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Sample records for 240pu 243am 209bi

  1. Microscopic Calculations of 240Pu Fission

    SciTech Connect

    Younes, W; Gogny, D

    2007-09-11

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

  2. 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.

  3. 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.

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

    SciTech Connect

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

    1988-11-01

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

  5. Extension of 239+240Pu sediment geochronology to coarse-grained marine sediments

    USGS Publications Warehouse

    Kuehl, Steven A.; Ketterer, Michael E.; Miselis, Jennifer L.

    2012-01-01

    Sediment geochronology of coastal sedimentary environments dominated by sand has been extremely limited because concentrations of natural and bomb-fallout radionuclides are often below the limit of measurement using standard techniques. ICP-MS analyses of 239+240Pu from two sites representative of traditionally challenging (i.e., low concentration) environments provide a "proof of concept" and demonstrate a new application for bomb-fallout radiotracers in the study of sandy shelf-seabed dynamics. A kasten core from the New Zealand shelf in the Southern Hemisphere (low fallout), and a vibracore from the sandy nearshore of North Carolina (low particle surface area) both reveal measurable 239+240Pu activities at depth. In the case of the New Zealand site, independently verified steady-state sedimentation results in a 239+240Pu profile that mimics the expected atmospheric fallout. The depth profile of 239+240Pu in the North Carolina core is more uniform, indicating significant sediment resuspension, which would be expected in this energetic nearshore environment. This study, for the first time, demonstrates the utility of 239+240Pu in the study of sandy environments, significantly extending the application of bomb-fallout isotopes to coarse-grained sediments, which compose the majority of nearshore regions.

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

    SciTech Connect

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

    2015-02-01

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

  7. Temporal evolution of (137)Cs, (237)Np, and (239+240)Pu and estimated vertical (239+240)Pu export in the northwestern Mediterranean Sea.

    PubMed

    Bressac, M; Levy, I; Chamizo, E; La Rosa, J J; Povinec, P P; Gastaud, J; Oregioni, B

    2017-04-03

    The evolution of (137)Cs, (237)Np and (239+240)Pu at the DYFAMED station (NW Mediterranean) is discussed in relation to physical processes, downward fluxes of particles, and changes in the main input sources. The data set presented in this study represents the first complete (237)Np vertical profiles (0.12-0.27μBqL(-1)), and constitutes a baseline measurement to assess future changes. A similar behavior of Cs and Np has been evidenced, confirming that Np behaves conservatively. While the (137)Cs decrease has been driven by its radioactive decay, the vertical distribution of (237)Np has not substantially changed over the last decade. In the absence of recent major inputs, a homogenization of their vertical distribution occurred, partly due to deep convection events that became more intense during the last decade. In contrast, (239+240)Pu surface levels in the NW Mediterranean waters have fallen in the past four decades by a factor of 5. This decrease in surface has been balanced by higher concentrations in the deep-water layers. A first estimate of the downward (239+240)Pu fluxes in the NW Mediterranean Sea is proposed over more than two decades. This estimation, based on the DYFAMED sediment trap time-series data and published (239+240)Pu flux measurements, suggests that sinking particles have accounted for 60-90% of the upper layer (0-200m) Pu inventory loss over the period 1989-2013. The upper layer residence time of Pu is estimated to be ~28years, twice as long as the residence time estimated for the whole western Mediterranean (~15years). This difference highlights the slow removal of Pu in the open waters of the NW Mediterranean and confirms that most of the Pu removal occurs along the coastal margin where sedimentation rates are high.

  8. Large particle flux of 239+240Pu on the continental margin of the East China Sea.

    PubMed

    Yamada, Masatoshi; Aono, Tatsuo

    2002-03-15

    Settling particles were collected from three locations in the East China Sea continental margin and analyzed for 239+240Pu. Two types of sediment traps were used, cylindrical traps and conical time-series traps. Surface sediment samples collected from five locations were also analyzed for 239+240Pu. Data from cylindrical traps showed there was a clear tendency for total mass fluxes to increase with depth at all three stations, and there was an especially large increase near the bottom. 239+240Pu concentrations in settling particles increased with depth from 1.76 mBq/g at 97-m depth to 3.0 mBq/g at 120-m depth and ranged from approximately 3 to 4 mBq/g at depths greater than 120 m. 239+240Pu concentrations collected in the near-bottom traps were approximately two times higher than those in the underlying surface sediments. Like total mass fluxes there was a clear tendency for 239+240Pu fluxes to increase with depth at every station, and the highest 239+240Pu fluxes were observed near the bottom. 239+240Pu concentrations in the time-series traps had little variation throughout the sampling period, though the total mass fluxes showed a large variation. A high variability of 239+240Pu fluxes occurred in very short period of time (1/2 day). The large fluxes of 239+240Pu might be attributed to episodic lateral transport of particles that flow down the continental slope with the nepheloid layer which was considered to be significant for 239+240Pu transport on the continental slope in the East China Sea.

  9. Photoexcitation mechanisms and the fission process of /sup 209/Bi from threshold to the. delta. region

    SciTech Connect

    Arruda-Neto, J.D.T.; Sugawara, M.; Tamae, T.; Sasaki, O.; Ogino, H.; Miyase, H.; Abe, K.

    1985-06-01

    The absolute electrofission cross section of /sup 209/Bi was measured in the energy range 40--250 MeV. The data analysis, based on the virtual-photon technique, showed that the excitation mechanism which can cause the fission of /sup 209/Bi is the Levinger's modified quasi-deuteron, even at energies well above the pion threshold.

  10. Vertical distribution and inventories of (239+240)Pu and mercury in Sagua la Grande estuary, Cuba.

    PubMed

    Alonso-Hernández, C M; Martin-Perez, J; Gasco, C; Díaz-Asencio, M; Bolanos-Álvarez, Y; Gómez-Batista, M

    2012-10-01

    The vertical activity distribution and inventories of (239+240)Pu profile and Hg were determined in Sagua la Grande estuary, Cuba. The shape of the (239+240)Pu profile in the core column resembled very closely the history of atmospheric nuclear weapons' testing, and the maximum deposition in 1963 was recorded in the sediment core history. The (239+240)Pu activity concentrations in the surface layer sediments varied from 0.163 to 0.611 mBq g(-1). The inventory of (239+240)Pu was 42 ± 5.6 Bq m(-2), a value close to that expected from direct global fallout. Using the (239+240)Pu as a chronomarker the mass sedimentation rate in the area for the last 60 years was calculated, reaching values of 0.173 g cm(-2) y(-1). The mercury profile reflects the history of anthropogenic pollution in the estuary and perfectly describes the operation of the mercury-cell chlor-alkali plant, for production of NaOH, which began operations in 1980. The inventory of Hg was 2.42 ± 0.19 μg cm(-2). These results contribute to the scarce regional database for pollutants and anthropogenic radionuclides in the Caribbean marine environment, particularly in relation to (239+240)Pu.

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

    PubMed

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

    2016-10-01

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

  12. Experimental Study of the Cross Sections of α-Particle Induced Reactions on 209Bi

    NASA Astrophysics Data System (ADS)

    Hermanne, A.; Tárkányi, F.; Takács, S.; Szúcs, Z.

    2005-05-01

    Alpha particle induced reactions for generation of 211At used in therapeutic nuclear medicine and possible contaminants were investigated with the stacked foil activation technique on natural bismuth targets up to Eα=39 MeV. Excitation functions for the reactions 209Bi(α,2n)211At, 209Bi(α,3n)210At, 209Bi(α,x) 210Po obtained from direct alpha emission measurements and gamma spectra from decay products are compared with earlier literature values. Thick target yields have been deduced from the experimental cross sections.

  13. Experimental Study of the Cross Sections of {alpha}-Particle Induced Reactions on 209Bi

    SciTech Connect

    Hermanne, A.; Tarkanyi, F.; Takacs, S.; Szucs, Z.

    2005-05-24

    Alpha particle induced reactions for generation of 211At used in therapeutic nuclear medicine and possible contaminants were investigated with the stacked foil activation technique on natural bismuth targets up to E{alpha}=39 MeV. Excitation functions for the reactions 209Bi({alpha},2n)211At, 209Bi({alpha},3n)210At, 209Bi({alpha},x) 210Po obtained from direct alpha emission measurements and gamma spectra from decay products are compared with earlier literature values. Thick target yields have been deduced from the experimental cross sections.

  14. 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.

  15. Individual and workplace monitoring measurements made after a 240Pu incident and during the clean-up operations.

    PubMed

    Hochmann, R; Eisenwagner, H; Benesch, T; Hunt, J; Cruz-Suarez, R; Bulyha, S; Schmitzer, C

    2011-03-01

    On 3 August 2008, five glass vials containing around 7 GBq of (240)Pu in nitric acid solution burst in a laboratory operated by the IAEA in Seibersdorf, Austria. The vials were located in a fire-proof safe in the IAEA Safeguards Analytical Laboratory, and the release of the (240)Pu caused an air contamination in the room and in adjoining rooms. Immediate emergency work was carried out, which was then followed by a long period of clean-up operations. A large number of conventional individual and workplace monitoring measurements were carried out immediately after the incident and during the clean-up work. In addition, due to the fact that (240)Pu has a very low background presence in the environment, and that the IAEA laboratories operate an inductively coupled plasma mass spectrometry system capable of very low levels of detection of this radionuclide, a number of non-conventional measurements were made to detect (240)Pu on, for example, the photographic camera used to document the incident, on nasal swabs from the first responders, etc. Plastic beakers were left in the corridor of the controlled area to accumulate (240)Pu from precipitation to see whether it was possible to detect traces of the radionuclide. This paper presents the measurements obtained, and discusses their relevance to occupational radiation protection.

  16. The geochemistry of fallout plutonium in the North Atlantic: II. 240Pu /239Pu ratios and their significance

    NASA Astrophysics Data System (ADS)

    Buesseler, Ken O.; Sholkovitz, Edward R.

    1987-10-01

    A systematic decrease in the 240Pu /239Pu ratio in marine sediments is found with increasing water depth along a transect of cores between Woods Hole and Bermuda. The 240Pu /239Pu atom ratios range from ≅O.18 on the shelf to ≅O.10 at 5000 m but do not change with depth in individual cores. A model is presented which can account for the range of 240Pu /239Pu ratios found in this and other similar studies ( NOSHKIN and GATROUSIS, 1974; SCOTTet al., 1983). We propose that there have been at least two distinct sources of fallout Pu to this region. The major source of Pu is global stratospheric fallout, characterized by a 240Pu /239Pu ratio of 0.18 and a relatively long residence time in seawater. The second source is characterized by a much lower 240Pu /239Pu ratio, and relative to global fallout it must have been much more efficiently removed from the water column to deep-sea sediments. We suggest that surface-based low yield testing at the Nevada Test Site is the only source of low ratio fallout Pu which could account for the timing, inventories, and refractory characteristics of this second component of fallout Pu inputs to the North Atlantic.

  17. Measurement of Angular-Momentum-Dependent Fission Probabilities of 240Pu

    NASA Astrophysics Data System (ADS)

    Koglin, Johnathon; Burke, Jason; Jovanovic, Igor

    2016-09-01

    An experimental technique using the surrogate reaction method has been developed to measure fission probabilities of actinides as a function of angular momentum state of the fissioning nucleus near the fission barrier. In this work, the 240Pu (α ,α' f) reaction was used as a surrogate for 239Pu (n , f) . An array of 12 silicon telescopes positioned at 10 degree intervals from 40 to 140 degrees detect the outgoing reaction particle for identification and measurement of the excitation energy. The angular momentum state is determined by measuring the angular distribution of fission fragments. The expected distributions are predicted from the Wigner d function. An array of 50 photovoltaic (solar) cells detects fission fragments with 10-degree granularity. The solar cells are sensitive to fission fragments but have no response to light ions. Relative contributions from different angular momentum states are extracted from the measured distributions and compared across all α particle scattering angles to determine fission probability at a specific angular momentum state. The first experiment using this technique was recently completed using 37 MeV α particles incident on 240Pu. First results will be discussed. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. This material is based upon work supported by the U.S. Department of Homeland Security under Grant Award Nu.

  18. Determination of 240Pu/239Pu atom ratio in coastal surface seawaters from the western North Pacific Ocean and Japan Sea.

    PubMed

    Yamada, Masatoshi; Zheng, Jian

    2008-01-01

    Surface seawater samples were collected from a site in the vicinity of the nuclear fuel reprocessing facility at Rokkasho, Japan and sites along the Japan Sea coast. (239+240)Pu activities and (240)Pu/(239)Pu atom ratios were determined by alpha-spectrometry and isotope-dilution sector-field ICP-MS. The (240)Pu/(239)Pu atom ratio with the mean value of 0.227 +/- 0.006 was significantly higher than the mean global fallout ratio of 0.18. The contribution of the Pacific Proving Grounds close-in fallout was estimated to be 33% of the (239+240)Pu.

  19. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

  1. Induced Fission of (240)Pu within a Real-Time Microscopic Framework.

    PubMed

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

    2016-03-25

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

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

    DOE PAGES

    Sandhukhan, Jhilam; Nazarewicz, Witold; Schunck, Nicolas

    2016-01-20

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

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

    SciTech Connect

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

    2009-02-23

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

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

    PubMed

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

    2014-05-01

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

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

    PubMed

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

    2016-01-01

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

  6. Photoexcitation mechanisms and fission of /sup 209/Bi from threshold to the. delta. region

    SciTech Connect

    Arruda-Neto, J.D.T.; Sugawara, M.; Tamae, T.; Sasaki, O.; Ogino, H.; Miyase, H.; Abe, K.

    1986-09-01

    The absolute electrofission cross section of /sup 209/Bi was measured in the energy range 43--250 MeV; the photofission cross section was deduced by means of the virtual-photon technique in the same energy range. The analysis of the fission probability, which was estimated from the photofission cross section and photoabsorption cross sections available in the literature, showed that /sup 209/Bi undergoes fission through compound nucleus formation for energies between the threshold and the ..delta.. region. It was found that Levinger's modified quasi-deuteron model cross section accounts for all the compound nucleus cross section, even at energies well above the pion threshold. The ineffectiveness of the pion photoproduction excitation mechanism in inducing fission of /sup 209/Bi could be explained in terms of the role played by the pion mean free path inside the nucleus.

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

    NASA Astrophysics Data System (ADS)

    Suseno, Heny; Wisnubroto, Djarot S.

    2014-03-01

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

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

    SciTech Connect

    Suseno, Heny; Wisnubroto, Djarot S.

    2014-03-24

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

  9. The inflow of 238Pu and (239+240)Pu from the Odra and Pomeranian rivers catchments area to the Baltic Sea.

    PubMed

    Strumińska-Parulska, Dagmara I; Skwarzec, Bogdan; Tuszkowska, Agnieszka

    2012-11-01

    The aim of the work was to estimate plutonium inflow from the Odra River catchments area to the Baltic Sea. The highest activities of (238)Pu and (239+240)Pu were observed in a winter and a spring season. The highest annual surface inflow of (239+240)Pu from the Odra River watershed was observed for a mountain tributary the Bóbr (1230 Bq km(-2) year(-1)). The annual inflow of (238)Pu and (239+240)Pu to the Baltic Sea was estimated at 9.51 MBq and 45.86 MBq respectively and the highest plutonium surface runoff was observed for the Bóbr drainage.

  10. 239,240Pu/137Cs ratios in the water column of the North Pacific: a proxy of biogeochemical processes.

    PubMed

    Hirose, Katsumi; Aoyama, Michio; Povinec, Pavel P

    2009-03-01

    Anthropogenic radionuclides in seawater have been used as transient tracers of processes in the marine environment. Especially, plutonium in seawater is considered to be a valuable tracer of biogeochemical processes due to its particle-reactive properties. However, its behavior in the ocean is also affected by physical processes such as advection, mixing and diffusion. Here we introduce Pu/(137)Cs ratio as a proxy of biogeochemical processes and discuss its trends in the water column of the North Pacific Ocean. We observed that the (239,240)Pu/(137)Cs ratio in seawater exponentially increased with increasing depth (depth range: 100-1000 m). This finding suggests that the profiles of the (239,240)Pu/(137)Cs ratios in shallower waters directly reflect biogeochemical processes in the water column. A half-regeneration depth deduced from the curve fitting the observed data, showed latitudinal and longitudinal distributions, also related to biogeochemical processes in the water column.

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

    PubMed

    Tsumune, Daisuke; Aoyama, Michio; Hirose, Katsumi

    2003-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Yamada, Masatoshi; Zheng, Jian; Aono, Tatsuo

    2013-04-01

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

  13. 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

  14. Different Interaction Mechanisms of Eu(III) and (243)Am(III) with Carbon Nanotubes Studied by Batch, Spectroscopy Technique and Theoretical Calculation.

    PubMed

    Wang, Xiangxue; Yang, Shubin; Shi, Weiqun; Li, Jiaxing; Hayat, Tasawar; Wang, Xiangke

    2015-10-06

    Herein the sorption of Eu(III) and (243)Am(III) on multiwalled carbon nanotubes (CNTs) are studied, and the results show that Eu(III) and (243)Am(III) could form strong inner-sphere surface complexes on CNT surfaces. However, the sorption of Eu(III) on CNTs is stronger than that of (243)Am(III) on CNTs, suggesting the difference in the interaction mechanisms or properties of Eu(III) and (243)Am(III) with CNTs, which is quite different from the results of Eu(III) and (243)Am(III) interaction on natural clay minerals and oxides. On the basis of the results of density functional theory calculations, the binding energies of Eu(III) on CNTs are much higher than those of (243)Am(III) on CNTs, indicating that Eu(III) could form stronger complexes with the oxygen-containing functional groups of CNTs than (243)Am(III), which is in good agreement with the experimental results of higher sorption capacity of CNTs for Eu(III). The oxygen-containing functional groups contribute significantly to the uptake of Eu(III) and (243)Am(III), and the binding affinity increases in the order of ≡S-OH < ≡S-COOH < ≡S-COO(-). This paper highlights the interaction mechanism of Eu(III) and (243)Am(III) with different oxygen-containing functional groups of CNTs, which plays an important role for the potential application of CNTs in the preconcentration, removal, and separation of trivalent lanthanides and actinides in environmental pollution cleanup.

  15. 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.

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

    USGS Publications Warehouse

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

    1998-01-01

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

  17. 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).

  18. (239)Pu, (240)Pu, and (241)Am determination in hot particles by low level gamma-spectrometry.

    PubMed

    Jiménez-Ramos, M C; Hurtado, S; Chamizo, E; García-Tenorio, R; León-Vintró, L; Mitchell, P I

    2010-06-01

    A nondestructive method based on low-energy, high-resolution photon spectrometry is presented which allows accurate determination of (239)Pu, (240)Pu, and (241)Am (as a daughter of (241)Pu) activities in radioactive particles containing relatively high levels of plutonium isotopes. The proposed method requires only one measurement for the establishment of an absolute efficiency curve. Since the density and composition of the radioactive particles of interest may vary, a self-absorption correction is required for the accurate determination of isotopic activities and ratios. This correction is carried out for each individual particle using the convenient gamma-ray emissions of (241)Am.

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

    PubMed

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

    2015-06-01

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

  20. 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.

  1. 243Am + 48Ca: A Second Look at the Rf/Db Data Set

    SciTech Connect

    Henderson, R A; Moody, K J

    2008-01-29

    In December of 2005 a series of experiments were performed at the U400 Cyclotron at the Flerov Laboratory of Nuclear Reactions in Dubna, Russia, using the reaction {sup 243}Am ({sup 48}Ca,3n) {sup 288}115 which, after a sequence of five alpha decays, produces a long-lived ({approx}1d) fission activity that had been detected previously in experiments using the Dubna Gas Filled Recoil Separator (DGFRS). These experiments were attempts to establish the elemental identity of the fissioning species as dubnium (element 105), which in turn confirms the identity of the original parent nucleus as element 115 through genetic correlation of the subsequent alpha decays. A series of approximately 24-hour bombardments were followed by chemical separations designed to isolate the Group Four and Five chemical fractions, and then separate the Nb and Ta fractions, which are Group Five homologues of dubnium and should therefore behave chemically similar. The samples were prepared for alpha and fission measurement and counted for an extended period of time. Fission events were detected in the Ta-like fractions only, which correspond to the fission coming from either the {sup 268}Db isotope directly or long-lived electron-capture decay in {sup 268}Db followed by a short half-life fission of {sup 268}Rf. In May of 2007 the Rf and Db fractions were recounted for very long times on alpha spectrometers to look at what species remained after approximately 1.5 years of time. One of the issues to be resolved was the potential for actinide contamination of the counting samples, which might have adverse affects on the observed data from the original experiment. In the original experiment the samples had significant quantities of {beta}-{gamma} activity which made the absolute identification of the alpha activity in each sample difficult. By allowing the {beta}-{gamma} activity to decay away, it gives us the opportunity to make definitive identifications of any alpha emitting isotopes on the

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

    SciTech Connect

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

    2005-02-28

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

  3. 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.

  4. Pre-fission neutron emission in {sup 19}F+{sup 209}Bi reaction

    SciTech Connect

    Singh, Hardev; Sugathan, P.; Shidling, P. D.; Behera, B. R.; Singh, Gulzar; Govil, I. M.; Golda, K. S.; Jhingan, Akhil; Singh, R. P.; Chatterjee, M. B.; Datta, S. K.; Pal, Santanu; Viesti, G.

    2009-03-04

    The pre- and post-scission neutron multiplicities are measured for {sup 19}F+{sup 209}Bi reaction at E{sub lab} = 100, 104, 108, 112 and 116 MeV. The measured value of pre-scission neutron multiplicity was found to be increasing with the excitation energy. The comparison of experimental values with the statistical model calculations shows that the measured values are much larger than the model predictions. This difference in excess yield over the model predictions amounts to the survival time of 80{+-}5x10{sup -21} s for the {sup 228}U compound nucleus before it undergoes fission.

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

    SciTech Connect

    Noshkin, V.E.

    2001-02-01

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

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

    USGS Publications Warehouse

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

    2004-01-01

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

  7. 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.

  8. Time-resolved record of (236)U and (239,240)Pu isotopes from a coral growing during the nuclear testing program at Enewetak Atoll (Marshall Islands).

    PubMed

    Froehlich, M B; Chan, W Y; Tims, S G; Fallon, S J; Fifield, L K

    2016-12-01

    A comprehensive series of nuclear tests were carried out by the United States at Enewetak Atoll in the Marshall Islands, especially between 1952 and 1958. A Porites Lutea coral that was growing in the Enewetak lagoon within a few km of all of the high-yield tests contains a continuous record of isotopes, which are of interest (e.g. (14)C, (236)U, (239,240)Pu) through the testing period. Prior to the present work, (14)C measurements at ∼2-month resolution had shown pronounced peaks in the Δ(14)C data that coincided with the times at which tests were conducted. Here we report measurements of (236)U and (239,240)Pu on the same coral using accelerator mass spectrometry, and again find prominent peaks in the concentrations of these isotopes that closely follow those in (14)C. Consistent with the (14)C data, the magnitudes of these peaks do not, however, correlate well with the explosive yields of the corresponding tests, indicating that smaller tests probably contributed disproportionately to the debris that fell in the lagoon. Additional information about the different tests can also be obtained from the (236)U/(239)Pu and (240)Pu/(239)Pu ratios, which are found to vary dramatically over the testing period. In particular, the first thermonuclear test, Ivy-Mike, has characteristic (236)U/(239)Pu and (240)Pu/(239)Pu signatures which are diagnostic of the first arrival of nuclear test material in various archives.

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

    PubMed

    Yamada, M; Aono, T; Hirano, S

    1999-10-01

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

  10. 90Sr, 137Cs and (239,240)Pu concentration surface water time series in the Pacific and Indian Oceans--WOMARS results.

    PubMed

    Povinec, Pavel P; Aarkrog, Asker; Buesseler, Ken O; Delfanti, Roberta; Hirose, Katsumi; Hong, Gi Hoon; Ito, Toshimichi; Livingston, Hugh D; Nies, Hartmut; Noshkin, Victor E; Shima, Shigeki; Togawa, Orihiko

    2005-01-01

    Under an IAEA's Co-ordinated Research Project "Worldwide Marine Radioactivity Studies (WOMARS)" 90Sr, 137Cs and (239,240)Pu concentration surface water time series in the Pacific and Indian Oceans have been investigated. The Pacific and Indian Oceans were divided into 17 latitudinal boxes according to ocean circulation, global fallout patterns and the location of nuclear weapons test sites. The present levels and time trends in radionuclide concentrations in surface water for each box were studied and the corresponding effective half-lives were estimated. For the year 2000, the estimated average 90Sr, 137Cs and (239,240)Pu concentrations in surface waters of the Pacific and Indian Oceans varied from 0.1 to 1.5 mBq/L, 0.1 to 2.8 mBq/L, and 0.1 to 5.2 microBq/L, respectively. The mean effective half-lives for 90Sr and 137Cs in surface water were 12+/-1 years for the North, 20+/-1 years for the South and 21+/-2 years for the Equatorial Pacific. For (239,240)Pu the corresponding mean effective half-lives were 7+/-1 years for the North, 12+/-4 years for the South and 10+/-2 years for the Equatorial Pacific. For the Indian Ocean the mean effective half-lives of 137Cs and (239,240)Pu were 21+/-2 years and 9+/-1 years, respectively. There is evidence that fallout removal rates before 1970 were faster than those observed during recent decades. The estimated surface water concentrations of 90Sr, 137Cs and (239,240)Pu in latitudinal belts of the Pacific and Indian Oceans for the year 2000 may be used as the average levels so that any new contribution from nuclear facilities, nuclear weapons test sites, radioactive waste dumping sites and from possible nuclear accidents can be identified.

  11. Evidence for the synthesis of {sup 267}110 produced by the {sup 59}Co + {sup 209}Bi reaction

    SciTech Connect

    Ghiorso, A.; Lee, D.; Somerville, L.P. |

    1994-09-01

    An experiment to synthesize element 110 by the {sup 59}Co+{sup 209}Bi reaction has bee performed at the SuperHILAC at the Lawrence Berkeley Laboratory. One event with many of the expected characteristics of a successful of {sup 267}110 was observed. This event corresponds to a production cross section of about one picobarn.

  12. Evidence for the possible synthesis of element 110 produced by the {sup 59}Co+{sup 209}Bi reaction

    SciTech Connect

    Ghiorso, A.; Lee, D.; Somerville, L.P. |; Loveland, W.; Nitschke, J.M.; Ghiorso, W.; Seaborg, G.T.; Wilmarth, P.; Leres, R.; Wydler, A.; Nurmia, M.; Gregorich, K.; Czerwinski, K.; Gaylord, R.; Hamilton, T.; Hannink, N.J.; Hoffman, D.C.; Jarzynski, C.; Kacher, C.; Kadkhodayan, B.; Kreek, S.; Lane, M.; Lyon, A.; McMahan, M.A.; Neu, M.; Sikkeland, T.; Swiatecki, W.J.; Tuerler, A.; Walton, J.T.; Yashita, S.

    1995-05-01

    An experiment to synthesize element 110 by the {sup 59}Co+{sup 209}Bi reaction has been performed at the SuperHILAC at the Lawrence Berkeley Laboratory. One event with many of the expected characteristics of a successful synthesis of {sup 267}110 was observed. This event corresponds to a production cross section of about one picobarn.

  13. Data on photoneutron reactions from various experiments for 133Cs, 138Ba and 209Bi nuclei

    NASA Astrophysics Data System (ADS)

    Varlamov, V. V.; Ishkhanov, B. S.; Orlin, V. N.; Peskov, N. N.

    2016-07-01

    Basic methods for determining cross sections for photoneutron partial reactions are examined. They are obtained directly in experiments with quasimonoeneregetic annihilation photons or from the cross section for the ( γ, xn) = ( γ, 1 n) + 2( γ, 2 n) + 3( γ, 3 n) +... neutron-yield reaction in experiments with bremsstrahlung photons by introducing corrections based on statistical nuclear-reaction theory. The difference in the conditions of these experiments, which leads to discrepancies between their results because of sizable systematic errors, is analyzed. Physical criteria are used to study the reliability of data on the photodisintegration of 133Cs, 138Ba, and 209Bi nuclei. The cross sections for partial and total reactions satisfying the reliability criteria are evaluated within the experimental-theoretical method ( σ eval( γ, in) = F i theor × σ expt( γ, xn)) on the basis of the experimental cross sections σ expt( γ, xn) and the results of the calculations within the combined model of photonuclear reactions.

  14. Measurements of high-energy neutron-induced fission ofnatPb and 209Bi

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

    The CERN Neutron Time-Of-Flight (n_TOF) facility is well suited to measure low cross sections as those of neutron-induced fission in subactinides. The cross section ratios of natPb and 209Bi relative to 235U and 238U were measured using PPAC detectors and a fragment coincidence method that allows us to identify the fission events. The present experiment provides first results for neutron-induced fission up to 1 GeV. Good agreement is found with previous experimental data below 200 MeV. The comparison with proton-induced fission indicates that the limiting regime where neutron-induced and proton-induced fission reach equal cross sections is close to 1 GeV.

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

    PubMed

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

    2016-01-01

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

  16. 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.

  17. Effect of chemical pollution on forms of 137Cs, 90Sr and 239,240Pu in arctic soil studied by sequential extraction.

    PubMed

    Puhakainen, M; Riekkinen, I; Heikkinen, T; Jaakkola, T; Steinnes, E; Rissanen, K; Suomela, M; Thørring, H

    2001-01-01

    The aim of the present study was to determine the forms of 137Cs, 90Sr and 239,240Pu occurring in different soil horizons using sequential extraction of samples taken from four sites located along a pollution gradient from the copper-nickel smelter at Monchegorsk in the Kola Peninsula, Russia, and from a reference site in Finnish Lapland in 1997. A selective sequential-leaching procedure was employed using a modification of the method of Tessier, Cambell and Bisson ((1979). Analytical Chemistry, 51, 844-851). For 137Cs the organic (O) and uppermost mineral (E1) layer were studied, for 90Sr and 239,240Pu only the uppermost organic layer (Of). The fraction of 137Cs occurring in readily exchangeable form in the organic layer was about 50% at the reference site and decreased as a function of pollution, being 15% at the most polluted site in the Kola Peninsula. There was a clear positive correlation in the O layer between the distance from the smelter and the percentage of 137Cs extracted in the readily exchangeable fraction (Spearman correlation rsp = 0.7805, p = 0.0001), whereas in the E1 layer no correlation was evident. The distribution of 90Sr in the Of layer was similar at all sites, with the highest amounts occurring in exchangeable form and bound to organic matter, whereas stable Sr showed a somewhat different distribution with the highest amount in the oxide fraction. Most of the 239,240Pu was bound to organic matter. Chemical pollution affected the exchangeable fraction of 239,240Pu, which was about 1% at the most polluted site and 4-6% at the other sites.

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

  19. Determination of the 240Pu/ 239Pu atomic ratio in soils from Palomares (Spain) by low-energy accelerator mass spectrometry

    NASA Astrophysics Data System (ADS)

    Chamizo, E.; García-León, M.; Synal, H.-A.; Suter, M.; Wacker, L.

    2006-08-01

    In 1966, the nuclear fuel of two thermonuclear bombs was released over the Spanish region of Palomares, due to a B52 bomber accident during a refuelling operation. Since then, much effort has been made to assess its impact to the different environmental compartments of this area in South-East Spain, mostly by measuring the 239+240Pu activity concentration and the 238Pu/239+240Pu activity ratio. Nevertheless, these measurements do not give enough information on the problem. In order to recognize unambiguously small traces of the weapon-grade plutonium released in the accident, the ratio of the two major isotopes of plutonium, 240Pu/239Pu, has to be determined. In this work, this ratio has been measured in low- and high-activity samples from Palomares by means of low-energy accelerator mass spectrometry (AMS). That way, we will show the potential of the new generation of compact AMS facilities in terms of plutonium characterization at ultra-trace levels.

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

    PubMed

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

    2016-01-01

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

  1. 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

  2. Recoil-α-fission and recoil-α-α-fission events observed in the reaction 48Ca + 243Am

    NASA Astrophysics Data System (ADS)

    Forsberg, U.; Rudolph, D.; Andersson, L.-L.; Di Nitto, A.; Düllmann, Ch. E.; Fahlander, C.; Gates, J. M.; Golubev, P.; Gregorich, K. E.; Gross, C. J.; Herzberg, R.-D.; Heßberger, F. P.; Khuyagbaatar, J.; Kratz, J. V.; Rykaczewski, K.; Sarmiento, L. G.; Schädel, M.; Yakushev, A.; Åberg, S.; Ackermann, D.; Block, M.; Brand, H.; Carlsson, B. G.; Cox, D.; Derkx, X.; Dobaczewski, J.; Eberhardt, K.; Even, J.; Gerl, J.; Jäger, E.; Kindler, B.; Krier, J.; Kojouharov, I.; Kurz, N.; Lommel, B.; Mistry, A.; Mokry, C.; Nazarewicz, W.; Nitsche, H.; Omtvedt, J. P.; Papadakis, P.; Ragnarsson, I.; Runke, J.; Schaffner, H.; Schausten, B.; Shi, Yue; Thörle-Pospiech, P.; Torres, T.; Traut, T.; Trautmann, N.; Türler, A.; Ward, A.; Ward, D. E.; Wiehl, N.

    2016-09-01

    Products of the fusion-evaporation reaction 48Ca + 243Am were studied with the TASISpec set-up at the gas-filled separator TASCA at the GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany. Amongst the detected thirty correlated α-decay chains associated with the production of element Z = 115, two recoil-α-fission and five recoil- α- α-fission events were observed. The latter five chains are similar to four such events reported from experiments performed at the Dubna gas-filled separator, and three such events reported from an experiment at the Berkeley gas-filled separator. The four chains observed at the Dubna gas-filled separator were assigned to start from the 2n-evaporation channel 289115 due to the fact that these recoil- α- α-fission events were observed only at low excitation energies. Contrary to this interpretation, we suggest that some of these recoil- α- α-fission decay chains, as well as some of the recoil- α- α-fission and recoil-α-fission decay chains reported from Berkeley and in this article, start from the 3n-evaporation channel 288115.

  3. Alpha scattering from /sup 209/Bi at 50. 5 MeV

    SciTech Connect

    Chatterjee, A.; Gupta, S.K.; Kailas, S.; Kerekatte, S.S.

    1988-04-01

    The cross sections for the elastic and inelastic scattering of alpha particles from /sup 209/Bi have been measured at 50.5 MeV for angles up to 92/sup 0/ in steps of 1/sup 0/. An optical model analysis of the elastic scattering data has been made, starting with the parameters predicted from systematics and consistent with those determined at higher energies. The large angular range combined with the relatively small errors in the measurement restrict the real potential to just three discrete families. A nearside-farside decomposition of the data clearly reveals the Fraunhofer diffraction pattern superimposed on the large background of Fresnel diffraction. The inelastic scattering data have been analyzed in terms of the collective model using the distorted wave Born approximation, for which the distorted waves were generated by the optical model analysis of the elastic scattering data. The values of the deformation lengths (..beta..R) obtained are compared with those reported in the literature.

  4. Structure of /sup 209/Bi deduced from the /sup 208/Pb(t,2n. gamma. ) reaction

    SciTech Connect

    Maier, K.H.; Nail, T.; Sheline, P.K.

    1983-04-01

    States in /sup 209/Bi were populated with the /sup 208/Pb(t,2n) reaction. Incident triton energies between 11 and 16 MeV were used. Gamma-ray excitation functions, angular distributions, and ..gamma..-..gamma..-time coincidence spectra were measured. Approximately 50 newly-observed ..gamma.. rays have been assigned to transitions in /sup 209/Bi. Previously-unresolved doublets at E/sub x/ = 2600, 3135, and 3154 keV have been identified. A new level at 3270 keV is reported, and the 3197-keV level is verified. /sup 209/Bi level energies are reported with an accuracy of 600 eV or less. A level scheme for E/sub x/<4.14 MeV is presented, including spin-parity assignments. A new M1 transition between the (5/2)/sup +/ and (3/2)/sup +/ members of the ..pi..h/sub 9/2/x3/sup -/ septuplet is reported. The 19 levels belonging to the ..nu..g/sub 9/2/p/sub 1/2/ /sup -1/, ..pi..h/sub 9/2/ are identified.

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

    PubMed

    Schimmack, W; Auerswald, K; Bunzl, K

    2001-01-01

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

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

    PubMed

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

    2008-09-01

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

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

    SciTech Connect

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

    2011-08-15

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

  8. 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.; ...

    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

  9. 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

    2015-04-07

    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.

  10. Systematic analysis of above-barrier fusion of {sup 9,10,11}Be+{sup 209}Bi

    SciTech Connect

    Hinde, D. J.; Dasgupta, M.

    2010-06-15

    Measurements of fusion for {sup 9,10,11}Be allow testing of the relative importance to fusion and breakup of the alpha-cluster structure found in all these Be isotopes, compared with the neutron-halo structure only present for {sup 11}Be. However, disagreements exist among different published experimental data sets for the reactions of {sup 9,10,11}Be with {sup 209}Bi. Accurate measurements of above-barrier cross sections for the products of complete fusion (fission and evaporation residues) in the reaction of {sup 9}Be with {sup 209}Bi and {sup 208}Pb provide the basis for a reanalysis of above-barrier fusion for {sup 10,11}Be+{sup 209}Bi. This includes procedures making full use of the higher precision stable beam data and resolves many of the disagreements. The improved self-consistency of the analysis allows investigation of the experimental average fusion barriers. Although showing some scatter, these suggest a higher barrier for the neutron halo nucleus {sup 11}Be. Comparison of published cross sections for fusion associated with capture of all the charge of the projectile suggest that all these Be isotopes show significant suppression of complete fusion, a surprising result given that the alpha-breakup threshold energies are 1.57 MeV for {sup 9}Be but over 7 MeV for {sup 10,11}Be. Further experimental studies to investigate in more detail the division between complete and incomplete fusion for reactions of {sup 10,11}Be are needed.

  11. Analysis of complete, incomplete and total fusion data of 9Be +169Tm, 187Re, 209Bi reactions

    NASA Astrophysics Data System (ADS)

    Kharab, Rajesh; Chahal, Rajiv; Kumar, Rajiv

    2016-11-01

    We have analyzed the incomplete fusion (ICF), complete fusion (CF) and total fusion (TF) excitation functions for reactions induced by 9Be on 169Tm, 187Re and 209Bi targets at near barrier energies using Wong’s formula in conjunction with the energy dependent Woods-Saxon potential. A phenomenological selection function is proposed to separate out the contribution of ICF and CF cross-sections in TF cross-section. The variation of relative contribution of ICF and CF in TF with respect to incident beam energy is very well reproduced through this approach.

  12. Long-term {alpha}- and spontaneous fission measurement of a Rf/Db sample chemically prepared in a {sup 48}Ca on {sup 243}Am experiment

    SciTech Connect

    Dressler, Rugard; Eichler, Robert; Schumann, Dorothea; Shishkin, Sergey

    2009-05-15

    Results from long-term measurements of a chemically separated Db/Rf sample prepared from the products of a {sup 48}Ca on {sup 243}Am irradiation are presented. The sample with the highest spontaneous fission activity out of eight samples produced in the course of chemical experiments performed in 2004 was selected for these measurements. We conclude that there is no evidence for SF-decay originating from heavy actinide isotopes in this sample. Hence, it is appropriate to assign the SF-events observed in this experiment to decay products of {sup 288}115.

  13. Measurement of the neutron-induced fission cross-section of 243Am relative to 235U from 0.5 to 20 MeV

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    The ratio of the neutron-induced fission cross-sections of 243Am and 235U was measured in the energy range from 0.5 to 20 MeV with uncertainties of ≈ 4%. The experiment was performed at the CERN n_TOF facility using a fast ionization chamber. With the good counting statistics that could be achieved thanks to the high instantaneous flux and the low backgrounds, the present results are useful for resolving discrepancies in previous data sets and are important for future reactors with improved fuel burn-up.

  14. Second order phase transitions from octupole-nondeformed to octupole-deformed shape in the alternating parity bands of nuclei around 240Pu based on data

    NASA Astrophysics Data System (ADS)

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

    2012-08-01

    Background: Shape phase transitions in finite quantal systems are very interesting phenomena of general physical interest. There is a very restricted number of the examples of nuclei demonstrating this phenomenon.Purpose: Based on experimental excitation spectra, there is a second order phase transition in the alternating parity bands of some actinide nuclei.Method: The mathematical techniques of supersymmetric quantum mechanics, two-center octupole wave functions ansatz, and the Landau theory of phase transitions are used to analyze the experimental data on alternating parity bands.Results: The potential energy of the octupole collective motion is determined and analyzed for all observed values of the angular momentum of the alternating parity band states in 232Th, 238U, and 240Pu.Conclusion: It is shown that as a function of increasing angular momentum there is a second order phase transition from the octupole-nondeformed to the octupole-deformed shape in the considered nuclei.

  15. 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.

  16. New Results for Elements 115, 117, and 118 Produced in the Reactions 243Am+48Ca and 249BK/249Cf+48Ca

    NASA Astrophysics Data System (ADS)

    Utyonkov, V. K.; Oganessian, Yu. Ts.; Abdullin, F. Sh.; Alexander, C.; Binder, J.; Boll, R. A.; Dmitriev, S. N.; Ezold, J.; Felker, K.; Gostic, J. M.; Grzywacz, R. K.; Hamilton, J. H.; Henderson, R. A.; Itkis, M. G.; Miernik, K.; Miller, D.; Moody, K. J.; Polyakov, A. N.; Ramayya, A. V.; Roberto, J. B.; Ryabinin, M. A.; Rykaczewski, K. P.; Sagaidak, R. N.; Shaughnessy, D. A.; Shirokovsky, I. V.; Shumeiko, M. V.; Stoyer, M. A.; Stoyer, N. J.; Subbotin, V. G.; Sukhov, A. M.; Tsyganov, Yu. S.; Voinov, A. A.; Vostokin, G. K.

    2014-09-01

    The reactions of 243Am and 249Bk with 48Ca have been reinvestigated to provide new evidence for the discovery of elements 113, 115, and 117. Three isotopes 287-289115 were synthesized in the 243Am+48Ca reactions at five projectile energies, providing excitation functions and α-decay spectra of the produced isotopes. Decay properties of 287,288115 and of all the daughter products agree with the data of the experiment in which these nuclei were synthesized for the first time. The new 289115 events demonstrate the same decay properties as those observed for 289115 populated by a decay of 293117 produced in the 249Bk+48Ca reaction to provide cross-bombardment evidence. Results of recent experiments at the Dubna gas-filled recoil separator aimed at studying production crosssections, excitation functions, and nuclear decay properties for isotopes 293,294117 synthesized in the 249Bk+48Ca reaction at five projectile energies are presented. In addition, a single decay of 294118 was observed from the reaction with 249Cf - a result of the in-growth of 249Cf in the 249Bk target.

  17. Lightest Isotope of Bh Produced Via the 209Bi(52Cr,n)260BhReaction

    SciTech Connect

    Nelson, Sarah L.; Gregorich, Kenneth E.; Dragojevic, Irena; Garcia, Mitch A.; Gates, Jacklyn M.; Sudowe, Ralf; Nitsche, Heino

    2007-05-07

    The lightest isotope of Bh known was produced in the new {sup 209}Bi({sup 52}Cr,n){sup 260}Bh reaction at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. Positive identification was made by observation of eight correlated alpha particle decay chains in the focal plane detector of the Berkeley Gas-Filled Separator. {sup 260}Bh decays with a 35{sub -9}{sup +19} ms half-life by alpha particle emission mainly by a group at 10.16 MeV. The measured cross section of 59{sub -20}{sup +29} pb is approximately a factor of four larger than compared to recent model predictions. The influences of the N = 152 and Z = 108 shells on alpha decay properties are discussed.

  18. Lightest Isotope of Bh Produced via the {sup 209}Bi({sup 52}Cr,n){sup 260}Bh Reaction

    SciTech Connect

    Nelson, S. L.; Dragojevic, I.; Garcia, M. A.; Gates, J. M.; Nitsche, H.; Gregorich, K. E.; Sudowe, R.

    2008-01-18

    The lightest isotope of Bh was produced in the new {sup 209}Bi({sup 52}Cr,n){sup 260}Bh reaction at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. Positive identification was made by observation of eight correlated alpha particle decay chains in the focal plane detector of the Berkeley Gas-Filled Separator. {sup 260}Bh decays with a 35{sub -9}{sup +19} ms half-life by alpha particle emission mainly by a group at 10.16 MeV. The measured cross section of 59{sub -20}{sup +29} pb is compared to model predictions. The influence of the N=152 and Z=108 shells on alpha decay properties is discussed.

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

    PubMed

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

    2016-03-01

    In order to assess how environmental factors are affecting the distribution and migration of radioiodine and plutonium that were emitted from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, we quantified iodine and (239,240)Pu concentration changes in soil samples with different land uses (urban, paddy, deciduous forest and coniferous forest), as well as iodine speciation in surface water and rainwater. Sampling locations were 53-63 km northwest of the FDNPP within a 75-km radius, in close proximity of each other. A ranking of the land uses by their surface soil (<4 cm) stable (127)I concentrations was coniferous forest > deciduous forest > urban > paddy, and (239,240)Pu concentrations ranked as deciduous forest > coniferous forest > paddy ≥ urban. Both were quite distinct from that of (134)Cs and (137)Cs: urban > coniferous forest > deciduous forest > paddy, indicating differences in their sources, deposition phases, and biogeochemical behavior in these soil systems. Although stable (127)I might not have fully equilibrated with Fukushima-derived (129)I, it likely still works as a proxy for the long-term fate of (129)I. Surficial soil (127)I content was well correlated to soil organic matter (SOM) content, regardless of land use type, suggesting that SOM might be an important factor affecting iodine biogeochemistry. Other soil chemical properties, such as Eh and pH, had strong correlations to soil (127)I content, but only within a given land use (e.g., within urban soils). Organic carbon (OC) concentrations and Eh were positively, and pH was negatively correlated to (127)I concentrations in surface water and rain samples. It is also noticeable that (127)I in the wet deposition was concentrated in both the deciduous and coniferous forest throughfall and stemfall water, respectively, comparing to the bulk rainwater. Further, both forest throughfall and stemflow water consisted exclusively of organo-iodine, suggesting all inorganic iodine in the

  20. Standardization of (166m)Ho and 243Am/239Np by live-timed anti-coincidence counting with extending dead time.

    PubMed

    da Silva, C J; Loureiro, J S; Delgado, J U; Poledna, R; Moreira, D S; Iwahara, A; Tauhata, L; da Silva, R L; Lopes, R T

    2012-09-01

    The National Laboratory for Metrology of Ionizing Radiation (LNMRI)/Brazil acquired (166m)Ho and (243)Am/(239)Np solutions from commercial suppliers in order to realize primary standardization and therefore reducing the associated uncertainties. The method used in the standardization was the live-timed 4πβ(LS)-γ(ΝaI(Tl)) anticoincidence counting. The live-timed anticoincidence system is operated since 2006 in LNMRI and is composed of two MTR2 modules donated by Laboratoire National Henri Becquerel (LNE-LNHB)/France. The data acquisition system uses a homemade LabView program and an Excel file for calculus. These systems have been used for primary standardization at LNMRI for many radionuclides and recently took part in the (124)Sb and (177)Lu International Key Comparisons with good performance.

  1. Fission Cross-section Measurements of (233)U, (245)Cm and (241,243)Am at CERN n_TOF Facility

    SciTech Connect

    Calviani, M.; Koehler, Paul Edward; N_TOF collaboration,

    2011-01-01

    Neutron-induced fission cross-sections of minor actinides have been measured using the n-TOF white neutron source at CERN, Geneva, as part of a large experimental program aiming at collecting new data relevant for nuclear astrophysics and for the design of advanced reactor systems. The measurements at n-TOF take advantage of the innovative features of the n-TOF facility, namely the wide energy range, high instantaneous neutron flux and good energy resolution. Final results on the fission cross-section of {sup 233}U, {sup 245}Cm and {sup 243}Am from thermal to 20 MeV are here reported, together with preliminary results for {sup 241}Am. The measurement have been performed with a dedicated Fast Ionization Chamber (FIC), a fission fragment detector with a very high efficiency, relative to the very well known cross-section of {sup 235}U, measured simultaneously with the same detector.

  2. 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.

  3. Inventories of 239+240Pu, 137Cs, and excess 210Pb in sediments from freshwater and brackish lakes in Rokkasho, Japan, adjacent to a spent nuclear fuel reprocessing plant.

    PubMed

    Ueda, Shinji; Ohtsuka, Yoshihito; Kondo, Kunio; Hisamatsu, Shun'ichi

    2009-10-01

    We investigated the vertical profiles of (239+240)Pu, (137)Cs, and excess (210)Pb ((210)Pb(ex)) in sediment core samples obtained from two freshwater lakes and two brackish lakes situated near the first commercial spent nuclear fuel reprocessing plant in Rokkasho, Japan, before the final test of the plant using actual spent nuclear fuel. The inventory of (239+240)Pu in those lakes was larger than that in soil in Rokkasho, which indicated the inflow of (239+240)Pu from the catchment area in addition to direct deposition on the lake surfaces. The (137)Cs inventory in sediments of the brackish lakes was lower than that in the soil, which showed that part of the (137)Cs was removed from the sediments by the brackish water or that it was not deposited into the sediments, because of the high solubility of Cs in brackish water. The (137)Cs inventory in sediments of the freshwater lakes was higher than that of the brackish lakes, and comparable with that in soil except for one core sample out of four. The (239+240)Pu/(137)Cs ratio in freshwater lake sediments was higher than that in soil, and that indicated that part of the (137)Cs was lost from the sediments. The low inventory of (137)Cs may be attributable to competition for absorption sites in sediments with ammonium ions formed in the reducing environment which occurs from summer to fall in the sediments. Those data will be used as background data on the artificial radionuclides in the lakes to assess the effect of released radionuclides on their concentrations.

  4. 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.

  5. Thick target yield measurement of 211At through the nuclear reaction 209Bi(α, 2n)

    NASA Astrophysics Data System (ADS)

    Alfarano, A.; Abbas, K.; Holzwarth, U.; Bonardi, M.; Groppi, F.; Alfassi, Z.; Menapace, E.; Gibson, P. N.

    2006-05-01

    Radionuclide Therapy (RNT) and Radioimmunotherapy (RIT) are potentially of great interest for cancer therapy. In many therapeutic applications alpha emitters should be much more effective than already-approved beta emitters due to the short range and high linear energy transfer of alpha particles. 213Bi is an important alpha emitter already used in clinical trials but the half-life of this radioisotope is short (46 minutes) and so its use is limited for certain therapies. 211At is potentially very interesting for medical purposes because of its longer half-life of 7.2 hours, and suitable decay scheme. We have studied the cyclotron-based production of 211At via the reaction 209Bi(α, 2n), this production route probably being the most promising in the long term. The energy dependence of thick target yields and the reaction cross sections for the production of 211At and 210At were determined and found to be in good agreement with literature. The best energy to produce 211At is 28-29 MeV. The possible production of the undesired, highly radiotoxic, and long-lived alpha-emitting 210Po (138.38 days), which is produced from decay of 210At, is also discussed.

  6. Exploring contributions from incomplete fusion in Li,76+209Bi and Li,76+198Pt reactions

    NASA Astrophysics Data System (ADS)

    Parkar, V. V.; Jha, V.; Kailas, S.

    2016-08-01

    We use the breakup absorption model to simultaneously describe the measured cross sections of complete fusion (CF), incomplete fusion (ICF), and total fusion (TF) in nuclear reactions induced by weakly bound nuclei Li,76 on 209Bi and 198Pt targets. The absorption cross sections are calculated using the continuum discretized coupled channels (CDCC) method with different choices of short-range imaginary potentials to get the ICF, CF, and TF cross sections. It is observed that the cross sections for deuteron ICF / deuteron capture and α ICF / α capture are of similar magnitude, in the case of the 6Li projectile, while the cross sections for the triton ICF / triton capture is more dominant than that of α ICF / α capture in the case of the 7Li projectile. Both these observations are also corroborated by the experimental data. The ratio of ICF to TF cross sections, which defines the value of fusion suppression factor, is found to be in agreement with the data available from the literature. The cross-section ratios of CF/TF and ICF/TF show opposite behavior at below-barrier energies the former decreases while the latter increases as the energy is lowered, which shows the dominance of ICF at below-barrier energies. We have also studied the correlation of the ICF cross sections with the noncapture breakup (NCBU) cross sections as a function of energy, which shows that the NCBU is more significant than ICF at below-barrier energies.

  7. 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

  8. New Insights into the 243Am 48Ca Reaction Products Previously Observed in the Experiments on Elements 113, 115, and 117

    SciTech Connect

    Oganessian, Yuri Ts.; Abdullin, F. Sh.; Dmitriev, S.; Gostic, J. M.; Hamilton, Joseph; Henderson, R.; Itkis, M. G.; Moody, K.; Polyakov, A. N.; Ramayya, A. V.; Roberto, James B; Rykaczewski, Krzysztof Piotr; Sagaidak, R. N.; Shaughnessy, D.; Shirokovsky, I. V.; Stoyer, M.; Subbotin, V. G.; Sukhov, A. M.; Tsyganov, Yu. S.; Utyonkov, V.; Voinov, A. A.; Vostokin, G. K.

    2012-01-01

    Results of a new series of experiments on the study of production cross sections and decay properties of the isotopes of element 115 in the reaction {sup 243}Am + {sup 48}Ca are presented. Twenty-one new decay chains originating from {sup 288}115 were established as the product of the 3n-evaporation channel by measuring the excitation function at three excitation energies of the compound nucleus {sup 291}115. The decay properties of all newly observed nuclei are in full agreement with those we measured in 2003. At the lowest excitation energy E* = 33 MeV, for the first time we registered the product of the 2n-evaporation channel, {sup 289}115, which was also observed previously in the reaction {sup 249}Bk + {sup 48}Ca as the daughter nucleus of the decay of {sup 293}117. The maximum cross section for the production of {sup 288}115 is found to be 8.5 pb at E* {approx} 36 MeV.

  9. New insights into the 243Am + 48Ca reaction products previously observed in the experiments on elements 113, 115, and 117.

    PubMed

    Oganessian, Yu Ts; Abdullin, F Sh; Dmitriev, S N; Gostic, J M; Hamilton, J H; Henderson, R A; Itkis, M G; Moody, K J; Polyakov, A N; Ramayya, A V; Roberto, J B; Rykaczewski, K P; Sagaidak, R N; Shaughnessy, D A; Shirokovsky, I V; Stoyer, M A; Subbotin, V G; Sukhov, A M; Tsyganov, Yu S; Utyonkov, V K; Voinov, A A; Vostokin, G K

    2012-01-13

    Results of a new series of experiments on the study of production cross sections and decay properties of the isotopes of element 115 in the reaction (243)Am+(48)Ca are presented. Twenty-one new decay chains originating from (288)115 were established as the product of the 3n-evaporation channel by measuring the excitation function at three excitation energies of the compound nucleus (291)115. The decay properties of all newly observed nuclei are in full agreement with those we measured in 2003. At the lowest excitation energy E*=33 MeV, for the first time we registered the product of the 2n-evaporation channel, (289)115, which was also observed previously in the reaction (249)Bk+(48)Ca as the daughter nucleus of the decay of (293)117. The maximum cross section for the production of (288)115 is found to be 8.5 pb at E*≈36 MeV.

  10. Effects of deformations and orientations in the fission of the actinide nuclear system 254Fm* formed in the 11B + 243Am reaction

    NASA Astrophysics Data System (ADS)

    Kaur, Manpreet; Sharma, Manoj K.; Gupta, Raj K.

    2012-12-01

    We have studied the decay of actinide nuclear system 254Fm* formed in 11B + 243Am reaction using the dynamical cluster decay model (DCM), with choices of spherical, quadrupole deformation β2 alone and higher multipole deformations β2-β4. For β2 deformations, the optimum orientations θiopt are used whereas for higher multipole deformations the compact orientations θic of decaying fragments are taken in to account. Besides static-β2 deformations, the effects of dynamical-β2 deformations are also explored. The calculated cross sections find excellent agreement with the available experimental data with spherical as well as deformed choices of fragmentations, enabling us to account for the role of important nuclear deformation effects in the 11B-induced nuclear reaction. Spontaneous decay of 254Fm with cold elongated configuration and optimum orientation is also worked out. The mass distributions of excited fermium isotopes in the neighborhood of 254Fm* are also explored. In addition, the roles of temperature, angular momentum, and fission fragment anisotropies are investigated in the context of the chosen reaction.

  11. Neutron-induced fission cross section measurement of 233U, 241Am and 243Am in the energy range 0.5 MeV ⩽ En ⩽ 20 MeV at n_TOF at CERN

    NASA Astrophysics Data System (ADS)

    Belloni, F.; Milazzo, P. M.; Calviani, M.; Colonna, N.; Mastinu, P.; Abbondanno, U.; Aerts, G.; Álvarez, H.; Álvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Barbagallo, M.; Baumann, P.; Bečvář, F.; Berthoumieux, E.; Calviño, F.; Cerutti, F.; Cano-Ott, D.; Capote, R.; Carrapiço, C.; Carrillo de Albornoz, A.; Cennini, P.; Chepel, V.; Chiaveri, E.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillmann, I.; Dolfini, R.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Fitzpatrick, L.; Frais-Koelbl, H.; Fujii, K.; Furman, W.; Goncalves, I.; González-Romero, E.; Goverdovski, A.; Gramegna, F.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Isaev, S.; Jericha, E.; Käppeler, F.; Kadi, Y.; Karadimos, D.; Karamanis, D.; Ketlerov, V.; Kerveno, M.; Koehler, P.; Konovalov, V.; Kossionides, E.; Krtička, M.; Lampoudis, C.; Lederer, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marques, L.; Marrone, S.; Martínez, T.; Massimi, C.; Meaze, M. H.; Mengoni, A.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; O'Brien, S.; Oshima, M.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Pigni, M. T.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Praena, J.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rosetti, M.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Santos, C.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J. L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Wallner, A.; Walter, S.; Wendler, H.; Wiescher, M.; Wisshak, K.; n TOF Collaboration

    2012-10-01

    Neutron-induced fission cross section measurements of 233U, 243Am and 241Am relative to 235U have been carried out at the neutron time-of-flight facility n_TOF at CERN. A fast ionization chamber has been employed. All samples were located in the same detector; therefore the studied elements and the reference 235U target are subject to the same neutron beam.

  12. Radiochemical study of the medium energy pion double charge exchange reactions: /sup 209/Bi(pi/sup +/pi/sup -/)/sup 209-x/At

    SciTech Connect

    Clark, J.L.

    1980-01-01

    Carrier-free radiochemical techniques have been used to measure cross sections for the double charge exchange reactions of the type /sup 209/Bi(pi/sup +/, pi/sup -/xn)/sup 209-x/At for 100, 180, and 300 MeV incident pions. The observed formation of astatine products with mass numbers ranging from 208 to 205 is interpreted as evidence of processes in which energy deposited in the initial double charge exchange interaction is subsequently dissipated through neutron evaporation. The excitation functions for these reactions are seen to rise rapidly with decreasing incident pion energy with the maximum results for this study at 100 MeV. The astatine production cross secions measured for these positive pion irradiations of thick bismuth targets must be corrected for secondary processes, particularly the pion induced production of fast alpha particles which can contribute to the total cross sections through reactions like /sup 209/Bi(alpha,xn)/sup 213-x/At. The importance of these secondary contributions was studied through a series of negative pion irradiations of bismuth in which secondary pathways furnish the only means of producing astatine. The failure of evaporation calculations to reproduce the astatine product mass yields observed in these secondary studies suggests that direct mechanisms for energetic complex particle formation are quite important. Values for the alpha decay branches of /sup 207/At, /sup 208/At, and /sup 209/At were determined through a study of the electron capture and alpha decay characteristics of chemically purified astatine fractions.

  13. Modelling Deposition and Erosion rates with RadioNuclides (MODERN) - Part 2: A comparison of different models to convert (239+240)Pu inventories into soil redistribution rates at unploughed sites.

    PubMed

    Arata, Laura; Alewell, Christine; Frenkel, Elena; A'Campo-Neuen, Annette; Iurian, Andra-Rada; Ketterer, Michael E; Mabit, Lionel; Meusburger, Katrin

    2016-10-01

    Sheet erosion is one of the major threats to alpine soils. To quantify its role and impact in the degradation processes of alpine grasslands, the application of Fallout Radionuclides (FRN) showed very promising results. The specific characteristics of plutonium 239 + 240 ((239+240)Pu), such as the homogeneous fallout distribution, the long half-life and the cost and time effective measurements make this tracer application for investigating soil degradation in Alpine grasslands more suitable than any other FRN (e.g. (137)Cs). However, the conversion of (239+240)Pu inventories into soil erosion rates remains a challenge. Currently available conversion models have been developed mainly for (137)Cs with later adaptation to other FRN (e.g. Excess (210)Pb, and (7)Be), each model being defined for specific land use (ploughed and/or unploughed) and processes (erosion or deposition). As such, they may fail in describing correctly the distribution of Pu isotopes in the soil. A new conversion model, MODERN, with an adaptable algorithm to estimate erosion and deposition rates from any FRN inventory changes was recently proposed (Arata et al., 2016). In this complementary contribution, the authors compare the application of MODERN to other available conversion models. The results show a good agreement between soil redistribution rates obtained from MODERN and from the models currently used by the FRN scientific community (i.e. the Inventory Method).

  14. Unusual potential behavior for the weakly bound nucleus 9Be in elastic scattering from 208Pb and 209Bi near the threshold

    NASA Astrophysics Data System (ADS)

    Yu, N.; Zhang, H. Q.; Jia, H. M.; Zhang, S. T.; Ruan, M.; Yang, F.; Wu, Z. D.; Xu, X. X.; Bai, C. L.

    2010-07-01

    The elastic scattering angular distributions of the weakly bound 9Be projectile from 208Pb and 209Bi have been measured for 14 beam energies near the threshold from 37 to 50 MeV. The parameters of the optical potential are extracted by means of phenomenological optical model analysis with PTOLEMY. Both of the systems show unusual potential behavior in the vicinity of the Coulomb barrier that the strength of the imaginary (absorptive) part of the potential is increasing (rather than decreasing) with decreasing energy, which is quite different from the results of some previous reports. This unusual threshold phenomenon indicates that the breakup channel is strongly coupled with the elastic channel and has obvious effects on the optical potential. The analyses also show that high precision elastic scattering angular distributions, especially those below the Coulomb barrier, are very important for extracting correct threshold behavior of the optical potential.

  15. Energy dependence of the optical potentials for the 9Be +208Pb and 9Be +209Bi systems at near-Coulomb-barrier energies

    NASA Astrophysics Data System (ADS)

    Gómez Camacho, A.; Yu, N.; Zhang, H. Q.; Gomes, P. R. S.; Jia, H. M.; Lubian, J.; Lin, C. J.

    2015-04-01

    We analyze the energy dependence of the interacting optical potential, at near barrier energies, for two systems involving the weakly bound projectile 9Be and the heavy 208Pb and 209Bi targets, by the simultaneous fit of elastic scattering angular distributions and fusion excitation functions. The approach used consists of dividing the optical potential into two parts. A short-range potential VF+i WF that is responsible for fusion, and a superficial potential VDR+i WDR for direct reactions. It is found, for both systems studied, that the fusion imaginary potential WF presents the usual threshold anomaly (TA) observed in tightly bound systems, whereas the direct reaction imaginary potential WDR shows a breakup threshold anomaly (BTA) behavior. Both potentials satisfy the dispersion relation. The direct reaction polarization potential predominates over the fusion potential and so a net overall behavior is found to follow the BTA phenomenon.

  16. Production cross sections of {sub 105}{sup 261}Ha from the {sup 250}Cf({sup 15}N,4n) and {sup 243}Am({sup 22}Ne,4n) reactions

    SciTech Connect

    Lane, M.R.; Gregorich, K.E.; Lee, D.M.; Wierczinski, B.; McGrath, C.A.; Hendricks, M.B.; Shaughnessy, D.A.; Strellis, D.A.; Sylwester, E.R.; Wilk, P.A.; Hoffman, D.C. |

    1998-12-01

    We have measured the production cross section of 1.8-s {sup 261}Ha from two different reactions. It was produced in the {sup 250}Cf({sup 15}N,4n) reaction at 84 MeV and in the {sup 243}Am({sup 22}Ne,4n) reaction at 116 MeV. Our rotating wheel system with a special parent-daughter stepping mode was used to detect {alpha}-{alpha} correlations between {sup 261}Ha and {sup 257}Lr. We measured 13 and 9 correlations in the two reactions, respectively. Assuming a 100{percent} {alpha} branch, we have determined the production cross section of {sup 261}Ha to be 0.51{plus_minus}0.20thinspnb in the {sup 250}Cf({sup 15}N,4n) reaction at 84 MeV, and 0.25{plus_minus}0.11thinspnb in the {sup 243}Am({sup 22}Ne,4n) reaction at 116 MeV. Based on the number of fission events observed in the latter reaction, we have been able to set an upper limit of 18{percent} for the spontaneous fission branch of {sup 261}Ha. {copyright} {ital 1998} {ital The American Physical Society}

  17. 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

  18. Comparison of reactions for the production of 258,257Db: 208Pb(51V,xn) and 209Bi(50Ti,xn)

    SciTech Connect

    Gates, Jacklyn M.; Nelson, Sarah L.; Gregorich, Kenneth E.; Dragojevic, Irena; Dullmann, Christoph E.; Ellison, Paul A.; Folden III, Charles M.; Garcia, Mitch A.; Stavsetra, Liv; Sudowe, Ralf; Hoffman, Darleane C.; Nitsche, Heino

    2008-09-29

    Excitation functions for the 1n and 2n exit channels of the 208Pb(51V,xn)259-xDb reaction were measured. A maximum cross section of the 1n exit channel of 2070+1100/-760 pb was measured at an excitation energy of 16.0 +- 1.8 MeV. For the 2n exit channel, a maximum cross section of 1660+450/-370 pb was measured at 22.0 +- 1.8 MeV excitation energy. The 1n excitation function for the 209Bi(50Ti,n)258Db reaction was remeasured, resulting in a cross section of 5480+1750/-1370 pb at an excitation energy of 16.0 +- 1.6 MeV, in agreement with previous values [F. P. Hebberger, et al., Eur. Phys. J. A 12, 57 (2001)]. Differences in cross section maxima are discussed in terms of the fusion probability below the barrier.

  19. Characteristics of Symmetric and Asymmetric Fission Modes as a Function of the Compound Nucleus Excitation in the Proton-Induced Fission of 233Pa, 239Np and 243Am

    SciTech Connect

    Beresova, M.; Kliman, J.; Krupa, L.; Bogatchev, A. A.; Itkis, I. M.; Itkis, M. G.; Kniajeva, G. N.; Kondratiev, N. A.; Kozulin, E. M.; Pokrovsky, I. V.; Dorvaux, O.; Khlebnikov, S.; Lyapin, V.; Rubchenia, W.; Stuttge, L.; Trzaska, W.; Vakhtin, D.

    2007-05-22

    Average preequilibrium average statistical prescission and postscission neutron multiplicities as well as average {gamma}-ray multiplicity , average energy emitted by {gamma}-rays and average energy per one gamma quantum <{epsilon}{gamma}> as a function of mass and total kinetic energy (TKE) of fission fragments were measured in the proton-induced reactions p+232Th{yields}233Pa, p+238U{yields}239Np and p+242Pu{yields}243Am (at proton energy Ep=13, 20, 40 and 55 MeV). The fragment mass and energy distributions (MEDs) have been analyzed in terms of the multimodal fission. The decomposition of the experimental MEDs onto the MEDs of the distinct modes has been fulfilled in the framework of a method that is free from any parameterization of the distinct fission mode mass distribution shapes. The main characteristics for symmetric and asymmetric modes have been studied in their dependence on the compound nucleus composition and proton energy. The manifestation of multimodal fission in average {gamma}-ray multiplicities of fission fragments was also studied in this work.

  20. 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.

  1. Nuclear level densities in {sup 208}Bi and {sup 209}Po from the neutron spectra in the (p, n) reactions on {sup 208}Pb and {sup 209}Bi nuclei

    SciTech Connect

    Zhuravlev, B. V. Lychagin, A. A. Titarenko, N. N.; Demenkov, V. G.; Trykova, V. I.

    2010-07-15

    The spectra of neutrons from the (p, n) reactions on the {sup 208}Pb and {sup 209}Bi nuclei were measured in the proton-energy range 8-11 MeV. These measurements were performed by using a time-of-flight spectrometer of fast neutrons on the basis of the pulsed tandem accelerator EGP-15 of the Institute of Physics and Power Engineering (Obninsk, Russian Federation). A high resolution and stability of the time-of-flight spectrometermade it possible to identify reliably low-lying discrete levels alongwith the continuum section of the neutron spectra. The measured data were analyzed on the basis of the statistical equilibrium and preequilibrium models of nuclear reactions. The respective calculations were performed by using the precise formalism of Hauser-Feshbach statistical theory together with the generalized model of a superfluid nucleus and the back-shifted Fermi gas model for the nuclear-level density. The nuclear-level densities in {sup 208}Bi and {sup 209}Po were determined along with their energy dependencies and model parameters. Our results are discussed together with available experimental data and recommendations of model systematics.

  2. Comparison of reactions for the production of {sup 258,257}Db: {sup 208}Pb({sup 51}V,xn) and {sup 209}Bi({sup 50}Ti,xn)

    SciTech Connect

    Gates, J. M.; Nelson, S. L.; Dragojevic, I.; Duellmann, Ch. E.; Ellison, P. A.; Folden III, C. M.; Garcia, M. A.; Hoffman, D. C.; Nitsche, H.; Gregorich, K. E.; Stavsetra, L.; Sudowe, R.

    2008-09-15

    Excitation functions for the 1n and 2n exit channels of the {sup 208}Pb({sup 51}V,xn){sup 259-x}Db reaction were measured. A maximum cross section of the 1n exit channel of 2070{sub -760}{sup +1100} pb was measured at an excitation energy of 16.0 {+-} 1.8 MeV. For the 2n exit channel, a maximum cross section of 1660{sub -370}{sup +450} pb was measured at 22.0 {+-} 1.8 MeV excitation energy. The 1n excitation function for the {sup 209}Bi({sup 50}Ti,n){sup 258}Db reaction was remeasured, resulting in a cross section of 5480{sub -1370}{sup +1730} pb at an excitation energy of 16.0 {+-} 1.6 MeV, in agreement with previous values [F. P. Hessberger et al., Eur. Phys. J. A 12, 57 (2001)]. Differences in cross section maxima are discussed in terms of the fusion probability below the barrier.

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

    SciTech Connect

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

    2007-10-01

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

  4. American National Standard: for nuclear criticality control of special actinide elements

    SciTech Connect

    Not Available

    1981-01-01

    This standard is applicable to operations with the following: /sup 237/Np, /sup 238/Pu, /sup 240/Pu, /sup 241/Pu, /sup 242/Pu, /sup 241/Am, /sup 242m/Am, /sup 243/Am, /sup 243/Cm, /sup 244/Cm, /sup 245/Cm, /sup 247/Cm, /sup 249/Cf and /sup 251/Cf. Subcritical mass limits are presented for isolated fissionable units. The limits are not applicable to interacting units.

  5. Electrochemical oxidation of 243Am(III) in nitric acid by a terpyridyl-derivatized electrode

    SciTech Connect

    Dares, C. J.; Lapides, A. M.; Mincher, B. J.; Meyer, T. J.

    2015-11-05

    A high surface area, tin-doped indium oxide electrode surface-derivatized with a terpyridine ligand has been applied to the oxidation of trivalent americium to Am(V) and Am(VI) in nitric acid. Potentials as low as 1.8 V vs. the saturated calomel electrode are used, 0.7 V lower than the 2.6 V potential for one-electron oxidation of Am(III) to Am(IV) in 1 M acid. This simple electrochemical procedure provides, for the first time, a method for accessing the higher oxidation states of Am in non-complexing media for developing the coordination chemistries of Am(V) and Am(VI) and, more importantly, for separation of americium from nuclear waste streams.

  6. 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.

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

    SciTech Connect

    Dubose, F.

    2012-02-21

    In nuclear material processing facilities, it is often necessary to balance the competing demands of accuracy and throughput. While passive neutron multiplicity counting is the preferred method for relatively fast assays of plutonium, the presence of low-Z impurities (fluorine, beryllium, etc.) rapidly erodes the assay precision of passive neutron counting techniques, frequently resulting in unacceptably large total measurement uncertainties. Conversely, while calorimeters are immune to these impurity effects, the long count times required for high accuracy can be a hindrance to efficiency. The higher uncertainties in passive neutron measurements of impure material are driven by the resulting large (>>2) {alpha}-values, defined as the ({alpha},n):spontaneous fission neutron emission ratio. To counter impurity impacts for high-{alpha} materials, a known-{alpha} approach may be adopted. In this method, {alpha} is determined for a single item using a combination of gamma-ray and calorimetric measurements. Because calorimetry is based on heat output, rather than a statistical distribution of emitted neutrons, an {alpha}-value determined in this way is far more accurate than one determined from passive neutron counts. This fixed {alpha} value can be used in conventional multiplicity analysis for any plutonium-bearing item having the same chemical composition and isotopic distribution as the original. With the results of single calorimeter/passive neutron/gamma-ray measurement, these subsequent items can then be assayed with high precision and accuracy in a relatively short time, despite the presence of impurities. A calorimeter-based known-{alpha} multiplicity analysis technique is especially useful when requiring rapid, high accuracy, high precision measurements of multiple plutonium bearing items having a common source. The technique has therefore found numerous applications at the Savannah River Site. In each case, a plutonium (or mixed U/Pu) bearing item is divided into multiple containers. A single item from that batch is then selected for both neutron and calorimetric measurements; all remaining items undergo a neutron measurement only. Using the technique mentioned above, the 'true' {alpha} value determined from the first (calorimeter and passive neutron measured) item is used in multiplicity analysis for all other items in the batch. The justification for using this {alpha} value in subsequent calculations is the assumption that the chemical composition and isotopic distribution of all batch items are the same, giving a constant ({alpha},n):spontaneous fission ratio. This analysis method has been successfully applied to the KIS Facility, significantly improving measurement uncertainties and reducing processing times for numerous items. Comprehensive plans were later developed to extend the use of this method to other applications, including the K-Area Shuffler and the H-Area Pu-Blending Project. While only the feasibility study for the Shuffler has been completed, implementation of the method in the H-Area Pu-Blending Project is currently in progress and has been successfully applied to multiple items. This report serves to document the details of this method in order to serve as a reference for future applications. Also contained herein are specific examples of the application of known-{alpha} multiplicity analysis.

  8. {sup 209}Bi NMR in heavy-electron system YbBiPt

    SciTech Connect

    Reyes, A.P.; Le, L.P.; Heffner, R.H.; Ahrens, E.T.; Fisk, Z.; Canfield, P.C.

    1994-06-01

    Bismuth NMR Knight shift and spin lattice relaxation rate 1/T{sub 1} are reported between 35--325K in the low-carrier heavy fermion system YbBiPt. The Knight shift is strongly temperature dependent and negative. Its temperature dependence tracks the bulk susceptibility with a hyperfine coupling constant A{sub hf} = {minus}7.89 kOe/{mu}B. At low temperatures 1/T{sub 1} exhibits a dramatic increase, such that the average 4f spin correlation time {tau}{sub f} shows a crossover behavior at about 75K. The rate 1/{tau}{sub f} is proportional to temperature, but with a different proportionality constant above and below about 75K. The linear temperature dependence is consistent with non-interacting 4f local moments which are relaxed via Korringa-type scattering with the conduction electrons. Below 75K, we infer that the reduced thermal excitation of a higher crystal-field multiplet is responsible for the dramatic decrease in the rate of 4f relaxation.

  9. The Am-243 Neutron Capture Measurement at the n_TOF Facility

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

    The 243Am neutron capture cross section has been measured at the n_TOF facility1 in the 0.7 eV-2 keV energy range. The n_TOF Total Absorption Calorimeter2 (TAC) composed by 40 BaF2 crystals has been used in the measurement for detecting the electromagnetic cascades produced in the 243Am(n, γ) reactions. All current evaluations in the resolved resonance region are based essentially in fission measurements and in only one transmission measurement.3 The analysis of the measurement has been finished recently, and it is ready for its distribution to the EXFOR nuclear database. In addition, the data obtained with the TAC provide valuable information on the level density in the compound nucleus 244Am and on its electromagnetic de-excitation scheme. In particular, the 243Am data will be combined with data from previous measurements of 241Am, 240Pu, 237Np and 233,234,236U and with future measurements of 235,238U for a systematic investigation of the photon strength functions in actinides.

  10. 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.

  11. R-matrix analysis of the {sup 240}Pu neutron cross sections in the thermal to 5700 eV energy range

    SciTech Connect

    Derrien, H.; Bouland, O.; Larson, N.M.; Leal, L.C.

    1997-08-01

    Resonance analysis of high resolution neutron transmission data and of fission cross sections were performed in the neutron energy range from the thermal regions to 5,700 eV by using the Reich-Moore Bayesian code SAMMY. The experimental data base is described and the method of analysis is given. The experimental data were carefully examined in order to identify more resonances than those found in the current evaluated data files. The statistical properties of the resonance parameters are given. A new set of the average values of the parameters is proposed, which could be used for calculation of the average cross sections in the unresolved resonance region. The resonance parameters are available IN ENDF-6 format at the national or international data centers.

  12. Current Inconsistencies in {sup 238}Pu, {sup 241,243}Am and {sup 242}Cm Evaluations and their Impact on Uncertainties

    SciTech Connect

    Maslov, V.M.

    2008-12-15

    Improvements in the nuclear reaction modeling and nuclear parameter systematics, consistent with the description of neutron data on major actinides {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U and {sup 239}Pu will be shown to provide a sound basis for critical assessment of the fission, capture, inelastic scattering, and (n,xn) reaction cross sections on minor actinides. This will largely help to avoid substituting possible model deficiencies by enlarging parameter uncertainties in the conventional nuclear models. In a number of minor actinides, the uncertainty estimation of cross sections and prompt fission neutron spectra would require complete re-evaluation of basic data. Otherwise, extremely large cross section uncertainty estimates will have to be adopted, especially in the case of poorly investigated Np, Pu, Am, Cm targets.

  13. 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.

  14. 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.

  15. 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.

  16. ANDES Measurements for Advanced Reactor Systems

    NASA Astrophysics Data System (ADS)

    Plompen, A. J. M.; Hambsch, F.-J.; Kopecky, S.; Nyman, M.; Rouki, C.; Salvador Castiñeira, P.; Schillebeeckx, P.; Belloni, F.; Berthoumieux, E.; Gunsing, F.; Lampoudis, C.; Calviani, M.; Guerrero, C.; Cano-Ott, D.; Gonzalez Romero, E.; Aïche, M.; Jurado, B.; Mathieu, L.; Derckx, X.; Farget, F.; Rodrigues Tajes, C.; Bacquias, A.; Dessagne, Ph.; Kerveno, M.; Borcea, C.; Negret, A.; Colonna, N.; Goncalves, I.; Penttilä, H.; Rinta-Antila, S.; Kolhinen, V. S.; Jokinen, A.

    2014-05-01

    A significant number of new measurements was undertaken by the ANDES “Measurements for advanced reactor systems” initiative. These new measurements include neutron inelastic scattering from 23Na, Mo, Zr, and 238U, neutron capture cross sections of 238U, 241Am, neutron induced fission cross sections of 240Pu, 242Pu, 241Am, 243Am and 245Cm, and measurements that explore the limits of the surrogate technique. The latter study the feasibility of inferring neutron capture cross sections for Cm isotopes, the neutron-induced fission cross section of 238Pu and fission yields and fission probabilities through full Z and A identification in inverse kinematics for isotopes of Pu, Am, Cm and Cf. Finally, four isotopes are studied which are important to improve predictions for delayed neutron precursors and decay heat by total absorption gamma-ray spectrometry (88Br, 94Rb, 95Rb, 137I). The measurements which are performed at state-of-the-art European facilities have the ambition to achieve the lowest possible uncertainty, and to come as close as is reasonably achievable to the target uncertainties established by sensitivity studies. An overview is presented of the activities and achievements, leaving detailed expositions to the various parties contributing to the conference.

  17. Highly enriched isotopes of uranium and transuranium elements for scientific investigation

    NASA Astrophysics Data System (ADS)

    Vesnovskii, Stanislav P.; Polynov, Vladimir N.

    1992-08-01

    The paper describes the production of highly enriched isotopes of uranium, plutonium, americium and curium by means of electromagnetic separation for scientific and applied research in physics, chemistry, geology and other fields. The equipment and radiochemical methods used allows to provide the isotopic pure samples in quantities sufficient to set up nuclear physics experiments, to produce reference materials and standard sources for calibration of radiometrical and mass spectrometrical equipment and for use in radionuclear metrology. For a series of nuclei unique characteristics of isotopic enrichment and radiochemical and chemical purity 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%; 242mAm: 85.6%; 243Am: 99.2-99.94%; 243Cm: 99.99%; 245Cm: 99.998%; 246Cm: 99.8%; 247Cm: 90%; 248Cm: 97%. Methods of radiochemical and chemical separation, product certification, fabrication of special sources or targets and layers of highly enriched isotopes on various substrates are presented.

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

    SciTech Connect

    Brewer, R.W.; Pruvost, N.L.; Rombough, C.T.

    1996-12-31

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

  19. Chemical resolution of Pu+ from U+ and Am+ using a band-pass reaction cell inductively coupled plasma mass spectrometer.

    PubMed

    Tanner, Scott D; Li, Chunsheng; Vais, Vladimir; Baranov, Vladimir I; Bandura, Dmitry R

    2004-06-01

    Determination of the concentration and distribution of the Pu and Am isotopes is hindered by the isobaric overlaps between the elements themselves and U, generally requiring time-consuming chemical separation of the elements. A method is described in which chemical resolution of the elemental ions is obtained through ion-molecule reactions in a reaction cell of an ICPMS instrument. The reactions of "natural" U(+), (242)Pu(+), and (243)Am(+) with ethylene, carbon dioxide, and nitric oxide are reported. Since the net sensitivities to the isotopes of an element are similar, chemical resolution is inferred when one isobaric element reacts rapidly with a given gas and the isobar (or in this instance surrogate isotope) is unreactive or slowly reactive. Chemical resolution of the m/z 238 isotopes of U and Pu can be obtained using ethylene as a reaction gas, but little improvement in the resolution of the m/z 239 isobars is obtained. However, high efficiency of reaction of U(+) and UH(+) with CO(2), and nonreaction of Pu(+), allows the sub-ppt determination of (239)Pu, (240)Pu, and (242)Pu (single ppt for (238)Pu) in the presence of 7 orders of magnitude excess U matrix without prior chemical separation. Similarly, oxidation of Pu(+) by NO, and nonreaction of Am(+), permit chemical resolution of the isobars of Pu and Am over 2-3 orders of magnitude relative concentration. The method provides the potential for analysis of the actinides with reduced sample matrix separation.

  20. 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.

  1. Fabrication and characterization of MCC approved testing material: ATM-9 glass

    SciTech Connect

    Wald, J.W.

    1986-06-01

    The Materials Characterization Center ATM-9 glass is designed to be representative of glass to be produced by the Defense Waste Processing Facility at the Savannah River Plant, Aiken, South Carolina. ATM-9 glass contains all of the major components of the DWPF glass and corresponds to a waste loading of 29 wt %. The feedstock material for this glass was supplied by Savannah River Laboratory, Aiken, SC, as SRL-165 Black Frit to which was added Ba, Cs, Md, Nd, Zr, as well as /sup 99/Tc, depleted U, /sup 237/Np, /sup 239 +240/Pu, and /sup 243/Am. The glass was produced under reducing conditions by the addition of 0.7 wt % graphite during the final melting process. Three kilograms of the glass were produced from April to May of 1984. On final melting, the glass was formed into stress-annealed rectangular bars of two sizes: 1.9 x 1.9 x 10 cm and 1.3 x 1.3 x 10 cm. Seventeen bars of each size were made. The analyzed composition of ATM-9 glass is listed. Examination by optical microscopy of a single transverse section from one bar showed random porosity estimated at 0.36 vol % with nominal pore diameters ranging from approx. 5 ..mu..m to 200 ..mu..m. Only one distinct second phase was observed and it was at a low concentraction level in the glass matrix. The phase appeared as spherical metallic particles. X-ray diffraction analysis of this same sample did not show any diffraction peaks from crystalline components, indicating that the glass contained less than 5 wt % of crystalline devitrification products. The even shading on the radiograph exposure indicated a generally uniform distribution of radioactivity throughout the glass matrix, with no distinct high-concentration regions.

  2. 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.

  3. Measurement and calculation of high-actinide burnup in the prototype fast reactor

    SciTech Connect

    Broadhead, B.L.; Raman, S.; Dickens, J.K. )

    1991-01-01

    An agreement was signed in May 1979 as a part of a long-term cooperative program between the United Kingdom and the US under the liquid-metal fast breeder reactor agreement of 1976. This agreement included an experiment to carry out irradiations of physics specimens of fissile and fertile actinides to improve our knowledge of basic nuclear physics phenomena. Three fuel pins were prepared by the US to contain the actinide physics samples; two of these pins were irradiated at the Dounreay prototype fast reactor (PFR) for a total irradiation of 63 full-power days. The third pin has only recently been removed from the PFT, following an irradiation of > 500 full-power days. Each pin houses 35 capsules containing milligram quantities of actinide oxides of {sup 231}Pa, {sup 230}Th, {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 244}Pu, {sup 241}Am, {sup 243}Am, {sup 243}Cm, {sup 244}Cm, {sup 246}Cm, and {sup 248}Cm. Following the return of the first fuel pin (FP-1) to the United States in May 1984, the actinide samples were prepared for studies of fission product yields, isotopics, and material concentrations. The measurements were repeated for the second fuel pin (FP-2) to remedy several problems encountered in the processing of the FP-1 pin. A brief description of the measured and calculated {sup 137}Cs yields for both FP-1 and FP-2 are included in this paper.

  4. 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.

  5. Activity measurements of a suite of radionuclides (241Am, 239,240Pu, 238Pu, 238U, 234U, 235U, 232Th, 230Th, 228Th, 228Ra, 137Cs, 210Pb, 90Sr and 40K) in biota reference material (Ocean Shellfish): CCRI(II)-S3

    NASA Astrophysics Data System (ADS)

    Nour, S.; Karam, L. R.; Inn, K. G. W.

    2012-01-01

    In 2005, the CCRI decided that a comparison undertaken from 2002 to 2008 by the NIST (under the auspices of the Inter-America Metrology System [SIM]) in the development of a new biota (Ocean Shellfish) standard reference material (SRM) was sufficiently well constructed that it could be converted into a supplementary comparison under CCRI(II), with comparison identifier CCRI(II)-S3. This would enable the comparison to be used to support calibration and measurement capability (CMC) claims for radionuclide measurements in reference materials (specifically, animal-based organic materials). Previous comparisons of radionuclides have been of single or multiple nuclides in non-complex matrices and results of such could not be extended to support capabilities to measure the same nuclides in reference materials. The results of this comparison have been used to determine the certified reference value of the SRM. The key comparison working group (KCWG) of the CCRI(II) has approved this approach as a mechanism to link all the results to certified 'reference values' in lieu of the key comparison reference value (KCRV) of these specified radionuclides in this type of matrix (shellfish) so as to support CMCs of similar materials submitted by the present participants. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  6. SUPPLEMENTARY COMPARISON: Activity measurements of a suite of radionuclides (40K, 137Cs, 210Pb, 210Po, 228Ra, 232Th, 234U, 235U, 238U, 238Pu, 239Pu, 239+240Pu, 241Am) in vegetal reference material (seaweed)

    NASA Astrophysics Data System (ADS)

    Outola, I.; Inn, K. G. W.; Karam, L. R.

    2008-01-01

    In 2005, the CCRI decided that a comparison undertaken from 2002 to 2005 by the NIST (SIM) in the development of a new seaweed standard reference material (SRM) was sufficiently well constructed that it could be converted into a supplementary comparison under CCRI(II), with comparison identifier CCRI(II)-S1, so as to support calibration and measurement capability (CMC) claims for radionuclide measurements in reference material (specifically, plant material). Previous comparisons of radionuclides have been of single or multiple nuclides in non-complex matrices and results of such could not be extended to support capabilities to measure the same nuclides in reference materials. The results of this comparison have been reported to the participants, and were also used to determine the certified reference values of the SRM. The key comparison working group (KCWG) of the CCRI(II) has approved this approach as a mechanism to link all the results to the certified 'reference values' in lieu of the key comparison reference value (KCRV) of these specified radionuclides in this type of matrix (vegetative) so as to support CMCs of similar materials. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI Section II, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  7. SUPPLEMENTARY COMPARISON: Activity measurements of a suite of radionuclides (90Sr, 137Cs, 210Pb, 210Po, 228Ra, 234U, 235U, 238U, 238Pu, 239,240Pu) in soil reference material (Rocky Flats II): CCRI(II)-S2

    NASA Astrophysics Data System (ADS)

    Nour, S.; Inn, K. G. W.; Karam, L. R.

    2009-01-01

    In 2005, the CCRI decided that a comparison undertaken from 2002 to 2007 by the NIST (SIM) in the development of a new soil (Rocky Flats II) standard reference material (SRM) was sufficiently well constructed that it could be converted into a supplementary comparison under CCRI(II), with comparison identifier CCRI(II)-S2, so as to support calibration and measurement capability (CMC) claims for radionuclide measurements in reference material (specifically, low calcium-content soils). Previous comparisons of radionuclides have been of single or multiple nuclides in non-complex matrices and results of such could not be extended to support capabilities to measure the same nuclides in reference materials. The results of this comparison have been reported to the participants, and have been used to determine the certified reference value of the SRM. The key comparison working group (KCWG) of the CCRI(II) has approved this approach as a mechanism to link all the results to certified 'reference values' in lieu of the key comparison reference value (KCRV) of these specified radionuclides in this type of matrix (soil) so as to support CMCs of similar materials. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI Section II, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  8. PRELIMINARY CROSS SECTION AND NU-BAR COVARIANCES FOR WPEC SUBGROUP 26

    SciTech Connect

    ROCHMAN,D.

    2007-01-31

    We report preliminary cross section covariances developed for the WPEC Subgroup 26 for 45 out of 52 requested materials. The covariances were produced in 15- and 187-group representations as follows: (1) 36 isotopes ({sup 16}O, {sup 19}F, {sup 23}Na, {sup 27}Al, {sup 28}Si, {sup 52}Cr, {sup 56,56}Fe, {sup 58}Ni, {sup 90,91,92,94}Zr, {sup 166,167,168,170}Er, {sup 206,207,208}Pb, {sup 209}Bi, {sup 233,234,236}U, {sup 237}Np, {sup 238,240,241,242}Pu, {sup 241,242m,243}Am, {sup 242,243,244,245}Cm) were evaluated using the BNL-LANL methodology. For the thermal region and the resolved and unresolved resonance regions, the methodology has been based on the Atlas-Kalman approach, in the fast neutron region the Empire-Kalman method has been used; (2) 6 isotopes ({sup 155,156,157,158,160}Gd and {sup 232}Th) were taken from ENDF/B-VII.0; and (3) 3 isotopes ({sup 1}H, {sup 238}U and {sup 239}Pu) were taken from JENDL-3.3. For 6 light nuclei ({sup 4}He, {sup 6,7}Li, {sup 9}Be, {sup 10}B, {sup 12}C), only partial cross section covariance results were obtained, additional work is needed and they do not report the results here. Likewise, the cross section covariances for {sup 235}U, which they recommend to take from JENDL-3.3, will be included once the multigroup processing is successfully completed. Covariances for the average number of neutrons per fission, total {nu}-bar, are provided for 10 actinides identified as priority by SG26. Further work is needed to resolve some of the issues and to produce covariances for the full set of 52 materials.

  9. Determination of Np-237 by radiochemical neutron activation analysis combined with extraction chromatography.

    PubMed

    Kalmykov, St N; Aliev, R A; Sapozhnikov, D Yu; Sapozhnikov, Yu A; Afinogenov, A M

    2004-01-01

    A procedure for determination of 237Np, 238Pu, 239,240Pu and 241Pu in environmental samples is described. Neptunium-237 is determined using radiochemical neutron activation analysis with pre- and post-irradiation chemistry based on solvent extraction and extraction chromatography. 238Pu, 239,240Pu is determined using alpha spectrometry and 241Pu by liquid scintillation spectrometry. The vertical profiles of 237Np, 238Pu, 239,240Pu in bottom sediments from the Black Sea are presented.

  10. Modeling report of the CEA cadarache MINERVE reactor for the OSMOSE project.

    SciTech Connect

    Klann, R.; Perret, G.; Hudelot, J. P.; Antony, M.

    2005-02-25

    The OSMOSE program (Oscillation in Minerve of isotopes in ''Eupraxic'' spectra) is a collaboration between the U.S. Department of Energy (DOE) and the Commissariat a l' Energie Atomique (CEA). It aims at measuring integral absorption rates of minor actinides by the oscillation technique in the MINERVE experimental facility located at the CEA Cadarache Research Center. The OSMOSE program also includes a complete analytical program to understand and resolve potential discrepancies between calculated and measured values. The OSMOSE program began in 2001 and will continue until 2013. The Argonne National Laboratory has developed Monte Carlo and deterministic calculation models of the MINERVE facility to determine core and safety parameters such as axial and radial fission rate distributions, control rod worth, spectral indices, and the reactivity worth of oscillated samples. Oscillation samples include calibration samples with different uranium enrichments and boron concentrations and the OSMOSE samples--separated actinides including {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. Seven different neutron spectra will be created in the MINERVE facility: an overmoderated UO{sub 2} matrix (representative of a fuel processing plant or flooded storage cask), a UO{sub 2} matrix in water (representative of LWRs), a mixed oxide fuel matrix (representative of cores containing MOX fuels), two epithermal spectra (representative of under-moderated reactors), a moderated fast spectrum (representative of fast reactors which have some slowing down due to 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 currently investigated core

  11. The OSMOSE program for the qualification of integral cross sections of actinides: Preliminary results in a PWR-UOx spectrum

    SciTech Connect

    Hudelot, J. P.; Antony, M.; Bernard, D.; Fougeras, P.

    2006-07-01

    The need for improved nuclear data for minor actinides has been stressed by various organizations throughout the world - especially for studies relating to plutonium management, waste incineration, transmutation of waste, and Pu burning in future nuclear concepts. Several international programs have indicated a strong desire to obtain accurate integral reaction rate data for improving the major and minor actinides cross sections. Data on major actinides (i.e. {sup 235}U, {sup 236}U, {sup 238}U, {sup 239}Pu, {sup 240}Pu, {sup 241}Pu, {sup 242}Pu and {sup 241}Am) are reasonably well-known and available in the Evaluated Nuclear Data Files (JEFF, JENDL, ENDF-BX However information on the minor actinides (i.e. {sup 232}Th, {sup 233}U, {sup 237}Np, {sup 238}Pu, {sup 242}Am, {sup 243}Am, {sup 243}Cm, {sup 235}Cm, {sup 244}Cm, {sup 245}Cm, {sup 246}Cm and {sup 247}Cm) is less well-known and considered to be relatively poor in some cases, having to rely on model and extrapolation of few data points. In this framework, the ambitious OSMOSE program between the Commissariat a l'Energie Atomique (CEA), Electricite de France (EDF) and the U.S. Dept. of Energy (DOE) has been undertaken with the aim of measuring the integral absorption rate parameters of actinides in the MINERVE experimental facility located at the CEA Cadarache Research Center. The OSMOSE Program (Oscillation in Minerve of isotopes in 'Eupraxic' Spectra) includes a complete analytical program associated with the experimental measurement program and aims at understanding and resolving potential discrepancies between calculated and measured values. In the OSMOSE program, the reactivity worth of samples containing separated actinides are measured in different neutron spectra using an oscillation technique with an overall expected accuracy better than 3%. Reactivity effects of less than 10 pcm (0.0001 or approximately 1.5 cents) are measured and compared with calibrations to determine the differential reactivity

  12. Experiments on nuclear fission induced by radioactive beams

    SciTech Connect

    Skobelev, N.K.

    1994-07-01

    The cross sections of {sup 209}Bi nuclear fission induced by secondary beams of {sup 6}He and {sup 4}He are measured under identical conditions. The experimental data are in good agreement with earlier results on the fission cross section of the {sup 4}He + {sup 209}Bi reaction. The measured values of the cross section of {sup 209}Bi fission induced by {sup 6}He ions are much higher than the cross sections of fission induced by {alpha}-particles. It is found that the fission threshold for the {sup 6}He + {sup 209}Bi reaction is shifted as compared to that of the {sup 4}He + {sup 209}Bi reaction. Various factors that can be responsible for the observed peculiarities in the {sup 209}Bi fission induced by the {sup 6}He ions are analyzed. 25 refs., 5 figs.

  13. Determination of plutonium isotopes in seawater reference materials using isotope-dilution ICP-MS.

    PubMed

    Zheng, Jian; Yamada, Masatoshi

    2012-09-01

    We analyzed the activities of (239)Pu, (240)Pu, (239+240)Pu, (241)Pu, the ratio of number of atoms (atom ratio) for (240)Pu/(239)Pu, and the activity ratio of (241)Pu/(239+240)Pu in seawater reference materials, IAEA-443 and IAEA-381, using a highly sensitive isotope dilution sector field inductively coupled plasma mass spectrometry method. With a mean chemical yield of 65% determined with (242)Pu as a tracer, we found that the experimentally established values in IAEA-443 for (239)Pu, (240)Pu, (241)Pu and (239+240)Pu activities are almost the same as those in IAEA-381. Regarding the (239+240)Pu activity, we provided the most precise and accurate result among the twelve laboratories, which participated in the interlaboratory comparison. In addition, for the (240)Pu/(239)Pu atom ratio, our results for IAEA-381 (0.2315±0.0008) and IAEA-443 (0.2325±0.0008) are in good agreement with the IAEA information value (0.229±0.006), but have much smaller uncertainty. Since the new seawater reference material, IAEA-443, is commercially available, it can be used not only for method validation for seawater plutonium isotope ratio and activity analysis, but also for more general use as a plutonium isotope standard for mass discrimination correction for other environmental samples.

  14. Accelerator mass spectrometry (AMS) in plutonium analysis.

    PubMed

    Strumińska-Parulska, Dagmara I

    The paper summarizes the results of the (240)Pu/(239)Pu atomic ratio studies in atmospheric fallout samples collected in 1986 over Gdynia (Poland) as well as three Baltic fish species collected in 1997 using the accelerator mass spectrometry. A new generation of AMS has been developed during last years and this method is an efficient and good technique to measure long-lived radioisotopes in the environment and provides the most accurate determination of the atomic ratios between (240)Pu and (239)Pu. The nuclide compositions of plutonium in filter samples correspond to their means of production. AMS measurements of atmospheric fallout collected in April showed sufficient increase of the (240)Pu/(239)Pu atomic ratio from 0.28 from March to 0.47. Also such high increase of (240)Pu/(239)Pu atomic ratio, close to reactor core (240)Pu/(239)Pu atomic ratio, was observed in September and equaled 0.47.

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

    USGS Publications Warehouse

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

    2004-01-01

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

  16. Method for the preparation of radon-211

    DOEpatents

    Meyer, Geerd-J.; Lambrecht, Richard M.

    1982-01-01

    A method for the production of .sup.211 Rn comprising bombarding .sup.209 Bi with .sup.7 Li particles utilizing the nuclear reaction .sup.209 Bi(.sup.7 Li,5n).sup.211 Rn. The method provides a simple spectrum from which .sup.211 Rn can be easily isolated in a highly pure condition.

  17. Plutonium, (137)Cs and uranium isotopes in Mongolian surface soils.

    PubMed

    Hirose, K; Kikawada, Y; Igarashi, Y; Fujiwara, H; Jugder, D; Matsumoto, Y; Oi, T; Nomura, M

    2017-01-01

    Plutonium ((238)Pu and (239,240)Pu), (137)Cs and plutonium activity ratios ((238)Pu/(239,240)Pu) as did uranium isotope ratio ((235)U/(238)U) were measured in surface soil samples collected in southeast Mongolia. The (239,240)Pu and (137)Cs concentrations in Mongolian surface soils (<53 μm of particle size) ranged from 0.42 ± 0.03 to 3.53 ± 0.09 mBq g(-1) and from 11.6 ± 0.7 to 102 ± 1 mBq g(-1), respectively. The (238)Pu/(239,240)Pu activity ratios in the surface soils (0.013-0.06) coincided with that of global fallout. The (235)U/(238)U atom ratios in the surface soil show the natural one. There was a good correlation between the (239,240)Pu and (137)Cs concentrations in the surface soils. We introduce the migration depth to have better understanding of migration behaviors of anthropogenic radionuclides in surface soil. We found a difference of the migration behavior between (239,240)Pu and (137)Cs from (137)Cs/(239,240)Pu - (137)Cs plots for the Mongolian and Tsukuba surface soils; plutonium in surface soil is migrated easier than (137)Cs.

  18. Plutonium and americium behavior in coral atoll environments

    SciTech Connect

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

    1984-02-01

    Inventories of /sup 239 +240/Pu and /sup 241/Am greatly in excess of global fallout levels persist in the benthic environments of Bikini and Enewetak Atolls. Quantities of /sup 239 +240/Pu and lesser amounts of /sup 241/Am are continuously mobilizing from these sedimentary reservoirs. The amount of /sup 239 +240/Pu mobilized to solution at any time represents 0.08 to 0.09% of the sediment inventories to a depth of 16 cm. The mobilized /sup 239 +240/Pu has solute-like characteristics and different valence states coexist in solution - the largest fraction of the soluble plutonium is in an oxidized form (+V,VI). The adsorption of plutonium to sediments is not completely reversible because of changes that occur in the relative amounts of the mixed oxidation states in solution with time. Further, any characteristics of /sup 239 +240/Pu described at one location may not necessarily be relevant in describing its behavior elsewhere following mobilization and migration. The relative amounts of /sup 241/Am to /sup 239 +240/Pu in the sedimentary deposits at Enewetak and Bikini may be altered in future years because of mobilization and radiological decay. Mobilization of /sup 239 +240/Pu is not a process unique to these atolls, and quantities in solution derived from sedimentary deposits can be found at other global sites. These studies in the equatorial Pacific have significance in assessing the long-term behavior of the transuranics in any marine environment. 22 references, 1 figure, 13 tables.

  19. A preliminary study for the development of reference material using oyster for determination of (137)Cs, (90)Sr and plutonium isotopes.

    PubMed

    Lee, Sang-Han; Oh, Jung-Suk; Lee, Jong-Man; Lee, Kyung-Bum; Park, Tae-Soon; Lee, Min-Kie; Kim, Seung-Hwan; Choi, Jong-Ki

    2016-03-01

    A new reference material for the determination of (137)Cs, (90)Sr and Pu isotopes ((238)Pu and (239,240)Pu) is being developed using dried oyster matrix by Korea Research Institute of Standards and Science (KRISS). The oyster was collected from Tongyoung harbour, southern part of Korea and the artificial radionuclides ((137)Cs, (90)Sr, (238)Pu and (239,240)Pu) were spiked into the material. After pretreatment and processing, the material was tested for homogeneity and massic activities were determined by measuring (137)Cs, (90)Sr, (238)Pu and (239,240)Pu. The reference value and extended uncertainty for those isotopes will be reported later.

  20. Particle-size speciation of Pu isotopes in surface soils from Inner Mongolia (China) and its implications for Asian Dust monitoring.

    PubMed

    Dong, Wei; Zheng, Jian; Guo, Qiuju

    2017-02-01

    To study the applications of Pu isotopes in long-distance dust migration monitoring, Pu isotopes in surface soil of Inner Mongolia have been analyzed using SF-ICP-MS after size fractionation. (240)Pu/(239)Pu atom ratios ranged narrowly (0.169-0.200) and indicated global fallout character, while (239+240)Pu activities increased with decreasing particle size. A spherical model could well simulate (239+240)Pu activities as a function of particle diameter when soil particle size was less than 600µm, and the soil particle surface sorption phenomenon of Pu isotopes in natural soil samples was revealed. Furthermore, (239+240)Pu activity in fine particles (sized less than 53µm) had good consistency with that in atmospheric depositions of Japan since the 2000s, suggesting new Asian Dust sources (i.e. central Inner Mongolia) other than the well-known Chinese deserts.

  1. Anthropogenic plutonium in the North Jiangsu tidal flats of the Yellow Sea in China.

    PubMed

    Liu, Zhiyong; Zheng, Jian; Pan, Shaoming; Gao, Jianhua

    2013-08-01

    The (239+240)Pu activities and (240)Pu/(239)Pu atom ratios were analyzed using a double-focusing SF-ICP-MS for sediment core samples obtained in 2007-2008 from the North Jiangsu tidal flats in the Yellow Sea in China. Particular attention was focused on the (240)Pu/(239)Pu atom ratios in the sediment to identify the origins of Pu isotopes. The profiles of (239+240)Pu activities in the sediment cores are similar to those of the (137)Cs activities. The (240)Pu/(239)Pu atom ratios in the tidal flats showed typical global fallout values, indicating that this area did not receive the possible early direct close-in fallout or oceanic current transported Pu from the Pacific Proving Grounds (PPG). If any, the contribution of the PPG source Pu to the total Pu inventory is negligible. This is different from the sediments in the Yangtze River estuary in the East China Sea, where the PPG source Pu contributed ca. 45 % to the total inventory. In addition, the observation of the global fallout origin Pu in the North Jiangsu tidal flats indicated that the nuclear power plant in the region was not causing any alteration/contamination to the (240)Pu/(239)Pu atom ratios. The (239+240)Pu and (137)Cs activities/inventories in the sediment cores showed correlation to the mean clay sediment compositions (fine particles) in the tidal flats. Therefore, mud deposits are served as sinks for the anthropogenic radionuclides in the tidal flats and the Yellow Sea. Integrated with the previously reported spatial distributions of (239+240)Pu and (137)Cs activities in the surface sediments of the Yellow Sea, the mechanism of Pu transport with the ocean currents and the scavenging characteristics in the Yellow Sea were discussed.

  2. Characterization of Pu concentration and its isotopic composition in a reference fallout material.

    PubMed

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

    2010-02-01

    Because there is no reference material for fallout plutonium isotope monitoring, preparation of such a material is necessary for quality control of fallout radionuclides analysis for atmospheric environmental studies. In this work, we report the characterization of Pu activity and its isotopic composition in a reference fallout material prepared by the Meteorological Research Institute (MRI), Japan. This material was prepared from samples collected at 14 stations throughout Japan in 1963-1979, with reference values of (137)Cs, (90)Sr and (239)(+)(240)Pu activities. We analyzed the activities of (239)(+)(240)Pu and (241)Pu, and the atom ratios of (240)Pu/(239)Pu and (241)Pu/(239)Pu using an isotope dilution sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS). The (239)(+)(240)Pu activities in this fallout material using acid leaching and total digestion were 6.56+/-0.20 mBq/g and 6.79+/-0.16 mBq/g, respectively. Atom ratios of (240)Pu/(239)Pu were 0.1915+/-0.0030 and 0.1922+/-0.0044, respectively. Both (240)Pu/(239)Pu and (241)Pu/(239)Pu atom ratios were slightly higher than those of global fallout, which could be attributed to the deposition of fallout radionuclides resulting from the Chinese nuclear weapons tests conducted in the 1970s. The dominant host phases of (239)(+)(240)Pu were found to be organic matter-sulfides (70%) with a relative high (240)Pu/(239)Pu atom ratio, and Fe-Mn oxides (19%) using a sequential extraction method.

  3. Plutonium isotope ratio variations in North America

    SciTech Connect

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

    2010-12-14

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

  4. SHE research at RIKEN/GARIS

    NASA Astrophysics Data System (ADS)

    Morita, Kosuke

    2015-12-01

    In this contribution, heavy-element research at RIKEN, Japan is reviewed. Nuclei of the heaviest elements were produced by the reactions 208Pb(64Ni, n)271Ds, 209Bi(64Ni, n)272Rg, 208Pb(70Zn, n)277Cn, and 209Bi(70Zn, n)278113. Alpha decays of those products and their consecutive alpha/spontaneous fission decays were studied using a gas-filled type recoil separator. New nuclei, 278113, 274Rg, and 270Mt, were observed in the 209Bi + 70Zn reaction.

  5. ²³⁹Pu and ²⁴⁰Pu inventories and ²⁴⁰Pu/²³⁹Pu atom ratios in the equatorial Pacific Ocean water column.

    PubMed

    Yamada, Masatoshi; Zheng, Jian

    2012-07-15

    The (239+240)Pu concentrations and (240)Pu/(239)Pu atom ratios were determined by alpha spectrometry and inductively coupled plasma mass spectrometry for seawater samples from two stations, one at the equator and the other in the equatorial South Pacific. To better understand the fate of Pu isotopes, this study dealt with the contribution of the close-in fallout Pu from the Pacific Proving Grounds (PPG) in water columns of the Pacific Ocean. The (239)Pu, (240)Pu and (239+240)Pu inventories over the depth interval 0-3000 m at the equator station were 10.4, 8.9 and 19.3 Bq m(-2), respectively. Further, no noticeable difference was observed in (239)Pu, (240)Pu and (239+240)Pu inventories over the depth interval 0-3000 m between the two stations. The total (239+240)Pu inventories were significantly higher than the expected cumulative deposition density of global fallout. Water column (239+240)Pu inventories measured in this study were lower than those reported for comparable stations in the Geochemical Ocean Sections Study, indicating that these inventories have been decreasing at average rates of 0.89 ± 0.07 and 0.16 ± 0.07 Bq m(-2)yr(-1) at the equator and equatorial South Pacific stations, respectively, from 1973 to 1990. The obtained (240)Pu/(239)Pu atom ratios were higher than the mean global fallout ratio of 0.18. These high atom ratios proved the existence of close-in tropospheric fallout Pu from the PPG in the Marshall Islands. The (239+240)Pu inventories originating from the close-in fallout in the entire water column were estimated to be 11.1 Bq m(-2) at the equator station and 7.1 Bq m(-2) at the equatorial South Pacific Ocean station, and the relative percentages of close-in fallout Pu were 40% at the former and 34% at the latter. A significant amount of close-in fallout Pu originating from the PPG has been transported to deep layers below the 1000 m depth in the equatorial Pacific Ocean.

  6. 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.

  7. 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.

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

    PubMed

    Lee, M H; Clark, S B

    2005-08-01

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

  9. Excess plutonium in soil near the Nevada Test Site, USA.

    PubMed

    Turner, Mary; Rudin, Mark; Cizdziel, James; Hodge, Vernon

    2003-01-01

    Two soil profiles were collected from undisturbed areas near the Nevada Test Site (NTS). The activity of 137Cs in the surface layer of the downwind Queen City Summit profile is three times higher than at the upwind site at Searchlight, NV (41.1+/-0.6 mBq/g vs. 13.0+/-0.4 mBq/g), and the 239,240Pu activity is 100 times greater (51+/-2 mBq/g vs. 0.52+/-0.03 mBq/g). An examination of the literature suggests that the 137Cs/239,240Pu and the 239,240Pu/238Pu activity ratios in soils and sediments from the northern hemisphere, due to fallout from atmospheric atomic weapons testing, have generalized values of 36+/-4 and 30+/-4, respectively (as of 1 July 1995). Deviations from these values may indicate possible contamination by sources other than fallout. Data from the surface soil of the downwind Queen City Summit profile yield a 137Cs/239,240Pu ratio of 0.81+/-0.02 and a 239,240Pu/238Pu ratio of 78+/-6. Clearly, an increase in 239,240Pu relative to 137Cs or 238Pu can account for these observations. There is compelling evidence that this "excess" 239,240Pu came from activities at the NTS during the aboveground testing of nuclear devices, more than likely from safety tests, some 40 years ago, and/or during the interim by the wind-driven resuspension of contaminated surface soil on the NTS and its transport off-site. Moreover, the two concentration profiles show that high percentages of both of these elements are retained for decades in the upper few centimeters of soil in Nevada's desert environment.

  10. Radiochemical study of the combined (p,π0) and (p,γ) reactions on bismuth with protons from 62 to 480 MeV

    NASA Astrophysics Data System (ADS)

    Ward, T. E.; Singh, P. P.; Friesel, D. L.; Yavin, A.; Doron, A.; D'Auria, J. M.; Sheffer, G.; Dillig, M.

    1981-08-01

    The excitation function for the combined 209Bi(p,γ)210Po and 209Bi(p,π0)210Po reactions was measured for proton energies from 62 to 480 MeV. The measurements were made using standard radiochemical and residual α-counting techniques. Below pion-production threshold the radiative proton-capture cross section was observed to decrease with increasing proton energy. Above threshold the combined cross section increases to about 10 μb at 170 MeV. From a smooth extrapolation of the (p,γ) cross section to energies above pion-production threshold, an estimate of a cross section for the (p,π0) process is obtained. A theoretical fit of the summed total cross section into all particle bound states was made using a density of states factor, a two nucleon t matrix, and by taking into account the initial state (proton) and final state (pion) distortions using optical potentials. [NUCLEAR REACTIONS 209Bi(p,γ)210Po+209Bi(p,π0)210Po, 209Bi(p,2n)208Po, 209Bi(p,4n)206Po, Ep=62-480 MeV, measured polonium-production cross section, thin targets, radiochemical method, α counting, theoretical fit to the (p,π0) data using two-nucleon model.

  11. Feasibility of using 236U to reconstruct close-in fallout deposition from the Hiroshima atomic bomb.

    PubMed

    Sakaguchi, A; Kawai, K; Steier, P; Imanaka, T; Hoshi, M; Endo, S; Zhumadilov, K; Yamamoto, M

    2010-10-15

    The first results on the feasibility of using (236)U to reconstruct the level and spatial distribution of close-in fallout deposition from the Hiroshima A-bomb are reported, coupled with the use of global fallout (137)Cs and (239+240)Pu. The results for global fallout (236)U in soil samples (0-30cm) from Ishikawa prefecture showed that the deposition density of (236)U from the global fallout can be accurately evaluated using AMS. All deposited (236)U, (137)Cs and (239+240)Pu appeared to have been recovered using 30-cm cores. It was also noted from the depth profiles for (236)U/(239+240)Pu and (236)U/(137)Cs ratios that the downward behavior of (236)U in the soil was apparently similar to that of (239+240)Pu, while the (137)Cs was liable to be retained in upper layers compared with (236)U and (239+240)Pu. The accumulated levels were 1.78×10(13)atomsm(-2) for (236)U, 4340Bqm(-2) for (137)Cs and 141Bqm(-2) for (239+240)Pu. The ratios of (236)U/(137)Cs and (236)U/(239+240)Pu were (4.10±0.12)×10(9) and (1.26±0.04)×10(11)atomsBq(-1), respectively. Results of (236)U, (137)Cs and (239+240)Pu measurements for the seven soil cores (0-30cm) from Hiroshima were discussed on the basis of ratios of (236)U/(137)Cs and (236)U/(239+240)Pu by comparing with those from the background area in Ishikawa, indicating that the global fallout dominates the current level of (236)U accumulation in soil in the Black-rain area around Hiroshima after the Hiroshima bomb, and the contribution of the close-in fallout (236)U produced by the Hiroshima A-bomb seems difficult to observe.

  12. 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.

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

    SciTech Connect

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

    1981-05-01

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

  14. 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.

  15. Comparative behavior of plutonium and americium in the equatorial Pacific

    SciTech Connect

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

    1983-01-01

    Inventories of /sup 239 +240/Pu and /sup 241/Am greatly in excess of global fallout levels persist in the benthic environments of Bikini and Enewetak Atolls. The amount of /sup 239 +240/Pu mobilized to solution at the atolls can be predicted from a distribution coefficient K/sub d/ of 2.3 x 10/sup 5/ and the mean sediment concentrations. The mobilized /sup 239 +240/Pu has solute-like characteristics and different valence states coexist in solution - the largest fraction of the soluble plutonium is in an oxidized form (+V,VI). The adsorption of plutonium to sediments is not completely reversible because of changes that occur in the relative amounts of the mixed oxidation states in solution with time. Characteristics of /sup 239 +240/Pu described at one location may not necessarily describe its behavior elsewhere. The relative amounts of /sup 241/Am to /sup 239 +240/Pu may be altered in future years because of mobilization and radiological decay.

  16. 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.

  17. 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.

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

    PubMed

    Nakano, Masanao; Povinec, Pavel P

    2003-01-01

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

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

    PubMed

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

    2014-04-11

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

  20. Plutonium and radiocesium in the water column of the Hudson River estuary

    NASA Astrophysics Data System (ADS)

    Linsalata, P.; Simpson, H. J.; Olsen, C. R.; Cohen, N.; Trier, R. M.

    1985-12-01

    Isotopes of plutonium (Pu), cesium (Cs), and cobalt (Co) introduced into the Hudson River Estuary from fallout deposition, the erosion of fallout-contaminated surface soils, and nuclear reactor effluent (isotopes of Cs and Co only) have been measured in water column samples collected from 1975 to 1980 Isotopic measurements conducted independently by two research groups utilizing different sampling and analytical techniques have been summarized. The major conclusions drawn from the work are that for water samples collected by the two laboratories over similar time periods, the mean concentrations of nonfilterable239,240Pu (<0.45 μm) were identical at 0.13 fCi/l, mean concentrations of both137Cs and239,240Pu in suspended particulates were more divergent at 2,270±920 pCi/kg (±1 SD) and 1,430±430 pCi/kg for137Cs, and 19±8 pCi/kg and 12±4 pCi/kg for239,240Pu The behavior of239,240Pu and137Cs within the water column is shown to diverge within brackish waters Specifically, the magnitude of the137Cs distribution coefficient ( K d ) can be expressed as an inverse power function of the chloride ion concentrations for chlorinities between 0.1 and 4 g Cl-/l No difference in the239,240Pu K d has been observed between fresh and brackish waters Based on the expected inventories of239,240Pu and137Cs within watershed soils, the current downstream transport of these radionuclides represents fractional mobilization rates on the order of 1 4 (×10-4) per year

  1. Plutonium, cesium and uranium series radionuclides in the Hudson River estuary and other environments. Annual technical progress report, December 1, 1979-November 30, 1980

    SciTech Connect

    Simpson, H. J.; Trier, R. M.; Olsen, C. R.

    1980-01-01

    Radionuclide activities were measured in a large number of sediment cores and suspended particle samples throughout the salinity range of the Hudson River estuary. Activities of /sup 137/Cs, /sup 134/Cs and /sup 60/Co determined by gamma spectrometry and /sup 239/ /sup 240/Pu and /sup 238/Pu determined by alpha spectrometry indicate reasonably rapid accumulation rates in the sediments of marginal cove areas, and very rapid deposition in the harbor region adjacent to New York City, resulting in /sup 239/ /sup 240/Pu accumulations there more than an order of magnitude greater than the fallout delivery rate. Measurable amounts of reactor-derived /sup 134/Cs and /sup 60/Co are found in nearly al sediment samples containing appreciable /sup 137/Cs between 15 km upstream of Indian Point and the downstream extent of our sampling about 70 km south of the reactor. Fallout /sup 239/ /sup 240/Pu reaching the Hudson appears to be almost completely retained within the systems by particle deposition, while 70 to 90% of the /sup 137/Cs derived from both reactor releases and fallout has been exported to the coastal waters in solution. Activity levels of /sup 239/ /sup 240/Pu in New York harbor sediments indicate a significant source in addition to suspended particles carried down the Hudson. The most likely cause appears to be transport into the estuary of particles from offshore waters having higher specific activities of /sup 239/ /sup 240/Pu. Measurements of fallout /sup 239/ /sup 240/Pu in a saline lake with a high carbonate ion concentration yielded water column activities about two orders of magnitude greater than has been found for fallout plutonium in other continental waters, indicating extensive mobility in some natural water environments. Experiments using lake water suggest that carbonate ion may indeed be a critical factor in regulating plutonium solubility and that low molecular weight complexes are primarily responsible for enhanced plutonium solubility.

  2. 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.

  3. Self-regulating neutron coincidence counter

    DOEpatents

    Baron, N.

    1980-06-16

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

  4. Radionuclide tracing of water masses and processes in the water column and sediment in the Algerian Basin.

    PubMed

    Noureddine, A; Benkrid, M; Maoui, R; Menacer, M; Boudjenoun, R; Kadi-hanifi, M; Lee, S-H; Povinec, P P

    2008-08-01

    Caesium-137 and (239,240)PU were analysed in the water column along the Algerian coast. The (137)Cs activity concentration in surface water increased from the west to the east from 1.6 to 3.3 mBq L(-1), documenting a presence of Modified Atlantic Water (MAW) in the region. Higher concentrations observed in deep waters may be due to an intrusion of Levantine Intermediate Water (LIW), which has been carrying higher levels of (137)Cs from Chernobyl accident. The (239,240)Pu sub-surface concentration peaked at about 250 m water depth as a result of biogeochemical processes in the water column. The observed (239,240)Pu/(137)Cs activity ratio at the surface (0.003) was significantly lower than that in global fallout (0.04). This decrease exceeds that expected from radioactive decay of (137)Cs, and confirms that Pu due to its adsorption on sinking particles is more effectively removed from surface layers than is (137)Cs. An increase of the (239,240)Pu/(137)Cs activity ratio with depth suggests that (239,240)Pu, similarly as (137)Cs, should be also transported by advection to maintain the observed ratios in deep waters. An intrusion of LIW may enhance therefore both the (137)Cs and (239,240)Pu concentrations in deep waters. The average (238)Pu/(239+240)Pu activity ratio in seawater was 0.03+/-0.02, confirming a global fallout origin of Pu in the Algerian Basin. Caesium-137 and (239,240)Pu inventories in the water column were estimated to be from 2.7+/-0.5 kBq m(-2) to 3.8+/-0.7 kBq m(-2), and from 13.8+/-2.6 Bq m(-2) to 41+/-7B qm(-2), respectively. The (137)Cs massic activities in surface sediment were almost constant, the average activity was 9.0+/-0.8 Bq kg(-1). Sedimentation rates obtained using the (210)Pb method were from 0.1 to 0.7 cm y(-1), and resulting penetration depths of (137)Cs in the sediment cores were from 15 to over 40 cm. The (137)Cs peaks found in the sediment cores were associated with the Chernobyl accident (1986) and global fallout (1964). The (137

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

    DOE PAGES

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

    2015-08-30

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

  6. Impact of Saharan dust events on radionuclide levels in Monaco air and in the water column of the northwest Mediterranean Sea.

    PubMed

    Pham, Mai Khanh; Chamizo, Elena; Mas Balbuena, José Luis; Miquel, Juan-Carlos; Martín, Jacobo; Osvath, Iolanda; Povinec, Pavel P

    2017-01-01

    Characterization of atmospheric aerosols collected in Monaco (2004-2008) and in sediment traps at 200 m and 1000 m water depths at the DYFAMED (Dynamics of Atmospheric Fluxes in the Mediterranean Sea) station (2004) was carried out to improve our understanding of the impact of Saharan dust on ground-level air and on the water column. Activity concentrations of natural ((210)Pb, (210)Po, uranium and radium isotopes) and anthropogenic ((137)Cs, (239)Pu, (240)Pu, and (239+240)Pu) radionuclides and their isotopic ratios confirmed a Saharan impact on the investigated samples. In association with a large particulate matter deposition event in Monaco on 20 February 2004, the (137)Cs (∼40 Bq kg(-1)) and (239+240)Pu (∼1 Bq kg(-1)) activities were almost a factor of two higher than other Saharan deposition dust events. This single-day particle flux represented 72% of the annual atmospheric deposition in Monaco. The annual deposition of Saharan dust on the sea was 232-407 mBq m(-2) for (137)Cs and 6.8-9.8 mBq m(-2) for (239+240)Pu and contributed significantly (28-37% for (137)Cs and 34-45% for (239+240)Pu) to the total annual atmospheric input to the northwest Mediterranean Sea. The (137)Cs/(239+240)Pu activity ratios in dust samples collected during different Saharan dust events confirmed their global fallout origin or mixing with local re-suspended soil particles. In the sediment trap samples the (137)Cs activity varied by a factor of two, while the (239+240)Pu activity was constant, confirming the different behaviors of Cs (dissolved) and Pu (particle reactive) in the water column. The (137)Cs and (239+240)Pu activities of sinking particles during the period of the highest mass flux collected in 20 February 2004 at the 200 m and 1000 m water depths represented about 10% and 15%, respectively, of annual deposition from Saharan dust events.

  7. Sedimentation in the Southern Okinawa Trough: enhanced particle scavenging and teleconnection between the Equatorial Pacific and western Pacific margins

    NASA Astrophysics Data System (ADS)

    Lee, Shih-Yu; Huh, Chih-An; Su, Chih-Chieh; You, Chen-Feng

    2004-11-01

    Owing to its location, geomorphology and hydrodynamic conditions, the southernmost part of the Southern Okinawa Trough (SOT) acts like an efficient receptacle for sediments from Taiwan and the East China Sea shelf. The high sediment flux coupled with the passage, bifurcation, upwelling, swirling and detour of Kuroshio in the SOT area result in intense particle scavenging, with sedimentary inventories of 210Pb and 239, 240Pu far greater than expected from local atmospheric input and in situ water column production. The unusually high inventories, as well as the deposition history of Pu isotopes must be explained by advective transport of Pu westward from the Marshall Islands, the largest source of Pu in the Pacific, by the North Equatorial Current (NEC) followed by northward transport of Kuroshio to the SOT area. The high sedimentation rate in the SOT area enabled us to differentiate the subsurface peak of 239, 240Pu resulting from the global fallout maximum in AD 1963 and the subsurface maximum of 240Pu/239Pu caused by close-in fallout from neutron-rich thermonuclear tests conducted by the US during AD 1952-1954 at the Enewetak and Bikini Atolls. The vertical offset between the subsurface peaks of 239, 240Pu and 240Pu/239Pu in sediments suggests that deposition of the 240Pu/239Pu maximum preceded that of the 239, 240Pu maximum by 3-5 yr and that the transit time of the 240Pu-enriched Pu from its source (at ∼12°N, 162°E) to the SOT area is ∼6 yr. The mean velocity of NEC thus calculated is ∼0.022 m s-1. The present is the key to the past. This study reveals teleconnection between the Equatorial Pacific and the western Pacific margins and suggests that ODP and IMAGES cores recently collected from the SOT area holds great promise for the reconstruction of high-resolution paleoceanographic records along the trajectories of NEC and Kuroshio.

  8. Plutonium isotopes derived from Nagasaki atomic bomb in the sediment of Nishiyama reservoir at Nagasaki, Japan.

    PubMed

    Saito-Kokubu, Y; Esaka, F; Yasuda, K; Magara, M; Miyamoto, Y; Sakurai, S; Usuda, S; Yamazaki, H; Yoshikawa, S; Nagaoka, S

    2007-04-01

    The source of plutonium in sediments deposited at Nishiyama reservoir at Nagasaki was characterized by their (240)Pu/(239)Pu atom ratio. The average ratio was approximately 0.03, except in two layers. The main source of the plutonium was the Nagasaki atomic bomb. The plutonium continues to flow into the reservoir even now. The (240)Pu/(239)Pu atom ratios in two layers were higher than the average, which showed that plutonium in these layers were made of those of nuclear tests added to those of the atomic bomb.

  9. Fluence, dosimetry, and steel-dpa rates in EBR-II

    SciTech Connect

    Meneghetti, D.; Kucera, D.A.

    1984-01-01

    Sensitivities of steel displacements-per-atom (dpa) rates to fluence-rate spectra in regions of th Experimental Breeder Reactor II (EBR-II) are presented. Low sensitivities in EBR-II of ratios of dpa-to-fission rates assuming /sup 240/Pu as a dosimeter suggests its possible use for adjusting calculated dpa-rates for effects of errors in calculated fluence-spectra. Extension of the method to outer regions, having more degraded spectra, by use of /sup 10/B-shielded /sup 240/Pu dosimeters is also suggested.

  10. US Mussel Watch 1976-1978: an overview of the trace-metal, DDE, PCB, hydrocarbon, and artificial radionuclide data. [Mytilus edulis, M. californianus, Crassostrea sp

    SciTech Connect

    Farrington, J.W.; Goldberg, E.D.; Risebrough, R.W.; Martin, J.H.; Bowen, V.T.

    1983-08-01

    Data are presented for trace metals, polychlorinated biphenyls (PCBs), aromatic hydrocarbons and /sup 239/ /sup 240/Pu in Mytilus edulis, M. californianus, and Crassostrea sp. collected in the US Mussel Watch program in 1976-1978 from 62 locations on the US east and west coasts. General similarities in geographical distributions of concentrations were present in all 3 years with at least an order of magnitude elevation of concentrations of Pb, PCBs, and fossil fuel hydrocarbons in bivalves sampled near the larger urban areas. Elevated Cd and /sup 239/ /sup 240/Pu concentrations in bivalves from the central California coast are apparently related to enrichments of Cd and nuclear weapons testing fallout /sup 239/ /sup 240/Pu in intermediate depth water of the North Pacific and upwelling of this water associated with the California Current system. Data have revealed no evidence of local or regional systematic elevations of environmental concentrations of /sup 239/ /sup 240/Pu as a result of effluent releases from nuclear power reactors.

  11. Analysis of plutonium isotope ratios including (238)Pu/(239)Pu in individual U-Pu mixed oxide particles by means of a combination of alpha spectrometry and ICP-MS.

    PubMed

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

    2017-04-01

    Isotope ratio analysis of individual uranium-plutonium (U-Pu) mixed oxide particles contained within environmental samples taken from nuclear facilities is proving to be increasingly important in the field of nuclear safeguards. However, isobaric interferences, such as (238)U with (238)Pu and (241)Am with (241)Pu, make it difficult to determine plutonium isotope ratios in mass spectrometric measurements. In the present study, the isotope ratios of (238)Pu/(239)Pu, (240)Pu/(239)Pu, (241)Pu/(239)Pu, and (242)Pu/(239)Pu were measured for individual Pu and U-Pu mixed oxide particles by a combination of alpha spectrometry and inductively coupled plasma mass spectrometry (ICP-MS). As a consequence, we were able to determine the (240)Pu/(239)Pu, (241)Pu/(239)Pu, and (242)Pu/(239)Pu isotope ratios with ICP-MS after particle dissolution and chemical separation of plutonium with UTEVA resins. Furthermore, (238)Pu/(239)Pu isotope ratios were able to be calculated by using both the (238)Pu/((239)Pu+(240)Pu) activity ratios that had been measured through alpha spectrometry and the (240)Pu/(239)Pu isotope ratios determined through ICP-MS. Therefore, the combined use of alpha spectrometry and ICP-MS is useful in determining plutonium isotope ratios, including (238)Pu/(239)Pu, in individual U-Pu mixed oxide particles.

  12. Comparative analysis of (239)Pu, (137)Cs, (210)Pb and (40)K spatial distributions in the top soil layer at the Baltic coast.

    PubMed

    Luksiene, B; Druteikiene, R; Gvozdaite, R; Gudelis, A

    2006-01-01

    This paper presents the results of an investigation into the spatial distribution of radionuclides of artificial ((239,240)Pu, (137)Cs) and natural ((210)Pb, (40)K) origins in the upper (0-5 cm) soil layers on the Baltic coastline of Lithuania ( approximately 5 km(2) area). The samples were analysed by gamma ray spectrometry and combined radiochemical procedures. The highest (210)Pb, (239,240)Pu and (137)Cs activity concentrations were determined in the forest samples, whereas (40)K activity was rather homogeneous across the study area. Relatively high (239,240)Pu and (40)K activity concentrations were determined along the surf zone. The (210)Pb and (137)Cs activity concentrations showed a gradual increase from the surf zone to the forest. The average activity concentrations of (239,240)Pu, (137)Cs, (210)Pb and (40)K in the beach and forest samples, respectively, were as follows: 0.32+/-0.08 and 0.74+/-0.14; 50+/-4 and 1190+/-50; 4.7+/-2.0 and 48+/-6; 186+/-15 and 216+/-17 Bq/kg.

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

    PubMed

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

    2015-04-16

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

  14. Characterization of plutonium in deep-sea sediments of the Sulu and South China Seas.

    PubMed

    Dong, Wei; Zheng, Jian; Guo, Qiuju; Yamada, Masatoshi; Pan, Shaoming

    2010-08-01

    Anthropogenic Pu isotopes are important geochemical tracers for sediment studies. Their distributions and sources in the water columns as well as the sediments of the North Pacific have been intensively studied; however, information about Pu in the Southeast Asian seas is limited. To study the isotopic composition of Pu, and thus to identify its sources, we collected sediment core samples in the South China Sea and the Sulu Sea during the KH-96-5 Cruise of the R/V Hakuho Maru. We analysed the activities of (239+240)Pu and the atom ratios of (240)Pu/(239)Pu using isotope dilution sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS). The (240)Pu/(239)Pu atom ratios in the sediments of both areas (inventory weighted mean: 0.251 for the South China Sea and 0.280 for the Sulu Sea) were higher than the global fallout value (0.178+/-0.019), suggesting the existence of Pu from the Pacific Proving Grounds in the North Pacific. Low inventories of (239+240)Pu in sediments were observed in the South China Sea (3.75 Bq/m(2)) and the Sulu Sea (1.38 Bq/m(2)). Most of the Pu input is still present in the water column. Scavenging and benthic mixing processes were considered to be the main processes controlling the distribution of Pu in the deep-sea sediments of both study areas.

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

    PubMed Central

    Zheng, Jian; Tagami, Keiko; Uchida, Shigeo

    2015-01-01

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

  16. The role of plutonium as a resource now and in the future

    SciTech Connect

    Ray, D.L.

    1988-01-01

    This paper is the author's predictions of the role of plutonium as a resource. /sup 238/Pu is considered as a fuel for radiothermal generators in satellites and space probes. /sup 239/Pu is acknowledged to be vital in weapons applications. /sup 239/Pu and /sup 240/Pu are discussed from the viewpoint of commercial electrical generation.

  17. What Are the Legal and Policy Implications of Conducting Preemption and Interdiction Against a Weapons of Mass Destruction?

    DTIC Science & Technology

    2002-01-01

    kg 17 kg 20 kg Uranium 233 Neptunium 237 Americium 241 15 kg 60 kg 100 kg Source: O’Neil 1997, 4. 38 With regard to the question of preassembly or...1996, 2). That is not specifically enriched weapons grade HEU or Pu 239, but does include Pu 239, Pu 240, Pu 241, Pu 242, Uranium 233, Neptunium - 237

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

    PubMed Central

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

    2013-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  20. Evaluation of the neutron cross sections for Pu-240

    SciTech Connect

    Weston, L.W.; Arthur, E.D.

    1987-04-01

    The present evaluation is proposed to supersede the ENDF/B-V, Revision 2 file for /sup 240/Pu. In this work, resonance parameters, cross sections, energy distributions, and angular distributions have been modified. These changes are outlined in detail and appropriate references included. 37 refs., 21 figs., 2 tabs.

  1. Recent organic carbon accumulation (~100 years) along the Cabo Frio, Brazil upwelling region

    NASA Astrophysics Data System (ADS)

    Sanders, Christian J.; Caldeira, Pedro P.; Smoak, Joseph M.; Ketterer, Michael E.; Belem, Andre; Mendoza, Ursula M. N.; Cordeiro, Lívia G. M. S.; Silva-Filho, Emmanoel V.; Patchineelam, Sambasiva R.; Albuquerque, Ana Luiza S.

    2014-03-01

    Six sediment cores were obtained from the Cabo Frio shelf region of coastal Brazil to quantify the accumulation of organic carbon in a highly productive upwelling region. The sampled locations, 10-60 km offshore at ~100 m water depth, were investigated for excess 210Pb (210Pbex) as well as 239+240Pu fallout activities to determine sedimentary dynamics. The 210Pbex and 239+240Pu dating models show that the sediment accumulation rates varied substantially throughout this complex hydrodynamic system (0.8-5.5 mm yr-1). Excess 210Pb and 239+240Pu fluxes indicate lateral transport, with varying intensity along the continental shelf. The stations with the greatest 210Pbex and 239+240Pu sediment inventories are also the sites with the highest carbon accumulation rates (CAR). The total organic carbon (TOC) and total nitrogen (TN) contents, along with the δ13C results, indicate that the organic matter deposited in this region is mainly of marine origin. The results of this work suggest that lateral transport, with varying intensity along the shelf, contribute to the large quantities of marine plankton buried at specific depositional settings in the Cabo Frio upwelling region (~1-8 mol of OC cm-2 yr-1).

  2. Depositional behaviors of plutonium and thorium isotopes at Tsukuba and Mt. Haruna in Japan indicate the sources of atmospheric dust.

    PubMed

    Hirose, K; Igarashi, Y; Aoyama, M; Inomata, Y

    2010-02-01

    Monthly plutonium and thorium depositions at Tsukuba (28m asl) and Mt. Haruna (1370m asl) were measured during 2006 and 2007 (Jan 2006-Dec 2007 at Tsukuba, Nov 2006-Dec 2007 at Mt. Haruna). The monthly (239,240)Pu depositions ranged from 0.044 to 2.67mBq m(-2) at Tsukuba and from 0.05 to 0.9mBq m(-2) at Mt. Haruna during the measurement periods. Monthly (239,240)Pu deposition did not differ markedly between the two sites except in April 2007. Seasonal pattern of monthly (239,240)Pu depositions at both sites showed high in spring and low in summer, and typical of seasonal variations in northeastern Asia. Thorium deposition at Tsukuba was higher than that at Mt. Haruna except in May and June 2007. (230)Th/(232)Th activity ratios were used to partition deposition samples into locally and remotely derived fractions. The results revealed that a major proportion of total (239,240)Pu and Th deposits are derived from remote sources, especially in spring.

  3. Highly accurate measurements of the spontaneous fission half-life of 240,242Pu

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    Fast spectrum neutron-induced fission cross-section data for transuranic isotopes are of special demand from the nuclear data community. In particular highly accurate data are needed for the new generation IV nuclear applications. The aim is to obtain precise neutron-induced fission cross sections for 240Pu and 242Pu. To do so, accurate data on spontaneous fission half-lives must be available. Also, minimizing uncertainties in the detector efficiency is a key point. We studied both isotopes by means of a twin Frisch-grid ionization chamber with the goal of improving the present data on the neutron-induced fission cross section. For the two plutonium isotopes the high α-particle decay rates pose a particular problem to experiments due to piling-up events in the counting gas. Argon methane and methane were employed as counting gases, the latter showed considerable improvement in signal generation due to its higher drift velocity. The detection efficiency for both samples was determined, and improved spontaneous fission half-lives were obtained with very low statistical uncertainty (0.13% for 240Pu and 0.04% for 242Pu): for 240Pu, T1/2,SF=1.165×1011 yr (1.1%), and for 242Pu, T1/2,SF=6.74×1010 yr (1.3%). Systematic uncertainties are due to sample mass (0.4% for 240Pu and 0.9% for 242Pu) and efficiency (1%).

  4. Distribution of artificial radionuclides in deep sediments of the Mediterranean Sea.

    PubMed

    Garcia-Orellana, J; Pates, J M; Masqué, P; Bruach, J M; Sanchez-Cabeza, J A

    2009-01-01

    Artificial radionuclides enter the Mediterranean Sea mainly through atmospheric deposition following nuclear weapons tests and the Chernobyl accident, but also through the river discharge of nuclear facility effluents. Previous studies of artificial radionuclides impact of the Mediterranean Sea have focussed on shallow, coastal sediments. However, deep sea sediments have the potential to store and accumulate pollutants, including artificial radionuclides. Deep sea marine sediment cores were collected from Mediterranean Sea abyssal plains (depth >2000 m) and analysed for (239,240)Pu and (137)Cs to elucidate the concentrations, inventories and sources of these radionuclides in the deepest areas of the Mediterranean. The activity - depth profiles of (210)Pb, together with (14)C dating, indicate that sediment mixing redistributes the artificial radionuclides within the first 2.5 cm of the sedimentary column. The excess (210)Pb inventory was used to normalize (239,240)Pu and (137)Cs inventories for variable sediment fluxes. The (239,240)Pu/(210)Pb(xs) ratio was uniform across the entire sea, with a mean value of 1.24x10(-3), indicating homogeneous fallout of (239,240)Pu. The (137)Cs/(210)Pb(xs) ratio showed differences between the eastern (0.049) and western basins (0.030), clearly significant impact of deep sea sediments from the Chernobyl accident. The inventory ratios of (239,240)Pu/(137)Cs were 0.041 and 0.025 in the western and eastern basins respectively, greater than the fallout ratio, 0.021, showing more efficient scavenging of (239,240)Pu in the water column and major sedimentation of (137)Cs in the eastern basin. Although areas with water depths of >2000 m constitute around 40% of the entire Mediterranean basin, the sediments in these regions only contained 2.7% of the (239,240)Pu and 0.95% of the (137)Cs deposited across the Sea in 2000. These data show that the accumulation of artificial radionuclides in deep Mediterranean environments is much lower than

  5. Radionuclide transport from soil to air, native vegetation, kangaroo rats and grazing cattle on the Nevada test site.

    PubMed

    Gilbert, R O; Shinn, J H; Essington, E H; Tamura, T; Romney, E M; Moor, K S; O'Farrell, T P

    1988-12-01

    Between 1970 and 1986 the Nevada Applied Ecology Group (NAEG), U.S. Department of Energy, conducted environmental radionuclide studies at weapons-testing sites on or adjacent to the Nevada Test Site. In this paper, NAEG studies conducted at two nuclear (fission) sites (NS201, NS219) and two nonnuclear (nonfission) sites (Area 13 [Project 57] and Clean Slate 2) are reviewed, synthesized and compared regarding (1) soil particle-size distribution and physical-chemical characteristics of 239 + 240Pu-bearing radioactive particles, (2) 239 + 240Pu resuspension rates and (3) transuranic and fission-product radionuclide transfers from soil to native vegetation, kangaroo rats and grazing cattle. The data indicate that transuranic radionuclides were transferred more readily on the average from soil to air, the external surfaces of native vegetation and to tissues of kangaroo rats at Area 13 than at NS201 or NS219. The 239 + 240Pu resuspension factor for undisturbed soil at Area 13 was three to four orders-of-magnitude larger than at NS201 and NS219, the geometric mean (GM) vegetation-over-soil 239 + 240Pu concentration ratio was from ten to 100 times larger than at NS201, and the GM GI-over-soil, carcass-over-soil and pelt-over-soil 239 + 240Pu ratios for kangaroo rats were about ten times larger than at NS201. These results are consistent with the finding that Area 13, compared with NS201 or NS219, has a higher percentage of radioactivity associated with smaller soil particles and a larger percentage of resuspendable and respirable soil. However, the resuspension factor increased by a factor of 27 at NS201 when the surface soil was disturbed, and by a factor of 12 at NS219 following a wildfire. The average (GM) concentration of 239 + 240Pu for the GI (and contents) of Area 13 kangaroo rats and for the rumen contents of beef cattle that grazed Area 13 were very similar (400 vs. 440 Bq kg-1 dry wt, respectively) although the variability between individuals was very large. The

  6. 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.

  7. Characterization of selected radionuclides in sediment and surface water in Standley Lake, Great Western Reservoir, and Mower Reservoir, Jefferson County, Colorado, 1992

    USGS Publications Warehouse

    Clow, D.W.; Johncox, D.A.

    1995-01-01

    Lake sediment and surface water from Standley Lake, Great Western Reservoir, and Mower Reservoir, near Denver, Colorado, were sampled and analyzed for selected radionuclides during August through October, 1992. Sample concentrations were summarized and compared to results from a study conducted in 1983-84. Median plutonium-239,240 (239,240Pu) concentrations in lake-sediment grab samples from Standley Lake, Great Western Reservoir, and Mower Reservoir were 0.037, 0.105, and 0.351 picocuries per gram (pCi/g). The maximum concen- tration of 239,240Pu dissolved in lake water was 0.009 picocuries per liter, substantially below limits suggested by the Colorado Department of Health and the Environment. Dissolved concentrations of gross alpha and uranium isotopes were below National Drinking Water Standards in all water samples. There was no statistically significant difference between 239,240Pu concentration in lake-sediment grab samples collected from Standley Lake in 1983-84 and in 1992; however, there was a small, but statistically significant, difference at Great Western Reservoir (p<0.05). In 1992 at Great Western Reservoir, median 239,240Pu concentrations were 0.040 pCi/g lower than in 1983-84. There was a small, but statistically significant (p<0.05) difference in 239,240Pu concentrations in lake- bottom-sediment cores collected in 1983-84 and in 1992. Measured concentrations tended to be higher in 1983-84 than in 1992. The differences were greatest at concentrations above 1.5 pCi/g; in those samples concentrations were 10 to 30% higher in 1983-84 than in 1992.

  8. 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.

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

    PubMed

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

    2012-01-01

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

  10. Radionuclide transport from soil to air, native vegetation, kangaroo rats and grazing cattle on the Nevada test site

    SciTech Connect

    Gilbert, R.O.; Shinn, J.H.; Essington, E.H.; Tamura, T.; Romney, E.M.; Moor, K.S.; O'Farrell, T.P.

    1988-12-01

    Between 1970 and 1986 the Nevada Applied Ecology Group (NAEG), U.S. Department of Energy, conducted environmental radionuclide studies at weapons-testing sites on or adjacent to the Nevada Test Site. In this paper, NAEG studies conducted at two nuclear (fission) sites (NS201, NS219) and two nonnuclear (nonfission) sites (Area 13 (Project 57) and Clean Slate 2) are reviewed, synthesized and compared regarding (1) soil particle-size distribution and physical-chemical characteristics of 239 + 240Pu-bearing radioactive particles, (2) 239 + 240Pu resuspension rates and (3) transuranic and fission-product radionuclide transfers from soil to native vegetation, kangaroo rats and grazing cattle. The data indicate that transuranic radionuclides were transferred more readily on the average from soil to air, the external surfaces of native vegetation and to tissues of kangaroo rats at Area 13 than at NS201 or NS219. The 239 + 240Pu resuspension factor for undisturbed soil at Area 13 was three to four orders-of-magnitude larger than at NS201 and NS219, the geometric mean (GM) vegetation-over-soil 239 + 240Pu concentration ratio was from ten to 100 times larger than at NS201, and the GM GI-over-soil, carcass-over-soil and pelt-over-soil 239 + 240Pu ratios for kangaroo rats were about ten times larger than at NS201. These results are consistent with the finding that Area 13, compared with NS201 or NS219, has a higher percentage of radioactivity associated with smaller soil particles and a larger percentage of resuspendable and respirable soil. However, the resuspension factor increased by a factor of 27 at NS201 when the surface soil was disturbed, and by a factor of 12 at NS219 following a wildfire.

  11. Plutonium and 137Cs in surface water of the South Pacific Ocean.

    PubMed

    Hirose, K; Aoyama, M; Fukasawa, M; Kim, C S; Komura, K; Povinec, P P; Sanchez-Cabeza, J A

    2007-08-01

    The present plutonium and 137Cs concentrations in South Pacific Ocean surface waters were determined. The water samples were collected in the South Pacific mid-latitude region (32.5 degrees S) during the BEAGLE expedition conducted in 2003-04 by JAMSTEC. 239,240Pu concentrations in surface seawater of the South Pacific were in the range of 0.5 to 4.1 mBq m(-3), whereas 137Cs concentrations ranged from 0.07 to 1.7 Bq m(-3). The observed 239,240Pu and 137Cs concentrations in the South Pacific were almost of the same level as those in the North Pacific subtropical gyre. The surface 239,240Pu in the South Pacific subtropical gyre showed larger spatial variations than 137Cs, as it may be affected by physical and biogeochemical processes. The 239,240Pu/137Cs activity ratios, which reflect biogeochemical processes in seawater, were generally smaller than that observed in global fallout, except for the most eastern station. The 239,240Pu/137Cs ratios in the South Pacific tend to be higher than that in the North Pacific. The relationships between anthropogenic radionuclides and oceanographic parameters such as salinity and nutrients were examined. The 137Cs concentrations in the western South Pacific (the Tasman Sea) and the eastern South Pacific were negatively correlated with the phosphate concentration, whereas there is no correlation between the 137Cs and nutrients concentrations in the South Pacific subtropical gyre. The mutual relationships between anthropogenic radionuclides and oceanographic parameters are important for better understanding of transport processes of anthropogenic radionuclides and their fate in the South Pacific.

  12. Fallout of uranium and plutonium from recent volcanic eruptions

    SciTech Connect

    Sandoval, D.N.

    1984-01-01

    The concentrations of /sup 234/U, /sup 235/U, /sup 238/U in rain water were measured in a total of 102 individual samples which were collected at Fayetteville, Arkansas, from July 1980 through April 1983. A spectacular increase in the heavy isotope of uranium (/sup 238/U) was observed in the months of July, August (1980); January through April, November and December 1981. This large increase in /sup 238/U in rain appeared to have had its origin in the May 1980 eruption of Mount St. Helens. An increase in the concentration of /sup 238/U in rain, smaller than 1981, was observed, which seems to have originated from the El Chichon volcano eruption in March 1982, and the spring peak or so-called cycling effect. A striking increase in the average bimonthly concentration of /sup 239,240/Pu occurred during the months of September-October 1980 (15.6 fCi/l) and March-April 1981 (29.4 fCi/l). The excess deposition of /sup 239,240/Pu brought down by the rain at Fayetteville, Arkansas, from March 1980 through December 1982 was found to be 1.01 fCi/cm/sup 2/. The total amount of /sub 239,240/Pu deposited at Fayetteville, Arkansas, from March through December 1982, was found to be about 30 times higher than the total amount calculated from reported literature values. The excess /sup 239,240/Pu has been attributed to stratospheric /sub 239,240/Pu from nuclear weapons testing prior to the 25th Chinese nuclear test.

  13. Arctic Ocean sea ice drift origin derived from artificial radionuclides.

    PubMed

    Cámara-Mor, P; Masqué, P; Garcia-Orellana, J; Cochran, J K; Mas, J L; Chamizo, E; Hanfland, C

    2010-07-15

    Since the 1950s, nuclear weapon testing and releases from the nuclear industry have introduced anthropogenic radionuclides into the sea, and in many instances their ultimate fate are the bottom sediments. The Arctic Ocean is one of the most polluted in this respect, because, in addition to global fallout, it is impacted by regional fallout from nuclear weapon testing, and indirectly by releases from nuclear reprocessing facilities and nuclear accidents. Sea-ice formed in the shallow continental shelves incorporate sediments with variable concentrations of anthropogenic radionuclides that are transported through the Arctic Ocean and are finally released in the melting areas. In this work, we present the results of anthropogenic radionuclide analyses of sea-ice sediments (SIS) collected on five cruises from different Arctic regions and combine them with a database including prior measurements of these radionuclides in SIS. The distribution of (137)Cs and (239,240)Pu activities and the (240)Pu/(239)Pu atom ratio in SIS showed geographical differences, in agreement with the two main sea ice drift patterns derived from the mean field of sea-ice motion, the Transpolar Drift and Beaufort Gyre, with the Fram Strait as the main ablation area. A direct comparison of data measured in SIS samples against those reported for the potential source regions permits identification of the regions from which sea ice incorporates sediments. The (240)Pu/(239)Pu atom ratio in SIS may be used to discern the origin of sea ice from the Kara-Laptev Sea and the Alaskan shelf. However, if the (240)Pu/(239)Pu atom ratio is similar to global fallout, it does not provide a unique diagnostic indicator of the source area, and in such cases, the source of SIS can be constrained with a combination of the (137)Cs and (239,240)Pu activities. Therefore, these anthropogenic radionuclides can be used in many instances to determine the geographical source area of sea-ice.

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

    PubMed

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

    2011-11-01

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

  15. Pu, 137Cs and excess 210Pb in Russian Arctic sediments

    NASA Astrophysics Data System (ADS)

    Baskaran, M.; Asbill, Shaunna; Santschi, Peter; Brooks, James; Champ, Michael; Adkinson, Dan; Colmer, Matthew R.; Makeyev, Vyacheslav

    1996-05-01

    The activity ratios of Pu and radiocesium isotopes have been used to delineate the major sources (such as global and close-in (debris) fallout, nuclear fuel reprocessing and fabrication plant effluents) in the environment. We have measured 238Pu, 239,240Pu, 137Cs, and excess 210Pb concentrations in 107 surficial sediments as well as in 5 sediment cores collected in the summer months of 1993 and 1994 from the Ob and Yenisey Rivers (Russia) and the Kara sea. A comparison of the sediment core inventories of 239,240Pu and 137Cs, along with the 238Pu/ 239,240Pu activity ratios, with those expected from global fallout allows us to estimate the relative amounts, if any, of reactor-derived 238Pu and 239,240Pu from the dumped reactor sites in the study area. In surficial sediment samples collected in 1993 and 1994, the 239,240Pu concentrations varied between 4.2 and 856 mBq kg -1, with a mean of 239 mBq kg -1. In samples with a measurable 238Pu, the 238Pu/ 239,240Pu activity ratios varied between 0.010 and 0.069, with an average value of 0.035 ± 0.014. This range can be compared to the average 238Pu/ 239,240Pu activity ratio of 0.030 for the year 1993 from nuclear weapons testing and SNAP fallout obtained from soil studies, indicating very little (≤ 5%) additional sources of 238Pu to the sediments in the study area. The inventories of Pu in the 5 sediment cores from the study area varied between 2.67 ± 0.67 and 24.5 ± 2.2 Bq m -2 with a mean value of 8.83 Bq m -2. The 137Cs concentrations in the upper 3 cm of the sediments varied between below detection limit to 71.4 Bq kg -1, with a mean of 14.9 Bq kg -1. The 137Cs inventories in the 5 sediment cores varied between 156.7 ± 28.3 and 1600 ± 153.3 Bq m -2, with a mean value of 583.3 Bq m -2. The mean ratio of inventories of Pu to that of 137Cs, 0.015, is comparable to the values in other places in the Arctic region. There is a significant correlation between total organic carbon and concentrations of 137Cs, 239,240Pu

  16. Experimental detection of alpha-particles from the radioactive decay of natural bismuth.

    PubMed

    de Marcillac, Pierre; Coron, Noël; Dambier, Gérard; Leblanc, Jacques; Moalic, Jean-Pierre

    2003-04-24

    The only naturally occurring isotope of bismuth, 209Bi, is commonly regarded as the heaviest stable isotope. But like most other heavy nuclei abundant in nature and characterized by an exceptionally long lifetime, it is metastable with respect to alpha-decay. However, the decay usually evades observation because the nuclear structure of 209Bi gives rise to an extremely low decay probability and, moreover, generates low-energy alpha-particles difficult to detect. Indeed, dedicated experiments attempting to record the alpha-decay of 209Bi in nuclear emulsions failed. However, scintillating bolometers operated at temperatures below 100 mK offer improved detection efficiency and sensitivity, whereas a broad palette of targets could be available. Here we report the successful use of this method for the unambiguous detection of 209Bi alpha-decay in bismuth germanate detectors cooled to 20 mK. We measure an energy release of 3,137 +/- 1 (statistical) +/- 2 (systematic) keV and a half-life of (1.9 +/- 0.2) x 10(19) yr, which are in agreement with expected values.

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

    NASA Astrophysics Data System (ADS)

    Ketterer, Michael E.; Szechenyi, Scott C.

    2008-07-01

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

  18. Stations VZD and VZE: composition of ending inventory reports

    SciTech Connect

    Not Available

    1984-02-10

    The inventory of the following materials at stations VZD and VZE is given: depleted uranium; enriched uranium; /sup 242/Pu; /sup 241/Am; /sup 243/Am; curium; berkelium; californium; plutonium; lithium; /sup 233/U, normal uranium; neptunium; /sup 238/Pu; deuterium; tritium; and thorium.

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

    SciTech Connect

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

    1989-12-01

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

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

    PubMed

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

    2014-05-01

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

  1. The High Altitude Sampling Program: Radioactivity in the stratosphere: Final report

    SciTech Connect

    Leifer, R; Juzdan, Z R

    1986-12-01

    Radioactivity data are presented from Project Airstream (aircraft) for the year 1983 and for Project Ashcan (balloon) for the years 1982 and 1984. Due to budgetary constraints both Projects Airstream and Ashcan have been terminated. This will be the final report containing radioactivity data collected during projects airstream and ashcan. Included are gross gamma, gamma spectral and radiochemical analyses of filter samples. Quality control samples submitted along with the air filter samples were analyzed and the results are presented. Low activity on many of the filters precludes the estimation of the stratospheric inventories of /sup 239,240/Pu and /sup 90/Sr. Based on data with count errors <20%, the mean Northern Hemisphere stratospheric /sup 90/Sr and /sup 239,240/Pu concentration for November 1983 was 0.2 +- 0.1 and 0.009 +- 0.006 Bq/1000 scm, respectively.

  2. 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.

  3. Plutonium and americium inventories in atmospheric fallout and sediment cores from Blelham Tarn, Cumbria (UK).

    PubMed

    Michel, H; Barci-Funel, G; Dalmasso, J; Ardisson, G; Appleby, P G; Haworth, E; El-Daoushy, F

    2002-01-01

    The objective of this paper is to report on the results of a study of 238Pu, 239 + 240Pu and 241Am inventories onto Blelham Tarn in Cumbria (UK). The atmospheric fallout inventory was obtained by analysing soil cores and the results are in good agreement with the literature: 101 Bq m(-2) for 239 + 240Pu; 4.5 Bq m(-2) for 238Pu and 37 Bq m(-2) for 241Am. The sediment core inventory for the whole lake is compared to the atmospheric fallout inventory. The sediment activity is 60-80% higher than the estimated fallout activity, showing a catchment area contribution and in particular the stream input.

  4. Presence of plutonium contamination in soils from Palomares (Spain).

    PubMed

    Jiménez-Ramos, M C; García-Tenorio, R; Vioque, I; Manjón, G; García-León, M

    2006-08-01

    More than 30 years after the occurrence of an aircraft accident which involved the detonation of two nuclear weapons in the surrounding area of the village of Palomares (Spain), the affected terrestrial area has been investigated for remaining transuranic contamination. Evidence from the presence of this contamination was initially found through the analysis of the 241Am inventories in superficial soil samples collected in the region, and was confirmed through the analysis of the (239+240)Pu inventories and their associated 238Pu/(239+240)Pu activity ratios in the same samples. However, it was also observed that a considerable fraction of the remaining contamination in the area was present in particulate form, i.e. as "hot particles". The work performed in our laboratory for identification, isolation and characterisation of these "hot particles" as well as some conclusions obtained from these analyses are outlined in this paper.

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

    PubMed

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

    2008-03-01

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

  6. First results on 236U levels in global fallout.

    PubMed

    Sakaguchi, A; Kawai, K; Steier, P; Quinto, F; Mino, K; Tomita, J; Hoshi, M; Whitehead, N; Yamamoto, M

    2009-07-01

    The global fallout (236)U level in soil was deduced from measurements of (236)U, (239+240)Pu and (137)Cs in surface soils which are solely influenced by global fallout. A total of 12 soil cores from the depths of 0-10, 0-20 and 0-30 cm were collected at a flat forest area in Japan. Concentrations of (239+240)Pu and (238)U were determined by alpha-particle spectrometry, while the (236)U/(238)U ratio was measured with accelerator mass spectrometry (AMS). Consistent (236)U/(239)Pu ratios between 0.212 and 0.253 were found. Using this ratio, the total global fallout of (236)U on the earth is estimated to be as much as ca. 900 kg. This knowledge will contribute to the promotion of research on U isotopes, including (236)U, for the fields of geo-resources, waste management and geochemistry.

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

    NASA Astrophysics Data System (ADS)

    Ketterer, Michael; Moan, Matthew; Gremillion, Paul

    2010-05-01

    Lead and copper smelting has been conducted at El Paso since the late 1800's, and as a result, environmental media near the smelter have become contaminated. A study has been conducted to investigate the sources and spatial distribution of metal pollutants (Pb, Cd, Zn, Hg, As, Cu) and concomitant tracers (Ag, In, Sb, Bi) in soils from the smelter vicinity. Sampled locations were residential and non-residential locations in El Paso (Texas, USA), Anapra (New Mexico, USA) and Ciudad Juarez (Chihuahua, Mexico). Lead isotope studies indicate that the soil Pb is derived from smelting, and is consistent with two-component mixing between lead ores from Chihuahua (northern Mexico) having 206Pb/204Pb of 18.6 - 18.8 and ores from the Hanover, New Mexico (USA) mining district with 206Pb/204Pb of ~ 17.6. The Pb isotope results also exclude other common anthropogenic Pb sources such as paint and gasoline emissions as being major contributors. Concentrations of Hg and Pb of up to 10 and 11,000 ppm were found in surface soils within 1 km of the smelter. The metal concentration results clearly indicate that soils near the smelter (< 5 km) exhibit much higher concentrations of smelter-related elements than do soils from control locations (> 10 km distant). A general trend of decreasing concentrations vs. distance from the smelter was also observed. However, the results indicate that metal concentrations vary widely even at a fixed distance from the smelter point source. This phenomenon results from a combination of natural and anthropogenic processes that disturb and re-distribute soils in the surface environment. The site conditions consist of a very arid environment with little vegetation cover that is frequently disturbed by high winds and severe episodic rainfall. To study these effects, we have investigated stratospheric fallout plutonium (239+240Pu) as a proxy measure of disturbed vs. undisturbed soil conditions. The premise is that 'undisturbed' locations will have high 239+240

  8. Pu and Am determination in the environment—method development

    NASA Astrophysics Data System (ADS)

    Afonin, M.; Simonoff, M.; Donard, O.; Michel, H.; Ardisson, G.

    2003-01-01

    A high resolution inductively coupled plasma mass spectrometric (HR-ICP-MS) method for the determination of plutonium isotopes, Am and the 240Pu/239Pu isotope ratio utilising modification of Pu-02-RC Plutonium in Soil Samples, Pu-03-RC Plutonium in Soil Residue—Total Dissolution Method, Pu-11-RC Plutonium Purification—Ion Exchange Technique, Pu-12-RC Plutonium and/or Americium in Soil or Sediments, HASL-300 was developed. Total plutonium concentrations (239+240Pu) measured in environmental samples by this HR-ICP-MS method were in good agreement with recommended data obtained from a-spectrometry. It was achieved the decreasing of the time to analyze the samples over than 33%.

  9. Radionuclide Concentrations in Honey Bees from Area G at TA-54 during 1998

    SciTech Connect

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

    1999-06-01

    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 Jemez Springs, NM. Samples were analyzed for various radionuclides. Area G sample results from both colonies were higher than the upper (95%) level background concentration for {sup 239,240}Pu, {sup 3}H, and total uranium. Sample results from one colony were higher than the upper (95%) level background concentration for {sup 238}Pu.

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

    PubMed

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

    2014-12-02

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

  11. Accumulation of atmospheric radionuclides and heavy metals in cryoconite holes on an Arctic glacier.

    PubMed

    Łokas, Edyta; Zaborska, Agata; Kolicka, Małgorzata; Różycki, Michał; Zawierucha, Krzysztof

    2016-10-01

    Surface of glaciers is covered by mineral and organic dust, together with microorganisms forming cryoconite granules. Despite fact that glaciers and ice sheets constitute significance part of land surface, reservoir of freshwater, and sites of high biological production, the knowledge on the cryoconite granules still remain unsatisfactory. This study presents information on radionuclide and heavy metal contents in cryoconites. Cryoconites collected from the Hans Glacier in SW Spitsbergen reveal high activity concentrations of anthropogenic ((238,239,240)Pu, (137)Cs, (90)Sr) and natural ((210)Pb) radionuclides. The (238)Pu/(239+240)Pu activity ratios in these cryoconites significantly exceed the mean global fallout ratio (0.025). The (238)Pu/(239+240)Pu ranged from 0.064 to 0.118. The (239+240)Pu/(137)Cs varied from 0.011 ± 0.003 to 0.030 ± 0.007. Such activity ratios as observed in these cryoconites were significantly higher than the values characterizing global fallout, pointing to possible contributions of these radionuclides from other sources. Heavy metals (Pb, Cd, Cu, Zn, Fe, and Mn) in cryoconites exceed both UCC concentrations and local rocks' concentrations, particularly for cadmium. The concentration ratios of stable lead isotopes ((206)Pb/(207)Pb, (208)Pb/(206)Pb) were determined to discriminate between the natural and anthropogenic sources of Pb in cryoconites and to confirm the strong anthropogenic contribution to heavy metal deposition in the Arctic. In investigated cryoconite holes, two groups of invertebrates, both extremophiles, Tardigrada and Rotifera were detected. Our study indicate that cryoconites are aggregates of mineral and organic substances on surfaces of glaciers are able to accumulate large amounts of airborne pollutants bound to extracellular polymeric substances secreted by microorganisms.

  12. Werner-Wheeler mass tensor for fusionlike configuration

    SciTech Connect

    Gherghescu, R.A.; Poenaru, D.N.

    2005-08-01

    The Werner-Wheeler approach is used to calculate the components of the mass tensor for a binary configuration of two intersected spheroids. Four free coordinates form the deformation space: the small semiaxis of the projectile, the two semiaxis ratios of the spheroids, and the distance between centers. A correction term is also calculated, due to the center of mass motion. Final results are presented for the fusion channel {sup 54}Cr+{sup 240}Pu, and all possible couplings are analyzed.

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

    PubMed

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

    2015-04-01

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

  14. Analysis of core soil and water samples from the Cactus Crater Disposal Site at Enewetak atoll

    SciTech Connect

    Robison, W.L.; Noshkin, V.E.

    1981-02-18

    Core soil samples and water samples were collected from the Cactus Crater Disposal Site at Enewetak for analysis of /sup 137/Cs, /sup 90/Sr, /sup 239 +240/Pu and /sup 241/Am by both gamma spectroscopy and, through a contractor laboratory, by wet chemistry procedures. The samples processing methods, the analytical methods and the analytical quality control are all procedures developed for the continuing Marshall Island radioecology and dose assessment work.

  15. Biogeochemical studies of long-lived radionuclides in marine environments

    SciTech Connect

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

    1985-01-01

    Research results from several studies relevant to seabed dispoal of radioactive wastes are briefly discussed. The studies include: (1) mobilization of plutonium from Enewetak and Bikini lagoon sediments to seawater; (2) concentrations of /sup 90/Sr, /sup 137/Cs, /sup 239+240/Pu, /sup 241/Am, /sup 207/Bi and /sup 210/Pb-/sup 210/Bi-/sup 210/Po in fish from the Marshall Islands; and (3) plutonium in northeast Atlantic sediments. (ACR)

  16. Behaviour and transport of radionuclides in soil and vegetation of a sand dune ecosystem.

    PubMed

    Copplestone, D; Johnson, M S; Jones, S R

    2001-01-01

    A sand dune ecosystem in the vicinity of the British Nuclear Fuels reprocessing plant at Sellafield, Cumbria, UK was used to examine the spatial, temporal and depth distributions of 134Cs, 137Cs, 238Pu, 239 + 240Pu and 241Am in soil and in two species of vegetation (Festuca rubra, Ammophila arenaria). Core samples showed evidence of the accumulation of radionuclides derived mainly from sea-to-land transfer. Accumulated deposits of radioactivity (0-0.1 m) lie within the range: 1.1-3.4 Bq kg-1 (134Cs), 260-440 Bq kg-1 (137Cs), 31-40 Bq kg-1 (238Pu), 150-215 Bq kg-1 (239 + 240Pu) and 190-240 Bq kg-1 (241Am). Soil profiles showed greater activity concentrations in their deeper regions and this is attributed to leaching of radionuclides in percolating drainage water accentuated by the coarse texture, low organic matter and clay mineral content of coastal sands. Radionuclide activity concentrations in F. rubra and A. arenaria were similar, in the ranges 20-70 Bq kg-1 (137Cs), 1-5 Bq kg-1 (238Pu), 10-30 Bq kg-1 (239 + 240Pu) and 10-65 Bq kg-1 (241Am). Clear temporal and spatial variations were observed in both species of vegetation, reflecting the weather conditions antecedent to the sampling period and the influence of sea-to-land transfer. Concentration ratios (vegetation:soil) for activity concentrations in the two species were similar, in the ranges: 0.05-0.14 (137Cs), 0.025-0.097 (238Pu), 0.022-0.057 (239 + 240Pu) and 0.025-0.212 (241Am).

  17. Isotopic compositions of (236)U and Pu isotopes in "black substances" collected from roadsides in Fukushima prefecture: fallout from the Fukushima Dai-ichi nuclear power plant accident.

    PubMed

    Sakaguchi, Aya; Steier, Peter; Takahashi, Yoshio; Yamamoto, Masayoshi

    2014-04-01

    Black-colored road dusts were collected in high-radiation areas in Fukushima Prefecture. Measurement of (236)U and Pu isotopes and (134,137)Cs in samples was performed to confirm whether refractory elements, such as U and Pu, from the fuel core were discharged and to ascertain the extent of fractionation between volatile and refractory elements. The concentrations of (134,137)Cs in all samples were exceptionally high, ranging from 0.43 to 17.7 MBq/kg, respectively. (239+240)Pu was detected at low levels, ranging from 0.15 to 1.14 Bq/kg, and with high (238)Pu/(239+240)Pu activity ratios of 1.64-2.64. (236)U was successfully determined in the range of (0.28 to 6.74) × 10(-4) Bq/kg. The observed activity ratios for (236)U/(239+240)Pu were in reasonable agreement with those calculated for the fuel core inventories, indicating that trace amounts of U from the fuel cores were released together with Pu isotopes but without large fractionation. The quantities of U and (239+240)Pu emitted to the atmosphere were estimated as 3.9 × 10(6) Bq (150 g) and 2.3 × 10(9) Bq (580 mg), respectively. With regard to U, this is the first report to give a quantitative estimation of the amount discharged. Appreciable fractionation between volatile and refractory radionuclides associated with the dispersal/deposition processes with distance from the Fukushima Dai-ichi Nuclear Power Plant was found.

  18. Solubility of hot fuel particles from Chernobyl--influencing parameters for individual radiation dose calculations.

    PubMed

    Garger, Evgenii K; Meisenberg, Oliver; Odintsov, Oleksiy; Shynkarenko, Viktor; Tschiersch, Jochen

    2013-10-15

    Nuclear fuel particles of Chernobyl origin are carriers of increased radioactivity (hot particles) and are still present in the atmosphere of the Chernobyl exclusion zone. Workers in the zone may inhale these particles, which makes assessment necessary. The residence time in the lungs and the transfer in the blood of the inhaled radionuclides are crucial for inhalation dose assessment. Therefore, the dissolution of several kinds of nuclear fuel particles from air filters sampled in the Chernobyl exclusion zone was studied. For this purpose filter fragments with hot particles were submersed in simulated lung fluids (SLFs). The activities of the radionuclides (137)Cs, (90)Sr, (239+240)Pu and (241)Am were measured in the SLF and in the residuum of the fragments by radiometric methods after chemical treatment. Soluble fractions as well as dissolution rates of the nuclides were determined. The influence of the genesis of the hot particles, represented by the (137)Cs/(239+240)Pu ratio, on the availability of (137)Cs was demonstrated, whereas the dissolution of (90)Sr, (239+240)Pu and (241)Am proved to be independent of genesis. No difference in the dissolution of (137)Cs and (239+240)Pu was observed for the two applied types of SLF. Increased solubility was found for smaller hot particles. A two-component exponential model was used to describe the dissolution of the nuclides as a function of time. The results were applied for determining individual inhalation dose coefficients for the workers at the Chernobyl construction site. Greater dose coefficients for the respiratory tract and smaller coefficients for the other organs were calculated (compared to ICRP default values). The effective doses were in general lower for the considered radionuclides, for (241)Am even by one order of magnitude.

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

    NASA Astrophysics Data System (ADS)

    Utyonkov, V. K.; Brewer, N. T.; Oganessian, Yu. Ts.; Rykaczewski, K. P.; Abdullin, F. Sh.; Dmitriev, S. N.; Grzywacz, R. K.; Itkis, M. G.; Miernik, K.; Polyakov, A. N.; Roberto, J. B.; Sagaidak, R. N.; Shirokovsky, I. V.; Shumeiko, M. V.; Tsyganov, Yu. S.; Voinov, A. A.; Subbotin, V. G.; Sukhov, A. M.; Sabel'nikov, A. V.; Vostokin, G. K.; Hamilton, J. H.; Stoyer, M. A.; Strauss, S. Y.

    2015-09-01

    Irradiations of 239Pu and 240Pu targets with 48Ca beams aimed at the synthesis of Z =114 flerovium isotopes were performed at the Dubna Gas Filled Recoil Separator. A new spontaneously fissioning (SF) isotope 284Fl was produced for the first time in the 240Pu+48Ca (250 MeV) and 239Pu+48Ca (245 MeV) reactions. The cross section of the 239Pu(48Ca,3 n )284Fl reaction channel was about 20 times lower than predicted by theoretical models and about 50 times lower than the maximum fusion-evaporation cross section for the 3 n and 4 n channels measured in the 244Pu+48Ca reaction. In the 240Pu+48Ca experiment, performed at 245 MeV in order to maximize the 3 n -evaporation channel, three decay chains of 285Fl were detected. The α -decay energy of 285Fl was measured for the first time and decay properties of its descendants 281Cn, 277Ds, 273Hs, 269Sg, and 265Rf were determined with higher accuracy. The assignment of SF events observed during the irradiation of the 240Pu target with a 250 MeV 48Ca beam to 284Fl decay is presented and discussed. The cross sections at both 48Ca energies are similar and exceed that observed in the reaction with the lighter isotope 239Pu by a factor of 10. The decay properties of the synthesized nuclei and their production cross sections indicate a rapid decrease of stability of superheavy nuclei as the neutron number decreases from the predicted magic neutron number N =184 .

  20. OPERATIONS TOGGLE, ARBOR and BEDROCK Events: DIAMOND SCULLS, DIDO QUEEN, HUSKY ACE, MING BLADE, HYBLA FAIR and DINING CAR, 20 July 1972 - 5 April 1975

    DTIC Science & Technology

    1987-11-30

    58m co 58 Co 60 iOpp8r ( 29 ) . . . . . . . . . . . . . Cu 64 Curium (96, . . . . . . . . . . . . . Cm 242 Cm 243 Cm 244 Cm 245 Cm 246...was conducted in the LOS pipe. 242 On 12 April (D+7), miners continued to prepare the tunnel for experiment recovery. Work also continued in...Pt 191 Pt 193m Pt 197m Pt 197 Plutonium (94) . . . . . . . . . . Pu 236 Pu 239 Pu 240 Pu 241 Pu 242 Polonium (84

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

    PubMed

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

    2004-01-01

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

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

    PubMed

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

    2014-08-19

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

  3. Resonance Region Nuclear Data Analysis to Support Advanced Fuel Cycle Development

    SciTech Connect

    Dunn, Michael E; Derrien, Herve; Leal, Luiz C; Gil, Choong-Sup; Kim, D.

    2011-01-01

    The Oak Ridge National Laboratory (ORNL) and the Korean Atomic Energy Research Institute (KAERI) are performing collaborative research as part of a three-year United States (U.S.) / Republic of Korea (ROK) International Nuclear Energy Research Initiative (I-NERI) project to provide improved neutron cross-section data with uncertainty or covariance data important for advanced fuel cycle and nuclear safeguards applications. ORNL and KAERI have initiated efforts to prepare new cross-section evaluations for 240Pu, 237Np, and the stable Cm isotopes. At the current stage of the I-NERI project, ORNL has recently completed a preliminary resonance-region cross-section evaluation with covariance data for 240Pu and initiated resonance evaluation efforts for 237Np and 244Cm. Likewise, KAERI is performing corresponding high-energy cross-section analyses (i.e., above the resonance region) for the noted isotopes. The paper provides results pertaining to the new resonance region evaluation efforts with emphasis on the new 240Pu evaluation.

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

    PubMed

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

    2012-04-01

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

  5. Tritium and plutonium in waters from the Bering and Chukchi Seas

    USGS Publications Warehouse

    Landa, E.R.; Beals, D.M.; Halverson, J.E.; Michel, R.L.; Cefus, G.R.

    1999-01-01

    During the summer of 1993, seawater in the Bering and Chukchi Seas was sampled on a joint Russian-American cruise [BERPAC] of the RV Okean to determine concentrations of tritium, 239Pu and 240Pu. Concentrations of tritium were determined by electrolytic enrichment and liquid scintilation counting. Tritium levels ranged up to 420 mBq L-1 showed no evidence of inputs other than those attribute atmospheric nuclear weapons testing. Plutonium was recovered from water samples by ferric hydroxide precipitation, and concentrations were determined by thermal ionization mass spectrometry. 239+240Pu concentrations ranged from <1 to 5.5 [mu]Bq L-1. These concentrations are lower than those measured in water samples from other parts of the ocean during the mid-1960's to the late 1980's. The 240Pu:239Pu ratios, although associated with large uncertainties, suggest that most of the plutonium is derived from world-wide fallout. As points of comparison, the highest concentrations of tritium and plutonium observed here were about five orders of magnitude lower than the maximum permissible concentrations allowed in water released to the off-site environs from licensed nuclear facilities in the United States. This study and others sponsored by the International Atomic Energy Agency and the Office of Naval Research's Arctic Nuclear Waste Assessment Program are providing data for the assessment of potential radiological impacts in the Arctic regions associated with nuclear waste disposal by the former Soviet Union.

  6. 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.

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

    PubMed Central

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

    2011-01-01

    The vertical distribution of the 236U/238U isotopic ratio was investigated in soil samples from three different locations on La Palma (one of the seven Canary Islands, Spain). Additionally the 240Pu/239Pu atomic ratio, as it is a well establish tool for the source identification, was determined. The radiochemical procedure consisted of a U separation step by extraction chromatography using UTEVA® Resin (Eichrom Technologies, Inc.). Afterwards Pu was separated from Th and Np by anion exchange using Dowex 1x2 (Dow Chemical Co.). Furthermore a new chemical procedure with tandem columns to separate Pu and U from the matrix was tested. For the determination of the uranium and plutonium isotopes by alpha spectrometry thin sources were prepared by microprecipitation techniques. Additionally these fractions separated from the soil samples were measured by Accelerator Mass Spectrometry (AMS) to get information on the isotopic ratios 236U/238U, 240Pu/239Pu and 236U/239Pu, respectively. The 236U concentrations [atoms/g] in each surface layer (∼2 cm) were surprisingly high compared to deeper layers where values around two orders of magnitude smaller were found. Since the isotopic ratio 240Pu/239Pu indicated a global fallout signature we assume the same origin as the probable source for 236U. Our measured 236U/239Pu value of around 0.2 is within the expected range for this contamination source. PMID:21481502

  8. Deposition of artificial radionuclides from atmospheric Nuclear Weapon Tests estimated by soil inventories in French areas low-impacted by Chernobyl.

    PubMed

    Le Roux, Gaël; Duffa, Céline; Vray, Françoise; Renaud, Philippe

    2010-03-01

    Soil inventories of anthropogenic radionuclides were investigated in altitudinal transects in 2 French regions, Savoie and Montagne Noire. Rain was negligible in these 2 areas the days after the Chernobyl accident. Thus anthropogenic radionuclides are coming hypothetically only from Global Fallout following Atmospheric Nuclear Weapon Tests. This is confirmed by the isotopic signatures ((238)Pu/(239+240)Pu; (137)Cs/(239+240)Pu; and (241)Am/(239+240)Pu) close to Global Fallout value. In Savoie, a peat core age-dated by (210)Pb(ex) confirmed that the main part of deposition of anthropogenic radionuclides occurred during the late sixties and the early seventies. In agreement with previous studies, the anthropogenic radionuclide inventories are well correlated with the annual precipitations. However, this is the first time that a study investigates such a large panel of annual precipitation and therefore of anthropogenic radionuclide deposition. It seems that at high-altitude sites, deposition of artificial radionuclides was higher possibly due to orographic precipitations.

  9. Isotopic composition and distribution of plutonium in northern South China Sea sediments revealed continuous release and transport of Pu from the Marshall Islands.

    PubMed

    Wu, Junwen; Zheng, Jian; Dai, Minhan; Huh, Chih-An; Chen, Weifang; Tagami, Keiko; Uchida, Shigeo

    2014-03-18

    The (239+240)Pu activities and (240)Pu/(239)Pu atom ratios in sediments of the northern South China Sea and its adjacent Pearl River Estuary were determined to examine the spatial and temporal variations of Pu inputs. We clarified that Pu in the study area is sourced from a combination of global fallout and close-in fallout from the Pacific Proving Grounds in the Marshall Islands where above-ground nuclear weapons testing was carried out during the period of 1952-1958. The latter source dominated the Pu input in the 1950s, as evidenced by elevated (240)Pu/(239)Pu atom ratios (>0.30) in a dated sediment core. Even after the 1950s, the Pacific Proving Grounds was still a dominant Pu source due to continuous transport of remobilized Pu from the Marshall Islands, about 4500 km away, along the North Equatorial Current followed by the transport of the Kuroshio current and its extension into the South China Sea through the Luzon Strait. Using a simple two end-member mixing model, we have quantified the contributions of Pu from the Pacific Proving Grounds to the northern South China Sea shelf and the Pearl River Estuary are 68% ± 1% and 30% ± 5%, respectively. This study also confirmed that there were no clear signals of Pu from the Fukushima Daiichi Nuclear Power Plant accident impacting the South China Sea.

  10. Sediment studies at Bikini Atoll part 2. inventories of transuranium elements in surface sediments

    SciTech Connect

    Noshkin, V.E.; Eagle, R.J.; Wong, K.M.; Robison, W.L.

    1997-10-01

    This is the second of three reports on Bikini sediment studies, which discusses the concentrations and inventories of {sup 241}Am and {sup 239+240}Pu in sediments from the lagoon. Surface sediment samples were collected from 87 locations over the entire lagoon at Bikini Atoll during 1979. The collections were made to map the distribution of long-lived radionuclides associated with the bottom material and to show what modifications occurred in the composition of the sediment as a result of the testing program. Present inventories for {sup 241}Am and {sup 239+240}Pu in the surface 2 cm of sediment are estimated to be 14 and 17 TBq, respectively. These values are estimated to represent only 14% of the total inventory in the sediment column. Sediment inventories of {sup 239+240}Pu and {sup 241}Am are changing only slowly with time through chemical- physical processes that continuously mobilize small amounts of the transuranics to the water column. The lowest concentrations and inventories are associated with deposits logoonward of the eastern reef.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  12. The average number of prompt neutrons and the distributions of prompt neutron emission number for spontaneous fission of plutonium-240, curium-242, and curium-244

    SciTech Connect

    Huanqiao, Z.; Shaoming, L.; Shengyue, D.; Zuhau, L.

    1984-03-01

    (The average number of prompt neutron v /SUB p/ and the distributions of prompt neutron number probability P(v) for spontaneous fission of /sup 240/Pu, /sup 242/Cm, and /sup 244/Cm relative to v /SUB p/ (/sup 252/Cf) have been measured using a large gadolinium-loaded liquid scintillation counter with a coincidence method.)The results were v /SUB p/ (/sup 240/Pu)=2.141+ or 0.016, v /SUB p/ (/sup 242/Cm)=2.562 + or - 0.020, and v /SUB p/ (/sup 244/Cm)= 2.721 + or - 0.021. (The measured distributions of prompt neutron number were fitted with Gaussian curves by a weighted least-squares method.) The widths of Gaussian distribution are 1.149 + or - 0.047, 1.159 + or - 0.074, and 1.175 + or 0.098 for /sup 240/Pu, /sup 242/Cm, and /sup 244/Cm, respectively. (The results as well as a previous measurement of spontaneous fission of /sup 252/Cf show the linear variation of sigma with v /SUB p/ at the first order of approximation.) The data were fitted by a least-squares method, and the result is given by a sigma= 0.980+0.076v /SUB p/ . This fact demonstrates the trend that the width of the excitation energy distribution of fission fragments increases with the average excitation energy of the fission fragments in the range of nuclides mentioned above.

  13. 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.

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

    PubMed

    Everett, S E; Tims, S G; Hancock, G J; Bartley, R; Fifield, L K

    2008-02-01

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

  15. Assessment of the global fallout of plutonium isotopes and americium-241 in the soil of the central region of Saudi Arabia.

    PubMed

    Shabana, E I; Al-Shammari, H L

    2001-01-01

    A radiochemical technique for determination of plutonium isotopes and 241Am in soil samples is tested against IAEA-standard reference materials to determine its accuracy and precision for reliable results. The technique is then used in the investigation of topsoil samples, collected from the natural environment of the central region of Saudi Arabia, to assess the effect of fallout accumulation of these radionuclides in the region. Plutonium and americium were sequentially separated from all other components of the sample by anion-exchange chromatography and co-precipitated with Nd3+ as fluorides. The precipitates were mounted on membrane filters and measured using a high-resolution alpha-spectrometer. The results of the analysis of the reference materials showed satisfactory sensitivity and precision of the technique. The results of the analyzed soil samples show activity levels ranging from < LLD to 0.089 and from 240Pu, respectively. 241Am levels ranged from 240Pu and 241Am/239+240Pu activity ratios ranged from 0 to 0.216 and 0.3-1.23, respectively. A discussion based on the observed data is presented.

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

    PubMed

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

    2011-03-01

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

  17. Organic matter controls on iodine and plutonium in atmospheric depositions, streams, and soils in the Fukushima Prefecture

    NASA Astrophysics Data System (ADS)

    Xu, C.; Zhang, S.; Sugiyama, Y.; Ohte, N.; Ho, Y. F.; Fujitake, N.; Kaplan, D. I.; Yeager, C. M.; Schwehr, K. A.; Santschi, P. H.

    2015-12-01

    In order to assess how environmental factors are controlling the distribution and migration of radioiodine and plutonium that were emitted from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, we quantified iodine and 239,240Pu concentration changes in soil samples with different land uses (urban, paddy, deciduous forest and coniferous forest), as well as iodine speciation in surface water and rainwater. A ranking of the land uses by their stable 127I and by their 239,240Pu concentrations were quite distinct from that of 134,137Cs, indicating 137Cs might not be a good geochemical proxy for radioactive 129I or Pu in the long-term, post-FDNPP accident. Being a proxy for the long-term fate of 129I, soil 127I content was well correlated to soil organic matter (SOM) content, regardless of land use type, suggesting that SOM might be an important factor controlling iodine biogeochemistry. Other soil chemical properties, such as Eh and pH, had strong correlations to soil 127I content, but only within a given land use (e.g., within urban soils). Organic carbon (OC) and Eh were positively, and pH was negatively correlated to 127I concentrations in surface water and rain samples. It is also noticeable that 127I in the bulk deposition was concentrated along the rainwater passage likely due to plant evapotranspiration activity, with all inorganic iodine being completely converted to organo-iodine by plant organic matter. 239,240Pu activities of all soil samples were well within the global fallout range, but the Fukushima-derived 239,240Pu was detectable at a distance ~61 km away, NW of FDNPP. However, it is confined to the litter layer, even three years after the FDNPP accident-derived emissions. 239,240Pu activities were significantly correlated with soil OC and nitrogen contents, indicating Pu may be associated with nitrogen-containing SOM, similar to what has been observed at other locations in the United States, e.g., Savannah River Site (SRS) and Rocky Flats

  18. Using sequential extraction techniques to assess the partitioning of plutonium and neptunium-237 from multiple sources in sediments from the Ob River (Siberia).

    PubMed

    Kenna, Timothy C

    2009-07-01

    Sequential extraction techniques have been developed to assess partitioning of anthropogenic radionuclides ((240)Pu, (239)Pu, and (237)Np), originating from a variety of sources, as identified by using bulk sediment isotopic composition. Sediments were leached sequentially with a series of six chemical treatments designed to approximate different environmental processes that may occur or to selectively extract trace metals contained in different solid phases of the sediments (i.e., exchangeable, reducible, carbonate, organic, acid leachable, and refractory). Results indicate the majority of Pu and Np is similarly distributed within many of the extracted fractions, with the largest percentage (66-97%) of both elements being observed in sediments treated with buffered citrate dithionite (CDB), which targets easily reduced constituents such as Mn and Fe hydrous oxides. While these results do indicate an association of Pu and Np with redox sensitive elements, the environmental implications are unclear given that the CDB treatment is more extreme than naturally occurring conditions. Minor amounts of Np partition differently from Pu in sediments. The NH(4)-acetate treatment, which is designed to liberate trace metals that are loosely adsorbed onto the surfaces of sedimentary materials such as hydrated iron oxides and humic substances, or present at exchangeable sites in clay minerals, mobilized approximately 12% of the total Np while Pu levels were below detection. The H(2)O(2) treatment, which is designed to liberate trace metals bound to organic matter, mobilized approximately 8 and approximately 1% of Np and Pu, respectively. These results indicate that a minor portion of the total Np may be affected by environmental conditions that have little or no effect on Pu. Between 7 and 24% of the Pu was observed in treatments designed to liberate Pu and Np that are tightly bound to lithogenic phases or refractory silicates. The (240)Pu/(239)Pu observed in accessible and

  19. Method for the preparation of radon-211. [Patent application

    DOEpatents

    Meyer, G.J.; Lambrecht, R.M.

    1980-10-10

    A method is claimed for the production of /sup 211/Rn which can be easily isolated from the target and obtained in high yields. It is claimed that the radioisotope /sup 211/Rn can be prepared by the bombardment of /sup 209/Bi with /sup 7/Li particles using the nuclear reaction /sup 209/Bi(/sup 7/Li,5n)/sup 211/Rn. The /sup 211/Rn can be isolated from the target quite easily by degassing at elevated temperatures and the radiochemical purity of the product is better than 98%. It can thus be used as a generator system for /sup 211/At which is of potential interest in biomedical applications. The excitation function for this reaction is about from 40 to 60 MeV and the cross section for /sup 211/Rn production reaches 650 mb at 53 MeV producing a saturation yield of 5.5 ..mu..Ci/nA.

  20. Studies of heavy ion reactions and transuranic nuclei. Progress report, August 1, 1979-July 31, 1980. [Univ. of Rochester, New York, 8/1/79-7/31/80

    SciTech Connect

    Huizenga, J.R.

    1980-07-01

    The study of heavy-ion reaction mechanisms at the SuperHILAC and LAMPF is reported. Preprints of five articles and manuscripts of four recent conference papers are given, along with complete citations of publications and a list of personnel. Significant work was performed in the following areas: the bombarding energy dependence of the /sup 209/Bi + /sup 136/Xe reaction; the fragment yields for specific Z and A for projectile-like fragments produced in the reaction of 8.3-MeV/u /sup 56/Fe ions with targets of /sup 56/Fe, /sup 165/Ho, /sup 209/Bi, and /sup 238/U; and time distributions of fragments from delayed fission after muon capture for muonic /sup 235/U, /sup 238/U, /sup 237/Np, /sup 239/Pu, and /sup 242/Pu. (RWR)

  1. Asymptotic and near-target direct breakup of 6Li and 7Li

    NASA Astrophysics Data System (ADS)

    Kalkal, Sunil; Simpson, E. C.; Luong, D. H.; Cook, K. J.; Dasgupta, M.; Hinde, D. J.; Carter, I. P.; Jeung, D. Y.; Mohanto, G.; Palshetkar, C. S.; Prasad, E.; Rafferty, D. C.; Simenel, C.; Vo-Phuoc, K.; Williams, E.; Gasques, L. R.; Gomes, P. R. S.; Linares, R.

    2016-04-01

    Background: Li,76 and 9Be are weakly bound against breakup into their cluster constituents. Breakup location is important for determining the role of breakup in above-barrier complete fusion suppression. Recent works have pointed out that experimental observables can be used to separate near-target and asymptotic breakup. Purpose: Our purpose is to distinguish near-target and asymptotic direct breakup of Li,76 in reactions with nuclei in different mass regions. Method: Charged particle coincidence measurements are carried out with pulsed Li,76 beams on 58Ni and 64Zn targets at sub-barrier energies and compared with previous measurements using 208Pb and 209Bi targets. A detector array providing a large angular coverage is used, along with time-of-flight information to give definitive particle identification of the direct breakup fragments. Results: In interactions of 6Li with 58Ni and 64Zn, direct breakup occurs only asymptotically far away from the target. However, in interactions with 208Pb and 209Bi, near-target breakup occurs in addition to asymptotic breakup. Direct breakup of 7Li into α -t is not observed in interactions with 58Ni and 64Zn. However, near-target dominated direct breakup was observed in measurements with 208Pb and 209Bi. A modified version of the Monte Carlo classical trajectory model code platypus, which explicitly takes into account lifetimes associated with unbound states, is used to simulate sub-barrier breakup reactions. Conclusions: Near-target breakup in interactions with Li,76 is an important mechanism only for the heavy targets 208Pb and 209Bi. There is insignificant near-target direct breakup of 6Li and no direct breakup of 7Li in reactions with 58Ni and 64Zn. Therefore, direct breakup is unlikely to suppress the above-barrier fusion cross section in reactions of Li,76 with 58Ni and 64Zn nuclei.

  2. Dry-distillation of astatine-211 from irradiated bismuth targets: a time-saving procedure with high recovery yields.

    PubMed

    Lindegren, S; Bäck, T; Jensen, H J

    2001-08-01

    Astatine-211 was produced via the 209Bi(alpha,2n) 211At reaction. The radionuclide was isolated with a novel procedure employing dry-distillation of the irradiated target material. The astatine was condensed as a dry residue in a PEEK-capillary cryotrap. Distillation was completed within 1-2 min with isolation yields of 92 +/- 3%. Subsequent work-up of the nuclide resulted in final recovery yields of 79 +/- 3%.

  3. Alternating parity structure in doubly odd /sup 218/Ac

    SciTech Connect

    Debray, M.E.; Davidson, M.; Kreiner, A.J.; Davidson, J.; Falcone, G.; Hojman, D.; Santos, D.

    1989-03-01

    States in doubly odd /sup 218/Ac have been studied using in-beam ..cap alpha..-, ..gamma..-, and e/sup -/-spectroscopy techniques mainly through the /sup 209/Bi(/sup 12/C,3n)= fusion-evaporation reaction. /sup 218/Ac shows a band structure, with interleaved states of alternating parities connected by enhanced B(E1) transitions, which is strikingly similar to the one in its isotone /sup 217/Ra.

  4. Estimating total fusion cross sections by using a coupled-channel method

    NASA Astrophysics Data System (ADS)

    Choi, Ki-Seok; Cheoun, Myung-Ki; Kim, K. S.; Kim, T. H.; So, W. Y.

    2017-01-01

    We calculate the total fusion cross sections for the 6He + 209Bi, 6Li + 209Bi,9Be + 208Pb, 10Be + 209Bi, and 11Li + 208Pb systems by using a coupled-channel (CC) method and compare the results with the experimental data. In the CC approach for the total fusion cross sections, we exploit a globally determined Wood-Saxon potential with Akyüz-Winther parameters and couplings of the ground state to the low-lying excited states in the projectile and the target nuclei. The total fusion cross sections obtained with the CC are compared with those obtained without the CC couplings. The latter approach is tantamount to a one-dimensional barrier penetration model. Finally, our approach is applied to understand new data for the 11Li+208Pb system. Possible ambiguities inherent in those approaches are discussed in detail for further applications to the fusion system of halo and/or neutron-rich nuclei.

  5. Fission cross section measurements of actinides at LANSCE

    SciTech Connect

    Tovesson, Fredrik; Laptev, Alexander B; Hill, Tony S

    2010-01-01

    Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications. By combining measurement at two LANSCE facilities, Lujan Center and the Weapons Neutron Research center (WNR), differential cross sections can be measured from sub-thermal energies up to 200 MeV. Incident neutron energies are determined using the time-of-flight method, and parallel-plate ionization chambers are used to measure fission cross sections relative to the {sup 235}U standard. Recent measurements include the {sup 233,238}U, {sup 239,242}Pu and {sup 243}Am neutron-induced fission cross sections. In this paper preliminary results for cross section data of {sup 243}Am and {sup 233}U will be presented.

  6. Laser-optical studies of the spontaneous-fission isomer /sup 240m/Am

    SciTech Connect

    Beene, J.R.; Bemis, C.E. Jr.; Kramer, S.D.; Young, J.P.

    1982-01-01

    Improved optical pumping experiments on the /sup 240m/Am fission isomer have been performed using the Laser Induced Nuclear Polarization (LINUP) technique. Results of these experiments are discussed in terms of the constraints they place on the spectroscopic properties of /sup 240m/Am. In addition, a quantitative analysis of the isomer shift in terms of nuclear shape is undertaken making use of recent muonic x-ray data on /sup 241/Am and /sup 243/Am.

  7. Study of the fission isomer 240mAm (S. F. ) using laser-induced nuclear polarization. [Cross section of 238U(7Li,5n) at 48 MeV

    SciTech Connect

    Beene, J. R.; Bemis, Jr., C. E.; Young, J. P.; Kramer, S. D.

    1980-01-01

    The optical isomer shift was measured for the spontaneously fissioning isomer /sup 240m/Am. This shift is approximately 27 times greater than the /sup 241/Am-/sup 243/Am isotope shift, and confirms the conventional identification of fission isomers with large deformation. The measured isomer shift is consistent with a nuclear quadrupole moment of 30.4 b, in agreement with theoretical expectations. 2 figures. (RWR)

  8. Total and spontaneous fission half-lives of the americium and curium nuclides

    SciTech Connect

    Holden, N.E.

    1984-01-01

    The total half-life and the half-life for spontaneous fission are evaluated for the various long-lived nuclides of interest. Recommended values are presented for /sup 241/Am, /sup 242m/Am, /sup 243/Am, /sup 242/Cm, /sup 243/Cm, /sup 244/Cm, /sup 245/Cm, /sup 246/Cm, /sup 247/Cm, /sup 248/Cm, and /sup 250/Cm. The uncertainties are provided at the 95% confidence limit for each of the recommended values.

  9. Anharmonicity of the excited octupole band in actinides using supersymmetric quantum mechanics

    NASA Astrophysics Data System (ADS)

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

    2013-09-01

    Background: Low-lying octupole collective excitations play an important role in the description of the structure of nuclei in the actinide region. Ground state alternating parity rotational bands combining both positive and negative parity states are known in several nuclei. However, only recently it has been discovered in 240Pu an excited positive parity rotational band having an octupole nature and demonstrating strong anharmonicity of the octupole motion in the band head energies.Purpose: To suggest a model describing both ground state and excited alternating parity bands, which includes a description of the anharmonic effects in the bandhead excitation energies and can be used to predict the energies of the excited rotational bands of octupole nature and the E1 transition probabilities.Methods: The mathematical technique of the supersymmetric quantum mechanics with a collective Hamiltonian depending only on the octupole collective variable which keeps axial symmetry is used to describe the ground state and excited alternating parity rotational bands.Results: The excitation energies of the states belonging to the lowest negative parity and the excited positive parity bands are calculated for 232Th, 238U, and 240Pu. The E1 transition matrix elements are also calculated for 240Pu.Conclusions: It is shown that the suggested model describes the excitation energies of the states of the lowest negative parity band with the accuracy around 10 keV. The anharmonicity in the bandhead energy of the excited positive parity band is described also. The bandhead energy of the excited positive parity band is described with the accuracy around 100 keV.

  10. Plutonium and other alpha emitters in mushrooms from Poland, Spain and Ukraine.

    PubMed

    Mietelsk, J W; Baeza, A S; Guillen, J; Buzinny, M; Tsigankov, N; Gaca, P; Jasińska, M; Tomankiewicz, E

    2002-05-01

    The paper presents results on Pu, U and Th isotope activity concentration measurements in some mushroom samples collected in Poland, Spain and Ukraine. The sampling sites differ a lot with regard to observed levels of Pu, its origin and isotope ratios as well as the environmental properties. Some of the Polish samples were collected in the northeastern part of the country with up to 30 Bq/m2 of Chernobyl Pu deposition. Other Polish and the Spanish samples are from areas with almost exclusively global fallout Pu present. Ukrainian samples were collected in a highly contaminated area with a deposition of about 3.7 kBq/m2 of Chernobyl (239-240)Pu. The maximum (239+240)Pu activity concentration was found equal to (54+/-4) Bq/kg (dw--dry weight) for a Ukrainian Cantharellus cibarius sample. Ukrainian samples have an extremely high radiocesium level, with maximum of (51+/-4) MBq/kg (dw). The maximum (239+240)Pu activity concentration for Polish samples was (81+/-5) mBq/kg (dw) for Xerocomus badius. From the isotopic ratio in this sample it can be concluded that Chernobyl fallout is the origin of Pu. More than twice as large was the Spanish maximum for Hebeloma cylindrosporum but with only global fallout Pu. Some aspects of the transfer of nuclides to fruit bodies is discussed and in some cases the transfer factors or aggregation coefficients were calculated. Especially high transfer factors were found for Hebeloma cylindrosporum from Spain.

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

    PubMed

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

    2013-09-01

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

  12. 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.

  13. Historical trace element distribution in sediments from the Mississippi River delta

    USGS Publications Warehouse

    Swarzenski, P.W.; Baskaran, M.; Rosenbauer, R.J.; Orem, W.H.

    2006-01-01

    Five sediment cores were collected on the shelf of the inner Mississippi Bight in June 2003 for a suite of radionuclides to establish geochronologies and trace elements to examine patterns of contaminant deposition and accumulation. Core sites were chosen to reflect a matrix of variable water depths, proximity to the Mississippi River mouth as the primary source for terrigenous particles, and extent and duration of summertime water column hypoxia. The vertical distribution of 239,240Pu and 210Pbxs (= 210Pbtotal - 226Ra) provided reliable geochronological age constraints to develop models for mass accumulation rates and historic trace element inputs and variations. Mass accumulation rates ranged from 0.27 to 0.87 g cm-2 yr-1 and were internally consistent using either 210Pbxs or 239,240Pu. Measured inventories of 137Cs, 239,240Pu, and 210Pbxs were compared to atmospheric deposition rates to quantify potential sediment focusing or winnowing. Observed variability in calculated mass accumulation rates may be attributed foremost to site-specific proximity to the river mouth (i.e., sediment source), variability in water depth, and enhanced sediment focusing at the Mississippi River canyon site. Trace element concentrations were first normalized to Al, and then Al-normalized enrichment factors (ANEF) were calculated based on preanthropogenic and crustal trace element abundances. These ANEFs were typically > 1 for V and Ba, while for most other elements studied, either no enrichment or depletion was observed. The enrichment of Ba may be related, in part, to the seasonal occurrence of oxygen-depleted subsurface waters off the Mississippi River delta, as well as being an ubiquitous by-product of the petroleum industry. ?? 2006 Estuarine Research Federation.

  14. High-Performance Method for Determination of Pu Isotopes in Soil and Sediment Samples by Sector Field-Inductively Coupled Plasma Mass Spectrometry.

    PubMed

    Wang, Zhongtang; Zheng, Jian; Ni, Youyi; Men, Wu; Tagami, Keiko; Uchida, Shigeo

    2017-02-21

    Plutonium is extensively studied in radioecology (e.g., soil to plant transfer and radiological assessment) and geochemistry (e.g., sediment dating). Here, we reported a new chemical separation method for rapid determination of Pu in soil and sediment samples, based on the following investigations: extraction behaviors of interfering elements (IEs, for inductively coupled plasma mass spectrometry (ICPMS) measurement) on TEVA resin; decontamination of U using TEVA, UTEVA, and DGA resins; and the impact of coprecipitation on Pu determination. The developed method consists of four steps: HNO3 leaching for Pu release; CaF2/LaF3 coprecipitation for the removal of major metals and U; the proposed TEVA + UTEVA + DGA procedure for the removal of U, Pb, Bi, Tl, Hg, Hf, Pt, and Dy; and ICPMS measurement. The accuracy of this method in determining (239+240)Pu activity and (240)Pu/(239)Pu and (241)Pu/(239)Pu isotopic ratios was validated by analyzing five standard reference materials (soil, fresh water sediment, and ocean sediment). This method is characterized by its stable and high Pu recovery (90-97% for soil; 92-98% for sediment) and high decontamination factor of U (1.6 × 10(7)), which is the highest reported for soil and sediment samples. In addition, the short analytical time of 12 h and the method detection limits, which are the lowest yet reported in literature, of 0.56 μBq g(-1) (0.24 fg g(-1)) for (239)Pu, 1.2 μBq g(-1) (0.14 fg g(-1)) for (240)Pu, and 0.34 mBq g(-1) (0.09 fg g(-1)) for (241)Pu (calculated on the basis of a 1 g soil sample) allow the rapid determination of ultratrace level Pu in soil and sediment samples.

  15. The effect of carbonate soil on transport and dose estimates for long-lived radionuclides at a U.S. Pacific test site

    SciTech Connect

    Conrado, C L; Hamilton, T F; Robison, W L; Stoker, A C

    1999-01-01

    The US conducted a series of nuclear tests from 1946 to 1958 at Bikini, a coral atoll, in the Marshall Islands (MI). The aquatic and terrestrial environments of the atoll are still contaminated with several long-lived radionuclides that were generated during testing. The four major radionuclides found in terrestrial plants and soils are Cesium-137 ({sup 137}Cs), Strontium-90 ({sup 90}Sr), Plutonium-239+240 ({sup 239+240}Pu) and Americium-241 ({sup 241}Am). {sup 137}Cs in the coral soils is more available for uptake by plants than {sup 137}Cs associated with continental soils of North America or Europe. Soil-to-plant {sup 137}Cs median concentration ratios (CR) (kBq kg{sup {minus}1} dry weight plant/kBq kg{sup {minus}1} dry weight soil) for tropical fruits and vegetables range between 0.8 and 36, much larger than the range of 0.005 to 0.5 reported for vegetation in temperate zones. Conversely, {sup 90}Sr median CRs range from 0.006 to 1.0 at the atoll versus a range from 0.02 to 3.0 for continental silica-based soils. Thus, the relative uptake of {sup 137}Cs and {sup 90}Sr by plants in carbonate soils is reversed from that observed in silica-based soils. The CRs for {sup 239+240}Pu and {sup 241}Am are very similar to those observed in continental soils. Values range from 10{sup {minus}6} to 10{sup {minus}4} for both {sup 239+240}Pu and {sup 241}Am. No significant difference is observed between the two in coral soil.

  16. WDC - Advanced system for characterization of {alpha}-bearing waste in 200 l and 400 l drums: performances and lessons learned from the first industrial measurement campaigns

    SciTech Connect

    Libens, A.; Vandorpe, M.; Cuchet, J.M.

    2007-07-01

    The Waste Drum Characterization installation was originally developed for the assay of alpha-bearing waste in standard 200 1 (55 gallons) drums during the dismantling operations of the Siemens mixed-oxide (MOX) facility in Hanau (Germany). That installation was validated and qualified by the German authorities, its main performances being: - Counting efficiency for coincident neutrons: approx. 1%; Lowest Limit of Detection (LLD): 75 mg {sup 240}Pu{sub eq}; Pu content per drum: up to 100 g tot. (35 g {sup 240}Pu{sub eq}) - Measurement duration: approx. 20 minutes. The success of this system, a passive neutron coincidence counter combined with a high resolution gamma spectrometer, led to the radiological characterization and qualification of about 1,700 drums during the period 2001 - 2004. In 2005, after completion of the dismantling operations of the Siemens MOX facility, Tecnubel took over the WDC installation which could be used in the frame of the future dismantling of the Belgonucleaire's MOX plant in Dessel (Belgium), which can be comparable to the Siemen's one. This second (and new) life for the WDC means that it must be rigorously retested and validated against the Belgian authorities requirements. Furthermore, and additionally to the future use in the Belgonucleaire's facility, Tecnubel was faced with new challenges, namely: Assay of 400 l drums together with the 200 l packages; Determination of the real LLD taking into account the background in different Belgian nuclear facilities, the determination of a value of {approx}5 mg {sup 240}Pu{sub eq} being an objective; - Assay of mixed alpha/beta-gamma wastes; Transportability of the WDC from one plant to another; Assistance to different nuclear operators for the licensing of the WDC for their own waste types. This paper describes the installation itself and its performances, presents the difficulties encountered during the new challenge and the results of the performed revalidation tests; it gives the

  17. Short term soil erosion dynamics in alpine grasslands - Results from a Fallout Radionuclide repeated-sampling approach

    NASA Astrophysics Data System (ADS)

    Arata, Laura; Meusburger, Katrin; Zehringer, Markus; Ketterer, Michael E.; Mabit, Lionel; Alewell, Christine

    2016-04-01

    Improper land management and climate change has resulted in accelerated soil erosion rates in Alpine grasslands. To efficiently mitigate and control soil erosion and reduce its environmental impact in Alpine grasslands, reliable and validated methods for comprehensive data generation on its magnitude and spatial extent are mandatory. The use of conventional techniques (e.g. sediment traps, erosion pins or rainfall simulations) may be hindered by the extreme topographic and climatic conditions of the Alps. However, the application of the Fallout Radionuclides (FRNs) as soil tracers has already showed promising results in these specific agro-ecosystems. Once deposited on the ground, FRNs strongly bind to fine particles at the surface soil and move across the landscape primarily through physical processes. As such, they provide an effective track of soil and sediment redistribution. So far, applications of FRN in the Alps include 137Cs (half-life: 30.2 years) and 239+240Pu (239Pu [half-life = 24110 years] and 240Pu [half-life = 6561 years]). To investigate short term (4-5 years) erosion dynamics in the Swiss Alps, the authors applied a FRNs repeated sampling approach. Two study areas in the central Swiss Alps have been investigated: the Urseren Valley (Canton Uri), where significant land use changes occurred in the last centuries, and the Piora Valley (Canton Ticino), where land use change plays a minor role. Soil samples have been collected at potentially erosive sites along the valleys over a period of 4-5 years and measured for 137Cs and 239+240Pu activity. The inventory change between the sampling years indicates high erosion and deposition dynamics at both valleys. High spatial variability of 137Cs activities at all sites has been observed, reflecting the heterogeneous distribution of 137Cs fallout after the Chernobyl power plant accident in 1986. Finally, a new modelling technique to convert the inventory changes to quantitative estimates of soil erosion has

  18. Passive NMIS Measurements to Estimate the Shape of Plutonium Assemblies

    SciTech Connect

    Mattingly, J.K.; Chiang, L.G.; March-Leuba, J.A.; Mihalczo, J.T.; Mullens, J.A.; Perez, R.B.; Valentine, T.E.

    1999-07-22

    A new technique to estimate the shape attribute of plutonium assemblies using the Nuclear Materials Identification System (NMIS) is described. The proposed method possesses a number of advantages. It is passive no external radiation source is required to estimate the shape of plutonium assemblies. Instead, inherent gamma and neutron emissions from spontaneous fission of {sup 240}Pu and subsequent induced fission of {sup 239}Pu are detected to estimate the shape attribute. The technique is also stationary: shape is estimated without scanning the assembly by moving the detectors relative to the assembly. The proposed method measures third order correlations between triplets of gamma/neutron-sensitive detectors. The real coincidence of a pair of gammas is used as a ''trigger'' to approximately identify the time of a spontaneous or induced fission event. The spatial location of this fission event is inferred from the real coincidence of a subsequent neutron with the initial pair of correlated gammas by using the neutron's time-of-flight (approximately the delay between the gamma pair and the neutron) and the fission neutron spectra of {sup 240}Pu and {sup 239}Pu. The spatial distribution of fission sites and hence the approximate shape of the plutonium assembly is thereby inferred by measuring the distribution of a large number of these correlated triplets. Proof-of-principle measurements were performed using {sup 252}Cf as a surrogate for {sup 240}Pu to demonstrate that the technique is feasible. For the simple shapes approximated with {sup 252}Cf sources, the measurements showed that the proposed method is capable of correctly identifying the shape and accurately estimating its size to within a few percent of actual.

  19. 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.

  20. Uranium and plutonium in anoxic marine sediments of the Santiago River mouth (Eastern Pacific, Mexico).

    PubMed

    Almazán-Torres, María Guadalupe; Ordóñez-Regil, Eduardo; Ruiz-Fernández, Ana Carolina

    2016-11-01

    The uranium (U) and plutonium (Pu) content with depth in a sediment core collected in the continental shelf off the mouth of the Santiago River in the Mexican Pacific was studied to evaluate the contamination effects of the effluent of the Santiago-Lerma River as it moves into the sea. The large mass of terrestrial detritus delivered by the river influences the physicochemical and geochemical processes in the seafloor. Abnormal concentrations of U and Pu in sediments were examined as indicative of the effects of anoxic conditions. One of the indicators of pollution of seawater is the bacterial activity of the shallow seabed layer; and among the prevailing bacteria, the magnetotactic ones induce the formation of euhedral and framboidal shapes (pyrite). These pyrite entities are by-products of anoxic environments loaded with decomposing detrital material and are very abundant in the surface layers of the sediment core analyzed. The pyrite formation is the result of a biochemical reaction between iron and organic sulphur reduced by bacteria, and the pyrite entities precipitate to the seafloor. In the same upper zone of the profile, (238)U is readily immobilized, while (234)U is oxidized and dissolved in seawater by the effect of hot atom chemistry. This may cause the activity ratio (AR) (234)U/(238)U disequilibrium (near 0.41). Furthermore, in the shallow layer of the sediment core, an abnormally high concentration of (239+240)Pu was detected. In this upper layer, the activity concentrations found were 3.19 Bq kg(-1) for (238)U, 1.32 kg(-1) for (234)U and 2.78 Bq kg(-1) for (239+240)Pu. In the lower fractions of the sediment core, normal values of AR (234)U/(238)U (≈1) were found, with traces of (239+240)Pu.

  1. Plutonium Isotopes ((239-241)Pu) Dissolved in Pacific Ocean Waters Detected by Accelerator Mass Spectrometry: No Effects of the Fukushima Accident Observed.

    PubMed

    Hain, Karin; Faestermann, Thomas; Fimiani, Leticia; Golser, Robin; Gómez-Guzmán, José Manuel; Korschinek, Gunther; Kortmann, Florian; Lierse von Gostomski, Christoph; Ludwig, Peter; Steier, Peter; Tazoe, Hirofumi; Yamada, Masatoshi

    2017-02-21

    The concentration of plutonium (Pu) and the isotopic ratios of (240)Pu to (239)Pu and (241)Pu to (239)Pu were determined by accelerator mass spectrometry (AMS) in Pacific Ocean water samples (20 L each) collected in late 2012. The isotopic Pu ratios are important indicators of different contamination sources and were used to identify a possible release of Pu into the ocean by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. In particular, (241)Pu is a well-suited indicator for a recent entry of Pu because (241)Pu from fallout of nuclear weapon testings has already significantly decayed. A total of 10 ocean water samples were prepared at the Radiochemie München of the TUM and analyzed at the Vienna Environmental Research Laboratory (VERA). Several samples showed a slightly elevated (240)Pu/(239)Pu ratio of up to 0.22 ± 0.02 compared to global fallout ((240)Pu/(239)Pu = 0.180 ± 0.007), whereas all measured (241)Pu-to-(239)Pu ratios were consistent with nuclear weapon fallout ((241)Pu/(239)Pu < 2.4 × 10(-3)), which means that no impact from the Fukushima accident was detected. From the average (241)Pu-to-(239)Pu ratio of 8-2(+3) ×10(-4) at a sampling station located at a distance of 39.6 km to FDNPP, the 1-σ upper limit for the FDNPP contribution to the (239)Pu inventory in the water column was estimated to be 0.2%. Pu, with the signature of weapon-grade Pu was found in a single sample collected around 770 km off the west coast of the United States.

  2. Superconducting calorimetric alpha particle sensors for nuclear nonproliferation applications

    SciTech Connect

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

    2008-09-22

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

  3. Long-range tropospheric transport of uranium and plutonium weapons fallout from Semipalatinsk nuclear test site to Norway.

    PubMed

    Wendel, Cato Christian; Fifield, L Keith; Oughton, Deborah H; Lind, Ole Christian; Skipperud, Lindis; Bartnicki, Jerzy; Tims, Stephen G; Høibråten, Steinar; Salbu, Brit

    2013-09-01

    A combination of state-of-the-art isotopic fingerprinting techniques and atmospheric transport modelling using real-time historical meteorological data has been used to demonstrate direct tropospheric transport of radioactive debris from specific nuclear detonations at the Semipalatinsk test site in Kazakhstan to Norway via large areas of Europe. A selection of archived air filters collected at ground level at 9 stations in Norway during the most intensive atmospheric nuclear weapon testing periods (1957-1958 and 1961-1962) has been screened for radioactive particles and analysed with respect to the concentrations and atom ratios of plutonium (Pu) and uranium (U) using accelerator mass spectrometry (AMS). Digital autoradiography screening demonstrated the presence of radioactive particles in the filters. Concentrations of (236)U (0.17-23nBqm(-3)) and (239+240)Pu (1.3-782μBqm(-3)) as well as the atom ratios (240)Pu/(239)Pu (0.0517-0.237) and (236)U/(239)Pu (0.0188-0.7) varied widely indicating several different sources. Filter samples from autumn and winter tended to have lower atom ratios than those sampled in spring and summer, and this likely reflects a tropospheric influence in months with little stratospheric fallout. Very high (236)U, (239+240)Pu and gross beta activity concentrations as well as low (240)Pu/(239)Pu (0.0517-0.077), (241)Pu/(239)Pu (0.00025-0.00062) and (236)U/(239)Pu (0.0188-0.046) atom ratios, characteristic of close-in and tropospheric fallout, were observed in filters collected at all stations in Nov 1962, 7-12days after three low-yield detonations at Semipalatinsk (Kazakhstan). Atmospheric transport modelling (NOAA HYSPLIT_4) using real-time meteorological data confirmed that long range transport of radionuclides, and possibly radioactive particles, from Semipalatinsk to Norway during this period was plausible. The present work shows that direct tropospheric transport of fallout from atmospheric nuclear detonations periodically may have

  4. Analysis of the 50-year records of the atmospheric deposition of long-lived radionuclides in Japan.

    PubMed

    Hirose, K; Igarashi, Y; Aoyama, M

    2008-11-01

    Long-lived anthropogenic radionuclides ((137)Cs, (90)Sr, and Pu isotopes) have been determined in monthly atmospheric deposition samples collected in Japan since 1956. The maximum annual deposition occurred in 1963 after the large-scale atmospheric nuclear weapons testing of 1961-1962. In the 1980s, the fallout from the Chinese nuclear weapons tests was observed and the released radionuclides from the Chernobyl accident affected radioactive deposition in Japan until the early 1990s. Recently, the deposition rates have been boosted by the resuspension of radionuclides in deposited particles, the (239,240)Pu content of which may originate from dusts from the East Asian continent deserts and arid areas.

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

    PubMed

    Konegger-Kappel, Stefanie; Prohaska, Thomas

    2016-01-01

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

  6. Effect of carbonate soil on transport and dose estimates from long-lived radionuclides at U. S. Pacific Test Site

    SciTech Connect

    Conrado, C.L.; Hamilton, T.F.; Robison, W.L.; Stoker, A.C.

    1998-09-01

    The United States conducted a series of nuclear tests from 1946 to 1958 at Bikini, a coral atoll, in the Marshall Islands (MI). The aquatic and terrestrial environments of the atoll are still contaminated with several long-lived radionuclides that were generated during testing. The four major radionuclides found in terrestrial plants and soils are Cesium-137 ({sup 137} Cs), Strontium-90 ({sup 90} Sr), Plutonium-239+ 240 ({sup 239+240}Pu) and Americium-241 ({sup 241}Am). {sup 137}Cs in the coral soils is more available for uptake by plants than {sup 137}Cs associated with continental soils of North America or Europe. Soil-to-plant {sup 137}Cs median concentration ratios (CR) (kBq kg{sup {minus}1} dry weight plant/kBq kg {sup {minus}1} dry weight soil) for tropical fruits and vegetables range between 0.8 and 36, much larger than the range of 0.005 to 0.5 reported for vegetation in temperate zones. Conversely, {sup 90}Sr median CRs range from 0.006 to 1.0 at the atoll versus a range from 0.02 to 3.0 for continental silica-based soils. Thus, the relative uptake of {sup 137}Cs and {sup 90}Sr by plants in carbonate soils is reversed from that observed in silica-based soils. The CRs for {sup 239+240}Pu and {sup 241}Am are very similar to those observed in continental soils. Values range from 10{sup {minus}6} to 10{sup {minus}4} for both {sup 239+240}Pu and {sup 241}Am. No significant difference is observed between the two in coral soil. The uptake of {sup 137}Cs by plants is enhanced because of the absence of mineral binding sites and the low concentration of potassium in the coral soil. {sup 137}Cs is bound to the organic fraction of the soil, whereas {sup 90}Sr, {sup 239+240}Pu and {sup 241}Am are primarily bound to soil particles. Assessment of plant uptake for {sup 137}Cs and {sup 90}Sr into locally grown food crops was a major contributing factor in (1) reliably predicting the radiological dose for returning residents, and (2) developing a strategy to limit the

  7. Pu isotopes in the western North Pacific Ocean before the accident at Fukushima Dai-ichi Nuclear Power Station

    NASA Astrophysics Data System (ADS)

    Yamada, M.; Zheng, J.; Aono, T.

    2011-12-01

    Anthropogenic radionuclides such as Pu-239 (half-life: 24100 yr), Pu-240 (half-life: 6560 yr) and Pu-241 (half-life: 14.325 yr) mainly have been released into the environment as the result of atmospheric nuclear weapons testing. In the North Pacific Ocean, two distinct sources of Pu isotopes can be identified; i.e., the global stratospheric fallout and close-in tropospheric fallout from nuclear weapons testing at the Pacific Proving Grounds in the Marshall Islands. The atom ratio of Pu-240/Pu-239 is a powerful fingerprint to identify the sources of Pu in the ocean. The Pu-240/Pu-239 atom ratios in seawater and marine sediment samples collected in the western North Pacific before the accident at Fukushima Dai-ichi Nuclear Power Station will provide useful background data for understanding the process controlling Pu transport and for distinguishing future Pu sources. The atom ratios of Pu-240/Pu-239 in water columns from the Yamato and Tsushima Basins in the Japan Sea were significantly higher than the mean global fallout ratio of 0.18; however, there were no temporal variation of atom ratios during the period from 1984 to 1993 in the Japan Sea. The total Pu-239+240 inventories in the whole water columns were approximately doubled during the period from 1984 to 1993 in the two basins. The atom ratio of Pu-240/Pu-239 in surface water from Sagami Bay, western North Pacific Ocean, was 0.224 and showed no notable variation from the surface to the bottom with the mean atom ratio being 0.234. The atom ratios for the Pacific coast, near the Rokkasho nuclear fuel reprocessing plant, were approximately the same as the 0.224 ratio obtained from Sagami Bay, western North Pacific margin. The atom ratios in the surficial sediments from Sagami Bay ranged from 0.229 to 0.247. The mean atom ratio in the sediment columns in the East China Sea ranged from 0.248 for the Changjiang estuary to 0.268 for the shelf edge. The observed atom ratios were significantly higher than the mean

  8. Evaluation of New Inorganic Sorbents for Strontium and Actinide Removal from High-Level Nuclear Waste Solutions

    SciTech Connect

    Hobbs, D.T.; Nyman, M.; Medvedev, D.G.; Tripathi, A.; Clearfield, A.

    2004-03-28

    Monosodium titanate (MST), a hydrous metal oxide sorbent, is the baseline material for the removal of 90Sr and alpha-emitting radionuclides (principally 238Pu, 239Pu, 240Pu and 237Np) from alkaline waste solutions generated during the processing of irradiated nuclear materials at the Savannah River Site. This material exhibits excellent performance characteristics for strontium removal. Plutonium removal is also good, but problematic at the estimated bonding concentration. We are currently developing new inorganic materials for improved sorption characteristics. These materials include sodium nonatitanates, pharmacosiderites and heteropolyniobates. We will present results evaluating the performance of these materials with simulated and actual high level nuclear waste solutions.

  9. Alternating-parity collective states of yrast and nonyrast bands in lanthanide and actinide nuclei

    SciTech Connect

    Nadirbekov, M. S. Yuldasheva, G. A.; Denisov, V. Yu.

    2015-03-15

    Excited collective states of even-even nuclei featuring quadrupole and octupole deformations are studied within a nonadiabatic collective model with a Gaussian potential energy. Rotational states of the yrast band and vibrational-rotational states of nonyrast bands are considered in detail. The energies of alternating-parity excited states of the yrast band in the {sup 164}Er, {sup 220}Ra, and {sup 224}Th nuclei; the yrast and first nonyrast bands in the {sup 154}Sm and {sup 160}Gd nuclei; and the yrast, first nonyrast, and second nonyrast bands in the {sup 224}Ra and {sup 240}Pu nuclei are described well on the basis of the proposed model.

  10. Development of a standardized sequential extraction protocol for simultaneous extraction of multiple actinide elements

    DOE PAGES

    Faye, Sherry A.; Richards, Jason M.; Gallardo, Athena M.; ...

    2017-02-07

    Sequential extraction is a useful technique for assessing the potential to leach actinides from soils; however, current literature lacks uniformity in experimental details, making direct comparison of results impossible. This work continued development toward a standardized five-step sequential extraction protocol by analyzing extraction behaviors of 232Th, 238U, 239,240Pu and 241Am from lake and ocean sediment reference materials. Results produced a standardized procedure after creating more defined reaction conditions to improve method repeatability. A NaOH fusion procedure is recommended following sequential leaching for the complete dissolution of insoluble species.

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

    NASA Astrophysics Data System (ADS)

    Vogt, Ramona; Randrup, Jorgen

    2013-04-01

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

  12. Environmental application of stable xenon and radioxenonmonitoring

    SciTech Connect

    Dresel, P. Evan; Olsen, Khris B.; Hayes, James C.; McIntyre,Justin I.; Waichler, Scott R.; Milbrath, Brian D.; Cooper, Matt; Kennedy,B. Mack

    2006-09-05

    Characterization of transuranic waste is needed to makedecisions about waste site remediation. Soil-gas sampling for xenonisotopes can be used to define the locations of spent fuel andtransuranic wastes. Radioxenon in the subsurface is characteristic oftransuranic waste and can be measured with extreme sensitivity usinglarge-volume soilgas samples. Measurements at the Hanford Site showed133Xe and 135Xe levels indicative of 240Pu spontaneous fission. Stablexenon isotopic ratios from fission are distinct from atmospheric xenonbackground. Neutron capture by 135Xe produces an excess of 136Xe inreactor-produced xenon providing a means of distinguishing spent fuelfrom separated transuranic materials.

  13. Induced Fission of Pu240 within a Real-Time Microscopic Framework

    SciTech Connect

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

    2016-03-01

    We describe the fissioning dynamics of 240Pu from a configuration in the proximity of the outer fission barrier to full scission and the formation of the fragments within an implementation of the Density Functional theory extended to superfluid systems and real-time dynamics. While the fission products emerge with properties very similar to those determined experimentally, the fission dynamics appears to be quite complex, with various shape and pairing modes being excited during the evolution. Consequently the time scale of the evolution turned out to be much slower than previously expected.

  14. Total and spontaneous fission half-lives of the uranium and plutonium nuclides

    SciTech Connect

    Holden, N.E.

    1984-01-01

    The total half-life and the half-life for spontaneous fission are evaluated for the various long-lived nuclides of interest. Recommended values are presented for /sup 232/U, /sup 233/U, /sup 234/U, /sup 235/U, /sup 236/U, /sup 238/U, /sup 236/Pu, /sup 238/Pu, /sup 239/Pu, /sup 240/Pu, /sup 241/Pu, /sup 242/Pu, and /sup 244/Pu. The uncertainties are provided at the 95% confidence limit for each of the recommended values.

  15. 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

  16. ORNL actinide materials and a new detection system for superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Rykaczewski, Krzysztof P.; Roberto, James B.; Brewer, Nathan T.; Utyonkov, Vladimir K.

    2016-12-01

    The actinide resources and production capabilities at Oak Ridge National Laboratory (ORNL) are reviewed, including potential electromagnetic separation of rare radioactive materials. The first experiments at the Dubna Gas Filled Recoil Separator (DGFRS) with a new digital detection system developed at ORNL and University of Tennessee Knoxville (UTK) are presented. These studies used 240Pu material provided by ORNL and mixed-Cf targets made at ORNL. The proposal to use an enriched 251Cf target and a large dose of 58Fe beam to reach the N = 184 shell closure and to observe new elements with Z = 124, 122 and 120 is discussed.

  17. Transfer of aged Pu to cattle grazing on a contaminated environment

    SciTech Connect

    Gilbert, R.O.; Engel, D.W.; Smith, D.D.; Shinn, J.H.; Anspaugh, L.R.; Eisele, G.R.

    1988-03-01

    Estimates are obtained of the fraction of ingested or inhaled 239+240Pu transferred to blood and tissues of a reproducing herd of beef cattle, individuals of which grazed within fenced enclosures for up to 1064 d under natural conditions with no supplemental feeding at an arid site contaminated 16 y previously with Pu oxide. The estimated (geometric mean (GM)) fraction of Pu transferred from the gastrointestinal tract to blood serum was about 5 x 10(-6) (geometric standard error (GSE) = 1.4) with an approximate upper bound of about 2 x 10(-5). These results are in reasonable agreement with the value of 1 x 10(-5) recommended for human radiation protection purposes by the International Commission on Radiological Protection (ICRP) for insoluble Pu oxides that are free of very small particles. Also, results from a laboratory study by Stanley (St75), in which large doses of /sup 238/Pu were orally administered daily to dairy cattle for 19 consecutive days, suggest that aged 239+240Pu at this arid grazing site may not be more biologically available to blood serum than fresh 239+240Pu oxide. The estimated fractions of 239+240Pu transferred from blood serum to tissues of adult grazing cattle were: femur (3.2 X 10(-2), 1.8; GM, GSE), vertebra (1.4 X 10(-1), 1.6), liver (2.3 X 10(-1), 2.0), muscle (1.3 X 10(-1), 1.9), female gonads (7.9 X 10(-5), 1.5), and kidney (1.4 X 10(-3), 1.7). The blood-to-tissue fractional transfers for cattle initially exposed in utero were greater than those exposed only as adults by a factor of about 4 for femur (statistically significant) and of about 2 for other tissues (not significant). The estimated (GM) fraction of inhaled Pu initially deposited in the pulmonary lung was 0.34 (GSE = 1.3) for adults and 0.15 (GSE = 1.3) for cattle initially exposed in utero (a statistically significant difference).

  18. Fractionation of plutonium in environmental and bio-shielding concrete samples using dynamic sequential extraction.

    PubMed

    Qiao, Jixin; Hou, Xiaolin

    2010-03-01

    Fractionation of plutonium isotopes ((238)Pu, (239,240)Pu) in environmental samples (i.e. soil and sediment) and bio-shielding concrete from decommissioning of nuclear reactor were carried out by dynamic sequential extraction using an on-line sequential injection (SI) system combined with a specially designed extraction column. Plutonium in the fractions from the sequential extraction was separated by ion exchange chromatography and measured using alpha spectrometry. The analytical results show a higher mobility of plutonium in bio-shielding concrete, which means attention should be paid to the treatment and disposal of nuclear waste from decommissioning.

  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. Inconsistencies between (14)C and short-lived radionuclides-based sediment accumulation rates: Effects of long-term remineralization.

    PubMed

    Baskaran, M; Bianchi, T S; Filley, T R

    2016-09-06

    (14)C is the most widely utilized geochronometer to investigate geological, geochemical and geophysical problems over the past 5 decades. Establishment of precise sedimentation rates is crucial for the reconstruction of paleo-climate, -ecological and - environmental studies when extrapolation of sedimentation rates is utilized for time scales beyond the dating range. However, agreement between short-term and long-term sedimentation rates in anthropogenically unperturbed sediment cores has not been shown. Here we show that the AMS (14)C-based long-term mass accumulation rate (MAR) of an organic-rich (>70%) sediment core from Mud Lake, Florida to be ∼5 times lower than the short-term MAR obtained using (239,240)Pu, (137)Cs and excess (210)Pb ((210)Pbxs). The measured sediment inventories of (210)Pbxs, (137)Cs and (239,240)Pu are comparable to the atmospheric fallout for the sampling site, indicating very little accelerated sediment erosion over the past several decades. Presence of sharp fallout peaks of (239,240)Pu indicates very little sediment mixing. The penetration depths of (137)Cs and (239,240)Pu were found to be much deeper than expected and this is attributed to their post-depositional mobility. MAR calculated using (14)C-ages in successive layers also indicated decreasing MARs with depth, and was reflective of progressive remineralization. Using first-order kinetics, the sediment remineralization rate was found to be 4.4 × 10(-4) y(-1) and propose that over the long-term, remineralization of organic-rich sediment affected the long-term MAR, but not the ratio of (14)C/(12)C. Thus, the MAR and linear sedimentation rate obtained using (14)C (and other isotope-based methods) could be erroneous, although (14)C ages may not be affected by such remineralization. Long-term remineralization rates of organic matter has a direct bearing on the biogeochemical cycling of elements in aqueous systems and mass balance of elements needs to be taken into consideration.

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

    PubMed

    Strumińska-Parulska, Dagmara I

    2014-12-15

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

  2. Mass and charge distributions in chlorine-induced nuclear reactions

    SciTech Connect

    Marchetti, A.A.

    1991-12-31

    Projectile-like fragments were detected and characterized in terms of A, Z, and energy for the reactions {sup 37}Cl on {sup 40}Ca and {sup 209}Bi at E/A = 7.3 MeV, and {sup 35}Cl, on {sup 209}Bi at E/A = 15 MeV, at angles close to the grazing angle. Mass and charge distributions were generated in the N-Z plane as a function of energy loss, and have been parameterized in terms of their centroids, variances, and coefficients of correlation. Due to experimental problems, the mass resolution corresponding to the {sup 31}Cl on {sup 209}Bi reaction was very poor. This prompted the study and application of a deconvolution technique for peak enhancement. The drifts of the charge and mass centroids for the system {sup 37}Cl on {sup 40}Ca are consistent with a process of mass and charge equilibration mediated by nucleon exchange between the two partners, followed by evaporation. The asymmetric systems show a strong drift towards larger asymmetry, with the production of neutron-rich nuclei. It was concluded that this is indicative of a net transfer of protons from the light to the heavy partner, and a net flow of neutrons in the opposite direction. The variances for all systems increase with energy loss, as it would be expected from a nucleon exchange mechanism; however, the variances for the reaction {sup 37}Cl on {sup 40}Ca are higher than those expected from that mechanism. The coefficients of correlation indicate that the transfer of nucleons between projectile and target is correlated. The results were compared to the predictions of two current models based on a stochastic nucleon exchange mechanism. In general, the comparisons between experimental and predicted variances support this mechanism; however, the need for more realistic driving forces in the model calculations is indicated by the disagreement between predicted and experimental centroids.

  3. Mass and charge distributions in chlorine-induced nuclear reactions. [[sup 35]Cl at E/A = 15 MeV, [sup 37]Cl at E/A = 7. 3 MeV

    SciTech Connect

    Marchetti, A.A.

    1991-01-01

    Projectile-like fragments were detected and characterized in terms of A, Z, and energy for the reactions [sup 37]Cl on [sup 40]Ca and [sup 209]Bi at E/A = 7.3 MeV, and [sup 35]Cl, on [sup 209]Bi at E/A = 15 MeV, at angles close to the grazing angle. Mass and charge distributions were generated in the N-Z plane as a function of energy loss, and have been parameterized in terms of their centroids, variances, and coefficients of correlation. Due to experimental problems, the mass resolution corresponding to the [sup 31]Cl on [sup 209]Bi reaction was very poor. This prompted the study and application of a deconvolution technique for peak enhancement. The drifts of the charge and mass centroids for the system [sup 37]Cl on [sup 40]Ca are consistent with a process of mass and charge equilibration mediated by nucleon exchange between the two partners, followed by evaporation. The asymmetric systems show a strong drift towards larger asymmetry, with the production of neutron-rich nuclei. It was concluded that this is indicative of a net transfer of protons from the light to the heavy partner, and a net flow of neutrons in the opposite direction. The variances for all systems increase with energy loss, as it would be expected from a nucleon exchange mechanism; however, the variances for the reaction [sup 37]Cl on [sup 40]Ca are higher than those expected from that mechanism. The coefficients of correlation indicate that the transfer of nucleons between projectile and target is correlated. The results were compared to the predictions of two current models based on a stochastic nucleon exchange mechanism. In general, the comparisons between experimental and predicted variances support this mechanism; however, the need for more realistic driving forces in the model calculations is indicated by the disagreement between predicted and experimental centroids.

  4. Formation of superheavy elements in cold fusion reactions

    NASA Astrophysics Data System (ADS)

    Smolańczuk, Robert

    2001-04-01

    We calculate the formation cross sections of transactinides (superheavy elements), as well as heavy actinides (No and Lr), which have been or might be obtained in fusion reactions with the evaporation of only one neutron. We use both more realistic fusion barrier and survival probability of the compound nucleus in comparison with the original phenomenological model [Phys. Rev. C 59, 2634 (1999)] that prompted the Berkeley experiment on the synthesis of a new superheavy element 118 [Phys. Rev. Lett. 83, 1104 (1999)]. Calculations are performed for asymmetric and symmetric target-projectile combinations and for reactions with stable and radioactive-ion beams. The formation cross sections measured at GSI-Darmstadt for transactinides and heavy actinides, as well as that for superheavy element 118 reported by the LBNL-Berkeley group, are reproduced within a factor of 2.4, on average. Based on the obtained relatively large cross sections, we predict that optimal reactions with stable beams for the synthesis of so far unobserved superheavy elements 119, 120, and 121 are 209Bi(86Kr, 1n)294119, 208Pb(88Sr, 1n)295120, and 209Bi(88Sr, 1n)296121, respectively. This is because of the magic of both the target and the projectile that leads to larger Q value and, consequently, lower effective fusion barrier with larger transmission probability. The same effect is responsible for relatively large cross sections predicted for the symmetric reactions 136Xe(124Sn, 1n)259Rf, 136Xe(136Xe, 1n)271Hs,138Ba(136Xe, 1n)273110, and 140Ce(136Xe, 1n)275112. Although shell effects in the magic nuclei 124Sn, 136Xe, 138Ba, and 140Ce are not as strong as in 208Pb and 209Bi, they act on both the target and the projectile and lead to the prediction of measurable cross sections.

  5. ANALYSIS AND EXAMINATION OF MOX FUEL FROM NONPROLIFERATION PROGRAMS

    SciTech Connect

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

    2013-01-01

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

  6. 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

    2015-02-03

    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.

  7. Twenty-four years of follow-up for a Hanford plutonium wound case.

    PubMed

    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 239+240Pu 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 17 mo resulted in urinary excretion of about 7 kBq. The case was published in 1988, but now 24 y of follow-up data are available. Annual bioassays have included in-vivo measurements of 241Am in the wound, skeleton, liver, lung, and axillary lymph nodes, 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 measurements have shown erratic detection of 241Am, and the lung measurements indicate Am but as interference from activity in the axillary lymph nodes and skeleton rather than activity in the lung. Urine excretion of Pu since termination of chelation therapy has typically ranged from 10 to 20 mBq d, with Am excretion about 10% of that for 239+240Pu. Annual routine medical exams have not identified any adverse health effects associated with the intake.

  8. Plutonium Detection with Straw Neutron Detectors

    SciTech Connect

    Mukhopadhyay, Sanjoy; Maurer, Richard; Guss, Paul

    2014-03-27

    A kilogram of weapons grade plutonium gives off about 56,000 neutrons per second of which 55,000 neutrons come from spontaneous fission of 240Pu (~6% by weight of the total plutonium). Actually, all even numbered isotopes (238Pu, 240Pu, and 242Pu) produce copious spontaneous fission neutrons. These neutrons induce fission in the surrounding fissile 239Pu with an approximate multiplication of a factor of ~1.9. This multiplication depends on the shape of the fissile materials and the surrounding material. These neutrons (typically of energy 2 MeV and air scattering mean free path >100 meters) can be detected 100 meters away from the source by vehicle-portable neutron detectors. [1] In our current studies on neutron detection techniques, without using 3He gas proportional counters, we designed and developed a portable high-efficiency neutron multiplicity counter using 10B-coated thin tubes called straws. The detector was designed to perform like commercially available fission meters (manufactured by Ortec Corp.) except instead of using 3He gas as a neutron conversion material, we used a thin coating of 10B.

  9. 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.

  10. 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.

  11. Radioactivity In Marine Organisms From Northeast Atlantic Ocean

    SciTech Connect

    Carvalho, Fernando P.; Oliveira, Joao M.

    2008-08-07

    Naturally-occurring radionuclides such as {sup 238}U, {sup 234}U, {sup 230}Th, {sup 226}Ra, {sup 210}Po, {sup 210}Pb and {sup 232}Th, and artificial radionuclides such as {sup 137}Cs, {sup 239+240}Pu and {sup 241}Am, were measured in a large number of marine species. In common fish species, typical concentrations of {sup 210}Po ranged from 10{sup 2} to 10{sup 4} mBq kg{sup -1} (wet weight), {sup 226}Ra concentrations ranged from 1x10{sup 2} to 5xl0{sup 2} mBq kg{sup -1}, {sup 238}U was at about 10 mBq kg{sup -1} and {sup 232}Th at about 0.5 mBq kg{sup -1}. Radiation doses to marine organisms originated by naturally-occurring and artificial radionuclides accumulated in tissues and by external radiation sources were computed and compared. Internal sources generally give higher contribution to the absorbed radiation dose than external sources. Amongst radionuclides accumulated in fish muscle and acting as internal radiation sources, natural {sup 210}Po and {sup 40}K give the largest contribution to the absorbed radiation dose, while artificial radionuclides such as {sup 137}Cs and {sup 239+240}Pu contribute with less than 0.5% to the absorbed radiation dose from all internal sources.

  12. Trench 'bathtubbing' and surface plutonium contamination at a legacy radioactive waste site.

    PubMed

    Payne, Timothy E; Harrison, Jennifer J; Hughes, Catherine E; Johansen, Mathew P; Thiruvoth, Sangeeth; Wilsher, Kerry L; Cendón, Dioni I; Hankin, Stuart I; Rowling, Brett; Zawadzki, Atun

    2013-01-01

    Radioactive waste containing a few grams of plutonium (Pu) was disposed between 1960 and 1968 in trenches at the Little Forest Burial Ground (LFBG), near Sydney, Australia. A water sampling point installed in a former trench has enabled the radionuclide content of trench water and the response of the water level to rainfall to be studied. The trench water contains readily measurable Pu activity (~12 Bq/L of (239+240)Pu in 0.45 μm-filtered water), and there is an associated contamination of Pu in surface soils. The highest (239+240)Pu soil activity was 829 Bq/kg in a shallow sample (0-1 cm depth) near the trench sampling point. Away from the trenches, the elevated concentrations of Pu in surface soils extend for tens of meters down-slope. The broader contamination may be partly attributable to dispersion events in the first decade after disposal, after which a layer of soil was added above the trenched area. Since this time, further Pu contamination has occurred near the trench-sampler within this added layer. The water level in the trench-sampler responds quickly to rainfall and intermittently reaches the surface, hence the Pu dispersion is attributed to saturation and overflow of the trenches during extreme rainfall events, referred to as the 'bathtub' effect.

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

    PubMed Central

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

    2013-01-01

    The contamination of Japan after the Fukushima accident has been investigated mainly for volatile fission products, but only sparsely for actinides such as plutonium. Only small releases of actinides were estimated in Fukushima. Plutonium is still omnipresent in the environment from previous atmospheric nuclear weapons tests. We investigated soil and plants sampled at different hot spots in Japan, searching for reactor-borne plutonium using its isotopic ratio 240Pu/239Pu. By using accelerator mass spectrometry, we clearly demonstrated the release of Pu from the Fukushima Daiichi power plant: While most samples contained only the radionuclide signature of fallout plutonium, there is at least one vegetation sample whose isotope ratio (0.381 ± 0.046) evidences that the Pu originates from a nuclear reactor (239+240Pu activity concentration 0.49 Bq/kg). Plutonium content and isotope ratios differ considerably even for very close sampling locations, e.g. the soil and the plants growing on it. This strong localization indicates a particulate Pu release, which is of high radiological risk if incorporated. PMID:24136192

  14. Comparative skeletal distribution of americium and plutonium in man, monkey and baboon

    SciTech Connect

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

    1988-10-01

    The skeletal distributions of americium and plutonium in four humans were compared with the skeletal distributions of these radioelements in baboons and monkeys. With respect to the skeletal distribution of these elements, excellent agreement was noted among the four human cases; americium data was available for all four cases and plutonium for three. The human case database was thus adequate for comparison with those of other primates. A statistically significant correlation was found between the /sup 241/Am and /sup 239/Pu + /sup 240/Pu skeletal distributions in the humans and those in non-human primates. Trabecular bone had the highest concentrations of /sup 241/Am and /sup 239 +240/Pu in man, baboon, and monkey. Scaling factors are proposed to convert the percentages of skeletal activity in animal bones to the corresponding percentages in the bones of the human skeleton. However, considerable variation was found between the humans and animals in the percentages of the skeletal activity found in the same bone. 12 refs., 7 tabs.

  15. Radionuclide Concentration in Soils and Vegetation at Low-Level Radioactive Waste Disposal Area G during 2005

    SciTech Connect

    P.R. Fresquez; M.W. McNaughton; M.J. Winch

    2005-10-01

    Soil samples were collected at 15 locations and unwashed overstory and understory vegetation samples were collected from up to nine locations within and around the perimeter of Area G, the primary disposal facility for low-level radioactive solid waste at Los Alamos National Laboratory (LANL). Soil and plant samples were also collected from the proposed expansion area west of Area G for the purpose of gaining preoperational baseline data. Soil and plant samples were analyzed for radionuclides that have shown a history of detection in past years; these included {sup 3}H, {sup 238}Pu, {sup 239,240}Pu, {sup 241}Am, {sup 234}U, {sup 235}U, and {sup 238}U for soils and {sup 3}H, {sup 238}Pu, and {sup 239,240}Pu for plants. As in previous years, the highest levels of {sup 3}H in soils and vegetation were detected at the south portion of Area G near the {sup 3}H shafts; whereas, the highest concentrations of the Pu isotopes were detected in the northern and northeastern portions near the pads for transuranic waste. All concentrations of radionuclides in soils and vegetation, however, were still very low (pCi range) and far below LANL screening levels and regulatory standards.

  16. Radiological situation in the vicinity of Semipalatinsk nuclear test site: Dolon, Mostik, Cheremushka and Budene settlements.

    PubMed

    Sakaguchi, Aya; Yamamoto, Masayoshi; Hoshi, Masaharu; Imanaka, Tetsuji; Apsalikov, Kazbek N; Gusev, Boris I

    2006-02-01

    The present situation of radioactive contamination at the village of Dolon and nearby villages such as Mostik, Cheremushka and Budene was investigated to serve as an aid to resolve dose discrepancy between model calculations and TL measurements made for external gamma-ray dose in air in Dolon. The paper was focused on the reevaluation of the accumulated levels and distribution of long-lived radionuclides 137Cs and Pu isotopes in soil using long core samples up to a depth of 30 and 100 cm. The inventories of 137Cs and 239,240Pu found were in the wide range of 140-10,310 and 140-14,320 Bq/m2, respectively. Most of the Pu in soil was tightly incorporated into various sizes of fused particles. Both 137Cs and 239,240Pu in soil were accumulated in the smaller soil size fraction of <125 microm, and the presence of hot particles, probably due to Pu, was clearly observed by star-like patterns from alpha-tracks. The obtained data will be helpful for evaluating the current and future radiation risks to the people living around there.

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

    SciTech Connect

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

    2010-02-01

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

  18. Actinide measurements by AMS using fluoride matrices

    NASA Astrophysics Data System (ADS)

    Cornett, R. J.; Kazi, Z. H.; Zhao, X.-L.; Chartrand, M. G.; Charles, R. J.; Kieser, W. E.

    2015-10-01

    Actinides can be measured by alpha spectroscopy (AS), mass spectroscopy or accelerator mass spectrometry (AMS). We tested a simple method to separate Pu and Am isotopes from the sample matrix using a single extraction chromatography column. The actinides in the column eluent were then measured by AS or AMS using a fluoride target matrix. Pu and Am were coprecipitated with NdF3. The strongest AMS beams of Pu and Am were produced when there was a large excess of fluoride donor atoms in the target and the NdF3 precipitates were diluted about 6-8 fold with PbF2. The measured concentrations of 239,240Pu and 241Am agreed with the concentrations in standards of known activity and with two IAEA certified reference materials. Measurements of 239,240Pu and 241Am made at A.E. Lalonde AMS Laboratory agree, within their statistical uncertainty, with independent measurements made using the IsoTrace AMS system. This work demonstrated that fluoride targets can produce reliable beams of actinide anions and that the measurement of actinides using fluorides agree with published values in certified reference materials.

  19. Minimum Critical Values Study

    SciTech Connect

    Fox, P.B.

    2005-07-11

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

  20. 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.; ...

    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

  1. Vertical distribution and migration of global fallout Pu in forest soils in southwestern China.

    PubMed

    Bu, Wenting; Zheng, Jian; Guo, Qiuju; Uchida, Shigeo

    2014-10-01

    Soil samples collected in southwestern China were analyzed for Pu isotopes. The (240)Pu/(239)Pu atom ratios were around 0.18, which indicated the dominant source of global fallout. Consistent sub-surface maximums followed by exponential decline of (239+240)Pu activities in the soil cores were observed. Most of the Pu has still remained in the 0-10 cm layers since its deposition. Convection velocities and dispersion coefficients for Pu migration in the soils were estimated by the convection-dispersion equation (CDE) model. The effective convection velocities and effective dispersion coefficients ranged from 0.05 to 0.11 cm/y and from 0.06 to 0.29 cm(2)/y, respectively. Other factors that control the vertical migration of Pu in soil besides precipitation, soil particle size distribution and organic matter were suggested. Long-term migration behaviors of Pu in the soils were simulated. The results provide the Pu background baseline for further environmental monitoring and source identification of non-global fallout Pu inputs in the future.

  2. Transfer of natural and anthropogenic radionuclides to ants, bryophytes and lichen in a semi-natural ecosystem.

    PubMed

    Dragović, Snezana; Howard, Brenda J; Caborn, Jane A; Barnett, Catherine L; Mihailović, Nevena

    2010-07-01

    Few data are available to quantify the transfer of both natural and anthropogenic radionuclides to detritivorous invertebrates to facilitate estimation of the internal dose to such biota in models used to assess radiation exposure. To enhance the available data, activity concentrations of (137)Cs, (40)K, (90)Sr, (239 + 240)Pu, (241)Am, (235)U and (238)U were measured in ants (Formicidae) and corresponding undisturbed soil collected from the Zlatibor mountain in Serbia and ant/soil concentration ratios (CR) calculated. The (241)Am concentration ratios for ants were fourfold higher than those calculated for ants in a previous study whereas they are similar to the more numerous data previously reported for a range of detritivorous invertebrates in other studies. CR values for (137)Cs in ants were similar to the few other reported values and slightly lower than those for a range of detritivorous invertebrates. Those for (239 + 240)Pu were slightly higher than those for ants in two other studies but they were close to upper limit of a range of data reported for detritivorous invertebrates. All the CR values will be included in a future revision of the ERICA Tool database and will particularly improve the information available for uranium.

  3. Plutonium distribution and oxidation states in a reactor leaching ponds system

    SciTech Connect

    Ibrahim, S.; Culp, T. )

    1989-10-01

    Concentrations of 239,240Pu and 238Pu in water, net plankton (algal material), suspended particulates and sediment, as well as Pu oxidation states in filtered water, were determined in a test reactor leaching ponds system in southeastern Idaho. The highest Pu concentration in the ponds system was found in net plankton, and concentrations varied significantly between sampling dates. Plutonium Concentration Ratios (CR) for plankton ranged from 3 X 10(4) to 4 X 10(5). The lowest Pu concentration was found in filtered water, primarily because of the absence of complexing agents. The majority of Pu in filtered water was in true solution (60-87%) or present in colloidal particles smaller than 0.22 micron. Plutonium association with sediment was inversely related to particle size. The environmental distribution coefficients (Kd) for Pu ranged from 1.6 X 10(4) to 1.2 X 10(5) reflecting the importance of sediments as the main reservoir for Pu in the ponds system. No significant differences were noted between CR or Kd values for 239,240Pu and 238Pu. The reduced Pu oxidation states (III and IV) fractions ranged from 57% to 71% of the total dissolved Pu in water. This is in contrast with oxidation states distribution from other large aquatic systems (Great Lakes and the Irish Sea) where Pu is predominately in oxidized (V and VI) forms.

  4. Studies of Np and Pu in the marine environment of Swedish-Danish waters and the North Atlantic Ocean.

    PubMed

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

    2005-01-01

    The long-lived anthropogenic radionuclides (237)Np, (239)Pu and (240)Pu were determined in marine environmental samples (seaweed and seawater) collected from Swedish-Danish waters and the North Atlantic Ocean at various locations on different occasions during the period 1991-2001. The measurements were performed with sector field Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and conventional alpha spectrometry. The (237)Np activity concentrations in Fucus vesiculosus and surface seawater from the Swedish west coast and Danish waters ranged from 0.16+/-0.02 to 1.02+/-0.09 mBq kg(-1) (dry weight) and 0.65+/-0.02 to 1.69+/-0.02 mBq m(-3), respectively, depending on the location and sampling year. Most of the (237)Np in these waters is believed to originate from the Sellafield nuclear reprocessing plant, with some contribution from global fallout. The (240)Pu/(239)Pu atomic ratios in F. vesiculosus samples are reported in this study with an overall average of 0.17+/-0.03. The (237)Np and (239)Pu activity concentrations observed in surface seawater collected in North Atlantic waters ranged from 0.16+/-0.01 to 0.62+/-0.08 mBq m(-3) and from 0.64+/-0.05 to 4.27+/-0.08 mBq m(-3), respectively, and the (237)Np/(239)Pu atomic ratios were a good indicator of conservative behaviour of Np in marine waters.

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

    PubMed

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

    2015-10-01

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

  6. Modernizing the Fission Basis

    NASA Astrophysics Data System (ADS)

    Tonchev, Anton; Henderson, Roger; Schunck, Nicolas; Sroyer, Mark; Vogt, Ramona

    2016-09-01

    In 1939, Niels Bohr and John Wheeler formulated a theory of neutron-induced nuclear fission based on the hypothesis of the compound nucleus. Their theory, the so-called ``Bohr hypothesis,'' is still at the heart of every theoretical fission model today and states that the decay of a compound nucleus for a given excitation energy, spin, and parity is independent of its formation. We propose the first experiment to validate to 1-2% absolute uncertainties the practical consequences of the Bohr hypothesis during induced nuclear fission. We will compare the fission product yields (FPYs) of the same 240Pu compound nucleus produced via two different reactions (i) n+239Pu and (ii) γ+240 Pu. These high-precision FPYs measurements will be extremely beneficial for our fundamental understanding of the nuclear fission process and nuclear reactions from first principles. This work was performed under the auspices of US DOE by LLNL under Contract DE-AC52-07NA27344. Funding was provided via the LDRD-ERD-069 project.

  7. AMS of the Minor Plutonium Isotopes.

    PubMed

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

    2013-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

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

  9. Main results of the 2012 joint Norwegian-Russian expedition to the dumping sites of the nuclear submarine K-27 and solid radioactive waste in Stepovogo Fjord, Novaya Zemlya.

    PubMed

    Gwynn, Justin P; Nikitin, Aleksander; Shershakov, Viacheslav; Heldal, Hilde Elise; Lind, Bjørn; Teien, Hans-Christian; Lind, Ole Christian; Sidhu, Rajdeep Singh; Bakke, Gunnar; Kazennov, Alexey; Grishin, Denis; Fedorova, Anastasia; Blinova, Oxana; Sværen, Ingrid; Lee Liebig, Penny; Salbu, Brit; Wendell, Cato Christian; Strålberg, Elisabeth; Valetova, Nailja; Petrenko, Galina; Katrich, Ivan; Logoyda, Igor; Osvath, Iolanda; Levy, Isabelle; Bartocci, Jean; Pham, Mai Khanh; Sam, Adam; Nies, Hartmut; Rudjord, Anne Liv

    2016-01-01

    This paper reports the main results of the 2012 joint Norwegian-Russian expedition to investigate the radioecological situation of the Stepovogo Fjord on the eastern coast of Novaya Zemlya, where the nuclear submarine K-27 and solid radioactive waste was dumped. Based on in situ gamma measurements and the analysis of seawater and sediment samples taken around the submarine, there was no indication of any leakage from the reactor units of K-27. With regard to the radioecological status of Stepovogo Fjord, activity concentrations of all radionuclides in seawater, sediment and biota in 2012 were in general lower than reported from the previous investigations in the 1990s. However in 2012, the activity concentrations of (137)Cs and, to a lesser extent, those of (90)Sr remained elevated in bottom water from the inner part of Stepovogo Fjord compared with surface water and the outer part of Stepovogo Fjord. Deviations from expected (238)Pu/(239,240)Pu activity ratios and (240)Pu/(239)Pu atom ratios in some sediment samples from the inner part of Stepovogo Fjord observed in this study and earlier studies may indicate the possibility of leakages from dumped waste from different nuclear sources. Although the current environmental levels of radionuclides in Stepovogo Fjord are not of immediate cause for concern, further monitoring of the situation is warranted.

  10. Anthropogenic and naturally occurring radionuclide content in near surface air in Cáceres (Spain).

    PubMed

    Baeza, Antonio; Rodríguez-Perulero, Antonio; Guillén, Javier

    2016-12-01

    The anthropogenic ((137)Cs, (90)Sr, (239+240)Pu and (241)Am) and naturally occurring radionuclide ((40)K, (234,238)U, (228,230,232)Th, (226)Ra and (210)Pb) content in near surface air present seasonal variations related to natural processes, such as soil erosion, resuspension of fine particles of soil and radon exhalation from soil ((210)Pb). The objective is to analyze seasonal variations of their concentrations and compare with radiological events (Fukushima fallout and wild fire) in a location without any known source of anthropogenic radionuclides. The (210)Pb, (40)K, and (137)Cs presented annual variations, with maximum activity levels in summer. Solar radiation and rainfall were correlated with (210)Pb and (40)K. The (234,238)U, (228,230,232)Th, (226)Ra, (137)Cs and (90)Sr presented positive correlation with monthly mean values of temperature. The ratio (90)Sr/(137)Cs was within the range of those reported for soils in Spain. Finally, the maximal effective dose rate was estimated to be 37 and 88 μSv/y for infants and adults, respectively, well below 1 mSv/y reference level. The main contributor to effective dose was (210)Pb, about 92%, followed by: (210)Pb ≫ (228,230,232)Th > (226)Ra, (234,238)U > (7)Be, (239+240)Pu > (40)K, (90)Sr > (137)Cs > (22)Na.

  11. Vertical and horizontal fluxes of plutonium and americium in the western Mediterranean and the Strait of Gibraltar.

    PubMed

    León Vintró, L; Mitchell, P I; Condren, O M; Downes, A B; Papucci, C; Delfanti, R

    1999-09-30

    New data on the vertical distributions of plutonium and americium in the waters of the western Mediterranean and the Strait of Gibraltar are examined in terms of the processes governing their delivery to, transport in and removal from the water column within the basin. Residence times for plutonium and americium in surface waters of approximately 15 and approximately 3 years, respectively, are deduced, and it is shown that by the mid 1990s only approximately 35% of the 239,240Pu and approximately 5% of the 241Am deposited as weapons fallout still resided in the water column. Present 239,240Pu inventories in the water column and the underlying sediments are estimated to be approximately 25 TBq and approximately 40 TBq, respectively, which reconcile well with the time-integrated fallout deposition in this zone, taken to be approximately 69 TBq. The data show that there are significant net outward fluxes of plutonium and americium from the basin through the Strait of Gibraltar at the present time. These appear to be compensated by net inward fluxes of similar magnitude through the Strait of Sicily. Thus, the time-integrated fallout deposition in the western basin can be accounted for satisfactorily in terms of present water column and sediment inventories. Enhanced scavenging on the continental shelves, as evidenced by the appreciably higher transuranic concentrations in shelf sediments, supports this contention.

  12. Trench ‘Bathtubbing’ and Surface Plutonium Contamination at a Legacy Radioactive Waste Site

    PubMed Central

    2013-01-01

    Radioactive waste containing a few grams of plutonium (Pu) was disposed between 1960 and 1968 in trenches at the Little Forest Burial Ground (LFBG), near Sydney, Australia. A water sampling point installed in a former trench has enabled the radionuclide content of trench water and the response of the water level to rainfall to be studied. The trench water contains readily measurable Pu activity (∼12 Bq/L of 239+240Pu in 0.45 μm-filtered water), and there is an associated contamination of Pu in surface soils. The highest 239+240Pu soil activity was 829 Bq/kg in a shallow sample (0–1 cm depth) near the trench sampling point. Away from the trenches, the elevated concentrations of Pu in surface soils extend for tens of meters down-slope. The broader contamination may be partly attributable to dispersion events in the first decade after disposal, after which a layer of soil was added above the trenched area. Since this time, further Pu contamination has occurred near the trench-sampler within this added layer. The water level in the trench-sampler responds quickly to rainfall and intermittently reaches the surface, hence the Pu dispersion is attributed to saturation and overflow of the trenches during extreme rainfall events, referred to as the ‘bathtub’ effect. PMID:24256473

  13. Importance of colloids in the transport within the dissolved phase (<450 nm) of artificial radionuclides from the Rhône river towards the Gulf of Lions (Mediterranean Sea).

    PubMed

    Eyrolle, Frédérique; Charmasson, Sabine

    2004-01-01

    The significance of colloidal fractions regarding the transport of artificial radionuclides in natural water systems is underlined by using sequential ultrafiltration both in the Rhône freshwater and the marine area under and outside the influence of the river outflow. Indeed, the Rhodanian aquatic system represents an interesting test site as various artificial radionuclides are released into the Rhône river by several nuclear installations. We focused our study on (137)Cs, (106)Ru, (60)Co, (238)Pu and (239+240)Pu. Our results show that Fe, Al and Organic carbon (OC) are the main components of colloidal matter. Colloids represent about 15% of dissolved (<450 nm) OC and 25% of dissolved Fe and Al exported towards the sea. Within the dissolved (< 450 nm) phase, these colloidal compounds are shown to account for the transport of 40% for both Co and Ru, 60% for (238)Pu and (239+240)Pu and have no significance on (137)Cs flux.

  14. 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.

  15. Energy Dependent Bias in the Weighted Point Model.

    SciTech Connect

    Santi, P. A.; Geist, W. H.

    2005-01-01

    While the weighted point multiplicity model has successfully reduced the bias that is associated with variable multiplication of neutrons within a sample (which was assumed constant in the standard point multiplicity model), other potential sources of bias still exists within the weighted point model. One significant source of bias arises from the assumption that the energies of the neutrons from ({alpha},n) reactions on impurities in the sample have the same average energy as neutrons emitted from the spontaneous fission of {sup 240}Pu. An investigation into the effects that neutron energy has on the assay results (effective {sup 240}Pu mass, alpha, and multiplication) of the weighted point multiplicity model has been performed using MCNPX, Version 2.5f for impure plutonium metal samples in a number of different detector systems. The effects of energy dependence of the detection efficiency and gate fractions on the assay results, as well as the measured singles, doubles, and triples rates were also studied. Methods for mitigating the effects of neutron energy on the weighted-point multiplicity model results will be presented and discussed.

  16. 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.

  17. Proton-induced polonium production in massive lead bismuth target irradiated by 660 MeV protons

    NASA Astrophysics Data System (ADS)

    Polanski, Aleksander; Petrochenkov, Sergey; Pohorecki, Wladyslaw

    2006-06-01

    The paper presents study of polonium production in bismuth foils placed in lead target. Proton-induced production of residual nuclei 206Po, 207Po, 208Po, 209Po, 210Po in 209Bi foils placed in lead target irradiated by 660 MeV protons was calculated. A comparison with calculated spatial distribution of polonium production using an MCNPX code and experimental results has been performed. The results of calculation will be useful for design of target of Subcritical Assembly in Dubna (SAD).

  18. Low-energy fusion dynamics of weakly bound nuclei: A time dependent perspective

    NASA Astrophysics Data System (ADS)

    Diaz-Torres, A.; Boselli, M.

    2016-05-01

    Recent dynamical fusion models for weakly bound nuclei at low incident energies, based on a time-dependent perspective, are briefly presented. The main features of both the PLATYPUS model and a new quantum approach are highlighted. In contrast to existing timedependent quantum models, the present quantum approach separates the complete and incomplete fusion from the total fusion. Calculations performed within a toy model for 6Li + 209Bi at near-barrier energies show that converged excitation functions for total, complete and incomplete fusion can be determined with the time-dependent wavepacket dynamics.

  19. Analysis of nucleon-induced fission cross sections of lead and bismuth at energies from 45 to 500 MeV

    SciTech Connect

    Prokofyev, A.V.; Mashnik, S.G.; Sierk, A.J.

    1998-08-01

    In order to investigate the applicability of the Cascade-Exciton model (CEM) of nuclear reactions to fission cross sections and hoping to learn more about intermediate-energy fission, the authors use an extended version of the CEM, as realized in the code CEM95 to perform a detailed analysis of proton- and neutron-induced fission cross sections of {sup 209}Bi and {sup 208}Pb nuclei and of the linear momentum transfer to the fissioning nuclei in the 45--500 meV energy range.

  20. Isomer ratio measurements as a probe of the dynamics of breakup and incomplete fusion

    SciTech Connect

    Gasques, L. R.; Dasgupta, M.; Hinde, D. J.; Peatey, T.; Diaz-Torres, A.; Newton, J. O.

    2006-12-15

    The incomplete fusion mechanism following breakup of {sup 6,7}Li and {sup 9}Be projectiles incident on targets of {sup 209}Bi and {sup 208}Pb is investigated through isomer ratio measurements for the {sup 212}At and {sup 211}Po products. The phenomenological analysis presented in this paper indicates that incomplete fusion brings relatively more angular momentum into the system than equivalent reactions with a direct beam of the fused fragment. This is attributed to the trajectories of breakup fragments. Calculations with a 3D classical trajectory model support this. Isomer ratio measurements for incomplete fusion reactions can provide a test of new theoretical models of breakup and fusion.

  1. Remark on: the neutron spherical optical-model absorption.

    SciTech Connect

    Smith, A. B.; Nuclear Engineering Division

    2007-06-30

    The energy-dependent behavior of the absorption term of the spherical neutron optical potential for doubly magic {sup 208}Pb and the neighboring {sup 209}Bi is examined. These considerations suggest a phenomenological model that results in an intuitively attractive energy dependence of the imaginary potential that provides a good description of the observed neutron cross sections and that is qualitatively consistent with theoretical concepts. At the same time it provides an alternative to some of the arbitrary assumptions involved in many conventional optical-model interpretations reported in the literature and reduces the number of the parameters of the model.

  2. Anomalous nuclear magnetic resonance spectra in powdered Bi2Se3

    NASA Astrophysics Data System (ADS)

    Nisson, D. M.; Dioguardi, A. P.; Klavins, P.; Peng, X.; Yu, D.; Curro, N. J.; Curro Collaboration

    2014-03-01

    We present 209Bi NMR spectra and relaxation rate data on single crystal and powder samples of the topological insulator material Bi2Se3, including data on nanoscale powders with percentages of surface nuclei on the order of 2%. Powder samples are measured as-prepared, annealed to relieve mechanical strains, and fixed in epoxy to prevent alignment of grains with the applied magnetic field of 9 T. Our results reveal anomalous behavior in both the angular dependence of the single crystal spectra and in the powder spectra. All powder spectra display features not accounted for by summation of spectra of single crystal orientations.

  3. Need for remeasurements of nuclear magnetic dipole moments

    NASA Astrophysics Data System (ADS)

    Gustavsson, Martin G.; Mårtensson-Pendrill, Ann-Marie

    1998-11-01

    The need for a reassessment of nuclear magnetic dipole moments is prompted by recent experiments on the ground-state hyperfine structure in highly charged hydrogenlike systems which are sufficiently sensitive to probe QED effects. This work gives an overview of the magnetic dipole moments for the nuclei of interest, i.e., 165Ho, 185,187Re, 203,205Tl, 207Pb, and 209Bi. It is found that the present uncertainties in the nuclear magnetic dipole moment limit the interpretation of the accurate experimental hyperfine structures for these systems.

  4. Comparison of Complementary Reactions in the Production of Mt

    SciTech Connect

    Nelson, Sarah; Gregorich, Kenneth; Dragojevic, Irena; Ellison, Paul; Garcia, Mitch Andre; Gates, Jacklyn; Stavsetra, Liv; Ali, Mazhar; Nitsche, Heino

    2009-01-21

    The new reaction 208Pb(59Co,n)266Mt was studied using the Berkeley Gas-filled Separator at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. A cross section of 7.7+5.2-3.3 pb was measured at a compound nucleus excitation energy of 14.9 MeV. The measured decay properties of 266Mt and its daughters correspond well with existing data. We compare this experimental result to transactinide compound nucleus formation model predictions, and the previously studied 209Bi(58Fe,n)266Mt reaction.

  5. Study of heavy ion range in different solid state nuclear track detector materials

    NASA Astrophysics Data System (ADS)

    Diwan, P. K.; Singh, Lakhwant; Singh, Gurinder; Kumar, Shyam

    2000-03-01

    The range of several heavy ions as 238U, 208Pb, 197Au, 139La, 58Ni and 56Fe in sodalime glass; 197Au and 58Ni in muscovite mica and Lexan polycarbonate; 209Bi and 197Au in CR-39 have been determined experimentally. The calculations of range for these projectile-target combinations have been made using the Benton and Henke [10], Mukherjee and Nayak [11], Ziegler et al. [12] and Hubert et al. [14] semiempirical formulations. Finally a comparison has been made with the experimental results.

  6. Fractional processes and nuclear disassembly in very-heavy-ion collisions in the Fermi energy regime

    SciTech Connect

    Schroeder, W.U.

    1991-01-01

    Exclusive measurements of charged products and neutrons were performed for the reactions {sup 197}Au + (29 MeV/u) {sup 208}Pb and {sup 209}Bi + (28.2 MeV/u) {sup 136}Xe. The multiplicities of neutrons and charged particles are found to indicate collision impact parameters with different sensitivities. Characteristic correlations observed between massive products and light particles suggest the dominance of the damped-reaction mechanism in the Fermi energy domain. For central collisions, massive fragments are no longer observed, and a considerable fraction of the mass of the system is found disassembled into light particles and clusters. 75 refs., 19 figs.

  7. Comparison of complementary reactions in the production of Mt

    SciTech Connect

    Nelson, S. L.; Dragojevic, I.; Ellison, P. A.; Garcia, M. A.; Gates, J. M.; Nitsche, H.; Gregorich, K. E.; Dvorak, J.; Stavsetra, L.; Ali, M. N.

    2009-02-15

    The new reaction {sup 208}Pb({sup 59}Co,n){sup 266}Mt was studied using the Berkeley Gas-filled Separator at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. A cross section of 7.7{sub -3.3}{sup +5.2} pb was measured at a compound nucleus excitation energy of 14.9 MeV. The measured decay properties of {sup 266}Mt and its daughters correspond well with existing data. We compare this experimental result to transactinide compound nucleus formation model predictions, and the previously studied {sup 209}Bi({sup 58}Fe,n){sup 266}Mt reaction.

  8. Reaction-dependent spin population and evidence of breakup in {sup 18}O

    SciTech Connect

    Hojman, D.; Pacheco, A.J.; Testoni, J.E.; Davidson, J.; Davidson, M.; Cardona, M.A.; Fernandez-Niello, J.O.; Kreiner, A.J.; Arazi, A.; Capurro, O.A.; Marti, G.V.; Bazzacco, D.; Lenzi, S.M.; Lunardi, S.; Alvarez, C. Rossi; Ur, C.; Burlon, A.; Debray, M.E.; De Angelis, G.; De Poli, M.

    2006-04-15

    Angular distributions and angular correlations have been measured for the emission of one and two {alpha}-particles in the {sup 18}O+{sup 207,208}Pb,{sup 209}Bi reactions at several beam energies above the Coulomb barrier. The results rule out fusion evaporation as the main reaction mechanism for the channels involving {alpha}-particle emission and support the interpretation of the breakup of the {sup 18}O projectiles into at least {sup 14}C+{alpha} and {sup 10}Be+{sup 8}Be before fusion.

  9. Actinide neutron-induced fission cross section measurements at LANSCE

    SciTech Connect

    Tovesson, Fredrik K; Laptev, Alexander B; Hill, Tony S

    2010-01-01

    Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications in a wide energy range from sub-thermal energies up to 200 MeV. A parallel-plate ionization chamber are used to measure fission cross sections ratios relative to the {sup 235}U standard while incident neutron energies are determined using the time-of-flight method. Recent measurements include the {sup 233,238}U, {sup 239-242}Pu and {sup 243}Am neutron-induced fission cross sections. Obtained data are presented in comparison with ex isting evaluations and previous data.

  10. Behavior of americium and berkelium ions in solutions under intense alpha radiation

    SciTech Connect

    Frolov, A.A.; Frolova, L.M.; Vasil'ev, V.Ya.

    1987-09-01

    The information in the literature on the radiation-chemical behavior of americium and berkelium is devoted mainly to the reduction of americium(V) and (VI) upon the irradiation of solutions by alpha particles formed as a result of the decay of /sup 241,243/Am and to the reduction of berkelium(IV) upon the irradiation of solutions by beta particles emitted by the nuclide /sup 249/Bk. In the present work they studied the behavior of ions of the elements indicated in perchlorate and nitrate solutions under intense internal alpha radiation. Curium-244, which was introduced into the solution, served as the source of the alpha particles.

  11. Spectroscopy of element 115 decay chains.

    PubMed

    Rudolph, D; Forsberg, U; Golubev, P; Sarmiento, L G; Yakushev, A; Andersson, L-L; Di Nitto, A; Düllmann, Ch E; Gates, J M; Gregorich, K E; Gross, C J; Heßberger, F P; Herzberg, R-D; Khuyagbaatar, J; Kratz, J V; Rykaczewski, K; Schädel, M; Åberg, S; Ackermann, D; Block, M; Brand, H; Carlsson, B G; Cox, D; Derkx, X; Eberhardt, K; Even, J; Fahlander, C; Gerl, J; Jäger, E; Kindler, B; Krier, J; Kojouharov, I; Kurz, N; Lommel, B; Mistry, A; Mokry, C; Nitsche, H; Omtvedt, J P; Papadakis, P; Ragnarsson, I; Runke, J; Schaffner, H; Schausten, B; Thörle-Pospiech, P; Torres, T; Traut, T; Trautmann, N; Türler, A; Ward, A; Ward, D E; Wiehl, N

    2013-09-13

    A high-resolution α, x-ray, and γ-ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum für Schwerionenforschung. Thirty correlated α-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z=115. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z>112. Comprehensive Monte Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.

  12. Spectroscopy of element 115 decay chains

    SciTech Connect

    Rudolph, Dirk; Forsberg, U.; Golubev, P.; Sarmiento, L. G.; Yakushev, A.; Andersson, L.-L.; Di Nitto, A.; Duehllmann, Ch. E.; Gates, J. M.; Gregorich, K. E.; Gross, Carl J; Hessberger, F. P.; Herzberg, R.-D; Khuyagbaatar, J.; Kratz, J. V.; Rykaczewski, Krzysztof Piotr; Schaedel, M.; Aberg, S.; Ackermann, D.; Block, M.; Brand, H.; Carlsson, B. G.; Cox, D.; Derkx, X.; Eberhardt, K.; Even, J.; Fahlander, C.; Gerl, J.; Jaeger, E.; Kindler, B.; Krier, J.; Kojouharov, I.; Kurz, N.; Lommel, B.; Mistry, A.; Mokry, C.; Nitsche, H.; Omtvedt, J. P.; Papadakis, P.; Ragnarsson, I.; Runke, J.; Schaffner, H.; Schausten, B.; Thoerle-Pospiech, P.; Torres, T.; Traut, T.; Trautmann, N.; Tuerler, A.; Ward, A.; Ward, D. E.; Wiehl, N.

    2013-01-01

    A high-resolution a, X-ray and -ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum fu r Schwerionenforschung. Thirty correlated a-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z = 115. The data includes first candidates of fingerprinting the decay step Mt --> Bh with characteristic X rays. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z > 112. Comprehensive Monte-Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.

  13. Sequential determination of Pu and Am radioisotopes in environmental samples; a comparison of two separation procedures.

    PubMed

    Jakopic, Rozle; Tavcar, Polona; Benedik, Ljudmila

    2007-05-01

    Two separation methods for the sequential determination of Am and Pu radionuclides are presented and the results obtained are compared. Analysis involves leaching the sample with concentrated nitric acid (HNO(3)), followed by radiochemical separation using extraction chromatographic resins (UTEVA, TRU) and anion exchange. Sources for alpha spectrometry were prepared by micro-precipitation on neodymium fluoride (NdF(3)). The chemical recoveries were determined using (242)Pu and (243)Am tracers. The methods were tested on reference materials and on two sediments. All the results were in good agreement with the reference values. The evaluation of uncertainty is also included.

  14. Fission cross section calculations of actinides with EMPIRE code

    SciTech Connect

    Sin, M.; Oblozinsky, P.; Herman,M.; Capote,R.

    2010-04-30

    The cross sections of the neutron induced reactions on {sup 233,234,236}U, {sup 237}Np, {sup 238,242}Pu, {sup 241,243}Am, {sup 242,246}Cm carried out in the energy range 1 keV-20 MeV with EMPIRE code are presented, emphasizing the fission channel. Beside a consistent, accurate set of evaluations, the paper contains arguments supporting the choice of the reaction models and input parameters. A special attention is paid to the fission parameters and their uncertainties.

  15. Preparation of Microvolume Anion-Exchange Cartridge for Inductively Coupled Plasma Mass Spectrometry-Based Determination of (237)Np Content in Spent Nuclear Fuel.

    PubMed

    Asai, Shiho; Hanzawa, Yukiko; Konda, Miki; Suzuki, Daisuke; Magara, Masaaki; Kimura, Takaumi; Ishihara, Ryo; Saito, Kyoichi; Yamada, Shinsuke; Hirota, Hideyuki

    2016-03-15

    Microvolume anion-exchange porous polymer disk-packed cartridges were prepared for Am/Np separation, which is required prior to the measurement of Neptunium-237 ((237)Np) with inductively coupled plasma mass spectrometry (ICPMS). Disks with a volume of 0.08 cm(3) were cut out from porous sheets having anion-exchange-group-containing polymer chains densely attached on the pore surface. Four different amine-based groups, N,N-dimethylaminoethyl methacrylate, trimethylammonium, diethylamine, and triethylenediamine (TEDA), were selected as the anion-exchange groups to be introduced into the porous sheets. The separation performances of Am/Np were evaluated using a standard solution of (243)Am, which had the same activity as its daughter nuclide (239)Np in secular equilibrium. (239)Np recovery of close to 100% with practically no contamination of (243)Am was achieved using the TEDA-introduced disk-packed cartridge. The time to elute (239)Np from the cartridge was approximately 40 s. The TEDA-introduced disk-packed cartridge was applied to the separation of Np from a spent nuclear fuel sample to confirm its separation performance. A known amount of (243)Am ((239)Np) was added to the spent nuclear fuel sample solution to monitor the chemical yield of Np. The chemical yield of Np calculated from a measured concentration of (239)Np was 90.4%. Am leakage in the Np-eluted solution was less than 1 ppt, corresponding to 0.001% of the original Am concentration in the sample. This indicates that no additional (239)Np was produced by the decay of the (243)Am remaining in the Np-eluted solution, thus providing a reliable chemical yield. U, which can cause a serious spectral interference involving the peak tail from the mass spectrum of (238)U, was thoroughly removed with the TEDA cartridge, providing interference-free measurement of (237)Np. The concentration of (237)Np obtained by ICPMS was 718 ± 12 ng/mg-U, which agrees well with the theoretically calculated value. Compared with

  16. Report on 241,242Am(n,x) surrogate cross section measurement

    SciTech Connect

    Burke, J T; Ressler, J J; Gostic, J; Henderson, R A; Bernstein, L A; Escher, J E; Bleuel, D; Kritcher, A; Matoon, C; Scielzo, N D; Stoyer, M A

    2011-02-16

    The main goal of this measurement is to determine the {sup 242}Am(n,f) and {sup 241}Am(n,f) cross sections via the surrogate {sup 243}Am. Gamma-ray data was also collected for the purpose of measuring the (n,2n) cross-sections. The experiment was conducted using the STARS/LIBERACE experimental facility located at the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory the first week of February 2011. A description of the experiment and status of the data analysis follow.

  17. Nuclear Data Sheets for A=243

    DOE PAGES

    Nesaraja, Caroline D; McCutchan, Elizabeth A.

    2014-09-30

    We present available information pertaining to the nuclear structure of all nuclei with mass numbers A=243. Various decay and reaction data are evaluated and compared. Adopted data, levels, spin, parity and configuration assignments are given. When there are insufficient data, expected values from systematics of nuclear properties or/and theoretical calculations are quoted. Unexpected or discrepant experimental results are also noted. A summary and compilation of the discovery of various isotopes in this mass region is given in 2013Fr02 (243Np, 243Pu, 243Am, 243Cm, 243Bk, and 243Cf), 2011Me01 (243Es), and 2013Th02 (243Fm).

  18. Study of Neutron-Induced Fission Cross Sections of U, Am, and Cm at n_TOF

    NASA Astrophysics Data System (ADS)

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

    2010-08-01

    Neutron induced fission cross sections of several isotopes have been measured at the CERN n_TOF spallation neutron facility. Between them some measurements involve isotopes (233U, 241Am, 243Am, 245Cm) relevant for applications to nuclear technologies. The n_TOF facility delivers neutrons with high instantaneous flux and in a wide energy range, from thermal up to 250 MeV. The experimental apparatus consists of an ionization chamber that discriminates fission fragments and α particles coming from natural radioactivity of the samples. All the measurements were performed referring to the standard cross section of 235U.

  19. Selected spectroscopic results on element 115 decay chains

    DOE PAGES

    Rudolph, D.; Forsberg, U.; Golubev, P.; ...

    2014-08-24

    We observed thirty correlated α-decay chains in an experiment studying the fusion-evaporation reaction 48Ca + 243Am at the GSI Helmholtzzentrum fur Schwerionenforschung. The decay characteristics of the majority of these 30 chains are consistent with previous observations and interpretations of such chains to originate from isotopes of element Z = 115. High-resolution α-photon coincidence spectroscopy in conjunction with comprehensive Monte-Carlo simulations allow to propose excitation schemes of atomic nuclei of the heaviest elements, thereby probing nuclear structure models near the 'Island of Stability' with unprecedented experimental precision.

  20. Comparison of complementary reactions for the production of {sup 261,262}Bh

    SciTech Connect

    Nelson, S. L.; Folden III, C. M.; Dragojevic, I.; Garcia, M. A.; Gates, J. M.; Nitsche, H.; Gregorich, K. E.; Sudowe, R.; Duellmann, Ch. E.; Eichler, R.

    2008-08-15

    Two heavy-ion induced fusion reactions producing {sup 261,262}Bh were studied using the Berkeley Gas-filled Separator at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. An excitation function for the production of {sup 262}Bh via the reaction {sup 209}Bi({sup 54}Cr,n){sup 262}Bh was measured with a maximum cross section from a fit to the data of 430 {+-} 110 pb observed at a compound nucleus excitation energy of 15.7 MeV. New data have been measured for the 1n exit channel of the {sup 208}Pb({sup 55}Mn, n){sup 262}Bh reaction. We present an updated excitation function with an observed maximum cross section of 530{+-}100 pb at a compound nucleus excitation energy of 14.1 MeV. Events corresponding to the 2n exit channel for the {sup 209}Bi({sup 54}Cr,2n){sup 261}Bh and {sup 208}Pb({sup 55}Mn,2n){sup 261}Bh reactions were also observed and are presented as partial excitation functions. The measured decay properties correspond well with existing experimental data. We compare these experimental results to cross section predictions from a model by Swiatecki et al. and discuss entrance channel effects on the magnitude of 1n cross sections.

  1. Probable new type of reaction mechanism: Double. cap alpha. direct transfer process

    SciTech Connect

    Xu Shu-wei; Wu Guo-hua; Miao Rong-zhi; Han Fei

    1983-10-01

    It is assumed that /sup 8/Be consists of two ..cap alpha.. particles which are close to each other in configuration space. A spectroscopic density of /sup 8/Be cluster in the residue nuclei is then obtained, which is proportional to the square of the preformation probability of ..cap alpha.. particle at nuclear surface. Using the improved method of parametrization of EFR-DWBA overlap integral,/sup 1//sup en-dash//sup 2/ we calculate the double differential energy spectra and angular distributions of ..cap alpha.. particles for the reactions /sup 209/Bi (/sup 12/C, ..cap alpha..) /sup 217/Fr and extract the preformation probability of ..cap alpha.. particle at the surface of /sup 217/Fr nuclei from fitting the experimental data. The agreement within the range of calculation error between the preformation probabilities extracted from transfer reactions and ..cap alpha.. decay suggests that the reaction /sup 209/Bi(/sup 12/C, ..cap alpha..) /sup 217/Fr may be explained as a double ..cap alpha.. direct transfer process.

  2. Measurement of activation cross-sections for high-energy neutron-induced reactions of Bi and Pb

    NASA Astrophysics Data System (ADS)

    Zaman, Muhammad; Kim, Guinyun; Kim, Kwangsoo; Naik, Haladhara; Shahid, Muhammad; Lee, Manwoo

    2015-08-01

    The cross-sections for 209Bi(n, 4n)206Bi, 209Bi(n, 5n)205Bi, natPb(n, xn)204mPb, natPb(n, xn)203Pb, natPb(n, xn)202mPb,natPb(n, xn)201Pb, natPb(n, xn)200Pb, natPb(n, αxn)203Hg and natPb(n, p xn)202Tl reactions were determined at the Korean Institute of Radiological and Medical Sciences (KIRAMS), Korea in the neutron energy range of 15.2 to 37.2 MeV. The above cross-sections were obtained by using the activation and off-line γ-ray spectrometric technique. The quasi-monoenergetic neutron used for the above reactions are based on the 9Be(p, n) reaction. Simulations of the spectral flux from the Be target were done using the MCNPX program. The cross-sections were estimated with the TALYS 1.6 code using the default parameter. The data from the present work and literature were compared with the data from the EAF-2010 and the TENDL-2013 libraries, and calculated values of TALYS 1.6 code. It shows that appropriate level density model, the γ-ray strength function, and the spin cut-off parameter are needed to obtain a good agreement between experimental data and theoretical values from TALYS 1.6 code.

  3. Nuclear Data Sheets for A=241

    SciTech Connect

    Martin, M.J.

    2005-09-15

    Detailed level schemes, decay schemes, and the experimental data on which they are based are presented for all nuclides with mass number A=241. The experimental data are evaluated; inconsistencies and discrepancies are noted; and adopted values for excitation energies, {gamma}-ray energies and intensities, as well as for other nuclear properties are given. This evaluation supersedes the earlier nuclear data sheets for A=241 (1994Ak06,1985El03). New data include an extensive study of the levels, gammas, and band structure in {sup 241}Pu via (n,{gamma}), (d,p), and (d,t) (1998Wh01) and in {sup 241}Am via ({sup 209}Bi,{sup 209}Bi'{gamma}) (2004Ab16,2002AbZV). Levels in {sup 241}Cm have been studied via -bar decay (2003As01,2003AsZY) and {alpha} decay (1996Ma72). All experimental internal conversion data have been reanalyzed by the evaluator using the 'frozen orbital hole' internal conversion coefficients of 2002Ba85.

  4. Tight-binding theory of NMR shifts in topological insulators Bi2Se3 and Bi2Te3

    NASA Astrophysics Data System (ADS)

    Boutin, Samuel; Ramírez-Ruiz, Jorge; Garate, Ion

    2016-09-01

    Motivated by recent nuclear magnetic resonance (NMR) experiments, we present a microscopic s p3 tight-binding model calculation of the NMR shifts in bulk Bi2Se3 and Bi2Te3 . We compute the contact, dipolar, orbital and core polarization contributions to the carrier-density-dependent part of the NMR shifts in 209Bi,125Te, and 77Se. The spin-orbit coupling and the layered crystal structure result in a contact Knight shift with strong uniaxial anisotropy. Likewise, because of spin-orbit coupling, dipolar interactions make a significant contribution to the isotropic part of the NMR shift. The contact interaction dominates the isotropic Knight shift in 209Bi NMR, even though the electronic states at the Fermi level have a rather weak s -orbital character. In contrast, the contribution from the contact hyperfine interaction to the NMR shift of 77Se and 125Te is weak compared to the dipolar and orbital shifts therein. In all cases, the orbital shift is at least comparable to the contact and dipolar shifts, while the shift due to core polarization is subdominant (except for Te nuclei located at the inversion centers). By artificially varying the strength of spin-orbit coupling, we evaluate the evolution of the NMR shift across a band inversion but find no clear signature of the topological transition.

  5. Nuclear Structure Investigations of Neutron Deficient Nuclei in the Region Z = 103 to 105

    SciTech Connect

    Heberger, F.P.; Hofmann, S.; Ackermann, D.; Armbruster, P.; Munzenberg, G.; Stodel, Ch.; Lavrentev, A.Yu.; Popeko, A.G.; Yeremin, A.V.; Saro, S.; Leino, M.

    1999-12-31

    The isotopes {sup 257,255}Rf, {sup 257,256}Db, {sup 253,252}Lr have been produced in bombardments of {sup 207,208}Pb and {sup 209}Bi target nuclei with {sup 50}Ti and identified by their {alpha}-decay. New or improved decay data could be obtained. Analysis of the fine structure of the {alpha}-decay pattern of {sup 257}Rf allowed the construction of a first tentative level scheme for the daughter nucleus {sup 253}No and also the identification of a low lying high spin isomeric state, while from {alpha}-{gamma} coincidence measurements for {sup 255}Rf a first tentative level scheme of the daughter nucleus {sup 251}No was derived. For {sup 257}Db we found that two nuclear levels decay by {alpha}-emission and populate also different levels in the daughter nucleus {sup 253}Lr. The levels are produced by the reaction process. In bombardments of {sup 209}Bi with {sup 50}Ti at E*{sub cn} = 26.4 MeV and 30.8 MeV the previously unknown isotopes {sup 256}Db and {sup 22}Lr were identified.

  6. Nuclear structure investigations of neutron deficient nuclei in the region Z=103 to 105

    SciTech Connect

    Hessberger, F. P.; Hofmann, S.; Armbruster, P.; Muenzenberg, G.; Stodel, Ch.; Ackermann, D.; Lavrentev, A. Yu.; Popeko, A. G.; Yeremin, A. V.; Saro, S.; Leino, M.

    1999-11-16

    The isotopes {sup 257,255}Rf, {sup 257,256}Db, {sup 253,252}Lr have been produced in bombardments of {sup 207,208}Pb and {sup 209}Bi target nuclei with {sup 50}Ti and identified by their {alpha}-decay. New or improved decay data could be obtained. Analysis of the fine structure of the {alpha}-decay pattern of {sup 257}Rf allowed the construction of a first tentative level scheme for the daughter nucleus {sup 253}No and also the identification of a low lying high spin isomeric state, while from {alpha}-{gamma}- coincidence measurements for {sup 255}Rf a first tentative level scheme of the daughter nucleus {sup 251}No was derived. For {sup 257}Db we found that two nuclear levels decay by {alpha}-emission and populate also different levels in the daughter nucleus {sup 253}Lr. The levels are produced by the reaction process. In bombardments of {sup 209}Bi with {sup 50}Ti at E{sub CN}*=26.4 MeV and 30.8 MeV the previously unknown isotopes {sup 256}Db and {sup 252}Lr were identified.

  7. Studies of heavy-ion reactions and transuranic nuclei. Progress report, September 1, 1992--August 31, 1993

    SciTech Connect

    Schroeder, W.U.

    1993-08-01

    This report contain papers on the following topics: The Cold-Fusion Saga; Decay Patterns of Dysprosium Nuclei Produced in {sup 32}S + {sup 118,124}Sn Fusion Reactions; Unexpected Features of Reactions Between Very Heavy Ions at Intermediate Bombarding Energies; Correlations Between Neutrons and Charged Products from the Dissipative Reaction {sup 197}Au+{sup 208}Pb at E/A = 29 MeV; Dissipative Dynamics of Projectile-Like Fragment Production in the Reaction {sup 209}Bi+{sup 136}Xe at E/A = 28.2 MeV; Dynamical Production of Intermediate-Mass Fragments in Peripheral {sup 209}Bi+{sup 136}Xe Collisions at E{sub lab}/A = 28.2 MeV; The Rochester 960-Liter Neutron Multiplicity Meter; A Simple Pulse Processing Concept for a Low-Cost Pulse-Shape-Based Particle Identification; A One-Transistor Preamplifier for PMT Anode Signals; A Five-Channel Multistop TDC/Event Handler for the SuperBall Neutron Multiplicity Meter; Construction of the SuperBall -- a 16,000-Liter Neutron Detector for Calorimetric Studies of Intermediate-Energy Heavy-Ion Reactions; A Computer Code for Light Detection Efficiency Calculations for Photo-multipliers of a Neutron Detector; Evaluation of Gd-Loaded Liquid Scintillators for the SuperBall Neutron Calorimeter; and Measurement of the Interaction of Cosmic-Ray {mu}{sup {minus}} with a Muon Telescope.

  8. NMR Evidence for the Topologically Nontrivial Nature in a Family of Half-Heusler Compounds

    PubMed Central

    Zhang, Xiaoming; Hou, Zhipeng; Wang, Yue; Xu, Guizhou; Shi, Chenglong; Liu, EnKe; Xi, Xuekui; Wang, Wenhong; Wu, Guangheng; Zhang, Xi-xiang

    2016-01-01

    Spin-orbit coupling (SOC) is expected to partly determine the topologically nontrivial electronic structure of heavy half-Heusler ternary compounds. However, to date, attempts to experimentally observe either the strength of SOC or how it modifies the bulk band structure have been unsuccessful. By using bulk-sensitive nuclear magnetic resonance (NMR) spectroscopy combined with first-principles calculations, we reveal that 209Bi NMR isotropic shifts scale with relativity in terms of the strength of SOC and average atomic numbers, indicating strong relativistic effects on NMR parameters. According to first-principles calculations, we further claim that nuclear magnetic shieldings from relativistic p1/2 states and paramagnetic contributions from low-lying unoccupied p3/2 states are both sensitive to the details of band structures tuned by relativity, which explains why the hidden relativistic effects on band structure can be revealed by 209Bi NMR isotropic shifts in topologically nontrivial half-Heusler compounds. Used in complement to surface-sensitive methods, such as angle resolved photon electron spectroscopy and scanning tunneling spectroscopy, NMR can provide valuable information on bulk electronic states. PMID:26980406

  9. NMR Evidence for the Topologically Nontrivial Nature in a Family of Half-Heusler Compounds.

    PubMed

    Zhang, Xiaoming; Hou, Zhipeng; Wang, Yue; Xu, Guizhou; Shi, Chenglong; Liu, EnKe; Xi, Xuekui; Wang, Wenhong; Wu, Guangheng; Zhang, Xi-Xiang

    2016-03-16

    Spin-orbit coupling (SOC) is expected to partly determine the topologically nontrivial electronic structure of heavy half-Heusler ternary compounds. However, to date, attempts to experimentally observe either the strength of SOC or how it modifies the bulk band structure have been unsuccessful. By using bulk-sensitive nuclear magnetic resonance (NMR) spectroscopy combined with first-principles calculations, we reveal that (209)Bi NMR isotropic shifts scale with relativity in terms of the strength of SOC and average atomic numbers, indicating strong relativistic effects on NMR parameters. According to first-principles calculations, we further claim that nuclear magnetic shieldings from relativistic p1/2 states and paramagnetic contributions from low-lying unoccupied p3/2 states are both sensitive to the details of band structures tuned by relativity, which explains why the hidden relativistic effects on band structure can be revealed by (209)Bi NMR isotropic shifts in topologically nontrivial half-Heusler compounds. Used in complement to surface-sensitive methods, such as angle resolved photon electron spectroscopy and scanning tunneling spectroscopy, NMR can provide valuable information on bulk electronic states.

  10. NMR Evidence for the Topologically Nontrivial Nature in a Family of Half-Heusler Compounds

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoming; Hou, Zhipeng; Wang, Yue; Xu, Guizhou; Shi, Chenglong; Liu, Enke; Xi, Xuekui; Wang, Wenhong; Wu, Guangheng; Zhang, Xi-Xiang

    2016-03-01

    Spin-orbit coupling (SOC) is expected to partly determine the topologically nontrivial electronic structure of heavy half-Heusler ternary compounds. However, to date, attempts to experimentally observe either the strength of SOC or how it modifies the bulk band structure have been unsuccessful. By using bulk-sensitive nuclear magnetic resonance (NMR) spectroscopy combined with first-principles calculations, we reveal that 209Bi NMR isotropic shifts scale with relativity in terms of the strength of SOC and average atomic numbers, indicating strong relativistic effects on NMR parameters. According to first-principles calculations, we further claim that nuclear magnetic shieldings from relativistic p1/2 states and paramagnetic contributions from low-lying unoccupied p3/2 states are both sensitive to the details of band structures tuned by relativity, which explains why the hidden relativistic effects on band structure can be revealed by 209Bi NMR isotropic shifts in topologically nontrivial half-Heusler compounds. Used in complement to surface-sensitive methods, such as angle resolved photon electron spectroscopy and scanning tunneling spectroscopy, NMR can provide valuable information on bulk electronic states.

  11. Correlation between strain and defects in Bi implanted Si

    NASA Astrophysics Data System (ADS)

    Palade, C.; Lepadatu, A.-M.; Slav, A.; Ciurea, M. L.; Lazanu, S.

    2016-06-01

    The strain in Si containing group-V impurities is a topical subject of study due to its potential applications in quantum computing. In this paper we study 209Bi implanted Si concerning the correlation between the strain produced by stopped Bi ions and trapping characteristics of the defects resulted from implantation. The depths distributions of stopped ions and primary defects are simulated and the distributions of permanent defects are modelled for Si implanted with low fluence 209Bi ions of 28 MeV kinetic energy. For comparison, these depths distributions were similarly calculated for 127I ions with the same fluence and energy, implanted in Si. The results are compared with each other and correlated with the characteristics of traps in these systems, previously obtained. We demonstrate that the intensity of the strain field is the most important factor in changing of trap parameters, while the superposition between the region with strain and the region where defects are located is a second order effect.

  12. Estimation of Radiation Doses in the Marshall Islands Based on Whole Body Counting of Cesium-137 (137Cs) and Plutonium Urinalysis

    SciTech Connect

    Daniels, J; Hickman, D; Kehl, S; Hamilton, T

    2007-06-11

    Under the auspices of the U.S. Department of Energy (USDOE), researchers from the Lawrence Livermore National Laboratory (LLNL) have recently implemented a series of initiatives to address long-term radiological surveillance needs at former nuclear test sites in the Republic of the Marshall Islands (RMI). The aim of this radiological surveillance monitoring program (RSMP) is to provide timely radiation protection for individuals in the Marshall Islands with respect to two of the most important internally deposited fallout radionuclides-cesium-137 ({sup 137}Cs) and long-lived isotopes 239 and 240 of plutonium ({sup 239+240}Pu) (Robison et al., 1997 and references therein). Therefore, whole-body counting for {sup 137}Cs and a sensitive bioassay for the presence of {sup 239+240}Pu excreted in urine were adopted as the two most applicable in vivo analytical methods to assess radiation doses for individuals in the RMI from internally deposited fallout radionuclides (see Hamilton et al., 2006a-c; Bell et al., 2002). Through 2005, the USDOE has established three permanent whole-body counting facilities in the Marshall Islands: the Enewetak Radiological Laboratory on Enewetak Atoll, the Utrok Whole-Body Counting Facility on Majuro Atoll, and the Rongelap Whole-Body Counting Facility on Rongelap Atoll. These whole-body counting facilities are operated and maintained by trained Marshallese technicians. Scientists from LLNL provide the technical support and training necessary for maintaining quality assurance for data acquisition and dose reporting. This technical basis document summarizes the methodologies used to calculate the annual total effective dose equivalent (TEDE; or dose for the calendar year of measurement) based on whole-body counting of internally deposited {sup 137}Cs and the measurement of {sup 239+240}Pu excreted in urine. Whole-body counting provides a direct measure of the total amount (or burden) of {sup 137}Cs present in the human body at the time of

  13. USTUR WHOLE BODY CASE 0269: DEMONSTRATING EFFECTIVENESS OF I.V. CA-DTPA FOR PU

    SciTech Connect

    James, Anthony C.; Sasser , Lyle B.; Stuit, Dorothy B.; Glover, Samuel E.; Carbaugh, Eugene H.

    2008-01-28

    This whole body donation case (USTUR Registrant) involved a single acute inhalation of an acidic Pu(NO3)4 solution in the form of an aerosol ‘mist.’ Chelation treatment with i.v. Ca-EDTA was initiated on the day of the intake, and continued intermittently over 6 months. After 2½ years with no further treatment, a course of i.v. Ca-DTPA was administered. A total of 400 measurements of 239+240Pu excreted in urine were recorded; starting on the first day (both before and during the initial Ca-EDTA chelation), and continuing for 37 years. This sampling included all intervals of chelation. In addition, 91 measurements of 239+240Pu-in-feces were recorded over this whole period. The Registrant died about 38 years after the intake, at age 79 y, with extensive carcinomatosis secondary to adenocarcinoma of the prostate gland. At autopsy, all major soft tissue organs were harvested for radiochemical analyses of their 238Pu, 239+240Pu and 241Am content. Also, all types of bone (comprising about half the skeleton) were harvested for radiochemical analyses, as well as samples of skin, subcutaneous fat and muscle. This comprehensive dataset has been applied to derive ‘chelation-enhanced’ transfer rates in the ICRP Publication 67 plutonium biokinetic model, representing the behaviour of blood-borne and tissue-incorporated plutonium during intervals of therapy. The resulting model of the separate effects of i.v. Ca-EDTA and Ca-DTPA chelation shows that the therapy administered in this case succeeded in reducing substantially the long-term burden of plutonium in all body organs, except for the lungs. The calculated reductions in organ content at the time of death are approximately 40% for the liver, 60% for other soft tissues (muscle, skin, glands, etc.), 50% for the kidneys, and 50% for the skeleton. Essentially all of the substantial reduction in skeletal burden occurred in trabecular bone. This modeling exercise demonstrated that 3-y-delayed Ca-DTPA therapy was as

  14. Radiation release at the nation's only operating deep geological repository--an independent monitoring perspective.

    PubMed

    Thakur, P; Ballard, S; Hardy, R

    2014-11-04

    Recent incidents at the nation's only operating deep geologic nuclear waste repository, the Waste Isolation Pilot Plant (WIPP), resulted in the release of americium and plutonium from one or more defense-related transuranic (TRU) waste containers into the environment. WIPP is a U.S. Department of Energy mined geologic repository that has been in operation since March, 1999. Over 85,000 m3 of waste in various vented payload containers have been emplaced in the repository. The primary radionuclides within the disposed waste are 239+240Pu and 241Am, which account for more than 99% of the total TRU radioactivity disposed and scheduled for disposal in the repository. For the first time in its 15 years of operation, there was an airborne radiation release from the WIPP at approximately 11:30 PM Mountain Standard Time (MST) on Friday, February 14, 2014. The radiation release was likely caused by a chemical reaction inside a TRU waste drum that contained nitrate salts and organic sorbent materials. In a recent news release, DOE announced that photos taken of the waste underground showed evidence of heat and gas pressure resulting in a deformed lid, in material expelled through that deformation, and in melted plastic and rubber and polyethylene in the vicinity of that drum. Recent entries into underground Panel 7 have confirmed that at least one waste drum containing a nitrate salt bearing waste stream from Los Alamos National Laboratory was breached underground and was the most likely source of the release. Further investigation is underway to determine if other containers contributed to the release. Air monitoring across the WIPP site intensified following the first reports of radiation detection underground to ascertain whether or not there were releases to the ground surface. Independent analytical results of air filters from sampling stations on and near the WIPP facility have been released by us at the Carlsbad Environmental Monitoring & Research Center and confirmed

  15. Nuclear Data Sheets for A = 240

    SciTech Connect

    Singh, Balraj; Browne, E.

    2008-10-15

    Evaluated experimental data for radioactive decays and reactions for known nuclides (U, Np, Pu, Am, Cm, Bk, Cf) of A = 240 are presented together with adopted values for level energies, {gamma}-ray energies, relative branching ratios and other nuclear properties. This revision was primarily motivated by the need for re-evaluation of absolute gamma-ray intensities from the {epsilon} decay of {sup 240}Am to {sup 240}Pu. These quantities are essential for determining precise and accurate cross-sections for the {sup 241}Am(n,2n){sup 240}Am reaction using fast neutrons (see e.g. Americium Workshop, Santa Fe, New Mexico, September 2007, 2008To06, 2007Ta01, 2006Pe14) and {sup 241}Am({gamma},n) reaction (see e.g. 2006Ri08). For {sup 240}U, the {gamma}-ray data have now become available. The data sets for {sup 244}Pu {alpha} decay to {sup 240}U; {sup 244}Cm {alpha} decay to {sup 240}Pu and {sup 244}Cf {alpha} decay to {sup 240}Cm have been adapted from evaluations by 1998Ak04 and 2003Ak04. For {sup 244}Cm decay, evaluation by 2006BeZL under the Decay Data Evaluation Project (DDEP) is also used. The {gamma}-ray data (energies and intensities) for {sup 240}Cm decay are not considered (by the evaluators) as well established. Most detailed data are available only for {sup 240}Pu. Extensive data in the second potential well are available for this nuclide together with fission isomers and several superdeformed (SD) structures. For other nuclides spectroscopic data are rather sparse in the literature; especially for the following radioactive decays: The {epsilon} decays of {sup 240}Cf, {sup 240}Bk and {sup 240}Cm; multipolarities of {gamma}-ray transitions in {sup 240}Np from {sup 240}U {beta}{sup -} decay; {gamma}-ray transitions from {sup 244}Cf {alpha} decay and %{epsilon} branch of {sup 244}Cf decay; spins and parities of excited states in {sup 240}U and multipolarities of associated {gamma}-ray transitions in {sup 240}U. This work supersedes earlier full evaluations of A

  16. Radionuclide concentrations in underground waters of Mururoa and Fangataufa Atolls.

    PubMed

    Mulsow, S; Coquery, M; Dovlete, C; Gastaud, J; Ikeuchi, Y; Pham, M K; Povinec, P P

    1999-09-30

    In 1997 an expedition to Mururoa and Fangataufa Atolls was carried out to sample underground waters from cavity-chimneys and carbonate monitoring wells. The aim of this study was to determine the prevailing concentration and distribution status of radionuclides. Elemental analysis of interstitial waters was carried out in the water fraction as well as in particles collected at 11 underground monitoring wells. 238Pu, 239,240Pu, 241Am, 137Cs, 90Sr, 3H, 125Sb, 155Eu and 60Co were analyzed in both fractions by alpha-, beta- and gamma-spectrometry. Measurements showed that at 60% of the sites, pH and Eh seemed to be related to tidal cycles; in contrast HTO was constant during the sampling time. Interstitial waters from carbonates and transition zones shared similar chemical composition that were not different from that of the surrounding seawater. Waters collected from basalt cavities left after nuclear tests, (Aristee and Ceto) have a different chemical signature characterized by a deficiency in Mg, K and SO4 as well as enrichment in Sr, Si, Al and Cl compared to the rest of the stations. Radionuclide concentrations present in both, water and particulate fractions, were significantly higher at Ceto and Aristee than at any other monitoring wells, except for Fuseau and Mitre monitoring wells (Fangataufa) where values similar to Ceto were found (e.g. 239,240Pu: > 20 mBq g-1). Considering that Pu isotopes showed high Kd values compared to non-sorbing radionuclides such as 3H, 90Sr and 137Cs it is very unlikely that migration from cavities to monitoring wells accounts for the concentration of Pu isotopes and Am at Fuseau 30 and Mitre 27. Perhaps the contact of lagoon waters with the well before sealing could be a possible source of the transuranics found at these sites. The 238Pu/239,240Pu ratios measured in the particles were similar to that of the lagoon (0.38), thus supporting this hypothesis. The fact that transuranics were found only in the particle fraction, in the

  17. 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

  18. Reconstruction of local fallout composition and gamma-ray exposure in a village contaminated by the first USSR nuclear test in the Semipalatinsk nuclear test site in Kazakhstan.

    PubMed

    Imanaka, Tetsuji; Yamamoto, Masayoshi; Kawai, Kenta; Sakaguchi, Aya; Hoshi, Masaharu; Chaizhunusova, Nailya; Apsalikov, Kazbek

    2010-11-01

    After the disintegration of the USSR in end of 1991, it became possible for foreign scientists to visit Kazakhstan, in order to investigate the radiological consequences of nuclear explosions that had been conducted at the Semipalatinsk nuclear test site (SNTS). Since the first visit in 1994, our group has been continuing expeditions for soil sampling at various areas around SNTS. The current level of local fallout at SNTS was studied through γ-spectrometry for (137)Cs as well as α-spectrometry for (239,240)Pu. Average values of soil inventory from wide areas around SNTS were 3,500 and 3,700 Bq m(-2) for (137)Cs and (239,240)Pu, respectively, as of January 1, 2000. The average level of (137)Cs is comparable to that in Japan due to global fallout, while the level of (239,240)Pu is several tens of times larger than that in Japan. Areas of strong contamination were found along the trajectories of radioactive fallout, information on which was declassified after the collapse of the USSR. Our recent efforts of soil sampling were concentrated on the area around the Dolon village heavily affected by the radioactive plume from the first USSR atomic bomb test in 1949 and located 110 km east from ground zero of the explosion. Using soil inventory data, retrospective dosimetry was attempted by reconstructing γ-ray exposure from fission product nuclides deposited on the ground. Adopting representative parameters for the initial (137)Cs deposition (13 kBq m(-2)), the refractory/volatile deposition ratio (3.8) and the plume arrival time after explosion (2.5 h), an absorbed dose in air of 600 mGy was obtained for the 1-year cumulative dose in Dolon village, due to the first bomb test in 1949. Considering possible ranges of the parameters, 350 and 910 mGy were estimated for high and low cases of γ-ray dose in air, respectively. It was encouraging that the deduced value was consistent with other estimations using thermal luminescence and archived monitoring data. The present

  19. Americium, plutonium and uranium contamination and speciation in well waters, streams and atomic lakes in the Sarzhal region of the Semipalatinsk Nuclear Test Site, Kazakhstan.

    PubMed

    León Vintró, L; Mitchell, P I; Omarova, A; Burkitbayev, M; Jiménez Nápoles, H; Priest, N D

    2009-04-01

    New data are reported on the concentrations, isotopic composition and speciation of americium, plutonium and uranium in surface and ground waters in the Sarzhal region of the Semipalatinsk Test Site, and an adjacent area including the settlement of Sarzhal. The data relate to filtered water and suspended particulate from (a) streams originating in the Degelen Mountains, (b) the Tel'kem 1 and Tel'kem 2 atomic craters, and (c) wells on farms located within the study area and at Sarzhal. The measurements show that (241)Am, (239,240)Pu and (238)U concentrations in well waters within the study area are in the range 0.04-87mBq dm(-3), 0.7-99mBq dm(-3), and 74-213mBq dm(-3), respectively, and for (241)Am and (239,240)Pu are elevated above the levels expected solely on the basis of global fallout. Concentrations in streams sourced in the Degelen Mountains are similar, while concentrations in the two water-filled atomic craters are somewhat higher. Suspended particulate concentrations in well waters vary considerably, though median values are very low, at 0.01mBq dm(-3), 0.08mBq dm(-3) and 0.32mBq dm(-3) for (241)Am, (239,240)Pu and (238)U, respectively. The (235)U/(238)U isotopic ratio in almost all well and stream waters is slightly elevated above the 'best estimate' value for natural uranium worldwide, suggesting that some of the uranium in these waters is of test-site provenance. Redox analysis shows that on average most of the plutonium present in the microfiltered fraction of these waters is in a chemically reduced form (mean 69%; 95% confidence interval 53-85%). In the case of the atomic craters, the proportion is even higher. As expected, all of the americium present appears to be in a reduced form. Calculations suggest that annual committed effective doses to individual adults arising from the daily ingestion of these well waters are in the range 11-42microSv (mean 21microSv). Presently, the ground water feeding these wells would not appear to be contaminated with

  20. Ustur whole body case 0269: demonstrating effectiveness of i.v. CA-DTPA for Pu.

    PubMed

    James, A C; Sasser, L B; Stuit, D B; Glover, S E; Carbaugh, E H

    2007-01-01

    This whole body donation case (USTUR Registrant) involved a single acute inhalation of an acidic Pu(NO3)4 solution in the form of an aerosol 'mist'. Chelation treatment with intravenously (i.v.) Ca-EDTA was initiated on the day of the intake, and continued intermittently over 6 months. After 2.5 y with no further treatment, a course of i.v. Ca-DTPA was administered. A total of 400 measurements of 239+240Pu excreted in urine were recorded; starting on the first day (both before and during the initial Ca-EDTA chelation) and continuing for 37 y. This sampling included all intervals of chelation. In addition, 91 measurements of 239+240Pu-in-feces were recorded over this whole period. The Registrant died about 38 y after the intake, at age 79 y, with extensive carcinomatosis secondary to adenocarcinoma of the prostate gland. At autopsy, all major soft tissue organs were harvested for radiochemical analyses of their 238Pu, 239+240Pu and 241Am content. Also, all types of bone (comprising about half the skeleton) were harvested for radiochemical analyses, as well as samples of skin, subcutaneous fat and muscle. This comprehensive data set has been applied to derive 'chelation-enhanced' transfer rates in the ICRP Publication 67 plutonium biokinetic model, representing the behaviour of blood-borne and tissue-incorporated plutonium during intervals of therapy. The resulting model of the separate effects of i.v. Ca-EDTA and Ca-DTPA chelation shows that the therapy administered in this case succeeded in reducing substantially the long-term burden of plutonium in all body organs, except for the lungs. The calculated reductions in organ content at the time of death are approximately 40% for the liver, 60% for other soft tissues (muscle, skin, glands, etc.), 50% for the kidneys and 50% for the skeleton. Essentially, all of the substantial reduction in skeletal burden occurred in trabecular bone. This modelling exercise demonstrated that 3-y-delayed Ca-DTPA therapy was as effective

  1. Sedimentation and mixing rates of radionuclides in Barents Sea sediments off Novaya Zemlya

    NASA Astrophysics Data System (ADS)

    Smith, J. N.; Ellis, K. M.; Naes, K.; Dahle, S.; Matishov, D.

    Radionuclide measurements have been conducted on sediment cores collected in 1992 in the south-eastern region of the Barents Sea, known as the Pechora Sea. Cesium-137 and 239,24OPu activities in surface sediments are generally less than 30 Bq/kg, with the highest levels being measured in sediments off the southwestern coastline of the island of Novaya Zemlya. High correlations between both 137Cs and 239,24OPu and the concentration of fine (< 63 μm) particles in surface sediments indicate that much of the variance in radionuclide concentrations throughout the Pechora Sea can be explained by particle size fractionation. However, elevated activities of 137Cs (138 Bq/kg), 60Co (92 Bq/kg), 241Am (433 Bq/kg), and especially 239,24OPu (8.47 × 103 Bq/kg) were measured in one surface sediment sample from the fjord of Chernaya Bay on the southern coast of Novaya Zemlya. The source of radioactive contamination is two underwater nuclear tests conducted in Chernaya Bay in 1955 and 1957. The 238Pu /239,240Vu activity ratio of 0.0245 in Chernaya Bay is equivalent to values measured in global fallout. The 240Pu /239Pu atom ratio (0.0304), measured by mass spectrometry, is much lower than values (0.18) typical of global fallout, but is consistent with ratios measured for fallout from the early (1951-1955) series of weapons tests at the Nevada Test Site. The timing of the Chernaya Bay source term, estimated from the 241Am /241Pu ratio, is consistent with the timing of the 1955 and 1957 underwater nuclear tests. Relatively low initial yields of 241Pu ( 241Pu /239Pu atom ratio = 0.00 123) in these tests have resulted in relatively low 241Am /239,240Pu activity ratios (0.05) in recent sediments in Chernaya Bay. Radionuclide tracer profiles in cores from the Pechora Sea can be simulated using a two-layer biodiffusion model with rapid, near-homogeneous mixing in the surface mixed layer and reduced mixing in the deep layer. Lead-210 profiles are consistent with a wide range of

  2. Accelerator Mass Spectrometry of Actinides in Ground- and Seawater: An Innovative Method Allowing for the Simultaneous Analysis of U, Np, Pu, Am, and Cm Isotopes below ppq Levels.

    PubMed

    Quinto, Francesca; Golser, Robin; Lagos, Markus; Plaschke, Markus; Schäfer, Thorsten; Steier, Peter; Geckeis, Horst

    2015-06-02

    (236)U, (237)Np, and Pu isotopes and (243)Am were determined in ground- and seawater samples at levels below ppq (fg/g) with a maximum sample size of 250 g. Such high sensitivity was possible by using accelerator mass spectrometry (AMS) at the Vienna Environmental Research Accelerator (VERA) with extreme selectivity and recently improved efficiency and a significantly simplified separation chemistry. The use of nonisotopic tracers was investigated in order to allow for the determination of (237)Np and (243)Am, for which isotopic tracers either are rarely available or suffer from various isobaric mass interferences. In the present study, actinides were concentrated from the sample matrix via iron hydroxide coprecipitation and measured sequentially without previous chemical separation from each other. The analytical method was validated by the analysis of the Reference Material IAEA 443 and was applied to groundwater samples from the Colloid Formation and Migration (CFM) project at the deep underground rock laboratory of the Grimsel Test Site (GTS) and to natural water samples affected solely by global fallout. While the precision of the presented analytical method is somewhat limited by the use of nonisotopic spikes, the sensitivity allows for the determination of ∼10(5) atoms in a sample. This provides, e.g., the capability to study the long-term release and retention of actinide tracers in field experiments as well as the transport of actinides in a variety of environmental systems by tracing contamination from global fallout.

  3. Interaction of Fast Nucleons with Actinide Nuclei Studied with GEANT4

    NASA Astrophysics Data System (ADS)

    Malyshkin, Yu.; Pshenichnov, I.; Mishustin, I.; Greiner, W.

    2014-04-01

    We model interactions of protons and neutrons with energies from 1 to 1000 MeV with 241Am and 243Am nuclei. The calculations are performed with the Monte Carlo model for Accelerator Driven Systems (MCADS) which we developed based on the GEANT4 toolkit of version 9.4. This toolkit is widely used to simulate the propagation of particles in various materials which contain nuclei up to uranium. After several extensions we apply this toolkit also to proton- and neutron-induced reactions on Am. The fission and radiative neutron capture cross sections, neutron multiplicities and distributions of fission fragments were calculated for 241Am and 243Am and compared with experimental data. As demonstrated, the fission of americium by energetic protons with energies above 20 MeV can be well described by the Intra-Nuclear Cascade Liège (INCL) model combined with the fission-evaporation model ABLA. The calculated average numbers of fission neutrons and mass distributions of fission products agree well with the corresponding data. However, the proton-induced fission below 20 MeV is described less accurately. This is attributed to the limitations of the Intra-Nuclear Cascade model at low projectile energies.

  4. Kilogram-scale purification of americium by ion exchange

    SciTech Connect

    Wheelwright, E.J.

    1980-05-01

    Sequential anion and cation exchange processes have been used for the final purification of /sup 241/Am recovered during the reprocessing of aged plutonium metallurgical scrap. Plutonium was removed by absorption on Dowex 1, X-3.5 (30 to 50 mesh) anion exchange resin from 6.5 to 7.5 M HNO/sub 3/ feed solution. Following a water dilution to 0.75 to 1.0 M HNO/sub 3/, americium was absorbed on Dowex 50W, X-8 (50 to 100 mesh) cation exchange resin. Final purification was accomplished by elution of the absorbed band down 3 to 4 successive beds of the same resin, preloaded with Zn/sup 2+/, with an NH/sub 4/OH buffered chelating agent. The recovery of mixed /sup 241/Am-/sup 243/Am from power reactor reprocessing waste has been demonstrated. Solvent extraction was used to recover a HNO/sub 3/ solution of mixed lanthanides and actinides from waste generated by the reprocessing of 13.5 tons of Shippingport Power Reactor blanket fuel. Sequential cation exchange band-displacement processes were then used to separate americium and curium from the lanthanides and then to separate approx. 60 g of /sup 244/Cm from 1000 g of mixed /sup 241/Am-/sup 243/Am.

  5. Report on 240Am(n,x) surrogate cross section test measurement

    SciTech Connect

    Ressler, J J; Burke, J T; Gostic, J; Bleuel, D; Escher, J E; Henderson, R A; Koglin, J; Reed, T; Scielzo, N D; Stoyer, M A

    2012-02-01

    The main goal of the test measurement was to determine the feasibility of the {sup 243}Am(p,t) reaction as a surrogate for {sup 240}Am(n,f). No data cross section data exists for neutron induced reactions on {sup 240}Am; the half-life of this isotope is only 2.1 days making direct measurements difficult, if not impossible. The 48-hour experiment was conducted using the STARS/LIBERACE experimental facility located at the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory in August 2011. A description of the experiment and results is given. The beam energy was initially chosen to be 39 MeV in order to measure an equivalent neutron energy range from 0 to 20 MeV. However, the proton beam was not stopped in the farady cup and the beam was deposited in the surrounding shielding material. The shielding material was not conductive, and a beam current, needed for proper tuning of the beam as well as experimental monitoring, could not be read. If the {sup 240}Am(n,f) surrogate experiment is to be run at LBNL, simple modifications to the beam collection site will need to be made. The beam energy was reduced to 29 MeV, which was within an energy regime of prior experiments and tuning conditions at STARS/LIBERACE. At this energy, the beam current was successfully tuned and measured. At 29 MeV, data was collected with both the {sup 243}Am and {sup 238}U targets. An example particle identification plot is shown in Fig. 1. The triton-fission coincidence rate for the {sup 243}Am target and {sup 238}U target were measured. Coincidence rates of 0.0233(1) cps and 0.150(6) cps were observed for the {sup 243}Am and {sup 238}U targets, respectively. The difference in count rate is largely attributed to the available target material - the {sup 238}U target contains approximately 7 times more atoms than the {sup 243}Am. A proton beam current of {approx}0.7 nA was used for measurements on both targets. Assuming a full experimental run under similar conditions, an estimate for the

  6. A survey of radioactive fallout data in Alaska

    SciTech Connect

    DePhillips, M.P.

    1995-10-23

    Considerable attention has been directed by the scientific community to assessing the levels and fate of radionuclides in Arctic ecosystems. The following text and tables present available data and discussion of radionuclide fallout in Alaska. A literature search of 23 on-line databases (Table 1) using Alaska, Strontium (Sr), Cesium (Cs), Plutonium (Pu) and Radionuclide as constraint terms responded with 177 possible citations. After eliminating duplicate citations, 31 articles were available: 17 were relevant to the subject matter; the remainder addressed geologic issues. All of the cited literature addressed {sup 137}Cs, {sup 90}Sr and {sup 239,240}Pu as a result of radionuclide fallout from nuclear testing or accidental release.

  7. Direct high-resolution alpha spectrometry from nuclear fuel particles in an outdoor air sample.

    PubMed

    Pöllänen, R; Siiskonen, T

    2008-01-01

    The potential use of direct high-resolution alpha spectrometry to identify the presence of transactinium elements in air samples is illustrated in the case when alpha-particle-emitting radionuclides are incorporated in nuclear fuel particles. Alpha particle energy spectra are generated through Monte Carlo simulations assuming a nuclide composition similar to RBMK (Chernobyl) nuclear fuel. The major alpha-particle-emitting radionuclides, in terms of activity, are 242Cm, 239Pu and 240Pu. The characteristics of the alpha peaks are determined by fuel particle properties as well as the type of the air filter. It is shown that direct alpha spectrometry can be readily applied to membrane filter samples containing nuclear fuel particles when rapid nuclide identification is of relevance. However, the development of a novel spectrum analysis code is a prerequisite for unfolding complex alpha spectra.

  8. AFCI-2.0 Library of Neutron Cross Section Covariances

    SciTech Connect

    Herman, M.; Herman,M.; Oblozinsky,P.; Mattoon,C.; Pigni,M.; Hoblit,S.; Mughabghab,S.F.; Sonzogni,A.; Talou,P.; Chadwick,M.B.; Hale.G.M.; Kahler,A.C.; Kawano,T.; Little,R.C.; Young,P.G.

    2011-06-26

    Neutron cross section covariance library has been under development by BNL-LANL collaborative effort over the last three years. The primary purpose of the library is to provide covariances for the Advanced Fuel Cycle Initiative (AFCI) data adjustment project, which is focusing on the needs of fast advanced burner reactors. The covariances refer to central values given in the 2006 release of the U.S. neutron evaluated library ENDF/B-VII. The preliminary version (AFCI-2.0beta) has been completed in October 2010 and made available to the users for comments. In the final 2.0 release, covariances for a few materials were updated, in particular new LANL evaluations for {sup 238,240}Pu and {sup 241}Am were adopted. BNL was responsible for covariances for structural materials and fission products, management of the library and coordination of the work, while LANL was in charge of covariances for light nuclei and for actinides.

  9. Polonium, uranium and plutonium in the southern Baltic ecosystem

    NASA Astrophysics Data System (ADS)

    Skwarzec, B.

    1999-01-01

    This paper presents the results of the measurement of polonium, uranium and plutonium alpha radio-nuclides in seawater and biota of the southern Baltic ecosystem as well as the recognition of their accumulation processes in the trophic chain. Investigation of the polonium210Po and plutonium239+240Pu concentrations in Baltic biota revealed that these radionuclides are strongly accumulated by some species. Mean values of the bioconcentration factor (BCF) fell within the range 9·102 to 3.7·104. The Baltic Sea algae, benthic animals and fish concentrated uranium radioisotopes only to a small extent and mean BCF values for this element range from 1 to 55, which is several orders of magnitude lower than that for polonium and plutonium. Moreover, it was found that Baltic fish constitute an important source of polonium210Po for humans.

  10. Cold fission as heavy ion emission

    NASA Astrophysics Data System (ADS)

    Poenaru, D. N.; Maruhn, J. A.; Greiner, W.; Ivaşcu, M.; Mazilu, D.; Gherghescu, R.

    1987-09-01

    The last version of the analytical superasymmetric fission model is applied to study cold fission processes. Strong shell effects are present either in one or both fission fragments. A smooth behaviour is observed when the proton or the neutron numbers are changed by four units. Increasing Z and N, in the transuranium region, a sharp transition from asymmetry with a large peak-to-valley ratio to symmetry at Z=100 and/or N=164 is obtained. The transition toward asymmetry at higher Z and N is much smoother. The most probable cold fission light fragments from234U,236U,239Np and240Pu are100Zr,104Mo,106Mo and106Mo, respectively, in good agreement with experimental data. The unified treatment of alpha decay, heavy ion radioactivities and cold fission is illustrated for234U — the first nucleus in which all three groups have been already observed.

  11. From symmetric cold fission fragment mass distributions to extremely asymmetric alpha decay

    NASA Astrophysics Data System (ADS)

    Poenaru, D. N.; Ivascu, M.; Maruhn*, J. A.; Greiner*, W.

    1987-12-01

    The analytical superasymmetric fission model, successful in the study of extremely asymmetric decay modes like α-decay and heavy ion radioactivities, is applied to cold fission phenomena. The three groups of processes are described in a unifield manner, showing that cold fission could be considered heavy cluster emission. For 234U all groups have been detected. The highest symmetry of the gragment mass distributions should be observed for the neutron rich nucleus 264Fm, leading to doubly magic products 132Sn. The most probable light fragments from cold fission of 234,236U, 239Np and 240Pu are 100Zr, 104,106,108Mo respectively, in good agreement with experimental data.

  12. Geotrupine beetles (Coleoptera: Scarabaeoidea) as bio-monitors of man-made radioactivity.

    PubMed

    Mietelski, Jerzy W; Szwałko, Przemysław; Tomankiewicz, Ewa; Gaca, Paweł; Grabowska, Sylwia

    2003-04-01

    Adults of the geotrupine beetle Anoplotrupes stercorosus (Coleoptera, Geotrupidae), a common European forest insect species, were used in the role of bio-monitors for mainly man-made radionuclides in a forest environment. Activities of 137Cs, 40K, 238Pu, (239+240)Pu, 90Sr and 241Am were studied. Samples originated from four areas in Poland, two from the north-east and two from the south of the country. The north-eastern areas were previously recognized as the places where hot particle fallout from Chernobyl took place. Results confirmed the differences in the activities between north-eastern and southern locations. Significant correlations were found between activities of 40K and 137Cs, and between activities of plutonium and americium isotopes. An additional study of the concentration of radionuclides within the bodies of beetles showed a general pattern of distribution of radioisotopes in the insect body.

  13. 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.

  14. Radioactive contamination of the Techa River, the Urals.

    PubMed

    Trapeznikov, A V; Pozolotina, V N; Chebotina MYa; Chukanov, V N; Trapeznikova, V N; Kulikov, N V; Nielsen, S P; Aarkrog, A

    1993-11-01

    The Techa River in the Urals was contaminated with high-level radioactive waste from the MAJAK nuclear installation around 1950. The total discharge to the river amounted to 100 PBq with 90Sr and 137Cs contributing approximately 10 PBq each. This study has shown that the river presently contains approximately 0.3 TBq 90Sr, > 6 TBq 137Cs, and approximately 8 GBq 239,240Pu. The estimates were made for the part of the river starting 50 km from the point of discharge and ending 240 km downstream at the confluence with the Iset River. Radioactivity was measured only in the upper 0.10-m sediments layer. The external dose rates from the contamination range from 0.1-30 microGy h-1. The activity concentrations decrease exponentially or by power functions with distance.

  15. Minor Actinides, Major Challenges, the Needs for and Benefits of International Collaboration

    NASA Astrophysics Data System (ADS)

    Plompen, A. J. M.

    2014-04-01

    The role of experiments for the determination of minor actinide nuclear data is presented as essential to meet the tight uncertainties requirements derived by sensitivity analyses for innovative systems designed to significantly reduce the amount of high level nuclear waste. Recent, ongoing and planned experiments are highlighted emphasizing international collaboration and the European context. Specifically, the role of the MANREAD CRP, the European projects ANDES, ERINDA and EURFRAT, and the NEA databank and WPEC subgroups will be addressed. For 241Am capture and 240Pu fission are used to illustrate the generic situation with minor actinide experimental data and the discrepancy between achieved and target uncertainties. The importance of new high quality experiments, high quality reporting, diversity, new techniques, methods and facilities is stressed.

  16. Sources of plutonium in the atmosphere and stratosphere-troposphere mixing

    PubMed Central

    Hirose, Katsumi; Povinec, Pavel P.

    2015-01-01

    Plutonium isotopes have primarily been injected to the stratosphere by the atmospheric nuclear weapon tests and the burn-up of the SNAP-9A satellite. Here we show by using published data that the stratospheric plutonium exponentially decreased with apparent residence time of 1.5 ± 0.5 years, and that the temporal variations of plutonium in surface air followed the stratospheric trends until the early 1980s. In the 2000s, plutonium and its isotope ratios in the atmosphere varied dynamically, and sporadic high concentrations of 239,240Pu reported for the lower stratospheric and upper tropospheric aerosols may be due to environmental events such as the global dust outbreaks and biomass burning. PMID:26508010

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

    NASA Astrophysics Data System (ADS)

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

    2002-12-01

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

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

    SciTech Connect

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

    2010-12-01

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

  19. 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.

  20. The underwater coincidence counter for plutonium measurements in mixed-oxide fuel assemblies manual

    SciTech Connect

    G. W. Eccleston; H. O. Menlove; M. Abhold; M. Baker; J. Pecos

    1999-05-01

    This manual describes the Underwater Coincidence Counter (UWCC) that has been designed for the measurement of plutonium in mixed-oxide (MOX) fuel assemblies prior to irradiation. The UWCC uses high-efficiency {sup 3}He neutron detectors to measure the spontaneous-fission and induced-fission rates in the fuel assembly. Measurements can be made on MOX fuel assemblies in air or underwater. The neutron counting rate is analyzed for singles, doubles, and triples time correlations to determine the {sup 240}Pu effective mass per unit length of the fuel assembly. The system can verify the plutonium loading per unit length to a precision of less than 1% in a measurement time of 2 to 3 minutes. System design, components, performance tests, and operational characteristics are described in this manual.

  1. Field test and evaluation of the passive neutron coincidence collar for prototype fast reactor fuel subassemblies

    SciTech Connect

    Menlove, H.O.; Keddar, A.

    1982-08-01

    The passive neutron Coincidence Collar, which was developed for the verification of plutonium content in fast reactor fuel subassemblies, has been field tested using Prototype Fast Reactor fuel. For passive applications, the system measures the /sup 240/Pu-effective mass from the spontaneous fission rate, and in addition, a self-interrogation technique is used to determine the fissile content in the subassembly. Both the passive and active modes were evaluated at the Windscale Works in the United Kingdom. The results of the tests gave a standard deviation 0.75% for the passive count and 3 to 7% for the active measurement for a 1000-s counting time. The unit will be used in the future for the verification of plutonium in fresh fuel assemblies.

  2. 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.

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

    SciTech Connect

    Li, T.K.

    1985-01-01

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

  4. IAEA-447: a new certified reference material for environmental radioactivity measurements.

    PubMed

    Shakhashiro, A; Tarjan, S; Ceccatelli, A; Kis-Benedek, G; Betti, M

    2012-08-01

    The environment program of the International Atomic Energy Agency (IAEA) includes activities to produce and certify reference materials for environmental radioactivity measurements. This paper describes methodologies applied in preparation and certification of the new IAEA-447 moss-soil certified reference material. In this work, the massic activities and associated standard uncertainties of (40)K, (90)Sr, (137)Cs, (208)Tl, (210)Pb, (210)Po, (212)Pb, (214)Pb, (214)Bi, (226)Ra, (228)Ac, (234)Th, (234)U, (238)U, (238)Pu, (239+240)Pu, (241)Pu and (241)Am were established. Details of the analytical methods including radiochemical procedures were reported. Analytical challenges and lessons learned from the reported results in the worldwide IAEA proficiency test using this material was summarized and best analytical practices to improve the performance for environmental radioactivity determinations were recommended. IAEA-447 is an important reference material for quality control and method validation of gamma-ray spectrometry and radiochemical analytical procedures.

  5. 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.

  6. Light fragment preformation in cold fission of 282Cn

    NASA Astrophysics Data System (ADS)

    Poenaru, D. N.; Gherghescu, R. A.

    2016-11-01

    In a previous article, published in Phys. Rev. C 94, 014309 (2016), we have shown for the first time that the best dynamical trajectory during the deformation toward fission of the superheavy nucleus 286Fl is a linearly increasing radius of the light fragment, R_2. This macroscopic-microscopic result reminds us about the α or cluster preformation at the nuclear surface, assumed already in 1928, and proved microscopically many times. This time we give more detailed arguments for the nucleus 282Cn. Also similar figures are presented for heavy nuclei 240Pu and 252 Cf. The deep minimum of the total deformation energy near the surface is shown for the first time as a strong argument for cluster preformation.

  7. Pre-operational radio-environmental studies of Plant Vogtle

    SciTech Connect

    Winn, W.G.; Sigg, R.A.

    1989-05-01

    This baseline study evaluates radioactivity in the environment near Plant Vogtle before initial reactor startup in 1987. These data will distinguish between any future radio-environmental effects from SRS and Plant Vogtle. Alpha, beta, and gamma-spectrometric methods analyzed river, stream, sediment, and soil samples. The study detected manmade radionuclides {sup 3}H, {sup 60}Co, {sup 134}Cs, {sup 137}Cs, {sup 239}Pu, {sup 240}Pu, and {sup 241}Pu. However, all concentration levels are extremely low and are consistent with levels expected from fallout and from SRS operations in its early years. The measurements begun in this study continue to be used to monitor Vogtle post-startup effluents. 12 refs., 6 figs., 7 tabs.

  8. Radiological dose assessments of atolls in the Northern Marshall Islands

    SciTech Connect

    Robison, W.L.

    1983-11-01

    Methods and models used to estimate the radiation doses to a returning population of the atolls in the Marshall Islands are presented. In this environment natural processes have acted on source-term radionuclides for nearly 30 years. The data bases developed for the models, and the results of the radiological dose analyses at the various atolls are described. The major radionuclides in order of their contribution to the total estimated doses were /sup 137/Cs, /sup 90/Sr, /sup 239/ /sup 240/Pu, /sup 241/Am, and /sup 60/Co. Exposure pathways in order of their contribution to the estimated doses were: terrestrial food chain, external ..gamma.., marine food chain, inhalation, and cistern water and ground water. 56 references, 13 figures, 16 tables.

  9. 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.

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

    SciTech Connect

    Vogt, R; Randrup, J

    2011-09-16

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

  11. Induced fission of Pu240 within a real-time microscopic framework

    DOE PAGES

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

    2016-03-25

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

  12. 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

  13. Comparisons of HELIOS Calculated Isotope Concentrations to Measured Values for Several Reactor Systems

    SciTech Connect

    Charlton, W.S.; Perry, R.T.; Fearey, B.L.; Parish, T.A.

    1998-10-21

    Heavy metal and fission product noble gas concentrations in spent fuel from two different PWR'S were calculated using HELIOS and compared to measured results from the literature. It was found that for the U-235/U-238 and Pu-240/Pu-239 isotopic ratios, the HELIOS calculation agreed to within the experimental uncertainty. For the Xe-131/Xe-134 isotopic ratios, HELIOS tended to overestimate the result by up to 4%. Conversely for the Xe-132/Xe-134 ratios, HELIOS underestimated the result by a slight amount ({approximately}1%). This suggests that either the fission product yields for Xe-131 and Xe-132 should be slightly altered or that the absorption cross-section for Xe-131 should be slightly increased. More analysis is necessary to determine which of these two alternatives is more appropriate. This work has shown that the accuracy of HELIOS (within 2% for heavy metals and within 4% for fission noble gases) is sufficient for most analyses.

  14. 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.

  15. 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.

  16. 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.

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

    SciTech Connect

    Kaplan, D.; Buesseler, K.

    2010-06-29

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

  18. Sources of plutonium in the atmosphere and stratosphere-troposphere mixing

    NASA Astrophysics Data System (ADS)

    Hirose, Katsumi; Povinec, Pavel P.

    2015-10-01

    Plutonium isotopes have primarily been injected to the stratosphere by the atmospheric nuclear weapon tests and the burn-up of the SNAP-9A satellite. Here we show by using published data that the stratospheric plutonium exponentially decreased with apparent residence time of 1.5 ± 0.5 years, and that the temporal variations of plutonium in surface air followed the stratospheric trends until the early 1980s. In the 2000s, plutonium and its isotope ratios in the atmosphere varied dynamically, and sporadic high concentrations of 239,240Pu reported for the lower stratospheric and upper tropospheric aerosols may be due to environmental events such as the global dust outbreaks and biomass burning.

  19. Interspecies comparison of the metabolism and dosimetry of inhaled mixed oxides of plutonium and uranium

    SciTech Connect

    Boecker, B.B.; Mewhinney, J.A.; Eidson, A.F.

    1997-12-01

    Three studies were conducted to provide information on the biological fate, distribution of radiation doses among tissues, and implications for potential health consequences of an inhalation exposure to mixed-oxide nuclear fuel materials. In each study, Fischer-344 rats, beagle dogs, and cynomolgus monkeys inhaled one of three aerosols: 750{degrees}C calcined mixed oxides of UO{sub 2} and PuO{sub 2}, 1750{degrees}C sintered (U,Pu)O{sub 2}, or 850{degrees}C calcined {open_quotes}pure{close_quotes} PuO{sub 2}. These materials were collected from glove-box enclosures immediately after industrial processing of mixed-oxide fuel materials. Lung retention, tissue distribution, and mode of excretion of {sup 238-240}Pu, {sup 241}Am, and uranium (when present) were quantified by radiochemical analysis of tissue and excreta samples from animals sacrificed at selected times to 6.5 yr after inhalation exposure.

  20. Sources of plutonium in the atmosphere and stratosphere-troposphere mixing.

    PubMed

    Hirose, Katsumi; Povinec, Pavel P

    2015-10-28

    Plutonium isotopes have primarily been injected to the stratosphere by the atmospheric nuclear weapon tests and the burn-up of the SNAP-9A satellite. Here we show by using published data that the stratospheric plutonium exponentially decreased with apparent residence time of 1.5 ± 0.5 years, and that the temporal variations of plutonium in surface air followed the stratospheric trends until the early 1980s. In the 2000s, plutonium and its isotope ratios in the atmosphere varied dynamically, and sporadic high concentrations of (239,240)Pu reported for the lower stratospheric and upper tropospheric aerosols may be due to environmental events such as the global dust outbreaks and biomass burning.

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

    NASA Astrophysics Data System (ADS)

    Bouland, Olivier H.

    2016-03-01

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

  2. Subcritical measurements with a cylindrical tank of Pu-U nitrate

    SciTech Connect

    Mihalczo, J.T.; Valentine, T.E.; King, W.T.

    1997-04-01

    This series of measurements with a mixed Pu-U nitrate solution (280 g Pu/liter, 180 g U/liter) in a 35.54-cm-diam cylindrical tank provides a wide variety of experimental data for subcritical configurations that can be used to verify calculational methods and nuclear data. The Pu contained 7.85 wt% {sup 240}Pu and the uranium was natural uranium. The measurements performed were: inverse count rate, prompt neutron decay constants, inverse kinetics, and frequency analysis by the {sup 252}Cf source driven method. These data are presented in sufficient detail that the results of the experiments can be calculated directly. For purposes of extrapolating to the delayed critical height the ratio of spectral densities was linear with height and thus provided the best estimate of critical height.

  3. Determination of origin and intended use of plutonium metal using nuclear forensic techniques.

    PubMed

    Rim, Jung H; Kuhn, Kevin J; Tandon, Lav; Xu, Ning; Porterfield, Donivan R; Worley, Christopher G; Thomas, Mariam R; Spencer, Khalil J; Stanley, Floyd E; Lujan, Elmer J; Garduno, Katherine; Trellue, Holly R

    2017-04-01

    Nuclear forensics techniques, including micro-XRF, gamma spectrometry, trace elemental analysis and isotopic/chronometric characterization were used to interrogate two, potentially related plutonium metal foils. These samples were submitted for analysis with only limited production information, and a comprehensive suite of forensic analyses were performed. Resulting analytical data was paired with available reactor model and historical information to provide insight into the materials' properties, origins, and likely intended uses. Both were super-grade plutonium, containing less than 3% (240)Pu, and age-dating suggested that most recent chemical purification occurred in 1948 and 1955 for the respective metals. Additional consideration of reactor modeling feedback and trace elemental observables indicate plausible U.S. reactor origin associated with the Hanford site production efforts. Based on this investigation, the most likely intended use for these plutonium foils was (239)Pu fission foil targets for physics experiments, such as cross-section measurements, etc.

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

    PubMed Central

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

    2012-01-01

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

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

    DOE PAGES

    Isselhardt, B. H.; Savina, M. R.; Kucher, A.; ...

    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

  6. 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.

  7. International program to improve decay data for transactinium nuclides

    NASA Astrophysics Data System (ADS)

    Helmer, R. G.; Reich, C. W.

    1986-01-01

    To help meet an identified need for precise decay data, in 1977 the IAEA organized an international Coordinated Research Program (CRP) to measure and evaluate half-lives and γ- and α-emission probabilities for selected transactinium nuclides of importance for reactor technology. The CRP goals were (1) to determine a list of data that needed improvement, (2) to encourage new measurements, and (3) to evaluate the available data. All three phases of this work are now complete. Our participation in this effort has involved the measurement of γ-ray emission probabilities for 232,233,235U, 238,239,240,241Pu, 229Th and 233Pa, as well as participating in the data evaluation. The γ-emission probabilities were determined from the measurement of γ-emission rates with the goal of obtaining uncertainties of ≤ 1%. γ-measurements were made on calibrated Ge detectors. These calibrations were done by standard methods, generally involving measurements at ˜ 60 γ-ray energies from 14 to 2700 keV. The efficiency-calibration functions were assigned uncertainties ranging from 2% below 50 keV to 0.50% from 400 to 1400 keV. The determination of the decay rates of the various sources involved several techniques. The 238Pu, 239Pu and 240Pu samples were calibrated by gross α-emission-rate measurements at NBS. The 235U sample was taken from an NBS-calibrated spike solution. The 241Pu and 233U samples were calibrated by isotope-dilution mass spectrometry based on spikes of the calibrated 239Pu, 240Pu and 235U materials. Some of our results are given, together with a comparison of some present and previous results.

  8. Tracer-level radioactive pilot-scale test of in situ vitrification for the stabilization of contaminated soil sites at ORNL

    SciTech Connect

    Spalding, B.P.; Jacobs, G.K.; Naney, M.T. ); Dunbar, N.W. ); Tixier, J.S.; Powell, T.D. )

    1992-11-01

    A field demonstration of in situ vitrification (ISV) was completed in May 1991, and produced approximately 12 Mg of melted earthen materials containing 12.7 mCi of radioactivity within 500 g of sludge in amodel of an old seepage trench waste disposal unit. Past waste disposal operations at Oak Ridge National Laboratory have left several contaminated seepage sites. In planning for remediation of such sites, ISV technology has been identified as a leading candidate because of the high risks associated with any retrieval option and because of the usual high quality of vitreous waste form. Major isotopes placed in the test trench were [sup 137]Cs and [sup 90]Sr, with lesser amounts of [sup 6O]Co, [sup 241]Am, and [sup 239,240]Pu. A total of 29 MWh of electrical power was delivered to the ground over a 5-day period producing a melt depth of 8.5 ft. During melting, 2.4% of the [sup 137]Cs volatilized from the melt into an off-gas containment hood and was captured quantitatively on a high efficiency particulate air filter. No volatilization of [sup 90]Sr, [sup 241]Am, or [sup 239,240]Pu was detected and > 99.993% retention of these isotopes in the melt was estimated. The use of added rare earth tracers (Ce, La, and Nd), as surrogates for transuranic isotopes, led to estimated melt retentions of >99.9995% during the test. The molten material, composed of the native soil and dolomitic limestone used for filling the test trench, reached a processing temperature of 1500[degrees]C. Standardized leaching procedures using Product Consistency Testing indicated that the ISV product has excellent characteristics relative to other vitreous nuclear waste forms.

  9. Application of a magnetic extraction technique to assess radionuclide-mineral association in Cumbrian shoreline sediments.

    PubMed

    McCubbin, David; Leonard, Kinson S; Young, Alan K; Maher, Barbara A; Bennett, Stephen

    2004-01-01

    An assessment has been made of the association of (239+240)Pu, 241Am and 210Po (in secular equilibrium with 210Pb) with iron minerals using a magnetic extraction technique. Grab samples of beach sand from the Cumbrian (UK) coastline were subjected to successive extractions with an approximately 0.1 T ferrite magnet and an approximately 0.3 T rare-earth magnet procedure to separate magnetic iron oxide minerals. Radionuclide concentrations in the magnetic extracts were enhanced (by approximately 4-6-fold) relative to the residue. Those in the approximately 0.1 T magnet extracts were broadly similar to those in the antiferromagnetic material extracted by the approximately 0.3 T magnet, despite the very large differences in magnetic property values between the two fractions (one to two orders of magnitude). The percentage of magnetic material in terms of mass was small and therefore, the majority of these radionuclides (on average 88%) were associated with the residue. Removal of stable Fe was incomplete. Given that the radionuclides may also bind to paramagnetic (nonmagnetic) Fe minerals, the data were extrapolated by normalising the results to quantitative Fe removal. This yielded average values of 37%, 45% and 46% for (239+240)Pu, 241Am and 210Po(210Pb), respectively, as upper limits for the fraction associated with magnetic + nonmagnetic Fe minerals. There are significant uncertainties inherent in quantifying data from this extraction technique. Nevertheless, it seems reasonable to conclude that radionuclide association with Fe minerals is unlikely to have a significant impact upon the physical dispersion of sediment contaminated by Sellafield discharges in the Irish Sea. However, it may be an important factor in governing Pu redox and redissolution behaviour.

  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. Pairing-induced speedup of nuclear spontaneous fission

    DOE PAGES

    Sadhukhan, Jhilam; Dobaczewski, J.; Nazarewicz, W.; ...

    2014-12-22

    Collective inertia is strongly influenced at the level crossing at which the quantum system changes its microscopic configuration diabatically. Pairing correlations tend to make the large-amplitude nuclear collective motion more adiabatic by reducing the effect of these configuration changes. Competition between pairing and level crossing is thus expected to have a profound impact on spontaneous fission lifetimes. To elucidate the role of nucleonic pairing on spontaneous fission, we study the dynamic fission trajectories of 264Fm and 240Pu using the state-of-the-art self-consistent framework. We employ the superfluid nuclear density functional theory with the Skyrme energy density functional SkM* and a density-dependentmore » pairing interaction. Along with shape variables, proton and neutron pairing correlations are taken as collective coordinates. The collective inertia tensor is calculated within the nonperturbative cranking approximation. The fission paths are obtained by using the least action principle in a four-dimensional collective space of shape and pairing coordinates. Pairing correlations are enhanced along the minimum-action fission path. For the symmetric fission of 264Fm, where the effect of triaxiality on the fission barrier is large, the geometry of the fission pathway in the space of the shape degrees of freedom is weakly impacted by pairing. This is not the case for 240Pu, where pairing fluctuations restore the axial symmetry of the dynamic fission trajectory. The minimum-action fission path is strongly impacted by nucleonic pairing. In some cases, the dynamical coupling between shape and pairing degrees of freedom can lead to a dramatic departure from the static picture. As a result, in the dynamical description of nuclear fission, particle-particle correlations should be considered on the same footing as those associated with shape degrees of freedom.« less

  12. The plutonium isotopic composition of marine biota on Enewetak Atoll: a preliminary assessment.

    PubMed

    Hamilton, Terry F; Martinelli, Roger E; Kehl, Steven R; McAninch, Jeffrey E

    2008-10-01

    We have determined the level and distribution of gamma-emitting radionuclides, plutonium activity concentrations, and 240Pu/239Pu atom ratios in tissue samples of giant clam (Tridacna gigas and Hippopus hippopus), a top snail (Trochus nilaticas) and sea cucumber (Holothuria atra) collected from different locations around Enewetak Atoll. The plutonium isotopic measurements were performed using ultra-high sensitivity accelerator mass spectrometry (AMS). Elevated levels of plutonium were observed in the stomachs (includes the stomach lining) of Tridacna clam (0.62 to 2.98 Bq kg(-1), wet wt.), in the soft parts (edible portion) of top snails (0.25 to 1.7 Bq kg(-1)), wet wt.) and, to a lesser extent, in sea cucumber (0.015 to 0.22 Bq kg(-1), wet wt.) relative to muscle tissue concentrations in clam (0.006 to 0.021 Bq kg(-1), wet wt.) and in comparison with previous measurements of plutonium in fish. These data and information provide a basis for re-evaluating the relative significance of dietary intakes of plutonium from marine foods on Enewetak Atoll and, perhaps most importantly, demonstrate that discrete 240Pu239Pu isotope signatures might well provide a useful investigative tool to monitor source-term attribution and consequences on Enewetak Atoll. One potential application of immediate interest is to monitor and assess the health and ecological impacts of leakage of plutonium (as well as other radionuclides) from a low-level radioactive waste repository on Runit Island relative to background levels of fallout contamination in Enewetak Atoll lagoon.

  13. Risk assessment of soil-based exposures to plutonium at experimental sites located on the Nevada Test Site and adjoining areas

    SciTech Connect

    Layton, D.W.; Anspaugh, L.R.; Bogen, K.T.; Straume, T.

    1993-06-01

    In the late 1950s and early 1960s, a series of tests was conducted at or near the Nevada Test Site to study issues involving plutonium-bearing devices. These tests resulted in the dispersal of about 5 TBq of {sup 239,240}Pu on the surficial soils at the test locations. Access to the sites is strictly controlled; therefore, it does not constitute a threat to human health at the present time. However, because the residual {sup 239} Pu decays slowly (half-life of 24,110 y), the sites could indeed represent a long-term hazard if they are not remediated and if institutional controls are lost. To investigate the magnitude of the potential health risks for this no-remediation case, we defined three basic exposure scenarios that could bring individuals in contact with {sup 239,240}Pu at the sites: (1) a resident living in a subdivision located at a test site, (2) a resident farmer, and (3) a worker at a commercial facility. Our screening analyses indicated that doses to organs are dominated by the intemal deposition of Pu via the inhalation pathway, and thus our risk assessment focused on those factors that affect inhalation exposures and associated doses, including inhalation rates, activity patterns, tenure at a residence or occupation, indoor/outdoor air relationships, and resuspension outdoors. Cancer risks were calculated as a function of lifetime cumulative doses to the key target organs (i.e., bone surface, liver, and lungs) and risk factors for those organs. Uncertainties in the predicted cancer risks were analyzed using Monte-Carlo simulations of the probability distributions used to represent assessment parameters. The principal sources of uncertainty in the estimated risks were population mobility, the relationship between indoor and outdoor contaminant levels, and the dose and risk factors for bone, liver, and lung.

  14. Concentrations of radionuclides in fish collected from Bikini Atoll between 1977 and 1984

    SciTech Connect

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

    1986-07-01

    This report summarizes all available data on the concentrations of radionuclides in fish from Bikini Atoll between 1977 and 1984. As found in other global studies, /sup 137/Cs is most highly accumulated in edible flesh of all species of fish, the lowest fractions are found in the bone or liver. The mean concentration of /sup 137/Cs in muscle of reef fish from the southern part of the atoll is comparable to the global fallout concentration measured in market samples of fish collected from Chicago, Illinois, in 1982. /sup 90/Sr is generally associated with non-edible parts of fish, such as bone or viscera. Twenty-five to fifty percent of the total body burden of /sup 60/Co is accumulated in the muscle tissue; the remainder is distributed among the liver, skin, and viscera. The mean concentration of /sup 60/Co in fish has been decreasing at a rate faster than radiological decay alone. Most striking is the range of /sup 207/Bi concentrations among different species of fish collected at the same time and place. Highest concentrations of /sup 207/Bi were consistently detected in the muscle (and other tissues) of goatfish and some of the pelagic lagoon fish. In other reef fish, such as mullet, surgeonfish, and parrotfish, /sup 207/Bi was usually below detection limits by gamma spectrometry. Over 70% of the whole-body activity of /sup 207/Bi in goatfish is associated with the muscle tissue, whereas less than 5% is found in the muscle of mullet and surgeonfish. Neither /sup 239 +240/Pu nor /sup 241/Am is significantly accumulated in the muscle tissue of any species of fish. Apparently, /sup 238/Pu is in a more readily available form for accumulation by fishes than /sup 239 +240/Pu. Based on a daily ingestion rate of 200 q of fish flesh, dose rates to individuals through the fish-food ingestion pathway are well below current Federal guidelines.

  15. Radionuclide concentrations in fish and invertebrates from Bikini Atoll

    SciTech Connect

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

    1988-01-01

    As in other global studies, /sub 137/Cs was found in the highest concentrations in edible flesh of all species of fish and in the lowest concentrations in the bone or liver. The mean concentration of /sup 137/Cs in muscle of reef fish from the southern part of the atoll is comparable to the global-fallout concentration measured in market samples of fish collected from Chicago, IL, USA, in 1982. Strontium-90 is associated generally with non-edible parts of fish, such as bone or viscera. Twenty-five to fifty percent of the total body burden of /sub 60/Co is accumulated in the muscle tissue; the remainder is distributed among the liver, skin, and viscera. The mean concentration of /sub 60/Co in fish has been decreasing at a rate faster than radiological decay alone. Most striking is the range of /sup 207/Bi concentrations among different species of fish collected at the same time and place. Highest concentrations of /sup 207/Bi were consistently detected in the muscle and other tissues of goatfish and some of the pelagic lagoon fish. In other reef fish, such as mullet, surgeonfish, and parrotfish, /sub 207/Bi was usually below detection limits by gamma spectrometry. Over 70% of the whole-body activity of /sup 207/Bi in goatfish is associated with the muscle tissue, whereas less than 5% is found in the muscle of mullet and surgeonfish. Neither /sup 239 +240/Pu nor /sup 241/Am is accumulated significantly in the muscle tissue of any species of fish. Apparently, /sup 238/Pu is in a more readily available form for accumulation by fishes than /sup 239 +240/Pu. Based on a daily ingestion rate of 200 g of fish flesh, dose rates to individuals through the fish-food ingestion pathway are well below current Federal guidelines. 24 refs., 1 fig., 27 tabs

  16. The Northern Marshall Islands radiological survey: Data and dose assessments

    SciTech Connect

    Robison, W.L.; Noshkin, V.E.; Conrado, C.L.

    1997-07-01

    Fallout from atmospheric nuclear tests, especially from those conducted at the Pacific Proving Grounds between 1946 and 1958, contaminated areas of the Northern Marshall Islands. A radiological survey at some Northern Marshall Islands was conducted from September through November 1978 to evaluate the extent of residual radioactive contamination. The atolls included in the Northern Marshall Islands Radiological Survey (NMIRS) were Likiep, Ailuk, Utirik, Wotho, Ujelang, Taka, Rongelap, Rongerik, Bikar, Ailinginae, and Mejit and Jemo Islands. The original test sites, Bikini and Enewetak Atolls, were also visited on the survey. An aerial survey was conducted to determine the external gamma exposure rate. Terrestrial (soil, food crops, animals, and native vegetation), cistern and well water samples, and marine (sediment, seawater, fish and clams) samples were collected to evaluate radionuclide concentrations in the atoll environment. Samples were processed and analyzed for {sup 137}Cs, {sup 90}Sr, {sup 239+240}Pu and {sup 241}Am. The dose from the ingestion pathway was calculated using the radionuclide concentration data and a diet model for local food, marine, and water consumption. The ingestion pathway contributes 70% to 90% of the estimated dose. Approximately 95% of the dose is from {sup 137}Cs accounts for about 10% to 30% of the dose. {sup 239+240}Pu and {sup 241}Am are the major contributors to dose via the inhalation pathway; however, inhalation accounts for only about 1% of the total estimated dose, based on surface soil levels and resuspension studies. All doses are computed for concentrations decay corrected to 1996. The maximum annual effective dose from manmade radionuclides at these atolls ranges from .02 mSv y{sup -1}. The background dose in the Marshall Islands is estimated to be 2.4 mSv y{sup -1} to 4.5 mSv y{sup -1}. The 50-y integral dose ranges from 0.5 to 65 mSv. 35 refs., 2 figs., 9 tabs.

  17. Characterization and Source Term Assessments of Radioactive Particles from Marshall Islands Using Non-Destructive Analytical Techniques

    SciTech Connect

    Jernstrom, J; Eriksson, M; Simon, R; Tamborini, G; Bildstein, O; Carlos-Marquez, R; Kehl, S R; Betti, M; Hamilton, T

    2005-06-11

    A considerable fraction of radioactivity entering the environment from different nuclear events is associated with particles. The impact of these events can only be fully assessed where there is some knowledge about the mobility of particle bound radionuclides entering the environment. The behavior of particulate radionuclides is dependent on several factors, including the physical, chemical and redox state of the environment, the characteristics of the particles (e.g., the chemical composition, crystallinity and particle size) and on the oxidative state of radionuclides contained in the particles. Six plutonium-containing particles stemming from Runit Island soil (Marshall Islands) were characterized using non-destructive analytical and microanalytical methods. By determining the activity of {sup 239,240}Pu and {sup 241}Am isotopes from their gamma peaks structural information related to Pu matrix was obtained, and the source term was revealed. Composition and elemental distribution in the particles were studied with synchrotron radiation based micro X-ray fluorescence (SR-{mu}-XRF) spectrometry. Scanning electron microscope equipped with energy dispersive X-ray detector (SEMEDX) and secondary ion mass spectrometer (SIMS) were used to examine particle surfaces. Based on the elemental composition the particles were divided into two groups; particles with plain Pu matrix, and particles where the plutonium is included in Si/O-rich matrix being more heterogeneously distributed. All of the particles were identified as fragments of initial weapons material. As containing plutonium with low {sup 240}Pu/{sup 239}Pu atomic ratio, {approx}2-6%, which corresponds to weapons grade plutonium, the source term was identified to be among the safety tests conducted in the history of Runit Island.

  18. The use of non-destructive passive neutron measurement methods in dismantling and radioactive waste characterization

    SciTech Connect

    Jallu, F.; Allinei, P. G.; Bernard, P.; Loridon, J.; Soyer, P.; Pouyat, D.; Torreblanca, L.; Reneleau, A.

    2011-07-01

    The cleaning up and dismantling of nuclear facilities lead to a great volume of technological radioactive wastes which need to be characterized in order to be sent to the adequate final disposal or interim storage. The control and characterization can be performed with non-destructive nuclear measurements such as gamma-ray spectrometry. Passive neutron counting is an alternative when the alpha-gamma emitters cannot be detected due to the presence of a high gamma emission resulting from fission or activation products, or when the waste matrix is too absorbing for the gamma rays of interest (too dense and/or made of high atomic number elements). It can also be a complement to gamma-ray spectrometry when two measurement results must be confronted to improve the confidence in the activity assessment. Passive neutron assays involve the detection of spontaneous fission neutrons emitted by even nuclides ({sup 238}Pu, {sup 240}Pu, {sup 242}Pu, {sup 242}Cm, {sup 244}Cm...) and neutrons resulting from ({alpha}, n) reactions with light nuclides (O, F, Be...). The latter is conditioned by the presence of high {alpha}-activity radionuclides ({sup 234}U, {sup 238}Pu, {sup 240}Pu, {sup 241}Am...) and low-Z elements, which depends on the chemical form (metallic, oxide or fluorine) of the plutonium or uranium contaminant. This paper presents the recent application of passive neutron methods to the cleaning up of a nuclear facility located at CEA Cadarache (France), which concerns the Pu mass assessment of 2714 historic, 100 litre radioactive waste drums produced between 1980 and 1997. Another application is the dismantling and decommissioning of an uranium enrichment facility for military purposes, which involves the {sup 235}U and total uranium quantifications in about a thousand, large compressors employed in the gaseous diffusion enrichment process. (authors)

  19. Isotopic Pu, Am and Cm signatures in environmental samples contaminated by the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Yamamoto, M; Sakaguchi, A; Ochiai, S; Takada, T; Hamataka, K; Murakami, T; Nagao, S

    2014-06-01

    Dust samples from the sides of roads (black substances) have been collected together with litter and soil samples at more than 100 sites contaminated heavily in the 20-km exclusion zones around Fukushima Dai-ichi Nuclear Power Plant (FDNPP) (Minamisoma City, and Namie, Futaba and Okuma Towns), in Iitate Village located from 25 to 45 km northwest of the plant and in southern areas from the plant. Isotopes of Pu, Am and Cm have been measured in the samples to evaluate their total releases into the environment from the FDNPP and to get the isotopic compositions among these nuclides. For black substances and litter samples, in addition to Pu isotopes, (241)Am, (242)Cm and (243,244)Cm were determined for most of samples examined, while for soil samples, only Pu isotopes were determined. The results provided a coherent data set on (239,240)Pu inventories and isotopic composition among these transuranic nuclides. When these activity ratios were compared with those for fuel core inventories in the FDNPP accident estimated by a group at JAEA, except (239,240)Pu/(137)Cs activity ratios, fairly good agreements were found, indicating that transuranic nuclides, probably in the forms of fine particles, were released into the environment without their large fractionations. The obtained data may lead to more accurate information about the on-site situation (e.g., burn-up, conditions of fuel during the release phase, etc.), which would be difficult to get otherwise, and more detailed information on the dispersion and deposition processes of transuranic nuclides and the behavior of these nuclides in the environment.

  20. LONG-TERM DYNAMICS OF RADIONUCLIDE VERTICAL MIGRATION IN SOILS OF THE CHERNOBYL NUCLEAR POWER PLANT EXCLUSION ZONE

    SciTech Connect

    Farfan, E

    2009-11-19

    The radioactive fallout from the Chernobyl Nuclear Power Plant (ChNPP) accident consisted of fuel and condensation components. An important radioecological task associated with the late phase of the accident is to evaluate the dynamics of radionuclide mobility in soils. Identification of the variability (or invariability) in the radionuclide transfer parameters makes it possible to (1) accurately predict migration patterns and biological availability of radionuclides and (2) evaluate long-term exposure trends for the population who may reoccupy the remediated abandoned areas. In 1986-1987, a number of experimental plots were established within various tracts of the fallout plume to assist with the determination of the long-term dynamics of radionuclide vertical migration in the soils. The transfer parameters for {sup 137}Cs, {sup 90}Sr, and {sup 239,240}Pu in the soil profile, as well as their ecological half-time of the radionuclide residence (T{sub 1/2}{sup ecol}) values in the upper 5-cm thick soil layers of different grasslands were estimated at various times since the accident. Migration characteristics in the grassland soils tend to decrease as follows: {sup 90}Sr > {sup 137}Cs {ge} {sup 239,240}Pu. It was found that the {sup 137}Cs absolute T{sub 1/2}{sup ecol} values are 3-7 times higher than its radioactive decay half-life value. Therefore, changes in the exposure dose resulting from the soil deposited {sup 137}Cs now depend only on its radioactive decay. The {sup 90}Sr T{sub 1/2}{sup ecol} values for the 21st year after the fallout tend to decrease, indicating an intensification of its migration capabilities. This trend appears consistent with a pool of mobile {sup 90}Sr forms that grows over time due to destruction of the fuel particles.

  1. Study of radioactive isotopes of beryllium, polonium, uranium, and plutonium in the atmosphere

    SciTech Connect

    Lee, S.C.

    1986-01-01

    Radiochemical measurements were carried out for /sup 239.240/Pu in a total of 94 rain and snow samples collected at Fayetteville (36/sup 0/ N, 94/sup 0/W), Arkansas, during the period between May 1983 and November 1985. The concentrations of /sup 7/Be in most of these samples were also measured and these results were compared with previous samples. Average concentrations of cosmic-ray-produced radionuclide /sup 7/Be in rain remained fairly constant year after year. The annual rate of /sup 7/Be deposition at Fayetteville, Arkansas, was calculated from these data to be 5.2 dpm/cm/sup 2//year, which corresponds to a value of 2.8 x 10/sup -2/ atoms/cm/sup 2//second for the /sup 7/Be production rate in the atmosphere. The concentrations of bomb-produced radionuclides such as /sup 89/Sr, /sup 90/Sr and /sup 239.240/Pu in rain have drastically decreased since the last nuclear test explosion was conducted by the government of People's Republic of China in 1980. The concentrations of uranium isotopes and radon daughters in rain, on the other hand, were found to be affected by atmospheric injections of volcanic ashes from the 1980 eruption of Mount St. Helens and the 1982 eruption of El Chichon volcano in Mexico. Moreover, the burnups of the nuclear-powered Soviet satellites have caused marked increases in the levels of /sup 235/U and /sup 234/U in some of the rain samples. A sharp increase in the /sup 210/Po//sup 7/Be ratio in rain samples collected toward the end of 1980 and the beginning of 1981 was attributed to an atmospheric injection of /sup 210/Po from a series of major eruptions of Mount St. Helens.

  2. Particle count monitoring of reverse osmosis water treatment for removal of low-level radionuclides

    SciTech Connect

    Moritz, E.J.; Hoffman, C.R.; Hergert, T.R.

    1995-03-01

    Laser diode particle counting technology and analytical measurements were used to evaluate a pilot-scale reverse osmosis (RO) water treatment system for removal of particulate matter and sub-picocurie low-level radionuclides. Stormwater mixed with Waste Water Treatment Plant (WWTP) effluent from the Rocky Flats Environmental Technology Site (RFETS), formerly a Department of Energy (DOE) nuclear weapons production facility, were treated. No chemical pretreatment of the water was utilized during this study. The treatment system was staged as follows: multimedia filtration, granular activated carbon adsorption, hollow tube ultrafiltration, and reverse osmosis membrane filtration. Various recovery rates and two RO membrane models were tested. Analytical measurements included total suspended solids (TSS), total dissolved solids (TDS), gross alpha ({alpha}) and gross beta ({beta}) activity, uranium isotopes {sup 233/234}U and {sup 238}U, plutonium {sup 239/240}Pu, and americium {sup 241}Am. Particle measurement between 1--150 microns ({mu}) included differential particle counts (DPC), and total particle counts (TPC) before and after treatment at various sampling points throughout the test. Performance testing showed this treatment system produced a high quality effluent in clarity and purity. Compared to raw water levels, TSS was reduced to below detection of 5 milligrams per liter (mg/L) and TDS reduced by 98%. Gross {alpha} was essentially removed 100%, and gross {beta} was reduced an average of 94%. Uranium activity was reduced by 99%. TPC between 1-150{mu} were reduced by an average 99.8% to less than 1,000 counts per milliliter (mL), similar in purity to a good drinking water treatment plant. Raw water levels of {sup 239/240}Pu and {sup 241}Am were below reliable quantitation limits and thus no removal efficiencies could be determined for these species.

  3. Northern Marshall Islands radiological survey: radionuclide concentrations in fish and clams and estimated doses via the marine pathway

    SciTech Connect

    Robison, W.L.; Noshkin, V.E.; Phillips, W.A.; Eagle, R.J.

    1981-08-18

    The survey consisted, in part, of an aerial radiological reconnaissance to map the external gamma-ray exposure rates. As a secondary phase, terrestrial and marine samples were collected to assess the radiological dose from pertinent food chains to atoll inhabitants. The marine sample collection, processing, and dose assessment methodology are presented as well as the concentration data for /sup 90/Sr, /sup 137/Cs, /sup 238/Pu, /sup 239 +240/Pu, /sup 241/Am, and any of the other gamma emitters in fish and clam muscle tissue from the different species collected. Doses are calculated from the average radionuclide concentrations in fish and clam muscle tissue assuming an average daily intake of 200 and 10 g, respectivelty. The /sup 90/Sr concentration in muscle tissue is very low and there is little difference in the average concentrations from the different fish from different atolls or islands. The /sup 239 +240/Pu concentration in the muscle tissue of all reef species, however, is higher than that in pelagic lagoon fish. In contrast, /sup 137/Cs concentrations are lowest in the muscle tissue of the bottom-feeding reef species and highest in pelagic logoon fish. Recent measurements of radionuclide concentrations in fish muscle tissue and other marine dietary items from international sources show that the average concentrations in species from the Marshall Islands are comparable to those in fish typically consumed as food in the United States and are generally lower than those in most international marine dietary items. The whole-body dose rates based on continuous consumption of 200 g/d of fish range from 0.028 to 0.1 mrem/y; the bone-marrow dose rates range from 0.029 to 0.12 mrem/y. The dose commitment, or 30-y integral doses, range from 0.00063 to 0.0022 rem for the whole body and from 0.00065 to 0.0032 rem for the bone marrow. (ERB)

  4. Radionuclide Concentrations in soils an Vegetation at Low-Level Radioactive Waste Disposal Area G During 2004

    SciTech Connect

    P.R. Fresquez; E.A. Lopez

    2004-11-01

    Soil samples were collected at 15 locations and unwashed overstory and understory vegetation samples were collected at nine locations within and around the perimeter of Area G, the primary disposal facility for low-level radioactive solid waste at Los Alamos National Laboratory (LANL). These samples were analyzed for {sup 3}H, {sup 238}Pu, {sup 239,240}Pu, {sup 90}Sr, {sup 241}Am, {sup 137}Cs, {sup 234}U, {sup 235}U, and {sup 238}U. Soil samples collected at Area G contained detectable concentrations of 3H (27%), {sup 239,240}Pu (60%), {sup 238}Pu (40%), and {sup 241}Am (47%) above regional statistical reference levels (RSRLs). In contrast, the levels of {sup 137}Cs, {sup 90}Sr, and U in all of the soil samples at Area G were either nondetectable or within RSRLs. The highest levels of {sup 3}H in soils were detected in the southwestern portion of Area G near the {sup 3}H shafts, whereas the highest concentrations of the Pu isotopes were detected in the northern and northeastern portions. All concentrations of {sup 3}H and Pu in soils, however, were far below LANL screening action levels. As for vegetation, most radionuclides in/on plants were either nondetectable or within RSRLs. The exceptions were {sup 3}H in overstory and some understory vegetation, particularly in the southwestern portion of Area G, which correlated very well with the soils data in that area. Also, there was some foliar contamination from {sup 241}Am and Pu isotopes in/on a few plant samples--the highest concentrations occurring in the northern section of Area G.

  5. 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.

  6. Concentrations of plutonium and americium in plankton from the western Mediterranean Sea.

    PubMed

    Sanchez-Cabeza, Joan-Albert; Merino, Juan; Masqué, Pere; Mitchell, Peter I; Vintró, L León; Schell, William R; Cross, Lluïsa; Calbet, Albert

    2003-07-20

    Understanding the transfer of radionuclides through the food chain leading to man and in particular, the uptake of transuranic nuclides by plankton, is basic to assess the potential radiological risk of the consumption of marine products by man. The main sources of transuranic elements in the Mediterranean Sea in the past were global fallout and the Palomares accident, although at present smaller amounts are released from nuclear establishments in the northwestern region. Plankton from the western Mediterranean Sea was collected and analyzed for plutonium and americium in order to study their biological uptake. The microplankton fractions accounted for approximately 50% of the total plutonium contents in particulate form. At Garrucha (Palomares area), microplankton showed much higher 239,240 Pu activity, indicating the contamination with plutonium from the bottom sediments. Concentration factors were within the range of the values recommended by the International Atomic Energy Agency. Continental shelf mesoplankton was observed to efficiently concentrate transuranics. In open seawaters, concentrations were much lower. We speculate that sediments might play a role in the transfer of transuranics to mesoplankton in coastal waters, although we cannot discard that the difference in species composition may also play a role. In Palomares, both 239,240 Pu and 241Am showed activities five times higher than the mean values observed in continental shelf mesoplankton. As the plutonium isotopic ratios in the contaminated sample were similar to those found in material related to the accident, the contamination was attributed to bomb debris from the Palomares accident. Concentration factors in mesoplankton were also in relatively good agreement with the ranges recommended by IAEA. In the Palomares station the highest concentration factor was observed in the sample that showed predominance of the dynoflagellate Ceratium spp. Mean values of the enrichment factors showed, on

  7. Modeling and assessing the influence of linear energy transfer on multiple bit upset susceptibility

    NASA Astrophysics Data System (ADS)

    Geng, Chao; Liu, Jie; Xi, Kai; Zhang, Zhan-Gang; Gu, Song; Liu, Tian-Qi

    2013-10-01

    The influence of the metric of linear energy transfer (LET) on single event upset (SEU), particularly multiple bit upset (MBU) in a hypothetical 90-nm static random access memory (SRAM) is explored. To explain the odd point of higher LET incident ion but induced lower cross section in the curve of SEU cross section, MBUs induced by incident ions 132Xe and 209Bi with the same LET but different energies at oblique incidence are investigated using multi-functional package for single event effect analysis (MUFPSA). In addition, a comprehensive analytical model of the radial track structure is incorporated into MUFPSA, which is a complementation for assessing and interpreting MBU susceptibility of SRAM. The results show that (i) with the increase of incident angle, MBU multiplicity and probability each present an increasing trend; (ii) due to the higher ion relative velocity and longer range of δ electrons, higher energy ions trigger the MBU with less probability than lower energy ions.

  8. Towards saturation of the electron-capture delayed fission probability: The new isotopes 240Es and 236Bk

    NASA Astrophysics Data System (ADS)

    Konki, J.; Khuyagbaatar, J.; Uusitalo, J.; Greenlees, P. T.; Auranen, K.; Badran, H.; Block, M.; Briselet, R.; Cox, D. M.; Dasgupta, M.; Di Nitto, A.; Düllmann, Ch. E.; Grahn, T.; Hauschild, K.; Herzán, A.; Herzberg, R.-D.; Heßberger, F. P.; Hinde, D. J.; Julin, R.; Juutinen, S.; Jäger, E.; Kindler, B.; Krier, J.; Leino, M.; Lommel, B.; Lopez-Martens, A.; Luong, D. H.; Mallaburn, M.; Nishio, K.; Pakarinen, J.; Papadakis, P.; Partanen, J.; Peura, P.; Rahkila, P.; Rezynkina, K.; Ruotsalainen, P.; Sandzelius, M.; Sarén, J.; Scholey, C.; Sorri, J.; Stolze, S.; Sulignano, B.; Theisen, Ch.; Ward, A.; Yakushev, A.; Yakusheva, V.

    2017-01-01

    The new neutron-deficient nuclei 240Es and 236Bk were synthesised at the gas-filled recoil separator RITU. They were identified by their radioactive decay chains starting from 240Es produced in the fusion-evaporation reaction 209Bi(34S,3n)240Es. Half-lives of 6 (2)s and 22-6+13s were obtained for 240Es and 236Bk, respectively. Two groups of α particles with energies Eα = 8.19 (3)MeV and 8.09 (3)MeV were unambiguously assigned to 240Es. Electron-capture delayed fission branches with probabilities of 0.16 (6) and 0.04 (2) were measured for 240Es and 236Bk, respectively. These new data show a continuation of the exponential increase of ECDF probabilities in more neutron-deficient isotopes.

  9. A laser system for the spectroscopy of highly charged bismuth ions

    NASA Astrophysics Data System (ADS)

    Albrecht, S.; Altenburg, S.; Siegel, C.; Herschbach, N.; Birkl, G.

    2012-06-01

    We present and characterize a laser system for the spectroscopy on highly charged 209Bi82+ ions at a wavelength of 243.87 nm. For absolute frequency stabilization, the laser system is locked to a near-infra-red laser stabilized to a rubidium transition line using a transfer cavity based locking scheme. Tuning of the output frequency with high precision is achieved via a tunable rf offset lock. A sample-and-hold technique gives an extended tuning range of several THz in the UV. This scheme is universally applicable to the stabilization of laser systems at wavelengths not directly accessible to atomic or molecular resonances. We determine the frequency accuracy of the laser system using Doppler-free absorption spectroscopy of Te2 vapor at 488 nm. Scaled to the target wavelength of 244 nm, we achieve a frequency uncertainty of σ 244 nm=6.14 MHz (one standard deviation) over six days of operation.

  10. The Equilibrium and Pre-equilibrium Triton Emission Spectra of Some Target Nuclei for ( n, xt) Reactions up to 45 MeV Energy

    NASA Astrophysics Data System (ADS)

    Tel, E.; Kaplan, A.; Aydın, A.; Özkorucuklu, S.; Büyükuslu, H.; Yıldırım, G.

    2010-08-01

    Although there have been significant research and development studies on the inertial and magnetic fusion reactor technology, there is still a long way to go to penetrate commercial fusion reactors to the energy market. Tritium self-sufficiency must be maintained for a commercial power plant. For self-sustaining (D-T) fusion driver tritium breeding ratio should be greater than 1.05. So, working out the systematics of ( n,t) reaction cross sections and triton emission differential data are important for the given reaction taking place on various nuclei at different energies. In this study, ( n,xt) reactions for some target nuclei as 16O, 27Al, 59Co and 209Bi have been investigated up to 45 MeV incident neutron energy. In the calculations of the triton emission spectra, the pre-equilibrium and equilibrium effects have been used. The calculated results have been compared with the experimental data taken from the literature.

  11. Study of the 15N(p,n)15O reaction as a monoenergetic neutron source for the measurement of differential scattering cross sections

    NASA Astrophysics Data System (ADS)

    Poenitz, E.; Nolte, R.; Schmidt, D.; Chen, G.

    2017-03-01

    The 15N(p,n) reaction is a promising candidate for the production of monoenergetic neutrons with energies of up to 5.7 MeV at the facilities where the T(p,n)3He reaction cannot be used. The characteristic properties of this reaction were studied focusing on its suitability as a source of monoenergetic neutrons for the measurement of differential scattering cross sections in the neutron energy range of 2 MeV to 5 MeV . For this purpose differential and integral cross sections were measured and the choice of optimum target conditions was investigated. The reaction has already been used successfully to measure of elastic and inelastic neutron scattering cross sections for natPb in the energy range from 2 MeV to 4 MeV and for 209Bi and 181Ta at 4 MeV .

  12. Schottky Mass Measurements of Cooled Proton-Rich Nuclei at the GSI Experimental Storage Ring

    SciTech Connect

    Radon, T.; Schlitt, B.; Beckert, K.; Bosch, F.; Eickhoff, H.; Franzke, B.; Geissel, H.; Hausmann, M.; Irnich, H.; Klepper, O.; Kluge, H.; Kozhuharov, C.; Kraus, G.; Muenzenberg, G.; Nickel, F.; Nolden, F.; Patyk, Z.; Reich, H.; Scheidenberger, C.; Schwab, W.; Steck, M.; Suemmerer, K.; Kerscher, T.; Beha, T.; Loebner, K.E.; Fujita, Y.; Jung, H.C.; Wollnik, H.; Novikov, Y.

    1997-06-01

    High-precision mass measurements of proton-rich isotopes in the range of 60{le}Z{le}84 were performed using the novel technique of Schottky spectrometry. Projectile fragments produced by {sup 209}Bi ions at 930{ital A} MeV were separated with the magnetic spectrometer FRS and stored and cooled in the experimental storage ring (ESR). A typical mass resolving power of 350000 and a precision of 100keV were achieved in the region A{approx}200 . Masses of members of {alpha} chains linked by precise Q{sub {alpha}} values but not yet connected to the known masses were determined. In this way it is concluded that {sup 201}Fr and {sup 197}At are proton unbound. {copyright} {ital 1997} {ital The American Physical Society}

  13. Hindrance of complete fusion in the {sup 8}Li+{sup 208}Pb system at above-barrier energies

    SciTech Connect

    Aguilera, E. F.; Martinez-Quiroz, E.; Rosales, P.; Kolata, J. J.; DeYoung, P. A.; Peaslee, G. F.; Mears, P.; Guess, C.; Becchetti, F. D.; Lupton, J. H.; Chen, Yu

    2009-10-15

    The {sup 211,212}At yields resulting from the interaction of the radioactive projectile {sup 8}Li with a {sup 208}Pb target have been measured at energies between 3 and 8.5 MeV above the Coulomb barrier. They are signatures for fusion of the whole charge but not necessarily the whole mass of the projectile, so they are included in a corresponding operational definition of complete fusion. Within this definition, a fusion suppression factor of 0.70{+-}0.02 (stat.) {+-}0.04 (syst.) is deduced from a comparison to a one-dimensional barrier-penetration-model calculation using parameters extrapolated from values for {sup 6,7}Li+{sup 209}Bi and {sup 9}Be+{sup 208}Pb taken from the literature. Possible incomplete fusion processes are discussed and the results are fitted with a phenomenological model assuming breakup prior to fusion followed by capture of a {sup 7}Li fragment.

  14. Measurement of neutron multiplicity from fission of {sup 228}U and nuclear dissipation

    SciTech Connect

    Singh, Hardev; Behera, B. R.; Singh, Gulzar; Govil, I. M.; Golda, K. S.; Jhingan, Akhil; Singh, R. P.; Sugathan, P.; Chatterjee, M. B.; Datta, S. K.; Pal, Santanu; Ranjeet; Mandal, S.; Shidling, P. D.; Viesti, G.

    2009-12-15

    Pre- and post-scission neutron multiplicities are measured at different excitation energies of the compound nucleus {sup 228}U populated using the {sup 19}F+{sup 209}Bi reaction. The measured yield of pre-scission and total neutrons are compared with the statistical model calculation for the decay of a compound nucleus. The statistical model calculations are performed using the Bohr-Wheeler transition state fission width as well as the dissipative dynamical fission width due to Kramers. Comparison between the measured and the calculated values shows that, while the Bohr-Wheeler fission width grossly underestimates the pre-scission neutron yield, a large amount of dissipation is required in the Kramers width to fit the experimental pre-scission multiplicities. Various factors contributing to the large excitation energy dependence of the fitted values of the dissipation coefficient are discussed.

  15. Four Decades of Hyperfine Anomalies

    NASA Astrophysics Data System (ADS)

    Gustavsson, Martin G. H.; Mårtensson-Pendrill, Ann-Marie

    Isotopic differences in the distribution of nuclear charge and magnetization give rise to "hyperfine structure anomalies" which were observed already in the 1950s. More recently, the distribution of nuclear magnetization has been found to complicate the interpretation of the measured hyperfine splittings in highly charged hydrogen-like ions. In this paper, results of numerical calculations for a few hydrogen-like systems (133Cs, 165Ho, 185,187Re and 209Bi) of current experimental interest are presented in terms of moments of the nuclear charge and magnetization distribution, thereby displaying directly the sensitivity and emphasizing the need for a better understanding of nuclear wavefunctions. In addition, we also present results of many-body perturbation theory calculations for Cs hyperfine anomalies, in connection with experiments planned at ISOLDE.

  16. Realizing the potential of the Actinium-225 radionuclide generator in targeted alpha-particle therapy applications

    PubMed Central

    Miederer, Matthias; Scheinberg, David A.; McDevitt, Michael R.

    2013-01-01

    Alpha particle-emitting isotopes have been proposed as novel cytotoxic agents for augmenting targeted therapy. Properties of alpha particle radiation such as their limited range in tissue of a few cell diameters and their high linear energy transfer leading to dense radiation damage along each alpha track are promising in the treatment of cancer, especially when single cells or clusters of tumor cells are targeted. Actinium-225 (225Ac) is an alpha particle-emitting radionuclide that generates 4 net alpha particle isotopes in a short decay chain to stable 209Bi, and as such can be described as an alpha particle nanogenerator. This article reviews the literature pertaining to the research, development, and utilization of targeted 225Ac to potently and specifically affect cancer. PMID:18514364

  17. Additive empirical parametrization and microscopic study of deuteron breakup

    NASA Astrophysics Data System (ADS)

    Avrigeanu, M.; Avrigeanu, V.

    2017-02-01

    Comparative assessment of the total breakup proton-emission cross sections measured for 56 MeV deuteron interaction with target nuclei from 12C to 209Bi, with an empirical parametrization and recently calculated microscopic neutron-removal cross sections was done at the same time with similar data measured at 15, 25.5, 70, and 80 MeV. Comparable mass dependencies of the elastic-breakup (EB) cross sections provided by the empirical parametrization and the microscopic results have been also found at the deuteron energy of 56 MeV, while the assessment of absolute-values variance up to a factor of two was not possible because of the lack of EB measurements at energies higher than 25.5 MeV. While the similarities represent an additional validation of the microscopic calculations, the cross-section difference should be considered within the objectives of further measurements.

  18. Influence of breakup on fusion barrier distributions

    NASA Astrophysics Data System (ADS)

    Patel, D.; Nayak, B. K.; Mukherjee, S.; Biswas, D. C.; Mirgule, E. T.; John, B. V.; Gupta, Y. K.; Mukhopadhyay, S.; Prajapati, G.; Danu, L. S.; Rath, P. K.; Desai, V.; Deshmukh, N.; Saxena, A.

    2013-04-01

    Fusion barrier distributions have been extracted from the quasi-elastic scattering excitation functions, measured at backward angle θlab = 160° in reactions of 6,7Li+209Bi. The present results have been compared with the barrier distributions obtained from the fusion excitation function measurements for the above mentioned systems. The fusion barrier distributions from the quasi-elastic scattering excitation functions have been analyzed with simplified Coupled Channels calculations using Fresco. Inclusions of resonant states for both 6,7Li projectiles improve the predictions to describe the measured quasi-elastic scattering excitation functions and barrier distributions. For both the reactions peak positions of fusion barrier distributions are shifted towards a lower energy side in comparison to that obtained from the fusion excitation function measurements. The observed discrepancy in peak positions of barrier distributions obtained from quasi-elastic scattering and fusion excitation function measurements has been discussed in terms of total reaction threshold distribution.

  19. Entrance channel effects in superheavy element production

    NASA Astrophysics Data System (ADS)

    Nasirov, Avazbek; Giardina, Giorgio; Mandaglio, Giuseppe; Muminov, Akhtam

    2016-12-01

    The difference between evaporation residue cross sections measured in the cold (X+208Pb, 209Bi) and hot (48Ca+actinides) fusion reactions can be related to the stage of compound nucleus (CN) formation and/or to the stage of its survival against fission. The cold fusion reactions are favorable in synthesis of the superheavy elements (SHE) with charge numbers Z < 112 in comparison with the hot fusion reactions due to small excitation energy and large fission barrier of the CN formed in these reactions. The strong decrease of the cross sections of the synthesis of the SHE Z = 113 in the cold fusion reactions in comparison with the ones in the hot fusion reactions is the result of the increase of hindrance to the CN formation in the cold fusion reactions. The origin of the intrinsic fusion barrier, B, causing the strong decrease of the probability PCN in the cold fusion is discussed.

  20. Alpha Cyclotron Production Studies of the Alpha Emitter 211AT/211gPO for High-Let Metabolic Radiotherapy

    NASA Astrophysics Data System (ADS)

    Morzenti, S.; Bonardi, M. L.; Groppi, F.; Zona, C.; Canella, L.; Menapace, E.; Alfassi, Z. B.; Abbas, K.; Holzwarth, U.

    2006-04-01

    A series of high specific activity accelerator-produced radionuclides in no-carrier-added (NCA) form, for uses in metabolic radiotherapy and for PET, has been investigated and produced at JRC-Ispra Cyclotron Laboratory. In this study we present, in particular, the NCA 211At/211gPo (LET = 130 eV.nm-1, t1/2= 7.214 h), produced by 209Bi(α,2n) reaction, with internal spike of gamma emitter 210At (e.g. negligible amount of 210Po as radiotoxic long-lived impurity), for high-LET targeted radiotherapy and immunoradiotherapy. A selective radiochemical separation, based on liquid/liquid extraction, of At radionuclides from Bi target and Po impurities has been developed. High resolution gamma, X and alpha spectrometric techniques have been adopted for quality controls of different radiochemical fractions.

  1. Realizing the potential of the Actinium-225 radionuclide generator in targeted alpha particle therapy applications.

    PubMed

    Miederer, Matthias; Scheinberg, David A; McDevitt, Michael R

    2008-09-01

    Alpha particle-emitting isotopes have been proposed as novel cytotoxic agents for augmenting targeted therapy. Properties of alpha particle radiation such as their limited range in tissue of a few cell diameters and their high linear energy transfer leading to dense radiation damage along each alpha track are promising in the treatment of cancer, especially when single cells or clusters of tumor cells are targeted. Actinium-225 (225 Ac) is an alpha particle-emitting radionuclide that generates 4 net alpha particle isotopes in a short decay chain to stable 209 Bi, and as such can be described as an alpha particle nanogenerator. This article reviews the literature pertaining to the research, development, and utilization of targeted 225 Ac to potently and specifically affect cancer.

  2. Primary mass standard based on atomic masses

    NASA Astrophysics Data System (ADS)

    Becker, Peter; Gläser, Michael

    2006-04-01

    The paper summarises the activities of several national and international Metrology Institutes in replacing the kilogram artefact, the unit of mass, by the mass of a certain number of atoms, in particular the atomic masses of silicon or bismuth. This task is based on two different experiments: a very accurate determination of the Avogadro constant, NA, measuring the density and lattice parameter of an enriched silicon-28 crystal, and the accumulation of decelerated bismuth-209 ions by using a mass separator. The relative measurement uncertainties reached so far are in the first case 2 parts in 107, and in the latter several part in 104. The bismuth experiment is still in an early state of the work. The ratios between the masses of 28Si or 209Bi, respectively, and the present atomic mass standard, the mass of 12C, can be determined with an accuracy now approaching 10-10 using high precision Penning traps mass spectrometers.

  3. Measuring the cross sections of heavy-metal spallation induced by deuterons with energies of 2, 2.94, and 3.5 GeV per nucleon

    NASA Astrophysics Data System (ADS)

    Artyushenko, M. Yu.; Baldin, A. A.; Berlev, A. I.; Bukhal, O. V.; Voronko, V. A.; Gusak, K. V.; Zhuk, I. V.; Kudashkin, I. V.; Paraipan, M.; Potapenko, A. S.; Safronova, A. A.; Sotnikov, V. V.; Tyutyunnikov, S. I.

    2016-07-01

    The cross sections for the spallation of the heavy-metal nuclei 181Ta, 197Au, 207Pb, 209Bi, 232Th, and 238U induced by relativistic deuterons with energies of 2, 2.94, and 3.5 GeV per nucleon are measured using the deuteron beam from the Nuclotron accelerator of the JINR Laboratory of High Energy Physics in Dubna, Russia. The cross-section measurements employ a combined experimental technique involving the solidstate nuclear-track detectors and the activation gamma spectrometry. Adding our measurements to the database of experimental nuclear data will make it possible to test the computer codes used for selecting the parameters of the ADS-type facilities.

  4. Excitation energy dependence of the level density parameter close to the doubly magic 208Pb

    NASA Astrophysics Data System (ADS)

    Roy, Pratap; Banerjee, K.; Bhattacharya, C.; Pandey, R.; Sen, A.; Manna, S.; Kundu, S.; Rana, T. K.; Ghosh, T. K.; Mukherjee, G.; Roy, T.; Dhal, A.; Dey, A.; Meena, J. K.; Saha, A. K.; Pandit, Deepak; Mukhopadhyay, S.; Bhattacharya, S.

    2016-12-01

    Neutron evaporation spectra have been measured from 4He+208Pb and 4He+209Bi reactions by using 4He-ion beams of several bombarding energies. Excitation-energy dependence of the level density parameter has been studied for the two systems in the excitation energy range of ˜18 -50 MeV. For both the reactions an overall reduction of the asymptotic level density parameter with increasing excitation energy (temperature) is observed. The trend of the data was compared with the Thomas-Fermi model predictions and found to be in reasonable agreement. The value of the shell damping parameter has been extracted from the lowest-energy data in the case of Po,211210 and At,212211 nuclei close to the Z =82 and N =126 shell closure, and it was found to be consistent with the recent measurement in the vicinity of doubly magic 208Pb nucleus.

  5. Excitations of one-valence-proton, one-valence-neutron nucleus {sup 210}Bi from cold-neutron capture

    SciTech Connect

    Cieplicka-Oryńczak, N.; Fornal, B.; Szpak, B.; Leoni, S.; Bottoni, S.; Bazzacco, D.; Blanc, A.; Jentschel, M.; Köster, U.; Mutti, P.; Soldner, T.; Bocchi, G.; France, G. de; Simpson, G.; Urban, W.

    2015-10-15

    The low-spin structure of one-proton, one-neutron {sup 210}Bi nucleus was investigated in cold-neutron capture reaction on {sup 209}Bi. The γ-coincidence measurements were performed with use of EXILL array consisted of 16 HPGe detectors. The experimental results were compared to shell-model calculations involving valence particles excitations. The {sup 210}Bi nucleus offers the potential to test the effective proton-neutron interactions because most of the states should arise from the proton-neutron excitations. Additionally, it was discovered that a few states should come from the couplings of valence particles to the 3{sup −} octupole vibration in {sup 208}Pb which provides also the possibility of testing the calculations involving the core excitations.

  6. g factor of the J/sup. pi. / = 25/2/sup +/ isomer in /sup 205/Tl and the anomalous orbital magnetism of the proton

    SciTech Connect

    Maier, K.H.; Becker, J.A.; Carlson, J.B.; Lanier, R.G.; Mann, L.G.; Struble, G.L.; Nail, T.; Sheline, R.K.; Stoeffl, W.; Ussery, L.

    1982-02-15

    The nuclear gyromagnetic ratio of the 3291-keV J/sup ..pi../ = 25/2/sup +/ /sup 205/Tl level has been measured with use of ..gamma..-ray perturbed angular distribution techniques with the result g = 0.544 +- 0.008. The state was populated with the reaction /sup 204/Hg(t,2n)/sup 205/Tl. With use of the known quantities g(/sup 206/Pb 7/sup -/; E/sub x/ = 2200 keV) and g(/sup 209/Bi 9/2/sup +/; E/sub x/ = 0 keV) the proton orbital magnetic g factor for the 1h orbital was deduced to be g/sub 1/ = 1.115 +- 0.02. This result has been corrected for wave-function admixtures and core polarization effects.

  7. Studies of neutron-deficient mendelevium isotopes at SHIP

    NASA Astrophysics Data System (ADS)

    Antalic, S.; Heßberger, F. P.; Hofmann, S.; Ackermann, D.; Heinz, S.; Kindler, B.; Kojouharov, I.; Kuusiniemi, P.; Leino, M.; Lommel, B.; Mann, R.; Šáro, Š.

    2010-01-01

    The radioactive decay of the isotopes 247Md , 246Md and their daughter products was investigated by means of α - α and α - γ coincidence spectroscopy. The isotopes were produced using the fusion reaction 40Ar + 209Bi. Decay schemes are suggested for 247Md and 243Es . A new isomeric state in 246Md with a half-life of ( 4.4±0.8 s was observed. Previous data of electron-capture delayed fission of 246Md and 242Es were confirmed. The probability for this decay branch in 246Md was measured to be P ECDF > 0.10 . The probability for electron-capture delayed fission in the case of 242Es was determined to be P ECDF = 0.013+0.012 -0.007.

  8. Inclusive measurement of (p,. pi. /sup -/xn) double charge exchange reactions on bismuth from threshold to 800 MeV

    SciTech Connect

    Dombsky, M.; D'Auria, J.M.; Kelson, I.; Yavin, A.I.; Ward, T.E.; Clark, J.L.; Ruth, T.; Sheffer, G.

    1985-07-01

    The energy dependence of the total angle-integrated cross section for the production of astatine isotopes from (p,..pi../sup -/xn) double charge exchange reactions on bismuth (/sup 209/Bi) was measured from 120 to 800 MeV using activation and radiochemical techniques. Chemical yields were estimated by direct radioassaying of /sup 211/At activity in thin (approx.1 mg/cm/sup 2/), irradiated bismuth targets. Calculations of the contributions of secondary (two-step) reactions to these measured astatine yields were performed, based partially upon the observed /sup 211/At activity although even at the highest energies, the contribution to products lighter than /sup 207/At was negligible. These data for products with as many as seven neutrons removed from the doubly coherent product (/sup 210/At) display nearly Gaussian shapes for the mass distributions of the astatine residues, with the maximum occurring for about /sup 204/At. The most probable momentum transfer deduced from these distributions for the initial ..pi../sup -/ production step was 335 MeV/c. The observed excitation functions display a behavior similar to that observed for the yield of /sup 210/Po from a (p,..pi../sup 0/) reaction on /sup 209/Bi, but radically different from that observed for inclusive ..pi../sup -/ reactions on a heavy nucleus. These data are discussed in terms of recent theoretical approaches to negative pion production from bismuth. In addition, a simple, schematic model is developed to treat the rapidly decreasing percentage of the total inclusive ..pi../sup -/ emission which is observed for this double charge exchange reaction. This model reflects the opacity of a nucleus to a source of internal energetic protons.

  9. Optical Spectroscopic Measurements of Isotope Shift and Hyperfine Structure in BISMUTH-207, BISMUTH-208 and LEAD-205.

    NASA Astrophysics Data System (ADS)

    Barboza Flores, Marcelino

    The isotope shift and hyperfine structure (hfs) of 38-yr ^{207}Bi and 3.7 times 10^5 -yr ^{208}Bi were measured, in the 6p^3 ^4S_ {1/2} - 6p^2 7s ^4P_{1/2} 306.7-nm resonance line, as well as the isotope shift of 1.4 times 10^7-yr ^ {205}Pb in the 6p^2 ^3P_0 - 6p7s ^3P_1 283.3-nm transition. A 9.1-m focal-length Czerny-Turner grating monochromator with a 25-cm wide diffraction grating (resolving power ~10^6) was used to obtain high resolution absorption spectra of an atomic vapor of lead and bismuth. The spectra were recorded photoelectrically using a signal-averaging spectrum scanning technique. The measured isotope shifts are IS(^ {207}Bi-^{209} Bi) = 0.0999(20) cm^{-1} , IS(^{208}Bi- ^{209}Bi) = 0.072(6) cm ^{-1} and IS(^ {205}Pb-^{208} Pb) = -123.9(2.0) times 10^{-3} cm ^{-1}. The derived magnetic dipole (A) and electric quadrupole (B) hfs interaction constants are A(^4P_{1/2})= 0.1630(3) cm^{-1}, B( ^4S_{3/2}) = -0.016(3) cm^{-1} for ^{207}Bi and A( ^4P_{1/2}) = 0.1639(20) cm^{-1} for ^ {208}Bi. The nuclear magnetic dipole (mu) and electric quadrupole moment (Q) were found to be mu(^{207 }Bi) = 4.051(7)mu_{N }, Q(^{207}Bi) = -0.60(11)b and mu(^ {208}Bi) = 4.52(6)mu_ {N}. The magnetic dipole moments agree with theoretical predictions based on the nuclear shell model including configuration mixing and meson exchange contributions.

  10. GSI experiments on the synthesis of superheavy elements

    SciTech Connect

    Hessberger, F. P.; Hofmann, S.; Ninov, V.; Armbruster, P.; Folger, H.; Muenzenberg, G.; Stodel, Ch.; Lavrentev, A.; Popeko, A. G.; Yeremin, A. N.; Leino, M. E.; Saro, S.

    1998-02-15

    Evaporation residue production was investigated at SHIP in cold fusion reactions of Pb- and Bi-target nuclei with projectiles of elements between Ti (Z=22) and Se (Z=34) leading to compound nuclei Z{sub CN}=104-116. The isotopes {sup 269}110, {sup 271}110, {sup 272}111, and {sup 277}112 of the elements Z=110, Z=111 and Z=112 were unambiguously identified for the first time in bombardments of {sup 208}Pb, {sup 209}Bi with {sup 62,64}Ni and {sup 70}Zn. Excitation functions for {sup 50}Ti+{sup 208}Pb and {sup 58}Fe+{sup 208}Pb were measured with high precision, three new spontaneous fission (sf) activities {sup 253}104, {sup 254}104, {sup 258}106 were identified. A small {alpha}-decay branch of the even-even nucleus {sup 256}104 (b{sub {alpha}}{approx_equal}0.003) was confirmed, allowing to estimate mass excesses {delta}mc{sup 2} for N-Z=48 nuclei up to {sup 264}Hs (Z=108). An analysis of the {alpha}-decay chains observed in a bombardment of {sup 209}Bi with {sup 58}Fe projectiles showed evidence for an isomeric state in {sup 266}Mt (Z=109). We further report on an attempt to produce element 116 and a second isotope of element 112 by the reactions {sup 82}Se+{sup 208}Pb and {sup 68}Zn+{sup 208}Pb, respectively.

  11. The influence of radioactive decay on actinide magnetic susceptibility measurements obtained using the Evans method.

    PubMed

    Autillo, Matthieu; Kaden, Peter; Geist, Andreas; Guerin, Laetitia; Moisy, Philippe; Berthon, Claude

    2014-05-14

    In order to explain the higher magnetic susceptibility of some aquo actinide ions than predicted by Hund's rules, the molar magnetic susceptibilities of two americium isotopes ((241)Am and (243)Am) were measured using the Evans method. The results obtained show a growing change in the magnetic susceptibility with α and also a β(-) activity increase in solution. β(-) particle effects appear to be stronger than radicals formed by α particles on the experimental values. The temperature dependence of Am(iii) magnetic susceptibility has been observed but from experiments carried out here, it appears to be difficult to prove whether this effect arises from radicals or β(-). Finally, magnetic susceptibilities of americium recorded in different media (HClO4, HCl, and HNO3) have been compared to alpha and beta emissions' impact.

  12. Total and spontaneous fission half-lives for americium and curium nuclides

    SciTech Connect

    Holden, N.E.

    1985-01-01

    The long-lived nuclides of the americium curium elements are of interest for their use in certain safeguard applications and for nuclear reactor burnup studies in waste management. Recommended values are presented for /sup 241,242m,243/Am, and for /sup 242,243,244,245,246,247,248,250/Cm. These values result from a consistent evaluation of all these half-lives. These preliminary estimates were presented earlier. The uncertainties are provided at the 95% confidence limit for each of the recommended values. It will be noted that many of the recommended errors considerably exceed errors quoted by individual authors in their publication, by up to an order of magnitude, e.g., the total half-life of /sup 242,246,248/Cm and the spontaneous fission half-life of /sup 244/Cm. 65 refs., 18 tabs.

  13. Total and spontaneous fission half-lives for americium and curium nuclides

    NASA Astrophysics Data System (ADS)

    Holden, N. E.

    The long-lived nuclides of the americium curium elements are of interest for their use in certain safeguard applications and for nuclear reactor burnup studies in waste management. Recommended values are presented for /sup 241,242m,243/Am, and for /sup 242,243,244,245,246,247,248,250/Cm. These values result from a consistent evaluation of all these half-lives. These preliminary estimates were presented earlier. The uncertainties are provided at the 95% confidence limit for each of the recommended values. It will be noted that many of the recommended errors considerably exceed errors quoted by individual authors in their publication, by up to an order of magnitude, e.g., the total half-life of /sup 242,246,248/Cm and the spontaneous fission half-life of (244)Cm.

  14. Rapid determination of (237)Np in soil samples by multi-collector inductively-coupled plasma mass spectrometry and gamma spectrometry.

    PubMed

    Yi, Xiaowei; Shi, Yanmei; Xu, Jiang; He, Xiaobing; Zhang, Haitao; Lin, Jianfeng

    A radiochemical procedure is developed for the determination of (237)Np in soil with multi-collector inductively-coupled plasma mass spectrometry (MC-ICP-MS) and gamma-spectrometry. (239)Np (milked from (243)Am) was used as an isotopic tracer for chemical yield determination. The neptunium in the soil is separated by thenoyl-trifluoracetone extraction from 1 M HNO3 solution after reducing Np to Np(IV) with ferrous sulfamate, and then purified with Dowex 1 × 2 anion exchange resin. (239)Np in the resulting solution is measured with gamma-spectrometry for chemical yield determination while the (237)Np is measured with MC-ICP-MS. Measurement results for soil samples are presented together with those for two reference samples. By comparing the determined value with the reference value of the (237)Np activity concentration, the feasibility of the procedure was validated.

  15. Actinide targets for the synthesis of super-heavy elements

    DOE PAGES

    Roberto, J.; Alexander, Charles W.; Boll, Rose Ann; ...

    2015-06-18

    Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of 48Ca beams on actinide targets. These target materials, including 242Pu, 244Pu, 243Am, 245Cm, 248Cm, 249Cf, and 249Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing themore » production of rare actinides including 249Bk, 251Cf, and 254Es are described.« less

  16. 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.

  17. 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.

  18. Actinide targets for the synthesis of super-heavy elements

    NASA Astrophysics Data System (ADS)

    Roberto, J. B.; Alexander, C. W.; Boll, R. A.; Burns, J. D.; Ezold, J. G.; Felker, L. K.; Hogle, S. L.; Rykaczewski, K. P.

    2015-12-01

    Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of 48Ca beams on actinide targets. These target materials, including 242Pu, 244Pu, 243Am, 245Cm, 248Cm, 249Cf, and 249Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing the production of rare actinides including 249Bk, 251Cf, and 254Es are described.

  19. Nuclear Data Sheets for A = 243

    SciTech Connect

    Nesaraja, C.D.; McCutchan, E.A.

    2014-09-15

    Available information pertaining to the nuclear structure of all nuclei with mass numbers A=243 is presented. Various decay and reaction data are evaluated and compared. Adopted data, levels, spin, parity and configuration assignments are given. When there are insufficient data, expected values from systematics of nuclear properties or/and theoretical calculations are quoted. Unexpected or discrepant experimental results are also noted. A summary and compilation of the discovery of various isotopes in this mass region is given in 2013Fr02 ({sup 243}Np, {sup 243}Pu, {sup 243}Am, {sup 243}Cm, {sup 243}Bk, and {sup 243}Cf), 2011Me01 ({sup 243}Es), and 2013Th02 ({sup 243}Fm)

  20. Optimal reaction for synthesis of superheavy element 117

    SciTech Connect

    Liu, Z. H.; Bao Jingdong

    2009-09-15

    Fusion reactions leading to the formation of superheavy element 117 are systematically analyzed. Among the reactions considered, the {sup 250}Bk({sup 48}Ca,4n){sup 294}117 reaction has the largest evaporation residue (ER) cross section of about 2 pb. However, this reaction is hard to realize experimentally because it is difficult to accumulate sufficient amount of target material due to the short lifetime of {sup 250}Bk nucleus. For the reaction {sup 48}Ca+{sup 249}Bk, our estimation shows that the ER cross sections in 3n and 4n channels may be expected to be greater than 1 pb. Therefore, {sup 48}Ca and {sup 249}Bk should be the optimal projectile-target combination for synthesis of superheavy element 117 in practice. In addition, as a main result of systematic analysis, we find that the ER cross section exponentially depends on the mass difference (in unit of temperature) of fission and neutron emission saddle points. Therefore, it is of essential importance for the successful synthesis of superheavy nuclei to select the isotopic composition of projectile and/or target so as the mass difference of fission and neutron emission saddle points as large as possible. Entrance channel effects are examined by means of a comparison of the reactions {sup 48}Ca+{sup 245}Bk, {sup 50}Ti+{sup 243}Am, and {sup 55}Mn+{sup 238}U leading to the same compound nucleus {sup 293}117. The ER cross sections of the reactions {sup 50}Ti+{sup 243}Am and {sup 55}Mn+{sup 238}U are much smaller than that of {sup 48}Ca+{sup 245}Bk.

  1. Radionuclides, Heavy Metals, and Polychlorinated Biphenyls in Soils Collected Around the Perimeter of Low-Level Radioactive Waste Disposal Area G during 2006

    SciTech Connect

    P. R. Fresquez

    2007-02-28

    Twenty-one soil surface samples were collected in March around the perimeter of Area G, the primary disposal facility for low-level radioactive solid waste at Los Alamos National Laboratory (LANL). Three more samples were collected in October around the northwest corner after elevated tritium levels were detected on an AIRNET station located north of pit 38 in May. Also, four soil samples were collected along a transect at various distances (48, 154, 244, and 282 m) from Area G, starting from the northeast corner and extending to the Pueblo de San Ildefonso fence line in a northeasterly direction (this is the main wind direction). Most samples were analyzed for radionuclides ({sup 3}H, {sup 238}Pu, {sup 239,240}Pu, {sup 241}Am, {sup 234}U, {sup 235}U, and {sup 238}U), inorganic elements (Al, Ba, Be, Ca, Cr, Co, Cu, Fe, Mg, Mn, Ni, K, Na, V, Hg, Zn, Sb, As, Cd, Pb, Se, Ag, and Tl) and polychlorinated biphenyl (PCB) concentrations. As in previous years, the highest levels of {sup 3}H in soils (690 pCi/mL) were detected along the south portion of Area G near the {sup 3}H shafts; whereas, the highest concentrations of {sup 241}Am (1.2 pCi/g dry) and the Pu isotopes (1.9 pCi/g dry for {sup 238}Pu and 5 pCi/g dry for {sup 239,240}Pu) were detected along the northeastern portions near the transuranic waste pads. Concentrations of {sup 3}H in three soil samples and {sup 241}Am and Pu isotopes in one soil sample collected around the northwest corner in October increased over concentrations found in soils collected at the same locations earlier in the year. Almost all of the heavy metals, with the exception of Zn and Sb in one sample each, in soils around the perimeter of Area G were below regional statistical reference levels (mean plus three standard deviations) (RSRLs). Similarly, only one soil sample collected on the west side contained PCB concentrations--67 {micro}g/kg dry of aroclor-1254 and 94 {micro}g/kg dry of aroclor-1260. Radionuclide and inorganic element

  2. Low-Level Plutonium Bioassay Measurements at the Lawrence Livermore National Laboratory

    SciTech Connect

    Hamilton, T; Brown, T; Hickman, D; Marchetti, A; Williams, R; Kehl, S

    2007-06-18

    Plutonium-239 ({sup 239}Pu) and plutonium-240 ({sup 240}Pu) are important alpha emitting radionuclides contained in radioactive debris from nuclear weapons testing. {sup 239}Pu and {sup 240}Pu are long-lived radionuclides with half-lives of 24,400 years and 6580 years, respectively. Concerns over human exposure to plutonium stem from knowledge about the persistence of plutonium isotopes in the environment and the high relative effectiveness of alpha-radiation to cause potential harm to cells once incorporated into the human body. In vitro bioassay tests have been developed to assess uptakes of plutonium based on measured urinary excretion patterns and modeled metabolic behaviors of the absorbed radionuclides. Systemic plutonium absorbed by the deep lung or from the gastrointestinal tract after ingestion is either excreted or distributed to other organs, primarily to the liver and skeleton, where it is retained for biological half-times of around 20 and 50 years, respectively. Dose assessment and atoll rehabilitation programs in the Marshall Islands have historically given special consideration to residual concentrations of plutonium in the environment even though the predicted dose from inhalation and/or ingestion of plutonium accounts for less than 5% of the annual effective dose from exposure to fallout contamination. Scientists from the Lawrence Livermore National Laboratory (LLNL) have developed a state-of-the-art bioassay test to assess urinary excretion rates of plutonium from Marshallese populations. This new heavy-isotope measurement system is based on Accelerator Mass Spectrometry (AMS). The AMS system at LLNL far exceeds the standard measurement requirements established under the latest United States Department of Energy (DOE) regulation, 10CFR 835, for occupational monitoring of plutonium, and offers several advantages over classical as well as competing new technologies for low-level detection and measurement of plutonium isotopes. The United States

  3. 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

  4. 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).

  5. Source term estimation and the isotopic ratio of radioactive material released from the WIPP repository in New Mexico, USA.

    PubMed

    Thakur, P

    2016-01-01

    After almost 15 years of operations, the Waste Isolation Pilot Plant (WIPP) had one of its waste drums breach underground as a result of a runaway chemical reaction in the waste it contained. This incident occurred on February 14, 2014. Moderate levels of radioactivity were released into the underground air. A small portion of the contaminated underground air also escaped to the surface through the ventilation system and was detected approximately 1 km away from the facility. According to the source term estimation, the actual amount of radioactivity released from the WIPP site was less than 1.5 mCi. The highest activity detected on the surface was 115.2 μBq/m(3) for (241)Am and 10.2 μBq/m(3) for (239+240)Pu at a sampling station located 91 m away from the underground air exhaust point and 81.4 μBq/m(3) of (241)Am and 5.8 μBq/m(3) of (239+240)Pu at a monitoring station located approximately 1 km northwest of the WIPP facility. The dominant radionuclides released were americium and plutonium, in a ratio that matches the content of the breached drum. Air monitoring across the WIPP site intensified following the first reports of radiation detection underground to determine the extent of impact to WIPP personnel, the public, and the environment. In this paper, the early stage monitoring data collected by an independent monitoring program conducted by the Carlsbad Environmental Monitoring & Research Center (CEMRC) and an oversight monitoring program conducted by the WIPP's management and operating contractor, the Nuclear Waste Partnership (NWP) LLC were utilized to estimate the actual amount of radioactivity released from the WIPP underground. The Am and Pu isotope ratios were measured and used to support the hypothesis that the release came from one drum identified as having breached that represents a specific waste stream with this radionuclide ratio in its inventory. This failed drum underwent a heat and gas producing reaction that overpowered its vent and

  6. Plutonium age dating reloaded

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  7. PLUTONIUM UPTAKE AND BEHAVIOR IN PLANTS OF THE DESERT SOUTHWEST: A PRELIMINARY ASSESSMENT

    SciTech Connect

    Caldwell, E.; Duff, M.; Ferguson, C.

    2011-03-01

    Eight species of desert vegetation and associated soils were collected from the Nevada National Security Site (N2S2) and analyzed for 238Pu and 239+240Pu concentrations. Amongst the plant species sampled were: atmospheric elemental accumulators (moss and lichen), the very slow growing, long-lived creosote bush and the rapidly growing, short-lived cheatgrass brome. The diversity of growth strategies provided insight into the geochemical behavior and bio-availability of Pu at the N2S2. The highest concentrations of Pu were measured in the onion moss (24.27 Bq kg-1 238Pu and 52.78 Bq kg-1 239+240Pu) followed by the rimmed navel lichen (8.18 Bq kg-1 and 18.4 Bq kg-1 respectively), pointing to the importance of eolian transport of Pu. Brome and desert globemallow accumulated between 3 and 9 times higher concentrations of Pu than creosote and sage brush species. These results support the importance of species specific elemental accumulation strategies rather than exposure duration as the dominant variable influencing Pu concentrations in these plants. Total vegetation elemental concentrations of Ce, Fe, Al, Sm and others were also analyzed. Strong correlations were observed between Fe and Pu. This supports the conclusion that Pu was accumulated as a consequence of the active accumulation of Fe and other plant required nutrients. Cerium and Pu are considered to be chemical analogs. Strong correlations observed in plants support the conclusion that these elements displayed similar geochemical behavior in the environment as it related to the biochemical uptake process of vegetation. Soils were also sampled in association with vegetation samples. This allowed for the calculation of a concentration ratio (CR). The CR values for Pu in plants were highly influenced by the heterogeneity of Pu distribution among sites. Results from the naturally occurring elements of concern were more evenly distributed between sample sites. This allowed for the development of a pattern of plant

  8. Findings of the first comprehensive radiological monitoring program of the Republic of the Marshall Islands.

    PubMed

    Simon, S L; Graham, J C

    1997-07-01

    The Marshall Islands was the primary site of the United States atomic weapons testing program in the Pacific. From 1946 through 1958, 66 atomic weapons were detonated in the island country. For several decades, monitoring was conducted by the U.S. Department of Energy (or its predecessor agencies) on the test site atolls and neighboring atolls. However, 70% of the land area of the over 1,200 islands in the Marshall Islands was never systematically monitored prior to 1990. For the 5-y period from 1990 through 1994, the Government of the Republic of the Marshall Islands undertook an independent program to assess the radiological conditions throughout its 29 atolls. The scientific work was performed under the auspices of the Section 177 Agreement of the Compact of Free Association, U.S. public law 99-239, signed in 1986 by President Ronald Reagan. Although the total land area of the nations is a scant 180 km2, the islands are distributed over 6 x 10(5) km2 of ocean. Consequently, logistics and instrumentation were main considerations, in addition to cultural and language issues. The core of the monitoring program was in-situ gamma spectrometry measurements made on more than 400 islands. Native foods including coconuts and other tropical fruits were sampled as well as more than 200 soil profiles and more than 800 surface soil samples. The fruits, soil profiles and surface soil samples have been analyzed for all gamma emitters with an emphasis on determining concentrations of 137Cs; the surface soil samples were also analyzed for 239+240Pu. All measurements were conducted in a radiological laboratory built in the capital city of the Marshall Islands specifically for the purposes of this study. The program was extensively assisted in the field and in the laboratory by Marshallese workers. The interpretation of environmental radiation data in the Marshall Islands required thoughtful analysis because the atolls lie along a latitude and precipitation gradient that effected

  9. Angular momentum of fission fragments in low energy fission of actinides

    SciTech Connect

    Naik, H.; Dange, S.P.; Singh, R.J.

    2005-01-01

    Independent isomeric yield ratios (IYR) of {sup 128}Sb, {sup 130}Sb, {sup 132}Sb, {sup 131}Te, {sup 133}Te, {sup 132}I, {sup 134}I, {sup 136}I, {sup 135}Xe, and {sup 138}Cs have been determined in fast neutron induced fission of {sup 232}Th, {sup 238}U, {sup 240}Pu, and {sup 244}Cm as well as in thermal neutron induced fission of {sup 232}U and {sup 238}Pu using radiochemical and offline {gamma}-ray spectrometric techniques. From the IYR, fragment angular momenta (J{sub rms}) have been deduced using a spin-dependent statistical model analysis. These data along with the literature data for {sup 230}Th*, {sup 234}U*, {sup 236}U*, {sup 240}Pu*, {sup 242}Pu*, {sup 244}Cm(SF), {sup 246}Cm*, {sup 250}Cf*, and {sup 252}Cf(SF) for fifteen even-Z fissioning systems show the following important features: (i) The J{sub rms} of the odd-Z fission products are higher than those of the even-Z fission products, indicating the odd-even effect. For both the odd-Z and even-Z fission products, the J{sub rms} increase with Z{sub F}{sup 2}/A{sub F}. (ii) The J{sub rms} of fragments with spherical 50-p and 82-n shells are lower compared to those of fragments outside the spherical shell, indicating the effect of shell closure proximity. (iii) The J{sub rms} of the fission products increase with mass number in spite of fluctuations in shell closure proximity and odd-even effects but do not show any correlation with the neutron emission curve. (iv) In all fifteen even-Z fissioning systems from Th to Cf, the yield-weighted J{sub rms} values show an anticorrelation with the elemental yields. (v) The odd-even fluctuation on J{sub rms} does not change drastically from Th to Cf, unlike the proton odd-even effect ({delta}{sub p}) which decreases significantly with the increase of Coulomb parameter (Z{sub F}{sup 2}/A{sub F}{sup 1/3})

  10. 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

  11. The Northern Marshall Islands Radiological Survey: data and dose assessments.

    PubMed

    Robison, W L; Noshkin, V E; Conrado, C L; Eagle, R J; Brunk, J L; Jokela, T A; Mount, M E; Phillips, W A; Stoker, A C; Stuart, M L; Wong, K M

    1997-07-01

    Fallout from atmospheric nuclear tests, especially from those conducted at the Pacific Proving Grounds between 1946 and 1958, contaminated areas of the Northern Marshall Islands. A radiological survey at some Northern Marshall Islands was conducted from September through November 1978 to evaluate the extent of residual radioactive contamination. The atolls included in the Northern Marshall Islands Radiological Survey (NMIRS) were Likiep, Ailuk, Utirik, Wotho, Ujelang, Taka, Rongelap, Rongerik, Bikar, Ailinginae, and Mejit and Jemo Islands. The original test sites, Bikini and Enewetak Atolls, were also visited on the survey. An aerial survey was conducted to determine the external gamma exposure rate. Terrestrial (soil, food crops, animals, and native vegetation), cistern and well water samples, and marine (sediment, seawater, fish and clams) samples were collected to evaluate radionuclide concentrations in the atoll environment. Samples were processed and analyzed for 137Cs, 90Sr, 239+240Pu and 241Am. The dose from the ingestion pathway was calculated using the radionuclide concentration data and a diet model for local food, marine, and water consumption. The ingestion pathway contributes 70% to 90% of the estimated dose. Approximately 95% of the dose is from 137Cs. 90Sr is the second most significant radionuclide via ingestion. External gamma exposure from 137Cs accounts for about 10% to 30% of the dose. 239+240Pu and 241Am are the major contributors to dose via the inhalation pathway; however, inhalation accounts for only about 1% of the total estimated dose, based on surface soil levels and resuspension studies. All doses are computed for concentrations decay corrected to 1996. The maximum annual effective dose from manmade radionuclides at these atolls ranges from .02 mSv y(-1) to 2.1 mSv y(-1). The background dose in the Marshall Islands is estimated to be 2.4 mSv y(-1). The combined dose from both background and bomb related radionuclides ranges from slightly

  12. Retrospective search for evidence of the 1957 Windscale fire in NE Ireland using 129I and other long-lived nuclides.

    PubMed

    Gallagher, D; McGee, E J; Mitchell, P I; Alfimov, V; Aldahan, A; Possnert, G

    2005-05-01

    The accident at Windscale in October 1957 resulted in the release to the atmosphere of a large quantity of radioactivity. The presented work is a retrospective search for evidence of contamination from the accident in the northeastern region of Ireland. A lake yielding a high-resolution sedimentary record was identified near the northeast coast of Ireland. This site was used to reconstruct the history of radionuclide input to the region, based on the analysis of a set of cores extracted from the lake. A chronology for sediment accumulation within the lake was established using radioisotopic dating techniques (including 270Pb). High-resolution gamma and alpha spectrometry techniques were used to quantify concentrations of 137Cs, 239,240Pu and 241Am, all of which were released during the accident. The primary radioactive component of the release was 131I (T1/2 = 8 days), but this short-lived isotope has long since decayed. However, 129I (T1/2 = 1.57 x 10(7) years) was also released during the accident, and in a known ratio to 131I. Recent advances in accelerator mass spectrometry now make it feasible to measure 129I at ultra-trace level and thereby retrospectively reconstruct 131I deposition. Clearly resolved concentration profiles for 137Cs, 239,240Pu and 241Am in the lake cores reflect known historical fallout trends. The data suggest that any contamination from the Windscale fire that might have reached this catchment has been overwritten by input from the testing of nuclear weapons in the atmosphere. A time-series for 129I in lake sediment shows that concentrations in recent sediments are approximately 10 times greater than concentrations recorded in strata corresponding to the period of maximum fallout of other radionuclides from atmospheric testing of nuclear weapons (1964). These recent increases in 129I are attributed to increased emissions from the nuclear industry. The study yields no evidence of any enhancement in radioisotope concentrations, over and

  13. USTUR whole body case 0262: 33-y follow-up of PuO2 in a skin wound and associated axillary node.

    PubMed

    James, A C; Sasser, L B; Stuit, D B; Wood, T G; Glover, S E; Lynch, T P; Dagle, G E

    2007-01-01

    This whole body donation case (USTUR Registrant) involved two suspected PuO2 inhalation intakes, each indicated by a measurable Pu alpha activity in a single urine sample, followed about 1(1/2) y later by a puncture wound to the thumb while working in a Pu glovebox. The study is concerned with modelling simultaneously the biokinetics of deposition and retention in the respiratory tract and at the wound site; and the biokinetics of Pu subsequently transferred to other body organs, until the donor's death. Urine samples taken after the wound incident had readily measurable Pu alpha activity over the next 14 y, before dropping below the minimum detectable excretion rate (<0.4 mBq d(-1)). The Registrant died about 33 y after the wound intake, at the age of 71, from hepatocellular carcinoma with extensive metastases. At autopsy, all major soft tissue organs were harvested for analysis of their 238Pu, 239+240Pu and 241Am content. The amount of 239+240Pu retained at the wound site was 68 +/- 7 Bq (1 SD), measured by low-energy planar Ge spectrometry. A further 56.0 +/- 1.2 Bq was retained in an associated axillary lymph node, measured by radiochemistry. Simultaneous mathematical analysis (modelling) of all in vivo urinary excretion data, together with the measured lung, thoracic lymph node, wound, axillary lymph node and systemic tissue contents at death, yielded estimated intake amounts of 757 and 1504 Bq, respectively, for the first and second inhalation incidents, and 204 Bq for the total wound intake. The inhaled Pu material was highly insoluble, with an estimated long-term absorption rate from the lungs of 2 x 10(-5) d(-1). The Pu material deposited at the wound site was mixed: approximately 14% was rapidly absorbed, approximately 49% was absorbed at the rate of about 6 x 10(-5) d(-1), and the remainder ( approximately 37%) was absorbed extremely slowly (at the rate of about 5 x 10(-6) d(-1)). Thus, it was estimated that only approximately 40% of the Pu initially

  14. Quantifying aeolian soil loss after forest conversion in the Chaco ecoregion

    NASA Astrophysics Data System (ADS)

    Sperl, Daniel; Veerle, Vanacker; Tibor, Dunai

    2016-04-01

    The Chaco ecoregion (NW Argentina) is characterized by the highest forest loss rates worldwide, as a result of agricultural expansion at agro-industrial scale. The conversion of dry forests to agricultural plots enhances the soil erosion vulnerability by exposure of bare soil after deforestation. The unconsolidated loess-type sediments are particularly susceptible to wind erosion during the prolonged dry season. In this study, the role of land use and management on soil erosion will be analysed. All investigated plots are characterized by flat topography. For this reason it is very likely that observed soil losses will be largely due to wind erosion, since such low gradients are not amenable to efficient water erosion. We hypothesise that changes in land use have a high impact on the mobilization of sediments in the Chaco ecoregion. We posit that a transformation from forest into crop/rangelands, will lead to enhanced mobilization of sediments by wind, whereas the establishment of no-tillage farming in this region might slow translocation rates down to near natural levels. Within this study we are using fallout radionuclides - a product of the atmospheric nuclear weapon testing era of the 1950s and 1960s - to investigate the impacts of wind erosion. This is possible since the used fallout radionuclides Plutonium (239+240Pu) and Caesium (137Cs) predominantly bind on small particle sizes, which can be transported by wind. Based on soil samples taken in three individual study regions, we examined the losses of fallout radionuclide inventories, from six agricultural plots per region, differing only in cultivation time (0-39 years). To gauge local fallout input, we further sampled two adjacent reference sites - so called stable surface - in each study region. For this study we measured the remaining activities of the radionuclide pair 239+240Pu via AMS and of 137Cs using a γ-spectrometer. The results for both radionuclides suggest that > 25 % of the initial inventory

  15. Environmental and health impacts of February 14, 2014 radiation release from the nation's only deep geologic nuclear waste repository.

    PubMed

    Thakur, P; Lemons, B G; Ballard, S; Hardy, R

    2015-08-01

    The environmental impact of the February 14, 2014 radiation release from the nation's only deep geologic nuclear waste repository, the Waste Isolation Pilot Plant (WIPP) was assessed using monitoring data from an independent monitoring program conducted by the Carlsbad Environmental Monitoring & Research Center (CEMRC). After almost 15 years of safe and efficient operations, the WIPP had one of its waste drums rupture underground resulting in the release of moderate levels of radioactivity into the underground air. A small amount of radioactivity also escaped to the surface through the ventilation system and was detected above ground. It was the first unambiguous release from the WIPP repository. The dominant radionuclides released were americium and plutonium, in a ratio that matches the content of the breached drum. The accelerated air monitoring campaign, which began following the accident, indicates that releases were low and localized, and no radiation-related health effects among local workers or the public would be expected. The highest activity detected was 115.2 μBq/m(3) for (241)Am and 10.2 μBq/m(3) for (239+240)Pu at a sampling station located 91 m away from the underground air exhaust point and 81.4 μBq/m(3) of (241)Am and 5.8 μBq/m(3) of (239+240)Pu at a monitoring station located approximately one kilometer northwest of the WIPP facility. CEMRC's recent monitoring data show that the concentration levels of these radionuclides have returned to normal background levels and in many instances, are not even detectable, demonstrating no long-term environmental impacts of the recent radiation release event at the WIPP. This article presents an evaluation of almost one year of environmental monitoring data that informed the public that the levels of radiation that got out to the environment were very low and did not, and will not harm anyone or have any long-term environmental consequence. In terms of radiological risk at or in the vicinity of the

  16. Nucleon localization and fragment formation in nuclear fission

    NASA Astrophysics Data System (ADS)

    Zhang, C. L.; Schuetrumpf, B.; Nazarewicz, W.

    2016-12-01

    Background: An electron localization measure was originally introduced to characterize chemical bond structures in molecules. Recently, a nucleon localization based on Hartree-Fock densities has been introduced to investigate α -cluster structures in light nuclei. Compared to the local nucleonic densities, the nucleon localization function has been shown to be an excellent indicator of shell effects and cluster correlations. Purpose: Using the spatial nucleon localization measure, we investigate the emergence of fragments in fissioning heavy nuclei. Methods: To illustrate basic concepts of nucleon localization, we employ the self-consistent energy density functional method with a quantified energy density functional optimized for fission studies. Results: We study the particle densities and spatial nucleon localization distributions along the fission pathways of 264Fm, 232Th, and 240Pu. We demonstrate that the fission fragments are formed fairly early in the evolution, well before scission. We illustrate the usefulness of the localization measure by showing how the hyperdeformed state of 232Th can be understood in terms of a quasimolecular state made of 132Sn and 100Zr fragments. Conclusions: Compared to nucleonic distributions, the nucleon localization function more effectively quantifies nucleonic clustering: its characteristic oscillating pattern, traced back to shell effects, is a clear fingerprint of cluster/fragment configurations. This is of particular interest for studies of fragment formation and fragment identification in fissioning nuclei.

  17. Plutonium determination in seawater by inductively coupled plasma mass spectrometry: A review.

    PubMed

    Cao, Liguo; Bu, Wenting; Zheng, Jian; Pan, Shaoming; Wang, Zhongtang; Uchida, Shigeo

    2016-05-01

    Knowing the concentration and isotopic ratio of Pu in seawater is of critical importance for assessing Pu contamination and investigating oceanic processes. In recent decades, the concentration of (239+240)Pu in seawater, particularly for surface seawater, has presented an exponential decreasing trend with time; thus determination of Pu in seawater has become a challenge nowadays. Here, we have summarized and critically discussed a variety of reported analytical methods for Pu determination in seawater sample based on inductively coupled plasma mass spectrometry (ICP-MS) analytical technique for rapid ultra-trace detection of Pu. Generally, pretreatments for seawater sample include co-precipitation, valence adjustment and chemical separation and purification procedures, all of which are comprehensively reviewed. Overall, the selected anion-exchange, extraction resins and operation condition are important for decontamination of interference from matrix elements and achieving satisfactory chemical yields. In addition, other mass spectrometric and radiometric detections are briefly addressed and compared with the focus on assessing ICP-MS. Finally, we discuss some issues and prospects in determination and application of Pu isotopes in seawater samples for future research.

  18. 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.

  19. Plutonium isotopes as tracers for ocean processes: a review.

    PubMed

    Lindahl, Patric; Lee, Sang-Han; Worsfold, Paul; Keith-Roach, Miranda

    2010-03-01

    Since the first nuclear weapons tests in the 1940s, pulsed inputs of plutonium isotopes have served as excellent tracers for understanding sources, pathways, dynamics and the fate of pollutants and particles in the marine environment. Due to the well-defined spatial and temporal inputs of Pu, the long half-lives of (240)Pu and (239)Pu and its unique chemical properties, Pu is a potential tracer for various physical and biogeochemical ocean processes, including circulation, sedimentation and biological productivity, and hence a means of assessing the impacts of global climate change. Due to the source dependency of the Pu isotopic signature, plutonium isotopes are beginning to be exploited as tools for the evaluation and improvement of regional and global ocean models that will enhance understanding of past and future changes in the oceans. This paper addresses the major sources of Pu and the physical and biogeochemical behaviour in the marine environment. Finally, the use of Pu isotopes as tracers for various oceanic processes (e.g. water mass transport, particle export, and sedimentation) is considered.

  20. Beyond the relativistic mean-field approximation -- collective correlations

    NASA Astrophysics Data System (ADS)

    Li, Zhipan; Nikšić, Tamara; Vretenar, Dario; Yao, Jiangming

    Semi-empirical relativistic energy density functionals (EDFs) or effective interactions implicitly comprise short-range correlations related to the repulsive core of the inter-nucleon interaction, and long-range correlations mediated by nuclear resonance modes. To model spectroscopic properties of finite nuclei, the self-consistent mean-field method must be extended to include collective correlations that arise from restoration of broken symmetries and fluctuations in collective coordinates. These correlations are sensitive to shell effects, vary with particle number, and cannot be included in a universal EDF. We review and compare recent advances in "beyond mean-field" methods based on relativistic EDFs: the angular-momentum and particle-number projected triaxial generator coordinate method, the five-dimensional quadrupole collective Hamiltonian and the axial quadrupole-octupole collective Hamiltonian models. Illustrative applications include low-energy collective excitation spectra and electromagnetic transition rates of nuclei characterised by quadrupole and/or octupole deformations: 24Mg, 76Kr, 240Pu and 224Ra, in comparison with available data.

  1. Numerical accuracy of mean-field calculations in coordinate space

    NASA Astrophysics Data System (ADS)

    Ryssens, W.; Heenen, P.-H.; Bender, M.

    2015-12-01

    Background: Mean-field methods based on an energy density functional (EDF) are powerful tools used to describe many properties of nuclei in the entirety of the nuclear chart. The accuracy required of energies for nuclear physics and astrophysics applications is of the order of 500 keV and much effort is undertaken to build EDFs that meet this requirement. Purpose: Mean-field calculations have to be accurate enough to preserve the accuracy of the EDF. We study this numerical accuracy in detail for a specific numerical choice of representation for mean-field equations that can accommodate any kind of symmetry breaking. Method: The method that we use is a particular implementation of three-dimensional mesh calculations. Its numerical accuracy is governed by three main factors: the size of the box in which the nucleus is confined, the way numerical derivatives are calculated, and the distance between the points on the mesh. Results: We examine the dependence of the results on these three factors for spherical doubly magic nuclei, neutron-rich 34Ne , the fission barrier of 240Pu , and isotopic chains around Z =50 . Conclusions: Mesh calculations offer the user extensive control over the numerical accuracy of the solution scheme. When appropriate choices for the numerical scheme are made the achievable accuracy is well below the model uncertainties of mean-field methods.

  2. Dependence of Fission-Fragment Properties On Excitation Energy For Neutron-Rich Actinides

    NASA Astrophysics Data System (ADS)

    Ramos, D.; Rodríguez-Tajes, C.; Caamaño, M.; Farget, F.; Audouin, L.; Benlliure, J.; Casarejos, E.; Clement, E.; Cortina, D.; Delaune, O.; Derkx, X.; Dijon, A.; Doré, D.; Fernández-Domínguez, B.; de France, G.; Heinz, A.; Jacquot, B.; Navin, A.; Paradela, C.; Rejmund, M.; Roger, T.; Salsac, M. D.; Schmitt, C.

    2016-03-01

    Experimental access to full isotopic fragment distributions is very important to determine the features of the fission process. However, the isotopic identification of fission fragments has been, in the past, partial and scarce. A solution based on the use of inverse kinematics to study transfer-induced fission of exotic actinides was carried out at GANIL, resulting in the first experiment accessing the full identification of a collection of fissioning systems and their corresponding fission fragment distribution. In these experiments, a 238U beam at 6.14 AMeV impinged on a carbon target to produce fissioning systems from U to Am by transfer reactions, and Cf by fusion reactions. Isotopic fission yields of 250Cf, 244Cm, 240Pu, 239Np and 238U are presented in this work. With this information, the average number of neutrons as a function of the atomic number of the fragments is calculated, which reflects the impact of nuclear structure around Z=50, N=80 on the production of fission fragments. The characteristics of the Super Long, Standard I, Standard II, and Standard III fission channels were extracted from fits of the fragment yields for different ranges of excitation energy. The position and contribution of the fission channels as function of excitation energy are presented.

  3. Effect of Potassium on Uptake of 137Cs in Food Crops Grown on Coral Soils: Annual Crops at Bikini Atoll

    SciTech Connect

    Stone, E R; Robinson, W

    2002-02-01

    In 1954 a radioactive plume from the thermonuclear device code named BRAVO contaminated the principal residential islands, Eneu and Bikini, of Bikini Atoll (11{sup o} 36 minutes N; 165{sup o} 22 minutes E), now part of the Republic of the Marshall Islands. The resulting soil radioactivity diminished greatly over the three decades before the studies discussed below began. By that time the shorter-lived isotopes had all but disappeared, but strontium-90 ({sup 90}Sr), and cesium-137, ({sup 137}Cs) were reduced by only one half-life. Minute amounts of the long-lived isotopes, plutonium-239+240 ({sup 239+240}Pu) and americium-241 ({sup 241}Am), were present in soil, but were found to be inconsequential in the food chain of humans and land animals. Rather, extensive studies demonstrated that the major concern for human health was {sup 137}Cs in the terrestrial food chain (Robison et al., 1983; Robison et al., 1997). The following papers document results from several studies between 1986 and 1997 aimed at minimizing the {sup 137}Cs content of annual food crops. The existing literature on radiocesium in soils and plant uptake is largely a consequence of two events: the worldwide fallout of 1952-58, and the fallout from Chernobyl. The resulting studies have, for the most part, dealt either with soils containing some amount of silicate clays and often with appreciable K, or with the short-term development of plants in nutrient cultures.

  4. SOLID PHASE MICROEXTRACTION SAMPLING OF HIGH EXPLOSIVE RESIDUES IN THE PRESENCE OF RADIONUCLIDES AND RADIONUCLIDE SURROGATE METALS

    SciTech Connect

    Duff, M; S Crump, S; Robert02 Ray, R; Donna Beals, D

    2007-04-13

    The Federal Bureau of Investigation (FBI) Laboratory currently does not have on site facilities for handling radioactive evidentiary materials and there are no established FBI methods or procedures for decontaminating high explosive (HE) evidence while maintaining evidentiary value. One experimental method for the isolation of HE residue involves using solid phase microextraction or SPME fibers to remove residue of interest. Due to their high affinity for organics, SPME fibers should have little affinity for most metals. However, no studies have measured the affinity of radionuclides for SPME fibers. The focus of this research was to examine the affinity of dissolved radionuclide ({sup 239/240}Pu, {sup 238}U, {sup 237}Np, {sup 85}Sr, {sup 133}Ba, {sup 137}Cs, {sup 60}Co and {sup 226}Ra) and stable radionuclide surrogate metals (Sr, Co, Ir, Re, Ni, Ba, Cs, Nb, Zr, Ru, and Nd) for SPME fibers at the exposure conditions that favor the uptake of HE residues. Our results from radiochemical and mass spectrometric analyses indicate these metals have little measurable affinity for these SPME fibers during conditions that are conducive to HE residue uptake with subsequent analysis by liquid or gas phase chromatography with mass spectrometric detection.

  5. Uptake and depuration of 131I by the edible periwinkle Littorina littorea: uptake from seawater.

    PubMed

    Vives i Batlle, J; Wilson, R C; McDonald, P; Parker, T G

    2005-01-01

    Uptake and depuration experiments for the edible periwinkle Littorina littorea have been performed using 131I-labelled seawater. Throughout the experimental phase the winkles were fed on unlabelled Chondrus crispus. 131I concentrations in winkles during uptake followed linear first-order kinetics with an uptake half-time of 11 days, whereas for depuration a triphasic sequence with biological half-lives of 4, 23 and 56 days was determined. In general, iodine turnover in winkles via labelled seawater appears to be slower than observed for other molluscs (2-3 days). Most of the activity prior to and after depuration is found to be in the shell, with indications that shell and soft parts accumulate and depurate 131I at a similar rate. The operculum displays the highest specific activity of all fractions with a concentration factor of 750 l kg(-1). Concentration factors for whole winkle, shell, soft parts and digestive gland are in the order of 40-60 l kg(-1), higher than the IAEA recommended CF value for iodine in molluscs of 10 l kg(-1). The 131I CF in winkles is closer to that of the conservative radionuclides 99Tc and 137Cs than the CF of the particle reactive radionuclides (239,240)Pu and 241Am.

  6. Radionuclides in Small Mammals Collected at the Dual-Axis Radiographic Hydrodynamic Test (DARHT) Facility during 2001-- 2003

    SciTech Connect

    P.R. Fresquez

    2005-01-20

    Rodents are effective indicators of environmental contamination and the Dual-Axis Radiographic Hydrodynamic Test (DARHT) Facility Mitigation Action Plan specifies the (radionuclide) comparison of small mammals to baseline levels to determine if there are any impacts as a result of operations. Consequently, samples of (whole body) field mice (Peromyscus spp.) were collected from within the grounds of the DARHT facility at Los Alamos National Laboratory, Technical Area 15, from 2001 through 2003. Samples were analyzed for {sup 3}H, {sup 137}Cs, {sup 90}Sr, {sup 241}Am, {sup 238}Pu, {sup 239,240}Pu, {sup 234}U, {sup 235}U, and {sup 238}U. Results, which represent three years since the start of operations in 2000, were compared with baseline statistical reference level (BSRL) data established over a four-year-long preoperational period. Most radionuclides in mice were either at nondetectable levels or within BSRLs. The few radionuclides that were above BSRLs included U isotopes; and the ratios of some samples indicated depleted U sources. Although the amounts of U in some samples were just above BSRLs, and since depleted U is less soluble and less toxic (chemical and radioactive) than naturally occurring U, the very small levels in the mice collected around the DARHT facility grounds are unlikely to pose a threat to predators that feed upon them.

  7. Radiological survey of shoreline vegetation from the Hanford Reach of the Columbia River, 1990--1992

    SciTech Connect

    Antonio, E.J.; Poston, T.M.; Rickard, W.H. Jr.

    1993-09-01

    A great deal of interest exists concerning the seepage of radiologically contaminated groundwater into the Columbia River where it borders the US Department of Energy`s Hanford Site (Hanford Reach). Areas of particular interest include the 100-N Area, the Old Hanford Townsite, and the 300 Area springs. While the radiological character of the seeps and springs along the Hanford Site shoreline has been studied, less attention has been given to characterizing the radionuclides that may be present in shoreline vegetation. The objective of this study was to characterize radionuclide concentrations in shoreline plants along the Hanford Reach of the Columbia River that were usable by humans for food or other purposes. Vegetation in two areas was found to have elevated levels of radionuclides. Those areas were the 100-N Area and the Old Hanford Townsite. There was also some indication of uranium accumulation in milfoil and onions collected from the 300 Area. Tritium was elevated above background in all areas; {sup 60}Co and {sup 9O}Sr were found in highest concentrations in vegetation from the 100-N Area. Technetium-99 was found in 2 of 12 plants collected from the Old Hanford Townsite and 1 of 10 samples collected upstream from the Vernita Bridge. The concentrations of {sup 137}Cs, {sup 238}Pu, {sup 239,240}Pu, and isotopes of uranium were just above background in all three areas (100-N Area, Old Hanford Townsite, and 300 Area).

  8. The Influence of Hydrothermal Plumes on the Distribution of Anthropogenic Radionuclides Between the Particulate and Dissolved Phases: Results from U.S. Geotraces Equatorial Pacific Zonal Transect GP16

    NASA Astrophysics Data System (ADS)

    Kenna, T. C.; Villa Alfageme, M.; Casacuberta Arola, N.; Masque, P.

    2014-12-01

    Here we present and discuss the results from the analysis of samples from selected stations collected on the US GEOTRACES Equatorial Pacific Zonal Transect (GP16) completed in 2013. The section, between Peru and Tahiti, encompasses a range of processes that influence the supply, removal, and internal cycling of trace metals and offers the opportunity to gain a better understanding of the drivers of the transport and fate of contaminants in the ocean. The capability to analyze water and filtered particulate samples in the quantities available, allows us to determine the partitioning of selected radionuclides among dissolved and particulate forms (Kd) and estimate Pu-particulate fluxes. The overarching objective of our work is to determine the concentrations of several anthropogenic radionuclides, including 239Pu, 240Pu, 237Np, and 137Cs with sufficient resolution to define their basin-wide distributions in the Pacific Ocean. Data collected in the East Pacific Rise hydrothermal plume allows a discussion on the partitioning behavior of plutonium and neptunium.

  9. External radiation exposure of the population of Utah from Nevada weapons tests

    SciTech Connect

    Beck, H.L.; Krey, P.W.

    1982-01-01

    The external gamma radiation exposure of the population of Utah from nuclear weapons tests carried out at the Nevada Test Site (NTS) during 1951 to 1958 has been reconstructed from measurements of residual /sup 137/Cs and /sup 239/ /sup 240/Pu in soil. The maximum time integrated (to infinity) free air exposure in any major population center is estimated to have been approx. 4 R at St. George and Hurricane. Exposures decreased with distance from the NTS to lower than 0.2 R at Richfield and Gunnison in south central Utah, before increasing again to levels of 1 to 2 R in the more populous northern valleys around Provo, Salt Lake City, and Ogden. These relatively higher exposures, coupled with the much larger population, probably resulted in a total population dose (person-rads) to the heretofore supposedly low fallout counties of northern Utah significantly greater than that for the supposedly high fallout areas nearer the NTS. Nevertheless, the total doses incurred from Nevada tests were probably only a few times greater than doses incurred from Nevada tests were probably only a few times greater than the doses which this northern valley population, as well as the rest of the US population, incurred from worldwide weapons fallout from all other atmospheric weapons tests. The mean exposure estimates for towns in southwest Utah nearest the NTS are somewhat lower but reasonably consistent with other retrospective estimates based on radiation surveys made directly after the tests.

  10. 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

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  12. Pu isotopes in soils collected downwind from Lop Nor: regional fallout vs. global fallout

    NASA Astrophysics Data System (ADS)

    Bu, Wenting; Ni, Youyi; Guo, Qiuju; Zheng, Jian; Uchida, Shigeo

    2015-07-01

    For the first time, soil core samples from the Jiuquan region have been analyzed for Pu isotopes for radioactive source identification and radiological assessment. The Jiuquan region is in downwind from the Lop Nor Chinese nuclear test (CNT) site. The high Pu inventories (13 to 546 Bq/m2) in most of the sampling locations revealed that this region was heterogeneously contaminated by the regional fallout Pu from the CNTs. The contributions of the CNTs to the total Pu in soils were estimated to be more than 40% in most cases. The 240Pu/239Pu atom ratios in the soils ranged from 0.059 to 0.186 with an inventory-weighted average of 0.158, slightly lower than that of global fallout. This atom ratio could be considered as a mixed fingerprint of Pu from the CNTs. In addition, Pu in soils of Jiuquan region had a faster downward migration rate compared with other investigated places in China.

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

    PubMed

    Zheltonozhsky, V; Mück, K; Bondarkov, M

    2001-01-01

    Both after the Chernobyl accident and nuclear weapon detonations, agglomerates of radioactive material, so-called hot particles, were released or formed which show a behaviour in the environment quite different from the activity released in gaseous or aerosol form. The differences in their characteristic properties, in the radionuclide composition and the uranium and actinide contents are described in detail for these particles. While nuclear bomb hot particles (both from fission and fusion bombs) incorporate well detectable trace amounts of 60Co and 152Eu, these radionuclides are absent in Chernobyl hot particles. In contrast, Chernobyl hot particles contain 125Sb and 144Ce which are absent in atomic bomb HPs. Obvious differences are also observable between fusion and fission bombs' hot particles (significant differences in 152Eu/l55Eu, 154Eu/155Eu and 238Pu/239Pu ratios) which facilitate the identification of HPs of unknown provensence. The ratio of 239Pu/240Pu in Chernobyl hot particles could be determined by a non-destructive method at 1:1.5. A non-destructive method to determine the content of non-radioactive elements by Kalpha-emission measurements was developed by which inactive Zr, Nb, Fe and Ni could be verified in the particles.