sup 238}Pu/kg body mass, of 1.5 {mu}m and 3.0 {mu}, particles, respectively. The particles dissolved slowly resulting in translocation of the Pu to liver, bone and other sites. The dogs were observed for biological effects over their life span. Necropsies were performed at death, and tissues were examined microscopically. The principal late-occurring effects were tumors of the lung, skeleton, and liver. Risk factors estimated for these cancers were 2800 lung cancers/10{sup 4} Gy, 800 liver cancers/10{sup 4} Gy, and 6200 bone cancers/10{sup 4} Gy for dogs. The potential hazard from {sup 238}Pu to humans may include tumors of the lung, bone and liver because of the likelihood of similarity of the dose patterns for the two species. 10 refs., 1 fig., 3 tabs.

  9. /sup 238/Pu fuel form processes quarterly report, April-June 1980

    SciTech Connect

    Folger, R. L.

    1980-06-01

    Savannah River Laboratory (SRL) completed the development of a production process to fabricate /sup 238/PuO/sub 2/ fuel forms for the GPHS. The fabrication flowsheet was based on a flowsheet originally developed at Los Alamos National Scientific Laboratory (LANSL). A summary report of the SRL process development effort is presented.

  10. Hematological responses after inhaling {sup 238}PuO{sub 2}: An extrapolation from beagle dogs to humans

    SciTech Connect

    Scott, B.R.; Muggenburg, B.A.; Welsh, C.A.; Angerstein, D.A.

    1994-11-01

    The alpha emitter plutonium-238 ({sup 238}Pu), which is produced in uranium-fueled, light-water reactors, is used as a thermoelectric power source for space applications. Inhalation of a mixed oxide form of Pu is the most likely mode of exposure of workers and the general public. Occupational exposures to {sup 238}PuO{sub 2} have occurred in association with the fabrication of radioisotope thermoelectric generators. Organs and tissue at risk for deterministic and stochastic effects of {sup 238}Pu-alpha irradiation include the lung, liver, skeleton, and lymphatic tissue. Little has been reported about the effects of inhaled {sup 238}PuO{sub 2} on peripheral blood cell counts in humans. The purpose of this study was to investigate hematological responses after a single inhalation exposure of Beagle dogs to alpha-emitting {sup 238}PuO{sub 2} particles and to extrapolate results to humans.

  11. Modifying effects of preexisting pulmonary fibrosis on biological responses of rats to inhaled 239PuO2

    SciTech Connect

    Lundgren, D.L.; Mauderly, J.L.; Rebar, A.H.; Gillett, N.A.; Hahn, F.F. )

    1991-03-01

    We investigated the modifying effects of preexisting, bleomycin-induced pulmonary fibrosis on the deposition, retention, and biological effects of inhaled 239PuO2 in the rat. Among rats exposed to similar airborne concentrations of 239PuO2, initial lung burdens of 239Pu per kilogram body mass were similar whether or not pulmonary fibrosis was present. However, clearance of 239Pu from the lungs was significantly decreased in the rats with preexisting pulmonary fibrosis. The incidence of lung lesions (epithelial hyperplasia, diffuse macrophage increases and aggregation, and loose and dense connective tissue) was significantly greater among rats with preexisting pulmonary fibrosis than among the exposed controls. Rats with preexisting fibrosis had shorter life spans than 239PuO2-exposed control rats. When groups of rats with similar alpha doses to the lungs were compared, the incidences of neoplastic lesions in the lung, the times to death of rats with lung neoplasms, and the risk of lung tumors per unit of alpha dose to the lungs in rats with or without pulmonary fibrosis were similar. The results of this study suggest that humans with uncomplicated pulmonary fibrosis may not be more sensitive to the carcinogenic effects of inhaled 239PuO2 than are individuals with normal lungs, assuming that the total alpha doses to the lungs are similar.

  12. 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.

  13. 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.

  14. 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

  15. Analysis of 238Pu and 56Fe Evaluated Data for Use in MYRRHA

    NASA Astrophysics Data System (ADS)

    Díez, C. J.; Cabellos, O.; Martínez, J. S.; Stankovskiy, A.; Van den Eynde, G.; Schillebeeckx, P.; Heyse, J.

    2014-04-01

    A sensitivity analysis on the multiplication factor, keff, to the cross section data has been carried out for the MYRRHA critical configuration in order to show the most relevant reactions. With these results, a further analysis on the 238Pu and 56Fe cross sections has been performed, comparing the evaluations provided in the JEFF-3.1.2 and ENDF/B-VII.1 libraries for these nuclides. Then, the effect in MYRRHA of the differences between evaluations are analysed, presenting the source of the differences. With these results, recommendations for the 56Fe and 238Pu evaluations are suggested. These calculations have been performed with SCALE6.1 and MCNPX-2.7e.

  16. A new design of 238Pu activity sources for use in intercomparison exercises.

    PubMed

    Leprince, B; de Sanoit, J

    2002-08-01

    In the framework of a BIPM 238Pu comparison exercise, a new design for a-radiation counting sources was developed. These sources are constructed with a gold-coated Vyns film stretched over a stainless-steel disk. To improve the crystallization of the radioactive salt, the physical properties of the gold-coated polymer surface which receives the radioactivity deposit is modified. A pad of polystyrene micro-spheres (Estapor K-007) mixed with a wetting agent (Tween 20) is directly electrosprayed before the radioactive drop is deposited. After hot air-drying, the source is finally sealed with a thin Vyns film covering the entire radioactive spot. This new design makes it possible to create 238Pu sources that are easy and safe to handle, homogeneous and stable during ageing.

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

    DOE PAGES

    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.

  18. /sup 235/U and /sup 239/Pu sample-mass determinations and intercomparisons

    SciTech Connect

    Poenitz, W.P.; Meadows, J.W.

    1983-11-01

    The masses of fifteen /sup 235/U samples obtained from seven laboratories were determined and intercompared. The present results indicate that sample masses are well enough known (+- 0.3%) for the required high-accuracy-fission cross-section measurements. A comparison of four /sup 239/Pu samples indicates problems in the order of 1 to 3% which are more likely, to be related to counting efficiencies than to sample masses. The half-life of /sup 234/U was determined as (2.457 +- 0.005) . 10/sup 5/ yrs. 27 references.

  19. Uptake of 244Cm, 238Pu and other radionuclides by trees inhabiting a contaminated flood plain.

    PubMed

    Pinder, J E; McLeod, K W; Alberts, J J; Adriano, D C; Corey, J C

    1984-09-01

    The plant uptake of 244Cm, 137Cs, 238Pu and 90Sr was measured for trees in a flood plain forest whose soils were contaminated by aqueous discharges from a nuclear-fuel chemical separations facility. Uptake of the naturally occurring radionuclide 226Ra was also measured. The relative availability of the nuclides was 238Pu less than 244Cm less than 137Cs less than 226Ra less than or equal to 90Sr. The concentration ratios for 238Pu and 244Cm, 3 X 10(-4) and 3.6 X 10(-3), respectively, were similar to those reported for other plant-soil systems. The ratios for 137Cs and 90Sr, 0.11 and 3.9, were similar to those reported for other southeastern soils. However, the ratio for 226Ra, 2.1, was greater than that normally reported. These ratios, which were determined in the field, were generally similar to those reported for greenhouse studies on the same soil.

  20. Measurement of 239Pu in soil and plants in the Nishiyama District of Nagasaki.

    PubMed

    Okajima, S; Shimasaki, T; Kubo, T

    1990-05-01

    Nishiyama district in Nagasaki is located approximately 3000 m east of the hypocenter of the atomic bomb that was dropped on 9 August 1945. This district is also known as an area where there was a concentrated radioactive fallout with the black rain that was carried by a westerly wind. The Nagasaki atomic bomb was a Pu bomb, and the fallout must have included 239Pu without fission in addition to fission products. The presence of 239Pu in Nishiyama district has been confirmed previously. In this study, the distribution of 239 + 240Pu concentration in the uncultivated soil and the transfer factor of 239 + 240Pu to agricultural products in Nishiyama district were examined. The concentration of 239 + 240Pu in the uncultivated soil was 20 Bq kg-1, which was approximately eight times as high as that in the control districts. The transfer factor of 239 + 240Pu to agricultural products was 10(-4) - 10(-3), which was 1/100-1/200 of that of 137Cs.

  1. 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.

  2. 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.

  3. Neutron capture and (n,2n) measurements on 241Am

    SciTech Connect

    Vieira, D; Jandel, M; Bredeweg, T; Bond, E; Clement, R; Couture, A; Haight, R; O'Donnell, J; Reifarth, R; Ullmann, J; Wilhelmy, J; Wouters, J; Tonchev, A; Hutcheson, A; Angell, C; Crowell, A; Fallin, B; Hammond, S; Howell, C; Karowowski, H; Kelley, J; Pedroni, R; Tornow, W; Macri, R; Agvaanluvsan, U; Becker, J; Dashdorj, D; Stoyer, M; Wu, C

    2007-07-18

    We report on a set of neutron-induced reaction measurements on {sup 241}Am which are important for nuclear forensics and advanced nuclear reactor design. Neutron capture measurements have been performed on the DANCE detector array at the Los Alamos Neutron Scattering CEnter (LANSCE). In general, good agreement is found with the most recent data evaluations up to an incident neutron energy of {approx} 300 keV where background limits the measurement. Using mono-energetic neutrons produced in the {sup 2}H(d,n){sup 3}He reaction at Triangle University Nuclear Laboratory (TUNL), we have measured the {sup 241}Am(n,2n) excitation function from threshold (6.7 MeV) to 14.5 MeV using the activation method. Good agreement is found with previous measurements, with the exception of the three data points reported by Perdikakis et al. around 11 MeV, where we obtain a much lower cross section that is more consistent with theoretical estimates.

  4. 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.

  5. 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.

  6. Bayesian estimation of the relative toxicity of (239)Pu and (226)Ra with dependent competing risks

    NASA Astrophysics Data System (ADS)

    Xiao, Shili

    The purpose of this dissertation research is to compare the toxicity of the alpha-emitting, bone-seeking radionuclides sp{239}Pu and sp{226}Ra, develop a model for radiation induced osteosarcomas, and analyze the survival data of beagles exposed to these radionuclides. This research integrates the knowledge of radiation protection, survival theory and methods (competing risks, maximum likelihood estimation, and Bayesian techniques), numerical integration techniques (Monte Carlo, Lattice rule and Gauss-quadrature) and object-oriented programming in C++. The outline of this research is: (1) survival data preprocessing, (2) model identification and selection, (3) introduction of FGM model, the dependent competing risk model created by Farlie, Gumbel and Morgenstern, to the study of survival data with dependent competing risks: osteosarcomas and other diseases, development of the crude density of the FGM model and construction of the likelihood function for the FGM model, (4) Bayesian estimates of the posterior marginal density of the toxicity ratio in the FGM model using several numerical integration techniques (Monte Carlo, Lattice rule and Gaussian Quadrature), (5) construction of the likelihood function for the independent competing risk model, Bayesian estimate of the posterior marginal density of toxicity ratio in the model using Monte Carlo method, which is compared with the posterior marginal densities for the toxicity ratio obtained from the FGM model, (6) Bayesian estimates of all other parameters in the FGM model using Monte Carlo method, (7) Comparison of the cumulative hazard for sp{239}Pu calculated according to the model with Nelson's cumulative hazard plot under Bayesian point estimates of parameters and the mean activity in each injection level, (8) Comparison of the toxicity of plutonium in osteosarcoma with that of radium under Bayesian point estimates of parameters an d the selected activit of 0.85 muCsbi, (7) discuss Bayesian prediction of the

  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. Relationship between dose of injected /sup 239/Pu and bone sarcoma mortality in young adult beagles

    SciTech Connect

    Peterson, A.V.; Prentice, R.L.; Marek, P.

    1982-04-01

    The effect of /sup 239/Pu on bone sarcoma mortality in young adult beagles is examined using data from a follow-up study conducted at the Radiobiology Laboratory at the University of Utah. A (proportional-hazards) model, which specifies that bone sarcoma mortality depends on both dose of injected plutonium and time since injection as the product of a dose factor and a time factor, is used both for describing the data and for performing inference about the relationship between dose of plutonium and bone sarcoma mortality. Relative bone sarcoma mortality rates are found to be approximately linear as a function of dose. There is evidence that relative bone sarcoma mortality decreases with time since injection.

  9. 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.

  10. 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.

  11. Long-term exposure of /sup 238/PuO/sub 2/ to a terrestrial environment

    SciTech Connect

    Patterson, J.H.; Herrera, B.; Nelson, G.B.; Steinkruger, F.J.; Matlack, G.M.; Pavone, D.

    1982-12-01

    In many space missions that use radioisotope thermoelectric generators, /sup 238/PuO/sub 2/ is used as the source of heat. We exposed some of this heat-source material to simulated terrestrial environments for an 8-yr period. During this time we monitored the release of plutonium to water, air, and soil. Plutonium was found in the air, especially after the beginning of a rain, and in the water that percolated through the soil after a rain, but the major part of the plutonium was held in the soil.

  12. Interaction of a /sup 238/Pu fueled-sphere assembly with a simulated terrestrial environment

    SciTech Connect

    Steinkruger, F.J.; Patterson, J.H.; Herrera, B.; Nelson, G.B.; Matlack, G.M.; Waterbury, G.R.; Pavone, D.

    1981-02-01

    A /sup 238/Pu fueled sphere assembly (FSA) was exposed to a simulated humid environment on sandy soil for 3 y. After a 70-week exposure, plutonium was first detected in measurable quantities in rain and condensate samples. A core sample taken in the ninety-third week contained 302 ng of plutonium. Examination of the FSA after exposure revealed a hole in the bottom of the graphite impact shell (GIS) and a leaking weld on the vent assembly of the postimpact containment shell (PICS). These two openings may be the pathways for plutonium entry into the environment from the FSA.

  13. Toward a measurement of α -decay lifetime change at high pressure: The case of 241Am

    NASA Astrophysics Data System (ADS)

    Nissim, Noaz; Belloni, Fabio; Eliezer, Shalom; Delle Side, Domenico; Martinez Val, José Maria

    2016-07-01

    This paper suggests that a change in the lifetime of the α -decay process in 241Am may be detected at high pressures achievable in the laboratory, essentially, due to the extraordinary high compressibility of Am at the megabar range. The Thomas-Fermi model was used to calculate the effect of high pressure on the atomic electron density and the variation of the atomic potential of 241Am . It was found that at pressures of about 0.5 Mbar the relative change in the lifetime of 241Am is about -2 ×10-4 . Detailed experimental procedures to measure this effect by compressing the 241Am metal in a diamond-anvil cell are presented where diagnostics is based on counting of the 60-keV γ rays accompanying the α decay and/or mass spectrometry on the 237Np/241Am isotope ratio.

  14. Development of 241Am lung monitoring system using an imaging plate.

    PubMed

    Hirota, Masahiro; Kurihara, Osamu; Takada, Chie; Takasaki, Koji; Momose, Takumaro; Deji, Shizuhiko; Ito, Shigeki; Saze, Takuya; Nishizawa, Kunihide

    2007-07-01

    A new 241Am lung monitoring system without shielding was devised by using an imaging plate system. The Lawrence Livermore National Laboratory's realistic torso phantom containing a 241Am lung was covered by imaging plates sealed in lightproof bags. The imaging plate system displayed 241Am lung images characteristic of the lung shape of the torso phantom. The imaging plate system's lower detection limits of 14 Bq for 60 min exposure and 6 Bq for 300 min were the same levels as those of the phoswich detectors and the germanium detectors placed in shielded rooms. The imaging plate system for 60 min exposure detected about 2% of the annual limit of 740 Bq for 241Am inhalation. A lung monitoring system using imaging plates is applicable for 241Am lung monitoring.

  15. 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

  16. 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

  17. Neutron capture cross section of {sup 241}Am

    SciTech Connect

    Jandel, M.; Bredeweg, T. A.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O'Donnell, J. M.; Haight, R. C.; Kawano, T.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Agvaanluvsan, U.; Parker, W. E.; Wu, C. Y.; Becker, J. A.

    2008-09-15

    The neutron capture cross section of {sup 241}Am for incident neutrons from 0.02 eV to 320 keV has been measured with the detector for advanced neutron capture experiments (DANCE) at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be 665{+-}33 b. Our result is in good agreement with other recent measurements. Resonance parameters for E{sub n}<12 eV were obtained using an R-matrix fit to the measured cross section. The results are compared with values from the ENDF/B-VII.0, Mughabghab, JENDL-3.3, and JEFF-3.1 evaluations. {gamma}{sub n} neutron widths for the first three resonances are systematically larger by 5-15% than the ENDF/B-VII.0 values. The resonance integral above 0.5 eV was determined to be 1553{+-}7 b. Cross sections in the resolved and unresolved energy regions above 12 eV were calculated using the Hauser-Feshbach theory incorporating the width-fluctuation correction of Moldauer. The calculated results agree well with the measured data, and the extracted averaged resonance parameters in the unresolved resonance region are consistent with those for the resolved resonances.

  18. High-silicon 238PuO2 fuel characterization study: Half module impact tests

    NASA Astrophysics Data System (ADS)

    Reimus, Mary Ann H.

    1997-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of 238Pu decay to an array of thermoelectric elements. The modular GPHS design was developed to address both survivability during launch abort and return from orbit. Previous testing conducted in support of the Galileo and Ulysses missions documented the response of GPHSs to a variety of fragment-impact, aging, atmospheric reentry, and Earth-impact conditions. The evaluations documented in this report are part of an ongoing program to determine the effect of fuel impurities on the response of the heat source to conditions baselined during the Galileo/Ulysses test program. In the first two tests in this series, encapsulated GPHS fuel pellets containing high levels of silicon were aged, loaded into GPHS module halves, and impacted against steel plates. The results show no significant differences between the response of these capsules and the behavior of relatively low-silicon fuel pellets tested previously.

  19. 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.

  20. Using 239Pu as a tracer for fine sediment sources in the Daly River, Northern Australia

    NASA Astrophysics Data System (ADS)

    Lal, R.; Fifield, L. K.; Tims, S. G.; Wasson, R. J.; Howe, D.

    2015-04-01

    The Daly River drains a large (52500 km2) and mainly undisturbed catchment in the Australian wet-dry tropics. Clearing and cropping since 2002 have raised concerns about possible increased sediment input into the river and motivated this study of its fine sediment sources. Using 239Pu as a tracer it is shown that the fine sediments originate mainly from erosion by gullying and channel change. Although the results also indicate that the surface soil contribution to the river channel sediments from sheet erosion has increased to 5-22% for the Daly River and 7-28% for the Douglas River (a tributary of the Daly River) in 2009 vs. 3-6% for the Daly River and 4-9% for the Douglas River in 2005. This excess top soil likely originates from thecleared land adjacent to the Daly River since 2005. However, channel widening largely as a result of hydrologic change is still the dominant sediment source in this catchment.

  1. [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

  2. Relationship between bronchiolar dose and lung carcinoma induction following inhalation of /sup 239/PuO/sub 2/ in rats

    SciTech Connect

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

    1988-08-01

    This manuscript describes preliminary observations in a lifespan and serial sacrifice study with 3332 female, Wistar rats exposed to high-fired /sup 239/PuO/sub 2/ aerosols. Sufficient numbers of sham-control and low dose (equivalent to maximal permissible occupational lung deposition of 0.6 kBq in standard man) animals are provided to statistically estimate lung cancer risk and define the cellular-microdosimetric relationships leading to lung tumor formation. Whole-body counting for /sup 169/Yb tagged /sup 239/PuO/sub 2/ aerosol provided a very accurate method for determining Pu ILB in individual rats (Sanders et al., 1986). The experimental design, methodology and early results of the lifespan study have been previously reported (Sanders et al., 1986, 1988a). 7 refs., 3 figs.

  3. 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.

  4. 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.

  5. Measurement of plutonium isotopes, 239Pu and 240Pu, in air-filter samples from Seville (2001-2002)

    NASA Astrophysics Data System (ADS)

    Chamizo, E.; García-León, M.; Enamorado, S. M.; Jiménez-Ramos, M. C.; Wacker, L.

    2010-05-01

    Since the last nuclear atmospheric test carried out by the People Republic of China in 1980 and since the Chernobyl accident in 1986, the plutonium hasn't been directly released into the atmosphere. However, nowadays, it is still present in the troposphere. This is due to plutonium-bearing soil particles physical resuspension processes. In this work, we study for the first time the temporal variation of plutonium isotopes, 239Pu and 240Pu, baseline concentrations on a monthly basis in surface air from Seville (Spain), and their correlation with some tracers of mineral dust, during 2001 and 2002. The Pu analyses were performed by low-energy Accelerator Mass Spectrometry (AMS). The 239Pu plus 240Pu ( 239+240Pu) activity levels achieved maximums during the summer period, characterized by the absence of rains, and minimums during the rainy seasons, laying in the range 1-20 nBq m -3. The 240Pu/ 239Pu two-year average atomic ratio was 0.18 ± 0.03, in agreement with the fallout plutonium. A good correlation with Pu and Al and Ti levels is observed. They are crustal components usually used as tracers of African dust over European countries. The hypothesis of the influence of the Saharan dust intrusions is supported as well through the study of Total Ozone Mass Spectrometer (TOMS) daily images.

  6. 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.

  7. Brazilian gamma-neutron dosemeter: response to 241AmBe and 252Cf neutron sources.

    PubMed

    Souto, E B; Campos, L L

    2011-03-01

    With the aim of improving the monitoring of workers potentially exposed to neutron radiation in Brazil, the IPEN/CNEN-SP in association with PRO-RAD designed and developed a passive individual gamma-neutron mixed-field dosemeter calibrated to be used to (241)AmBe sources. To verify the dosimetry system response to different neutron spectra, prototypes were irradiated with a (252)Cf source and evaluated using the dose-calculation algorithm developed for (241)AmBe sources.

  8. Placental transfer and distribution of /sup 241/Am in the rat

    SciTech Connect

    Hisamatsu, S.; Takizawa, Y.

    1983-04-01

    The placental transfer and distribution of /sup 241/Am in the feto-placental system were studied in pregnant rats. Rats were injected intravenously with /sup 241/Am citrate at 15 or 18 days of gestation. Groups injected at 15 days of gestation were sacrificed 2, 24, 48, or 120 hr after injection, and the group injected at 18 days was sacrificed 24 hr after. The radioactivities of /sup 241/Am in fetus, fetal membrane, and placenta were determined, and its distribution in the feto-placental system was investigated by high-speed autoradiography using a silver-activated zinc sulfide-coated membrane as an intensifying screen. The deposition of /sup 241/Am in feto-placenta units increased with the number of days of gestation. Results of autoradiography revealed that major deposition sites of /sup 241/Am in the fetus are the skeleton and liver. Heavy deposition of /sup 241/Am in the yolksac splanchnopleure and its existence in the exocoelom strongly suggest that the yolk sac placenta plays an important role in the placental transfer of this nuclide.

  9. Radionuclide contaminant analysis of small mammals at Area G, Technical Area 54, 1996 (with cumulative summary for 1994--1996)

    SciTech Connect

    Biggs, J.R.; Bennett, K.D.; Fresquez, P.R.

    1997-07-01

    Small mammals were sampled at two waste burial sites at Area G, Technical Area (TA) 54 and a control site within the proposed Area G expansion area in 1996 to (1) identify radionuclides that are present within rodent tissues at waste burial sites, (2) to compare the amount of radionuclide uptake by small mammals at waste burial sites to a control site, and (3) to identify the primary mode of contamination to small mammals, either through surface contact or ingestion/inhalation. Three composite samples of approximately five animals per sample were collected at each site. Pelts and carcasses of each animal were separated and analyzed independently. Samples were analyzed for {sup 241}Am, {sup 90}Sr, {sup 238}Pu, {sup 239}Pu, total U, {sup 137}Cs, and {sup 3}H. Higher levels of total U, {sup 241}Am, {sup 238}Pu, and {sup 239}Pu were detected in pelts as compared to the carcasses of small mammals at TA-54. Concentrations of other measured radionuclides in carcasses were nearly equal to or exceeded the mean concentrations in the pelts. Due to low sample sizes in total number of animals captured, statistical analysis to compare site to site could not be conducted. However, mean concentrations of total U, {sup 238}Pu, {sup 239}Pu, and {sup 137}Cs in rodent carcasses were higher at Site 1 than site 2 or the Control Site and {sup 241}Am was higher at Site 2 than Site 1 or the Control Site.

  10. 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).

  11. /sup 238/Pu fuel form processes. Bimonthly report, September-October 1979

    SciTech Connect

    Folger, R. L.

    1980-02-01

    Progress in the Savannah River /sup 238/Pu Fuel Form Program is summarized. Full-scale fabrication tests continued as 4 pellets (General-Purpose Heat Source Pellets 10, 11, 12, and 13) were hot pressed and 3 pellets (GPHS Pellets 9, 10, and 11) underwent final heat treatment. The successful drilling of a one-eighth-inch diameter hole from the top of GPHS Pellet 8 to the center of the pellet after 2 1/2 months of storage and testing is one of several indications of the overall ruggedness of GPHS fuel pellets fabricated in the PEF. Microstructural analysis of a full-scale GPHS fuel pellet fabricated at LASL (LASL-GPHS Pellet 31) indicated that density gradients and internal cracking were more severe in this pellet than in SRL-GPHS pellets. As-received powder, oxygen-exchanged powder, and ball-milled powder samples from LASL were characterized by SEM analysis and by Coulter Counter particle size analysis.

  12. Precision measurement of the 238Pu(n,γ) cross section

    NASA Astrophysics Data System (ADS)

    Chyzh, A.; Wu, C. Y.; Kwan, E.; Henderson, R. A.; Gostic, J. M.; Bredeweg, T. A.; Couture, A.; Haight, R. C.; Lee, H. Y.; O'Donnell, J. M.; Ullmann, J. L.

    2013-10-01

    The neutron-capture cross section for 238Pu was measured by using the detector for advanced neutron-capture experiments (DANCE) array, which is a highly segmented and highly efficient 4π γ-ray calorimeter. The neutron-capture events were recognized by the total γ-ray energy deposited in DANCE, which is equal to the reaction Q value plus the incident neutron energy. The absolute neutron-capture cross section was derived as a function of incident neutron energy from thermal to about 30 keV. The measured cross section for incident neutron energy below 18 eV was performed for the first time by using the direct method and does not support the most recently adopted changes in endf/b-vii.1 where the neutron-capture cross section was lowered by as much as a factor of ˜3 in the neighborhood of 0.3 eV from those evaluated in endf/b-vii.0.

  13. Production of 238PuO2 heat sources for the Cassini mission

    NASA Astrophysics Data System (ADS)

    George, Timothy G.; Foltyn, Elizabeth M.

    1998-01-01

    NASA's Cassini mission to Saturn, scheduled to launch in October, 1997, is perhaps the most ambitious interplanetary explorer ever constructed. Electric power for the spacecraft's science instruments and on-board computers will be provided by three radioisotope thermoelectric generators (RTGs) powered by 216 238PuO2-fueled General-Purpose Heat Source (GPHS) capsules. In addition, critical equipment and instruments on the spacecraft and Huygens probe will be warmed by 128 Light-Weight Radioisotope Heater Units (LWRHUs). Fabrication and assembly of the GPHS capsules and LWRHU heat sources was performed at Los Alamos National Laboratory (LANL) between January 1994 and September 1996. During this production campaign, LANL pressed and sintered 315 GPHS fuel pellets and 181 LWRHU pellets. By October 1996, NMT-9 had delivered a total of 235 GPHS capsules to EG&G Mound Applied Technologies (EG&G MAT) in Miamisburg, Ohio. EG&G MAT conditioned the capsules for use, loaded the capsules into the Cassini RTGs, tested the RTGs, and coordinated transportation to Kennedy Space Center (KSC). LANL also fabricated and assembled a total of 180 LWRHUs. The LWRHUs required for the Cassini spacecraft were shipped to KSC in mid-1997.

  14. An emergency urine bioassay method for 241Am by extraction chromatography and liquid scintillation counting.

    PubMed

    Sadi, Baki B; Li, Chunsheng; Masoud, Ali; Ko, Raymond; Kramer, Gary H

    2010-09-01

    An emergency urine bioassay method has been developed for the determination of (241)Am in human urine samples. The method is based on extraction chromatographic separation of (241)Am from urine on a single DGA (N,N,N',N'-tetraoctyldiglycolamide) resin column followed by liquid scintillation counting of (241)Am. The minimum detectable activity (MDA) for the method was 0.02 Bq. Considering the volume of urine sample (17.2 ml) used by the method; the MDA was 1.3 Bq l(-1). Measurement accuracy (relative bias, B(r)) and repeatability (relative precision, S(B)) of the method were found to be -3.4 and 8.9 %, respectively, when urine samples were spiked with (241)Am (20 Bq l(-1)). Excellent linearity (r(2) > 0.999) was established over the range of 2-200 Bq l(-1). The method was also found to be robust (S(B)=10.2 %) against matrix effects from different urine samples. Performance of the rapid bioassay method for accuracy and repeatability were evaluated against the performance criteria for radiobioassay (ANSI N13.30) and found to be in compliance. Considering the simplicity, excellent analytical figures of merit and fast sample turnaround time (<1 h), it is a very promising rapid bioassay method for supporting the medical response to an emergency where internal contamination of (241)Am is involved.

  15. ^241Am(n,γ) absolute cross sections measured with DANCE

    NASA Astrophysics Data System (ADS)

    Jandel, M.; Bredeweg, T. A.; Fowler, M. M.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O'Donnell, J. M.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Agvaanluvsan, U.; Macri, R. A.; Sheets, S. A.; Wu, C. Y.; Becker, J. A.

    2007-10-01

    ^241Am is present in plutonium due to the beta decay of ^241Pu (t1/2=14.38 years). As such ^241Am can be used as a detector for nuclear forensics. A precise measurement of ^241Am(n,γ) cross section is thus needed for this application. The measurement is also of interest for advanced reactor design as part of the Global Nuclear Energy Partnership (GNEP). The Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory (LANL) was used for neutron capture cross section measurement on ^241Am. The high granularity of DANCE (160 BaF2 detectors in a 4π geometry) enables the efficient detection of prompt gamma-rays following a neutron capture. DANCE is located on the 20.26 m neutron flight path 14(FP14) at the Manuel Lujan Jr. Neutron Scattering Center at the Los Alamos Neutron Science Center (LANSCE). The absolute ^241Am(n,γ) cross sections were obtained in the range of neutron energies from 0.02 eV to 320 keV. The results will be compared to existing evaluations in detail.

  16. Case Study: Three Acute 241Am Inhalation Exposures with DTPA Therapy

    SciTech Connect

    Carbaugh, Eugene H.; Lynch, Timothy P.; Cannon, Curt; Lewis, Loren L.

    2010-10-01

    Three workers incurred inhalation exposures to 241Am oxide as a result of waste sorting and compaction activities. The magnitudes of the exposures were not fully recognized until the following day when an in vivo chest count identified a significant lung deposition of 241Am in a male worker, and DTPA chelation therapy was initiated. Two additional workers (one female and one male) were then identified as sufficiently exposed to also warrant therapy. In vivo bioassay measurements were performed over the ensuing 6 months to quantify the 241Am activity in the lungs, liver, and skeleton. Urine and fecal samples were collected and showed readily detectable 241Am. Clinical lab tests and medical evaluations all showed normal results. There were no significant adverse clinical health effects from the therapy. The estimated 241Am inhalation intakes for the three workers were 1800 Bq, 630 Bq, and 150 Bq. Lung retention showed somewhat longer pulmonary clearance half-times than standard inhalation class W or absorption Type M assumptions. The three underwent slightly different therapy regimes, with therapy effectiveness factors (defined as the ratio of the reference doses without therapy relative to the final assessed doses) of 4.65, 1.93, and 1.67, respectively.

  17. Behavior of 241Am in fast reactor systems - a safeguards perspective

    SciTech Connect

    Beddingfield, David H; Lafleur, Adrienne M

    2009-01-01

    Advanced fuel-cycle developments around the world currently under development are exploring the possibility of disposing of {sup 241}Am from spent fuel recycle processes by burning this material in fast reactors. For safeguards practitioners, this approach could potentially complicate both fresh- and spent-fuel safeguards measurements. The increased ({alpha},n) production in oxide fuels from the {sup 241}Am increases the uncertainty in coincidence assay of Pu in MOX assemblies and will require additional information to make use of totals-based neutron assay of these assemblies. We have studied the behavior of {sup 241}Am-bearing MOX fuel in the fast reactor system and the effect on neutron and gamma-ray source-terms for safeguards measurements. In this paper, we will present the results of simulations of the behavior of {sup 241}Am in a fast breeder reactor system. Because of the increased use of MOX fuel in thermal reactors and advances in fuel-cycle designs aimed at americium disposal in fast reactors, we have undertaken a brief study of the behavior of americium in these systems to better understand the safeguards impacts of these new approaches. In this paper we will examine the behavior of {sup 241}Am in a variety of nuclear systems to provide insight into the safeguards implications of proposed Am disposition schemes.

  18. 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).

  19. Estimates of helium gas release in 238PuO 2 fuel particles for radioisotope heat sources and heater units

    NASA Astrophysics Data System (ADS)

    El-Genk, Mohamed S.; Tournier, Jean-Michel

    2000-06-01

    Release data of noble gases (Xe and Kr) from small-grain (7-40 μm), large-grain (⩾300 μm), and monocrystal UO 2 fuel particles, during isothermal irradiation up to 6.4 at.% and 2030 K are reviewed and their applicability to estimate helium release from 238PuO 2 fuel particles (⩾300 μm in diameter) is examined. Coated 238PuO 2 particles have recently been proposed for use in radioisotope power systems and heater units employed in planetary exploration missions. These fuel particles are intentionally sized and designed to prevent any adverse radiological effect and retain the helium gas generated by the radioactive decay of 238Pu, a desired feature for some planetary missions. Results suggest that helium release from large-grain (⩾300 μm) particles of K could be <7% at 1723 K, <0.6% at 1042 K, and even less for polycrystalline particles fabricated using sol-gel processes. Results also suggest that helium release from small-grain plutonia particles at 1723 K could be >80% but less than 7% at 1042 K, which is in general agreement with the experiments conducted at Los Alamos National Laboratory more than two decades ago. In these experiments, the helium gas release from small-grain (7-40 μm) 238PuO 2 fuel pellets has been measured during steady-state heating at temperatures up to 1886 K and ramp heating to 1723 K.

  20. Interactions of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Interim summary

    SciTech Connect

    Patterson, J.H.; Steinkruger, F.J.; Matlack, G.M.

    1980-09-01

    Observations and some conclusions made of the interactions of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments may be used in predicting heat source behavior in the event of contact of these heat sources with land or ocean and in assessing the risk to the environment. These studies indicate that plutonium transport from the heat sources is mostly a physical process involving the movement of extremely fine particles rather than the chemical migration of plutonium ions.

  1. 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.

  2. Time-dependent local and average structural evolution of δ-phase 239Pu-Ga alloys

    DOE PAGES

    Smith, Alice I.; Page, Katharine L.; Siewenie, Joan E.; Losko, Adrian S.; Vogel, Sven C.; Gourdon, Olivier A.; Richmond, Scott; Saleh, Tarik A.; Ramos, Michael; Schwartz, Daniel S.

    2016-08-05

    Here, plutonium metal is a very unusual element, exhibiting six allotropes at ambient pressure, between room temperature and its melting point, a complicated phase diagram, and a complex electronic structure. Many phases of plutonium metal are unstable with changes in temperature, pressure, chemical additions, or time. This strongly affects structure and properties, and becomes of high importance, particularly when considering effects on structural integrity over long periods of time [1]. This paper presents a time-dependent neutron total scattering study of the local and average structure of naturally aging δ-phase239Pu-Ga alloys, together with preliminary results on neutron tomography characterization.

  3. 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

  4. 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.

  5. Modeling of selected ceramic processing parameters employed in the fabrication of 238PuO2 fuel pellets

    DOE PAGES

    Brockman, R. A.; Kramer, D. P.; Barklay, C. D.; Cairns-Gallimore, D.; Brown, J. L.; Huling, J. C.; Van Pelt, C. E.

    2011-10-01

    Recent deep space missions utilize the thermal output of the radioisotope plutonium-238 as the fuel in the thermal to electrical power system. Since the application of plutonium in its elemental state has several disadvantages, the fuel employed in these deep space power systems is typically in the oxide form such as plutonium-238 dioxide (238PuO2). As an oxide, the processing of the plutonium dioxide into fuel pellets is performed via ''classical'' ceramic processing unit operations such as sieving of the powder, pressing, sintering, etc. Modeling of these unit operations can be beneficial in the understanding and control of processing parameters withmore » the goal of further enhancing the desired characteristics of the 238PuO2 fuel pellets. A finite element model has been used to help identify the time-temperature-stress profile within a pellet during a furnace operation taking into account that 238PuO2 itself has a significant thermal output. The results of the modeling efforts will be discussed.« less

  6. Modeling of Selected Ceramic Processing Parameters Employed in the Fabrication of 238PuO 2 Fuel Pellets

    NASA Astrophysics Data System (ADS)

    Brockman, R. A.; Kramer, D. P.; Barklay, C. D.; Cairns-Gallimore, D.; Brown, J. L.; Huling, J. C.; Van Pelt, C. E.

    Recent deep space missions utilize the thermal output of the radioisotope plutonium-238 as the fuel in the thermal to electrical power system. Since the application of plutonium in its elemental state has several disadvantages, the fuel employed in these deep space power systems is typically in the oxide form such as plutonium-238 dioxide (238PuO2). As an oxide, the processing of the plutonium dioxide into fuel pellets is performed via "classical" ceramic processing unit operations such as sieving of the powder, pressing, sintering, etc. Modeling of these unit operations can be beneficial in the understanding and control of processing parameters with the goal of further enhancing the desired characteristics of the 238PuO2 fuel pellets. A finite element model has been used to help identify the time-temperature-stress profile within a pellet during a furnace operation taking into account that 238PuO2 itself has a significant thermal output. Results of the modeling efforts will be discussed.

  7. In vivo measurement of 241Am in the lungs confounded by activity deposited in other organs.

    PubMed

    Lobaugh, Megan L; Spitz, Henry B; Glover, Samuel E

    2015-01-01

    Radioactive material deposited in multiple organs of the body is likely to confound a result of an in vivo measurement performed over the lungs, the most frequently monitored organ for occupational exposure. The significance of this interference was evaluated by measuring anthropometric torso phantoms containing lungs, liver, skeleton, and axillary lymph nodes, each with a precisely known quantity of 241Am uniformly distributed in the organs. Arrays of multiple high-resolution germanium detectors were positioned over organs within the torso phantom containing 241Am or over proximal organs without activity to determine the degree of measurement confounding due to photons emitted from other source organs. A set of four mathematical response functions describes the measured count rate with detectors positioned over each of the relevant organs and 241Am contained in the measured organ or one of the other organs selected as a confounder. Simultaneous solution of these equations by matrix algebra, where the diagonal terms of the matrix are calibration factors for a direct measurement of activity in an organ and the off-diagonal terms reflect the contribution (i.e., interference or cross-talk) produced by 241Am in a confounding organ, yields the activity deposited in each of the relevant organs. The matrix solution described in this paper represents a method for adjusting a result of 241Am measured directly in one organ for interferences that may arise from 241Am deposited elsewhere and represents a technically valid procedure to aid in evaluating internal dose based upon in vivo measurements for those radioactive materials known to deposit in multiple organs.

  8. In vivo measurement of 241Am in the lungs confounded by activity deposited in other organs.

    PubMed

    Lobaugh, Megan L; Spitz, Henry B; Glover, Samuel E

    2015-01-01

    Radioactive material deposited in multiple organs of the body is likely to confound a result of an in vivo measurement performed over the lungs, the most frequently monitored organ for occupational exposure. The significance of this interference was evaluated by measuring anthropometric torso phantoms containing lungs, liver, skeleton, and axillary lymph nodes, each with a precisely known quantity of 241Am uniformly distributed in the organs. Arrays of multiple high-resolution germanium detectors were positioned over organs within the torso phantom containing 241Am or over proximal organs without activity to determine the degree of measurement confounding due to photons emitted from other source organs. A set of four mathematical response functions describes the measured count rate with detectors positioned over each of the relevant organs and 241Am contained in the measured organ or one of the other organs selected as a confounder. Simultaneous solution of these equations by matrix algebra, where the diagonal terms of the matrix are calibration factors for a direct measurement of activity in an organ and the off-diagonal terms reflect the contribution (i.e., interference or cross-talk) produced by 241Am in a confounding organ, yields the activity deposited in each of the relevant organs. The matrix solution described in this paper represents a method for adjusting a result of 241Am measured directly in one organ for interferences that may arise from 241Am deposited elsewhere and represents a technically valid procedure to aid in evaluating internal dose based upon in vivo measurements for those radioactive materials known to deposit in multiple organs. PMID:25437522

  9. Species-dependent effective concentration of DTPA in plasma for chelation of 241Am

    PubMed Central

    Sueda, Katsuhiko; Sadgrove, Matthew P.; Jay, Michael; Di Pasqua, Anthony J.

    2013-01-01

    Diethylenetriaminepentaacetic acid (DTPA) is a chelating agent that is used to facilitate the elimination of radionuclides, such as americium, from contaminated individuals. Its primary site of action is in the blood, where it competes with various biological ligands, including transferrin and albumin, for the binding of radioactive metals. To evaluate the chelation potential of DTPA under these conditions, the competitive binding of 241Am between DTPA and plasma proteins was studied in rat, beagle and human plasma in vitro. Following incubation of DTPA and 241Am in plasma, the 241Am-bound ligands were fractionated by ultrafiltration and ion-exchange chromatography, and each fraction was assayed for 241Am content by gamma scintillation counting. Dose-response curves of DTPA for 241Am binding were established, and these models were used to calculate the 90% maximal effective concentration, or EC90, of DTPA in each plasma system. The EC90 were determined to be 31.4, 15.9 and 10.0 μM in rat, beagle and human plasma, respectively. These values correspond to plasma concentrations of DTPA that maximize 241Am chelation while minimizing excess DTPA. Based on the pharmacokinetic profile of DTPA in humans, after a standard 30 μmol kg−1 intravenous bolus injection, the plasma concentration of DTPA remains above EC90 for approximately 5.6 h. Likewise, the effective duration of DTPA in rat and beagle were determined to be 0.67 and 1.7 h, respectively. These results suggest that species differences must be considered when translating DTPA efficacy data from animals to humans and offer further insights into improving the current DTPA treatment regimen. PMID:23799506

  10. Soft tissue tumors in beagles injected with {sup 241}Am citrate

    SciTech Connect

    Lloyd, R.D.; Taylor, G.N.; Angus, W.

    1995-02-01

    The occurrence of soft tissue tumors has been studied in 117 beagles assigned to 8 dosage groups of between 2 and 26 animals each and injected with 0.07 to 104 kBq {sup 241}Am kg{sup -1} as the citrate. In addition, 133 control beagles given no radioactivity were used as a comparison group. All 250 dogs were maintained under identical conditions and were observed for their entire lifespans. An important competing risk for the appearance of soft tissue tumors appeared to be the occurrence of skeletal malignancy, and at the highest injected activity (104) kBq kg{sup -1}, kidney and liver failure brought about the death of both of the two dogs in this group. Thyroid and liver were the only soft tissues that exhibited greater concentrations of {sup 241}Am than the skeleton. Liver tumors were associated {sup 241}Am exposure (p < 0.001), but the thyroid tumor rate was not increased significantly in the irradiated animals (p > 0.10) as compared with the occurrence in controls. There was a greater relative occurrence of all vaginal tumors in control animals than in dogs given {sup 241}Am, a situation also found for all tumors of the pancreas, skin, testis, and mammary glands and for malignant ovarian tumors. All of these differences were statistically significant. The survival of animals given 0.07 to 0.59 kBq {sup 241}Am Kg{sup -1} could not be established (p > 0.10) as significantly different from controls, but the survival of all groups given 1.8 to 104 kBq kg{sup -1} was decreased (p < 0.05). There was no indication in our studies of a positive association between relative exposure to {sup 241}Am and the occurrence of mammary tumors, mast cell sarcomas originating outside the liver, lymphosarcoma or tumors of marrow, including leukemia. 20 refs., 1 fig., 8 tabs.

  11. Biological effects of α-radiation exposure by (241)Am in Arabidopsis thaliana seedlings are determined both by dose rate and (241)Am distribution.

    PubMed

    Biermans, Geert; Horemans, Nele; Vanhoudt, Nathalie; Vandenhove, Hildegarde; Saenen, Eline; Van Hees, May; Wannijn, Jean; Vangronsveld, Jaco; Cuypers, Ann

    2015-11-01

    Human activity has led to an increasing amount of radionuclides in the environment and subsequently to an increased risk of exposure of the biosphere to ionising radiation. Due to their high linear energy transfer, α-emitters form a threat to biota when absorbed or integrated in living tissue. Among these, (241)Am is of major concern due to high affinity for organic matter and high specific activity. This study examines the dose-dependent biological effects of α-radiation delivered by (241)Am at the morphological, physiological and molecular level in 14-day old seedlings of Arabidopsis thaliana after hydroponic exposure for 4 or 7 days. Our results show that (241)Am has high transfer to the roots but low translocation to the shoots. In the roots, we observed a transcriptional response of reactive oxygen species scavenging and DNA repair pathways. At the physiological and morphological level this resulted in a response which evolved from redox balance control and stable biomass at low dose rates to growth reduction, reduced transfer and redox balance decline at higher dose rates. This situation was also reflected in the shoots where, despite the absence of a transcriptional response, the control of photosynthesis performance and redox balance declined with increasing dose rate. The data further suggest that the effects in both organs were initiated in the roots, where the highest dose rates occurred, ultimately affecting photosynthesis performance and carbon assimilation. Though further detailed study of nutrient balance and (241)Am localisation is necessary, it is clear that radionuclide uptake and distribution is a major parameter in the global exposure effects on plant performance and health. PMID:26204519

  12. Performance analysis of coated 238PuO2 fuel particles compact for radioisotope heater units

    NASA Astrophysics Data System (ADS)

    Tournier, Jean-Michel; El-Genk, Mohamed S.

    2000-01-01

    A fuel form consisting of coated plutonia fuel particles dispersed in a graphite matrix is being investigated for use in Radioisotope Heater Units (RHUs). The fuel particles consist of a 238PuO2 kernel (300-1200 μm in diameter), a 5-μm PyC inner coating and a ZrC outer coating (>=10 μm). The latter, an extremely strong material at high temperatures, serves as a pressure vessel for maintaining the integrity of the fuel particle and containing the helium generated by radioactive decay. Parametric analyses compared the thermal powers of the coated particle fuel compact (CPFC) RHU and LWRHU. Both utilize Fine-Weave Pierced Fabric (FWPF) aeroshell and PyC insulation sleeves. During normal operation, the fuel temperature is ~800 K, but could reach as much as 1723 K during an accidental re-entry heating. Assuming full helium release, a single-size particle (500 μm) fuel compact would maintain its integrity at a temperature of 1723 K, after 10 years storage time before launch. When replacing the LWRHU fuel pellet, Pt-alloy clad and inner PyC insulation sleeve with CPFC, the calculated thermal power of the CPFC-RHU is 1.5, 2.3 and 2.4 times that of LWRHU, for 100%, 10%, and 5% helium release, respectively, with little change in total mass. A fuel compact using binary-size particles (300 and 1200 μm diameters) would deliver 15% more thermal power. A one-dimensional, transient thermal analysis of the CPFC-RHU showed that during accidental re-entry the maximum fuel temperature in the CPFC would be 1734 K. .

  13. /sup 238/Pu fuel form processes. Quarterly report, April-June 1982

    SciTech Connect

    j

    1982-11-01

    Progress in studies of /sup 238/Pu fuel form processes is reported. Analytical studies of weld-quench cracking in DOP-26 iridium alloy-clad vent sets in General Purpose Heat Sources (GPHS) showed that weld-quench cracking is much more severe in MER alloy than in LR and NR alloys. Spark source mass spectrometry indicated that areas in DOP-26 alloy with severe weld-quench cracking have high thorium inhomogeneity. Secondary ion mass spectrometry revealed differences in LR and MR alloys that may be related to their dissimilar susceptibilities for weld-quench cracking. Impact ductility tests showed that welds in DOP-26 alloy clad vent sets made using parameters similar to PuFF production welding had high elongations. Decontamination of encapsulated GPHS pellets in PuFF was demonstrated using a solution of 3.5 M HNO/sub 3/ + 6.4 M HF which is capable of reducing transferable contamination below the specified 10/sup 3/ dpm upper limit in <30 minutes at a bath temperature of 80/sup 0/C using ultrasonic cleaning. Decontamination vessels were constructed to trap and condense acid vapors during decontamination. Impact and metallographic data showed that although the micro and macrostructures between LANL and SRL pellets have large differences, the difference in impact response between these two types of pellets is not correspondingly large. Both types of pellets have impacted successfully. The micro and macrostructures of SRP pellets made with either low fired shards sintered in Ar/5%O/sub 2/ or Ar are intermediate between those of the LANL and SRL pellets. Therefore, either type of SRP pellet should impact successfully.

  14. PROPERTIES AND BEHAVIOR OF 238PU RELEVANT TO DECONTAMINATION OF BUILDING 235-F

    SciTech Connect

    Duncan, A.; Kane, M.

    2009-11-24

    This report was prepared to document the physical, chemical and radiological properties of plutonium oxide materials that were processed in the Plutonium Fuel Form Facility (PuFF) in building 235-F at the Savannah River Plant (now known as the Savannah River Site) in the late 1970s and early 1980s. An understanding of these properties is needed to support current project planning for the safe and effective decontamination and deactivation (D&D) of PuFF. The PuFF mission was production of heat sources to power Radioisotope Thermoelectric Generators (RTGs) used in space craft. The specification for the PuO{sub 2} used to fabricate the heat sources required that the isotopic content of the plutonium be 83 {+-} 1% Pu-238 due to its high decay heat of 0.57 W/g. The high specific activity of Pu-238 (17.1 Ci/g) due to alpha decay makes this material very difficult to manage. The production process produced micron-sized particles which proved difficult to contain during operations, creating personnel contamination concerns and resulting in the expenditure of significant resources to decontaminate spaces after loss of material containment. This report examines high {sup 238}Pu-content material properties relevant to the D&D of PuFF. These relevant properties are those that contribute to the mobility of the material. Physical properties which produce or maintain small particle size work to increase particle mobility. Early workers with {sup 238}PuO{sub 2} felt that, unlike most small particles, Pu-238 oxide particles would not naturally agglomerate to form larger, less mobile particles. It was thought that the heat generated by the particles would prevent water molecules from binding to the particle surface. Particles covered with bound water tend to agglomerate more easily. However, it is now understood that the self-heating effect is not sufficient to prevent adsorption of water on particle surfaces and thus would not prevent agglomeration of particles. Operational

  15. Neutronics Simulations of 237Np Targets to Support Safety-Basis and 238Pu Production Assessment Efforts at the High Flux Isotope Reactor

    SciTech Connect

    Chandler, David; Ellis, Ronald James

    2015-01-01

    Fueled by two highly enriched uranium-bearing fuel elements surrounded by a large concentric ring of beryllium reflector, the High Flux Isotope Reactor (HFIR) provides one of the highest neutron fluxes in the world and is used to produce unique isotopes like plutonium-238. The National Aeronautics and Space Administration use radioisotope thermoelectric generators powered by 238Pu for deep-space missions. As part of the US Department of Energy s task to reestablish the domestic production of 238Pu, a technology demonstration sub-project has been initiated to establish a new 238Pu supply chain. HFIR safety-basis neutronics calculations are being performed to ensure the target irradiations have no adverse impacts on reactor performance and to calculate data required as input to follow-on thermal-structural, thermal-hydraulic and radionuclide/dose analyses. Plutonium-238 production assessments are being performed to estimate the amount of 238Pu that can be produced in HFIR s permanent beryllium reflector. It is estimated that a total of 0.96 1.12 kg 238Pu (~1.28 1.49 kg PuO2 at 85% 238Pu/Pu purity) could be produced per year in HFIR s permanent beryllium reflector irradiation facilities if they are all utilized.

  16. Promotion of pulmonary carcinogenesis by plutonium particle aggregation following inhalation of /sup 239/PuO/sub 2/

    SciTech Connect

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

    1988-12-01

    Promotion of lung tumor formation from inhaled /sup 239/PuO/sub 2/ in rats may be associated with aggregation of plutonium particles near bronchioles. The relationship of plutonium particle aggregation in the lung and the development of lung tumors after inhalation of /sup 239/PuO/sub 2/ was studied in 664 life span rats with mean lung doses ranging from 0.35 to 20 Gy. Plutonium particle concentration and aggregation were determined from autoradiographic sections of the left lung lobe. The increase in particles/cm2 and mean number of particles per aggregate up to 20 Gy were directly proportional to lung dose. Aggregates with greater than 25 particles increased linearly with dose from 0.2% at 1.4 Gy to 8.2% at 20 Gy, in a pattern similar to increasing severity of pulmonary fibrosis and incidence of lung tumors. Lung tumor incidence increased from about 6% at 1.4 Gy to 83% at 8 Gy; no further increase in lung tumors was seen at doses greater than 8 Gy. Maximum lung tumor incidence at 8 Gy corresponded to a particle concentration of 130/cm2 and four particles/aggregate with 4% of aggregates having greater than 25 particles. Aggregation of inhaled plutonium particles in clusters of greater than 25 particles resulted in daily doses of only a few centigray to focal tissue regions containing clustered particles, yet these doses appeared sufficient to cause pulmonary fibrosis and promotion of pulmonary carcinogenesis.

  17. 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.

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

    NASA Astrophysics Data System (ADS)

    Knowles, Justin; Skutnik, Steven; Glasgow, David; Kapsimalis, Roger

    2016-10-01

    Rapid nondestructive assay methods for trace fissile material analysis are needed in both nuclear forensics and safeguards communities. To address these needs, research at the Oak Ridge National Laboratory High Flux Isotope Reactor Neutron Activation Analysis facility has developed a generalized nondestructive assay method to characterize materials containing fissile isotopes. This method relies on gamma-ray emissions from short-lived fission products and makes use 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 complete characterization of isotopic identification, mass ratios, and absolute mass determination. Successful single fissile isotope mass recoveries of less than 6% recovery bias have been conducted on standards of 235U and 239Pu as low as 12 ng in less than 10 minutes. Additionally, mixtures of fissile isotope standards containing 235U and 239Pu have been characterized as low as 198 ng of fissile mass with less than 7% recovery bias. 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 facilities, and account for increasingly complex sample matrices.

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

    DOE PAGES

    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

  20. 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}.

  1. 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.

  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. Decay data evaluation project (DDEP): updated evaluations of the 233Th and 241Am decay characteristics.

    PubMed

    Chechev, Valery P; Kuzmenko, Nikolay K

    2010-01-01

    The results of new decay data evaluations are presented for (233)Th (beta(-)) decay to nuclear levels in (233)Pa and (241)Am (alpha) decay to nuclear levels in (237)Np. These evaluated data have been obtained within the Decay Data Evaluation Project using information published up to 2009.

  4. 239+240Pu concentration and isotope ratio (240Pu/239Pu) in aerosols during high dust (Yellow Sand) period, Korea.

    PubMed

    Choi, Man Sik; Lee, Dong-Soo; Choi, Jae-Cheon; Cha, Hyun-Ju; Yi, Hee-Il

    2006-10-15

    Concentration and isotope ratio of Pu were analyzed for aerosols collected at Anmyeondo located in the western coast of Korea using multiple collector inductively coupled plasma mass spectrometer equipped with desolvated micro-concentric nebulizer. Aerosols were collected from June 2001 to April 2002 using high volume air sampler. The samples consist of high dust samples (Yellow Sand), and also low dust samples; maximum Al concentration was 74.2 microg/m(3) and minimum was 0.17 microg/m(3). Pu was concentrated using 0.1 ml TEVA resin columns after conc. HNO(3) extraction. Isotope dilution using (242)Pu spike and mass bias correction using (233)U and (236)U mixed solution enabled the quantification of Pu and measurement of isotope ratio simultaneously. The contribution of (238)U from both spikes and samples was minimized by careful chemical separation and optimization of spike concentration. The (238)U(1)H and tail contribution on (239)Pu peak were about 0.75 x 10(-5) and 1 x 10(-5) of (238)U intensity, respectively, and they were corrected from (239)Pu using externally determined ((238)U(1)H + tailing)/(238)U ratio and (238)U measurement during acquisition. The detection limits of this analytical procedure were 0.61 fg/ml and 0.56 fg/ml for (239)Pu and (240)Pu, respectively (4 nBq/m(3) and 12 nBq/m(3) for (239)Pu and (240)Pu, respectively). The precision of isotope ratio measurement was better than 2% for larger quantity than 20 fg of (239)Pu. In spring, maximum concentration of 0.580 microBq/m(3) for (239)Pu and 0.404 microBq/m(3) for (240)Pu was observed when Al concentration was maximum, so called as Yellow Sand event. Pu concentrations in aerosols are well correlated with Al, a tracer of soil dust. The ratios of Pu/Al were 0.0082 (microBq/microg) and 0.0055 (microBq/microg) for (239)Pu/Al and (240)Pu/Al, respectively. Isotope ratios of Pu ((240)Pu/(239)Pu) in Yellow Sand samples show 0.191+/-0.014 close to those of global fallout. These facts indicate that

  5. Distribution of nuclear bomb Pu in Nishiyama area, Nagasaki, estimated by accurate and precise determination of 240Pu/239Pu ratio in soils.

    PubMed

    Yoshida, S; Muramatsu, Y; Yamazaki, S; Ban-Nai, T

    2007-01-01

    Plutonium isotopes in forest soils collected in Nishiyama area, Nagasaki, were successfully determined by high resolution inductively coupled plasma mass spectrometry after the treatment with a microwave decomposition system. The (240)Pu/(239)Pu atom ratios observed in the samples in the Nishiyama area were obviously lower than the range of the global fallout. The low ratios (minimum 0.032) observed in Nishiyama area indicated the influence of detonation of the Pu nuclear weapon in 1945. Since the area is contaminated also by global fallout, the (240)Pu/(239)Pu atom ratio can be more sensitive indicator of bomb-derived Pu than Pu activity concentration.

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

    PubMed

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

    2014-06-01

    The variation of the (236)U and (239)Pu concentrations as a function of depth has been studied in a soil profile at a site in the Southern Hemisphere well removed from nuclear weapon test sites. Total inventories of (236)U and (239)Pu as well as the (236)U/(239)Pu isotopic ratio were derived. For this investigation a soil core from an undisturbed forest area in the Herbert River catchment (17°30' - 19°S) which is located in north-eastern Queensland (Australia) was chosen. The chemical separation of U and Pu was carried out with a double column which has the advantage of the extraction of both elements from a relatively large soil sample (∼20 g) within a day. The samples were measured by Accelerator Mass Spectrometry using the 14UD pelletron accelerator at the Australian National University. The highest atom concentrations of both (236)U and (239)Pu were found at a depth of 2-3 cm. The (236)U/(239)Pu isotopic ratio in fallout at this site, as deduced from the ratio of the (236)U and (239)Pu inventories, is 0.085 ± 0.003 which is clearly lower than the Northern Hemisphere value of ∼0.2. The (236)U inventory of (8.4 ± 0.3) × 10(11) at/m(2) was more than an order of magnitude lower than values reported for the Northern Hemisphere. The (239)Pu activity concentrations are in excellent agreement with a previous study and the (239+240)Pu inventory was (13.85 ± 0.29) Bq/m(2). The weighted mean (240)Pu/(239)Pu isotopic ratio of 0.142 ± 0.005 is slightly lower than the value for global fallout, but our results are consistent with the average ratio of 0.173 ± 0.027 for the southern equatorial region (0-30°S).

  7. Determination of Pu isotopes and 241Am in a reference fallout material using SF-ICP-MS.

    PubMed

    Zheng, Jian; Zhang, Yongsan; Yamada, Masatoshi; Wu, Fengchang; Igarashi, Yasuhito; Hirose, Katsumi

    2011-07-01

    This paper reports on the characterisation of activities of Pu and (241)Am, and Pu isotopic composition in a reference fallout material prepared by the Meteorological Research Institute (MRI), Japan, from samples collected at 14 stations throughout Japan in 1963-1979. The acid leaching and total digestion were used to compare whether there is difference in Pu and (241)Am activities and Pu isotopic composition between these two methods. The results of activities of (239+240)Pu and (241)Pu, and Pu isotopic composition have been reported in the previous work (Sci. Total Environ. 2010, 408, 1139-1144). In this study, the (241)Am activity and (241)Am/(239+240)Pu activity ratio in the reference fallout material are reported, and the usefulness of Pu atom ratios and (241)Am/(239+240)Pu activity ratio for source identification is discussed.

  8. Development of an 241Am applicator for intracavitary irradiation of gynecologic cancers.

    PubMed

    Nath, R; Peschel, R E; Park, C H; Fischer, J J

    1988-05-01

    Sealed sources of 241Am that emit primarily 60 keV photons produce relative dose distributions in water comparable to those from 137Cs or 226Ra sources and can produce dose rates of up to 100 cGy/hr at 1 cm in water. Also, 241Am gamma rays can be effectively shielded by thin layers of high atomic number materials (HVL is 1/8th mm of lead) placed on the applicator or inside some body cavities (for example, hypaque in bladder, barium sulphate in rectum). These properties of 241Am sources open a new approach to optimizing intracavitary irradiation of various cancers by allowing a reduction in dose and volume of irradiated critical organs or by increasing tumor doses. The relative ease with which highly effective shielding is achievable with 241Am sources would allow the design and fabrication of partially shielded applicators which can produce asymmetric dose distributions to allow unidirectional irradiation of localized lesions. Design and dosimetry characteristics of a gynecological applicator containing 241Am sources are presented. The applicator consists of a 2, 3, or 4 segment vaginal plaque (loaded with 2 and 5 Ci 241Am sources) and a tandem made up of a single 8 Ci 241Am source. Dose rates at 2 cm from the plaques are 42.0, 47.4, 58.3 and 56.7 cGy/hr for 5-5, 5-4-5, 5-5-5, and 5-4-4-5 Ci plaques, respectively. The 5-4-5 Ci plaque in combination with the 8 Ci tandem produces dose rates of 60.0 and 22.8 cGy/hr to points A and B, respectively. Surface dose rates on the plaque applicators are 143, 124, 142 and 132 cGy/hr for 5-5, 5-4-5, 5-5-5 and 5-4-4-5 Ci applicators, respectively. The shielding effect of a 0.5 mm thick lead foil on one side of the 5-4-5 Ci applicator is found to be a factor of 16.8; for example, the dose rate at 2 cm from the unshielded side is 42.0 cGy/hr compared to a dose rate of 2.5 cGy/hr at 2 cm from the shielded side. Initial clinical experience with this applicator in the treatment of recurrent gynecological lesions is also presented

  9. Ultra-trace analysis of plutonium by thermal ionization mass spectrometry with a continuous heating technique without chemical separation.

    PubMed

    Lee, Chi-Gyu; Suzuki, Daisuke; Esaka, Fumitaka; Magara, Masaaki; Song, Kyuseok

    2015-08-15

    Thermal ionization mass spectrometry (TIMS) with a continuous heating technique is known as an effective method for measuring the isotope ratio in trace amounts of uranium. In this study, the analytical performance of thermal ionization mass spectrometry with a continuous heating technique was investigated using a standard plutonium solution (SRM 947). The influence of the heating rate of the evaporation filament on the precision and accuracy of the isotope ratios was examined using a plutonium solution sample at the fg level. Changing the heating rate of the evaporation filament on samples ranging from 0.1fg to 1000fg revealed that the influence of the heating rate on the precision and accuracy of the isotope ratios was slight around the heating rate range of 100-250mA/min. All of the isotope ratios of plutonium (SRM 947), (238)Pu/(239)Pu, (240)Pu/(239)Pu, (241)Pu/(239)Pu and (242)Pu/(239)Pu, were measured down to sample amounts of 70fg. The ratio of (240)Pu/(239)Pu was measured down to a sample amount of 0.1fg, which corresponds to a PuO2 particle with a diameter of 0.2μm. Moreover, the signals of (239)Pu could be detected with a sample amount of 0.03fg, which corresponds to the detection limit of (239)Pu of 0.006fg as estimated by the 3-sigma criterion. (238)Pu and (238)U were clearly distinguished owing to the difference in the evaporation temperature between (238)Pu and (238)U. In addition, (241)Pu and (241)Am formed by the decay of (241)Pu can be discriminated owing to the difference in the evaporation temperature. As a result, the ratios of (238)Pu/(239)Pu and (241)Pu/(239)Pu as well as (240)Pu/(239)Pu and (242)Pu/(239)Pu in plutonium samples could be measured by TIMS with a continuous heating technique and without any chemical separation processes.

  10. Ultra-trace analysis of plutonium by thermal ionization mass spectrometry with a continuous heating technique without chemical separation.

    PubMed

    Lee, Chi-Gyu; Suzuki, Daisuke; Esaka, Fumitaka; Magara, Masaaki; Song, Kyuseok

    2015-08-15

    Thermal ionization mass spectrometry (TIMS) with a continuous heating technique is known as an effective method for measuring the isotope ratio in trace amounts of uranium. In this study, the analytical performance of thermal ionization mass spectrometry with a continuous heating technique was investigated using a standard plutonium solution (SRM 947). The influence of the heating rate of the evaporation filament on the precision and accuracy of the isotope ratios was examined using a plutonium solution sample at the fg level. Changing the heating rate of the evaporation filament on samples ranging from 0.1fg to 1000fg revealed that the influence of the heating rate on the precision and accuracy of the isotope ratios was slight around the heating rate range of 100-250mA/min. All of the isotope ratios of plutonium (SRM 947), (238)Pu/(239)Pu, (240)Pu/(239)Pu, (241)Pu/(239)Pu and (242)Pu/(239)Pu, were measured down to sample amounts of 70fg. The ratio of (240)Pu/(239)Pu was measured down to a sample amount of 0.1fg, which corresponds to a PuO2 particle with a diameter of 0.2μm. Moreover, the signals of (239)Pu could be detected with a sample amount of 0.03fg, which corresponds to the detection limit of (239)Pu of 0.006fg as estimated by the 3-sigma criterion. (238)Pu and (238)U were clearly distinguished owing to the difference in the evaporation temperature between (238)Pu and (238)U. In addition, (241)Pu and (241)Am formed by the decay of (241)Pu can be discriminated owing to the difference in the evaporation temperature. As a result, the ratios of (238)Pu/(239)Pu and (241)Pu/(239)Pu as well as (240)Pu/(239)Pu and (242)Pu/(239)Pu in plutonium samples could be measured by TIMS with a continuous heating technique and without any chemical separation processes. PMID:25966386

  11. Sources and distributions of 137Cs, 238Pu, 239,240Pu radionuclides in the north-western Barents Sea.

    PubMed

    Zaborska, Agata; Mietelski, Jerzy Wojciech; Carroll, JoLynn; Papucci, Carlo; Pempkowiak, Janusz

    2010-04-01

    Sediment deposits are the ultimate sink for anthropogenic radionuclides entering the marine environment. The major sources of anthropogenic radionuclides to the Barents Sea are fallout from nuclear weapons tests, long range transport from other seas, and river and non-point freshwater supplies. In this study we investigated activity concentrations, ratios, and inventories of the anthropogenic radionuclides, 137Cs, 238Pu, 239,240Pu in dated sediment cores collected along a north-south transect in the northwestern Barents Sea. The data were used to evaluate the influence of different sources on the derived spatial and temporal patterns of anthropogenic radionuclides in seafloor sediment deposits. Activity concentrations of 137Cs ranged from <0.1 Bq/kg to 10.5 Bq/kg while 239,240Pu ranged from <0.01 Bq/kg to 2.74 Bq/kg and 238Pu activity concentrations ranged from <0.01 Bq/kg to 0.22 Bq/kg. Total inventories of 137Cs ranged from 29.5+/-1.5 Bq/m2 to 152.7+/-5.6 Bq/m2 and for 239,240Pu inventories (6 sediment layers only) ranged from 9.5+/-0.3 Bq/m2 to 29.7+/-0.4 Bq/m2. Source contributions varied among stations and between the investigated radionuclides. The 238Pu/239,240Pu ratios up to 0.18 indicate discharges from nuclear fuel reprocessing plants as a main contributor of plutonium. Based on 238Pu/239,240Pu ratio, it was calculated that up to 19-27% of plutonium is supplied from sources other than atmospheric global fallout. Taking into account Atlantic current flow trajectories and that both activity concentrations and inventories of plutonium negatively correlate with latitude, Sellafield is a major source for the Barents Sea. Concentrations and inventories of 137Cs correlate positively with latitude and negatively with distance from the Svalbard archipelago. The 137Cs concentrations are highest in an area of intensive melting of sea ice formed along the Siberian coast. Thus, sea ice and supplies from Svalbard may be important source of 137Cs to the Barents Sea

  12. Effect of Fe2+ Oxidation on the Removal of 238Pu from Neptunium Solution by Anion Exchange

    SciTech Connect

    KYSER, EDWARD

    2004-06-01

    The effect of ferrous sulfamate (FS) oxidation and variation in nitric acid concentration on the removal of {sup 238}Pu contamination from Np by the HB-Line anion exchange flowsheet has been tested. Significant rejection of {sup 238}Pu was observed by washing with a reductive wash solution containing 6.0 to 6.8 M nitric acid (HNO{sub 3}) with as little as 30% of the Fe{sup 2+} from the FS remaining in its reduced form. To achieve the desired 30% removal of {sup 238}Pu from the process, conditions should be controlled to maintain the Fe{sup 2+}/Fe{sup 3+} ratio in the reductive wash to be greater than 60%/40% (or 1.5). Since Fe{sup 2+} oxidation is strongly affected by temperature and nitric acid concentration, these parameters (as well as time after FS addition) need to be controlled to ensure predictable results. A shortened-height column was utilized in these tests to match changes in the plant equipment. Lab experiments scaled to plant batch sizes of 2000 g Np were observed with modest losses for ''up-flow'' washing. The following are recommended conditions for removing {sup 238}Pu from Np solutions by anion exchange in HB-Line: (1) Feed conditions: ''Up-flow'' 6.4-8.0 M HNO{sub 3}, 0.02 M hydrazine (N{sub 2}H{sub 4}), 0.05 M excess FS. (2) Reductive Wash conditions: ''Up-flow'' 6 Bed volumes (BV) of 6.4 M HNO{sub 3}, 0.05 M FS (minimum 0.03M Fe{sup 2+} during wash cycle), 0.05 M hydrazine, less than 1.8 mL/min/cm{sup 2} flowrate. (3) Decontamination Wash conditions: ''Up-flow'' 1-2 BV of 6.4-8.0 M HNO{sub 3}, no FS, no hydrazine, less than 1.8 mL/min/cm{sup 2} flowrate. (4) Elution conditions: ''Down-flow'' 0.17 M HNO{sub 3}, 0.05 M hydrazine, no FS.

  13. 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

  14. Evaluating the 239Pu prompt fission neutron spectrum induced by thermal to 30 MeV neutrons

    DOE PAGES

    Neudecker, Denise; Talou, Patrick; Kawano, Toshihiko; Kahler, Albert Comstock; Rising, Michael Evan; White, Morgan Curtis

    2016-03-15

    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. In conclusion, selected evaluation results and first benchmarkmore » calculations using this evaluation are briefly discussed.« less

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

    NASA Astrophysics Data System (ADS)

    Lal, R.; Tims, S. G.; Fifield, L. K.; Wasson, R. J.; Howe, D.

    2013-01-01

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

  16. 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.

  17. Fission Product Yield Study of 235U, 238U and 239Pu Using Dual-Fission Ionization Chambers

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    To resolve long-standing differences between LANL and LLNL regarding the correct fission basis for analysis of nuclear test data [M.B. Chadwick et al., Nucl. Data Sheets 111, 2891 (2010); H. Selby et al., Nucl. Data Sheets 111, 2891 (2010)], a collaboration between TUNL/LANL/LLNL has been established to perform high-precision measurements of neutron induced fission product yields. The main goal is to make a definitive statement about the energy dependence of the fission yields to an accuracy better than 2-3% between 1 and 15 MeV, where experimental data are very scarce. At TUNL, we have completed the design, fabrication and testing of three dual-fission chambers dedicated to 235U, 238U, and 239Pu. The dual-fission chambers were used to make measurements of the fission product activity relative to the total fission rate, as well as for high-precision absolute fission yield measurements. The activation method was employed, utilizing the mono-energetic neutron beams available at TUNL. Neutrons of 4.6, 9.0, and 14.5 MeV were produced via the 2H(d,n)3He reaction, and for neutrons at 14.8 MeV, the 3H(d,n)4He reaction was used. After activation, the induced γ-ray activity of the fission products was measured for two months using high-resolution HPGe detectors in a low-background environment. Results for the yield of seven fission fragments of 235U, 238U, and 239Pu and a comparison to available data at other energies are reported. For the first time results are available for neutron energies between 2 and 14 MeV.

  18. Distribution characteristics of ¹³⁷Cs, Pu isotopes and ²⁴¹Am in soil in Korea.

    PubMed

    Lee, S H; Oh, J S; Lee, J M; Lee, K B; Park, T S; Lujaniene, G; Valiulis, D; Sakalys, J

    2013-11-01

    Cesium-137, Plutonium isotopes and (241)Am were studied in soil samples collected from Korea between 2006 and 2008 to provide information on the distribution and origin of Pu isotopes and (241)Am. The vertical profiles of radionuclides showed higher activity concentrations at the surface layer and then gradually decreased with depth. A good correlation between (137)Cs and (239,240)Pu was observed, whereas a poor relationship between (137)Cs and (241)Am was found. The (238)Pu/(239,240)Pu, (241)Am/(239,240)Pu and (239,240)Pu/(137)Cs activity ratios were concordant to those of the global fallout ratios. Furthermore, the atomic ratios of (240)Pu/(239)Pu in the samples provided the information of Pu depositional history and the origin of Pu isotopes in Korea.

  19. Measurement of the {sup 241}Am({gamma},n){sup 240}Am reaction in the giant dipole resonance region

    SciTech Connect

    Tonchev, A. P.; Howell, C. R.; Hutcheson, A.; Kwan, E.; Raut, R.; Rusev, G.; Tornow, W.; Hammond, S. L.; Huibregtse, C.; Kelley, J. H.; Kawano, T.; Vieira, D. J.; Wilhelmy, J. B.

    2010-11-15

    The photodisintegration cross section of the radioactive nucleus {sup 241}Am has been obtained using activation techniques and monoenergetic {gamma}-ray beams from the HI{gamma}S facility. The induced activity of {sup 240}Am produced via the {sup 241}Am({gamma},n) reaction was measured in the energy interval from 9 to 16 MeV utilizing high-resolution {gamma}-ray spectroscopy. The experimental data for the {sup 241}Am({gamma},n) reaction in the giant dipole resonance energy region are compared with statistical nuclear-model calculations.

  20. Precision Cross Section Measurement for the ^241Am(γ,n) Reaction at HIγS

    NASA Astrophysics Data System (ADS)

    Tonchev, A.; Hutcheson, A.; Howell, C. R.; Kwan, E.; Rusev, G.; Tornow, W.; Hammond, S.; Karwowski, H. J.; Huibregtse, C.; Kelley, J. H.; Vieira, D. L.; Wilhelmy, J. B.; Stoyer, M. A.

    2008-10-01

    The photodisintegration cross section on radioactive ^241Am target has been measured for the first time using monoenergetic γ-ray beams from the HIγS facility. Induced activity from ^240Am produced via the (γ,n) reaction was measured by the activation technique using high resolution HPGe detectors. The (γ,n) cross section was determined both by measuring the absolute γ-flux and by comparison to the ^197Au(γ,n) cross section used as a standard. In the following, we report new data for the excitation function of the ^241Am(γ,n ) reaction from near threshold to 16 MeV incident γ-ray energy and we compare the data with statistical nuclear-model calculations performed with the GNASH, EMPIRE, and TALYS codes.

  1. Measurement of the ^241Am(n,2n) Reaction Cross Section with the Activation Technique

    NASA Astrophysics Data System (ADS)

    Tonchev, A.; Crowell, A.; Fallin, B.; Howell, C.; Hutcheson, A.; Tornow, W.; Kelley, J.; Angell, C.; Karwowski, H.; Pedroni, R.; Becker, J.; Dashdorj, D.; Macri, R.; Wilhelmy, J.; Bond, E.; Fitzpatrick, J.; Slemmons, A.; Vieira, D.

    2006-10-01

    High-precision measurements of the ^241Am(n,2n)^240Am reaction have been performed with neutron energies from 8.8 to 14.0 MeV. The monoenergetic neutron beams were produced via the ^2H(d,n)^3He reaction using the 10 MV Tandem accelerator at TUNL. The radioactive targets consisted of 1mg highly-enriched ^241Am sandwiched between four different thin monitor foils. They were irradiated with a neutron flux of 3x10^7 n cm-2 s-1. After each irradiation the induced activity in the targets and monitors was measured off-line with 60% HPGe detectors. Our preliminary neutron induced cross sections will be compared with recent literature results and statistical model calculations using the GNASH and EMPIRE codes.

  2. AN INTERLABORATORY COMPARISON ON THE DETERMINATION OF 241Am, 244Cm AND 252Cf IN URINE.

    PubMed

    Gerstmann, Udo C; Taubner, Kerstin; Hartmann, Martina

    2016-09-01

    An intercomparison exercise on the determination of (241)Am, (244)Cm and (252)Cf in urine was performed. Since it was designed with regard to emergency preparedness, the detection limit for each nuclide was set to 0.1 Bq per 24-h urine sample. Most of the participating laboratories were established bioassay laboratories. However, some laboratories that routinely determine (241)Am only in environmental samples were also invited in order to explore their potential for emergency bioassay analysis. Another aspect of the intercomparison was to investigate the performance of all laboratories concerning the chemical yields of the (243)Am tracer in comparison with (244)Cm and (252)Cf. In summary, both types of laboratories showed good results. There was a negative bias for the results of (244)Cm and (252)Cf, which can be explained by slightly different radiochemical behaviours of americium, curium and californium and which is in agreement with results reported in the literature. PMID:26535001

  3. Investigation of the 241Am(n ,2 n )240Am cross section

    NASA Astrophysics Data System (ADS)

    Kalamara, A.; Vlastou, R.; Kokkoris, M.; Diakaki, M.; Tsinganis, A.; Patronis, N.; Axiotis, M.; Lagoyannis, A.

    2016-01-01

    The 241Am(n ,2 n )240Am reaction cross section has been measured at four energies, 10.0, 10.4, 10.8, and 17.1 MeV, by means of the activation technique, relative to the 27Al(n ,α )24Na reaction reference cross section. Quasi-monoenergetic neutron beams were produced via the 2H(d ,n )3He and the 3H(d ,n )4He reactions at the 5.5 MV Tandem T11/25 accelerator laboratory of NCSR "Demokritos". The high purity 241Am targets were provided by JRC-IRMM, Geel, Belgium. The induced γ -ray activity of 240Am was measured with high-resolution high-purity germanium (HPGe) detectors. Auxiliary Monte Carlo simulations were performed with the mcnp code. The present results are in agreement with data obtained earlier and predictions obtained with the empire code.

  4. Standardization of 241Am by digital coincidence counting, liquid scintillation counting and defined solid angle counting.

    PubMed

    Balpardo, C; Capoulat, M E; Rodrigues, D; Arenillas, P

    2010-01-01

    The nuclide (241)Am decays by alpha emission to (237)Np. Most of the decays (84.6%) populate the excited level of (237)Np with energy of 59.54 keV. Digital coincidence counting was applied to standardize a solution of (241)Am by alpha-gamma coincidence counting with efficiency extrapolation. Electronic discrimination was implemented with a pressurized proportional counter and the results were compared with two other independent techniques: Liquid scintillation counting using the logical sum of double coincidences in a TDCR array and defined solid angle counting taking into account activity inhomogeneity in the active deposit. The results show consistency between the three methods within a limit of a 0.3%. An ampoule of this solution will be sent to the International Reference System (SIR) during 2009. Uncertainties were analysed and compared in detail for the three applied methods. PMID:20031433

  5. Standardization of 241Am by digital coincidence counting, liquid scintillation counting and defined solid angle counting.

    PubMed

    Balpardo, C; Capoulat, M E; Rodrigues, D; Arenillas, P

    2010-01-01

    The nuclide (241)Am decays by alpha emission to (237)Np. Most of the decays (84.6%) populate the excited level of (237)Np with energy of 59.54 keV. Digital coincidence counting was applied to standardize a solution of (241)Am by alpha-gamma coincidence counting with efficiency extrapolation. Electronic discrimination was implemented with a pressurized proportional counter and the results were compared with two other independent techniques: Liquid scintillation counting using the logical sum of double coincidences in a TDCR array and defined solid angle counting taking into account activity inhomogeneity in the active deposit. The results show consistency between the three methods within a limit of a 0.3%. An ampoule of this solution will be sent to the International Reference System (SIR) during 2009. Uncertainties were analysed and compared in detail for the three applied methods.

  6. Postmortem tissue contents of {sup 241}Am in a person with a massive acute exposure

    SciTech Connect

    McInroy, J.F.; Kathren, R.L.; Toohey, R.E. |

    1995-09-01

    {sup 241}Am was determined radiochemically in the tissues of USTUR Case 246, a 76-y-old man who died of cardiovascular disease 11 y after massive percutaneous exposure following a chemical explosion in a glove box. This worker was treated extensively with a chelation drug, DTPA, for over 4 y after exposure. The estimate {sup 241}Am deposition at the time of death was 540 kBq, of which 90% was in the skeleton, 5.1% in the liver, and 3.5% in muscle and fat. Among the soft tissues, the highest concentrations were observed in liver (22 Bq g{sup -1}), certain cartilaginous structures such as the larynx (15 Bq g{sup -1}) and the red marrow (9.7 Bq g{sup -1}), as compared with the mean soft tissue concentration of approximately 1 Bq g{sup -1}. Concentration in muscle was approximately that of the soft tissue average, while concentrations in the pancreas, a hilar lymph node and fat were less than the average. Concentrations in bone ash were inversely related to the ratio of ash weight to wet weight a surrogate for bone volume-to-surface ratio. the distribution of activity in this case is reasonable consistent with that observed in another human case, when allowance is made for chelation therapy, and also tends to support more recent models of {sup 241}Am metabolism. 26 refs., 2 figs., 4 tabs.

  7. High-silicon {sup 238}PuO{sub 2} fuel characterization study: Half module impact tests

    SciTech Connect

    Reimus, M.A.H.

    1997-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of [sup 238]Pu decay to an array of thermoelectric elements. The modular GPHS design was developed to address both survivability during launch abort and return from orbit. Previous testing conducted in support of the Galileo and Ulysses missions documented the response of GPHSs to a variety of fragment- impact, aging, atmospheric reentry, and Earth-impact conditions. The evaluations documented in this report are part of an ongoing program to determine the effect of fuel impurities on the response of the heat source to conditions baselined during the Galileo/Ulysses test program. In the first two tests in this series, encapsulated GPHS fuel pellets containing high levels of silicon were aged, loaded into GPHS module halves, and impacted against steel plates. The results show no significant differences between the response of these capsules and the behavior of relatively low-silicon fuel pellets tested previously.

  8. [Chromosome and cytome analysis of the somatic cells of nuclear-chemical production workers with incorporated 239Pu].

    PubMed

    Timoshevskiĭ, V A; Lebedev, I N; Vasil'ev, S A; Sukhanova, N N; Iakovleva, Iu S; Torkhova, N B; Puzyrev, V P

    2010-01-01

    The analysis of plutonium production factors has been carried out by using two methodical approaches: assessment of chromosomal aberrations level in routine and G-banded metaphases and molecular-cytogenetic investigation of aneugenic/clastogenic damages in cytokinesis-block binuclear lymphocytes by FISH with centromere specific DNA probes. The obtaining data point out for the first time about both aneugenic and clastogenic influences of incorporated 239Pu with activity range from 0.37 to 6.95 kBq. Correlation analysis of chromosome aberrations with cytome abnormalities allowed finding significant connection between number parameters of metaphase and interphase approaches. The results of this study support the suggestion that aberrant chromosomes are involved preferable in aneugenic events. The FISH technique in binucleated cytokinesis-blocked lymphocytes allows extending of detecting spectrum of chromosome damages and glance of aneugenic mechanisms. Correlations between metaphase and interphase-FISH results point out a high sensitivity of FISH cytome assay, which could be used as an independent test for detection both clastogenic and aneugenic environment influences.

  9. 240Pu/239Pu isotopic ratios and 239 + 240Pu total measurements in surface and deep waters around Mururoa and Fangataufa atolls compared with Rangiroa atoll (French Polynesia).

    PubMed

    Chiappini, R; Pointurier, F; Millies-Lacroix, J C; Lepetit, G; Hemet, P

    1999-09-30

    The average values of 240Pu/239Pu mass isotopic ratios of plutonium deposited in Mururoa and Fangataufa atoll sediments by French atmospheric nuclear tests range from 3.5 to 5%. In order to assess the near field and far field influence of those deposits in the open ocean, two water profiles were measured for 239 + 240Pu and 240Pu/239Pu using, for the first time, an Inductively Coupled Plasma Mass Spectrometer which was developed to achieve femtogram detection limits. One site was located at the limit of the French territorial waters, which is 22 km distant from Mururoa. The second site was located close to Rangiroa atoll, at a distance of approximately 1200-km from French nuclear test sites. The sample volumes were approximately 500 litres and plutonium was purified prior to mass spectrometry and alpha spectrometry measurements. In Rangiroa, the 239 + 240Pu profile is comparable with those already determined in world open oceans but the maximum detected activity, 9 mBq/m3 at 500-600 m is a lot lower than those measured in the northern hemisphere. 240Pu/239Pu ratios were measured between 500 and 1000 m and were not statistically different from the typical 0.18 +/- 0.01 ratio which characterises the global fallout. Consequently, any influence of plutonium from the tests in Mururoa and Fangataufa is not apparent at Rangiroa. The vertical distribution of 239 + 240Pu near Mururoa shows similar changes with depth but with a slight increase in concentration. 240Pu/239Pu mass ratios vary with depth, from 7 to 10% in the upper 500 m and in the deep waters (below 1000 m) to 15-16% between 600 and 1000 m. A contribution from plutonium deposited in the sediments at Mururoa and Fangataufa is observed at the limit of territorial waters, especially in surface and deep waters.

  10. 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.

  11. /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.

  12. Air concentrations of 239Pu and 240Pu and potential radiation doses to persons living near Pu-contaminated areas in Palomares, Spain.

    PubMed

    Iranzo, E; Salvador, S; Iranzo, C E

    1987-04-01

    On 17 January 1966, an accident during a refueling operation resulted in the destruction of an air force KC-135 tanker and a B-52 bomber carrying four thermonuclear weapons. Two weapons, whose parachutes opened, were found intact. The others experienced non-nuclear explosion with some burning and release of the fissile fuel at impact. Joint efforts by the United States and Spain resulted in remedial action and a long-term program to monitor the effectiveness of the cleanup. Air concentrations of 239Pu and 240Pu have been continuously monitored since the accident. The average annual air concentration for each location was used to estimate committed dose equivalents for individuals living and working around the air sampling stations. The average annual 239Pu and 240Pu air concentrations during the 15-y period corresponding to 1966-1980 and the potential committed dose equivalents for various tissues due to the inhalation of the 239Pu and 240Pu average annual air concentration during this period are shown and discussed in the report.

  13. Air concentrations of /sup 239/Pu and /sup 240/Pu and potential radiation doses to persons living near Pu-contaminated areas in Palomares, Spain

    SciTech Connect

    Iranzo, E.; Salvador, S.; Iranzo, C.E.

    1987-04-01

    On 17 January 1966, an accident during a refueling operation resulted in the destruction of an air force KC-135 tanker and a B-52 bomber carrying four thermonuclear weapons. Two weapons, whose parachutes opened, were found intact. The others experienced non-nuclear explosion with some burning and release of the fissile fuel at impact. Joint efforts by the United States and Spain resulted in remedial action and a long-term program to monitor the effectiveness of the cleanup. Air concentrations of /sup 239/Pu and /sup 240/Pu have been continuously monitored since the accident. The average annual air concentration for each location was used to estimate committed dose equivalents for individuals living and working around the air sampling stations. The average annual /sup 239/Pu and /sup 240/Pu air concentrations during the 15-y period corresponding to 1966-1980 and the potential committed dose equivalents for various tissues due to the inhalation of the /sup 239/Pu and /sup 240/Pu average annual air concentration during this period are shown and discussed in the report.

  14. Feasibility study of 235U and 239Pu characterization in radioactive waste drums using neutron-induced fission delayed gamma rays

    NASA Astrophysics Data System (ADS)

    Nicol, T.; Pérot, B.; Carasco, C.; Brackx, E.; Mariani, A.; Passard, C.; Mauerhofer, E.; Collot, J.

    2016-10-01

    This paper reports a feasibility study of 235U and 239Pu characterization in 225 L bituminized waste drums or 200 L concrete waste drums, by detecting delayed fission gamma rays between the pulses of a deuterium-tritium neutron generator. The delayed gamma yields were first measured with bare samples of 235U and 239Pu in REGAIN, a facility dedicated to the assay of 118 L waste drums by Prompt Gamma Neutron Activation Analysis (PGNAA) at CEA Cadarache, France. Detectability in the waste drums is then assessed using the MCNPX model of MEDINA (Multi Element Detection based on Instrumental Neutron Activation), another PGNAA cell dedicated to 200 L drums at FZJ, Germany. For the bituminized waste drum, performances are severely hampered by the high gamma background due to 137Cs, which requires the use of collimator and shield to avoid electronics saturation, these elements being very penalizing for the detection of the weak delayed gamma signal. However, for lower activity concrete drums, detection limits range from 10 to 290 g of 235U or 239Pu, depending on the delayed gamma rays of interest. These detection limits have been determined by using MCNPX to calculate the delayed gamma useful signal, and by measuring the experimental gamma background in MEDINA with a 200 L concrete drum mock-up. The performances could be significantly improved by using a higher interrogating neutron emission and an optimized experimental setup, which would allow characterizing nuclear materials in a wide range of low and medium activity waste packages.

  15. 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.

  16. Air concentrations of 239Pu and 240Pu and potential radiation doses to persons living near Pu-contaminated areas in Palomares, Spain.

    PubMed

    Iranzo, E; Salvador, S; Iranzo, C E

    1987-04-01

    On 17 January 1966, an accident during a refueling operation resulted in the destruction of an air force KC-135 tanker and a B-52 bomber carrying four thermonuclear weapons. Two weapons, whose parachutes opened, were found intact. The others experienced non-nuclear explosion with some burning and release of the fissile fuel at impact. Joint efforts by the United States and Spain resulted in remedial action and a long-term program to monitor the effectiveness of the cleanup. Air concentrations of 239Pu and 240Pu have been continuously monitored since the accident. The average annual air concentration for each location was used to estimate committed dose equivalents for individuals living and working around the air sampling stations. The average annual 239Pu and 240Pu air concentrations during the 15-y period corresponding to 1966-1980 and the potential committed dose equivalents for various tissues due to the inhalation of the 239Pu and 240Pu average annual air concentration during this period are shown and discussed in the report. PMID:3570788

  17. Electronic structure of polycrystalline Cd metal using {sup 241}Am radioisotope

    SciTech Connect

    Dhaka, M. S.; Sharma, G.; Mishra, M. C.; Sharma, B. K.

    2014-04-24

    Electronic structure study of the polycrystalline cadmium metal is reported. The experimental measurement is undertaken on a polycrystalline sheet sample using 59.54 keV radioisotope of {sup 241}Am. These results are compared with the ab initio calculations. The theoretical calculations are performed using linear combination of atomic orbitals (LCAO) method employing the density functional theories (DFT) and Hartree-Fock (HF) and augmented plane wave (APW) methods. The spherically averaged APW and LCAO based theoretical Compton profiles are in good agreement with the experimental measurement however the APW based theoretical calculations show best agreement.

  18. 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

  19. Determination of (n,γ) Cross Sections of 241Am by Cold Neutron Activation

    NASA Astrophysics Data System (ADS)

    Genreith, C.; Rossbach, M.; Révay, Zs.; Kudejova, P.

    2014-05-01

    Accurate cross section data of actinides are crucial for criticality calculations of GEN IV reactors and transmutation but also for analytical purposes such as nuclear waste characterization, decommissioning of nuclear installations and safeguard applications. Tabulated data are inconsistent and sometimes associated with large uncertainties. Neutron activation with external cold neutron beams from high flux reactors offers a chance for determination of accurate capture cross sections scalable to the whole 1/√{E}-region even for isotopes with low-lying resonances like 241Am. Preparation of 241Am samples for irradiation at the PGAA station of the FRM II in Garching has been optimized together with PTB in Braunschweig. Two samples were irradiated together with gold flux monitors to extract the thermal neutron capture cross section after appropriate corrections for attenuation of neutrons and photons in the sample. For one sample, the thermal ground state neutron capture cross section was measured as 663.0 ± 28.8 b. The thermal neutron capture cross section was calculated to 725.4 ± 34.4 b. For the other sample, a ground state neutron capture cross section of 649.9 ± 28.2 b was measured and a thermal neutron capture cross section of 711.1 ± 33.9 b was derived.

  20. Orally administered DTPA penta-ethyl ester for the decorporation of inhaled 241Am

    PubMed Central

    Sueda, Katsuhiko; Sadgrove, Matthew P.; Huckle, James E.; Leed, Marina G. D.; Weber, Waylon M.; Doyle-Eisele, Melanie; Guilmette, Raymond A.; Jay, Michael

    2014-01-01

    Diethylenetriaminepentaacetic acid (DTPA) is an effective decorporation agent to facilitate the elimination of radionuclides from the body, but its permeability-limited oral bioavailability limits its utility in mass-casualty emergencies. To overcome this limitation, a prodrug strategy using the penta-ethyl ester form of DTPA is under investigation. Pharmacokinetic and biodistribution studies were conducted in rats by orally administering [14C]DTPA penta-ethyl ester, and this prodrug and its hydrolysis products were analyzed as a single entity. Compared to a previous reporting of intravenously administered DTPA, the oral administration of this prodrug resulted in a sustained plasma concentration profile with higher plasma exposure and lower clearance. An assessment of the urine composition revealed that the bioactivation was extensive but incomplete, with no detectable levels of the penta- or tetra-ester forms. Tissue distribution at 12 h was limited, with approximately 73% of the administered dose being associated with the gastrointestinal tract. In the efficacy study, rats were exposed to aerosols of 241Am nitrate before receiving a single oral treatment of the prodrug. The urinary excretion of 241Am was found to be 19% higher than with the control. Consistent with prior reports of DTPA, the prodrug was most effective when the treatment delays were minimized. PMID:24619514

  1. Determination of 241Am in Urine Using Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICP-MS)

    PubMed Central

    Xiao, Ge; Saunders, David; Jones, Robert L.; Caldwell, Kathleen L.

    2016-01-01

    Quantification of 241Am in urine at low levels is important for assessment of individuals’ or populations’ accidental, environmental, or terrorism-related internal contamination, but no convenient, precise method has been established to rapidly determine these low levels. Here we report a new analytical method to measure 241Am as developed and validated at the Centers for Disease Control and Prevention (CDC) by means of the selective retention of Am from urine directly on DGA resin, followed by SF-ICP-MS detection. The method provides rapid results with a Limit of Detection (LOD) of 0.22 pg/L (0.028 Bq/L), which is lower than 1/3 of the C/P CDG for 241Am at 5 days post-exposure. The results obtained by this method closely agree with CDC values as measured by Liquid Scintillation Counting, and with National Institute of Standards Technology (NIST) Certified Reference Materials (CRM) target values. PMID:27375308

  2. Long-term exposure of /sup 238/PuO/sub 2/ to a terrestrial environment. Volume 2

    SciTech Connect

    Patterson, J.H.; Heaton, R.C.; Herrera, B.; Nelson, G.B.; Steinkruger, F.J.

    1983-09-01

    Two environmental simulation chambers were used to study the behavior of a /sup 238/PuO/sub 2/ heat source deposited in a humid, temperate environment. Large fragments from an impact-tested source were deposited in the first chamber, and fines from the source were placed in the second. Plutonium released into the soil, the soil drainages, and the condensates from the dehumidifiers were monitored throughout the experiment. The concentration of plutonium released into the soil drainages increased with time, obeying an apparent exponential growth curve over the duration of the experiment (5.7 yr). The bulk of the released plutonium, up to 0.3% of the source, was retained in the soil. A simulated cleanup operation at the conclusion of the experiment, which included removal of the source and the top inch of soil, resulted in an increased rate of plutonium release into the soil drainage and essentially no observable change of release rate into the air. Large chunks of PuO/sub 2/ deposited in one of the chambers underwent spontaneous disintegration into smaller pieces; after 2 yr the deposited material could barely be distinguished from the fines deposited in the other chamber.

  3. High-silicon {sup 238}PuO{sub 2} fuel characterization study: Half module impact tests

    SciTech Connect

    Reimus, M.A.

    1997-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements. The modular GPHS design was developed to address both survivability during launch abort and return from orbit. Previous testing conducted in support of the Galileo and Ulysses missions documented the response of GPHSs to a variety of fragment-impact, aging, atmospheric reentry, and Earth-impact conditions. The evaluations documented in this report are part of an ongoing program to determine the effect of fuel impurities on the response of the heat source to conditions baselined during the Galileo/Ulysses test program. In the first two tests in this series, encapsulated GPHS fuel pellets containing high levels of silicon were aged, loaded into GPHS module halves, and impacted against steel plates. The results show no significant differences between the response of these capsules and the behavior of relatively low-silicon fuel pellets tested previously. {copyright} {ital 1997 American Institute of Physics.}

  4. Multimode approach to {sup 241}Am and {sup 237}Np fission induced by 660-MeV protons

    SciTech Connect

    Karapetyan, G. S. Balabekyan, A. R.; Demekhina, N. A.; Adam, J.

    2009-06-15

    The results obtained by measuring cross sections for the formation of fragments originating from {sup 241}Am and {sup 237}Np fission induced by 660-MeV protons are presented. The charge and mass distributions of fragments are analyzed within the multimode-fission model, symmetric and asymmetric fission channels being separated. The contributions of various fission components are estimated, and the fission cross sections for the {sup 241}Am and {sup 237}Np nuclei are calculated along with the fissilities of these nuclei.

  5. Recovery of {sup 241}Am/Be neutron sources, Wooster, Ohio

    SciTech Connect

    Tompkins, J.A.; Wannigman, D.; Hatler, V.

    1998-07-01

    In August 1997, the Nuclear Regulatory Commission (NRC) submitted to the US Department of Energy (DOE) a partial list of licensed radioactive sealed sources to be recovered under a pilot project initiating Radioactive Source Recovery Program (RSRP) operations. The first of the pilot project recoveries was scheduled for September 1997 at Eastern Well Surveys in Wooster, Ohio, a company with five unwanted sealed sources on the NRC list. The sources were neutron emitters, each containing {sup 241}Am/Be with activities ranging from 2.49 to 3.0 Ci. A prior radiological survey had established that one of these sources, a Gulf Nuclear Model 71-1 containing 3 Ci of {sup 241}Am, was contaminated with {sup 241}Am and might be leaking. The other four sources were obsolete and could no longer be used by Eastern Well Surveys for their intended application in well-logging applications due to NRC decertification of these sources. All of the sources exceeded the limits established for Class C waste under 10 CFR 61.55 and, as a result, are the ultimate responsibility of the DOE under the provisions of PL 99-240. This report describes the cooperative effort between the DOE and NRC to recover the sources and transport them to Los Alamos National Laboratory (LANL) for deactivation under the RSRP. This operation alleviated any potential risk to the public health and safety from the site which might result from the leaking neutron sources or the potential mismanagement of unwanted sources. The on-site recovery occurred on September 23, 1997, and was performed by personnel from LANL and its contractor and was observed by staff from the Region III office of the NRC. All aspects of the recovery were successfully accomplished, and the sources were received at LANL on September 29, 1997. Experience gained during this operation will be used to formulate operational poilicies and procedures which will contribute to the eventual routine recovery operations of a full-scale RSRP.

  6. A calibration phantom for direct, in vivo measurement of 241Am in the axillary lymph nodes.

    PubMed

    Zeman, Rachel; Lobaugh, Megan; Spitz, Henry; Glover, Samuel; Hickman, David

    2009-09-01

    A calibration phantom was developed at the University of Cincinnati (UC) to determine detection efficiency and estimate the quantity of activity deposited in the axillary lymph nodes of a worker who had unknowingly sustained a wound contaminated with 241Am at some distant time in the past. This paper describes how the Livermore Torso Phantom was modified for calibrating direct, in vivo measurements of 241Am deposited in the axillary lymph nodes. Modifications involved milling a pair of parallel, flat bottom, cylindrical holes into the left and right shoulders (below the humeral head) of the Livermore Torso Phantom in which solid, 1.40-cm-diameter cylindrical rods were inserted. Each rod was fabricated using a muscle tissue substitute. One end of each rod contained a precisely known quantity of Am sealed in a 1-cm-diameter, 2.54-cm-deep well to simulate the axillary lymph nodes when inserted into the modified Livermore Torso Phantom. The fixed locations for the axillary lymph nodes in the phantom were determined according to the position of the Level I and the combined Level II + III axillary lymph nodes reported in the literature. Discrete calibration measurements for 241Am in the simulated axillary lymph nodes located in the right and left sides of the thorax were performed using pairs of high-resolution germanium detectors at UC and Lawrence Livermore National Laboratory. The percent efficiency for measuring the 59.5 keV photon from Am deposited in the right and left axillary lymph nodes using a pair of 3,000 mm2 detectors is 2.60 +/- 0.03 counts gamma-1 and 5.45 +/- 0.07 counts gamma-1, respectively. Activity deposited in the right and left axillary lymph nodes was found to contribute 12.5% and 19.7%, respectively, to a lung measurement and 1.2% and 0.2%, respectively, to a liver measurement. Thus, radioactive material mobilized from a wound in a finger or hand and deposited in the axillary lymph nodes has been shown to confound results of a direct, in vivo

  7. 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

  8. 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

  9. 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.

  10. Bone surface deposition of /sup 241/Am in a person with occupational exposure

    SciTech Connect

    Schlenker, R.A.; Oltman, B.G.; Kathren, R.L.

    1988-01-01

    We have measured the /sup 241/Am concentrations in the vicinity of bone surfaces in 11 samples of cortical bone from a man whose occupational exposure occurred 25 to 27 years before death. Concentrations in bone surface deposits ranged between 44 and 185 Bq/cm/sup 3/; concentrations in subjacent bone ranged between 0 and 8.4 Bq/cm/sup 3/. Thicknesses of the bone surface deposits were in the range 0.6 to 1.2 ..mu..m. An analysis of dose rates indicates that bone surface deposits contributed 40% or more of the terminal dose rate to bone surface tissues. Half-lives for the reduction of bone surface concentrations are estimated at 4.8 to 24 years, compared with the 100-year estimates obtained by using current ICRP methodologies. These data are important for the estimation of the dose rate to bone surface tissues for radiation protection. 10 refs., 3 figs., 1 tab.

  11. Comparison of bone lesions induced by inhaled sup 90 SrCl sub 2 or sup 238 PuO sub 2

    SciTech Connect

    Hahn, F.F.; Gillett, N.A.; Boecker, B.B.; Guilmette, R.A.; Muggenburg, B.A.

    1991-01-01

    Radionuclides inhaled in a soluble form translocate from the lung to other organs of the body. A frequent site of deposition and retention is the skeleton. If the dose delivered to the skeleton is high enough, bone tumors may result. Both {sup 90}SrCl{sub 2} and {sup 238}PuO{sub 2} are radionuclides that have induced bone neoplasms in Beagle dogs after inhalation exposure. In this paper, we compare and contrast the bone tumors induced by these two radionuclides that have emissions with widely different energy and linear energy transfer characteristics. The results show that the alpha-emitting radionuclide, {sup 238}Pu, induced primary bone cancers that were 89% osteosarcomas, primarily of the vertebra, pelvis and humerus. The beta-emitting radionuclide, {sup 90}Sr, induced bone cancers that were osteosarcomas, but included significant numbers of hemangiosacromas (29%). The tumors were primarly of the skull, rib, pelvis, and scapula. Radiation osteodystrophy was a frequent finding with {sup 238}Pu exposure, but rare with {sup 90}Sr exposure. In neither case, however, did radiation osteodystrophy appear necessary for the neoplastic process. 5 refs., 3 tabs.

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

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

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

  13. Cross-section measurements for 239Pu(n,f) and 6Li(n, α) with a lead slowing-down spectrometer

    NASA Astrophysics Data System (ADS)

    Rochman, D.; Haight, R. C.; O'Donnell, J. M.; Wender, S. A.; Vieira, D. J.; Bond, E. M.; Bredeweg, T. A.; Wilhelmy, J. B.; Granier, T.; Ethvignot, T.; Petit, M.; Danon, Y.; Romano, C.

    2006-08-01

    We present fission cross-section measurements with ˜10 ng of 239Pu performed using the LANSCE Lead Slowing-Down Spectrometer. Results of Li6(n,α) measurements with a sample size of 760 ng of 6Li are also reported. This technical achievement demonstrates the feasibility of measuring neutron-induced fission cross-section on samples with 10 ng of fissile actinides that are available on ultra-small quantities. Furthermore, results on neutron-induced alpha emission show that measurements for astrophysics purposes are feasible with the LSDS.

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

    PubMed

    Bu, Kaixuan; Cizdziel, James V; Dasher, Douglas

    2013-10-01

    Three underground nuclear tests, including the Unites States' largest, were conducted on Amchitka Island, Alaska. Monitoring of the radiological environment around the island is challenging because of its remote location. In 2008, the Department of Energy (DOE) Office of Legacy Management (LM) became responsible for the long term maintenance and surveillance of the Amchitka site. The first DOE LM environmental survey occurred in 2011 and is part of a cycle of activities that will occur every 5 years. The University of Alaska Fairbanks, a participant in the 2011 study, provided the lichen (Cladonia spp.), freshwater moss (Fontinalis neomexicanus), kelp (Eualaria fistulosa) and horse mussel (Modiolus modiolus) samples from Amchitka Island and Adak Island (a control site). These samples were analyzed for (239)Pu and (240)Pu concentration and (240)Pu/(239)Pu atom ratio using inductively coupled plasma sector field mass spectrometry (ICP-SFMS). Plutonium concentrations and (240)Pu/(239)Pu atom ratios were generally consistent with previous terrestrial and marine studies in the region. The ((239)+)(240)Pu levels (mBq kg(-1), dry weight) ranged from 3.79 to 57.1 for lichen, 167-700 for kelp, 27.9-148 for horse mussel, and 560-573 for moss. Lichen from Adak Island had higher Pu concentrations than Amchitka Island, the difference was likely the result of the higher precipitation at Adak compared to Amchitka. The (240)Pu/(239)Pu atom ratios were significantly higher in marine samples compared to terrestrial and freshwater samples (t-test, p < 0.001); lichen and moss averaged 0.184 ± 0.007, similar to the integrated global fallout ratio, whereas kelp and mussel (soft tissue) averaged 0.226 ± 0.003. These observations provide supporting evidence that a large input of isotopically heavier Pu occurred into the North Pacific Ocean, likely from the Marshall Island high yield nuclear tests, but other potential sources, such as the Kamchatka Peninsula Rybachiy Naval Base and

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

    PubMed

    Bu, Kaixuan; Cizdziel, James V; Dasher, Douglas

    2013-10-01

    Three underground nuclear tests, including the Unites States' largest, were conducted on Amchitka Island, Alaska. Monitoring of the radiological environment around the island is challenging because of its remote location. In 2008, the Department of Energy (DOE) Office of Legacy Management (LM) became responsible for the long term maintenance and surveillance of the Amchitka site. The first DOE LM environmental survey occurred in 2011 and is part of a cycle of activities that will occur every 5 years. The University of Alaska Fairbanks, a participant in the 2011 study, provided the lichen (Cladonia spp.), freshwater moss (Fontinalis neomexicanus), kelp (Eualaria fistulosa) and horse mussel (Modiolus modiolus) samples from Amchitka Island and Adak Island (a control site). These samples were analyzed for (239)Pu and (240)Pu concentration and (240)Pu/(239)Pu atom ratio using inductively coupled plasma sector field mass spectrometry (ICP-SFMS). Plutonium concentrations and (240)Pu/(239)Pu atom ratios were generally consistent with previous terrestrial and marine studies in the region. The ((239)+)(240)Pu levels (mBq kg(-1), dry weight) ranged from 3.79 to 57.1 for lichen, 167-700 for kelp, 27.9-148 for horse mussel, and 560-573 for moss. Lichen from Adak Island had higher Pu concentrations than Amchitka Island, the difference was likely the result of the higher precipitation at Adak compared to Amchitka. The (240)Pu/(239)Pu atom ratios were significantly higher in marine samples compared to terrestrial and freshwater samples (t-test, p < 0.001); lichen and moss averaged 0.184 ± 0.007, similar to the integrated global fallout ratio, whereas kelp and mussel (soft tissue) averaged 0.226 ± 0.003. These observations provide supporting evidence that a large input of isotopically heavier Pu occurred into the North Pacific Ocean, likely from the Marshall Island high yield nuclear tests, but other potential sources, such as the Kamchatka Peninsula Rybachiy Naval Base and

  16. 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.

  17. 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.

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

    DOE PAGES

    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

  19. 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.

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

    DOE PAGES

    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

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 241Pu and 241Am in sediments from coastal basins off California and Mexico

    NASA Astrophysics Data System (ADS)

    Koide, Minoru; Goldberg, Edward D.; Hodge, Vernon F.

    1980-07-01

    In sediments deposited in the coastal basins off the western North American continent since the early 1960's, there is more 241Am activity than one would predict if its presence was solely due to the decay of 241Pu that was produced during the testing of weapons in 1961-1962 (taken as July 1, 1962 for calculations). This excess can be accounted for by the decay of 241Pu, if pre-1962 fallout (fallout from the pre-moratorium testing) has been continuously introduced into the recent sediments along with fallout from post-moratorium testing. This hypothesis is supported by the plutonium depth profiles which do not reflect direct fallout from the atmosphere, as characterized by two peaks corresponding to the two major weapons testing periods, but continuously increasing plutonium and americium concentrations from 1954 to 1974. Thus, the nuclides may be coming from a large reservoir that has accumulated and mixed fallout since 1952. Such a concentration gradient for all of the nuclides requires their immobilization in the sediment after deposition.

  7. Partial-wave analysis of n +241Am reaction cross sections in the resonance region

    NASA Astrophysics Data System (ADS)

    Noguere, G.; Bouland, O.; Kopecky, S.; Lampoudis, C.; Schillebeeckx, P.; Plompen, A.; Gunsing, F.; Sage, C.; Sirakov, I.

    2015-07-01

    Cross sections for neutron-induced reactions of 241Am in the resonance region have been evaluated. Results of time-of-flight cross section experiments carried out at the GELINA, LANSCE, ORELA and Saclay facilities have been combined with optical model calculations to derive consistent cross sections from the thermal energy region up to the continuum region. Resolved resonance parameters were derived from a resonance shape analysis of transmissions, capture yields, and fission yields in the energy region up to 150 eV using the refit code. From a statistical analysis of these parameters, a neutron strength function (104S0=1.01 ±0.12 ), mean level spacing (D0=0.60 ±0.01 eV) and average radiation width (<Γγ 0>=43.3 ±1.1 meV) for s -wave resonances were obtained. Neutron strength functions for higher partial waves (l >0 ) together with channel and effective scattering radii were deduced from calculations based on a complex mean-field optical model potential, applying an equivalent hard-sphere scattering radius approximation.

  8. Plants as bio-monitors for Cs-137, Pu-238, Pu-239,240 and K-40 at the Savannah River Site.

    PubMed

    Caldwell, Eric Frank; Duff, Martine C; Ferguson, Caitlin E; Coughlin, Daniel P

    2011-05-01

    The Savannah River Site was constructed in South Carolina to produce plutonium (Pu) in the 1950s. Discharges associated with these now-ceased operations have contaminated large areas within the site, particularly streams associated with reactor cooling basins. Evaluating the exposure risk of contamination to an ecosystem requires methodologies that can assess the bioavailability of contaminants. Plants, as primary producers, represent an important mode of transfer of contaminants from soils and sediments into the food chain. The objective of this study was to identify local area plants for their ability to act as bio-monitors of radionuclides. The concentrations of cesium-137 ((137)Cs), potassium-40 ((40)K), (238)Pu and (239,240)Pu in plants and their associated soils were determined using γ and α spectrometry. The ratio of contamination concentration found in the plant relative to the soil was calculated to assess a concentration ratio (CR). The highest CR for (137)Cs was found in Pinus palustris needles (CR of 2.18). The correlation of soil and plant (137)Cs concentration was strong (0.76) and the R(2) (0.58) from the regression was significant (p = 0.006). This suggests the ability to predict the degree of (137)Cs contamination of a soil through analysis of the pine needles. The (238)Pu and (239,240)Pu concentrations were most elevated within the plant roots. Extremely high CR values were found in Sparganium americanum (bur-reed) roots with a value of 5.86 for (238)Pu and 5.66 for (239,240)Pu. The concentration of (40)K was measured as a known congener of (137)C. Comparing (40)K and (137)C concentrations in each plant revealed an inverse relationship for these radioisotopes. Correlating (40)K and (137)Cs was most effective in identifying plants that have a high affinity for (137)Cs uptake. The P. palustris and S. americanum proved to be particularly strong accumulators of all K congeners from the soil. Some species that were measured, warrant further

  9. Plants as bio-monitors for Cs-137, Pu-238, Pu-239,240 and K-40 at the Savannah River Site.

    PubMed

    Caldwell, Eric Frank; Duff, Martine C; Ferguson, Caitlin E; Coughlin, Daniel P

    2011-05-01

    The Savannah River Site was constructed in South Carolina to produce plutonium (Pu) in the 1950s. Discharges associated with these now-ceased operations have contaminated large areas within the site, particularly streams associated with reactor cooling basins. Evaluating the exposure risk of contamination to an ecosystem requires methodologies that can assess the bioavailability of contaminants. Plants, as primary producers, represent an important mode of transfer of contaminants from soils and sediments into the food chain. The objective of this study was to identify local area plants for their ability to act as bio-monitors of radionuclides. The concentrations of cesium-137 ((137)Cs), potassium-40 ((40)K), (238)Pu and (239,240)Pu in plants and their associated soils were determined using γ and α spectrometry. The ratio of contamination concentration found in the plant relative to the soil was calculated to assess a concentration ratio (CR). The highest CR for (137)Cs was found in Pinus palustris needles (CR of 2.18). The correlation of soil and plant (137)Cs concentration was strong (0.76) and the R(2) (0.58) from the regression was significant (p = 0.006). This suggests the ability to predict the degree of (137)Cs contamination of a soil through analysis of the pine needles. The (238)Pu and (239,240)Pu concentrations were most elevated within the plant roots. Extremely high CR values were found in Sparganium americanum (bur-reed) roots with a value of 5.86 for (238)Pu and 5.66 for (239,240)Pu. The concentration of (40)K was measured as a known congener of (137)C. Comparing (40)K and (137)C concentrations in each plant revealed an inverse relationship for these radioisotopes. Correlating (40)K and (137)Cs was most effective in identifying plants that have a high affinity for (137)Cs uptake. The P. palustris and S. americanum proved to be particularly strong accumulators of all K congeners from the soil. Some species that were measured, warrant further

  10. Counting 241Am in the BfS human skull phantom on contact-evaluation in the human monitoring laboratory.

    PubMed

    Li, Chunsheng; Hauck, Barry; Capello, Kevin; Nogueira, Pedro; Lopez, Maria A; Kramer, Gary H

    2015-03-01

    Skull counting can be used to assess the activity of radionuclides internally deposited in the bone. The Human Monitoring Laboratory (HML) at Health Canada conducted the measurement of 241Am in the BfS (Bundesamt für Strahlenschuts) skull phantom on contact with the skull for various positions. By placing the detector in contact, the HML can improve the counting efficiency by over 20% compared to placing the detector 1 cm above the surface of the skull. Among all the positions tested, the forehead position is the preferred counting geometry due to the design of HML's counting facility and the comfort it would provide to the individual being counted, although this counting position did not offer the highest counting efficiency for the gamma rays (either the 59.5 keV or the 26.3 keV) emitted by 241Am.

  11. Counting 241Am in the BfS human skull phantom on contact-evaluation in the human monitoring laboratory.

    PubMed

    Li, Chunsheng; Hauck, Barry; Capello, Kevin; Nogueira, Pedro; Lopez, Maria A; Kramer, Gary H

    2015-03-01

    Skull counting can be used to assess the activity of radionuclides internally deposited in the bone. The Human Monitoring Laboratory (HML) at Health Canada conducted the measurement of 241Am in the BfS (Bundesamt für Strahlenschuts) skull phantom on contact with the skull for various positions. By placing the detector in contact, the HML can improve the counting efficiency by over 20% compared to placing the detector 1 cm above the surface of the skull. Among all the positions tested, the forehead position is the preferred counting geometry due to the design of HML's counting facility and the comfort it would provide to the individual being counted, although this counting position did not offer the highest counting efficiency for the gamma rays (either the 59.5 keV or the 26.3 keV) emitted by 241Am. PMID:25627952

  12. 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.

  13. 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

  14. Development of the MICROMEGAS detector for measuring the energy spectrum of alpha particles by using a 241Am source

    NASA Astrophysics Data System (ADS)

    Kim, Do Yoon; Ham, Cheolmin; Shin, Jae Won; Park, Tae-Sun; Hong, Seung-Woo; Andriamonje, Samuel; Kadi, Yacine; Tenreiro, Claudio

    2016-05-01

    We have developed MICROMEGAS (MICRO MEsh GASeous) detectors for detecting a particles emitted from an 241Am standard source. The voltage applied to the ionization region of the detector is optimized for stable operation at room temperature and atmospheric pressure. The energy of a particles from the 241Am source can be varied by changing the flight path of the a particle from the 241Am source. The channel numbers of the experimentally-measured pulse peak positions for different energies of the a particles are associated with the energies deposited by the alpha particles in the ionization region of the detector as calculated by using GEANT4 simulations; thus, the energy calibration of the MICROMEGAS detector for a particles is done. For the energy calibration, the thickness of the ionization region is adjusted so that a particles may completely stop in the ionization region and their kinetic energies are fully deposited in the region. The efficiency of our MICROMEGAS detector for a particles under the present conditions is found to be ~97.3%.

  15. Influence of self-absorption corrections in the quantification of 210Pb and 241Am for sediment dating

    NASA Astrophysics Data System (ADS)

    González, J. Carrazana; Vargas, M. Jurado; Castillo, R. Gil

    2016-10-01

    The nuclides 210Pb and 241Am are used in geochronological studies. In this work, we examine the influence of the sediment chemical composition on the self-attenuation corrections needed for the accurate determination of specific activities for 210Pb and 241Am used for sediment dating. A theoretical exercise was carried out evaluating the relative bias obtained by four different analytical laboratories in the quantification of the 210Pb and 241Am activity concentration by gamma-ray spectrometry. The laboratories considered the same density for the sediment sample, but each one used a different chemical composition in the Monte Carlo calculations, and six different HPGe detectors (including n and p-types). An estimate of the impact that would have the relative biases found in the estimation of the 210Pb sediment ages, applying the Constant Rate of Supply (CRS) dating model, is also given. In addition, the performance scores that the laboratories would have obtained in a hypothetical IAEA proficiency test are also presented.

  16. 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.

  17. USTUR case 0259 whole body donation: a comprehensive test of the current ICRP models for the behavior of inhaled 238PuO2 ceramic particles. U.S. Transuranium and Uranium Registries.

    PubMed

    James, A C; Filipy, R E; Russell, J J; McInroy, J F

    2003-01-01

    An analysis of 238Pu in the whole body donation to the U.S. Transuranium and Uranium Registries (USTUR) is presented. This donor accidentally inhaled an unusual physical form of plutonium, predominantly the 238Pu isotope in the form of a highly insoluble ceramic. Along with six other workers accidentally exposed at the same time, this donor excreted little or no 238Pu in his urine for several months. Subsequently, however, and, with no further intakes, the urinary excretion of 238Pu by all of these workers increased progressively. Such a pattern of increasing urinary excretion of plutonium resulting from a single acute inhalation was unknown at the time. The subject of this study provided a unique opportunity to analyze not only the pattern of urinary excretion for 17 y following this unusual intake but also the complete distribution of 238Pu in his donated body tissues and skeleton at death. Radiochemical analyses of tissues from this whole body donation were used to perform critical tests of the applicability and accuracy of the respiratory tract model and the systemic biokinetic models for plutonium currently recommended by the International Commission on Radiological Protection. The respiratory tract model was applied to analyze the donor's long-term urinary excretion pattern. The facility provided by this model to represent progressive transformation of insoluble particles in the lungs into a more soluble form, applied in conjunction with the systemic biokinetic model, predicted the total amount of 238Pu measured in the donor's body to within 17% accuracy. The measured division of 238Pu between the donor's lungs and systemic organs was predicted to within 10%. Small adjustments to several rate constants in these models provided precise predictions of the absolute amounts of 238Pu in the lungs, thoracic lymph nodes, liver, red bone marrow, skeleton (including the distribution of 238Pu between trabecular and cortical bone matrices derived from the radiochemical

  18. Effect of various concentrations of DTPA chelating agent in soil on uptake and distribution of /sup 241/Am in bush bean plants

    SciTech Connect

    Wallace, A.; Romney, E.M.; Mueller, R.T.

    1981-07-01

    We grew bush bean plants in pots containing Yolo loam soil in a glasshouse for 15 days with a uniformly applied level of /sup 241/Am in soil and with various concentrations of DTPA applied to the soil. The objective was to demonstrate that the effects assigned to this chelating agent on uptake of /sup 241/Am by plants will vary with concentration of the chelating agent. On a concentration basis, the DTPA resulted in transport of much more /sup 241/Am into primary leaves than into trifoliate leaves. The ratio of /sup 241/Am in primary leaves to that in trifoliate leaves increased with increasing concentration of DTPA. The concentration ratios in each plant part also increased with increasing DTPA.

  19. The influence of internally deposited alpha ({sup 239}Pu) or beta-gamma ({sup 144}Ce) emitting radionuclides on the sensitivity of Chinese hamster bone marrow cells to {sup 60}CO induced chromosome aberrations

    SciTech Connect

    Brooks, A.L.; McDonald, K.E.; Kitchin, R.M.

    1994-12-31

    The current study was designed to determine if protracted low-dose-rate exposures from either high-({sup 239}Pu) or low-({sup 144}Ce) LET radiation from internally deposited radioactive materials changes the frequency of chromosome aberrations induced by acute {sup 60}Co exposure. THe potential for interaction was evaluated 30 days after injection with either 0 or 0.85 kBq {sup 144}Ce g{sup -1} body weight or 0.0 or 2.2 Bq of {sup 239}Pu g{sup -1}. Injection with {sup 239}Pu or {sup 144}Ce resulted in few aberrations in bone marrow cells 30 days after injection. The presence of internally deposited {sup 239}Pu or {sup 144}Ce did not significantly alter the total frequency of {sup 60}Co induced aberrations. However, the frequency of {sup 60}Co induced chromatid exchanges was significantly greater (P=0.03) in bone marrow cells of animals with {sup 144}Ce body burdens (0.14{+-}0.03 chromatid exchanges/cell). Such data illustrates that changes in cellular responsiveness may be dependent on the LET of the isotope, the dose rate of the primary dose and the type of damage being evaluated.

  20. Results of The Excreta Bioassay Quality Control Program For April 1, 2008 through March 31, 2009

    SciTech Connect

    Antonio, Cheryl L.

    2010-06-01

    A total of 62 urine samples and 6 spiked fecal samples were submitted during the report period (April 1, 2008 through March 31, 2009) 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. 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 34% 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. IDP concluded that GEL was performing well for all analyses tested, and concerns identified earlier were satisfactorily resolved (see section on Follow-up on Concerns During the Fourth Contract Year).

  1. Results of The Excreta Bioassay Quality Control Program For April 1, 2010 Through March 31, 2011

    SciTech Connect

    Antonio, Cheryl L.

    2012-07-19

    A total of 76 urine samples and 10 spiked fecal samples were submitted during the report period (April 1, 2010 through March 31, 2011) to GEL Laboratories, LLC in South Carolina by the Hanford Internal Dosimetry Program (IDP) to check the accuracy, precision, and detection levels of their analyses. Urine analyses for 14C, Sr, for 238Pu, 239Pu, 241Am, 243Am, 235U, 238U, 238U-mass and fecal analyses for 241Am, 238Pu and 239Pu were tested this year. The number of QC urine samples submitted during the report period represented 1.1% 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 31% of the analyses processed by GEL during the first year of contract 112512 were quality control samples. GEL tested the performance of 23 radioisotopes, all of which met or exceeded the specifications in the Statement of Work within statistical uncertainty except the slightly elevated relative bias for 243,244Cm (Table 4).

  2. Radionuclide concentrations in vegetation at radioactive-waste disposal Area G during the 1994 growing season

    SciTech Connect

    Fresquez, P.R.; Biggs, J.B.; Bennett, K.D.

    1995-07-01

    Overstory (pinon pine) and understory (grass and forb) vegetation samples were collected within and around selected points at Area G-a low-level radioactive solid-waste disposal facility at Los Alamos National Laboratory-for the analysis of tritium ({sup 3}H), strontium ({sup 90}Sr), plutonium ({sup 238} Pu and {sup 239}Pu), cesium ({sup 137}Cs), americium ({sup 241}Am), and total uranium. In general, most vegetation samples collected within and around Area G contained radionuclide levels in higher concentrations than vegetation collected from background areas. Tritium, in particular, was detected as high as 5,800 pCi/mL in overstory vegetation collected outside the fence just west of the tritium shafts; this suggests that tritium is migrating from this waste repository through subsurface pathways. Also, understory vegetation collected north of the transuranic (TRU) pads (outside the fence of Area G) contained the highest values of {sup 90}Sr, {sup 238}Pu, {sup 239}Pu, {sup 137}Cs, and {sup 241}Am, and may be a result of surface holding, storage, or disposal activities.

  3. Results Of The Excreta Bioassay Quality Control Program For April 1, 2007 Through March 31, 2008

    SciTech Connect

    Antonio, Cheryl L.

    2008-12-31

    A total of 79 urine samples, 3 blank fecal and 5 spiked artificial fecal samples were submitted during the report period (April 1, 2007 through March 31, 2008) 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 tritium, Sr, 238Pu, 239Pu, 241Am, 243Am 235U, 238U, elemental uranium and fecal analyses for 241Am, 238Pu and 239Pu were tested this year. The number of QC urine samples submitted during the report period represented 1.8% 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 35% of the analyses processed by GEL during the third year of this contract were quality control samples. GEL tested the performance of 24 radioisotopes, all of which met or exceeded the specifications in the Statement of Work within statistical uncertainty (Table 4). IDP concluded that GEL was performing well for all analyses tested, and concerns identified earlier were satisfactorily resolved.

  4. Minior Actinide Doppler Coefficient Measurement Assessment

    SciTech Connect

    Nolan E. Hertel; Dwayne Blaylock

    2008-04-10

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

  5. An attempt to decrease anisotropic emissions of neutrons from a cylindrical 241Am-Be-encapsulation source.

    PubMed

    Kowatari, M; Tanimura, Y; Yoshizawa, M

    2014-10-01

    An attempt to decrease the anisotropic emissions of neutrons from a cylindrical (241)Am-Be-encapsulated X3 source was conducted with Monte Carlo calculations and experiments. The influence of metal materials and shapes of the external casing to the anisotropy factor were focussed on. Results obtained by calculations using MCNP4C implied that a light and spherical-shaped external casing decreases the anisotropic emission of neutrons. Experimental results using the spherical-shaped aluminium protection case also revealed that the anisotropy factor was close to 1.0 with wide zenith angle ranges.

  6. Comparison of bone scans and radiography for detecting bone neoplasms in dogs exposed to /sup 238/PuO/sub 2/

    SciTech Connect

    Wolff, R.K.; Merickel, B.S.; Rebar, A.H.; Mewhinney, J.A.

    1980-11-01

    Radioisotopic bone scans and radiography were used to detect bone neoplasms in 144 dogs that inhaled alpha-particle-emitting /sup 238/PuO/sub 2/ particles. Radiography was used routinely to survey the skeleton of the dogs. Nineteen dogs developed bone neoplasms; 17 of these were studied with bone scans and radiography; both methods showed a high degree of success in detecting bone neoplasms. Predominant regions of occurrence have been the lumbar region of the spine and the humerus. The bone scanning method used gamma-camera detection of IV injected 99mTc-labeled methylene diphosphonate. All neoplasms detected radiographically also were identified by bone scans. In addition, 3 lesions confirmed histologically as osteosarcomas were detected by bone scanning, but were missed by radiography. Bone scanning was a more sensitive means for the detection of bone neoplasms than were routine radiographic procedures.

  7. Environmental and radiological safety studies: interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, April 1-June 30, 1981

    SciTech Connect

    Matlack, G.M.; Patterson, J.H.

    1981-09-01

    The containers for /sup 238/PuO/sub 2/ heat sources in radioisotope thermoelectric generators are designed with large safety factors to ensure they will withstand reentry from orbit and impact with the earth and safely contain the nuclear fuel until it is recovered. Existing designs have proved more than adequately safe, but the Space and Terrestrial Division of the Department of Energy Office of Advanced Nuclear Systems and Projects continually seeks more information about the heat sources to improve their safety. The work discussed here includes studies of the effects on the heat source of terrestrial and aquatic environments to obtain data for design of even safer systems. This report includes data from environmental chamber experiments that simulate terrestrial conditions, experiments to measure PuO/sub 2/ dissolution rates, soil column experiments to measure sorption of plutonium by soils, and several aquatic experiments.

  8. Gastrointestinal absorption of metals (51Cr, 65Zn, 95mTc, 109Cd, 113Sn, 147Pm, and 238Pu) by rats and swine.

    PubMed

    Sullivan, M F; Miller, B M; Goebel, J C

    1984-12-01

    Adult and neonatal rats and neonatal pigs were gavaged with solutions of metal radionuclides to determine gastrointestinal absorption. Zinc-65 and technetium-95m were well-absorbed by both age groups; chromium-51, cadmium-109, tin-113, promethium-147, and plutonium-238 were not. The quantities of the poorly absorbed metals that were absorbed by neonates were between 4 and 100 times higher than those absorbed by adult rats. Autoradiograms prepared from the entire small intestine of the neonatal rat showed that 109Cd was retained in the duodenum. In contrast, measurements in the piglets showed much higher 109Cd retention in the ileum than in the duodenum. Autoradiograms and radiochemical measurements of 147Pm and 238Pu in both neonatal rats and swine showed the highest level of retention in the ileum. The results indicate that, for most of the metals studied, absorption from the gastrointestinal tract is substantially higher for neonatal than for adult rats.

  9. Orally Administered DTPA Di-ethyl Ester for Decorporation of 241Am in dogs: Assessment of Safety and Efficacy in an Inhalation-Contamination Model

    PubMed Central

    Huckle, James E.; Sadgrove, Matthew P.; Pacyniak, Erik; Leed, Marina G. D.; Weber, Waylon M.; Doyle-Eisele, Melanie; Guilmette, Raymond A.; Agha, Bushra J.; Susick, Robert L.; Mumper, Russell J.; Jay, Michael

    2016-01-01

    Purpose Currently two injectable products of diethylenetriaminepentaacetic acid (DTPA) are U.S. Food and Drug Administration (FDA) approved for decorporation of 241Am, however, an oral product is considered more amenable in a mass casualty situation. The diethyl ester of DTPA, named C2E2, is being developed as an oral drug for treatment of internal radionuclide contamination. Materials and methods Single dose decorporation efficacy of C2E2 administered 24-hours post contamination was determined in beagle dogs using a 241Am nitrate inhalation contamination model. Single and multiple dose toxicity studies in beagle dogs were performed as part of an initial safety assessment program. In addition, the genotoxic potential of C2E2 was evaluated by the in vitro bacterial reverse mutation Ames test, mammalian cell chromosome aberration cytogenetic assay and an in vivo micronucleus test. Results Oral administration of C2E2 significantly increased 241Am elimination over untreated controls and significantly reduced the retention of 241Am in tissues, especially liver, kidney, lung and bone. Daily dosing of 200 mg/kg/day for 10 days was well tolerated in dogs. C2E2 was found to be neither mutagenic or clastogenic. Conclusions The di-ethyl ester of DTPA (C2E2) was shown to effectively enhance the elimination of 241Am after oral administration in a dog inhalation-contamination model and was well tolerated in toxicity studies. PMID:25912343

  10. Determination of Fission Product Yields of 235U, 238U and 239Pu for Neutron Energies from 0.5 to 14.8 MeV

    NASA Astrophysics Data System (ADS)

    Gooden, Matthew; Arnold, Charles; Becker, John; Bhatia, Chitra; Bhike, Megha; Fallin, Brent; Fowler, Malcolm; Howell, Calvin; Kelley, John; Stoyer, Mark; Tonchev, Anton; Tornow, Werner; Viera, David; Wilhelmy, Jerry

    2013-10-01

    A joint TUNL-LANL-LLNL collaboration has been formed to study the issue of possible energy dependences for fission product isotopes. Work has been carried out at the TUNL 10 MV Tandem accelerator which produces nearly mono-energetic neutrons via either 2H(d,n)3He,3H(d,n)4He, or 3H(p,n)3He reactions. Three dual fission ionization chambers dedicated to 235U, 238U and 239Pu thick target foils and thin monitor foils respectively, were exposed to the neutron beams. After irradiation, thick target foils were gamma counted over a period of 1-2 months and characteristic gamma rays from fission products were recorded using HPGe detectors at TUNL's low background counting area. Using the dual fission chambers fission product yields relative to total number of fissions were determined at a high precision of 2-3% as well as absolute fission product yields at a lower precision of 5-6%. Results will be presented for a number of fission product isotopes at 1.38, 4.6 and 14.8 MeV as well as preliminary results at 9 MeV.

  11. Energy Dependence of Neutron-Induced Fission Product Yields of 235U, 238U and 239Pu Between 0.5 and 14.8 MeV

    NASA Astrophysics Data System (ADS)

    Gooden, Matthew; Tornow, Werner; Tonchev, Anton; Vieira, Dave; Wilhelmy, Jerry; Arnold, Charles; Fowler, Malcolm; Stoyer, Mark

    2014-09-01

    Under a joint collaboration between TUNL-LANL-LLNL, a set of absolute fission product yield measurements have been performed. The energy dependence of a number of cumulative fission products between 0.5 and 14.8 MeV have been measured using quasi-monoenergetic neutron beams for three actinide targets, 235U, 238U and 239Pu, between 0.5 and 14.8 MeV. The FPYs were measured by a combination of activation utilizing specially designed dual-fission chambers and γ-ray counting. The dual-fission chambers are back-to-back ionization chambers encasing a target with thin deposits of the same target isotope in each chamber. This method allows for the direct measurement of the fission rate in the activation target with no reference to the fission cross-section, reducing uncertainties. γ-ray counting was performed on well-shield HPGe detectors over a period of 2 months per activation to properly identify fission products. Reported are absolute cumulative fission product yields for incident neutron energies of 0.5, 1.37, 2.4, 4.6 and 14.8 MeV.

  12. Determination of Fission Product Yields of 235U, 238U and 239Pu for Neutron Energies from 0.5 to 14.8 MeV

    NASA Astrophysics Data System (ADS)

    Gooden, Matthew; Arnold, Charles; Becker, John; Bhatia, Chitra; Bhike, Megha; Fowler, Malcolm; Howell, Calvin; Kelley, John; Stoyer, Mark; Tonchev, Anton; Tornow, Werner; Vieira, Dave; Wilhelmy, Jerry

    2014-03-01

    A joint TUNL-LANL-LLNL collaboration has been formed to study the issue of possible energy dependences for certain fission product isotopes. Work has been carried out at the TUNL 10 MV Tandem accelerator which produces nearly mono-energetic neutrons via either 2H(d,n)3He,3H(d,n)4He,or3H(p,n)3He reactions. Three dual fission ionization chambers dedicated to 235U, 238U and 239Pu thick target foils and thin monitor foils respectively, were exposed to the neutron beams. After irradiation, thick target foils were gamma counted over a period of 1-2 months and characteristic gamma rays from fission products were recorded using HPGe detectors at TUNL's low background counting area. Using the dual fission chambers, relative fission product yield were determined at a high precision of 2-3 % as well as absolute fission product yields at a lower precision of 5-6 %. Preliminary results will be presented for a number of fission product isotopes over the incident neutron energy range of 0.5 to 14.8 MeV.

  13. 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

  14. 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.

  15. 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.

  16. Accelerate the transition of radioisotopes or unwanted weapons-grade ^239Pu into stable nuclei with a system of high frequency modulation for a net energy gain

    NASA Astrophysics Data System (ADS)

    Pamfiloff, Eugene

    2006-10-01

    A process of high frequency stimulation of nucleons can be utilized for the accelerated fission, decay or controlled transition of unstable isotopes. For example ^238U could be persuaded to transition promptly into ^206Pb, where portions of the total mass difference of 29873.802 MeV per nucleus becomes available energy. The proposals of this paper describe an effective system for nuclei stimulation configured to accelerate such a series of 14 transitions over several milliseconds, instead of 4.47 x 10^9 years. Positive ions or ionized capsules of fuel suspended by magnetic fields and subjected to the system of correlated frequency modulation of multiple beam lines, tailored to the specific target, will emit sufficient energy to stimulate subsequent targets. The system can be applied to all radioisotopes, including ^232Th, nuclear waste product isotopes such as ^239Pu, and a variety of other suitable unstable or stable nuclei. Through the proposed confinement system and application of high frequency stimulation in the 10^22 to 10^24 Hz regime, the change in rest mass can be applied to both the fragmentation of subsequent, periodically injected targets, and the production of heat, making a continuous supply of energy possible. The system allows the particle fragmentation process to be brought into the laboratory and provides potential solutions to the safe disposal of fissile material.

  17. Accelerate the transition of radioisotopes and unwanted weapons-grade ^239Pu into stable nuclei with a system of high frequency modulation for a net energy gain

    NASA Astrophysics Data System (ADS)

    Pamfiloff, Eugene

    2006-10-01

    A process of high frequency stimulation of nucleons can be utilized for the accelerated fission, decay or controlled transition of unstable isotopes. ^238U could be persuaded to transition promptly into the stable ^206Pb isotope, where a portion of the total mass difference of 29873.802 MeV per nucleus becomes available energy. The proposals of this paper describe an effective system for nuclei stimulation configured to accelerate such a series of 14 transitions over several milliseconds, instead of 4.47 x 10^9 years. Positive ions or ionized capsules of fuel suspended by magnetic fields and subjected to the system of correlated frequency modulation of multiple beam lines, tailored to the specific target, will emit sufficient energy to stimulate subsequent targets. The system can be applied to all radioisotopes, nuclear waste product isotopes such as ^239Pu, and a variety of other suitable unstable or stable nuclei. Through the proposed confinement system and application of high frequency stimulation in the 10^22 to 10^24 Hz regime, the change in mass can be applied to both the fragmentation of subsequent, periodically injected targets, and the production of heat, making a continuous supply of energy possible. The system allows the particle fragmentation process to be brought into the lab and provides potential solutions to the safe disposal of fissile material.

  18. Accelerate the transition of radioisotopes and unwanted weapons-grade ^239Pu into stable nuclei with a system of high frequency modulation for a net energy gain

    NASA Astrophysics Data System (ADS)

    Pamfiloff, Eugene

    2006-11-01

    A process of high frequency stimulation of nucleons can be utilized for the accelerated fission, decay or controlled transition of unstable isotopes. ^238U could be persuaded to transition promptly into the stable ^206Pb isotope, where a portion of the total mass difference of 29873.802 MeV per nucleus becomes available energy. The proposals of this paper describe an effective system for nuclei stimulation configured to accelerate such a series of 14 transitions over several milliseconds, instead of 4.47 x 10^9 years. Positive ions or ionized capsules of fuel suspended by magnetic fields and subjected to the system of correlated frequency modulation of multiple beam lines, tailored to the specific target, will emit sufficient energy to stimulate subsequent targets. The system can be applied to all radioisotopes, nuclear waste product isotopes such as ^239Pu, and a variety of other suitable unstable or stable nuclei. Through the proposed confinement system and application of high frequency stimulation in the 10^22 to 10^24 Hz regime, the change in mass can be applied to both the fragmentation of subsequent, periodically injected targets, and the production of heat, making a continuous supply of energy possible. The system allows the particle fragmentation process to be brought into the lab and provides potential solutions to the safe disposal of fissile material.

  19. 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.

  20. High-Resolution Inductively Coupled Plasma Optical Emission Spectrometry for (234)U/(238)Pu Age Dating of Plutonium Materials and Comparison to Sector Field Inductively Coupled Plasma Mass Spectrometry.

    PubMed

    Krachler, Michael; Alvarez-Sarandes, Rafael; Rasmussen, Gert

    2016-09-01

    Employing a commercial high-resolution inductively coupled plasma optical emission spectrometry (HR-ICP-OES) instrument, an innovative analytical procedure for the accurate determination of the production age of various Pu materials (Pu powder, cardiac pacemaker battery, (242)Cm heat source, etc.) was developed and validated. This undertaking was based on the fact that the α decay of (238)Pu present in the investigated samples produced (234)U and both mother and daughter could be identified unequivocally using HR-ICP-OES. Benefiting from the high spectral resolution of the instrument (<5 pm) and the isotope shift of the emission lines of both nuclides, (234)U and (238)Pu were selectively and directly determined in the dissolved samples, i.e., without a chemical separation of the two analytes from each other. Exact emission wavelengths as well as emission spectra of (234)U centered around λ = 411.590 nm and λ = 424.408 nm are reported here for the first time. Emission spectra of the isotopic standard reference material IRMM-199, comprising about one-third each of (233)U, (235)U, and (238)U, confirmed the presence of (234)U in the investigated samples. For the assessment of the (234)U/(238)Pu amount ratio, the emission signals of (234)U and (238)Pu were quantified at λ = 424.408 nm and λ = 402.148 nm, respectively. The age of the investigated samples (range: 26.7-44.4 years) was subsequently calculated using the (234)U/(238)Pu chronometer. HR-ICP-OES results were crossed-validated through sector field inductively coupled plasma mass spectrometry (SF-ICPMS) analysis of the (234)U/(238)Pu amount ratio of all samples applying isotope dilution combined with chromatographic separation of U and Pu. Available information on the assumed ages of the analyzed samples was consistent with the ages obtained via the HR-ICP-OES approach. Being based on a different physical detection principle, HR-ICP-OES provides an alternative strategy to the well-established mass

  1. High-Resolution Inductively Coupled Plasma Optical Emission Spectrometry for (234)U/(238)Pu Age Dating of Plutonium Materials and Comparison to Sector Field Inductively Coupled Plasma Mass Spectrometry.

    PubMed

    Krachler, Michael; Alvarez-Sarandes, Rafael; Rasmussen, Gert

    2016-09-01

    Employing a commercial high-resolution inductively coupled plasma optical emission spectrometry (HR-ICP-OES) instrument, an innovative analytical procedure for the accurate determination of the production age of various Pu materials (Pu powder, cardiac pacemaker battery, (242)Cm heat source, etc.) was developed and validated. This undertaking was based on the fact that the α decay of (238)Pu present in the investigated samples produced (234)U and both mother and daughter could be identified unequivocally using HR-ICP-OES. Benefiting from the high spectral resolution of the instrument (<5 pm) and the isotope shift of the emission lines of both nuclides, (234)U and (238)Pu were selectively and directly determined in the dissolved samples, i.e., without a chemical separation of the two analytes from each other. Exact emission wavelengths as well as emission spectra of (234)U centered around λ = 411.590 nm and λ = 424.408 nm are reported here for the first time. Emission spectra of the isotopic standard reference material IRMM-199, comprising about one-third each of (233)U, (235)U, and (238)U, confirmed the presence of (234)U in the investigated samples. For the assessment of the (234)U/(238)Pu amount ratio, the emission signals of (234)U and (238)Pu were quantified at λ = 424.408 nm and λ = 402.148 nm, respectively. The age of the investigated samples (range: 26.7-44.4 years) was subsequently calculated using the (234)U/(238)Pu chronometer. HR-ICP-OES results were crossed-validated through sector field inductively coupled plasma mass spectrometry (SF-ICPMS) analysis of the (234)U/(238)Pu amount ratio of all samples applying isotope dilution combined with chromatographic separation of U and Pu. Available information on the assumed ages of the analyzed samples was consistent with the ages obtained via the HR-ICP-OES approach. Being based on a different physical detection principle, HR-ICP-OES provides an alternative strategy to the well-established mass

  2. Advanced Monte Carlo modeling of prompt fission neutrons for thermal and fast neutron-induced fission reactions on {sup 239}Pu

    SciTech Connect

    Talou, P.; Kawano, T.; Becker, B.; Danon, Y.; Chadwick, M. B.

    2011-06-15

    Prompt fission neutrons following the thermal and 0.5 MeV neutron-induced fission reaction of {sup 239}Pu are calculated using a Monte Carlo approach to the evaporation of the excited fission fragments. Exclusive data such as the multiplicity distribution P({nu}), the average multiplicity as a function of fragment mass {nu}-bar(A), and many others are inferred in addition to the most used average prompt fission neutron spectrum {chi}(E{sub in},E{sub out}), as well as average neutron multiplicity {nu}-bar. Experimental information on these more exclusive data help constrain the Monte Carlo model parameters. The calculated average total neutron multiplicity is {nu}-bar{sub c}=2.871 in very close agreement with the evaluated value {nu}-bar{sub e}=2.8725 present in the ENDF/B-VII.0 library. The neutron multiplicity distribution P({nu}) is in very good agreement with the evaluation by Holden and Zucker. The calculated average spectrum differs in shape from the ENDF/B-VII.0 spectrum, evaluated with the Madland-Nix model. In particular, we predict more neutrons in the low-energy tail of the spectrum (below about 300 keV) than the Madland-Nix calculations, casting some doubts on how much scission neutrons contribute to the shape of the low-energy tail of the spectrum. The spectrum high-energy tail is very sensitive to the total kinetic energy distribution of the fragments as well as to the total excitation energy sharing at scission. Present experimental uncertainties on measured spectra above 6 MeV are too large to distinguish between various theoretical hypotheses. Finally, comparisons of the Monte Carlo results with experimental data on {nu}-bar(A) indicate that more neutrons are emitted from the light fragments than the heavy ones, in agreement with previous works.

  3. Procedures for the use of Lexan and Makrofol SSNTDs in the detection of environmental concentrations of {sup 235}U and {sup 239}Pu

    SciTech Connect

    Henderson, C.L.

    1993-03-01

    Solid State Nuclear Track Detectors are used to study a variety of atomic particles. Polycarbonate SSNTD is used to study environmental concentrations of {sup 235}U and {sup 239}Pu in human urine and feces through fission track analysis. The samples of interest are deposited upon a Lexan slide, covered with a piece of Makrofol and exposed to a neutron fluence of 1.1 X 10{sup 17}. The fissile isotopes in the sample fission and the resulting fission fragments pass through either the surface of the Lexan or the surface of the Makrofol. The positive Coulombic attraction of the ionized fission fragments causes the electrons of the polycarbonate lattice to move towards the path of these particles, resulting in the breakage of chemical bonds in the lattice. The detector is then chemically etched in 6.5 N KOH that preferentially dissolves the damaged polycarbonate left in the path of the fission fragment. The chemically etched fission tracks are permanent records of the path of the fission fragment. The etched fission tracks in Lexan are optically counted using a microscope and the fission tracks in Makrofol are counted using a Spark Chamber. The amount of fissile material in the original sample can be calculated from the number of fission tracks. This paper presents further details of procedures for etching fission tracks in Lexan and Makrofol and for operating a Spark Chamber to count etched fission tracks in Makrofol. The physics of fission track formation in dielectric detectors is also discussed, as well as the physics of the Spark Chamber.

  4. Experience in the management of disused lightning rods containing 241Am in a research institute in Brazil.

    PubMed

    Vicente, Roberto; Potiens, Ademar; Sakata, Solange; Dellamano, José

    2013-11-01

    Radioactive lightning rods (RLR) were manufactured and installed in Brazil for almost two decades, before they were prohibited in 1989. Structures protected by this type of lightning preventers included residential buildings, schools, commercial and industrial facilities, among others. It is estimated that about 3.4 TBq of 241Am were used by manufacturers, and a total of 75,000 pieces with a mean activity of about 46 MBq were in the market. While only a fraction of the total has been recovered, the almost twenty thousand pieces already collected at the Nuclear and Energy Research Institute (IPEN) had their sources successfully separated from the remaining recyclable metal scrap and are now encapsulated in lead containers for final disposal. PMID:24077081

  5. In situ determination of /sup 241/Am on Enewetak Atoll. Date of survey: July 1977-December 1979

    SciTech Connect

    Tipton, W.J.; Fritzsche, A.E.; Jaffe, R.J.; Villaire, A.E.

    1981-11-01

    An in situ gamma ray spectrometer system was operated at Enewetak Atoll from July 1977 to December 1979 in support of the Enewetak Cleanup Project. The system employed a high purity germanium planar detector suspended at a height of 7.4 m above ground. Conversion factors were established to relate measured photopeak count rate data to source concentration in the soil. Data obtained for /sup 241/Am, together with plutonium-to-americium ratios obtained from soil sample analyses, were used to establish area-averaged surface (0 to 3 cm) transuranic concentration values. In areas which exceeded cleanup criteria, measurements were made in an iterative fashion to guide soil removal until levels were reduced below the cleanup criteria. Final measurements made after soil removal had been completed were used to document remaining surface transuranic concentration values and to establish external exposure rate levels due to /sup 137/Cs and /sup 60/Co.

  6. Experience in the management of disused lightning rods containing 241Am in a research institute in Brazil.

    PubMed

    Vicente, Roberto; Potiens, Ademar; Sakata, Solange; Dellamano, José

    2013-11-01

    Radioactive lightning rods (RLR) were manufactured and installed in Brazil for almost two decades, before they were prohibited in 1989. Structures protected by this type of lightning preventers included residential buildings, schools, commercial and industrial facilities, among others. It is estimated that about 3.4 TBq of 241Am were used by manufacturers, and a total of 75,000 pieces with a mean activity of about 46 MBq were in the market. While only a fraction of the total has been recovered, the almost twenty thousand pieces already collected at the Nuclear and Energy Research Institute (IPEN) had their sources successfully separated from the remaining recyclable metal scrap and are now encapsulated in lead containers for final disposal.

  7. 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.

  8. Radionuclide contaminant analysis of small mammals at Area G, TA-54, Los Alamos National Laboratory, 1995

    SciTech Connect

    Bennett, K.; Biggs, J.; Fresquez, P.

    1997-01-01

    At Los Alamos National Laboratory, small mammals were sampled at two waste burial sites (Site 1-recently disturbed and Site 2-partially disturbed) at Area G, Technical Area 54 and a control site on Frijoles Mesa (Site 4) in 1995. Our objectives were (1) to identify radionuclides that are present within surface and subsurface soils at waste burial sites, (2) to compare the amount of radionuclide uptake by small mammals at waste burial sites to a control site, and (3) to identify if the primary mode of contamination to small mammals is by surface contact or ingestion/inhalation. Three composite samples of at least rive animals per sample were collected at each site. Pelts and carcasses of each animal were separated and analyzed independently. Samples were analyzed for {sup 241}Am, {sup 90}Sr , {sup 238}Pu, {sup 239}Pu, total U, {sup 137}Cs, and {sup 3}H. Significantly higher (parametric West at p=0.05) levels of total U, {sup 241}Am, {sup 238}Pu and {sup 239}Pu were detected in pelts than in carcasses of small mammals at TA-54. Concentrations of other measured radionuclides in carcasses were nearly equal to or exceeded the mean concentrations in the pelts. Our results show higher concentrations in pelts compared to carcasses, which is similar to what has been found at waste burial/contaminated sites outside of Los Alamos National Laboratory. Site 1 had a significantly higher (alpha=0.05, P=0.0125) mean tritium concentration in carcasses than Site 2 or Site 4. In addition Site 1 also had a significantly higher (alpha=0.05, p=0.0024) mean tritium concentration in pelts than Site 2 or Site 4. Site 2 had a significantly higher (alpha=0.05, P=0.0499) mean {sup 239}Pu concentration in carcasses than either Site 1 or Site 4.

  9. Radionuclide contaminant analysis of small mammals at Area G, TA-54, 1994

    SciTech Connect

    Biggs, J.; Bennett, K.; Fresquez, P.

    1995-09-01

    Small mammals were sampled at two waste burial sites (1 and 2) at Area G, TA-54 and a control site outside Area G (Site 3) to identify radionuclides that are present within surface and subsurface soils at waste burial sites, to compare the amount of radionuclide uptake by small mammals at waste burial sites to a control site, and to identify the primary mode of contamination to small mammals, either through surface contact or ingestion/inhalation. Three composite samples of at least five animals per sample were collected at each site. Pelts and carcasses of each animal were separated and analyzed independently. Samples were analyzed for {sup 241}Am, {sup 90}Sr, {sup 238}Pu, {sup 239}Pu, total U, and gamma spectroscopy (including {sup 137}Cs). Significantly higher (parametric t-test at p = 0.05) levels of total U, {sup 241}Am, {sup 238}Pu, {sup 239}Pu, and {sup 40}K were detected in pelts as compared to the carcasses of small mammals at TA-54. Concentrations of other measured radionuclides in carcasses were nearly equal to or exceeded the mean concentrations in the pelts. The authors results show higher concentrations in pelts compared to carcasses which is similar to what has been found at waste burial/contaminated sites outside of Los Alamos National Laboratory. Site 1 had significantly higher (alpha = 0.05, F = 0.0095) total U concentrations in carcasses than Sites 2 and 3. Site 2 had significantly higher (alpha = 0.05, F = 0.0195) {sup 239}Pu concentrations in carcasses than either Site 1 or Site 3. A significant difference in {sup 90}Sr concentration existed between Sites 1 and 2 (alpha = 0.05, F = 0.0681) and concentrations of {sup 40}K at Site 1 were significantly different from Site 3.

  10. Bioavailability of trace contaminants ({sup 241}Am, {sup 57}Co, {sup 137}Cs) to a benthic bivalve from pore waters and sediments

    SciTech Connect

    Gagnon, C.; Stupakoff, I.; Fisher, N.S.

    1995-12-31

    Sediments are major repositories of contaminants in marine ecosystems and can serve as a source of some contaminants for benthic organisms. The authors used the clam Macoma balthica, a species employed in monitoring coastal contamination, to compare experimentally three uptake sources: overlying water, ingested surface sediment and anoxic pore water. They studied the bioavailability of selected radionuclides ({sup 241}Am, {sup 57}Co, {sup 137}Cs) representing a large range of particle reactivity. For comparison, the authors also used CH{sub 3} {sup 203}Hg, which is highly assimilated by marine organisms. Clams were exposed separately to contaminated overlying water, surface oxic sediment and anoxic sediment. Radioactivity in animals was determined at the end of the exposure period. {sup 137}CS, which is not particle reactive in seawater, was not bioaccumulated from any source. {sup 241}Am and {sup 57}Co concentration factors in clams obtained from overlying water were approximately an order of magnitude lower than that of CH{sub 3} {sup 203}Hg. Ingested oxidized sediment particles do not appear to be a significant source for these radionuclides. {sup 241}Am, {sup 57}Co and CH{sub 3} {sup 203}Hg were bioconcentrated from anoxic pore waters, but the highly particle-reactive {sup 241}Am was mostly adsorbed onto the clam`s shell. The bioconcentration of CH{sub 3} {sup 203}Hg from pore waters was, however, only one tenth of that from overlying water.

  11. Environmental and radiological safety studies. Interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, July 1-September 30, 1980

    SciTech Connect

    Waterbury, G.R.

    1981-01-01

    The containers for /sup 238/PuO/sub 2/ heat sources in radioisotope thermoelectric generators are designed with large safety factors to ensure that they will withstand reentry from orbit and impact with the earth and safely contain the nuclear fuel until it is recovered. Existing designs have proved more than adequately safe, but the Space and Terrestrial Division of the Department of Energy Office of Advanced Nuclear Systems and Projects continually seeks more information about the heat sources to improve their safety. The work discussed here includes studies of the effects on the heat source of terrestrial and aquatic environments to obtain data for design of even safer systems. The data obtained in several ongoing experiments are presented; these data tables will be updated quarterly. Discussions of experimental details are minimized and largely repetitive in succeeding reports. Compilations of usable data generated in each experiment are emphasized. These compilations include data from environmental chamber experiments that simulate terrestrial conditions, experiments to measure PuO/sub 2/ dissolution rates, soil column experiments to measure sorption of plutonium by soils, and several aquatic experiments.

  12. Environmental and radiological safety studies: interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, January 1-March 31, 1981

    SciTech Connect

    Waterbury, G.R.

    1981-09-01

    The containers for /sup 238/PuO/sub 2/ heat souces in radioisotope thermoelectric generators are designed with large safety factors to ensure that they will withstand reentry from orbit and impact with the earth and safely contain the nuclear fuel until it is recovered. Existing designs have proved more than adequately safe, but the Space and Terrestrial Division of the Department of Energy Office of Advanced Nuclear Systems and Projects continually seeks more information about the heat sources to improve their safety. The work discussed here includes studies of the effects on the heat source of terrestrial and aquatic environments to obtain data for design of even safer systems. The data obtained in several ongoing experiments are presented; these data tables will be updated quarterly. Discussions of experimental details are minimized and largely repetitive in succeeding reports. Compilations of usable data generated in each experiment are emphasized. These compilations include data from environmental chamber experiments that simulate terrestrial conditions, experiments to measure PuO/sub 2/ dissolution rates soil column experiments to measure sorption of plutonium by soils, and several aquatic experiments.

  13. 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.

  14. EFFICIENCY STUDY OF A LEGe DETECTOR SYSTEM FOR THE ASSESSMENT OF 241Am IN SKULL AT CIEMAT WHOLE BODY COUNTER.

    PubMed

    Pérez López, B; Navarro, J F; López Ponte, M A; Nogueira, P

    2016-09-01

    (241)Am incorporation due to an incident or chronic exposure causes an internal dose, which can be evaluated from the total activity of this isotope in the skeleton several months after the intake. For this purpose, it is necessary to perform in vivo measurements of this bone-seeker radionuclide in appropriate counting bone geometries with very low attenuation of surrounded tissue and to extrapolate to total activity in the skeleton (ICRP 89, Basic anatomical and physiological data for use in radiological protection: reference values. 2001. 265). The work here presented refers to direct measurements of americium in the Cohen skull phantom at the CIEMAT Whole Body Counter (WBC) using low-energy germanium (LEGe) detectors inside a shielding room. The main goal was to determinate the most adequate head counting geometry for the in vivo detection of americium in the bone. The calibration of the in vivo LEGe system was performed with four detectors with 2 cm of distance to Cohen phantom. Two geometries were measured, on junction of frontal to parietal bones and frontal bone. The efficiencies are very similar in both geometries, the preferred counting geometry is the most comfortable for the person, with the LEGe detectors in the highest part of the frontal bone, near the junction with the parietal bone, CIEMAT WBC participated in a skull intercomparison exercise organised by WG7 of EURADOS (European Radiation Dosimetry Group e.V.). Efficiencies using three different skull phantoms were obtained. Measurements were performed for different head counting positions, four of them in the plane of symmetry and others over the temporal bone. The detector was placed in parallel with the calibration phantom at a distance of 1 cm. The main gamma emission of (241)Am, 59.5 keV (36 %), was used for comparing efficiency values. The lower efficiency was obtained over the frontal and occipital bones. Measurement with one LEGe detector over the parietal bone is the most efficient. The

  15. 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

  16. 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

  17. 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

  18. 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.

  19. Detection and dosimetry studies on the response of silicon diodes to an 241Am-Be source

    NASA Astrophysics Data System (ADS)

    Lotfi, Y.; Zaki Dizaji, H.; Abbasi Davani, F.

    2014-06-01

    Silicon diode detectors show potential for the development of an active personal dosimeter for neutron and photon radiation. Photons interact with the constituents of the diode detector and produce electrons. Fast neutrons interact with the constituents of the diode detector and converter, producing recoil nuclei and causing (n,α) and (n,p) reactions. These photon- and neutron-induced charged particles contribute to the response of diode detectors. In this work, a silicon pin diode was used as a detector to produce pulses created by photon and neutron. A polyethylene fast neutron converter was used as a recoil proton source in front of the detector. The total registered photon and neutron efficiency and the partial contributions of the efficiency, due to interactions with the diode and converter, were calculated. The results show that the efficiency of the converter-diode is a function of the incident photon and neutron energy. The optimized thicknesses of the converter for neutron detection and neutron dosimetry were found to be 1 mm and 0.1 mm respectively. The neutron records caused by the (n,α) and (n,p) reactions were negligible. The photon records were strongly dependent upon the energy and the depletion layer of the diode. The photons and neutrons efficiency of the diode-based dosimeter was calculated by the MCNPX code, and the results were in good agreement with experimental results for photons and neutrons from an 241Am-Be source.

  20. Radionuclide Contaminant Analysis of Small Mammals at Area G, Technical Area 54, 1997 (with cumulative summary 1994-1997)

    SciTech Connect

    James R. Biggs; Kathryn D. Bennett; P. R. Fresquez

    1998-12-01

    In 1997, small mammals were sampled at four locations at Area G, Technical Area 54, a control site within the proposed Area G expansion area, and a background site on Frijoles Mesa. The purpose of the sampling was to (1) identify radionuclides that are present within rodent tissues at waste burial sites, (2) compare the amount of radionuclide uptake by small mammals at waste burial sites to a control site, and (3) identifi the primary mode of contamination to small mammals, either through surface contact or ingestion/inhalation. Three composite samples of approximately five animals per sample were collected at each site. Pelts and carcasses of each animal were separated and analyzed independently. Samples were analyzed for 241Am, 90Sr, 238Pu, 239Pu, total U, 137Cs, and 3H. Higher levels of total U and 137CS were detected in pelts as compared to the carcasses of small mammals, and 90Sr was found to be higher in carcasses. Concentrations of other measured radionuclides in carcasses were not found to be statistically different (p< 0.05) from that measured in pelts. However, pelts generally had higher concentrations than carcasses, indicating surface contamination may be the primary contamination mode. Low sample sizes in total number of animals captured during 1997 prevented statistical analysis to compare site to site to all but four sites. Mean concentrations of 241Am, 238Pu, 239Pu, and 3H in small mammal carcasses were found to be statistically greater at the transuranic (TRU) waste pad #2. In addition, mean concentrations of total U, ~lAm, and 3H in pelts of small mammals were also statistically greater. The Control Site and Background Site consistently had the lowest mean concentrations of radionuclides. Year to year comparison of mean radionuclide concentrations was conducted where suftlcient sample size existed. We found 241Am, 238Pu, 239Pu, and 3H mean concentrations in carcasses to be statistically greater in 1997 than previous years at TRU waste pad #2

  1. Measurement of the ^241Am(n,2n) reaction cross section from 7.6 to 14.5 MeV

    NASA Astrophysics Data System (ADS)

    Tonchev, A.; Angell, C.; Becker, J.; Bond, E.; Dashdorj, D.; Fallin, B.; Fitzpatrick, J.; Howell, C.; Hutcheson, A.; Karwowski, H.; Kelley, J.; Macri, R.; Pedroni, R.; Slemmons, A.; Stoyer, M.; Tornow, W.; Vieira, D.; Wilhelmy, J.; Wu, C.

    2007-10-01

    High-precision measurements of the ^241Am(n,2n)^240Am reaction have been performed with neutron energies from 7.6 to 14.5 MeV. The monoenergetic neutron beams were produced via the ^2H(d,n)^3He reaction using the 10 MV Tandem accelerator at TUNL. The radioactive targets consisted of 1mg highly-enriched ^241Am, sandwiched between three different thin monitor foils. They were irradiated with a neutron flux of 3x10^7 n cm-2s-1. After each irradiation the induced activity in the targets and monitors was measured off-line with 60% HPGe detectors. Our neutron induced cross sections will be compared with recent literature results and statistical model calculations.

  2. [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

  3. [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.

  4. Rapid sequential determination of Pu, 90Sr and 241Am nuclides in environmental samples using an anion exchange and Sr-Spec resins.

    PubMed

    Lee, M H; Ahn, H J; Park, J H; Park, Y J; Song, K

    2011-02-01

    This paper presents a quantitative and rapid method of sequential separation of Pu, (90)Sr and (241)Am nuclides in environmental soil samples with an anion exchange resin and Sr Spec resin. After the sample solution was passed through an anion exchange column connected to a Sr Spec column, Pu isotopes were purified from the anion exchange column. Strontium-90 was separated from other interfering elements by the Sr Spec column. Americium-241 was purified from lanthanides by the anion exchange resin after oxalate co-precipitation. Measurement of Pu and Am isotopes was carried out using an α-spectrometer. Strontium-90 was measured by a low-level liquid scintillation counter. The radiochemical procedure of Pu, (90)Sr and (241)Am nuclides investigated in this study validated by application to IAEA reference materials and environmental soil samples.

  5. Prompt fission neutron spectra from fission induced by 1 to 8 MeV neutrons on {sup 235}U and {sup 239}Pu using the double time-of-flight technique

    SciTech Connect

    Noda, S.; Haight, R. C.; Nelson, R. O.; Devlin, M.; O'Donnell, J. M.; Chatillon, A.; Granier, T.; Belier, G.; Taieb, J.; Kawano, T.; Talou, P.

    2011-03-15

    Prompt fission neutron spectra from {sup 235}U and {sup 239}Pu were measured for incident neutron energies from 1 to 200 MeV at the Weapons Neutron Research facility (WNR) of the Los Alamos Neutron Science Center, and the experimental data were analyzed with the Los Alamos model for the incident neutron energies of 1-8 MeV. A CEA multiple-foil fission chamber containing deposits of 100 mg {sup 235}U and 90 mg {sup 239}Pu detected fission events. Outgoing neutrons were detected by the Fast Neutron-Induced {gamma}-Ray Observer array of 20 liquid organic scintillators. A double time-of-flight technique was used to deduce the neutron incident energies from the spallation target and the outgoing energies from the fission chamber. These data were used for testing the Los Alamos model, and the total kinetic energy parameters were optimized to obtain a best fit to the data. The prompt fission neutron spectra were also compared with the Evaluated Nuclear Data File (ENDF/B-VII.0). We calculate average energies from both experimental and calculated fission neutron spectra.

  6. Complex aberrations in lymphocytes exposed to mixed beams of (241)Am alpha particles and X-rays.

    PubMed

    Staaf, Elina; Deperas-Kaminska, Marta; Brehwens, Karl; Haghdoost, Siamak; Czub, Joanna; Wojcik, Andrzej

    2013-08-30

    Modern radiotherapy treatment modalities are associated with undesired out-of-field exposure to complex mixed beams of high and low energy transfer (LET) radiation that can give rise to secondary cancers. The biological effectiveness of mixed beams is not known. The aim of the investigation was the analysis of chromosomal damage in human peripheral blood lymphocytes (PBL) exposed to a mixed beam of X-rays and alpha particles. Using a dedicated exposure facility PBL were exposed to increasing doses of alpha particles (from (241)Am), X-rays and a mixture of both. Chromosomal aberrations were analysed in chromosomes 2, 8 and 14 using fluorescence in situ hybridisation. The found and expected frequencies of simple and complex aberrations were compared. Simple aberrations showed linear dose-response relationships with doses. A higher than expected frequency of simple aberrations was only observed after the highest mixed beam dose. A linear-quadratic dose response curve for complex aberrations was observed after mixed-beam exposure. Higher than expected frequencies of complex aberrations were observed for the two highest doses. Both the linear-quadratic dose-response relationship and the calculation of expected frequencies show that exposure of PBL to mixed beams of high and low LET radiation leads to a higher than expected frequency of complex-type aberrations. Because chromosomal changes are associated with cancer induction this result may imply that the cancer risk of exposure to mixed beams in radiation oncology may be higher than expected based on the additive action of the individual dose components.

  7. 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.

  8. 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

  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. 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

  11. Characterization of neutron flux spectra in the irradiation sites of a 37 GBq 241Am-Be isotopic source

    NASA Astrophysics Data System (ADS)

    Yücel, Haluk; Budak, Mustafa Guray; Karadag, Mustafa; Yüksel, Alptuğ Özer

    2014-11-01

    For the applicability of instrumental neutron activation analysis (NAA) technique, an irradiation unit with a 37 GBq 241Am-Be neutron source was installed at Institute of Nuclear Sciences of Ankara University. Design and configuration properties of the irradiation unit are described. It has two different sample irradiation positions, one is called site #1 having a pneumatic sample transfer system and the other is site #2 having a location for manual use. In order to characterize neutron flux spectra in the irradiation sites, the measurement results were obtained for thermal (Фth) and epithermal neutron fluxes (Фepi), thermal to epithermal flux ratio (f) and epithermal spectrum shaping factors (α) by employing cadmium ratios of gold (Au) and molybdenum (Mo) monitors. The activities produced in these foils were measured by using a p-type, 44.8% relative efficiency HPGe well detector. For the measured γ-rays, self-absorption and true coincidence summing effects were taken into account. Additionally, thermal neutron self-shielding and resonance neutron self-shielding effects were taken into account in the measured results. For characterization of site #1, the required parameters were found to be Фth = (2.11 ± 0.05) × 103 n cm-2 s-1, Фepi = (3.32 ± 0.17) × 101 n cm-2 s-1, f = 63.6 ± 1.5, α = 0.045 ± 0.009, respectively. Similarly, those parameters were measured in site #2 as Фth = (1.49 ± 0.04) × 103 n cm-2 s-1, Фepi = (2.93 ± 0.15) × 101 n cm-2 s-1, f = 50.9 ± 1.3 and α = 0.038 ± 0.008. The results for f-values indicate that good thermalization of fast neutrons on the order of 98% was achieved in both sample irradiation sites. This is because an optimum combination of water and paraffin moderator is used in the present configuration. In addition, the shielding requirements are met by using natural boron oxide powder (5.5 cm) and boron loaded paraffin layers against neutrons, and a 15 cm thick lead bricks against gamma-rays from source and its

  12. New measurements of (n,γ) and (n,fission) cross sections and capture-to-fission ratios for ^233,235U and ^239Pu using the DANCE 4π BaF2 array

    NASA Astrophysics Data System (ADS)

    Bredeweg, T. A.; Jandel, M.; Fowler, M. M.; Bond, E. M.; Haight, R. C.; Keksis, A. L.; O'Donnell, J. M.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Becker, J. A.; Parker, W. E.; Wu, C. Y.; Baker, J. D.; McGrath, C. A.

    2009-10-01

    Accurate neutron nuclear data are important to many issues in stockpile stewardship, nuclear reactor design and re-certification, nuclear non-proliferation and nuclear forensics. Of particular interest are the production and destruction reactions for all of the major and most of the minor actinides. The competition between capture and fission in many of the actinides presents both an obstacle and an opportunity for large γ detector arrays such as DANCE. Additional instrumentation is required to deconvolve the two contributions to the total observed γ-ray spectrum. However, conducting a simultaneous measurement can simplify background treatment and other sources of systematic uncertainty. An outline of the current experimental program will be presented along with results from neutron capture measurements on ^233,235U and ^239Pu.

  13. Concentrations of 137Cs, 90Sr, 108m Ag, 239+240 Pu and atom ratio of 240Pu/239Pu in tanner crabs, Chionoecetes japonicus and Chionoecetes opilio collected around Japan.

    PubMed

    Morita, Takami; Ohtsuka, Yoshihito; Fujimoto, Ken; Minamisako, Yoko; Iida, Rika; Nakamura, Masae; Kayama, Toshiharu

    2010-12-01

    The anthropogenic radionuclides, (137)Cs, (90)Sr, (108m)Ag, (239+240)Pu, were measured in two Chionoecetes species, red queen crab (Chionoecetes japonicus) and snow crab (Chionoecetes opilio) collected around Japan during 1996-2007. There was no increase in the concentrations of these radionuclides and no large variation of the atom ratio of (240)Pu/(239)Pu during this research period. These results indicated that the source of the radionuclides was not the radioactive wastes dumped by the former USSR and Russia and originated from past nuclear weapon tests. The higher atom ratio in the crab species than that from global fallout would be contributed by the Pacific Proving Grounds close-in fallout. The variability of the concentration of radionuclides in the crab species would result from the variability of the composition and quantity in the diet. However, the decrease in the concentration of radionuclides with sampling depth would depend on the concentration in the seawater and diet.

  14. 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.

  15. Baseline concentrations of radionuclides and heavy metals in soils and vegetation around the DARHT facility: Construction phase (1996)

    SciTech Connect

    Fresquez, P.R.; Haagenstad, H.T.; Naranjo, L. Jr.

    1997-04-01

    As part of the Department of Energy`s Mitigation Action Plan for the Dual Axis Radiographic Hydrodynamic Test (DARHT) Facility at Los Alamos National Laboratory (LANL), baseline concentrations of radionuclides ({sup 3}H, {sup 137}Cs, {sup 90}Sr, {sup 238}Pu, {sup 239}Pu, {sup 241}Am, total U), and heavy metals (Ag, As, Ba, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se and Tl) in soil, sediment, and vegetation (overstory and understory) around the DARHT facility during the construction phase in 1996 were determined. Also, U and Be concentrations in soil samples collected in 1993 from within the proposed DARHT facility area are reported. Most radionuclides in soils, sediments, and vegetation were within current background and/or long-term regional statistical reference levels.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. Standardization of (241)Am, (124)Sb and (131)I by live-timed anti-coincidence counting with extending dead time.

    PubMed

    da Silva, Carlos J; Iwahara, A; Poledna, R; de Oliveira, E M; de Prinzio, M A R R; Delgado, José U; Lopes, Ricardo T

    2008-01-01

    The National Metrology Laboratory for Ionizing Radiation (LNMRI)/Brazil has implemented a live-timed anti-coincidence system with extending dead time to complement the existing systems in its Radionuclide Laboratory for activity measurements of radioactive sources. In this new system, the proportional counter has been replaced by a liquid-scintillation-counter for alpha and beta detection. In order to test the performance of the new system, radioactive solutions of (131)I, (124)Sb and (241)Am have been standardized. In this work the measurement method, the results and the associated uncertainties are described and discussed. PMID:18356060

  1. Systematic evaluation of options to avoid generation of noncertifiable transuranic (TRU) waste at Los Alamos National Laboratory

    SciTech Connect

    Boak, J.M.; Kosiewicz, S.T.; Triay, I.; Gruetzmacher, K.; Montoya, A.

    1998-03-01

    At present, >35% of the volume of newly generated transuranic (TRU) waste at Los Alamos National Laboratory is not certifiable for transport to the Waste Isolation Pilot Plant (WIPP). Noncertifiable waste would constitute 900--1,000 m{sup 3} of the 2,600 m{sup 3} of waste projected during the period of the Environmental Management (EM) Accelerated Cleanup: Focus on 2006 plan (DOE, 1997). Volume expansion of this waste to meet thermal limits would increase the shipped volume to {approximately}5,400 m{sup 3}. This paper presents the results of efforts to define which TRU waste streams are noncertifiable at Los Alamos, and to prioritize site-specific options to reduce the volume of certifiable waste over the period of the EM Accelerated Cleanup Plan. A team of Los Alamos TRU waste generators and waste managers reviewed historic generation rates and thermal loads and current practices to estimate the projected volume and thermal load of TRU waste streams for Fiscal Years 1999--2006. These data defined four major problem TRU waste streams. Estimates were also made of the volume expansion that would be required to meet the permissible wattages for all waste. The four waste streams defined were: (1) {sup 238}Pu-contaminated combustible waste from production of Radioactive Thermoelectric Generators (RTGs) with {sup 238}Pu activity which exceeds allowable shipping limits by 10--100X. (2) {sup 241}Am-contaminated cement waste from plutonium recovery processes (nitric and hydrochloric acid recovery) are estimated to exceed thermal limits by {approximately}3X. (3) {sup 239}Pu-contaminated combustible waste, mainly organic waste materials contaminated with {sup 239}Pu and {sup 241}Am, is estimated to exceed thermal load requirements by a factor of {approximately}2X. (4) Oversized metal waste objects, (especially gloveboxes), cannot be shipped as is to WIPP because they will not fit in a standard waste box or drum.

  2. 241 Am ( n ,γ) cross section in the neutron energy region between 0.02 eV and 300 keV

    NASA Astrophysics Data System (ADS)

    Jandel, M.; Bredeweg, T. A.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O'Donnell, J. M.; Haight, R. C.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Macri, R. A.; Wu, C. Y.; Becker, J. A.

    2008-04-01

    The Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory (LANL) was used for a neutron capture cross section measurement on 241 Am . The high granularity of the DANCE array (160 BaF2 detectors in a 4π geometry) enables an efficient detection of prompt gamma rays following neutron capture. The preliminary results on the 241 Am ( n ,γ) cross section are presented from 0.02 eV to 300 keV. The cross section at thermal energy E n = 0.0253 eV was determined to be 665±33 barns. Resonance parameters were obtained using the SAMMY7 fit to the measured cross section in the resonance region. Significant discrepancies were found between our results and data evaluations for the first three lowest lying resonances. The cross section for neutrons with E n >l keV agrees well with the ENDF/B-VII.0 and JENDL-3.3 evaluations.

  3. Effects of arctic temperatures on distribution and retention of the nuclear waste radionuclides 241Am, 57Co, and 137Cs in the bioindicator bivalve Macoma balthica

    USGS Publications Warehouse

    Hutchins, D.A.; Stupakoff, I.; Hook, S.; Luoma, S.N.; Fisher, N.S.

    1998-01-01

    The disposal of radioactive wastes in Arctic seas has made it important to understand the processes affecting the accumulation of radionuclides in food webs in coldwater ecosystems. We examined the effects of temperature on radionuclide assimilation and retention by the bioindicator bivalve Macoma balthica using three representative nuclear waste components, 241Am, 57Co, and 137Cs. Experiments were designed to determine the kinetics of processes that control uptake from food and water, as well as kinetic constants of loss. 137Cs was not accumulated in soft tissue from water during short exposures, and was rapidly lost from shell with no thermal dependence. No effects of temperature on 57Co assimilation or retention from food were observed. The only substantial effect of polar temperatures was that on the assimilation efficiency of 241Am from food, where 10% was assimilated at 2??C and 26% at 12??C. For all three radionuclides, body distributions were correlated with source, with most radioactivity obtained from water found in the shell and food in the soft tissues. These results suggest that in general Arctic conditions had relatively small effects on the biological processes which influence the bioaccumulation of radioactive wastes, and bivalve concentration factors may not be appreciably different between polar and temperate waters.

  4. {sup 241}Am(n,{gamma}) cross section in the neutron energy region between 0.02 eV and 300 keV

    SciTech Connect

    Jandel, M.; Bredeweg, T. A.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O' Donnell, J. M.; Haight, R. C.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Macri, R. A.; Wu, C. Y.; Becker, J. A.

    2008-04-17

    The Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory (LANL) was used for a neutron capture cross section measurement on {sup 241}Am. The high granularity of the DANCE array (160 BaF2 detectors in a 4{pi} geometry) enables an efficient detection of prompt gamma rays following neutron capture. The preliminary results on the {sup 241}Am(n,{gamma}) cross section are presented from 0.02 eV to 300 keV. The cross section at thermal energy E{sub n} = 0.0253 eV was determined to be 665{+-}33 barns. Resonance parameters were obtained using the SAMMY7 fit to the measured cross section in the resonance region. Significant discrepancies were found between our results and data evaluations for the first three lowest lying resonances. The cross section for neutrons with E{sub n}>l keV agrees well with the ENDF/B-VII.0 and JENDL-3.3 evaluations.

  5. Method for Ultratrace Level (241)Am Determination in Large Soil Samples by Sector Field-Inductively Coupled Plasma Mass Spectrometry: With Emphasis on the Removal of Spectral Interferences and Matrix Effect.

    PubMed

    Wang, Zhongtang; Zheng, Jian; Cao, Liguo; Tagami, Keiko; Uchida, Shigeo

    2016-07-19

    A new method using sector field-inductively coupled plasma mass spectrometry (SF-ICPMS) was developed for the determination of (241)Am in large soil samples to provide realistic soil-plant transfer parameter data for dose assessment of nuclear waste disposal plans. We investigated four subjects: extraction behaviors of interfering elements (Bi, Tl, Hg, Pb, Hf, and Pt) on DGA resin (normal type, abbreviated as DGA-N); soil matrix element removal (Mg, Fe, Al, K, Na) using Fe(OH)3, CaF2, and CaC2O4 coprecipitations; Am and rare earth elements (REEs) separation on DGA-N and TEVA resins; and optimization of SF-ICPMS (equipped with a high efficiency nebulizer (HEN)) for Am determination. Our method utilized concentrated HNO3 to leach Am from 2 to 20 g soil samples. The CaC2O4 coprecipitation was used to remove major metals in soil and followed by Am/interfering elements separation using the proposed UTEVA + DGA-N procedure. After a further separation of REEs on TEVA resin, (241)Am was determined by HEN-SF-ICPMS. This method eliminated the matrix effect in ICPMS (241)Am measurement for large soil samples. The high decontamination factors (DFs) of interfering elements enable their thorough removal, and in particular, the DF of Pu (7 × 10(5)) was the highest ever reported in (241)Am studies; thus, this method is capable of analyzing (241)Pu-contaminated Fukushima Daiichi Nuclear Power Plant (FDNPP) sourced soil samples. A low detection limit of 0.012 mBq g(-1) for (241)Am was achieved. The chemical recovery of Am (76-82%) was stable for soil samples. This method can be employed for the low level (241)Am determination in large size soil samples that are contaminated with (241)Pu. PMID:27322003

  6. 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.; Arnold, C.; Bredeweg, T.; Vieira, D.; Wilhelmy, J.; Tonchev, A.; Stoyer, M.; Bhike, M.; Krishichayan, F.; Tornow, W.; Fowler, M.

    2015-10-01

    Under a joint collaboration between TUNL-LANL-LLNL, a set of absolute fission product yield measurements has been performed. The energy dependence of a number of cumulative fission product yields (FPY) have been measured using quasi-monoenergetic neutron beams for three actinide targets, 235U, 238U and 239Pu, between 0.5 and 14.8 MeV. The FPYs were measured by a combination of fission counting using specially designed dual-fission chambers and ?-ray counting. Each dual-fission chamber is a back-to-back ionization chamber encasing an activation target in the center with thin deposits of the same target isotope in each chamber. This method allows for the direct measurement of the total number of fissions in the activation target with no reference to the fission cross-section, thus reducing uncertainties. ?-ray counting of the activation target was performed on well-shielded HPGe detectors over a period of 2 months post irradiation to properly identify fission products. Reported are absolute cumulative fission product yields for incident neutron energies of 0.5, 1.37, 2.4, 3.6, 4.6, 5.5, 7.5, 8.9 and 14.8 MeV. These results are compared to previous measurements and theoretical estimates. This work was performed under the auspices of the USDoE by Los Alamos National Security, LLC under Contract DE-AC52-06NA25396.

  7. New measurements of (n,γ) and (n,fission) cross sections and capture-to-fission ratios for ^233,235U and ^239Pu using the DANCE 4π BaF2 array

    NASA Astrophysics Data System (ADS)

    Bredeweg, T. A.; Jandel, M.; Fowler, M. M.; Bond, E. M.; Haight, R. C.; Keksis, A. L.; O'Donnell, J. M.; Reifarth, R.; Rundberg, R. S.; Slemmons, A. K.; Ullmann, J. L.; Vieira, D. J.; Wouters, J. M.; Becker, J. A.; Wu, C. Y.; Baker, J. D.; McGrath, C. A.

    2010-11-01

    Accurate neutron-induced reaction data are important to many issues in stockpile stewardship, nuclear reactor design and re-certification, nuclear non-proliferation and nuclear forensics. Of particular interest are the production and destruction reactions for all of the major and most of the minor actinides, including both neutron-induced capture and fission. The competition between capture and fission presents both an obstacle and an opportunity for large γ detector arrays such as the DANCE array (Detector for Advanced Neutron Capture Experiments), which cannot clearly differentiate γ-rays resulting from the two exit channels. With the addition of a high efficiency, 4π fission-tagging detector it is possible to deconvolve the two contributions to the total γ-ray spectrum. Using these tools we are able to conduct simultaneous fission/capture measurements which can simplify background treatment and other sources of systematic uncertainty. An outline of the current experimental program will be presented along with results from neutron capture measurements on ^233,235U and ^239Pu.

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. Ageing of a phosphate ceramic used to immobilize chloride contaminated actinide waste

    SciTech Connect

    Metcalfe, Brian L.; Donald, Ian W.; Fong, Shirley K.; Gerrard, Lee A.; Strachan, Denis M.; Scheele, Randall D.

    2009-03-31

    AWE has developed a process for the immobilization of ILW waste containing a significant quantity of chloride using Ca3(PO4)2 as the host material. Waste ions are incorporated into two phosphate based phases, chlorapatite, Ca5(PO4)3Cl, and spodiosite, Ca2(PO4)Cl. Non-active trials performed at AWE using samarium as the actinide surrogate demonstrated the durability of these phases in aqueous solution. Trials of the process using actinide-doped material were performed at PNNL which confirmed the immobilized wasteform resistant to aqueous leaching. Initial leach trials conducted on 239Pu /241Am loaded ceramic at 40°C/28 days gave normalized mass losses of 1.2 x 10-5 g.m-2 and 2.7 x 10-3 g.m-2 for Pu and Cl respectively. In order to assess the response of the phases to radiation-induced damage, accelerated ageing trials were performed on samples in which the 239Pu was replaced by 238Pu. No changes to the crystalline structure of the waste were detected using XRD after the samples had experienced a radiation dose of 4 x 1018 α.g-1. Leach trials showed that there had been an increase in the P and Ca release rates but no change in the Pu release rate.

  13. 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.

  14. Ageing of a phosphate ceramic used to immobilize chloride contaminated actinide waste

    NASA Astrophysics Data System (ADS)

    Metcalfe, B. L.; Donald, I. W.; Fong, S. K.; Gerrard, L. A.; Strachan, D. M.; Scheele, R. D.

    2009-03-01

    A process for the immobilization of intermediate level waste containing a significant quantity of chloride using Ca3(PO4)2 as the host material has been developed. Waste ions are incorporated into two phosphate-based phases, chlorapatite [Ca5(PO4)3Cl] and spodiosite [Ca2(PO4)Cl]. Non-active trials performed using Sm as the actinide surrogate demonstrated the durability of these phases in aqueous solution. Trials of the process, in which actinide-doped materials were used, were performed at PNNL which confirmed the wasteform resistant to aqueous leaching. Initial leach trials conducted on 239Pu/241Am loaded ceramic at 313 K/28 days gave normalized mass losses of 1.2 × 10-5 g m-2 and 2.7 × 10-3 g m-2 for Pu and Cl, respectively. In order to assess the response of the phases to radiation-induced damage, accelerated ageing trials were performed on samples in which the 239Pu was replaced with 238Pu. No changes to the crystalline structure of the waste were detected in the XRD spectra after the samples had experienced an α radiation fluence of 4 × 1018 g-1. Leach trials showed that there was an increase in the P and Ca release rates but no change in the Pu release rate.

  15. Alpha Coincidence Detection for the Assay of Actinides

    SciTech Connect

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

    2013-11-15

    Abstract – Interferences in both decay counting and mass counting techniques limit their application for some environmental monitoring applications. For example, 238U interferes with 238Pu in mass spectrometry measurements, while in conventional alpha spectroscopy measurements it is nearly impossible to separate 238Pu from 241Am and 239Pu from 240Pu. These interferences are typically resolved by using chemical separation and/or different measurement techniques for different isotopes. We are investigating radiation detector concepts to simultaneously assay these four isotopes with minimal sample preparation by exploiting radiation signatures measured in coincidence with the typical alpha decays of these isotopes. Particles in coincidence with the alpha decay include conversion electrons, gamma rays, x-rays, and Auger electrons. Each decay has a unique energy distribution enabling the separation of the isotopes. We are exploring two basic detector concepts to achieve these goals: a silicon-based design and a gas-detector design. The silicon system provides the potential for higher energy resolution at the cost of lower efficiency compared to a gas detector. In this paper, we will describe our evaluation of the different detector concepts, which will include detection efficiency, ability to resolve the isotopes, sample preparation and equipment requirements.

  16. Effective atomic number of some sugars and amino acids for scattering of (241)Am and (137)Cs gamma rays at low momentum transfer.

    PubMed

    Vinaykumar, L; Umesh, T K

    2015-09-01

    In this paper, we report the effective atomic number of some H, C, N and O based sugars and amino acids. These have been determined by using a handy expression which is based on the theoretical angle integrated small angle (coherent+incoherent) scattering cross sections of seven elements of Z≤13 in four angular ranges of (0-4°), (0-6°), (0-8°) and (0-10°)for (241)Am (59.54 keV) and (137)Cs (661.6 keV) gamma rays. The theoretical scattering cross sections were computed by a suitable numerical integration of the atomic form factor and incoherent scattering function compilations of Hubbell et al. (1975) which make use of the non-relativistic Hartree-Fock (NRHF) model for the atomic charge distribution of the elements in the angular ranges of interest. The angle integrated small angle scattering cross sections of the H, C, N and O based sugars and amino acids measured by a new method reported recently by the authors were used in the handy expression to derive their effective atomic number. The results are compared with the other available data and discussed. Possible conclusions are drawn based on the present study. PMID:26073268

  17. Effective atomic number of some sugars and amino acids for scattering of (241)Am and (137)Cs gamma rays at low momentum transfer.

    PubMed

    Vinaykumar, L; Umesh, T K

    2015-09-01

    In this paper, we report the effective atomic number of some H, C, N and O based sugars and amino acids. These have been determined by using a handy expression which is based on the theoretical angle integrated small angle (coherent+incoherent) scattering cross sections of seven elements of Z≤13 in four angular ranges of (0-4°), (0-6°), (0-8°) and (0-10°)for (241)Am (59.54 keV) and (137)Cs (661.6 keV) gamma rays. The theoretical scattering cross sections were computed by a suitable numerical integration of the atomic form factor and incoherent scattering function compilations of Hubbell et al. (1975) which make use of the non-relativistic Hartree-Fock (NRHF) model for the atomic charge distribution of the elements in the angular ranges of interest. The angle integrated small angle scattering cross sections of the H, C, N and O based sugars and amino acids measured by a new method reported recently by the authors were used in the handy expression to derive their effective atomic number. The results are compared with the other available data and discussed. Possible conclusions are drawn based on the present study.

  18. Vegetation uptake from burial ground alpha waste trenches

    SciTech Connect

    Murphy, C.E. Jr.; Tuckfield, R.C.

    1989-01-01

    This study was conducted as part of an evaluation of the potential radiological consequences of reinhabiting the SRS burial ground. The objective was to determine the uptake of buried, low-level, transuranic waste from unlined earthen trenches by forest vegetation. Two tree plots were established in 1979. One plot was put over a trench containing alpha waste and the other in an area without trenches. When the tree seedlings were sampled during 1979 and 1980, and analysized for {sup 239}Pu and {sup 238}Pu, there was only a small difference in radionuclude concentration between trees planted over the trench and those planted on the control plot because of the limited root intrusion into the trench by the seedlings. However, when trees were sample in 1986, 1987, and 1988 and analyzed for {sup 241}Am, {sup 238}Pu, {sup 239}Pu, and {sup 237}Np activity, the average activity of all of these isotopes was significantly higher over the trenches than in the control plot. These measurements indicate that tree roots will extract transuranic isotopes from buried, low-level waste. The amount of radioisotopes moved from the trenches to the surface is small and the level in the trees is low enough that dose from exposure will be small. The long term effects of transport of radioisotopes from the trenches to the surface soil was evaluated by estimating the accumulation in the surface soil. Transuranic activity in selected food crops was calculated using the soil activity and the literature derived concentration factors. In all cases, the activity of the transuranic isotopes in the edible portion of the plants was quite low. The activity in the leaf tissue was much higher than in the seed. However, it should be noted that in only one case was the activity higher than the naturally occurring activity of {sup 40}K in the pine foliage.

  19. 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

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

    DOE PAGES

    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

  1. Evidence for the Remobilization of Sellafield Waste Radionuclides in an Intertidal Salt Marsh, West Cumbria, U.K.

    NASA Astrophysics Data System (ADS)

    Morris, K.; Butterworth, J. C.; Livens, F. R.

    2000-11-01

    Intertidal sediments in north-west England contain enhanced levels of artificial radionuclides due to the authorized release of low-level liquid waste from the Sellafield reprocessing site. In this paper, the behaviour of 99Tc, 137Cs, 237Np, 238Pu, 239Pu, 240Pu, 239+240Pu and 241Am in an intertidal marsh sediment is described. The radionuclide data, together with stable element data, allow detailed interpretation of the behaviour of these artificial radionuclides in a natural environment. For 241Am and 239+240Pu, for which the Sellafield discharge history is well known, the distributions down the sediment core show a high correlation with the Sellafield discharge history. The sediment profiles for other less widely studied radionuclides, 99Tc and 237Np, have been examined in relation to both the post-1978 published discharge histories and the behaviour of other Sellafield-derived radionuclides in the core. There is strong evidence that significant post-depositional remobilization of a proportion of the most labile elements, 237Np, 137Cs and 99Tc, is occurring at the marsh.

  2. Preparation of actinide specimens for the US/UK joint experiment in the Dounreay Prototype Fast Reactor

    SciTech Connect

    Quinby, T C; Adair, H L; Kobisk, E H

    1982-05-01

    A joint research program involving the United States and the United Kingdom was initiated about four years ago for the purpose of studying the fuel behavior of higher actinides using in-core irradiation in the fast reactor at Dounreay, Scotland. Simultaneously, determination of integral cross sections of a wide variety of higher actinide isotopes (physics specimens) was proposed. Coincidental neutron flux and energy spectral measurements were to be made using vanadium encapsulated dosimetry materials in the immediate region of the fuel pellets and physics samples. The higher actinide samples chosen for the fuel study were /sup 241/Am and /sup 244/Cm in the forms of Am/sub 2/O/sub 3/, Cm/sub 2/O/sub 3/, and Am/sub 6/Cm(RE)/sub 7/O/sub 21/, where (RE) represents a mixture of lanthanides. Milligram quantities of actinide oxides of /sup 248/Cm, /sup 246/Cm, /sup 244/Cm, /sup 243/Cm, /sup 243/Am, /sup 241/Am, /sup 244/Pu, /sup 242/Pu, /sup 241/Pu, /sup 240/Pu, /sup 239/Pu, /sup 238/Pu, /sup 237/Np, /sup 238/U, /sup 236/U, /sup 235/U, /sup 234/U, /sup 233/U, /sup 232/Th, /sup 230/Th, and /sup 231/Pa were encapsulated to obtain nuclear cross section and reaction rate data for these materials.

  3. The applicability of MGA method for depleted and natural uranium isotopic analysis in the presence of actinides (232Th, 237Np, 233Pa and 241Am).

    PubMed

    Yücel, Haluk

    2007-11-01

    The multi-group analysis (MGA) method for the determination of uranium isotopic abundances in depleted uranium (DU) and natural uranium (NU) samples is applied in this study. A set of non-destructive gamma-ray measurements of DU and NU samples were performed using a planar Ge detector. The relative abundances of 235U and 238U isotopes were compared with the declared values of the standards. The relative abundance for 235U obtained by MGA for a "clean" DU or NU sample with a content of uranium>1wt% is determined with an accuracy of about +/-5%. However, when several actinides such as 232Th, 237Np, 233Pa and 241Am are present along with uranium isotopes simulating "dirty" DU or NU, it has been observed that MGA method gives erroneous results. The 235U abundance results for the samples were 6-25 times higher than the declared values in the presence of above-mentioned actinides, since MGA is utilized the X-ray and gamma-ray peaks in the 80-130 keV energy region, covering XKalpha and XKbeta regions. After the least-squares fitting of the spectra, it is found that the increases in the intensities of the X-ray and gamma-ray peaks of uranium are remarkably larger in the complex 80-130 keV region. On the other hand, it is observed that the interferences of the actinide peaks are relatively less dominant in the higher gamma-ray region of 130-300 keV. The results imply the need for dirty DU and NU samples that the MGA method should utilize the higher energy gamma-rays (up to 1001 keV of (234m)Pa) combined with lower energies of the spectra, which may be collected in a two detector mode (a planar Ge and a high efficient coaxial Ge).

  4. The applicability of MGA method for depleted and natural uranium isotopic analysis in the presence of actinides (232Th, 237Np, 233Pa and 241Am).

    PubMed

    Yücel, Haluk

    2007-11-01

    The multi-group analysis (MGA) method for the determination of uranium isotopic abundances in depleted uranium (DU) and natural uranium (NU) samples is applied in this study. A set of non-destructive gamma-ray measurements of DU and NU samples were performed using a planar Ge detector. The relative abundances of 235U and 238U isotopes were compared with the declared values of the standards. The relative abundance for 235U obtained by MGA for a "clean" DU or NU sample with a content of uranium>1wt% is determined with an accuracy of about +/-5%. However, when several actinides such as 232Th, 237Np, 233Pa and 241Am are present along with uranium isotopes simulating "dirty" DU or NU, it has been observed that MGA method gives erroneous results. The 235U abundance results for the samples were 6-25 times higher than the declared values in the presence of above-mentioned actinides, since MGA is utilized the X-ray and gamma-ray peaks in the 80-130 keV energy region, covering XKalpha and XKbeta regions. After the least-squares fitting of the spectra, it is found that the increases in the intensities of the X-ray and gamma-ray peaks of uranium are remarkably larger in the complex 80-130 keV region. On the other hand, it is observed that the interferences of the actinide peaks are relatively less dominant in the higher gamma-ray region of 130-300 keV. The results imply the need for dirty DU and NU samples that the MGA method should utilize the higher energy gamma-rays (up to 1001 keV of (234m)Pa) combined with lower energies of the spectra, which may be collected in a two detector mode (a planar Ge and a high efficient coaxial Ge). PMID:17606378

  5. $sup 238$Pu fuel form activities

    SciTech Connect

    Not Available

    1987-06-01

    This report for STYPu Fuel Form Activities has one main section: SRP-PuFF Facility. The SRL portion of this program has been completed. The program status, budget information, and milestone schedules are discussed. The SRP portion of this report summarizes production of STYPuO2 fuel forms for use in radioisotopic thermoelectric generators (RTG's) in the Plutonium Fuel Form (Puff) Facility at the Savannah River Plant. The PuFF Facility has been placed in a production readiness mode of operation pending funding of additional heat source programs.

  6. Circulatory kinetics of intravenously injected {sup 238}Pu(IV) citrate and {sup 14}C-CaNa{sub 3}-DTPA in mice: Comparison with rat, dog, and Reference Man

    SciTech Connect

    Durbin, P.W.; Kullgren, B.; Schmidt, C.T.

    1997-02-01

    New ligands for in vivo chelation of Pu(IV) are being synthesized and evaluated in mice for efficacy and toxicity. Biokinetic studies of the new ligands, CaNa{sub 3}-DTPA, and Pu(IV) are major components of those investigations. Young adult female mice were injected intravenously (iv) with {sup 3}H-inulin, {sup 14}C-CaNa{sub 3}-DTPA, or {sup 238}Pu(IV) citrate to provide base- line data for plasma clearance, tissue uptake, and excretion rates and to determine the dilution volume (VOD) and renal clearance rate (RC) of filterable substances. Published plasma clearance data in Reference Man, dog, and rat were collected. Based on combined data for {sup 3}H-inulin and {sup 14}C-CaNa{sub 3}-DTPA, VOD = 17% of body weight and RC = 18 mL kg{sup -1} min{sup -1} for mice. Retention of {sup 14}C-CaNa{sub 3}-DTPA in the four species is proportional to body weight and inversely proportional to RC: Integrals of the retention of {sup 14}C-CaNa{sub 3}-DTPA from R(t) = 1.0 to R(t) = 0.05 are 108, 43, 28, and 10 DF min, respectively, for Reference Man, dog, rat, and mouse. Clearances of iv-injected Pu(IV) citrate from plasma are in the same order: The plasma curve integrals from injection to 1440 min are 840, 640, 280, and 67 DF min, respectively, for Reference Man, dog, rat, and mouse. In mice, a large fraction of newly injected Pu(IV) is rapidly transferred to the interstitial water of bulk soft tissue (excluding liver and kidneys), from which it is cleared at the same rate as from the plasma. Rapid plasma clearance, escape into interstitial water (22%ID at 20 min), significant early urinary excretion (8%ID in 12 h), and prompt deposition in liver and skeleton (complete in 12 h) are evidence of inefficient binding to plasma protein of newly injected Pu(IV) in mice. Slow plasma clearance, little early urinary excretion, and delayed deposition in liver and skeleton reflect more efficient binding of newly injected Pu(IV) in Reference Man and dog. 39 refs., 6 figs., 3 tabs.

  7. Bayesian integration of radioisotope dating (210Pb, 137Cs, 241Am, 14C) and an 18-20th century mining history of Brotherswater, English Lake District

    NASA Astrophysics Data System (ADS)

    Schillereff, Daniel; Chiverrell, Richard; Macdonald, Neil; Hooke, Janet; Welsh, Katharine; Piliposyan, Gayane; Appleby, Peter

    2014-05-01

    Lake sediment records are often a useful tool for investigating landscape evolution as geomorphic changes in the catchment are reflected by altered sediment properties in the material transported through the watershed and deposited at the lake bed. Recent research at Brotherswater, an upland waterbody in the Lake District, northwest England, has focused on reconstructing historical floods from their sedimentary signatures and calculating long-term sediment and carbon budgets from fourteen sediment cores extracted from across the basin. Developing accurate chronological control is essential for these tasks. One sediment core (BW11-2; 3.5 m length) from the central basin has been dated using artificial radionuclide measurements (210Pb, 137Cs, 241Am) for the uppermost sediments and radiocarbon (14C) for lower sediments. The core appears to span the past 1500 years, however a number of problems have arisen. We present our explanations for these errors, the independent chronological techniques used to generate an accurate age-depth model for this core and methods for its transferral to the other 13 cores extracted from the basin. Two distinct 137Cs markers, corresponding to the 1986 Chernobyl disaster and 1960s weapons testing, confirm the 210Pb profile for sediment deposition since ~1950, but calculations prior to this appear erroneous, possibly due to a hiatus in the sediment record. We used high-resolution geochemical profiles (measured by XRF) to cross-correlate with a second 210Pb-dated chronology from a more distal location, which returned more sensible results. Unfortunately, the longer 14C sequence exhibits two age-reversals (radiocarbon dates that are too old). We believe the uppermost two dates are erroneous, due to a shift in inflow location as a flood prevention method ~1900 A.D., dated using information from historical maps. The lower age-reversal coincides with greater supply of terrigenous material to the lake (increased Zr, K, Ti concentrations

  8. Relative biological effectiveness for induction of cancer by protracted alpha versus beta internal irradiation

    SciTech Connect

    Raabe, O.G.

    1996-06-01

    Three-dimensional dose-rate/time/ response mathematical surfaces describe radiation effects in lifetime studies of beagles after Intake by injection or inhalation of selected radionuclides (including {alpha}-emitters {sup 226}Ra, {sup 239}Pu, {sup 238}Pu, and {sup 241}Am and {Beta}-emitters {sup 90}Sr, {sup 91}Y, and {sup 144}Ce) and in people after intake of {sup 226}Ra. For each effect t{sub m}=K{sub m}d{sup -s}, where t{sub m} is the median elapsed time to death with the specified effect after intake, d is the time-weighted average absorbed radiation dose-rate to the target organ, K{sub m} is the median distribution coefficient, and s is the negative slope parameter. Using maximum likelihood survival regression methods, for fatal cancer induction s was found to be one-third for {alpha} radiation and two-thirds for {beta} radiation. Because the slopes of the response curves for high LET {alpha} emitters differ from those for the low LET {Beta} emitters, the observed relative biological effectiveness, RBE({alpha}/{beta}), varies as a function of time-weighted average dose rate. At high dose rates, this radiation-induced cancer RBE({alpha}/{beta}) is small, but as dose rate goes down, the radiation-induced cancer RBE({alpha}/{beta}) rises without limit; actually the RBE({beta}/{alpha}) for producing radiation-induced cancer approaches zero. For example, for {sup 239}Pu dioxide in lung at 0.1 Gy d{sup -1} vs. {sup 90}Sr, the RBE({alpha}/{beta})=5, while at 1 mGy d{sup -1}, RBE({alpha}/{Beta})=50. The bone cancer RBE({alpha}/{beta})=l at 0.16 Gy d{sup -1} but RBE({alpha}/{beta})=30 at 1 mGy d{sup -1} for {sup 226}Ra/{sup 90}Sr in bone. Since {sup 238}Pu and {sup 239}Pu are about 10 times more effective than {sup 226}Ra in producing bone cancer, the apparent RBE({alpha}/{beta})=300 for plutonium in bone at 1 mG d{sup -1}.

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

    SciTech Connect

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

    1993-09-01

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

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

    SciTech Connect

    Guilmette, R.A., Griffith, W.C.; Hickman, A.W.

    1991-12-31

    Results of experimental studies in which animals inhaled {sup 238}PuO{sub 2} or {sup 239}PuO{sub 2} aerosols have shown that the biokinetics and associated radiation dose patterns for these two isotopes differ significantly due to differences in in-vivo solubility caused by the 260-fold difference in specific activity between {sup 238}PuO{sub 2} and {sup 239}PuO{sub 2}. We have adapted a biokinetics and dosimetry model derived from results of the ITRI dog studies to humans and have calculated dose commitments and annual limits on intake (ALI) for both Pu isotopes. Our results show that the ALI calculated in this study is one-third that for class Y {sup 238}Pu from ICRP 30, and one-half or equal to that for class Y {sup 239}Pu, depending on how activity in the thoracic lymph nodes is treated dosimetrically.

  11. 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%.

  12. 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

  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. Radionuclide contaminant analysis of small mammels, plants and sediments within Mortandad Canyon, 1994

    SciTech Connect

    Bennett, K.; Biggs, J.; Fresquez, P.

    1996-01-01

    Small mammals, plants and sediments were sampled at one upstream location (Site 1) and two downstream locations (Site 2 and Site 3) from the National Pollution Discharge Elimination System outfall {number_sign}051-051 in Mortandad Canyon, Los Alamos County, New Mexico. The purpose of the sampling was to identify radionuclides potentially present, to quantitatively estimate and compare the amount of radionuclide uptake at specific locations (Site 2 and Site 3) within Mortandad Canyon to an upstream site (Site 1), and to identify the primary mode (inhalation ingestion, or surface contact) of contamination to small mammals. Three composite samples of at least five animals per sample were collected at each site. Pelts and carcasses of each animal were separated and analyzed independently. In addition, three composite samples were also collected for plants and sediments at each site. Samples were analyzed for {sup 241}Am, {sup 90}Sr, {sup 238}Pu, {sup 239}Pu, and total U. With the exception of total U, all mean radionuclide concentrations in small mammal carcasses and sediments were significantly higher at Site 2 than Site 1 or Site 3. No differences were detected in the mean radionuclide concentration of plant samples between sites. However, some radionuclide concentrations found at all three sites were higher than regional background. No differences were found between mean carcass radionuclide concentrations and mean pelt radionuclide concentrations, indicating that the two primary modes of contamination may be equally occurring.

  15. Tissue-equivalent torso phantom for calibration of transuranic-nuclide counting facilities

    SciTech Connect

    Griffith, R.V.; Anderson, A.L.; Dean, P.N.; Fisher, J.C.; Sundbeck, C.W.

    1986-01-16

    Several tissue-equivalent human-torso phantoms have been constructed for the calibration of counting systems used for in-vivo measurement of transuranic radionuclides. The phantoms contain a simulated human rib cage (in some cases, real bone) and removable model organs, and they include tissue-equivalent chest plates that can be placed over the torso to simulate people with a wide range of statures. The organs included are the lungs, liver, and tracheobronchial lymph nodes. Polyurethane with varying concentrations of added calcium was used to simulate the linear photon-attenuation properties of various human tissues, including lean muscle, adipose-muscle mixtures, cartilage, and bone. Foamed polyurethane was used to simulate lung tissue. Organs have been loaded with highly pure /sup 238/Pu, /sup 239/Pu, /sup 241/Am, and other radionuclides of interest. The validity of the phantom as a calibration standard has been checked in separate intercomparison studies using human subjects whose lungs contained a plutonium simulant. The resulting phantom calibration factors generally compared to within +-20% of the average calibration factors obtained for the human subjects.

  16. 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.

  17. 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

    2016-05-17

    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.

  18. Fission Rate Ratios of FCA-IX Assemblies as Integral Experiment for Assessment of TRU's Fission Cross Sections

    NASA Astrophysics Data System (ADS)

    Fukushima, Masahiro; Tsujimoto, Kazufumi; Okajima, Shigeaki

    2016-03-01

    At the fast critical assembly (FCA) of JAEA, central fission rate ratios for TRU such as 237Np, 238Pu, 239Pu, 242Pu, 241Am, 243Am, and 244Cm were measured in the seven uraniumfueled assemblies (FCA-IX assemblies) with systematically changed neutron spectra. The FCA-IX assemblies were constructed with simplicity both in geometry and composition. By virtue of these FCA-IX assemblies where the simple combinations of uranium fuel and diluent (graphite and stainless steel) in their core regions were systematically varied, the neutron spectra of them cover from the intermediate to fast one. Taking their advantages, benchmark models with respect to the central fission rate ratios had been recently developed for the evaluation of the TRU's fission cross sections. As an application of these benchmark models, the Japanese Evaluated Nuclear Data Library JENDL-4.0 was utilized by a Monte Carlo calculation code. Several results show large discrepancies between the calculation and experimental values. The benchmark models would be well suited for the evaluation and modification of the nuclear data for the TRU's fission cross sections.

  19. 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.

  20. 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

  1. EMP Attachment 1 DOE-SC PNNL Site Sampling and Analysis Plan

    SciTech Connect

    Meier, Kirsten M.

    2011-11-10

    This Sampling and Analysis Plan (SAP) is written for the radiological environmental air surveillance program for the DOE-SC PNNL Site, Richland Washington. It provides the requirements for planning sampling events, and the requirements imposed on the analytical laboratory analyzing the air samples. The actual air sampling process is in procedure EPRP-AIR-029. The rationale for analyte selection, media, and sampling site location has been vetted through the data quality objectives (DQO) process (Barnett et al. 2010). The results from the DQO process have been reviewed and approved by the Washington State Department of Health. The DQO process (Barnett et al. 2010) identified seven specific radionuclides for analysis along with the need for gross alpha and gross beta radiological analyses. The analytes are {sup 241}Am, {sup 243}Am, {sup 244}Cm, {sup 60}Co, {sup 238}Pu, {sup 239}Pu, and {sup 233}U. The report also determined that air samples for particulates are the only sample matrix required for the monitoring program. These samples are collected on 47-mm glass-fiber filters.

  2. Variability in the edible fraction content of 60Co, 99Tc, 110mAg, 137Cs and 241Am between individual crabs and lobsters from Sellafield (north eastern Irish Sea).

    PubMed

    Swift, D J; Nicholson, M D

    2001-01-01

    We investigated the variability of anthropogenic radionuclide content of the edible fractions of individual edible crabs (Cancer pagurus L.) and European lobsters (Homarus gammarus L.) caught commercially in the Sellafield offshore area. Sixteen female and 18 male crabs and 20 female and 17 male lobsters were selected from commercial catches made between 25 May and 5 June 1997. Each gender group was selected to be within the known weight range for commercially caught crustacea from the area. Four artificial radionuclides (60Co, 110mAg, 137Cs or 241Am) were detected by gamma-spectrometry. The edible fraction content of these radionuclides between males and females for either species were not statistically significantly different. 99Tc was analysed by chemical separation and beta-counting. 99Tc concentrations in female crabs tended to be higher (172 +/- 205 (16) Bq kg-1(wet); mean +/- standard deviation (n samples)) than those in males (85 +/- 58 (18) Bq kg-1 (wet)), although this was not a statistically significant difference. For both male and female crabs, 99Tc concentrations tended to decrease with increasing whole live weights. For 99Tc in lobsters the picture is less clear. Female lobsters contained more activity (14800 +/- 7400 (20) Bq kg-1 (wet)) than males (7100 +/- 3900 (17) Bq kg-1 (wet)). The results were used to discuss the implications for sampling and monitoring. PMID:11381940

  3. 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.

  4. 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

  5. [239Pu and chromosomal aberrations in human peripheral blood lymphocytes].

    PubMed

    Okladnikova, N D; Osovets, S V; Kudriavtseva, T I

    2009-01-01

    The genome status in somatic cells was assessed using the chromosomal aberration (CA) test in peripheral blood lymphocytes from 194 plutonium workers exposed to occupational radiation mainly from low-transportable compounds of airborne 230Pu. Pu body burden at the time of cytogenetic study varied from values close to the method sensitivity to values multiply exceeding the permissible level. Standard (routine) methods of peripheral blood lymphocytes cultivation were applied. Chromatid- and chromosomal-type structural changes were estimated. Aberrations were estimated per 100 examined metaphase cells. The quantitative relationship between the CA frequency and Pu body burden and the absorbed dose to the lung was found. Mathematical processing of results was carried out based on the phenomenological model. The results were shown as theoretical and experimental curves. The threshold of the CA yield was 0.43 +/- 0.03 kBq (Pu body burden) and 6.12 +/- 1.20 cGy (absorbed dose to the lung).

  6. 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.

  7. Twenty-four Years of Follow-Up for a Hanford Plutonium Wound Case

    SciTech Connect

    Carbaugh, Eugene H.; Lynch, Timothy P.; Antonio, Cheryl L.; Medina-Del Valle, Fernando

    2010-10-01

    A 1985 plutonium puncture wound resulted in the initial deposition of 48 kBq of transuranic alpha activity, primarily 239Pu and 241Am, in a worker’s right index finger. Surgical excisions in the week following reduced the long-term residual wound activity to 5.4 kBq, and 164 DTPA chelation therapy administrations over a 17-month period resulted in urinary excretion of about 7 kBq. The case was published in 1988, but now 20 additional years of follow-up data are available. Annual bioassay measurements have included wound counts, skeleton counts, liver counts, lung counts, axillary lymph node counts, and urinalyses for plutonium and 241Am. These measurements have shown relatively stable levels of 241Am at the wound site, with gradually increasing amounts of 241Am detected in the skeleton. Liver counts has shown erratic detection of 241Am, and lung counts indicate 241Am as shine from the axillary lymph nodes and skeleton. Urine excretion of 239Pu since termination of chelation therapy has typically ranged from 10 to 20 mBq d-1, with 241Am excretion being about 10% of that for 239Pu. In addition, the worker has undergone annual routine medical exams, which have not identified any adverse health effects associated with the intake.

  8. Americium As A Potential Power Source For Space Missions

    NASA Astrophysics Data System (ADS)

    Cordingley, Leon; Rice, Tom; Sarsfield, Mark J.; Stephenson, Keith; Tinsley, Tim

    2011-10-01

    Electrical power sources used in outer planet missions are a key enabling technology for data acquisition and communications. Power sources generate electricity from the thermal energy from alpha decay of the radioisotope 238Pu via thermoelectric conversion. Production of 238Pu requires specialist facilities including a nuclear reactor and reprocessing plants that are expensive to build and operate, so naturally, a more economical alternative is attractive to the industry. Within Europe 241Am is a feasible alternative to 238Pu that can provide a heat source for radioisotope thermoelectric generators (RTGs) and radioisotope heating units (RHUs). Whilst there are implications associated with the differences between 238Pu and 241Am, these technological challenges are surmountable.

  9. Highly enriched isotope samples of uranium and transuranium elements for scientific investigation

    NASA Astrophysics Data System (ADS)

    Vesnovskii, Stanislav P.; Polynov, Vladimir N.; Danilin, Lev. D.

    1992-02-01

    The paper describes the production of highly enriched isotopes of uranium, plutonium, americium and curium by electromagnetic separation for scientific and applied researches in physics, chemistry, geology, medicine, biology and other fields. Using the equipment described, the isotopes are produced in quantities sufficient to set up nuclear physical experiments, to produce nuclear reference materials and standard sources for calibration of radiometrical and mass spectrometrical equipment, in radionuclide metrology, etc. For the following isotopes the indicated degrees of isotopic enrichment were achieved: 233U - 99.97%; 235U - 99.97%; 236U - 98.0%; 238U - 99.997%; 238Pu - 99.6%; 239Pu - 99.9977%; 240Pu - 99.9-100%; 241Pu - 96.998%; 242Pu - 97.8-99.96%; 244Pu - 96.7%; 241Am - 99.6%; 242Am - 73.6%; 243Am - 99.2-99.94%; 243Cm - 99.99%; 245Cm - 99.998%; 246Cm - 99.8%; 247Cm - 90%; 248Cm - 97%. Methods for preparing layers of highly enriched isotopes on various substances are presented: - electrochemical deposition of transuranic elements from aqueous-organic and organic media and vacuum spraying: - the method of foil and coating formation via compounds in the vapour phase; - the method of fabrication of layers of transuranic elements on superthin (1-2 μm) metal substrates with additional isolating polymer-metal coatings (0.2-0.4 μm), that substantially decrease material transfer from the active layer and increase safety of product handling.

  10. 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.

  11. OSMOSE program : statistical review of oscillation measurements in the MINERVE reactor R1-UO2 configuration.

    SciTech Connect

    Stoven, G.; Klann, R.; Zhong, Z.; Nuclear Engineering Division

    2007-08-28

    The OSMOSE program is a collaboration on reactor physics experiments between the United States Department of Energy and the France Commissariat Energie Atomique. At the working level, it is a collaborative effort between the Argonne National Laboratory and the CEA Cadarache Research Center. The objective of this program is to measure very accurate integral reaction rates in representative spectra for the actinides important to future nuclear system designs, and to provide the experimental data for improving the basic nuclear data files. The main outcome of the OSMOSE measurement program will be an experimental database of reactivity-worth measurements in different neutron spectra for the heavy nuclides. This database can then be used as a benchmark to verify and validate reactor analysis codes. The OSMOSE program (Oscillation in Minerve of isotopes in Eupraxic Spectra) aims at improving neutronic predictions of advanced nuclear fuels through oscillation measurements in the MINERVE facility on samples containing the following separated actinides: {sup 232}Th, {sup 233}U, {sup 234}U, {sup 235}U, {sup 236}U, {sup 238}U, {sup 237}Np, {sup 238}Pu, {sup 239}Pu, {sup 240}Pu, {sup 241}Pu, {sup 242}Pu, {sup 241}Am, {sup 243}Am, {sup 244}Cm, and {sup 245}Cm. The first part of this report provides an overview of the experimental protocol and the typical processing of a series of experimental results which is currently performed at CEA-Cadarache. In the second part of the report, improvements to this technique are presented, as well as the program that was created to process oscillation measurement results from the MINERVE facility in the future.

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

    SciTech Connect

    Maxwell, S.; Jones, V.

    2009-05-27

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

  13. Prediction of in vivo background in phoswich lung count spectra

    SciTech Connect

    Richards, N.W. . Office of Radiation Protection)

    1999-05-01

    Phoswich scintillation counters are used to detect actinides deposited in the lungs. The resulting spectra, however, contain Compton background from the decay of [sup 40]K, which occurs naturally in the striated muscle tissue of the body. To determine the counts due to actinides in a lung count spectrum, the counts due to [sup 40]K scatter must first be subtracted out. The [sup 40]K background in the phoswich NaI(Tl) spectrum was predicted from an energy region of interest called the monitor region, which is above the [sup 238]Pu region and the [sup 241]Am region, where photopeaks from [sup 238]Pu and [sup 241]Am region, where photopeaks from [sup 238]Pu and [sup 241]Am occur. Empirical models were developed to predict the backgrounds in the [sup 238]Pu and [sup 241]Am regions by testing multiple linear and nonlinear regression models. The initial multiple regression models contain a monitor region variable as well as the variables gender, (weight/height)[sup [alpha

  14. Alpha spectrometry applications with mass separated samples.

    PubMed

    Dion, M P; Eiden, Gregory C; Farmer, Orville T; Liezers, Martin; Robinson, John W

    2016-01-01

    (241)Am has been deposited using a novel technique that employs a commercial inductively coupled plasma mass spectrometer. This work presents results of high-resolution alpha spectrometry on the (241)Am samples using a small area passivated implanted planar silicon detector. We have also investigated the mass-based separation capability by developing a (238)Pu sample, present as a minor constituent in a (244)Pu standard, and performed subsequent radiometric counting. With this new sample development method, the (241)Am samples achieved the intrinsic energy resolution of the detector used for these measurements. There was no detectable trace of any other isotopes contained in the (238)Pu implant demonstrating the mass-based separation (or enhancement) attainable with this technique. PMID:26583262

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

    SciTech Connect

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

    1996-03-01

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

  16. 241Am INGROWTH AND ITS EFFECT ON INTERNAL DOSE.

    PubMed

    Konzen, Kevin

    2016-07-01

    Generally, plutonium has been manufactured to support commercial and military applications involving heat sources, weapons, and reactor fuel. This work focuses on three typical plutonium mixtures while observing the potential of Am ingrowth and its effect on internal dose. The term "ingrowth" is used to describe Am production due solely to the decay of Pu as part of a plutonium mixture, where it is initially absent or present in a smaller quantity. Dose calculation models do not account for Am ingrowth unless the Pu quantity is specified. This work suggested that Am ingrowth be considered in bioassay analysis when there is a potential of a 10% increase to the individual's committed effective dose. It was determined that plutonium fuel mixtures, initially absent of Am, would likely exceed 10% for typical reactor grade fuel aged less than 30 y; however, heat source grade and aged weapons grade fuel would normally fall below this threshold. Although this work addresses typical plutonium mixtures following separation, it may be extended to irradiated commercial uranium fuel and is expected to be a concern in the recycling of spent fuel. PMID:27218291

  17. 241Am INGROWTH AND ITS EFFECT ON INTERNAL DOSE.

    PubMed

    Konzen, Kevin

    2016-07-01

    Generally, plutonium has been manufactured to support commercial and military applications involving heat sources, weapons, and reactor fuel. This work focuses on three typical plutonium mixtures while observing the potential of Am ingrowth and its effect on internal dose. The term "ingrowth" is used to describe Am production due solely to the decay of Pu as part of a plutonium mixture, where it is initially absent or present in a smaller quantity. Dose calculation models do not account for Am ingrowth unless the Pu quantity is specified. This work suggested that Am ingrowth be considered in bioassay analysis when there is a potential of a 10% increase to the individual's committed effective dose. It was determined that plutonium fuel mixtures, initially absent of Am, would likely exceed 10% for typical reactor grade fuel aged less than 30 y; however, heat source grade and aged weapons grade fuel would normally fall below this threshold. Although this work addresses typical plutonium mixtures following separation, it may be extended to irradiated commercial uranium fuel and is expected to be a concern in the recycling of spent fuel.

  18. Recovery of 238PuO2 by Molten Salt Oxidation Processing of 238PuO2 Contaminated Combustibles (Part II)

    NASA Astrophysics Data System (ADS)

    Remerowski, Mary Lynn; Dozhier, C.; Krenek, K.; VanPelt, C. E.; Reimus, M. A.; Spengler, D.; Matonic, J.; Garcia, L.; Rios, E.; Sandoval, F.; Herman, D.; Hart, R.; Ewing, B.; Lovato, M.; Romero, J. P.

    2005-02-01

    Pu-238 heat sources are used to fuel radioisotope thermoelectric generators (RTG) used in space missions. The demand for this fuel is increasing, yet there are currently no domestic sources of this material. Much of the fuel is material reprocessed from other sources. One rich source of Pu-238 residual material is that from contaminated combustible materials, such as cheesecloth, ion exchange resins and plastics. From both waste minimization and production efficiency standpoints, the best solution is to recover this material. One way to accomplish separation of the organic component from these residues is a flameless oxidation process using molten salt as the matrix for the breakdown of the organic to carbon dioxide and water. The plutonium is retained in the salt, and can be recovered by dissolution of the carbonate salt in an aqueous solution, leaving the insoluble oxide behind. Further aqueous scrap recovery processing is used to purify the plutonium oxide. Recovery of the plutonium from contaminated combustibles achieves two important goals. First, it increases the inventory of Pu-238 available for heat source fabrication. Second, it is a significant waste minimization process. Because of its thermal activity (0.567 W per gram), combustibles must be packaged for disposition with much lower amounts of Pu-238 per drum than other waste types. Specifically, cheesecloth residues in the form of pyrolyzed ash (for stabilization) are being stored for eventual recovery of the plutonium.

  19. Radionuclide concentrations in honey bees from Area G at TA-54 during 1997. Progress report

    SciTech Connect

    Haarmann, T.K.; Fresquez, P.R.

    1998-07-01

    Honey bees were collected from two colonies located at Los Alamos National Laboratory`s Area G, Technical Area 54, and from one control (background) colony located near Jamez Springs, NM. Samples were analyzed for the following: cesium ({sup 137}Cs), americium ({sup 241}Am), plutonium ({sup 238}Pu and {sup 239,240}Pu), tritium ({sup 3}H), total uranium, and gross gamma activity. Area G sample results from both colonies were higher than the upper (95%) level background concentration for {sup 238}Pu and {sup 3}H.

  20. Calibration of a DSSSD detector with radioactive sources

    SciTech Connect

    Guadilla, V.; Tain, J. L.; Agramunt, J.; Algora, A.; Domingo-Pardo, C.; Rubio, B.

    2013-06-10

    The energy calibration of a DSSSD is carried out with the spectra produced by a {sup 207}Bi conversion electron source, a {sup 137}Cs gamma source and a {sup 239}Pu/{sup 241}Am/{sup 244}Cm triple alpha source, as well as employing a precision pulse generator in the whole dynamic range. Multiplicity and coincidence of signals in different strips for the same event are also studied.

  1. Uncertainty analysis of doses from ingestion of plutonium and americium.

    PubMed

    Puncher, M; Harrison, J D

    2012-02-01

    Uncertainty analyses have been performed on the biokinetic model for americium currently used by the International Commission on Radiological Protection (ICRP), and the model for plutonium recently derived by Leggett, considering acute intakes by ingestion by adult members of the public. The analyses calculated distributions of doses per unit intake. Those parameters having the greatest impact on prospective doses were identified by sensitivity analysis; the most important were the fraction absorbed from the alimentary tract, f(1), and rates of uptake from blood to bone surfaces. Probability distributions were selected based on the observed distribution of plutonium and americium in human subjects where possible; the distributions for f(1) reflected uncertainty on the average value of this parameter for non-specified plutonium and americium compounds ingested by adult members of the public. The calculated distributions of effective doses for ingested (239)Pu and (241)Am were well described by log-normal distributions, with doses varying by around a factor of 3 above and below the central values; the distributions contain the current ICRP Publication 67 dose coefficients for ingestion of (239)Pu and (241)Am by adult members of the public. Uncertainty on f(1) values had the greatest impact on doses, particularly effective dose. It is concluded that: (1) more precise data on f(1) values would have a greater effect in reducing uncertainties on doses from ingested (239)Pu and (241)Am, than reducing uncertainty on other model parameter values and (2) the results support the dose coefficients (Sv Bq(-1) intake) derived by ICRP for ingestion of (239)Pu and (241)Am by adult members of the public.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Uptake and translocation of neptunium-237, plutonium-238, plutonium-239,240, americium-241, and curium-244 by a wheat crop

    SciTech Connect

    Schulz, R.K.; Ruggieri, M.R.

    1981-07-01

    We carried out a plant uptake and translocation experiment in which a wheat crop was grown on Yolo soil contaminated with /sup 237/Np, /sup 238/Pu, /sup 239/ /sup 240/Pu, /sup 241/Am, and /sup 244/Cm. Studying pot-to-pot variability, we found the data a coefficient of variation of 21 percent. About 9 percent of this variability we ascribe to that of radioanalyses of the plant material. Both uptake and translocation of /sup 238/Pu and /sup 239/ /sup 240/Pu were found to be identical. Likewise, both uptake and translocation of /sup 241/Am and /sup 244/Cm were identical. The Pu concentration was about 10/sup 3/ lower in the grain than in the bottom one-half of the stem plus leaves.

  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. Elk and Deer Study, Material Disposal Area G, Technical Area 54: Source document

    SciTech Connect

    J. K. Ferenbaugh; P. R. Fresquez; M. H. Ebinger; G. J. Gonzales; P. A. Jordan

    1999-09-01

    As nuclear research has become more prevalent, environmental contamination from the disposal of radioactive waste has become a prominent issue. At Los Alamos National Laboratory (LANL) in northern New Mexico, radioactive contamination from disposal operations has raised some very specific concerns. Material Disposal Area G (Area G) is the primary low-level radioactive waste disposal site at LANL and occupies an area adjacent to land belonging to the Native American community of the Pueblo of San Ildefonso. Analyses of soil and vegetation collected from the perimeter of Area G have shown concentrations of radionuclides greater than background concentrations established for northern New Mexico. As a result, Pueblo residents had become concerned that contaminants from Area G could enter tribal lands through various ecological pathways. The residents specifically questioned the safety of consuming meat from elk and deer that forage near Area G and then migrate onto tribal lands. Consequently, this study addresses the uptake of {sup 3}H, {sup 90}Sr, {sup tot}U, {sup 238}Pu, {sup 239}Pu, {sup 241}Am, and {sup 137}Cs by elk (Cervus elaphus) and deer (Odocoileus hemionus) that forage around the perimeter of Area G and the associated doses to the animals and to humans who consume these animals. Radionuclide uptake by and internal dose to animals was estimated using equations modified from National Council on Radiological Protection Report 76. The Residual Radiation computer code was used to estimate the external dose to animals and the dose to humans consuming meat. Soil and water concentrations from the perimeter of Area G and from background regions in northern New Mexico were averaged over 4 years (1993--1996) and used as input data for the models. Concentration estimates generated by the model correspond to the concentration range measured in actual tissue samples from elk and deer collected at LANL. The highest dose estimates for both animals (0.028 mrad/d) and humans

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

    NASA Astrophysics Data System (ADS)

    Abdullah, Ramadhan Hayder; Sabr, Barzan Nehmat

    2016-03-01

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

  10. 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

  11. Post-Irradiation Examination of 237Np Targets for 238Pu Production

    SciTech Connect

    Morris, Robert Noel; Baldwin, Charles A; Hobbs, Randy W; Schmidlin, Joshua E

    2015-01-01

    Oak Ridge National Laboratory is recovering the US 238Pu production capability and the first step in the process has been to evaluate the performance of a 237Np target cermet pellet encased in an aluminum clad. The process proceeded in 3 steps; the first step was to irradiate capsules of single pellets composed of NpO2 and aluminum power to examine their shrinkage and gas release. These pellets were formed by compressing sintered NpO2 and aluminum powder in a die at high pressure followed by sintering in a vacuum furnace. Three temperatures were chosen for sintering the solution precipitated NpO2 power used for pellet fabrication. The second step was to irradiate partial targets composed of 8 pellets in a semi-prototypical arrangement at the two best performing sintering temperatures to determine which temperature gave a pellet that performed the best under the actual planned irradiation conditions. The third step was to irradiate ~50 pellets in an actual target configuration at design irradiation conditions to assess pellet shrinkage and gas release, target heat transfer, and dimensional stability. The higher sintering temperature appeared to offer the best performance after one cycle of irradiation by having the least shrinkage, thus keeping the heat transfer gap between the pellets and clad small minimizing the pellet operating temperature. The final result of the testing was a target that can meet the initial production goals, satisfy the reactor safety requirements, and can be fabricated in production quantities. The current focus of the program is to verify that the target can be remotely dissembled, the pellets dissolved, and the 238Pu recovered. Tests are being conducted to examine these concerns and to compare results to code predictions. Once the performance of the full length targets has been quantified, the pellet 237Np loading will be revisited to determine if it can be increased to increase 238Pu production.

  12. /sup 238/Pu fuel-form processes. Quarterly report, October-December 1982

    SciTech Connect

    Not Available

    1983-05-01

    A welding test in which multiple quenches are made in a single clad vent set was used to compare weld-quench cracking susceptibilities of S, V and X batches of DOP-26 iridium alloy. Results indicate that V-batch alloy is probably acceptable for production welding but use of X-batch alloy remains questionable. Analysis of fracture index of vacuum outgasses General-Purpose Heat Source (GPHS) production pellets from spring 1981 through August 1982 showed a cyclical trend in pellet fracture index. A noticeable reduction in the magnitude of the fracture index was observed starting in May 1982. However, the cyclic nature persisted. Since September 1982, the fracture index has been the lowest in production history. The cyclic pattern of the fracture index may also have been broken. ORNL has cross calibrated their contained and uncontained spark source mass spectrometers (SSMS) to ensure the results obtained with each will be correlatable with each other. SSMS analysis of iridium archive rings indicates that aluminum may be lost from the iridium clads during their two vacuum heat treatment steps. A method of measuring the surface area of both feed powder and shards using a Blaine tester is being evaluated. The results suggest that the method may be useful in correlating powder and shard properties with GPHS pellet quality.

  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. /sup 238/Pu fuel form processes. Quarterly report, April-June 1981

    SciTech Connect

    Folger, R.L.

    1981-12-01

    An analytical program has been started to determine the cause of cracking in DOP-26 iridium alloy during welding of GPHS clad vent sets. Analyses revealed that (1) intergranular cracking in the interior weld bead occurs in the heat-affected zone adjacent to the arc quench taper and at weld edges, (2) grain surfaces exposed by cracking exhibit a characteristic ridge network topography, and (3) no elements that could cause hot shortness were detected in the ridge networks.

  15. Report of Iridium/{sup 238}PuO{sub 2} Compatibility Test

    SciTech Connect

    Taylor, D.H.

    2001-08-09

    This study indicates that the chemical purity of the fuel used presently to fabricate fueled clad vent sets will not present any special problems to the performance of the fueled clad vent sets as intended. However, cation impurities in the fuel can have a deleterious effect on the iridium cladding and vents and should be minimized as much as practical.

  16. /sup 238/Pu fuel form processes. Quarterly report, July-September 1982

    SciTech Connect

    Not Available

    1982-12-01

    Fracture tendency of pellets after final heat treatment or vacuum outgassing during production has been reviewed. A statistical analysis of fracture tendency has revealed a cyclical trend. The period of the cycle on average is about every 50 pellets. Phosphorus is considered detrimental to the impact behavior of iridium. Tests show that phosphorus is easily picked up by PuO/sub 2/ through a variety of pathways and is difficult to remove by heating techniques such as are possible in the PuFF Facility. High-temperature impact ductility of CVS welds may be related to grain structure in the weld centerline. Heating at 1500/sup 0/C causes finely structured thorium-bearing patches on grain surfaces in welds to agglomerate into particles. Heating at 2000/sup 0/C appears to heal grain boundary cavities and pores. High-temperature creep has been identified as another mechanism for producing grain boundary cavities that cause weld-quench cracking. 17 figures, 11 tables.

  17. Neptunium, plutonium, and americium solubility and speciation studies in a neutral electrolyte with a total carbonate concentration simulating UE-25P No. 1 well water

    SciTech Connect

    Becraft, K.A.; Torretto, P.C.; Nitsche, H.

    1995-12-01

    In these experiments we have approached the solubility equilibrium from oversaturation. Results are given for solubility and speciation experiments of {sup 237}NpO{sub 2}+, {sup 239}Pu{sup 4+}, and {sup 241}Am{sup 3+} in a neutral electrolyte (0.1 M NaC1O{sub 4}) containing a total carbonate concentration similar to UE-25p No. 1 groundwater (0.015 M) at 25{degrees} C and at three pH values (6, 7, and 8.5). In these experiments, the solubility-controlling solids were identified and the speciation and/or oxidation states present in the supernatant solutions were determined. Trivalent neodymium was used as an oxidation state analog for {sup 241}Am(III) in order to reduce the radiolysis effects in the solutions. The {sup 241}Am(III) was included as a tracer for radioanalytical counting of samples.

  18. Plutonium aerosol fluxes and pulmonary exposure rates during resuspension from bare soils near a chemical separation facility

    SciTech Connect

    Shinn, J.H.; Homan, D.N.; Gay, D.D.

    1982-11-01

    The purpose of this study was to examine the plutonium aerosol fluxes (Curies per ground area per unit time) from a bare soil near a chemical separation facility and to determine the characteristics of the plutonium-bearing aerosols, which are of consequence in deposition of the alpha-emitters into the lung. These characteristics are the plutonium aerosol concentration (Curies per unit volume of air), the particle size distribution, the radioactivity size distribution, the enhancement factors, and others. The site was the agricultural field adjacent to H-area of Savannah River Plant near Aiken, South Carolina, where low-level releases of /sup 239/Pu and /sup 240/Pu occurred from 1967 through 1974. The releases then changed primarily to /sup 238/Pu. Results indicate that plutonium aerosol concentrations were not greatly increased by removing the vegetation and cultivating the field. Following a rain which stabilized the surface /sup 239/Pu concentrations were 37% of normal to 144% of normal as the field dried. The /sup 239/Pu concentration was broadly distributed over particle sizes and had MAD 2.7 ..mu..m. The /sup 239/Pu concentration distributions were found to be 12% respirable and the maximum concentration observed, 4.94 x 10/sup -17/ Ci m/sup -3/, amounted to an inconsequential exposure of less than 10/sup -5/ lifetime background dose for 100 days exposure. /sup 239/Pu flux was not greatly increased as the dust flux increased because /sup 239/Pu activity of the aerosols decreased with time to counteract the increased dust flux.

  19. Evolving Density and Static Mechanical Properties in Plutonium from Self-Irradiation

    SciTech Connect

    Chung, B W; Thompson, S R; Lema, K E; Hiromoto, D S; Ebbinghaus, B B

    2008-07-31

    Plutonium, because of its self-irradiation by alpha decay, ages by means of lattice damage and helium in-growth. These integrated aging effects result in microstructural and physical property changes. Because these effects would normally require decades to measure, studies are underway to assess the effects of extended aging on the physical properties of plutonium alloys by incorporating roughly 7.5 weight % of highly specific activity isotope {sup 238}Pu into the {sup 239}Pu metal to accelerate the aging process. This paper presents updated results of self-irradiation effects on {sup 238}Pu-enriched alloys measured by immersion density, dilatometry, and tensile tests. After nearly 90 equivalent years of aging, both the immersion density and dilatometry show that the enriched alloys continue to decreased in density by {approx}0.002% per year, without void swelling. Quasi-static tensile measurements show that the aging process increases the strength of plutonium alloys.

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

    SciTech Connect

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

    1998-04-01

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

  1. Development concept for a small, split-core, heat-pipe-cooled nuclear reactor

    NASA Technical Reports Server (NTRS)

    Lantz, E.; Breitwieser, R.; Niederauer, G. F.

    1974-01-01

    There have been two main deterrents to the development of semiportable nuclear reactors. One is the high development costs; the other is the inability to satisfy with assurance the questions of operational safety. This report shows how a split-core, heat-pipe cooled reactor could conceptually eliminate these deterrents, and examines and summarizes recent work on split-core, heat-pipe reactors. A concept for a small reactor that could be developed at a comparatively low cost is presented. The concept would extend the technology of subcritical radioisotope thermoelectric generators using 238 PuO2 to the evolution of critical space power reactors using 239 PuO2.

  2. Radioactivity in soils and sediments in and adjacent to the Los Alamos area, 1974-1977

    SciTech Connect

    Purtymun, W.D.; Peters, R.J.; Stoker, A.K.

    1980-02-01

    Soils and sediments are analyzed for gross alpha, gross beta, /sup 238/Pu, /sup 239/Pu, /sup 137/Cs, /sup 90/Sr, and total uranium as part of the continuing Environmental Monitoring Program at the Los Alamos Scientific Laboratory. This report documents the levels of radioactivity of radionuclides in soils and sediments in northern New Mexico from natural sources and worldwide fallout as well as at seven on-site soil and sediment stations which contain radioactivity contributed by the Laboratory for the period 1974 through 1977.

  3. Effects of self-irradiation in plutonium alloys

    DOE PAGES

    Chung, B. W.; Lema, K. E.; Allen, P. G.

    2015-09-16

    In this paper, we present updated results of self-irradiation effects on 238Pu-enriched 239Pu alloys measured by immersion density, dilatometry, and tensile tests. We obtained the self-irradiation equivalent time of nearly 200 years, nearly 100 years longer than in our previous papers. At this extended aging, we find the rate of decrease in density has slowed significantly, stabilizing around 15.73 g/cc, without signs of void swelling. The volume expansion measured at 35°C also shows apparent saturation at less than 0.25%. Quasi-static tensile measurement still show gradual increase in the strength of plutonium alloys with age.

  4. Adsorption and diffusion of plutonium in soil

    SciTech Connect

    Brown, D A

    1980-01-01

    The behavior of plutonium (Pu) was studied in three soils that varied in texture, CEC, pH, organic matter content and mineralogy (Fuquay, Muscatine, Burbank). Two isotopes, /sup 238/Pu and /sup 239/Pu, were used in order to detect Pu over a range of several orders of magnitude. Unless added in a chelated form, Pu was added to the soil as a nitrate in .01 N HNO/sub 3/ to simulate the release of acidic waste on the soil and to prevent rapid Pu hydrolysis or polymerization.

  5. Distribution and behaviour of transuranic elements in the physical and biological compartments of the channel french shore

    NASA Astrophysics Data System (ADS)

    Germain, P.; Miramand, P.

    1984-06-01

    Biological samples (algae, suspension feeders molluscs living in contact with sediments, annelids), sediments and sea water were taken at 5 stations along the Channel shore from 1978 to 1981 in order to determine 239+240Pu, 238Pu, 241Am and 244Cm levels. In Northern Cotentin, radioactivity levels for 239+240Pu, 238Pu and 241Am were respectively about 1-10, 0.5-7 and 1-19 pCi kg -1 fresh weight in biological samples, 24-90, 11-28 and 24-31 pCi kg -1 dry weight in sediments, 1-7, 5-40 and 2-15 fCi 1 -1 in sea water. For stations far from the La Hague outlet (Seine river and Mont Saint Michel bays) levels for 239+240Pu, 238Pu and 241Am were respectively about 0.3-5, 0.1-2 and 0.2-3 pCi kg -1 fresh weight in biological samples, 30-80, 5-26 and 14-40 pCi kg -1 dry weight in sediments, and 1-, 3-4 and 3-8 fCi 1 -1 in sea water. Labelling of industrial wastes was demonstrated by the values of the 238Pu/ 239+240Pu ratios. The evolution of plutonium isotopes in sea water and in the other environmental compartments and the bio-availability of americium are discussed. Sediment-animal transfers are quantified and their processes specified. An assessment of plutonium and americium hazards from ingestion of molluscs shows that the ingested activity represents 1.1×10 -4 only of the ALI (ingestion) recommended by ICRP for members of the public.

  6. 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.

  7. 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

  8. 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

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

    SciTech Connect

    Maxwell, S.

    2010-07-26

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

  10. Peak Stripping Methodology for Plutonium Analysis in the Presence of Neptunium

    SciTech Connect

    Hodge, Christ

    2005-05-17

    Quantitative Plutonium analysis depends upon the accurate identification of the assay peak. The Np[Pa] equilibrium pair introduces interfering peaks in {sup 239}Pu, {sup 238}Pu, and {sup 235}U assay peak region. When an interfering peak is present, it negates the assay unless an appropriate technique can be developed to deal with the interference. Peak Stripping is one such technique. Peak stripping involves an algorithm to strip an entire peak from another, resulting in a spectrum that can then be analyzed for the isotope of interest. A simpler method is a ''pseudo-peak-stripping'' whereby the effects of the interfering peak are quantified and those effects are stripped from the assay data. In this case the integrated peak areas are analyzed and corrected. There are two methods presented in this paper. Both assimilate the integrated data for the assay peak regions (in this case {sup 238}Pu, {sup 239}Pu, and {sup 235}U) and for the Neptunium/Protactinium secular equilibrium pair (Np[Pa]). Using Np[Pa] assumes that the Protactinium has come to equilibrium with Neptunium. This requires only {approx}6 months from the time chemical purification. Therefore it is a valid assumption in most cases. A correction is then applied to the assay peak areas to ''strip'' the underlying effects of Np[Pa].

  11. TRU waste-sampling program

    SciTech Connect

    Warren, J.L.; Zerwekh, A.

    1985-08-01

    As part of a TRU waste-sampling program, Los Alamos National Laboratory retrieved and examined 44 drums of /sup 238/Pu- and /sup 239/Pu-contaminated waste. The drums ranged in age from 8 months to 9 years. The majority of drums were tested for pressure, and gas samples withdrawn from the drums were analyzed by a mass spectrometer. Real-time radiography and visual examination were used to determine both void volumes and waste content. Drum walls were measured for deterioration, and selected drum contents were reassayed for comparison with original assays and WIPP criteria. Each drum tested at atmospheric pressure. Mass spectrometry revealed no problem with /sup 239/Pu-contaminated waste, but three 8-month-old drums of /sup 238/Pu-contaminated waste contained a potentially hazardous gas mixture. Void volumes fell within the 81 to 97% range. Measurements of drum walls showed no significant corrosion or deterioration. All reassayed contents were within WIPP waste acceptance criteria. Five of the drums opened and examined (15%) could not be certified as packaged. Three contained free liquids, one had corrosive materials, and one had too much unstabilized particulate. Eleven drums had the wrong (or not the most appropriate) waste code. In many cases, disposal volumes had been inefficiently used. 2 refs., 23 figs., 7 tabs.

  12. 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.

  13. Determination of plutonium content in high burnup pressurized water reactor fuel samples and its use for isotope correlations for isotopic composition of plutonium.

    PubMed

    Joe, Kihsoo; Jeon, Young-Shin; Han, Sun-Ho; Lee, Chang-Heon; Ha, Yeong-Keong; Song, Kyuseok

    2012-06-01

    The content of plutonium isotopes in high burnup pressurized water reactor fuel samples was examined using both alpha spectrometry and mass spectrometry after anion exchange separation. The measured values were compared with results calculated by the ORIGEN-2 code. On average, the ratios (m/c) of the measured values (m) over the calculated values (c) were 1.22±0.16 for (238)Pu, 1.02±0.14 for (239)Pu, 1.08±0.06 for (240)Pu, 1.06±0.16 for (241)Pu, and 1.13±0.08 for (242)Pu. Using the Pu data obtained in this work, correlations were derived between the alpha activity ratios of (238)Pu/((239)Pu+(240)Pu), the alpha specific activities of Pu, and the atom % abundances of the Pu isotopes. Using these correlations, the atom % abundances of the plutonium isotopes in the target samples were calculated. These calculated results agreed within a range from 2 to 8% of the experimentally derived values according to the isotopes of plutonium.

  14. 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.

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

    DOE PAGES

    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.

  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. 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. Source and long-term behavior of transuranic aerosols in the WIPP environment.

    PubMed

    Thakur, P; Lemons, B G

    2016-10-01

    Source and long-term behavior transuranic aerosols ((239+240)Pu, (238)Pu, and (241)Am) in the ambient air samples collected at and near the Waste Isolation Pilot Plant (WIPP) deep geologic repository site were investigated using historical data from an independent monitoring program conducted by the Carlsbad Environmental Monitoring and Research Center and an oversight monitoring program conducted by the management and operating contractor for WIPP at and near the facility. An analysis of historical data indicates frequent detections of (239+240)Pu and (241)Am, whereas (238)Pu is detected infrequently. Peaks in (239+240)Pu and (241)Am concentrations in ambient air generally occur from March to June timeframe, which is when strong and gusty winds in the area frequently give rise to blowing dust. Long-term measurements of plutonium isotopes (1985-2015) in the WIPP environment suggest that the resuspension of previously contaminated soils is likely the primary source of plutonium in the ambient air samples from WIPP and its vicinity. There is no evidence that WIPP is a source of environmental contamination that can be considered significant by any health-based standard. PMID:27394421

  19. Source and long-term behavior of transuranic aerosols in the WIPP environment.

    PubMed

    Thakur, P; Lemons, B G

    2016-10-01

    Source and long-term behavior transuranic aerosols ((239+240)Pu, (238)Pu, and (241)Am) in the ambient air samples collected at and near the Waste Isolation Pilot Plant (WIPP) deep geologic repository site were investigated using historical data from an independent monitoring program conducted by the Carlsbad Environmental Monitoring and Research Center and an oversight monitoring program conducted by the management and operating contractor for WIPP at and near the facility. An analysis of historical data indicates frequent detections of (239+240)Pu and (241)Am, whereas (238)Pu is detected infrequently. Peaks in (239+240)Pu and (241)Am concentrations in ambient air generally occur from March to June timeframe, which is when strong and gusty winds in the area frequently give rise to blowing dust. Long-term measurements of plutonium isotopes (1985-2015) in the WIPP environment suggest that the resuspension of previously contaminated soils is likely the primary source of plutonium in the ambient air samples from WIPP and its vicinity. There is no evidence that WIPP is a source of environmental contamination that can be considered significant by any health-based standard.

  20. Investigation of storage-phosphor autoradiography for the rapid quantitative screening of air filters for emergency response purposes

    NASA Astrophysics Data System (ADS)

    Gallardo, Athena Marie

    Past nuclear accidents, such as Chernobyl, resulted in a large release of radionuclides into the atmosphere. Radiological assessment of the vicinity of the site of the incident is vital to assess the exposure levels and dose received by the population and workers. Therefore, it is critical to thoroughly understand the situation and risks associated with a particular event in a timely manner in order to properly manage the event. Current atmospheric radiological assessments of alpha emitting radioisotopes include acquiring large quantities of air samples, chemical separation of radionuclides, sample mounting, counting through alpha spectrometry, and analysis of the data. The existing methodology is effective, but time consuming and labor intensive. Autoradiography, and the properties of phosphor imaging films, may be used as an additional technique to facilitate and expedite the alpha analysis process in these types of situations. Although autoradiography is not as sensitive to alpha radiation as alpha spectrometry, autoradiography may benefit alpha analysis by providing information about the activity as well as the spatial distribution of radioactivity in the sample under investigation. The objective for this research was to develop an efficient method for quantification and visualization of air filter samples taken in the aftermath of a nuclear emergency through autoradiography using 241Am and 239Pu tracers. Samples containing varying activities of either 241Am or 239Pu tracers were produced through microprecipitation and assayed by alpha spectroscopy. The samples were subsequently imaged and an activity calibration curve was produced by comparing the digital light units recorded from the image to the known activity of the source. The usefulness of different phosphor screens was examined by exposing each type of film to the same standard nuclide for varying quantities of time. Unknown activity samples created through microprecipiation containing activities of

  1. Separation of actinides using capillary extraction chromatography-inductively coupled plasma mass spectrometry.

    PubMed

    Peterson, Dominic S; Montoya, Velma M

    2009-08-01

    Trace levels of actinides have been separated on capillary extraction chromatography columns. Detection of the actinides was achieved using an inductively coupled plasma mass spectrometer, which was coupled with the extraction chromatography system. In this study, we compare 30-cm long, 4.6 mm i.d. columns to capillary columns (750 microm i.d.) with lengths from 30 cm up to 150 cm. The columns that were tested were packed with TRU resin. We were able to separate a mixture of five actinides ((232)Th, (238)U, (237)Np, (239)Pu, and (241)Am). This work has application to rapid bioassay as well as automated separations of actinide materials.

  2. IN-SITU ASSAY OF TRANSURANIC RADIONUCLIDES IN THE VADOSE ZONE USING HIGH-RESOLUTION SPECTRAL GAMMA LOGGING - A HANFORD CASE STUDY

    SciTech Connect

    ROHAY VJ; HENWOOD P; MCCAIN R

    2009-11-30

    High-resolution spectral gamma logging in steel-cased boreholes is used to detect and quantify transuranic radionuclides in the subsurface. Pu-239, Pu-241, Am-241, and Np-237 are identified based on characteristic decay gammas. Typical minimum detectable levels are on the order of 20 to 40 nCi/g. In intervals of high transuranic concentrations, gamma rays from other sources may complicate analysis and interpretation. Gamma rays detected in the borehole may originate from three sources: decay of the parent transuranic radionuclide or a daughter; alpha interactions; and interactions with neutrons resulting from either spontaneous fission or alpha particle interactions.

  3. Isotopic ratio correlation for the isotopic composition analysis of plutonium in Am-Pu mixed samples having high americium content.

    PubMed

    Patra, Sabyasachi; Agarwal, Chhavi; Chaudhury, Sanhita; Newton Nathaniel, T; Gathibandhe, M; Goswami, A

    2013-08-01

    Interference of high amount of americium in the plutonium isotopic composition analysis has been studied by simulating gamma-ray spectra for Am-Pu samples over a wide composition range (5-97% (241)Am) for both power and research reactor grade plutonium. An alternate way for isotopic composition analysis has been proposed by correlating the isotopic ratios available in our old database with the experimentally obtained (241)Pu/(239)Pu isotopic ratio. The proposed method has been validated using simulated spectra of known isotopic compositions.

  4. Accumulation of anthropogenic radionuclides in cryoconites on Alpine glaciers.

    PubMed

    Tieber, A; Lettner, H; Bossew, P; Hubmer, A; Sattler, B; Hofmann, W

    2009-07-01

    Cryoconites are airborne sediments which accumulate on the surface of glaciers. In samples of cryoconites a temperate Austrian glacier high activity concentrations of anthropogenic radionuclides were found, which stem from global and Chernobyl fallouts. Radionuclides identified were (137)Cs, (134)Cs, (238)Pu, (239+240)Pu, (90)Sr, (241)Am, (60)Co, (154)Eu, (207)Bi, and (125)Sb. Given the approximately known isotopic ratios, Cs and Pu can be separated into the contributions of either source of origin. Published (137)Cs/(134)Cs and (239+240)Pu/(238)Pu ratios were used for the discrimination of the Dachstein-glacier cryoconites according to their origin from global or Chernobyl fallout. Two different groups of cryoconites were identified, an older population dominated by nuclear weapons fallout and a younger one with predominant Chernobyl fallout. With those data a simple model was formulated to demonstrate the transition and mixing of these two populations on the glacier surface. PMID:19450909

  5. Alternative Radioisotopes for Heat and Power Sources

    NASA Astrophysics Data System (ADS)

    Tinsley, T.; Sarsfield, M.; Rice, T.

    Production of 238Pu requires considerable facilities including a nuclear reactor and reprocessing plants that are very expensive to build and operate. Thus, a more economical alternative is very attractive to the industry. There are many alternative radioisotopes that exist but few that satisfy the criteria of performance, availability and cost to produce. Any alternative to 238Pu must exist in a chemical form that is compatible with the materials required to safely encapsulate the heat source at the high temperatures of operation and potential launch failure scenarios. The chemical form must also have suitable thermal properties to ensure maximum energy conversion efficiencies when integrated into radioisotope thermoelectric generators over the required mission durations. In addition, the radiation dose must be low enough for operators during production and not so prohibitive that excessive shielding mass is required on the space craft. This paper will focus on the preferred European alternative of 241Am, and the issues that will need to be addressed.

  6. Accumulation of anthropogenic radionuclides in cryoconites on Alpine glaciers.

    PubMed

    Tieber, A; Lettner, H; Bossew, P; Hubmer, A; Sattler, B; Hofmann, W

    2009-07-01

    Cryoconites are airborne sediments which accumulate on the surface of glaciers. In samples of cryoconites a temperate Austrian glacier high activity concentrations of anthropogenic radionuclides were found, which stem from global and Chernobyl fallouts. Radionuclides identified were (137)Cs, (134)Cs, (238)Pu, (239+240)Pu, (90)Sr, (241)Am, (60)Co, (154)Eu, (207)Bi, and (125)Sb. Given the approximately known isotopic ratios, Cs and Pu can be separated into the contributions of either source of origin. Published (137)Cs/(134)Cs and (239+240)Pu/(238)Pu ratios were used for the discrimination of the Dachstein-glacier cryoconites according to their origin from global or Chernobyl fallout. Two different groups of cryoconites were identified, an older population dominated by nuclear weapons fallout and a younger one with predominant Chernobyl fallout. With those data a simple model was formulated to demonstrate the transition and mixing of these two populations on the glacier surface.

  7. 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.

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

    SciTech Connect

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

    1997-07-01

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

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

    SciTech Connect

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

    2010-06-23

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

  10. The mechanism of the hydrothermal alteration of cerium- and plutonium-doped zirconolite

    NASA Astrophysics Data System (ADS)

    Pöml, P.; Geisler, T.; Cobos-Sabaté, J.; Wiss, T.; Raison, P. E.; Schmid-Beurmann, P.; Deschanels, X.; Jégou, C.; Heimink, J.; Putnis, A.

    2011-03-01

    A comprehensive study on the aqueous stability of Ce- and Pu-doped zirconolite has been performed. Four series of hydrothermal experiments were carried out with Ce-doped zirconolite powders: (1) a solution series (1 M HCl, 2 M NaCl, 1 M NaOH, 1 M NH 3, pure H 2O), (2) a temperature series ( T = 100-300 °C), (3) a surface area-to-fluid volume ratio series, and (4) a series using different reactor materials (Teflon ©, Ni, and Ag). In addition, experiments on 238Pu- and 239Pu-doped zirconolite ceramics in a 1 M HCl solution have been performed. The 238Pu-doped zirconolite had already accumulated significant radiation damage and was X-ray amorphous, while the 239Pu-doped zirconolite was still well-crystalline. The results of the different experimental series can be summarized as follows: (1) After 14 days the degree of alteration is insignificant for all solutions other than 1 M HCl, which was therefore used for all other experimental series; (2) TiO 2 and m-ZrO 2 replaced the zirconolite grains to varying degrees in the 1 M HCl solution, i.e., zirconolite dissolution is incongruent; (3) the degree of alteration increases only slightly with increasing temperature; (4) the alteration rate is independent on the surface to volume ratio; (5) Ag dissolved from the silver reactors dramatically increases the reaction rate, while Ni from the Ni reactors reduces the solubility of Ti and Zr in the HCl solution, indicating that background electrolytes have a strong effect on the alteration rate. From the experiment with the Pu-doped samples at 200 °C in a 1 M HCl solution it was found that the amorphous 238Pu-doped zirconolite was altered to a significantly greater extent than the crystalline counterparts. The results suggest a coupled dissolution-reprecipitation mechanism, which is discussed in detail.

  11. Monte Carlo modeling of spallation targets containing uranium and americium

    NASA Astrophysics Data System (ADS)

    Malyshkin, Yury; Pshenichnov, Igor; Mishustin, Igor; Greiner, Walter

    2014-09-01

    Neutron production and transport in spallation targets made of uranium and americium are studied with a Geant4-based code MCADS (Monte Carlo model for Accelerator Driven Systems). A good agreement of MCADS results with experimental data on neutron- and proton-induced reactions on 241Am and 243Am nuclei allows to use this model for simulations with extended Am targets. It was demonstrated that MCADS model can be used for calculating the values of critical mass for 233,235U, 237Np, 239Pu and 241Am. Several geometry options and material compositions (U, U + Am, Am, Am2O3) are considered for spallation targets to be used in Accelerator Driven Systems. All considered options operate as deep subcritical targets having neutron multiplication factor of k∼0.5. It is found that more than 4 kg of Am can be burned in one spallation target during the first year of operation.

  12. 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.

  13. Gas generation and migration studies involving recently generated /sup 238/Pu-contaminated waste for the TRU Waste Sampling Program

    SciTech Connect

    Zerwekh, A.; Warren, J.L.

    1986-07-01

    This study is part of the multicontractor TRU Waste Sampling Program. Radiolytically generated gases were vented through a filtering device to determine its effectiveness in maintaining hydrogen concentrations within acceptably safe levels. In the second part of the study measurements were made to determine the ability of these gases, particularly hydrogen, to migrate through a sealed rigid polyethylene drum liner. Void volumes in these drums were found to be generally in excess of 90%. The carbon composite filter was found to satisfactorily vent hydrogen up to moderately high levels of alpha activity in the waste substrate. The sealed 90-mil liner was found to inhibit, but not prevent, the migration of hydrogen and other radiolytically generated gases.

  14. Plutonium isotopic analysis system for plutonium samples enriched in sup 238 Pu in EP 60/61 containers

    SciTech Connect

    Ruhter, W.D.

    1990-06-01

    This user's manual is addressed to the Savannah River Site personnel (routine operators and supervisors) who perform measurements with the Pu-238 isotopic analysis system. Each chapter begins with a table of contents that lists the section title, illustrations, and tabular data presented in that chapter. The first chapter in this manual is an introduction to the system. Chapter 2 lists required settings for the system's commercial nuclear instrument modules. System operating procedures are given in Chapter 3. Chapter 4 contains routine and supervisorial operator interactions. Chapter 5 describes the system's short- and long-printout output formats. Chapter 6 gives instructions for changing system parameters. Error messages are listed and described Chapter 7. Chapter 8 contains a reference article on measuring relative plutonium isotopics in plutonium samples enriched in Pu-238. All commercial items mentioned in this manual are assumed to be functioning correctly for the purposes of system operation. Users are referred to individual equipment manufacturers' manuals for details of operation, trouble-shooting, and maintenance of this commercial equipment.

  15. Plutonium isotopic analysis system for plutonium samples enriched in sup 238 Pu in EP 60/61 containers

    SciTech Connect

    Ruhter, W.D.; DeWitt, K.W.; Pederson, K.B.; Watkins, J.A.

    1990-06-01

    This hardware manual is addressed to Savannah River Site supervisors and to authorized mechanical and electrical maintenance and service personnel. Each chapter begins with a table of contents that lists the section titles, illustrations, and tabular data presented in that chapter. The first chapter in this manual is an introduction to the Pu-238 isotopic analysis system. Chapter 2 lists major components of the system and includes electronic block and wiring diagrams. Commercial nuclear instrument modules and their required settings are described in Chapter 3. Chapter 4 contains service and preventive maintenance procedures, as well as a troubleshooting log. In Chapter 5 is a list of spare parts and all relevant mechanical drawings for the system. Chapter 6 contains reference articles. All commercial items mentioned in this manual are assumed to be functioning correctly for the purposes of system operation. Users are referred to individual equipment manufacturers' manuals for details of operation, troubleshooting, and maintenance of this commercial equipment. 31 figs., 1 tab.

  16. Sources and pathways of artificial radionuclides to soils at a High Arctic site.

    PubMed

    Lokas, E; Bartmiński, P; Wachniew, P; Mietelski, J W; Kawiak, T; Srodoń, J

    2014-11-01

    Activity concentrations, inventories and activity ratios of (137)Cs, (238)Pu, (239 + 240)Pu and (241)Am in soil profiles were surveyed in the dry tundra and the adjoining proglacial zones of glaciers at a High Arctic site on Svalbard. Vertical profiles of radionuclide activities were determined in up to 14-cm-thick soil sequences. Additionally, soil properties (pH, organic matter, texture, mineral composition and sorption capacity) were analyzed. Results obtained in this study revealed a large range of activity concentrations and inventories of the fallout radionuclides from the undetectable to the uncommonly high levels (inventories of 30,900 ± 940, 47 ± 6, 886 ± 80 and 296 ± 19 Bq/m(2) for (137)Cs, (238)Pu, (239 + 240)Pu and (241)Am, respectively) found in two profiles from the proglacial zone. Concentration of these initially airborne radionuclides in the proglacial zone soils is related to their accumulation in cryoconites that have a large ability to concentrate trace metals. The cryoconites develop on the surface of glaciers, and the material they accumulate is deposited on land surface after the glaciers retreat. The radionuclide inventories in the tundra soils, which effectively retain radionuclides due to high organic matter contents, were comparable to the global fallout deposition for this region of the world. The (238)Pu/(239 + 240)Pu activity ratios for tundra soils suggested global fallout as the dominant source of Pu. The (238)Pu/(239 + 240)Pu and (239 + 240)Pu/(137)Cs activity ratios in the proglacial soils pointed to possible contributions of these radionuclides from other, unidentified sources. PMID:24946703

  17. Deposition of Saharan Dust in Monaco Rain 2001 2002: Radionuclides and Elemental Composition

    NASA Astrophysics Data System (ADS)

    Pham, M. K.; La Rosa, J. J.; Lee, S.-H.; Oregioni, B.; Povinec, P. P.

    2005-01-01

    Data on concentrations and activity ratios of natural and anthropogenic radio-nuclides as well as concentrations of major and trace elements in red-coloured particles (Saharan dusts) collected in Monaco rain in 2001 and 2002 (5 samples from 4 events) are presented. Different distributions of particle size as well as different activities of natural radionuclides and concentrations of trace metals have been observed for two sets of samples. The 235U/238U activity ratio is around 0.04 showing virgin natural terrestrial origin of the particles. The anthropogenic radionuclides 137Cs, 238Pu, 239+240Pu and 241Am are of global fallout origin and their annual atmospheric input to the ocean in the particulate form is estimated to be 28 37% for 137Cs, 34 45% for 239+240Pu and 36 51% for 241Am of the total annual depositional fluxes of these radionuclides to the northwest Mediterranean.

  18. MOX and MOX with 237Np/241Am Inert Fission Gas Generation Comparison in ATR

    SciTech Connect

    G. S. Chang; M. Robel; W. J. Carmack; D. J. Utterbeck

    2006-06-01

    The treatment of spent fuel produced in nuclear power generation is one of the most important issues to both the nuclear community and the general public. One of the viable options to long-term geological disposal of spent fuel is to extract plutonium, minor actinides (MA), and potentially long-lived fission products from the spent fuel and transmute them into short-lived or stable radionuclides in currently operating light-water reactors (LWR), thus reducing the radiological toxicity of the nuclear waste stream. One of the challenges is to demonstrate that the burnup-dependent characteristic differences between Reactor-Grade Mixed Oxide (RG-MOX) fuel and RG-MOX fuel with MA Np-237 and Am 241 are minimal, particularly, the inert gas generation rate, such that the commercial MOX fuel experience base is applicable. Under the Advanced Fuel Cycle Initiative (AFCI), developmental fuel specimens in experimental assembly LWR-2 are being tested in the northwest (NW) I-24 irradiation position of the Advanced Test Reactor (ATR). The experiment uses MOX fuel test hardware, and contains capsules with MOX fuel consisting of mixed oxide manufactured fuel using reactor grade plutonium (RG-Pu) and mixed oxide manufactured fuel using RG-Pu with added Np/Am. This study will compare the fuel neutronics depletion characteristics of Case-1 RG-MOX and Case-2 RG-MOX with Np/Am.

  19. Species-dependent chelation of (241)Am by DTPA Di-ethyl ester.

    PubMed

    Huckle, James E; Sadgrove, Matthew P; Mumper, Russell J; Jay, Michael

    2015-04-01

    Diethylenetriaminepentaacetic acid (DTPA) is an FDA-approved chelating agent for enhancing the elimination of transuranic elements such as americium from the body. Early access to therapy minimizes deposition of these radionuclides in tissues such as the bone. Due to its poor oral bioavailability, DTPA is administered as an IV injection, delaying access. Therefore, a diethyl-ester analog of DTPA, named C2E2, was synthesized as a means to increase oral absorption. As a hexadentate ligand, it was hypothesized that C2E2 was capable of binding americium directly. Therefore, the protonation constants and americium stability constant for C2E2 were determined by potentiometric titration and a solvent extraction method, respectively. C2E2 was shown to bind americium with a log K of 19.6. The concentrations of C2E2, its metabolite C2E1, and DTPA required to achieve effective binding in rat, beagle, and human plasma were studied in vitro. Dose response curves for each ligand were established, and the 50% maximal effective concentrations were determined for each species. As expected, higher concentrations of C2E2 were required to achieve the same degree of binding as DTPA. The results indicated that chelation in beagle plasma is more representative of the human response than rats. Finally, the pharmacokinetics of C2E2 were investigated in beagles, and the data was fit to a two-compartment model with elimination from the central compartment, along with first-order absorption. Based on the in vitro data, a 100 mg kg dose of C2E2 can be expected to have an effective duration of action of 3.8 h in beagles. PMID:25706138

  20. Species-Dependent Chelation of 241Am by DTPA Di-ethyl Ester

    PubMed Central

    Huckle, James E.; Sadgrove, Matthew P.; Mumper, Russell J.; Jay, Michael

    2014-01-01

    Diethylenetriaminepentaacetic acid (DTPA) is an FDA approved chelating agent for enhancing the elimination of transuranic elements such as americium from the body. Early access to therapy minimizes deposition of these radionuclides in tissues such as the bone. Due to its poor oral bioavailability, DTPA is administered as an IV injection, delaying access. Therefore a diethyl-ester analog of DTPA, named C2E2, was synthesized as a means to increase oral absorption. As a hexadentate ligand, it was hypothesized that C2E2 was capable of binding americium directly. Therefore, the protonation constants and americium stability constant for C2E2 were determined by potentiometric titration and a solvent extraction method, respectively. C2E2 was shown to bind americium with a log K of 19.6. The concentrations of C2E2, its metabolite C2E1, and DTPA required to achieve effective binding in rat, beagle, and human plasma were studied in vitro. Dose response curves for each ligand were established and the 50% maximal effective concentrations were determined for each species. As expected, higher concentrations of C2E2 were required to achieve the same degree of binding as DTPA. The results indicated that chelation in beagle plasma is more representative of the human response than rats. Finally, the pharmacokinetics of C2E2 were investigated in beagles and the data was fit to a two-compartment model with elimination from the central compartment, along with first-order absorption. Based on the in vitro data, a 100 mg kg−1 dose of C2E2 can be expected to have an effective duration of action of 3.8 hours in beagles. PMID:25706138

  1. Two new rodent models for actinide toxicity studies. [/sup 237/Pu, /sup 241/Am

    SciTech Connect

    Taylor, G.N.; Jones, C.W.; Gardner, P.A.; Lloyd, R.D.; Mays, C.W.; Charrier, K.E.

    1981-04-01

    Two small rodent species, the grasshopper mouse (Onychomys leucogaster) and the deer mouse (Peromyscus maniculatus), have tenacious and high retention in the liver and skeleton of plutonium and americium following intraperitoneal injection of Pu and Am in citrate solution. Liver retention of Pu and Am in the grasshopper mouse is higher than liver retention in the deer mouse. Both of these rodents are relatively long-lived, breed well in captivity, and adapt suitably to laboratory conditions. It is suggested that these two species of mice, in which plutonium retention is high and prolonged in both the skeleton and liver, as it is in man, may be useful animal models for actinide toxicity studies.

  2. OSMOSE experiment representativity studies.

    SciTech Connect

    Aliberti, G.; Klann, R.; Nuclear Engineering Division

    2007-10-10

    The OSMOSE program aims at improving the neutronic predictions of advanced nuclear fuels through measurements in the MINERVE facility at the CEA-Cadarache (France) on samples containing the following separated actinides: Th-232, U-233, U-234, U-235, U-236, U-238, Np-237, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, Am-241, Am-243, Cm-244 and Cm-245. The goal of the experimental measurements is to produce a database of reactivity-worth measurements in different neutron spectra for the separated heavy nuclides. This database can then be used as a benchmark for integral reactivity-worth measurements to verify and validate reactor analysis codes and integral cross-section values for the isotopes tested. In particular, the OSMOSE experimental program will produce very accurate sample reactivity-worth measurements for a series of actinides in various spectra, from very thermalized to very fast. The objective of the analytical program is to make use of the experimental data to establish deficiencies in the basic nuclear data libraries, identify their origins, and provide guidelines for nuclear data improvements in coordination with international programs. To achieve the proposed goals, seven different neutron spectra can be created in the MINERVE facility: UO2 dissolved in water (representative of over-moderated LWR systems), UO2 matrix in water (representative of LWRs), a mixed oxide fuel matrix, two thermal spectra containing large epithermal components (representative of under-moderated reactors), a moderated fast spectrum (representative of fast reactors which have some slowing down in moderators such as lead-bismuth or sodium), and a very hard spectrum (representative of fast reactors with little moderation from reactor coolant). The different spectra are achieved by changing the experimental lattice within the MINERVE reactor. The experimental lattice is the replaceable central part of MINERVE, which establishes the spectrum at the sample location. This configuration

  3. Radionuclide Leaching from Residual Solids Remaining after Acid Dissolution of K East Area Sludge Composite

    SciTech Connect

    Delegard, C.H.; Rinehart, D.E.; Carlson, C.D.; Soderquist, C.Z.; Fadeff, S.K.

    1999-04-02

    Laboratory tests were performed to examine the efficacy of various leach treatments for decontaminating dissolver residual solids (KEACRESID1) produced during a 24-hour dissolution of K East Basin floor and Weasel Pit sludge composite in boiling 6 M HNO{sub 3}. The scope of this testing has been described in Section 4.5 of ''Testing Strategy to Support the Development of K Basin Sludge Treatment Process'' (Flament 1998). Radionuclides sorbed or associated with the residual solids generated in the K Basin sludge treatment process can restrict disposal of this solid to the Environmental Restoration Disposal Facility (ERDF). The starting dissolver residual solid for this testing, KEACRESID1, is a visibly heterogeneous material. This material contains radionuclides at concentrations above the ERDF Waste Acceptance Criteria for transuranics (TRU) by about a factor of 3, for {sup 239}Pu by a factor of 10, and for {sup 241}Am by a factor of 1.6. It meets the ERDF criterion for {sup 137}Cs by a factor of 4 and for uranium by a factor of 10. Therefore, the radionuclides of greatest interest in this leaching study are first {sup 239}Pu, and then {sup 241}Am, {sup 137}Cs, and uranium.

  4. Calcium Phosphate: A potential host for halide contaminated plutonium wastes.

    SciTech Connect

    Metcalfe, Brian L.; Donald, Ian W.; Fong, Shirley K.; Gerrard, Lee A.; Strachan, Denis M.; Scheele, Randall D.

    2009-07-06

    The presence of significant quantities of fluoride and chloride in four types of legacy wastes from plutonium pyrochemical reprocessing required the development of a new wasteform which could adequately immobilize the halides in addition to the Pu and Am. Using a simulant chloride-based waste (Type I waste) and Sm as the surrogate for the Pu3+ and Am3+ present in the waste, AWE developed a process which utilised Ca3(PO4)2 as the host material. The waste was successfully incorporated into two crystalline phases, chlorapatite, [Ca5(PO4)3Cl], and spodiosite, [Ca2(PO4)Cl]. Radioactive studies performed at PNNL with 239Pu and 241Am confirmed the process. A slightly modified version of the process in which CaHPO4 was used as the host was successful in immobilizing a more complex multi-cation oxide–based waste (Type II) which contained significant concentrations of Cl and F in addition to 239Pu and 241Am. This waste resulted in the formation of cation-doped whitlockite, Ca3-xMgx(PO4)2, β-calcium phosphate, β-Ca2P2O7 and chlor-fluorapatite rather than the chlorapatite and spodiosite formed with Type I waste.

  5. Radionuclide Leaching from Residual Solids Remaining after Acid Dissolution of Composite K East Canister Sludge

    SciTech Connect

    Delegard, C.H.; Rinehart, D.E.; Soderquist, C.Z.; Fadeff, S.K.

    1999-04-02

    Laboratory tests were performed to examine mixed nitric/hydrofluoric acid leach treatments for decontaminating dissolver residual solids (KECDVSR24H-2) produced during a 20- to 24-hr dissolution of a composite K East (KE) Basin canister sludge in 95 C 6 M nitric acid (HNO{sub 3}). The scope of this testing has been described in Section 4.5 of ''Testing Strategy to Support the Development of K Basin Sludge Treatment Process'' (Flament 1998). Radionuclides sorbed or associated with the residual solids generated in the K Basin sludge treatment process can restrict disposal of this solid to the Environmental Restoration Disposal Facility (ERDF). The starting dissolver residual solid for this testing, KECDVSR24H-2, contains radionuclides at concentrations which exceed the ERDF Waste Acceptance Criteria for TRU by about a factor of 70, for {sup 239}Pu by a factor of 200, and for {sup 241}Am by a factor of 50. The solids also exceed the ERDF criterion for {sup 137}Cs by a factor of 2 and uranium by a factor of 5. Therefore, the radionuclides of greatest interest in this leaching study are first {sup 239}Pu and {sup 241}Am (both components of TRU) and then uranium and {sup 137}Cs.

  6. 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

  7. 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.

  8. 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

  9. Almost twenty years' search of transuranium isotopes in effluents discharged to air from nuclear power plants with VVER reactors.

    PubMed

    Hölgye, Z; Filgas, R

    2006-04-01

    Airborne effluents of 5 stacks (stacks 1-5) of three nuclear power plants, with 9 pressurized water reactors VVER of 4,520 MWe total power, were searched for transuranium isotopes in different time periods. The search started in 1985. The subject of this work is a presentation of discharge data for the period of 1998-2003 and a final evaluation. It was found that 238Pu, 239,240Pu, 241Am, 242Cm, and 244Cm can be present in airborne effluents. Transuranium isotope contents in most of the quarterly effluent samples from stacks 2, 4 and 5 were not measurable. Transuranium isotopes were present in the effluents from stack l during all 9 years of the study and from stack 3 since the 3rd quarter of 1996 as a result of a defect in the fuel cladding. A relatively high increase of transuranium isotopes in effluents from stack 3 occurred in the 3rd quarter of 1999, and a smaller increase occurred in the 3rd quarter of 2003. In each instance 242Cm prevailed in the transuranium isotope mixtures. 238Pu/239,240Pu, 241Am/239,240Pu, 242Cm/239,240Pu, and 244Cm/239,240Pu ratios in fuel for different burn-up were calculated, and comparison of these ratios in fuel and effluents was performed.

  10. Influence of cell position relative to planar alpha-particle sources on survival and preneoplastic transformation of primary rat tracheal epithelial cells

    SciTech Connect

    Terzaghi-Howe, M.; Turner, J.E.; Ford, J.R.

    1996-04-01

    Rat tracheal epithelial cells exposed directly on planar {sup 210}Po sources exhibited exponential cell killing; however, no significant increase in induction of preneoplastic transformation was observed over a range of {alpha}-particle fluences (0.017-0.050 {mu}m{sup {minus}2}). In contrast, up to 10-fold increases in frequencies of preneoplastic transformants, above control levels, were observed after exposure of rat tracheal epithelial cells to similar {alpha}-particle fluences on {sup 238}Pu and {sup 241}Am sources. Two alternative hypotheses are evaluated as an explanation for this apparent difference in the biological effect of {alpha} particles emitted from different sources: (a) possible interactions between effects produced by {alpha} particles and by low-energy photons, which occur with {sup 238}Pu and {sup 241}Am but not with {sup 210}Po; and (b) the influence of spatial relationships between exposed cells and the surface of the planar source. The data suggest that the cell-to-source spatial relationships affect both survival and transformation markedly. 29 refs., 4 figs., 6 tabs.

  11. Assay of long-lived radionuclides in low-level wastes from power reactors

    SciTech Connect

    Cline, J.E.; Noyce, J.R.; Coe, L.J.; Wright, K.W.

    1985-04-01

    The 10 CFR Part 61 waste classification system includes several nuclides which are difficult to assay without expensive radiochemical methods. In order for waste generators to classify wastes practically, NRC Staff has recommended the use of correlation factors to scale the difficult-to-measure nuclides with nuclides which can be measured more easily (i.e., gamma emitters such as /sup 60/Co or /sup 137/Cs). In this study, Science Applications International Corporation (SAIC) performed complete radiochemical assays for all the 10 CFR Part 61 waste classification nuclides on over 100 samples. These data, along with almost 800 other samples in the SAIC data base, were used to assess the validity of correlation factors suggested for use in nuclear power plant wastes. Specific generic correlation factors are recommended with other approaches to correlate nuclides for which generic scaling factors are not defensible. The primary nuclide correlations studied were /sup 14/C, /sup 55/Fe, /sup 59/Ni, /sup 63/Ni, and /sup 94/Nb, with /sup 60/Co; /sup 90/Sr, /sup 99/Tc, /sup 129/I, /sup 135/Cs, and /sup 239, 240/Pu with /sup 137/Cs; /sup 238/Pu, /sup 239, 240/Pu, /sup 241/Pu, /sup 241/Am, /sup 242/Cm, and /sup 243, 244/Cm with /sup 144/Ce; and /sup 238/Pu, /sup 241/Pu, /sup 241/Am, /sup 242/Cm and /sup 243, 244/Cm with /sup 239, 240/Pu.

  12. Nevada Test Site Radionuclide Inventory and Distribution Program: Report No. 3, Areas 3, 7, 8, 9, and 10

    SciTech Connect

    McArthur, R D; Mead, S W

    1987-02-01

    As part of the Nevada Test Site Radionuclide Inventory and Distribution Program, 115 soil samples were collected and more than 1200 in situ measurements of gamma-emitting radionuclides were made in the northern and eastern parts of Yucca Flat. Analysis of the data led to estimated inventories of 215 Ci of /sup 239,240/Pu, 128 Ci of /sup 137/Cs, 92 Ci of /sup 90/Sr, 36 Ci each of /sup 241/Am and /sup 60/Co, 31 Ci of /sup 102m/Rh, 27 Ci of /sup 238/Pu, 25 Ci of /sup 174/Lu, 10 Ci of /sup 152/Eu, 8 Ci of /sup 155/Eu, 7 Ci of /sup 154/Eu, 5 Ci of /sup 125/Sb, 4 Ci of /sup 101/Rh, and 2 Ci of /sup 134/Cs in the surface soil of the accessible portion of Areas 8 and 10. Similar calculations with the data from Areas 3, 7, and 9 gave estimates of 145 Ci of /sup 239,240/Pu, 89 Ci of /sup 152/Eu, 62 Ci of /sup 90/Sr, 25 Ci of /sup 137/Cs, 14 Ci of /sup 154/Eu, 11 Ci of /sup 241/Am, 6 Ci each of /sup 60/Co and /sup 238/Pu, and 4 Ci of /sup 155/Eu. Additional in situ measurements at 30 locations in the southern part of Yucca Flat confirmed the low levels of radioactivity found there by an aerial survey. 1 ref., 57 figs., 10 tabs.

  13. Radionuclide concentrations in vegetation at a solid radioactive waste-disposal area in southeastern Idaho

    SciTech Connect

    Arthur, W.J. III

    1982-07-01

    Concentrations of /sup 238/Pu, /sup 239,240/Pu, and /sup 241/Am in crested wheatgrass (Agropyron cristatum (L.) Gaertn) and Russian thistle (Salsola kali L.) samples collected at a solid radioactive waste-disposal area in southeastern Idaho were significantly (P less than or equal to 0.05) greater than concentrations in control vegetation. No significant differences were found for /sup 90/Sr or /sup 137/Cs concentrations between the waste-disposal and control-area vegetation. Russian thistle had more radionuclide contamination than crested wheatgrass, presumably because of its greater rooting depth and spreading growth. The total radionuclide inventory of /sup 90/Sr, /sup 137/Cs, /sup 238/Pu, /sup 239,240/Pu, and /sup 241/Am in vegetation at the 36-ha waste-disposal area (77 ..mu..Ci) was not significantly (P > 0.05) greater than the 17 ..mu..Ci in control-area vegetation. Ninety percent of the radioactivity in waste-disposal area vegetation and 99% in control-area vegetation were attributed to /sup 90/Sr and /sup 137/Cs. The Pu inventory in Subsurface Disposal Area (SDA) vegetation was only 0.02% of the quantity of Pu estimated to occur in SDA surface soils in 1974. Accumulation of radionuclides by vegetation is not considered a major mode of radionuclide transport through the environment surrounding this radioactive-waste-disposal area.

  14. Investigation and optimisation of mobile NaI(Tl) and 3He-based neutron detectors for finding point sources

    NASA Astrophysics Data System (ADS)

    Nilsson, Jonas M. C.; Finck, Robert R.; Rääf, Christopher

    2015-06-01

    Neutron radiation produces high-energy gamma radiation through (n,γ) reactions in matter. This can be used to detect neutron sources indirectly using gamma spectrometers. The sensitivity of a gamma spectrometer to neutrons can be amplified by surrounding it with polyvinyl chloride (PVC). The hydrogen in the PVC acts as a moderator and the chlorine emits prompt gammas when a neutron is captured. A 4.7-l 3He-based mobile neutron detector was compared to a 4-l NaI(Tl)-detector covered with PVC using this principle. Methods were also developed to optimise the measurement parameters of the systems. The detector systems were compared with regard to their ability to find 241AmBe, 252Cf and 238Pu-13C neutron sources. Results from stationary measurements were used to calculate optimal integration times as well as minimum detectable neutron emission rates. It was found that the 3He-based detector was more sensitive to 252Cf sources whereas the NaI(Tl) detector was more sensitive to 241AmBe and 238Pu-13C sources. The results also indicated that the sensitivity of the detectors to sources at known distances could theoretically be improved by 60% by changing from fixed integration times to list mode in mobile surveys.

  15. Further studies on the absorption of actinide elements from the gastrointestinal tract of neonatal animals.

    PubMed

    Sullivan, M F; Gorham, L S

    1982-10-01

    Plutonium retention was measured after intragastric administration to neonatal rats, dogs and swine. At 1 week after administration, substantially more of the actinide remained in swine and dogs than in rats. The quantity of 238Pu absorbed by piglets was markedly influenced by such factors as compound solubility, mass of plutonium administered, oxidation state of the actinide, and age of the animal at gavage. Cortisone treatment reduced absorption, but was less effective in piglets than in neonatal rats. Measurements of 238Pu transport from ligated segments of the neonatal swine intestine indicated highest absorption from the duodenum, where the actinide was shown, autoradiographically, to be deposited in the epithelial region; in the ileum, deposition was predominantly in the lacteal region. Absorption of actinides by neonatal swine decreased in the order of 233U greater than 238Pu greater than 237Np greater than 244Cm greater than 241Am. Measurements at 1 yr after gavage showed a much higher retention by swine than by rats.

  16. 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.

  17. 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

  18. A compact gas-filled avalanche counter for DANCE

    NASA Astrophysics Data System (ADS)

    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.

    2012-12-01

    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. It was also used 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.

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

    PubMed

    Suzuki, Daisuke; Esaka, Fumitaka; Miyamoto, Yutaka; Magara, Masaaki

    2015-02-01

    Uranium and plutonium isotope ratios in individual uranium-plutonium (U-Pu) mixed particles with various U/Pu atomic ratios were analyzed without prior chemical separation by thermal ionization mass spectrometry (TIMS). Prior to measurement, micron-sized particles with U/Pu ratios of 1, 5, 10, 18, and 70 were produced from uranium and plutonium certified reference materials. In the TIMS analysis, the peaks of americium, plutonium, and uranium ion signals were successfully separated by continuously increasing the evaporation filament current. Consequently, the uranium and plutonium isotope ratios, except the (238)Pu/(239)Pu ratio, were successfully determined for the particles at all U/Pu ratios. This indicates that TIMS direct analysis allows for the measurement of individual U-Pu mixed particles without prior chemical separation. PMID:25479434

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

    DOE PAGES

    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

  1. A compact gas-filled avalanche counter for DANCE

    DOE PAGES

    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.

  2. [Dosage of irradiation of the population in the Bryansk region with plutonium deposited in the soil after the Chernobyl AES accident].

    PubMed

    Ivanova, N P; Shvydko, N S

    1991-01-01

    Proceeding from the data on 238Pu, 239Pu, 240Pu concentrations in the soil in different areas of the Bryansk Region, exposed to radioactive contamination after the Chernobyl accident, radiation dose exposures of residents as well as agricultural workers were assessed. Criteria of the ecological and radiation-hygienic standardization were used for calculation of values of dose factors, binding the alimentary and inhalation components of an irradiation dose with characteristics of Pu deposition in the soil. Inhalation of soil particles accounted for approximately 90% of a total radiation dose of the "soil" Pu component, and the alimentary component-for approximately 10% (of this, 99% were attributed to plant products). The authors proposed prognostic assessment of an expected effective equivalent dose for a period of 70 years for people, residing in these areas (0.08-0.45 cSi for the population and 0.6-3.2 cSi for mechanics).

  3. Radiochemical Separations for the Pretreatment of High Level Nuclear Wastes at the Savannah River Site

    SciTech Connect

    Hobbs, D.T.

    2003-09-03

    A significant fraction of the high-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) must be pretreated to remove 137Cs, 90Sr and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. Separation processes planned at the SRS include caustic side solvent extraction for 137Cs and sorption onto monosodium titanate (MST) for 90Sr and alpha-emitters. The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes 238Pu, 239Pu and 240Pu. This paper describes the planned Sr/actinide separation process and summarizes recent tests and demonstrations with simulated and actual tank waste solutions.

  4. High-resolution solid-state nuclear magnetic resonance experiments on highly radioactive ceramics

    NASA Astrophysics Data System (ADS)

    Farnan, Ian; Cho, Herman; Weber, William J.; Scheele, Randall D.; Johnson, Nigel R.; Kozelisky, Anne E.

    2004-12-01

    A triple-containment magic-angle spinning rotor insert system has been developed and a sample handling procedure formulated for safely analyzing highly radioactive solids by high-resolution solid-state NMR. The protocol and containment system have been demonstrated for magic-angle spinning (MAS) experiments on ceramic samples containing 5-10 wt % 239Pu and 238Pu at rotation speeds of 3500 Hz. The technique has been used to demonstrate that MAS NMR experiments can be used to measure amorphous atomic number fractions produced by accelerated internal radiation damage. This will allow incorporated α-emitters with short half-lives to be used to model the long-term radiation tolerance of potential ceramic radioactive waste forms. This is an example of MAS NMR spectroscopy on samples containing fissionable isotopes.

  5. Radiation damage effects in candidate titanates for Pu disposition: Pyrochlore

    NASA Astrophysics Data System (ADS)

    Strachan, D. M.; Scheele, R. D.; Buck, E. C.; Icenhower, J. P.; Kozelisky, A. E.; Sell, R. L.; Elovich, R. J.; Buchmiller, W. C.

    2005-10-01

    Laboratory experiments on titanate ceramics were performed to verify whether certain assumptions are valid regarding the swelling, chemical durability, and microcracking that might occur as 239Pu decays. Titanate ceramics are the material of choice for the immobilization of surplus weapons-grade Pu. The short-lived isotope 238Pu, was incorporated into the ceramic formulation to accelerate the effects of radiation-induced damage. We report on the effects of this damage on the density (volumetric swelling <6%), crystal structure of pyrochlore-bearing specimens (amorphous after about 2 × 1018 α/g), and dissolution (no change from the fully crystalline specimen). Even though the specimens became amorphous during the tests, there was no evidence for microcracking in the photomicrographs from the scanning electron microscope. Thus, although pyrochlore is susceptible to radiation-induced damage, the material remains chemically and physically viable as a material for immobilizing surplus weapons-grade Pu.

  6. DEVELOPMENT OF AN IMPROVED SODIUM TITANATE FOR THE PRETREATMENT OF HIGH LEVEL NUCLEAR WASTE AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Hobbs D. T.; Poirier, M. R.; Barnes, M. J.; Stallings, M. E.; Nyman, M. D.

    2005-11-22

    High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove {sup 137}Cs, {sup 90}Sr and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. Separation processes planned at SRS include caustic side solvent extraction, for {sup 137}Cs removal, and sorption of {sup 90}Sr and alpha-emitting radionuclides onto monosodium titanate (MST). The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes {sup 238}Pu, {sup 239}Pu and {sup 240}Pu. This paper describes recent results to produce an improved sodium titanate material that exhibits increased removal kinetics and capacity for {sup 90}Sr and alpha-emitting radionuclides compared to the baseline MST material.

  7. Design and operation of a remotely operated plutonium waste size reduction and material handling process

    SciTech Connect

    Stewart, III, J A; Charlesworth, D L

    1986-01-01

    Noncombustible /sup 238/Pu and /sup 239/Pu waste is generated as a result of normal operation and decommissioning activity at the Savannah River Plant, and is being retrievably stored there. As part of the long-term plant to process the stored waste and current waste for permanent disposal, a remote size reduction and material handling process is being cold-tested at Savannah River Laboratory. The process consists of a large, low-speed shredder and material handling system, a remote worktable, a bagless transfer system, and a robotically controlled manipulator. Initial testing of the shredder and material handling system and a cycle test of the bagless transfer system has been completed. Fabrication and acceptance testing of the Telerobat, a robotically controlled manipulator has been completed. Testing is scheduled to begin in 3/86. Design features maximizing the ability to remotely maintain the equipment were incorporated. Complete cold-testing of the equipment is scheduled to be completed in 1987.

  8. Group Constants Generation of the Pseudo Fission Products for Fast Reactor Burnup Calculations

    SciTech Connect

    Gil, Choong-Sup; Kim, Do Heon; Chang, Jonghwa

    2005-05-24

    The pseudo fission products for the burnup calculations of the liquid metal fast reactor were generated. The cross-section data and fission product yield data of ENDF/B-VI were used for the pseudo fission product data of U-235, U-238, Pu-239, Pu-240, Pu-241, and Pu-242. The pseudo fission product data can be used with the KAFAX-F22 or -E66, which are the MATXS-format libraries for analyses of the liquid metal fast reactor at KAERI and were distributed through the OECD/NEA. The 80-group MATXS-format libraries of the 172 fission products were generated and the burnup chains for generation of the pseudo fission products were prepared.

  9. Method for detecting and correcting for isotope burn-in during long-term neutron dosimetry exposure

    DOEpatents

    Ruddy, Francis H.

    1988-01-01

    A method is described for detecting and correcting for isotope burn-in during-long term neutron dosimetry exposure. In one embodiment, duplicate pairs of solid state track recorder fissionable deposits are used, including a first, fissionable deposit of lower mass to quantify the number of fissions occuring during the exposure, and a second deposit of higher mass to quantify the number of atoms of for instance .sup.239 Pu by alpha counting. In a second embodiment, only one solid state track recorder fissionable deposit is used and the resulting higher track densities are counted with a scanning electron microscope. This method is also applicable to other burn-in interferences, e.g., .sup.233 U in .sup.232 Th or .sup.238 Pu in .sup.237 Np.

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

    PubMed

    Suzuki, Daisuke; Esaka, Fumitaka; Miyamoto, Yutaka; Magara, Masaaki

    2015-02-01

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

  11. Analysis of the effects of inter-individual variation in the distribution of plutonium in skeleton and liver.

    PubMed

    Klein, W; Breustedt, B

    2014-01-01

    One important parameter for biokinetic plutonium modelling is the ratio between the contents of plutonium in liver and skeleton. Autopsy data show a vast inter-individual variation in the partitioning between these organs. The capacity of recent biokinetic models for plutonium to reproduce these variations was studied. Autopsy data for plutonium amounts in liver and skeleton for both (238)Pu and (239)Pu isotopes can be merged into a single data set following several statistical tests. Simulations with different parameter values generate a mapping between the autopsy values and the model parameters. The observed partitioning distribution can be transformed into a distribution of transfer rates, which would result in the observed data. Besides, the variation in the partitioning between liver and skeleton leads via biliary pathway to a variation in the excretion ratio. This can be used to estimate an individual partitioning factor, which can be used in individual case assessments.

  12. Recommended Method To Account For Daughter Ingrowth For The Portsmouth On-Site Waste Disposal Facility Performance Assessment Modeling

    SciTech Connect

    Phifer, Mark A.; Smith, Frank G. III

    2013-06-21

    A 3-D STOMP model has been developed for the Portsmouth On-Site Waste Disposal Facility (OSWDF) at Site D as outlined in Appendix K of FBP 2013. This model projects the flow and transport of the following radionuclides to various points of assessments: Tc-99, U-234, U-235, U-236, U-238, Am-241, Np-237, Pu-238, Pu-239, Pu-240, Th-228, and Th-230. The model includes the radioactive decay of these parents, but does not include the associated daughter ingrowth because the STOMP model does not have the capability to model daughter ingrowth. The Savannah River National Laboratory (SRNL) provides herein a recommended method to account for daughter ingrowth in association with the Portsmouth OSWDF Performance Assessment (PA) modeling.

  13. Group Constants Generation of the Pseudo Fission Products for Fast Reactor Burnup Calculations

    NASA Astrophysics Data System (ADS)

    Gil, Choong-Sup; Kim, Do Heon; Chang, Jonghwa

    2005-05-01

    The pseudo fission products for the burnup calculations of the liquid metal fast reactor were generated. The cross-section data and fission product yield data of ENDF/B-VI were used for the pseudo fission product data of U-235, U-238, Pu-239, Pu-240, Pu-241, and Pu-242. The pseudo fission product data can be used with the KAFAX-F22 or -E66, which are the MATXS-format libraries for analyses of the liquid metal fast reactor at KAERI and were distributed through the OECD/NEA. The 80-group MATXS-format libraries of the 172 fission products were generated and the burnup chains for generation of the pseudo fission products were prepared.

  14. X-ray absorption fine structure of aged, Pu-doped glass and ceramic waste forms

    NASA Astrophysics Data System (ADS)

    Hess, N. J.; Weber, W. J.; Conradson, S. D.

    1998-04-01

    X-ray absorption spectroscopic (XAS) studies were performed on three compositionally identical, Pu-doped, borosilicate glasses prepared 15 years ago at different α-activities by varying the 239Pu/ 238Pu isotopic ratio. The resulting α-activities ranged from 1.9×10 7 to 4.2×10 9 Bq/g and have current, accumulated doses between 8.8×10 15 to 1.9×10 18 α-decays/g. Two ceramic, polycrystalline zircon (ZrSiO 4) samples prepared 16 years ago with 10.0 wt% Pu was also investigated. Varying the 239Pu/ 238Pu isotopic ratio in these samples resulted in α-activities of 2.5×10 8 and 5.6×10 10 Bq/g and current, accumulated doses of 1.2×10 17 and 2.8×10 19 α-decays/g. The multicomponent composition of the waste forms permitted XAS investigations at six absorption edges for the borosilicate glass and at three absorption edges for the polycrystalline zircons. For both waste forms, analysis of extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES) spectra indicates that the local environment around the cations exhibits different degrees of disorder as a result of the accumulated α-decay dose. In general, cations with short cation-oxygen bonds show little effect from self-radiation whereas cations with long cation-oxygen bonds show a greater degree of disorder with accumulated α-decay dose.

  15. 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.

  16. Deconvolution of mixed gamma emitters using peak parameters

    SciTech Connect

    Gadd, Milan S; Garcia, Francisco; Magadalena, Vigil M

    2011-01-14

    When evaluating samples containing mixtures of nuclides using gamma spectroscopy the situation sometimes arises where the nuclides present have photon emissions that cannot be resolved by the detector. An example of this is mixtures of {sup 241}Am and plutonium that have L x-ray emissions with slightly different energies which cannot be resolved using a high-purity germanium detector. It is possible to deconvolute the americium L x-rays from those plutonium based on the {sup 241}Am 59.54 keV photon. However, this requires accurate knowledge of the relative emission yields. Also, it often results in high uncertainties in the plutonium activity estimate due to the americium yields being approximately an order of magnitude greater than those for plutonium. In this work, an alternative method of determining the relative fraction of plutonium in mixtures of {sup 241}Am and {sup 239}Pu based on L x-ray peak location and shape parameters is investigated. The sensitivity and accuracy of the peak parameter method is compared to that for conventional peak decovolution.

  17. U, Np, Pu and Am Prompt Fission Neutron Spectra

    SciTech Connect

    Maslov, Vladimir M.

    2008-05-12

    Prompt fission neutron spectra (PFNS) components due to soft and hard pre-fission neutrons are revealed in PFNS data of {sup 232}Th(n,F), {sup 238}U(n,F), {sup 235}U(n,F) and {sup 239}Pu(n,F) reactions for E{sub n}{<=}20 MeV. Average energies of these PFNS are systematically shifted to higher values, so that Th fission fragments look least heated, while those of Pu--most heated. The average energy is correlated with the emissive fission chances contributions to the observed fission cross sections. The predicted contribution of (n,xnf) neutrons is most pronounced in case of {sup 232}Th(n,F) reaction. The approach, based on the consistent description of {sup 237}Np(n,F), {sup 237}Np(n,2n){sup 236s}Np and {sup 241}Am(n,F), {sup 241}Am(n,2n) is used to predict the PFNS of the {sup 237}Np(n,F) and {sup 241}Am(n,F) reactions.

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

    DOE PAGES

    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

  19. Sources of the transuranic elements plutonium and neptunium in arctic marine sediments.

    SciTech Connect

    Cooper, L. W.; Kelley, J. M.; Bond, L. A.; Orlandini, K. A.; Grebmeier, J. M.; Environmental Research; ORNL; PNNL; Univ. of Tennessee

    2000-01-01

    We report here thermal ionization mass spectrometry measurements of {sup 239}Pu, {sup 240}Pu, {sup 241}Pu, {sup 242}Pu, and {sup 237}Np isolated from oceanic, estuarine, and riverine sediments from the Arctic Ocean Basin. {sup 238}Pu/{sup 239+240}Pu activity ratios are also reported for alpha spectrometric analyses undertaken on a subset of these samples. Our results indicate that the Pu in sediments on the Alaskan shelf and slope, as well as that in the deep basins (Amerasian and Eurasian) of the Arctic Ocean, has its origin in stratospheric and tropospheric fallout. Sediments from the Ob and Yenisei Rivers show isotopic Pu signatures that are distinctly different from those of northern-hemisphere stratospheric fallout and indicate the presence of weapons-grade Pu originating from nuclear fuel reprocessing wastes generated at Russian facilities within these river catchments. Consequently, sediments of the Eurasian Arctic Ocean, particularly those in the Barents and Kara Seas, probably contain a mixture of Pu from stratospheric fallout, tropospheric fallout, and fuel-reprocessing wastes of riverine origin. In particular, the {sup 241}Pu/{sup 239}Pu ratios observed in these sediments are inconsistent with significant contributions of Pu to the arctic sediments studied from western European reprocessing facilities, principally Sellafield in the UK. Several other potential sources of Pu to arctic sediments can also be excluded as significant based upon the transuranic isotope ratios presented.

  20. Radionuclide Concentrations in Soils and Vegetation at Low-Level Radioactive Waste Disposal Area G during the 1997 Growing Season

    SciTech Connect

    L. Naranjo, Jr.; P. R. Fresquez; R. J. Wechsler

    1998-08-01

    Soil and overstory and understory vegetation (washed and unwashed) collected at eight locations within and around Area G-a low-level radioactive solid-waste disposal facility at Los Alamos National Laboratory-were analyzed for 3H, 238Pu, 239Pu, 137CS, 234U, 235U, 228AC, Be, 214Bi, 60Co, 40& 54Mn, 22Na, 214Pb and 208Tl. In general, most radionuclide concentrations, with the exception of 3Ef and ~9Pu, in soils and overstory and understory vegetation collected from within and around Area G were within upper (95'%) level background concentrations. Although 3H concentrations in vegetation from most sites were significantly higher than background (>2 pCi mL-l), concentrations decreased markedly in comparison to last year's results. The highest `H concentration in vegetation was detected from a juniper tree that was growing over tritium shaft /+150; it contained 530,000 pCi 3H mL-l. Also, as in the pas~ the transuranic waste pad area contained the highest levels of 239Pu in soils and in understory vegetation as compared to other areas at Area G.

  1. 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

  2. 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.

  3. Value of burnup credit beyond actinides

    SciTech Connect

    Lancaster, D.; Fuentes, E.; Kang, Chi

    1997-12-01

    DOE has submitted a topical report to the NRC justifying burnup credit based only on actinide isotopes (U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, and Am-241). When this topical report is approved, it will allow a great deal of the commercial spent nuclear fuel to be transported in significantly higher capacity casks. A cost savings estimate for shipping fuel in 32 assembly (burnup credit) casks as opposed to 24 assembly (non-burnup credit) casks was previously presented. Since that time, more detailed calculations have been performed using the methodology presented in the Actinide-Only Burnup Credit Topical Report. Loading curves for derated casks have been generated using actinide-only burnup credit and are presented in this paper. The estimates of cost savings due to burnup credit for shipping fuel utilizing 32, 30, 28, and 24 assembly casks where only the 24 assembly cask does not burnup credit have been created and are discussed. 4 refs., 2 figs.

  4. 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.

  5. Plutonium-238 alpha-decay damage study of the ceramic waste form.

    SciTech Connect

    Frank, S M; Barber, T L; Cummings, D G; DiSanto, T; Esh, D W; Giglio, J J; Goff, K M; Johnson, S G; Kennedy, J R; Jue, J-F; Noy, M; O'Holleran, T P; Sinkler, W

    2006-03-27

    An accelerated alpha-decay damage study of a glass-bonded sodalite ceramic waste form has recently been completed. The purpose of this study was to investigate the physical and chemical durability of the waste form after significant exposure to alpha decay. This accelerated alpha-decay study was performed by doping the ceramic waste form with {sup 238}Pu which has a much greater specific activity than {sup 239}Pu that is normally present in the waste form. The alpha-decay dose at the end of the four year study was approximately 1 x 10{sup 18} alpha-decays/gram of material. An equivalent time period for a similar dose of {sup 239}Pu would require approximately 1100 years. After four years of exposure to {sup 238}Pu alpha decay, the investigation observed little change to the physical or chemical durability of the ceramic waste form (CWF). Specifically, the {sup 238}Pu-loaded CWF maintained it's physical integrity, namely that the density remained constant and no cracking or phase de-bonding was observed. The materials chemical durability and phase stability also did not change significantly over the duration of the study. The only significant measured change was an increase of the unit-cell lattice parameters of the plutonium oxide and sodalite phases of the material and an increase in the release of salt components and plutonium of the waste form during leaching tests, but, as mentioned, these did not lead to any overall loss of waste form durability. The principal findings from this study are: (1) {sup 238}Pu-loaded CWF is similar in microstructure and phase composition to referenced waste form. (2) Pu was observed primarily as oxide comprised of aggregates of nano crystals with aggregates ranging in size from submicron to twenty microns in diameter. (3) Pu phases were primarily found in the intergranular glassy regions. (4) PuO phase shows expected unit cell volume expansion due to alpha decay damage of approximately 0.7%, and the sodalite phase unit cell volume

  6. Plutonium isotopic analysis system for plutonium samples enriched in sup 238 Pu in EP 60/61 and fuel-clad containers

    SciTech Connect

    Ruhter, W.D.

    1991-07-01

    This user's manual is addressed to the Hanford Site personnel (routine operators and supervisors) who perform measurements with the Pu-238 isotopic analysis system. Each chapter begins with a table of contents that lists the section titles, illustrations, and tabular data presented in that chapter. The first chapter in this manual is an introduction to the system. Chapter 2 lists required settings for the system's commercial nuclear instrument modules. System operating procedures are given in Chapter 3. Chapter 4 contains routine and supervisorial operator interactions. Chapter 5 describes the system's short- and long-printout output formats. Chapter 6 gives instructions for changing system parameters. Error messages are listed and described in Chapter 7. Chapter 8 contains reference articles on measuring relative plutonium isotopics in solid samples.

  7. Environmental and radiological safety studies: Interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, September 26-December 25, 1981

    SciTech Connect

    Matlack, G.M.; Patterson, J.H.

    1982-02-01

    Although existing radioisotope thermoelectric generator designs have proved more than adequately safe, more information is continually sought about the heat sources to improve their safety. The work here includes studies of the effects on the heat sources of terrestrial and aquatic environments and also of the effect of the heat sources on various simulated environments. This progress report presents recent data from environmental chamber and aquatic experiments and gives the present status of the experiments.

  8. Environmental and radiological safety studies. Interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, July 1-September 25, 1981

    SciTech Connect

    Matlack, G.M.; Patterson, J.H.

    1981-11-01

    Although existing radioisotope thermoelectric generator designs have proved more than adequately safe, more information is continually sought about the heat sources to improve their safety. The work here includes studies of the effects on the heat sources of terrestrial and aquatic environments and also of the effects of the heat sources on various simulated environments. This progress report presents recent data from environmental chamber and aquatic experiments and gives the present status of the experiments.

  9. Environmental and radiological safety studies: interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, April 1- June 30, 1982

    SciTech Connect

    Matlack, G.M.; Patterson, J.H.; Stalnaker, N.D.

    1982-09-01

    Although existing radioisotope thermoelectric generator designs have proved more than adequately safe, more information is continually sought about the heat sources to improve their safety. The work here includes studies of the effects on the heat sources on terrestrial and aquatic environments and also of the effects of the heat sources on various simulated environments. This progress report presents recent data from environmental chamber and aquatic experiments and gives the present status of the experiments.

  10. Environmental and radiological safety studies: interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, July 1-September 30, 1982

    SciTech Connect

    Matlack, G.M.; Patterson, J.H.; Stalnaker, N.D.

    1982-12-01

    Although existing radioisotope thermoelectric generator designs have proved more than adequately safe, more information is continually sought about the heat sources to improve their safety. The work here includes studies of the effects on the heat sources of terrestrial and aquatic environments and also of the effects of the heat sources on various simulated environments. This progress report presents recent data from environmental chamber and aquatic experiments and gives the present status of the experiments.

  11. 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.

  12. Sea to land transfer of anthropogenic radionuclides to the North Wales coast, Part I: external gamma radiation and radionuclide concentrations in intertidal sediments, soil and air.

    PubMed

    Bryan, S E; McDonald, P; Hill, R; Wilson, R C

    2008-01-01

    Previous projects specifically aimed at performing radiological assessments in the vicinity of North Wales, investigating the presence and transfer of radionuclides from sea to land, were in 1986 and 1989. Since then, changes have occurred in the radioactive discharges from the British Nuclear Group Sellafield site. Annual discharges of (137)Cs, (238)Pu, (239,340)Pu and (241)Am have decreased markedly whereas, up until recent years, discharges of (99)Tc have increased. It is therefore desirable to quantify current transfer processes of radionuclides in the North Wales region and thus provide an update on 15-year-old studies. A field campaign was conducted collecting soil samples from 10 inland transects and air particulates on air filters from three High Volume Air Samplers, along the northern coast of Wales at Amlwch, Bangor Pier and Flint. Complementary field data relating to external gamma dose rates were collected at the soil sites. The field data generated for (137)Cs, (238)Pu, (239,340)Pu and (241)Am were consistent with what had been reported 15 years previously. Therefore, there has been no increase in the supply of these Sellafield-derived radionuclides to the terrestrial environment of the North Wales coast. The (99)Tc data in sediments were consistent with reported values within annual monitoring programmes, however, a relatively high activity concentration was measured in one sediment sample. This site was further investigated to determine the reason why such a high value was found. At present there is no clear evidence as to why this elevated concentration should be present, but the role of seaweed and its capacity in accumulating (99)Tc and transferring it to sediment is of interest. The analysis of the field samples for (99)Tc, (137)Cs, (238)Pu, (239,240)Pu and (241)Am has provided a data set that can be used for the modelling of the transfer of anthropogenic radionuclides from sea to land and its subsequent radiological implications and is reported

  13. Radionuclide concentrations in vegetation at the Los Alamos National Laboratory in 1998

    SciTech Connect

    G. J. Gonzales; P. R. Fresquez; M. A. Mullen; L. Naranjo, Jr.

    2000-03-01

    This report summarizes and evaluates the concentrations of {sup 3}H, {sup 137}Cs, {sup 238}Pu, {sup 239,240}Pu, {sup 241}Am, {sup 90}Sr, and total U in understory and overstory vegetation collected from Los Alamos National Laboratory (LANL), its perimeter, and regional background areas in 1998. Comparisons to conservative toxicity reference value safe limits were also made. The arithmetic mean LANL radionuclide concentrations in understory were 501 pCi L{sup {minus}1} for {sup 3}H, 0.581 pCi ash g{sup {minus}1} for {sup 137}Cs, 0.001 pCi ash g{sup {minus}1} for {sup 238}Pu, 0.008 pCi ash g{sup {minus}1} for {sup 239,240}Pu, 0.007 pCi ash g{sup {minus}1} for {sup 241}Am, 1.46 pCi ash g{sup {minus}1} for {sup 90}Sr, and 0.233 {micro}g ash g{sup {minus}1} for total uranium. The mean LANL radionuclide concentrations in overstory were 463 pCi L{sup {minus}1} for {sup 3}H, 1.51 pCi ash g{sup {minus}1} for {sup 137}Cs, 0.0004 pCi ash g{sup {minus}1} {sup 238}Pu, 0.008 pCi ash g{sup {minus}1} for {sup 239,240}Pu, 0.014 pCi ash g{sup {minus}1} for {sup 241}Am, 1.97 pCi ash g{sup {minus}1} for {sup 90}Sr, and 0.388 {micro}g ash g{sup {minus}1} for total uranium. Concentrations of radionuclides and total U in both understory and overstory vegetation at LANL generally were not statistically higher than in perimeter and regional background vegetation ({alpha} = 0.05). The exceptions were LANL {sup 3}H > perimeter {sup 3}H (understory) and LANL {sup 3}H background {sup 3}H (overstory). All maximum radionuclide concentrations were lower than toxicity reference values. With the exception of total U, the relationship between contaminant concentration in soil vs. vegetation was insignificant ({alpha} = 0.05). Generally, as the concentration of total U in soil decreased, the concentration in vegetation increased. This held true for both understory and overstory and regardless of whether data were separated by general location (LANL, perimeter, and background) or not. There was no

  14. Use of in vivo counting measurements to estimate internal doses from (241)Am in workers from the Mayak production association.

    PubMed

    Sokolova, Alexandra B; Suslova, Klara G; Efimov, Alexander V; Miller, Scott C

    2014-08-01

    Comparisons between results of in vivo counting measurements of americium burden and results from radiochemical analyses of organ samples taken at autopsy of 11 cases of former Mayak workers were made. The in vivo counting measurements were performed 3-8 y before death. The best agreement between in vivo counting measurements for americium and autopsy data was observed for the skull. For lungs and liver, the ratios of burden measured by in vivo counting to those obtained from radiochemical analyses data ranged from 0.7-3.8, while those for the skull were from 1.0-1.1. There was a good correlation between the estimates of americium burden in the entire skeleton obtained from in vivo counting with those obtained from autopsy data. Specifically, the skeletal burden ratio, in vivo counting/autopsy, averaged 0.9 ± 0.1. The prior human americium model, D-Am2010, used in vivo counting measurements for americium in the skeleton to estimate the contents of americium and plutonium at death. The results using this model indicate that in vivo counting measurements of the skull can be used to estimate internal doses from americium in the Mayak workers. Additionally, these measurements may also be used to provide a qualitative assessment of internal doses from plutonium. PMID:24978284

  15. The uptake of plutonium-238, 239, 240, americium-241, strontium-90 and caesium-137 into potatoes.

    PubMed

    Popplewell, D S; Ham, G J; Johnson, T E; Stather, J W; Sumner, S A

    1984-09-01

    Transfer factors have been measured for 239 Pu + 240 Pu, 241 Am, 90 Sr and 137 Cs into potatoes grown in a blend of soil which included silt polluted with radioactive waste discharged into the Irish Sea. The experiment has been carried out over four seasons and attempts to assess the radiological consequences to the consumer which would arise if potatoes were to be grown in land heavily contaminated with the silt. During the course of the experiment plutonium and americium became less available for uptake, 90 Sr became slightly more available and 137 Cs remained nearly constant in its availability. The values of the transfer factors are among the lowest reported for these radionuclides into potatoes.

  16. Artificial neural networks technology for neutron spectrometry and dosimetry.

    PubMed

    Vega-Carrillo, H R; Hernández-Dávila, V M; Manzanares-Acuña, E; Gallego, E; Lorente, A; Iñiguez, M P

    2007-01-01

    Artificial Neural Network Technology has been applied to unfold neutron spectra and to calculate 13 dosimetric quantities using seven count rates from a Bonner Sphere Spectrometer with a (6)LiI(Eu). Two different networks, one for spectrometry and another for dosimetry, were designed. To train and test both networks, 177 neutron spectra from the IAEA compilation were utilised. Spectra were re-binned into 31 energy groups, and the dosimetric quantities were calculated using the MCNP code and the fluence-to-dose conversion coefficients from ICRP 74. Neutron spectra and UTA4 response matrix were used to calculate the expected count rates in the Bonner spectrometer. Spectra and H(10) of (239)PuBe and (241)AmBe were experimentally obtained and compared with those determined with the artificial neural networks. PMID:17522034

  17. Carcinogenesis From Inhaled (PuO2)-Pu-239 in Beagles: Evidence for Radiation Homeostasis at Low Doses?

    SciTech Connect

    Fisher, Darrell R.; Weller, Richard E.

    2010-09-01

    From the early 1970s to the late 1980s, Pacific Northwest National Laboratory conducted life-span studies in beagle dogs on the biological effects of inhaled plutonium (239PuO2, 238PuO2, and 239Pu[NO3]4) to help predict risks associated with accidental intakes in workers. Years later, the purpose of the present follow-up study is to reassess the dose-response relationship for lung cancer induction in the 239PuO2 dogs compared to controls, with particular focus on the dose-response at low lung doses. A 239PuO2 aerosol (2.3 μm AMAD, 1.9 μm GSD) was administered to six groups of 20 young (18-month old) beagle dogs (10 males and 10 females) by inhalation at six different activity levels, as previously described in Laboratory reports. Control dogs were sham-exposed. In dose level 1, initial pulmonary lung depositions were 130 ± 48 Bq (3.5 ± 1.3 nCi), corresponding to 1 Bq g-1 lung tissue (0.029 ± 0.001 nCi g-1. Groups 2 through 6 received initial lung depositions (mean values) of 760, 2724, 10345, 37900, and 200000 Bq (22, 79, 300, 1100, and 5800 nCi) 239PuO2, respectively. For each dog, the absorbed dose to lungs was calculated from the initial lung burden and the final lung burden at time of death and lung mass, assuming a single, long-term retention function. Insoluble plutonium oxide exhibited long retention times in the lungs. Increased dose-dependent mortality due to lung cancer (bronchiolar-alveolar carcinoma, adenocarcinoma, epidermoid carcinoma) and radiation pneumonitis (highest exposures group) was observed in dogs exposed to 239PuO2. Calculated lung doses ranged from a few cGy in early-sacrificed dogs to 7764 cGy in dogs that experienced early deaths from radiation pneumonitis. Data were regrouped by lifetime lung dose and plotted as a function of lung tumor incidence. Lung tumor incidence in controls and zero-dose exposed dogs was 18% (5/28). However, no lung tumors were observed in 16 dogs with the lowest lung doses (8 to 22 cGy, mean 14.4 ± 7.6 c

  18. Characterization studies of actinide contamination on Johnston Atoll

    SciTech Connect

    Wolf, S.F.; Bates, J.K.; Brown, N.R.; Buck, E.C.; Dietz, N.L.; Fortner, J.A.; Gong, Meiling

    1994-07-01

    This paper presents results that indicates that plutonium and americium contamination of Johnson Atoll soil and sludge from the cleanup plant settling pond is dispersed. The {sup 241}Am/{sup 239}Pu ratio was essentially identical for all analyzed material. Except for one ``hot particle,`` no discrete Pu particles were located in untreated coral soil by SEM even though our sample contained both {sup 241}Am and {sup 239}Pu activity measurable by gammaray spectrometry. Alpha particle spectrometry analysis of sequentially filtered sludge showed small that activity is associated with particles as 0.4 {mu}m in diameter. Thin section analysis revealed that the ``hot particle`` was a fragment of stainless steel with a layer of oxidized Pu, U, and other metals deposited on the outside. This Pu-containing layer was covered with a layer of coral soil that formed on the oxidized Pu/U phase during the process of weathering on JA. Analyses of all samples except the ``hot particle`` with SEM or TEM coupled with EDS did not reveal the presence of any distinct Pu phases, despite measurable activity in these samples. Together, these findings are consistent with the Pu and Am being highly dispersed throughout the contaminated soil and sludge. Direct evidence for association of Pu with coral was observed in the thin section of the ``hot particle.`` A possible mechanism for the dispersal of contamination is that weathering of fragments from the aborted missile leads to complexation of Pu with calcium carbonate followed by adsorption onto the coral soil surface. This process has not led to measurable fractionation of Am from its Pu parent.

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

    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

  20. 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.

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

    PubMed

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

    2001-08-31

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

  2. 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.

  3. 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.

  4. The Characterization of Biotic and Abiotic Media Upgradient and Downgradient of the Los Alamos Canyon Weir

    SciTech Connect

    P.R. Fresquez

    2006-01-15

    As per the Mitigation Action Plan for the Special Environmental Analysis of the actions taken in response to the Cerro Grande Fire, sediments, vegetation, and small mammals were collected directly up- and downgradient of the Los Alamos Canyon weir, a low-head sediment control structure located on the northeastern boundary of Los Alamos National Laboratory, to determine contaminant impacts, if any. All radionuclides ({sup 3}H, {sup 137}Cs, {sup 238}Pu, {sup 239,240}Pu, {sup 90}Sr, {sup 241}Am, {sup 234}U, {sup 235}U and {sup 238}U) and trace elements (Ag, As, Ba, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se, and Tl) in these media were low and most were below regional upper level background concentrations (mean plus three sigma). The very few constituents that were above regional background concentrations were far below screening levels (set from State and Federal standards) for the protection of the human food chain and the terrestrial environment.

  5. The concentration of radionuclides and metals in vegetation adjacent to and in the SRL Seepage Basins

    SciTech Connect

    Murphy, C. E. Jr.

    1992-12-14

    In 1991 the trees on the dikes surrounding the SRL Seepage Basins were sampled and analyzed to inventory the contaminants transported from the basins into the vegetation. Tree leaves and wood were collected and analyzed for {sup 90}Sr, {sup 60}Co, {sup 137}Cs, {sup 238}Pu, {sup 239,240}Pu, {sup 242,244}Cm, {sup 241}Am, Ba, Cr, Hg, Mg, Mn, Ni, and Pb. The concentrations of contaminants were influenced by sample type (leaves versus wood), species type (pines versus hardwoods), and location relative to distance from the basin. The total inventory of each contaminant in the trees was estimated. The relationships between leaf and wood, pines and hardwood, location, and mass of the material in each of these classes were used to weight the total inventory estimate. The radionuclide with the largest inventory was 0.7 mCi for {sup 90}Sr. The metallic contaminant with the largest inventory was Mn at 200 gm.

  6. The concentration of radionuclides and metals in vegetation adjacent to and in the SRL Seepage Basins

    SciTech Connect

    Murphy, C. E. Jr.

    1992-12-14

    In 1991 the trees on the dikes surrounding the SRL Seepage Basins were sampled and analyzed to inventory the contaminants transported from the basins into the vegetation. Tree leaves and wood were collected and analyzed for [sup 90]Sr, [sup 60]Co, [sup 137]Cs, [sup 238]Pu, [sup 239,240]Pu, [sup 242,244]Cm, [sup 241]Am, Ba, Cr, Hg, Mg, Mn, Ni, and Pb. The concentrations of contaminants were influenced by sample type (leaves versus wood), species type (pines versus hardwoods), and location relative to distance from the basin. The total inventory of each contaminant in the trees was estimated. The relationships between leaf and wood, pines and hardwood, location, and mass of the material in each of these classes were used to weight the total inventory estimate. The radionuclide with the largest inventory was 0.7 mCi for [sup 90]Sr. The metallic contaminant with the largest inventory was Mn at 200 gm.

  7. Concentrations of radionuclides in reef and lagoon pelagic fish from the Marshall Islands

    SciTech Connect

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

    1981-07-01

    A radiological survey was conducted from September through November of 1978 to assess the concentrations of persistent man-made radionuclides in the terrestrial and marine environments of 11 atolls and 2 islands of the Northern Marshall Islands. The atolls and islands include Rongelap, Utirik, Taka, Bikar, Rongerik, Ailinginae, Likiep, Jemo, Ailuk, Mejet, Wotho, Ujelang and Bikini. Over 4000 terrestrial and marine samples were collected for radionuclide analysis from 76 different islands. Soils, vegetation, indigenous animals, and cistern and groundwater were collected from the islands. Reef fish, pelagic species, clams, lagoon water, and sediments were obtained from the lagoons. A report is given of all available concentration data for /sup 137/Cs, /sup 90/Sr, /sup 239+240/Pu, /sup 238/Pu, /sup 241/Am as well as naturally occurring /sup 40/K and other gamma emitting radionuclides in tissues and organs of different species of fish collected from the atolls.

  8. Multidentate terephthalamidate and hydroxypyridonate ligands: towards new orally active chelators.

    PubMed

    Abergel, Rebecca J; Raymond, Kenneth N

    2011-01-01

    The limitations of current therapies for the treatment of iron overload or radioisotope contamination have stimulated efforts to develop new orally bioavailable iron and actinide chelators. Siderophore-inspired tetradentate, hexadentate and octadentate terephthalamidate and hydroxypyridonate ligands were evaluated in vivo as selective and efficacious iron or actinide chelating agents, with several metal loading and ligand assessment procedures, using (59)Fe, (238)Pu, and (241)Am as radioactive tracers. The compounds presented in this study were compared to commercially available therapeutic sequestering agents [deferoxamine (DFO) for iron and diethylenetriaminepentaacetic acid (DPTA) for actinides] and are unrivaled in terms of affinity, selectivity and decorporation efficacy, which attests to the fact that high metal affinity may overcome the low bioavailability properties commonly associated to multidenticity. PMID:21599440

  9. 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

  10. Safe radioisotope thermoelectric generators and heat sources for space applications

    NASA Astrophysics Data System (ADS)

    O'Brien, R. C.; Ambrosi, R. M.; Bannister, N. P.; Howe, S. D.; Atkinson, H. V.

    2008-07-01

    Several isotopes are examined as alternatives to 238Pu that is traditionally used in radioisotope thermoelectric generators (RTGs) and heating units (RHUs). The radioisotopes discussed include 241Am, 208Po, 210Po, and 90Sr. The aim of this study is to facilitate the design of an RTG with a minimal radiation dose rate and mass including any required shielding. Applications of interest are primarily space and planetary exploration. In order to evaluate the properties of the alternative radioisotopes a Monte Carlo model was developed to examine the radiation protection aspect of the study. The thermodynamics of the power generation process is examined and possible materials for the housing and encapsulation of the radioisotopes are proposed. In this study we also present a historical review of radioisotope thermoelectric generators (RTGs) and the thermoelectric conversion mechanism in order to provide a direct comparison with the performance of our proposed alternative isotope systems.

  11. Dose Estimates from Ingestion of Marine and Terrestrial Animals Harvested in the Beaufort Sea and Northwestern Alaska

    SciTech Connect

    W. C. T. Inkret; M. E. Schillaci; D. W. Efurd; M. E. Ennis; M. J. Hameedi; J. M. Inkret; T. H. T. Little; G. Miller

    2000-11-01

    Between 1993 and 1995, marine and terrestrial animal samples were collected from the Beaufort Sea and northwest Alaska. These samples were analyzed at Los Alamos National Laboratory for the presence of the anthropogenic radionuclides, {sup 90}Sr, {sup 137}Cs, {sup 238}Pu, {sup 239+240}Pu, and {sup 241}Am. The measurement data were combined with food consumption rates based on survey results for populations residing in three northwest Alaskan communities and published age-dependent ingestion dose coefficients to estimate potential radiological impacts from the consumption of traditional animal foods harvested in this region. The results of this study indicate that committed equivalent doses to adults from {sup 90}Sr and {sup 137}Cs, due to consumption of traditional food sources are consistent with currently accepted estimates of average doses to adults in North America due to atmospheric nuclear weapons testing fallout.

  12. Concentrations of Radionuclides and Trace Elements in Soils and Vegetation Around the DARHT Facility during 2004

    SciTech Connect

    P.R. Fresquez

    2004-10-01

    Samples of soil, sediment, and unwashed overstory and understory vegetation were collected at four locations around the Dual-Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory (LANL). All samples were analyzed for concentrations of {sup 3}H, {sup 137}Cs, {sup 90}Sr, {sup 238}Pu, {sup 239,240}Pu, {sup 241}Am, {sup 234}U, {sup 235}U, {sup 238}U, Ag, As, Ba, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se, and Tl. These results, which represent five years since the start of operations, were compared with baseline statistical reference level (BSRL) data established over a four-year-long preoperational period prior to DARHT operations, and to LANL and U.S. Environmental Protection Agency Screening Action Levels (SALs). Most radionuclides and trace elements in soil, sediment, and vegetation were below BSRL values and those soils/sediments that were above BSRLs were far below SALs.

  13. MULTIDENTATE TEREPHTHALAMIDATE AND HYDROXYPYRIDONATE LIGANDS: TOWARDS NEW ORALLY ACTIVE CHELATORS

    SciTech Connect

    Abergel, Rebecca J.; Raymond, Kenneth N.

    2011-07-13

    The limitations of current therapies for the treatment of iron overload or radioisotope contamination have stimulated efforts to develop new orally bioavailable iron and actinide chelators. Siderophore-inspired tetradentate, hexadentate and octadentate terephthalamidate and hydroxypyridonate ligands were evaluated in vivo as selective and efficacious iron or actinide chelating agents, with several metal loading and ligand assessment procedures, using {sup 59}Fe, {sup 238}Pu, and {sup 241}Am as radioactive tracers. The compounds presented in this study were compared to commercially available therapeutic sequestering agents [deferoxamine (DFO) for iron and diethylenetriaminepentaacetic acid (DPTA) for actinides] and are unrivaled in terms of affinity, selectivity and decorporation efficacy, which attests to the fact that high metal affinity may overcome the low bioavailability properties commonly associated to multidenticity.

  14. X-ray fluorescence as a tool for investigating archaeological finds

    NASA Astrophysics Data System (ADS)

    Čechák, T.; Hložek, M.; Musílek, L.; Trojek, T.

    2007-09-01

    X-ray fluorescence analysis (XRFA) is an outstanding method for investigations of various objects of historic and cultural significance, as it is non-destructive, can be used without any sampling of the analysed artefacts and, if necessary, measurements can be carried out in situ. The laboratory at CTU FNSPE is equipped for XRFA with radionuclides 55Fe, 238Pu and 241Am and with a small X-ray tube (30 kV) as excitation sources, and with Si(Li) and Si-PIN semiconductor spectrometers for detecting XRF spectra. This paper deals with XRFA of archaeological finds. Practical examples are selected from investigations of ceramic objects from excavations in the Czech Republic.

  15. Detection of plutonium isotopes at lowest quantities using in-source resonance ionization mass spectrometry.

    PubMed

    Raeder, S; Hakimi, A; Stöbener, N; Trautmann, N; Wendt, K

    2012-11-01

    The in-source resonance ionization mass spectrometry technique was applied for quantification of ultratrace amounts of plutonium isotopes as a proof of principle study. In addition to an overall detection limit of 10(4) to 10(5) atoms, this method enables the unambiguous identification and individual quantification of the plutonium isotopes (238)Pu and (241)Pu which are of relevance for dating of radiogenic samples. Due to the element-selective ionization process, these isotopes can be measured even under a high surplus of isobaric contaminations from (238)U or (241)Am, which considerably simplifies chemical preparation. The technique was developed, tested, and characterized on a variety of synthetic and calibration samples and is presently applied to analyze environmental samples.

  16. Performance testing of radiobioassay laboratories: In vitro measurements (urinalysis): Final report

    SciTech Connect

    MacLellan, J.A.; Traub, R.J.; Fisher, D.R.

    1988-03-01

    This report provides results of the two-round nationwide in vitro bioassay intercomparison study. Conclusions were based on analyses by 35 bioassay laboratories of nearly 1400 artificial urine samples containing known quantities of radionuclides. The test radionuclides were H, /sup 89/Sr, /sup 238/Pu, /sup 241/Am, /sup 137/Cs, /sup 60/Co, and natural uranium. The data reported included background count rates, total samples counts, counting times, counting efficiencies, sample yields, and estimated errrors of the determinations. The measurement data were evaluated according to statistical methods presented in the November 1985 version of the draft ANSI Standard N13.30. If a laboratory failed a performance test for any one of the three criteria, the laboratory was considered to have failed the test for that category. 22 refs., 18 figs., 14 tabs

  17. Territory contamination with the radionuclides representing the fuel component of Chernobyl fallout.

    PubMed

    Kashparov, V A; Lundin, S M; Zvarych, S I; Yoshchenko, V I; Levchuk, S E; Khomutinin, Y V; Maloshtan, I M; Protsak, V P

    2003-12-30

    The data obtained through a series of experiments were used to specify the correlation of activities of the fuel component radionuclides of Chernobyl fallout and to create the maps of the 30-km Chernobyl zone terrestrial density of contamination with 154Eu, 238Pu, 239+240Pu and 241Am (on 01.01.2000). In the year 2000, total inventories of the fuel component radionuclides in the upper 30-cm soil layer of the 30-km Chernobyl zone in Ukraine (outside the ChNPP industrial site, excluding the activity located in the radioactive waste storages and in the cooling pond) were estimated as: 90Sr--7.7 x 10(14) Bq; 137Cs--2.8 x 10(15) Bq; 154Eu--1.4 x 10(13) Bq; 238Pu--7.2 x 10(12) Bq; 239+240Pu--1.5 x 10(13) Bq; 241Am--1.8 x 10(13) Bq. These values correspond to 0.4-0.5% of their amounts in the ChNPP unit 4 at the moment of the accident. The current estimate is 3 times lower than the previous widely-cited estimates. Inventories of the fuel component radionuclides were also estimated in other objects within the 30-km zone and outside it. This allowed more accurate data to be obtained on the magnitude of a relative release of radionuclides in the fuel particles (FP) matrix during the Chernobyl accident outside the ChNPP industrial site. It amounts to 1.5+/-0.5% of these radionuclides in the reactor, which is 2 times lower than the previous estimates. Two-thirds of the radionuclides release in the FP was deposited on the territory of Ukraine. PMID:14630415

  18. Minor Actinides Loading Optimization for Proliferation Resistant Fuel Design - BWR

    SciTech Connect

    G. S. Chang; Hongbin Zhang

    2009-09-01

    One approach to address the United States Nuclear Power (NP) 2010 program for the advanced light water reactor (LWR) (Gen-III+) intermediate-term spent fuel disposal need is to reduce spent fuel storage volume while enhancing proliferation resistance. One proposed solution includes increasing burnup of the discharged spent fuel and mixing minor actinide (MA) transuranic nuclides (237Np and 241Am) in the high burnup fuel. Thus, we can reduce the spent fuel volume while increasing the proliferation resistance by increasing the isotopic ratio of 238Pu/Pu. For future advanced nuclear systems, MAs are viewed more as a resource to be recycled, and transmuted to less hazardous and possibly more useful forms, rather than simply disposed of as a waste stream in an expensive repository facility. MAs play a much larger part in the design of advanced systems and fuel cycles, not only as additional sources of useful energy, but also as direct contributors to the reactivity control of the systems into which they are incorporated. A typical boiling water reactor (BWR) fuel unit lattice cell model with UO2 fuel pins will be used to investigate the effectiveness of adding MAs (237Np and/or 241Am) to enhance proliferation resistance and improve fuel cycle performance for the intermediate-term goal of future nuclear energy systems. However, adding MAs will increase plutonium production in the discharged spent fuel. In this work, the Monte-Carlo coupling with ORIGEN-2.2 (MCWO) method was used to optimize the MA loading in the UO2 fuel such that the discharged spent fuel demonstrates enhanced proliferation resistance, while minimizing plutonium production. The axial averaged MA transmutation characteristics at different burnup were compared and their impact on neutronics criticality and the ratio of 238Pu/Pu discussed.

  19. Nevada test site radionuclide inventory and distribution program: Report number 4, Areas 18 and 20

    SciTech Connect

    McArthur, R D; Mead, S W

    1988-04-01

    As part of the Radionuclide Inventory and Distribution Program on the Nevada Test Site, in situ measurements of gamma-emitting radionuclides were made at more than 600 locations in six regions near ground zeros in Areas 18 and 20. In addition, several soil samples were collected from each region and analyzed to determine inverse relaxation lengths and radionuclide ratios. Analysis of the data from Area 20 led to estimated inventories of 23 Ci of /sup 241/Am, 30 Ci of /sup 238/Pu, 41 Ci of /sup 239,240/Pu, 18 Ci of /sup 60/Co, 6.4 Ci of /sup 137/Cs, 6.0 Ci of /sup 90/Sr, 17 Ci of /sup 152/Eu, 19 Ci of /sup 154/Eu, and 6.6 Ci of /sup 155/Eu. For Area 18, the estimated inventories were 27 Ci of /sup 241/Am, 4.9 Ci of /sup 238/Pu, 150 Ci of /sup 239,240/Pu, 1.3 Ci of /sup 60/Co, 4.9 Ci of /sup 137/Cs, 13 Ci of /sup 90/Sr, 2.1 Ci of /sup 152/Eu, 1.3 Ci of /sup 154/Eu, and 1.4 Ci of /sup 155/Eu. The locations of the measurements in Area 18 were chosen by importance sampling, which permits the calculation of an estimate of the sampling error. Maps of radionuclide distributions were also generated for all regions except the area near the Palanquin and Cabriolet ground zeros. 3 refs., 65 figs., 7 tabs.

  20. Radionuclide concentrations in terrestrial vegetation and soil on and around the Hanford Site, 1983 through 1993

    SciTech Connect

    Poston, T.M.; Antonio, E.J.; Cooper, A.T.

    1995-08-01

    This report reviews concentrations of {sup 60}Co, {sup 90}Sr, {sup 137}Cs, U isotopes, {sup 238}Pu, {sup 239,240}Pu, and {sup 241}Am in soil and vegetation samples collected from 1983 through 1993 during routine surveillance of the Hanford Site. Sampling locations were grouped in study areas associated with operational areas on the Site. While radionuclide concentrations were very low and representative of background concentrations from historic fallout, some study areas on the Site contained slightly elevated concentrations compared to other study areas onsite and offsite. The 100 Areas had concentrations of {sup 60}Co comparable to the minimum detectable concentration of 0.02 pCi/g in soil. Concentrations of {sup 90}Sr, {sup 137}Cs, {sup 238}Pu, {sup 239,240}Pu, and {sup 241}Am in 200 Area soils were slightly elevated. The 300 Area had a slight elevation of U in soil. These observations were expected because many of the sampling locations were selected to monitor specific facilities or operations at the operational areas. Generally, concentrations of the radionuclides studied were greater and more readily measured in soil samples compared to vegetation samples. The general pattern of concentrations of radionuclide concentrations in vegetation by area mirrored that observed in soil. Declines in {sup 90}Sr in soil appear to be attributed to radioactive decay and possibly downward migration out of the sampling horizon. The other radionuclides addressed in this report strongly sorb to soil and are readily retained in surface soil. Because of their long half-lives compared to the length of the study period, there was no significant indication that concentrations of U isotopes and Pu isotopes were decreasing over time.