Science.gov

Sample records for 137cs gamma rays

  1. Current response of a TlBr detector to {sup 137}Cs {gamma}-ray radiation

    SciTech Connect

    Gazizov, I. M.; Zaletin, V. M.; Kukushkin, V. M.; Khrunov, V. S.

    2011-05-15

    The current response of a TlBr detector to {sup 137}Cs {gamma}-ray radiation has been studied in the dose-rate range 0.033-3.84 Gy/min and within the voltage range 1-300 V; the detectors are based on pure and doped TlBr crystals grown from the melt by the Bridgman-Stockbarger method. The mass fraction of Pb or Ca introduced into the TlBr crystals was 1-10 ppm for Pb and 150 ppm for Ca. The current response of nominally undoped TlBr samples was nearly linear over two decades of studied dose rates. Deep hole levels associated with cationic vacancies V{sub c}{sup -} determine the dependence of the current response on the voltage in the high electric fields. The parameters of the carriers' transport {mu}{tau} are determined. The TlBr crystals grown in vacuum and in the bromine vapor exhibit a large mobility-lifetime product of 4.3 Multiplication-Sign 10{sup -4} and 6.4 Multiplication-Sign 10{sup -5} cm{sup 2}V{sup -1}, respectively. The value of {mu}{tau} is in the range (4-9) Multiplication-Sign 10{sup -5} cm{sup 2}V{sup -1} for crystals doped with a divalent cation.

  2. Replacement of 137Cs irradiators with x-ray irradiators.

    PubMed

    Dodd, Brian; Vetter, Richard J

    2009-02-01

    Self-shielded 137Cs irradiators have been used for many years to irradiate blood products to prevent graft vs. host disease and to irradiate cells and small animals in research. A report by the National Academy of Sciences recommends that careful consideration be given to replacement of 137Cs irradiators with x-ray irradiators. Several manufacturers and users of x-ray irradiators were contacted to determine costs of replacing and maintaining 137Cs irradiators with x-ray units and to assess users' experience with x-ray irradiators. Purchase costs of x-ray units are similar to 137Cs irradiators, but maintenance costs are significantly higher if annual service contracts are used. Performance of the two irradiator types appears to be equivalent, but in some cases x-ray irradiations may need to be performed in multiple configurations to achieve adequate uniformity in dose. No literature reports were found that evaluated the biological effectiveness of x rays vs. 137Cs gamma rays; therefore, a careful study should be conducted to determine the biological effectiveness of x rays vs. 137Cs gamma rays for biological responses relevant to transfusion medicine and immunological research. Throughput may be problematic for large transfusion medicine programs, and back-up plans may be necessary in case the x-ray unit needs to be taken out of service for extended maintenance. Disposition of a 137Cs irradiator will add to the cost of replacement with an x-ray unit, but disposal may be possible through the U.S. Department of Energy's Off-Site Source Recovery Program.

  3. Determination of 137Cs activity in soil from Qatar using high-resolution gamma-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Al-Sulaiti, Huda; Nasir, Tabassum; Al Mugren, K. S.; Alkhomashi, N.; Al-Dahan, N.; Al-Dosari, M.; Bradley, D. A.; Bukhari, S.; Matthews, M.; Regan, P. H.; Santawamaitre, T.; Malain, D.; Habib, A.; Al-Dosari, Hanan; Al Sadig, Ibrahim; Daar, Eman

    2016-10-01

    With interest in establishing baseline concentrations of 137Cs in soil from the Qatarian peninsula, we focus on determination of the activity concentrations in 129 soil samples collected across the State of Qatar prior to the 2011 Fukushima Dai-ichi nuclear power plant accident. As such, the data provides the basis of a reference map for the detection of releases of this fission product. The activity concentrations were measured via high-resolution gamma-ray spectrometry using a hyper-pure germanium detector enclosed in a copper-lined passive lead shield that was situated in a low-background environment. The activity concentrations ranged from 0.21 to 15.41 Bq/kg, with a median value of 1 Bq/kg, the greatest activity concentration being observed in a sample obtained from northern Qatar. Although it cannot be confirmed, it is expected that this contamination is mainly due to releases from the Chernobyl accident of 26 April 1986, there being a lack of data from Qatar before the accident. The values are typically within but are sometimes lower than the range indicated by data from other countries in the region. The lower values than those of others is suggested to be due to variation in soil characteristics as well as metrological factors at the time of deposition.

  4. Comparison of the effectiveness of exposure to low LET helium particles (4He) and gamma rays (137Cs) on the disruption of cognitive performance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rats were exposed to either Helium (4He) particles (1000 MeV/n; 0.1 – 10 cGy; head-only) or Cesium 137Cs gamma rays (50 – 400 cGy; whole body) and the effects of irradiation on cognitive performance evaluated. The results indicated that exposure to doses of 4He particles as low as 0.1 cGy disrupted...

  5. A gamma-ray detector for in-situ measurement of 137Cs radioactivity in snowfields and glaciers

    NASA Astrophysics Data System (ADS)

    Dunphy, Philip P.; Dibb, Jack E.; Chupp, Edward L.

    1994-12-01

    The rate of snow deposition at various cold regions on the earth is an important quantity for glaciological and climatological studies. Radioactive debris from above-ground tests of nuclear weapons (mainly 1954-1970) and from the Chernobyl accident (1986) have been deposited on glaciers and snowfields, where they can be used as time and depth markers to determine the subsequent accumulation of snow. We discuss a technique to locate these markers that has been used just recently — in-situ measurement of γ-rays from 137Cs. These γ-rays, which are associated with radioactive fallout, have a distinctive depth profile and serve as markers of the historical nuclear events. The γ-ray measurement involves lowering a scintillation detector down a borehole in the snow or ice and recording the response to the 137Cs γ-rays as a function of depth. The in-situ measurement can be done relatively quickly and can replace sample retrieval, or it can be used to decide which ice or snow samples should be transported for later analysis in the laboratory. The feasibility of in-situ γ-ray measurement has been demonstrated at sites in the French Alps and Greenland. We report on a portable detector system that is being developed for use in Antarctica. It is based, as much as possible, on inexpensive, commercially available detectors and electronics. The advantages and disadvantages of this approach are discussed. The problems involved with making these measurements in a harsh environment and the steps taken to deal with them are also presented.

  6. Determination of the activity concentration levels of the artificial radionuclide137Cs in soil samples collected from Qatar using high-resolution gamma-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Al-Sulaiti, Huda; Nasir, Tabassum; Al Mugren, K. S.; Alkhomashi, N.; Al-Dahan, N.; Al-Dosari, M.; Bradley, D. A.; Bukhari, S.; Regan, P. H.; Santawamaitre, T.; Malain, D.; Habib, A.; Al-Dosari, Hanan; Daar, Eman

    2016-09-01

    The goal of this study was to establish the first baseline measurements for radioactivity concentration of the artificial radionuclide 137Cs in soil samples collected from the Qatarian peninsula. The work focused on the determination of the activity concentrations levels of man-made radiation in 129 soil samples collected across the landscape of the State of Qatar. All the samples were collected before the most recent accident in Japan, “the 2011 Fukushima Dai-ichi nuclear power plant accident”. The activity concentrations have been measured via high-resolution gamma-ray spectrometry using a hyper-pure germanium detector situated in a low-background environment with a copper inner-plated passive lead shield. A radiological map showing the activity concentrations of 137Cs is presented in this work. The concentration wasfound to range from 0.21 to 15.41 Bq/kg. The highest activity concentration of 137Cs was observed in sample no. 26 in North of Qatar. The mean value was found to be around 2.15 ± 0.27 Bq/kg. These values lie within the expected range relative to the countries in the region. It is expected that this contamination is mainly due to the Chernobyl accident on 26 April 1986, but this conclusion cannot be confirmed because of the lack of data before this accident.

  7. Chromosomal mutations and chromosome loss measured in a new human-hamster hybrid cell line, ALC: studies with colcemid, ultraviolet irradiation, and 137Cs gamma-rays

    NASA Technical Reports Server (NTRS)

    Kraemer, S. M.; Waldren, C. A.; Chatterjee, A. (Principal Investigator)

    1997-01-01

    Small mutations, megabase deletions, and aneuploidy are involved in carcinogenesis and genetic defects, so it is important to be able to quantify these mutations and understand mechanisms of their creation. We have previously quantified a spectrum of mutations, including megabase deletions, in human chromosome 11, the sole human chromosome in a hamster-human hybrid cell line AL. S1- mutants have lost expression of a human cell surface antigen, S1, which is encoded by the M1C1 gene at 11p13 so that mutants can be detected via a complement-mediated cytotoxicity assay in which S1+ cells are killed and S1- cells survive. But loss of genes located on the tip of the short arm of 11 (11p15.5) is lethal to the AL hybrid, so that mutants that have lost the entire chromosome 11 die and escape detection. To circumvent this, we fused AL with Chinese hamster ovary (CHO) cells to produce a new hybrid, ALC, in which the requirement for maintaining 11p15.5 is relieved, allowing us to detect mutations events involving loss of 11p15.5. We evaluated the usefulness of this hybrid by conducting mutagenesis studies with colcemid, 137Cs gamma-radiation and UV 254 nm light. Colcemid induced 1000 more S1- mutants per unit dose in ALC than in AL; the increase for UV 254 nm light was only two-fold; and the increase for 137Cs gamma-rays was 12-fold. The increase in S1- mutant fraction in ALC cells treated with colcemid and 137Cs gamma-rays were largely due to chromosome loss and 11p deletions often containing a breakpoint within the centromeric region.

  8. Comparison of the Effectiveness of Exposure to Low-LET Helium Particles ((4)He) and Gamma Rays ((137)Cs) on the Disruption of Cognitive Performance.

    PubMed

    Rabin, Bernard M; Carrihill-Knoll, Kirsty L; Shukitt-Hale, Barbara

    2015-09-01

    In this study, the effects of radiation exposure on cognitive performance were evaluated. Rats were exposed to either helium ((4)He) particles (1,000 MeV/n; 0.1-10 cGy; head only) or cesium (137)Cs gamma rays (50-400 cGy; whole body), after which their cognitive performance was evaluated. The results indicated that exposure to doses of (4)He particles as low as 0.1 cGy disrupted performance in a variety of cognitive tasks, including plus-maze performance (baseline anxiety), novel location recognition (spatial performance) and operant responding on an ascending fixed-ratio reinforcement schedule (motivation and responsiveness to changes in environmental contingencies) but not on novel object recognition performance (learning and memory). In contrast, after exposure to (137)Cs gamma rays only plus-maze performance was affected. There were no significant effects on any other task. Because exposure to both types of radiation produce oxidative stress, these results indicate that radiation-produced oxidative stress may be a necessary condition for the radiation-induced disruption of cognitive performance, but it is not a sufficient condition.

  9. Molecular characterisation of murine acute myeloid leukaemia induced by 56Fe ion and 137Cs gamma ray irradiation

    PubMed Central

    Bacher, Jeffery W.

    2013-01-01

    Exposure to sparsely ionising gamma- or X-ray irradiation is known to increase the risk of leukaemia in humans. However, heavy ion radiotherapy and extended space exploration will expose humans to densely ionising high linear energy transfer (LET) radiation for which there is currently no understanding of leukaemia risk. Murine models have implicated chromosomal deletion that includes the hematopoietic transcription factor gene, PU.1 (Sfpi1), and point mutation of the second PU.1 allele as the primary cause of low-LET radiation-induced murine acute myeloid leukaemia (rAML). Using array comparative genomic hybridisation, fluorescence in situ hybridisation and high resolution melt analysis, we have confirmed that biallelic PU.1 mutations are common in low-LET rAML, occurring in 88% of samples. Biallelic PU.1 mutations were also detected in the majority of high-LET rAML samples. Microsatellite instability was identified in 42% of all rAML samples, and 89% of samples carried increased microsatellite mutant frequencies at the single-cell level, indicative of ongoing instability. Instability was also observed cytogenetically as a 2-fold increase in chromatid-type aberrations. These data highlight the similarities in molecular characteristics of high-LET and low-LET rAML and confirm the presence of ongoing chromosomal and microsatellite instability in murine rAML. PMID:22987027

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

    PubMed

    Vinaykumar, L; Umesh, T K

    2015-09-01

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

  11. Microdosimetric analysis confirms similar biological effectiveness of external exposure to gamma-rays and internal exposure to 137Cs, 134Cs, and 131I.

    PubMed

    Sato, Tatsuhiko; Manabe, Kentaro; Hamada, Nobuyuki

    2014-01-01

    The risk of internal exposure to 137Cs, 134Cs, and 131I is of great public concern after the accident at the Fukushima-Daiichi nuclear power plant. The relative biological effectiveness (RBE, defined herein as effectiveness of internal exposure relative to the external exposure to γ-rays) is occasionally believed to be much greater than unity due to insufficient discussions on the difference of their microdosimetric profiles. We therefore performed a Monte Carlo particle transport simulation in ideally aligned cell systems to calculate the probability densities of absorbed doses in subcellular and intranuclear scales for internal exposures to electrons emitted from 137Cs, 134Cs, and 131I, as well as the external exposure to 662 keV photons. The RBE due to the inhomogeneous radioactive isotope (RI) distribution in subcellular structures and the high ionization density around the particle trajectories was then derived from the calculated microdosimetric probability density. The RBE for the bystander effect was also estimated from the probability density, considering its non-linear dose response. The RBE due to the high ionization density and that for the bystander effect were very close to 1, because the microdosimetric probability densities were nearly identical between the internal exposures and the external exposure from the 662 keV photons. On the other hand, the RBE due to the RI inhomogeneity largely depended on the intranuclear RI concentration and cell size, but their maximum possible RBE was only 1.04 even under conservative assumptions. Thus, it can be concluded from the microdosimetric viewpoint that the risk from internal exposures to 137Cs, 134Cs, and 131I should be nearly equivalent to that of external exposure to γ-rays at the same absorbed dose level, as suggested in the current recommendations of the International Commission on Radiological Protection.

  12. Investigation of (235)U, (226)Ra, (232)Th, (40)K, (137)Cs, and heavy metal concentrations in Anzali international wetland using high-resolution gamma-ray spectrometry and atomic absorption spectroscopy.

    PubMed

    Zare, Mohammad Reza; Kamali, Mahdi; Fallahi Kapourchali, Maryam; Bagheri, Hashem; Khoram Bagheri, Mahdi; Abedini, Ali; Pakzad, Hamid Reza

    2016-02-01

    Measurements of natural radioactivity levels and heavy metals in sediment and soil samples of the Anzali international wetland were carried out by two HPGe-gamma ray spectrometry and atomic absorption spectroscopy techniques. The concentrations of (235)U, (226)Ra, (232)Th, (40)K, and (137)Cs in sediment samples ranged between 1.05 ± 0.51-5.81 ± 0.61, 18.06 ± 0.63-33.36 ± .0.34, 17.57 ± 0.38-45.84 ± 6.23, 371.88 ± 6.36-652.28 ± 11.60, and 0.43 ± 0.06-63.35 ± 0.94 Bq/kg, while in the soil samples they vary between 2.36-5.97, 22.71-38.37, 29.27-42.89, 472.66-533, and 1.05-9.60 Bq/kg for (235)U, (226)Ra, (232)Th, (40)K, and (137)Cs, respectively. Present results are compared with the available literature data and also with the world average values. The radium equivalent activity was well below the defined limit of 370 Bq/kg. The external hazard indices were found to be less than 1, indicating a low dose. Heavy metal concentrations were found to decrease in order as Fe > Mn > Sr > Zn > Cu > Cr > Ni > Pb > Co > Cd. These measurements will serve as background reference levels for the Anzali wetland.

  13. Comparison Between the NIST and the KEBS for the Determination of Air Kerma Calibration Coefficients for Narrow X-Ray Spectra and (137)Cs Gamma-Ray Beams.

    PubMed

    O'Brien, Michelle; Minniti, Ronaldo; Masinza, Stanslaus Alwyn

    2010-01-01

    Air kerma calibration coefficients for a reference class ionization chamber from narrow x-ray spectra and cesium 137 gamma-ray beams were compared between the National Institute of Standards and Technology (NIST) and the Kenya Bureau of Standards (KEBS). A NIST reference-class transfer ionization chamber was calibrated by each laboratory in terms of the quantity air kerma in four x-ray reference radiation beams of energies between 80 kV and 150 kV and in a cesium 137 gamma-ray beam. The reference radiation qualities used for this comparison are described in detail in the ISO 4037 publication.[1] The comparison began in September 2008 and was completed in March 2009. The results reveal the degree to which the participating calibration facility can demonstrate proficiency in transferring air kerma calibrations under the conditions of the said facility at the time of the measurements. The comparison of the calibration coefficients is based on the average ratios of calibration coefficients.

  14. Analysis of mutant quantity and quality in human-hamster hybrid AL and AL-179 cells exposed to 137Cs-gamma or HZE-Fe ions

    NASA Technical Reports Server (NTRS)

    Waldren, C.; Vannais, D.; Drabek, R.; Gustafson, D.; Kraemer, S.; Lenarczyk, M.; Kronenberg, A.; Hei, T.; Ueno, A.; Chatterjee, A. (Principal Investigator)

    1998-01-01

    We measured the number of mutants and the kinds of mutations induced by 137Cs-gamma and by HZE-Fe (56Fe [600 MeV/amu, LET = 190 KeV/micrometer) in standard AL human hamster hybrid cells and in a new variant hybrid, AL-179. We found that HZE-Fe was more mutagenic than 137Cs-gamma per unit dose (about 1.6 fold), but was slightly less mutagenic per mean lethal dose, DO, at both the S1 and hprt- loci of AL cells. On the other hand, HZE-Fe induced about nine fold more complex S1- mutants than 137Cs-gamma rays, 28% vs 3%. 137Cs-gamma rays induced about twice as many S1- mutants and hprt-mutants in AL-179 as in AL cells, and about nine times more of the former were complex, and potentially unstable kinds of mutations.

  15. Exploiting Kalman Filtering Non-linear Exponential Fitting to Promote the Energy Resolution of 137Cs and 60Co Gamma Ray Spectra.

    PubMed

    Guo, Huiping; Tian, Chenyang; Xue, Hongbin; Lv, Ning; Wei, Yingguang; Fu, Guangzhi; Lv, Wenhui; Zhao, Kuo; Hou, Yijie

    2017-03-01

    For Cs and Co gamma ray spectra, gamma ray energy is proportional to the amplitude of the pulse signal, and energy resolution can be improved by pulse signal processing with mathematical algorithms. Influenced by system measurement noise and baseline fluctuation, the pulse amplitude is difficult to calculate accurately. A method that combines the Kalman filter baseline estimation with the non-linear exponential fitting has been used. By this method, the pulse signal is divided into two parts: one is the raising edge before the pulse peak, and another is after the pulse peak. The pulse amplitude equals the difference between the pulse starting height and the pulse peak height. The pulse starting height is obtained by Kalman filter baseline estimation on the rising edge of the pulse starting point. The pulse peak height is calculated by nonlinear exponential fitting on the falling edge of the pulse highest point. When the sampling rate is 100 MHz, the pulse signals obtained from a Cd(Zn)Te detector are analyzed by this method. Results have shown that the processed pulses have a more distinguishable amplitude distribution; energy resolution for the Cs spectrum is approximately 2.97% at 662 keV (~19.66 keV FWHM), and for the Co spectrum it is 2.61% at 1,332 keV (~34.76 keV FWHM).

  16. Radiation damage and recovery properties of common plastics PEN (Polyethylene Naphthalate) and PET (Polyethylene Terephthalate) using a 137Cs gamma ray source up to 1.4 Mrad and 14 Mrad

    NASA Astrophysics Data System (ADS)

    Wetzel, J.; Tiras, E.; Bilki, B.; Onel, Y.; Winn, D.

    2016-08-01

    Polyethylene naphthalate (PEN) and polyethylene teraphthalate (PET) are cheap and common polyester plastics used throughout the world in the manufacturing of bottled drinks, containers for foodstuffs, and fibers used in clothing. These plastics are also known organic scintillators with very good scintillation properties. As particle physics experiments increase in energy and particle flux density, so does radiation exposure to detector materials. It is therefore important that scintillators be tested for radiation tolerance at these generally unheard of doses. We tested samples of PEN and PET using laser stimulated emission on separate tiles exposed to 1 Mrad and 10 Mrad gamma rays with a 137Cs source. PEN exposed to 1.4 Mrad and 14 Mrad emit 71.4% and 46.7% of the light of an undamaged tile, respectively, and maximally recover to 85.9% and 79.5% after 5 and 9 days, respectively. PET exposed to 1.4 Mrad and 14 Mrad emit 35.0% and 12.2% light, respectively, and maximally recover to 93.5% and 80.0% after 22 and 60 days, respectively.

  17. Simulation and Measurement of Absorbed Dose from 137 Cs Gammas Using a Si Timepix Detector

    NASA Technical Reports Server (NTRS)

    Stoffle, Nicholas; Pinsky, Lawrence; Empl, Anton; Semones, Edward

    2011-01-01

    The TimePix readout chip is a hybrid pixel detector with over 65k independent pixel elements. Each pixel contains its own circuitry for charge collection, counting logic, and readout. When coupled with a Silicon detector layer, the Timepix chip is capable of measuring the charge, and thus energy, deposited in the Silicon. Measurements using a NIST traceable 137Cs gamma source have been made at Johnson Space Center using such a Si Timepix detector, and this data is compared to simulations of energy deposition in the Si layer carried out using FLUKA.

  18. A first attempt to derive soil erosion rates from 137Cs airborne gamma measurements in two Alpine valleys

    NASA Astrophysics Data System (ADS)

    Arata, Laura; Meusburger, Katrin; Bucher, Benno; Mabit, Lionel; Alewell, Christine

    2016-04-01

    The application of fallout radionuclides (FRNs) as soil tracers is currently one of the most promising and effective approach for evaluating soil erosion magnitudes in mountainous grasslands. Conventional assessment or measurement methods are laborious and constrained by the topographic and climatic conditions of the Alps. The 137Cs (half-life = 30.2 years) is the most frequently used FRN to study soil redistribution. However the application of 137Cs in alpine grasslands is compromised by the high heterogeneity of the fallout due to the origin of 137Cs fallout in the Alps, which is linked to single rain events occurring just after the Chernobyl accident when most of the Alpine soils were still covered by snow. The aim of this study was to improve our understanding of the 137Cs distribution in two study areas in the Central Swiss Alps: the Ursern valley (Canton Uri), and the Piora valley (Canton Ticino). In June 2015, a helicopter equipped with a NaI gamma detector flew over the two study sites and screened the 137Cs activity of the top soil. The use of airborne gamma measurements is particularly efficient in case of higher 137Cs concentration in the soil. Due to their high altitude and high precipitation rates, the Swiss Alps are expected to be more contaminated by 137Cs fallout than other parts of Switzerland. The airborne gamma measurements have been related to several key parameters which characterize the areas, such as soil properties, slopes, expositions and land uses. The ground truthing of the airborne measurements (i.e. the 137Cs laboratory measurements of the soil samples collected at the same points) returned a good fit. The obtained results offer an overview of the 137Cs concentration in the study areas, which allowed us to identify suitable reference sites, and to analyse the relationship between the 137Cs distribution and the above cited parameters. The authors also derived a preliminary qualitative and a quantitative assessment of soil redistribution

  19. Mortality of the harvester ant (Pogonomyrmex owyheei) after exposure to /sup 137/Cs gamma radiation

    SciTech Connect

    Gano, K.A.

    1981-01-01

    Harvester ants, Pogonomyrmex owyheei Cole, irradiated with 3.5 kR to 268 kR of /sup 137/Cs gamma radiation, were maintained at simulated summer (27/sup 0/C) and winter (7/sup 0/C) temperature regimes. After thirty days, the cool series was warmed to 27/sup 0/C and observed for mortality along with the warm series.Though mortality was delayed in the cool series, each series reached 50% mortality at similar rates. Because the harvester ant is extremely tolerant to radiation and experimental rates used far exceed possible environmental exposure, it is unlikely that ant colonies dwelling among low-level nuclear waste storage sites will be deleteriously affected by radiation. This species has the capability of tunneling to a depth well within the range of some buried waste. Since these harvester ants are potential transporters of buried waste, they should be considered as a biotic factor in radioactive waste management operations in semi-arid regions.

  20. Mortality of the harvester ant (Pogonomyrmex owyheei) after exposure to /sup 137/Cs gamma radiation

    SciTech Connect

    Gano, K.A.

    1981-01-01

    Harvester ants, Pogonomyrmex owyheei Cole, irradiated with 3.5 kR to 268 kR of /sup 137/Cs gamma radiation, were maintained at simulated summer (27/sup 0/C) and winter (7/sup 0/C) temperature regimes. After thirty days, the cool series was warmed to 27/sup 0/C and observed for mortality along with the warm series. Though mortality was delayed in the cool series, each series reached 50% mortality at similar rates. Because the harvester ant is extremely tolerant to radiation and experimental rates used far exceed possible environmental exposure, it is unlikely that ant colonies dwelling among low-level nuclear waste storage sites will be deleteriously affected by radiation. This species has the capability of tunneling to a depth well within the range of some buried waste. Since these harvester ants are potential transporters of buried waste, they should be considered as a biotic factor in radioactive waste management operations in semi-arid regions.

  1. Induction of genomic instability in TK6 human lymphoblasts exposed to 137Cs gamma radiation: comparison to the induction by exposure to accelerated 56Fe particles

    NASA Technical Reports Server (NTRS)

    Evans, Helen H.; Horng, Min-Fen; Ricanati, Marlene; Diaz-Insua, M.; Jordan, Robert; Schwartz, Jeffrey L.

    2003-01-01

    The induction of genomic instability in TK6 human lymphoblasts by exposure to (137)Cs gamma radiation was investigated by measuring the frequency and characteristics of unstable clones isolated approximately 36 generations after exposure. Clones surviving irradiation and control clones were analyzed for 17 characteristics including chromosomal aberrations, growth defects, alterations in response to a second irradiation, and mutant frequencies at the thymidine kinase and Na(+)/K(+) ATPase loci. Putative unstable clones were defined as those that exhibited a significant alteration in one or more characteristics compared to the controls. The frequency and characteristics of the unstable clones were compared in clones exposed to (137)Cs gamma rays or (56)Fe particles. The majority of the unstable clones isolated after exposure to either gamma rays or (56)Fe particles exhibited chromosomal instability. Alterations in growth characteristics, radiation response and mutant frequencies occurred much less often than cytogenetic alterations in these unstable clones. The frequency and complexity of the unstable clones were greater after exposure to (56)Fe particles than to gamma rays. Unstable clones that survived 36 generations after exposure to gamma rays exhibited increases in the incidence of dicentric chromosomes but not of chromatid breaks, whereas unstable clones that survived 36 generations after exposure to (56)Fe particles exhibited increases in both chromatid and chromosome aberrations.

  2. 137Cs measurement uncertainties and detection limits for airborne gamma spectrometry (AGS) data analysed using a spectral windows method.

    PubMed

    Cresswell, A J; Sanderson, D C W; White, D C

    2006-02-01

    The uncertainties associated with airborne gamma spectrometry (AGS) measurements analysed using a spectral windows method, and associated detection limits, have been investigated. For individual short measurements over buried 137Cs activity detection limits of 10 kBq m(-2) are achieved. These detection limits are reduced for superficial activity and longer integration times. For superficial activity, detection limits below 1 kBq m(-2) are achievable. A comparison is made with the detection limits for other data processing methods.

  3. Gamma spectrometry efficiency calibration using Monte Carlo methods to measure radioactivity of 137Cs in food samples.

    PubMed

    Alrefae, T

    2014-12-01

    A simple method of efficiency calibration for gamma spectrometry was performed. This method, which focused on measuring the radioactivity of (137)Cs in food samples, was based on Monte Carlo simulations available in the free-of-charge toolkit GEANT4. Experimentally, the efficiency values of a high-purity germanium detector were calculated for three reference materials representing three different food items. These efficiency values were compared with their counterparts produced by a computer code that simulated experimental conditions. Interestingly, the output of the simulation code was in acceptable agreement with the experimental findings, thus validating the proposed method.

  4. Diverse delayed effects in human lymphoblastoid cells surviving exposure to high-LET (56)Fe particles or low-LET (137)Cs gamma radiation

    NASA Technical Reports Server (NTRS)

    Evans, H. H.; Horng, M. F.; Ricanati, M.; Diaz-Insua, M.; Jordan, R.; Schwartz, J. L.

    2001-01-01

    To obtain information on the origin of radiation-induced genomic instability, we characterized a total of 166 clones that survived exposure to (56)Fe particles or (137)Cs gamma radiation, isolated approximately 36 generations after exposure, along with their respective control clones. Cytogenetic aberrations, growth alterations, responses to a second irradiation, and mutant frequencies at the Na(+)/K(+) ATPase and thymidine kinase loci were determined. A greater percentage of clones that survived exposure to (56)Fe particles exhibited instability (defined as clones showing one or more outlying characteristics) than in the case of those that survived gamma irradiation. The phenotypes of the unstable clones that survived exposure to (56)Fe particles were also qualitatively different from those of the clones that survived gamma irradiation. A greater percentage (20%) of the unstable clones that survived gamma irradiation than those that survived exposure to (56)Fe particles (4%) showed an altered response to the second irradiation, while an increase in the percentage of clones that had an outlying frequency of ouabain-resistant and thymidine kinase mutants was more evident in the clones exposed to (56)Fe particles than in those exposed to gamma rays. Growth alterations and increases in dicentric chromosomes were found only in clones with more than one alteration. These results underscore the complex nature of genomic instability and the likelihood that radiation-induced genomic instability arises from different original events.

  5. Accumulation and distribution of 137Cs in tropical plants

    NASA Astrophysics Data System (ADS)

    Anjos, R. M.; Carvalho, C.; Mosquera, B.; Veiga, R.; Sanches, N.; Bastos, J.; Macario, K.

    2007-02-01

    The accumulation and distribution of 40K and 137Cs in several tropical plant species were studied through measurements of gamma-ray spectra, focusing on establishing the suitability of using radiocesium to trace the plant uptake of nutrients such as potassium.

  6. Vertical distribution of (137)Cs activity concentration in marine sediments at Amvrakikos Gulf, western of Greece.

    PubMed

    Tsabaris, C; Patiris, D L; Fillis-Tsirakis, E; Kapsimalis, V; Pilakouta, M; Pappa, F K; Vlastou, R

    2015-06-01

    The aim of the present work is the study of (137)Cs migration in sediment column taking into account the sedimentation rate in the Amvrakikos Gulf, at the western part of Greece. Marine core sediments were collected and the measurements were performed using the high resolution gamma-ray spectrometry method. The vertical distribution of (137)Cs activity concentration, as part of anthropogenic marine radioactivity, provided averaged sedimentation rate by identifying the depths of activity concentrations due to the Chernobyl accident and the nuclear tests signals. Furthermore, (137)Cs measurements were reproduced using the proposed one-dimensional diffusion-advection model which provides mainly as an output, the sedimentation rate and the average diffusivity of (137)Cs in the sediment column. The proposed model estimates the temporal variation of (137)Cs activity concentration from 1987 (one year after the Chernobyl accident) till today (2014).

  7. Quality Control of Pavements and Tarmacs Using ({sup 137}Cs){gamma} Compton Scattering

    SciTech Connect

    Pino, F.; Barros, H.; Bernal, M.; Sajo-Bohus, L.; Palacios, D.; Greaves, E. D.; Viesti, G.

    2010-08-04

    The {gamma} Compton scattering over a volume of concrete has been studied in order to design an instrument for density measurements. It will be used for the quality control in road construction, where large surfaces must be monitored. The experimental results and Monte Carlo simulations of the {gamma} Compton scattering over homogeneous and inhomogeneous volumes of concrete are shown. MC simulations have been useful to optimize the values of several parameters to improve the experimental set up and to estimate the extension of the explored volume.

  8. Summary of the BIPM.RI(I)-K5 comparison for air kerma in 137Cs gamma radiation

    NASA Astrophysics Data System (ADS)

    Allisy-Roberts, P. J.; Kessler, C.; Burns, D. T.

    2013-01-01

    International comparisons of air kerma in 137Cs gamma radiation beams have been made at the Bureau International des Poids et Mesures (BIPM) since 1994. Twelve national metrology institutes have taken part, seven of which have repeated the comparison over the intervening years. The key comparison reference value (KCRV) is taken as the BIPM evaluation, each comparison result being the ratio of the national metrology institute (NMI) evaluation to that of the BIPM standard under the same reference conditions. The degrees of equivalence between each NMI and the KCRV and a graphical presentation are given using the most recent published result for eleven NMIs. 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).

  9. Persistence of 137Cs in the litter layers of forest soil horizons of Mount IDA/Kazdagi, Turkey.

    PubMed

    Karadeniz, Özlem; Karakurt, Hidayet; Çakır, Rukiye; Çoban, Fatih; Büyükok, Emir; Akal, Cüneyt

    2015-01-01

    In 2010-2012, an extensive study was performed in forest sites of Mount IDA (Kazdagi)/Edremit 26 years after the Chernobyl accident. The (137)Cs activity concentrations were determined by gamma-ray spectrometry in the forest soil layers (OL, OF + OH and A horizons) separately. Based on 341 surface soil samples and 118 soil profiles, activity concentrations of (137)Cs in OL horizons varied between 0.25 ± 0.14 and 70 ± 1 Bq kg(-1), while the ranges of (137)Cs activity concentrations in OF + OH and A horizons were 13 ± 1-555 ± 3 Bq kg(-1) and 2 ± 1-253 ± 2 Bq kg(-1), respectively. Cesium-137 deposition in the study area was estimated to be in the range of 1-39 kBq m(-2) and a linear relationship between the deposition of (137)Cs and the altitude was observed. The distributions of (137)Cs activities in OL, OF + OH and A horizons throughout the region were mapped in detail. The highest (137)Cs activities were found in OF + OH horizons, with markedly lower (137)Cs activity in mineral horizons of soil profiles. It is observed that (137)Cs content of humus layer increases with the thickness of the humus layer for coniferous forest sites. The (137)Cs activity concentrations were higher than the recommended screening limits (150 Bq kg(-1)) at some of the investigated areas. The current activity concentration of top soil layers indicates that over many years since the initial deposition, (137)Cs activity is keeping still high in the organic horizons.

  10. Cross equator transport of 137Cs from North Pacific Ocean to South Pacific Ocean ( BEAGLE2003 cruises)

    NASA Astrophysics Data System (ADS)

    Aoyama, M.; Fukasawa, M.; Hirose, K.; Hamajima, Y.; Kawano, T.; Povinec, P. P.; Sanchez-Cabeza, J. A.

    2011-04-01

    The anthropogenic radionuclides such as 137Cs, 90Sr, 99Tc, 129I and some transuranics are important tracers of transport and biogeochemical processes in the ocean. 137Cs, with a half-life of 30 years, a major fission product present in a dissolved form in seawater, is a good tracer of oceanic circulation at a time scale of several decades. At WOCE P6 line along 30°S during the BEAGLE cruise in 2003, surface seawater (around 80 L) was collected a few meters below the ocean surface by a pumping system. Water column samples (from 5 to 20 L) were collected using a Rosette multisampling system and Niskin bottles. 137Cs was separated from seawater samples using ammonium phosphomolybdate (AMP) and analysed for 137Cs in low-level HPGe gamma-ray spectrometers. Results allowed to draw a detailed picture of the distribution of 137Cs in the South Pacific Ocean along P6 line. A 137Cs depth section was depicted from about 160 samples. 137Cs concentrations in the subsurface layers ranged from 0.07 ± 0.04 Bq m -3 to 1.85 ± 0.145 Bq m -3, high in the Tasman Sea and very low in the eastern region where upwelling occurs. Water column inventories of 137Cs from surface to 1000 dbar depth ranged from 270 ± 104 to 1048 ± 127 Bq m -2. It was concluded that the source of higher 137Cs concentration and inventories in the Tasman Sea was 137Cs deposited in the mid latitude of the North Pacific Ocean and transported across the equator during four decades.

  11. Measurement of natural and 137Cs radioactivity concentrations at Izmit Bay (Marmara Sea), Turkey

    NASA Astrophysics Data System (ADS)

    Öksüz, I.; Güray, R. T.; Özkan, N.; Yalçin, C.; Ergül, H. A.; Aksan, S.

    2016-03-01

    In order to determine the radioactivity level at Izmit Bay Marmara Sea, marine sediment samples were collected from five different locations. The radioactivity concentrations of naturally occurring 238U, 232Th and 40K isotopes and also that of an artificial isotope 137Cs were measured by using gamma-ray spectroscopy. Preliminary results show that the radioactivity concentrations of 238U and 232Th isotopes are lower than the average worldwide values while the radioactivity concentrations of the 40K are higher than the average worldwide value. A small amount of 137Cs contamination, which might be caused by the Chernobyl accident, was also detected.

  12. 137Cs in the western South Pacific Ocean.

    PubMed

    Yamada, Masatoshi; Wang, Zhong-Liang

    2007-09-01

    The 137Cs activities were determined for seawater samples from the East Caroline, Coral Sea, New Hebrides, South Fiji and Tasman Sea (two stations) Basins of the western South Pacific Ocean by gamma spectrometry using a low background Ge detector. The 137Cs activities ranged from 1.4 to 2.3 Bq m(-3) over the depth interval 0-250 m and decreased exponentially from the subsurface to 1000 m depth. The distribution profiles of 137Cs activity at these six western South Pacific Ocean stations did not differ from each other significantly. There was a remarkable difference for the vertical profiles of 137Cs activity between the East Caroline Basin station in this study and the GEOSECS (Geochemical Ocean Sections Study) station at the same latitude in the Equatorial Pacific Ocean; the 137Cs inventory over the depth interval 100-1000 m increased from 400+/-30 Bq m(-2) to 560+/-30 Bq m(-2) during the period from 1973 to 1992. The total 137Cs inventories in the western South Pacific Ocean ranged from 850+/-70 Bq m(-2) in the Coral Sea Basin to 1270+/-90 Bq m(-2) in the South Fiji Basin. Higher 137Cs inventories were observed at middle latitude stations in the subtropical gyre than at low latitude stations. The 137Cs inventories were 1.9-4.5 times (2.9+/-0.7 on average) and 1.7-4.3 times (3.1+/-0.7 on average) higher than that of the expected deposition density of atmospheric global fallout at the same latitude and that of the estimated 137Cs deposition density in 10 degrees latitude by 10 degrees longitude grid data obtained by Aoyama et al. [Aoyama M, Hirose K, Igarashi Y. Re-construction and updating our understanding on the global weapons tests 137Cs fallout. J Environ Monit 2006;8:431-438], respectively. The possible processes for higher 137Cs inventories in the western South Pacific Ocean than that of the expected deposition density of atmospheric global fallout may be attributable to the inter-hemisphere dispersion of the atmospheric nuclear weapons testing 137Cs from

  13. Up-regulation of 8-oxo-dGTPase activity of MTH1 protein in the brain, testes and kidneys of mice exposed to (137)Cs gamma radiation.

    PubMed

    Bialkowski, Karol; Szpila, Anna; Kasprzak, Kazimierz S

    2009-08-01

    Abstract Mammalian MTH1 protein is an antimutagenic (2'-deoxy)ribonucleoside 5'-triphosphate pyrophosphohydrolase that prevents the incorporation of oxidatively modified nucleotides into nucleic acids. It decomposes most specifically the miscoding products of oxidative damage to purine nucleic acid precursors (e.g. 8-oxo-dGTP, 2-oxo-dATP, 2-oxo-ATP, 8-oxo-GTP) that may cause point mutations or transcription errors when incorporated into DNA and RNA, respectively. The increased expression of MTH1 mRNA and MTH1 protein was previously proposed as a molecular marker of oxidative stress. Therefore, we hypothesized that increased 8-oxo-dGTPase activity of MTH1 protein in mouse organs could serve as a dose-dependent marker of exposure to ionizing radiation, which is known to induce oxidative stress. To test our hypothesis, we measured 8-oxo-dGTPase activity in six organs of male BL6 mice after exposure to 0, 10, 25 and 50 cGy and 1 Gy of (137)Cs gamma radiation given as a single whole-body dose (1 Gy/min). The mice were killed 4, 8 and 24 h after irradiation. A statistically significant induction of 8-oxo-dGTPase was found in brains, testes and kidneys but not in lungs, hearts or livers. Brains, which demonstrated the highest (4.3-fold) increase of 8-oxo-dGTPase activity, were shown to express approximately 50% higher levels of MTH1 protein. However, due to the lack of a simple positive correlation between the dose and the observed 8-oxo-dGTPase activity in brain, testes and kidneys, we conclude that measurements of 8-oxo-dGTPase activity in these organs may serve as a rough indicator rather than a quantifiable marker of radiation-induced oxidative stress.

  14. Gene Expression Response of Mice after a Single Dose of 137Cs as an Internal Emitter

    PubMed Central

    Paul, Sunirmal; Ghandhi, Shanaz A.; Weber, Waylon; Doyle-Eisele, Melanie; Melo, Dunstana; Guilmette, Raymond; Amundson, Sally A.

    2014-01-01

    Cesium-137 is a radionuclide of concern in fallout from reactor accidents or nuclear detonations. When ingested or inhaled, it can expose the entire body for an extended period of time, potentially contributing to serious health consequences ranging from acute radiation syndrome to increased cancer risks. To identify changes in gene expression that may be informative for detecting such exposure, and to begin examining the molecular responses involved, we have profiled global gene expression in blood of male C57BL/6 mice injected with 137CsCl. We extracted RNA from the blood of control or 137CsCl-injected mice at 2, 3, 5, 20 or 30 days after exposure. Gene expression was measured using Agilent Whole Mouse Genome Microarrays, and the data was analyzed using BRB-ArrayTools. Between 466–6,213 genes were differentially expressed, depending on the time after 137Cs administration. At early times (2–3 days), the majority of responsive genes were expressed above control levels, while at later times (20–30 days) most responding genes were expressed below control levels. Numerous genes were overexpressed by day 2 or 3, and then underexpressed by day 20 or 30, including many Tp53-regulated genes. The same pattern was seen among significantly enriched gene ontology categories, including those related to nucleotide binding, protein localization and modification, actin and the cytoskeleton, and in the integrin signaling canonical pathway. We compared the expression of several genes three days after 137CsCl injection and three days after an acute external gamma-ray exposure, and found that the internal exposure appeared to produce a more sustained response. Many common radiation-responsive genes are altered by internally administered 137Cs, but the gene expression pattern resulting from continued irradiation at a decreasing dose rate is extremely complex, and appears to involve a late reversal of much of the initial response. PMID:25162453

  15. Stabilisation/solidification of (137)Cs-contaminated soils using novel high-density grouts: γ-ray shielding properties, contaminant immobilisation and a γRS index-based approach for in situ applicability.

    PubMed

    Falciglia, Pietro P; Romano, Stefano; Vagliasindi, Federico G A

    2017-02-01

    In this work, γ-ray shielding and Cs immobilisation performances of high-density magnetite (MG) and iron powder (IP) in Portland cement (PC) based-S/S treatment were investigated. Experimental results were elaborated using a γ-radiation shielding (γRS) index-based approach for assessing the effectiveness of in situ S/S of (137)Cs-contaminated soils. Main results reveal that the replacement of PC by MG or IP (up to 50%) leads to a marked increase (up to about 4-fold) in the γ-ray shielding performance, whereas a further material addition decreases the S/S shielding performance. The highest γRS index of ∼26% (662 keV) was found in the case of IP addition (33.3%). The use of MG-mixes allows reaching slightly slower γRS index jointly with the highest Cs-immobilisation of 97.8%. In this case, calculation shows a maximum (137)Cs-contamination level successfully treatable by in situ S/S up to ∼2.9 or ∼14.5 kBq kg(-1) for the realistic or low probability scenario, respectively, highlighting the possibility to remediate a very wide range of real contamination. Findings show MG - PC S/S as the best choice and could provide a basis for decision-making of S/S remediation of (137)Cs-contaminated sites.

  16. Induction of Genomic Instability In Vivo by Low Doses of 137Cs gamma rays

    SciTech Connect

    Rithidech, Kanokporn; Simon, Sanford, R.; Whorton, Elbert, B.

    2006-01-06

    The overall goal of this project is to determine if low doses (below or equal to the level traditionally requiring human radiation protection, i.e. less than or equal to 10 cGy) of low LET radiation can induce genomic instability. The magnitude of genomic instability was measured as delayed chromosome instability in bone marrow cells of exposed mice with different levels of endogenous DNA-dependent protein kinase catalytic subunit (DNA-PKcs) activity, i.e. high (C57BL/6J mice), intermediate (BALB/cJ mice), and extremely low (Scid mice). In addition, at early time points (1 and 4 hrs) following irradiation, levels of activation of nuclear factor-kappa B (NF-{kappa}B), a transcription factor known to be involved in regulating the expression of genes responsible for cell protection following stimuli, were measured in these cells. Bone marrow cells were collected at different times following irradiation, i.e. 1 hr, 4 hrs, 1 month, and 6 months. A total of five mice per dose per strain were sacrificed at each time point for sample collection. As a result, a total of 80 mice from each strain were used. The frequency and the type of metaphase chromosome aberrations in bone marrow cells collected from exposed mice at different times following irradiation were used as markers for radiation-induced genomic instability. A three-color fluorescence in situ hybridization (FISH) protocol for mouse chromosomes 1, 2, and 3 was used for the analysis of delayed stable chromosomal aberrations in metaphase cells. All other visible chromatid-type aberrations and gross structural abnormalities involving non-painted chromosomes were also evaluated on the same metaphase cells used for scoring the stable chromosomal aberrations of painted chromosomes. Levels of nuclear factor-kappa B (NF-{kappa}B) activation were also determined in cells at 1 and 4 hrs following irradiation (indicative of early responses).

  17. Key comparison BIPM.RI(I)-K5 of the air kerma standards of the ININ, Mexico and the BIPM in 137Cs gamma radiation

    NASA Astrophysics Data System (ADS)

    Kessler, C.; Burns, D. T.; Alvarez Romero, J. T.; De la Cruz Hernández, D.; Cabrera Vertti, M. R.; Tovar-Muñoz, V. M.

    2015-01-01

    A direct comparison of the standards for air kerma of the Instituto Nacional de Investigaciones Nucleares (ININ), Mexico, and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 137Cs radiation beam of the BIPM in February 2015. The comparison result, evaluated as a ratio of the ININ and the BIPM standards for air kerma, is 1.0048 with a combined standard uncertainty of 2.0 × 10-3. The results are analysed and presented in terms of degrees of equivalence for entry in the BIPM key comparison database. 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).

  18. Plutonium as a chronomarker in Australian and New Zealand sediments: a comparison with (137)Cs.

    PubMed

    Hancock, G J; Leslie, C; Everett, S E; Tims, S G; Brunskill, G J; Haese, R

    2011-10-01

    The construction of high resolution chronologies of sediment profiles corresponding to the last 50-100 years usually entails the measurement of fallout radionuclides (210)Pb and (137)Cs. The anthropogenic radionuclide, (137)Cs, originating from atmospheric nuclear weapons testing can provide an important "first appearance" horizon of known age (1954-1955), providing much-needed validation for the sometimes uncertain interpretations associated with (210)Pb geochronology. However, while (137)Cs usually provides a strong signal in sediment in the northern hemisphere, total fallout of (137)Cs in the southern hemisphere was only 25% that of the north and the low activities of (137)Cs seen in Australian and New Zealand sediments can make its horizon of first appearance somewhat arguable. Low (137)Cs fallout also limited the size of the 1963-1964 fallout peak, a peak that is usually seen in northern hemisphere sediment profiles but is often difficult to discern south of the equator. This paper shows examples of the use of nuclear weapons fallout Pu as a chronomarker in sediment cores from Australia (3 sites) and New Zealand (1 site). The Pu profiles of five cores are examined and compared with the corresponding (137)Cs profiles and (210)Pb geochronologies. We find that Pu has significant advantages over (137)Cs, including greater measurement sensitivity using alpha spectrometry and mass spectrometric techniques compared to (137)Cs measurements by gamma spectrometry. Moreover, Pu provides additional chronomarkers associated with changes in the Pu isotopic composition of fallout during the 1950s and 1960s. In particular, the (238)Pu/(239+240)Pu activity ratio shows distinct shifts in the early 1950s and the mid to late 1960s, providing important known-age horizons in southern hemisphere sediments. For estuarine and near-shore sediments Pu sometimes has another significant advantage over (137)Cs due to its enrichment in bottom sediment relative to (137)Cs resulting from the

  19. Key comparison BIPM.RI(I)-K5 of the air kerma standards of the VSL and the BIPM in 137Cs gamma radiation

    NASA Astrophysics Data System (ADS)

    Kessler, C.; Burns, D. T.; Jansen, B. J.; de Pooter, J. A.

    2016-01-01

    A direct comparison of the standards for air kerma of the VSL, Netherlands, and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 137Cs radiation beam of the BIPM in April 2016. The comparison result, evaluated as a ratio of the VSL and the BIPM standards for air kerma, is 0.9952 with a combined standard uncertainty of 3.8 × 10-3. The results for an indirect comparison made at the same time are consistent with the direct results at the level of 1 part in 104. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. 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).

  20. Study of influence of plastic scintillators thicknesses to detect Beta particles and Gamma radiation by means of spectral analysis of {sup 90}Sr, {sup 90}Y and {sup 137}Cs sources

    SciTech Connect

    Cardenas, Jose Patricio Nahuel; Filho, Tufic Madi; Pereira, Maria da Conceicao Costa; Santos, Brianna B. dos; Correa, Eduardo de L.; Santos, Lucas Rodrigues dos; Lopes, Anderson Figueredo; Silva, Alexandre F.P. da; Santos, Diogo F. dos; Camilo, Douglas de S.; Purgato, Rafael T.; Aredes, Vitor O.G.

    2015-07-01

    The Nuclear and Energy Research Institute - IPEN, offers post-graduate programs, namely: Nuclear Technology - Applications (TNA), Nuclear Technology - Materials (TNM), Nuclear Technology - Reactors (TNR). The Institute programs mission is to form expert technicians, physicists and engineers with a strong knowledge in their discipline to work in the nuclear area. The course: 'Theoretical Fundamentals and Practices of the Instrumentation used in Nuclear Data Acquisition' covers the use of laboratory nuclear instrumentation and the accomplishment of experiments to obtain nuclear parameters. One of these experimental exercises is object of this work: 'Study of influence of plastic scintillators to detect Beta particles and Gamma radiation by means of spectral analysis of {sup 90}Sr, {sup 90}Y and {sup 137}Cs sources'. The use of scintillators plastic for the detection has the advantage of low cost, high mechanical strength, is not hygroscopic and can be manufactured in large volumes. This work aims to present the analysis of relative efficiency of detection of plastic scintillators of various thicknesses for beta particles and gamma radiation by the spectrum of {sup 137}Cs and {sup 90}Sr. Due to lack of resolution of the detectors plastic scintillators we worked with relative efficiency. The evaluation was done by reading deposited energy, using the software MAESTRO, for each detector thickness. For beta particles was observed an ideal thickness around 3 mm and the better photon efficiency was observed with increasing the thickness of the detector. The present experiment does not intend to establish a new technique for this subject: it solely aims student's practical exercises in nuclear properties of elements and detectors being part of the nuclear experimental course. (authors)

  1. Accuracy of field spectrometry in estimating 137Cs contamination in high altitude alpine soils.

    PubMed

    Agnesod, G; Lazzaron, R; Operti, C; Zappa, C

    2001-01-01

    In situ gamma ray spectrometry is an attractive method for providing information on the concentrations of radionuclides in the soil. This method requires separate knowledge of the soil density and of the radioactivity distribution relative to soil depth. In-field gamma spectrometry measurements were performed together with sampling of the soil at the same site for subsequent gamma spectrometry analysis in the laboratory. Results of 137Cs concentration were compared in order to: (i) verify the effectiveness of in situ gamma spectrometry in averaging local inhomogeneties in the soil; and (ii) quantify the sensitivity of the gamma ray spectrometry soil radioactivity evaluation with respect to the variability of the depth profiles obtained from a single site sampling. The site of study is a high altitude pasture, in the Alpine environment.

  2. Comparison of optimised germanium gamma spectrometry and multicollector inductively coupled plasma mass spectrometry for the determination of 134Cs, 137Cs and 154Eu single ratios in highly burnt UO 2

    NASA Astrophysics Data System (ADS)

    Caruso, S.; Günther-Leopold, I.; Murphy, M. F.; Jatuff, F.; Chawla, R.

    2008-05-01

    Non-destructive and destructive methods have been compared to validate their corresponding assessed accuracies in the measurement of 134Cs/137Cs and 154Eu/137Cs isotopic concentration ratios in four spent UO2 fuel samples with very high (52 and 71 GWd/t) and ultra-high (91 and 126 GWd/t) burnup values, and about 10 (in the first three samples) and 4 years (in the latter sample) cooling time. The non-destructive technique tested was high-resolution gamma spectrometry using a high-purity germanium detector (HPGe) and a special tomographic station for the handling of highly radioactive 400 mm spent fuel segments that included a tungsten collimator, lead filter (to enhance the signal to Compton background ratio and reduce the dead time) and paraffin wax (to reduce neutron damage). The non-destructive determination of these isotopic concentration ratios has been particularly challenging for these segments because of the need to properly derive non-Gaussian gamma-peak areas and subtract the background from perturbing capture gammas produced by the intrinsic high-intensity neutron emissions from the spent fuel. Additionally, the activity distribution within each pin was determined tomographically to correct appropriately for self-attenuation and geometrical effects. The ratios obtained non-destructively showed a 1σ statistical error in the range 1.9-2.9%. The destructive technique used was a high-performance liquid chromatographic separation system, combined online to a multicollector inductively coupled plasma mass spectrometer (HPLC-MC-ICP-MS), for the analysis of dissolved fuel solutions. During the mass spectrometric analyses, special care was taken in the optimisation of the chromatographic separation for Eu and the interfering element Gd, as also in the mathematical correction of the 154Gd background from the 154Eu signal. The ratios obtained destructively are considerably more precise (1σ statistical error in the range 0.4-0.8% for most of the samples, but up to

  3. A biokinetic model for {sup 137}Cs

    SciTech Connect

    Melo, D.R.; Lipsztein, J.L.; Oliveira, C.A.N.; Lundgren, D.L.

    1997-08-01

    An improved biokinetic model for {sup 137}Cs in humans was developed based on an analysis of data obtained from individuals internally contaminated during an accident in Goiania, Brazil, and other data. Seventeen children (ten girls and seven boys 1-10 y old), ten adolescents (four females and six males), and thirty adults, (fifteen females and fifteen males) contaminated in the accident in Goiania contributed to this study. {sup 137}Cs retention was determined through periodic measurements in a whole-body counter. In addition to the data on {sup 137}Cs retention from these individuals, data from a study on the metabolism of {sup 137}Cs in immature, adult, and aged Beagle dogs and data from the literature were used in the formulation of the {sup 137}Cs biokinetic model presented. Mathematically, the retention of cesium is described by three exponential terms, and the retention model is based on a step function of body weight. When the ICRP Publication 56 model for cesium was compared to the model suggested in this paper, it was determined that the ICRP model predicts lower effective doses in 5-y-old children and higher effective doses in infants, adolescents, and adults.

  4. Distribution of the 134Cs/137Cs ratio around the Fukushima Daiichi nuclear power plant using an unmanned helicopter radiation monitoring system

    NASA Astrophysics Data System (ADS)

    Torii, T.; Nishizawa, Y.

    2015-12-01

    Many radioactive substances were released by the Fukushima Daiichi nuclear power plant accident occurred on March 11, 2011 in the atmosphere. A lot of short half-life nuclides which are 131I, 132Te (132I) and 133I, etc., in addition to longer half-lived nuclides such as 134Cs and 137Cs. The estimated release amount of these nuclides from the reactor 1st to 3rd unit is reported, but it's found to be quite different in the short half-lived nuclides by the reactor units. Because the radioactivity ratio of 134Cs and 137Cs was slight different between the reactor units, it can be considered that the valuable source is obtained by the measurement of 134Cs/137Cs ratio in the environment around the Fukushima Daiichi nuclear power station at the present stage when the nuclides with short half-lives had already decayed. We have measured high-resolution gamma-ray spectrum using an unmanned helicopter equipped with LaBr3(Ce) detector in a 3-km range from the power station which was near to the release source of the radioactive cesium. Because the LaBr3(Ce) detector has high resolution of gamma rays, the discrimination of many nuclides is possible. In addition, there is extremely much number of the data provided by the distribution measurement with the unmanned helicopter. Because a new map was illustrated by the analysis of the 134Cs/137Cs ratio, we report the outline.

  5. An E5 transition in the 137Cs decay

    NASA Astrophysics Data System (ADS)

    Moran, K.; McCutchan, E. A.; Zhu, S.; Lister, C. J.; Merchan, E.; Shearman, R.

    2013-10-01

    The beta decay of 137Cs is mainly to the Jπ = 11/2- 661.66 keV isomeric excited state in 137Ba and is usually followed by emission of a single gamma ray as the nucleus relaxes to the Jπ = 3/2+ ground state. It is a well-known standard γ-ray calibration reference. There is only one intermediate state, with Jπ = 1/2+ at 283.50 keV. The γ-ray decay branch to this level has never been observed. The transition must be of E5 or M6 multipolarity. The phase space limitation hinders this decay and a ~10-8 branch can be anticipated from the few known E5 decay matrix elements. The use of the Gammasphere detector array at Argonne National Lab allows a search for these rare events by selection of an optimal detector opening angle for coincidences, chosen to minimize the effects of Compton cross-scattering in the array. In this manner the E5 cascade transition was observed and the branching ratio measured. Rigorous E5 transitions are only known in four other cases to date, so this measurement adds significantly to the body of knowledge surrounding E5 matrix elements. This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Grant No. DE-FG02-94ER40848 and Contracts No. DE-AC02-98CH10946 and DE-AC02-06CH11357.

  6. Modification of. gamma. -irradiation-induced change in myoglobin by. cap alpha. -mercaptopropionylglycine and its related compounds and the formation of sulfmyoglobin. [/sup 137/Cs

    SciTech Connect

    Motohashi, N.; Mori, I.; Sugiura, Y.; Tanaka, H.

    1981-06-01

    The effect of some sulfhydryl-containing amides in the modification of ..gamma..-irradiation-induced change in myoglobin was investigated, and the results were compared with those for cysteine and cysteamine, and discussed in terms of their chemical structures. An abnormal green pigment, sulfmyoglobin, was formed from metmyoglobin solution by the sulfhydryl-containing amide but not by corresponding mercaptocarboxylic acids. When the metmyoglobin solution was irradiated in the presence of some thiols, the formation of sulfmyoglobin and metsulfmyoglobin was observed. The degree of the formation of sulfymoglobin was found to be dependent on the ability of the thiols to release sulfur. The presence of the -CONH-bond in their molecules seemed to enhance the release of sulfur. The mechanism of the formation of sulfmyoglobin is also discussed.

  7. Distributions of (137)Cs and (210)Pb in moss collected from Belarus and Slovakia.

    PubMed

    Aleksiayenak, Yu V; Frontasyeva, M V; Florek, M; Sykora, I; Holy, K; Masarik, J; Brestakova, L; Jeskovsky, M; Steinnes, E; Faanhof, A; Ramatlhape, K I

    2013-03-01

    In the present work, moss samples collected in Slovakia and Belarus were assayed with respect to gamma-emitting radionuclides. The results for (137)Cs and (210)Pb are discussed. Moss was used for the first time in Belarus, as a biological indicator of radioactive environmental pollution in consequence of the Chernobyl accident in 1986. In Belarus, the maximum activity of (137)Cs was observed in the Gomel region near Mazyr (6830 Bq/kg) and the minimum activity in the Vitebsyevsk Region near Luzhki-Yazno (5 Bq/kg). "Hot spots" were also observed near the towns Borisow and Yuratsishki. The results of measurements of (137)Cs in moss samples collected in 2000, 2006 and 2009 in the same localities of Slovakia are presented and compared with the results of air monitoring of (137)Cs carried out in Slovakia from 1977 until 2010. Measurements of the (210)Pb concentration in moss samples collected over the territory of Slovakia showed, that the median value exceed 2.3 times median value of (210)Pb obtained for Belarus moss. For that reason, the inhalation dose for man from (210)Pb and (137)Cs in Slovakia is more than twice as high as in Belarus, in spite of the initially very high (137)Cs exposure in the latter country.

  8. 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.

  9. Isotope ratios of (235)U/(238)U and (137)Cs/(235)U in black rain streaks on plaster wall caused by fallout of the Hiroshima atomic bomb.

    PubMed

    Shizuma, Kiyoshi; Endo, Satoru; Fujikawa, Yoko

    2012-02-01

    Radiological investigations of fallout from the atomic bomb detonated over Hiroshima city on 6 August 1945 are important to estimate doses for inhabitants. The authors have analyzed the concentrations of (137)Cs, (235)U, and (238)U in streaks of black rain caused by the atomic bomb using gamma-ray spectroscopy and the ICP-QMS method. The black rain streaks were deposited on a plaster wall of a house located 3.7 km west of the hypocenter that has been kept in the same condition as after the rainfall. Cesium-137 ((137)Cs) was detected from black streak samples. Concentration of (137)Cs in the black rain streaks is twice as high as fallout deposition on the ground in this area. A (235)U/(238)U atom ratio of 0.00887 was found, which is higher than the natural ratio, reflecting the fact that the atomic bomb "Little Boy" used enriched uranium as fuel. The ratio (137)Cs/(235)U was determined to be 0.0091, which is about eight times higher than the estimated ratio of 0.00113 based on the fission yield.

  10. A comparison of {sup 137}Cs radioactivity in localized evergreen and deciduous plant species

    SciTech Connect

    Rangel, R.C.; Schlapper, G.A.; McLain, M.E.; Pitt, W.W.

    1996-06-01

    A vegetation study at the Comanche Steam Electric Station (CPSES) in Texas was conducted in 1991 and 1992. The CPSES is a commercial nuclear power plant. The CPSES environmental monitoring program collects broadleaf vegetation samples as per the Nuclear Regulatory Commission (NRC). Broadleaf trees are scarce in the area because of local climate, soils, and geology. The dominate tree is an evergreen juniper. Few broadleaves are available during winter for sampling. This study compared the environmental {sup 137}C s radioactivity between broadleaf and evergreen foliage. The study`s objective was to determine if {sup 137}C s radioactivity is statistically the same in the deciduous and evergreen vegetation. Radioactivity from the same statistical population could allow the sampling program to collect evergreen (junipers) foliage. Broadleaf and evergreen tree leaf samples were collected on and off the CPSES area. Gamma-ray spectrometry was performed on the samples to measure {sup 137}Cs radioactivity. The means of the {sup 137}Cs concentrations in broadleaf and evergreen foliage samples were found to be statistically the same and therefore from the same population. This study`s conclusion is that evergreen leaves from juniper trees can be used to supplement and/or substitute for the broadleaf samples currently collected. This change in foliage collection, if approved by the NRC, would allow the CPSES to better satisfy its environmental sampling regulatory requirements.

  11. Reactive barriers for {sup 137}Cs retention

    SciTech Connect

    KRUMHANSL,JAMES L.; BRADY,PATRICK V.; ANDERSON,HOWARD L.

    2000-05-19

    {sup 137}Cs was dispersed globally by cold war activities and, more recently, by the Chernobyl accident. Engineered extraction of {sup 137}Cs from soils and groundwaters is exceedingly difficult. Because the half life of {sup 137}Cs is only 30.2 years, remediation might be more effective (and less costly) if {sup 137}Cs bioavailability could be demonstrably limited for even a few decades by use of a reactive barrier. Essentially permanent isolation must be demonstrated in those few settings where high nuclear level wastes contaminated the environment with {sup 135}Cs (half life 2.3x10{sup 6} years) in addition to {sup 137}Cs. Clays are potentially a low-cost barrier to Cs movement, though their long-term effectiveness remains untested. To identify optimal clays for Cs retention Cs resorption was measured for five common clays: Wyoming Montmorillonite (SWy-1), Georgia Kaolinites (KGa-1 and KGa-2), Fithian Illite (F-Ill), and K-Metabentonite (K-Mbt). Exchange sites were pre-saturated with 0.16 M CsCl for 14 days and readily exchangeable Cs was removed by a series of LiNO{sub 3} and LiCl washes. Washed clay were then placed into dialysis bags and the Cs release to the deionized water outside the bags measured. Release rates from 75 to 139 days for SWy-1, K-Mbt and F- 111 were similar; 0.017 to 0.021% sorbed Cs released per day. Both kaolinites released Cs more rapidly (0.12 to 0.05% of the sorbed Cs per day). In a second set of experiments, clays were doped for 110 days and subjected to an extreme and prolonged rinsing process. All the clays exhibited some capacity for irreversible Cs uptake so most soils have some limited ability to act as a natural barrier to Cs migration. However, the residual loading was greatest on K-Mbt ({approximately} 0.33 wt% Cs). Thus, this clay would be the optimal material for constructing artificial reactive barriers.

  12. 137Cs distribution among annual rings of different tree species contaminated after the Chernobyl accident.

    PubMed

    Soukhova, N V; Fesenko, S V; Klein, D; Spiridonov, S I; Sanzharova, N I; Badot, P M

    2003-01-01

    The distributions of 137Cs among annual rings of Pinus sylvestris and Betula pendula at four experimental sites located in the most contaminated areas in the Russian territory after the Chernobyl accident in 1986 were studied. Trees of different ages were sampled from four forest sites with different tree compositions and soil properties. The data analysis shows that 137Cs is very mobile in wood and the 1986 rings do not show the highest contamination. The difference between pine and birch in the pattern of radial 137Cs distribution can be satisfactorily explained by the difference in radial ray composition. 137Cs radial distribution in the wood can be described as the sum of two exponential functions for both species. The function parameters are height, age and species dependent. The distribution of 137Cs in birch wood reveals much more pronounced dependence on site characteristics and/or the age of trees than pines. The data obtained can be used to assess 137Cs content in wood.

  13. Biological effects of {sup 137}CsCl injected in beagle dogs

    SciTech Connect

    Nikula, K.J.; Muggenburg, B.A.; Griffith, W.C.

    1995-06-01

    The toxicity of intravenously administered {sup 137}CsCl in the beagle dog was investigated as part of a program to evaluate the biological effects of internally deposited fission-product radionuclides. The intravenous route of exposure was chosen for simplicity and accuracy because it was known that after intravenous injection, inhalation or ingestion, internally deposited {sup 137}CsCl is rapidly absorbed and distributed throughout the body, exposing the whole body to {beta}-particle and {gamma} radiations. Fifty-four dogs were injected intravenously with {sup 137}Cs to provide one group of six dogs with mean initial body burdens of 141 MBq {sup 137}Cs/kg body mass and four groups of 12 dogs each with mean initial body burdens of 104, 72, 52 and 36 MBq {sup 137}Cs/kg. Twelve dogs were injected with isotonic saline as study controls. Because the number of study controls dogs was small, data from an additional 49 control dogs from other studies at the Inhalation Toxicology Research Institute that were performed over a similar span of years were also used. There was a significant, dose-dependent decrease in survival of the {sup 137}Cs-injected dogs. Eleven {sup 137}Cs-injected dogs, including all six in the highest initial body burden group, died within 81 days after injection, primarily due to hematopoietic cell damage resulting in severe pancytopenia. An additional 25 dogs had transient hematological dyscrasia but survived for long times. All {sup 137}Cs-injected male dogs had marked damage to the germinal epithelium of the testicular seminiferous tubules with azoospermia in the long-term survivors. benign and malignant neoplasms occurred in a variety of organs in {sup 137}Cs-injected dogs, rather than in a single target organ. When individual organs were considered, the incidence of malignant neoplasms was increased in the liver and in the nasal cavity and paranasal sinuses of the {sup 137}Cs-injected dogs. 34 refs., 6 figs., 6 tabs.

  14. AFCF and clinoptilolite use in reduction of (137)Cs deposition in several days' contaminated broiler chicks.

    PubMed

    Mitrovic, B; Vitorovic, G; Vitorovic, D; Dakovic, A; Stojanovic, M

    2007-01-01

    The objective of this study was to investigate the binding efficiency of AFCF and clinoptilolite, mixed to the feed and administered orally using gastric tube to chronically (137)Cs alimentary contaminated broiler chicks. Seventy-five male Hybro broiler chicks, between 35 and 47 days of age were divided into five groups (15 birds per group) reared in cages (five birds in a cage) and fed a standard diet. Every day during 13 days of the experimental period all chicks received orally 1 ml CsCl water solution with activity of 1310 Bq ml(-1)(137)Cs (gastric tube). Group 1 was the control group and received no binders. The experimental groups received the binders. Group 2 received 0.2 g of AFCF in the form of water solution (gastric tube); group 3 received 0.2% AFCF in the feed; group 4 received 2g clinoptilolite in the form of water suspension (gastric tube) and group 5 received 2% clinoptilolite in the feed. Five chicks from each group were sacrificed on days 4, 10 and 13 of the experimental period. Using gamma spectrometric methods specific activity of (137)Cs was determined in the samples of breast meat, liver and gizzard. The results obtained showed that administering binders to the chronically contaminated broiler chicks significantly (p<0.01) reduced (137)Cs transfer and deposition in breast meat, liver and gizzard. Decreasing deposition of (137)Cs in breast meat and internal organs increased with time of contamination and binders' administration. With AFCF as a cesium binder, on day 13 of measuring the (137)Cs activity in breast meat was 80-83% lower than that in the control group, 89% in liver and 83-84% in gizzard. Natural clinoptilolite demonstrated lower binding efficiency. On day 13 of measuring the (137)Cs activity in breast meat was 53-69% lower than that in the control group, 67-60% in liver and 59-71% in gizzard.

  15. Influence of phantom materials on the energy dependence of LiF:Mg,Ti thermoluminescent dosimeters exposed to 20-300 kV narrow x-ray spectra, 137Cs and 60Co photons.

    PubMed

    Massillon-J L, G; Cabrera-Santiago, A; Minniti, R; O'Brien, M; Soares, C G

    2014-08-07

    LiF:Mg,Ti, are widely used to estimate absorbed-dose received by patients during diagnostic or medical treatment. Conveniently, measurements are usually made in plastic phantoms. However, experimental conditions vary from one group to another and consequently, a lack of consensus data exists for the energy dependence of thermoluminescent (TL) response. This work investigated the energy dependence of TLD-100 TL-response and the effect of irradiating the dosimeters in different phantom materials for a broad range of energy photons in an attempt to understand the parameters that affect the discrepancies reported by various research groups. TLD-100s were exposed to 20-300 kV narrow x-ray spectra, (137)Cs and (60)Co photons. Measurements were performed in air, PMMA, wt1, polystyrene and TLDS as surrounding material. Total air-kerma values delivered were between 50 and 150 mGy for x-rays and 50 mGy for (137)Cs and (60)Co beams; each dosimeter was irradiated individually. Relative response, R, defined as the TL-response per air-kerma and relative efficiency, RE, described as the TL-response per absorbed-dose (obtained through Monte Carlo (MC) and analytically) were used to describe the TL-response. Both R and RE are normalized to the responses in a (60)Co beam. The results indicate that the use of different phantom materials affects the TL-response and this response varies with energy and material type. MC simulations reproduced qualitatively the experimental data: a) R increases, reaches a maximum at ~25 keV and decreases; b) RE decreases, down to a minimum at ~60 keV, increases to a maximum at ~150 keV and after decreases. Independent of the phantom materials, RE strongly depends on how the absorbed dose is evaluated and the discrepancies between RE evaluated analytically and by MC simulation are around 4% and 18%, dependent on the photon energy. The comparison between our results and that reported in the literature suggests that the discrepancy observed

  16. 137Cs re-sampling as a method for soil erosion assessment in Alpine grasslands

    NASA Astrophysics Data System (ADS)

    Arata, Laura; Meusburger, Katrin; Bissig, Nicole; Mabit, Lionel; Alewell, Christine

    2014-05-01

    Over the past decades, radioactive fallout 137Cs has been used as a tracer to provide information on soil erosion and sedimentation rates. However, the method may produce relatively large uncertainties in Alpine grasslands. The latter difficulties are caused by a combination of (i) the heterogeneous distribution of atmospheric 137Cs Chernobyl fallout, (ii) the partly snow covered ground in Alpine areas during the fallout event in April 1986, which results in inhomogeneous 137Cs distribution during snow melt and (iii) uncertainties in finding undisturbed references sites in the geomorphological and anthropogenic highly active slopes of the Alps. To overcome these difficulties, our aim is to replace the classical 137Cs approach, where an undisturbed reference site is compared to erosional sites, with a re-sampling approach, where we re-sample sites which have already been measured for 137Cs inventories in the past. Thus, we use temporal instead of spatial reference. The study area is located in the Central Swiss Alps in the Urseren Valley. Potential erosional sites have been sampled in 2007 and re-sampled in 2012. Two different grassland types were investigated: hayfield (2 sites) and pasture without dwarf shrubs (3 sites). For each site, 4 to 9 sampling points have been defined, and at each point two soil samples have been collected. To reduce the random error, the two soil samples were bulked prior to gamma-analysis. 137Cs inventories of the two sampling years were calculated and used to assess recent soil erosion in the experimental sites. Our results show that within the 5 years measurable soil erosion and deposition processes have occurred within the sites, as indicated by the relevant difference between the 137Cs inventories of 2007 and 2012. 64% of the sites exhibit a decrease in 137Cs inventories, 20% of the sites an increase, and the remaining 16% no significant difference. In particular, hayfield sites have been affected by erosion processes, mostly due to

  17. Using Atmospheric (137)Cs Measurements and Hysplit to Confirm Chernobyl as a Source of (137)Cs in Europe

    DTIC Science & Technology

    2001-10-01

    USING ATMOSPHERIC 137CS MEASUREMENTS AND HYSPLIT TO CONFIRM CHERNOBYL AS A SOURCE OF 137CS IN EUROPE Erik L. Swanberg1 and Steven G. Hoffert2...Veridian Systems1, Autometric2 Sponsored by Defense Threat Reduction Agency Contract No. DTRA01-99-C-0031 ABSTRACT The Chernobyl ...this 137Cs is the ground contaminated by the Chernobyl accident. The PIDC routinely uses HYSPLIT (HYbrid Single-Particle Lagrangian Integrated

  18. Gamma-ray shielding properties of some travertines in Turkey

    SciTech Connect

    Akkurt, Iskender; Guenoglu, Kadir

    2012-09-06

    The radiation is an essential phenomenon in daily life. There are various amounts of radioactivite substances in the underground and the earth was irradiated by this substances. Humans are exposed to various kind of radiation from these sources. The travertines are usually used as a coating material in buildings. In this study, the photon attenuation coefficients of some travertines have been measured using a gamma spectroscopy with NaI(Tl) detector. The measurements have been performed using {sup 60}Co source which gives 1173 and 1332 keV energies gamma rays and {sup 137}Cs source which gives 662 keV energy gamma rays and the results will be discussed.

  19. Factors affecting 137Cs bio- availability under the application of different fertilizing systems

    NASA Astrophysics Data System (ADS)

    Fedorkova, M. V.; Belova, N. I.

    2012-04-01

    Although it has been 25 years since the Chernobyl accident, it was generally found that radiocaesium remained bio-availability in some regions. Plant uptake of 137Cs is depended from quantity of exchangeable radionuclide and strongly influenced by soil properties. The addition of fertilizers to soil induces chemical and biological changes that influence the distribution of free ions the different phases (soil and soil solution). In this study we try to estimate influence of different soil conditions affecting the 137Cs bio-availability under the application of manure and inorganic fertilizers. Our research carried out in 2001-2008 years on contaminated after Chernobyl accident sod-podzolic soil during of prolonged field experiment. The experimental site was located in south-west of Bryansk region, Russia. Contamination density by 137Cs in the sampling point was equal to 475±30 kBq/m2. The sequence of crops in rotation was: 1) potato; 2) oats 3) lupine 4) winter rye. Three fertilizing systems were compared: organic - 80 tons per hectare of cow manure; inorganic fertilizing system - different rates of NPK (low, temperate and high) and mixed - 40 tons per hectare of cow manure + NPK. Main soil properties and chemical form of 137Cs and K (potassium) were detected. Radiocaesium activity was determined in soil and plant samples by gamma spectrometry, using a high purity Ge detectors. Overall efficiency was known to an accuracy of about 10-12%. Obtained results shows, that various fertilizing systems influence soil properties, chemical forms of 137Cs and K in soil and radionuclide soil-to-plant transfer in different ways. The highest reduction of exchangeable 137Cs in soil was found in case with application of organic fertilizers and also - temperate NPK rates. Part of exchangeable 137Cs is equal 6.8% (from total activity) in case of manure, 7.8% in case of inorganic fertilizers with control value - 10.2%. Caesium mobility in soil is affected by such soil properties as

  20. Tracing soil erosion impacts on soil organisms using 137Cs and soil nematodes

    NASA Astrophysics Data System (ADS)

    Baxter, Craig; Rowan, John S.; McKenzie, Blair M.; Neilson, Roy

    2014-05-01

    The application of environmental radionuclides in soil tracing and erosion studies is now well established in geomorphology. Sediment and erosion-tracing studies are undertaken for a range of purposes in the earth sciences but until now few studies have used the technique to answer biological questions. An experiment was undertaken to measure patterns of soil loss and gain over 50 years, effectively calculating a field-scale sediment budget, to investigate soil erosion relationships between physical and biological soil components. Soil nematodes were identified as a model organism, a ubiquitous and abundant group sensitive to disturbance and thus useful indicator taxa of biological and physico-chemical changes. A field site was selected at the James Hutton Institute's experimental Balruddery Farm in NE Scotland. 10 metre-resolution topographical data was collected with differential GPS. Based on these data, a regular 30 m-resolution sampling grid was constructed in ArcGIS, and a field-sampling campaign undertaken. 104 soil cores (~50 cm-deep) were collected with a percussion corer. Radio-caesium (137Cs) activity concentrations were measured using high-purity germainum gamma-ray spectroscopy, and 137Cs areal activities derived from these values. Organic matter content by loss on ignition and grain-size distribution by laser granulometry were also measured. Additional samples were collected to characterise the soil nematode community, both for abundance and functional (trophic) composition using a combination of low-powered microscopy and molecular identification techniques (dTRFLP). Results were analysed with ArcGIS software using the Spatial Analyst package. Results show that spatial relationships between physical, chemical and biological parameters were complex and interrelated. Previous field management was found to influence these relationships. The results of this experiment highlight the role that soil erosion processes play in medium-term restructuring of the

  1. Activity levels of 137Cs and 40K in the skin and the cutaneous organs of a cow.

    PubMed

    Pichl, Elke; Rabitsch, Herbert

    2003-08-01

    We have performed an extensive study to determine the activity distributions of radiocesium (137Cs) and of the radioisotope 40K of potassium in the whole body of a cow. ICRP assumes that cesium and potassium are distributed homogeneously throughout the whole body of an organism. The current investigation measured concentrations of 137Cs and 40K in components of the skin, horns, and hooves of a cow. Activity levels of 137Cs were caused by the long-term ingestion following the Chernobyl fallout, whereas the naturally occurring potassium (40K) is an essential part of cow's normal diet. The cow was born at the time of the fallout following the Chernobyl accident and had ingested heavily contaminated forage during its entire lifetime. Activities of 137Cs and 40K were determined simultaneously by gamma spectrometry. All activities are related to the day of slaughter and include also corrections for self attenuation of photons caused by the different densities of the samples. Radionuclide concentrations in samples were corrected for moisture losses incurred during freezing and sample preparation. Surface contamination on the skin was estimated by rinsing it in heated water followed by removal of the epidermis and hair. In comparison with the activities of the components of the skin we observed a considerable amount of external contamination on the surface of the skin. But with respect to whole body countings of the animal this amount of external contamination appears to be negligible. It was found that activity ratios of 137Cs to 40K are greater than 1 in all measured components. The average activity concentrations of 137Cs and 40K in the common integument are 23.3 Bq kg(-1) and 13.3 Bq kg(-1), respectively. The highest activity concentrations of 137Cs and 40K were measured in clean hair and hypodermis. Despite being its largest organ, the cow's skin contains probably less than 1% of the animal's whole body 137Cs activity.

  2. 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.

  3. 40K/137Cs discrimination ratios to the aboveground organs of tropical plants.

    PubMed

    Sanches, N; Anjos, R M; Mosquera, B

    2008-07-01

    In the present work, the accumulation of caesium and potassium in aboveground plant parts was studied in order to improve the understanding on the behaviour of monovalent cations in several compartments of tropical plants. We present the results for activity concentrations of (137)Cs and (40)K, measured by gamma spectrometry, from five tropical plant species: guava (Psidium guajava), mango (Mangifera indica), papaya (Carica papaya), banana (Musa paradisíaca), and manioc (Manihot esculenta). Caesium and potassium have shown a high level of mobility within the plants, exhibiting the highest values of concentration in the growing parts (fruits, leaves, twigs, and barks) of the woody fruit and large herbaceous shrub (such as manioc) species. In contrast, the banana and papaya plants exhibited the lowest levels of (137)Cs and (40)K in their growing parts. However, a significant correlation between activity concentrations of (137)Cs and (40)K was observed in these tropical plants. The (40)K/(137)Cs discrimination ratios were approximately equal to unity in different compartments of each individual plant, suggesting the possibility of using caesium to predict the behaviour of potassium in several tropical species.

  4. The transfer of {sup 137}Cs from barley to beer

    SciTech Connect

    Proehl, G.; Mueller, H.; Voigt, G.

    1997-01-01

    Beer has been brewed from barley contaminated with {sup 137}Cs as a consequence of the Chernobyl accident. The {sup 137}Cs activity has been measured in all intermediate steps and in the by-products of the production process. About 35 % of the {sup 137}Cs in barley were recovered in beer. Processing factors defined as the concentration ratio of processed and raw products were determined to be 0.61, 3.3, 0.1 and 0.11 for malt, malt germs, spent grains and beer, respectively. 4 refs., 2 tabs.

  5. /sup 137/Cs radioactive dating of Lake Ontario sediment cores

    SciTech Connect

    Ward, T.E.; Breeden, J.; Komisarcik, K.; Porter, R.; Czuczwa, J.; Kaminski, R.; McVeety, B.D.

    1987-12-01

    The distribution of /sup 137/Cs in sediment cores from Lake Ontario provides estimates of the sediment accumulation rates. Geochronology with /sup 210/Pb dating and distribution of Ambrosia (ragweed) pollen compare well with /sup 137/Cs dating. These methods can determine with precision, changes in sedimentation occurring over the past 100 years or so. Typical sedimentation rates of 0.18-0.36 cm/yr were measured. 16 refs., 3 figs., 2 tabs.

  6. Combining radiometric images, 137Cs, geochemical and digital elevation data to quantify erosion dynamics

    NASA Astrophysics Data System (ADS)

    Carrier, F.; Tourliere, B.; Bonte, P.; Perrin, J.; Bourdon, B.; Pili, E.

    2003-04-01

    In this study, gamma-spectroscopic airborne data, digital elevation data, together with river and sediment geochemical data have been combined to quantify chemical and physical erosion within a rather small watershed (150 km2). In addition, the 137Cs technique is applied to have a better understanding of present-day erosion and weathering processes. The Hyrome watershed, South-East Armorican Massif (France), mainly consists of brioverian micaschists. We have examined particularly how past and present physical and chemical erosion is distributed within the drainage basin. In order to enhance these merged effects all the data are combined by Hierarchy Ascending Classification (HAC - cluster analysis). The multivariable analysis sorts each individual data point into separate groups characterized by radiometry, geochemistry, slope and difference between altitude and base level affinities. HAC groups delineate zones used to select target sites inside the watershed. The radiometric airborne data clearly show that the plateau areas are depleted in K and U as a result of chemical erosion while Th is fairly constant. In contrast, the valleys are characterized by larger K and U concentrations reflecting the bedrock original composition. This probably indicates more recent incision and/or faster physical erosion. The 137Cs is used as a tracer of soil erosion because of its adsorption since 40 years on surface soil particles. Suitable undisturbed sites have been found for 137Cs measurements using a field-portable HP-Ge gamma detector and then on core samples. The 137Cs technique provides a quantitative estimation of erosion and weathering processes and a qualitative determination of origin, transport and accumulation zones from those pre-selected with HAC. This data will be used to establish how the present-day erosion and soil redistribution relate to the pattern of erosion visible by airborne gamma-spectrometry.

  7. Assessing soil erosion at landscape level: A step forward in the up-scaling of 137Cs measurements through the use of in-situ lanthanum bromide scintillator

    NASA Astrophysics Data System (ADS)

    Gonsalves, Basil C.; Darby, Iain G.; Toloza, Arsenio; Mabit, Lionel; Kaiser, Ralf B.; Dercon, Gerd

    2014-05-01

    Measuring Fallout Radionuclides (FRN), in particular 137Cs, is a well-established method to estimate soil erosion and deposition in agricultural landscapes. While extremely sensitive, laboratory based gamma-ray spectrometry requires careful handling and preparation of measurement samples with a lengthy measuring time (~1 day), In-situ gamma-ray spectrometry can give near instantaneous results, allowing prompt decisions to be made and identification of critical spots of soil erosion, while the equipment is in the field. The aim of this investigation was to compare the precision of the in-situ FRN measurements, made by a cost-effective lanthanum bromide (LaBr3 (Ce)) scintillation detector of 137Cs against those from conventional (high-purity germanium HPGe detector) but laborious laboratory based gamma-ray spectrometry for assessing soil erosion. As preliminary test, five cores of a gleyic Cambisol - per increments of 5 cm until 1 m depth - were collected at the experimental research station of the Austrian Agency for Health and Food Safety located in Grabenegg 130 km west of Vienna. Three soil cores were sampled at the study site and, in the vicinity of this experimental site, two additional cores were collected at two different undisturbed reference sites. Laboratory gamma analyses were carried out during 50 000 seconds using a HPGe coaxial detector. The gamma measurements performed at the laboratory confirmed the undisturbed status of the two selected reference sites (i.e. exponential decrease with depth of the 137Cs content). Using the surface area of the sampling tool, the 137Cs areal activities of the cores sampled in the study site have been established at 2134±465 Bq m-2, 1835±356 Bq m-2 and 2553±340 Bq m-2, and, for the two reference sites at 3221±444 Bq m-2 and 3946±527 Bq m-2. At the same location and prior to collect the five soil cores, in-situ measurements using a lanthanum bromide (LaBr3 (Ce)) scintillator were performed. The detector was placed

  8. Evaluation of in vivo detection properties of 22Na, 65Zn, 86Rb, 109Cd and 137Cs in plant tissues using real-time radioisotope imaging system.

    PubMed

    Sugita, Ryohei; Kobayashi, Natsuko I; Hirose, Atsushi; Tanoi, Keitaro; Nakanishi, Tomoko M

    2014-02-21

    In plant research, radioisotope imaging provides useful information about physiological activities in various tissues and elemental transport between plant organs. To expand the usage of imaging techniques, a new system was developed to visualize beta particles, x-rays and gamma-rays emitted from plant bodies. This real-time radioisotope imaging system (RRIS) visualizes radioactivity after conversion into light with a CsI(Tl) scintillator plate. Herein, the RRIS detection properties of the gamma-ray emitters (22)Na, (65)Zn, (86)Rb, (109)Cd and (137)Cs were evaluated in comparison with those of radioluminography (RLG) using an imaging plate. The lower quantitative detection limit (Bq mm(-2)) during a 15 min period ranged from 0.1 to 4, depending on the nuclide, similar to that of RLG. When the quantitative ability to detect radiation from various Arabidopsis tissues was analyzed, the quantitative capability in silique and the thick internode tended to be low. In an EGS5 simulation, beta particles were the greatest contributors to RRIS imaging of (22)Na, (86)Rb and (137)Cs, and low-energy x-rays contributed significantly to (65)Zn and (109)Cd detection. Thus, both self-absorption and air space between the sample and scintillator surface could impair quantitative RRIS imaging. Despite these issues, RRIS is suggested for quantitative time-course measurements of radionuclide motion within plants.

  9. Implications of excess 210Pb and 137Cs in sediment cores from Mikawa Bay, Japan.

    PubMed

    Lu, Xueqiang; Matsumoto, Eiji

    2009-01-01

    Four sediment cores were collected from Mikawa Bay, Japan, and excess 210Pb and 137Cs were measured by gamma spectrometry. Sedimentation rates for the four cores were determined by 210Pb method. The sedimentation rate range is 0.10-0.70 g/(cm2 x year). The bio-mixing depth for each core is less than 7.0 cm, and was determined by the excess 210Pb profiles as well. Therefore, the bioturbation is slight. The 210Pb-derived dates coincided with the results from 137Cs geochronology. Acceleration in sedimentation rate due to environmental alteration has been found in cores A2.5 and 05AS8, representing two depocenters due to their topography. Evidence of the Tokai Flood in 2000 was found in core 05AS8 according to the profiles of both radioisotopes and trace metals.

  10. Distribution pattern of 90Sr and 137Cs in the Nile delta and the adjacent regions after Chernobyl accident.

    PubMed

    Shawky, S; el-Tahawy, M

    1999-02-01

    Strontium and cesium contents in surface soil samples across the Nile Delta and the north coast of Egypt after the Chernobyl accident have been investigated. The concentration of 137Cs and 90Sr was determined using a high resolution gamma spectrometer based on hyperpure germanium detector (HPGe) and a liquid scintillation counter (LSC) respectively. 90Sr was determined through its decay product 90Y using Cerenkov counting. The determination of 90Sr was based on tributylphosphate (TBP) extraction of yttrium from nitric acid extract of ashed samples. The radioactivity of soils ranged between 18.5 and 2175 Bq/m2 with a mean of 652 Bq/m2 and 234 and 3129 Bq/m2 with a mean of 760 Bq/m2 for 137Cs and 90Sr respectively. An estimated absorbed dose equivalent due to the measured deposit of 137Cs was found to be 0.062 murem/h.

  11. 137Cs in a raised bog in central Sweden.

    PubMed

    Rosén, K; Vinichuk, M; Johanson, K J

    2009-07-01

    The vertical distribution of (137)Cs activity in peat soil profiles and (137)Cs activity concentration in plants of various species was studied in samples collected at two sites on a raised bog in central Sweden. One site (open bog) was in an area with no trees and only a few sparsely growing plant species, while the other (low pine) was less than 100 m from the open bog site and had slowly growing Scots pine, a field layer dominated by some ericaceous plants and ground well-covered by plants. The plant samples were collected in 2004-2007 and were compared with samples collected in 1989 from the same open bog and low pine sites. Ground deposition of (137)Cs in 2005 was similar at both sites, 23,000 Bq m(-2). In the open bog peat profile it seems to be an upward transport of caesium since a clear peak of (137)Cs activity was found in the uppermost 1-4 cm of Sphagnum layers, whereas at the low pine site (137)Cs was mainly found in deeper (10-12 cm) layers. The migration rate was 0.57 cm yr(-1) at the open bog site and the migration centre of (137)Cs was at a depth of 10.7, while the rate at the low pine site was 0.78 cm yr(-1) and the migration centre was at 14.9 cm. Heather (Calluna vulgaris) was the plant species with the highest (137)Cs activity concentrations at both sites, 43.5 k Bq(-1) DM in 1989 decreasing to 20.4 in 2004-2007 on open bog and 22.3 k Bq kg(-1) DM in 1989 decreasing to 11.2 k Bq(-1) DM by the period 2004-2007 on the low pine site. (137)Cs transfer factors in plants varied between 0.88 and 1.35 on the open bog and between 0.48 and 0.69 m(2)kg(-1) DM at the low pine site.

  12. Determination of the Sensibility Factors for TLD-100 Powder on the Energy of X-Ray of 50, 250 kVp; 192Ir, 137Cs and 60Co

    SciTech Connect

    Loaiza, Sandra P.; Alvarez, Jose T.

    2006-09-08

    TLD-100 powder is calibrated in terms of absorbed dose to water Dw, using the protocols AAPM TG61, AAPM TG43 and IAEA-TRS 398, for the energy of RX 50, 250 kVp, 137Cs and 60Co respectively. The calibration curves, TLD Response R versus Dw, are fitted by weighted least square by a quadratic polynomials; which are validated with the lack of fit and the Anderson-Darling normality test. The slope of these curves corresponds to the sensibility factor: Fs R/DW, [Fs] = nC Gy-1. The expanded uncertainties U's for these factors are obtained from the ANOVA tables. Later, the Fs' values are interpolated using the effective energy hvefec for the 192Ir. The SSDL sent a set of capsules with powder TLD-100 for two Hospitals. These irradiated them a nominal dose of Dw = 2 Gy. The results determined at SSDL are: for the Hospital A the Dw is overestimated in order to 4.8% and the Hospital B underestimates it in the range from -1.4% to -17.5%.

  13. Digital logarithmic airborne gamma ray spectrometer

    NASA Astrophysics Data System (ADS)

    Zeng, Guo-Qiang; Zhang, Qing-Xian; Li, Chen; Tan, Cheng-Jun; Ge, Liang-Quan; Gu, Yi; Cheng, Feng

    2014-07-01

    A new digital logarithmic airborne gamma ray spectrometer is designed in this study. The spectrometer adopts a high-speed and high-accuracy logarithmic amplifier (LOG114) to amplify the pulse signal logarithmically and to improve the utilization of the ADC dynamic range because the low-energy pulse signal has a larger gain than the high-energy pulse signal. After energy calibration, the spectrometer can clearly distinguish photopeaks at 239, 352, 583 and 609 keV in the low-energy spectral sections. The photopeak energy resolution of 137Cs improves to 6.75% from the original 7.8%. Furthermore, the energy resolution of three photopeaks, namely, K, U, and Th, is maintained, and the overall stability of the energy spectrum is increased through potassium peak spectrum stabilization. Thus, it is possible to effectively measure energy from 20 keV to 10 MeV.

  14. Evaluation of the activity concentrations of (137) Cs and (40)K in some Chanterelle mushrooms from Poland and China.

    PubMed

    Falandysz, Jerzy; Zalewska, Tamara; Apanel, Anna; Drewnowska, Małgorzata; Kluza, Karolina

    2016-10-01

    The activity concentrations of (137)Cs and (40)K in mushrooms of the genus Cantharellus (Cantharellus cibarius, Cantharellus tubaeformis, and Cantharellus minor) collected across Poland from 1997 to 2013 and in Yunnan province of China in 2013 were determined using gamma spectrometry with an HPGe detector, respectively. Activity concentrations of (137)Cs in C. cibarius from the places in Poland varied from 64 ± 3 to 1600 ± 47 Bq kg(-1) db in 1997-2004 and 4.2 ± 1.2 to 1400 ± 15 Bq kg(-1) db in 2006-2013. In the Chinese Cantharellus mushrooms, the activity level of (137)Cs was very low, i.e., at a range <1.2 to 1.2 ± 0.6 Bq kg(-1) dry biomass. The natural radionuclide (40)K was at similar activity level in C. cibarius collected across Poland and in China, and fluctuations in levels of (40)K over the years and locations in Poland were small. In C. cibarius from diverse sites in Poland, content of (137)Cs highly fluctuated in 1998-2013 but no clear downward trend was visible (Fig. 1). Published activity levels of (137)Cs in fruitbodies of Cantharellus such Cantharellus californicus, Cantharellus cascadensis, C. cibarius, Cantharellus cinnabarius, Cantharellus formosus, Cantharellus iuteocomus, Cantharellus lutescens, Cantharellus minor, Cantharellus pallens [current name C. cibarius], Cantharellus subalbidus, Cantharellus subpruinosus, and C. tubaeformis collected worldwide were compared. In the Polish cuisine, mushrooms of the genus Cantharellus are blanched before frying or pickling, and this kind of treatment, and additionally also pickling, both very efficiently remove alkali elements (and radioactivity from (134/137)Cs) from flesh of the species.

  15. Fallout 137Cs in reindeer herders in Arctic Norway.

    PubMed

    Skuterud, Lavrans; Thørring, Håvard

    2015-03-03

    Reindeer herders in the Arctic were among the most heavily exposed populations to the global fallout from nuclear weapons testing in the 1950s and 1960s, due to high transfer of radionuclides in the lichens-reindeer-human food chain. Annual studies of (137)Cs in reindeer herders in Kautokeino, Norway, were initiated in 1965 to monitor radiation doses and follow environmental (137)Cs behavior. The (137)Cs concentrations declined from the peak in 1965 with effective half-times of 6-8 years, only interrupted by a temporary doubling in levels from 1986 to 1987 due to the Chernobyl fallout. During the period of 1950-2010 an average herder received an integrated effective dose from incorporated (137)Cs of about 18 mSv. This dose represents an insignificant increase in the risk for developing cancer. Health studies even show a significantly lower cancer incidence among Sámis and reindeer herders in northern Norway compared to other populations in the same area.

  16. Gamma-ray imaging with coaxial HPGe detector

    SciTech Connect

    Niedermayr, T; Vetter, K; Mihailescu, L; Schmid, G J; Beckedahl, D; Kammeraad, J; Blair, J

    2005-04-12

    We report on the first experimental demonstration of Compton imaging of gamma rays with a single coaxial high-purity germanium (HPGe) detector. This imaging capability is realized by two-dimensional segmentation of the outside contact in combination with digital pulse-shape analysis, which enables to image gamma rays in 4{pi} without employing a collimator. We are able to demonstrate the ability to image the 662keV gamma ray from a {sup 137}Cs source with preliminary event selection with an angular accuracy of 5 degree with an relative efficiency of 0.2%. In addition to the 4{pi} imaging capability, such a system is characterized by its excellent energy resolution and can be implemented in any size possible for Ge detectors to achieve high efficiency.

  17. Radiobiological studies using gamma and x rays.

    SciTech Connect

    Potter, Charles Augustus; Longley, Susan W.; Scott, Bobby R.; Lin, Yong; Wilder, Julie; Hutt, Julie A.; Padilla, Mabel T.; Gott, Katherine M.

    2013-02-01

    There are approximately 500 self-shielded research irradiators used in various facilities throughout the U.S. These facilities use radioactive sources containing either 137Cs or 60Co for a variety of biological investigations. A report from the National Academy of Sciences[1] described the issues with security of particular radiation sources and the desire for their replacement. The participants in this effort prepared two peer-reviewed publications to document the results of radiobiological studies performed using photons from 320-kV x rays and 137Cs on cell cultures and mice. The effectiveness of X rays was shown to vary with cell type.

  18. Track-average LET of secondary electrons generated in LiF:Mg,Ti and liquid water by 20-300 kV x-ray, 137Cs and 60Co beams

    NASA Astrophysics Data System (ADS)

    Cabrera-Santiago, A.; Massillon-JL, G.

    2016-11-01

    Electrons generated in matter by photons could be a fundamental basis for an adequate analysis of radiation effects and damage. We have studied separately the ‘primary electrons’ generated directly by photons from the ‘secondary electrons’ (SE) produced by electron-electron interactions. In this work, track-average linear energy transfer, {{L}Δ,\\text{T}} , of SE in LiF:Mg,Ti and liquid water produced by twelve photon energy beams from 20 kV x-ray to 60Co gamma rays have been investigated using the EGSnrc Monte Carlo Code. The exposure of LiF:Mg,Ti in different phantom materials has been considered. Depending on the photon energy, SE represent 40%-90% of the total electron fluence (TEF) between 1 keV and 10 keV, being higher when the photon energy increases. Independent of the medium, {{L}Δ,\\text{T}} versus mean photon energy displays a local minimum at around 40 keV, followed by a local maximum at ~80 keV-100 keV. The {{L}Δ,\\text{T}} of SE generated by the x-ray beams are of order of 11 keV µm-1 to 19 keV µm-1 in LiF:Mg,Ti and 5 keV µm-1 to 9 keV µm-1 in liquid water which represent 3-5 times those produced by 60Co gamma rays in both media. These values were considerably greater than those of TEF, by factors of 3-8. Furthermore, {{L}Δ,\\text{T}} of SE generated in liquid water by 20 kV-200 kV x-rays are similar to those of 76 MeV-120 MeV 3He ions. Contrary to the TEF, where {{L}Δ,\\text{T}} were independent of the phantom material, at low photon energies {{L}Δ,\\text{T}} of SE was found to be sensitive to the surrounding medium showing higher values within the phantom than in air. This result, which agrees with published experimental results, implies the importance of the SE ionization density for an understanding of dosimeter response induced by photon beams.

  19. A (137)Cs erosion model with moving boundary.

    PubMed

    Yin, Chuan; Ji, Hongbing

    2015-12-01

    A novel quantitative model of the relationship between diffused concentration changes and erosion rates using assessment of soil losses was developed. It derived from the analysis of surface soil (137)Cs flux variation under persistent erosion effect and based on the principle of geochemistry kinetics moving boundary. The new moving boundary model improves the basic simplified transport model (Zhang et al., 2008), and mainly applies to uniform rainfall areas which show a long-time soil erosion. The simulation results for this kind of erosion show under a long-time soil erosion, the influence of (137)Cs concentration will decrease exponentially with increasing depth. Using the new model fit to the measured (137)Cs depth distribution data in Zunyi site, Guizhou Province, China which has typical uniform rainfall provided a good fit with R(2) = 0.92. To compare the soil erosion rates calculated by the simple transport model and the new model, we take the Kaixian reference profile as example. The soil losses estimated by the previous simplified transport model are greater than those estimated by the new moving boundary model, which is consistent with our expectations.

  20. Temporal variation of post-accident atmospheric (137)Cs in an evacuated area of Fukushima Prefecture: Size-dependent behaviors of (137)Cs-bearing particles.

    PubMed

    Ochiai, Shinya; Hasegawa, Hidenao; Kakiuchi, Hideki; Akata, Naofumi; Ueda, Shinji; Tokonami, Shinji; Hisamatsu, Shun'ichi

    2016-12-01

    The concentrations of (137)Cs in the air, which were divided into coarse (>1.1 μm ϕ) and fine (<1.1 μm ϕ) fractions of particulate matter (PM), were measured from October 2012 to December 2014 in an area evacuated after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. Total atmospheric (137)Cs concentrations showed a clear seasonal variation, with high concentrations during summer and autumn related to the dominant easterly wind blowing from the highly radioactivity contaminated area. This seasonal peak was dominated by (137)Cs in the coarse PM fraction. The (137)Cs specific activity (massic (137)Cs concentration) in the coarse PM was also found to increase significantly in summer, whereas that in the fine PM showed no variability during the year. These results show that coarse and fine (137)Cs-bearing PM have different origins and behaviors in the resuspension process. The seasonal variation in atmospheric (137)Cs concentration was well correlated with the mean (137)Cs surface contamination (deposition density) around the observation site weighted by the frequency of wind direction, indicating that the atmospheric (137)Cs concentration in the observation site was explained by the distribution of the (137)Cs surface contamination and the frequency of different wind directions. We introduced a resuspension factor corrected for wind direction, consisting of the ratio of the atmospheric (137)Cs concentration to the weighted mean (137)Cs surface contamination, which evaluated the intensity of resuspension better than the conventional resuspension factor. This ratio ranged from 5.7 × 10(-11) to 8.6 × 10(-10) m(-1) and gradually decreased during the study period.

  1. Neutron detection in a high gamma ray background with liquid scintillators

    SciTech Connect

    Stevanato, L.; Cester, D.; Viesti, G.; Nebbia, G.

    2013-04-19

    The capability of liquid scintillator (namely 2'' Multiplication-Sign 2'' cells of EJ301 and EJ309) of detecting neutrons in a very high gamma ray background is explored. A weak {sup 252}Cf source has been detected in a high {sup 137}Cs gamma ray background corresponding to a dose rate of 100 {mu}Sv/h with probability of detection in compliance with IEC requirements for hand held instruments. Tests were performed with new generation of CAEN digitizers, in particular the V1720 (8 Channel 12bit 250 MS/s) one.

  2. Effect of selective sorptive agents on leachability of {sup 137}Cs and {sup 90}Sr

    SciTech Connect

    Spence, R.D.

    1998-06-01

    Decades ago it was established that illite effectively improves {sup 137}Cs leach resistance. Subsequently, illite has become a standard ingredient used at Oak Ridge National Laboratory in grouts developed to stabilize {sup 137}Cs. Adding illite improves {sup 137}Cs leach resistance by three orders of magnitude, and increasing the illite concentration can add another order of magnitude improvement. Adding crystalline silicotitanate, a selective sorptive agent developed more recently for {sup 137}Cs, not only improves {sup 137}Cs leach resistance by an order-of-magnitude over that obtained using illite but also improves {sup 85}Sr leach resistance by two orders of magnitude.

  3. Variation in sensitivity to. gamma. -ray-induced chromosomal aberrations during the mitotic cycle of the sea urchin egg

    SciTech Connect

    Ejima, Y.; Nakamura, I.; Shiroya, T.

    1982-11-01

    Sea urchin eggs were irradiated with /sup 137/Cs ..gamma.. rays at various stages of the mitotic cycle, and chromosomal aberrations at the first postirradiation mitosis and embryonic abnormalities at later developmental stages were examined. The radiosensitivity of the eggs to both endpoints varied in parallel with the mitotic stage at the time of irradiation, suggesting a possible relationship between chromosomal damage and embryonic abnormalities.

  4. Fukushima 137Cs at the base of planktonic food webs off Japan

    NASA Astrophysics Data System (ADS)

    Baumann, Z.; Fisher, N. S.; Gobler, C. J.; Buesseler, K. O.; George, J. A.; Breier, C. F.; Nishikawa, J.

    2015-12-01

    The potential bioaccumulation of 137Cs in marine food webs off Japan became a concern following the release of radioactive contaminants from the damaged Fukushima nuclear power plant into the coastal ocean. Previous studies suggest that 137Cs activities increase with trophic level in pelagic food webs, however, the bioaccumulation of 137Cs from seawater to primary producers, to zooplankton has not been evaluated in the field. Since phytoplankton are frequently the largest component of suspended particulate matter (SPM) we used SPM concentrations and particle-associated 137Cs to understand bioaccumulation of 137Cs in through trophic pathways in the field. We determined particle-associated 137Cs for samples collected at 20 m depth from six stations off Japan three months after the initial release from the Fukushima nuclear power plant. At 20 m SPM ranged from 0.65 to 1.60 mg L-1 and rapidly declined with depth. The ratios of particulate organic carbon to chlorophyll a suggested that phytoplankton comprised much of the SPM in these samples. 137Cs activities on particles accounted for on average 0.04% of the total 137Cs in seawater samples, and measured concentration factors of 137Cs on small suspended particles were comparatively low (∼102). However, when 137Cs in crustacean zooplankton was derived based only on modeling dietary 137Cs uptake, we found predicted and measured 137Cs concentrations in good agreement. We therefore postulate the possibility that the dietary route of 137Cs bioaccumulation (i.e., phytoplankton ingestion) could be largely responsible for the measured levels in the copepod-dominated (%) zooplankton assemblages in Japanese coastal waters. Finally, our data did not support the notion that zooplankton grazing on phytoplankton results in a biomagnification of 137Cs.

  5. Mutant quantity and quality in mammalian cells (AL) exposed to cesium-137 gamma radiation: effect of caffeine

    NASA Technical Reports Server (NTRS)

    McGuinness, S. M.; Shibuya, M. L.; Ueno, A. M.; Vannais, D. B.; Waldren, C. A.; Chatterjee, A. (Principal Investigator)

    1995-01-01

    We examined the effect of caffeine (1,3,7-trimethylxanthine) on the quantity and quality of mutations in cultured mammalian AL human-hamster hybrid cells exposed to 137Cs gamma radiation. At a dose (1.5 mg/ml for 16 h) that reduced the plating efficiency (PE) by 20%, caffeine was not itself a significant mutagen, but it increased by approximately twofold the slope of the dose-response curve for induction of S1- mutants by 137Cs gamma radiation. Molecular analysis of 235 S1- mutants using a series of DNA probes mapped to the human chromosome 11 in the AL hybrid cells revealed that 73 to 85% of the mutations in unexposed cells and in cells treated with caffeine alone, 137Cs gamma rays alone or 137Cs gamma rays plus caffeine were large deletions involving millions of base pairs of DNA. Most of these deletions were contiguous with the region of the MIC1 gene at 11p13 that encodes the S1 cell surface antigen. In other mutants that had suffered multiple marker loss, the deletions were intermittent along chromosome 11. These "complex" mutations were rare for 137Cs gamma irradiation (1/63 = 1.5%) but relatively prevalent (23-50%) for other exposure conditions. Thus caffeine appears to alter both the quantity and quality of mutations induced by 137Cs gamma irradiation.

  6. Root endophytic bacteria of a (137)Cs and Mn accumulator plant, Eleutherococcus sciadophylloides, increase (137)Cs and Mn desorption in the soil.

    PubMed

    Yamaji, Keiko; Nagata, Satoshi; Haruma, Toshikatsu; Ohnuki, Toshihiko; Kozaki, Tamotsu; Watanabe, Naoko; Nanba, Kenji

    2016-03-01

    We found that root endophytes of (137)Cs accumulator plant produce siderophores, resulting in the desorption of (137)Cs from the contaminated soil collected at Fukushima, Japan. We selected an endemic Japanese deciduous tree, Eleutherococcus sciadophylloides (Franch. et Sav), that accumulates high concentrations of (137)Cs and Mn. Root endophytic bacteria were isolated from E. sciadophylloides and microbial siderophore production was evaluated via chrome azurol S (CAS) Fe and CAS Al assays. Of the 463 strains that we isolated, 107 (23.1%) produced the siderophores. Using eight strains that showed high siderophore production in our assays, we examined desorption of (137)Cs, Mn, Fe and Al by the bacterial culture filtrates from (137)Cs-contaminated soil after decomposing the soil organic matter using hydrogen peroxide. We found (137)Cs and Mn desorption concomitant with Al and Fe desorption, as well as a decrease of pH. We also detected succinic acid, a well-known siderophore, in the bacterial culture filtrates of our two root endophytic bacteria. Our results strongly suggest that the root endophytic bacteria of E. sciadophylloides produce the siderophores that enhance (137)Cs and Mn desorption in the rhizosphere, making the resulting (137)Cs and Mn ions easier for E. sciadophylloides to absorb from the rhizosphere.

  7. Recent changes in Red Lake (Romania) sedimentation rate determined from depth profiles of 210Pb and 137Cs radioisotopes.

    PubMed

    Begy, R; Cosma, C; Timar, A

    2009-08-01

    This work presents a first estimation of the sedimentation rate for the Red Lake (Romania). The sediment accumulation rates were determined by two well-known methods for recent sediment dating: (210)Pb and (137)Cs methods. Both techniques implied used the gamma emission of the above-mentioned radionuclides. The (210)Pb and (137)Cs concentrations in the sediment were measured using a gamma spectrometer with a HpGe detector, Gamma-X type. Activities ranging from 41+/-7 to 135+/-34Bq/kg were found for (210)Pb and from 3+/-0.5 to 1054+/-150Bq/kg for (137)Cs. The sediment profile indicates acceleration in sedimentation rate in the last 18 years. Thus, the sedimentation process for the Red Lake can be divided in two periods, the last 18 years, and respectively, the period before that. Using the Constant Rate of (210)Pb Supply method values between 0.18+/-0.04 and 1.85+/-0.5g/cm(2) year (0.32+/-0.08 and 2.83+/-0.7cm/year) were obtained. Considering both periods, an average sedimentation rate of 0.87+/-0.17g/cm(2) year (1.17cm/year) was calculated. Considering an average depth of 5.41m for the lake and the sedimentation rate estimated for the last 18 years, it could be estimated that the lake will disappear in 195 years.

  8. Distribution and possible dietary intake of radioactive 137Cs, 40K and 226Ra with the pantropical mushroom Macrocybe gigantea in SW China.

    PubMed

    Falandysz, Jerzy; Zhang, Ji; Zalewska, Tamara; Apanel, Anna; Wang, Yuanzhong; Wiejak, Anna

    2015-01-01

    There is scarcity of data on contamination with radiocesium 134/137Cs of edible mushrooms from the Southwestern Asia. This study aimed to get insight into activity concentration of artificial nuclides 134/137Cs and natural 40K and 226Ra in mushrooms from Yunnan province, which is major producer in China. The specimens of pantropical mushroom Macrocybe gigantea were collected from the wild and from a farm across Yunnan land in 2012-2013 and analyzed using gamma spectrometry with hyperpure germanium coaxial detector (HPGe). M. gigantea showed low activity concentrations of 137Cs (median value for dehydrated caps was 4.5 Bq kg(-1) and 5.4 Bq kg(-1) for stipes) while 134Cs was not detected. Natural radionuclide 40K showed 2-3 orders of magnitude greater activity concentration compared to artificial 137Cs in M. gigantea. The activity concentrations of 226Ra from uranium and radium decay series for most of the consignments of M. gigantea examined were below the method's limit of detection. The nominal effective dose equivalent for the Yunnan people from the dietary intake of 137Cs was assessed to be below 0.01 μSv per annum on the average, and that from 40K to be below 0.1 μSv per annum. Data available for the first time on activity concentrations of 137Cs in wild-grown saprobic mushroom from this region of Asia suggest low pollution with radiocesium from fallout there. Hence, the likely health risks from intake of 137Cs from cooked M. gigantea are in practice of mushrooms absent for human consumers there. Because of abundance of mushrooms in Yunnan and high significance of the region as producer and exporter a wider study using many species is necessary to fill a gap on possible radioactive contamination and risk to mushroom consumers.

  9. Continuous measurement of radionuclide distribution off Fukushima using a towed sea-bed gamma ray spectrometer

    NASA Astrophysics Data System (ADS)

    Thornton, Blair; Ohnishi, Seiki; Ura, Tamaki; Odano, Naoteru; Fujita, Tsuneo

    2013-09-01

    Instrumentation and data processing methods to continuously map the distribution of radionuclides on the seafloor have been developed and applied to survey radioactive discharge from the Fukushima Dai-ichi Nuclear Power Plant following the M9.0 earthquake and tsunami that struck the east coast of Japan on March 11 2011. The instrument consists of a flexible rubber hose with an integrated gamma ray spectrometer that measures the full gamma spectrum between 0.1 and 1.8 MeV while being towed along the seafloor by a ship. The data processing methods described allow for quantification of 137Cs and 134Cs concentration in marine sediments, and a technique has been developed to optimize the spatial resolution of the measurements for each radioactive species for a given level of statistical uncertainty. The system was deployed during August and November 2012 to measure the distribution of radionuclides along three transects within an 80 km radius of the plant. Increased levels of 137Cs and 134Cs were recorded and their distributions mapped continuously over distances of 1.6, 12.5 and 22 km respectively. The levels of 137Cs and 134Cs were found to vary significantly with location. The in situ measurements show good agreement with laboratory analyzed samples obtained during the surveys. The results demonstrate that the instrument and data processing techniques described enable high resolution, quantitative measurements of 137Cs and 134Cs in marine sediments, and provide an effective solution for rapid, low cost monitoring of radioactive material on the seafloor.

  10. Gamma ray generator

    SciTech Connect

    Firestone, Richard B; Reijonen, Jani

    2014-05-27

    An embodiment of a gamma ray generator includes a neutron generator and a moderator. The moderator is coupled to the neutron generator. The moderator includes a neutron capture material. In operation, the neutron generator produces neutrons and the neutron capture material captures at least some of the neutrons to produces gamma rays. An application of the gamma ray generator is as a source of gamma rays for calibration of gamma ray detectors.

  11. 137Cs inventory in semi-isolated basins of the western South Pacific

    NASA Astrophysics Data System (ADS)

    Yamada, M.; Wang, Z.

    2007-12-01

    The main introduction routes of 137Cs into the Pacific Ocean are worldwide global fallout from atmospheric nuclear weapons testing and close-in fallout from U. S. tests conducted on the Bikini and Enewetak Atolls. The objectives of this study are to measure the 137Cs activities in water columns of the western South Pacific Ocean and to discuss the processes controlling the 137Cs inventory. The 137Cs activities were determined for seawater samples from the East Caroline, Coral Sea, New Hebrides, South Fiji and Tasman Sea Basins of the western South Pacific Ocean. The 137Cs activities in surface waters ranged from 1.7 Bq m- 3 in the Tasman Sea Basin to 2.3 Bq m-3 in the East Caroline Basin. The latitudinal 137Cs distributions in surface waters showed the opposite trend to the expected deposition density from global fallout. The distribution profiles of 137Cs activity at these six western South Pacific Ocean stations did not differ from each other significantly. The total 137Cs inventories in the western South Pacific Ocean ranged from 850 Bq m-2 in the Coral Sea Basin to 1270 Bq m-2 in the South Fiji Basin. Higher 137Cs inventories were observed at middle latitude stations in the subtropical gyre than at low latitude stations. The 137Cs inventories were 1.9 - 4.5 times higher than that of the expected deposition density of atmospheric global fallout at the same latitude. The possible sources of excess 137Cs inventories in the western South Pacific Ocean might be attributable to both the inter-hemisphere dispersion of the atmospheric nuclear weapons testing 137Cs from the northern stratosphere to the southern one and its subsequent deposition, and water- bearing transport of 137Cs from the North Pacific Ocean to the South Pacific.

  12. Potential of largemouth bass as vectors of 137Cs dispersal.

    PubMed

    Paller, M H; Fletcher, D E; Jones, T; Dyer, S A; Isely, J J; Littrell, J W

    2005-01-01

    We conducted a radio telemetry study on the movements of potentially contaminated largemouth bass between Steel Creek, a restricted access (137)Cs contaminated stream on the Savannah River Site (located in South Carolina, USA), and the publicly accessible Savannah River. Largemouth bass were relatively mobile in lower Steel Creek and the portion of the Savannah River near Steel Creek, and there was considerable movement between these two habitats. Largemouth bass had home ranges of about 500 linear meters of shoreline in the Savannah River but sometimes moved long distances. Such movements occurred primarily during the spawning season, largely upstream, and increased when water levels were changing or elevated. However, approximately 90% of the largemouth bass observations were within 10 km of Steel Creek. The total quantity of (137)Cs transported into the Savannah River by largemouth bass was much less than transported by water and suspended sediments discharged from Steel Creek. We conclude that largemouth bass from the Savannah River Site are unlikely to be responsible for long distance dispersal of substantial radiological contamination in the Savannah River.

  13. 137Cs in recent tsunami deposits - a potential tracer of selective tsunami sediment entrainment?

    NASA Astrophysics Data System (ADS)

    Spiske, M.; Bahlburg, H.; Suckow, A.

    2012-12-01

    The tsunami of 27 February, 2010 affected a 600 km long stretch of the central Chilean coastline. We documented the tsunami deposits 4 months after the event in 2010 and two years later in 2012. The broad coastal plain at La Trinchera was inundated ca. 430 m inland and up to 8 m above sea level. A ca. 10 cm thick layer of tsunami sand was deposited on top of marsh sediments. A comparison of this layer in 2010 and 2012 reveals a change in the relative mineral composition and related grain size. In 2010 the layer consisted of 90-93% heavy minerals, 1-4% quartz, 2-3% organics and 1-3% feldspar. In 2012 the relative abundances changed to 63-76% heavy minerals, 10-12% quartz, 16-20% organics and 5-7% feldspar, as a result of the erosion of parts of the finer grained heavy minerals. Furthermore, the thickness decreased to ca. 8 cm. The concentration of the artificial radionuclide 137Cs was recorded using high-resolution gamma-spectrometry. Especially in the northern hemisphere, 137Cs is a tracer for radioactive fallout emitted mainly during nuclear tests in the 1950s to 1960s, peaking around 1963, or nuclear bombing and accidents. In contrast, Cs-concentrations in the southern hemisphere are about four times lower (<1 Bq/kg). Generally, the Cs-signal in terrestrial sediments is higher compared to marine deposits due to Cs-dilution in sea water. For recent (younger than ca. 60 years) onshore tsunami sediments, a mixed Cs-signal is expected because a tsunami can entrain sediments from different depositional environments and different stratigraphic age levels. At La Trinchera, gamma-spectrometry revealed a 137Cs-content of 0.5 Bq/kg for the lower ca. 5 cm of the tsunami layer. The 137Cs-concentration of the upper 5 cm was below the detection limit of 0.1 Bq/kg. Even though the tsunami layer appears to be structureless, the Cs-content may help to distinguish between two distinctive depositional units within the layer. We suggest that the lower part represents reworked

  14. Reconstruction of 137Cs activity in the ocean following the Fukushima Daiichi Nuclear Power Plant Accident

    NASA Astrophysics Data System (ADS)

    Tsumune, Daisuke; Aoyama, Michio; Tsubono, Takaki; Tateda, Yutaka; Misumi, Kazuhiro; Hayami, Hiroshi; Toyoda, Yasuhiro; Maeda, Yoshiaki; Yoshida, Yoshikatsu; Uematsu, Mitsuo

    2014-05-01

    A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant following the earthquake and tsunami of 11 March 2011 resulted in the release of radioactive materials to the ocean by two major pathways, direct release from the accident site and atmospheric deposition. We reconstructed spatiotemporal variability of 137Cs activity in the ocean by the comparison model simulations and observed data. We employed a regional scale and the North Pacific scale oceanic dispersion models, an atmospheric transport model, a sediment transport model, a dynamic biological compartment model for marine biota and river runoff model to investigate the oceanic contamination. Direct releases of 137Cs were estimated for more than 2 years after the accident by comparing simulated results and observed activities very close to the site. The estimated total amounts of directly released 137Cs was 3.6±0.7 PBq. Directly release rate of 137Cs decreased exponentially with time by the end of December 2012 and then, was almost constant. The daily release rate of 137Cs was estimated to be 3.0 x 1010 Bq day-1 by the end of September 2013. The activity of directly released 137Cs was detectable only in the coastal zone after December 2012. Simulated 137Cs activities attributable to direct release were in good agreement with observed activities, a result that implies the estimated direct release rate was reasonable, while simulated 137Cs activities attributable to atmospheric deposition were low compared to measured activities. The rate of atmospheric deposition onto the ocean was underestimated because of a lack of measurements of dose rate and air activity of 137Cs over the ocean when atmospheric deposition rates were being estimated. Observed 137Cs activities attributable to atmospheric deposition in the ocean helped to improve the accuracy of simulated atmospheric deposition rates. Although there is no observed data of 137Cs activity in the ocean from 11 to 21 March 2011, observed data of

  15. Uptake and elimination of 137Cs by climbing perch (Anabus testudineus).

    PubMed

    Malek, M A

    1999-12-01

    This work describes the uptake and retention/biological elimination of 137Cs by climbing perch (Anabus testudineus) under laboratory conditions. The accumulated 137Cs concentration in the whole body of the fish was measured at certain intervals up to 38 d. A significant accumulation of 137Cs was found, but a steady state accumulation of 137Cs was not achieved by the end of the experiment. The bioaccumulation factors and the distribution of the radionuclide in edible parts of the fish were determined. The effective half-life of 137Cs in the fish species was found to be approximately 147 d (average) for elderly and adult fishes and approximately 300 d for younger fishes. Accumulation of 137Cs in the edible parts of the fish was found to be approximately 77% of whole body accumulation.

  16. Ambient dose equivalent rate in Goiânia 12 years after the 137Cs radiological accident.

    PubMed

    Yoshimura, E M; Umisedo, N K; Facure, A; Anjos, R M; Okuno, E

    2001-06-01

    This paper describes the situation of ambient dose equivalent rates in four of the main foci of 137Cs contamination in the city of Goiânia, Brazil, in 1999, 12 y after one of the worst radiological accidents in the world. During the decontamination, all the buildings of the three highly contaminated sites were demolished and the top soil removed. Afterwards, the soil of two of these lots was covered with concrete, and they remain vacant today. The soil of the third of these lots, identified here as E, previously known as junkyard II, was covered only with clean soil. Three to four years after the accident, new houses were constructed on this lot, and some very poor people live and work there collecting recyclable material. Gamma ray spectrometry, with a portable survey meter, was performed in the quoted places along with outdoor measurements in many other locations of Goiânia. The average ambient dose equivalent rate due to natural background radiation from radionuclides in the soil and cosmic radiation in non-contaminated areas of the city of Goiânia is 62 nSv h(-1). In most of the highly contaminated sites during the accident, the average ambient dose equivalent rate ranged from around 100 to 1,000 nSv h(-1). The only exception was site E, where values of ambient dose equivalent rate as high as 2.6 microSv h(-1) were found.

  17. REMOVAL OF 137Cs FROM DISSOLVED HANFORD TANK SALTCAKE BY TREATMENT WITH IONSIV IE-911

    SciTech Connect

    Rapko, Brian M.; Sinkov, Serguei I.; Levitskaia, Tatiana G.

    2005-03-01

    This paper describes the preparation of a 137Cs-depleted form of dissolved Hanford tank saltcake. A composite feed solution was treated with IONSIV{reg_sign} IE-911, which effectively reduced the concentration of 137Cs. This allowed for subsequent testing of waste immobilization without significant radiological hazard. Limited characterization of the initial feed solution and a more extensive characterization of the 137Cs-depleted material also are provided.

  18. Suppression of gamma-ray sensitivity of liquid scintillators for neutron detection

    NASA Astrophysics Data System (ADS)

    Swiderski, L.; Moszyński, M.; Wolski, D.; Iwanowska, J.; Szczęśniak, T.; Schotanus, P.; Hurlbut, C.

    2011-10-01

    Methods to reduce gamma-ray sensitivity of a liquid scintillator EJ309 have been studied. Zero-crossing pulse shape discrimination method was used to separate events generated by neutron and gamma radiation between 60- keVee and 4 MeVee. The measurements were carried out under irradiation from an intense 137Cs source, yielding dose rate of 10 mR/h at the detector. A Pu-Be source was used to establish neutron integration window. Pile-up rejection (PUR) circuit was used to reduce gamma-ray induced events under irradiation from an intense gamma-ray source. Further, application of lead, tin and copper shields was done in order to decrease intrinsic gamma-neutron detection efficiency.

  19. Inferring the chemical form of 137Cs deposited by the Fukushima Dai-ichi Nuclear Power Plant accident by measuring (137)Cs incorporated into needle leaves and male cones of Japanese cedar trees.

    PubMed

    Kanasashi, Tsutomu; Takenaka, Chisato; Sugiura, Yuki

    2016-05-15

    We hypothesized that the water-soluble (ionic) and water-insoluble (stable) radiocesium from the initial fallout of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident was distributed in various proportions in the surrounding areas and that this distribution was reflected in the trees that suffered deposition from the initial fallout. This study attempted to evaluate local variations in the chemical form of (137)Cs derived from the initial fallout of the FDNPP accident and whether its chemical form affected the radiocesium concentration in the tissues currently growing in trees, even after the initial fallout ceased. For these estimations, the ratio between the (137)Cs concentration in Cryptomeria japonica needle leaves in the tree crown, which existed before the FDNPP accident and subsequently directly exposed to the initial fallout ((137)Cs pre-accident N), and the amount of (137)Cs in the initial fallout itself ((137)Cs fallout) was determined ((137)Cs pre-accident N/(137)Cs fallout) at 66 sites. In addition, the (137)Cs ratios between the male cones produced in 2012 ((137)Cs male cone) and needle leaves that had elongated in the spring of 2011 ((137)Cs 2011N) was determined at 82 sites ((137)Cs male cone/(137) Cs 2011N). Most of the sites with lower (137)Cs pre-accident N /(137)Cs fallout ratios were distributed in eastern Fukushima, relatively close to the Pacific Ocean coastline. Lower (137)Cs pre-accident N/(137)Cs fallout and higher (137)Cs malecone/(137)Cs 2011N were found to be associated with higher proportions of (137)Cs in ionic forms. These observations are consistent with the hypothesis, and likely reflect regional variations in the chemical form of the deposited radiocesium.

  20. 137Cs uptake with cafeteria food after the Chernobyl accident

    SciTech Connect

    Voigt, G.; Paretzke, H.G. )

    1992-11-01

    After the Chernobyl accident, the activity concentrations of radiocesium were measured in both the meals served at the cafeteria of a research center and in the employees eating there. The time-dependent means of monthly 137Cs activities in meals and people show a similar distribution pattern with highest values between March and July 1987, i.e., only 1 y after the accident. In meals, the highest activities were found when the menu consisted of pork, milk, or milk products. The 50-y cumulative effective dose calculated from the whole-body measurements is 0.21 mSv for male and 0.15 mSv for female employees. Cafeteria food contributed only a small share to this exposure.

  1. Recent 137Cs deposition in sediments of Admiralty Bay, Antarctica.

    PubMed

    Sanders, Christian J; Santos, Isaac R; Patchineelam, Sambasiva R; Schaefer, Carlos; Silva-Filho, Emmanoel V

    2010-05-01

    Cesium-137, radium-226 and lead-210 profiles of a 25 cm sediment core give an indication of recent changes in land-ocean interactions at a polar coastal environment (Admiralty Bay, King George Island, Antarctica). The linear sedimentation accumulation rate at the study site calculated from the unsupported (210)Pb profile was 6.7 mm/year from 1965 to 2005. A 3.5-fold increase in (137)Cs concentrations was observed in the top layer of this sediment core. This sharp increase seems to indicate a recent redistribution of fallout radionuclides previously deposited on soil, vegetation and snow. These results imply enhanced land-ocean interactions at this site likely as a result of climate change. Because our results are based on a single core, additional investigations are needed to confirm our observations.

  2. TRIPLICATE SODIUM IODIDE GAMMA RAY MONITORS FOR THE SMALL COLUMN ION EXCHANGE PROGRAM

    SciTech Connect

    Couture, A.

    2011-09-20

    This technical report contains recommendations from the Analytical Development (AD) organization of the Savannah River National Laboratory (SRNL) for a system of triplicate Sodium Iodide (NaI) detectors to be used to monitor Cesium-137 ({sup 137}Cs) content of the Decontaminated Salt Solution (DSS) output of the Small Column Ion Exchange (SCIX) process. These detectors need to be gain stabilized with respect to temperature shifts since they will be installed on top of Tank 41 at the Savannah River Site (SRS). This will be accomplished using NaI crystals doped with the alpha-emitting isotope, Americium-241({sup 241}Am). Two energy regions of the detector output will be monitored using single-channel analyzers (SCAs), the {sup 137}Cs full-energy {gamma}-ray peak and the {sup 241}Am alpha peak. The count rate in the gamma peak region will be proportional to the {sup 137}Cs content in the DSS output. The constant rate of alpha decay in the NaI crystal will be monitored and used as feedback to adjust the high voltage supply to the detector in response to temperature variation. An analysis of theoretical {sup 137}Cs breakthrough curves was used to estimate the gamma activity expected in the DSS output during a single iteration of the process. Count rates arising from the DSS and background sources were predicted using Microshield modeling software. The current plan for shielding the detectors within an enclosure with four-inch thick steel walls should allow the detectors to operate with the sensitivity required to perform these measurements. Calibration, testing, and maintenance requirements for the detector system are outlined as well. The purpose of SCIX is to remove and concentrate high-level radioisotopes from SRS salt waste resulting in two waste streams. The concentrated high-level waste containing {sup 137}Cs will be sent to the Defense Waste Processing Facility (DWPF) for vitrification and the low-level DSS will be sent to the Saltstone Production Facility (SPF

  3. 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.

  4. 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.

  5. Upward mobilization of 137Cs in surface soils of Chamaecyparis obtusa Sieb. et Zucc. (hinoki) plantation in Japan.

    PubMed

    Fukuyama, Taijiro; Takenaka, Chisato

    2004-01-05

    The use of 137Cs has recently been adopted to estimate erosion in hinoki plantations in Japan. However, there have been several reports of the upward mobilization of 137Cs in forest humus layers. In this study, the vertical distribution of 137Cs within the soil profile was measured in a hinoki plantation. In order to confirm the upward migration of 137Cs from mineral soil to fresh surface litter and to identify mechanisms of the transfer, changes in 137Cs specific activity in the contents of litterbags were examined in a hinoki plantation. A controlled laboratory experiment was also conducted to assess the effect of microbial activity on the upward migration of 137Cs. As a result, the higher 137Cs activities in the surface organic layer of a hinoki plantation than in fresh litter and the increasing 137Cs total content of litterbags with time demonstrated the upward mobilization of 137Cs from mineral soil to the surface organic layer. Physical movement of soil particles by raindrop splash was considered an important process in 137Cs upward migration. The results of our laboratory experiment indicate an influence from soil microbial activity on the upward mobilization of 137Cs. Thus, upward migration of 137Cs and constant litter removal by runoff may induce 137Cs loss from steep forested catchments and underestimation of the 137Cs inventory leading to the overestimation of soil redistribution rates.

  6. Behaviour of (137)Cs in forest humus detected across the territory of the Czech Republic.

    PubMed

    Škrkal, Jan; Pilátová, Helena; Rulík, Petr; Suchara, Ivan; Sucharová, Julie; Holá, Marie

    2017-03-22

    The activity concentration of (137)Cs in samples of coniferous forest humus collected across the territory of the Czech Republic in 1995 and 2005 was analysed, and it was found significantly correlated with the surface deposition caused by the Chernobyl accident. The effective (12.8 y) and environmental (22.3 y) half-lives of radiocaesium in humus were calculated and compared with those in spruce bark. The impact of important forest stand factors, that is, precipitation, content of organic matter, age of trees and pH, on the behaviour of (137)Cs in humus was studied. It was observed that humus samples with a higher proportion of organic matter, higher pH(H2O) and pH(CaCl2) contained higher amounts of (137)Cs. Conversely, with the age of trees, the activity concentration of (137)Cs in humus is decreasing. Higher precipitation and humus acidity decrease the reduction rate of the (137)Cs in humus. These stand factors increase bioavailability of (137)Cs in humus. The transfer and retention of available (137)Cs in biomass of organisms living in humus for a long time can satisfactorily explain the longer residence time of (137)Cs in humus affected by the studied factors.

  7. Gamma-ray imaging with a Si/CsI(Tl) Compton detector.

    PubMed

    Hoover, A S; Sullivan, J P; Baird, B; Brumby, S P; Kippen, R M; McCluskey, C W; Rawool-Sullivan, M W; Sorensen, E B

    2006-12-01

    We present results from Compton imaging of gamma-ray sources using an instrument constructed from thin silicon scattering detectors and CsI(Tl) absorbing detectors. We have successfully imaged single and double point sources for several common radioactive isotopes ((137)Cs, (60)Co, (22)Na, (54)Mn). The measured angular resolution is 11.6( composite function) FWHM at 662keV. In parallel with the hardware effort, a GEANT4-based simulation code was developed. Comparisons between real and simulated data are discussed.

  8. A new technique for processing airborne gamma ray spectrometry data for mapping low level contaminations.

    PubMed

    Aage, H K; Korsbech, U; Bargholz, K; Hovgaard, J

    1999-12-01

    A new technique for processing airborne gamma ray spectrometry data has been developed. It is based on the noise adjusted singular value decomposition method introduced by Hovgaard in 1997. The new technique opens for mapping of very low contamination levels. It is tested with data from Latvia where the remaining contamination from the 1986 Chernobyl accident together with fallout from the atmospheric nuclear weapon tests includes 137Cs at levels often well below 1 kBq/m2 equivalent surface contamination. The limiting factors for obtaining reliable results are radon in the air, spectrum stability and accurate altitude measurements.

  9. Results of 1999 Spectral Gamma-Ray and Neutron Moisture Monitoring of Boreholes at Specific Retention Facilities in the 200 East Area, Hanford Site

    SciTech Connect

    DG Horton; RR Randall

    2000-01-18

    Twenty-eight wells and boreholes in the 200 East Are% Hanford Site, Washington were monitored in 1999. The monitored facilities were past-practice liquid waste disposal facilities and consisted of six cribs and nineteen ''specific retention'' cribs and trenches. Monitoring consisted of spectral gamma-ray and neutron moisture logging. All data are included in Appendix B. The isotopes {sup 137}Cs, {sup 60}Co, {sup 235}U, {sup 238}U, and {sup 154}Eu were identified on spectral gamma logs from boreholes monitoring the PUREX specific retention facilities; the isotopes {sup 137}Cs, {sup 60}Co, {sup 125}Sb, and {sup 154}Eu were identified on the logs from boreholes at the BC Controlled Area cribs and trenches; and {sup 137}Cs, {sup 60}Co, and {sup 125}Sb were, identified on the logs from boreholes at the BX specific retention trenches. Three boreholes in the BC Controlled Area and one at the BX trenches had previous spectral gamma logs available for comparison with 1999 logs. Two of those logs showed that changes in the subsurface distribution of {sup 137}CS and/or {sup 60}Co had occurred since 1992. Although the changes are not great, they do point to continued movement of contaminants in the vadose zone. The logs obtained in 1999 create a larger baseline for comparison with future logs. Numerous historical gross gamma logs exist from most of the boreholes logged. Qualitative comparison of those logs with the 1999 logs show many substantial changes, most of which reflect the decay of deeper short-lived isotopes, such as {sup 106}Ru and {sup 125}Sb, and the much slower decay of shallower and longer-lived isotopes such as {sup 137}Cs. The radionuclides {sup 137}Cs and {sup 60}Co have moved in two boreholes since 1992. Given the amount of movement and the half-lives of the isotopes, it is expected that they will decay to insignificant amounts before reaching groundwater. However, gamma ray logging cannot detect many of the contaminants of interest such as {sup 99}Tc, NO

  10. 137Cs as a tracer of recent sedimentary processes in Lake Michigan

    USGS Publications Warehouse

    Cahill, R.A.; Steele, J.D.

    1986-01-01

    To determine recent sediment movement, we measured the levels of 137Cs (an artificial radionuclide produced during nuclear weapons testing) of 118 southern Lake Michigan samples and 27 in Green Bay. These samples, taken from 286 grab samples of the upper 3 cm of sediment, were collected in 1975 as part of a systematic study of Lake Michigan sediment. 137Cs levels correlated well with concentrations of organic carbon, lead, and other anthropogenic trace metals in the sediment. 137Cs had a higher correlation with silt-sized than with clay-sized sediment (0.55 and 0.46, respectively). Atmospherically derived 137Cs and trace metals are being redistributed by sedimentary processes in Lake Michigan after being incorporated in suspended sediment. We determined a distribution pattern of 137Cs that represents areas of southern Lake Michigan where sediment deposition is occurring. ?? 1986 Dr W. Junk Publishers.

  11. 137Cs in soil and fallout around Zagreb (Croatia) at the time of the Fukushima accident.

    PubMed

    Šoštarić, Marko; Petrinec, Branko; Babić, Dinko

    2013-12-01

    This paper addresses the noticeable increase of 137Cs activity concentrations in soil and fallout in the area surrounding Zagreb (Croatia) that occurred at the time of the 2011 Fukushima accident. This topic is important for public health as 137Cs is highly toxic due to its long half-life of radioactive decay and chemical similarity to potassium. 137Cs concentrations in fallout were much greater than in soil, but remained present longer in the latter. While being detectable in our measurements, 137Cs did not spread through the food chain in amounts exceeding the maximum allowed level of radioactive food contamination. However, more thorough and consistent measurements need to be done in order to establish the precise activity trends of 137Cs in Zagreb soil and fallout.

  12. [sup 137]Cs levels in deer following the Three Mile Island accident

    SciTech Connect

    Field, R.W. )

    1993-06-01

    White-tailed deer (Odocoileus virgianus) tongues were assayed to assess whether or not significant widespread [sup 137]Cs contamination occurred in the vicinity of Three Mile Island Nuclear Station as a result of the 1979 accident. White-tailed deer tongues harvested from 10 Pennsylvania counties more than 88 km away from Three Mile Island had significantly higher [sup 137]Cs levels than deer tongues harvested from counties surrounding the nuclear plant. The mean deer tongue [sup 137]Cs levels found in Pennsylvania white-tailed deer were lower than [sup 137]Cs levels found in deer from other parts of the US sampled shortly after culmination of major atmospheric nuclear testing. These findings support the conclusions of previous studies suggesting that only minimal quantities of [sup 137]Cs escaped from the damaged Three Mile Island plant after the accident.

  13. Latitudinal variation and residence time of (137)Cs in Indian coastal environment.

    PubMed

    Sartandel, S J; Jha, S K; Tripathi, R M

    2015-11-15

    Anthropogenic (137)Cs activity concentration, in surface sea water along the western and eastern coast of India has been estimated using the in-situ pre-concentration approach. Activity levels of (137)Cs ranges from 0.09-1.30Bqm(-3) with an overall mean of 0.69±0.29Bqm(-3). Latitudinal variation and higher depletion in activity concentration of (137)Cs at few locations were observed. Temporal change of (137)Cs in sea water along Indian coast unveils a lower effective half-life of 13.8±0.7y in comparison to Asia Pacific regional sea water. The results prevailed that the spatial distribution confers no fresh input of (137)Cs in Indian coastal region.

  14. METHOD FOR SIMULTANEOUS 90SR AND 137CS IN-VIVO MEASUREMENTS OF SMALL ANIMALS AND OTHER ENVIRONMENTAL MEDIA DEVELOPED FOR THE CONDITIONS OF THE CHERNOBYL EXCLUSION ZONE

    SciTech Connect

    Farfan, E.; Jannik, T.

    2011-10-01

    To perform in vivo simultaneous measurements of the {sup 90}Sr and {sup 137}Cs content in the bodies of animals living in the Chernobyl Exclusion Zone (ChEZ), an appropriate method and equipment were developed and installed in a mobile gamma beta spectrometry laboratory. This technique was designed for animals of relatively small sizes (up to 50 g). The {sup 90}Sr content is measured by a beta spectrometer with a 0.1 mm thick scintillation plastic detector. The spectrum processing takes into account the fact that the measured object is 'thick-layered' and contains a comparable quantity of {sup 137}Cs, which is a characteristic condition of the ChEZ. The {sup 137}Cs content is measured by a NaI scintillation detector that is part of the combined gamma beta spectrometry system. For environmental research performed in the ChEZ, the advantages of this method and equipment (rapid measurements, capability to measure live animals directly in their habitat, and the capability of simultaneous {sup 90}Sr and {sup 137}Cs measurements) far outweigh the existing limitations (considerations must be made for background radiation and the animal size, skeletal shape and body mass). The accuracy of these in vivo measurements is shown to be consistent with standard spectrometric and radiochemical methods. Apart from the in vivo measurements, the proposed methodology, after a very simple upgrade that is also described in the article, works even more accurately with samples of other media, such as soil and plants.

  15. Comparative study of (137)Cs distribution in broilers and pheasants and possibilities for protection.

    PubMed

    Mitrović, Branislava M; Vitorović, Gordana; Vićentijević, Mihajlo; Vitorović, Duško; Pantelić, Gordana; Lazarević-Macanović, Mirjana

    2012-03-01

    The aim of the present study was to investigate distribution of (137)Cs in leg and breast meat of broilers and pheasants following single alimentary contamination and administration of two protectors (AFCF and clinoptilolite). The birds were administered a single dose of (137)CsCl, with an activity of 750 Bq. Protectors were given via gastric tube or mixed in the forage pellets. AFCF given via gastric tube decreased the (137)Cs concentration by a factor of 7.8 in broilers leg meat and 7.4 in broilers breast meat. When AFCF was mixed in pellets, the (137)Cs concentration was 19.5 times lower in broilers leg meat and 22.1 times lower in broilers breast meat, than in the control group. In pheasants, AFCF administered via gastric tube decreased the (137)Cs concentration by a factor of 12.4 in leg meat and by a factor of 13.7 in breast meat, respectively. In group 4, where pheasants were administered AFCF mixed in pellets, the (137)Cs concentration was 3.7 times lower in leg and breast meat, than in the control group. For comparison, clinoptilolite administered via gastric tube decreased the (137)Cs concentration 1.8 times in broilers leg meat and 2.0 times in breast meat, compared to the control group. In pheasants, (137)Cs concentration was 2.9 times lower in leg meat and 2.6 times lower in breast meat. Clinoptilolite mixed in the feed had relatively low efficiency of protection in broilers ((137)Cs concentration was 1.4 times lower in leg meat and 1.6 lower in breast meat). A similar trend was observed in pheasants ((137)Cs concentration was 1.6 lower in leg and breast meat).

  16. Spatial pattern of 137Cs in soils in a mixed deciduous forest in Fukushima, Japan

    NASA Astrophysics Data System (ADS)

    Takada, M.; Yamada, T.; Takahara, T.; Okuda, T.

    2015-12-01

    Spatial heterogeneity of 137Cs contamination was studied in a forest floor of Fukushima region, c.a. 40 km NW of Fukushima Daiichi Nuclear Power Plant (FDNPP) focusing on downwards flow from forest canopy via stemflow and throughfall which play major role in determining spatial contamination of 137Cs after the FNDP accident. Setting a study plot (400 m2) in a secondary mixed deciduous forest, dominated by Quercus crispula and Abies firma in canopy layer in August and November 2014, we sampled the souk from surface to 5 cm in depth of soils and measured 137Cs in every 2 m grids and at tree stem bases. The total estimated activity of 137Cs in soil within the study plot was approximately 210 kBq/m2, but showed large spatial heterogeneity showing 30 times of difference between the lowest and highest activities. The activity decreased with increasing distances from tree stem bases. High activity around tree stem bases was presumably due to the stemflow containing 137Cs seeped into soil only around tree stem bases that raised radioactivity in soil locally in the areas. Relatively low activity away from trees (outside canopies) may be due to small effects of stemflow and throughfall. Activity of 137Cs around bases of deciduous broadleaf trees increased with increasing the tree size. Because larger trees have higher potentials to capture larger amount of 137Cs on the tree surface, cumulative activity of 137Cs included in stemflow may increase with increasing the tree size. However evergreen coniferous tree species (Abies firma) did not show such a pattern relating to the tree size. The difference is assumed to be affected by phenological characteristics as the accident happened in winter and deciduous broadleaf trees did not have leaves and 137Cs deposited on tree bodies, while evergreen coniferous tree had leaves and 137Cs was intercepted by the canopies.

  17. Temporal variation of 137Cs water column inventory in the North Pacific since the 1960s.

    PubMed

    Aoyama, M; Hirose, K

    2003-01-01

    The temporal variation of water column inventories of 137Cs in the North Pacific since the 1960s was examined based on the analysis of the 137Cs profiles in HAM database. 137Cs in seawater in the North Pacific have originated mainly from global fallout from atmospheric nuclear weapons tests, which occurred in the early 1960s. In the 1960s, both the meridional distribution of 137Cs inventory in the North Pacific and that of fallout on land stations showed mid-latitude maximum. The region with higher deposition at land stations, however, was more northern than the latitudes where the 137Cs inventory in the North Pacific showed a maximum. The difference of the latitude where maximum 137Cs deposition/inventory was observed reflects the difference of the geographical distribution of the precipitation amount in the Pacific and Atlantic Oceans followed by the different warm current systems in each ocean. A good positive relation between 137Cs inventory and annual precipitation amount was discovered in the ocean stations at the middle latitude in the North Pacific. The horizontal distribution of 137Cs inventories at the middle latitudes in the North Pacific is characterized as west-high and east-low in the early 1960s, which was basically controlled by the distribution of annual precipitation amount. Eastward advection, then, modified it to be less difference in 1966-1967 after the highest deposition periods in 1963-1965. In the 1970s and 1980s, increases of the 137Cs inventory at the lower latitude of 10-20 deg. N are found. Surface and subsurface southward transports are considered as the source of this increasing 137Cs inventory.

  18. Effects of radiocesium inventory on (137)Cs concentrations in river waters of Fukushima, Japan, under base-flow conditions.

    PubMed

    Ochiai, Shinya; Ueda, Shinji; Hasegawa, Hidenao; Kakiuchi, Hideki; Akata, Naofumi; Ohtsuka, Yoshihito; Hisamatsu, Shun'ichi

    2015-06-01

    To investigate the behavior of nuclear accident-derived (137)Cs in river water under base-flow conditions, concentrations of dissolved and particulate (137)Cs were measured at 16 sampling points in seven rivers of Fukushima Prefecture, Japan, in 2012 and 2013. The concentration of dissolved (137)Cs was significantly correlated with the mean (137)Cs inventory in the catchment area above each sampling point in both sampling years. These results suggest that the concentration of dissolved (137)Cs under base-flow conditions is primarily determined by the (137)Cs inventory of the catchment area above the sampling point. However, the concentration of particulate (137)Cs did not show a clear relationship with either the mean (137)Cs inventory or the dissolved (137)Cs concentration, thus indicating that particulate and dissolved forms do not effectively interact in rivers. To evaluate the contribution of the (137)Cs inventory within catchment areas, we analyzed relations between the (137)Cs concentration and the mean (137)Cs inventory over the area within certain flow path lengths that were traced along the river and slope above the sampling point. Coefficients of determination for dissolved (137)Cs concentrations were highest for the longest flow path, i.e., the whole catchment area, and lower for shorter flow paths. Coefficients of determination for particulate (137)Cs concentrations were only moderately high for the shortest flow path in 2012, whereas the values were quite low for all flow paths in 2013. These results suggest that dissolved (137)Cs can originate from a larger area of the catchment even under base-flow conditions; however, particulate (137)Cs did not show such behavior. The results also show that under base-flow conditions, dissolved and particulate (137)Cs behave independently during their transport from river catchments to the ocean.

  19. 137Cs vertical migration in a deciduous forest soil following the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Nakanishi, Takahiro; Matsunaga, Takeshi; Koarashi, Jun; Atarashi-Andoh, Mariko

    2014-02-01

    The large amount of (137)Cs deposited on the forest floor because of the Fukushima Dai-ichi Nuclear Power Plant accident represents a major potential long-term source for mobile (137)Cs. To investigate (137)Cs mobility in forest soils, we investigated the vertical migration of (137)Cs through seepage water, using a lysimetric method. The study was conducted in a deciduous forest soil over a period spanning 2 month to 2 y after the Fukushima nuclear accident. Our observations demonstrated that the major part of (137)Cs in the litter layer moved into the mineral soil within one year after the accident. On the other hand, the topsoil prevented migration of (137)Cs, and only 2% of (137)Cs in the leachate from litter and humus layer penetrated below a 10 cm depth. The annual migration below a 10 cm depth accounted for 0.1% of the total (137)Cs inventory. Therefore, the migration of (137)Cs by seepage water comprised only a very small part of the total (137)Cs inventory in the mineral soil, which was undetectable from the vertical distribution of (137)Cs in the soil profile. In the present and immediate future, most of the (137)Cs deposited on the forest floor will probably remain in the topsoil successively, although a small but certain amount of bioavailable (137)Cs exists in forest surface soil.

  20. Fallout volume and litter type affect (137)Cs concentration difference in litter between forest and stream environments.

    PubMed

    Sakai, Masaru; Gomi, Takashi; Negishi, Junjiro N

    2016-11-01

    It is important to understand the changes in the (137)Cs concentration in litter through leaching when considering that (137)Cs is transferred from basal food resources to animals in forested streams. We found that the difference of (137)Cs activity concentration in litter between forest and stream was associated with both litter type and (137)Cs fallout volume around Fukushima, Japan. The (137)Cs activity concentrations in the litter of evergreen conifers tended to be greater than those in the litter of broad-leaved deciduous trees because of the absence of deciduous leaves during the fallout period in March 2011. Moreover, (137)Cs activity concentrations in forest litter were greater with respect to the (137)Cs fallout volume. The (137)Cs activity concentrations in stream litter were much lower than those in forest litter when those in forest litter were higher. The (137)Cs leaching patterns indicated that the differences in (137)Cs activity concentration between forest and stream litter could change with changes in both fallout volume and litter type. Because litter is an important basal food resource in the food webs of both forests and streams, the (137)Cs concentration gradient reflects to possible (137)Cs transfer from lower to higher trophic animals. Our findings will improve our understanding of the spatial heterogeneity and variability of (137)Cs concentrations in animals resident to the contaminated landscape.

  1. Cell death (apoptosis) in mouse intestine after continuous irradiation with gamma rays and with beta rays from tritiated water

    SciTech Connect

    Ijiri, K.

    1989-04-01

    Apoptosis is a pattern of cell death involving nuclear pycnosis, cytoplasmic condensation, and karyorrhexis. Apoptosis induced by continuous irradiation with gamma rays (externally given by a 137Cs source) or with beta rays (from tritiated water injected ip) was quantified in the crypts of two portions of mouse bowel, the small intestine and descending colon. The time-course change in the incidence of apoptosis after each type of radiation could be explained on the basis of the innate circadian rhythm of the cells susceptible to apoptotic death and of the excretion of tritiated water (HTO) from the body. For 6-h continuous gamma irradiation at various dose rates (0.6-480 mGy/h) and for 6 h after injection of HTO of various radioactivities (0.15-150 GBq per kg body wt), the relationships between dose and incidence of apoptosis were obtained. Survival curves were then constructed from the curves for dose vs incidence of apoptosis. For the calculation of the absorbed dose from HTO, the water content both of the mouse body and of the cells was assumed to be 70%. One megabecquerel of HTO per mouse (i.e., 40 MBq/kg body wt) gave a dose rate of 0.131 mGy/h. The mean lethal doses (D0) were calculated for gamma rays and HTO, and relative biological effectiveness values of HTO relative to gamma rays were obtained. The D0 values for continuous irradiation with gamma rays were 210 mGy for small intestine and 380 mGy for descending colon, and the respective values for HTO were 130 and 280 mGy, indicating the high radiosensitivity of target cells for apoptotic death. The relative biological effectiveness of HTO relative to 137Cs gamma rays for cell killing in both the small intestine and the descending colon in the mouse was 1.4-2.1.

  2. Hanford Isotope Project strategic business analysis Cesium-137 (Cs-137)

    SciTech Connect

    1995-10-01

    The purpose of this business analysis is to address the beneficial reuse of Cesium 137 (Cs-137) in order to utilize a valuable national asset and possibly save millions of tax dollars. Food irradiation is the front runner application along with other uses. This business analysis supports the objectives of the Department of Energy National Isotope Strategy distributed in August 1994 which describes the DOE plans for the production and distribution of isotope products and services. As part of the Department`s mission as stated in that document. ``The Department of Energy will also continue to produce and distribute other radioisotopes and enriched stable isotopes for medical diagnostics and therapeutics, industrial, agricultural, and other useful applications on a businesslike basis. This is consistent with the goals and objectives of the National Performance Review. The Department will endeavor to look at opportunities for private sector to co-fund or invest in new ventures. Also, the Department will seek to divest from ventures that can more profitably or reliably be operated by the private sector.``

  3. Undergraduate Research Projects in Atomic Collisions and Gamma-ray Spectroscopy

    NASA Astrophysics Data System (ADS)

    Sanders, J. M.; Varghese, S. L.; Haywick, D. W.; Fearn, M. L.

    2003-08-01

    Research projects at University of South Alabama, an undergraduate physics department, have employed a 150-kV Cockcroft-Walton accelerator for atomic collisions and sodium-iodide and high-purity germanium detectors for gamma-ray studies. The atomic collision experiments dealt with electron capture and electron loss in collisions of protons and hydrogen atoms with hydrocarbon molecules. Gamma-ray studies with NaI scintillators determined the potassium content of food using 40K gamma-rays. Environmental studies of river sedimentation use a HPGe detector to determine 137Cs and 210Pb content. Students learn the physics of the interactions of ionizing radiation with matter, while acquiring a familiarity with high-vacuum technique, electronics, data acquisition and analysis, and reporting of results.

  4. Gamma-Ray Telescopes

    NASA Astrophysics Data System (ADS)

    Weekes, T.; Murdin, P.

    2000-11-01

    Gamma-rays are the highest-energy photons in the ELECTROMAGNETIC SPECTRUM and their detection presents unique challenges. On one hand it is easy to detect γ-rays. The interaction cross-sections are large and above a few MeV the pair production interaction, the dominant γ-ray interaction with matter, is easily recognized. Gamma-ray detectors were far advanced when the concept of `γ-ray astronomy' ...

  5. Gamma ray transients

    NASA Technical Reports Server (NTRS)

    Cline, Thomas L.

    1987-01-01

    The discovery of cosmic gamma ray bursts was made with systems designed at Los Alamos Laboratory for the detection of nuclear explosions beyond the atmosphere. HELIOS-2 was the first gamma ray burst instrument launched; its initial results in 1976, seemed to deepen the mystery around gamma ray transients. Interplanetary spacecraft data were reviewed in terms of explaining the behavior and source of the transients.

  6. Gamma-Ray Mutagenesis in Bacteriophage T4

    PubMed Central

    Conkling, Mark A.; Grunau, John A.; Drake, John W.

    1976-01-01

    137Cs-gamma irradiation of bacteriophage T4 induces large deletions plus a variety of types of point mutations. All mutations arise with single-hit kinetics, and all by a misrepair process. The estimated point mutation rate is 1.5 x 10-9 per locus per rad. PMID:1269910

  7. Computational modeling of 137Cs contaminant transfer associated with sediment transport in Abukuma River.

    PubMed

    Iwasaki, T; Nabi, M; Shimizu, Y; Kimura, I

    2015-01-01

    A numerical model capable of simulating the transfer of (137)Cs in rivers associated with transport of fine sediment is presented. The accident at Fukushima Dai-ichi Nuclear Power Plant (FDNPP) released radionuclides into the atmosphere, and after fallout several radionuclides in them, such as radiocesium ((134)Cs, (137)Cs) and radioiodine ((131)I) were adsorbed on surface soil particles around FDNPP and transported by surface water. To understand the transport and deposition of the radioactive contaminant along with surface soil particles and its flux to the ocean, we modeled the transport of the (137)Cs contaminant by computing the water flow and the associated washload and suspended load transport. We have developed a two-dimensional model to simulate the plane flow structure, sediment transport and associated (137)Cs contaminant transport in rivers by combining a shallow water flow model and an advection-diffusion equation for the transport of sediment. The proposed model has been applied to the lower reach of Abukuma River, which is the main river in the highly contaminated area around FDNPP. The numerical results indicate that most (137)Cs supplied from the upstream river reach with washload would directly reach to Pacific Ocean. In contrast, washload-oriented (137)Cs supplied from the upstream river basin has a limited role in the radioactive contamination in the river. The results also suggest that the proposed framework of computational model can be a potential tool for understanding the sediment-oriented (137)Cs behavior in rivers.

  8. Activities and geochronology of (137)Cs in lake sediments resulting from sediment resuspension.

    PubMed

    Matisoff, Gerald

    2017-02-01

    In lakes with a large surface area to watershed ratio (137)Cs delivery is primarily by direct atmospheric fallout to the lake surface, where its activity in the sediments has been used to estimate the exposure to organisms and sediment mass deposition rates. Comparison of (137)Cs in the historical atmospheric fallout record with (137)Cs activity profiles in sediment cores reveals that although the general features of a maxima in the fallout deposition can be matched to activity peaks in the core, the general shape of the (137)Cs profile is not an exact replica of the fallout history. Instead, the sediment reflects post-depositional processes such as resuspension, bioturbation, partitioning of (137)Cs between the sediment solids and the pore fluids, and molecular diffusion of (137)Cs through the pore fluids. Presented here is a model that couples these processes to a system time averaging (STA) model that accounts for the time history of (137)Cs fallout and the particle residence time in the water column or in the 'active' surface sediment subject to resuspension. Sediment profiles are examined by comparing reasonable ranges of each of the coefficients of each of these major processes and by applying the model to cores collected from two large, shallow lakes, Lake Erie (USA/Canada) and Lake Winnipeg (Canada). The results indicate that the STA model with molecular diffusion and sediment resuspension best describes the data from these large, shallow lakes.

  9. Mapping fields of 137Cs contamination in soils in the context of their stability and hierarchical spatial structure

    NASA Astrophysics Data System (ADS)

    Korobova, E.; Romanov, S.

    2009-04-01

    Technogenic radioisotopes now dispersed in the environment are involved in natural and technogenic processes forming specific geochemical fields and serving as tracers of modern mass migration and geofield transformation. Cs-137 radioisotopes having a comparatively long life time are known for a fast fixation by the top soil layer; radiocesium activity can be measured in the surface layer in field conditions. This makes 137Cs rather convenient for the study and modeling a behavior of toxic elements in soils [1-3, 5] and for the investigation of relative stability and hierarchical fractal structures of the soil contamination of the atmospheric origin [2]. The objective of the experimental study performed on the test site in Bryansk region was to find and prove polycentric regularities in the structure of 137Cs contamination field formed after the Chernobyl accident in natural conditions. Such a character of spatial variability can be seen on the maps showing different soil parameters and chemical element distribution measured in grids [3-5]. The research was undertaken to support our idea of the regular patterns in the contamination field structure that enables to apply a mathematical theory of the field to the geochemical fields modeling on the basis of a limited number of direct measurements sufficient to reproduce the configuration and main parameters of the geochemical field structure on the level of the elementary landscape geochemical system (top-slope-bottom). Cs-137 field measurements were verified by a direct soil sampling. Soil cores dissected into subsamples with increments of 2, 5 and 10 cm, were taken to the depth of 40 cm at points with various surface activity located at different elements of relief. According to laboratory measurements 137Cs inventory in soils varied from 344 to 3448 kBq/m2 (983 kBq/m2 on the average). From 95,1% to 98,0% to of the total inventory was retained in the top 20-cm soil layer. This confirmed that field gamma spectrometry

  10. Long-term transport and dispersion of 137Cs released into ocean off Fukushima nuclear accident

    NASA Astrophysics Data System (ADS)

    Zhao, Chang; Qiao, Fangli; Wang, Guansuo; Xia, Changshui; Jung, KyungTae

    2014-05-01

    In the following days after the Fukushima nuclear accident which happened in 11th March 2011, significant amounts of radioactive materials (131I, 134Cs and 137Cs) had been leaking into the terrestrial and marine environments. The radionuclides model was used to study the distribution of the 137Cs in the Pacific and the Indian Ocean released from the Fukushima accident. The simulation on the distribution of 137Cs agrees well with the the observed profiles in the 9th November 2011, which proved the validaty of the model. In the first year of our model run, the 137Cs is carried eastward by the Kuroshio and its extension, spreading southward and northword meanwhile. Four or five years after the accident, the 137Cs reaches the US coast with the surface waters of the Pacific Ocean; its concentration is no higher than 3 Bq/m3. Ten years after the accident, all the North Pacific Ocean is labeled with the 137Cs from the Fukushima. The concentration is less than 1 Bq/m3 at that time. Thirty years after the accident, the concentration of 137Cs in both the Pacific and the Indian Ocean is below 0.1 Bq/m3. Since the spreading path of 137Cs from the Fukushima nuclear accident is just the migration route of the Pacific tuna, a kind of fish inhabit the western and eastern North Pacific, it may cause radioactive contamination to the fish. In the offshore seas of China, the 137Cs from Fukushima nuclear accident is very low (<0.2 Bq/m3) .

  11. Behavior of 131I and 137Cs in environments released from the Fukushima nuclear disaster

    NASA Astrophysics Data System (ADS)

    Ohta, T.; Mahara, Y.; Kubota, T.; Igarashi, T.

    2011-12-01

    The devastating tsunami that caused by the great earthquake (M = 9.0) off the coast of northeastern Honshu on 11 March 2011 destroyed large coastal areas of Tohoku and north Kanto, Japan. Radionuclides, including 131I, 134Cs, and 137Cs, were released into the atmosphere from the Fukushima Daiichi plants. Concentration of levels of 131I, 134Cs, and 137Cs in Ibaraki Prefecture, Japan, released from the Fukushima Daiichi plant were investigated in the soil and precipitation. The concentrations of 131I and 137Cs in the soil from the surface to 1 cm depth in Ibaraki Prefecture were 9360-13,400 Bq/kg and 720-3250 Bq/kg, respectively. The concentration of 137Cs at this soil observation site originating from the Fukushima plant was 8.4 to 21 times that found locally after the Nagasaki atomic bomb explosion. Most of the 134Cs and 137Cs from rainwater were trapped by the surface soil and sand to a depth of 1 cm, whereas only about 30% of the 131I was collected by the surface soil, suggesting that 131I would move deeper than 137Cs and 134Cs. The 131I in the rainwater was in the anion exchangeable form, and all of it could be collected by anion exchangeable mechanisms, whereas 30% of the 131I that had passed through the soil could not be trapped by the anion exchange resin, suggesting that the chemical form of this 30% was in a changeable, organic-bound form. The 131I, 134Cs, and 137Cs that were absorbed on soil were difficult to be dissolved into water. As the half-life of 131I is short and 137Cs is strongly adsorbed on the surface soil and sand, these radionuclides would be unlikely to reach the groundwater before completely decaying; contamination of groundwater with 131I and 137Cs supplied from rainwater to the surface soil is therefore exceedingly unlikely. As the 137Cs is likely to migrate only 0.6 cm in 10 years, people living in the Fukushima and Kanto areas will be exposed to radiation from 137Cs in the surface soil and sand. For protection, surface soils and sands

  12. Gamma-ray astrophysics

    NASA Technical Reports Server (NTRS)

    Stecker, F. W. (Editor); Trombka, J. I. (Editor)

    1973-01-01

    Conference papers on gamma ray astrophysics are summarized. Data cover the energy region from about 0.3 MeV to a few hundred GeV and theoretical models of production mechanisms that give rise to both galactic and extragalactic gamma rays.

  13. Gamma-Ray Pulsars

    NASA Technical Reports Server (NTRS)

    Harding, Alice K.

    2011-01-01

    The Fermi Gamma-Ray Space Telescope has revolutionized the study of pulsar physics with the detection of over 80 gamma-ray pulsars. Several new populations have been discovered, including 24 radio quiet pulsars found through gamma-ray pulsations alone and about 20 millisecond gamma-ray pulsars. The gamma-ray pulsations from millisecond pulsars were discovered by both folding at periods of known radio millisecond pulsars or by detecting them as gamma-ray sources that are followed up by radio pulsar searches. The second method has resulted in a phenomenally successful synergy, with -35 new radio MSPs (to date) having been discovered at Fermi unidentified source locations and the gamma-ray pulsations having then been detected in a number of these using the radio timing solutions. The higher sensitivity and larger energy range of the Fermi Large Area Telescope has produced detailed energy-dependent light curves and phase-resolved spectroscopy on brighter pulsars, that have ruled out polar cap models as the major source of the emission in favor of outer magnetosphere accelerators. The large number of gamma-ray pulsars now allows for the first time meaningful population and sub-population studies that are revealing surprising properties of these fascinating sources.

  14. Assessment of natural radioactivity and (137)Cs in some coastal areas of the Saudi Arabian gulf.

    PubMed

    Al-Ghamdi, H; Al-Muqrin, A; El-Sharkawy, A

    2016-03-15

    The levels of natural radioactivity have been investigated in some Saudi Arabian Gulf coastal areas. Sampling sites were chosen according to the presence of nearby non-nuclear industrial activities such as, the two main water desalination plants in Al Khobar and Al Jubail, and Maaden phosphate complex in Ras Al Khair, to ensure that effluents discharges into the Arabian Gulf didn't enhance radioactivity in seawater and shore sediments. Seawater samples were analyzed for radium isotopes (Ra-226 & Ra-228) and measured by gamma spectrometry using high purity germanium detector, after radiochemical separation of the isotopes by co-precipitation with MnO2. Shore sediment samples were analyzed for (226)Ra, (228)Ra ((232)Th), (4)°K and (137)Cs using gamma sepectrometry. A small variation was observed in the activity concentrations of the investigated radioisotopes, and the activity levels were comparable to those reported in literature. Quality assurance and methods validation were established through the efficiency calibration of the detectors, the estimation of uncertainties, the use of blanks, the analysis of standard reference materials and the intercomparison and proficiency tests. Radiological hazards were assessed, and the annual effective dose had an average value of 0.02 mSv. On the basis of the current results, we may conclude that any radiological hazards to the public visiting these shores are not expected.

  15. Age-dependent accumulation of (137)Cs by pike Esox lucius in the Yenisei River.

    PubMed

    Zotina, T A; Trofimova, E A; Dementyev, D V; Bolsunovsky, A Ya

    2016-05-01

    Age-dependent accumulation of (137)Cs in the muscles and bodies of the pike Esox lucius (aged two to seven years) inhabiting a section of the Yenisei River polluted with artificial radionuclides has been studied. The content of (137)Cs in muscles varied from 0.5 to 7.0 Bq/kg of fresh weight. The maximum content of the radionuclide has been found in juveniles. The content of (137)Cs in pike muscles and body decreased considerably with age. The high content of (137)Cs in the muscles of juveniles is probably a consequence of their higher intensity of feeding as compared to older individuals, which is due to the intense growth of juveniles.

  16. High spatial resolution observations of 137Cs in northern Britain and Ireland from airborne geophysical survey.

    PubMed

    Scheib, Cathy; Beamish, David

    2010-09-01

    This study reports the (137)Cs data derived from three regional and national scale High Resolution Airborne Resource and Environmental Surveys (HiRES) in northern Britain and Ireland. The detailed spatial resolution, combined with the large areas these surveys collectively cover, gives insight into large-scale deposition patterns and possible subsequent re-distribution of (137)Cs on a level that was previously not possible. The largest survey area considered covers the whole of Northern Ireland. All three data sets display some clustering of higher (137)Cs activities on high ground together with regional scale NNW-SSE and NW-SE banding features. We interpret these as representing a series of rainfall interceptions of the repeated passage of the Chernobyl plume. Our observations, obtained at 200 m flight line intervals, appear to provide significant detail in relation to existing knowledge of large scale along-wind deposition of (137)Cs.

  17. A comparison of {sup 137}Cs radioactivity in localized evergreen and deciduous plant species

    SciTech Connect

    Rangel, R.C.

    1996-05-01

    A vegetation study at the Comanche Peak Steam Electric Station (CPSES) near Glen Rose, Texas was conducted in 1991 and 1992. The CPSES is a commercial nuclear power plant owned and operated by Texas Utilities Electric of Dallas, Texas. The US Nuclear Regulatory Commission (USNRC) requires the CPSES to routinely sample broadleaf vegetation in place of milk samples. Few commercial dairies exist in the vicinity. Broadleaf tree species are scarce because the climate and local limestone geology have produced a dry rolling hill topography. An evergreen juniper is the dominant tree species. Few broadleaves during the winter season have hindered year-round sampling. This study compares the environmental {sup 137}Cs concentrations between broadleaf and evergreen foliage at CPSES. Soil {sup 137}Cs concentrations from each vegetation location were also compared to the foliage {sup 137}Cs concentrations. The study`s objective was to determine if the deciduous and evergreen vegetation {sup 137}Cs concentrations are statistically the same.

  18. Long-term retention of (137)Cs in three forest soil types with different soil properties.

    PubMed

    Suchara, Ivan; Sucharová, Julie; Holá, Marie; Pilátová, Helena; Rulík, Petr

    2016-07-01

    Current (137)Cs activity concentrations were studied at three localities in individual soil horizons of Stagnosol, Arenic Podzol and Haplic Cambisol soil units in soil blocks with dimensions of 20 × 20 × 40 cm situated below pine canopies (n = 3) and spruce canopies (n = 3), and below small canopy gaps, at least 15 × 15 m in area (n = 3 + 3), which have probably endured since 1986. The main zone of (137)Cs accumulation in all the localities was found to be in the organic horizons (H and F). No significant transport and accumulation of (137)Cs into illuvial soil horizons (Bm, Bs or Bhs, Bv and Bv/IIC) was found. The estimated current total (137)Cs activity concentrations in the soil blocks 40 cm in depth were only slightly higher below the coniferous canopy than they were below nearby canopy gaps. The inventory of (137)Cs in the soils was found to be in accordance with the estimated (137)Cs inputs from the Chernobyl fallout and from global fallout. The low amounts of (137)Cs found accumulated in the aboveground biomass (mosses, grasses, needles) did not substantially bias the studied radiocaesium balance in the soils. The vertical migration rate of (137)Cs in soils (cm/year) had a tendency to be higher below canopies than below canopy gaps and below pine canopies than below spruce canopies. We expected the current (137)Cs activity concentrations in the individual soil horizons to be related to the studied soil parameters: pH (H2O), pH (CaCl2), content of organic matter and mineral portion and portion of humic and fulvic acid contents (Q4/6). However, this was not confirmed. Similarly, we observed a weak tendency toward higher (137)Cs activity in soils below the canopy than in soils below canopy gaps. The available gaps used in our study may have been too small, and they may have been affected by an accumulation of litter and humus containing (137)Cs from the surrounding plots situated below neighbouring canopies.

  19. Investigation of LaBr3:Ce probe for gamma-ray spectroscopy and dosimetry

    NASA Astrophysics Data System (ADS)

    Maghraby, Ahmed M.; Alzimami, K. S.; Alkhorayef, M. A.; Alsafi, K. G.; Ma, A.; Alfuraih, A. A.; Alghamdi, A. A.; Spyrou, N. M.

    2014-02-01

    The main thrust of this work is the investigation of performance of relatively new commercial LaBr3:Ce probe (Inspector 1000™ with LaBr3:Ce crystal) for gamma-ray spectroscopy and dosimetry measurements in comparison to LaCl3:Ce and NaI:Tl scintillators. The crystals were irradiated by a wide range of energies (57Co, 22Na, 18F, 137Cs and 60Co). The study involved recording of detected spectra and measurement of energy resolution, photopeak efficiency, internal radioactivity measurements as well as dose rate. The Monte Carlo package, Geant4 Application for Tomographic Emission (GATE) was used to validate the experiments. Overall results showed very good agreement between the measurements and the simulations. The LaBr3:Ce crystal has excellent energy resolution, energy resolutions of (3.37±0.05)% and (2.98±0.07)% for a 137Cs 662 keV and a 60Co 1332 keV gamma-ray point sources respectively, were recorded. The disadvantage of the lanthanum halide scintillators is their internal radioactivity. Inspector 1000™ with LaBr3:Ce scintillator has shown an accurate and quick dose measurements at Positron Emission Tomography (PET) Units which allows accurate assessment of the radiation dose received by staff members compared to the use of electronic personal dosimeters (EPD).

  20. 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.

  1. Detailed deposition density maps constructed by large-scale soil sampling for gamma-ray emitting radioactive nuclides from the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Saito, Kimiaki; Tanihata, Isao; Fujiwara, Mamoru; Saito, Takashi; Shimoura, Susumu; Otsuka, Takaharu; Onda, Yuichi; Hoshi, Masaharu; Ikeuchi, Yoshihiro; Takahashi, Fumiaki; Kinouchi, Nobuyuki; Saegusa, Jun; Seki, Akiyuki; Takemiya, Hiroshi; Shibata, Tokushi

    2015-01-01

    Soil deposition density maps of gamma-ray emitting radioactive nuclides from the Fukushima Dai-ichi Nuclear Power Plant (NPP) accident were constructed on the basis of results from large-scale soil sampling. In total 10,915 soil samples were collected at 2168 locations. Gamma rays emitted from the samples were measured by Ge detectors and analyzed using a reliable unified method. The determined radioactivity was corrected to that of June 14, 2011 by considering the intrinsic decay constant of each nuclide. Finally the deposition maps were created for (134)Cs, (137)Cs, (131)I, (129m)Te and (110m)Ag. The radioactivity ratio of (134)Cs-(137)Cs was almost constant at 0.91 regardless of the locations of soil sampling. The radioactivity ratios of (131)I and (129m)Te-(137)Cs were relatively high in the regions south of the Fukushima NPP site. Effective doses for 50 y after the accident were evaluated for external and inhalation exposures due to the observed radioactive nuclides. The radiation doses from radioactive cesium were found to be much higher than those from the other radioactive nuclides.

  2. Factors controlling the spatiotemporal variation of (137)Cs in seabed sediment off the Fukushima coast: implications from numerical simulations.

    PubMed

    Misumi, Kazuhiro; Tsumune, Daisuke; Tsubono, Takaki; Tateda, Yutaka; Aoyama, Michio; Kobayashi, Takuya; Hirose, Katsumi

    2014-10-01

    We used numerical simulations to investigate major controls on spatiotemporal variations of (137)Cs activities in seabed sediments off the Fukushima coast during the first year after the Fukushima Daiichi Nuclear Power Plant accident. The numerical model we used includes (137)Cs transfer between bottom water and sediment by adsorption and desorption, and radioactive decay. The model successfully reproduced major features of the observed spatiotemporal variations of (137)Cs activities in sediments. The spatial pattern of (137)Cs in sediments, which mainly reflected the history of (137)Cs activities in bottom water overlying the sediments and the sediment particle size distribution, became established during the first several months after the accident. The simulated temporal persistence of the (137)Cs activity in the sediments was due to adsorption of (137)Cs onto the sediment mineral fraction having a long desorption timescale of (137)Cs. The simulated total (137)Cs inventory in sediments integrated over the offshore area, where most of the monitoring stations were located, was on the order of 10(13) Bq; this value is consistent with a previous estimate based on observed data. Taking into account (137)Cs activities in sediments in both the coastal area and in the vicinity of the power plant, the simulated total inventory of (137)Cs in sediments off the Fukushima coast increased to a value on the order of 10(14) Bq.

  3. Sediment and (137)Cs behaviors in the Ogaki Dam Reservoir during a heavy rainfall event.

    PubMed

    Kurikami, Hiroshi; Kitamura, Akihiro; Yokuda, Satoru Thomas; Onishi, Yasuo

    2014-11-01

    We performed a simulation of sediment and (137)Cs behaviors in the Ogaki Dam Reservoir, one of the main irrigation reservoirs in the Fukushima prefecture, Japan, during a heavy rainfall event occurred in 2013. The one-dimensional river and reservoir simulation scheme TODAM, Time-dependent One-dimensional Degradation and Migration, was applied for calculating the time dependent migration of sediment and (137)Cs in dissolved and sediment-sorbed forms in the reservoir. Continuous observational data achieved in the upper rivers were used as the input boundary conditions for the simulation. The simulation results were compared with the continuous data achieved in the lower river and we confirmed the predicted values of sediment and (137)Cs in sediment-sorbed form at the exit of reservoir satisfactorily reproduced the observational data. We also performed sediment and (137)Cs behavioral simulation by changing the water level of the reservoir, because such a dam operation could control the quantities of sediment and (137)Cs discharge from and/or deposition in the reservoir. The simulation clarified that the reservoir played an important role to delay and buffer the movement of radioactive cesium in heavy rainfall events and the buffer effect of the reservoir depended on particle sizes of suspended sediment and the water level. It was also understood that silt deposition was the main source of the bed contamination (except for the initial fallout impact), while clay was the main carrier of (137)Cs to the lower river at a later stage of rainfall events.

  4. Temporal variations of 90Sr and 137Cs concentrations and the 137Cs/90Sr activity ratio in marine brown algae, Undaria pinnatifida and Laminaria longissima, collected in coastal areas of Japan.

    PubMed

    Morita, Takami; Fujimoto, Ken; Kasai, Hiromi; Yamada, Haruya; Nishiuchi, Kou

    2010-05-01

    The anthropogenic radionuclides, 90Sr and 137Cs, were measured in two marine algal species, wakame seaweed (Undaria pinnatifida) and edible kelp (Laminaria longissima), collected in four coastal areas of Japan during 1998-2008. Although 90Sr and 137Cs could be detected at all sampling sites, the concentrations of 90Sr and 137Cs were at low levels and those in some samples were below the detection limit. These low concentrations and the small variation of both concentrations and the 137Cs/90Sr activity ratio indicate that the source of 90Sr and 137Cs detected in this study originated from the global fallout deposition following atmospheric nuclear-bomb tests in the past. There were no significant differences in both concentrations of 90Sr and 137Cs in wakame seaweed among three sampling sites. Although wakame seaweed is extensively distributed in southern and central Japan, it does not occur in northern areas and so edible kelp was monitored. The concentrations of 90Sr and 137Cs in edible kelp were significantly different from those in wakame seaweed in some sampling sites. These differences could be due to the difference in the concentrations of 90Sr and 137Cs in the surrounding seawater or the difference in species. The combined data with data from the previous report and the preexisting database showed that wakame seaweed incorporated 137Cs through a different pathway from that of 90Sr. The combined data also suggested that wakame seaweed responded differently to the source of 137Cs.

  5. Gamma ray optics

    SciTech Connect

    Jentschel, M.; Guenther, M. M.; Habs, D.; Thirolf, P. G.

    2012-07-09

    Via refractive or diffractive scattering one can shape {gamma} ray beams in terms of beam divergence, spot size and monochromaticity. These concepts might be particular important in combination with future highly brilliant gamma ray sources and might push the sensibility of planned experiments by several orders of magnitude. We will demonstrate the experimental feasibility of gamma ray monochromatization on a ppm level and the creation of a gamma ray beam with nanoradian divergence. The results are obtained using the inpile target position of the High Flux Reactor of the ILL Grenoble and the crystal spectrometer GAMS. Since the refractive index is believed to vanish to zero with 1/E{sup 2}, the concept of refractive optics has never been considered for gamma rays. The combination of refractive optics with monochromator crystals is proposed to be a promising design. Using the crystal spectrometer GAMS, we have measured for the first time the refractive index at energies in the energy range of 180 - 2000 keV. The results indicate a deviation from simple 1/E{sup 2} extrapolation of X-ray results towards higher energies. A first interpretation of these new results will be presented. We will discuss the consequences of these results on the construction of refractive optics such as lenses or refracting prisms for gamma rays and their combination with single crystal monochromators.

  6. Gamma-ray astronomy

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Lingenfelter, R. E.

    1982-01-01

    Cosmic gamma rays, the physical processes responsible for their production and the astrophysical sites from which they were seen are reported. The bulk of the observed gamma ray emission is in the photon energy range from about 0.1 MeV to 1 GeV, where observations are carried out above the atmosphere. There are also, however, gamma ray observations at higher energies obtained by detecting the Cerenkov light produced by the high energy photons in the atmosphere. Gamma ray emission was observed from sources as close as the Sun and the Moon and as distant as the quasar 3C273, as well as from various other galactic and extragalactic sites. The radiation processes also range from the well understood, e.g. energetic particle interactions with matter, to the still incompletely researched, such as radiation transfer in optically thick electron positron plasmas in intense neutron star magnetic fields.

  7. Gamma ray astronomy

    NASA Technical Reports Server (NTRS)

    Paciesas, William S.

    1991-01-01

    Miscellaneous tasks related to the development of the Bursts and Transient Source Experiment on the Gamma Ray Observatory and to analysis of archival data from balloon flight experiments were performed. The results are summarized and relevant references are included.

  8. Assessment of 137Cs and 90Sr Fluxes in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Matishov, Gennady; Usiagina, Irina; Kasatkina, Nadezhda; Ilin, Gennadii

    2014-05-01

    On the basis of published and own data the annual balance of radionuclide income/outcome was assessed for 137Cs and 90Sr in the Barents Sea for the period from 1950s to the presnt. The scheme of the isotope balance calculation in the Barents Sea included the following processes:atmospheric fallout; river run-off; liquid radioactive wastes releases, income from the Norwegian and the White Seas; outflow to the adjacent areas through the Novaya Zemlya straits and the transects Svalbard-Franz Josef Land and Franz Josef Land-Novaya Zemlya; radioactive decay. According to the multiyear dynamics, the inflow of 137Cs and 90Sr to the Barents Sea was significantly preconditioned by currents from the Norwegian Sea. Three peaks of 137Cs and 90Sr isotope concentrations were registered for the surface waters on the western border of the Barents Sea. The first one was observed in the mid-1960s and was conditioned by testing of nuclear weapons. The increase of isotope concentrations in 1975 and 1980 was preconditioned by the discharge of atomic waste by the Sellafield nuclear reprocessing plant. Nowadays, after the sewage disposal plant was built, the annual discharge of nuclear waste from Sellafield plant is low. The Norwegian Sea was a major source of 137Cs and 90Sr isotope income into the Barents Sea for the period of 1960-2014. Currently, the transborder transfer of 90Sr and 137Cs from the Norwegian Sea into the Barents Sea constitutes about 99% of income for each element. Atmospheric precipitation had a major impact in the 1950-1960s after the testing of the nuclear weapons, and in 1986 after the accident at Chernobyl Nuclear Power Station. In 1963, the atmospheric precipitation of 137Cs reached 1050 TBq; and that of 90Sr, 630 TBq. In 1986, a significant amount of 137Cs inflow (up to 1010 TBq/year) was registered. The 137Cs isotope income exceeded the 90Sr income in the 1960s-1980s, and equal amounts penetrated into the Barents Sea from the Norwegian Sea in the 1990s. Before

  9. Leaves of higher plants as biomonitors of radionuclides (137Cs, 40K, 210Pb and 7Be) in urban air.

    PubMed

    Todorović, Dragana; Popović, Dragana; Ajtić, Jelena; Nikolić, Jelena

    2013-01-01

    Leaves of linden (Tilia tomentosa L. and Tilia cordata Mill.) and horse chestnut (Aesculus hippocastanum L.) were analysed as biomonitors of radionuclides in urban air. Samples of soils, leaves and aerosols were collected in Belgrade, Serbia. Activities of (137)Cs, (40)K, (210)Pb and (7)Be in the samples were measured on an HPGe detector by standard gamma spectrometry. "Soil-to-leaves" transfer factors were calculated. Student's t test and linear Pearson correlation coefficients were used for statistical analysis. Differences in local conditions at the sampling sites were not significant, and the mechanisms of the radionuclides' accumulation in both plant species are similar. Ceasium-137 was detected in some of the leaf samples only. Transfer factors for (137)Cs and (40)K were (0.03-0.08) and 1.3, respectively. The concentrations of (210)Pb and (7)Be in leaves were higher in autumn than in spring, and there were some similarities in their seasonal patterns in leaves and in air. Weak to medium correlation was obtained for the (210)Pb and (7)Be activities in leaves and aerosols. Large positive correlation was obtained for the (210)Pb activities in linden leaves and the mean activity in aerosols for the preceding months. Different primary modes of radionuclides accumulation in leaves were observed. Since large positive correlation was obtained for the (210)Pb activity in linden leaves and the mean in aerosols for the preceding months, mature linden leaves could be used as biomonitors of recent (210)Pb activity in air.

  10. Effects of chronic 137Cs ingestion on barrier properties of jejunal epithelium in rats.

    PubMed

    Dublineau, I; Grison, S; Grandcolas, L; Baudelin, C; Paquet, F; Voisin, P; Aigueperse, J; Gourmelon, P

    2007-05-15

    Environmental contamination by 137Cs is of particular public health interest because of the various sources of fallout originating from nuclear weapons, radiological source disruptions, and the Chernobyl disaster. This dispersion may lead to a chronic ecosystem contamination and subsequent ingestion of contaminated foodstuffs. The aim of this study was to thus determine the impact of a chronic ingestion of low-dose 137Cs on small intestine functions in rats. The animals received 150 Bq per day in drinking water over 3 mo. At these environmental doses, 137Cs contamination did not modify the crypt and villus architecture. In addition, epithelial integrity was maintained following the chronic ingestion of 137Cs, as demonstrated by histological analyses (no breakdown of the surface mucosa) and electrical transepithelial parameters (no change in potential difference and tissue conductance). Furthermore, cesium contamination seemed to induce contradictory effects on the apoptosis pathway, with an increase in the gene expression of Fas/FasL and a decrease in the apoptotic cell number present in intestinal mucosa. No marked inflammation was observed following chronic ingestion of 137Cs, as indicated by neutrophil infiltration and gene expression of cytokines and chemokines. Results indicated no imbalance in the Th1/Th2 response induced by cesium at low doses. Finally, evaluation of the functionality of the jejunal epithelium in rats contaminated chronically with 137Cs did not demonstrate changes in the maximal response to carbachol, nor in the cholinergic sensitivity of rat jejunal epithelium. In conclusion, this study shows that chronic ingestion of 137Cs over 3 mo at postaccidental doses exerts few biological effects on the epithelium of rat jejunum with regard to morphology, inflammation status, apoptosis/proliferation processes, and secretory functions.

  11. Compact high-resolution gamma-ray computed tomography system for multiphase flow studies

    SciTech Connect

    Bieberle, A.; Nehring, H.; Berger, R.; Arlit, M.; Haerting, H.-U.; Schubert, M.; Hampel, U.

    2013-03-15

    In this paper, a compact high-resolution gamma-ray Computed Tomography (CompaCT) measurement system for multiphase flow studies and tomographic imaging of technical objects is presented. Its compact and robust design makes it particularly suitable for studies on industrial facilities and outdoor applications. Special care has been given to thermal ruggedness, shock resistance, and radiation protection. Main components of the system are a collimated {sup 137}Cs isotopic source, a thermally stabilised modular high-resolution gamma-ray detector arc with 112 scintillation detector elements, and a transportable rotary unit. The CompaCT allows full CT scans of objects with a diameter of up to 130 mm and can be operated with any tilting angle from 0 Degree-Sign (horizontal) to 90 Degree-Sign (vertical).

  12. [137Cs profile distribution character and its implication for soil erosion on Karst slopes of northwest Guangxi].

    PubMed

    Feng, Teng; Chen, Hong-song; Zhang, Wei; Nie, Yun-peng; Wang, Ke-lin

    2011-03-01

    This paper studied the profile distribution characters of 137Cs and soil organic carbon (SOC) on the Karst slopes and in the fissures in typical peak-cluster depression in Northwest Guangxi, aimed to approach the applicability of 137Cs method on Karst slopes and the implication of 37Cs for the characteristics of slope soil erosion. In all test profiles, there was a significant correlation between 137Cs and SOC, indicating that both of them might have the same loss pathway. On the slopes under secondary forests, 137Cs mainly existed within the depth 0-24 cm. On the upper middle and middle slope sites, 137Cs had an exponential decrease with depth, indicating no or slight surface erosion; while on the foot slope site, the distribution pattern of 137Cs indicated severer erosion. On the slopes with cultivated lands, 137Cs distributed uniformly within the plough layer. In the upper middle and middle slopes profiles, 137Cs mainly existed in the depth around 15 cm and far less than the background value, indicating severe soil erosion; while in foot slope profiles, 137Cs was aggraded to the depth 45 cm. A discontinuous distribution of 137Cs in the profiles was detected on the foot slopes under secondary forests, on the upper middle and foot slopes of cultivated lands, and in the fissures, indicating that the soil particles on Karst slopes had a trend of losing with rainwater to the underground, but the loss quantity was negligible, compared with surface erosion.

  13. The gamma-ray observatory

    NASA Technical Reports Server (NTRS)

    1991-01-01

    An overview is given of the Gamma Ray Observatory (GRO) mission. Detection of gamma rays and gamma ray sources, operations using the Space Shuttle, and instruments aboard the GRO, including the Burst and Transient Source Experiment (BATSE), the Oriented Scintillation Spectrometer Experiment (OSSE), the Imaging Compton Telescope (COMPTEL), and the Energetic Gamma Ray Experiment Telescope (EGRET) are among the topics surveyed.

  14. An anticoincidence-shielded gamma-ray spectrometer for analysis of low level environmental radionuclides.

    PubMed

    Byun, Jong In; Choi, Yun Ho; Kwak, Seung Im; Hwang, Han-Yull; Chung, Kun-Ho; Choi, Geun Sik; Park, Doo-Won; Lee, Chang Woo

    2003-05-01

    We developed an ultralow-level background gamma-ray spectrometer, using active and passive shield devices at the same time. Cosmic-ray-induced background is suppressed by means of active shield devices consisting of plastic scintillating plates of 50mm thick and anti-coincidence electronic system. The observed background rate was 0.34 s(-1) (=0.12s(-1) per 100 cm(3) Ge volume) for energy regions between 50 and 3000 ke V. The detection efficiency curve for 10(3)ml Marinelli beaker samples is obtained over all the energy regions. The advantages of the method are demonstrated by measuring the activity of 137Cs in powdered milk sample prepared without taking any chemical procedure. The MDA for 137Cs is estimated to be (17+/-1.7)mBq at a confidence level of 95% and it is about a factor of 10 lower than the MDA obtained from the previous cryostat assembly with 10-cm thick lead shielding.

  15. Bioconcentration of fallout sup 137 Cs by fungi and red-backed voles (Clethrionomys gapperi)

    SciTech Connect

    Mihok, S.; Schwartz, B.; Wiewel, A.M. )

    1989-12-01

    Cesium-137 and 40K concentrations were measured in vegetation and in red-backed voles (Clethrionomys gapperi) in southeastern Manitoba, Canada, following the Chernobyl accident in 1986. Voles from wet coniferous habitats contained concentrations of {sup 137}Cs twenty- to fiftyfold higher than voles from deciduous habitats. Maximum {sup 137}Cs values were observed in autumn. Voles captured in a spruce bog at this time contained an average body burden of about 11 Bq. Concentrations in vegetation samples were similar to those found by other researchers. Overall, there was only minimal evidence of contamination attributable to Chernobyl in either vegetation or voles. The primary source of {sup 137}Cs in voles appeared to be dietary, particularly mushrooms that contained up to 74 Bq g-1 ash. Based on physiological constraints, mushrooms were the only plausible source of {sup 137}Cs in autumn diets. Elevated values at other times in coniferous areas may have been related to the consumption of epiphytic lichens. These findings suggest that fungi, or the animals that consume them, can serve as sensitive indicators of {sup 137}Cs contamination in the environment.

  16. Monitoring 137Cs and 134Cs at marine coasts in Indonesia between 2011 and 2013.

    PubMed

    Suseno, Heny; Prihatiningsih, Wahyu Retno

    2014-11-15

    Environmental samples (seawater, sediments and biota) were collected along the eastern and western Indonesian coasts between 2011 and 2013 to anticipate the possible impacts of the Fukushima radioactive releases in Indonesia. On the eastern coasts (south and north Sulawesi), the (137)Cs concentrations in the seawater and sediments were 0.12-0.32 Bq m(-3) and 0.10-1.03 Bq kg(-1), respectively. On the western coasts (West Sumatra, Bangka Island, North Java, South Java and Madura island), the (137)Cs concentrations in the seawater and sediments were 0.12-0.66 Bq m(-3) and 0.19-1.64 Bq kg(-1), respectively. In general, the (137)Cs concentrations in the fish from several Indonesian coasts were 137)Cs concentrations in mollusk, crab and prawn were 10.65-38.78, 4.02 and 6.16 mBq kg(-1), respectively. (134)Cs was not detected in the seawater, sediments or biota. Thus, it was concluded that (137)Cs on the eastern and western Indonesian coasts originated from global fallout.

  17. Accuracy of post-bomb 137Cs and 14C in dating fluvial deposits

    USGS Publications Warehouse

    Ely, L.L.; Webb, R.H.; Enzel, Y.

    1992-01-01

    The accuracy and precision of 137Cs and 14C for dating post-1950 alluvial deposits were evaluated for deposits from known floods on two rivers in Arizona. The presence of 137Cs reliably indicates that deposition occurred after intensive above-ground nuclear testing was initiated around 1950. There was a positive correlation between the measured level of 137Cs activity and the clay content of the sediments, although 137Cs was detected even in sandy flood sediments with low clay content. 137Cs is a valuable dating tool in arid environments where organic materials for 14C or tree-ring dating are scarce and observational records are limited. The 14C activity measured in different types of fine organic detritus yielded dates within 1 to 8 yr of a 1980 flood deposit, and the accuracy was species-dependent. However, undifferentiated mixtures of fine organic materials from several post-bomb deposits of various ages repeatedly yielded dates between 1958 and 1962, and detrital charcoal yielded a date range of 1676-1939. In semiarid environments, the residence time of most types of organic debris precludes accurate annual resolution of post-bomb 14C dates. ?? 1992.

  18. Prussian Blue decorporation of {sup 137}Cs in beagles of different ages

    SciTech Connect

    Melo, D.R.; Lundgren, D.L.; Muggenburg, B.A.; Guilmette, R.A.

    1996-08-01

    A 6-wk study was conducted using immature (4.7 mo), young adult (2.4 y), and aged (13.5 y) male beagles to determine the modifying effect of age on the effectiveness of Prussian Blue decorporation therapy for the removal of injected {sup 137}Cs. Whole-body clearance rates for injected {sup 137}Cs decreased with increasing age in the dogs. Treatment with Prussian Blue changed the ratio of fecal to urinary {sup 137}Cs excretion from 0.8 in untreated dogs to 2.2 in treated animals. The {sup 137}Cs concentrations in tissues of untreated and Prussian Blue-treated dogs at the end of the 6-wk study were similar, with the greatest concentrations in the skeletal muscle tissue, spleen, and kidneys. There was a lower concentration of {sup 137}Cs in the livers of the treated dogs. The reductions in the average total whole-body doses resulting from Prussian Blue treatment during the course of this study were 51% in the immature, 31% in the young adult, and 38% in the aged dogs. Because of the differences in the intake of Prussian Blue by the dogs in the different groups relative to their body weight, it is unclear as to the relative effectiveness of Prussian Blue in dogs of different ages. 33 refs., 1 fig., 5 tabs.

  19. [The optimization of the soil acidity of agrocenosis contaminated 137Cs and 90Sr: threshold parameters].

    PubMed

    Putiatin, Iu V; Seraia, T M

    2005-01-01

    During the field researches were determined the differences between agrochemical optimum of the acidity of the Sod-podzol loamy sand soil, which provides high productivity of the crops and the pH-value, which provides the minimal accumulation of 137Cs and of 90Sr by the biomass (the ecological optimum). On the average for the majority of the agricultural plants the minimal accumulations of 137Cs and of 90Sr are noticed under pHKCl 6.7, which is higher than agrochemical optimum on 0.7. The efficiency of liming under the discrimination of 137Cs and of 90Sr is much higher in soils with low values of pH. On the average, in crop rotation due to decreasing of the acidity in the soil from 4.9 to 5.9 pHKCl, the crop yield has grown on 9%, 137Cs contents has decreased on 16.7%, 90Sr--on 23.7%. The further decreasing of the soil acidity (from 5.9 to 6.8 pHKCl) was poorly effective: the productivity didn't change essentially. The transfer of 137Cs decreased on 8.9% and of 90Sr on 8.4%.

  20. Gamma ray camera

    DOEpatents

    Perez-Mendez, V.

    1997-01-21

    A gamma ray camera is disclosed for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array. 6 figs.

  1. Gamma Ray Astronomy

    NASA Technical Reports Server (NTRS)

    Wu, S. T.

    2000-01-01

    The project has progressed successfully during this period of performance. The highlights of the Gamma Ray Astronomy teams efforts are: (1) Support daily BATSE data operations, including receipt, archival and dissemination of data, quick-look science analysis, rapid gamma-ray burst and transient monitoring and response efforts, instrument state-of-health monitoring, and instrument commanding and configuration; (2) On-going scientific analysis, including production and maintenance of gamma-ray burst, pulsed source and occultation source catalogs, gamma-ray burst spectroscopy, studies of the properties of pulsars and black holes, and long-term monitoring of hard x-ray sources; (3) Maintenance and continuous improvement of BATSE instrument response and calibration data bases; (4) Investigation of the use of solid state detectors for eventual application and instrument to perform all sky monitoring of X-Ray and Gamma sources with high sensitivity; and (5) Support of BATSE outreach activities, including seminars, colloquia and World Wide Web pages. The highlights of this efforts can be summarized in the publications and presentation list.

  2. Gamma ray camera

    DOEpatents

    Perez-Mendez, Victor

    1997-01-01

    A gamma ray camera for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array.

  3. Geoinformational modelling of the land use of Polesye and Opolje landscapes in Bryansk region (Russia) under conditions of 137Cs radionuclides contamination

    NASA Astrophysics Data System (ADS)

    Nenko, Christina; Linnik, Vitaliy; Volkova, Nadezhda

    2015-04-01

    the existing agricultural lands. For this purpose, geographic information system (GIS) of the territory was created. It contains following layers: aero-gamma spectrometry data with interval of 100 m; soil types (scale 1: 50,000); relief (SRTM data); schematic map of agricultural lands and forests. The analysis of the secondary redistribution of radionuclides was conducted for the radio-ecological zoning of the territory, as well as the stock of 137Cs was calculated according to types of land use. It made it possible to evaluate the contamination of milk (using transfer coefficients "soil-plant-milk") for different natural landscapes. Evaluation of factors of radionuclides' migration in landscape also allows to predict possible trends in distribution of contamination and to develop recommendations regarding the future use of the territory.

  4. Estimation of Radiation Doses in the Marshall Islands Based on Whole Body Counting of Cesium-137 (137Cs) and Plutonium Urinalysis

    SciTech Connect

    Daniels, J; Hickman, D; Kehl, S; Hamilton, T

    2007-06-11

    measurement. The amount of {sup 137}Cs detected is often reported in activity units of kilo-Becquerel (kBq), where 1 kBq equals 1000 Bq and 1 Bq = 1 nuclear transformation per second (t s{sup -1}). [However, in the United States the Curie (Ci) continues to be used as the unit of radioactivity; where 1 Ci = 3.7 x 10{sup 10} Bq.] The detection of {sup 239}Pu and {sup 240}Pu in bioassay (urine) samples indicates the presence of internally deposited (systemic) plutonium in the body. Urine samples that are collected in the Marshall Islands from volunteers participating in the RSMP are transported to LLNL, where measurements for {sup 239+240}Pu are performed using a state-of-the-art technology based on Accelerator Mass Spectrometry (AMS) (Hamilton et al., 2004, 2007; Brown et al., 2004). The urinary excretion of plutonium by RSMP volunteers is usually described in activity units, expressed as micro-Becquerel ({micro}Bq) of {sup 239+240}Pu (i.e., representing the sum of the {sup 239}Pu and {sup 240}Pu activity) excreted (lost) per day (d{sup -1}), where 1 {micro}Bq d{sup -1} = 10{sup -6} Bq d{sup -1} and 1 Bq = 1 t s{sup -1}. The systemic burden of plutonium is then estimated from biokinetic relationships as described by the International Commission on Radiological Protection (e.g., see ICRP, 1990). In general, nuclear transformations are accompanied by the emission of energy and/or particles in the form of gamma rays ({gamma}), beta particles ({beta}), and/or alpha particles ({alpha}). Tissues in the human body may adsorb these emissions, where there is a potential for any deposited energy to cause biological damage. The general term used to quantify the extent of any radiation exposure is referred to as the dose. The equivalent dose is defined by the average absorbed dose in an organ or tissue weighted by the average quality factor for the type and energy of the emission causing the dose. The effective dose equivalent (EDE; as applied to the whole body), is the sum of the average

  5. Levels of 137Cs in muddy sediments on the seabed in the Bay of Cadiz (Spain). Part II. Model of vertical migration of (137)Cs.

    PubMed

    Ligero, R A; Barrera, M; Casas-Ruiz, M

    2005-01-01

    This second part of the study reports the development of a model to describe the vertical migration of the artificial radioisotope (137)Cs in the sediment column on the seabed of the Bay of Cadiz. The application of the model provides an overall picture of the process of sedimentation in the Inner Bay of Cadiz. The spatial distribution of the rate of sedimentation enables us to study the sources of sediments and the means by which the sediments have been transported. A method has been derived from the rate of sedimentation to perform the dating of the layers of sediment. The model describes the behaviour of (137)Cs in the area under study, taking into account the time of residence in the zones that are the source of accumulation, the origin of the sedimentary material, together with the diffusion of the radionuclide in the sediment of the seabed.

  6. Monte Carlo simulation of in situ LaBr gamma-ray spectrometer for marine environmental monitoring.

    PubMed

    Su, Genghua; Zeng, Zhi; Cheng, Jianping

    2011-07-01

    Monte Carlo simulation of energy-response functions of gamma rays from natural/artificial radionuclides in seawater and simulation of energy spectrum due to self-activity in LaBr crystal were carried out using MCNPX codes and MATLAB programs for the in situ LaBr gamma-ray spectrometer immersed in homogeneous seawater. The effective detection distance, the detection efficiency and the minimum detectable activity concentration (MDAC) for artificial radionuclides (137)Cs were worked out as an instance. Similar researches for NaI detector was also implemented for comparison. The results indicate that the self-activity in LaBr deteriorates the MDAC to merely several times of that of NaI detector. The LaBr detector is possible to be used as in situ gamma-ray spectrometer for monitoring of artificial radionuclides in seawater.

  7. Multifractal analysis of the 137Cs fallout pattern in Austria resulting from the Chernobyl accident.

    PubMed

    Pausch, G; Bossew, P; Hofmann, W; Steger, F

    1998-06-01

    The cumulative deposition of the 137Cs fallout in Austria resulting from the passage of the Chernobyl cloud has been investigated by applying correlation dimension and hyperbolic frequency distribution methods. For the analysis, a total of 1,881 deposition values were used, which were collected by the Federal Environmental Agency of Austria and the Federal Ministry of Health, representing all available measurements of 137Cs in soil made in Austria after the Chernobyl accident. From these data a hyperbolic exponent for the frequency distribution of 4.0 and a set of fractal correlation dimensions, which decrease from 1.426 +/- 0.022 (for the whole network) to 0.706 +/- 0.047 (for 137Cs values > or = 100 kBq m(-2)), were derived, thus confirming that the fallout pattern can be described as a multifractal.

  8. Uptake of Carrier-free 137Cs by Ramalina reticulata 1

    PubMed Central

    Handley, Raymond; Overstreet, Roy

    1968-01-01

    The uptake of carrier-free 137Cs by Ramalina reticulata Kremp. does not appear to be directly linked to metabolism. The results indicate the presence of a barrier to entry of 137Cs. The barrier is stabilized by Ca ions. Removal of Ca by pretreatment of the tissue in monovalent salt solutions increases the uptake of 137Cs. Uptake under anaerobiosis is also greater than normal, but in this case, Ca displaced from the barrier membrane is not lost from the tissue and normal permeability is rapidly re-established when aerobic conditions are restored. Under anaerobiosis Ca2+ increases damage to the respiratory mechanism presumably by increasing retention of toxic products. PMID:16656927

  9. Clinical and hematological aspects of sup 137 Cs: The Goiania radiation accident

    SciTech Connect

    Brandao-Mello, C.E.; Oliveira, A.R.; Valverde, N.J.; Farina, R.; Cordeiro, J.M. )

    1991-01-01

    Fifty persons involved in the {sup 137}Cs accident in Goiania showed symptoms of whole-body and local acute irradiation and also external or internal contamination mainly due to ingestion or absorption of {sup 137}Cs. Fourteen of the 50 developed severe bone marrow depression characterized by neutropenia and thrombocytopenia. Eight of these 14 received GM-CSF intravenously. None were submitted to bone marrow transplantation. Four of the 14 died due to hemorrhage and infection. For those with significant internal contamination evaluated by in-vitro and in-vivo assays, Prussian Blue was administered with doses ranging from 1.5 to 10 g d-1. Besides Prussian Blue, other measures were taken to increase decorporation of {sup 137}Cs, including administration of diuretics, water overload, and ergometric exercises. From 50 to 100 persons are being followed in a medical protocol.

  10. Prediction of spatial variation in global fallout of 137Cs using precipitation.

    PubMed

    Pálsson, S E; Howard, B J; Wright, S M

    2006-08-31

    Deposition from atmospheric nuclear weapons tests (termed global fallout) has been shown to be proportional to the rate of precipitation. Here we describe methods for using precipitation and radionuclide deposition information for a reference site to estimate global fallout at other locations. These methods have been used to estimate global fallout in Iceland, identified during the Arctic Monitoring and Assessment Programme (AMAP) by Wright et al. [Wright, S.M., Howard, B.J., Strand, P., Nylén, T., Sickel, M.A.K., 1999. Prediction of 137Cs deposition from atmospheric nuclear weapons tests within the Arctic. Environ Pollut 104, 131-143.] as one of the Arctic areas which received the highest global fallout, but where measurements of contamination were sparse, and difficult to obtain due to the remote and inaccessible terrain of much of the country. Measurements of global fallout 137Cs deposition have been made in Iceland at sites close to meteorological stations to ensure that precipitation data were of high quality. The AMAP modeling approach, based on measured precipitation and radionuclide deposition data, was applied using a reference monitoring station located close to Reykjavik. The availability of good precipitation data and locally based estimates of time dependent ratios of 137Cs deposition to precipitation during the fallout period gave a better correlation between predicted and measured 137Cs global fallout (r2=0.96) than that achieved using the much more heterogeneous set of data collected by AMAP over the whole of the Arctic. Having obtained satisfactory results with the model for a number of calibration sites alongside meteorological stations we then produced a map of estimated 137Cs deposition based on a model of estimated precipitation. This deposition map was then successfully validated (r2=0.85) for sites where 137Cs deposition was measured; the associated uncertainty in predictions was also estimated.

  11. 137Cs dynamics in the forest of Fukushima after the nuclear power plant accident in March 2011

    NASA Astrophysics Data System (ADS)

    Endo, I.; Ohte, N.; Iseda, K.; Kobayashi, N.; Hirose, A.; Tanoi, K.

    2013-12-01

    The accident of Fukushima Daiichi nuclear power plant after the earthquake and Tsunami in March 11th 2011, caused large amount of radioactive Cesium (137Cs) emission into the environment. In the region of Fukushima Prefecture, forest dominates more than 70 % of the land area. River water from the forest area is used for food production and also for drinking water. Thus, it is important to understand the dynamics of 137Cs deposited in the forest to predict how the radioactive Cs diffuse and discharge from the forest catchments. We measured 137Cs concentration of the tree body, litter fall, throughfall, and stemflow, in order to clarify how 137Cs deposited on the above ground biomass of the forest are transported to the forest floor. We set forest site at the upstream part of Kami-Oguni River catchment, northern part of Fukushima Prefecture. Three plots (2 deciduous stands and 1 Japanese cedar (Cryptomeria japonica) plantation stand) were set in the forest site. Quercus serrata and C. japonica, which are representative tree species, were chosen at each plot and concentration of 137Cs on the bark, sapwood and heartwood were measured every 2 m from the ground to tree top. From each plot, 137Cs concentration of leaf litter was measured among species. Water samples of throughfall and stemflow were filtered and 137Cs concentration in suspended matter was measured. 137Cs was deposited on the bark of Q. serrata at high concentration (9-18 kBq/kg) but there were no clear relationship between tree height and concentration. 137Cs concentration of the sapwood (41 Bq/kg) was relatively higher than that of the heartwood (5 Bq/kg). It was suggested that 137Cs may be absorbed from bark and/or root. The concentration of 137Cs deposited in leaf litter varied from non-detected level to above 30 kBq/kg. The concentration was higher at evergreen tree than deciduous tree. It is considered that the litter of evergreen tree was derived from leaves on the tree canopy at the time of the

  12. Evaluation of radiological data of some saturated fatty acids using gamma ray spectrometry

    NASA Astrophysics Data System (ADS)

    Kore, Prashant S.; Pawar, Pravina P.; Palani Selvam, T.

    2016-02-01

    Radiological parameters such as mass attenuation coefficients (μm), total attenuation cross section (σtot), molar extinction coefficient (ε), mass energy absorption coefficient (μen/ρ) and effective electronic cross section (σt, el) of saturated fatty acids, namely butyric acid (C4H8O2), caproic acid (C6H12O2), enanthic acid (C7H14O2), caprylic acid (C8H16O2), pelargonic acid (C9H18O2) and valeric acid (C5H10O2) were measured using NaI(Tl)-based gamma spectrometry. Radioactive sources used in the study are 57Co, 133Ba, 137Cs, 54Mn, 60Co and 22Na. Gamma ray transmission method in a narrow beam good geometry set up was used in the study. The measured data were compared against Win-XCOM-based data. The agreement is within 1%.

  13. Scission gamma rays

    SciTech Connect

    Danilyan, G. V.; Klenke, J.; Krakhotin, V. A.; Kuznetsov, V. L.; Novitsky, V. V.; Pavlov, V. S.; Shatalov, P. B.

    2009-11-15

    Gamma rays probably emitted by the fissioning nucleus {sup 236}U* at the instant of the break of the neck or within the time of about 10{sup -21} s after or before this were discovered in the experiment devoted to searches for the effect of rotation of the fissioning nucleus in the process {sup 235}U(n,{gamma}f) and performed in a polarized beam of cold neutrons from the MEPHISTO Guideline at the FRM II Munich reactor. Detailed investigations revealed that the angular distribution of these gamma rays is compatible with the assumption of the dipole character of the radiation and that their energy spectrum differs substantially from the spectrum of prompt fission gamma rays. In the measured interval 250-600 keV, this spectrum can be described by an exponential function at the exponent value of {alpha} = -5 x 10{sup -3} keV{sup -1}. The mechanism of radiation of such gamma rays is not known at the present time. Theoretical models based on the phenomenon of the electric giant dipole resonance in a strongly deformed fissioning nucleus or in a fission fragment predict harder radiation whose spectrum differs substantially from the spectrum measured in the present study.

  14. Determination of (137)Cs half-life with an ionization chamber.

    PubMed

    Juget, Frédéric; Nedjadi, Youcef; Buchillier, Thierry; Bochud, François; Bailat, Claude

    2016-12-01

    The half-life of (137)Cs was measured with an ionization chamber by following the decay of 5 sources over a 30 years period between 1983 and 2013. The ratio between the ionization chamber current for the cesium sources and (226)Ra source was used for the half-life calculation. The value found for the (137)Cs half-life is 10,955.2±10.7 days, where the uncertainty evaluation combines type A and B for one standard deviation.

  15. Accumulation and distributions of {sup 137}Cs in fresh water snail Pila ampullacea

    SciTech Connect

    Suseno, Heny

    2014-10-24

    Pila ampullacea are found in tropical freshwaters of Indonesia. This snail exhibit several characteristics of ideal indicator organisms in order to understand the bioaccumulation of {sup 137}Cs. Biokinetic experiment was performaced in aquaria system and under influenced of concentration K{sup +} in water. The result of experiment shown that Under difference K{sup +} concentration in water, Pila ampullacea have capability to accumulated {sup 137}Cs with CF value range 8.95 to 12.52 ml.g{sup −1}. Both uptake and depuration rate were influenced by concentration of K{sup +} in water.

  16. Gamma Ray Bursts

    NASA Technical Reports Server (NTRS)

    Gehrels, Neil; Meszaros, Peter

    2012-01-01

    Gamma-ray bursts (GRBs) are bright flashes of gamma-rays coming from the cosmos. They occur roughly once per day ,last typically lOs of seconds and are the most luminous events in the universe. More than three decades after their discovery, and after pioneering advances from space and ground experiments, they still remain mysterious. The launch of the Swift and Fermi satellites in 2004 and 2008 brought in a trove of qualitatively new data. In this review we survey the interplay between these recent observations and the theoretical models of the prompt GRB emission and the subsequent afterglows.

  17. Mutant quantity and quality in mammalian cells (A{sub L}) exposed to cesium-137 gamma radiation: Effect of caffeine

    SciTech Connect

    McGuinness, S.M.; Shibuya, M.L.; Ueno, A.M.

    1995-06-01

    We examined the effect of caffeine (1,3,7-trimethylxanthine) on the quantity and quality of mutations in cultured mammalian A{sub L} human-hamster hybrid cells exposed to {sup 137}Cs {gamma} radiation. At a dose (1.5 mg/ml for 16 h) that reduced the plating efficiency (PE) by 20%, caffeine was not itself a significant mutagen, but it increased by approximately twofold the slope of the dose-response curve for induction of S1{sup {minus}} mutants by {sup 137}Cs {gamma} radiation. Molecular analysis of 235 S1{sup {minus}} mutants using a series of DNA probes mapped to the human chromosome 11 in the A{sub L} hybrid cells revealed that 73 to 85% of the mutations in unexposed cells and in cells treated with caffeine alone, {sup 137}Cs {gamma} rays alone or {sup 137}Cs {gamma} rays plus caffeine were large deletions involving millions of base pairs of DNA. Most of these deletions were contiguous with the region of the MIC1 gene at 11p13 that encodes the S1 cell surface antigen. In other mutants that had suffered multiple marker loss, the deletions were intermittent along chromosome 11. These {open_quotes}complex{close_quotes} mutations were rare for {sup 137}Cs {gamma} irradiation (1/63 = 1.5%) but relatively prevalent (23-50%) for other exposure conditions. Thus caffeine appears to alter both the quantity and quality of mutations induced by {sup 137}Cs {gamma} irradiation. 62 refs., 3 figs., 3 tabs.

  18. Determination of 137Cs and 60Co pollution in the area of the Laguna Verde Nuclear Power Plant, Mexico.

    PubMed

    Salas Mar, Bernardo

    2015-11-01

    The project 'Radiological Analysis of Environmental Samples in the Gulf of Mexico and the coast of Quintana Roo', had the aim of identifying and quantifying anthropogenic radionuclides in environmental samples consisting of silt, sand and sea water. This paper presents the results of the radiological analysis of these samples, which was made in the multichannel system for gamma spectrometry with hyperpure germanium detector in the Laboratory of Radiological Analysis of Environmental Samples, located at the Physics Department, Faculty of Sciences, of the Autonomous National University of Mexico (UNAM). The sampled points are along the coast of the contiguous states of Tamaulipas, Veracruz, Tabasco, Campeche, Yucatan and Quintana Roo. This paper presents the qualitative and quantitative concentrations of the main identified anthropogenic radionuclides (60)Co and (137)Cs.

  19. A case study of soil erosion and sedimentation magnitudes in Morocco using 137-Cs & 210-Pbex

    NASA Astrophysics Data System (ADS)

    Mabit, L.,; Benmansour, M.,; Nouira, A.,

    2010-05-01

    Despite the severity of land degradation in Morocco, only limited data are available on the actual magnitude of soil erosion rates. Most of the previous research used conventional measurements. Since the mid 1990's only a few studies reported the use of the 137-Cs approach and, excess lead-210 (210-Pbex) as soil tracer in Morocco. The site under investigation is a one hectare agricultural field dominated by cereals under conventional tillage (plough depth ~ 16 cm) and semiarid climate located in Marchouch 68 km south east from Rabat (Morocco). In this field, 50 soil core samples were collected along 5 parallel transects. The initial 137-Cs and 210-Pb fallout were assessed through 12 core samples collected in an undisturbed pasture located 3 km from the field studied. After γ-spectrometry analysis, the areal activities of 137-Cs and 210-Pbex were converted into soil redistribution rates using the convertion model Mass Balance Model II (MBM II). Soil redistribution rates obtained from both isotopes were analyzed using geostatistic approach and a classical interpolation concept (Inverse Distance Weighting (IDW)). Maps of soil redistribution were established and a sediment budget for the whole field was calculated. For the reference site, the vertical distribution associated with both radionuclides was similar and concentrated in the top 10 cm with a clear exponential decrease with depth. The reference inventories values were estimated at 3305 Bq m-2 (n = 12; CV of 30%) and 1445 Bq m-2 (n = 12; CV of 18%) for 210-Pbex and 137-Cs, respectively. For the cultivated site, experimental variograms of soil redistribution rate calculated from the data provided by the 137-Cs and 210-Pbex results were fitted. Following the optimization of variographic parameters and the cross-validation analysis, the geostatistical study of the data set reported a very weak autocorrelation. So, a simple spatialisation of the data set using IDW2 was used to spatialise the soil redistribution

  20. Detection of Anomalous Gamma-Ray Spectra for On-Site Inspection

    SciTech Connect

    Seifert, Carolyn E.; Myjak, Mitchell J.; Pfund, David M.

    2009-05-29

    This work aims to solve some of the technical and logistical challenges inherent in performing On Site Inspection activities under the authority of the Comprehensive Nuclear-Test-Ban Treaty. Inspectors require equipment that can reliably identify the radionuclide signatures of nuclear test explosions amid a background of environmental contamination. Detection of these radiation anomalies by mobile search teams in the air or on the ground can narrow the search field and target specific areas for more detailed inspection or sampling. The need to protect confidential information of the inspected State Party, especially regarding past nuclear testing activities, suggests that full access to measured gamma-ray spectra should be limited. Spectral blinding techniques---in which only a fraction of the information derived from the spectra is displayed and stored---have the potential to meet the needs of both the OSI team and the State Party. In this paper, we describe one such algorithm that we have developed for identifying anomalous spectra from handheld, mobile, or aerial sensors. The algorithm avoids potential sensitivities by reducing the gamma-ray spectrum into a single number that is displayed and stored. A high value indicates that the spectrum is anomalous. The proposed technique does not rely on identifying specific radionuclides, operates well in the presence of high background variability, and can be configured to ignore specific spectral components. In previous work, the algorithm has proven very effective in classifying gamma-ray spectra as anomalous or not, even with poor statistical information. We performed a limited simulation of an airborne search scenario to demonstrate the potential algorithm for OSI missions. The technique successfully detected an injected source of interest whose count rate was an order of magnitude below background levels. We also configured the algorithm to ignore 137Cs as irrelevant to the mission. The resulting alarm metrics were

  1. Seasonal variation of soil-to-plant transfer of K and fallout sup 134,137 Cs in peatland vegetation

    SciTech Connect

    Bunzl, K.; Kracke, W. )

    1989-10-01

    For three plants from a peat bog (Trichophorum caespitosum, Molinia coerulea, Calluna vulgaris) the concentration of 137Cs, the ratio 137Cs:134Cs, and stable K was determined in intervals of about 14 d from June to November 1987. The results show that for two grasses, Trichophorum caespitosum and Molinia coerulea (which have only perennial roots but sprout every year while the old leaves wither), the concentration of 137Cs decreased considerably during the growing season (1800-240, respectively, 4000-320 Bq kg-1 dry weight). A remarkably similar behavior was observed for the seasonal variability of K and radiocesium in the two grass species, which resulted in a nearly constant ratio of 137Cs:K during the year. In contrast, for the evergreen plant Calluna vulgaris (heather) which was contaminated surficially by the Chernobyl fallout, the concentrations of K and 137Cs were rather constant during 1987 (leaves about 10,000; stems about 5000 Bq kg-1 dry weight), even though radiocesium was taken up by the leaves and transported within the plant. For the two grasses, the plant:soil concentration ratios (CR) were obtained separately for total 137Cs, 137Cs from the global fallout, and Chernobyl-derived 137Cs. The CR of 137Cs from the global fallout decreased for Trichophorum caespitosum from 1.9 in the spring to 0.08 in the autumn, and for Chernobyl-derived 137Cs from 1.4 to 0.2. For Molinia coerulea, a similar behavior was observed. Possible reasons for the seasonal variability of the CR values and the different behavior of 137Cs from the global fallout and from the Chernobyl debris are discussed.

  2. Celestial gamma ray study

    NASA Technical Reports Server (NTRS)

    Michelson, Peter F.

    1995-01-01

    This report documents the research activities performed by Stanford University investigators as part of the data reduction effort and overall support of the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Observatory. This report is arranged chronologically, with each subsection detailing activities during roughly a one year period of time, beginning in June 1991.

  3. Gamma ray astronomy

    NASA Technical Reports Server (NTRS)

    Paciesas, William S.

    1991-01-01

    Miscellaneous tasks related to the development of the Burst and Transient Source Experiment on the Gamma Ray Observatory and to collection, analysis, and interpretation of data from the MSFC Very Low Frequency transient monitoring program were performed. The results are summarized and relevant references are included.

  4. Gamma ray astronomy

    NASA Technical Reports Server (NTRS)

    Paciesas, William S.

    1992-01-01

    Miscellaneous tasks related to mission operations and data analysis for the Burst and Transient Source Experiment on the Gamma Ray Observatory, to collection, analysis, and interpretation of data from the Marshall Space Flight Center Very Low Frequency transient monitoring program, and to compilation and analysis of induced radioactivity data were performed. The results are summarized and relevant references are included.

  5. (137)Cs, (40)K and (210)Po in marine mammals from the southern Baltic Sea.

    PubMed

    Ciesielski, Tomasz; Góral, Marta; Szefer, Piotr; Jenssen, Bjørn Munro; Bojanowski, Ryszard

    2015-12-15

    This study provides information on baseline concentrations of the radionuclides Cesium-137, Potassium-40 and Polonium-210 in sea mammals from the Baltic Sea. The radionuclides were analyzed in the liver, kidney and muscle of harbor porpoises, striped dolphins, and gray and ringed seals from the Polish coast by γ- and α-spectrometry. Median (137)Cs activities were 14.8, 13.2 and 23.2 Bq kg(-1) w.w. in the liver, kidney and muscles, respectively. Activities of (40)K and (210)Po in the respective tissues were found to be 79.1, 79.8 and 111 Bq kg(-1) for (40)K and 58.1, 59.2 and 32.9 Bq kg(-1) for (210)Po. The measured (137)Cs concentrations were extraordinarily high in comparison to those reported in sea mammals from other locations. However, dose assessments did not imply health effects from (137)Cs exposure in Baltic Sea mammals. Correlations between (137)Cs tissue activities and reported sea water concentrations highlight the potential use of marine mammals for biomonitoring purposes.

  6. Natural radionuclides and (137)Cs distributions and their relationship with sedimentological processes in Patras Harbour, Greece.

    PubMed

    Papaefthymiou, H; Papatheodorou, G; Moustakli, A; Christodoulou, D; Geraga, M

    2007-01-01

    Surficial and subsurficial sediment samples derived from gravity cores, selected from the harbour of Patras, Greece, were analyzed for grain size, water content, bulk density, specific gravity, organic carbon content and specific activities of natural radionuclides and (137)Cs. The specific activities of (232)Th, (226)Ra, (40)K and (137)Cs were measured radiometrically. The radionuclides (238)U and (232)Th were also analyzed using the INAA. The differences found between the specific activities of the natural radionuclides measured by the two methods are of no statistical significance. The sediment cores selection was based on a detailed bathymetric and marine seismic survey. Through the study of the detailed bathymetric map and the seismic profiles it was shown that ship traffic is highly influential to the harbour bathymetry. The granulometric and geotechnical properties of the sediments and therefore the specific activities of the natural radionuclides and (137)Cs seem to be controlled by the ship traffic. Relationship between radionuclide activity concentrations and granulometric/geotechnical parameters was defined after the treatment of all the analyses using R-mode factor analysis. The natural radionuclide activities are related to the fine fraction and bulk density of the sediments, while (137)Cs is mainly influenced by the organic carbon content. In addition, (238)U and (226)Ra seem to be in close relation with the heavy minerals fraction in coarse-grained sediments with high specific gravity.

  7. Fish pollution with anthropogenic 137Cs in the southern Baltic Sea.

    PubMed

    Zalewska, Tamara; Suplińska, Maria

    2013-02-01

    This paper presents the results of a study on changes in (137)Cs activity concentrations in three fish species from the southern Baltic Sea: cod (Gadus morhua), herring (Clupea harengus) and flounder (Platichtys flesus), in the period 2000-2010. During the study period a marked decline in cesium activity concentration in fish muscle tissue was observed, which reflected changes in radionuclide activity concentration in seawater. No statistically significant temporal trends were determined in changes of concentration factors (CF(fish/seawater)) calculated for the examined fish species. The analysis of (137)Cs activity as a function of ichthyological parameters revealed the lack of a relationship between radionuclide activity concentrations in herring muscle tissue and the fish age in an narrow age range (2-4 years). However, a reverse proportionality of total fish mass, as well as body length, against (137)Cs activity concentrations in muscles was well documented. The latter observation can be the direct result of the dilution effect related to the increase of fish body weight. (137)Cs activity concentration in muscle tissue of the five fish species forms a declining sequence: Gadus morhua, Platichthys flesus, Clupea harengus, Perca fluviatilis and Neogobius melanostomus.

  8. Transfer of 137Cs in tea and other foods to man after the chernobyl accident in Turkey

    NASA Astrophysics Data System (ADS)

    Çetiner, M. A.; Özmen, A.

    1995-07-01

    The transfer fraction of 137Cs to man from ingestion of radioactively contaminated tea has been calculated. A transfer of 32% was calculated using the ( a, T1, T2) parameters of the 137Cs retention function recommended in ICRP-30. An alternate method using the 40K body burden yielded a transfer fraction of 33.6%.

  9. 137Cs and 210Po in Pacific Walrus and Bearded Seal from St. Lawrence Island, Alaska

    SciTech Connect

    Hamilton, T F; Seagars, D J; Jokela, T; Layton, D

    2005-02-02

    The activity concentration of Cesium-137 ({sup 137}Cs) and naturally-occurring Polonium-210 ({sup 210}Po) were measured in the muscle tissue, kidney and liver of Pacific walrus (Odobenus rosmarus divergens) and bearded seal (Erignathus barbatus) collected by native hunters from the Bering Sea. The mean {sup 137}Cs concentrations in muscle, liver and kidney of Pacific walrus were 0.07, 0.09 and 0.07 Bq kg{sup -1} (N= 5, wet weight), respectively, and 0.17, 0.10, and 0.17 Bq kg{sup -1} (N=2, wet weight), respectively, in bearded seal. In general, {sup 137}Cs tissue concentrations are significantly lower than those previously reported for mammals from other regions. By comparison, {sup 210}Po activity concentrations appear to be higher than those reported elsewhere but a larger variation. The mean {sup 210}Po concentration in the muscle tissue, liver and kidney of Pacific walrus (N=5, wet weight) were 28.7, 189, and 174 Bq kg{sup -1}, respectively. This compares with {sup 210}Po concentration values (N=2, wet weight) of 27, 207, and 68 Bq kg{sup -1} measured in the muscle tissue, liver and kidney, of bearded seal, respectively. Estimated bioaccumulation factors--as defined by the radionuclide concentration ratio between the target tissue to that in sea water--were two to three orders of magnitude higher for {sup 210}Po that those of {sup 137}Cs. We conclude from radiological dose estimates that ingestion of {sup 137}Cs in foods derived from walrus and seal will pose no threat to human health. This work has important implications for assessing health risks to Alaskan coastal communities concerned about the dumping of nuclear waste in the Russia Arctic.

  10. Enviromental influences on the {sup 137}Cs kinetics of the yellow-bellied turtle (Trachemys Scripta)

    SciTech Connect

    Peters, E.L.; Brisbin, L.I. Jr.

    1996-02-01

    Assessments of ecological risk require accurate predictions of contaminant dynamics in natural populations. However, simple deterministic models that assume constant uptake rates and elimination fractions may compromise both their ecological realism and their general application to animals with variable metabolism or diets. In particular, the temperature-dependent model of metabolic rates characteristic of ectotherms may lead to significant differences between observed and predicted contaminant kinetics. We examined the influence of a seasonally variable thermal environment on predicting the uptake and annual cycling of contaminants by ectotherms, using a temperature-dependent model of {sup 137}Cs kinetics in free-living yellow-bellied turtles, Trachemys scripta. We compared predictions from this model with those of deterministics negative exponential and flexibly shaped Richards sigmoidal models. Concentrations of {sup 137}Cs in a population if this species in Pond B, a radionuclide-contaminated nuclear reactor cooling reservoir, and {sup 137}Cs uptake by the uncontaminated turtles held captive in Pond B for 4 yr confirmed both the pattern of uptake and the equilibrium concentrations predicted by the temperature-dependent model. Almost 90% of the variance on the predicted time-integrated {sup 137}Cs concentration was explainable by linear relationships with model paramaters. The model was also relatively insensitive to uncertainties in the estimates of ambient temperature, suggesting that adequate estimates of temperature-dependent ingestion and elimination may require relatively few measurements of ambient conditions at sites of interest. Analyses of Richards sigmoidal models of {sup 137}Cs uptake indicated significant differences from a negative exponential trajectory in the 1st yr after the turtles` release into Pond B. 76 refs., 7 figs., 5 tabs.

  11. Reducing the 137Cs-load in the organism of "Chernobyl" children with apple-pectin.

    PubMed

    Nesterenko, V B; Nesterenko, A V; Babenko, V I; Yerkovich, T V; Babenko, I V

    2004-01-10

    As a complement of standard radioprotective measures, apple-pectin preparations are given, especially in the Ukraine, to reduce the 137Cs uptake in the organism of children. The question has been raised: is oral pectin also useful when children receive radiologically clean food, or does this polysaccharide only act in binding 137Cs in the gut, blocking its intestinal absorption? In this case, pectin would be useless if radiologically clean food could be given. The study was a randomised, double blind placebo-controlled trial comparing the efficacy of a dry and milled apple-extract containing 15-16% pectin with a similar placebo-powder, in 64 children originating from the same group of contaminated villages of the Gomel oblast. The average 137Cs load was of about 30 Bq/kg bodyweight (BW). The trial was conducted during the simultaneous one-month stay in the sanatorium Silver Spring. In this clean radiological environment only radiologically "clean" food is given to the children. The average reduction of the 137Cs levels in children receiving oral pectin powder was 62.6%, the reduction with "clean" food and placebo was 13.9%, the difference being statistically significant (p <0.01). The reduction of the 137Cs load is medically relevant, as no child in the placebo group reached values below 20 Bq/kg BW (which is considered by Bandazhevsky as potentially associated with specific pathological tissue damages), with an average value of 25.8 +/- 0.8 Bq/kg. The highest value in the apple-pectin group was 15.4 Bq/kg, the average value being 11.3 +/- 0.6 Bq/kg BW.

  12. 137Cs and 210Po in Pacific walrus and bearded seal from St. Lawrence Island, Alaska.

    PubMed

    Hamilton, Terry; Seagars, Dana; Jokela, Terry; Layton, David

    2008-06-01

    The activity concentration of Cesium-137 ((137)Cs) and naturally-occurring Polonium-210 ((210)Po) were measured in the muscle tissue, kidney and liver of Pacific walrus (Odobenus rosmarus divergens) and bearded seal (Erignathus barbatus) collected by native hunters from the Bering Sea during May 1996. The mean (137)Cs concentrations in muscle, liver and kidney of Pacific walrus were 0.07, 0.09 and 0.07 Bq kg(-1) (n=5, wet weight), respectively, and 0.17, 0.10, and 0.17 Bq kg(-1) (n=2, wet weight), respectively, in bearded seal. In general, (137)Cs tissue concentrations are significantly lower than those previously reported for mammals from other regions. By comparison, (210)Po activity concentrations are more variable and appear to be higher level compared with mammal data from other regions. The mean (210)Po concentration in the muscle tissue, liver and kidney of Pacific walrus (n=5, wet weight) were 28.7, 189, and 174 Bq kg(-1), respectively. This compares with (210)Po concentration values (n=2, wet weight) of 27, 207 and 68 Bq kg(-1) measured in the muscle tissue, liver and kidney, of bearded seal, respectively. Estimated concentration factors--as defined by the radionuclide concentration ratio between the target tissue to that in sea water--were two to three orders of magnitude higher for (210)Po that those of (137)Cs. We conclude from radiological dose estimates that ingestion of (137)Cs in foods derived from walrus and seal will pose no threat to human health. This work has important implications for assessment of risks of Alaskan coastal communities concerned about the dumping of nuclear waste in the Russia Arctic.

  13. 7Be, 210Pb and 137Cs concentrations in cloud water.

    PubMed

    Bourcier, L; Masson, O; Laj, P; Paulat, P; Pichon, J-M; Chausse, P; Gurriaran, R; Sellegri, K

    2014-02-01

    Cloud water was sampled during 8 months, in 2008 and 2009, at the puy de Dome high-altitude atmospheric research station (France). The concentrations of (7)Be and (210)Pb, both naturally occurring radionuclides, and (137)Cs of anthropogenic origin, were determined. Those values are useful for a better knowledge of the aftermath cloud deposition and more generally for wet deposition assessment of radionuclides. This is of primary interest in case of a nuclear accident, especially considering (137)Cs deposition, both for high-altitude locations that are regularly embedded by clouds and also for lowlands where fog can occur. The (7)Be and (210)Pb average activity concentrations in cloud water found were 1.9±0.11 mBq m(-3) air and 140±10 μBq m(-3) air, respectively. For (137)Cs, the average concentration was 0.14±0.02 μBq m(-3) air. This very low-level is representative of the long term post-accidental background level. Indeed, for the studied period, the last accidental (137)Cs release was that of Chernobyl accident, in April 1986. To our knowledge this is the first data about (137)Cs reference level determination in cloud water. The comparison between cloud water and rain water concentrations showed a ratio cloud/rain ranging between 3.4 and 8.1, in agreement with previous studies performed on inorganic compounds. Scavenging efficiencies of aerosols by cloud droplets were also calculated with the additional aerosol concentrations routinely measured at the station and were quite low (0.13-0.40) compared to what has previously been observed for inorganic soluble ions.

  14. The influence of biotic and abiotic factors on (137)Cs accumulation in higher fungi after the accident at Chernobyl NPP.

    PubMed

    Zarubina, N

    2016-09-01

    Levels of soil contamination with (137)Cs, the belonging of fungi to a certain ecological group, the localization depth of the main part of mycelium in soil are the primary factors influencing the value of (137)Cs specific activity in higher fungi after the accident at Chernobyl NPP. It has been found that the value of (137)Cs specific activity in fungi of one species could vary by more than 10 times during a vegetation period. A correlation between the changes of (137)Cs content in fungi during the vegetation period and the amount of precipitates during various periods preceding the collection of samples has not been determined. An assumption has been proposed stating dependence between peculiarities of mycelium growth during the vegetation period and the changes of (137)Cs specific activity in fungi.

  15. (137)Cs concentration in zooplankton and its relation to taxonomic composition in the western North Pacific Ocean.

    PubMed

    Kaeriyama, Hideki; Watabe, Teruhisa; Kusakabe, Masashi

    2008-12-01

    To study the role of zooplankton in the transport of (137)Cs in the ocean, zooplankton samples were collected in October 2005 and June 2006 in the western North Pacific Ocean. The peak zooplankton biomass was observed in the surface layer, and gelatinous plankton was more abundant in October 2005 than in June 2006 reflecting exchange of water masses. The concentrations of (137)Cs in zooplankton varied from 11 to 24 mBq kg wet(-1) and were higher in October 2005 than in June 2006. The elevated abundance of gelatinous zooplankton probably led to higher concentration of (137)Cs in zooplankton in October 2005. Annual export fluxes of (137)Cs by ontogenetic vertical migrant copepods were estimated to be 0.8 and 0.6 mBq m(-2) year(-1) at 200 and 1000 m depths, respectively; this suggested that transport of (137)Cs by zooplankton may be no trivial pathway.

  16. Novel deployment of elpasolites as a dual neutron / gamma- ray directional detector

    NASA Astrophysics Data System (ADS)

    Guckes, Amber

    At a time when upholding national security has never been more important, there exists a need for the advancement of radiation detection technologies. Neutron and photon detectors are essential to fulfilling mission areas including detection and localization of missing, stolen or smuggled radiological or nuclear materials, quantification of the effects of a radiological or nuclear event, and supporting nonproliferation efforts. The aim of this study was to evaluate a new radiation detector based on the scintillation elpasolite compound Cs2LiYCl6:Ce (CLYC) for simultaneous measurements of neutron and photon flux and the localization of radiation sources. Previous studies performed on the CLYC scintillator indicate its potential for thermal neutron and gamma-ray measurements. This study is dedicated to the novel application of the CLYC as a dual neutron / photon detector and as part of a directional detection system. Both computational modeling and an experimental study were carried out within this research project. As part of the computational study, the response of a CLYC scintillator detector to gamma rays induced by thermal neutron interaction with Cl and 7Li nuclei was investigated using the MCNP6 code. In addition, arrays of three and four CLYC detectors were modeled in order to evaluate the directional detection of both a thermal neutron source and a gamma-ray source. It was shown that little or no quality of source direction determination would be lost when three detectors were used in the array compared to four detectors. In the experimental study, the photon spectroscopy capabilities of the CLYC detectors were evaluated. A gamma-ray energy resolution of 4.9% was measured for the 662-keV peak of 137Cs and 3.6% for the 1.33-MeV peak of 60Co. Using a thermal neutron source, the pulse shape discrimination analysis was successfully performed for the CLYC detector signal waveforms. Thermal neutrons and gamma rays were separated with an exceptional figure of merit

  17. Analysis of 50-y record of surface (137)Cs concentrations in the global ocean using the HAM-global database.

    PubMed

    Inomata, Yayoi; Aoyama, Michio; Hirose, Katsumi

    2009-01-01

    We investigated spatial and temporal variations in (137)Cs concentrations in the surface waters of the global ocean for the period from 1957 to 2005 using the "HAM database - a global version". Based on the 0.5-y average value of (137)Cs concentrations in the surface water in each sea area, we classified the temporal variations into four types. (1) In the North Pacific Ocean where there was high fallout from atmospheric nuclear weapons tests, the rates of decrease in the (137)Cs concentrations changed over the five decades: the rate of decrease from the 1950s to the 1970s was much faster than that after the 1970s, and the (137)Cs concentrations were almost constant after the 1990s. Latitudinal differences in (137)Cs concentrations in the North Pacific Ocean became small with time. (2) In the equatorial Pacific and Indian Oceans, the (137)Cs concentrations varied within a constant range in the 1970s and 1980s, suggesting the advection of (137)Cs from areas of high global fallout in the mid-latitudes of the North Pacific Ocean. (3) In the eastern South Pacific and Atlantic Oceans (south of 40 degrees S), the concentrations decreased exponentially over the five decades. (4) In the Arctic and North Atlantic Oceans, including marginal seas, (137)Cs concentrations were strongly controlled by discharge from nuclear reprocessing plants after the late 1970s. The apparent half-residence times of (137)Cs in the surface waters of the global ocean from 1970 to 2005 ranged from 4.5 to 36.8 years. The apparent half-residence times were longer in the equatorial region and shorter in the higher latitudes. There was no notable difference between the latitudinal distributions of the apparent half-residence times in the Pacific and Indian Oceans. These results suggest that (137)Cs in the North Pacific Ocean is transported to the equatorial, South Pacific, and Indian Oceans by the oceanic circulation.

  18. Vertical and lateral distribution of fallout (137)Cs and soil properties along representative toposequences of central Rif, Morocco.

    PubMed

    Mesrar, Haytam; Sadiki, Abdelhamid; Faleh, Ali; Quijano, Laura; Gaspar, Leticia; Navas, Ana

    2017-04-01

    The purpose of this study is to understand and quantify the relationships between current (137)Cs inventories and the soil properties and the physiographic characteristics. A total of 36 cores were taken in seven transects with different slopes, lithology and land use. The analysis focused on the (137)Cs mass activity as well as inventories and its relationship with soil properties as grain size and organic matter. The mass activity of (137)Cs and the inventories varied between 3.6 and 63.7 Bq kg(-1) and between 521.7 and 3304.4 Bq m(-2), respectively. At uncultivated soils, high concentrations of (137)Cs are located in the top 10 cm and decreased exponentially in depth. Cultivated soils record disturbed and heterogeneous (137)Cs profiles with values of mass activity and inventories up to 38.7 Bq kg(-1) and 2510.8 Bq m(-2), respectively. The (137)Cs inventories were significantly higher in uncultivated soils (mean: 2086.9 Bq m(-2)) compared to cultivated soils (mean: 1397.1 Bq m(-2)). The (137)Cs mass activity showed a significant positive correlation with organic matter, silt and clay, but it was negatively correlated with sand and pH respectively. High levels of (137)Cs were found at altitudes between 500 m and 640 m a.s.l, and at slopes from 8° to 11°, as well as in dense scrub land and Fersialitic soils. A principal component analysis showed that more than 86.7% of the variance in (137)Cs mass activity was explained by the organic matter content and the land use. The results of this study provide insights into the effects of soil properties and physiographic factors on the behaviour of (137)Cs in soils of Mediterranean environments of North Africa and strengthen the reliability of this radioisotope as an erosion tracer.

  19. Gamma ray astronomy

    NASA Technical Reports Server (NTRS)

    Paciesas, William S.

    1994-01-01

    The Burst and Transient Source Experiment (BATSE) is one of four instruments on the Compton observatory which was launched by the space shuttle Atlantis on April 5, 1991. As of mid-March, 1994, BATSE detected more than 925 cosmic gamma-ray bursts and more than 725 solar flares. Pulsed gamma rays have been detected from at least 16 sources and emission from at least 28 sources (including most of the pulsed sources) has been detected by the earth occultation technique. UAH participation in BATSE is extensive but can be divided into two main areas, operations and data analysis. The daily BATSE operations tasks represent a substantial level of effort and involve a large team composed of MSFC personnel as well as contractors such as UAH. The scientific data reduction and analysis of BATSE data is also a substantial level of effort in which UAH personnel have made significant contributions.

  20. Topics in gamma ray astronomy

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Lingenfelter, R. E.

    1986-01-01

    Observations of gamma rays from solar flares, gamma ray bursts, the Galactic center, galactic nucleosynthesis, SS433, and Cygnus X-3, and their effects on astrophysical problems are discussed. It is observed that gamma ray spectra from solar flares are applicable to the study of particle acceleration and confinement and the determination of chemical abundances in the solar atmosphere. The gamma ray lines from the compact galactic object SS433 are utilized to examine the acceleration of jets, and analysis of the gamma ray lines of Cygnus X-3 reveal that particles can be accelerated in compact sources to ultrahigh energies.

  1. Modeling watershed-scale (137)Cs transport in a forested catchment affected by the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Wei, Lezhang; Kinouchi, Tsuyoshi; Yoshimura, Kazuya; Velleux, Mark L

    2017-02-02

    The Fukushima nuclear accident in 2011 resulted in (137)Cs contamination of large areas in northeast Japan. A watershed-scale (137)Cs transport model was developed and applied to a forested catchment in Fukushima area. This model considers (137)Cs wash-off from vegetation, movement through soils, and transport of dissolved and particulate (137)Cs adsorbed to clay, silt and sand. Comparisons between measurements and simulations demonstrated that the model well reproduced (137)Cs concentrations in the stream fed from the catchment. Simulations estimated that 0.57 TBq of (137)Cs was exported from the catchment between June, 2011 and December, 2014. Transport largely occurred with eroded sediment particles at a ratio of 17:70:13 of clay, silt, and sand. The overall (137)Cs reduction ratio by rainfall-runoff wash-off was about 1.6%. Appreciable (137)Cs remained in the catchment at the end of 2014. The largest rate of (137)Cs reduction by wash-off was simulated to occur in subwatersheds of the upper catchment. However, despite relatively low initial deposition, middle portions of the watershed exported proportionately more (137)Cs by rainfall-runoff processes. Simulations indicated that much of the transported (137)Cs originates from erosion over hillsides and river banks. These results suggested that areas where (137)Cs accumulates with redeposited sediments can be targeted for decontamination and also provided insight into (137)Cs transport at the watershed scale to assess risk management and decontamination planning efforts.

  2. Unidentified Gamma-Ray Sources: Hunting Gamma-Ray Blazars

    SciTech Connect

    Massaro, F.; D'Abrusco, R.; Tosti, G.; Ajello, M.; Gasparrini, A.Paggi.D.

    2012-04-02

    One of the main scientific objectives of the ongoing Fermi mission is unveiling the nature of the unidentified {gamma}-ray sources (UGSs). Despite the large improvements of Fermi in the localization of {gamma}-ray sources with respect to the past {gamma}-ray missions, about one third of the Fermi-detected objects are still not associated to low energy counterparts. Recently, using the Wide-field Infrared Survey Explorer (WISE) survey, we discovered that blazars, the rarest class of Active Galactic Nuclei and the largest population of {gamma}-ray sources, can be recognized and separated from other extragalactic sources on the basis of their infrared (IR) colors. Based on this result, we designed an association method for the {gamma}-ray sources to recognize if there is a blazar candidate within the positional uncertainty region of a generic {gamma}-ray source. With this new IR diagnostic tool, we searched for {gamma}-ray blazar candidates associated to the UGS sample of the second Fermi {gamma}-ray catalog (2FGL). We found that our method associates at least one {gamma}-ray blazar candidate as a counterpart each of 156 out of 313 UGSs analyzed. These new low-energy candidates have the same IR properties as the blazars associated to {gamma}-ray sources in the 2FGL catalog.

  3. Observation of gamma-rays from fallout collected at Ibaraki, Japan, during the Fukushima nuclear accident.

    PubMed

    Saegusa, Jun; Kikuta, Yasuaki; Akino, Hitoshi

    2013-07-01

    Gamma-ray pulse height distributions were measured for a fallout sample collected at Ibaraki, Japan, during the Fukushima accident in March 2011. The fallout was collected in a pan of water and then evaporated to dryness on a stainless-steel holder. The sample was measured by a germanium detector three times over a year. In the pulse height distribution of the initial measurement, approximately 140 peaks were observed in the 50-2048 keV energy region. Most of these peaks were either total absorption peaks or sum peaks of Te, I or Cs isotopes. Unlike fallout samples at the past nuclear accidents, nuclides such as Ce and Ru were not detected whereas (110m)Ag was prominently observed. The radioactivity concentration of (137)Cs was determined to be at least 1.4×10(4) Bq m(-2), approximately 14% of which was attributed to rainout.

  4. Radiocaesium (137Cs) in marine mammals from Svalbard, the Barents Sea and the North Greenland Sea.

    PubMed

    Andersen, Magnus; Gwynn, Justin P; Dowdall, Mark; Kovacs, Kit M; Lydersen, Christian

    2006-06-15

    Specific activities of the anthropogenic radionuclide, 137Cs, were determined in marine mammals from Svalbard and the Barents and North Greenland Seas. Muscle samples were collected from 12 polar bears, 15 ringed seals, 10 hooded seals, 7 bearded seals, 14 harp seals, one walrus, one white whale and one blue whale in the period 2000-2003. The mean concentrations (+/-SD) of 137Cs were: 0.72+/-0.62 Bq/kg wet weight (w.w.) for polar bears; 0.49+/-0.07 Bq/kg w.w. for ringed seals; 0.25+/-0.10 Bq/kg w.w. for hooded seals; 0.22+/-0.11 Bq/kg w.w. for bearded seals; 0.36+/-0.13 Bq/kg w.w. for harp seals; 0.67 Bq/kg w.w. for the white whale sample; 0.24 Bq/kg w.w. for the blue whale; and below detection limit for the walrus. Significant differences in 137Cs specific activities between some of the species were found. Ringed seals had higher specific activities than the other seal species in the study. Bearded seals and hooded seals had similar values, which were both significantly lower than the harp seal values. The results in the present study are consistent with previous reported results, indicating low specific activities of 137Cs in Arctic marine mammals in the Barents Sea and Greenland Sea region during the last 20 years. The species specific differences found may be explained by varying diet or movement and distribution patterns between species. No age related patterns were found in specific activities for the two species (polar bears and hooded seals) for which sufficient data was available. Concentration factors (CF) of 137Cs from seawater were determined for polar bears, ringed, bearded, harp and hooded seals. Mean CF values ranged from 79+/-32 (SD) for bearded seals sampled in 2002 to 244+/-36 (SD) for ringed seals sampled in 2003 these CF values are higher than those reported for fish and benthic organisms in the literature, suggesting bioaccumulation of 137Cs in the marine ecosystem.

  5. Biological effects of {sup 137}CsCl injected in beagle dogs of different dogs

    SciTech Connect

    Nikula, K.J.; Boecker, B.B.; Griffith, W.C.

    1996-11-01

    The toxicity of {sup 137}Cs in the beagle dog was investigated at the Inhalation Toxicology Research Institute (ITRI) and Argonne National Laboratory (ANL) as part of programs to evaluate the biological effects of both radionuclides in atomic bomb fallout and internally deposited fission-product radionuclides. In the ITRI study, young adult dogs were exposed once by intravenous injection to a range of {sup 137}Cs concentrations; the results have recently been published. The purpose of the present report is to summarize the ANL study and to compare the results of the two studies. At ANL, 63 dogs in three age groups (15 juveniles, 142-151 days old; 38 young adults, 388-427 days old; and 10 middle-aged dogs, 1387-2060 days old) were given {sup 137}Cs intravenously at levels (61-162f MBq/kg) near those expected to be lethal within 30 days after injection. There were 17 control dogs from the same colony. Twenty-three of the dogs injected with {sup 137}Cs, including all middle-aged dogs, died within 52 days after injection due to hematopoietic cell damage resulting in severe pancytopenia that led to fatal hemorrhage and/or septicemia. The other significant early effect was damage to the germinal epithelium of the seminiferous tubules. The design of the ANL study revealed an age- and gender-related differential radiosensitivity for early effects. The middle-aged dogs died significantly earlier due to complications of hematological dyscrasia compared to the juvenile and young adult dogs, and the middle-aged females died significantly earlier than the middle-aged males. The most significant non-neoplastic late effects in the {sup 137}Cs-injected dogs from ANL and ITRI were atrophy of the germinal epithelium of seminiferous tubules with azoospermia, and a significant dose-dependent decrease in survival. The survival of the ANL dogs was decreased more than that of the ITRI dogs at similar radiation doses from {sup 137}Cs. 19 refs., 6 figs., 4 tabs.

  6. Radionuclide concentration in cabbage samples due to gamma radiation in Samsun, Turkey

    NASA Astrophysics Data System (ADS)

    Altıkulaç, Aydan; Gümüş, Hasan

    2016-11-01

    Establishing of radioactivity planes in foodstuff has emphasis because it allows the evaluation of population exposure to radiation by take nourishment. In this paper, the activity concentrations of 226Ra, 232Th, 40K and 137Cs were determined in cabbage samples collected from Samsun city of Turkey using a gamma ray spectrometry method with a HPGe detector. The mean concentration value of 226Ra, 232Th, 40K and 137Cs in cabbage samples were 1.11±0.03 Bqkg-1, 1.44±0.04 Bqkg-1, 743.75±21.21 Bqkg-1 and 0.18±0.003 Bqkg-1, respectively. The calculated total annual effective dose received from 226Ra, 232Th, 40K and 137Cs due to cabbage samples by population of Samsun province was quite lower than the World average value as suggested by UNSCEAR.

  7. Development and calibration of a real-time airborne radioactivity monitor using direct gamma-ray spectrometry with two scintillation detectors.

    PubMed

    Casanovas, R; Morant, J J; Salvadó, M

    2014-07-01

    The implementation of in-situ gamma-ray spectrometry in an automatic real-time environmental radiation surveillance network can help to identify and characterize abnormal radioactivity increases quickly. For this reason, a Real-time Airborne Radioactivity Monitor using direct gamma-ray spectrometry with two scintillation detectors (RARM-D2) was developed. The two scintillation detectors in the RARM-D2 are strategically shielded with Pb to permit the separate measurement of the airborne isotopes with respect to the deposited isotopes.In this paper, we describe the main aspects of the development and calibration of the RARM-D2 when using NaI(Tl) or LaBr3(Ce) detectors. The calibration of the monitor was performed experimentally with the exception of the efficiency curve, which was set using Monte Carlo (MC) simulations with the EGS5 code system. Prior to setting the efficiency curve, the effect of the radioactive source term size on the efficiency calculations was studied for the gamma-rays from (137)Cs. Finally, to study the measurement capabilities of the RARM-D2, the minimum detectable activity concentrations for (131)I and (137)Cs were calculated for typical spectra at different integration times.

  8. 135Cs/137Cs isotopic composition of environmental samples across Europe: Environmental transport and source term emission applications

    DOE PAGES

    Snow, Mathew S.; Snyder, Darin C.

    2015-11-02

    135Cs/137Cs isotopic analyses represent an important tool for studying the fate and transport of radiocesium in the environment; in this work the 135Cs/137Cs isotopic composition in environmental samples taken from across Europe is reported. Surface soil and vegetation samples from western Russia, Ukraine, Austria, and Hungary show consistent aged thermal fission product 135Cs/137Cs isotope ratios of 0.58 ± 0.01 (age corrected to 1/1/15), with the exception of one sample of soil-moss from Hungary which shows an elevated 135Cs/137Cs ratio of 1.78 ± 0.12. With the exception of the outlier sample from Hungary, surface soil/vegetation data are in quantitative agreement withmore » values previously reported for soils within the Chernobyl exclusion zone, suggesting that radiocesium at these locations is primarily composed of homogenous airborne deposition from Chernobyl. Seawater samples taken from the Irish Sea show 135Cs/137Cs isotope ratios of 1.22 ± 0.11 (age corrected to 1/1/15), suggesting aged thermal fission product Cs discharged from Sellafield. Furthermore, the differences in 135Cs/137Cs isotope ratios between Sellafield, Chernobyl, and global nuclear weapons testing fallout indicate that 135Cs/137Cs isotope ratios can be utilized to discriminate between and track radiocesium transport from different nuclear production source terms, including major emission sources in Europe.« less

  9. Lunar based gamma ray astronomy

    NASA Astrophysics Data System (ADS)

    Haymes, R. C.

    Gamma ray astronomy represents the study of the universe on the basis of the electromagnetic radiation with the highest energy. Gamma ray astronomy provides a crucial tool for the understanding of astronomical phenomena, taking into account nucleosynthesis in supernovae, black holes, active galaxies, quasars, the sources of cosmic rays, neutron stars, and matter-antimatter annihilation. Difficulties concerning the conduction of studies by gamma ray astronomy are related to the necessity to perform such studies far from earth because the atmosphere is a source of gamma rays. Studies involving the use of gamma ray instruments in earth orbit have been conducted, and more gamma ray astronomy observations are planned for the future. Imperfections of studies conducted in low earth orbit could be overcome by estalishing an observatory on the moon which represents a satellite orbiting at 60 earth radii. Details concerning such an observatory are discussed.

  10. Accumulation of /sup 137/Cs in commercial fish of the Belyarsk nuclear power station cooling supply

    SciTech Connect

    Trapeznikova, V.N.; Kulikov, N.V.; Trapeznikov, A.V.

    1984-07-01

    Results are presented of a comparative study of the accumulation of /sup 137/Cs in basic species of commercial fish of the Beloyarsk reservoir which is used as the cooling supply for the Beloyarsk nuclear power station. Possible reasons for interspecies differences in accumulation of the radionuclide are indicated, and the increased accumulation of /sup 137/Cs by free-living fish in the zone of heated water effluent from the station and the reduced accumulation of the emitter in carp, which are cultivated on artificial food in cages, are noted. Levels of the content of the radionuclide are compared in roach and farm carp from the cooling supplies of the Beloyarsk station and the Reftinsk power plant in the Urals.

  11. Ecological half-life of 137Cs in lichens in an alpine region.

    PubMed

    Machart, Peter; Hofmann, Werner; Türk, Roman; Steger, Ferdinand

    2007-01-01

    About 17 years after the Chernobyl accident, lichen samples were collected in an alpine region in Austria (Bad Gastein), which was heavily contaminated by the Chernobyl fallout. Measured 137Cs activity concentrations in selected lichens (Cetraria islandica, Cetraria cucullata, and Cladonia arbuscula) ranged from 100 to 1100 Bq kg(-1) dry weight, depending on lichen species and sampling site. Ecological half-lives for 137Cs in different lichen samples, obtained by comparison with earlier measurements of the same lichen species at the same site, ranged from 2 to 6 years, with average values between 3 and 4 years. Comparison with earlier studies indicated that ecological half-lives hardly changed during the last 10 years, suggesting that ecological clearance mechanisms (e.g. washout or soil transfer) did not vary substantially at the selected sampling area.

  12. [Modifying effect of incorporated 137Cs on the mechanism of adrenergic control of myocardial contraction].

    PubMed

    Lobanok, L M; Bulanova, K Ia; Gerasimovich, N V; Sineleva, M V; Miliutin, A A

    1994-01-01

    Incorporated 137Cs (absorbed dose of 0.26 Gy) causes decrease of myocardial's contractile function and inotropic response to beta-adrenagonists effect, isoproterenol-stimulated adenylate cyclase activity and beta-adrenoreceptors affinity. Adrenergic effects, mediated by alpha-adrenergic structures on heart contractile function, on the contrary, become stronger, that is due to the increase of the receptors' density on sarcolemma surface.

  13. Chernobyl {sup 137}Cs used to determine sediment accretion rates at selected northern European coastal wetlands

    SciTech Connect

    Callaway, J.C.; DeLaune, R.D.; Patrick, W.H. Jr.

    1996-05-01

    Sediment cores were collected form five coastal wetlands along the North Sea (England and Netherlands) and Baltic Sea (Poland). {sup 137}Cs dating was used to assess sediment accretion rates, including rates based on the {sup 137}Cs peak from the 1986 accident at Chernobyl. Peaks form the Chernobyl fallout were found in cores from the Oder and Vistula Rivers in Poland, from the Eastern Scheldt in the Netherlands, and in one of the two cores from Stiffkey Marsh, UK. No evidence of Chernobyl fallout was found in cores from Dengie Marsh, UK. The Chernobyl {sup 137}Cs peak serves as an excellent marker for short-term accretion rates because of its high activity. Vertical accretion rates (cm yr{sup {minus}1}) based on 1963 and 1986 peaks were similar at most sites; differences may be due to large inputs of sediment from storms or recent accumulation of organic matter. Large differences in sediment characteristics and accretion rates were found between samples from Poland and western Europe. Vertical accretion rates over the period 1963-1986 ranged from 0.26 to 0.85 cm{sup {minus}1} and from 0.30 to 1.90 cm yr{sup {minus}1} over the 1986-1991 period. Vertical accretion rates for the period these sites are in imminent danger of excessive flooding. The Chernobyl {sup 137}Cs peak will be especially useful for studies of short-term (i.e. very recent) sedimentation in the near future and for comparisons of sediment processes over different time scales. 33 refs., 4 figs., 4 tabs.

  14. Modeling (137)Cs bioaccumulation in the salmon-resident killer whale food web of the Northeastern Pacific following the Fukushima Nuclear Accident.

    PubMed

    Alava, Juan José; Gobas, Frank A P C

    2016-02-15

    To track the long term bioaccumulation of (137)Cs in marine organisms off the Pacific Northwest coast of Canada, we developed a time dependent bioaccumulation model for (137)Cs in a marine mammalian food web that included fish-eating resident killer whales. The model outcomes show that (137)Cs can be expected to gradually bioaccumulate in the food web over time as demonstrated by the increase of the apparent trophic magnification factor of (137)Cs, ranging from 0.76 after 1 month of exposure to 2.0 following 30 years of exposure. (137)Cs bioaccumulation is driven by relatively rapid dietary uptake rates, moderate depuration rates in lower trophic level organisms and slow elimination rates in high trophic level organisms. Model estimates of the (137)Cs activity in species of the food web, based on current measurements and forecasts of (137)Cs activities in oceanic waters and sediments off the Canadian Pacific Northwest, indicate that the long term (137)Cs activities in fish species including Pacific herring, wild Pacific salmon, sablefish and halibut will remain well below the current (137)Cs-Canada Action Level for consumption (1000 Bq/kg) following a nuclear emergency. Killer whales and Pacific salmon are expected to exhibit the largest long term (137)Cs activities and may be good sentinels for monitoring (137)Cs in the region. Assessment of the long term consequences of (137)Cs releases from the Fukushima aftermath should consider the extent of ecological magnification in addition to ocean dilution.

  15. The effective and environmental half-life of 137Cs at Coral Islands at the former US nuclear test site.

    PubMed

    Robison, William L; Conrado, Cynthia L; Bogen, Kenneth T; Stoker, A Carol

    2003-01-01

    The United States (US) conducted nuclear weapons testing from 1946 to 1958 at Bikini and Enewetak Atolls in the northern Marshall Islands. Based on previous detailed dose assessments for Bikini, Enewetak, Rongelap, and Utirik Atolls over a period of 28 years, cesium-137 (137Cs) at Bikini Atoll contributes about 85-89% of the total estimated dose through the terrestrial food chain as a result of uptake of 137Cs by food crops. The estimated integral 30, 50, and 70-year doses were based on the radiological decay of 137Cs (30-year half-life) and other radionuclides. However, there is a continuing inventory of 137Cs and 90Sr in the fresh water portion of the groundwater at all contaminated atolls even though the turnover rate of the fresh groundwater is about 5 years. This is evidence that a portion of the soluble fraction of 137Cs and 90Sr inventory in the soil is lost by transport to groundwater when rainfall is heavy enough to cause recharge of the lens, resulting in loss of 137Cs from the soil column and root zone of the plants. This loss is in addition to that caused by radioactive decay. The effective rate of loss was determined by two methods: (1) indirectly, from time-dependent studies of the 137Cs concentration in leaves of Pisonia grandis, Guettarda specosia, Tournefortia argentea (also called Messerschmidia), Scaevola taccada, and fruit from Pandanus and coconut trees (Cocos nucifera L.), and (2) more directly, by evaluating the 137Cs/90Sr ratios at Bikini Atoll. The mean (and its lower and upper 95% confidence limits) for effective half-life and for environmental-loss half-life (ELH) based on all the trees studied on Rongelap, Bikini, and Enewetak Atolls are 8.5 years (8.0 years, 9.8 years), and 12 years (11 years, 15 years), respectively. The ELH based on the 137Cs/90Sr ratios in soil in 1987 relative to the 137Cs/90Sr ratios at the time of deposition in 1954 is less than 17 years. The magnitude of the decrease below 17 years depends on the ELH for 90Sr

  16. Hindcast of 137Cs in the North Pacific Ocean from 1945 to 2013 by eddy-resolving ROMS

    NASA Astrophysics Data System (ADS)

    Tsubono, Takaki; Misumi, Kazuhiro; Tsumune, Daisuke; Aoyama, Michio; Hirose, Katsumi

    2014-05-01

    We conducted the hindcast of 137Cs activity in the North Pacific Ocean from 1945 to 2013, before and after the Fukushima Dai-ichi Nuclear Power Plant (1F NPP) accident. We used the Regional Ocean Model System (ROMS) with high resolution (1/12°-1/4° in horizontal, 45 levels in vertical), of which domain was the North Pacific Ocean. This model employed the CORE normal year forcing data for a driving forcing and the 50 years averaged SODA data for boundary conditions. The reconstructed global fallout due to atmospheric nuclear weapons' tests and Chernobyl accident was employed for atmospheric input flux of 137Cs from 1945 to 2013. After the accident, the atmospheric deposition and direct release of 137Cs from 1F NPP were also employed for input condition. Five ensemble calculations of 137Cs activity were conducted by moving the start period of the input flux for one year. The simulated vertical distributions of 137Cs activity along 165°E represented the overall patterns of the observed 137Cs activity before (in 2002) and after (in 2012) the accident, in particular the high activity core of the 137Cs around North Pacific Subtropical Mode Water and Central Mode Water, indicating that this model can represent the subduction process and formation of the Mode Waters. The simulated 137Cs activity in the surface ranged from 0.75 to 2.Bq m-3 in the north of Kuroshio Extension in 2011 before the accident. The main body of high 137Cs activity water from 1F NPP was transported in the northern part of Kuroshio Extension after the accident. In Sep. 2012, 18 months after the accident, the main body of high 137Cs activity water (≥ 10 Bq m-3) was located at around 40°N, 150°E-160°W. The water over 10 Bq m-3 of 137Cs activity was not detected in surface layer, but in the layer of σθ=25.8-26.2 at two small areas (44°N, 180°W-165°W and 48°N, 160°W-140°W). This model simulation suggests that the main body of high 137Cs activity water from 1F NPP has never reached the

  17. Determination and analysis of distribution coefficients of 137Cs in soils from Biscay (Spain).

    PubMed

    Elejalde, C; Herranz, M; Legarda, F; Romero, F

    2000-10-01

    The distribution coefficient of (137)Cs has been determined in 58 soils from 12 sampling points from Biscay by treating 10 g with 25 ml of an aqueous solution with an activity of 1765 Bq in the radionuclide, by shaking during 64 h and measuring the residual activity with a suitable detector. Soils were characterised by sampling depth, particle size analysis and the usual chemical parameters. Soils were thereafter treated to fix the chemical forms of (137)Cs speciation by successive extractions in order to determine fractions due to exchangeable, associated with carbonates, iron oxide and organic matter fractions, obtaining by difference the amount taken by the rest of the soil constituents. For this research, 16 soils from four points were selected from the previous samples. The greatest mean percentages of (137)Cs sorption were with the rest (69.93), exchangeable (13.17) and organic matter (12.54%) fractions. This paper includes also the calculation of partial distribution coefficients for chemical species as well as relations of distribution coefficients both among them and with soil parameters.

  18. Single-photon transmission measurements in positron tomography using 137Cs.

    PubMed

    Yu, S K; Nahmias, C

    1995-07-01

    Transmission measurements are an essential step in the quantification of radioisotope distributions in vivo using positron tomographic techniques. The development of a new technique for measuring transmission data that relies on the detection of photons in 'singles' mode rather than 'coincidence' mode no longer restricts the choice of transmission sources to those that decay by positron emission. The motivation for using the 'singles' mode of operation is the substantial increase in count rate that can be achieved. This corresponds to a great increase in the statistical accuracy of the transmission data. We propose 137Cs as a suitable isotope for this purpose. 137Cs is more economical than 68Ge, the traditional source used for transmission measurements, in terms of longer half-life and lower financial cost. 137Cs can be used for transmission measurements without any recalibration of the tomograph, and the estimated spatial resolution is comparable to that obtained using annihilation photons. A simple extrapolation method is developed, which allows extrapolation of the attenuation coefficients measured at 662 keV to 511 keV. A dual-energy-window technique, whereby correction can be made on-the-fly during acquisition, is used for scatter correction. The measured linear attenuation coefficients agree with predicted values.

  19. The presence of natural radioactivity and 137Cs in the South China Sea bordering peninsular Malaysia.

    PubMed

    Amin, Y M; Mahat, R H; Nor, R M; Khandaker, Mayeen Uddin; Takleef, Ghazwa Hatem; Bradley, D A

    2013-10-01

    The presence of natural radioactivity and (137)Cs has been investigated in fresh media obtained from South China Sea locations off the coast of peninsular Malaysia. The media include seafood, sea water and sediment. The samples were collected some weeks prior to the devastating 2011 Tōhoku earthquake and associated tsunami, the occurrence of which precipitated the Fukushima incident. All samples showed the presence of naturally occurring (226)Ra, (228)Ra and primordial (40)K, all at typically prevailing levels. The concentrations of natural radioactivity in molluscs were found to be greater than that of other marine life studied herein, the total activity ranging from 337 to 393 Bq kg(-1) dry weight. The total activity in sea water ranged from 15 to 88 Bq l(-1). Sediment samples obtained at deep sea locations more than 20 km offshore further revealed the presence of (137)Cs. The activity of (137)Cs varied from ND to 0.5 Bq kg(-1) dry weight, the activity increasing with offshore distance and depth. The activity concentrations presented herein should be considered useful in assessing the impact of any future radiological contamination to the marine environment.

  20. Release, deposition and elimination of radiocesium ((137)Cs) in the terrestrial environment.

    PubMed

    Ashraf, Muhammad Aqeel; Khan, Ayesha Masood; Ahmad, Mushtaq; Akib, Shatirah; Balkhair, Khaled S; Bakar, Nor Kartini Abu

    2014-12-01

    Radionuclide contamination in terrestrial ecosystems has reached a dangerous level. The major artificial radionuclide present in the environment is (137)Cs, which is released as a result of weapon production related to atomic projects, accidental explosions of nuclear power plants and other sources, such as reactors, evaporation ponds, liquid storage tanks, and burial grounds. The release of potentially hazardous radionuclides (radiocesium) in recent years has provided the opportunity to conduct multidisciplinary studies on their fate and transport. Radiocesium's high fission yield and ease of detection made it a prime candidate for early radio-ecological investigations. The facility setting provides a diverse background for the improved understanding of various factors that contribute toward the fate and transfer of radionuclides in the terrestrial ecosystem. In this review, we summarize the significant environmental radiocesium transfer factors to determine the damaging effects of radiocesium on terrestrial ecosystem. It has been found that (137)Cs can trace the transport of other radionuclides that have a high affinity for binding to soil particles (silts and clays). Possible remedial methods are also discussed for contaminated terrestrial systems. This review will serve as a guideline for future studies of the fate and transport of (137)Cs in terrestrial environments in the wake of the Fukushima Nuclear Power Plant disaster in 2011.

  1. Spatial distribution of fallout 137Cs in the coastal marine environment of India.

    PubMed

    Jha, S K; Gothankar, S S; Sartandel, S; Pote, M B; Hemalatha, P; Rajan, M P; Vidyasagar, D; Indumati, S P; Shrivastava, R; Puranik, V D

    2012-11-01

    The data on the fallout (137)Cs in the coastal marine environment assume significance in view of massive expansion of nuclear power plants in the Asia-Pacific region and to fulfill the benchmark study required to evaluate the possible impact of the Fukushima radioactive releases in the Asia-Pacific region. Measurements of (137)Cs in sea water, along with salinity and temperature, were carried out at 30 locations covering the coastal area of the Arabian Sea and the Bay of Bengal. For the present study the Indian coastal area is divided in three different regions. The (137)Cs concentration in sea water of the entire Indian coastal region varies from 0.30 to 1.25 Bq m(-3). The data obtained in the present study was compared with the North Indian Ocean data and it was observed that there is a 33% decrease in the Arabian Sea (region I), 50% in the high rainfall coastal area (region II) and 24% in the Bay of Bengal (region III).

  2. Gamma-ray burst observations

    NASA Technical Reports Server (NTRS)

    Atteia, J.-L.

    1993-01-01

    The most important observational characteristics of gamma-ray bursts are reviewed, with emphasis on X-ray and gamma-ray data. The observations are used to derive some basic properties of the sources. The sources are found to be isotropically distributed; the burster population is limited in space, and the edge of the distribution is visible.

  3. Aging effect of 137Cs obtained from 137Cs in the Kanto loam layer from the Fukushima nuclear power plant accident and in the Nishiyama loam layer from the Nagasaki A-bomb explosion.

    PubMed

    Ohta, Tomoko; Mahara, Yasunori; Kubota, Takumi; Igarashi, Toshifumi

    2013-01-01

    We measured (134)Cs and (137)Cs in the surface soil of the Kanto loam in the eastern Tokyo metropolitan area and the Nishiyama loam in Nagasaki, Japan. The observed (137)Cs deposition in the Kanto loam from the Fukushima nuclear power plant (NPP) accident ranged from 4.0 to 77 kBq m(-2), which corresponds to 0.3-5 times of that in the Nishiyama loam. The (137)Cs retardation factor in the Kanto loam obtained seven months after the Fukusima NPP accident and in the Nishiyama loam after 36 and 38 years from the detonation of the Pu atomic bomb (A-bomb) ranged from 180 to 260 and 2000 to 10,000, respectively. This difference in the retardation factors is attributed to an aging effect that corresponds to seven months and 36 to 38 years after the deposition of (137)Cs occurred on the soil minerals.

  4. (137)Cs distributions in soil and trees in forest ecosystems after the radioactive fallout - Comparison study between southern Finland and Fukushima, Japan.

    PubMed

    Pumpanen, Jukka; Ohashi, Mizue; Endo, Izuki; Hari, Pertti; Bäck, Jaana; Kulmala, Markku; Ohte, Nobuhito

    2016-09-01

    The nuclear accidents at Chernobyl and Fukushima released large amounts of (137)Cs radionuclides into the atmosphere which spread over large forest areas. We compared the (137)Cs concentration distribution in different parts of two coniferous forest ecosystems (needle litter, stems and at different depths in the soil) over short and long term periods in Finland and Japan. We also estimated the change in (137)Cs activity concentrations in needle and soil between 1995 and 2013 in Southern Finland based on the back-calculated (137)Cs activity concentrations. We hypothesized that if the (137)Cs activity concentrations measured in 1995 and 2013 showed a similar decline in concentration, the (137)Cs activity concentration in the ecosystem was already stable in 1995. But if not, the (137)Cs activity concentrations were still changing in 2013. Our results showed that the vertical distribution of the (137)Cs fallout in the soil was similar in Hyytiälä and Fukushima. The highest (137)Cs concentrations were observed in the uppermost surface layers of the soil, and they decreased exponentially deeper in the soil. We also observed that (137)Cs activity concentrations estimated from the samples in 1995 and 2013 in Finland showed different behavior in the surface soil layers compared to the deep soil layer. These results suggested that the (137)Cs nuclei were still mobile in the surface soil layers 27 years after the accident. Our results further indicated that, in the aboveground parts of the trees, the (137)Cs concentrations were much closer to steady-state when compared to those of the surface soil layers based on the estimated declining rates of (137)Cs concentration activity in needles which were similar in 1995 and 2013. Despite its mobility and active role in the metabolism of trees, the (137)Cs remains in the structure of the trees for decades, and there is not much exchange of (137)Cs between the heartwood and surface layers of the stem.

  5. 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

  6. Field Deployment of Illite Clay as an InSitu Method for Remediating 137Cs-Contaminated Wetlands

    SciTech Connect

    Kaplan, D.I.

    2003-01-29

    The research reported herein centered on a field deployment of the in situ remediation method with the goal of learning if the clay amendments reduce the biological availability of 137Cs in contaminated wetlands.

  7. [137Cs and 90Sr accumulation in birch wood (Betula pendula Roth.) growing in regions with different soil conditions].

    PubMed

    Perevolotskiĭ, A N; Bulavik, I M; Perevolotskaia, T V; Paskrobko, L A; Andrush, S N

    2005-01-01

    The studies of 137Cs and 90Sr accumulation characteristics by birch wood (Betula pendula Roth.) growing in different edaphic conditions. Were conducted was stated that the increase in soil fertility from trophotops A to D results in 5-fold 137Cs transfer factor decrease and 2-fold decrease of 90Sr. Soil humidity increase for each grade of trophic net results happens the increase of 137Cs transfer factors to wood and decrease for 90Sr. Total activity of 37Cs and 90Sr in birch wood plantation depends on plantation productivity and on radionuclide transfer factors depending on different plantation conditions. In the most prevailing edaphotops (B2, B3, C2 and C3) birch wood accumulates 0.6-1.2% of 137Cs and 13-19% of 90Sr from total activity of radionuclides in biogeocenosis.

  8. Influence of soil types and osmotic pressure on growth and (137)Cs accumulation in blackgram (Vigna mungo L.).

    PubMed

    Win, Khin Thuzar; Oo, Aung Zaw; Bellingrath-Kimura, Sonoko Dorothea

    2017-04-01

    A pot experiment was conducted to study the effects of soil types and osmotic levels on growth and (137)Cs accumulation in two blackgram varieties differing in salinity tolerance grown in Fukushima contaminated soils. The contamination levels of the sandy clay loam and clay soil were 1084 and 2046 Bq kg(-1) DW, respectively. The (137)Cs activity was higher in both plants grown on the sandy clay loam than on the clay soil regardless of soil (137)Cs activity concentration. No significant differences were observed in all measured growth parameters between the two varieties under optimal water conditions for both types of soil. However, the growth, leaf water contents and (137)Cs activity concentrations in both plants were lower in both soil types when there was water stress induced by addition of polyethylene glycol. Water stress-induced reduction in total leaf area and total biomass, in addition to leaf relative water content, were higher in salt sensitive 'Mut Pe Khaing To' than in salt tolerant 'U-Taung-2' plants for both soil types. Varietal difference in decreased (137)Cs uptake under water stress was statically significant in the sandy clay loam soil, however, it was not in the clay soil. The transfer of (137)Cs from soil to plants (i.e., root, stem and leaf) was higher for the sandy clay loam for both plants when compared with those of the clay soil. The decreased activity of (137)Cs in the above ground samples (leaf and stem) in both plants in response to osmotic stress suggested that plant available (137)Cs decreased when soil water is limited by osmotic stress.

  9. The distribution of (137)Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden.

    PubMed

    Vinichuk, M; Johanson, K J; Rydin, H; Rosén, K

    2010-02-01

    We record the distribution of (137)Cs, K, Rb and Cs within individual Sphagnum plants (down to 20cm depth) as well as (137)Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris(137)Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher (137)Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of (137)Cs within the plants. The patterns of (137)Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The (137)Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10cm) of the plant (r=0.50). The strongest correlations were revealed between (137)Cs and Rb (r=0.89), and between (137)Cs and stable Cs (r=0.84). This suggests similarities between (137)Cs and Rb in uptake and relocation within the Sphagnum, but that (137)Cs differs from K.

  10. 137Cs and 40K soil-to-plant relationship in a seminatural grassland of the Giulia Alps, Italy.

    PubMed

    Ciuffo, L E C; Belli, M; Pasquale, A; Menegon, S; Velasco, H R

    2002-08-05

    To examine the soil-to-plant transfer of 137Cs and 40K, we performed a study based on sampling of natural soil and plants from an alpine pasture site situated in the Giulia Alps, Italy, during July 1997. High 137Cs activity was present in the upper most soil layer, and decreased one order of magnitude at a depth of 10 cm. An opposite gradient was observed for 40K. Simultaneous sampling of soil and plant material was performed in order to analyse transfer factor (TF) values. In spite of homogeneous 137Cs activities in soil, grass samples showed a high variability. A negative correlation was detected between 40K- and 137Cs-activities in plants. TF values for 137Cs were highly variable, thus suggesting that this parameter would be independent of 137Cs soil activity. Lower variability was observed for 40K TFs values. Our results suggest that TFs are highly variable parameters that appear to be independent on radionuclide soil activity. Because soil and plant characteristics strongly affect TF values, caution is necessary when TF values are used as the sole parameter to predict radionuclide uptake by plants in semi-natural ecosystems.

  11. Long-term simulations of the 137Cs dispersion from the Fukushima accident in the world ocean.

    PubMed

    Nakano, Masanao; Povinec, Pavel P

    2012-09-01

    The LAMER calculation code was used for simulation of the distribution of (137)Cs released after the Fukushima accident into the Pacific and Indian Oceans. The maximum (137)Cs concentration predicted for surface waters of the open NW Pacific Ocean in 2012 (21 Bq/m(3) at 38 °N, 164 °E) will be comparable to that observed during the early 1960s after atmospheric nuclear weapons tests. The (137)Cs in surface waters of the Pacific Ocean will reach the US coast 4-5 y after the accident, however, the levels will be low (<3 Bq/m(3)). All the North Pacific Ocean will be labeled with Fukushima (137)Cs 10 y after the accident with concentrations below 1 Bq/m(3). Thirty years after the accident the (137)Cs levels in the Pacific and Indian Oceans will be below 0.1 Bq/m(3), i.e. undetectable on the present global fallout background. The effective dose commitment with ingestion of marine biota found in 2012 in the open NW Pacific Ocean was estimated to be 1.7 μSv/y, mostly delivered by (134,137)Cs. The estimated dose is by about a factor of 500 lower than the present dose limit for the public.

  12. Aggregated Transfer Factors For Small Mammals Collected From the Exposed Sediments Of A 137 Cs Contaminated Reservoir

    SciTech Connect

    Paller, Michael H.; Jannika, G. Timothy; Wike, Lynn D

    2005-10-04

    {sup 137}Cs transfer factors were computed for small mammals collected from the dried sediment areas of a partially drained, contaminated reservoir. Soil {sup 137}Cs concentrations were heterogeneous on small and large spatial scales, with a geometric mean of 253.1 Bq/kg dry weight. About 50% of the variance in cotton rat Sigmodon hispidus tissue {sup 137}Cs levels was explained by variation in soil {sup 137}Cs levels. Soil to animal transfer factors (whole body dry weight) averaged 6.0 for cotton rats and 1.2 for cotton mice Peromyscus gossypinus. These values are similar to {sup 137}Cs transfer factors for herbivorous, homeothermic animals from other contaminated ecosystems. Site-specific transfer factors can significantly affect the estimation of dose. In the RESRAD-BIOTA dose model, the default transfer factor for {sup 137}Cs in terrestrial animals is 110 resulting in an estimate of radiation dose to terrestrial biota that is 16 times more than the dose calculated with the actual measured transfer factor.

  13. The usefulness of 137Cs as a tracer for soil erosion assessment: A critical reply to Parsons and Foster (2011)

    NASA Astrophysics Data System (ADS)

    Mabit, L.; Meusburger, K.; Fulajtar, E.; Alewell, C.

    2013-12-01

    A large number of geoscientists worldwide from different disciplines have recognized and have adopted the 137Cs method as an effective tracer to assess soil erosion rates during the last decades. The recent review of Parsons and Foster (2011) challenged the usefulness of this radioisotopic method primarily by questioning the assumption of the representativeness of the reference inventory and its conservative behavior and the 137Cs data conversion into soil erosion rates. While there are many studies published on 137Cs method, Parsons and Foster (2011) have not evaluated the full range of the existing literature. We present additional highly relevant studies, assessing and applying the 137Cs method successfully. While we agree that the applicability of the 137Cs method to assess soil erosion magnitude needs careful planning as well as expert knowledge, we highlight in our reply that if the method is based on suitable and statistically sound sampling, 137Cs is a very effective soil tracer to assess soil erosion magnitude.

  14. Relationship between the {sup 137}Cs whole-body counting results and soil and food contamination in farms near Chernobyl

    SciTech Connect

    Takatsuji, Toshihiro; Sato, Hitoshi; Takada, Jun

    2000-01-01

    The authors measured the radioactivity in the soil and child food samples from farms near Mogilev (56--270 GBq km{sup {minus}2} {sup 137}Cs), Gomel (36--810 GBq km{sup {minus}2} {sup 137}Cs), and Klincy (59--270 GBq km{sup {minus}2} {sup 137}Cs), who had whole-body {sup 137}Cs counting results measured as part of a health examination in the Chernobyl Sasakawa Health and Medical Cooperation Project. Soil contamination on the family farm seems to be the main source of human contamination because most of the people in the area live on small farms and they and their domestic animals eat crops from the farms. A clear correlation was found between the children's whole-body {sup 137}Cs counting results and the radioactivity in their food (correlation coefficient: 0.76; confidence level of correlation: 3.2 x 10{sup {minus}9}). There were also significant correlations between the whole-body {sup 137}Cs counting results and both the radioactivity of the soil samples (correlation coefficient: 0.22; confidence level of correlation: 0.0107) and the average contamination level of their current residence (correlation coefficient: 0.20; confidence level of correlation: 0.0174).

  15. Long-term reduction in (137)Cs concentration in food crops on coral atolls resulting from potassium treatment.

    PubMed

    Robison, William L; Stone, E L; Hamilton, T F; Conrado, C L

    2006-01-01

    Bikini Island was contaminated on March 1, 1954 by the Bravo detonation (U.S. nuclear test series, Castle) at Bikini Atoll. About 90% of the estimated dose from nuclear fallout to potential island residents is from cesium-137 ((137)Cs) transferred from soil to plants that are consumed by residents. Thus, radioecology research efforts have been focused on removing (137)Cs from soil and/or reducing its uptake into vegetation. Most effective was addition of potassium (K) to soil that reduces (137)Cs concentration in fruits to 3-5% of pretreatment concentrations. Initial observations indicated this low concentration continued for some time after K was last applied. Long-term studies were designed to evaluate this persistence in more detail because it is very important to provide assurance to returning populations that (137)Cs concentrations in food (and, therefore, radiation dose) will remain low for extended periods, even if K is not applied annually or biennially. Potassium applied at 300, 660, 1260, and 2070 kg ha(-1) lead to a (137)Cs concentration in drinking-coconut meat that is 34, 22, 10, and about 4% of original concentration, respectively. Concentration of (137)Cs remains low 8-10 y after K is last applied. An explanation for this unexpected result is discussed.

  16. Biomonitoring fallout 137Cs in resident and migratory fishes collected along the southern coast of India and assessment of dose.

    PubMed

    Khan, Mohan Feroz; Wesley, Samuel Godwin

    2012-05-01

    The globally distributed fallout radionuclide (137)Cs was monitored in 25 resident and 22 migratory fish species collected from some regions of west and east coast of southern India to establish a baseline data. The samples were collected during June 2008 to June 2009. Higher level of (137)Cs was noted in planktivorous fishes and lower level in herbivores. A significant variation in (137)Cs was observed between fishes with different feeding habits and different migratory pattern. Oceanodromic migratory fishes displayed higher cesium levels than other migratory types. Similarly, migratory fishes displayed higher (137)Cs concentration compared to resident fishes. The overall range of (137)Cs varied from 0.06 to 0.3 Bq/kg in fishes. The biological concentration varied from 55 to 250. The average external dose rate to fishes was calculated to be 2.7 × 10(-7) μGy/h, while the internal dose rate varied from 8.50 × 10(-6) to 5.27 × 10(-5) μGy/h. The hazard quotient for fishes was found to be less than 1. The average intake of (137)Cs via fishes to the public was calculated to be 3.5 Bq/year and subsequently the committed effective dose was 0.05 μSv/year. The data obtained were less than global average and comparable to those of many regions.

  17. Long-Term Reduction in 137Cs Concentration in Food Crops on Coral Atolls Resulting from Potassium Treatment

    SciTech Connect

    Robison, W; Stone, E; Hamilton, T; Conrado, C

    2005-04-08

    Bikini Island was contaminated March 1, 1954 by the Bravo detonation (U.S nuclear test series, Castle) at Bikini Atoll. About 90% of the estimated dose from nuclear fallout to potential island residents is from cesium-137 ({sup 137}Cs) transferred from soil to plants that are consumed by residents. Thus, radioecology research efforts have been focused on removing {sup 137}Cs from soil and/or reducing its uptake into vegetation. Most effective was addition of potassium (K) to soil that reduces {sup 137}Cs concentration in fruits to 3-5% of pretreatment concentrations. Initial observations indicated this low concentration continued for some time after K was last applied. Long-term studies were designed to evaluate this persistence in more detail because it is very important to provide assurance to returning populations that {sup 137}Cs concentrations in food (and, therefore, radiation dose) will remain low for extended periods, even if K is not applied annually or biennially. Potassium applied at 300, 660, 1260, and 1970 kg ha{sup -1} lead to a {sup 137}Cs concentration in drinking coconut meat that is 34, 22, 10, and about 4 % of original concentration, respectively. Concentration of {sup 137}Cs remains low 8 to 10 y after K is last applied. An explanation for this unexpected result is discussed.

  18. Long-Term Reduction in 137Cs Concentration in Food Crops on Coral Atolls Resulting from Potassium Treatment

    SciTech Connect

    Robison, W L; Stone, E L; Hamilton, T F; Conrado, C L

    2004-04-14

    Bikini Island was contaminated March 1, 1954 by the Bravo detonation (U.S nuclear test series, Castle) at Bikini Atoll. About 90% of the estimated dose from nuclear fallout to potential island residents is from cesium-137 ({sup 137}Cs) transferred from soil to plants that are consumed by residents. Thus, radioecology research efforts have been focused on removing {sup 137}Cs from soil and/or reducing its uptake into vegetation. Most effective was addition of potassium (K) to soil that reduces {sup 137}Cs concentration in fruits to 3-5% of pretreatment concentrations. Initial observations indicated this low concentration continued for some time after K was last applied. Long-term studies were designed to evaluate this persistence in more detail because it is very important to provide assurance to returning populations that {sup 137}Cs concentrations in food (and, therefore, radiation dose) will remain low for extended periods, even if K is not applied annually or biennially. Potassium applied at 300, 660, 1260, and 2070 kg ha{sup -1} lead to a {sup 137}Cs concentration in drinking coconut meat that is 34, 22, 10, and about 4% of original concentration, respectively. Concentration of {sup 137}Cs remains low 8 to 10 y after K is last applied. An explanation for this unexpected result is discussed.

  19. Inoculation with arbuscular mycorrhizae does not improve 137Cs uptake in crops grown in the Chernobyl region.

    PubMed

    Vinichuk, M; Mårtensson, A; Rosén, K

    2013-12-01

    Methods for cleaning up radioactive contaminated soils are urgently needed. In this study we investigated whether the use of arbuscular mycorrhizal (AM) fungi can improve (137)Cs uptake by crops. Barley, cucumber, perennial ryegrass, and sunflower were inoculated with AM fungi and grown in low-level radionuclide contaminated soils in a field experiment 70 km southwest of Chernobyl, Ukraine, during two successive years (2009-2010). Roots of barley, cucumber and sunflower plants were slightly or moderately infected with AM fungus and root infection frequency was negatively or non-correlated with (137)Cs uptake by plants. Roots of ryegrass were moderately infected with AM fungus and infection frequency was moderately correlated with (137)Cs uptake by ryegrass. The application of AM fungi to soil in situ did not enhance radionuclide plant uptake or biomass. The responsiveness of host plants and AM fungus combination to (137)Cs uptake varied depending on the soil, although mycorrhization of soil in the field was conditional and did not facilitate the uptake of radiocesium. The total amount of (137)Cs uptake by plants growing on inoculated soil was equal to amounts in plant cultivated on non-inoculated soil. Thus, the use of AM fungi in situ for bioremediation of soil contaminated with a low concentration of (137)Cs could not be recommended.

  20. Gamma Ray Bursts - Observations

    NASA Technical Reports Server (NTRS)

    Gehrels, N.; Cannizzo, J. K.

    2010-01-01

    We are in an exciting period of discovery for gamma-ray bursts. The Swift observatory is detecting 100 bursts per year, providing arcsecond localizations and sensitive observations of the prompt and afterglow emission. The Fermi observatory is observing 250 bursts per year with its medium-energy GRB instrument and about 10 bursts per year with its high-energy LAT instrument. In addition, rapid-response telescopes on the ground are providing new capabilities to study optical emission during the prompt phase and spectral signatures of the host galaxies. The combined data set is enabling great advances in our understanding of GRBs including afterglow physics, short burst origin, and high energy emission.

  1. The Compton Gamma Ray Observatory

    NASA Technical Reports Server (NTRS)

    Gehrels, N.; Chipman, E.; Kniffen, D.

    1994-01-01

    The Arthur Holly Compton Gamma Ray Observatory Compton) is the second in NASA's series of great Observatories. Launched on 1991 April 5, Compton represents a dramatic increase in capability over previous gamma-ray missions. The spacecraft and scientific instruments are all in good health, and many significant discoveries have already been made. We describe the capabilities of the four scientific instruments, and the observing program of the first 2 years of the mission. Examples of early discoveries by Compton are enumerated, including the discovery that gamma-ray bursts are isotropic but spatially inhomogeneous in their distribution; the discovery of a new class of high-energy extragalacatic gamma-ray sources, the gamma-ray AGNs; the discovery of emission from SN 1987A in the nuclear line of Co-57; and the mapping of emission from Al-26 in the interstellar medium (ISM) near the Galactic center. Future observations will include deep surveys of selected regions of the sky, long-tem studies of individual objects, correlative studies of objects at gamma-ray and other energies, a Galactic plane survey at intermediate gamma-ray energies, and improved statistics on gamma-ray bursts to search for small anisotropies. After completion of the all-sky survey, a Guest Investigator program is in progress with guest observers' time share increasing from 30% upward for the late mission phases.

  2. The Compton Gamma Ray Observatory

    NASA Astrophysics Data System (ADS)

    Gehrels, N.; Chipman, E.; Kniffen, D.

    1994-06-01

    The Arthur Holly Compton Gamma Ray Observatory Compton) is the second in NASA's series of great Observatories. Launched on 1991 April 5, Compton represents a dramatic increase in capability over previous gamma-ray missions. The spacecraft and scientific instruments are all in good health, and many significant discoveries have already been made. We describe the capabilities of the four scientific instruments, and the observing program of the first 2 years of the mission. Examples of early discoveries by Compton are enumerated, including the discovery that gamma-ray bursts are isotropic but spatially inhomogeneous in their distribution; the discovery of a new class of high-energy extragalacatic gamma-ray sources, the gamma-ray AGNs; the discovery of emission from SN 1987A in the nuclear line of Co-57; and the mapping of emission from Al-26 in the interstellar medium (ISM) near the Galactic center. Future observations will include deep surveys of selected regions of the sky, long-tem studies of individual objects, correlative studies of objects at gamma-ray and other energies, a Galactic plane survey at intermediate gamma-ray energies, and improved statistics on gamma-ray bursts to search for small anisotropies. After completion of the all-sky survey, a Guest Investigator program is in progress with guest observers' time share increasing from 30% upward for the late mission phases.

  3. High energy gamma ray astronomy

    NASA Technical Reports Server (NTRS)

    Fichtel, Carl E.

    1987-01-01

    High energy gamma ray astronomy has evolved with the space age. Nonexistent twenty-five years ago, there is now a general sketch of the gamma ray sky which should develop into a detailed picture with the results expected to be forthcoming over the next decade. The galactic plane is the dominant feature of the gamma ray sky, the longitude and latitude distribution being generally correlated with galactic structural features including the spiral arms. Two molecular clouds were already seen. Two of the three strongest gamma ray sources are pulsars. The highly variable X-ray source Cygnus X-3 was seen at one time, but not another in the 100 MeV region, and it was also observed at very high energies. Beyond the Milky Way Galaxy, there is seen a diffuse radiation, whose origin remains uncertain, as well as at least one quasar, 3C 273. Looking to the future, the satellite opportunities for high energy gamma ray astronomy in the near term are the GAMMA-I planned to be launched in late 1987 and the Gamma Ray Observatory, scheduled for launch in 1990. The Gamma Ray Observatory will carry a total of four instruments covering the entire energy range from 30,000 eV to 3 x 10 to the 10th eV with over an order of magnitude increase in sensitivity relative to previous satellite instruments.

  4. Gamma Ray Pulsars: Multiwavelength Observations

    NASA Technical Reports Server (NTRS)

    Thompson, David J.

    2004-01-01

    High-energy gamma rays are a valuable tool for studying particle acceleration and radiation in the magnetospheres of energetic pulsars. The seven or more pulsars seen by instruments on the Compton Gamma Ray Observatory (CGRO) show that: the light curves usually have double-peak structures (suggesting a broad cone of emission); gamma rays are frequently the dominant component of the radiated power; and all the spectra show evidence of a high-energy turnover. For all the known gamma-ray pulsars, multiwavelength observations and theoretical models based on such observations offer the prospect of gaining a broad understanding of these rotating neutron stars. The Gamma-ray Large Area Space Telescope (GLAST), now in planning for a launch in 2006, will provide a major advance in sensitivity, energy range, and sky coverage.

  5. Radioisotope identification method for poorly resolved gamma-ray spectrum of nuclear security concern

    NASA Astrophysics Data System (ADS)

    Ninh, Giang Nguyen; Phongphaeth, Pengvanich; Nares, Chankow; Hao, Quang Nguyen

    2016-01-01

    Gamma-ray signal can be used as a fingerprint for radioisotope identification. In the context of radioactive and nuclear materials security at the border control point, the detection task can present a significant challenge due to various constraints such as the limited measurement time, the shielding conditions, and the noise interference. This study proposes a novel method to identify the signal of one or several radioisotopes from a poorly resolved gamma-ray spectrum. In this method, the noise component in the raw spectrum is reduced by the wavelet decomposition approach, and the removal of the continuum background is performed using the baseline determination algorithm. Finally, the identification of radioisotope is completed using the matrix linear regression method. The proposed method has been verified by experiments using the poorly resolved gamma-ray signals from various scenarios including single source, mixing of natural uranium with five of the most common industrial radioactive sources (57Co, 60Co, 133Ba, 137Cs, and 241Am). The preliminary results show that the proposed algorithm is comparable with the commercial method.

  6. New concepts for scintillator/HgI[sub 2] gamma ray spectroscopy

    SciTech Connect

    Wang, Y.J.; Iwanczyk, J.S.; Patt, B.E. )

    1994-08-01

    The construction of a high energy resolution gamma ray detector consisting of a scintillator/mercuric iodide photodetector combination has been investigated. Several HgI[sub 2] photodetectors have been fabricated and tested with standard NIM electronics. The energy resolution of a scintillator/HgI[sub 2] pair was found to be 4.75%, full width at half maximum, for 662 keV [sup 137]Cs gamma ray photons. Of five detectors fabricated with the new technique, all produced resolutions better than 5.6% FWHM. This technology makes it possible to reliably produce high quality HgI[sub 2] photodetectors. New design concepts for the HgI[sub 2] photocell, including the transparent entrance electrode, detector geometry, and detector packaging, are described in the paper. Advantages of gamma ray spectrometers based upon crystal scintillators optically coupled to HgI[sub 2] photodetectors (in contrast to coupling the scintillators to the more conventional light sensors, i.e., photomultiplier tubes (PMTs)) include greater ruggedness, improved energy resolution, markedly smaller size and weight, reduced power, and insensitivity to magnetic field perturbations.

  7. Radioisotope identification method for poorly resolved gamma-ray spectrum of nuclear security concern

    SciTech Connect

    Ninh, Giang Nguyen; Phongphaeth, Pengvanich Nares, Chankow; Hao, Quang Nguyen

    2016-01-22

    Gamma-ray signal can be used as a fingerprint for radioisotope identification. In the context of radioactive and nuclear materials security at the border control point, the detection task can present a significant challenge due to various constraints such as the limited measurement time, the shielding conditions, and the noise interference. This study proposes a novel method to identify the signal of one or several radioisotopes from a poorly resolved gamma-ray spectrum. In this method, the noise component in the raw spectrum is reduced by the wavelet decomposition approach, and the removal of the continuum background is performed using the baseline determination algorithm. Finally, the identification of radioisotope is completed using the matrix linear regression method. The proposed method has been verified by experiments using the poorly resolved gamma-ray signals from various scenarios including single source, mixing of natural uranium with five of the most common industrial radioactive sources (57Co, 60Co, 133Ba, 137Cs, and 241Am). The preliminary results show that the proposed algorithm is comparable with the commercial method.

  8. Freundlich and dual Langmuir isotherm models for predicting 137Cs binding on Savannah River Site soils.

    PubMed

    Goto, Momoko; Rosson, Robert; Wampler, J Marion; Elliott, W Crawford; Serkiz, Steven; Kahn, Bernd

    2008-01-01

    Distribution of 137Cs and stable cesium between aqueous solution and near-surface soil samples from five locations at the Savannah River Site was measured in order to develop a predictive model for 137Cs uptake by the soils. Sorption of 137Cs in these soils appears to be mostly by hydroxy-interlayered vermiculite. Batch sorption studies with 4 d for equilibration were conducted at three cesium concentrations and at two backing electrolyte (NaNO3) concentrations. The soil-solution mixtures were pH-adjusted to evaluate the effects of pH on cesium sorption. Sorbed cesium was related to the equilibrium aqueous cesium concentrations by a Freundlich isotherm model. Model fits on logarithmic scales have a common slope of 0.60 +/- 0.03 for acidic mixtures and 0.69 +/- 0.04 for neutralized mixtures but have unique intercepts that are influenced by backing electrolyte concentration and pH. An ion-exchange model is proposed that pertains to all five soils and relates the Freundlich isotherms to the cation exchange capacity of soil and the aqueous concentrations of cesium, sodium, and a third ionic species that was hydrogen in the acidic mixtures and potassium in the neutralized mixtures. Model fits are consistent with Kd values in the entire range of 5-2,300 L kg(-1) determined for the five soil types. As an alternate model, dual Langmuir isotherms were fitted to the data. The results suggest cesium sorption by (1) relatively few interlayer-wedge sites, highly selective for cesium, and (2) much more abundant but less selective sites on internal and external planar surfaces.

  9. Evidence of 131I and (134,137)Cs activities in Bordeaux, France due to the Fukushima nuclear accident.

    PubMed

    Perrot, F; Hubert, Ph; Marquet, Ch; Pravikoff, M S; Bourquin, P; Chiron, H; Guernion, P-Y; Nachab, A

    2012-12-01

    Following the Fukushima nuclear accident, low-background gamma spectrometry measurements were performed with HPGe detectors at the PRISNA platform located at the CENBG laboratory in Bordeaux, France. Different kinds of samples were collected and measured between March 26 and May 14, 2011. The first fission product observed was (131)I with maximum activity values of 2.4 mBq/m(3) in atmospheric dusts in air, 3.5 Bq/L in rain water, 15 Bq/kg in grass and 0.9 Bq/L in cow milk. The (134,137)Cs isotopes were also detected in air and in grass at a maximum level of 0.2 mBq/m(3) and 0.7 Bq/kg respectively, around one order of magnitude less than (131)I activity, but they were below detection limits in the other samples. All these activity values were consistent with others measured in France by IRSN and were well below those reported in May 1986 after the Chernobyl accident.

  10. Development of a Small-Sized, Flexible, and Insertable Fiber-Optic Radiation Sensor for Gamma-Ray Spectroscopy

    PubMed Central

    Yoo, Wook Jae; Shin, Sang Hun; Lee, Dong Eun; Jang, Kyoung Won; Cho, Seunghyun; Lee, Bongsoo

    2015-01-01

    We fabricated a small-sized, flexible, and insertable fiber-optic radiation sensor (FORS) that is composed of a sensing probe, a plastic optical fiber (POF), a photomultiplier tube (PMT)-amplifier system, and a multichannel analyzer (MCA) to obtain the energy spectra of radioactive isotopes. As an inorganic scintillator for gamma-ray spectroscopy, a cerium-doped lutetium yttrium orthosilicate (LYSO:Ce) crystal was used and two solid-disc type radioactive isotopes with the same dimensions, cesium-137 (Cs-137) and cobalt-60 (Co-60), were used as gamma-ray emitters. We first determined the length of the LYSO:Ce crystal considering the absorption of charged particle energy and measured the gamma-ray energy spectra using the FORS. The experimental results demonstrated that the proposed FORS can be used to discriminate species of radioactive isotopes by measuring their inherent energy spectra, even when gamma-ray emitters are mixed. The relationship between the measured photon counts of the FORS and the radioactivity of Cs-137 was subsequently obtained. The amount of scintillating light generated from the FORS increased by increasing the radioactivity of Cs-137. Finally, the performance of the fabricated FORS according to the length and diameter of the POF was also evaluated. Based on the results of this study, it is anticipated that a novel FORS can be developed to accurately measure the gamma-ray energy spectrum in inaccessible locations such as narrow areas and holes. PMID:26343667

  11. In Situ Remediation of {sup 137}Cs Contaminated Wetlands Using Naturally Occurring Minerals

    SciTech Connect

    Kaplan, D.I.

    1999-08-11

    Cesium-137 has contaminated a large area of the wetlands on the Savannah River Site. Remediation of the contaminated wetlands is problematic because current techniques destroy the sensitive ecosystem and generate a higher dose to workers. To address this problem, we proposed a non-trusive, in situ technology to sequester 137Cs in sediments. One intention of this study was to provide information regarding a go/no go decision for future work. Since the proof-of-concept was successful and several minerals were identified as potential candidates for this technology, a go decision was made.

  12. Transfer of 137Cs from Chernobyl debris and nuclear weapons fallout to different Swedish population groups.

    PubMed

    Rääf, C L; Hubbard, L; Falk, R; Agren, G; Vesanen, R

    2006-08-15

    Data from measurements on the body burden of (134)Cs, (137)Cs and (40)K in various Swedish populations between 1959 and 2001 has been compiled into a national database. The compilation is a co-operation between the Departments of Radiation Physics in Malmö and Göteborg, the National Radiation Protection Authority (SSI) and the Swedish Defense Research Agency (FOI). In a previous study the effective ecological half time and the associated effective dose to various Swedish populations due to internal contamination of (134)Cs and (137)Cs have been assessed using the database. In this study values of human body burden have been combined with data on the local and regional ground deposition of fallout from nuclear weapons tests (only (137)Cs) and Chernobyl debris (both (134)Cs and (137)Cs), which have enabled estimates of the radioecological transfer in the studied populations. The assessment of the database shows that the transfer of radiocesium from Chernobyl fallout to humans varies considerably between various populations in Sweden. In terms of committed effective dose over a 70 y period from internal contamination per unit activity deposition, the general (predominantly urban) Swedish population obtains 20-30 microSv/kBq m(-2). Four categories of populations exhibit higher radioecological transfer than the general population; i.) reindeer herders ( approximately 700 microSv/kBq m(-2)), ii.) hunters in the counties dominated by forest vegetation ( approximately 100 microSv/kBq m(-2)), iii.) rural non-farming populations living in sub-arctic areas (40-150 microSv/kBq m(-2)), and iv.) farmers ( approximately 50 microSv/kBq m(-2)). Two important factors determine the aggregate transfer from ground deposition to man; i.) dietary habits (intakes of foodstuff originating from natural and semi-natural ecosystems), and ii.) inclination to follow the recommended food restriction by the authorities. The transfer to the general population is considerably lower

  13. Gamma-ray spectroscopic determination of iodine-131 and cesium-137 in foods: Two collaborative studies

    SciTech Connect

    Baratta, E.J.; Easterly, D.G. )

    1989-07-01

    The AOAC method for iodine-131, cesium-137, and barium-140 in milk by gamma-ray spectroscopy (48.025-48.029) was extended to include other foods for the radionuclides iodine-131 and cesium-137. Two collaborative studies were performed to validate this extension. In the first study, a food sample containing 119 pCi {sup 131}I/kg and 53 pCi {sup 137}Cs/kg was sent to each of 45 laboratories for triplicate analyses. For 25 responses, the mean of the reported values was 123.8 pCi/kg for iodine-131, and for 27 responses, the mean was 53.4 pCi/kg for cesium-137. Repeatability (within-laboratory) standard deviations (Sr) for iodine-131 and cesium-137 were 4.6 and 3.7 pCi/kg, respectively. Reproducibility (among-laboratories) standard deviations (SR) for iodine-131 and cesium-137 were 12.1 and 6.0 pCi/kg, respectively. In the second study, a food sample containing 25 pCi {sup 131}I/kg and 27 pCi {sup 137}Cs/kg was sent to each of 54 laboratories for triplicate analyses. For 21 responses, the mean of the reported values was 25.0 pCi/kg for iodine-131, and for 19 responses, the mean was 28.9 pCi/kg for cesium-137. Sr Values were 4.0 and 1.6 pCi/kg for iodine-131 and cesium-137, respectively, and SR values were 5.0 and 2.8 pCi/kg, respectively. The method extension was adopted official first action.

  14. Modeling dynamics of (137)Cs in forest surface environments: Application to a contaminated forest site near Fukushima and assessment of potential impacts of soil organic matter interactions.

    PubMed

    Ota, Masakazu; Nagai, Haruyasu; Koarashi, Jun

    2016-05-01

    A process-based model for (137)Cs transfer in forest surface environments was developed to assess the dynamic behavior of Fukushima-derived (137)Cs in a Japanese forest. The model simulation successfully reproduced the observed data from 3year migration of (137)Cs in the organic and mineral soil layers at a contaminated forest near Fukushima. The migration of (137)Cs from the organic layer to the mineral soil was explained by the direct deposition pattern on the forest floor and the turnover of litter materials in the organic layer under certain ecological conditions. Long-term predictions indicated that more than 90% of the deposited (137)Cs would remain within the top 5cm of the soil for up to 30years after the accident, suggesting that the forest acts as an effective long-term reservoir of (137)Cs with limited transfer via the groundwater pathway. The model was also used to explore the potential impacts of soil organic matter (SOM) interactions on the mobility and bioavailability of (137)Cs in the soil-plant system. The simulation results for hypothetical organic soils with modified parameters of (137)Cs turnover revealed that the SOM-induced reduction of (137)Cs adsorption elevates the fraction of dissolved (137)Cs in the soil solution, thereby increasing the soil-to-plant transfer of (137)Cs without substantially altering the fractional distribution of (137)Cs in the soil. Slower fixation of (137)Cs on the flayed edge site of clay minerals and enhanced mobilization of the clay-fixed (137)Cs in organic-rich soils also appeared to elevate the soil-to-plant transfer of (137)Cs by increasing the fraction of the soil-adsorbed (exchangeable) (137)Cs. A substantial proportion (approximate 30%-60%) of (137)Cs in these organic-rich soils was transferred to layers deeper than 5cm decades later. These results suggested that SOM influences the behavior of (137)Cs in forests over a prolonged period through alterations of adsorption and fixation in the soil.

  15. Life-long accumulation of 137Cs and 40K in the vertebral column of a cow.

    PubMed

    Pichl, Elke; Rabitsch, Herbert

    2013-01-01

    We have investigated the accumulation of (137)Cs and (40)K in all the tissues and organs of an adult slaughtered Austrian "mountain pasture cow". In this paper we present measured (137)Cs- and (40)K-activity concentrations in different tissues of the vertebral bodies, in their other bony components and in all the vertebrae forming the vertebral column. Data are also given for activity concentrations of adherent tissues, and for activities of both the components and the whole vertebral column. The dairy cow was born in a highly contaminated region of Styria, Austria, at the time of the radioactive fallout following the Chernobyl accident. Both radionuclides were incorporated during life-long ingestion and their accumulation in all the vertebrae up to the day of slaughtering was determined by high-purity germanium detectors. Our results show considerable variations of (137)Cs- and (40)K-activity concentrations in the components of a certain vertebra, within vertebrae of a particular region, and between vertebrae of different regions of the vertebral column. Particularly, the courses of (137)Cs- and (40)K-activity concentrations in trabecular bone, cortical bone and intervertebral discs of thoracic vertebral bodies are subdivided by a strong drop into two sections. Mean values of (137)Cs-concentration in vertebral bodies of these subsections vary by a factor 4. Compared with corresponding quantities for the skeleton, total mass, as well as total (137)Cs- and (40)K-activities of the whole vertebral column came to 14%, and approximately 38% for each (137)Cs and (40)K, respectively.

  16. Spatial patterns of (137)Cs inventories and soil erosion from earth-banked terraces in the Yimeng Mountains, China.

    PubMed

    Zhang, Yunqi; Long, Yi; An, Juan; Yu, Xingxiu; Wang, Xiaoli

    2014-10-01

    The Yimeng Mountains is one of China's most susceptible regions to soil erosion. In this region, slopes are composed of granite- or gneiss-derived soils that are commonly cultivated using earth-banked terraces. Based on the (137)Cs measurement for nine reference cores, the present study analysed the spatial patterns of (137)Cs inventory and soil erosion using 105 sampling points in a seven-level earth-banked terrace system. The mean (137)Cs inventory, standard deviation, coefficient of variation, and allowable error for the nine reference cores were 987 Bq m(-2), 71 Bq m(-2), 7%, and 6%, respectively, values that may reflect the heterogeneity of the initial (137)Cs fallout deposit. Within each terrace, the (137)Cs inventory generally increases from the rear edge to the front edge, accompanied by a decrease in the erosion rate. This results from planation by tillage and rainfall runoff during the development of the earth-banked terraces. Across the entire seven-level terrace system, (137)Cs inventories decrease from the highest terrace downwards, but increase in the lower terraces, whereas erosion rate displays the opposite trend. These trends are the result of the combined effects of the earth-bank segmented hillslope, the limited protection of the earth banks, and rainfall runoff in combination with tillage. The high coefficients of variation of (137)Cs inventories for the 21 sampling rows, with a mean value of 44%, demonstrate the combined effects of variations in original microtopography, anthropogenic disturbance, the incohesive soils weathered from underlying granite, and the warm climate. Although earth-banked terraces can reduce soil erosion to some extent, the estimated erosion rates for the study area are still very high.

  17. Potassium fertilization and (137)Cs transfer from soil to grass and barley in Sweden after the Chernobyl fallout.

    PubMed

    Rosén, K; Vinichuk, M

    2014-04-01

    Fertilization of soils contaminated by radionuclides with potassium (K) and its effect on (137)Cs transfer from soil to crops is well studied in field conditions; however experiments over many years are few. The effects of potassium fertilization on cesium-137 ((137)Cs) transfer to hay, pasture grass, and barley growing on organic rich soils and mineral sand and loam soils in a number of field experimental sites situated in different environments in Sweden are summarized and discussed. The basic experimental treatments were control (no K fertilizers were applied), 50, 100, and 200 kg K ha(-1). In the experiment, which lasted over 3-6 years, (137)Cs transfer factors in control treatments ranged between 0.0004 m(2) kg(-1) (barley grain on sand soil) and 0.07 m(2) kg(-1) (pasture grass on organic rich soil). Potassium application on soils with low clay content i.e. mineral sand and organic rich soils was effective at the 50-100 kg ha(-1) level. Application of 200 kg K ha(-1) resulted in a five-fold reduction in (137)Cs transfer for hay and up to four-fold for barley grain. The effects of potassium application were generally greater on sand than organic rich soil and were observed already in the first cut. After K application, the reduction in (137)Cs transfer to crops was correlated with (137)Cs:K ratios in plant material. Additional application of zeolite caused a 1.4 reduction of (137)Cs transfer to hay on sand and 1.8-fold reduction on organic rich soil; whereas, application of potash-magnesia and CaO had no effect.

  18. 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.

  19. Genotypic difference in (137)Cs accumulation and transfer from the contaminated field in Fukushima to azuki bean (Vigna angularis).

    PubMed

    Win, Khin Thuzar; Oo, Aung Zaw; Kojima, Katsuhiro; Salem, Djedidi; Yamaya, Hiroko; Bellingrath-Kimura, Sonoko Dorothea; Tomooka, Norihiko; Kaga, Akito; Ohkama-Ohtsu, Naoko; Yokoyama, Tadashi

    2016-07-01

    The screening of mini-core collection of azuki bean accessions (Vigna angularis (Willd.) Ohwi & Ohashi) for comparative uptake of (137)Cs in their edible portions was done in field trials on land contaminated by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. Ninety seven azuki bean accessions including their wild relatives from a Japanese gene bank, were grown in a field in the Fukushima prefecture, which is located approximately 51 km north of FDNPP. The contamination level of the soil was 3665 ± 480 Bq kg(-1) dry weight ((137)Cs, average ± SD). The soil type comprised clay loam, where the sand: silt: clay proportion was 42:21:37. There was a significant varietal difference in the biomass production, radiocaesium accumulation and transfer factor (TF) of radiocaesium from the soil to edible portion. Under identical agricultural practice, the extent of (137)Cs accumulation by seeds differed between the accessions by as much as 10-fold. Inter-varietal variation was expressed at the ratio of the maximum to minimum observed (137)Cs transfer factor for seeds ranged from 0.092 to 0.009. The total biomass, time to flowering and maturity, and seed yield had negative relationship to (137)Cs activity concentration in seeds. The results suggest that certain variety/varieties of azuki bean which accumulated less (137)Cs in edible portion with preferable agronomic traits are suitable to reduce the (137)Cs accumulation in food chain on contaminated land.

  20. 137Cs in fungal sporocarps in relation to vegetation in a bog, pine swamp and forest along a transect.

    PubMed

    Vinichuk, M; Rosén, K; Dahlberg, A

    2013-01-01

    In this study, we estimated the relative importance of vegetation and fungi for radiocesium uptake and biological retention in adjacent bog, pine swamp, and forest. The measurements for (137)Cs activity concentration in sporocarps (i.e. fruitbodies of fungi) and vegetation along a bog to forest transect were combined with complementary published data to calculate estimates. Aboveground vegetation comprised 17.7% of the total fallout-derived radiocesium in the system in bog, 16.5% in pine swamp, and 40.6% in forest. In fungal sporocarps grown along a gradient, (137)Cs activity comprised <0.001% of the total radiocesium for peat bog, <0.02% for pine swamp, and 0.11% for forest. Total (137)Cs activity in sporocarps increased along the gradient due to increased production of sporocarps in the presence of trees from 0.006 (bog), 0.097 (pine swamp) and 0.67 (forest) g dwt m(-2). Based on calculation of the total vegetation biomass and through relationships between fungal biomass in sporocarps and as mycelia in soil, the total (137)Cs activity located in fungi was estimated as 0.1% in bog, 2% in pine swamp, and 11% in forest. An analysis of the time-dependency of (137)Cs in the sporocarps in forest between 1990 and 2011 suggested an ecological half-life for (137)Cs between 8 and 13 years. Although fungi comprised a relatively small fraction of the total radiocesium in the systems, its activity decreased slowly with time, and ecological residence time for (137)Cs in sporocarps of fungi was long, suggesting they will continue to contribute to the accumulation and cycling of this radionuclide in forest.

  1. Pre- and post-accident (129)I and (137)Cs levels, and (129)I/(137)Cs ratios in soil near the Fukushima Dai-ichi Nuclear Power Plant, Japan.

    PubMed

    Matsunaka, Tetsuya; Sasa, Kimikazu; Sueki, Keisuke; Takahashi, Tsutomu; Satou, Yukihiko; Matsumura, Masumi; Kinoshita, Norikazu; Kitagawa, Jun-ichi; Matsuzaki, Hiroyuki

    2016-01-01

    To evaluate the deposition density and extent of subsurface infiltration of (129)I and (137)Cs in the restricted area that was highly contaminated by the accident of Fukushima Dai-ichi Nuclear Power Plant, cumulative inventories of (129)I and (137)Cs, concentrations of (129)I and (137)Cs, and (129)I/(137)Cs ratio in 30-cm-long soil columns were compared with pre-accident levels from the same area. The cores were collected before and after the accident from locations of S-1 (4 km west of FDNPP) and S-2 (8 km west of FDNPP). Deposition densities of (129)I and (137)Cs in the soil following the accident were 0.90-2.33 Bq m(-2) and 0.80-4.04 MBq m(-2), respectively, which were 14-39 and 320-510 times larger than the pre-accident levels of (129)I (59.3-63.3 mBq m(-2)) and (137)Cs (2.51-7.88 kBq m(-2)), respectively. Approximately 90% of accident-derived (129)I and (137)Cs deposited in the 30-cm soil cores was concentrated in the surface layer from 0 to 44-95 kg m(-2) of mass depth (0-4.3-6.2 cm depth) and from 0 to 16-25 kg m(-2) of mass depth (0-1.0-3.1 cm depth), respectively. The relaxation mass depths (h0) of 10.8-11.2 kg m(-2) for (129)I estimated in the previous study were larger than those of 8.1-10.6 kg m(-2) for (137)Cs at both sites, owing to the larger infiltration depth of radioiodine mainly by the gravitational water penetration in the surface soil in our study sites. Approximately 7-9% of the accident-derived (129)I was present in the lower layer from 44 to 100 kg m(-2) (4.3-8.6 cm depth) at S-1, and from 95 to 160 kg m(-2) (6.2-10.2 cm depth) at S-2. Approximately 1% of (137)Cs seems to infiltrate deeper than (129)I in the lower layer at each site in contrast to the surface layer.

  2. Estimation of sedimentation rate in the Middle and South Adriatic Sea using 137Cs.

    PubMed

    Petrinec, Branko; Franic, Zdenko; Ilijanic, Nikolina; Miko, Slobodan; Strok, Marko; Smodis, Borut

    2012-08-01

    (137)Cs activity concentrations were studied in the sediment profiles collected at five locations in the Middle and South Adriatic. In the sediment profiles collected from the South Adriatic Pit, the deepest part of the Adriatic Sea, two (137)Cs peaks were identified. The peak in the deeper layer was attributed to the period of intensive atmospheric nuclear weapon tests (early 1960s), and the other to the Chernobyl nuclear accident (1986). Those peaks could be used to estimate sedimentation rates by relating them to the respective time periods. Grain-size analysis showed no changes in vertical distribution through the depth of the sediment profile, and these results indicate uniform sedimentation, as is expected in deeper marine environments. It was not possible to identify respective peaks on more shallow locations due to disturbance of the seabed either by trawlers (locations PalagruŽa and Jabuka) or by river sediment (location Albania). The highest sedimentation rates were found in Albania (∼4 mm y(-1)) and Jabuka (3.1 mm y(-1)). For PalagruŽa, the sedimentation rate was estimated to be 1.8 mm y(-1), similar to the South Adriatic Pit where the sedimentation rate was estimated to be 1.8±0.5 mm y(-1). Low sedimentation rates found for the Middle and South Adriatic Sea are consistent with previously reported results for the rest of the Mediterranean.

  3. Removal of 137Cs from Dissolved Hanford Tank Saltcake by Treatment with IE-911

    SciTech Connect

    Rapko, Brian M. ); Sinkov, Serguei I. ); Levitskaia, Tatiana G. )

    2003-04-10

    The U.S. Department of Energy's Richland Operations Office plans to accelerate the cleanup of the Hanford Site. Testing new technology for the accelerated cleanup will require dissolved saltcake from single-shell tanks. However, the 137Cs will need to be removed from the saltcake to alleviate radiation hazards. A saltcake composite constructed from archived samples from Hanford Single Shell Tanks 241-S-101, 241-S-109, 241-S-110, 241-S-111, 241-U-106, and 241-U-109 was dissolved in water, adjusted to 5 M Na, and transferred from the 222-S building to the Radiochemical Processing Laboratory (RPL). At the RPL, the approximately 5.5 liters of solution was passed through a 0.2-micron polyethersulfone filter, collected, and homogenized. The filtered solution then was passed through an ion exchange column containing approximately 150 mL IONSIV IE-911, an engineered form of crystalline silicotitanate available from UOP, at approximately 200 mL/hour in a continuous operation until all of the feed solution had been run through the column. An analysis of the 137Cs concentrations in the initial feed solution and combined column effluent indicates that> 99.999 percent of the Cs in the feed solution was removed by this operation. This report describes the Cs-depletion operations together with a partial analysis of the as-received solution and a more extensive characterization of the Cs-depleted solution.

  4. Removal of 137-Cs from Dissolved Hanford Tank Saltcake by Treatment with IE-911

    SciTech Connect

    Rapko, Brian M.; Sinkov, Sergei I.; Levitskaia, Tatiana G.

    2003-12-09

    The U.S. Department of Energy’s Richland Operations Office plans to accelerate the cleanup of the Hanford Site. Testing new technology for the accelerated cleanup will require dissolved saltcake from single-shell tanks. However, the 137Cs will need to be removed from the saltcake to alleviate radiation hazards. A saltcake composite constructed from archived samples from Hanford Site single-shell tanks 241-S-101, 241-S-109, 241-S-110, 241-S-111, 241-U-106, and 241-U-109 was dissolved in water, adjusted to 5 M Na, and transferred from the 222-S Laboratory to the Radiochemical Processing Laboratory (RPL). At the RPL, the approximately 5.5 liters of solution was passed through a 0.2-micron polyethersulfone filter, collected, and homogenized. The filtered solution then was passed through an ion exchange column containing approximately 150 mL IONSIV® IE-911, an engineered form of crystalline silicotitanate available from UOP, at approximately 200 mL/hour in a continuous operation until all of the feed solution had been run through the column. An analysis of the 137Cs concentrations in the initial feed solution and combined column effluent indicates that > 99.999 percent of the Cs in the feed solution was removed by this operation. PNNR

  5. Adsorption and desorption kinetics of (60)Co and (137)Cs in fresh water rivers.

    PubMed

    Fiengo Pérez, Fabricio; Sweeck, Lieve; Bauwens, Willy; Van Hees, May; Elskens, Marc

    2015-11-01

    Radionuclides released in water systems--as well as heavy metals and organic toxicants--sorb to both the suspended solid particles and the bed sediments. Sorption is usually represented mathematically by the distribution coefficient. This approach implies equilibrium between phases and instantaneous fixation (release) of the pollutant onto (from) the surface of the soil particle. However, empirical evidence suggests that for some radionuclides the fixation is not achieved instantaneously and that the reversibility of the process can be slow. Here the adsorption/desorption kinetics of (60)Co and (137)Cs in fresh water environments were simulated experimentally and later on modelled mathematically, while the influence of the most relevant factors affecting the sorption were taken into account. The experimental results suggest that for adsorption and the desorption more than 24 h are needed to reach equilibrium, moreover, It was observed that the desorption rate constants for (60)Co and (137)Cs lie within ranges which are of two to three orders of magnitude lower than the adsorption rate constants.

  6. Study of environmental radioactivity in Palestine by in situ gamma-ray spectroscopy.

    PubMed

    Lahham, Adnan; Al-Masri, Hussein; Judeh, Adnan

    2009-07-01

    This work presents qualitative and quantitative evaluation of environmental radioactivity in the central and southern areas of the West Bank, Palestine. For this purpose, the technology of in situ gamma-ray spectroscopy is used with a scintillation of 7.6 x 7.6 cm NaI(Tl) crystal connected to multichannel analyzer InSpector 2000 from Canberra instruments and laptop computer. Gamma-ray spectra were collected using the detector placed 1 m above the ground surface. Calibration of the detection system for in situ measurements of gamma-emitting radionuclides in open terrain is performed theoretically using Monte Carlo techniques. Measurements are conducted in 18 locations in 3 regions across the West Bank. The vast majority of identified radionuclides are naturally occurring gamma-emitting sources (the decay products of (238)U, (232)Th and (40)K). The only identified anthropogenic radionuclide is (137)Cs. Activity concentrations of (40)K, (238)U, (232)Th as well as the total outdoor gamma dose rate from these radionuclides were determined from the gamma-ray spectra. The highest activity concentrations of the three primordial radionuclides were 203 Bq kg(-1) for (40)K, 32 Bq kg(-1) for (238)U and 30 Bq kg(-1) for (232)Th. The total outdoor gamma dose rate calculated for the whole study area at 1 m above ground ranged from 6 to 30 nGy h(-1) with a mean of 18 +/- 7 nGy h(-1), which represents about 30% of the world average value.

  7. Uncertainties in dose coefficients from ingestion of 131I, 137Cs, and 90Sr.

    PubMed

    Apostoaei, A Iulian; Miller, Laurence F

    2004-05-01

    Quantification of uncertainties in doses from intakes of radionuclides is important in risk assessments and epidemiologic studies of individuals exposed to radiation. In this study, the uncertainties in the doses per unit intake (i.e., dose coefficients) for ingestion of 131I, 137Cs, and 90Sr by healthy individuals have been determined. Age-dependent thyroid dose coefficients were derived for 131I. The analysis for 131I uses recent measurements of thyroid volume obtained by ultrasonography, which indicate a thyroid mass lower than that previously obtained using autopsy measurements. The coefficients for 137Cs are determined using the relationship between the biological half-lives and the amount of potassium in the human body. The most recent International Commission on Radiological Protection biokinetic model was employed to determine the uncertainties for 90Sr. For 137Cs and 90Sr, the dose coefficients represent exposure in adulthood and they were determined for all organs of radiological importance. The uncertainty in the estimated dose coefficients represent state of knowledge estimates for a reference individual, and they are described by lognormal distributions with a specified geometric mean (GM) and geometric standard deviation (GSD). The estimated geometric means vary only slightly from the dose coefficients reported by ICRP publications. The largest uncertainty is observed in the dose coefficients for bone surface (GSD = 2.6), and red bone marrow (GSD = 2.4) in the case of ingestion of 90Sr. For most other organs, the uncertainty in the 90Sr dose coefficients is characterized by a GSD of 1.8 (or less for some organs). For 131I, the uncertainty in the thyroid dose coefficients is well represented by a GSD of 1.7 for both sexes and all ages other than infants for whom a GSD of 1.8 is more appropriate. The lowest uncertainties are obtained for the dose coefficients from ingestion of 137Cs (GSD = 1.24 for males; 1.4 for females). A dominant source of

  8. Jet Shockwaves Produce Gamma Rays

    NASA Video Gallery

    Theorists believe that GRB jets produce gamma rays by two processes involving shock waves. Shells of material within the jet move at different speeds and collide, generating internal shock waves th...

  9. Post-Chernobyl 137Cs in the atmosphere of Thessaloniki: a consequence of the financial crisis in Greece.

    PubMed

    Stoulos, S; Ioannidou, A; Vagena, E; Koseoglou, P; Manolopoulou, M

    2014-02-01

    The background radiation level of (137)Cs at the urban atmosphere of Thessaloniki has been increased during the recent decade only due to the Fukushima accident fallout. Since then, no other signal of (137)Cs was observed until the winter period of 2013, when slightly elevated (137)Cs concentrations were measured. The (137)Cs signals observed were up to 12 μBq m(-3), mainly during holidays and weekends followed by lower or even non-detectable activities in the next working days. Those episodes are attributed to the increase of biomass products combustion for residential heating as this year the tax of oil for heating was drastically raised as a consequence of the financial crisis. A preliminary survey of various wood products as well as of bottom ashes from different domestic burning devices is presented. (137)Cs concentrations up to 11 Bq kg(-1) were measured in wood products and up to 500 Bq kg(-1) in ash samples.

  10. Use of (137)Cs technique for soil erosion study in the agricultural region of Casablanca in Morocco.

    PubMed

    Nouira, A; Sayouty, E H; Benmansour, M

    2003-01-01

    Accelerated erosion and soil degradation currently cause serious problems to the Oued El Maleh basin (Morocco). Furthermore, there is still only limited information on rates of soil loss for optimising strategies for soil conservation. In the present study we have used the (137)Cs technique to assess the soil erosion rates on an agricultural land in Oued el Maleh basin near Casablanca (Morocco). A small representative agricultural field was selected to investigate the soil degradation required by soil managers in this region. The transect approach was applied for sampling to identify the spatial redistribution of (137)Cs. The spatial variability of (137)Cs inventory has provided evidence of the importance of tillage process and the human effects on the redistribution of (137)Cs. The mean (137)Cs inventory was found about 842 Bq m(-2), this value corresponds to an erosion rate of 82 tha(-1) yr(-1) by applying simplified mass balance model in a preliminary estimation. When data on site characteristics were available, the refined mass balance model was applied to highlight the contribution of tillage effect in soil redistribution. The erosion rate was estimated about 50 tha(-1) yr(-1). The aspects related to the sampling procedures and the models for calculation of erosion rates are discussed.

  11. Gamma-ray-selected AGN

    NASA Astrophysics Data System (ADS)

    Giommi, Paolo

    2016-08-01

    The gamma-ray band is the most energetic part of the electromagnetic spectrum. As such it is also where selection effects are most severe, as it can only be reached by the most extreme non-thermal AGN. Blazars, with their emission dominated by non-thermal blue-shifted radiation arising in a relativistic jet pointed in the direction of the observer, naturally satisfy this though requirement. For this reason, albeit these sources are intrisically very rare (orders of magnitude less abundant than radio quiet AGN of the same optical magnitude) they almost completely dominate the extragalactic gamma-ray and very high energy sky. I will discuss the emission of different types of blazars and the selection effects that are at play in the gamma-ray band based on recent results from the current generation of gamma-ray astronomy satellites, ground-based Cherenkov telescopes, and Monte Carlo simulations.

  12. Effective half-lives of 134Cs and 137Cs in reindeer meat and in reindeer herders in Finland after the Chernobyl accident and the ensuing effective radiation doses to humans.

    PubMed

    Leppänen, Ari-Pekka; Muikku, Maarit; Jaakkola, Timo; Lehto, Jukka; Rahola, Tua; Rissanen, Kristina; Tillander, Michael

    2011-05-01

    Monitoring of 137Cs in reindeer herders and in reindeer meat in Finnish Lapland began in the early 1960s and has continued until today. The monitoring of 137Cs in reindeer herders and in reindeer meat in the Halla area began after the Chernobyl accident. In this study, reindeer herders together with reindeer meat samples were monitored for gamma-emitting radionuclides from two separate areas in the Finnish reindeer management area, Northern Finland and the Halla area. The effective half-lives determined for 137Cs in reindeer meat were from 3.0 ± 1.7 to 5.1 ± 0.5 y. For 134Cs, the observed effective half-lives in reindeer meat were from 1.3 ± 0.2 to 1.5 ± 0.1 y. The effective half-lives among male and female reindeer herders in Northern Finland were 5.5 ± 1.3 and 4.4 ± 0.9 y, respectively, for the body-burden of 137Cs. In the Halla reindeer herding cooperative, located to the south of Finnish Lapland in the province of Kuusamo, the effective half-lives in the reindeer herders were shorter, about 1-2 y. The 134Cs × 137Cs-1 ratios decreased more rapidly in reindeer meat and also in humans in the Halla area than in Northern Finland. This implies faster removal of Chernobyl-derived cesium from the reindeer-man food chain in the Halla area. The contribution of Chernobyl fallout (percent) in reindeer meat was 70% and 80% in the Paistunturi and Ivalo cooperatives, respectively, and 50% and 80% in the western and eastern part of Halla cooperative, respectively. In humans, the contribution of Chernobyl fallout to 137Cs in whole-body content was 60% in Northern Finland and 80% in the Halla area. The mean committed effective doses of Cs for reindeer herders in Finnish Lapland decreased from 0.36 mSv y-1 in 1987 to 0.053 mSv y-1 in 2005.

  13. Directional detector of gamma rays

    DOEpatents

    Cox, Samson A.; Levert, Francis E.

    1979-01-01

    A directional detector of gamma rays comprises a strip of an electrical cuctor of high atomic number backed with a strip of a second electrical conductor of low atomic number. These elements are enclosed within an electrical conductor that establishes an electrical ground, maintains a vacuum enclosure and screens out low-energy gamma rays. The detector exhibits a directional sensitivity marked by an increased output in the favored direction by a factor of ten over the output in the unfavored direction.

  14. Investigating the anisotropic scintillation response in anthracene through neutron, gamma-ray, and muon measurements

    DOE PAGES

    Schuster, Patricia; Brubaker, Erik

    2016-05-05

    Our paper reports a series of measurements that characterize the directional dependence of the scintillation response of crystalline anthracene to incident DT neutrons, DD neutrons, 137Cs gamma rays, and, for the first time, cosmic ray muons. Moreover, the neutron measurements give the amplitude and pulse shape dependence on the proton recoil direction over one hemisphere of the crystal, confirming and extending previous results in the literature. In similar measurements using incident gamma rays, no directional effect is evident, and any anisotropy with respect to the electron recoil direction is constrained to have a magnitude of less than a tenth ofmore » that present in the proton recoil events. Cosmic muons are measured at two directions, and no anisotropy is observed. Our set of observations indicates that high dE/dx is necessary for an anisotropy to be present for a given type of scintillation event, which in turn could be used to discriminate among different hypotheses for the underlying causes of the anisotropy, which are not well understood.« less

  15. 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.

  16. Porous three-dimensional graphene foam/Prussian blue composite for efficient removal of radioactive 137Cs

    PubMed Central

    Jang, Sung-Chan; Haldorai, Yuvaraj; Lee, Go-Woon; Hwang, Seung-Kyu; Han, Young-Kyu; Roh, Changhyun; Huh, Yun Suk

    2015-01-01

    In this study, a simple one-step hydrothermal reaction is developed to prepare composite based on Prussian blue (PB)/reduced graphene oxide foam (RGOF) for efficient removal of radioactive cesium (137Cs) from contaminated water. Scanning electron microscopy and transmission electron microscopy show that cubic PB nanoparticles are decorated on the RGO surface. Owing to the combined benefits of RGOF and PB, the composite shows excellent removal efficiency (99.5%) of 137Cs from the contaminated water. The maximum adsorption capacity is calculated to be 18.67 mg/g. An adsorption isotherm fit-well the Langmuir model with a linear regression correlation value of 0.97. This type of composite is believed to hold great promise for the clean-up of 137Cs from contaminated water around nuclear plants and/or after nuclear accidents. PMID:26670798

  17. Porous three-dimensional graphene foam/Prussian blue composite for efficient removal of radioactive (137)Cs.

    PubMed

    Jang, Sung-Chan; Haldorai, Yuvaraj; Lee, Go-Woon; Hwang, Seung-Kyu; Han, Young-Kyu; Roh, Changhyun; Huh, Yun Suk

    2015-12-16

    In this study, a simple one-step hydrothermal reaction is developed to prepare composite based on Prussian blue (PB)/reduced graphene oxide foam (RGOF) for efficient removal of radioactive cesium ((137)Cs) from contaminated water. Scanning electron microscopy and transmission electron microscopy show that cubic PB nanoparticles are decorated on the RGO surface. Owing to the combined benefits of RGOF and PB, the composite shows excellent removal efficiency (99.5%) of (137)Cs from the contaminated water. The maximum adsorption capacity is calculated to be 18.67 mg/g. An adsorption isotherm fit-well the Langmuir model with a linear regression correlation value of 0.97. This type of composite is believed to hold great promise for the clean-up of (137)Cs from contaminated water around nuclear plants and/or after nuclear accidents.

  18. Prediction of groundwater contamination with 137Cs and 131I from the Fukushima nuclear accident in the Kanto district.

    PubMed

    Ohta, Tomoko; Mahara, Yasunori; Kubota, Takumi; Fukutani, Satoshi; Fujiwara, Keiko; Takamiya, Koichi; Yoshinaga, Hisao; Mizuochi, Hiroyuki; Igarashi, Toshifumi

    2012-09-01

    We measured the concentrations of (131)I, (134)Cs, and (137)Cs released from the Fukushima nuclear accident in soil and rainwater samples collected March 30-31, 2011, in Ibaraki Prefecture, Kanto district, bordering Fukushima Prefecture to the south. Column experiments revealed that all (131)I in rainwater samples was adsorbed onto an anion-exchange resin. However, 30% of (131)I was not retained by the resin after it passed through a soil layer, suggesting that a portion of (131)I became bound to organic matter from the soil. The (137)Cs migration rate was estimated to be approximately 0.6 mm/y in the Kanto area, which indicates that contamination of groundwater by (137)Cs is not likely to occur in rainwater infiltrating into the surface soil after the Fukushima accident.

  19. Using 137 Cs measurements to investigate the influence of erosion and soil redistribution on soil properties.

    PubMed

    Du, P; Walling, D E

    2011-05-01

    Information on the interaction between soil erosion and soil properties is an important requirement for sustainable management of the soil resource. The relationship between soil properties and the soil redistribution rate, reflecting both erosion and deposition, is an important indicator of this interaction. This relationship is difficult to investigate using traditional approaches to documenting soil redistribution rates involving erosion plots and predictive models. However, the use of the fallout radionuclide (137)Cs to document medium-term soil redistribution rates offers a means of overcoming many of the limitations associated with traditional approaches. The study reported sought to demonstrate the potential for using (137)Cs measurements to assess the influence of soil erosion and redistribution on soil properties (particle size composition, total C, macronutrients N, P, K and Mg, micronutrients Mn, Mo, Fe, Cu and Zn and other elements, including Ti and As). (137)Cs measurements undertaken on 52 soil cores collected within a 7 ha cultivated field located near Colebrooke in Devon, UK were used to establish the magnitude and spatial pattern of medium-term soil redistribution rates within the field. The soil redistribution rates documented for the individual sampling points within the field ranged from an erosion rate of -12.9 t ha(-1) yr(-1) to a deposition rate of 19.2 t ha(-1) yr(-1). Composite samples of surface soil (0-5 cm) were collected immediately adjacent to each coring point and these samples were analysed for a range of soil properties. Individual soil properties associated with these samples showed significant variability, with CV values generally lying in the range 10-30%. The relationships between the surface soil properties and the soil redistribution rate were analysed. This analysis demonstrated statistically significant relationships between some soil properties (total phosphorus, % clay, Ti and As) and the soil redistribution rate, but for

  20. 137Cs(90Sr) and Pu isotopes in the Pacific Ocean sources & trends

    SciTech Connect

    Hamilton, T.F., Millies-Lacrox, J.C.; Hong, G.H.

    1996-11-01

    The main source of artificial radioactivity in the world`s oceans can be attributed to worldwide fallout from atmospheric nuclear weapons testing. Measurements of selected artificial radionuclides in the Pacific Ocean were first conducted in the 1960`s where it was observed that fallout radioactivity had penetrated the deep ocean. Extensive studies carried out during the 1973-74 GEOSECS provided the first comprehensive data on the lateral and vertical distributions of {sup 9O}Sr, {sup 137}Cs and Pu isotopes in the Pacific on a basin wide scale. Estimates of radionuclide inventories in excess of amounts predicted to be delivered by global fallout alone were attributed to close-in fallout and tropospheric inputs from early U.S. tests conducted on Bikini and Enewetak Atolls in the Equatorial Pacific. In general, levels of fallout radionuclides (including {sup 9O}Sr, {sup 137}Cs and Pu isotopes) in the surface waters of the Pacific Ocean have decreased considerably over the past 4 decades and are now much more homogeneously distributed. Resuspension and the subsequent deposition of fallout radionuclides from previously deposited debris on land has become an important source term for the surface ocean. This can be clearly seen in measurements of fallout radionuclides in mineral aerosols over the Korean Peninsula (Yellow dust events). Radionuclides may also be transported from land to sea in river runoff-these transport mechanisms are more important in the Pacific Ocean where large quantities of river water and suspended sands/fluvial sediments reach the coastal zone. Another unique source of artificial radionuclides in the Pacific Ocean is derived from the slow resolubilization and transport of radionuclides deposited in contaminated lagoon and slope sediments near U.S. and French test sites. Although there is a small but significant flux of artificial radionuclides depositing on the sea floor, > 80% of the total 239, {sup 240}Pu inventory and > 95% of the total {sup

  1. Compton Gamma-Ray Observatory

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This photograph shows the Compton Gamma-Ray Observatory being released from the Remote Manipulator System (RMS) arm aboard the Space Shuttle Atlantis during the STS-35 mission in April 1991. The GRO reentered the Earth's atmosphere and ended its successful mission in June 2000. For nearly 9 years, GRO's Burst and Transient Source Experiment (BATSE), designed and built by the Marshall Space Flight Center, kept an unblinking watch on the universe to alert scientist to the invisible, mysterious gamma-ray bursts that had puzzled them for decades. By studying gamma-rays from objects like black holes, pulsars, quasars, neutron stars, and other exotic objects, scientists could discover clues to the birth, evolution, and death of star, galaxies, and the universe. The gamma-ray instrument was one of four major science instruments aboard the Compton. It consisted of eight detectors, or modules, located at each corner of the rectangular satellite to simultaneously scan the entire universe for bursts of gamma-rays ranging in duration from fractions of a second to minutes. In January 1999, the instrument, via the Internet, cued a computer-controlled telescope at Las Alamos National Laboratory in Los Alamos, New Mexico, within 20 seconds of registering a burst. With this capability, the gamma-ray experiment came to serve as a gamma-ray burst alert for the Hubble Space Telescope, the Chandra X-Ray Observatory, and major gound-based observatories around the world. Thirty-seven universities, observatories, and NASA centers in 19 states, and 11 more institutions in Europe and Russia, participated in BATSE's science program.

  2. Compton Gamma-Ray Observatory

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This photograph shows the Compton Gamma-Ray Observatory (GRO) being deployed by the Remote Manipulator System (RMS) arm aboard the Space Shuttle Atlantis during the STS-37 mission in April 1991. The GRO reentered Earth atmosphere and ended its successful mission in June 2000. For nearly 9 years, the GRO Burst and Transient Source Experiment (BATSE), designed and built by the Marshall Space Flight Center (MSFC), kept an unblinking watch on the universe to alert scientists to the invisible, mysterious gamma-ray bursts that had puzzled them for decades. By studying gamma-rays from objects like black holes, pulsars, quasars, neutron stars, and other exotic objects, scientists could discover clues to the birth, evolution, and death of stars, galaxies, and the universe. The gamma-ray instrument was one of four major science instruments aboard the Compton. It consisted of eight detectors, or modules, located at each corner of the rectangular satellite to simultaneously scan the entire universe for bursts of gamma-rays ranging in duration from fractions of a second to minutes. In January 1999, the instrument, via the Internet, cued a computer-controlled telescope at Las Alamos National Laboratory in Los Alamos, New Mexico, within 20 seconds of registering a burst. With this capability, the gamma-ray experiment came to serve as a gamma-ray burst alert for the Hubble Space Telescope, the Chandra X-Ray Observatory, and major gound-based observatories around the world. Thirty-seven universities, observatories, and NASA centers in 19 states, and 11 more institutions in Europe and Russia, participated in the BATSE science program.

  3. The Compton Gamma Ray Observatory

    NASA Astrophysics Data System (ADS)

    Gehrels, N.; Chipman, E.; Kniffen, D. A.

    1993-01-01

    The Arthur Holly Compton Gamma Ray Observatory (Compton) was launched by the Space Shuttle Atlantis on 5 April 1991. The spacecraft and instruments are in good health and returning exciting results. The mission provides nearly six orders of magnitude in spectral coverage, from 30 keV to 30 GeV, with sensitivity over the entire range an order of magnitude better than that of previous observations. The 16,000 kilogram observatory contains four instruments on a stabilized platform. The mission began normal operations on 16 May 1991 and is now over half-way through a full-sky survey. The mission duration is expected to be from six to ten years. A Science Support Center has been established at Goddard Space Flight Center for the purpose of supporting a vigorous Guest Investigator Program. New scientific results to date include: (1) the establishment of the isotropy, combined with spatial inhomogeneity, of the distribution of gamma-ray bursts in the sky; (2) the discovery of intense high energy (100 MeV) gamma-ray emission from 3C 279 and other quasars and BL Lac objects, making these the most distant and luminous gamma-ray sources ever detected; (3) one of the first images of a gamma-ray burst; (4) the observation of intense nuclear and position-annihilation gamma-ray lines and neutrons from several large solar flares; and (5) the detection of a third gamma-ray pulsar, plus several other transient and pulsing hard X-ray sources.

  4. Influence of biologically-active substances on {sup 137}Cs and heavy metals uptake by Barley plant

    SciTech Connect

    Kruglov, Stanislav; Filipas, Alexander

    2007-07-01

    Available in abstract form only. Full text of publication follows: When solving the problem of contaminated agricultural lands rehabilitation, most of attention is concentrated on the effective means which allow the obtaining of ecologically safe production. The minimization of radionuclides and heavy metals (HM) content in farm products on the basis of their migration characteristics in agro-landscapes and with the regard for different factors influencing contaminants behavior in the soil-plant system is of great significance. Our investigation has shown that the effect of biologically active substances (BAS) using for seeds treatment on {sup 137}Cs transfer to barley grown on Cd contaminated soil was dependent on their properties and dosage, characteristics of soil contamination and biological peculiarities of plants, including stage of plants development. Seeds treatment by plant growth regulator Zircon resulted in a significant increase in {sup 137}Cs activity in harvest (40- 50%), increase in K concentration and significant reduction in Ca concentration. Increased Cd content in soil reduced {sup 137}Cs transfer to barley plants by 30-60% (p<0,05) and Zircon application further reduced its concentration. Ambiol and El also reduced {sup 137}Cs uptake by roots and Cd and Pb phyto-toxicity. The experimental data do not make it possible to link the BAS effect on inhibition of {sup 137}Cs absorption by plants directly with their influence on HM phyto-toxicity. The dependence of Concentration Ratio of {sup 137}Cs on the Ambiol and El dose was not proportional and the most significant decrease in the radionuclide uptake by plants was reported with the use of dose showing the most pronounced stimulating effect on the barley growth and development. The pre-sowing seed treatment with Ambiol increased Pb absorption by 35-50% and, on the contrary, decreased Cd uptake by plants by 30-40%. (authors)

  5. (137)Cs inter-plant concentration ratios provide a predictive tool for coral atolls with distinct benefits over transfer factors.

    PubMed

    Robison, William L; Hamilton, Terry F; Bogen, Kenneth T; Conrado, Cynthia L; Kehl, Steven R

    2008-01-01

    Inter-plant concentration ratios (IPCR) [Bqg(-1)(137)Cs in coral atoll tree food crops/Bqg(-1)(137)Cs in leaves of native plant species whose roots share a common soil volume] can replace transfer factors (TF) to predict (137)Cs concentration in tree food crops in a contaminated area with an aged source term. The IPCR strategy has significant benefits relative to TF strategy for such purposes in the atoll ecosystem. IPCR strategy applied to specific assessments takes advantage of the fact that tree roots naturally integrate (137)Cs over large volumes of soil. Root absorption of (137)Cs replaces large-scale, expensive soil sampling schemes to reduce variability in (137)Cs concentration due to inhomogeneous radionuclide distribution. IPCR [drinking-coconut meat (DCM)/Scaevola (SCA) and Tournefortia (TOU) leaves (native trees growing on all atoll islands)] are log-normally distributed (LND) with geometric standard deviation (GSD)=1.85. TF for DCM from Enewetak, Eneu, Rongelap and Bikini Atolls are LND with GSDs of 3.5, 3.0, 2.7, and 2.1, respectively. TF GSD for Rongelap copra coconut meat is 2.5. IPCR of Pandanus fruit to SCA and TOU leaves are LND with GSD=1.7 while TF GSD is 2.1. Because IPCR variability is much lower than TF variability, relative sampling error of an IPCR field sample mean is up 6- to 10-fold lower than that of a TF sample mean if sample sizes are small (10-20). Other IPCR advantages are that plant leaf samples are collected and processed in far less time with much less effort and cost than soil samples.

  6. 137Cs Inter-Plant Concentration Ratios Provide a Predictive Tool for Coral Atolls with Distinct Benefits Over Transfer Factors

    SciTech Connect

    Robison, W L; Hamilton, T F; Bogen, K; Corado, C L; Kehl, S R

    2007-07-17

    Inter-plant concentration ratios (IPCR), [Bq g{sup -1} {sup 137}Cs in coral atoll tree food-crops/Bq g{sup -1} {sup 137}Cs in leaves of native plant species whose roots share a common soil volume], can replace transfer factors (TF) to predict {sup 137}Cs concentration in tree food-crops in a contaminated area with an aged source term. The IPCR strategy has significant benefits relative to TF strategy for such purposes in the atoll ecosystem. IPCR strategy applied to specific assessments takes advantage of the fact tree roots naturally integrate 137Cs over large volumes of soil. Root absorption of {sup 137}Cs replaces large-scale, expensive soil sampling schemes to reduce variability in {sup 137}Cs concentration due to inhomogeneous radionuclide distribution. IPCR [drinking-coconut meat (DCM)/Scaevola (SCA) and Tournefortia (TOU) leaves (native trees growing on all atoll islands)] are log normally distributed (LND) with geometric standard deviation (GSD) = 1.85. TF for DCM from Enewetak, Eneu, Rongelap and Bikini Atolls are LND with GSD's of 3.5, 3.0, 2.7, and 2.1, respectively. TF GSD for Rongelap copra coconut meat is 2.5. IPCR of Pandanus fruit to SCA and TOU leaves are LND with GSD = 1.7 while TF GSD is 2.1. Because IPCR variability is much lower than TF variability, relative sampling error of an IPCR field sample mean is up 6- to 10-fold lower than that of a TF sample mean if sample sizes are small (10 to 20). Other IPCR advantages are that plant leaf samples are collected and processed in far less time with much less effort and cost than soil samples.

  7. Long-term behavior of (90)Sr and (137)Cs in the environment: Case studies in Switzerland.

    PubMed

    Corcho-Alvarado, J A; Balsiger, B; Sahli, H; Astner, M; Byrde, F; Röllin, S; Holzer, R; Mosimann, N; Wüthrich, S; Jakob, A; Burger, M

    2016-08-01

    We present long-term records of the (137)Cs and (90)Sr activity concentrations in soil, grass and milk from two lowland and two alpine pastures of Switzerland. The data is used for better understanding the long-term behavior of these radionuclides in the environment. Transfer factors between compartments are used as qualitative indicators of the magnitude of transfer and as a way to compare different elements (e.g. Cs and Sr) in similar conditions. The long-term behavior was quantified by means of the effective half-life which integrates all processes that cause a decrease of activity in a given medium such as leaching, fixation, erosion and radioactive decay. Our study shows that (90)Sr is more likely transferred from alpine soil to grass than (137)Cs. This is explained by a stronger fixation of Cs in the soils. We observed higher transfers of (90)Sr to grass in soils with lower Ca concentrations, and vice versa. In contrast, the transfer of (137)Cs to grass was not affected by the variations of the K content in the soil. We provide evidence that shows that (137)Cs, after intake by dairy cattle, is more likely transferred to milk than (90)Sr. However, as the (90)Sr and Ca transfers to milk are influenced by parameters/processes that were not taken into account in our study, our result cannot be entirely validated. The effective half-lives of (137)Cs and (90)Sr in soil, grass and milk corresponded with previous estimates in alpine soils. We have found that processes other than radioactive decay are responsible for a major decrease of the (90)Sr activity in soil. For (137)Cs, on the other hand, radioactive decay is among the most relevant process. Our data shows to be of interest in studying the trends of behavior of radionuclides in alpine regions.

  8. Investigation of the initial and volume recombination losses in gamma versatile cylindrical ionization chamber VGIC developed for gamma ray dosimetry

    SciTech Connect

    Fares, M.; Mameri, S.; Abdlani, I.; Negara, K.

    2015-07-01

    A versatile Gamma ionization chambers are used for flow control in systems with gamma nuclear reactors and reprocessing plants in and monitoring atmosphere around these facilities, this in order to protect staff. In the Laboratory Detection and Measures (LDM) Division for Study and Development of Nuclear Instrumentation (DSDNI) of CRNB, we designed, developed and characterized a versatile gamma ionization chamber (VGIC) to study experimentally its characteristics according to the geometry of the electrodes, the volume and pressure of the filler gas for the design of a gamma sealed chamber. The tests were conducted under the IEC (International Electro-technical Commission). In this paper, we present the results obtained in the various nuclear tests for characterization and calibration that we have made on the ionization chamber gamma VGIC prototype developed at our Department. To do this, three irradiators were operated at the Laboratory Calibration (SSDL) of the Department of Medical Physics Nuclear Research Center of Algiers (CRNA). Irradiator intensive gamma ({sup 60}Co: 1.25 MeV), one medium intensity gamma ({sup 137}Cs: 0.662 MeV) and 3rd low intensity ({sup 60}Co). Saturation curves and linearity were identified and the operating range and the sensitivity of the chamber have been deducted. The (I,V) characteristics of the chamber filled, with argon gas at 3 bar (0.3 M pa) pressure, for gamma ray irradiator sources were studied. To do so, the chamber was irradiated with gamma rays using different numbers of gamma sources (i.e. Up to 5). The plateau region is reached above 200 V and the detector operating voltage is found to be 600 V. It is observed that in the plateau region the slope is constant with an increase in the exposure rate. The (1/I, 1/V) and (I, l/V{sup 2}) characteristic curves reveal the presence of the initial and volume recombination losses. The volume recombination losses are found to be smaller than the initial recombination losses. Finally

  9. Epiphytic fruticose lichens as biomonitors for retrospective evaluation of the (134)Cs/(137)Cs ratio in Fukushima fallout.

    PubMed

    Ramzaev, V; Barkovsky, A; Gromov, A; Ivanov, S; Kaduka, M

    2014-12-01

    In 2011-2013, sampling of epiphytic fruticose lichens of the genera Usnea, Bryoria and Alectoria was carried out on Sakhalin and Kuril Islands (the Sakhalin region, Russia) to investigate contamination of these organisms with the Fukushima-derived (134)Cs and (137)Cs. Activities of the radionuclides were determined in all 56 samples of lichens taken for the analysis. After correction for radioactive decay (on 15 March 2011), the activity concentrations ranged from 2.1 Bq kg(-1) (d.w.) to 52 Bq kg(-1) for (134)Cs and from 2.3 Bq kg(-1) to 52 Bq kg(-1) for (137)Cs. Cesium-134 and (137)Cs activities for the whole set of lichens (n = 56) were strongly positively correlated; Spearman's rank correlation coefficient was calculated as 0.991 (P < 0.01). The activity concentrations of (134)Cs and (137)Cs in Usnea lichens from the Sakhalin and Kunashir islands declined with a factor of three in the period from 2011 to 2013. The average biological half-time for both cesium radionuclides in lichens of the genus Usnea is estimated as 1.3 y. The mean of 0.99 ± 0.10 and median of 0.99 were calculated for the decay corrected (134)Cs/(137)Cs activities ratios in the lichens (n = 56). The radionuclides ratio in the lichens did not depend on location of sampling site, species and the time that had passed after the Fukushima accident. The regression analysis has shown the background pre-Fukushima level of (137)Cs of 0.4 ± 0.3 Bq kg(-1), whereas the ratio between the Fukushima-borne (134)Cs and (137)Cs in the lichens was estimated as 1.04. The (134)Cs/(137)Cs activities ratio in lichens from the Sakhalin region is consistent with the ratios reported by others for the heavy contaminated areas on Honshu Island in Japan following the Fukushima accident. The activity concentrations of natural (7)Be in lichens from the Sakhalin region varied between 100 Bq kg(-1) and 600 Bq kg(-1); the activity concentrations did not exhibit temporal variations during a 2y

  10. Localized lesions induced by sup 137 Cs during the Goiania accident

    SciTech Connect

    Oliveira, A.R.; Brandao-Mello, C.E.; Valverde, N.J.; Farina, R.; Curado, M.P. )

    1991-01-01

    A description is given of initial symptoms and clinical observations regarding acute localized radiation lesions in 28 persons exposed to 137Cs during the Goiania radiological accident. Specialized procedures to estimate the extent and gravity of the lesions and establish a therapeutic strategy, as well as to anticipate the prognosis in each case, are briefly discussed. Measures taken for reduction of pain and inflammation are noted, and an explanation is given for difficulties encountered due to adverse working conditions and the serious clinical manifestations presented by various patients concomitantly with their lesions. Also noted is the difficulty in obtaining credible information regarding exposure, such as source-to-object distance, duration of exposure, and source activity, which precluded dosimetry studies in most cases.

  11. The influence of forest shelterbelts on 137Cs fallout in Chernobyl affected areas (Tula region, Russia).

    NASA Astrophysics Data System (ADS)

    Ivanov, Maxim; Shamshurina, Eugeniya; Tatyana, Paramonova; Vladimir, Belyaev; Angelina, Gavruchenkova; Nikolai, Lugovoy; Konstantinov, Pavel

    2015-04-01

    The radioactive fallout after Chernobyl accident caused serious contamination by 137Cs along extensive area of East-European plain.Cs137 fall down on earth surface in two ways: gravitational - "dry" and rainfall - "wet" way. "Dry" fallout is a result of direct deposition of radionuclides from atmosphere with average speed of about 0.1-1 mm/sec. The fate of "dry fall"is far less than rainfall mechanism. Erupted water steam of reactor zone full of radioactive material enriched precipitation with 137Cs. Therefore, the derived spatial structure of contamination was under control of rainfall pattern in May-June 1986. On the areas affected by rainfall fallout was the Southern part of Tula region in Middle Russia. It got name as "Plava hot spot" by the town in the center of this area. Tula is a traditional rural region, the vast areas covered by chernozem soils are cultivated for centuries. During cultivation forest cover was reduced that urged growth of wind erosion and loss of soil fertility. Hence, in the middle of 20 the century large arrangements for creation of forest shelterbelts were conducted. High efficiency of shelterbelts made them a widely provided part of new human-transformed landscape. Usually shelterbelts are set as a regular network across main direction of winds in particular region. Such organization help to reduce speed of air steam in the lowest 20-30 m layer of atmosphere. In addition, shelterbelts are very good collectors of snow in winter time which increase total moisture of soil and its fertility. Represented investigation is conducted to find out any correlation between shelterbelts and fallout of radionuclides. If such correlation is significant, it has to be taken into account for further environmental surveys. Two shelterbelts on the interfluve positions were chosen for detailed examination. Both selected objects emerged before 1986 but have different width, floristic composition, orientation and type of construction. One of shelterbelts is

  12. Vertical migration studies of 137Cs from nuclear weapons fallout and the Chernobyl accident.

    PubMed

    Almgren, S; Isaksson, M

    2006-01-01

    The vertical migration of (137)Cs originating from nuclear weapons fallout (NWF) and the Chernobyl accident has been studied at 33 sampling sites in western Sweden. An attempt to describe the present depth distribution with a solution to the convection-diffusion equation (CDE) with a pulse-like fallout event as the initial condition was made. A sum of two CDEs describing the NWF and Chernobyl debris was fitted to the actual depth profiles measured by soil sampling. The fitted depth profiles were used to correct in situ measurements for the actual depth distribution, showing good agreement with the accumulated activities in soil samples. As expected, the vertical migration was very slow and most caesium was still present in the upper soil layers. The ranges of the apparent convection velocity, v, and apparent diffusion coefficient, D, were between 0 and 0.35 cm/year and 0.06 and 2.63 cm(2)/year, respectively.

  13. [Radionuclides 90Sr and 137Cs in the benthos near the nuclear submarine "Komsomolets"].

    PubMed

    Kuznetsov, A P; Shmelev, I P; Demidov, A M; Efimov, B V; Shubko, V M

    1999-01-01

    We have analyzed the content of radionuclides 90Sr and 137Cs in the benthofauna and deposits near the nuclear submarine "Komsomolets." Analysis was performed on the basis of the materials of the 31st (1993) and 36th (1995) voyages of R/V "Akademik Mstislav Keldysh" in correspondence with the system of monitoring the state of the abiotic and biotic situation near the nuclear submarine "Komsomolets" (Norwegian Sea). Whereas during the 33rd voyage of this vessel (1994) the content of these elements in the benthic animals at stations located close to the submarine somewhat exceeded the background level of radioactivity (Kuznetsov et al., 1996), no such excess was found during the 31st and 36th voyages. Meanwhile, radioactive cobalt (60Co) was found in representatives of three groups of animals during the 31st voyage at two stations located near the submarine.

  14. EVALUATION OF THE MIGRATION POTENTIAL FOR 60Co AND 137Cs AT THE MAINE YANKEE SITE.

    SciTech Connect

    FUHRMANN,M.SULLIVAN,T.

    2002-08-08

    The objective of this report is to discuss the degree of sorption and desorption of {sup 137}Cs and {sup 60}Co that may be associated with the granite bedrock and the ''popcorn'' cement drain system that underlie the Maine Yankee Containment Foundation. The purpose is to estimate how much retardation of these two radionuclides takes place in groundwater that flows in the near-field of the Containment Foundation, specifically with respect to contamination originating at the PAB Test Pit. Specific concerns revolve around the potential for the contamination originating near the PAB to create a radioactive dose to a hypothetical ''resident farmer'' using a well intercepting this water to exceed 4 millirems/yr.

  15. The GAMMA-400 gamma-ray telescope for precision gamma-ray emission investigations

    NASA Astrophysics Data System (ADS)

    Topchiev, N. P.; Galper, A. M.; Bonvicini, V.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Bakaldin, A. V.; Bergstrom, L.; Berti, E.; Bigongiari, G.; Bobkov, S. G.; Boezio, M.; Bogomolov, E. A.; Bonechi, L.; Bongi, M.; Bottai, S.; Castellini, G.; Cattaneo, P. W.; Cumani, P.; Dalkarov, O. D.; Dedenko, G. L.; De Donato, C.; Dogiel, V. A.; Finetti, N.; Gascon, D.; Gorbunov, M. S.; Gusakov, Yu V.; Hnatyk, B. I.; Kadilin, V. V.; Kaplin, V. A.; Kaplun, A. A.; Kheymits, M. D.; Korepanov, V. E.; Larsson, J.; Leonov, A. A.; Loginov, V. A.; Longo, F.; Maestro, P.; Marrocchesi, P. S.; Martinez, M.; Men'shenin, A. L.; Mikhailov, V. V.; Mocchiutti, E.; Moiseev, A. A.; Mori, N.; Moskalenko, I. V.; Naumov, P. Yu; Papini, P.; Paredes, J. M.; Pearce, M.; Picozza, P.; Rappoldi, A.; Ricciarini, S.; Runtso, M. F.; Ryde, F.; Serdin, O. V.; Sparvoli, R.; Spillantini, P.; Stozhkov, Yu I.; Suchkov, S. I.; Taraskin, A. A.; Tavani, M.; Tiberio, A.; Tyurin, E. M.; Ulanov, M. V.; Vacchi, A.; Vannuccini, E.; Vasilyev, G. I.; Ward, J. E.; Yurkin, Yu T.; Zampa, N.; Zirakashvili, V. N.; Zverev, V. G.

    2016-02-01

    The GAMMA-400 gamma-ray telescope with excellent angular and energy resolutions is designed to search for signatures of dark matter in the fluxes of gamma-ray emission and electrons + positrons. Precision investigations of gamma-ray emission from Galactic Center, Crab, Vela, Cygnus, Geminga, and other regions will be performed, as well as diffuse gamma-ray emission, along with measurements of high-energy electron + positron and nuclei fluxes. Furthermore, it will study gamma-ray bursts and gamma-ray emission from the Sun during periods of solar activity. The GAMMA-400 energy range is expected to be from ∼20 MeV up to TeV energies for gamma rays, up to 10 TeV for electrons + positrons, and up to 1015 eV for cosmic-ray nuclei. For 100-GeV gamma rays, the GAMMA-400 angular resolution is ∼0.01° and energy resolution is ∼1% the proton rejection factor is ∼5x105. GAMMA-400 will be installed onboard the Russian space observatory.

  16. [Using 137Cs and 210Pb(ex) to trace the impact of soil erosion on soil organic carbon at a slope farmland in the black soil region].

    PubMed

    Fang, Hai-Yan; Sheng, Mei-Ling; Sun, Li-Ying; Cai, Qiang-Guo

    2013-07-01

    Soil cores were collected from a 28.5 hm2 slope farmland in the black soil region of Northeast China. Based on the sampled data of 137Cs, 210Pb(ex) and SOC, the potentials of applying 137Cs and 210Pb(ex) for assessing SOC redistribution were evaluated, aimed to approach the impact of soil erosion on soil organic carbon (SOC) in black soil region. At both planar and vertical directions, the 137Cs, 210Pb(ex) and SOC in the farmland had similar distribution patterns. Although there were large planar variations in the 137Cs and 210Pb(ex) areal activities and the SOC stock as affected by soil erosion and deposition, the 137Cs, 210Pb(ex) and SOC had similar changing trends over the landscape. Two depth distribution profiles were also used to study the relations of 137Cs and 210Pb(ex) with SOC. At eroded site, the radioactivities of 137Cs and 210Pb(ex) and the SOC mass fraction did not show large variations in 0-25 cm soil layer, but decreased sharply below 25 cm. For the deposition sample, the radioactivities of 137Cs and 210Pb(ex) in 0-100 cm soil increased firstly and then decreased. The SOC mass fraction also had similar depth distribution pattern in this soil layer. The 137Cs and 210Pb(ex) presented positive linear correlations with the SOC, indicating that 137Cs, 210Pb(ex) and SOC moved with the same physical mechanism in the farmland, and fallout 137Cs and 210Pb(ex) could be used to study spatio-temporal distribution characteristics of SOC in the black soil region under the condition of soil erosion.

  17. Geochronological reconstruction of 137Cs transport from the Coruh river to the SE Black Sea: comparative assessment of radionuclide retention in the mountainous catchment area

    NASA Astrophysics Data System (ADS)

    Gulin, S. B.; Polikarpov, G. G.; Martin, J.-M.

    2003-11-01

    The deposition record of 137Cs was traced in the SE Black Sea sediments adjacent to the Coruh river mouth in comparison with the earlier studied chronology of 137Cs deposition in front of the Danube delta (NW Black Sea). In both cases, the 137Cs profiles showed two subsurface peaks attributable to maximum fallout of 'bomb' and Chernobyl radionuclides. The Coruh profile revealed a larger contribution of 'bomb' 137Cs in comparison with the Chernobyl input, suggesting different coverage of NW and SE Black Sea regions with the Chernobyl fallout. The 137Cs-derived dating showed that maximum deposition of particulate bound 137Cs in sediments adjacent to the Coruh river mouth was delayed for ˜14 yr relative to date of Chernobyl accident, reflecting a buffer effect of the watershed soils. This transit time is 3 times longer than in the Danube catchment area, indicating a difference in retention processes in these mountainous (Coruh) and lowland (Danube) river basins. The 137Cs profile in Coruh sediments showed penetration of 137Cs to much greater depth than would be expected from 137Cs fallout chronology, suggesting the sediment mixing rate of 1.3 cm 2 yr -1. This value was used to evaluate deposition chronology of 137Cs, applying the model developed for pulse fallout case. Comparing the measured and modelled data has allowed differentiation of the flood-induced discharge of the 137Cs-containing suspended matter and the slower transit of eroded soil particles from the contaminated catchment areas. The obtained results may be used for the prediction of period when the pollutants, deposited over the river basins, can reach the Black Sea.

  18. The Gamma-ray Sky with Fermi

    NASA Technical Reports Server (NTRS)

    Thompson, David

    2012-01-01

    Gamma rays reveal extreme, nonthermal conditions in the Universe. The Fermi Gamma-ray Space Telescope has been exploring the gamma-ray sky for more than four years, enabling a search for powerful transients like gamma-ray bursts, novae, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as dark matter annihilation. Some results include a stringent limit on Lorentz invariance derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge gamma-ray structure associated with the center of our galaxy, surprising behavior from some gamma-ray binary systems, and a possible constraint on some WIMP models for dark matter.

  19. Gamma-ray Imaging Methods

    SciTech Connect

    Vetter, K; Mihailescu, L; Nelson, K; Valentine, J; Wright, D

    2006-10-05

    In this document we discuss specific implementations for gamma-ray imaging instruments including the principle of operation and describe systems which have been built and demonstrated as well as systems currently under development. There are several fundamentally different technologies each with specific operational requirements and performance trade offs. We provide an overview of the different gamma-ray imaging techniques and briefly discuss challenges and limitations associated with each modality (in the appendix we give detailed descriptions of specific implementations for many of these technologies). In Section 3 we summarize the performance and operational aspects in tabular form as an aid for comparing technologies and mapping technologies to potential applications.

  20. Towed seabed gamma ray spectrometer

    SciTech Connect

    Jones, D.G. )

    1994-08-01

    For more than 50 years, the measurement of radioactivity has been used for onshore geological surveys and in laboratories. The British Geological Survey (BGS) has extended the use of this type of equipment to the marine environment with the development of seabed gamma ray spectrometer systems. The present seabed gamma ray spectrometer, known as the Eel, has been successfully used for sediment and solid rock mapping, mineral exploration, and radioactive pollution studies. The range of applications for the system continues to expand. This paper examines the technological aspects of the Eel and some of the applications for which it has been used.

  1. Determination of distribution coefficient of {sup 137}Cs and {sup 90}Sr in soil from AERE, Savar

    SciTech Connect

    Mollah, A.S.; Ullah, S.M.

    1998-12-31

    The sorption characteristics of {sup 137}Cs and {sup 90}Sr on soil matrix have been studied by the batch technique. The sorption coefficients (K{sub d}) and retardation factor (R{sub f}) have been determined for these radionuclides on soil matrices collected from a number of locations in and around the proposed site for shallow land disposal of low-level radioactive wastes at the Atomic Energy Research Establishment (AERE) campus, Savar. The K{sub d} values varied from 1,278 to 2,156 ml/g for {sup 137}Cs and from 350 to 640 ml/g for {sup 90}Sr. The retardation factors varied from 1,709 to 3,072 for {sup 137}Cs and from 409 to 903 for {sub 90}Sr. The results obtained indicated that the AERE soils have good sorption capacity for {sup 137}Cs and {sup 90}Sr radionuclides. These data could be used in radionuclides transport and safety assessment models.

  2. Thirty years after Chernobyl: Long-term determination of (137)Cs effective half-life in the lichen Stereocaulon vesuvianum.

    PubMed

    Savino, F; Pugliese, M; Quarto, M; Adamo, P; Loffredo, F; De Cicco, F; Roca, V

    2017-04-05

    It has been widely shown that nuclear fallout includes substances, which accumulate in organisms such as crustaceans, fish, mushrooms and lichens, helping to evaluate the activity concentration of contaminants accumulated on a long time. In this context, radiocaesium deposited in soil following the Chernobyl accident on 26 April 1986 is known to have remained persistently available for plant uptake in many areas of Europe. Studies on the lichen Stereocaulon vesuvianum show the plant's high capacity to retain radionuclides from the substrate and the air. After the Chernobyl accident, starting from September 1986, at the Radioactivity Laboratory (LaRa) of the University of Naples Federico II, four monitoring campaigns to evaluate the activity concentration of four isotopes of the two elements caesium and ruthenium ((134)Cs, (137)Cs, (103)Ru and (106)Ru) were carried out until 1999. This study allowed the effective half-life of (134)Cs and (137)Cs to be estimated. Twenty-eight years after the accident, in December 2014, a further sampling was carried out; only (137)Cs was revealed beyond the detection limits, measuring activity concentrations ranging from 20 to 40 Bq/kg, while the other radionuclides were no longer observed due to their shorter half-life. The last sampling allowed more precise determination of the effective half-life of (137)Cs (6.2 ± 0.1 year), due to the larger dataset on a large time period.

  3. 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.

  4. Modelling temporal trends of 137Cs and 99Tc concentrations in Fucus vesiculosus from the eastern Irish coastline.

    PubMed

    Cournane, S; Vintró, L León; Mitchell, P I; McMahon, C A; Smith, K; Long, S

    2011-11-01

    Time series of 137Cs and 99Tc activity concentrations in the brown seaweed Fucus vesiculosus and seawater, gathered at three locations on the eastern Irish coastline during the period 1988-2008, have been modelled using a novel approach incorporating a variable uptake rate in the seaweed. Seasonal variations in the time series, identified using spectral analysis, were incorporated into the model which was used to determine transfer kinetic parameters and to predict 137Cs and 99Tc concentrations in seaweed, as influenced by levels in ambient seawater. An optimisation method combining evolutionary and grid search minimisation techniques was adopted to determine the best values for the model parameters, from which concentration factors (CF) and biological half-lives (tb1/2) for 137Cs and 99Tc in F. vesiculosus were calculated. CF values of 170-179 and 1.1×105 l kg(-1) (dry weight) were obtained for 137Cs and 99Tc, respectively, while the corresponding tb1/2 values were 39-47 and 32 days, respectively.

  5. The GAMMA-400 gamma-ray telescope angular resolution

    NASA Astrophysics Data System (ADS)

    Kheymits, Maxim; Leonov, Alexey

    The measurements of gamma-ray fluxes and cosmic-ray electrons and positrons in the energy range from 100 MeV to several TeV, which will be realized by the specially designed GAMMA-400 gamma-ray telescope, concern with the following broad range of science topics. Search for signatures of dark matter, surveying the celestial sphere in order to study point and extended sources of gamma-rays, measuring the energy spectra of Galactic and extragalactic diffuse gamma-ray emission, study of gamma-ray bursts and gamma-ray emission from the Sun. To clarify these scientific problems with the new experimental data the GAMMA-400 gamma-ray telescope possesses unique physical characteristics comparing with previous and present experiments. For gamma-ray energies more than 100 GeV GAMMA-400 provides the energy resolution nearby 1% and angular resolution better than 0.02 deg. The methods, developed to reconstruct the direction of incident gamma photon, are presented in this paper. The main point concerns with the space topology of high energy gamma photon interaction in the matter of GAMMA-400. Multiple secondary particles, generated inside gamma-ray telescope, produce significant problems to restore the direction of initial gamma photon. Also back-splash particles, i.e., charged particles and gamma photons generated in calorimeter and moved upward, mask the initial tracks of electron/positron pair from conversion of incident gamma photon. The processed methods allow us to reconstruct the direction of electromagnetic shower axis and extract the electron/positron trace. As a result, the direction of incident gamma photon with the energy of 100 GeV is calculated with an accuracy of more than 0.02 deg.

  6. Evolution and fluxes of 137Cs in the Black Sea/Turkish Straits System/North Aegean Sea

    NASA Astrophysics Data System (ADS)

    Delfanti, R.; Özsoy, E.; Kaberi, H.; Schirone, A.; Salvi, S.; Conte, F.; Tsabaris, C.; Papucci, C.

    2014-07-01

    The vertical profiles of 137Cs were determined in the North Aegean, Marmara and Black Seas, to assess inventories and fluxes of the radionuclide in these basins. The inventory of 137Cs in the Western Black Sea integrated from the surface down to 400 m water depth is 3.4 ± 0.1 kBq m- 2, which is surprisingly close to the amount determined in 1988, decay corrected to 2007 (2.9 ± 0.1 kBq m- 2). On the other hand, based on the comparison of profiles roughly 20 years apart, it is estimated that about 1 kBq m- 2 has been transferred from above the halocline to depths below the halocline, emphasizing the effective redistribution of tracers within the same period. We estimate that about 12 TBq y- 1 of 137Cs presently leaves the Black Sea with the upper layer flow through the Bosphorus and only 2 TBq y- 1 is returned with the lower layer inflow of Mediterranean water from the Marmara Sea. Accounting for river fluxes, estimated on the order of 2 TBq y- 1 few years after the Chernobyl accident, and possibly decreased by now, we can thus estimate a net rate of loss of about 8-10 TBq y- 1. Investigating the effective redistribution in the upper water column, the supply by the inflowing Mediterranean water alone does not explain the increase of 137Cs concentration and inventory at intermediate depths in the Western Black Sea. The most important mechanism transferring 137Cs and dissolved contaminants from the surface water to the sub-pycnocline layer appears to be the turbulent entrainment of a larger quantity of Black Sea water into the inflowing plume of Mediterranean water through mixing processes on the southwestern shelf and continental slope following its exit from the Bosphorus. This process produces an extra export of some10 TBq y- 1 of 137Cs from the surface to the sub-pycnocline depths of the Black Sea, a quantity comparable in magnitude to the total export out from the basin. It is the entrainment flux resulting from the mixing, and the further advection and

  7. Influence of water management and fertilizer application on (137)Cs and (133)Cs uptake in paddy rice fields.

    PubMed

    Wakabayashi, Shokichi; Itoh, Sumio; Kihou, Nobuharu; Matsunami, Hisaya; Hachinohe, Mayumi; Hamamatsu, Shioka; Takahashi, Shigeru

    2016-06-01

    Cesium-137 derived from the Tokyo Electric Power Company's Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident contaminated large areas of agricultural land in Eastern Japan. Previous studies before the accident have indicated that flooding enhances radiocesium uptake in rice fields. We investigated the influence of water management in combination with fertilizers on (137)Cs concentrations in rice plants at two fields in southern Ibaraki Prefecture. Stable Cs ((133)Cs) in the plants was also determined as an analogue for predicting (137)Cs behavior after long-term aging of soil (137)Cs. The experimental periods comprised 3 y starting from 2012 in one field, and 2 y from 2013 in another field. These fields were divided into three water management sections: a long-flooding section without midsummer drainage, and medial-flooding, and short-flooding sections with one- or two-week midsummer drainage and earlier end of flooding than the long-flooding section. Six or four types of fertilizer subsections (most differing only in potassium application) were nested in each water management section. Generally, the long-flooding treatment led to higher (137)Cs and (133)Cs concentrations in both straw and brown rice than medial- and short-flooding treatments, although there were some notable exceptions in the first experimental year at each site. Effects of differing potassium fertilizer treatments were cumulative; the effects on (137)Cs and (133)Cs concentrations in rice plants were not obvious in 2012 and 2013, but in 2014, these concentrations were highest where potassium fertilizer had been absent and lowest where basal dressings of K had been tripled. The relationship between (137)Cs and (133)Cs in rice plants was not correlative in the first experimental year at each site, but correlation became evident in the subsequent year(s). This study demonstrates a novel finding that omitting midsummer drainage and/or delaying drainage during the grain-filling period enhances

  8. Gamma ray spectroscopy in astrophysics. [conferences

    NASA Technical Reports Server (NTRS)

    Cline, T. L. (Editor); Ramaty, R. (Editor)

    1978-01-01

    Experimental and theoretical aspects of gamma ray spectroscopy in high energy astrophysics are discussed. Line spectra from solar, stellar, planetary, and cosmic gamma rays are examined as well as HEAO investigations, the prospects of a gamma ray observatory, and follow-on X-ray experiments in space.

  9. Relationship between caesium (137Cs) load, cardiovascular symptoms, and source of food in 'Chernobyl' children -- preliminary observations after intake of oral apple pectin.

    PubMed

    Bandazhevskaya, G S; Nesterenko, V B; Babenko, V I; Yerkovich, T V; Bandazhevsky, Y I

    2004-12-18

    Seventeen years after the nuclear power accident at Chernobyl, most of the radio-contamination among the population of Southern Belarus is caused by incorporation of long-lived radioisotopes. The varying levels of 137Cs observed among children in this area are explained by the source of their food, especially by the consumption of contaminated milk produced privately. We stratified children from rural areas of Belarus (caesium [137Cs] contamination >5 Ci/km(2)) by their 137Cs loads into three distinct groups (group 1, <5 Bq/kg body weight [BW]; group 2, 38.4 +/- 2.4 Bq/kg BW; group 3, 122 +/- 18.5 Bq/kg BW). We determined the relationship between the 137Cs load and the children's main source of food and recorded their cardiovascular symptoms. Cardiovascular symptoms, ECG alterations, and arterial hypertension were significantly more frequent in children with high 137Cs burden than in children with very low 137Cs burden. Children with moderate and high 137Cs loads (groups 2 and 3) received apple pectin, a food additive, for 16 days. Apple pectin significantly decreased 137Cs loads in these groups (39% and 28%, respectively). ECG alterations improved, while cardiovascular symptoms and hypertension did not change in any group.

  10. Modeling of leachable 137Cs in throughfall and stemflow for Japanese forest canopies after Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Loffredo, Nicolas; Onda, Yuichi; Kawamori, Ayumi; Kato, Hiroaki

    2014-09-15

    The Fukushima accident dispersed significant amounts of radioactive cesium (Cs) in the landscape. Our research investigated, from June 2011 to November 2013, the mobility of leachable Cs in forests canopies. In particular, (137)Cs and (134)Cs activity concentrations were measured in rainfall, throughfall, and stemflow in broad-leaf and cedar forests in an area located 40 km from the power plant. Leachable (137)Cs loss was modeled by a double exponential (DE) model. This model could not reproduce the variation in activity concentration observed. In order to refine the DE model, the main physical measurable parameters (rainfall intensity, wind velocity, and snowfall occurrence) were assessed, and rainfall was identified as the dominant factor controlling observed variation. A corrective factor was then developed to incorporate rainfall intensity in an improved DE model. With the original DE model, we estimated total (137)Cs loss by leaching from canopies to be 72 ± 4%, 67 ± 4%, and 48 ± 2% of the total plume deposition under mature cedar, young cedar, and broad-leaf forests, respectively. In contrast, with the improved DE model, the total (137)Cs loss by leaching was estimated to be 34 ± 2%, 34 ± 2%, and 16 ± 1% of the total plume deposition under mature cedar, young cedar, and broad-leaf forests, respectively. The improved DE model corresponds better to observed data in literature. Understanding (137)Cs and (134)Cs forest dynamics is important for forecasting future contamination of forest soils around the FDNPP. It also provides a basis for understanding forest transfers in future potential nuclear disasters.

  11. Combining multiple fallout radionuclides (137Cs, 7Be, 210Pbxs) improves our understanding of sediment source dynamics in tropical rivers

    NASA Astrophysics Data System (ADS)

    Evrard, O.; Laceby, J. P.; Huon, S.; Lefèvre, I.; Sengtaheuanghoung, O.; Ribolzi, O.

    2015-12-01

    Soil erosion has accelerated as a result of land use change, increasing the sediment supply to rivers worldwide. A thorough knowledge of sediment dynamics is required to design efficient management measures to control erosion and reduce sediment delivery from catchments. Fallout radionuclides are often used separately to provide spatial (137Cs) or temporal (7Be, 210Pbxs) information on sediment sources. In this study, we examine their combined application to simultaneously model spatial and temporal sediment source dynamics. To this end, potential sediment sources (n=84) and suspended sediment (n=16) were collected at two stations in a 12 km² catchment in Northern Laos during the first flood of the 2014 wet season. Part of the source material was directly sampled in ephemeral flow occurring on hillslopes to avoid the grain size selectivity problems that may occur during erosion and river transport processes. A distribution modelling approach quantified the relative contributions of recently eroded surface (labelled with both 7Be and 137Cs), recently eroded subsurface (depleted in both 7Be and 137Cs), re-suspended surface (depleted in 7Be and labelled with 137Cs) and re-suspended subsurface sources (enriched in 7Be and depleted in 137Cs). At an upstream sampling location, surface sources contributed the majority of sediment (55%) whereas subsurface sources dominated the supply of sediment downstream (74%). Importantly, re-suspended subsurface sources, labelled with 7Be, were a significant sediment source at the catchment outlet (60%). This approach demonstrates the utility of combining multiple radionuclides when investigating spatial and temporal sediment source dynamics in tropical catchments. In the future, sampling of source material in ephemeral flows occurring on hillslopes should be encouraged. Furthermore, the proposed approach should be tested in larger catchments to guide the implementation of efficient erosion control measures.

  12. Using 137Cs and 210Pb ex measurements to estimate soil redistribution rates on semi-arid grassland in Mongolia

    NASA Astrophysics Data System (ADS)

    Kato, H.; Onda, Y.; Tanaka, Y.

    2010-02-01

    In this study, two small experimental catchments were selected in semi-arid grassland in Mongolia. The Kherlen-bayan Ulaan (KBU) catchment has been subjected to intensive grazing as a wintering shelter for domestic livestock animals, and the number of livestock animals in the Baganuur (BGN) catchment has been increasing over the last few decades. The rates and patterns of soil erosion within the catchments were estimated based on cesium-137 ( 137Cs) and lead-210 ( 210Pb ex) inventories in bulk soil core samples. The medium-term (~ 40 years) soil erosion rates based on the 137Cs measurements indicated that annual soil loss from the KBU catchment was approximately three times greater than that from the BGN catchment. The 137Cs-derived rates and patterns of soil erosion indicated that soil in the KBU catchment was susceptible to surface erosion, with facilitated transport of eroded sediment to the catchment outlet. The 210Pb ex-derived soil erosion rates were generally greater than those derived from 137Cs in both catchments. If we assume that the soil erosion rate has been increasing with increasing domestic livestock numbers, the most plausible explanation is that the 210Pb ex-derived estimates represent recent increases in soil erosion. Furthermore, the 210Pb ex/ 137Cs inventory ratio showed a tendency to increase with downslope distance on the eroded hillslope in the BGN catchment. Assuming that the increase in inventory ratio is a result of constant fallout input of 210Pb ex on the eroded sediment during its transportation along the hillslope, the 210Pb ex inventory may not be suitable to estimate soil erosion rates at sites where downslope movement of sediment is slow. Further discussion regarding interpretation of 210Pb ex-derived soil loss is required, and the applicability of the 210Pb ex technique on semi-arid hillslopes remains to be determined.

  13. Desorption of 137Cs from Brachythecium mildeanum moss using acid solutions with pH 4.60-6.50

    NASA Astrophysics Data System (ADS)

    Čučulović, Ana; Veselinović, Dragan

    2015-12-01

    The desorption of 137Cs from the moss Brachythecium mildeanum (Schimp.) was performed using the following solutions: H2SO4 ( I), HNO3 ( II), H2SO4 + HNO3 ( III) with pH values of 4.60, 5.15, and 5.75, respectively, as well as distilled water (D) with pH 6.50. After five successive desorptions, each lasting 24 h, 20.5-37.6% 137Cs was desorbed from the moss using these solutions, while 30.7% of the starting content was desorbed using distilled water. The first desorption removed the highest percent of the original content of 137Cs in the moss (11.3-18.4%). This was determined by measuring 137Cs activity. If the current results are compared with those obtained earlier it may be concluded that 137Cs desorption from mosses is not species-dependent. The obtained results indicate the necessity of investigating the influence of acid rain, or rather, of H+ ions, on desorption of other ions from biological systems, i.e., the role of H+ ions in spreading other polluting compounds and thus producing secondary environmental pollution. From the results of this study it follows that acid rain will lead, through H+ ion action, to a similar increasing pollution of fallout waters with other ionic compounds which may not be present in the water before the contact with the plants and thus enable the pollution spreading. In the investigated system, the replacement of H+ ions from acid rains by more dangerous radioactive ions occured, increasing the concentration of the radioactive ions in the water, which demonstrates that the same process takes place in fallout water.

  14. The Gamma-ray Universe through Fermi

    NASA Technical Reports Server (NTRS)

    Thompson, David J.

    2012-01-01

    Gamma rays, the most powerful form of light, reveal extreme conditions in the Universe. The Fermi Gamma-ray Space Telescope and its smaller cousin AGILE have been exploring the gamma-ray sky for several years, enabling a search for powerful transients like gamma-ray bursts, novae, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as dark matter annihilation. Some results include a stringent limit on Lorentz invariance derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge ga.nuna-ray structure associated with the center of our galaxy, surprising behavior from some gamma-ray binary systems, and a possible constraint on some WIMP models for dark matter.

  15. Comparison of four methods used in determination of secondary shielding requirements for a teletherapy facility: a case study of 137Cs room in Tanzania.

    PubMed

    Muhogora, W E; Nyanda, A M; Ngoye, W M

    2004-12-01

    The performance of four methods often used to calculate the secondary barrier requirements is evaluated for a typical 137Cs-therapy room as a case study. The first two methods are provided by the NCRP49 and IAEA and both consider the influence of the primary, leakage and scattered radiation at a point as corrected for the workload, use and occupancy factors. A different shielding model encompasses the third method, which determines the doses as corrected for build-up effects assuming the narrow beam geometry. The fourth method is based on the calculation of the dose rates from the source activity with a relevant gamma constant. In all four methods, an appropriate transmission factor for the protective barrier in question is applied. The results show that for controlled area, the similarity in the calculated thicknesses using all four methods was nearly within 50%. For uncontrolled areas, a significant difference of magnitude up to a factor of 2.4 was found, which is mainly attributed to the non-consideration of occupancy factors in the latter two methods. Nevertheless, the non-agreement is useful to validate the specific assumptions taken for the employed shielding method. Despite being slightly high, it is concluded that the current shielding methods based on NCRP fundamentals are satisfactorily optimal in planning new therapy facilities. However for existing facilities, such as those undesigned according to the standard requirements, the combination of the four different methods with the dose rate measurements tend to offer a better cost effective shielding option. Retrospectively, additional 41-cm thick concrete is recommended for the unshielded southern barrier of the 137Cs room. Interestingly, the recommended thickness agrees to within +/-5% with that estimated by using the recently recommended method by IAEA.

  16. Gamma-ray Line Astronomy

    NASA Astrophysics Data System (ADS)

    Diehl, R.

    2005-07-01

    Gamma-ray lines from radioactive isotopes, ejected into interstellar space by cosmic nucleosynthesis events, are observed with new space telescopes. The Compton Observatory had provided a sky survey for the isotopes 56Co, 22Na, 44Ti, and 26Al, detecting supernova radioactivity and the diffuse glow of long-lived radioactivity from massive stars in the Galaxy. High-resolution spectroscopy is now being exploited with Ge detectors: Since 2002, with ESA's INTEGRAL satellite and the RHESSI solar imager two space-based Ge-gamma-ray telescopes are in operation, measuring Doppler broadenings and line shape details of cosmic gamma-ray lines. First year's results include a detection and line shape measurement of annihilation emission, and 26Al emission from the inner Galaxy and from the Cygnus region. 60Fe gamma-ray intensity is surprisingly low; it may have been detected by RHESSI at 10% of the 26Al brightness, yet is not seen by INTEGRAL. 44Ti emission from Cas A and SN1987A is being studied; no other candidate young supernova remnants have been found through 44Ti. 22Na from novae still is not seen.

  17. Fukushima simulation experiment: assessing the effects of chronic low-dose-rate internal 137Cs radiation exposure on litter size, sex ratio, and biokinetics in mice

    PubMed Central

    Nakajima, Hiroo; Yamaguchi, Yoshiaki; Yoshimura, Takashi; Fukumoto, Manabu; Todo, Takeshi

    2015-01-01

    To investigate the transgenerational effects of chronic low-dose-rate internal radiation exposure after the Fukushima Daiichi Nuclear Power Plant accident in Japan, 18 generations of mice were maintained in a radioisotope facility, with free access to drinking water containing 137CsCl (0 and 100 Bq/ml). The 137Cs distribution in the organs of the mice was measured after long-term ad libitum intake of the 137CsCl water. The litter size and the sex ratio of the group ingesting the 137Cs water were compared with those of the control group, for all 18 generations of mice. No significant difference was noted in the litter size or the sex ratio between the mice in the control group and those in the group ingesting the 137Cs water. The fixed internal exposure doses were ∼160 Bq/g and 80 Bq/g in the muscles and other organs, respectively. PMID:26825299

  18. Fukushima simulation experiment: assessing the effects of chronic low-dose-rate internal 137Cs radiation exposure on litter size, sex ratio, and biokinetics in mice.

    PubMed

    Nakajima, Hiroo; Yamaguchi, Yoshiaki; Yoshimura, Takashi; Fukumoto, Manabu; Todo, Takeshi

    2015-12-01

    To investigate the transgenerational effects of chronic low-dose-rate internal radiation exposure after the Fukushima Daiichi Nuclear Power Plant accident in Japan, 18 generations of mice were maintained in a radioisotope facility, with free access to drinking water containing (137)CsCl (0 and 100 Bq/ml). The (137)Cs distribution in the organs of the mice was measured after long-term ad libitum intake of the (137)CsCl water. The litter size and the sex ratio of the group ingesting the (137)Cs water were compared with those of the control group, for all 18 generations of mice. No significant difference was noted in the litter size or the sex ratio between the mice in the control group and those in the group ingesting the (137)Cs water. The fixed internal exposure doses were ∼160 Bq/g and 80 Bq/g in the muscles and other organs, respectively.

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

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

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

  20. Swift's 500th Gamma Ray Burst

    NASA Video Gallery

    On April 13, 2010, NASA's Swift Gamma-ray Burst Explorer satellite discovered its 500th burst. Swift's main job is to quickly localize each gamma-ray burst (GRB), report its position so that others...

  1. Gamma-ray shielding effectiveness of novel light-weight clay-flyash bricks

    NASA Astrophysics Data System (ADS)

    Mann, Harjinder Singh; Brar, G. S.; Mudahar, G. S.

    2016-10-01

    The radiation shielding parameters of lightweight clay-flyash bricks produced with different flyash aggregate compositions have been investigated by using 241Am (59.4 keV), 137Cs (661.6 keV), and 60Co (1173.2 keV and 1332.5 keV) radioactive sources. It was observed that the different percentages of flyash in clay lead to significant variations in these parameters. The elemental compositions of the clay-flyash bricks were analyzed using energy dispersive X-ray fluorescence spectrometry (EDXRF). The obtained results were compared to those pertaining to concrete in order to see the effect of flyash content on the radiation shielding properties. The radiation protection efficiency of the tested clay-flyash bricks demonstrated that multilayer exterior walls built from these bricks could effectively attenuate moderate-energy gamma rays. Bricks using residual flyash could be preferentially used for buildings to address the issues of radiation shielding, cost-effective radioactive waste management and disposal of flyash in a useful manner.

  2. Distribution of radioactive cesium ((134)Cs plus (137)Cs) in rice fractions during polishing and cooking.

    PubMed

    Hachinohe, Mayumi; Okunishi, Tomoya; Hagiwara, Shoji; Todoriki, Setsuko; Kawamoto, Shinichi; Hamamatsu, Shioka

    2015-03-01

    We investigated the distribution of cesium-134 ((134)Cs) and cesium-137 ((137)Cs) during polishing and cooking of rice to obtain their processing factors (Pf) and food processing retention factors (Fr) to make the information available for an adequate understanding of radioactive Cs dynamics. Polishing brown rice resulted in a decreased radioactive Cs concentration of the polished rice, but the bran and germ (outer layers) exhibited higher concentrations than brown rice. The Pf values for 100% polished rice and outer layers ranged from 0.47 to 0.48 and 6.5 to 7.8, respectively. The Fr values for 100% polished rice and outer layers were 0.43 and 0.58 to 0.60, respectively. The distribution of radioactive Cs in polished rice and outer layers was estimated at approximately 40 and 60%, respectively. On the other hand, cooked rice showed significantly lower levels of radioactive Cs than polished rice, and transfer of radioactive Cs into wash water was observed. The Pf and Fr values for cooked rice were 0.28 and 0.65 to 0.66, respectively. From these results, we can calculate that if the radioactive Cs concentration in brown rice is 100 Bq/kg, the concentrations of Cs in polished rice and cooked rice will be 47 to 48 Bq/kg and 13 Bq/kg, respectively.

  3. 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.

  4. A Case Study Correlating Innovative Gamma Ray Scanning Detection Systems Data to Surface Soil Gamma Spectrometry Results - 13580

    SciTech Connect

    Thompson, Shannon; Rodriguez, Rene; Billock, Paul; Lit, Peter

    2013-07-01

    HydroGeoLogic (HGL), Inc. completed a United States Environmental Protection Agency (USEPA) study to characterize radiological contamination at a site near Canoga Park, California. The characterized area contained 470 acres including the site of a prototype commercial nuclear reactor and other nuclear design, testing, and support operations from the 1950's until 1988 [1]. The site history included radiological releases during operation followed by D and D activities. The characterization was conducted under an accelerated schedule and the results will support the project remediation. The project has a rigorous cleanup to background agenda and does not allow for comparison to risk-based guidelines. To target soil sample locations, multiple lines of evidence were evaluated including a gamma radiation survey, geophysical surveys, historical site assessment, aerial photographs, and former worker interviews. Due to the time since production and decay, the primary gamma emitting radionuclide remaining is cesium-137 (Cs-137). The gamma ray survey covered diverse, rugged terrain using custom designed sodium iodide thallium-activated (NaI(Tl)) scintillation detection systems. The survey goals included attaining 100% ground surface coverage and detecting gamma radiation as sensitively as possible. The effectiveness of innovative gamma ray detection systems was tested by correlating field Cs-137 static count ratios to Cs-137 laboratory gamma spectrometry results. As a case study, the area encompassing the former location of the first nuclear power station in the U. S. was scanned, and second by second global positioning system (GPS)-linked gamma spectral data were evaluated by examining total count rate and nuclide-specific regions of interest. To compensate for Compton scattering from higher energy naturally occurring radionuclides (U-238, Th-232 and their progeny, and K-40), count rate ratios of anthropogenic nuclide-specific regions of interest to the total count rate were

  5. Gamma ray astrophysics. [emphasizing processes and absorption

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1974-01-01

    Gamma ray production processes are reviewed, including Compton scattering, synchrotron radiation, bremsstrahlung interactions, meson decay, nucleon-antinucleon annihilations, and pion production. Gamma ray absorption mechanisms through interactions with radiation and with matter are discussed, along with redshifts and gamma ray fluxes.

  6. Nuclear gamma rays from energetic particle interactions

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Kozlovsky, B.; Lingenfelter, R. E.

    1978-01-01

    Gamma ray line emission from nuclear deexcitation following energetic particle reactions is evaluated. The compiled nuclear data and the calculated gamma ray spectra and intensities can be used for the study of astrophysical sites which contain large fluxes of energetic protons and nuclei. A detailed evaluation of gamma ray line production in the interstellar medium is made.

  7. Behaviour of oceanic 137Cs following the Fukushima Daiichi Nuclear Power Plant accident for four years simulated numerically by a regional ocean model

    NASA Astrophysics Data System (ADS)

    Torn, M. S.; Koven, C. D.; Riley, W. J.; Zhu, B.; Hicks Pries, C.; Phillips, C. L.

    2014-12-01

    A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant (1F NPP) following the earthquake and tsunami of 11 March 2011 resulted in the release of radioactive materials to the ocean by two major pathways, direct release from the accident site and atmospheric deposition.We reconstructed spatiotemporal variability of 137Cs activity in the regional ocean for four years by numerical model, such as a regional scale and the North Pacific scale oceanic dispersion models, an atmospheric transport model, a sediment transport model, a dynamic biological compartment model for marine biota and river runoff model. Direct release rate of 137Cs were estimated for four years after the accident by comparing simulated results and observed activities very close to the site. The estimated total amounts of directly release was 3.6±0.7 PBq. Directly release rate of 137Cs decreased exponentially with time by the end of December 2012 and then, was almost constant. Decrease rate were quite small after 2013. The daily release rate of 137Cs was estimated to be the order of magnitude of 1010 Bq/day by the end of March 2015. The activity of directly released 137Cs was detectable only in the coastal zone after December 2012. Simulated 137Cs activities attributable to direct release were in good agreement with observed activities, a result that implies the estimated direct release rate was reasonable. There is no observed data of 137Cs activity in the ocean from 11 to 21 March 2011. Observed data of marine biota should reflect the history of 137Cs activity in this early period. We reconstructed the history of 137Cs activity in this early period by considering atmospheric deposition, river input, rain water runoff from the 1F NPP site. The comparisons between simulated 137Cs activity of marine biota by a dynamic biological compartment and observed data also suggest that simulated 137Cs activity attributable to atmospheric deposition was underestimated in this early period. The

  8. Behaviour of oceanic 137Cs following the Fukushima Daiichi Nuclear Power Plant accident for four years simulated numerically by a regional ocean model

    NASA Astrophysics Data System (ADS)

    Tsumune, D.; Tsubono, T.; Aoyama, M.; Misumi, K.; Tateda, Y.

    2015-12-01

    A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant (1F NPP) following the earthquake and tsunami of 11 March 2011 resulted in the release of radioactive materials to the ocean by two major pathways, direct release from the accident site and atmospheric deposition.We reconstructed spatiotemporal variability of 137Cs activity in the regional ocean for four years by numerical model, such as a regional scale and the North Pacific scale oceanic dispersion models, an atmospheric transport model, a sediment transport model, a dynamic biological compartment model for marine biota and river runoff model. Direct release rate of 137Cs were estimated for four years after the accident by comparing simulated results and observed activities very close to the site. The estimated total amounts of directly release was 3.6±0.7 PBq. Directly release rate of 137Cs decreased exponentially with time by the end of December 2012 and then, was almost constant. Decrease rate were quite small after 2013. The daily release rate of 137Cs was estimated to be the order of magnitude of 1010 Bq/day by the end of March 2015. The activity of directly released 137Cs was detectable only in the coastal zone after December 2012. Simulated 137Cs activities attributable to direct release were in good agreement with observed activities, a result that implies the estimated direct release rate was reasonable. There is no observed data of 137Cs activity in the ocean from 11 to 21 March 2011. Observed data of marine biota should reflect the history of 137Cs activity in this early period. We reconstructed the history of 137Cs activity in this early period by considering atmospheric deposition, river input, rain water runoff from the 1F NPP site. The comparisons between simulated 137Cs activity of marine biota by a dynamic biological compartment and observed data also suggest that simulated 137Cs activity attributable to atmospheric deposition was underestimated in this early period. The

  9. One-year, regional-scale simulation of 137Cs radioactivity in the ocean following the Fukushima Daiichi Nuclear Power Plant accident

    NASA Astrophysics Data System (ADS)

    Tsumune, D.; Tsubono, T.; Aoyama, M.; Uematsu, M.; Misumi, K.; Maeda, Y.; Yoshida, Y.; Hayami, H.

    2013-04-01

    A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant following the earthquake and tsunami of 11 March 2011 resulted in the release of radioactive materials to the ocean by two major pathways, direct release from the accident site and atmospheric deposition. A 1 yr, regional-scale simulation of 137Cs activity in the ocean offshore of Fukushima was carried out, the sources of radioactivity being direct release, atmospheric deposition, and the inflow of 137Cs deposited on the ocean by atmospheric deposition outside the domain of the model. Direct releases of 131I, 134Cs, and 137Cs were estimated for 1 yr after the accident by comparing simulated results and measured activities. The estimated total amounts of directly released 131I, 134Cs, and 137Cs were 11.1 ± 2.2 PBq, 3.5 ± 0.7 PBq, and 3.6 ± 0.7 PBq, respectively. The contributions of each source were estimated by analysis of 131I/137Cs and 134Cs/137Cs activity ratios and comparisons between simulated results and measured activities of 137Cs. Simulated 137Cs activities attributable to direct release were in good agreement with measured activities close to the accident site, a result that implies that the estimated direct release rate was reasonable, while simulated 137Cs activities attributable to atmospheric deposition were low compared to measured activities. The rate of atmospheric deposition onto the ocean was underestimated because of a~lack of measurements of deposition onto the ocean when atmospheric deposition rates were being estimated. Measured 137Cs activities attributable to atmospheric deposition helped to improve the accuracy of simulated atmospheric deposition rates. Simulated 137Cs activities attributable to the inflow of 137Cs deposited onto the ocean outside the domain of the model were in good agreement with measured activities in the open ocean within the model domain after June 2012. The contribution of inflow increased with time and was dominant (more than 99%) by the end of

  10. Dating of coastal marine sediments: 210Pb versus 137Cs signal on the Danube-influenced Black Sea shelf

    NASA Astrophysics Data System (ADS)

    Friedrich, Jana; Laptev, Gennady

    2010-05-01

    Coastal marine sediments represent a natural archive of pelagic processes, coastal erosion and river discharge of suspended matter. Correct dating of those sediments is a prerequisite for chronological reconstruction of the flux of pollutants and organic matter from the water column to the sediments and hence, the reconstruction of the pollution and eutrophication events. In the reconstruction of the sedimentation history during the pre-industrial and industrial periods, which usually spans the past 100 years, the natural occurring radionuclide 210Pb and the artificial radionuclides 137Cs and 241Am are widely applied tracers. 137Cs is used as an independent time marker for end the atmospheric bomb test fallout in 1963 and the Chernobyl accident in 1986. As the 137Cs signal is often weakened due to its mobility in sediments, 241Am, less mobile than 137Cs and derived from decay the bomb fallout of 241Pu, is used as a second time marker of the 1963 event. The northwestern shelf of the Black Sea has been seriously affected by eutrophication and pollution from the late 1960's to the mid-1990's, largely triggered by Danube River input of nutrients and pollutants. The aim of our study is ultimately to reconstruct the eutrophication history and recycling of nutrients following the deposition of organic matter. The ‘memory effect' of sediment recycling plays a critical role in maintaining eutrophic conditions in enclosed seas such as the Black Sea. Here we present results from sediment cores taken within the Danube River plume on the shallow northwestern shelf of the Black Sea. The cores have been dated in two laboratories to rule out artifacts. The sediment record is repeatedly interrupted by so-called turbidites that consist of stiff clay. The clay horizons display a drop in unsupported 210Pb and 137Cs and a higher signal of supported 210Pb than the non-clay horizons. Below the turbidite, the unsupported 210Pb and 137Cs increase again to values above the turbidite. This

  11. High efficiency CsI(Tl)/HgI{sub 2} gamma ray spectrometers

    SciTech Connect

    Wang, Y.J.; Patt, B.E.; Iwanczyk, J.S.; Cherry, S.R.; Shao, Y.

    1995-08-01

    CsI(Tl)/HgI{sub 2} gamma-ray spectrometers have been constructed using 0.5 inch diameter detectors which show excellent energy resolution: 4.58% FWHM for 662 keV {sup 137}Cs gamma-ray photons. Further efforts have been focused on optimization of larger size ({ge} 1 inch diameter) detector structures and improvement of low noise electronics. In order to take full advantage of scintillation detectors for high energy gamma-rays, larger scintillators are always preferred for their higher detection efficiencies. However, the larger capacitance and higher dark current caused by the larger size of the detector could result in a higher FWHM resolution. Also, the increased probability of including nonuniformities in larger pieces of crystals makes it more difficult to obtain the high resolutions one obtains from small detectors. Thus for very large volume scintillators, it may be necessary to employ a photodiode (PD) with a sensitive area smaller than the cross-section of the scintillator. Monte Carlo simulations of the light collection for various tapered scintillator/PD configuration were performed in order to find those geometries which resulted in the best light collection. According to the simulation results, scintillators with the most favorable geometry, the conical frustum, have been fabricated and evaluated. The response of a large conical frustum (top-2 inch, bottom-1 inch, 2 inch high) CsI(Tl) scintillator coupled with a 1 inch HgI{sub 2} PD was measured. The energy resolution of the 662 keV peak was 5.57%. The spectrum shows much higher detection efficiency than those from smaller scintillators, i.e., much higher peak-to-Compton ratio in the spectrum.

  12. Compton Gamma Ray Observatory Guest Investigator Program

    NASA Technical Reports Server (NTRS)

    Lingenfelter, Richard E.

    1997-01-01

    This paper presents a final report for the Compton Gamma Ray Observatory Guest Investigator Program from 06/01/91-07/31/97. The topics include: 1) Solar Flare Neutron Spectra and Accelerated Ions; 2) Gamma Ray Lines From The Orion Complex; 3) Implications of Nuclear Line Emission From The Orion Complex; 4) Possible Sites of Nuclear Line Emission From Massive OB Associations; 5) Gamma-Ray Burst Repitition and BATSE Position Uncertainties; 6) Effects of Compton Scattering on BATSE Gamma-Ray Burst Spectra; and 7) Selection Biases on the Spectral and Temporal Distribution of Gamma Ray Bursts.

  13. Terrestrial Gamma-Ray Flashes (TGFs)

    NASA Technical Reports Server (NTRS)

    Fishman, Gerald J.

    2010-01-01

    This slide presentation reviews the observation of Terrestrial Gamma Ray Flashes (TGFs) by Gamma-Ray Telescopes. These were: (1) BATSE /Compton Observatory, (2) Solar Spectroscopic Imager, (3) AGILE Gamma-ray Telescope, and (4) Gamma-ray Burst Monitor (GBM) on the Fermi Gamma-ray Space Telescope. It contains charts which display the counts over time, a map or the TGFs observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). and a map showing the latitude and longitude of 85 of the TGFs observed by the Fermi GBM.

  14. Future prospects for gamma-ray

    NASA Technical Reports Server (NTRS)

    Fichtel, C.

    1980-01-01

    Astrophysical phenomena discussed are: the very energetic and nuclear processes associated with compact objects; astrophysical nucleo-synthesis; solar particle acceleration; the chemical composition of the planets and other bodies of the solar system; the structure of our galaxy; the origin and dynamic pressure effects of the cosmic rays; the high energy particles and energetic processes in other galaxies, especially active ones; and the degree of matter antimater symmetry of the universe. The gamma ray results of GAMMA-I, the gamma ray observatory, the gamma ray burst network, solar polar, and very high energy gamma ray telescopes on the ground provide justification for more sophisticated telescopes.

  15. Concentrations of {sup 137}Cs and {sup 40}K in edible mushrooms collected in Japan and radiation dose due to their consumption

    SciTech Connect

    Ban-nai, Tadaaki; Muramatsu, Yasuyuki; Yoshida, Satoshi

    1997-03-01

    To estimate radiocesium intake due to eating mushrooms, about 100 samples belonging to 11 species were analyzed to establish to establish representative values for {sup 137}Cs and {sup 40}K in common edible mushrooms available in food markets. Concentration ranges were <0.047-39 Bq kg{sup -1} (wet wt) for {sup 137}Cs and 30-210 Bq kg{sup -1} (wet wt) for {sup 40}K. The median concentrations were 1.3 Bq kg{sup -1} (wet wt) for {sup 137}Cs and 97 Bq kg{sup -1} (wet wt) for {sup 40}K. The {sup 137}Cs concentration is cultivated mushrooms were markedly lower than those in wild mushrooms. The annual intake of {sup 137}Cs per person through mushrooms was calculated (using analytical results and food consumption data in Japan) to be 6.0 Bq for {sup 137}Cs, which is about 32% of the total dietary intake of this nuclide. The effective dose equivalent of {sup 137}Cs through mushroom was estimated to be 7.7 X 10{sup -8} Sv (range estimated from the standard deviation: 3.0 x 10{sup -8}-1.0 x 10{sup -7}). 19 refs., 1 fig., 2 tabs.

  16. Using 137Cs to study spatial patterns of soil erosion and soil organic carbon (SOC) in an agricultural catchment of the typical black soil region, Northeast China.

    PubMed

    Fang, Haiyan; Li, Qiuyan; Sun, Liying; Cai, Qiangguo

    2012-10-01

    Understanding the spatial pattern of soil organic carbon (SOC) is of great importance because of global environmental concerns. Soil erosion and its subsequent redistribution contribute significantly to the redistribution of SOC in agricultural ecosystems. This study investigated the relationships between (137)Cs and SOC over an agricultural landscape, and SOC redistribution was conducted for an agricultural catchment of the black soil region in Northeast China. The spatial patterns of (137)Cs and SOC were greatly affected by the established shelterbelts and the developed ephemeral gullies. (137)Cs were significantly correlated with SOC when (137)Cs were >2000 Bq m(-2), while no relation was observed between them when (137)Cs were <2000 Bq m(-2). Factors other than soil erosion such as vegetative productivity, mineralization of SOC, landscape position and management induced their spatial difference of (137)Cs and SOC. Using (137)Cs technique to directly study SOC dynamics must be cautious in the black soils. The net SOC loss rate across the entire catchment during 1954-2010 was 92.8 kg ha(-1) yr(-1), with around 42% of the eroded SOC being redeposited within the catchment. Such information can help guide shelterbelt establishment or other land management to reduce SOC loss in the agricultural ecosystems.

  17. Measurements of plutonium, 237Np, and 137Cs in the BCR 482 lichen reference material

    DOE PAGES

    Lavelle, Kevin B.; Miller, Jeffrey L.; Hanson, Susan K.; ...

    2015-10-01

    Select anthropogenic radionuclides were measured in lichen reference material, BCR 482. This material was originally collected in Axalp, Switzerland in 1991 and is composed of the epiphytic lichen Pseudevernia furfuracea. Samples from three separate bottles of BCR 482 were analyzed for uranium, neptunium, and plutonium isotopes by inductively coupled plasma mass spectrometry (ICP-MS) and analyzed for cesium-137 by gamma-ray spectrometry. The isotopic composition of the radionuclides measured in BCR 482 suggests contributions from both global fallout resulting from historical nuclear weapons testing and more volatile materials released following the Chernobyl accident.

  18. NOTE: A Monte Carlo study of dose rate distribution around the specially asymmetric CSM3-a 137Cs source

    NASA Astrophysics Data System (ADS)

    Pérez-Calatayud, J.; Lliso, F.; Ballester, F.; Serrano, M. A.; Lluch, J. L.; Limami, Y.; Puchades, V.; Casal, E.

    2001-07-01

    The CSM3 137Cs type stainless-steel encapsulated source is widely used in manually afterloaded low dose rate brachytherapy. A specially asymmetric source, CSM3-a, has been designed by CIS Bio International (France) substituting the eyelet side seed with an inactive material in the CSM3 source. This modification has been done in order to allow a uniform dose level over the upper vaginal surface when this `linear' source is inserted at the top of the dome vaginal applicators. In this study the Monte Carlo GEANT3 simulation code, incorporating the source geometry in detail, was used to investigate the dosimetric characteristics of this special CSM3-a 137Cs brachytherapy source. The absolute dose rate distribution in water around this source was calculated and is presented in the form of an along-away table. Comparison of Sievert integral type calculations with Monte Carlo results are discussed.

  19. Curing time effect on the fraction of {sup 137}Cs from cement-ion exchange resins-bentonite clay composition

    SciTech Connect

    Plecas, Ilija; Dimovic, Slavko

    2007-07-01

    To assess the safety of disposal of radioactive waste material in cement, curing conditions and time of leaching radionuclides {sup 137}Cs have been studied. Leaching tests in cement-ion exchange resins-bentonite matrix, were carried out in accordance with a method recommended by IAEA. Curing conditions and curing time prior to commencing the leaching test are critically important in leach studies since the extent of hydration of the cement materials determines how much hydration product develops and whether it is available to block the pore network, thereby reducing leaching. Incremental leaching rates R{sub n}(cm/d) of {sup 137}Cs from cement ion exchange resins-bentonite matrix after 180 days were measured. The results presented in this paper are examples of results obtained in a 20-year concrete testing project which will influence the design of the engineer trenches system for future central Serbian radioactive waste storing center. (authors)

  20. Spatial distribution of 137Cs in surface soil under different land uses in Chao Phraya watershed: Potential used as sediment source tracing

    NASA Astrophysics Data System (ADS)

    Srisuksawad, K.; porntepkasemsan, B.; Noipow, N.; Omanee, A.; Wiriyakitnateekul, W.; Chouybudha, R.; Srimawong, P.

    2015-05-01

    Sediment fingerprinting techniques involves the discrimination of sediment sources based on differences in source material properties and quantification of the relative contributions from these sources to sediment delivered downstream to the river catchments. Results of the previous study indicated that fallout radionuclides (FRNs); 137Cs and excess 210Pb (210Pbex) are the most suitable radionuclides to be used as sediments sources tracers. This study investigated the spatial distribution of 137Cs in soil under different land uses in Chao Phraya watershed; the most significant watershed in Thailand. Emphasis was placed on discriminating among potential sediment sources including the cultivated (upland crops), pasture field, uncultivated (swamp, forest, and grass field), and channel erosion (stream and river bank). One hundred and twenty four soil samples were collected from all sources and determining for 137Cs. The 137Cs mass activities in pasture areas varied from the limit of detection (LLD) to 1.22±0.05 with the average of 0.64±0.14 Bq kg-1. In cultivated areas the 137Cs mass activities varied from LLD to 1.41±0.04 with the average of 0.38±0.04 Bq kg-1. The 137Cs mass activities were higher in uncultivated areas varied from 0.12±0.03 to 1.73±0.05 with the average of 0.76±0.15 Bq kg-1. The 137Cs mass activities in channel bank varied from LLD to 1.16±0.04 with the average of 0.39±0.05 Bq kg-1.GIS and geospatial interpolations revealed pattern in the spatial concentrations of 137Cs and indicated important differences in its distributions showing the differences behaviour of 137Cs in different land uses.

  1. Correlations between potassium, rubidium and cesium ((133)Cs and (137)Cs) in sporocarps of Suillus variegatus in a Swedish boreal forest.

    PubMed

    Vinichuk, M; Rosén, K; Johanson, K J; Dahlberg, A

    2011-04-01

    An analysis of sporocarps of ectomycorrhizal fungi Suillus variegatus assessed whether cesium ((133)Cs and (137)Cs) uptake was correlated with potassium (K) or rubidium (Rb) uptake. The question was whether intraspecific correlations of Rb, K and (133)Cs mass concentrations with (137)Cs activity concentrations in sporocarps were higher within, rather than among, different fungal species, and if genotypic origin of sporocarps within a population affected uptake and correlation. Sporocarps (n = 51) from a Swedish forest population affected by the fallout after the Chernobyl accident were studied. The concentrations were 31.9 ± 6.79 g kg(-1) for K (mean ± SD, dwt), 0.40 ± 0.09 g kg(-1) for Rb, 8.7 ± 4.36 mg kg(-1) for (133)Cs and 63.7 ± 24.2 kBq kg(-1) for (137)Cs. The mass concentrations of (133)Cs correlated with (137)Cs activity concentrations (r = 0.61). There was correlation between both (133)Cs concentrations (r = 0.75) and (137)Cs activity concentrations (r = 0.44) and Rb, but the (137)Cs/(133)Cs isotopic ratio negatively correlated with Rb concentration. Concentrations of K and Rb were weakly correlated (r = 0.51). The (133)Cs mass concentrations, (137)Cs activity concentrations and (137)Cs/(133)Cs isotopic ratios did not correlate with K concentrations. No differences between, within or, among genotypes in S. variegatus were found. This suggested the relationships between K, Rb, (133)Cs and (137)Cs in sporocarps of S. variegatus is similar to other fungal species.

  2. Estimation of radionuclide ((137)Cs) emission rates from a nuclear power plant accident using the Lagrangian Particle Dispersion Model (LPDM).

    PubMed

    Park, Soon-Ung; Lee, In-Hye; Ju, Jae-Won; Joo, Seung Jin

    2016-10-01

    A methodology for the estimation of the emission rate of (137)Cs by the Lagrangian Particle Dispersion Model (LPDM) with the use of monitored (137)Cs concentrations around a nuclear power plant has been developed. This method has been employed with the MM5 meteorological model in the 600 km × 600 km model domain with the horizontal grid scale of 3 km × 3 km centered at the Fukushima nuclear power plant to estimate (137)Cs emission rate for the accidental period from 00 UTC 12 March to 00 UTC 6 April 2011. The Lagrangian Particles are released continuously with the rate of one particle per minute at the first level modelled, about 15 m above the power plant site. The presently developed method was able to simulate quite reasonably the estimated (137)Cs emission rate compared with other studies, suggesting the potential usefulness of the present method for the estimation of the emission rate from the accidental power plant without detailed inventories of reactors and fuel assemblies and spent fuels. The advantage of this method is not so complicated but can be applied only based on one-time forward LPDM simulation with monitored concentrations around the power plant, in contrast to other inverse models. It was also found that continuously monitored radionuclides concentrations from possibly many sites located in all directions around the power plant are required to get accurate continuous emission rates from the accident power plant. The current methodology can also be used to verify the previous version of radionuclides emissions used among other modeling groups for the cases of intermittent or discontinuous samplings.

  3. The use of 137Cs to establish longer-term soil erosion rates on footpaths in the UK.

    PubMed

    Rodway-Dyer, S J; Walling, D E

    2010-10-01

    There is increasing awareness of the damage caused to valuable and often unique sensitive habitats by people pressure as degradation causes a loss of plant species, disturbance to wildlife, on-site and off-site impacts of soil movement and loss, and visual destruction of pristine environments. This research developed a new perspective on the problem of recreational induced environmental degradation by assessing the physical aspects of soil erosion using the fallout radionuclide caesium-137 ((137)Cs). Temporal sampling problems have not successfully been overcome by traditional research methods monitoring footpath erosion and, to date, the (137)Cs technique has not been used to estimate longer-term soil erosion in regard to sensitive recreational habitats. The research was based on-sites within Dartmoor National Park (DNP) and the South West Coast Path (SWCP) in south-west England. (137)Cs inventories were reduced on the paths relative to the reference inventory (control), indicating loss of soil from the path areas. The Profile Distribution Model estimated longer-term erosion rates (ca. 40 years) based on the (137)Cs data and showed that the combined mean soil loss for all the sites on 'paths' was 1.41 kg m(-2) yr(-1) whereas the combined 'off path' soil loss was 0.79 kg m(-2) yr(-1), where natural (non-recreational) soil redistribution processes occur. Recreational pressure was shown to increase erosion in the long-term, as greater soil erosion occurred on the paths, especially where there was higher visitor pressure.

  4. Transfer factor of (90)Sr and (137)Cs to lettuce and winter wheat at different growth stage applications.

    PubMed

    Al Attar, Lina; Al-Oudat, Mohammad; Safia, Bassam; Ghani, Basem Abdul

    2015-12-01

    The effect of clay soil contamination time on the transfer factors (Fvs) of (137)Cs and (90)Sr was investigated in four different growth stages of winter wheat and lettuce crops. The experiment was performed in an open field using lysimeters. The Fvs were the ratio of the activity concentrations of the radionuclides in crops to those in soil, both as dry weight (Bq kg(-1)). Significant difference of log-Fvs was evaluated using one-way Analysis of Variance (ANOVA). Basically, Fvs of (90)Sr were higher than those of (137)Cs, despite of the application stage or crop' variety. Higher Fvs for both radionuclides were observed for lettuce in comparison to winter wheat. Fvs of (90)Sr showed comparable trends for both crops with enhanced Fvs obtained when contamination occurred in early stages, i.e. 1.20 for lettuce and 0.88 and 0.02 for winter wheat, straw and grains, respectively. Despite the fluctuation noted in the pattern of Fvs for (137)Cs, soil contaminated at the second stage gave the highest Fvs for lettuce and grains, with geometric means of 0.21 and 0.01, respectively. However, wheat-straw showed remarkable increase in Fv for the latest contamination (ripening stage), about 0.06. It could be concluded that soil contamination at early growth stages would represent high radiological risk for the scenarios studied with an exception to (137)Cs in winter wheat-straw which reflected greater hazard at the latest application.

  5. ASSESSMENT OF 90SR AND 137CS PENETRATION INTO REINFORCED CONCRETE (EXTENT OF 'DEEPENING') UNDER NATURAL ATMOSPHERIC CONDITIONS

    SciTech Connect

    Farfan, E.; Jannik, T.

    2011-10-01

    When assessing the feasibility of remediation following the detonation of a radiological dispersion device or improvised nuclear device in a large city, several issues should be considered including the levels and characteristics of the radioactive contamination, the availability of resources required for decontamination, and the planned future use of the city's structures and buildings. Currently, little is known about radionuclide penetration into construction materials in an urban environment. Knowledge in this area would be useful when considering costs of a thorough decontamination of buildings, artificial structures, and roads in an affected urban environment. Pripyat, a city substantially contaminated by the Chernobyl Nuclear Power Plant accident in April 1986, may provide some answers. The main objective of this study was to assess the depth of {sup 90}Sr and {sup 137}Cs penetration into reinforced concrete structures in a highly contaminated urban environment under natural weather conditions. Thirteen reinforced concrete core samples were obtained from external surfaces of a contaminated building in Pripyat. The concrete cores were drilled to obtain sample layers of 0-5, 5-10, 10-15, 15-20, 20-30, 30-40, and 40-50 mm. Both {sup 90}Sr and {sup 137}Cs were detected in the entire 0-50 mm profile of the reinforced cores sampled. In most of the cores, over 90% of the total {sup 137}Cs inventory and 70% of the total {sup 90}Sr inventory was found in the first 0-5 mm layer of the reinforced concrete. {sup 90}Sr had penetrated markedly deeper into the reinforced concrete structures than {sup 137}Cs.

  6. 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.

  7. 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.

  8. Reconstruction and forecast of doses due to ingestion of 137Cs and 90Sr after the Chernobyl accident.

    PubMed

    Kravets, A P; Pavlenko, Yu A

    2008-04-01

    The assessment doses due to ingestion of (137)Cs and (90)Sr for the population suffering from the Chernobyl accident was performed on the basis of the new mechanistic ecological model for assessment of radiological consequences of agricultural lands contamination (EMARC). The EMARC model allows estimation of internal doses based on ecological factors influencing the contamination of foodstuff, for the post-accidental years in the countries of the former Soviet Union. The EMARC model allows estimation of all quantities required in radiation hygiene practice. For example, the proposed analytical method may be used for both retrospective dose reconstruction and prospective estimates of annual dose and integrated "life-time" dose, for different age intervals. According to the EMARC model, estimated reference "life-time" doses for adults are between 7 and 269 microSv kBq(-1) m(2) for (137)Cs, and between 25 and 235 microSv kBq(-1) m(2) for (90)Sr. Maximal doses were estimated for persons who were 3, 9 and 11 years old, at the time of the accident and these doses exceed those for adults by a factors of 1, 5 for (90)Sr, and 1.4 for (137)Cs.

  9. Transport and sediment accumulation of sup 210 Pb and sup 137 Cs in two southeast Alaskan fjords

    SciTech Connect

    Sugai, S.F. )

    1991-05-01

    Sediment profiles of {sup 210}Pb and {sup 137}Cs in cores collected at increasing distances form the heads of Smeaton Bay and Boca de Quadra fjords indicate that watersheds influence the inventories of radioisotopes present and that the steep topographies of the fjords enhance sediment redistribution. Episodic deposition of terrestrially derived sediment was responsible for roughly 50% of the {sup 137}Cs and 45% of the {sup 210}Pb inventories in shallower (less than 180 m) locations in Wilson and Bakewell arms of Smeaton Bay. {sup 210}Pb sedimentation rates at shallower sites when corrected for episodic deposition were less than sedimentation rates obtained in the deep basins of the fjords where sediment focusing and increased primary productivity in the overlaying water column occur. Higher fluxes of dissolved Mn from surficial sediments and subsequent reoxidation in the overlying water may have enhanced scavenging of {sup 210}Pb in basin locatons resulting in higher inventories. Episodic events have occured frequently in Smeaton Bay and Boca de Quadra suggesting that steady-state conditions with respect to sedimenting particles can be achieved only when averaged over long time periods approaching the time over which {sup 137}Cs and {sup 210}Pb are useful.

  10. Use of anthropogenic radioisotopes to estimate rates of soil redistribution by wind I: Historic use of 137Cs

    NASA Astrophysics Data System (ADS)

    Van Pelt, R. Scott

    2013-06-01

    Wind erosion is increasingly scrutinized as a causative factor in soil degradation and fugitive dust emissions. Although models have been developed to predict wind erosion and dust emissions, they are not accurate in all locations. The temporal and spatial variability of aeolian processes makes local estimates of long-term average erosion costly and time consuming. Atmospheric testing of nuclear weapons during the 1950s and 1960s resulted in anthropogenic radioisotopes that had not previously existed being injected into stratospheric global circulation and subsequently deposited on the Earth's surface. Many of these radioisotopes are strongly adsorbed to soil particles and their movement on the landscape is a powerful method for investigating soil redistribution by wind, water, and tillage. 137Cs is the most commonly used anthropogenic radioisotope used to assess soil redistribution rates. Models have been developed to equate differences of radioisotope inventories with rates of soil redistribution and these models have been employed globally to assess soil redistribution on agricultural and natural landscapes. The radioisotope method for assessing soil redistribution rates has many advantages, but also a few limitations. One of the major limitations occurs when local sources of radioisotope contamination, particularly 137Cs, mask the pulse from global fallout, making temporal estimates of redistribution difficult or impossible. In this paper, I explore the importance, history, and applications of the radioisotopic technique using 137Cs, particularly as it applies to soil redistribution by wind.

  11. Spatial variation in the (137)Cs inventory in soils in a mixed deciduous forest in Fukushima, Japan.

    PubMed

    Takada, Momo; Yamada, Toshihiro; Takahara, Teruhiko; Okuda, Toshinori

    2016-09-01

    The spatial variation of the radiocesium inventory in forest soil was studied c.a. 44 km northwest of the Fukushima Daiichi Nuclear Power Plant, Japan. This study focuses on the effects of canopy interception and downward transfer from the forest canopy to the forest floor via stemflow and throughfall. We established a study plot (400 m(2)) in the canopy layer of a secondary mixed deciduous forest dominated by Japanese oak (Quercus crispula) and Japanese fir (Abies firma), in August and November 2014. Soil was sampled from 0 to 5 cm depth and (137)Cs was measured under the canopy using a 2-m grid and also at the tree trunk bases. We divided the study plot into the five different types of subplot according to the canopy projection areas and the tree species for the analysis. The geometric mean and coefficient of variation of the (137)Cs inventory were 202 kBq m(-2) and 0.11 (0.52 in the arithmetic coefficient of variation), respectively. Within the forest, the variation in the (137)Cs inventory under trees was larger than in crown gap areas. The large spatial variation may be attributed to canopy interception of the initial deposition and downward transfer of radiocesium via stemflow and throughfall.

  12. 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.

  13. Inventory and vertical migration of 90Sr fallout and 137Cs/90Sr ratio in Spanish mainland soils.

    PubMed

    Herranz, M; Romero, L M; Idoeta, R; Olondo, C; Valiño, F; Legarda, F

    2011-11-01

    In this paper the inventory of (90)Sr in 34 points distributed along the Spanish peninsular territory is presented. Obtained values range between 173 Bq/m(2) and 2047 Bq/m(2). From these data set and those (137)Cs data obtained in a previous work the (137)Cs/(90)Sr activity ratio has been established, laying this value between 0.9 and 3.6. Also the migration depth of both radionuclides has been analysed obtaining for (137)Cs an average value 57% lower than that obtained for (90)Sr. Additionally, this paper presents the results obtained in 11 sampling points in which the activity vertical profile has been measured. These profiles have been analysed to state the behaviour of strontium in soils and after, by using a convective-diffusive model, the parameters of the model which governs the vertical migration of (90)Sr in the soil, v (apparent convection velocity) and D (apparent diffusion coefficient) have been evaluated. Mean values obtained are 0.20 cm/year and 3.67 cm(2)/year, respectively.

  14. Gamma-ray astronomy: Nuclear transition region

    NASA Technical Reports Server (NTRS)

    Chupp, E. L.

    1976-01-01

    This monograph reviews the major theoretical and experimental efforts made during the past 12 years in gamma-ray astronomy over the energy range from 10 keV to about 100 MeV, where nuclear-transition lines are expected. Early attempts to detect celestial gamma rays are recounted, mechanisms of gamma-ray line and continuum production are examined, and formulas giving the various possible differential gamma-ray spectral shapes are provided. Predicted fluxes are discussed for solar gamma rays as well as for gamma emission from supernova remnants, supernovae, neutron stars, flare stars, the galactic core and disk, black holes, and diffuse sources. Gamma-ray interactions with matter are analyzed, particularly the photoelectric effect, Compton scattering from free electrons, and pair production in nuclear fields. Significant results are summarized for observations of gamma rays from the sun as well as from point and extended sources within and beyond the Galaxy, including diffuse fluxes and transient gamma-ray bursts. Factors pertaining to the design of gamma-ray astronomy experiments are considered, especially detector background limitations, gamma-ray production within instruments, and present-day detection methods.

  15. Report on the performance of a large-area, gamma-ray imager for search

    SciTech Connect

    Fabris, L; Ziock, K

    2005-10-07

    We are currently constructing a prototype, large-area, gamma-ray detector for conducting vehicle-mounted, mobile-search operations. The system is unique in that it relies on imaging to discriminate point sources of interest from the natural background variations. In a non-imaging instrument the background fluctuations mimic the signature seen from real sources at a distance and one is limited in sensitivity to detecting only those sources that overwhelm the local background variations --not just the counting statistics associated with a given measurement. The net result is that a larger detector is generally not more sensitive to detecting sources in the world at large. [1, 2] In a previous publication [3] we reported on the detection of a 1-mCi source at more than 80 meters from the detector using a proof-of-principle instrument (see Fig. 1) constructed to demonstrate how imaging removes the size limit on search instruments. In this report we document a systematic effort using the same detector to demonstrate that imaging detectors can reliably detect weak radiation sources at many 10's of meters. Specifically, we collected data on a 1-mCi {sup 137}Cs source 65 m from the path of the search instrument.

  16. Gamma-Ray Interactions for Reachback Analysts

    SciTech Connect

    Karpius, Peter Joseph; Myers, Steven Charles

    2016-08-02

    This presentation is a part of the DHS LSS spectroscopy training course and presents an overview of the following concepts: identification and measurement of gamma rays; use of gamma counts and energies in research. Understanding the basic physics of how gamma rays interact with matter can clarify how certain features in a spectrum were produced.

  17. Gamma-Ray Astronomy Technology Needs

    NASA Technical Reports Server (NTRS)

    Gehrels, N.; Cannizzo, J. K.

    2012-01-01

    In recent decades gamma-ray observations have become a valuable tool for studying the universe. Progress made in diverse 8re1lS such as gamma-ray bursts (GRBs), nucleosynthesis, and active galactic nuclei (AGNs) has complimented and enriched our astrophysical understanding in many ways. We present an overview of current and future planned space y-ray missions and discussion technology needs for- the next generation of space gamma-ray instruments.

  18. Future Hard X-ray and Gamma-Ray Missions

    NASA Astrophysics Data System (ADS)

    Krawczynski, Henric; Physics of the Cosmos (PCOS) Gamma Ray Science Interest Group (GammaSIG) Team

    2017-01-01

    With four major NASA and ESA hard X-ray and gamma-ray missions in orbit (Swift, NuSTAR, INTEGRAL, and Fermi) hard X-ray and gamma-ray astronomy is making major contributions to our understanding of the cosmos. In this talk, I will summarize the current and upcoming activities of the Physics of the Cosmos Gamma Ray Science Interest Group and highlight a few of the future hard X-ray and gamma-ray mission discussed by the community. HK thanks NASA for the support through the awards NNX14AD19G and NNX16AC42G and for PCOS travel support.

  19. The use of gamma spectrometry in the determination of fission products migration in irradiated fuel

    SciTech Connect

    2015-07-01

    Non destructive examinations realized in hot cells of LECA STAR facility give main data on irradiated fuel rods and pins. Among those examinations, gamma spectrometry allows access to fuel, inside the cladding, thanks to gamma rays of fission products such as {sup 137}Cs, {sup 154}Eu coming from pellets... From those gamma scannings we can detect the position and the length of the fuel column and of its pellets, calculate local burnup.. In the database of our lab we have already such gamma scannings on hundreds of rods or pins with different fuels, claddings and irradiations conditions (under nominal or non nominal). We have detected that in specific cases, an unusual shape of the {sup 137}Cs scanning (distribution quite different from those of {sup 154}Eu) can be explained by the migration of this isotope, moving to the cold sides of the pellet. This phenomenon is mainly associated with an increasing of the pellet's temperature. Based on our observations, we have developed a quantitative approach of the changes on the {sup 137}Cs scannings through the calculation of appropriate 'indicators'. Those calculations allow us to be able to localize, quantify and compare the {sup 137}Cs migration all along rods or pins. Those migration results are so quickly and easily achievable from gamma measurements and can then be easily correlated to other observations realized with destructive examinations, puncturing and calculations, already realized or to come. Because such a migration is the result of temperature increasing in the pellets, our indicators can be directly associated with this local temperature. In perspective, thermically activated phenomena such as geometrical changes in the shape of the pellets, fission gas release... can also indirectly be deduced from our indicators. (authors)

  20. Extrapolating soil redistribution rates estimated from 137Cs to catchment scale in a complex agroforestry landscape using GIS

    NASA Astrophysics Data System (ADS)

    Gaspar, Leticia; López-Vicente, Manuel; Palazón, Leticia; Quijano, Laura; Navas, Ana

    2015-04-01

    The use of fallout radionuclides, particularly 137Cs, in soil erosion investigations has been successfully used over a range of different landscapes. This technique provides mean annual values of spatially distributed soil erosion and deposition rates for the last 40-50 years. However, upscaling the data provided by fallout radionuclides to catchment level is required to understand soil redistribution processes, to support catchment management strategies, and to assess the main soil erosion factors like vegetation cover or topography. In recent years, extrapolating field scale soil erosion rates estimated from 137Cs data to catchment scale has been addressed using geostatistical interpolation and Geographical Information Systems (GIS). This study aims to assess soil redistribution in an agroforestry catchment characterized by abrupt topography and an intricate mosaic of land uses using 137Cs data and GIS. A new methodological approach using GIS is presented as an alternative of interpolation tools to extrapolating soil redistribution rates in complex landscapes. This approach divides the catchment into Homogeneous Physiographic Units (HPUs) based on unique land use, hydrological network and slope value. A total of 54 HPUs presenting specific land use, strahler order and slope combinations, were identified within the study area (2.5 km2) located in the north of Spain. Using 58 soil erosion and deposition rates estimated from 137Cs data, we were able to characterize the predominant redistribution processes in 16 HPUs, which represent the 78% of the study area surface. Erosion processes predominated in 6 HPUs (23%) which correspond with cultivated units in which slope and strahler order is moderate or high, and with scrubland units with high slope. Deposition was predominant in 3 HPUs (6%), mainly in riparian areas, and to a lesser extent in forest and scrubland units with low slope and low and moderate strahler order. Redistribution processes, both erosion and

  1. Linking spatial patterns of soil redistribution traced with 137Cs and soil nutrients in a Mediterranean mountain agroecosystem (NE Spain)

    NASA Astrophysics Data System (ADS)

    Quijano, Laura; Gaspar, Leticia; Navas, Ana

    2016-04-01

    Mediterranean mountain agroecosystems are prone to soil loss mainly due to the accelerated erosion as a consequence of human induced changes from agriculture and grazing practices over the last centuries and the climatic conditions (i.e. irregular and scarce precipitations and drought periods). Soil erosion leads to soil degradation inducing the loss of soil functions. The progressive decline of soil functions thereof soil quality is associated to a decrease of soil productivity and can threat the sustainability of cultivated soils. The use of fallout 137Cs as a soil movement tracer provides useful data to identify areas where loss and gain of 137Cs occurs and that of soil. This study aims to address soil movement and soil nutrient dynamics closely related to the status of soil degradation. A rain-fed cereal field (1.6 ha) representative of Mediterranean mountain agricultural landscapes (42°25'41''N 1°13'8''W) was selected to examine the effects of soil redistribution processes on the spatial variability of soil organic carbon (SOC) and nitrogen (SON) and their relationships with soil properties and topographic characteristics. From the hydrological point of view, the field is isolated due to the effect of landscape features and man-made structures. Climate is continental Mediterranean with an average annual rainfall of 500 mm and soils are Calcisols. The reference inventories of 137Cs and soil nutrients were established from 21 soil samples collected in nearby undisturbed areas under typical Mediterranean vegetation cover. A total of 156 bulk soil samples (30-50 cm depth) and 156 topsoil samples (5 cm) were collected on a 10 m grid. 137Cs and soil nutrients loss and gain areas were identified by comparing the reference inventories with the values of inventories at the sampling points. A new approach to characterize and measure active (ACF) and stable (SCF) carbon fraction contents by using a dry combustion method based on the oxidation temperature of carbon

  2. Double strand breaks induced by low doses of {gamma} rays or heavy ions: Quantitation in nonradioactive human DNA

    SciTech Connect

    Sutherland, B.M.; Bennett, P.V.; Sutherland, J.C.

    1996-07-15

    We have developed a method of quantitating low frequencies (0-30 sites/10{sup 9} base pairs) of double strand breaks in {approximately}1 {mu}g of nonradioactive human DNA. Unirradiated or irradiated DNA is digested with the restriction endonuclease NotI, producing cleavage fragments that include a major group centered at {approximately}1.2-1.3 Mbp. The DNA molecules are separated as a function of size by transverse alternating field electrophoresis. The frequency of double strand breaks is computed directly from the decrease in number average molecular length induced in the 1.2 to 1.3-Mbp cleavage fragment group by {sup 137}Cs {gamma} or Fe{sup 26+} (1.1 GeV/nucleon) irradiation vs the corresponding unirradiated DNA samples. The double strand break frequency can be quantitated easily in the dose range of 0-10 cGy of {gamma} rays. The frequency of breaks per unit dose calculated for {gamma} irradiation of DNA in human cells ({approximately}4.6 double strand breaks/10{sup 9} bp/Gy) who used methods requiring higher doses. 55 refs., 4 figs.

  3. [Forecast of collective radiation dose decrease of the population of Belarus as the result of optimization of moveable potassium contents in soils contaminated by 137Cs].

    PubMed

    Putiatin, Iu V; Adianova, O B

    2010-01-01

    Results of study on an efficiency of potassium moveable content for decrease of a collective dose from 137Cs to the population of Belarus are presented. On the basis of the "cost-benefit" analysis it is shown, that expenses for decreasing averted collective dose due to increase of potassium contents on arable lands amounts to more than 80 thousand US dollars per 1 man.-Sv depending on density of soil contamination of rural districts by 137Cs. It is found that high effect (costs less than 40 thousand US dollars per 1 man.-Sv on hectare of arable land) on averted collective dose from 137Cs at cultivation of cereals can be expected at an optimization of mobile potassium contents in sod-podzolic loamy sand soils with density of 137Cs contamination more than 925 kBq/m2, sand soils--more than 1184, light loam soils--more than 629 kBq/m2.

  4. Integration of Earth Observation Satellite Data and Real Time 137Cs Measurements in the Greek Marine Environment to GIS for Advances in Radiological Remote Control

    NASA Astrophysics Data System (ADS)

    Mavrokefalou, Georgia; Florou, Heleny; Sykioti, Olga; Parcharidis, Issaak

    2016-08-01

    In the present study an innovative tool is explored in terms of the radiological remote control. The levels of radionuclides in the marine environment, especially the soluble ones, are associated with other physical parameters. For this purpose, sea parameters such as sea surface temperature and ocean colour issued from satellite and field measurements have been utilized, in order to investigate potential relations with 137Cs activity concentrations. Such potential relations are expected to lead to an innovative tool based on remote sensing data and in situ 137Cs measurements for the remote radioactivity detection of the Greek marine ecosystem both for routine control and emergency recordings. Here, the first findings on the spatial correlations of 137Cs measurements with MODIS L3 ocean data in the Aegean Sea are presented, whereas temporal correlations of 137Cs measurements with MODIS L2 ocean and POSEIDON buoy data in Souda Bay area (Crete island) are also shown.

  5. Vertical distribution and temporal changes of 137Cs in soil profiles under various land uses after the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Takahashi, Junko; Tamura, Kenji; Suda, Tomoya; Matsumura, Ryo; Onda, Yuichi

    2015-01-01

    We monitored the vertical distribution of (137)Cs in soil profiles under eight different land uses for the 2 y after the Fukushima Dai-ichi Nuclear Power Plant accident, and discussed the temporal changes in the early-stage of the migration and the determinants of the initial distribution. The soil samples were collected for four surveys using a scraper plate at each study site, which consisted of three forests (mixed forest, mature cedar, and young cedar), two grasslands (pasture and meadow) and three abandoned agricultural fields (farm land, tobacco field, and paddy field). The land use patterns have a large influence on some soil properties and the migration processes of (137)Cs above ground, resulting in different distribution of (137)Cs in those soil profiles. Specifically, the secondary deposition of (137)Cs from the coniferous canopy, retention of (137)Cs by litter layer, and the homogenization of (137)Cs concentrations in surface soil by natural soil mixing such as the disturbance by cattle grazing, roots growing and the formation of needle ice were important to cause redistribution of the deposited (137)Cs. Only in the paddy field, the (137)Cs inventory in subsurface soils (5-10 cm) gradually increased and comprised 26% of the total (137)Cs in 2 y, showing the downward migration of (137)Cs to subsurface soil. In the other sites, it was considered that (137)Cs were strongly adsorbed by soil particles and rarely migrated downward as soluble form. Vertical distributions during the first survey were able to be used as the initial distributions and were well fitted to the exponential equation. The distribution parameters α (relaxation depth) and β (relaxation mass depth), calculated by the exponential equation were correlated with RIP (r = -0.806, p < 0.05), macro pore (r = 0.651, p = 0.11), and dispersible fine particle content (r = 0.856, p < 0.05). It indicated that the initial distribution would be influenced by the Cs fixation ability of

  6. Cause of death and neoplasia in mice continuously exposed to very low dose rates of gamma rays.

    PubMed

    Tanaka, I B; Tanaka, S; Ichinohe, K; Matsushita, S; Matsumoto, T; Otsu, H; Oghiso, Y; Sato, F

    2007-04-01

    Four thousand 8-week-old SPF B6C3F1 mice (2000 of each sex) were divided into four groups, one nonirradiated (control) and three irradiated. The irradiated groups were exposed to (137)Cs gamma rays at dose rates of 21, 1.1 and 0.05 mGy day(-1) for approximately 400 days with total doses equivalent to 8000, 400 and 20 mGy, respectively. All mice were kept until natural death, and pathological examination was performed to determine the cause of death. Neoplasms accounted for >86.7% of all deaths. Compared to the nonirradiated controls, the frequency of myeloid leukemia in males, soft tissue neoplasms and malignant granulosa cell tumors in females, and hemangiosarcoma in both sexes exposed to 21 mGy day(-1) were significantly increased. The number of multiple primary neoplasms per mouse was significantly increased in mice irradiated at 21 mGy day(-1). Significant increases in body weights were observed from 32 to 60 weeks of age in males and females exposed to 1.1 mGy day(-1) and 21 mGy day(-1), respectively. Our results suggest that life shortening (Tanaka et al., Radiat. Res. 160, 376-379, 2003) in mice continuously exposed to low-dose-rate gamma rays is due to early death from a variety of neoplasms and not from increased incidence of specific neoplasms.

  7. The dynamic time-over-threshold method for multi-channel APD based gamma-ray detectors

    NASA Astrophysics Data System (ADS)

    Orita, T.; Shimazoe, K.; Takahashi, H.

    2015-03-01

    t- Recent advances in manufacturing technology have enabled the use of multi-channel pixelated detectors in gamma-ray imaging applications. When obtaining gamma-ray measurements, it is important to obtain pulse height information in order to avoid unnecessary events such as scattering. However, as the number of channels increases, more electronics are needed to process each channel's signal, and the corresponding increases in circuit size and power consumption can result in practical problems. The time-over-threshold (ToT) method, which has recently become popular in the medical field, is a signal processing technique that can effectively avoid such problems. However, ToT suffers from poor linearity and its dynamic range is limited. We therefore propose a new ToT technique called the dynamic time-over-threshold (dToT) method [4]. A new signal processing system using dToT and CR-RC shaping demonstrated much better linearity than that of a conventional ToT. Using a test circuit with a new Gd3Al2Ga3O12 (GAGG) scintillator and an avalanche photodiode, the pulse height spectra of 137Cs and 22Na sources were measured with high linearity. Based on these results, we designed a new application-specific integrated circuit (ASIC) for this multi-channel dToT system, measured the spectra of a 22Na source, and investigated the linearity of the system.

  8. Rapid determination of radon daughters and of artificial radionuclides in air by online gamma-ray spectrometry.

    PubMed

    Hötzl, H; Winkler, R

    1993-01-01

    For the determination of airborne radionuclide concentrations in real time, a fixed filter device was constructed which fits directly onto a germanium detector with standard nuclear electronics and a multichannel analyzer buffer connected via a data line to a personal computer for remote control and on-line spectrum evaluation. The on-line gamma-ray spectrometer was applied to the study of radon decay product concentrations in ground-level air and to the rapid detection of any contamination of the environmental air by artificial radionuclides. At Munich-Neuherberg, depending on the meterological conditions, the measured air concentrations of 214Pb, the first gamma-ray-emitting member of the 222Rn decay series, varied from about 1 to 50 Bq m-3. For the artificial radionuclides 60Co, 131I and 137Cs the detection limits were determined as a function of the varying natural radon daughter concentrations at sampling and counting times of 1 h or 1 day. For these radionuclides minimum detectable air activity concentrations of 0.3 or 0.001 Bq m-3, respectively, were obtained at low radon daughter levels. At high radon daughter levels the respective detection limits were found to be higher by a factor of only about 2.

  9. Kinetics of the current response in TlBr detectors under a high dose rate of {gamma}-ray irradiation

    SciTech Connect

    Gazizov, I. M.; Zaletin, V. M.; Kukushkin, V. M.; Kuznetsov, M. S.; Lisitsky, I. S.

    2012-03-15

    The kinetics of the photocurrent response in doped and undoped TlBr samples subjected to irradiation with {gamma}-ray photons from a {sup 137}Cs source with the dose rate 0.033 to 3.84 Gy/min are studied. The crystals were grown by the directional crystallization of the melt method using the Bridgman-Stockbarger technique. The Pb impurity mass fraction introduced into the doped TlBr crystals was 1-10 ppm and amounted to 150 ppm for the Ca impurity. The crystals were grown in a vacuum, in bromine vapors, in a hydrogen atmosphere, and in air. Decay of the photocurrent is observed for extrinsic semiconductor crystals doped with bivalent cations (irrespective of the growth atmosphere), and also for crystals grown in hydrogen and crystals grown in an excess of thallium. The time constant of photocurrent decay {tau} amounted to 30-1400 s and was proportional to resistivity. It is shown that the current response can be related to photolysis in the TlBr crystals during irradiation with {gamma}-ray photons. The energy of hole traps responsible for a slow increase in the photo-current has been estimated and found to be equal to 0.6-0.85 eV.

  10. Gamma ray astronomy from satellites and balloons

    NASA Technical Reports Server (NTRS)

    Schoenfelder, V.

    1986-01-01

    A survey is given of gamma ray astronomy topics presented at the Cosmic Ray Conference. The major conclusions at the Cosmic Ray Conference in the field of gamma ray astronomy are given. (1) MeV-emission of gamma-ray bursts is a common feature. Variations in duration and energy spectra from burst to burst may explain the discrepancy between the measured log N - log S dependence and the observed isotropy of bursts. (2) The gamma-ray line at 1.809 MeV from Al(26) is the first detected line from a radioactive nucleosynthesis product. In order to understand its origin it will be necessary to measure its longitude distribution in the Milky Way. (3) The indications of a gamma-ray excess found from the direction of Loop I is consistent with the picture that the bulk of cosmic rays below 100 GeV is produced in galactic supernova remnants. (4) The interpretation of the large scale distribution of gamma rays in the Milky Way is controversial. At present an extragalactic origin of the cosmic ray nuclei in the GeV-range cannot be excluded from the gamma ray data. (5) The detection of MeV-emission from Cen A is a promising step towards the interesting field of extragalactic gamma ray astronomy.

  11. Evaluation of the Relationship between Current Internal 137Cs Exposure in Residents and Soil Contamination West of Chernobyl in Northern Ukraine.

    PubMed

    Kimura, Yuko; Okubo, Yuka; Hayashida, Naomi; Takahashi, Jumpei; Gutevich, Alexander; Chorniy, Sergiy; Kudo, Takashi; Takamura, Noboru

    2015-01-01

    After the Chernobyl Nuclear Power Plant accident, the residents living around the Chernobyl were revealed to have been internally exposed to 137Cs through the intake of contaminated local foods. To evaluate the current situation of internal 137Cs exposure and the relationship between the 137Cs soil contamination and internal exposure in residents, we investigated the 137Cs body burden in residents who were living in 10 selected cities from the northern part of the Zhitomir region, Ukraine, and collected soil samples from three family farms and wild forests of each city to measured 137Cs concentrations. The total number of study participants was 36,862, of which 68.9% of them were female. After 2010, the annual effective doses were less than 0.1 mSv in over 90% of the residents. The 137Cs body burden was significantly higher in autumn than other seasons (p < 0.001) and in residents living in more contaminated areas (p < 0.001). We also found a significant correlation between the proportion of residents in each city with an estimated annual exposure dose exceeding 0.1 mSv and 137Cs concentration of soil samples from family farms (r = 0.828, p = 0.003). In conclusion, more than 25 years after the Chernobyl accident, the internal exposure doses to residents living in contaminated areas of northern Ukraine is limited but still related to 137Cs soil contamination. Furthermore, the consumption of local foods is considered to be the cause of internal exposure.

  12. Status of (137)Cs contamination in marine biota along the Pacific coast of eastern Japan derived from a dynamic biological model two years simulation following the Fukushima accident.

    PubMed

    Tateda, Yutaka; Tsumune, Daisuke; Tsubono, Takaki; Misumi, Kazuhiro; Yamada, Masatoshi; Kanda, Jota; Ishimaru, Takashi

    2016-01-01

    Radiocesium ((134)Cs and (137)Cs) released into the Fukushima coastal environment was transferred to marine biota inhabiting the Pacific Ocean coastal waters of eastern Japan. Though the levels in most of the edible marine species decreased overtime, radiocesium concentrations in some fishes were still remained higher than the Japanese regulatory limit for seafood products. In this study, a dynamic food chain transfer model was applied to reconstruct (137)Cs levels in olive flounder by adopting the radiocesium concentrations in small demersal fish which constitute an important fraction of the diet of the olive flounder particularly inhabiting area near Fukushima. In addition, (137)Cs levels in slime flounder were also simulated using reported radiocesium concentrations in some prey organisms. The simulated results from Onahama on the southern border of the Fukushima coastline, and at Choshi the southernmost point where the contaminated water mass was transported by the Oyashio current, were assessed in order to identify what can be explained from present information, and what remains to be clarified three years after the Fukushima Dai-ichi nuclear power plant (1FNPP) accident. As a result, the observed (137)Cs concentrations in planktivorous fish and their predator fish could be explained by the theoretically-derived simulated levels. On the other hand, the slow (137)Cs depuration in slime flounder can be attributed to uptake from unknown sources for which the uptake fluxes were of a similar magnitude as the excretion fluxes. Since the reported (137)Cs concentrations in benthic invertebrates off Onahama were higher than the simulated values, radiocesium transfer from these benthic detritivorous invertebrates to slime flounder via ingestion was suggested as a cause for the observed slow depuration of (137)Cs in demersal fish off southern Fukushima. Furthermore, the slower depuration in the demersal fish likely required an additional source of (137)Cs, i

  13. The Fermi Gamma-Ray Space Telescope

    NASA Technical Reports Server (NTRS)

    Thompson, Dave; McEnery, Julie

    2011-01-01

    This slide presentation reviews the Gamma Ray Astronomy as enhanced by the Fermi Gamma Ray Space Telescope and Radio Astronomy as a synergistic relationship. Gamma rays often represent a significant part of the energy budget of a source; therefore, gamma-ray studies can be critical to understanding physical processes in such sources. Radio observations offer timing and spatial resolutions vastly superior to anything possible with gamma-ray telescopes; therefore radio is often the key to understanding source structure. Gamma-ray and radio observations can complement each other, making a great team. It reviews the Fermi Guest Investigator (GI) program, and calls for more cooperative work that involves Fermi and the Very Long Baseline Array (VLBA), a system of ten radio telescopes.

  14. GAMCIT: A gamma ray burst detector

    NASA Technical Reports Server (NTRS)

    Surka, Derek M.; Grunsfeld, John M.; Warneke, Brett A.

    1992-01-01

    The origin of celestial gamma ray bursts remains one of the great mysteries of modern astrophysics. The GAMCIT Get-Away-Special payload is designed to provide new and unique data in the search for the sources of gamma ray bursts. GAMCIT consists of three gamma ray detectors, an optical CCD camera, and an intelligent electronics system. This paper describes the major components of the system, including the electronics and structural designs.

  15. Understanding Doppler Broadening of Gamma Rays

    SciTech Connect

    Rawool-Sullivan, Mohini; Sullivan, John P.

    2014-07-03

    Doppler-broadened gamma ray peaks are observed routinely in the collection and analysis of gamma-ray spectra. If not recognized and understood, the appearance of Doppler broadening can complicate the interpretation of a spectrum and the correct identification of the gamma ray-emitting material. We have conducted a study using a simulation code to demonstrate how Doppler broadening arises and provide a real-world example in which Doppler broadening is found. This report describes that study and its results.

  16. Evaluation of the possibility to use the plant-microbe interaction to stimulate radioactive 137Cs accumulation by plants in a contaminated farm field in Fukushima, Japan.

    PubMed

    Djedidi, Salem; Terasaki, Akimi; Aung, Han Phyo; Kojima, Katsuhiro; Yamaya, Hiroko; Ohkama-Ohtsu, Naoko; Bellingrath-Kimura, Sonoko Dorothea; Meunchang, Phatchayaphon; Yokoyama, Tadashi

    2015-01-01

    Field experiments in a contaminated farmland in Nihonmatsu city, Fukushima were conducted to assess the effectiveness of the plant-microbe interaction on removal of radiocesium. Before plowing, 93.3% of radiocesium was found in the top 5 cm layer (5,718 Bq kg DW(-1)). After plowing, Cs radioactivity in the 0-15 cm layer ranged from 2,037 to 3,277 Bq kg DW(-1). Based on sequential extraction, the percentage of available radiocesium (water soluble + exchangeable) was fewer than 10% of the total radioactive Cs. The transfer of (137)Cs was investigated in three agricultural crops; komatsuna (four cultivars), Indian mustard and buckwheat, inoculated with a Bacillus or an Azospirillum strains. Except for komatsuna Nikko and Indian mustard, inoculation with both strains resulted in an increase of biomass production by the tested plants. The highest (137)Cs radioactivity concentration in above-ground parts was found in Bacillus-inoculated komatsuna Nikko (121 Bq kg DW(-1)), accompanied with the highest (137)Cs TF (0.092). Furthermore, komatsuna Nikko-Bacillus and Indian mustard-Azospirillum associations gave the highest (137)Cs removal, 131.5 and 113.8 Bq m(-2), respectively. Despite the beneficial effect of inoculation, concentrations of (137)Cs and its transfer to the tested plants were not very high; consequently, removal of (137)Cs from soil would be very slow.

  17. Accumulation and transfer of 137Cs and 90Sr in the plants of the forest ecosystem near the Ignalina Nuclear Power Plant.

    PubMed

    Lukšienė, B; Marčiulionienė, D; Gudelienė, I; Schönhofer, F

    2013-02-01

    The radioecological state of the forest ecosystem in the vicinity of the Ignalina Power Plant prior to decommissioning was analysed with specific emphasis on (137)Cs and (90)Sr activity concentrations in plant species growing in two reference sampling sites (Tilze and Grikiniskes). In the period of 1996-2008 the mean contamination of plants with (137)Cs was from 45 to 119 Bq/kg and with (90)Sr - from 3 to 42 Bq/kg. Measured (137)Cs TF values for soil-root transfer mainly ranged between 1.0-1.4, except for Calamagrostis arundinacea which had a TF value of 0.1. On average, the (137)Cs TF value from root to shoot was 1.7 fold higher than for soil to root transfer. (90)Sr TF values (soil-root) were in the range of 1.2-1.8 but for Calluna vulgaris it was 0.2. The mean root to shoot TF value for (90)Sr was 7.7 fold higher. These results indicate the higher (90)Sr bioavailability than that of (137)Cs in the forested area. The Grikiniskes reference site is located nearby the Ignalina NPP, specifically the heated water outlet channel, which results in altered microclimatic conditions. These specific microclimatic conditions result in relationships between (137)Cs TF (soil-root) values and pH, moisture and organic matter content in the soil at Grikiniskes which appear to be different to those at the Tilze reference sampling site.

  18. Long-term decrease of atmospheric test {sup 137}Cs in the soil-prairie plant-milk pathway in southern Chile

    SciTech Connect

    Schuller, P. Ellies, A.; Handl, J.

    1998-07-01

    The time dependency of nuclear test {sup 137}Cs in soil, prairie plants, and milk was observed on pastures of seven dairy farms in the 10th Region, Chile, from 1982 to 1997, without any appreciable deposition of radioactive fallout after 1983. Whereas the {sup 137}Cs concentration in the soil decreased at a rate close to that of the radionuclide`s physical decay during the whole observation period, the rate of decrease of the {sup 137}Cs concentration in the prairie plants and in the milk, having been very rapid between 1982--1990, became slower between 1991--1997. The effective half-lives of the concentration in plants were found to be 5.6 y and 12 y during the first and second observation periods, respectively. Similar half-lives of 5.5 y and 13 y were found for the concentration decline in milk during each period. These data clearly demonstrate a reduction in the long-term decrease of the {sup 137}Cs plant uptake, and consequently in the decrease of the {sup 137}Cs concentration in milk, resulting from a decline of {sup 137}Cs availability for prairie plants in the Hapludand soils over the whole 15-y observation period.

  19. Estimation of average burnup of damaged fuels loaded in Fukushima Dai-ichi reactors by using the {sup 134}Cs/{sup 137}Cs ratio method

    SciTech Connect

    Endo, T.; Sato, S.; Yamamoto, A.

    2012-07-01

    Average burnup of damaged fuels loaded in Fukushima Dai-ichi reactors is estimated, using the {sup 134}Cs/{sup 137}Cs ratio method for measured radioactivities of {sup 134}Cs and {sup 137}Cs in contaminated soils within the range of 100 km from the Fukushima Dai-ichi nuclear power plants. As a result, the measured {sup 134}Cs/{sup 137}Cs ratio from the contaminated soil is 0.996{+-}0.07 as of March 11, 2011. Based on the {sup 134}Cs/{sup 137}Cs ratio method, the estimated burnup of damaged fuels is approximately 17.2{+-}1.5 [GWd/tHM]. It is noted that the numerical results of various calculation codes (SRAC2006/PIJ, SCALE6.0/TRITON, and MVP-BURN) are almost the same evaluation values of {sup 134}Cs/ {sup 137}Cs ratio with same evaluated nuclear data library (ENDF-B/VII.0). The void fraction effect in depletion calculation has a major impact on {sup 134}Cs/{sup 137}Cs ratio compared with the differences between JENDL-4.0 and ENDF-B/VII.0. (authors)

  20. The Contribution of Sources to the Sustained Elevated Inventory of (137)Cs in Offshore Waters East of Japan after the Fukushima Dai-ichi Nuclear Power Station Accident.

    PubMed

    Takata, Hyoe; Kusakabe, Masashi; Inatomi, Naohiko; Ikenoue, Takahito; Hasegawa, Kazuyuki

    2016-07-05

    We have evaluated the contribution of sources of (137)Cs to the inventory of radiocesium in waters (surface area: 6160 km(2), water volume: 753 km(3)) off Fukushima Prefecture and neighboring prefectures from May 2011 to February 2015. A time-series of the inventory of (137)Cs in the offshore waters revealed a clearly decreasing trend from May 2011 (283.4 TBq) to February 2015 (1.89 TBq). The (137)Cs inventory about four years after the accident was approximately twice the background inventory of 1.1 TBq. The magnitudes of the (137)Cs influxes from sources into offshore waters for periods of 182-183 days were estimated from the first period (1 October 2011 to 31 March 2012: 15.3 TBq) to the last period (1 October 2014 to 31 March 2015: 0.41 TBq). We assumed that three sources contributed (137)Cs: continuous direct discharge from the Fukushima Dai-ichi Nuclear Power Station (FNPS) even after the massive discharge in late March 2011, desorption/dissolution from sediments, and fluvial input. Quantification of these sources indicated that the direct discharge from the FNPS is the principal source of (137)Cs to maintain the relatively high inventory in the offshore area.

  1. Time Dependence of the (137)Cs Concentration in Particles Discharged from Rice Paddies to Freshwater Bodies after the Fukushima Daiichi NPP Accident.

    PubMed

    Yoshimura, Kazuya; Onda, Yuichi; Wakahara, Taeko

    2016-04-19

    The concentration of particulate (137)Cs in paddy fields, which can be a major source of (137)Cs entering the water system, was studied following the Fukushima Daiichi Nuclear Power Plant accident. To parametrize the concentration and to estimate the time dependence, paddy fields covering various levels of (137)Cs deposition were investigated over the period 2011-2013 (n = 121). The particulate (137)Cs concentration (kBq kg-SS(-1)) showed a significant correlation with the initial surface deposition density (kBq m(-2)). This suggests that the entrainment coefficient (m(2) kg-SS(-1)), defined as the ratio between the particulate (137)Cs concentration and the initial surface deposition density, is an important parameter when modeling (137)Cs wash-off from paddy fields. The entrainment coefficient decreased with time following a double exponential function. The decrease rate constant of the entrainment coefficient was clearly higher than that reported for other land uses and for river water. The difference in the decrease rates of the entrainment coefficient suggests that paddy fields play a major role in radiocesium migration through the water system. An understanding of the decrease rate of the entrainment coefficient of paddy fields is therefore crucial to understand the migration of radiocesium in the water system.

  2. Migration of 137Cs in tributaries, lake water and sediment of Lago Maggiore (Italy, Switzerland) - analysis and comparison with Lago di Lugano and other lakes.

    PubMed

    Putyrskaya, Victoria; Klemt, Eckehard; Röllin, Stefan

    2009-01-01

    This paper describes the behaviour of 137Cs in Lago Maggiore and other pre-alpine lakes as a consequence of atmospheric nuclear weapons testing fallout and the fallout from the nuclear accident in Chernobyl. It presents data on the 137Cs distribution in tributaries, lake water, bottom sediments and reveals the role of (137)Cs as a marker of the sedimentation processes. The run-off of 137Cs from the watershed to the lake is described with a simple compartment model. Measurements of the activity concentration of (137)Cs in sediments are compared with the output of a model (diffusion-convection type) which describes the input of 137Cs into and its vertical distribution within the sediment. Varying sedimentation rates (0.05-0.90g(cm2y)(-1)) in Lago Maggiore are compared with data of other authors. Sedimentation rates and total distribution coefficients (of about 10(5) Lkg(-1)) in Lago Maggiore are discussed and compared with those of Lago di Lugano, Lake Constance, and Lake Vorsee.

  3. Long-term effects of single potassium fertilization on 137Cs levels in plants and fungi in a boreal forest ecosystem.

    PubMed

    Rosén, K; Vinichuk, M; Nikolova, I; Johanson, K

    2011-02-01

    We examined the long-term effects of a single application of potassium (K) fertilizer (100 kg K ha(-1)) in 1992 on (137)Cs uptake in a forest ecosystem in central Sweden. (137)Cs activity concentrations were determined in three low-growing perennial shrubs, heather (Calluna vulgaris), lingonberry (Vaccinium vitis-idaea) and bilberry (Vaccinium myrtillus), and in four wild fungal species (Cortinarius semisanguineus, Lactarius rufus, Rozites caperata and Suillus variegatus). Uptake of (137)Cs by plants and fungi growing on K-fertilized plots 17 years after application of the K fertilizer was significantly lower than in corresponding species growing in a non-fertilized control area. The (137)Cs activity concentration was 21-58% lower in fungal sporocarps and 40-61% lower in plants in the K-fertilized area compared with the control. Over the study period, this decrease in (137)Cs activity concentration was more consistent in plants than in fungi, although the effect was statistically significant and strongly pronounced in all species. The effect of K fertilization in reducing (137)Cs activity concentration in fungi and plants decreased over time but was still significant in 2009, 17 years after fertilization. This suggests that application of K fertilizer to forests is an appropriate and effective long-term measure to decrease radiocaesium accumulation in plants and fungi.

  4. Gamma-ray burst populations

    NASA Astrophysics Data System (ADS)

    Virgili, Francisco Javier

    Over the last fifty years the field of gamma-ray bursts has shown incredible growth, but the amassing of data has also left observers and theorists alike wondering about some of the basic questions surrounding these phenomena. Additionally, these events show remarkable individuality and extrema, ranging in redshift throughout the observable universe and over ten orders of magnitude in energy. This work focuses on analyzing groups of bursts that are different from the general trend and trying to understand whether these bursts are from different intrinsic populations and if so, what can be said about their progenitors. This is achieved through numerical Monte Carlo simulations and statistical inference in conjunction with current GRB observations. Chapter 1 gives a general introduction of gamma-ray burst theory and observations in a semi-historical context. Chapter 2 provides an introduction to the theory and practical issues surrounding the numerical simulations and statistics. Chapters 3--5 are each dedicated to a specific problem relating to a different type of GRB population: high-luminosity v. low-luminosity bursts, constraints from high-redshift bursts, and Type I v. Type II bursts. Chapter 6 follows with concluding remarks.

  5. Sneaky Gamma-Rays: Using Gravitational Lensing to Avoid Gamma-Gamma-Absorption

    NASA Astrophysics Data System (ADS)

    Boettcher, Markus; Barnacka, Anna

    2014-08-01

    It has recently been suggested that gravitational lensing studies of gamma-ray blazars might be a promising avenue to probe the location of the gamma-ray emitting region in blazars. Motivated by these prospects, we have investigated potential gamma-gamma absorption signatures of intervening lenses in the very-high-energy gamma-ray emission from lensedblazars. We considered intervening galaxies and individual stars within these galaxies. We find that the collective radiation field of galaxies acting as sources of macrolensing are not expected to lead to significant gamma-gamma absorption. Individual stars within intervening galaxies could, in principle, cause a significant opacity to gamma-gamma absorption for VHE gamma-rays if the impact parameter (the distance of closest approach of the gamma-ray to the center of the star) is small enough. However, we find that the curvature of the photon path due to gravitational lensing will cause gamma-ray photons to maintain a sufficiently large distance from such stars to avoid significant gamma-gamma absorption. This re-inforces the prospect of gravitational-lensing studies of gamma-ray blazars without interference due to gamma-gamma absorption due to the lensing objects.

  6. The Mystery of Gamma-Ray Bursts

    NASA Technical Reports Server (NTRS)

    Fishman, Gerald J.

    2004-01-01

    Gamma-ray bursts remain one of the greatest mysteries in astrophysics. Observations of gamma-ray bursts made by the BATSE experiment on the Compton Gamma-Ray Observatory will be described. Most workers in the field now believe that they originate from cosmological distances. This view has been reinforced by observations this year of several optical afterglow counterparts to gamma-ray bursts. A summary of these recent discoveries will be presented, along with their implications for models of the burst emission mechanism and the energy source of the bursts.

  7. Low-level gamma-ray spectrometry

    SciTech Connect

    Brodzinski, R.L.

    1990-10-01

    Low-level gamma-ray spectrometry generally equates to high-sensitivity gamma-ray spectrometry that can be attained by background reduction, selective signal identification, or some combination of both. Various methods for selectively identifying gamma-ray events and for reducing the background in gamma-ray spectrometers are given. The relative magnitude of each effect on overall sensitivity and the relative cost'' for implementing them are given so that a cost/benefit comparison can be made and a sufficiently sensitive spectrometer system can be designed for any application without going to excessive or unnecessary expense. 10 refs., 8 figs.

  8. Hard gamma ray emission from blazars

    NASA Technical Reports Server (NTRS)

    Marscher, Alan P.; Bloom, Steven D.

    1992-01-01

    The gamma-ray emission expected from compact extragalactic sources of nonthermal radiation is examined. The highly variable objects in this class should produce copious amounts of self-Compton gamma-rays in the compact relativistic jet. This is shown to be a likely interpretation of the hard gamma-ray emission recently detected from the quasar 3C 279 during a period of strong nonthermal flaring at lower frequencies. Ways of discriminating between the self-Compton model and other possible gamma-ray emission mechanisms are discussed.

  9. Gamma-ray irradiated polymer optical waveguides

    SciTech Connect

    Lai, C.-C.; Wei, T.-Y.; Chang, C.-Y.; Wang, W.-S.; Wei, Y.-Y.

    2008-01-14

    Optical waveguides fabricated by gamma-ray irradiation on polymer through a gold mask are presented. The gamma-ray induced index change is found almost linearly dependent on the dose of the irradiation. And the measured propagation losses are low enough for practical application. Due to the high penetrability of gamma ray, uniform refractive index change in depth can be easily achieved. Moreover, due to large-area printing, the uniformity of waveguide made by gamma-ray irradiation is much better than that by e-beam direct writing.

  10. Instrumentation for gamma-ray astronomy

    NASA Technical Reports Server (NTRS)

    Bertsch, David L.; Fichtel, Carl E.; Trombka, Jacob I.

    1988-01-01

    The current status of gamma-ray-telescope technology for ground, airborne, and space observations is surveyed and illustrated with drawings, diagrams, and graphs and tables of typical data. For the low- and medium-energy ranges, consideration is given to detectors and detector cooling systems, background-rejection methods, radiation damage, large-area detectors, gamma-ray imaging, data analysis, and the Compton-interaction region. Also discussed are the gamma-ray interaction process at high energies; multilevel automated spark-chamber gamma-ray telescopes; the Soviet Gamma-1 telescope; the EGRET instrument for the NASA Gamma-Ray Observatory; and Cerenkov, air-shower, and particle-detector instruments for the TeV and PeV ranges. Significant improvements in resolution and sensitivity are predicted for the near future.

  11. Modeling gamma-ray bursts

    NASA Astrophysics Data System (ADS)

    Maxham, Amanda

    Discovered serendipitously in the late 1960s, gamma-ray bursts (GRBs) are huge explosions of energy that happen at cosmological distances. They provide a grand physical playground to those who study them, from relativistic effects such as beaming, jets, shocks and blastwaves to radiation mechanisms such as synchrotron radiation to galatic and stellar populations and history. Through the Swift and Fermi space telescopes dedicated to observing GRBs over a wide range of energies (from keV to GeV), combined with accurate pinpointing that allows ground based follow-up observations in the optical, infrared and radio, a rich tapestry of GRB observations has emerged. The general picture is of a mysterious central engine (CE) probably composed of a black hole or neutron star that ejects relativistic shells of matter into intense magnetic fields. These shells collide and combine, releasing energy in "internal shocks" accounting for the prompt emission and flaring we see and the "external shock" or plowing of the first blastwave into the ambient surrounding medium has well-explained the afterglow radiation. We have developed a shell model code to address the question of how X-ray flares are produced within the framework of the internal shock model. The shell model creates randomized GRB explosions from a central engine with multiple shells and follows those shells as they collide, merge and spread, producing prompt emission and X-ray flares. We have also included a blastwave model, which can constrain X-ray flares and explain the origin of high energy (GeV) emission seen by the Fermi telescope. Evidence suggests that gamma-ray prompt emission and X-ray flares share a common origin and that at least some flares can only be explained by long-lasting central engine activity. We pay special attention to the time history of central engine activity, internal shocks, and observed flares. We calculate the gamma-ray (Swift/BAT band) and X-ray (Swift/XRT band) lightcurves for arbitrary

  12. Radiation doses for Marshall Islands Atolls Affected by U.S. Nuclear Testing:All Exposure Pathways, Remedial Measures, and Environmental Loss of 137Cs

    SciTech Connect

    Robison, W L; Hamilton, T F

    2009-04-20

    Rongelap Atoll (Robison et al., 1994; Simon et al., 1997), and Utrok Island at Utrok Atoll (Robison, et al., 1999) indicate that about 95-99% of the total estimated dose to people who may return to live at the atolls today (Utrok Island is populated) is the result of exposure to {sup 137}Cs. External gamma exposure from {sup 137}Cs in the soil accounts for about 10 to 15% of the total dose and {sup 137}Cs ingested during consumption of local food crops such as drinking coconut meat and fluid (Cocos nucifera L.), copra meat and milk, Pandanus fruit, and breadfruit accounts for about 85 to 90%. The other 1 to 2% of the estimated dose is from {sup 90}Sr, {sup 239+240}Pu, and {sup 241}Am. The {sup 90}Sr exposure is primarily through the food chain while the exposure to {sup 239+240}Pu, and {sup 241}Am is primarily via the inhalation pathway as a result of breathing re-suspended soil particles.

  13. Atmospheric Dispersion Modeling of 137Cs generated from Nuclear Spent Fuel under Hypothetic Accidental Condition in the BNPP Area

    NASA Astrophysics Data System (ADS)

    Lee, Jongkuk; Lee, Kwan-Hee; Yook, Daesik; Kim, Sung Il; Lee, Byung Soo

    2016-04-01

    This study presents the results of atmosphere dispersion modeling using CALPUFF code that are based on computational simulation to evaluate the environmental characteristics of the Barakah nuclear power plant (BNPP) in west area of UAE. According to meteorological data analysis (2012~2013), the winds from the north(7.68%) and west(9.05%) including NNW(41.63%), NW(28.55%), and WNW(6.31%) winds accounted for more than 90% of the wind directions. East(0.2%) and south(0.6%) direction wind, including ESE(0.31%), SE(0.38%), and SSE(0.38%) were rarely distributed during the simulation period. Seasonal effects were not showed. However, a discrepancy in the tendency between daytime and night-time was observed. Approximately 87% of the wind speed was distributed below 5.4m/s (17%, 47% and 23% between the speeds of 0.5-1.8m/s 1.8-3.3m/s and 3.3-5.4m/s, respectively) during the annual period. Seasonal wind speed distribution results presented very similar pattern of annual distribution. Wind speed distribution of day and night, on the other hand, had a discrepancy with annual modeling results than seasonal distribution in some sections. The results for high wind speed (more than 10.8m/s) showed that this wind blew from the west. This high wind speed is known locally as the 'Shamal', which occurs rarely, lasting one or two days with the strongest winds experienced in association with gust fronts and thunderstorms. Six variations of cesium-137 (137Cs) dispersion test were simulated under hypothetic severe accidental condition. The 137Cs dispersion was strongly influenced by the direction and speed of the main wind. From the test cases, east-south area of the BNPP site was mainly influenced by 137Cs dispersion. A virtual receptor was set and calculated for observation of the 137Cs movement and accumulation. Surface roughness tests were performed for the analysis of topographic conditions. According to the surface condition, there are various surface roughness length. Four types

  14. Assessment of soil erosion and deposition rates in a Moroccan agricultural field using fallout 137Cs and 210Pbex.

    PubMed

    Benmansour, M; Mabit, L; Nouira, A; Moussadek, R; Bouksirate, H; Duchemin, M; Benkdad, A

    2013-01-01

    In Morocco land degradation - mainly caused by soil erosion - is one of the most serious agroenvironmental threats encountered. However, only limited data are available on the actual magnitude of soil erosion. The study site investigated was an agricultural field located in Marchouch (6°42' W, 33° 47' N) at 68 km south east from Rabat. This work demonstrates the potential of the combined use of (137)Cs, (210)Pb(ex) as radioisotopic soil tracers to estimate mid and long term erosion and deposition rates under Mediterranean agricultural areas. The net soil erosion rates obtained were comparable, 14.3 t ha(-1) yr(-1) and 12.1 ha(-1) yr(-1) for (137)Cs and (210)Pb(ex) respectively, resulting in a similar sediment delivery ratio of about 92%. Soil redistribution patterns of the study field were established using a simple spatialisation approach. The resulting maps generated by the use of both radionuclides were similar, indicating that the soil erosion processes has not changed significantly over the last 100 years. Over the previous 10 year period, the additional results provided by the test of the prediction model RUSLE 2 provided results of the same order of magnitude. Based on the (137)Cs dataset established, the contribution of the tillage erosion impact has been evaluated with the Mass Balance Model 3 and compared to the result obtained with the Mass Balance Model 2. The findings highlighted that water erosion is the leading process in this Moroccan cultivated field, tillage erosion under the experimental condition being the main translocation process within the site without a significant and major impact on the net erosion.

  15. 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.

  16. Transfer of 137Cs and 60Co in a waste retention pond with emphasis on aquatic insects

    SciTech Connect

    Voshell, J.R. Jr.; Eldridge, J.S.; Oakes, T.W.

    1985-11-01

    The objectives of this research were (1) to analyze the transfers of 137Cs and 60Co in a retention pond, with emphasis on aquatic insects and (2) to determine if detectable concentrations of these radionuclides are exported by emerging aquatic insects. We analyzed the radionuclide concentrations in the following components: water solution, bottom sediments, suspended particulate matter, plankton, floating mats of filamentous algae, benthic macroinvertebrates, and emerging aquatic insects. Samples were collected quarterly from June 1981 to April 1982. The lowest concentrations (in picocuries per milliliter) occurred in solution (range: 1.4 X 10(2) to 3.2 X 10(2) for 137Cs and 8.1 X 10(-1) to 2.2 X 10(0) for 60Co). The highest concentrations (in picocuries per gram dry weight) occurred in the sediments (range: 1.5 X 10(4) to 1.1 X 10(8) for 137Cs and 1.0 X 10(2) to 4.3 X 10(6) for 60Co). The primary producers and aquatic insect consumers had concentrations of both radionuclides that were two to four orders of magnitude higher than the respective concentrations dissolved in water but two to three orders of magnitude lower than the concentrations in the sediments. The concentrations of both radionuclides decreased successively at higher trophic levels. There were considerable temporal variations as the radionuclides cycled among the abiotic and biotic components of the pond. Emerging adult aquatic insects had lower concentrations of both radionuclides than the immature stages that lived in the pond (adult/immature ratio about 0.25). Because the emerging adult insects contain detectable concentrations of radionuclides, have relatively long life spans, and disperse away from the aquatic habitat, we conclude that adult aquatic insects would be effective biological monitors.

  17. {sup 137}Cs exposure in the Marshallese populations: An assessment based on whole-body counting measurements (1989-1994)

    SciTech Connect

    Sun, L.C.; Clinton, J.H.; Kaplan, E.

    1997-07-01

    The Marshall Islands were the site of numerous tests of nuclear weapons by the United States. From 1946 to 1958, nuclear devices were detonated at Enemetak and Bikini Atolls. Following the inadvertent contamination of the northern islands downwind of the 1954 Bravo Test, Brookhaven National Laboratory became involved in the medical care and the radiological safety of the affected populations. One important technique employed in assessing the internally deposited radionuclides is whole-body counting. To estimate current and future exposures to 1376, data from 1989 to 1994 were analyzed and are reported in this paper. During this period, 3,618 measurements were made for the Marshallese. The cesium body contents were assumed to result from a series of chronic intakes. Also, it was assumed that cesium activity in the body reaches a plateau that is maintained over 365 d. We estimated the annual effective dose rate for each population, derived from the recommendations of the International Commission on Radiological Protection. The average {sup 137}Cs uptake measured by the whole-body counting method varies from one population to another; it was consistent with measurements of external exposure rate. The analysis. though based on limited data, indicates that there is no statistical support for a seasonal effect on {sup 137}Cs uptake. The critical population group for cesium uptake is adult males. Within the 5-y monitoring period, all internal exposures to {sup 137}Cs mere less than 0.2 mSv y{sup -1}. Similarly, a persistent average cesium effective dose rate of 2 {mu}Sv y{sup -1} was determined for Majuro residents. 73 refs., 6 figs., 10 tabs.

  18. Transfer of 137Cs and 60Co in a waste retention pond with emphasis on aquatic insects.

    PubMed

    Voshell, J R; Eldridge, J S; Oakes, T W

    1985-11-01

    The objectives of this research were (1) to analyze the transfers of 137Cs and 60Co in a retention pond, with emphasis on aquatic insects and (2) to determine if detectable concentrations of these radionuclides are exported by emerging aquatic insects. We analyzed the radionuclide concentrations in the following components: water solution, bottom sediments, suspended particulate matter, plankton, floating mats of filamentous algae, benthic macroinvertebrates, and emerging aquatic insects. Samples were collected quarterly from June 1981 to April 1982. The lowest concentrations (in picocuries per milliliter) occurred in solution (range: 1.4 X 10(2) to 3.2 X 10(2) for 137Cs and 8.1 X 10(-1) to 2.2 X 10(0) for 60Co). The highest concentrations (in picocuries per gram dry weight) occurred in the sediments (range: 1.5 X 10(4) to 1.1 X 10(8) for 137Cs and 1.0 X 10(2) to 4.3 X 10(6) for 60Co). The primary producers and aquatic insect consumers had concentrations of both radionuclides that were two to four orders of magnitude higher than the respective concentrations dissolved in water but two to three orders of magnitude lower than the concentrations in the sediments. The concentrations of both radionuclides decreased successively at higher trophic levels. There were considerable temporal variations as the radionuclides cycled among the abiotic and biotic components of the pond. Emerging adult aquatic insects had lower concentrations of both radionuclides than the immature stages that lived in the pond (adult/immature ratio about 0.25). Because the emerging adult insects contain detectable concentrations of radionuclides, have relatively long life spans, and disperse away from the aquatic habitat, we conclude that adult aquatic insects would be effective biological monitors.

  19. X-ray and gamma ray astronomy detectors

    NASA Technical Reports Server (NTRS)

    Decher, Rudolf; Ramsey, Brian D.; Austin, Robert

    1994-01-01

    X-ray and gamma ray astronomy was made possible by the advent of space flight. Discovery and early observations of celestial x-rays and gamma rays, dating back almost 40 years, were first done with high altitude rockets, followed by Earth-orbiting satellites> once it became possible to carry detectors above the Earth's atmosphere, a new view of the universe in the high-energy part of the electromagnetic spectrum evolved. Many of the detector concepts used for x-ray and gamma ray astronomy were derived from radiation measuring instruments used in atomic physics, nuclear physics, and other fields. However, these instruments, when used in x-ray and gamma ray astronomy, have to meet unique and demanding requirements related to their operation in space and the need to detect and measure extremely weak radiation fluxes from celestial x-ray and gamma ray sources. Their design for x-ray and gamma ray astronomy has, therefore, become a rather specialized and rapidly advancing field in which improved sensitivity, higher energy and spatial resolution, wider spectral coverage, and enhanced imaging capabilities are all sought. This text is intended as an introduction to x-ray and gamma ray astronomy instruments. It provides an overview of detector design and technology and is aimed at scientists, engineers, and technical personnel and managers associated with this field. The discussion is limited to basic principles and design concepts and provides examples of applications in past, present, and future space flight missions.

  20. Short-Term Environmental Impacts of Illite Clays When Used As An In SITU Method for Remediating 137Cs-Contaminated Wetland

    SciTech Connect

    KAPLAN, D.I.

    2004-05-17

    Over 1,200 hectares (3,000 acres) of wetlands such as L-Lake; Par Pond; Ponds A, 2, 4, 5, and B; canals; and several creeks (e.g. Steel Creek, Lower Three Runs, and Pen Branch) on the Savannah River Site (SRS) are contaminated with 560 Ci of 137Cs. These environmentally sensitive wetlands pose a significant remediation challenge to the Department of Energy (DOE). A new technology is needed to avoid environmentally destructive remediation. Current muck and truck technologies destroy the sensitive ecosystems, and may increase dose to workers. Because of relatively low amount of clay and weak 137Cs retention capabilities of kaolinite dominant sediments on the SRS, 137Cs has a greater bioavailability here than at any other DOE site. We have previously shown that naturally occurring illite minerals, with a high complexing capability for 137Cs, can sequester 137Cs and reduce its bioavailability when applied to 137Cs contaminated wetlands. Previous research showed that an in situ remediation method using illite minerals reduced 137Cs concentrations in the water 25- to 30-fold, in aquatic plants 3- to 5-fold, and in fish 2- to 3-fold. During this funding period (Fy03) we re-sampled study sites in Pond A and R-Canal that had been treated in 2001 with illite clays. The data revealed that 137Cs concentrations in water are still lower than untreated control sites, some 112 weeks later. This encouraging result indicates that the in situ remediation technique has a longer-term effectiveness than was previously reported. This positive finding occurred despite the study site experiencing a severe drought, as well as flooded conditions during the two-year period. Studies on the in situ application of illite minerals to 137Cs-contaminated wetlands continue to produce positive results. Additional measurements are needed, however, to determine the long-term effectiveness of the technique, and the environmental impacts on parameters not measured in this study. When coupled to earlier

  1. Radiation doses for Marshall Islands Atolls affected by U.S. nuclear testing: all exposure pathways, remedial measures, and environmental loss of (137)Cs.

    PubMed

    Robison, William L; Hamilton, Terry F

    2010-01-01

    Radiation doses calculated for people resettling Bikini Island at Bikini Atoll, Enjebi Island at Enewetak Atoll, Rongelap Island at Rongelap Atoll, and Utrōk Island at Utrōk Atoll are presented. Residence is assumed to begin in 2010. In previous dose assessments it was shown that (137)Cs accounts for about 98% of the total dose for returning residents. About 85 to 90% (depending on the atoll) is via consumption of locally grown foods containing (137)Cs, and about 10 to 15% is due to external exposure from (137)Cs in the soil. These assessments were made using only the radiological half-life of (137)Cs (30.1 y). We have shown since that there is an environmental loss of (137)Cs from soil to groundwater that results in a more rapid loss of (137)Cs from the atoll ecosystem. The mean effective half-life of (137)Cs at the atolls is 8.5 y. Moreover, treatment of coconut trees with potassium (K) reduces (137)Cs concentration in drinking coconut meat at Bikini Atoll to about 5% of pretreatment concentrations. The magnitude of reduction is dependent on the concentration of (137)Cs in soil, and thereby in food crops, and is less for Enjebi and Rongelap Islands than for Bikini Island. Treatment of food crops and fruit trees with K and removal of the top 15 cm of soil around houses and community buildings prior to construction to reduce external exposure where people spend most of their time has been presented to the communities as a "Combined Option" remediation strategy. Doses presented here are calculated using the Combined Option, effective half-life of (137)Cs at the atolls, and a diet of both imported and local foods. The average natural background dose in the Marshall Islands, plus the anthropogenic nuclear test-related dose at Bikini, Enjebi, and Rongelap Islands, is less for each of the islands than the average background dose in the U.S. and Europe.

  2. NEAR Gamma Ray Spectrometer Characterization and Repair

    NASA Technical Reports Server (NTRS)

    Groves, Joel Lee; Vajda, Stefan

    1998-01-01

    This report covers the work completed in the third year of the contract. The principle activities during this period were (1) the characterization of the NEAR 2 Gamma Ray Spectrometer using a neutron generator to generate complex gamma ray spectra and a large Ge Detecter to identify all the major peaks in the spectra; (2) the evaluation and repair of the Engineering Model Unit of the Gamma Ray Spectrometer for the NEAR mission; (3) the investigation of polycapillary x-ray optics for x-ray detection; and (4) technology transfer from NASA to forensic science.

  3. Activity concentrations of 226Ra, 232Th, 40K and 137Cs radionuclides in Turkish medicinal herbs, their ingestion doses and cancer risks

    NASA Astrophysics Data System (ADS)

    Parmaksız, Aydın; Ağuş, Yusuf

    2014-11-01

    Twenty-two medicinal herb samples, each representing a distinct species, were collected from Turkish markets and measured by the gamma spectrometric method. The activity concentration of 226Ra in medicinal herbs was found in the range of minimum detectable activity (MDA) and 15.1 ± 2.2 Bqkg-1. The activity concentration of 232Th ranged from MDA values to 3.5 ± 0.8 Bqkg-1. The activity concentration of 40K varied between 50.0 ± 16.8 and 1311.5 ± 57.3 Bqkg-1. All 137Cs activity concentrations of medicinal herbs were found to have lower than MDA values. The bone surface dose, lower large intestine and colon doses were found to be 182.9, 18.8 and 18.7 µSvy-1, respectively. The highest committed effective dose originated from the annual ingestion of 1 kg medicinal herb was calculated notably low as 9.0 µSv. The cancer risk of ingestion of medicinal herbs was found to be small enough to be neglected. The selected Turkish medicinal herbs are considered safe for human consumption.

  4. Level and origin of 129I and 137Cs in lichen samples (Cladonia alpestris) in central Sweden.

    PubMed

    Gómez-Guzmán, J M; López-Gutiérrez, J M; Holm, E; Pinto-Gómez, A R

    2011-02-01

    Lichen is a symbiosis between algae and fungi. They have for decades been used as bioindicators for atmospheric deposition of heavy metals, organic compounds and radioactive elements. Especially the species Cladonia alpestris and Cladonia rangiferina are important for the food chain lichen-reindeer-man. The concentration of (129)I was determined in lichen samples (Cladonia alpestris) contaminated by fallout from atmospheric nuclear tests explosions and the Chernobyl accident. The samples were collected at Lake Rogen District (62.3°N, 12.4°E) in central Sweden in the periods 1961-1975 and 1987-1998, and analysed with accelerator mass spectrometry (AMS) at CNA (Seville) to study its distribution in different layers. Data on the (137)Cs activity measured previously were also included in this study. The (129)I concentration ranged from (0.95 ± 0.13) × 10(8) at g(-1) in 1961 in the uppermost layer to (14.2 ± 0.5) × 10(8) at g(-1) in 1987 in deepest layer. The (129)I/(137)Cs atom ratio ranged between 0.12 and 0.27 for lichen samples collected in the period 1961-1975, indicating weapons tests fallout. For lichen samples collected between 1987 and 1998 the behaviour of (137)Cs concentrations reflected Chernobyl fallout. The concentrations of the two radionuclides followed each other quite well in the profile, reflecting the same origin for both. From the point of view of the spatial distribution in the lichen, it appears that (129)I was predominantly accumulated in the lowest layer, the opposite to (137)Cs for which the highest amounts were detected systematically in the topmost layer of lichen. This vertical distribution is important for radioecology because lichen is the initial link in the food chain lichen-reindeer-man, and reindeer only graze the upper parts of lichen carpets.

  5. Measurements of210Pb,137Cs, organic carbon and trace elements in sediments of the Illinois and Mississippi rivers

    USGS Publications Warehouse

    Cahill, R.A.; Autrey, A.D.

    1987-01-01

    Radiometric dating of sediment accumulations by137Cs and210Pb has been successfully initiated in the Illinois and Mississippi Rivers. Sedimentation rates measured at 13 locations range from 0.7 to 3.6 cm/y. Chemical analysis has been completed for up to 45 major and trace elements in core samples. The upper Illinois River contains higher metal levels than the Mississippi River. The amount of carbon (energy) lost to sediments in large floodplain rivers is estimated between 370 and 4000 g/m2/y. ?? 1987 Akade??miai Kiado??.

  6. Research in cosmic and gamma ray astrophysics

    NASA Technical Reports Server (NTRS)

    Stone, E. C.; Davis, L., Jr.; Mewaldt, R. A.; Prince, T. A.

    1989-01-01

    Research activities in cosmic rays, gamma rays, and astrophysical plasmas are covered. The activities are divided into sections and described, followed by a bibliography. The astrophysical aspects of cosmic rays, gamma rays, and of the radiation and electromagnetic field environment of the Earth and other planets are investigated. These investigations are performed by means of energetic particle and photon detector systems flown on spacecraft and balloons.

  7. Gamma Rays from Classical Novae

    NASA Technical Reports Server (NTRS)

    1997-01-01

    NASA at the University of Chicago, provided support for a program of theoretical research into the nature of the thermonuclear outbursts of the classical novae and their implications for gamma ray astronomy. In particular, problems which have been addressed include the role of convection in the earliest stages of nova runaway, the influence of opacity on the characteristics of novae, and the nucleosynthesis expected to accompany nova outbursts on massive Oxygen-Neon-Magnesium (ONeMg) white dwarfs. In the following report, I will identify several critical projects on which considerable progress has been achieved and provide brief summaries of the results obtained:(1) two dimensional simulation of nova runaway; (2) nucleosynthesis of nova modeling; and (3) a quasi-analytic study of nucleosynthesis in ONeMg novae.

  8. Distribution and Ratios of 137Cs and K in Control and K-treated Coconut Trees at Bikini Island where Nuclear Test Fallout Occurred: Effects and Implications

    SciTech Connect

    Robison, W L; Brown, P H; Stone, E L; Hamilton, T F; Conrado, C L; Kehl, S R

    2008-05-19

    Coconut trees growing on atolls of the Bikini Islands are on the margin of K deficiency because the concentration of exchangeable K in coral soil is very low ranging from only 20 to 80 mg kg{sup -1}. When provided with additional K, coconut trees absorb large quantities of K and this uptake of K significantly alters the patterns of distribution of {sup 137}Cs within the plant. Following a single K fertilization event, mean total K in trunks of K-treated trees is 5.6 times greater than in trunks of control trees. In contrast, {sup 137}Cs concentration in trunks of K-treated and control trees is statistically the same while {sup 137}Cs is significantly lower in edible fruits of K treated trees. Within one year after fertilization (one rainy season), K concentration in soil is back to naturally, low concentrations, however, the tissue concentrations of K in treated trees stays very high internally in the trees for years while {sup 137}Cs concentration in treated trees remains very low in all tree compartments except for the trunk. Potassium fertilization did not change soil Cs availability. Mass balance calculations suggest that the fertilization event increased above ground plant K content by at least a factor of 5 or 2.2 kg. Potassium concentrations and content were higher in all organs of K fertilized trees with the greatest increases seen in organs that receive a portion of tissue K through xylem transport (trunk, fronds and fruit husks) and lowest in organs supplied predominantly with K via the phloem (palm heart, spathe, coco meat and fluid). {sup 137}Cesium concentrations and contents were dramatically lower in all organs of K treated trees with greatest proportional reductions observed in organs supplied predominantly with K via the phloem (palm heart, spathe, coco meat and fluid). All trees remobilize both K and {sup 137}Cs from fronds as they proceed toward senescence. In control trees the reduction in concentration of K and {sup 137}Cs in fronds as they age

  9. Distribution and ratios of 137Cs and K in control and K-treated coconut trees at Bikini Island where nuclear test fallout occurred: effects and implications.

    PubMed

    Robison, William L; Brown, Patrick H; Stone, Earl L; Hamilton, Terry F; Conrado, Cynthia L; Kehl, Steven

    2009-01-01

    Coconut trees growing on atolls of the Bikini Islands are on the margin of K deficiency because the concentration of exchangeable K in coral soil is very low, ranging from only 20 to 80mgkg(-1). When provided with additional K, coconut trees absorb large quantities of K and this uptake of K significantly alters the patterns of distribution of 137Cs within the plant. Following a single K fertilization event, mean total K in trunks of K-treated trees is 5.6 times greater than in trunks of control trees. In contrast, 137Cs concentration in trunks of K-treated and control trees is statistically the same while 137Cs is significantly lower in edible fruits of K-treated trees. Within one year after fertilization (one rainy season), K concentration in soil is back to naturally low concentrations. However, the tissue concentrations of K in treated trees stays very high internally in the trees for years while 137Cs concentration in treated trees remains very low in all tree compartments except for the trunk. Potassium fertilization did not change soil Cs availability. Mass balance calculations suggest that the fertilization event increased above ground plant K content by at least a factor of 5 (2.2kg). Potassium concentrations and content were higher in all organs of K-fertilized trees with the greatest increases seen in organs that receive a portion of tissue K through xylem transport (trunk, fronds and fruit husks) and lowest in organs supplied predominantly with K via the phloem (palm heart, spathe, coco meat and fluid). The 137Cesium concentrations and contents were dramatically lower in all organs of K-treated trees with greatest proportional reductions observed in organs supplied predominantly with K via the phloem (palm heart, spathe, coco meat and fluid). All trees remobilize both K and 137Cs from fronds as they proceed toward senescence. In control trees the reduction in concentration of K and 137Cs in fronds as they age is logarithmic, but K remobilization is

  10. Scanning Gamma Ray Densitometer System for Detonations.

    DTIC Science & Technology

    in loaded detonators and delays. The 317 KEV gamma rays from an Ir192 source were collimated into a beam of 0.002 by 0.100 inch. A scanning system...minus 3%. With Ir192 , density measurements on NOL-130 were reproduced to plus or minus 5%, and on RDX to plus or minus 16%. Based on gamma ray

  11. Gamma-ray spectral analysis algorithm library

    SciTech Connect

    Egger, A. E.

    2013-05-06

    The routines of the Gauss Algorithms library are used to implement special purpose products that need to analyze gamma-ray spectra from Ge semiconductor detectors as a part of their function. These routines provide the ability to calibrate energy, calibrate peakwidth, search for peaks, search for regions, and fit the spectral data in a given region to locate gamma rays.

  12. ASTRONOMY: Neighborhood Gamma Ray Burst Boosts Theory.

    PubMed

    Schilling, G

    2000-07-07

    Titanic explosions that emit powerful flashes of energetic gamma rays are one of astronomy's hottest mysteries. Now an analysis of the nearest gamma ray burst yet detected has added weight to the popular theory that they are expelled during the death throes of supermassive stars.

  13. Very high-energy gamma rays from gamma-ray bursts.

    PubMed

    Chadwick, Paula M

    2007-05-15

    Very high-energy (VHE) gamma-ray astronomy has undergone a transformation in the last few years, with telescopes of unprecedented sensitivity having greatly expanded the source catalogue. Such progress makes the detection of a gamma-ray burst at the highest energies much more likely than previously. This paper describes the facilities currently operating and their chances for detecting gamma-ray bursts, and reviews predictions for VHE gamma-ray emission from gamma-ray bursts. Results to date are summarized.

  14. Chronic Internal Exposure to Low Dose 137Cs Induces Positive Impact on the Stability of Atherosclerotic Plaques by Reducing Inflammation in ApoE-/- Mice

    PubMed Central

    Le Gallic, Clélia; Phalente, Yohann; Manens, Line; Dublineau, Isabelle; Benderitter, Marc; Gueguen, Yann; Lehoux, Stephanie; Ebrahimian, Teni G.

    2015-01-01

    After Chernobyl and Fukushima Daï Chi, two major nuclear accidents, large amounts of radionuclides were released in the environment, mostly caesium 137 (137Cs). Populations living in contaminated territories are chronically exposed to radionuclides by ingestion of contaminated food. However, questions still remain regarding the effects of low dose ionizing radiation exposure on the development and progression of cardiovascular diseases. We therefore investigated the effects of a chronic internal exposure to 137Cs on atherosclerosis in predisposed ApoE-/- mice. Mice were exposed daily to 0, 4, 20 or 100 kBq/l 137Cs in drinking water, corresponding to range of concentrations found in contaminated territories, for 6 or 9 months. We evaluated plaque size and phenotype, inflammatory profile, and oxidative stress status in different experimental groups. Results did not show any differences in atherosclerosis progression between mice exposed to 137Cs and unexposed controls. However, 137Cs exposed mice developed more stable plaques with decreased macrophage content, associated with reduced aortic expression of pro-inflammatory factors (CRP, TNFα, MCP-1, IFNγ) and adhesion molecules (ICAM-1, VCAM-1 and E-selectin). Lesions of mice exposed to 137Cs were also characterized by enhanced collagen and smooth muscle cell content, concurrent with reduced matrix metalloproteinase MMP8 and MMP13 expression. These results suggest that low dose chronic exposure of 137Cs in ApoE-/- mice enhances atherosclerotic lesion stability by inhibiting pro-inflammatory cytokine and MMP production, resulting in collagen-rich plaques with greater smooth muscle cell and less macrophage content. PMID:26046630

  15. Chronic Internal Exposure to Low Dose 137Cs Induces Positive Impact on the Stability of Atherosclerotic Plaques by Reducing Inflammation in ApoE-/- Mice.

    PubMed

    Le Gallic, Clélia; Phalente, Yohann; Manens, Line; Dublineau, Isabelle; Benderitter, Marc; Gueguen, Yann; Lehoux, Stephanie; Ebrahimian, Teni G

    2015-01-01

    After Chernobyl and Fukushima Daï Chi, two major nuclear accidents, large amounts of radionuclides were released in the environment, mostly caesium 137 (137Cs). Populations living in contaminated territories are chronically exposed to radionuclides by ingestion of contaminated food. However, questions still remain regarding the effects of low dose ionizing radiation exposure on the development and progression of cardiovascular diseases. We therefore investigated the effects of a chronic internal exposure to 137Cs on atherosclerosis in predisposed ApoE-/- mice. Mice were exposed daily to 0, 4, 20 or 100 kBq/l 137Cs in drinking water, corresponding to range of concentrations found in contaminated territories, for 6 or 9 months. We evaluated plaque size and phenotype, inflammatory profile, and oxidative stress status in different experimental groups. Results did not show any differences in atherosclerosis progression between mice exposed to 137Cs and unexposed controls. However, 137Cs exposed mice developed more stable plaques with decreased macrophage content, associated with reduced aortic expression of pro-inflammatory factors (CRP, TNFα, MCP-1, IFNγ) and adhesion molecules (ICAM-1, VCAM-1 and E-selectin). Lesions of mice exposed to 137Cs were also characterized by enhanced collagen and smooth muscle cell content, concurrent with reduced matrix metalloproteinase MMP8 and MMP13 expression. These results suggest that low dose chronic exposure of 137Cs in ApoE-/- mice enhances atherosclerotic lesion stability by inhibiting pro-inflammatory cytokine and MMP production, resulting in collagen-rich plaques with greater smooth muscle cell and less macrophage content.

  16. CHANGES IN 137 CS CONCENTRATIONS IN SOIL AND VEGETATION ON THE FLOODPLAIN OF THE SAVANNAH RIVER OVER A 30 YEAR PERIOD

    SciTech Connect

    Paller, M.; Jannik, T.; Fledderman, P.

    2007-12-12

    {sup 137}Cs released during 1954-1974 from nuclear production reactors on the Savannah River Site, a US Department of Energy nuclear materials production site in South Carolina, contaminated a portion of the Savannah River floodplain known as Creek Plantation. {sup 137}Cs activity concentrations have been measured in Creek Plantation since 1974 making it possible to calculate effective half-lives for {sup 137}Cs in soil and vegetation and assess the spatial distribution of contaminants on the floodplain. Activity concentrations in soil and vegetation were higher near the center of the floodplain than near the edges as a result of frequent inundation coupled with the presence of low areas that trapped contaminated sediments. {sup 137}Cs activity was highest near the soil surface, but depth related differences diminished with time as a likely result of downward diffusion or leaching. Activity concentrations in vegetation were significantly related to concentrations in soil. The plant to soil concentration ratio (dry weight) averaged 0.49 and exhibited a slight but significant tendency to decrease with time. The effective half-lives for {sup 137}Cs in shallow (0-7.6 cm) soil and in vegetation were 14.9 (95% CI = 12.5-17.3) years and 11.6 (95% CI = 9.1-14.1) years, respectively, and rates of {sup 137}Cs removal from shallow soil and vegetation did not differ significantly among sampling locations. Potential health risks on the Creek Plantation floodplain have declined more rapidly than expected on the basis of radioactive decay alone because of the relatively short effective half-life of {sup 137}Cs.

  17. Spatiotemporal distribution of 137Cs in the sea surrounding Japanese Islands in the decades before the disaster at the Fukushima Daiichi Nuclear Power Plant in 2011.

    PubMed

    Watabe, Teruhisa; Oikawa, Shinji; Isoyama, Naohiko; Suzuki, Chiyoshi; Misonoo, Jun; Morizono, Shigemitsu

    2013-10-01

    The historic spatiotemporal distribution of 137Cs in the seawaters and sea-floor sediments adjacent to nuclear power plants in Japan are summarized, using data obtained over a period of time more than 20 years prior to the disaster at the Fukushima Daiichi Nuclear Power Plant in 2011. Relatively uniform distributions of 137Cs were observed both in the surface seawaters (1 m in depth) and in deeper seawaters (10 to 30 m above the seabed and ranging from tens to hundreds of meters in depth) independent of the geographical position, although lower concentrations were observed in significantly deeper bottom seawaters. Conversely, there were wide variations in 137Cs levels between sediments, such that higher 137Cs concentrations were observed in the deeper sampling locations. A mathematical model describing the successive transfer of 137Cs from surface waters through deeper waters to sediments suggested that the transfer rate of 137Cs from deep water to the sediments, and the loss rate from bottom sediments, were both greater than the transfer rate from surface water to deeper water. It was found that the calculated regression lines for 137Cs depletion rates over time for surface waters, deeper waters, and sediments were approximately parallel when plotted on a semi-logarithmic coordinate system, regardless of the sampling location. A radionuclide depletion half-life was calculated to be 4 months to 16 years with the geometric mean of 2.22 y for the sediments in the Fukushima region, suggesting that nuclear contamination will be remediated over time through sediment redistribution processes such as remobilization, bioturbation, and migration due to sea currents.

  18. Atmospheric gamma-ray and neutron flashes

    SciTech Connect

    Babich, L. P. Kudryavtsev, A. Yu. Kudryavtseva, M. L. Kutsyk, I. M.

    2008-01-15

    Gamma-ray pulses are calculated from 2D numerical simulations of an upward atmospheric discharge in a self-consistent electric field using the multigroup approach to the kinetics of relativistic runaway electrons (REs). Computed {gamma}-ray numbers and spectra are consistent with those of terrestrial {gamma}-ray flashes (TGFs) observed aboard spacecrafts. The RE flux is concentrated mainly within the domain of the Blue Jet fluorescence. This confirms that exactly the domain adjacent to a thundercloud is the source of the observed {gamma}-ray flashes. The yield of photonuclear neutrons is calculated. One {gamma}-ray pulse generates {approx}10{sup 14}-10{sup 15} neutrons. The possibility of the direct deposition of REs to the detector readings and the origin of the lightning-advanced TGFs are discussed.

  19. Unveiling the secrets of gamma ray bursts

    NASA Astrophysics Data System (ADS)

    Gomboc, Andreja

    2012-07-01

    Gamma Ray Bursts are unpredictable and brief flashes of gamma rays that occur about once a day in random locations in the sky. Since gamma rays do not penetrate the Earth's atmosphere, they are detected by satellites, which automatically trigger ground-based telescopes for follow-up observations at longer wavelengths. In this introduction to Gamma Ray Bursts we review how building a multi-wavelength picture of these events has revealed that they are the most energetic explosions since the Big Bang and are connected with stellar deaths in other galaxies. However, in spite of exceptional observational and theoretical progress in the last 15 years, recent observations raise many questions which challenge our understanding of these elusive phenomena. Gamma Ray Bursts therefore remain one of the hottest topics in modern astrophysics.

  20. Future Missions for Gamma-Ray Astronomy

    NASA Technical Reports Server (NTRS)

    Meegan, Charles; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Gamma-ray astronomy has made great advances in recent years, due largely to the recently completed 9-year mission of the Compton Gamma Ray Observatory. In this talk I will give an overview of what advances we may expect in the near future, with particular emphasis on earth-orbiting missions scheduled for flight within the next 5 years. Two missions, the High Energy Transient Explorer and Swift, will provide important new information on the sources of gamma-ray bursts. The Gamma-Ray Large Area Space Telescope will investigate high energy emission from a wide variety of sources, including active galaxies and gamma-ray pulsars. The contributions of ground-based and multiwavelength observations will also be addressed.

  1. Gamma-ray Astronomy and GLAST

    NASA Technical Reports Server (NTRS)

    McEnery, Julie

    2007-01-01

    The high energy gamma-ray (30 MeV to 100 GeV) sky has been relatively poorly studied. Most of our current knowledge comes from observations made by the Energetic Gamma Ray Experiment Telescope (EGRET) detector on the Compton Gamma Ray Observatory (CGRO), which revealed that the GeV gamma-ray sky is rich and vibrant. Studies of astrophysical objects at GeV energies are interesting for several reasons: The high energy gamma-rays are often produced by a different physical process than the better studied X-ray and optical emission, thus providing a unique information for understanding these sources. Production of such high-energy photons requires that charged particles are accelerated to equally high energies, or much greater. Thus gamma-ray astronomy is the study of extreme environments, with natural and fundamental connections to cosmic-ray and neutrino astrophysics. The launch of GLAST in 2008 will herald a watershed in our understanding of the high energy gamma-ray sky, providing dramatic improvements in sensitivity, angular resolution and energy range. GLAST will open a new avenue to study our Universe as well as to answer scientific questions EGRET observations have raised. In this talk, I will describe the GLAST instruments and capabilities and highlight some of the science we expect to address.

  2. Gamma-ray burst cosmology

    NASA Astrophysics Data System (ADS)

    Wang, F. Y.; Dai, Z. G.; Liang, E. W.

    2015-08-01

    Gamma-ray bursts (GRBs) are the most luminous electromagnetic explosions in the Universe, which emit up to 8.8 × 1054 erg isotropic equivalent energy in the hard X-ray band. The high luminosity makes them detectable out to the largest distances yet explored in the Universe. GRBs, as bright beacons in the deep Universe, would be the ideal tool to probe the properties of high-redshift universe: including the cosmic expansion and dark energy, star formation rate, the reionization epoch and the metal enrichment history of the Universe. In this article, we review the luminosity correlations of GRBs, and implications for constraining the cosmological parameters and dark energy. Observations show that the progenitors of long GRBs are massive stars. So it is expected that long GRBs are tracers of star formation rate. We also review the high-redshift star formation rate derived from GRBs, and implications for the cosmic reionization history. The afterglows of GRBs generally have broken power-law spectra, so it is possible to extract intergalactic medium (IGM) absorption features. We also present the capability of high-redshift GRBs to probe the pre-galactic metal enrichment and the first stars.

  3. Interception of the Fukushima reactor accident-derived 137Cs, 134Cs and 131I by coniferous forest canopies

    NASA Astrophysics Data System (ADS)

    Kato, Hiroaki; Onda, Yuichi; Gomi, Takashi

    2012-10-01

    The Fukushima Daiichi nuclear power plant accident resulted in extensive radioactive contamination of the surrounding forests. In this study, we analyzed fallout 137Cs, 134Cs, and 131I in rainwater, throughfall, and stemflow in coniferous forest plantations immediately after the accident. We show selective fractionation of the deposited radionuclides by the forest canopy and contrasting transfer of radiocesium and 131I from the canopy to the forest floor in association with precipitation. More than 60% of the total deposited radiocesium remained in the canopy after 5 month of the initial fallout, while marked penetration of the initially deposited 131I through the canopy was observed. The half-lives of 137Cs absorbed in the cypress and cedar canopies were calculated as 620 days and 890 days, respectively for the period of 0-160 days. The transfer of the deposited radiocesium from the canopy to the forest floor was slow compared with that of the spruce forest affected by fallout from the Chernobyl nuclear reactor accident.

  4. Input of 137Cs and 90Sr into plants from the surface of soil aggregates and the intraped space

    NASA Astrophysics Data System (ADS)

    Fokin, A. D.; Torshin, S. P.; Bebneva, Yu. M.; Gadzhiagaeva, R. A.; Zolotareva, Yu. I.; Umer, M. I.

    2014-12-01

    Soil aggregates with different localization of radionuclides—(a) only on the aggregate surface, (b) only in the intraped space, and (c) uniformly distributed throughout the aggregate volume—have been obtained under laboratory conditions, which has allowed separately assessing the roles of different aggregate parts in the uptake of radionuclides by plant roots and the reaggregation rate of the soil material. The uptake rate of the radionuclides localized on the surface of soil aggregates, especially 137Cs, by plants manifold exceeds their uptake observed at the localization of pollutants throughout the aggregate volume or only in their intraped material. The input rate of radionuclides into plants decreases with time. For 137Cs, this decrease is due to the strengthening of the sorption fixation of the radionuclide (about 15%) and the reaggregation of the soil material (85%). Under natural conditions, at a depth of 10 cm in the dark gray forest soil of a forest belt, aggregates 7-10 mm in size are subjected to 40-75% destruction and reaggregation on the average within a year, which corresponds, with consideration for the statistical dispersion of the initial data, to the aggregate lifetime of 1.5 to 3 years.

  5. Curing time effect on the fraction of {sup 137}Cs from immobilized radioactive evaporator sludge by cement

    SciTech Connect

    Dimovic, Slavko; Plecas, Ilija

    2007-07-01

    Available in abstract form only. Full text of publication follows: Traditional methods of processing evaporator concentrates from NPP are evaporation and cementation. These methods allow to transform a liquid radioactive waste into the rather inert form, suitable for a final disposal. To assess the safety for disposal of radioactive mortar-waste composition, the leaching of {sup 137}Cs from immobilized radioactive evaporator concentrate into a surrounding fluid has been studied. Leaching tests were carried out in accordance with a method recommended by IAEA. Curing conditions and curing time prior to commencing the leaching test are critically important in leach studies since the extent of hydration of the cement materials determines how much hydration product develops and whether it is available to block the pore network, thereby reducing leaching. Incremental leaching rates Rn(cm/d) of {sup 137}Cs from evaporator concentrates after 180 days were measured. The results presented in this paper are examples of results obtained in a 20-year concrete testing project which will influence the design of the engineer trenches system for future central Serbian radioactive waste storing center. (authors)

  6. 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.

  7. Cosmic rays, gamma rays and synchrotron radiation from the Galaxy

    SciTech Connect

    Orlando, Elena

    2012-07-30

    Galactic cosmic rays (CR), interstellar gamma-ray emission and synchrotron radiation are related topics. CR electrons propagate in the Galaxy and interact with the interstellar medium, producing inverse-Compton emission measured in gamma rays and synchrotron emission measured in radio. I present an overview of the latest results with Fermi/LAT on the gamma-ray diffuse emission induced by CR nuclei and electrons. Then I focus on the recent complementary studies of the synchrotron emission in the light of the latest gamma-ray results. Relevant observables include spectral indices and their variations, using surveys over a wide range of radio frequencies. As a result, this paper emphasizes the importance of using the parallel study of gamma rays and synchrotron radiation in order to constrain the low-energy interstellar CR electron spectrum, models of propagation of CRs, and magnetic fields.

  8. Cosmic rays, gamma rays and synchrotron radiation from the Galaxy

    DOE PAGES

    Orlando, Elena

    2012-07-30

    Galactic cosmic rays (CR), interstellar gamma-ray emission and synchrotron radiation are related topics. CR electrons propagate in the Galaxy and interact with the interstellar medium, producing inverse-Compton emission measured in gamma rays and synchrotron emission measured in radio. I present an overview of the latest results with Fermi/LAT on the gamma-ray diffuse emission induced by CR nuclei and electrons. Then I focus on the recent complementary studies of the synchrotron emission in the light of the latest gamma-ray results. Relevant observables include spectral indices and their variations, using surveys over a wide range of radio frequencies. As a result, thismore » paper emphasizes the importance of using the parallel study of gamma rays and synchrotron radiation in order to constrain the low-energy interstellar CR electron spectrum, models of propagation of CRs, and magnetic fields.« less

  9. Validation of gamma-ray detection techniques for safeguards monitoring at natural uranium conversion facilities

    NASA Astrophysics Data System (ADS)

    Dewji, S. A.; Lee, D. L.; Croft, S.; Hertel, N. E.; Chapman, J. A.; McElroy, R. D.; Cleveland, S.

    2016-07-01

    examined, including attenuation for transmission measurement of density and concentration. It was determined that transmission-corrected gamma-ray spectra provide a reliable way to monitor the 235U concentration of uranyl nitrate solution in transfer pipes in NUCPs. Furthermore, existing predictive and analysis methods are adequate to design and realize practical designs. The 137Cs transmission source employed in this work is viable but not optimal for 235U densitometry determination. Validated simulations assessed the viability of 133Ba and 57Co as alternative densitometry sources. All three gamma-ray detectors are viable for monitoring natural uranium feed; although high-purity germanium is easiest to interpret, it is, however, the least attractive as an installation instrument. Overall, for monitoring throughput in a facility such as UNCLE, emulating the uranium concentration and pump speeds of the Springfields conversion facility in the United Kingdom, an uncertainty of less than 0.17% is required in order to detect the diversion of 1 SQ of uranyl nitrate through changes in uranium concentration over an accountancy period of one year with a detection probability of 50%. Although calibrated gamma-ray detection systems are capable of determining the concentration of uranium content in NUCPs, it is only in combination with verifiable operator declarations and supporting data, such as flow rate and enrichment, that safeguards conclusions can be drawn.

  10. Validation of gamma-ray detection techniques for safeguards monitoring at natural uranium conversion facilities

    DOE PAGES

    Dewji, Shaheen A.; Lee, Denise L.; Croft, Stephen; ...

    2016-03-28

    lines is examined, including attenuation for transmission measurement of density and concentration. It was determined that transmission-corrected gamma-ray spectra provide a reliable way to monitor the 235U concentration of uranyl nitrate solution in transfer pipes in NUCPs. Furthermore, existing predictive and analysis methods are adequate to design and realize practical designs. The 137Cs transmission source employed in this work is viable but not optimal for 235U densitometry determination. Validated simulations assessed the viability of 133Ba and 57Co as alternative densitometry sources. All three gamma-ray detectors are viable for monitoring natural uranium feed; although high-purity germanium is easiest to interpret, it is, however, the least attractive as an installation instrument. Overall, for monitoring throughput in a facility such as UNCLE, emulating the uranium concentration and pump speeds of the Springfields conversion facility in the United Kingdom, an uncertainty of less than 0.17% is required in order to detect the diversion of 1 SQ of uranyl nitrate through changes in uranium concentration over an accountancy period of one year with a detection probability of 50%. As a result, calibrated gamma-ray detection systems are capable of determining the concentration of uranium content in NUCPs, it is only in combination with verifiable operator declarations and supporting data, such as flow rate and enrichment, that safeguards conclusions can be drawn.« less

  11. Design and environmental applications of an ultra-low-background, high-efficiency intrinsic Ge gamma-ray spectrometer

    SciTech Connect

    Wogman, N.A.

    1981-04-01

    A coincidence shielded intrinsic Ge gamma-ray spectrometer incorporating a 25% efficient, high resolution coaxial diode inside a 30 cm diameter NaI(Tl) shield is described. System design eliminates the major cause of background and minimizes cosmic-ray created background events through the use of electronic means. The system provides a peak-to-Compton ratio of greater than 1000 to 1 for /sup 137/Cs and high sensitivity for both low and high level radionuclide measurements. At 3 MeV the background is 0.000058 counts per minute per keV. At 1 MeV it is 0.00048 counts per minute per keV, and at 0.5 MeV it is 0.0045 counts per minute per keV. Traces of primordial radionuclides create background events such as at 2.614 MeV (0.016 counts per minute total peak area), at 2.448 MeV (0.0058 counts per minute per total peak area), and at 2.204 MeV (0.023 counts per minute per total peak area). The system is discussed with respect to its background design, methods to improve its design, and its application to measurements of neutron activated and environmental materials problems.

  12. An experimental approach to efficiency calibration for gamma-ray spectrometric analysis of large air particulate filters

    NASA Astrophysics Data System (ADS)

    Tomarchio, Elio

    2013-04-01

    A full-energy-peak efficiency (FEPE) calibration procedure for gamma-ray spectrometric analysis of air particulate samples collected on large filters is described herein. The experimental results are obtained for an unconventional measurement geometry, termed a "packet-sample". The sample is obtained from a large cellulose filter (45 cm×45 cm) used to collect air particulate samples that is resized to dimensions suitable for spectrometric measurements (6 cm×6 cm×0.7 cm). To determine the FEPEs, many standards were created, i.e., some filters containing a small amount of ThO2 and others containing a known amount of KCl. Efficiency curves obtained through best fits to experimental data for three high-purity germanium (HPGe) detectors, one of them for X-ray measurement, cover the energy range from 40 keV to 2600 keV. To validate the efficiency calibration procedure two experimental tests with the use of calibrated sources were conducted and, as application example, airborne concentrations of 131I (particulate matter), 134Cs and 137Cs at Palermo (Italy) in the days following the Fukushima accident in Japan were evaluated.

  13. Temporal changes in dissolved (137)Cs concentrations in groundwater and stream water in Fukushima after the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Iwagami, Sho; Tsujimura, Maki; Onda, Yuichi; Nishino, Masataka; Konuma, Ryohei; Abe, Yutaka; Hada, Manami; Pun, Ishwar; Sakaguchi, Aya; Kondo, Hiroaki; Yamamoto, Masayoshi; Miyata, Yoshiki; Igarashi, Yasuhito

    2017-01-01

    The concentration of dissolved (137)Cs in groundwater and stream water in the headwater catchments in Yamakiya district, located ∼35 km north west of Fukushima Dai-ichi Nuclear Power Plant (FDNPP), was monitored from June 2011 to July 2013, after the earthquake and tsunami disaster. Groundwater and stream water were sampled at intervals of approximately 2 months at each site. Intensive sampling was also conducted during rainstorm events. Compared with previous data from the Chernobyl NPP accident, the concentration of dissolved (137)Cs in stream water was low. In the Iboishi-yama catchment, a trend was observed for the concentration of dissolved (137)Cs in stream water to decline, which could be divided into two phases by October 2011 (a fast flush of activity as a result of rapid washoff and a slow decline as a result of soil fixation and redistribution processes). The highest (137)Cs concentration recorded at Iboishi-yama was 1.2 Bq/L on August 6, 2011, which then declined to 0.021-0.049 Bq/L during 2013 (in stream water under normal water-flow conditions). During the rainfall events, the concentration of dissolved (137)Cs in stream water increased temporarily. The concentration of dissolved (137)Cs in groundwater at a depth of 30 m at Iboishi-yama displayed a decreasing trend from 2011 to 2013, with a range from 0.039 Bq/L to 0.0025 Bq/L. The effective half-lives of stream water in the initial fast flush and secondary phases were 0.10-0.21 and 0.69-1.5 y, respectively in the three catchments. The effective half-life of groundwater was 0.46-0.58 y at Koutaishi-yama and 0.50-3.3 y at Iboishi-yama. The trend for the concentration of dissolved (137)Cs to decline in groundwater and stream water was similar throughout 2012-2013, and the concentrations recorded in deeper groundwater were closer to those in stream water. The declining trend of dissolved (137)Cs concentrations in stream water was similar to that of the loss of canopy (137)Cs by throughfall, as

  14. Hindcast and Forecast of 137Cs Activities in the North Pacific Ocean Waters from 1945 to 2020 by Eddy-resolving ROMS

    NASA Astrophysics Data System (ADS)

    Tsubono, T.; Misumi, K.; Tsumune, D.; Aoyama, M.; Hirose, K.

    2015-12-01

    We conducted a hindcast and forecast of 137Cs activities in the North Pacific waters from 1945 to 2020, before and after the Fukushima Dai-ichi Nuclear Power Plant (F1NPP) accident. We used the Regional Ocean Model System (ROMS) with high resolution (1/12º-1/4º in horizontal, 45 levels in vertical), of which domain was the North Pacific Ocean. The model was driven by the exactly repeating "Normal Year" forcing Coordinated Ocean Reference Experiment (CORE) forcing dataset (Large and Yeager, 2008) using bulk formulae and the model-predicted sea surface temperature and the 50 years averaged SODA data as boundary conditions. The reconstructed global fallout due to atmospheric nuclear weapons' tests and Chernobyl accident was employed for atmospheric flux of 137Cs from 1945 to 2011. After the accident, the atmospheric deposition and direct release of 137Cs from F1NPP were also employed for input condition. Five ensemble calculations of 137Cs activities in seawater were conducted under different initial conditions, but had identical forcing. The net input of 16 PBq of 137Cs from F1NPP, which was employed in this study, corresponded to 26% of the total amount (61 PBq) of 137Cs that was estimated in the North Pacific before the F1NPP accident in 2011. Before the accident in 2011, the 137Cs on surface ranged from 0.75 to 1.7 Bq m-3. The direct comparison between simulated and observed 134Cs activities in the surface layer represented that the root-mean-square error and correlation coefficient were 5.6 Bq m-3 and 0.86, respectively, suggesting the model result were consistent with the observations. The main body of high 137Cs activity water from F1NPP was transported to south of the Subarctic Front around 42°N via the Oyashio Coastal Current, the Oyashio intrusion, and the Kuroshio bifurcation and then to the western North Pacific. This model simulation suggested that the 137Cs activities in surface waters at P26 (P04) would increase to 4.1 Bq m-3 (4.3 Bq m-3 ) in 2015

  15. Software tool for xenon gamma-ray spectrometer control

    NASA Astrophysics Data System (ADS)

    Chernysheva, I. V.; Novikov, A. S.; Shustov, A. E.; Dmitrenko, V. V.; Pyae Nyein, Sone; Petrenko, D.; Ulin, S. E.; Uteshev, Z. M.; Vlasik, K. F.

    2016-02-01

    Software tool "Acquisition and processing of gamma-ray spectra" for xenon gamma-ray spectrometers control was developed. It supports the multi-windows interface. Software tool has the possibilities for acquisition of gamma-ray spectra from xenon gamma-ray detector via USB or RS-485 interfaces, directly or via TCP-IP protocol, energy calibration of gamma-ray spectra, saving gamma-ray spectra on a disk.

  16. The EGRET high energy gamma ray telescope

    NASA Technical Reports Server (NTRS)

    Hartman, R. C.; Bertsch, D. L.; Fichtel, C. E.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Kwok, P. W.; Lin, Y. C.; Mattox, J. R.; Mayer-Hasselwander, H. A.

    1992-01-01

    The Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (GRO) is sensitive in the energy range from about 20 MeV to about 30,000 MeV. Electron-positron pair production by incident gamma photons is utilized as the detection mechanism. The pair production occurs in tantalum foils interleaved with the layers of a digital spark chamber system; the spark chamber records the tracks of the electron and positron, allowing the reconstruction of the arrival direction of the gamma ray. If there is no signal from the charged particle anticoincidence detector which surrounds the upper part of the detector, the spark chamber array is triggered by two hodoscopes of plastic scintillators. A time of flight requirement is included to reject events moving backward through the telescope. The energy of the gamma ray is primarily determined by absorption of the energies of the electron and positron in a 20 cm deep NaI(Tl) scintillator.

  17. Transfer kinetics and coefficients of {sup 90}Sr, {sup 134}Cs, and {sup 137}Cs from forage contaminated by Chernobyl fallout to milk of cows

    SciTech Connect

    Fabbri, S.; Sogni, R.; Lusardi, E.

    1994-04-01

    A experiment was conducted to study kinetics, transfer coefficients, and biological half-lives of {sup 90}Sr, {sup 134}Cs, and {sup 137}Cs from feed to milk. A cow was fed a diet containing alfalfa hay contaminated by Chernobyl fallout for 14.5 wk. The time-dependent activity in milk was approximated by a two-compartment model with fast biological half-lives of 2, 0.9, and 1 d and slow biological half-lives of 36.9, 8.7, and 12.4 d for {sup 90}Sr, {sup 134}Cs, and {sup 137}Cs respectively. The transfer coefficients determined in the experiment were 0.0008 d L{sup -1} for {sup 90}Sr, 0.0029 d L{sup -1} for {sup 137}Cs, and 0.0031 d L{sup -1} for {sup 137}Cs. The biological elimination phases of {sup 134}Cs and {sup 137}Cs were described by a two-compartment model while a one-compartment model was proposed for {sup 90}Sr. 18 refs., 4 figs., 2 tabs.

  18. 135Cs activity and 135Cs/137Cs atom ratio in environmental samples before and after the Fukushima Daiichi Nuclear Power Plant accident

    NASA Astrophysics Data System (ADS)

    Yang, Guosheng; Tazoe, Hirofumi; Yamada, Masatoshi

    2016-04-01

    135Cs/137Cs is a potential tracer for radiocesium source identification. However, due to the challenge to measure 135Cs, there were no 135Cs data available for Japanese environmental samples before the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. It was only 3 years after the accident that limited 135Cs values could be measured in heavily contaminated environmental samples. In the present study, activities of 134Cs, 135Cs, and 137Cs, along with their ratios in 67 soil and plant samples heavily and lightly contaminated by the FDNPP accident were measured by combining γ spectrometry with ICP-MS/MS. The arithmetic means of the 134Cs/137Cs activity ratio (1.033 ± 0.006) and 135Cs/137Cs atom ratio (0.334 ± 0.005) (decay corrected to March 11, 2011), from old leaves of plants collected immediately after the FDNPP accident, were confirmed to represent the FDNPP derived radiocesium signature. Subsequently, for the first time, trace 135Cs amounts before the FDNPP accident were deduced according to the contribution of global and FDNPP accident-derived fallout. Apart from two soil samples with a tiny global fallout contribution, contributions of global fallout radiocesium in other soil samples were observed to be 0.338%–52.6%. The obtained 135Cs/137Cs database will be useful for its application as a geochemical tracer in the future.

  19. 135Cs activity and 135Cs/137Cs atom ratio in environmental samples before and after the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Yang, Guosheng; Tazoe, Hirofumi; Yamada, Masatoshi

    2016-04-07

    (135)Cs/(137)Cs is a potential tracer for radiocesium source identification. However, due to the challenge to measure (135)Cs, there were no (135)Cs data available for Japanese environmental samples before the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. It was only 3 years after the accident that limited (135)Cs values could be measured in heavily contaminated environmental samples. In the present study, activities of (134)Cs, (135)Cs, and (137)Cs, along with their ratios in 67 soil and plant samples heavily and lightly contaminated by the FDNPP accident were measured by combining γ spectrometry with ICP-MS/MS. The arithmetic means of the (134)Cs/(137)Cs activity ratio (1.033 ± 0.006) and (135)Cs/(137)Cs atom ratio (0.334 ± 0.005) (decay corrected to March 11, 2011), from old leaves of plants collected immediately after the FDNPP accident, were confirmed to represent the FDNPP derived radiocesium signature. Subsequently, for the first time, trace (135)Cs amounts before the FDNPP accident were deduced according to the contribution of global and FDNPP accident-derived fallout. Apart from two soil samples with a tiny global fallout contribution, contributions of global fallout radiocesium in other soil samples were observed to be 0.338%-52.6%. The obtained (135)Cs/(137)Cs database will be useful for its application as a geochemical tracer in the future.

  20. 135Cs activity and 135Cs/137Cs atom ratio in environmental samples before and after the Fukushima Daiichi Nuclear Power Plant accident

    PubMed Central

    Yang, Guosheng; Tazoe, Hirofumi; Yamada, Masatoshi

    2016-01-01

    135Cs/137Cs is a potential tracer for radiocesium source identification. However, due to the challenge to measure 135Cs, there were no 135Cs data available for Japanese environmental samples before the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. It was only 3 years after the accident that limited 135Cs values could be measured in heavily contaminated environmental samples. In the present study, activities of 134Cs, 135Cs, and 137Cs, along with their ratios in 67 soil and plant samples heavily and lightly contaminated by the FDNPP accident were measured by combining γ spectrometry with ICP-MS/MS. The arithmetic means of the 134Cs/137Cs activity ratio (1.033 ± 0.006) and 135Cs/137Cs atom ratio (0.334 ± 0.005) (decay corrected to March 11, 2011), from old leaves of plants collected immediately after the FDNPP accident, were confirmed to represent the FDNPP derived radiocesium signature. Subsequently, for the first time, trace 135Cs amounts before the FDNPP accident were deduced according to the contribution of global and FDNPP accident-derived fallout. Apart from two soil samples with a tiny global fallout contribution, contributions of global fallout radiocesium in other soil samples were observed to be 0.338%–52.6%. The obtained 135Cs/137Cs database will be useful for its application as a geochemical tracer in the future. PMID:27052481

  1. Study of the transfer of 137Cs from fodder to cow milk in the region around Narora Atomic Power Station NPP Site, India.

    PubMed

    Kumar, Deepak; Kumar, Avinash; Sharma, A K; Singh, B; Ravi, P M; Sarkar, P K

    2013-09-01

    Site-specific transfer coefficient from feed to cow's milk, for (137)Cs in the villages around Narora, a nuclear power station site in India, determined over a period of 17 y, is presented in this paper. In the transport model for the prediction of the concentration of (137)Cs in milk, the transfer coefficient from feed to milk, Fm, is an important parameter. The transfer coefficient value is determined from (137)Cs concentration in milk and grass samples of the Narora region, and the result ranged from 4.28E-03 to 3.30E-02 d l(-1) with a geometric mean value of 1.15E-03 d l(-1). The highest and the lowest values were only below one order of magnitude different from the mean, regardless of the type of diet, milk yield and age of the cow. The result is compared with that for (40)K, determined concurrently at the same region and ranged from 6.92E-03 to 8.01E-03 d l(-1) with a geometric mean value of 7.45E-03 d l(-1). This parameter is quite useful in decision-making for implementing countermeasures during a large-area contamination with (137)Cs in tropical areas like Narora. The ingestion dose from fallout (137)Cs through milk intake for adult and child is also estimated.

  2. Sampling design and required sample size for evaluating contamination levels of (137)Cs in Japanese fir needles in a mixed deciduous forest stand in Fukushima, Japan.

    PubMed

    Oba, Yurika; Yamada, Toshihiro

    2017-05-01

    We estimated the sample size (the number of samples) required to evaluate the concentration of radiocesium ((137)Cs) in Japanese fir (Abies firma Sieb. & Zucc.), 5 years after the outbreak of the Fukushima Daiichi Nuclear Power Plant accident. We investigated the spatial structure of the contamination levels in this species growing in a mixed deciduous broadleaf and evergreen coniferous forest stand. We sampled 40 saplings with a tree height of 150 cm-250 cm in a Fukushima forest community. The results showed that: (1) there was no correlation between the (137)Cs concentration in needles and soil, and (2) the difference in the spatial distribution pattern of (137)Cs concentration between needles and soil suggest that the contribution of root uptake to (137)Cs in new needles of this species may be minor in the 5 years after the radionuclides were released into the atmosphere. The concentration of (137)Cs in needles showed a strong positive spatial autocorrelation in the distance class from 0 to 2.5 m, suggesting that the statistical analysis of data should consider spatial autocorrelation in the case of an assessment of the radioactive contamination of forest trees. According to our sample size analysis, a sample size of seven trees was required to determine the mean contamination level within an error in the means of no more than 10%. This required sample size may be feasible for most sites.

  3. (210)Pb, (137)Cs and (7)Be in the sediments of coastal lakes on the polish coast: Implications for sedimentary processes.

    PubMed

    Woszczyk, Michał; Poręba, Grzegorz; Malinowski, Łukasz

    2017-04-01

    In this study we combined radioisotopes ((210)Pb, (137)Cs and (7)Be) and hydrodynamic modeling to investigate sedimentary processes in three coastal lakes on the Polish Baltic coast. The research aimed at establishing the depth of sediment mixing and its effects on sediment geochemistry as well as showing the relationship between lake water salinity and radionuclide distribution in the sediment cores. We established that the intensity of mixing displayed appreciable variability throughout the lakes and the thickness of sediment mixing layer was between <2 and 22 cm. The mixing was primarily due to wind-induced waves. The vertical mixing was shown to shift sulfidation of the sediments towards deeper layers. We found that the distributions of radioisotopes, (137)Cs in particular, in the sediment cores from coastal lakes were strongly affected by the early diagenetic processes, which caused diffusive migration of radionuclides. The inventories of (210)Pbex and (137)Cs in the lakes were positively related to salinity. The high inventories of both isotopes (3.2-10.9 kBq ·m(-2) for (210)Pbex and 3.0-6.0 kBq·m(-2) for (137)Cs) in coastal lakes were explained by enhanced sedimentation within estuarine mixing zone and delivery of "additional" (210)Pb and (137)Cs to the lakes during saltwater ingressions. The results of this study have implications for the paleolimnology, sedimentology and biogeochemistry of coastal lakes.

  4. 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.

  5. Gamma ray astronomy and black hole astrophysics

    NASA Technical Reports Server (NTRS)

    Liang, Edison P.

    1990-01-01

    The study of soft gamma emissions from black-hole candidates is identified as an important element in understanding black-hole phenomena ranging from stellar-mass black holes to AGNs. The spectra of Cyg X-1 and observations of the Galactic Center are emphasized, since thermal origins and MeV gamma-ray bumps are evident and suggest a thermal-pair cloud picture. MeV gamma-ray observations are suggested for studying black hole astrophysics such as the theorized escaping pair wind, the anticorrelation between the MeV gamma bump and the soft continuum, and the relationship between source compactness and temperature.

  6. Observations of Gamma-Ray Bursts

    NASA Technical Reports Server (NTRS)

    Fishman, G. J.

    1995-01-01

    Some basic observed properties of gamma-ray bursts are reviewed. Although some properties were known 25 years ago, new and more detailed observations have been made by the Compton Observatory in the past three years. The new observation with the greatest impact has been the observed isotropic distribution of bursts along with a deficiency of weak bursts which would be expected from a homogeneous burst distribution. This is not compatible with any known Galactic population of objects. Gamma-ray bursts show an enormous variety of burst morphologies and a wide spread in burst durations. The spectra of gamma-ray bursts are characterized by rapid variations and peak power which is almost entirely in the gamma-ray energy range. Delayed gamma-ray burst photons extending to GeV energies have been detected for the first time. A time dilation effect has also been reported to be observed in gamma-ray, bursts. The observation of a gamma-ray burst counterpart in another wavelength region has yet to be made.

  7. Gamma-Ray Burst Physics with GLAST

    SciTech Connect

    Omodei, N.; /INFN, Pisa

    2006-10-06

    The Gamma-ray Large Area Space Telescope (GLAST) is an international space mission that will study the cosmos in the energy range 10 keV-300 GeV, the upper end of which is one of the last poorly observed region of the celestial electromagnetic spectrum. The ancestor of the GLAST/LAT was the Energetic Gamma Ray Experiment Telescope (EGRET) detector, which flew onboard the Compton Gamma Ray Observatory (CGRO). The amount of information and the step forward that the high energy astrophysics made thanks to its 9 years of observations are impressive. Nevertheless, EGRET uncovered the tip of the iceberg, raising many questions, and it is in the light of EGRET's results that the great potential of the next generation gamma-ray telescope can be appreciated. GLAST will have an imaging gamma-ray telescope, the Large Area Telescope (LAT) vastly more capable than instruments own previously, as well as a secondary instrument, the GLAST Bursts Monitor, or GBM, to augment the study of gamma-ray bursts. Gamma-Ray Bursts (GRBs) science is one of the most exciting challenges for the GLAST mission, exploring the high energy emission of one of the most intense phenomena in the sky, shading light on various problems: from the acceleration of particles to the emission processes, to more exotic physics like Quantum Gravity effect. In this paper we report the work done so far in the simulation development as well as the study of the LAT sensitivity to GRB.

  8. Python in gamma-ray astronomy

    NASA Astrophysics Data System (ADS)

    Deil, Christoph Deil

    2016-03-01

    Gamma-ray astronomy is a relatively new window on the cosmos. The first source detected from the ground was the Crab nebula, seen by the Whipple telescope in Arizona in 1989. Today, about 150 sources have been detected at TeV energies using gamma-ray telescopes from the ground such as H.E.S.S. in Namibia or VERITAS in Arizona, and about 3000 sources at GeV energies using the Fermi Gamma-ray Space Telescope. Soon construction will start for the Cherenkov Telescope Array (CTA), which will be the first ground-based gamma-ray telescope array operated as an open observatory, with a site in the southern and a second site in the northern hemisphere. In this presentation I will give a very brief introduction to gamma-ray astronomy and data analysis, as well as a short overview of the software used for the various missions. The main focus will be on recent attempts to build open-source gamma-ray software on the scientific Python stack and Astropy: ctapipe as a CTA Python pipeline prototype, Fermipy and the Fermi Science Tools for Fermi-LAT analysis, Gammapy as a community-developed gamma-ray Python package and naima as a non-thermal spectral modeling and fitting package.

  9. Gamma-Ray Pulsar Studies With GLAST

    SciTech Connect

    Thompson, D.J.; /NASA, Goddard

    2011-11-23

    Some pulsars have their maximum observable energy output in the gamma-ray band, offering the possibility of using these high-energy photons as probes of the particle acceleration and interaction processes in pulsar magnetospheres. After an extended hiatus between satellite missions, the recently-launched AGILE mission and the upcoming Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) will allow gamma-ray tests of the theoretical models developed based on past discoveries. With its greatly improved sensitivity, better angular resolution, and larger energy reach than older instruments, GLAST LAT should detect dozens to hundreds of new gamma-ray pulsars and measure luminosities, light curves, and phase-resolved spectra with unprecedented resolution. It will also have the potential to find radio-quiet pulsars like Geminga, using blind search techniques. Cooperation with radio and X-ray pulsar astronomers is an important aspect of the LAT team's planning for pulsar studies.

  10. Detecting axionlike particles with gamma ray telescopes.

    PubMed

    Hooper, Dan; Serpico, Pasquale D

    2007-12-07

    We propose that axionlike particles (ALPs) with a two-photon vertex, consistent with all astrophysical and laboratory bounds, may lead to a detectable signature in the spectra of high-energy gamma-ray sources. This occurs as a result of gamma rays being converted into ALPs in the magnetic fields of efficient astrophysical accelerators according to the "Hillas criterion", such as jets of active galactic nuclei or hot spots of radio galaxies. The discovery of such an effect is possible by GLAST in the 1-100 GeV range and by ground-based gamma-ray telescopes in the TeV range.

  11. Cosmic gamma-ray lines - Theory

    NASA Technical Reports Server (NTRS)

    Lingenfelter, R. E.; Ramaty, R.

    1980-01-01

    The various processes that lead to gamma-ray line emission and the possible astrophysical sources of such emission are reviewed. The processes of nuclear excitation, radiative capture, positron annihilation, and cyclotron radiation, which may produce gamma-ray line emission from such diverse sources as the interstellar medium, novas, supernovas, pulsars, accreting compact objects, the galactic nucleus and the nuclei of active galaxies are considered. The significance of the relative intensities, widths, and frequency shifts of the lines are also discussed. Particular emphasis is placed on understanding those gamma-ray lines that have already been observed from astrophysical sources.

  12. Gamma-ray Albedo of the Moon

    SciTech Connect

    Moskalenko, Igor V.; Porter, Troy A.

    2007-06-14

    We use the GEANT4 Monte Carlo framework to calculate the gamma-ray albedo of the Moon due to interactions of cosmic ray (CR) nuclei with moon rock. Our calculation of the albedo spectrum agrees with the EGRET data. We show that the spectrum of gamma-rays from the Moon is very steep with an effective cutoff around 3 GeV (600 MeV for the inner part of the Moon disc). Since it is the only (almost) black spot in the gamma-ray sky, it provides a unique opportunity for calibration of gamma-ray telescopes, such as the forthcoming Gamma Ray Large Area Space Telescope (GLAST). The albedo flux depends on the incident CR spectrum which changes over the solar cycle. Therefore, it is possible to monitor the CR spectrum using the albedo gamma-ray flux. Simultaneous measurements of CR proton and helium spectra by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA), and observations of the albedo -rays by the GLAST Large Area Telescope (LAT), can be used to test the model predictions and will enable the GLAST LAT to monitor the CR spectrum near the Earth beyond the lifetime of PAMELA.

  13. Gamma-Ray Burst Progenitors

    NASA Astrophysics Data System (ADS)

    Levan, Andrew; Crowther, Paul; de Grijs, Richard; Langer, Norbert; Xu, Dong; Yoon, Sung-Chul

    2016-12-01

    We review our current understanding of the progenitors of both long and short duration gamma-ray bursts (GRBs). Constraints can be derived from multiple directions, and we use three distinct strands; (i) direct observations of GRBs and their host galaxies, (ii) parameters derived from modelling, both via population synthesis and direct numerical simulation and (iii) our understanding of plausible analog progenitor systems observed in the local Universe. From these joint constraints, we describe the likely routes that can drive massive stars to the creation of long GRBs, and our best estimates of the scenarios that can create compact object binaries which will ultimately form short GRBs, as well as the associated rates of both long and short GRBs. We further discuss how different the progenitors may be in the case of black hole engine or millisecond-magnetar models for the production of GRBs, and how central engines may provide a unifying theme between many classes of extremely luminous transient, from luminous and super-luminous supernovae to long and short GRBs.

  14. Radiological investigations at the "Taiga" nuclear explosion site, part II: man-made γ-ray emitting radionuclides in the ground and the resultant kerma rate in air.

    PubMed

    Ramzaev, V; Repin, V; Medvedev, A; Khramtsov, E; Timofeeva, M; Yakovlev, V

    2012-07-01

    Samples of soil and epigeic lichens were collected from the "Taiga" peaceful nuclear explosion site (61.30°N 56.60°E, the Perm region, Russia) in 2009 and analyzed using high resolution γ-ray spectrometry. For soil samples obtained at six different plots, two products of fission ((137)Cs and (155)Eu), five products of neutron activation ((60)Co, (94)Nb, (152)Eu, (154)Eu, (207)Bi) and (241)Am have been identified and quantified. The maximal activity concentrations of (60)Co, (137)Cs, and (241)Am for the soils samples were measured as 1650, 7100, and 6800 Bq kg(-1) (d.w.), respectively. The deposit of (137)Cs for the top 20 cm of soil on the tested plots at the "Taiga" site ranged from 30 to 1020 kBq m(-2); the maximal value greatly (by almost 3 orders of magnitude) exceeded the regional background (from global fallout) level of 1.4 kBq m(-2). (137)Cs contributes approximately 57% of the total ground inventory of the man-made γ-ray emitters for the six plots tested at the "Taiga" site. The other major radionuclides -(241)Am and (60)Co, constitute around 40%. Such radionuclides as (60)Co, (137)Cs, (241)Am, and (207)Bi have also been determined for the epigeic lichens (genera Cladonia) that colonized certain areas at the ground lip produced by the "Taiga" explosion. Maximal activity concentrations (up to 80 Bq kg(-1) for (60)Co, 580 Bq kg(-1) for (137)Cs, 200 Bq kg(-1) for (241)Am, and 5 Bq kg(-1) for (207)Bi; all are given in terms of d.w.) have been detected for the lower dead section of the organisms. The air kerma rates associated with the anthropogenic sources of gamma radiation have been calculated using the data obtained from the laboratory analysis. For the six plots tested, the kerma rates ranged from 50 to 1200 nGy h(-1); on average, 51% of the dose can be attributed to (137)Cs and 45% to (60)Co. These estimates agree reasonably well with the results of the in situ measurements made during our field survey of the "Taiga" site in August

  15. Interpretations and implications of gamma ray lines from solar flares, the galactic center in gamma ray transients

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Lingenfelter, R. E.

    1980-01-01

    Observations and theories of astrophysical gamma ray line emission are reviewed and prospects for future observations by the spectroscopy experiments on the planned Gamma Ray Observatory are discussed.

  16. Vertical distribution of 137Cs in alluvial soils of the Lokna River floodplain (Tula oblast) long after the Chernobyl accident and its simulation

    NASA Astrophysics Data System (ADS)

    Mamikhin, S. V.; Golosov, V. N.; Paramonova, T. A.; Shamshurina, E. N.; Ivanov, M. M.

    2016-12-01

    Profiles of vertical 137Cs distribution in alluvial meadow soils on the low and medium levels of the Lokna River floodplain (central part of the Plavsk radioactive spot in Tula oblast) 28 years after the Chernobyl fallout have been studied. A significant increase in the 137Cs pool is revealed on the low floodplain areas compared to the soils of interfluves due to the accumulation of alluvium, which hampers the reduction of the total radionuclide pool in alluvial soils because of radioactive decay. The rate of alluvium accumulation in the soil on the medium floodplain level is lower by three times on average. An imitation prognostic model has been developed, which considers the flooding and climatic conditions in the region under study. Numerical experiments have quantitatively confirmed the deciding role of low-mobile forms in the migration of maximum 137Cs content along the soil profile in the absence of manifested erosion-accumulation processes.

  17. Decontamination Efficiencies of Pot-Type Water Purifiers for 131I, 134Cs and 137Cs in Rainwater Contaminated during Fukushima Daiichi Nuclear Disaster

    PubMed Central

    Higaki, Shogo; Hirota, Masahiro

    2012-01-01

    Rainwater was contaminated by a large release of radionuclides into the environment during the Fukushima Daiichi nuclear disaster. It became a matter of concern for Japan when several water purification plants detected 131I contamination in the drinking water. In the present study, the decontamination efficiency of two easily obtainable commercial water purifiers were examined for rainwater contaminated with 131I, 134Cs and 137Cs. The water purifiers removed 94.2–97.8% of the 131I and 84.2–91.5% of the 134Cs and 137Cs after one filtration. Seven filtrations removed 98.2–99.6% of the 131I and over 98.0% of the 134Cs and 137Cs. From a practical perspective, over the fourth filtrations were not needed because of no significant improvements after the third filtration. PMID:22615935

  18. Cosmic ray albedo gamma rays from the quiet sun

    NASA Technical Reports Server (NTRS)

    Seckel, D.; Stanev, T.; Gaisser, T. K.

    1992-01-01

    We estimate the flux of gamma-rays that result from collisions of high energy galactic cosmic rays with the solar atmosphere. An important aspect of our model is the propagation of cosmic rays through the magnetic fields of the inner solar systems. We use diffusion to model propagation down to the bottom of the corona. Below the corona we trace particle orbits through the photospheric fields to determine the location of cosmic ray interactions in the solar atmosphere and evolve the resultant cascades. For our nominal choice of parameters, we predict an integrated flux of gamma rays (at 1 AU) of F(E(sub gamma) greater than 100 MeV) approximately = 5 x 10(exp -8)/sq cm sec. This can be an order of magnitude above the galactic background and should be observable by the Energetic Gamma Ray experiment telescope (EGRET).

  19. Research in cosmic and gamma ray astrophysics

    NASA Technical Reports Server (NTRS)

    Stone, Edward C.; Mewaldt, Richard A.; Prince, Thomas A.

    1992-01-01

    Discussed here is research in cosmic ray and gamma ray astrophysics at the Space Radiation Laboratory (SRL) of the California Institute of Technology. The primary activities discussed involve the development of new instrumentation and techniques for future space flight. In many cases these instrumentation developments were tested in balloon flight instruments designed to conduct new investigations in cosmic ray and gamma ray astrophysics. The results of these investigations are briefly summarized. Specific topics include a quantitative investigation of the solar modulation of cosmic ray protons and helium nuclei, a study of cosmic ray positron and electron spectra in interplanetary and interstellar space, the solar modulation of cosmic rays, an investigation of techniques for the measurement and interpretation of cosmic ray isotopic abundances, and a balloon measurement of the isotopic composition of galactic cosmic ray boron, carbon, and nitrogen.

  20. Gamma rays produce superior seedless citrus

    SciTech Connect

    Pyrah, D.

    1984-10-01

    Using gamma radiation, seedless forms of some varieties of oranges and grapefruit are being produced. Since it has long been known that radiation causes mutations in plants and animals, experiments were conducted to determine if seediness could be altered by exposing seeds or budwood to higher than natural doses of gamma radiation. Orange and grapefruit seeds and cuttings exposed to gamma rays in the early 1970's have produced trees that bear fruit superior to that now on the market.

  1. Inverse modeling of the (137)Cs source term of the Fukushima Dai-ichi Nuclear Power Plant accident constrained by a deposition map monitored by aircraft.

    PubMed

    Yumimoto, Keiya; Morino, Yu; Ohara, Toshimasa; Oura, Yasuji; Ebihara, Mitsuru; Tsuruta, Haruo; Nakajima, Teruyuki

    2016-11-01

    The amount of (137)Cs released by the Fukushima Dai-ichi Nuclear Power Plant accident of 11 March 2011 was inversely estimated by integrating an atmospheric dispersion model, an a priori source term, and map of deposition recorded by aircraft. An a posteriori source term refined finer (hourly) variations comparing with the a priori term, and estimated (137)Cs released 11 March to 2 April to be 8.12 PBq. Although time series of the a posteriori source term was generally similar to those of the a priori source term, notable modifications were found in the periods when the a posteriori source term was well-constrained by the observations. Spatial pattern of (137)Cs deposition with the a posteriori source term showed better agreement with the (137)Cs deposition monitored by aircraft. The a posteriori source term increased (137)Cs deposition in the Naka-dori region (the central part of Fukushima Prefecture) by 32.9%, and considerably improved the underestimated a priori (137)Cs deposition. Observed values of deposition measured at 16 stations and surface atmospheric concentrations collected on a filter tape of suspended particulate matter were used for validation of the a posteriori results. A great improvement was found in surface atmospheric concentration on 15 March; the a posteriori source term reduced root mean square error, normalized mean error, and normalized mean bias by 13.4, 22.3, and 92.0% for the hourly values, respectively. However, limited improvements were observed in some periods and areas due to the difficulty in simulating accurate wind fields and the lack of the observational constraints.

  2. Total cancer incidence in relation to 137Cs fallout in the most contaminated counties in Sweden after the Chernobyl nuclear power plant accident: a register-based study

    PubMed Central

    Alinaghizadeh, Hassan; Wålinder, Robert; Vingård, Eva; Tondel, Martin

    2016-01-01

    Objectives To determine the total cancer incidence in relation to a 5-year exposure to caesium-137 (137Cs) from the 1986 Chernobyl nuclear power plant accident. Methods A closed cohort was defined as all individuals living in the three most contaminated counties in mid-Sweden in 1986. Fallout of 137Cs was retrieved as a digital map from the Geological Survey of Sweden, demographic data from Statistics Sweden, and cancer diagnosis from the National Board of Health and Welfare. Individuals were assigned an annual 137Cs exposure based on their place of residence (1986–1990), from which 5-year cumulative 137Cs exposures were calculated, accounting for the physical decay of 137Cs and changing residencies. HRs were adjusted for age, sex, rural/non-rural residence and pre-Chernobyl total cancer incidence. Results The 734 537 people identified were categorised by exposure: the first quartile was low exposure (0.0–45.4 kBq/m2), the second and third quartiles were intermediate exposure (45.41–118.8 kBq/m2), and the fourth quartile was the highest exposure (118.81–564.71 kBq/m2). Between 1991 and 2010, 82 495 cancer cases were registered in the 3 counties. Adjusted HRs (95% CI) were 1.03 (1.01 to 1.05) for intermediate exposure and 1.05 (1.03 to 1.07) for the highest exposure compared to the reference exposure. Conclusions We found a small overall exposure–response pattern of the total cancer incidence related to 137Cs after adjustment for age, sex, rural residence and pre-Chernobyl cancer incidence. PMID:27998898

  3. 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.

  4. High-energy gamma rays from the intense 1993 January 31 gamma-ray burst

    NASA Technical Reports Server (NTRS)

    Sommer, M.; Bertsch, D. L.; Dingus, B. L.; Fichtel, C. E.; Fishman, G. J.; Harding, A. K.; Hartman, R. C.; Hunter, S. D.; Hurley, K.; Kanbach, G.

    1994-01-01

    The intense gamma-ray burst of 1993 January 31 was detected by the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Observatory. Sixteen gamma rays above 30 MeV were imaged in the telescope when only 0.04 gamma rays were expected by chance. Two of these gamma rays have energies of approximately 1 GeV, and the five bin spectrum of the 16 events is fitted by a power law of photon spectral index -2.0 +/- 0.4. The high-energy emission extends for at least 25 s. The most probable direction for this burst is determined from the directions of the 16 gamma rays observed by Egret and also by requiring the position to lie on annulus derived by the Interplanetary Network.

  5. Study of gamma-ray strength functions

    SciTech Connect

    Gardner, D.G.; Gardner, M.A.; Dietrich, F.S.

    1980-08-07

    The use of gamma-ray strength function systematics to calculate neutron capture cross sections and capture gamma-ray spectra is discussed. The ratio of the average capture width, GAMMA/sub ..gamma../-bar, to the average level spacing, D/sub obs/, both at the neutron separation energy, can be derived from such systematics with much less uncertainty than from separate systematics for values of GAMMA/sub ..gamma../-bar and D/sub obs/. In particular, the E1 gamma-ray strength function is defined in terms of the giant dipole resonance (GDR). The GDR line shape is modeled with the usual Lorentzian function and also with a new energy-dependent, Breit-Wigner (EDBW) function. This latter form is further parameterized in terms of two overlapping resonances, even for nuclei where photonuclear measurements do not resolve two peaks. In the mass ranges studied, such modeling is successful for all nuclei away from the N = 50 closed neutron shell. Near the N = 50 shell, a one-peak EDBW appears to be more appropriate. Examples of calculated neutron capture excitation functions and capture gamma-ray spectra using the EDBW form are given for target nuclei in the mass-90 region and also in the Ta-Au mass region. 20 figures.

  6. Growth and (137)Cs uptake of four Brassica species influenced by inoculation with a plant growth-promoting rhizobacterium Bacillus pumilus in three contaminated farmlands in Fukushima prefecture, Japan.

    PubMed

    Aung, Han Phyo; Djedidi, Salem; Oo, Aung Zaw; Aye, Yi Swe; Yokoyama, Tadashi; Suzuki, Sohzoh; Sekimoto, Hitoshi; Bellingrath-Kimura, Sonoko Dorothea

    2015-07-15

    The effectiveness of the plant growth-promoting rhizobacterium Bacillus pumilus regarding growth promotion and radiocesium ((137)Cs) uptake was evaluated in four Brassica species grown on different (137)Cs contaminated farmlands at Fukushima prefecture in Japan from June to August 2012. B. pumilus inoculation did not enhance growth in any of the plants, although it resulted in a significant increase of (137)Cs concentration and higher (137)Cs transfer from the soil to plants. The Brassica species exhibited different (137)Cs uptake abilities in the order Komatsuna>turnip>mustard>radish. TF values of (137)Cs ranged from 0.018 to 0.069 for all vegetables. Komatsuna possessed the largest root surface area and root volume, and showed a higher (137)Cs concentration in plant tissue and higher (137)Cs TF values (0.060) than the other vegetables. Higher (137)Cs transfer to plants was prominent in soil with a high amount of organic matter and an Al-vermiculite clay mineral type.

  7. Overview Animation of Gamma-ray Burst

    NASA Video Gallery

    Gamma-ray bursts are the most luminous explosions in the cosmos. Astronomers think most occur when the core of a massive star runs out of nuclear fuel, collapses under its own weight, and forms a b...

  8. Gamma-ray observatory INTEGRAL reloaded

    NASA Astrophysics Data System (ADS)

    van den Heuvel, Edward P. J.

    2017-04-01

    The scientific aims of the European Space Agency's International Gamma-Ray Astrophysics Laboratory are considerably extended because of its unique capability to identify electromagnetic counterparts to sources of gravitational waves and ultra-high-energy neutrinos.

  9. POPULATION SYNTHESIS AND GAMMA RAY BURST PROGENITORS

    SciTech Connect

    C. L. FREYER

    2000-12-11

    Population synthesis studies of binaries are always limited by a myriad of uncertainties from the poorly understood effects of binary mass transfer and common envelope evolution to the many uncertainties that still remain in stellar evolution. But the importance of these uncertainties depends both upon the objects being studied and the questions asked about these objects. Here I review the most critical uncertainties in the population synthesis of gamma-ray burst progenitors. With a better understanding of these uncertainties, binary population synthesis can become a powerful tool in understanding, and constraining, gamma-ray burst models. In turn, as gamma-ray bursts become more important as cosmological probes, binary population synthesis of gamma-ray burst progenitors becomes an important tool in cosmology.

  10. Gamma-ray spectroscopy - Requirements and prospects

    NASA Technical Reports Server (NTRS)

    Matteson, James L.

    1991-01-01

    The only previous space instrument which had sufficient spectral resolution and directionality for the resolution of astrophysical sources was the Gamma-Ray Spectrometer carried by HEAO-3. A broad variety of astrophysical investigations entail gamma-ray spectroscopy of E/Delta-E resolving power of the order of 500 at 1 MeV; it is presently argued that a sensitivity to narrow gamma-ray lines of a few millionths ph/sq cm, from about 10 keV to about 10 MeV, should typify the gamma-ray spectrometers of prospective missions. This performance is achievable with technology currently under development, and could be applied to the NASA's planned Nuclear Astrophysics Explorer.

  11. [Dependences of 137Cs and 90Sr concentration ratios in fish on the potassium and calcium concentrations in the freshwater reservoirs].

    PubMed

    Khomutinin, Iu V; Kashparov, V A; Kuz'menko, A V

    2011-01-01

    Activities of 137Cs and 90Sr, concentrations of the potassium and calcium ions in water and accumulation of the radionuclides in the organisms of various freshwater fish have been measured in the stagnant and semistagnant water reservoirs of Ukraine contaminated as a result of the Chernobyl accident. On the basis of the numerous experimental data for different regions the statistical parameters were derived describing the dependencies of the 137Cs and 90Sr concentration ratios in the muscle tissue of various fish species on the potassium and calcium concentrations in water, respectively.

  12. Small Column Ion Exchange Testing of Superlig 644 for Removal of 137Cs from Hanford Tank Waste Envelope C (Tank 241-AN-107)

    SciTech Connect

    DE Kurath; DL Blanchard; JR Bontha

    2000-06-28

    The current BNFL Inc. flowsheet for the pretreatment of the Hanford high-level tank wastes includes the use of Superlig{reg_sign} materials for removing {sup 137}Cs from the aqueous fraction of the waste. The Superlig materials applicable to cesium removal include the cesium-selective Superlig 632and Superlig 644. These materials have been developed and supplied by IBC Advanced Technologies, Inc., American Fork, Utah. This report describes the testing of the Superlig 644 ion exchange material in a small dual-column system. The bed volume of the lead column was 18.6 mL (L/D = 7), and the bed volume of the lag column was 15.9 mL (L/D = 6) during the loading phase. The sample processed was approximately 1.6 L of diluted waste ([Na{sup +}] = 4.84 M) from Tank 241-AN-107 (Envelope C). This sample had been previously treated for removal of Sr/transuranic (TRU) values and clarified in a single tube cross-flow filtration unit. All ion exchange process steps were tested, including resin-bed preparation, loading, feed displacement, water rinse, elution, eluant rinse, and resin regeneration. A summary of performance measures for both columns is shown in Table S1. The Cs {lambda} values represent a measure of the effective capacity of the SL-644 resin. The Cs {lambda} of 20 for the lead column is much lower than the estimated 150 obtained by the Savannah River Technology Center during Phase 1A testing. Equilibrium data obtained with batch contacts using the AN-107 Cs IX feed predicts a Cs {lambda} of 183. A Cs {lambda} for the lag column could not be determined due to insufficient breakthrough, but it appeared to work well and removed nearly all of the cesium not removed by the lead column. The low value for the lead column indicates that it did not perform as expected. This may have been due to air or gas in the bed that caused fluid channeling or blinding of the resin. The maximum decontamination factor (DF) for {sup 137}Cs listed in Table S1 is based on {sup 137}Cs

  13. Ingestion doses in Finland due to (90)Sr, (134)Cs, and (137)Cs from nuclear weapons testing and the Chernobyl accident.

    PubMed

    Rantavaara, A

    2008-11-01

    (90)Sr and (137)Cs in domestic foodstuffs and water have been analysed in Finland since the early 1960s, and (134)Cs since 1986. Using data on radionuclide deposition levels, agricultural production, and the processing and consumption of foodstuffs, the average intake and radiation dose from the ingestion of these radionuclides have been assessed. The estimated committed effective dose from the ingestion of (90)Sr, (137)Cs, and (134)Cs in food and water for the period 1960-2005 is 2.2 mSv, and for the period since the Chernobyl accident in 1986 it is 1.3 mSv.

  14. [Assessment of an association between fatty acid structure of lipids in pulmonary surfactant and 137Cs content in the body of children, residents of radiation-contaminated areas].

    PubMed

    Parkhomenko, V M; Kolpakov, I Ie; Studenykina, O M; Briuzhina, T S; Artemchuk, H P

    2012-01-01

    An evaluation of correlation between fatty acid composition in pulmonary surfactant lipids and 137Cs content in the body of children, residents of radiation-contaminated areas revealed that a increased incorporation of 137Cs promotes a disruption of fatty acid balance towards an increase in the saturation of the surfactant lipid complex, a destruction of lecithin fraction of surfactant, a decrease in antioxidant properties of surfactant system, an activation of lipid peroxidation processes in the respiratory area of lung by lipoxygenase type, a disturbance of polyunsaturated fatty acid metabolism on the stage of bioregulators-eicosanoid formation.

  15. Gamma-ray constraints on supernova nucleosynthesis

    NASA Technical Reports Server (NTRS)

    Leising, Mark D.

    1994-01-01

    Gamma-ray spectroscopy holds great promise for probing nucleosynthesis in individual supernova explosions via short-lived radioactivity, and for measuring current global Galactic supernova nucleosynthesis with longer-lived radioactivity. It was somewhat surprising that the former case was realized first for a Type II supernova, when both Co-56 and Co-57 were detected in SN 1987A. These provide unprecedented constraints on models of Type II explosions and nucleosynthesis. Live Al-26 in the Galaxy might come from Type II supernovae, and if it is eventually shown to be so, can constrain massive star evolution, supernova nucleosynthesis, and the Galactic Type II supernova rate. Type Ia supernovae, thought to be thermonuclear explosions, have not yet been detected in gamma-rays. This is somewhat surprising given current models and recent Co-56 detection attempts. Ultimately, gamma-ray measurements can confirm their thermonuclear nature, probe the nuclear burning conditions, and help evaluate their contributions to Galactic nucleosynthesis. Type Ib/c supernovae are poorly understood. Whether they are core collapse or thermonuclear events might be ultimately settled by gamma-ray observations. Depending on details of the nuclear processing, any of these supernova types might contribute to a detectable diffuse glow of Fe-60 gamma-ray lines. Previous attempts at detection have come very close to expected emission levels. Remnants of any type of age less that a few centuries might be detectable as individual spots of Ti-44 gamma-ray line emission. It is in fact quite surprising that previous surveys have not discovered such spots, and the constraints on the combination of nucleosynthesis yields and supernova rates are very interesting. All of these interesting limits and possibilities mean that the next mission, International Gamma-Ray Astrophysics Laboratory (INTEGRAL), if it has sufficient sensitivity, is very likely to lead to the realization of much of the great potential

  16. The Mystery of Gamma-Ray Bursts

    NASA Technical Reports Server (NTRS)

    Fishman, Gerald J.

    1998-01-01

    Gamma-ray bursts remain on of the greatest mysteries in astrophysics in spite of recent observational advances and intense theoretical work. Although some of the basic properties of bursts were known 25 years ago, new and more detailed observations have been made by the BATSE (Burst and Transient Source Experiment) experiment on the Compton Gamma Ray Observatory in the past five years. Recent observations of bursts and some proposed models will be discussed.

  17. Supernovae and gamma-ray bursts connection

    SciTech Connect

    Valle, Massimo Della

    2015-12-17

    I’ll review the status of the Supernova/Gamma-Ray Burst connection. Several pieces of evidence suggest that long duration Gamma-ray Bursts are associated with bright SNe-Ic. However recent works suggest that GRBs might be produced in tight binary systems composed of a massive carbon-oxygen cores and a neutron star companion. Current estimates of the SN and GRB rates yield a ratio GRB/SNe-Ibc in the range ∼ 0.4% − 3%.

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

    SciTech Connect

    Noshkin, V.E.

    2001-02-01

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

  19. Observed half-lives of 3H, 90Sr and 137Cs in hydrosphere in the Vltava River basin (Bohemia).

    PubMed

    Hanslík, Eduard; Jedináková-Krízová, Vera; Ivanovová, Diana; Kalinová, Eva; Sedlárová, Barbora; Simonek, Pavel

    2005-01-01

    A near field study was set up to follow the effects of the Temelin nuclear power plant construction. Reference levels of artificial radionuclides were monitored in the Vltava River upper course and its tributaries in the period 1990-2001. Monitoring continued even after the waste water release startup during the pilot operation in 2002. The assessment of the (90)Sr and (137)Cs concentrations histories in ground water, river bottom sediments and fish showed a decreasing trend. This trend was not influenced by the nuclear power plant pilot operation. In the case of tritium, trend of increasing concentration had been already observed since the pilot operation startup. The monitoring of changes in concentrations of artificial and natural radionuclides in influenced and uninfluenced profiles will be maintained to assess the possible influence of the operation of the Temelin nuclear power plant.

  20. Modelling tillage and water erosion by using WATEM/SEDEM and 137Cs measurements at field scale

    NASA Astrophysics Data System (ADS)

    Quijano, Laura; Beguería, Santiago; Gaspar, Leticia; Navas, Ana

    2016-04-01

    The estimation of soil redistribution rates is necessary to evaluate the environmental impact of soil erosion including the loss of fertile topsoil which is one of the main soil degradation problems in agricultural landscapes. Modelling approach offers a potential tool for quantifying soil redistribution and to propose site-specific control measures to minimize soil degradation in agroecosystems. Studies at field scale using spatially distributed data of 137Cs derived soil redistribution rates to calibrate and evaluate the uncertainties of distributed models are required but are still scarcely implemented. This study applies the WATEM/SEDEM model to estimate soil redistribution rates after calibration with 137Cs measurements. Furthermore, soil redistribution rates by tillage were estimated using the Mass Balance Model 3 (MBM3). A representative Mediterranean cultivated field located in the central part of the Ebro basin (NE Spain) was selected to conduct the study. A digital elevation model (DEM) at high resolution (2.5 m) of the study field was generated to characterize the land surface. The elevation of a total of 617 points was measured on a 5 m grid using a total topographic station and 156 bulk soil samples were collected on a 10 m grid for soil analysis. According to field observations and topographical surveys four hydrological units were identified within the study field characterized by different hydrological behavior. The results indicated that soil erosion predominated over soil deposition. Mean values of 137Cs derived soil erosion and deposition rates were 19.7 Mg ha-1 yr-1 and 12.6 Mg ha-1 yr-1, respectively. The rates obtained with WATEM/SEDEM model were lower; mean erosion was 3.9 Mg ha-1 yr-1 and mean deposition rates that occurred in 35% of the grid cells was 5.8 Mg ha-1 yr-1. Water erosion was the major factor controlling soil redistribution whereas tillage erosion was almost negligible. These results are in line with the tillage rates obtained