WorldWideScience

Sample records for 137cs gamma rays

  1. Scintillation characteristics on anthracene-doped naphthalene crystal for {sup 137}Cs-{gamma} ray source

    Balamurugan, N. [Crystal Growth Centre, Anna University, Chennai 600025 (India); Arulchakkaravarthi, A. [Electrical Engineering Department, University of South Carolina, SC (United States); Ramasamy, P. [Crystal Growth Centre, Anna University, Chennai 600025 (India) and SSN College of Engineering, Kalavakkam 603110 (India)]. E-mail: pramasamy@annauniv.edu

    2006-12-01

    In this paper, we report scintillation characterizations on anthracene-doped naphthalene (NA) crystal. Crystals of this scintillator have been grown using the Bridgman-growth process. The peak of NA crystal emission is at 425 nm. The luminescence intensity of the NA crystal is 3 times that of pure naphthalene crystal. Naphthalene when doped with anthracene has high light output and fast principal decay constant (<30 ns). For 662 keV {gamma} rays ({sup 137}Cs source), energy resolution of 18% (FWHM) has been recorded at room temperature for NA crystals coupled to a photomultiplier. The pulse height of NA is 10 times greater than the pure naphthalene crystal. The NA detector exhibited a good timing performance compared to trans-stilbene detector.

  2. The long term effects of {sup 137}Cs {gamma}-rays and tritiated water on induction on teratogenesis in rats

    Shoji, Shuneki [Hiroshima Univ., Research Institute for Radiation Biology and Medicine, Hiroshima (Japan)

    2003-07-01

    The purpose of the present study is to evaluate the teratogenesis caused by {sup 137}Cs {gamma}-rays radiation and tritiated water (tritium {beta}-rays, HTO) in rats under long-term exposures. Many congenital anomalies are caused by environmental factors, and it is likely that this assessment of teratogenesis will be very important in the future. Pregnant Donryu strain rats were irradiated with {sup 137}Cs {gamma}-rays on days 9-18 of gestation. The animals were sacrificed on day 18 of gestation and the contents of each uterine horn were examined. The numbers of surviving, dead and resorbed fetuses were recorded. The surviving fetuses were examined for external and visceral malformations. Also given here is a measure of the relative biological effectiveness (RBE) of tritiated water (HTO) compared to that for {sup 137}Cs {gamma}-rays regarding the induction of developmental anomalies such as neurocristopathy in pregnant Donryu rats. Radiation exposures were approximately 0, 1, 2, 3, 4, 5 and 6 Gy for both tritiated water and {sup 137}Cs {gamma}-rays. Teratogenesis was dose dependent for both radiation groups. Our studies show that {sup 137}Cs {gamma}-rays and HTO irradiation induce similar malformations of the cardiovascular, respiratory and skeletal systems in rat fetuses. However, a number of fetuses exhibiting growth retardation, general edema, persistent atrioventricular canal, eye defects, microcephaly and craniofacial defects following maternal exposure to HTO. These include hypoplasia of the pulmonary trunk (tetralogy of Fallot), DORV, ventricular septal defect, right aortic arch, coarctation of the aorta, aberrant right subclavian artery, hypoplasia of the thymus, craniofacial anomalies, hypoplasia or incomplete lungs and trachea, as well as limb and tail malformations in HTO syndrome. These results are similar to those found in human DiGeorge syndrome, which are considered pharyngeal arch syndromes related to a cephalic neutrocristopathy. A best estimation

  3. Field measurements of environmental radionuclides 137Cs and 210Pbex inventories using in-situ gamma-ray spectrometry

    In-situ measurement of environmental radionuclides 137Cs and 210Pbex has a potential to assess soil erosion and sedimentation rapidly. In this study, we measured the inventories of 137Cs and 210Pbex in the soil of Inner Mongolia grassland using an in-situ gamma detector with the 50 mm shield and Collimator mounted on a cart (ISOCS, In-situ Object Counting System). The detector was set up one meter above the ground with 90 degree collimator installed: the counting time is more than 3600s. The field survey data were compared with data from laboratory analysis of section cores. The results showed that the mean deviations of measured values between field and laboratory measurements are less than 8%, indicating a high precision for in-situ gamma spectrometry. The inventories of 210Pbex measured by in-situ γ spectrometry were much higher than the laboratory measurements due to a short measurement time in the field. The results from our pilot study indicated that in-situ gamma-ray spectrometry has the following advantages over traditional laboratory measurements: no time consuming sample collection, prompt availability of the results, averaging radionuclide activity over a large area and high precision. (authors)

  4. Activity concentration of 137Cs in soil samples from Punjab province (Pakistan) and estimation of gamma-ray dose rate for external exposure

    Punjab is one of the most populated provinces of Pakistan having 34 districts. There is always a need to have baseline background level information about 137Cs and the corresponding gamma-ray doses to the population. In this respect, soil samples were collected to a depth of 30-50 cm from all 34 district headquarters of the Punjab province of Pakistan and 137Cs activity concentrations were measured. 137Cs activity concentration was found to be in the range from 1.1 ± 1.0 to 5.3 ± 2.5 Bq kg-1. The average value of estimated external gamma-ray dose rate from all 34 districts of Punjab province was computed to be 0.18 ± 0.07 nSv h-1 from 137Cs in soil samples. The measured 137Cs activity concentration range was compared with the reported ranges in the literature from some of the other locations in the world. Results obtained in this study show that 137Cs concentration is of a lower level in the investigated area. The average value of estimated external effective dose rate is found far below the dose rate limit of 1.0 mSv y-1 for members of the general public recommended by the International Commission on Radiological Protection (ICRP) as well as the external gamma radiation dose of 0.48 mSv y-1 received per head from the natural sources of radiation assessed by UNSCEAR (2000). It is concluded that 137Cs soil contamination does not pose radiation hazards to the population in the investigated areas. (authors)

  5. Applicability study of using in-situ gamma-ray spectrometry technique for 137Cs and 210Pbex inventories measurement in grassland environments

    In-situ measurement of fallout radionuclides 137Cs and 210Pbex has the potential to assess soil erosion and sedimentation rapidly. In this study, inventories of 137Cs and 210Pbex in the soil of Inner Mongolia grassland were measured using an In-situ Object Counting System (ISOCS). The results from the field study indicate that in-situ gamma-ray spectrometry has the following advantages over traditional laboratory measurements: no extra time is required for sample collection, no reference inventories are required, more economic, prompt availability of the results, the ability to average radionuclide inventory over a large area, and high precision.

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

    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.

  7. Effects of the combinations of caffeine with 137Cs-gamma rays or tritiated water on the proliferation and malignant transformation CHL-1 cells

    The effects of the combinations of caffeine with 137Cs-gamma rays or tritiated water on the proliferation and malignant transformation in vitro in CHL-1 cells were observed in experiments. At the concentrations of caffeine from 1 mmol/L to 2 mmol/L, the dose ranges of 137Cs-gamma rays from 0.837 Gy and to 2.51 Gy and of tritium-beta radiation from 0.837 Gy to 0.528 Gy, the cell proliferation of CHL-1 cells was found to be inbigited when cells were exposed to caffeine, gamma and beta radiations, respectively, as well as when they were exposed to various combinations of caffeine with the two latters. The degree of inhibition of cell proliferation was dependent upon the concentration of caffeine and on the doses of radiation. In the transformation experiments, cell malignant transformation rates for all treated groups were higher than that for contol group and the rates for irradiated plus caffeine-treated groups were higher than those for corresponding single-agent-treated ones. After the subcutaneous injection of transformed cells into irradiated mice, tumours in size of about 2 mm3 were found in some animals and the tumour cells were identical with in-vitro-transformed CHL-1 cells histopathologically

  8. In service identification of the heterogeneous zone in petrochemical pipeline by using sealed gamma-ray source (60Co, 137Cs)

    In-service diagnoses of pipeline facilities are important for a systematic maintenance of them. Field applications by using sealed gamma-ray sources (60Co, 137Cs) were performed of identify the heterogeneous zone in the pipelines of a distillation tower and a flare stack respectively, From the results, the heterogeneous zones in the pipelines were successfully identified. In the case of the pipeline connected to the distillation tower, a vapor pocket was detected in the fluid under hydrodynamic conditions, which could explain the reason for a decrease of the flow rate. In another case, an area with some amount of catalyst deposits was found at the bottom of the gas pipeline which was connected to the flare stack. And these findings provided important information for the process operators. Diagnosis technique by using gamma radiation sources has been proven to be an effective and reliable method for providing information on a media distribution in a facility.

  9. Natural gamma radioactivity and of 137 Cs in soil of the Chimaltitan municipality, Jalisco, Mexico

    With the purpose of determining the activity due to the natural presence of the 226 Ra, 232 Th, 40 K and 137 Cs in soil samples, of the municipality of Chimaltitan Jalisco. A set of these samples was measured in a gamma ray spectrometric system based on a High-purity Germanium detector. It is well-known that approximately 87% of the dose of the received radiation by the population is due to sources of natural radiation and 13% of the anthropogenic radiation. The gamma radiation comes mainly from the 40 K and of those radionuclides of the series of radioactive decay of 238 U and 232 Th that its find dispersed thoroughly in the terrestrial crust. In this work its were analyzed twenty-two soil samples. It is enlarged the activity characterization for the radioisotopes of 226 Ra 232 Th, 40 K and 137 Cs. (Author)

  10. Calibration of a field-portable gamma detector to obtain in situ measurements of the 137Cs inventories of cultivated soils and floodplain sediments

    Over the past 10 years, a number of studies have exploited the potential for using measurements of fallout 137Cs inventories to document rates and patterns of soil erosion on cultivated land and to estimate rates of overbank sedimentation on river floodplains. Traditional procedures for applying the 137Cs technique involve the collection of soil or sediment cores from a study site and their subsequent transfer to the laboratory for preparation and analysis by gamma spectrometry. Such procedures are time consuming and there may be a considerable delay before the results are available. It is therefore difficult to obtain preliminary results, which could be used to guide the development of an ongoing sampling programme. The use of in situ gamma spectrometry measurements to quantify 137Cs inventories in soils and sediments offers a number of potential advantages over traditional procedures. However, in order to derive a reliable estimate of the 137Cs inventory for a measurement point, it is necessary to take account of the attenuation of 137Cs gamma rays by the soil matrix and information on the depth distribution of 137Cs in the soil or sediment is therefore required. In the present study, empirical relationships between in situ measurements of 137Cs activity and total 137Cs inventories have been established for soils from a cultivated field and for floodplain sediments, based on information on the vertical distribution of 137Cs in the soils and sediments provided by the forward scattering ratio derived from the field measured spectra. These relationships have been used to estimate 137Cs inventories from in situ measurements of 137Cs activity at other locations

  11. Measurement and Analysis of Specific Activities of 238U, 232Th,226Ra, 40K and 137Cs in Soil Samples from Phatthalung Province (Thailand) using Gamma Ray Spectrometry

    Full text: Specific activity of natural (238U, 232Th, 226Ra and 40K ) and anthropogenic radionuclide (137Cs) in 109 soil samples collected from 11 districts in Phathalung province have been measured and analyzed. Experimental results were obtained by using a high purity germanium (HPGe) detector and gamma spectrometry analysis system at Nuclear and Material Physics laboratory in Department of Physics Faculty of Science Thaksin University Songkhla Campus. Gamma ray radioactive standard sources 60Co, 137Cs and 133Ba were used to calibrate the measurement system. The KCl and two reference materials (RGU-1 and RGTh-1) obtained from the International Atomic Energy Agency were also used to analyze and compute the 40K, 238U (or 226Ra) and 232Th specific activity in all soil samples. The IAEA/SL-2 was also used to evaluate the specific activity of 137Cs in all soil samples. The measuring time of each sample was 10,800 seconds. It was found that specific activity ranged from 148.17 to 11276.78 Bq/kg for 40K, 58.29 to 518.45 Bq/kg for 226Ra, 8.40 to 236.19 Bq/kg for 232Th and 0.00 tp 12.39 Bq/kg for 137Cs with mean values of 3573.35 ± 203.89 Bq/kg, 135.89 ± 6.71 Bq/kg, 76.34 ± 5.32 Bq/kg and 1.05 ± 0.70 Bq/kg respectively. Furthermore, absorbed dose rate in air (D), radium equivalent activity (Raeq), external hazard index (Hex), and annual effective dose rate (AEDout) of this area were also evaluated by using the mean values of specific activities of the 40K, 226Ra and 232Th. Moreover, the experimental results were also compared with Office of Atoms for Peace (OAP) research data, Thailand and global radioactivity measurement and evaluations. The radioactive contour maps of specific activities of natural and anthropogenic radionuclides from this study were created by using the program ArcGis Version 9.2

  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.

    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. PMID:26490904

  13. KEY COMPARISON Comparison of the standards of air kerma of the ENEA-INMRI and the BIPM for 137Cs gamma rays

    Allisy-Roberts, P. J.; Kessler, C.; Toni, M.; Bovi, M.

    2010-01-01

    A comparison of the standards of air kerma of the Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti of the Ente per le Nuove Tecnologie, l'Energia e l'Ambiente, Italy (ENEA-INMRI) and of the Bureau International des Poids et Mesures (BIPM) was carried out in 137Cs radiation in 1998. The comparison result, updated for changes in the standards in 2003 and 2009, is 0.9927 (0.0067) and demonstrates that the ENEA-INMRI and BIPM standards are in agreement within the uncertainties. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI Section I, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  14. Natural gamma radioactivity and of {sup 137} Cs in soil of the Chimaltitan municipality, Jalisco, Mexico; Radiactividad gamma natural y del {sup 137} Cs en suelo del Municipio de Chimaltitan, Jalisco, Mexico

    Garay, A.; Mireles, F.; Quirino, L.L.; Davila, J.I.; Rios, C.; Lugo, J.F.; Soriano, J.M.; Angoli, A. [UAEN-Universidad Autonoma de Zacatecas, Cipres 10, Frac. La Penuela, 98000 Zacatecas (Mexico)]. e-mail: albinogaray@hotmail.com.mx

    2003-07-01

    With the purpose of determining the activity due to the natural presence of the {sup 226} Ra, {sup 232} Th, {sup 40} K and {sup 137} Cs in soil samples, of the municipality of Chimaltitan Jalisco. A set of these samples was measured in a gamma ray spectrometric system based on a High-purity Germanium detector. It is well-known that approximately 87% of the dose of the received radiation by the population is due to sources of natural radiation and 13% of the anthropogenic radiation. The gamma radiation comes mainly from the {sup 40} K and of those radionuclides of the series of radioactive decay of {sup 238} U and {sup 232} Th that its find dispersed thoroughly in the terrestrial crust. In this work its were analyzed twenty-two soil samples. It is enlarged the activity characterization for the radioisotopes of {sup 226} Ra {sup 232} Th, {sup 40} K and {sup 137} Cs. (Author)

  15. Radiation Damage and Recovery Properties of Common Plastics PEN (Polyethylene Naphthalate) and PET (Polyethylene Terephthalate) Using a 137Cs Gamma Ray Source Up To 1 MRad and 10 MRad

    Wetzel, J; Bilki, B; Onel, Y

    2016-01-01

    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 MRad and 10 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 MRad and 10 MRad emit 35.0% and 12.2% light, respectively, and maximally recover to 93.5% and 80.0% after 22 and 60 ...

  16. Performance of 20 Ci 137Cs -ray Compton spectrometer for the study of momentum densities

    B L Ahuja; M Sharma

    2005-07-01

    In this paper, we present the design and construction of a 20 Ci -ray Compton spectrometer that employs a 137Cs source with a strong line at 661.65 keV. The total resolution of the spectrometer in momentum scale is 0.40 a.u., which is much better than the conventional 241Am Compton spectrometers. The in-house 137Cs spectrometer is very useful for the measurement of momentum densities of heavy materials. The performance of the machine is assessed using aluminum, terbium and mercury samples and the experimental data from comparable apparatus.

  17. Studies on the gamma radiation environment in Sweden with special reference to 137Cs

    Gamma radiation in the environment today mainly originates from naturally occurring radionuclides, but anthropogenic radionuclides, such as 137Cs, contribute in some areas. In order to assess population exposure in case of fallout from nuclear weapons (NWF) or accidents, knowledge and monitoring of external gamma radiation and radionuclide concentrations in the environment is important. For this purpose 34 sampling sites were established in western Sweden and repeated soil sampling, field gamma spectrometry (in situ measurements), and dose rate measurements were performed. The variations in the activities between the different sampling occasions were found to be quite large. The naturally occurring radionuclides were the main source of outdoor dose rates. The uranium and thorium decay series contributed about equally to the total dose while the contribution from 40K was somewhat higher. The dose rates were mainly correlated to the ground cover, with higher levels on asphalt and cobble stones than on grass. The large scale deposition densities from NWF and the Chernobyl accident could be relatively well estimated by a model including the amount of precipitation and measured deposition at few reference sites. The deposition density from nuclear weapons tests in Sweden between 1962 and 1966 was found to be 1.42-2.70 kBq/m2 and the deposition density from Chernobyl in western Sweden ranged between 0.82-2.61 kBq/m2. The vertical migration of 137Cs was studied at the sampling sites in western Sweden and a solution to the convection-diffusion equation (CDE) was fitted to depth profiles. The vertical migration of 137Cs was found to be very slow and diffusive transport was dominant at most locations. The apparent convection velocity and diffusion coefficient were found to be 0-0.35 cm/year and 0.06-2.63 cm2/year, respectively. The average depth of the maximum activity was 5.4±2.2 cm. The fitted depth distributions for each location were used to correct in situ measurements

  18. Fallout 137Cs in soils from North Western Libya

    Fallout levels of 137Cs in surface soil from North Western Libya have been measured using gamma-ray spectrometry. The activity concentrations of 137Cs in soil ranged from 975 to 1720 mBq x kg-1. The areal activity concentrations ranged from 1300 to 2250 mBq x m-2, and were highly correlated with annual precipitation. The effective dose from external exposure to 137Cs is found to be 3 nSv x y-1. (author)

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

    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

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

    Harvester ants, Pogonomyrmex owyheei Cole, irradiated with 3.5 kR to 268 kR of 137Cs gamma radiation, were maintained at simulated summer (270C) and winter (70C) temperature regimes. After thirty days, the cool series was warmed to 270C 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. Analysis of 137Cs contamination in soil using in-situ gamma spectrometry

    Quantification of radioactive contamination in the environment is often desirable so that health implications can be determined and appropriate remedial measures taken. In-situ gamma spectrometry is a potentially powerful technique that has the advantage of speed and spatial averaging over a large area. Calibration, however, is complex not least because the distribution of the activity in the field is generally unknown. To overcome this problem, methods have previously been proposed to derive information about the vertical activity distribution. All of these methods assume a fixed simple activity distribution model, the parameters of which are derived from varying in-situ spectral region ratios. In this work, these methods have been extensively assessed and compared both theoretically and experimentally for the quantification of 137Cs contamination. In all cases, the best method was that which used a lead plate to alter the contributing angular interval. Experimentally, this Lead Plate Method predicted the activity concentration to within a factor of between 1.50 and 1.66 on average. A new method, using collimated detector measurements within a shallow well was developed and theoretically optimised in terms of number and depths of detector positions and type of collimation. This optimised Submerged Detector Method was assessed and compared with the Lead Plate Method both theoretically and experimentally. The latter comparison involved 19 sites across Wales, UK where there is a wide range of 137Cs activity levels and vertical distributions. The Submerged Detector Method was found to be more accurate both in the theoretical modelling assessment and in the experimental comparison, where the method was found to predict the activity concentration to within a factor of 1.35 on average. Distribution profiles predicted by the Submerged Detector Method were also found to be generally closer to the true profiles than those obtained using the Lead Plate Method. (author)

  2. Effect of 137Cs gamma radiation on the fibronectin content in basement membrane of mouse small intestine

    The distribution of fibronectin in the small intestine of the mouse was investigated using an indirect immunofluorescence technique. Tissue fibronectin was preferentially located in the basement membrane and in the muscularis layer. Semiquantitative immunofluorescence determination of tissue fibronectin in the basement membrane showed only minor changes at 24 or 48 hours after 10 or 20 Gy of 137Cs gamma irradiation. (Auth.)

  3. Calibration of radioprotection instruments and calibrated irradiation: characterization of gamma beam of 137Cs and 60Co

    Radioprotection Laboratory belongs to Dosimetry Reference Regional Centre of Atomic Energy National Commission, C.A.E. This laboratory offers the service of calibrations for radioprotection instruments as Geiger Muller detector, ionisation chamber, probe, proportional counters, electronic personal dosimeters and others used in nuclear medicine, radiotherapy centres, nuclear power plants, industry and in other applications of ionising radiation. Also it offers the service of calibrated irradiations. A gamma Irradiator and a Stabilipam 300 X-ray are the equipment of the Radioprotection Laboratory used for calibrations. Hopewell Designs Irradiator was installed to improve the quality of services in 2005. The irradiator has a 137Cs source of 10 Curies and a 60Co source of 1 Curie, approximately. Theoretical and experimental studies were done to analyse symmetry, flatness, penumbra and secondary radiation of photon beams. For symmetry, flatness and penumbra X-OMAT-V films and thermoluminescent dosimeters (TLDs) were used. Films were placed to 0.7 and 1 meter from collimator exit receiving 10, 40, 80, 100 and 120mGy. TLDs were placed to 1 and 1.80 meters from collimator on a surface higher than 137Cs beam cross section. Also studies were done to a distance of 1m and 1.80 from exit collimator using LiF powder in capsules. Irradiations were done without attenuators and with a collimator aperture of 8 C degrees. Results were compared to those obtained with Monte Carlo simulation (MCNP5c code). For secondary radiation calculation three methods were employed: Shadow-shield, Multiple distance and Monte Carlo simulation. Finally, from theoretical and experimental studies could conclude that the secondary radiation resulted to be lower than 3.5%, total radiation, symmetry and flatness were higher than 90% and penumbra was lower than 13 mm. Those results agree to recommendations ISO 4037 Standard. (author)

  4. Biological effects of turf bamboo by 137Cs γ-rays irradiation

    137Cs γ-rays was used to treat bamboo rhizome or culture of turf bamboo, and to evaluate the biological was studied. It showed that low dose of irradiation had no effect on bud germination, high dose of irradiation delayed the bud germination. Sasa pygmaea was more resistant to γ-rays irradiation, and the lethal dose of Sasa culture was 20 ∼ 30 Gy. For Sasa fortunei culture the lethal dose was less than 20 Gy; and the lethal dose of bamboo rhizome for Indocalamus latifolius was 10 ∼ 20 Gy, for other 3 species of bamboo, the lethal dose was more than 80 Gy. The morphological feature of Sasa pygmaea, or Indocalamus latifolius, or Indocalamus decorous after irradiation was not obvious, but the white strip in its green leaves of Shibataea chinensis irradiated with 5 and 10 Gy was observed. (authors)

  5. Study on the energy dependence of gamma radiation detectors for {sup 137}Cs and {sup 60}Co; Estudo da dependencia energetica de detectores de radiacao gama para {sup 137}Cs e {sup 60}Co

    Nonato, Fernanda B.C.; Diniz, Raphael E.; Carvalho, Valdir S.; Vivolo, Vitor; Caldas, Linda V.E., E-mail: fbnonato@ipen.b, E-mail: rediniz@ipen.b, E-mail: vcsouza@ipen.b, E-mail: vivolo@ipen.b, E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    38 Geiger-Mueller radiation detectors and 9 ionization chambers were calibrated, viewing to study the energy dependence of the monitor response for gamma radiation fields ({sup 137}Cs and {sup 60}Co). The results were considered satisfactory only for ionization chambers and for some Geiger-Mueller detectors

  6. The effects of gamma irradiation on leaching of 137Cs from organic matrix wasteforms

    The effects of γ-irradiation on the leaching behaviour of 137Cs in organic matrix wasteforms has been studied. The matrix materials used include epoxide, polyester and vinyl ester thermosetting resins and bitumen. Leaching of 137Cs in such matrices can be described by models, based on diffusion, which take into consideration such factors as non-representative surface layers, finite sample size, and sorption effects. In many cases, the changes observed on irradiation arise from modification of the sorptive capacity of the wasteform for 137Cs, producing changes in the experimentally observed diffusion coefficients. In samples containing wet wastes, enhanced leaching in the first few days is observed after irradiation. This arises from loss of water from the sample surfaces during irradiation producing an enhanced concentration of the radionuclide in the surface. (author)

  7. The long term effects of 137Cs γ-rays and tritiated water on induction on teratogenesis in rats

    The purpose of the present study is to evaluate the teratogenesis caused by 137Cs γ-rays radiation and tritiated water (tritium β-rays, HTO) in rats under long-term exposures. Many congenital anomalies are caused by environmental factors, and it is likely that this assessment of teratogenesis will be very important in the future. Pregnant Donryu strain rats were irradiated with 137Cs γ-rays on days 9-18 of gestation. The animals were sacrificed on day 18 of gestation and the contents of each uterine horn were examined. The numbers of surviving, dead and resorbed fetuses were recorded. The surviving fetuses were examined for external and visceral malformations. Also given here is a measure of the relative biological effectiveness (RBE) of tritiated water (HTO) compared to that for 137Cs γ-rays regarding the induction of developmental anomalies such as neurocristopathy in pregnant Donryu rats. Radiation exposures were approximately 0, 1, 2, 3, 4, 5 and 6 Gy for both tritiated water and 137Cs γ-rays. Teratogenesis was dose dependent for both radiation groups. Our studies show that 137Cs γ-rays and HTO irradiation induce similar malformations of the cardiovascular, respiratory and skeletal systems in rat fetuses. However, a number of fetuses exhibiting growth retardation, general edema, persistent atrioventricular canal, eye defects, microcephaly and craniofacial defects following maternal exposure to HTO. These include hypoplasia of the pulmonary trunk (tetralogy of Fallot), DORV, ventricular septal defect, right aortic arch, coarctation of the aorta, aberrant right subclavian artery, hypoplasia of the thymus, craniofacial anomalies, hypoplasia or incomplete lungs and trachea, as well as limb and tail malformations in HTO syndrome. These results are similar to those found in human DiGeorge syndrome, which are considered pharyngeal arch syndromes related to a cephalic neutrocristopathy. A best estimation of the RBE for this experiment was also discussed. (author)

  8. Effects of 15 Gy 137Cs γ-rays radiation of rat kidneys on bone metabolism

    The work was to observe the effects of γ-rays radiation of rat kidneys on rat bone metabolism. Ten male SD rats aged 6 months were irradiated at their kidneys with 15 Gy 137Cs γ-rays (0.91 Gy/min) and were raised for 3 months after the radiation. On collecting 24h urine of rats they were sacrificed for serum, kidney, spine, femur and tibia exams. Results show that the γ-ray irradiation could induce the pathological injuries of renal glomeruli, tubules and mesenchyme. Comparing to the control group, significant changes were found in the irradiated group in terms of their blood urea, nitrogen creatinine, urinal β-2 microglobulin, serum Ca and P, urine Ca and P, activity of serum alkaline phosphatase, 1,25 (OH)2 D3, serum PTH, urine PYD/creatinine, bone mineral density (BMD) of lumbar vertebras, mineral mass of No.4 lumbar vertebra, BMD, dehydrated weight and ash weight of right femur. Marked changes were also found in bone trabecula volume, average bone trabecula thick and the ratio of nodes/points, and rate of mineralization deposition. It was concluded that renal dysfunction and metabolic bone disease might occur with the character of accelerated bone turnover and decreased bone mass

  9. 137Cs fallout depth distributions in forest versus field sites: implications for external gamma dose rates

    The depth profile of 137Cs fallout in soil from atmospheric nuclear weapons tests was measured at neighboring field and forest areas for seven sites in northeastern US. The inferred dose rates in air at 1 m above the ground per unit inventory of 137Cs averaged a factor of 1.8 higher in forest as compared to field areas. Calculations indicate that dose rate in forest areas would be a factor of four higher than that over deeply ploughed land. Based on a limited set of historical measurements made since 1972, it appears that the dose rate per unit inventory in both field and forest areas has more or less stabilized after a sharp decrease following deposition events in the early 1960s. Estimated dose commitments for various land types are compared to the value suggested by UNSCEAR and implications with respect to certain population groups are discussed. The findings may have application in estimating future external doses from deposited 137Cs associated with Chernobyl fallout in Europe. (author)

  10. Comparisons of the standards for air kerma of the PTB and the BIPM for {sup 60}Co and {sup 137}Cs gamma radiation

    Allisy-Roberts, P.J.; Burns, D.T. [Bureau International des Poids et Mesures (BIPM), 92 - Sevres (France); Buermann, L.; Kramer, H.M. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)

    2005-11-15

    Direct comparisons of the standards for air kerma of the Physikalisch-Technische Bundesanstalt (PTB, Germany) and of the Bureau International des Poids et Mesures (BIPM) were carried out in the {sup 60}Co and {sup 137} Cs radiation beams of the BIPM in 2000. The results, expressed as ratios of the PTB and the BIPM standards for air kerma, indicate a relative difference in {sup 60}Co of 9.9 x 10{sup -3} with a combined standard uncertainty of 1.8 x 10{sup -3}, and in {sup 137}Cs of 6.4 x 10{sup -3} with a combined standard uncertainty of 2.8 x 10{sup -3}. The earlier comparisons in {sup 60}Co {gamma} rays made in 1971 (direct) and 1989 (indirect) resulted in an agreement of the two standards within 2 x 10{sup -3}. The differences obtained now are due to the application of new correction factors for wall effects and point source non-uniformity of the beam, k{sub wall} and k{sub pn}, for the PTB standards, which were calculated using Monte Carlo methods. (authors)

  11. Effect of combined treatment of caffeine benzamide and 137Cs γ-ray on mutation frequency in soybean

    The results of single treatment of caffeine or benzamide to M1 soybean are as follows. The seedling height, rate of mature plant, fertility, frequency of chromosomal aberration in root tip cells and activity of POD were obviously affected, and the same results were with M2. 137Cs γ-ray had damage and mutagenic effects on soybean. Combined treatment of the three methods enhanced M1 damage effect and M2 mutagenic effect. By the method of 3H-TdR, it was shown that caffeine inhibited the recovery of radiation damage and enforced the damage effect on M1 soybean and obviously increased mutagenic frequency of M2

  12. Scintillation characteristics on anthracene-doped naphthalene crystal for 137Csray source

    In this paper, we report scintillation characterizations on anthracene-doped naphthalene (NA) crystal. Crystals of this scintillator have been grown using the Bridgman-growth process. The peak of NA crystal emission is at 425 nm. The luminescence intensity of the NA crystal is 3 times that of pure naphthalene crystal. Naphthalene when doped with anthracene has high light output and fast principal decay constant (137Cs source), energy resolution of 18% (FWHM) has been recorded at room temperature for NA crystals coupled to a photomultiplier. The pulse height of NA is 10 times greater than the pure naphthalene crystal. The NA detector exhibited a good timing performance compared to trans-stilbene detector

  13. Neural networks in analysing 137Cs behaviour in the air in the Belgrade area

    Samolov Aleksandra D.

    2014-01-01

    Full Text Available The application of the principal component analysis and artificial neural network method in forecasting 137Cs behaviour in the air as the function of meteorological parameters is presented. The model was optimized and tested using 137Cs specific activities obtained by standard gamma-ray spectrometric analysis of air samples collected in Belgrade (Serbia during 2009-2011 and meteorological data for the same period. Low correlation (r = 0.20 between experimental values of 137Cs specific activities and those predicted by artificial neural network was obtained. This suggests that artificial neural network in the case of prediction of 137Cs specific activity, using temperature, insolation, and global Sun warming does not perform well, which can be explained by the relative independence of 137Cs specific activity of particular meteorological parameters and not by the ineffectiveness of artificial neural network in relating these parameters in general. [Projekat Ministarstva nauke Republike Srbije, br. TR34034

  14. 137Cs distribution and geochemistry of Lena River (Siberia) drainage basin lake sediments

    The Lena River is the second largest river that discharges into the Arctic Ocean. It is therefore important to determine not only the direct impact its discharge has on the 137Cs concentration of the Arctic, but also the potential its drainage basin has as a 137Cs source. 137Cs surface sediment concentrations and inventory values, which range from 4.97 to 338 Bq kg-1 and 357 to 1732 Bq m-2, respectively, were determined for the Lena River drainage basin lake samples, via gamma analysis. The average geochemical and mineralogical composition of a subset of samples was also determined using neutron activation analysis, X-ray diffraction and X-ray fluorescence spectrometry techniques. Results of these geochemical analyses allowed for the identification of key geochemical factors that influence the distribution of 137Cs in the Lena River drainage basin. 137Cs profiles indicate that Lena River drainage basin lacustrine sediments serve as a record of 137Cs fallout. Based on the downcore 137Cs, %illite, %smectite, %Al and %Mn distribution patterns, it was concluded that a small fraction of non-selectively bound 137Cs was remobilized at depth in some cores. Inconsistencies between the actual 137Cs fallout record and the 137Cs profiles determined for the lake sediments were attributed to 137Cs remobilization in subsurface sediments. In addition to establishing the agreement between the global atmospheric fallout record and the downcore 137Cs distribution patterns determined for these sediments, results indicate that 137Cs deposited during periods of maximum atmospheric release was buried and is not susceptible to surface erosion processes. However, mean 137Cs concentrations of the lacustrine surface sediments (125 Bq kg-1) are still significantly higher than those of the nearby Lena River estuary (11.22 Bq kg-1) and Laptev Sea (6.00 Bq kg-1). Our study suggests that the Lena River drainage basin has the potential to serve as a source of 137Cs to the adjacent Arctic Ocean

  15. Evaluation of the calibration uncertainty of gamma radiation monitors using a 137Cs source

    This study shows all the relevant components to the calculation of the calibration uncertainty of gamma radiation area monitors performed by the Lab. Ciencias Radiologicas of UERJ . The uncertainty components will be related with their respective estimated values, details about the uncertainty components calculations of positioning and field homogeneity will be shown. There were obtained the values of 3,8 % and 5,8 % to the expanded uncertainty (k=2) for the dosimetry and for the area monitors calibration, respectively. (author)

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

    The aim of the present work is the study of 137Cs 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 137Cs 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, 137Cs 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 137Cs in the sediment column. The proposed model estimates the temporal variation of 137Cs activity concentration from 1987 (one year after the Chernobyl accident) till today (2014). - Highlights: • Two sediment cores were studied using 137Cs as a tracer. • Two peaks are observed due to nuclear tests and Chernobyl accident. • Diffusivities, as well as 137Cs apparent sedimentation speeds are estimated

  17. Variability of water content and of depth profiles of global fallout 137Cs in grassland soils and the resulting external gamma-dose rates

    137Cs from global fallout of nuclear weapon testings in the 1950s and 1960s was determined in successive layers (0-30 cm) of eight undisturbed grassland soils in Bavaria, Germany. The maximum activity concentration was found in soil layers between 4 and 15 cm below the surface. Using the vertical distribution of the cesium activity, which varied considerably from site to site, the mean residence half-time of 137Cs from global fallout in each soil layer was evaluated with a compartment model. These values ranged from 1.0 to 6.3 years/cm. The mean residence half-time averaged over all soil layers and all sites was 2.7±1.4 years/cm and, thus, about twice the corresponding residence half-time of the Chernobyl-derived 137Cs as determined in the same soil layers (also in 1993). The dose rate of the external gamma-radiation due to 137Cs from global fallout in the soil determined from the depth distributions varied between 0.34 and 0.57 (mean: 0.45±0.07) nGy/h per kBq/m2. The effect of soil water content on the dose rate was studied by considering four states of the soil, from water content zero to complete water saturation of the total pore volume. It was shown that the difference between the dose rates at the permanent wilting point and the field capacity, which both represent the most relevant water contents of soils, was only 10% of the dose rate at the permanent wilting point for all sites. (orig.)

  18. Variability of water content and of depth profiles of global fallout {sup 137}Cs in grassland soils and the resulting external gamma-dose rates

    Schimmack, W.; Bunzl, K. [Institute of Radiation Protection, GSF - National Research Center for Environment and Health, Neuherberg (Germany); Steindl, H. [Institute of Soil Ecology, GSF - National Research Center for Environment and Health, Neuherberg (Germany)

    1998-04-01

    {sup 137}Cs from global fallout of nuclear weapon testings in the 1950s and 1960s was determined in successive layers (0-30 cm) of eight undisturbed grassland soils in Bavaria, Germany. The maximum activity concentration was found in soil layers between 4 and 15 cm below the surface. Using the vertical distribution of the cesium activity, which varied considerably from site to site, the mean residence half-time of {sup 137}Cs from global fallout in each soil layer was evaluated with a compartment model. These values ranged from 1.0 to 6.3 years/cm. The mean residence half-time averaged over all soil layers and all sites was 2.7{+-}1.4 years/cm and, thus, about twice the corresponding residence half-time of the Chernobyl-derived {sup 137}Cs as determined in the same soil layers (also in 1993). The dose rate of the external gamma-radiation due to {sup 137}Cs from global fallout in the soil determined from the depth distributions varied between 0.34 and 0.57 (mean: 0.45{+-}0.07) nGy/h per kBq/m{sup 2}. The effect of soil water content on the dose rate was studied by considering four states of the soil, from water content zero to complete water saturation of the total pore volume. It was shown that the difference between the dose rates at the permanent wilting point and the field capacity, which both represent the most relevant water contents of soils, was only 10% of the dose rate at the permanent wilting point for all sites. (orig.) With 4 figs., 2 tabs., 26 refs.

  19. Variability of water content and of depth profiles of global fallout 137Cs in grassland soils and the resulting external gamma-dose rates.

    Schimmack, W; Steindl, H; Bunzl, K

    1998-04-01

    137Cs from global fallout of nuclear weapon testings in the 1950s and 1960s was determined in successive layers (0-30 cm) of eight undisturbed grassland soils in Bavaria, Germany. The maximum activity concentration was found in soil layers between 4 and 15 cm below the surface. Using the vertical distribution of the cesium activity, which varied considerably from site to site, the mean residence half-time of 137Cs from global fallout in each soil layer was evaluated with a compartment model. These values ranged from 1.0 to 6.3 years/cm. The mean residence half-time averaged over all soil layers and all sites was 2.7 +/- 1.4 years/cm and, thus, about twice the corresponding residence half-time of the Chernobyl-derived 137Cs as determined in the same soil layers (also in 1993). The dose rate of the external gamma-radiation due to 137Cs from global fallout in the soil determined from the depth distributions varied between 0.34 and 0.57 (mean: 0.45 +/- 0.07) nGy/h per kBq/m2. The effect of soil water content on the dose rate was studied by considering four states of the soil, from water content zero to complete water saturation of the total pore volume. It was shown that the difference between the dose rates at the permanent wilting point and the field capacity, which both represent the most relevant water contents of soils, was only 10% of the dose rate at the permanent wilting point for all sites. PMID:9615340

  20. {sup 137}Cs in marine sediments of Admiralty Bay, King George Island, Antarctica

    Ferreira, Paulo Alves de Lima [Instituto Oceanográfico, Universidade de São Paulo (IO-USP), Pça. do Oceanográfico, 191, Butantã, SP, 05508 900 (Brazil); Ribeiro, Andreza Portella, E-mail: andrezpr@usp.br [Instituto Oceanográfico, Universidade de São Paulo (IO-USP), Pça. do Oceanográfico, 191, Butantã, SP, 05508 900 (Brazil); Mestrado de Gestão Ambiental e Sustentabilidade, Universidade Nove de Julho (UNINOVE), Avenida Francisco Matarazzo, 612, prédio C, andar térreo, Água Branca, São Paulo, SP, 05001 100 (Brazil); Nascimento, Mylene Giseli do; Martins, Cesar de Castro [Centro de Estudos do Mar, Universidade Federal do Paraná (CEM-UFPR), Av. Beira-mar, no number, Balneário Pontal do Sul, Pontal do Paraná, PR, 83255 971 (Brazil); Mahiques, Michel Michaelovitch de; Montone, Rosalinda Carmelo; Figueira, Rubens Cesar Lopes [Instituto Oceanográfico, Universidade de São Paulo (IO-USP), Pça. do Oceanográfico, 191, Butantã, SP, 05508 900 (Brazil)

    2013-01-15

    The radionuclide cesium-137 ({sup 137}Cs) is produced exclusively by anthropogenic processes and primarily by nuclear explosions. This study determined the reference inventory that is {sup 137}Cs associated with the element's original input, and utilized the levels of activity of this radionuclide previously measured in five sediment profiles collected from Admiralty Bay, Antarctica, to investigate the mobility of this element in the environment. {sup 137}Cs has a half-life of 30 years. Because of this, it is environmentally persistent and has been shown to accumulate in marine organisms. The mean reference inventory of this radionuclide in Admiralty Bay sediments, determined using high resolution gamma ray spectrometry, was 20.23 ± 8.94 Bq m{sup −2}, and within the ambient {sup 137}Cs activity range. A model of {sup 137}Cs diffusion–convection was applied to data collected from 1 cm intervals in sediment cores with the aim of providing insights with respect to this element's behavior in sediments. Model results showed a significant correlation between measured and modeled values using the concentrations of {sup 137}Cs, and estimated input into the system from the global fallout of past nuclear tests and expected values based on local sedimentation rates. Results highlight the importance of accounting for the vertical diffusion of {sup 137}Cs in marine sediments when used as a tracer for environmental processes and for assessing potential bioavailability. - Highlights: ► Cesium-137 ({sup 137}Cs) is produced exclusively by anthropogenic processes. ► A model of diffusion–convection simulated {sup 137}Cs environmental behavior. ► This is important for assessing the bioavailability of this toxic element. ► In Antarctica ice cover influenced the input to the sediments.

  1. 137Cs in marine sediments of Admiralty Bay, King George Island, Antarctica

    The radionuclide cesium-137 (137Cs) is produced exclusively by anthropogenic processes and primarily by nuclear explosions. This study determined the reference inventory that is 137Cs associated with the element's original input, and utilized the levels of activity of this radionuclide previously measured in five sediment profiles collected from Admiralty Bay, Antarctica, to investigate the mobility of this element in the environment. 137Cs has a half-life of 30 years. Because of this, it is environmentally persistent and has been shown to accumulate in marine organisms. The mean reference inventory of this radionuclide in Admiralty Bay sediments, determined using high resolution gamma ray spectrometry, was 20.23 ± 8.94 Bq m−2, and within the ambient 137Cs activity range. A model of 137Cs diffusion–convection was applied to data collected from 1 cm intervals in sediment cores with the aim of providing insights with respect to this element's behavior in sediments. Model results showed a significant correlation between measured and modeled values using the concentrations of 137Cs, and estimated input into the system from the global fallout of past nuclear tests and expected values based on local sedimentation rates. Results highlight the importance of accounting for the vertical diffusion of 137Cs in marine sediments when used as a tracer for environmental processes and for assessing potential bioavailability. - Highlights: ► Cesium-137 (137Cs) is produced exclusively by anthropogenic processes. ► A model of diffusion–convection simulated 137Cs environmental behavior. ► This is important for assessing the bioavailability of this toxic element. ► In Antarctica ice cover influenced the input to the sediments

  2. Genomic instability induced by 137Cs γ-ray irradiation in CHL surviving cells

    Objective: To study in parallel several possible manifestations of instability of surviving CHL cells after irradiation, namely the frequencies of mutation at locus, micronuclei and apoptosis. Methods: The frequencies of mutation at HGPRT locus, micronuclei and apoptosis were assayed at various times in surviving cells irradiated with γ-rays. Results: The surviving cells showed a persistently increased frequency of mutation at the HGPRT locus after irradiation until 53 days. Mutant fraction as high as 10-4 was scored, tens of times higher than those assayed in control cells studied in parallel. The frequency of bi nucleated cells with micronuclei determined within 24 hours after irradiation increased with dose and reached a peak value of (26.58 +- 2.48)% at 3 Gy, decreasing at higher doses to a plateau around 20%. The micronucleus frequency decreased steeply to about (14.47 +- 2.39)% within the first 3 days post-irradiation, and fluctuated at around 10% up to 56 days post-irradiation. The delayed efficiency of irradiated cells was significantly decreased. The frequency of apoptosis peaked about (24.90 +- 4.72)% at 10 Gy 48 h post-irradiation (γ-ray dose between 3-10 Gy) and then decreased to about 12% within 3 days. It was significantly higher than in control cells until 14 days. Conclusions: It shows that genomic instability induced by radiation can be transmitted to the progeny of surviving cells and may take many forms of expression such as lethal mutation, chromosome aberrations, gene mutation, etc

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

    In 2010–2012, an extensive study was performed in forest sites of Mount IDA (Kazdagi)/Edremit 26 years after the Chernobyl accident. The 137Cs 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 137Cs in OL horizons varied between 0.25 ± 0.14 and 70 ± 1 Bq kg−1, while the ranges of 137Cs 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 137Cs and the altitude was observed. The distributions of 137Cs activities in OL, OF + OH and A horizons throughout the region were mapped in detail. The highest 137Cs activities were found in OF + OH horizons, with markedly lower 137Cs activity in mineral horizons of soil profiles. It is observed that 137Cs content of humus layer increases with the thickness of the humus layer for coniferous forest sites. The 137Cs 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, 137Cs activity is keeping still high in the organic horizons. - Highlights: • 137Cs activity levels in the forested areas at the Mount IDA/Kazdagi were obtained. • Maps of 137Cs activities in the OL, OF+OH and A horizons were represented. • Activity concentrations of 137Cs in organic horizons varied from 13 to 555 Bq kg−1. • Deposited 137Cs is still present in the surface layers of the forest soils

  4. Radiochemical determination of 137Cs in foods

    A determination of radionuclides in food samples is important in commodities in order to attend to regulatory requirements for international trade. As a long-lived radioisotope of cesium, 137Cs is produced as a result of human nuclear activities and than its contamination level evaluation among others radionuclides in foods is necessary. A methodology for the determination of 137Cs in foods, pork and fish, is described. The procedures covered homogenization and freeze-drying of the samples. The 137Cs was measured by gamma spectrometry using Canberra 50% HPGe detector. The counting was carried out with Monte Carlo software for detection conditions optimization including geometry and chemical data information. A certified sample, SRM IAEA-375, was analyzed in order to evaluate the reliability of the method, and the results showed good agreement between the measured and certified values. (author)

  5. Analysis of 226Ra, 232Th 40К and 137Cs in samples of soil from some areas of Republic of Macedonia by using gamma spectrometry

    Todorovik Aleksandra

    2012-01-01

    Full Text Available Taking into consideration the importance of the distribution and transfer of radio nuclides in soil, an attempt was made in this work to determine the concentration of 226Ra, 232Th 40К and 137Cs in the same. The concentrations of activity in the gamma-absorbed dose rates of the terrestrial naturally occurring radio nuclides, as follows, 226Ra, 232Th and 40K were determined in samples of soil collected from some parts of Republic of Macedonia, i.e. from three major cities in the Republic of Macedonia. The samples are taken by means of a special dosage dispenser which enables sampling of samples at a depth of 0-5 cm, 5-10cm and 10-15cm, thus disabling the sampling above these layers of soil. An identification of radio nuclides and assessment of their activity has been performed by applying gamma spectrometry. The time of counting for each sample was 65000 s. in order to obtain statistically small mistake. The spectrums were analyzed by a commercially available software GENIE-2000 received from Canberra, Austria. The activity of soil had wide range of values: 20.3 to 82.9 Bq kg-1for 226Ra, 16.1 to 82.5 Bq kg-1 for 232Th, 325 to 799.0 Bq kg-1for 40К and 9.1 to 24.3 Bq kg-1for 137Cs, respectively. The concentrations of these radio nuclides have been compared with the available data from the other countries. Natural environmental radioactivity and the associated external exposure due to gamma radiation depend primarily on the geological and geographical conditions. Namely, the specific levels of terrestrial environmental radiation are related to the type of rocks from which the soils originate. The obtained data indicate that the average value of activity of 232Th is about higher than the one of 226Ra The concentration of activity of 40К in the soil has greater value than 32Th and 226Ra in all soils. The causes for the existence of 137Cs in these soils are the nuclear explosions, waste radioactive materials and other incidents. It reaches the

  6. Simulation smuggling study for shielded sources of 235U, 238U, 232Th, 137Cs and 60Co by using gamma detection

    In the present time, smuggling and illicit trafficking of nuclear and radioactive materials are targeted by international groups and networks. Hundreds of smuggled nuclear and radioactive materials have been seized and currently recorded in the Illicit Trafficking Database (ITDB) of the International Atomic Energy Agency (IAEA). As a matter of fact, these materials can be used for manufacturing of dirty or Radiological Dispersal Device (RDD) or for sabotage and malicious purposes. This work deals with gamma detection of shielded sources containing natural 235U , 238U , standard 232Th and mixed 137Cs and 60Co sources by using HpGe and NaI detectors. The detection was carried out through the main characteristic γ- energies ; 185.7 KeV for 235U ,(63.3 ,1001 KeV) for 238U , (583 and 911.2 KeV) for 232Th, 661.6 KeV for 137Cs and (1173.2 and 1332.5 keV) for 60Co. The radioactive sources used are 30nCi of 232Th , 1.99 μCi of mixed 137Cs and 60Co source and uranyl nitrate crystals. These radioactive sources were separately hid (placed) in containers of different materials; aluminum (Al) , cupper (Cu) and iron (Fe) of different wall thickness; 3, 6, 9, 12, 15, 18 mm. The sources were also measured together by NaI and HpGe detector. Overlapping of different gamma transitions leads to some difficulties to identify and discriminate between the investigated γ-energies particularly with using the low resolution NaI detector. The attenuation factors (I/Io), ratio of radiation intensity with and without shield (containers), were calculated for all the investigated energies. The relationship between the attenuation factor of γ-energies and the studied thickness was depicted and discussed. It was observed, as expected, that the studied gamma transitions were attenuated by the used different thickness of Fe, Cu and Al and hardly detected especially for low energy and at 18mm thickness. Generally, it can concluded that radioactive materials of small activity can easily be smuggled

  7. Comparisons of the standards for air kerma of the PTB and the BIPM for 60Co and 137Cs gamma radiation

    Direct comparisons of the standards for air kerma of the Physikalisch-Technische Bundesanstalt (PTB, Germany) and of the Bureau International des Poids et Mesures (BIPM) were carried out in the 60Co and 137 Cs radiation beams of the BIPM in 2000. The results, expressed as ratios of the PTB and the BIPM standards for air kerma, indicate a relative difference in 60Co of 9.9 x 10-3 with a combined standard uncertainty of 1.8 x 10-3, and in 137Cs of 6.4 x 10-3 with a combined standard uncertainty of 2.8 x 10-3. The earlier comparisons in 60Co γ rays made in 1971 (direct) and 1989 (indirect) resulted in an agreement of the two standards within 2 x 10-3. The differences obtained now are due to the application of new correction factors for wall effects and point source non-uniformity of the beam, kwall and kpn, for the PTB standards, which were calculated using Monte Carlo methods. (authors)

  8. Estimating and accounting for 137Cs source burial through in situ gamma spectrometry in salt marsh environments

    The use of in-situ gamma ray spectrometry provides a means of rapidly estimating environmental radioactivity inventories. However, one of the principal limitations of this technique has been the influence of variations in vertical activity distribution on the observed photon fluence. This paper demonstrates that the quantification of the forward scattered ratio of the spectrum (Q) can be used to: (i) estimate the mean mass depth (β) of the vertical activity distribution within sediment profiles, and (ii) provide a calibration correction coefficient for in-situ gamma spectrometry in environments which exhibit variable and non-exponential activity distributions, such as salt marshes around the Irish Sea

  9. 137 Cs content of some honey products in the period 1993-1998

    In this work, the 137 Cs content in some honey products collected from Arges and Sibiu zones in the period 1993-1998 is determined. The gamma ray measurements were carried out for 18-28 hours by means of a HPGe (EG/G ORTEC) detector of 30% relative efficiency and 2.1 KeV resolution for the 60 Co 1332.5 KeV gamma ray. The samples were placed in a lead container with 10 cm thick walls. The IAEA-321 reference material with certified specific activities for 137 Cs was used to check the analysis quality. The results were expressed in Bq/kg and Bq/l as appropriate. Comparisons with the measurements performed previously were done. The 137 Cs content of the analyzed samples depends on product, type and collecting time. The activity levels in honey increased in 1994, as compared to 1993 and 1995-1997, to 0.8 Bq/kg. The 137 Cs concentration in propolis is 5-10 times higher than that in honey. Compared to '80 period, the 137 Cs concentration in honey products is diminished. (authors)

  10. Monte Carlo simulation algorithm for pileup effect of pulses in gamma spectroscopy and pileup distortion calculation on 137Cs pulse height spectrum in NaI(Tl detector

    AA Mowlavi

    2011-12-01

    Full Text Available  In this paper, an algorithm base on Monte Carlo simulation for pileup effect in gamma spectrum of a detection system is presented whose its code was written in FORTRAN language. The code can be run in paralayzable and nonparalazable mode to obtain the pileup distortion and value of pulses pileup for any detection system. The result show, that the computed spectrum of 137Cs is in good agreement with the experimental spectrum in NaI(Tl detector. The free of pileup free spectrum and sub-spectra with different degrees of pulses of pileup are calculated. Also, we can apply it to different sources and detectors for pileup correction.

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

    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. {sup 137}Cs contamination in tea and yerba mate in South America

    Di Gregorio, D.E. E-mail: digregorio@tandar.cnea.gov.ar; Huck, H.; Aristegui, R.; De Lazzari, G.; Jech, A

    2004-07-01

    Gamma-ray spectra from more than 50 samples of food products available in stores of Buenos Aires city were measured using a germanium detector. Activity concentrations of {sup 137}Cs up to 10 Bq/kg were found in tea and yerba mate manufactured in Apostoles, Argentina. Further measurements of tea leaves, yerba mate leaves and soils, all coming from a cultivated area in that region, also show the presence of {sup 137}Cs contamination. The results suggest that the area was fertilized with a product that originated in a region affected by the fallout from the Chernobyl nuclear plant accident.

  13. {sup 137}Cs and relationships with major and trace elements in edible mushrooms from Mexico

    Gaso, M.I.; Segovia, N.; Cervantes, M.L.; Pena, P.; Acosta, E. [ININ, Ap. Post 18-1027, 11801 D.F. Mexico (Mexico); Morton, O. [IGF-UNAM, Ciudad Universitaria, 04510 D.F. Mexico (Mexico); Godinez, L. [IG-UNAM, Ciudad Universitaria, 04510 D.F. Mexico (Mexico)

    2000-10-30

    {sup 137}Cs and {sup 40}K specific activity together with major and trace elements were determined in soil samples and in different edible wild mushroom species collected from a seminatural temperate forest ecosystem located in the central part of the Mexican Volcanic Belt. The activity measurements were made using a gamma-ray spectrometer system with a high purity germanium (HpGe) detector. The major and trace elements were determined using emission spectrography and mass spectrometry, respectively. The aggregated transfer factors for 137Cs were estimated in 30 local mushroom species collected from 1993 to 1999. Differences as large as three orders of magnitude were observed. The contribution of mushrooms for the total 137Cs dietary intake by the local population was estimated to be 37%. Mushrooms also showed to be good accumulators for Rb, Cu, Cs and Se.

  14. 137Cs and relationships with major and trace elements in edible mushrooms from Mexico

    137Cs and 40K specific activity together with major and trace elements were determined in soil samples and in different edible wild mushroom species collected from a seminatural temperate forest ecosystem located in the central part of the Mexican Volcanic Belt. The activity measurements were made using a gamma-ray spectrometer system with a high purity germanium (HpGe) detector. The major and trace elements were determined using emission spectrography and mass spectrometry, respectively. The aggregated transfer factors for 137Cs were estimated in 30 local mushroom species collected from 1993 to 1999. Differences as large as three orders of magnitude were observed. The contribution of mushrooms for the total 137Cs dietary intake by the local population was estimated to be 37%. Mushrooms also showed to be good accumulators for Rb, Cu, Cs and Se

  15. Cumulative deposition of 137Cs in the soil of Korea

    The cumulative deposition of 137Cs in the soil of Korea has been studied. Using γ-ray spectrometry, the concentrations of 137Cs were determined for the soil samples collected to a depth of 20 cm. The average accumulated depositions of 137Cs were estimated roughly to be 2,501 ±499 Bq m-2 in the forest and 1,058 ±322 Bq m-2 in the hill. The inventory value of 137Cs in the forest is about two times higher than that in the hill. Except for some cases, the concentrations of 137Cs in the undisturbed soils decreased exponentially with increasing the soil depth. The influences of rainfall, organic matter content, clay content and pH on the deposition of 137Cs were studied using the field method. Among these factors, the organic matter content played the most important role in the retention and relative mobility of 137Cs in the soil. The other factors such as rainfall, clay content and pH showed weak correlation with the deposition of 137Cs in the soil

  16. Methodology of the 137 Cs for the soil erosion and deposition determination in a micro basin from the north of Parana State

    The measurement of 137 Cs redistribution in the field allows the determination of soil erosion/accumulation. The 137 Cs activity of soil samples, taken from a small basin at the North of Parana, were measured employing a HPGe gamma ray detector and a standard spectrometric nuclear electronic chain. Standard oil samples with known concentrations of 137 Cs were prepared for the detection efficiency determination. Soil loss or gain was measured at the top, midslope and low slope regions, for six different transects at the investigated small basin. (author)

  17. Study on dose-response relationship between prenatal exposure to 137Cs γ-ray and the developmental retardation of brain in rats

    The developmental retardation of brain in rats induced by prenatal exposure to 137Cs γ-rays had observed by measuring the five indexes reflecting changes in structure, function and biochemical substance of central nervous system. The results showed that when dose accumulatively absorbed by the offsprings was 0.07-2.7 Gy, with increase in the dose their cerebral weight was lightened, the cerebral ordinate length was reduced, the development of swimming function was delayed, the contents of eight kinds of free amino acids in the cerebrum were increased, the number of pyramidal cells in cerebral cortex was decreased as well as the relationship between percentages of the changes in the five indexes and logarithm absorbed doses (Gy) give a good fit to liner regression equation Y = A + BlgD

  18. Neoplastic transformation in BALB/3T3 cells induced by 137Cs γ-rays and assessment of chromosome aberrations and unscheduled DNA synthesis

    The results of this study show that the neoplastic transformation in BALB/3T3 cells can be induced directly by exposure to 137Cs γ-rays. Transformation frequencies for type II and III foci in the 1, 3 and 5 Gy irradiated groups are 14.56, 25.08, and 24.81 x 10-3, respectively, while that in the control group is 1.4 x 10-3. The killing effect of radiation leads to reduction of transformation frequency in the 5 Gy group. Chromosome aberrations in first post-exposure mitosis are 13.5, 22.05 and 41.05 per cent for 1, 3 and 5 Gy groups, respectively, being significantly higher than that in the control (1.5 per cent, P3H-thymidine show that UDS in cells increase significantly with the dose after exposure while no change in sister chromatid exchange is observed

  19. 137Cs metabolism during pregnancy

    Data from two pregnant women contaminated with 137 Cs, body burdens of 0.2 and 300 MBq, respectively, at the time of the Goiania accident, were compared. The first one, with lower 137 Cs body burden was exposed during the fourth month of pregnancy, while the second became pregnant three years and eight months after 137 Cs intake. For the first woman 137 Cs concentrations were similar for the mother, infant and placenta, indicating an easy and homogeneous transport of 137 Cs from mother to fetus. The whole-body monitoring data from the second woman, who became pregnant four years after intake, did not show a reduction in biological half-life during the pregnancy. Cs concentration in the mother was found to be 13 times higher than in the infant. One possible reason for this result is that four after intake. Cs is supposed to be concentrated mainly in skeletal muscle tissue. During the pregnancy the blood flux becomes higher in most of organs and tissues except brain, liver and skeletal muscle tissue. In this case, the physiological changes due to pregnancy did not modify the cesium retention. (author)

  20. Methodology of the {sup 137} Cs for the soil erosion and deposition determination in a micro basin from the north of Parana State; Metodologia do {sup 137} Cs para determinacao da erosao e deposicao de solo em uma microbacia do norte do Parana

    Andrello, Avacir Casanova

    1997-12-31

    The measurement of {sup 137} Cs redistribution in the field allows the determination of soil erosion/accumulation. The {sup 137} Cs activity of soil samples, taken from a small basin at the North of Parana, were measured employing a HPGe gamma ray detector and a standard spectrometric nuclear electronic chain. Standard oil samples with known concentrations of {sup 137} Cs were prepared for the detection efficiency determination. Soil loss or gain was measured at the top, midslope and low slope regions, for six different transects at the investigated small basin. (author) 47 refs., 31 figs., 11 tabs.

  1. The Role of Prussian Blue in Eliminating the Compositional Effects of 137Cs Internal Contamination

    Seventy male albino rats of two ages: growing (2-months age, 102 + 10 g /rat) and adults (4- months age, 280 + 15 g / rat) were used in this study. The rats were fed on a balanced diet (21% crude proteins, 3% crude fats and 4% crude fibers). The treatments of oral administration of a single dose (3700 Bq/growing rat and 7400 Bq/adult rat) of 137Cs (137Cs Cl salt) and prussian blue (PB, 300 mg/kg body weight/day for 60 days) were as the following combinations: [1] without 137Cs or PB, [2] 137Cs only, [3] PB only, [4] PB one day before 137Cs, [5] PB immediately after 137Cs, [6] PB one day after 137Cs, and [7] PB one week after 137Cs. All of body weight, total body water (TBW), fat-free body (FFB), total body fat (TBF), fat-free dry body (FFDB), total body protein (TBP), and total body ash (TBA). The data revealed that: adult rats had a significant (P137Cs treatment caused decreases in final body weight; % change of body weight, TBW, FFB, FFDB, TBP, TBA. In both growing and adult rats, PB administration, only before or at the same time of irradiation, could eliminate the effects of 137Cs-gamma irradiation on : final body weight, % change in body weight, FFB, FFDB, TBP. However, PB administration, one or seven days post treatment, eliminated 137Cs treatments effects on TBF

  2. Estimation of erosion rate using natural isotop 137Cs

    The investigation of erosion rate using natural isotope 137Cs had been done in hilliness area at GOULBURN-NWS-Australia. The presentation of 137Cs in natural was as a result of nuclear weapon testing in the middle of 1950's. Fallout of 137Cs input, when it reached the ground, it rapidly adsorbed at the soil. 137Cs bind very strong at the fine soil, so it can be used as tracer in the study of soil movement. Soil samples were taken using coring device (di=10 cm, h=20 cm), and were brought to laboratorium for short commun analysis. The preparation are drying, weighing, crushing and sieving. The 137Cs content of fine samples that pass the 1 mm sieve were analyzed using gamma-spectrometer. The total erosion rate was calculate by ploting the 137Cs values in the topography map of study area. The result showed that erosion was very low, and total erosion rate is 130 kg/ha.y. (authors)

  3. Mapping of 137Cs in Ida-Virumaa, June 2005. CGS Area Specific Spectrum Stripping and ESC from soil sampling

    Aage, Helle Karina; Korsbech, Uffe C C

    This report describes some results from a Baltic-Danish exercise with carborne gamma-ray spectrometry (CGS) measurements performed in Estonia in the summer of 2005. The goal was to measure the low level of contamination with 137Cs that still exists as part of the fall-out from the Chernobyl accid...

  4. 137Cs and 40K in the flesh of fish of the Indian Ocean and the Straits of Malacca

    The flesh of fish obtained from fishing industries based in Penang was dried and analyses for 137Cs and 40K concentration by gamma-ray spectrometry. Results for tuna, bluefin, round scad, prawns and anchovy are listed. Values of 137Cs concentration in the larger fish were very similar, about 9pCi/wet kg. 40K values varied between 0.6 and 3.9 nCi/wet kg with an average of 3.1 +- 0.3 nCi/wet kg for tuna. Results are compared with those reported for fish caught in other areas. The highest value of 137Cs activity found represents less than 0.4% of the value determined for natural 40K. (author)

  5. Separation of 137Cs from nuclear waste

    Sodium zirconate is one member of a family of new inorganic ion exchange materials which have high affinity for all actinides and fission product cations except for Cs+. A combination of cold, tracer and high level liquid waste experiments with sodium zirconate has shown that 70 to 80 and 80 to 100% of the Cs+ in high level liquid waste remains in solution following batch or column equilibration, respectively. The fact that 137Cs can be obtained in relatively pure form permits subsequent conversion directly to an insoluble radiation source. This is of prime importance in areas such as sewage sludge sterilization via γ-ray irradiation. (author)

  6. Study of calibration equations of 137Cs methodology for soil erosion determination

    Using the method of 137 Cs and gamma-ray spectrometry, soil samples of two plots erosion were studied at Londrina city. the soil class studied was a dystrophic dark red soil (LRd), with erosion indexes measured by Agronomic Institute of Parana State (IAPAR) using a conventional method, since 1976. Through the percentage reduction of 137 Cs related to the reference site, the soil losses were calculated using the proportional, mass balance and profile distribution models. Making the correlation between the 137 Cs concentrations and the erosion measured by IAPAR, two calibration equations were obtained and applied to the data set measured in the basin of the Unda river and compared to those models in the literature. As reference region, was chosen a natural forest located close to the plots. The average inventory of 137 Cs was 555± 16 Bq.m-2. The inventories of the erosion plots varied from 112 to 136 Bq.m-2 for samples collected until 30 cm depth. The erosion rates estimated by the models varied from 64 to 85 ton.ha-1.yr-1 for the proportional and profile distribution models, respectively, and 137 to 165 ton.ha-1 for the mass balance model, while the measured erosion obtained by IAPAR was 86 ton.ha-1.yr-1. From the two calibration equations obtained, the one that take into account the 137 Cs distribution with the soil profile was that showed the best consistence with the erosion rated for the basin of the Unda river (same soil class) in the range from 4 to 48 ton.ha-1.yr-1, while the proportional and profile distribution models applied rates from 7 to 45 ton.ha-1.yr-1 and 6 to 69 ton.ha-1.yr-1, respectively. (author)

  7. Radiochemical determination of {sup 137}Cs in foods

    Kastner, Geraldo F.; Ferreira, Andrea Vidal; Monteiro, Roberto P.G., E-mail: gfk@cdtn.br, E-mail: avf@cdtn.br, E-mail: rpgm@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    A determination of radionuclides in food samples is important in commodities in order to attend to regulatory requirements for international trade. As a long-lived radioisotope of cesium, {sup 137}Cs is produced as a result of human nuclear activities and than its contamination level evaluation among others radionuclides in foods is necessary. A methodology for the determination of {sup 137}Cs in foods, pork and fish, is described. The procedures covered homogenization and freeze-drying of the samples. The {sup 137}Cs was measured by gamma spectrometry using Canberra 50% HPGe detector. The counting was carried out with Monte Carlo software for detection conditions optimization including geometry and chemical data information. A certified sample, SRM IAEA-375, was analyzed in order to evaluate the reliability of the method, and the results showed good agreement between the measured and certified values. (author)

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

    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. (authors)

  9. 137Cs in freshwater fish in Finland

    The paper deals with an evaluation of the importance of Finnish freshwater fish as a source of 137Cs in the diet. Freshwater fish were analysed for 137Cs in 1982. The 137Cs concentration factors from water to edible fish were determined for the same year. The evaluation is based on an extensive surface water investigation performed from 1965 to 1967. Along with the continuous fallout monitoring since the beginning of the 1960'es, this material makes it possible to valuate the 137Cs levels in surface water right up to the 1980'es. In 1982 the Finns received an average of 90 Bq 137Cs from freshwater fish. This dose constitutes a quarter of the 137Cs uptake from the total food consumtion in Finland in 1982

  10. Standardization of /sup 137/Cs - some remarks on the efficiency function

    Ballaux, C. (Centre d' Etude de l' Energie Nucleaire, Mol (Belgium))

    1983-08-01

    A solution of /sup 137/Cs has been standardized by means of 4..pi..(NaI(Tl)) integral counting and by 4..pi..(PC)-..gamma.. efficiency tracing and extrapolation with /sup 134/Cs as tracer. Both methods giving nearly equal results, a ..gamma..-ray-emission probability per decay of 0.8516 +- 0.0020 is deduced for the 661.6-keV transition of sup(137m)Ba. The ..beta..-ray spectra of both cesium isotopes have been calculated in order to attempt to interpret the efficiency function.

  11. Uptake and transfer factors of 137Cs by mushrooms

    The 137Cs content of 118 species (668 samples) of higher fungi collected in the period from August 1984 to October 1989 at three different locations in Styria, Austria, was determined by gamma-spectrometry. The Cs-content of most mushrooms has been increasing since September 1986. In order to find out which factors determine the 137Cs-contamination of mushrooms and the transfer-value soil to mushroom, the concentration of total and plant-available radiocesium in soils as well as the pH-value, the content of humus, clay, silt, sand, exchangeable cations, the composition of the clay minerals, and the particle size distribution of the soils of two different locations were examined. The higher the 137Cs contamination of the soil, the thicker the layer of humus and the higher the content of humus, the lower the pH-value, and the lower the amount of essential cations, especially of K+, the higher the amount of 137Cs plant-available will be. Therefore, the contamination of the mushrooms in the coniferous forest of Koralpenblick (1000 m) is higher than in the mixed forest at the Rosenberg around Graz at approx. 500 m height. Of 26 different species of mushrooms measured at both sites, only 61% show the highest TF-values soil to mushrooms also at the Koralpenblick. In the spruce forest at Koralpenblick there are many species of mushrooms with high 137Cs-contamination which were not found at the Rosenberg. However, the properties of the species to which a mushroom belongs are more important than environmental conditions and soil properties. The transfer values of 40K stay within narrow bounds, whereas those of 137Cs differ widely. (orig.)

  12. Assessment of 137Cs Activity Concentration in Soil from Tea Plantation Areas in Cameron Highlands

    137Cs is well known man-made radionuclide produced from nuclear industry. Nuclear weapon tests and nuclear accidents had contributed to presence of 137Cs into the worldwide environment including Malaysia. It has spread out to the entire world through the air and water current. Since Cameron Highlands is located at high altitude, there is a better chance of the 137Cs to settle down on the trees and later the soil underneath. In this study, the soil samples were taken at the slopes of two different tea plantation areas namely A and B. The soil samples were oven dried, ground, sieved and packed and sealed properly in plastic containers before measurement. Each plastic container contains around 450 g of sample. The measurement of 137Cs activity concentration was done using HPGe detector gamma spectrometer. The spectrum was analyzed using Gamma Vision software to calculate the activity concentration of 137Cs with energy peak of 661.66 keV. The activity concentration of 137Cs found in the samples ranged from 0.23 to 1.90 and 0.11 to 3.01 Bq/ kg for tea plantation A and tea plantation B, respectively. From the activity concentration of 137Cs result, it was comparable to the others research regarding to 137Cs in the soil around Asian. (Author)

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

    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-κB), 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-κB) activation were also determined in cells at 1 and 4 hrs following irradiation (indicative of early responses)

  14. 137Cs in northern Adriatic sediments

    The activity of 137Cs in shallow northern Adriatic sediments was obtained on the basis of measurement results from 25 sediment box cores, sampled during the Adriatic Scientific COoperation Program (ASCOP) 16 cruise in the summer 1990. 137Cs was determined in surface sediments (0-3 cm) and 12-15 cm-deep sediment. It was found that the lowest caesium concentrations correspond to sands, which are spread along the Croatian coast. Parallel to the Italian coast, 137Cs concentrations in pelites are the highest. It seems that the influence of Po River is significant for 137Cs activities in recent marine sediments along Italian coast south of Po River delta. Significantly higher 137Cs activities in 0-3 cm sediment layer can be attributed to the deposition caused by Chernobyl accident. (author)

  15. Desorption of 137Cs+ from mosses

    OLGICA NEDIC

    2002-09-01

    Full Text Available Mosses are biomonitors that accumulate large amounts of various pollutants, including radionuclides. In this work we investigated the possibility of 137Cs extraction from mosses, as well as the significance of species specificity on the efficiency of 137Cs desorption. Salt and acid solutions were used as extraction media. It was shown that a 5 % solution of both ammonium oxalate and phosphoric acid was able to desorb 81.8 % of 137Cs+ from Homalothecium sericeum, which was 39.9 % more than desorption from water. At the same time, most of the desorbed 137Cs+ was incorporated in crystals that precipitated from the solution. An interspecies difference in respect to 137Cs+ desorption was noticed.

  16. Study on the effectiveness of some decontamination agents against skin contamination of {sup 137}Cs and {sup 60}Co

    Chon, Je Keun; Ji, Pyung Kook; Kwak, Sang Soo; Kim, Byung Tae; Park, Chong Mook [Nuclear Environment Technology Institute, Taejon (Korea, Republic of)

    1998-03-01

    In order to evaluate the effectiveness of some decontamination agents against skin contamination of {sup 60}Co and {sup 137}Cs, the experiments were carried out in this study. In the experiments, pig skin was used instead of human skin, {sup 60}CoCl{sub 2} and {sup 137}CsCl were used the liquid sources of skin contamination. To examine the effectiveness of decontamination agents, skin decontamination was tried using soup, EDTA, DAERICON which was developed for decontamination of radionuclides on the surface of building structure, and new decontamination agents such as IOCON, TRICON, and CHARCON, which were developed in this study. The absorption of radionuclides through the skin was evaluated by the gamma-ray detection on the surface of sample skin after radionuclides were penetrated into the skin during 16 hour soiling time. The results of this absorption experiment indicated that 11.5% and 3.2% of initial amounts of {sup 137}Cs and {sup 60}Co, respectively, were penetrated into the skin. In the experiment to remove the residual radioactivity fixed on the skin, KAERICON showed the decontamination rates up to 52.1%(decontamination factor of 2.1) and IOCON showed the equivalent decontamination rate (decontamination factor 1.9) for {sup 137}Cs. However, IOCON and CHARCON showed the poor decontamination rates of less than 20%(decontamination factor of 1.2) for {sup 60}Co, and KAERICON showed the poor decontamination rate (decontamination factor 1.1) for {sup 60}Co.

  17. Study on the effectiveness of some decontamination agents against skin contamination of 137Cs and 60Co

    In order to evaluate the effectiveness of some decontamination agents against skin contamination of 60Co and 137Cs, the experiments were carried out in this study. In the experiments, pig skin was used instead of human skin, 60CoCl2 and 137CsCl were used the liquid sources of skin contamination. To examine the effectiveness of decontamination agents, skin decontamination was tried using soup, EDTA, DAERICON which was developed for decontamination of radionuclides on the surface of building structure, and new decontamination agents such as IOCON, TRICON, and CHARCON, which were developed in this study. The absorption of radionuclides through the skin was evaluated by the gamma-ray detection on the surface of sample skin after radionuclides were penetrated into the skin during 16 hour soiling time. The results of this absorption experiment indicated that 11.5% and 3.2% of initial amounts of 137Cs and 60Co, respectively, were penetrated into the skin. In the experiment to remove the residual radioactivity fixed on the skin, KAERICON showed the decontamination rates up to 52.1%(decontamination factor of 2.1) and IOCON showed the equivalent decontamination rate (decontamination factor 1.9) for 137Cs. However, IOCON and CHARCON showed the poor decontamination rates of less than 20%(decontamination factor of 1.2) for 60Co, and KAERICON showed the poor decontamination rate (decontamination factor 1.1) for 60Co

  18. 137Cs Transfer Factor from Latosol Soil to Swamp Gabbages (Ipomea Reptans Poir)

    A study of 137Cs transfer factor from Latosol soil to swamp cabbages plant has been conducted using pot treatment system with complete random design. The aim of the research is to determine transfer factor of 137Cs from latosol soil to swamp cabbages plant. Cs-137 concentration administered was 7.5287 kBq/pot. The number of swamp cabbages planted in 137Cs treated soil and in cannot soil respectively was 12 pots filled with 1 kg soil/pot. After harvest, the weight of dried plant was measured. Transfer factor was determined according to the accumulation of 137Cs concentration in swamp cabbages and soil and counted using Spectrometer Gamma. It was found that is a significant difference between 137Cs concentration in swamp cabbages planted inthe treated soil and that of control soil. Transfer factor ranges between 0.02 and 0.13 with the averageof 0.08. (author)

  19. Biokinetic model for 137 Cs

    The main objective of this work was to provide a realistic biokinetic model for 137 Cs metabolism. This model was based on the retention of cesium in 57 people contaminated in the Goiania accident, ages 1 to 73 y old, complemented by data obtained in an experiment with beagle dogs, and data taken from the open literature. Cesium is distributed among all tissues and organs of the body. Its main retention site is the skeletal muscle tissue. Mathematically, cesium retention in the body may be described by a sum of three terms exponential equation. The first term represents the fraction which is rapidly eliminated in urine. This fraction is weight dependent (negative correlation). The second term represents the retention of cesium in tissues and organs of the body. For children and adolescents, the second term biological half-life is a function of the weight. For adults, it is correlated with sex. Men present a higher retention of cesium than women. The third term correspond to a retention fraction of the order of 0,1% of the initial body burden. It is characterized by a very long half-life and represents a subcellular retention of cesium in the skeletal muscle tissue. During pregnancy the transfer factor from the mother to the fetus is correlated to the amount of cesium in the blood and it is equal to 1, if the intake of cesium occurs pregnancy. (author)

  20. 40K, 134Cs and 137Cs in pollen, honey and soil surface layer in Croatia

    Specific activities of 40K, 134Cs and 137Cs in pollen, honey and in the first 25 cm of the surface soil layer were measured by gamma-spectrometry. Specific activity of 40K in pollen is about 1 order of magnitude higher than in honey. A 40K soil-to-pollen transfer coefficient (TC(40K)) of 0.436 ± 0.054 and a soil-to-honey transfer coefficient TC(40K) of 0.052 ± 0.008 were calculated as the mean of their respective values in 26 different segments of soil profile. Both parameters have very stable values over time as well as through different segments of vertical soil profile. 134Cs and 137Cs specific activities in pollen and honey decrease with time, resulting in a decrease of 137Cs soil-to-honey transfer factors (Tf(137Cs)) over time. The increase of the soil-to-honey Tf(137Cs) with increasing soil depth is a consequence of vertical distribution of 137Cs in soil. Soil-to-honey T f(137Cs) values are highest in meadow and mixed honey types and lowest in bush/tree honey. Similar trends are found for both Tf(134Cs) and Tf(137Cs). The results presented here indicate the importance of the caesium inventory in soil segments where plant root systems are developed

  1. Radioactivity of 238U, 232Th, 40K, and 137Cs and assessment of depleted uranium in soil of the Musandam Peninsula, Sultanate of Oman

    SALEH, Ibrahim Hindawy

    2012-01-01

    238U, 232Th, 40K, and 137Cs radioactivities were determined in soil samples collected from the Musandam Peninsula, Sultanate of Oman, using a high resolution gamma-ray spectroscopy system. In addition, total uranium was measured in selected soil samples by inductively coupled plasma optical emission spectroscopy (ICP-OES). The averages of radioactivity levels in the soil for 238U, 232Th, and 40K were 14.42 Bq kg-1, 9.95 Bq kg-1, 158.21 Bq kg-1, and 2770 Bq m-2 for 137Cs, respectively...

  2. 137Cs concentration in stingray (Dasyatis akajei)

    137Cs, which is of great interest and importance as an indicator of radioactive pollution in marine environments, is one of the long-lived artificial radio-nuclides introduced by the atmospheric deposition of debris from nuclear explosions mainly before 1962. For the estimation of effects of the effluents from nuclear facilities, it is necessary to know the natural variations in the concentration of 137Cs and factors affecting variations in marine organisms. We observed positive correlation between growth and 137Cs in 4 species among 14 major teleost species from fishing grounds along the coast of Japan. No increase in 137Cs concentration with increase of growth was observed in 2 species. In the remaining species no specific correlation is observed. These differences in the patterns were dependent on a change of feed habits with growth. As little is known of the 137Cs concentration in selachian we have investigated the natural variations of 137Cs in stingray. The correlation between growth and the concentration of 137Cs in stingray will be discussed. (author)

  3. Effects of 137Cs γ-rays irradiation and NaN3 treatment on germination rate and protective enzyme activity for seeds of Phyllostachys heterocycla cv · Pubescens

    The seeds of Phyllostachys heterocycla cv · Pubescens were treated by using 137Cs γ-rays irradiation and NaN3, and the effects of two mutation methods on the germination rates and protective enzyme activities in the germinating seeds were investigated, and set up a theoretical foundation for mutation breeding of bamboo. The results showed that 10Gy irradiation could promote seed germination. As the dose increased, seed germination rate was significantly inhibited in the case of NaN3 treatment. This showed that a mutagenic effect of γ-rays was more obvious than that of NaN3. The effects of different doses of γ-rays and different concentrations of NaN3 on the protective enzyme activity were extremely significant. And the obvious changing point occurred at both low and high doses (concentrations). The protective enzyme activity could reflect the sensitivity. The LD50 for the 137Cs γ-rays radiation and NaN3 concentration were 95.9Gy and 0.16 mmol/L, respectively, which could be considered as the optimum dose (concentration) for mutation breeding of bamboo. (authors)

  4. Accuracy of field spectrometry in estimating 137Cs contamination in high altitude Alpine soils

    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 inhomogenetics 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. (author)

  5. Study of calibration equations of {sup 137}Cs methodology for soil erosion determination; Estudo de equacoes de calibracao para metodologia do {sup 137}Cs de determinacao da erosao de solos

    Santos, Elias Antunes dos

    2001-02-01

    Using the method of {sup 137} Cs and gamma-ray spectrometry, soil samples of two plots erosion were studied at Londrina city. the soil class studied was a dystrophic dark red soil (LRd), with erosion indexes measured by Agronomic Institute of Parana State (IAPAR) using a conventional method, since 1976. Through the percentage reduction of {sup 137} Cs related to the reference site, the soil losses were calculated using the proportional, mass balance and profile distribution models. Making the correlation between the {sup 137} Cs concentrations and the erosion measured by IAPAR, two calibration equations were obtained and applied to the data set measured in the basin of the Unda river and compared to those models in the literature. As reference region, was chosen a natural forest located close to the plots. The average inventory of {sup 137} Cs was 555{+-} 16 Bq.m{sup -2}. The inventories of the erosion plots varied from 112 to 136 Bq.m{sup -2} for samples collected until 30 cm depth. The erosion rates estimated by the models varied from 64 to 85 ton.ha{sup -1}.yr{sup -1} for the proportional and profile distribution models, respectively, and 137 to 165 ton.ha{sup -1} for the mass balance model, while the measured erosion obtained by IAPAR was 86 ton.ha{sup -1}.yr{sup -1}. From the two calibration equations obtained, the one that take into account the {sup 137} Cs distribution with the soil profile was that showed the best consistence with the erosion rated for the basin of the Unda river (same soil class) in the range from 4 to 48 ton.ha{sup -1}.yr{sup -1}, while the proportional and profile distribution models applied rates from 7 to 45 ton.ha{sup -1}.yr{sup -1} and 6 to 69 ton.ha{sup -1}.yr{sup -1}, respectively. (author)

  6. Transfer of 137Cs into mother's milk

    The concern of nursing mothers about the contamination of foodstuffs after Chernobyl prompted this investigation of radiocaesium transfer to mother's milk. Between May 1987 and December 1988, duplicates of daily food intakes, as well as the corresponding mothers' milk samples, were collected from 12 nursing mothers for two to four weeks in order to measure the 137Cs activity. Once during the collection period, the total-body activity of each of the mothers involved was measured. Based on our results, 137Cs is transferred into mother's milk not only directly from food intake but also from the accumulated body burden. Approximately 19% of the 137Cs activity from the daily food intake and about 13% of the specific 137Cs body activity of the mother are transferred into 1 litre of mother's milk. (author)

  7. Erosion and sediment deposition evaluation on a slope under pasture in Jandaia-GO using the '137Cs fallout' technique

    Water erosion is one of the main forms of soil degradation and among the diverse factors that affect it, two of great importance are the soil cover and slope. Estimates of sediment distribution rates associated to the different uses and soil management practices are scarce and the employed methods in these determinations are in general costly and time consuming. Rates of sediment redistribution evaluated by means of the 137Cs technique are based on the comparison of inventories of individual points of a given position and an inventory of reference, whose value represents the amount of 137Cs of 'fallout' origin that was added to the local site. This allows evaluating situations of losses and accumulations of sediments by the erosive process. The objective of the present work was to analyze the sediment production in a pasture area and to measure the efficiency of riparian forests in trapping the erosion sediments coming from pasture, through the '137Cs fallout' redistribution analysis. The study was carried out in Jandaia/GO, Brazil, in two dowslope transects located in a pasture area. Samples were taken from seven points of two 140 m long transects, as well as from three soil profiles of a 15 m transect in the downstream riparian forests of each transect. Soil profiles were sampled in three layers of 20 cm (0-20, 20-40 and 40-60). The soil samples were air dried, sieved and then analyzed for 137Cs activity by a gamma ray detector (GEM-20180P, EG and ORTEC) coupled to a multichannel analyzer at CENA/USP. The results indicate variations of 137Cs activity in soil profiles and high erosion rates to the riparian forest to the pasture areas of the two transects, showing sediment movement from the pasture area to the riparian forest, which suggests that the current width of the forest is not wide enough to trap the sediments produced upslope in the pasture area. (author)

  8. Distribution of 137Cs in soil samples of Goa environment

    Systematic studies on distribution of 137Cs in soil samples of Goa region have been carried out using gamma spectrometric technique. Soil samples were collected from different places of Goa region and studied their depth profile and seasonal variation of the activity. Efforts have been to find the correlation between this radionuclide concentration and the soil organic matter content and possible inferences were drawn. (author)

  9. Carborne Gamma-Ray Spectrometry. Calibration and Applications

    Aage, Helle Karina; Korsbech, Uffe C C; Bargholz, Kim;

    2006-01-01

    Calibration of carborne gamma-ray spectrometry systems for 137Cs is carried out with a source successively placed at 791 positions within an area of 34m  62m. A computer model supplements the measurements. Hereby a sensitivity map for a surface contamination is generated as well as line and area...

  10. 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 UO2

    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

  11. Distribution of norm and 137Cs in soils of the Visakhapatnam region, Eastern India, and associated radiation dose.

    Mohapatra, S; Sahoo, S K; Vinod Kumar, A; Patra, A C; Lenka, P; Dubey, J S; Thakur, V K; Tripathi, R M; Puranik, V D

    2013-11-01

    The specific activity of naturally occurring radioactive materials and (137)Cs in surface soils around the new Bhabha Atomic Research Centre site at Visakhapatnam region, Eastern India, has been determined using high-resolution gamma-ray spectrometry as part of a baseline radiological survey. Radiation hazard for the samples was assessed by radium equivalent activity (Raeq) and absorbed gamma dose rate (D). The mean absorbed gamma dose rate was found to be 104.9 nGy h(-1). The average annual effective dose equivalent was found to be 0.13 mSv y(-1). PMID:23620565

  12. The effect of soil sterilization on the 137Cs transfer from soil to radish (Raphanus sativus var. sativus). Transfer experiment involving sterilized soil

    Three different types of soil were collected at each of three locations: a persimmon orchard, an ume (Prunus mume, so to speak, 'a Japanese apricot') orchard, and a paddy field located 50-55 km northwest from Fukushima Daiichi Nuclear Power Plant. The goal was to investigate the involvement of microbes inhabiting these soils on the behavior of 137Cs. The soils were sterilized with gamma ray irradiation for 30 hours (absorbed dose of 60 kGy) or with high-pressure steam (autoclave sterilization) at 121°C for 20 minutes. A radish cultivar (Raphanus sativus var. sativus) was then cultivated in those soils for 45 days, and the harvested taproots and leaves were testing using a Ge semiconductor detector for concentration of 137Cs. The result showed that the concentration of 137Cs in radishes cultivated in the sterilized soils with autoclave sterilization or gamma ray irradiation were significantly higher than in those cultivated in the unsterilized soils. An increase in the plant available 137Cs could be caused by NH4+ arisen from the multiple effects of the structural change of the soil, decomposition of organic matter, and/or extinction of the microbes by sterilization. (author)

  13. Distributions of 137Cs and 210Pb in moss collected from Belarus and Slovakia

    In the present work, moss samples collected in Slovakia and Belarus were assayed with respect to gamma-emitting radionuclides. The results for 137Cs and 210Pb 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 137Cs 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 137Cs 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 137Cs carried out in Slovakia from 1977 until 2010. Measurements of the 210Pb concentration in moss samples collected over the territory of Slovakia showed, that the median value exceed 2.3 times median value of 210Pb obtained for Belarus moss. For that reason, the inhalation dose for man from 210Pb and 137Cs in Slovakia is more than twice as high as in Belarus, in spite of the initially very high 137Cs exposure in the latter country. -- Highlights: ► Belarus moss was used as a biological indicator of 137Cs and 210Pb. ► Comparison with concentration of 137Cs and 210Pb in moss from Slovakia. ► Moss samples reflect the original distribution of Chernobyl fallout in Belarus. ► Regular decrease of the annual average activity of 137Cs in surface air in Slovakia. ► Median concentration of 210Pb in moss from Belarus is 2.3 times lower than in Slovakia

  14. Spatial 137Cs distribution in forest soil

    This work presents the distribution of radioactive caesium in several types of forest soil originating from the Lesisko reserve (Opole Province, Poland). Vertical distribution of 137Cs isotope was determined in the profiles related to physicochemical properties of different types of soils and their location. Thickness of emerging genetic horizons, structure and morphology of soil profiles were determined. The highest 137Cs activities were found in Of and A horizons. At the same time, there was a sudden drop of 137Cs activity in mineral horizons of soil profiles. By analysis of caesium radioisotope content and its distribution in soil profiles significant correlations were observed between certain physicochemical properties (e.g. pH value, hydrolytic acidity, granulometric composition) of soils in selected forest habitats. (author)

  15. In vitro fertilization rate of mouse oocytes with spermatozoa from the F1 offspring of males irradiated with 1.0 Gy 137Cs γ-rays

    Previous studies suggest that the spermatozoa from acutely irradiated male mice exhibit a reduced fertilization rate in vitro with the maximum decrease occurring for spermatozoa produced 6 weeks after irradiation. We have found that spermatozoa from unirradiated F1 males conceived 6 weeks after paternal F0 irradiation also exhibit a significantly reduced fertilization rate in vitro. After acute 137Cs γ-irradiation yielding an absorbed dose of 1.0 Gy, adult CD1 F0 male mice were mated at weekly intervals with unirradiated female CD1 mice. Unirradiated adult males from F1 litters conceived 5 and 6 weeks after paternal F0 irradiation were allowed to mature. Their epididymal spermatozoa were evaluated for in vitro fertilization rates using oocytes from unirradiated 8-12-week-old CD1 females. The mean fertilization rate for spermatozoa from F1 males conceived 5 weeks after paternal F0 irradiation (80.74±15.74 SD %, n=5) did not differ significantly from the control fertilization rate (89.40±10.94 SD %, n=8). However, the fertilization rate for spermatozoa from F1 males conceived 6 weeks after paternal F0 irradiation (56.14±21.93 SD %, n=5) was significantly less than the fertilization rate for control spermatozoa (p1 males conceived 5 weeks after paternal F0 irradiation (p0 irradiation can transmit a decrease in fertilization rate to the F1 generation males as well as exhibit decreased fertilization rate themselves when tested directly in vitro

  16. Application of multiple gamma-ray spectrum for analytical chemistry

    Hatsukawa, Yuichi; Hayakawa, Takehito; Shinohara, Noboru; Oshima, Masumi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2000-01-01

    Feasibility of application of the multi-gamma ray spectrum for analytical chemistry was examined. A specimen in which some minor fission products are included was measured at an array of ten germanium detectors with BGO Compton suppressors, GEMINI, and multiple gamma-ray spectra are measured. Even in very strong radiation fields from {sup 137}Cs isotope, some miner contents, {sup 106}Ru, {sup 125}Sb, {sup 144}Pr, {sup 207}Bi were detected by this method. (author)

  17. 137Cs metabolism in pregnant women

    Data from two pregnant women contaminated with 137Cs, body burdens of 0.2 and 300 MBq, respectively at the time of the Goiania accident, were compared. The first one, with lower body burden was exposed during the fourth month of pregnancy, while the second became pregnant three years and eight months after 137Cs intake. For the first woman 137Cs concentrations were equal for the mother, infant and placenta, indicating an easy and homogeneous transport of 137Cs from mother to foetus. The whole body monitoring data from the second woman, who became pregnant four years after intake, did not show a reduction in biological half-life during the pregnancy. Cs concentration in the mother was found to be 13 times higher than in the infant. One possible reason for this result is that four years after intake, Cs is supposed to be concentrated mainly in skeletal muscle tissue. During the pregnancy the blood flux becomes higher in most of the organs and tissues except brain, liver and skeletal muscle tissue. (author)

  18. Monte Carlo simulation in quantitative determination of 137Cs in sand and water samples

    To understand the distribution of radionuclides in the high background area, one mainly needs to analyse sand, soil, water and other food stuff samples by gamma-spectroscopy. Due to interaction of photons emitted by these radionuclides within the sample, the underestimation of quantity of radionuclides in the sample cannot be ruled out. To overcome this situation, the Monte Carlo method to determine the effect of multiple scattering in Compton profiles has been extended to take better account of interaction of radiation with environmental samples. In this paper, we present the feasibility of Monte Carlo simulation in determining the absorption and multiple scattering of gamma-rays from 137Cs radionuclides in the sand and water samples. It is seen that only 67 % and 90 % photons escaped from the sand and water respectively, can be detected by nuclear spectroscopy techniques. The high percentage of photoelectric absorption and Compton scattering of photons in these samples warrant the underestimation of quantitative determination of 137Cs in these samples. (author)

  19. Determination of 137Cs contamination depth distribution in building structures using geostatistical modeling of ISOCS measurements

    Decommissioning of nuclear building structures usually leads to large amounts of low level radioactive waste. Using a reliable method to determine the contamination depth is indispensable prior to the start of decontamination works and also for minimizing the radioactive waste volume and the total workload. The method described in this paper is based on geostatistical modeling of in situ gamma-ray spectroscopy measurements using the multiple photo peak method. The method has been tested on the floor of the waste gas surge tank room within the BR3 (Belgian Reactor 3) decommissioning project and has delivered adequate results. - Highlights: • 137Cs depth contamination was determined using the multiple photo peak method. • Geostatistical modeling was used to determine treatment depth areas and perform risk analysis. • Results were evaluated using laser scanning and long term gamma-ray spectroscopy. • Waste volume reduction of about 1/3 compared to a more traditional approach

  20. A carborne gamma-ray spectrometer system for natural radioactivity mapping and environmental monitoring

    Grasty, R.L.; Cox, J.R. [Exploranium Ltd., Mississauga, Ontario (Canada)

    1997-12-31

    This paper summarizes the experience gained in the use of a carborne gamma-ray spectrometer system for mapping both natural and man-made radiation. Particular emphasis is placed on the calibration of the system for converting the gamma-ray measurements to ground concentrations of potassium, uranium and thorium and the activity of {sup 137}Cs. During the Finnish Emergency Response Exercise (Resume95), the carborne system was shown to be effective in mapping both natural and man-made radiation from {sup 137}Cs fallout and in locating radioactive sources. The application of the carborne system for mineral exploration is also demonstrated. (au). 10 refs.

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

    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

  2. Plutonium as a chronomarker in Australian and New Zealand sediments: a comparison with {sup 137}Cs

    Hancock, G.J., E-mail: gary.hancock@csiro.au [CSIRO Land and Water, Black Mountain Laboratories, GPO Box 1666, Canberra, ACT 2601 (Australia); Leslie, C. [CSIRO Land and Water, Black Mountain Laboratories, GPO Box 1666, Canberra, ACT 2601 (Australia); Everett, S.E.; Tims, S.G. [Department of Nuclear Physics, Research School of Physics and Engineering, The Australian National University, Building 57, Canberra, ACT 0200 (Australia); Brunskill, G.J. [84 Alligator Creek Road, Alligator Creek, Queensland 4816 (Australia); Haese, R. [Geoscience Australia, GPO Box 378, Canberra, ACT 2601 (Australia)

    2011-10-15

    The construction of high resolution chronologies of sediment profiles corresponding to the last 50-100 years usually entails the measurement of fallout radionuclides {sup 210}Pb and {sup 137}Cs. The anthropogenic radionuclide, {sup 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 {sup 210}Pb geochronology. However, while {sup 137}Cs usually provides a strong signal in sediment in the northern hemisphere, total fallout of {sup 137}Cs in the southern hemisphere was only 25% that of the north and the low activities of {sup 137}Cs seen in Australian and New Zealand sediments can make its horizon of first appearance somewhat arguable. Low {sup 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 {sup 137}Cs profiles and {sup 210}Pb geochronologies. We find that Pu has significant advantages over {sup 137}Cs, including greater measurement sensitivity using alpha spectrometry and mass spectrometric techniques compared to {sup 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 {sup 238}Pu/{sup 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 {sup 137}Cs due to its

  3. 137Cs in forest ecosystems in Estonia

    Full text: In the recently published 'Europe's Environment' (1995) one can find the map on 137Cs cumulative deposition in Europe after the Chernobyl accident (source: De Corte et al., 1990). On this map most of the Eastern Europe including Baltic Sea region is practically uncovered. In this reason we decided to present data on accumulation of 137Cs in the forest ecosystems in Estonia. Field sampling for current study has been conducted in 1986 - 1994. 137Cs concentrations were measured in different compartments of model trees, ground vegetation layers, debris and topsoil. The amount of 137Cs varied from 1.9 kBq/m2 in continental Estonia to 28.8 kBq/m2 in north-eastern Ne part of Estonia. The results obtained correspond to data presented in Wahlstroem et al., (1992) for Finland. According to the 'Europe's Environment' criteria northeastern Estonia belongs to the third cumulative deposition zone (10 to 32 kBq/m2). In Estonia the total deposition of 137Cs varies in the range from practically zero to 3.9 kBq/m2 . The calculations of Realo et al. (1994) back to May 1, 1986 gave figures from 0 to 21 kBq/m2. In macro lichens Cetraria, Cladina, Cladonia the rapid changes in 137Cs concentrations were observed: 0.06 - 0.18 kBq/kg in 1982-85, 0.93 - 6.23 kBq/kg in 1986-87, 0.27 -4.26 kBq/kg in 1988-89, 0.05 - 1.46 kBq/kg in 1990-91 and, finally, 0.03 - 0.46 kBq/kg in 1993-94. At the end of the observation period average value of the 137Cs concentrations was the same as maximum before the CRA and decline of the concentrations was 4 times during six years. Average concentrations of 137Cs in two common forest mosses Pleurozium shreberi and Hylocomium splendens was 0.43 kBq/kg of dry matter and in forest debris 0.38 kBq/kg. In 1986 the highest concentration in mushrooms - 16.6 kBq/kg was found in Lactarius sp. (Martin, L., et al., 1991). In 1991 samples of 41 different mushroom species from 63 sample sites mostly in Scots pine stands were analyzed. The highest concentration of

  4. Variation of 137 Cs and 40 K content in grass-milk-milk product system in Ocna Sibiu area in 1999

    In this work, the 137 Cs and 40 K content in sheep milk, sheep milk products and grass from Ocna Sibiu area in 1999 were determined. The gamma ray measurements were carried out for 18-28 hours by means of a HPGe (EG/G ORTEC) detector of 30% relative efficiency and 2.1 KeV resolution for the 60 Co 1332.5 KeV radiation. The samples were placed in a lead container with 10 cm thick walls. The IAEA-321 reference material (powder milk) with certified specific activities for 137 Cs and 40 K were used to check the quality of analysis. The results were expressed in Bq/kg and Bq/l as appropriate. The concentration of 137 Cs in grass is about 5 times higher than that in the analyzed milk products. Also, a higher concentration is put into evidence in boiled and unboiled whey than that in milk and cheese. The 40 K concentration is about 25 times higher in grass than in the analyzed milk and milk products, while it is 2 times higher in boiled and unboiled whey than in milk and cheese. The 137 Cs concentration in grass, milk and milk products is lower as compared to that found in 80' period. (authors)

  5. Transfer factor of 137Cs from soil to wheat grains and dosimetry around Narora Atomic Power Station, Narora, India

    This field study was undertaken to quantify the transfer factor of 137Cs from agricultural soil to wheat grains and ingestion dose evaluation around Narora Atomic Power Station, Narora, India from 2010 to 2012. 137Cs activity was measured using NaI (Tl) well type gamma-spectrometry system. Transfer factor of 137Cs from soil to wheat grain samples was in the range of 0.12-0.46. Annual ingestion dose to man from 137Cs activity was significantly lower than permissible limit (1.0 mSv year-1). The risk measured due to 137Cs is also insignificant to members of public residing around Narora Atomic Power Station, Narora, India. (author)

  6. Effect of Cs-137 gamma radiation on fungus in aqueous suspension; Efeito da radiacao gama do {sup 137} Cs sobre fungos em suspensao

    Norberg, Antonio Neres [Instituto de Biologia do Exercito (IBEx), Rio de Janeiro, RJ (Brazil); Freire, Nicolau Maues da Serra [Universidade Federal Rural do Rio de Janeiro, RJ (Brazil). Dept. de Parasitologia Animal; Maliska, Carmelindo [Faculdade de Medicina Veterinaria Plinio Leite, Niteroi, RJ (Brazil)

    1996-07-01

    Aspergillus flavus is a fungus which produces mycotoxins responsible for most of the intoxications illness in humans and animals as a result of eating contaminated food. there is little information on the resistance of A. flavus to radiation. The objective of this research is to determine the lethal dose of gamma radiation for these microorganisms. Seventy six suspensions containing approximately 100.000 spores/ml received a dose of radiation between 0,2 and 2,2 kGy. In one sample they survived, with doses up to 3,0 kGy. The fungi were totally destroyed with a 2,2 kGy dose. An increase in the resistance to lower dose levels of radiation was observed, in relation to the fungi which had not received any irradiation. In conclusion, the Minimum Lethal Dose (MLD) of gamma irradiation for A. flavus is 2,2 kGy; the re-irradiation of the surviving fungi demonstrate the appearance of radio-resistant mutants. (author)

  7. Biological effects of 137Cs, incorporated into organism of rats

    Results of investigating mutagenous and hemotoxic effects of 137Cs on blood lymphocytes of rats are presented. 137Cs was orally administrated into organism of rats as 270 kBq/g chloride solution. 137Cs mutagenous effect was studied on metaphase plates of rat blood lymphocytes in course of rats lifetime experiment. It is stated that 137Cs inducing severe disturbances of genetic material in a great quantity of blood lymphocytes, causes their total killing

  8. Quantitative Model for Estimating Soil Erosion Rates Using 137Cs

    YANGHAO; GHANGQING; 等

    1998-01-01

    A quantitative model was developed to relate the amount of 137Cs loss from the soil profile to the rate of soil erosion,According th mass balance model,the depth distribution pattern of 137Cs in the soil profile ,the radioactive decay of 137Cs,sampling year and the difference of 137Cs fallout amount among years were taken into consideration.By introducing typical depth distribution functions of 137Cs into the model ,detailed equations for the model were got for different soil,The model shows that the rate of soil erosion is mainly controlled by the depth distrbution pattern of 137Cs ,the year of sampling,and the percentage reduction in total 137Cs,The relationship between the rate of soil loss and 137Cs depletion i neither linear nor logarithmic,The depth distribution pattern of 137Cs is a major factor for estimating the rate of soil loss,Soil erosion rate is directly related with the fraction of 137Cs content near the soil surface. The influences of the radioactive decay of 137Cs,sampling year and 137Cs input fraction are not large compared with others.

  9. A survey of 90Sr and 137Cs activity levels of retail foods in Japan

    A comprehensive survey was conducted on 90Sr and 137Cs activity levels in retail foods purchased from retail markets all over Japan during the period 1989-1994, and the annual effective dose equivalent due to dietary ingestion was estimated. The concentrations of 90Sr and 137Cs in the food samples were determined using γ-ray spectrometry and the radiochemical method. The following were clarified by this study: (1) The 90Sr and 137Cs activity concentration levels were below 1 Bq kg-1 for almost all food samples except for the dried foods. (2) The activity concentration levels of 90Sr and 137Cs in foods of animal origin were different from those of plant origin. Generally, the former had higher 137Cs and lower 90Sr activity concentrations than the latter. (3) The mean and maximum values of the annual effective dose equivalent from a dietary intake of 90Sr and 137Cs by the consumption of retail foods were estimated to be as low as 1·3 and 4·1 μSv, respectively. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  10. Reactive barriers for 137Cs retention

    137Cs was dispersed globally by cold war activities and, more recently, by the Chernobyl accident. Engineered extraction of 137Cs from soils and groundwaters is exceedingly difficult. Because the half life of 137Cs is only 30.2 years, remediation might be more effective (and less costly) if 137Cs 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 135Cs (half life 2.3x106 years) in addition to 137Cs. 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 LiNO3 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 (∼ 0.33 wt% Cs). Thus, this clay would be the optimal material for constructing artificial reactive barriers

  11. Determination of Corrections in the Absolute Measurement of 137Cs

    A method, of determining corrections in absolute measurements of 137Cs by 4π proportional counter is described. The correction for self-absorption of 137Cs beta particles from sources formed by vacuum deposition of CsCl on standard carrier films was determined. These samples, which had negligible self-absorption, were measured by 4π counter. The radioactive substance on the film was then dissolved, and by the addition of carrier was converted to a form similar to that of sources usually used for absolute measurement. The correction determined for self-absorption was higher than the value expected from comparison with other radionuclides having near Eβmax. The correction for internal conversion coefficient and gamma efficiency of the beta detector was determined with 137mBa samples. Barium was separated as BaSO4 precipitate and deposited on a standard carrier film used for absolute measurement with a layer thickness of about 1 mg/cm2. These samples were simultaneously measured by means of a 4π beta proportional counter and a Nal(Tl) scintillation counter. From corresponding counting rates in both counters, and from both known efficiencies, the value for a correction appropriate to one disintegration of 137mBa was calculated. The values measured were used further for computation of the internal conversion coefficient and the half-life of 137'mBa, which was ascertained to be 155 ± 3 s. (author)

  12. Assessment of the transfer of 137Cs in three types of vegetables consumed in Hong Kong

    A dynamic food chain model has been built for the modeling of the transfer of 137Cs in three types of vegetables consumed in Hong Kong, namely, white flowering cabbage (Brassica chinensis), head lettuce (Lactuca sativa) and celery (Apium graveolens). Some parameters have been estimated from the experimental data obtained in this work. The experimental data include the transfer factors of 137Cs from soil to the different vegetable species which are determined through high resolution gamma spectrometry, maximum crop biomasses for the vegetable species, the dry-to-fresh ratios for the vegetable species, the bulk density of soil layers and the average concentration of 137Cs in air. The derived parameters include the deposition rate and the root uptake rate, information for tillage, the logistic growth model and radionuclide concentrations in vegetables. The dynamic food chain model is solved by the Birchall-James algorithm to give the 137Cs concentration in subsurface soil, from the 0.1-25 cm soil layer, and the 137Cs concentration in harvested and unwashed vegetables. As validation of the model and parameters, the concentrations obtained experimentally and from the model are compared and are found to be in good agreement

  13. Residence half-time of 137Cs in the top-soils of Japanese paddy and upland fields

    A series of top-soil samples of 14 paddy fields and 10 upland fields in Japan, were annually collected during more than 30 years, to be examined in the contents of 137Cs. The data, which were obtained by the use of a gamma spectrometric system, received some statistical treatments to distinguish the annual decline of 137Cs contents from deviations. Then the authors calculated 'residence half-time of 137Cs' within top-soil, and 'eluviation rate of 137Cs' from top to the sub-layer of the soil. The following nationwide results were obtained irrespective of paddy or upland field: (1) The 'apparent residence half-time' was estimated as 16 - 17 years. This consists of both effects of eluviation and nuclear disintegration. (2) The true residence half-time' was reported as 41 - 42 years. This depends on the eluviation speed of 137Cs exclusively, because the influence of nuclear disintegration has been compensated. (3) The eluviation rate of 137Cs from top-soil down to the sub-soil was 1.6 - 1.7% per year. (4) The ratio of distribution of 137Cs between top-soil and the sub-soil was estimated to be 6:4 as average at the date of 1996. (author)

  14. Residence half-time of {sup 137}Cs in the top-soils of Japanese paddy and upland fields

    Komamura, Misako [National Inst. of Agro-Environmental Sciences, Tsukuba, Ibaraki (Japan); Tsumura, Akito; Kodaira, Kiyoshi

    1999-03-01

    A series of top-soil samples of 14 paddy fields and 10 upland fields in Japan, were annually collected during more than 30 years, to be examined in the contents of {sup 137}Cs. The data, which were obtained by the use of a gamma spectrometric system, received some statistical treatments to distinguish the annual decline of {sup 137}Cs contents from deviations. Then the authors calculated `residence half-time of {sup 137}Cs` within top-soil, and `eluviation rate of {sup 137}Cs` from top to the sub-layer of the soil. The following nationwide results were obtained irrespective of paddy or upland field: (1) The `apparent residence half-time` was estimated as 16 - 17 years. This consists of both effects of eluviation and nuclear disintegration. (2) The true residence half-time` was reported as 41 - 42 years. This depends on the eluviation speed of {sup 137}Cs exclusively, because the influence of nuclear disintegration has been compensated. (3) The eluviation rate of {sup 137}Cs from top-soil down to the sub-soil was 1.6 - 1.7% per year. (4) The ratio of distribution of {sup 137}Cs between top-soil and the sub-soil was estimated to be 6:4 as average at the date of 1996. (author)

  15. Radioactivity in the Exclusive Economic Zone of east coast Peninsular Malaysia. Distribution trends of 137Cs in surface seawater

    Large volumes of surface seawater samples were collected from thirty locations in the Exclusive Economic Zone (EEZ) of the east coast Peninsular Malaysia on June 2008 to study the activity concentrations of 137Cs. The results will serve as additional information to the existing baseline data and is very useful for monitoring fresh input of anthropogenic radionuclide into Malaysian marine environment. In this study, the activity concentrations of 137Cs were determined using co-precipitation technique, followed by Gamma Spectrometry measurement. The mean activity concentration of 137Cs ranged between 3.40 and 5.89 Bq/m3. Higher activity concentrations were observed at the coastal and towards the south of Peninsular Malaysia and were aligned with the high turbidity. These may due to the rapid diffusion of 137Cs from suspended particulates and fine sediments into surface seawater. The activity concentrations of 137Cs observed in this study were slightly higher than the concentrations reported in seawater at the Straits of Malacca, Vietnam and Philippines. This might be because the study area received more input of 137Cs that originated from global fallout and then deposited on land which later being transported subsequently into the coastal zone due to siltation and erosion processes. It could also be attributed to the intrusion of river waters containing higher concentrations of 137Cs. (author)

  16. Maps of surface activity of 137Cs of Slovakia on scale 1:200 000

    The present set of maps (13 maps) arose from the geological project 'Re-ambulation of 137Cs radioactivity map of Slovakia at scales 1:200 000 and 1:500 000' in phase of indicative geological survey of environmental factors. Maps document the state of contamination of the territory of Slovakia by one of the radioisotopes cesium-137 at the reference date 01.01.2005. In solving of geological tasks were used all available relevant data on measurements of 137Cs activity from the whole territory of the Slovak Republic for the period from 1990 to 2003 from results of air and ground gamma spectrometric measurements. (authors)

  17. Chronology of sedimentation in Cienfuegos bay, elucidated from 210Pb and 137Cs

    This article present the results of the use of radiotracers in geochronology technique for evaluate the anthropogenic impact on Cienfuegos Bay, Cuba. The excess 210Pb and 137Cs radionuclides were measurements on one sediment corer collected in Cienfuegos Bay using a gravity core. Each core was sliced and pre treatment for gamma spectrometric measurements and other complementary analyses. It was applied the Constant Rate Supply model for dating the 210Pb profile and it was used the 137Cs as an alternative method for dating calibration. The results show a good agreement between CRS method's results and 1963's 137Cs peak. Spatial and temporal evaluation of the radiotracers profiles have shown that sedimentation rate have changed in the last fourth years and it is associated to the economical and industrial development. It was demonstrated the significance of radiotracers in environmental impact on estuaries and semi enclosed bays

  18. 90Sr and 137Cs determination in milk and foodstuff samples in North and Middle Moravia

    Activities of radionuclides Sr-90 and Cs-137 in milk and parts of foodstuff have been determined in National Radiation Protection Institute for many years. Sr-90 activity in those samples determinate branch Ostrava by radiochemical procedure - precipitation with oxalic acid and measuring with using gas-flow proportional detector. Gamma spectrometry with HPGe detector is using for 137 Cs determination. (authors)

  19. Putative bioindicator of 137Cs in Perna viridis

    Green lipid mussels (Perna viridis L.) are utilized as bioindicators and bioconcentrators not only for marine radionuclide contamination but also for heavy metal bioaccumulation. Depurated P. viridis were incubated in 137Cs-spiked aquarium for 4 days. Soluble protein fractions of soft tissue obtained were electrophoresed (SDS-PAGE) to determine the exposure effects of 137Cs on P. viridis. Results showed the presence of a 154-kDa protein in 137Cs-spiked samples which could be a potential bioindicator of 137Cs in P. viridis. Other differences involving two more proteins (∼94-kDa and∼61 KDa) are reported. (Author)

  20. Speciation of 137Cs in the Baltic sea water

    A possibility of application of Filtrac 391 and Nuclepore filters, Ky-2-8-C exchanger and the Mtilon-T fiber impregnated with Fe, Co, Ni ferrocyanides for separation of particulate and ionic 137Cs in the sea water was investigated. Physico-chemical forms of 137Cs were investigated in the Baltic Sea water during 1995-1997. It was determined that 137Cs was mainly present in ionic form (62-93 %) both in the near-shore and open waters. Concentration of particulate 137Cs ranged from 255 to 625 Bq/kg (dry weight).The distribution coefficient (Kd) of radiocaesium reached values of 2100-9700. (author)

  1. An iterative approach for TRIGA fuel burn-up determination using nondestructive gamma-ray spectrometry

    Wang Tienko E-mail: tkw@faculty.nthu.edu.tw; Peir Jinnjer

    2000-01-01

    The purpose of this work is to establish a method for evaluating the burn-up values of the rod-type TRIGA spent fuel by using gamma-ray spectrometry of the short-lived fission products {sup 97}Zr/{sup 97}Nb, {sup 132}I, and {sup 140}La. Fuel irradiation history is not needed in this method. Short-lived fission-product activities were established by re irradiating the spent fuels in a nuclear reactor. Based on the measured activities, {sup 235}U burn-up values can be deduced by iterative calculations. The complication caused by {sup 239}Pu production and fission is also discussed in detail. The burn-up values obtained by this method are in good agreement with those deduced from the conventional method based on long-lived fission products {sup 137}Cs, {sup 134}Cs/{sup 137}Cs ratio and {sup 106}Ru/{sup 137}Cs ratio.

  2. An iterative approach for TRIGA fuel burn-up determination using nondestructive gamma-ray spectrometry

    The purpose of this work is to establish a method for evaluating the burn-up values of the rod-type TRIGA spent fuel by using gamma-ray spectrometry of the short-lived fission products 97Zr/97Nb, 132I, and 140La. Fuel irradiation history is not needed in this method. Short-lived fission-product activities were established by re irradiating the spent fuels in a nuclear reactor. Based on the measured activities, 235U burn-up values can be deduced by iterative calculations. The complication caused by 239Pu production and fission is also discussed in detail. The burn-up values obtained by this method are in good agreement with those deduced from the conventional method based on long-lived fission products 137Cs, 134Cs/137Cs ratio and 106Ru/137Cs ratio

  3. An iterative approach for TRIGA fuel burn-up determination using nondestructive gamma-ray spectrometry.

    Wang, T K; Peir, J J

    2000-01-01

    The purpose of this work is to establish a method for evaluating the burn-up values of the rod-type TRIGA spent fuel by using gamma-ray spectrometry of the short-lived fission products 97Zr/97Nb, 132I, and 140La. Fuel irradiation history is not needed in this method. Short-lived fission-product activities were established by reirradiating the spent fuels in a nuclear reactor. Based on the measured activities, 235U burn-up values can be deduced by iterative calculations. The complication caused by 239Pu production and fission is also discussed in detail. The burn-up values obtained by this method are in good agreement with those deduced from the conventional method based on long-lived fission products 137Cs, 134Cs/137Cs ratio and 106Ru/137Cs ratio. PMID:10670930

  4. Distribution of {sup 137}Cs in three representative soils of Pernambuco state, Brazil;Distribuicao de {sup 137}Cs em tres solos representativos do estado de Pernambuco

    Antunes, Patrik Diogo, E-mail: pdantunes@yahoo.com.b [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil). Dept. de Ciencias do Solo; Sampaio, Everardo Valadares de Sa Barretto; Ferreira Junior, Antonio Luiz Goncalves; Salcedo, Ignacio Hernan, E-mail: esampaio@ufpe.b, E-mail: antonio.ferreira@ariano.nlink.com.b, E-mail: salcedo@ufpe.b [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Galindo, Izabel Cristina Luna, E-mail: iclgalindo@uol.com.b [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil). Dept. de Agronomia

    2010-05-15

    Contents of {sup 137}Cs have been used to quantify soil loss or accumulations, based on values of reference sites with little soil disturbance in the last decades. In Northeastern Brazil no such sites have been evaluated yet. Three areas with flat topography, native vegetation and undisturbed soil were selected in of Goiania, Araripina and Sertania counties, state of Pernambuco. Four points in each area were marked at a distance of 20 to 50 m away from each other and soil samples were collected in 3 cm depth intervals, down to 30 cm. The {sup 137}Cs activities were determined using gamma spectrometry with a hyper pure germanium detector. Average contents of {sup 137}Cs (Bq m{sup -2}) were 71.6 +- 6.3 in Goiania, 64.0 +- 13.8 in Araripina and 95.5 +- 9.8 in Sertania. Values in this range have been reported in Paraiba and Bahia, and higher ones in the Southeastern region, confirming the reduction of stocks in areas closer to the equator. The highest activities occurred in the surface layers, ranging from 0.5 to 1.6 Bq kg{sup -1}, and decreased linearly with depth until the detection limits: 18 cm in Araripina, 15 cm in Goiania, and 9 cm in Sertania. In Goiania, the activity was highest (2.06 +- 1.0 Bq kg{sup -1}) in an organic horizon above a inorganic horizon. The high activities and stock and lower depth in Sertania could be explained by the predominance of 2:1 clay minerals versus 1:1 clay minerals in the other areas. {sup 137}Cs activities were positively correlated with water and KCl pH values and negatively correlated with Al concentrations. The results confirm that, in the reference areas, {sup 137}Cs activities are highest in the surface layers, decreasing regularly down the soil profile. (author)

  5. Distribution of 137Cs, 40K, 238U and 232Th in soils from Northern Venezuela

    More than one hundred undisturbed soil samples form Northern Venezuela and the islands of Margarita and Los Roques have been analyzed for 137Cs, 40K, 238U and 232Th by γ-ray spectroscopy. The specimens were taken from between 5-10 cm below the earth's surface. Thus, they are valid not only for the 137Cs deposition studies but also for the estimation of the natural γ-ray dose from primordial radionuclides that form the terrestrial component. The concentrations of 40K was directly determined from its 1461 keV γ-ray, while those of 137Cs, 238U and 232Th were performed using a γ-ray from one of their daughter radionuclides: the 661 keV γ-ray of 137mBa for 137Cs, the 1760 keV γ-ray of 214Bi for 238U and the 2620 keV γ-ray of 208Tl for 232Th. Finally, the concentration values were compared with those of global estimates. (author) 15 refs.; 4 figs.; 2 tabs

  6. 137 Cs in flowers, pollen and honey from the Republic of Croatia four years after the Chernobyl accident

    137Cs concentration was measured in flowers, pollen and honey, samples of which were collected from the Republic of Croatia 4 years after the Chernobyl accident. Radioactivity of 137Cs was measured by gamma-spectrometry. Cesium in honey corresponds well with 137Cs contamination of territory in the Republic of Croatia. Activity of 137Cs in pollen which is higher than in honey indicates that cesium behaves analogously to potassium. The results show that equal cesium concentration in the surface soil layer results in higher cesium activities in honey in the case of meadow flowers, ie honey bee pasture, than in cases when pasture is based on bush and tree flowers. Cesium activity average in honey, collected from the Republic of Croatia territory, is < 1 % of the permissible level of 600 Bq/kg

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

    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 137Cs 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-1137Cs (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 2 g 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 137Cs 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 137Cs transfer and deposition in breast meat, liver and gizzard. Decreasing deposition of 137Cs 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 137Cs 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 137Cs activity in breast meat was 53-69% lower than that in the control group, 67-60% in liver and 59-71% in gizzard

  8. Mechanisms of 137Cs migration in coniferous forest soils

    Field and laboratory studies demonstrate two processes involved in 137Cs migration in coniferous forest soil. The data illustrate that the effects of leaching and litter accumulation combine, over the time interval since deposition, to achieve the observed distribution of 137Cs in the soil profile. Today, under normal field conditions the rate of 137Cs leaching from forest humus is low and even extreme environmental conditions do not increase greatly the extent of 137Cs mobilisation by leaching. A three-phase model of 137Cs migration in the organic horizons of coniferous forest soils is proposed. The phases are discrete but at any point in time the behaviour of some portion of deposited 137Cs will be characteristic of one of the three phases. In the first phase 137Cs intercepted by the canopy is washed to the forest floor where a proportion (20-40% is reported) rapidly percolates through the organic horizons reaching the underlying soil; the remainder is retained in the organic horizons. In the second phase, which our study estimates to last about 5 years, the 137Cs contained within the Ol and Of horizons moves to the Oh horizon. Accumulation of relatively uncontaminated litter on top of the Ol horizon contributes to this migration, while 137Cs mobilised from the Ol and Of horizons by decomposition is leached to the Oh horizon. The 137Cs which reaches the Oh horizon, either by leaching or by decomposition and burial, enters the third phase in which the pace of migration is greatly reduced. Decomposition is slowest in the Oh horizon and the accumulation and turnover of Oh material is also very slow. At the site investigated in this study the bulk of the deposited 137Cs is in this third phase and we suggest that this phase will persist for many years to come

  9. Retention of 137Cs and 90Sr by mineral sorbents surrounding vitrified nuclear waste

    In June 1960, twenty-five 14-cm diameter hemispheres of vitrified nuclear waste (glass blocks) were buried in a shallow sand aquifer in the lower Perch Lake Basin, Chalk River Nuclear Laboratories, Ontario, Canada. Almost all leaching of the glass blocks occurred during the first 18 months of emplacement, and consequently the burial experiment approximated a single-injection source of 137Cs and 90Sr. After about 11 years, most of the 90Sr that was released had been advected and dispersed from the site, whereas the bulk of the 137Cs had travelled no more than 0.3 m from the blocks. Three piezometers were installed and five cores of sediment were collected at the glass block site in 1978. Mineralogically pure segregates of sand grains were prepared by hand and characterized using binocular, petrographic and scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. A technique also was developed to measure very low levels of 137Cs and 90Sr by counting small (10-100 mg) sediment samples directly with a thin window, flow proportional counter. Results show that sand-sized grains of altered biotite (biotite-vermiculite), biotite, muscovite, hornblende and serictized feldspar are able to retain 137Cs over a period of 18 years, and that grains of biotite-vermiculite, biotite and hematite-bearing feldspar (largely microline) can retain low levels of 90Sr over the same period of time. The amounts of 137Cs and 90Sr sorbed by the mineral grains ranged from undetectable levels to approximately 380 and 35 becquerels/gram sediment, respectively. This report contains the complete series of mineral segregates ranked on a weight basis according to the amounts of retained 137Cs and 90Sr. Ground-water quality data indicate that none of the retention is the result of the precipitation of strontium or cesium minerals

  10. Determination of {sup 135}Cs and {sup 137}Cs in environmental samples: A review

    Russell, B.C., E-mail: ben.russell@npl.co.uk [GAU-Radioanalytical, Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH (United Kingdom); National Physical Laboratory, Hampton Road, Teddington, Middlesex, TW11 0LW (United Kingdom); Croudace, Ian W.; Warwick, Phil E. [GAU-Radioanalytical, Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH (United Kingdom)

    2015-08-26

    Radionuclides of caesium are environmentally important since they are formed as significant high yield fission products ({sup 135}Cs and {sup 137}Cs) and activation products ({sup 134}Cs and {sup 136}Cs) during nuclear fission. They originate from a range of nuclear activities such as weapons testing, nuclear reprocessing and nuclear fuel cycle discharges and nuclear accidents. Whilst {sup 137}Cs, {sup 134}Cs and {sup 136}Cs are routinely measurable at high sensitivity by gamma spectrometry, routine detection of long-lived {sup 135}Cs by radiometric methods is challenging. This measurement is, however, important given its significance in long-term nuclear waste storage and disposal. Furthermore, the {sup 135}Cs/{sup 137}Cs ratio varies with reactor, weapon and fuel type, and accurate measurement of this ratio can therefore be used as a forensic tool in identifying the source(s) of nuclear contamination. The shorter-lived activation products {sup 134}Cs and {sup 136}Cs have a limited application but provide useful early information on fuel irradiation history and have importance in health physics. Detection of {sup 135}Cs (and {sup 137}Cs) is achievable by mass spectrometric techniques; most commonly inductively coupled plasma mass spectrometry (ICP-MS), as well as thermal ionisation (TIMS), accelerator (AMS) and resonance ionisation (RIMS) techniques. The critical issues affecting the accuracy and detection limits achievable by this technique are effective removal of barium to eliminate isobaric interferences arising from {sup 135}Ba and {sup 137}Ba, and elimination of peak tailing of stable {sup 133}Cs on {sup 135}Cs. Isobaric interferences can be removed by chemical separation, most commonly ion exchange chromatography, and/or instrumental separation using an ICP-MS equipped with a reaction cell. The removal of the peak tailing interference is dependent on the instrument used for final measurement. This review summarizes and compares the analytical procedures

  11. Determination of 135Cs and 137Cs in environmental samples: A review

    Radionuclides of caesium are environmentally important since they are formed as significant high yield fission products (135Cs and 137Cs) and activation products (134Cs and 136Cs) during nuclear fission. They originate from a range of nuclear activities such as weapons testing, nuclear reprocessing and nuclear fuel cycle discharges and nuclear accidents. Whilst 137Cs, 134Cs and 136Cs are routinely measurable at high sensitivity by gamma spectrometry, routine detection of long-lived 135Cs by radiometric methods is challenging. This measurement is, however, important given its significance in long-term nuclear waste storage and disposal. Furthermore, the 135Cs/137Cs ratio varies with reactor, weapon and fuel type, and accurate measurement of this ratio can therefore be used as a forensic tool in identifying the source(s) of nuclear contamination. The shorter-lived activation products 134Cs and 136Cs have a limited application but provide useful early information on fuel irradiation history and have importance in health physics. Detection of 135Cs (and 137Cs) is achievable by mass spectrometric techniques; most commonly inductively coupled plasma mass spectrometry (ICP-MS), as well as thermal ionisation (TIMS), accelerator (AMS) and resonance ionisation (RIMS) techniques. The critical issues affecting the accuracy and detection limits achievable by this technique are effective removal of barium to eliminate isobaric interferences arising from 135Ba and 137Ba, and elimination of peak tailing of stable 133Cs on 135Cs. Isobaric interferences can be removed by chemical separation, most commonly ion exchange chromatography, and/or instrumental separation using an ICP-MS equipped with a reaction cell. The removal of the peak tailing interference is dependent on the instrument used for final measurement. This review summarizes and compares the analytical procedures developed for determination of 135Cs/137Cs, with particular focus on ICP-MS detection and the methods applied

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

    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

  13. Erosion and sediment deposition evaluation in two slopes under different tillage systems using the '137Cs fallout' technique

    With the increasing of occupation of the Brazilian Cerrado a series of environmental problems followed by the deforestation as soil erosion and soil compaction are appearing, and many of than are being related to the CT used. The NT cropping system which is being adopted more recently in the 'cerrado' region, has revealed benefic to the soil, mainly in terms of soil erosion control. The objective of the present work was to analyze the effect of the No Tillage NT and Conventional Tillage CT systems on the erosion process and to measure the efficiency of the riparian forest in trapping the sediments produced by erosion coming from crop areas cultivated by both systems trough the technique of 137Cs 'fallout' redistribution analysis. The study was carried out in Goiatuba/GO in two sampling dowslope transects located in areas of CT and NT cropping systems. Samples were taken from five points in transects of 200 and 140 meters long respectively, as well as from three soil profiles of a 30 m transect in the downstream riparian forests of each area. Incremental depth samples were also taken from two pits inside each transect in the forest down to 40 and 60 cm depth for the CT and NT respectively. The soil samples were air dried and sieved and the 137Cs activity was analyzed for in a gamma ray detector (GEM-20180P, EG and ORTEC) coupled to a multichannel analyzer at CENA/USP. The results indicate variation of 137Cs in soil profiles and high erosion rates for both cropping areas also indicate a movement of sediments from the two cropping areas to the riparian forest. (author)

  14. Development of gamma-ray energy spectrum remote-measurement system based on LabVIEW

    Design techniques of a gamma-ray energy spectrum remote-measurement system based on Lab VIEW are described, including data acquicition and client control program, and network communication by DataSocket. The gamma-ray energy spectrum of 137Cs was measured by the system, indicating that performance of our remote-measurement system based on LabVIEW is better than that based on Java Applet. (authors)

  15. Plutonium, 137Cs and U in some pond and lake sediments FSurrounding areas of the semipalatinsk nuclear test site: with emphasis on anomalously high U accumulation

    Between 1949 and 1989, the former USSR conducted more than 450 nuclear explosions, including atmospheric, above ground and underground nuclear tests, at the proving ground (SNTS) near Semipalatinsk City in Eastern Kazakhstan. We have visited to these areas ten several times, and estimated current contamination levels and distribution of long-lived radionuclides 137Cs and Pu isotopes (238,239,240Pu) of the ground at various areas and radiation doses by TL using brick. Parallel to these soil and brick samplings, pond and lake sediment core samples were also taken from the water bodies (impoundments) scattered on the vicinity of the SNTS. They include from north to south, Pond Korosteli (maximum depth: 2-3 m), Lake Kanoneruka (deeper than 5 m), Pond Veramenka (ca.3 m), Lake Semanailka (deeper than 10 m) and Pond Alkat (ca. 1 m in summer season). In each pond and lake, sediment cores to 25440 cm depth were collected in September 1998 by inserting a polyvinyl chloride (PVC) pipe (5.0 cm i.d.) into the sediment by hand at the depths ranging approximately 1 to 3 m. The underlying final objective is to get information on total 137Cs and Pu deposition and their history of SNTS fallout within the regions of the study: After non-destructive gamma-ray measurements of 137Cs and natural radionuclides including 210Pb, Pu and U isotopes were determined by alpha-ray spectrometry after radiochelnical separation. We found some ponds and lakes which were accumulating an anomalously high U in the sediments. This 235U/238U activity ratios of U found are almost the same as that (0.046) of natural U. In this paper, depth profiles of 137Cs and Pu concentrations in the sediments from these impoundments are presented with emphasis on those of high U accumulation. (authors)

  16. Sediment environmental capacity of 137Cs in Daya Bay

    ZHANG Junli; CHEN Jiajun; XU Jialin; LI Yuanxin; HUANG Naiming

    2007-01-01

    Sediment environmental capacity of pollutants is very important for marine environmental management.Based on the methodology of a study on water,soil environmental capacity,and mass conservation theory in a system,the concept and model on sediment environmental capacity for 137Cs in Daya Bay were developed.The static capacity for 137Cs in the upper sediment near the shore at a shallow area was calculated,and the annual dynamic capacity and total dynamic capacity were also calculated through determination of the typical biomass in the sediment.The results showed that the estimated environmental capacity for 137Cs in sediments was approximately equal to the current input of 137Cs into the sediments.Controlling the input of 137Cs in the sediments within the environmental capacity guarantees the sustainability of the current situation of the Daya Bay ecosystem and avoidance of a significant degradation of the system.

  17. {sup 137}Cs accumulation in coastal sediments in Sweden

    Pettersson, H.B.L.; Salih, I. [Linkoeping Univ. (Sweden). Dept. of Radiation Physics; Herrmann, J. [Federal Maritime and Hydrographic Agency, Hamburg (Germany)

    2005-09-15

    Seabed sediment samples were collected in 1998, 2000 and 2001 at 20 sites located in the Baltic Sea and 4 sites in the Skagerrak. The objectives of the sampling campaigns were (i) to establish the coastal sediment distribution of {sup 137}Cs, (ii) to evaluate the vertical core distribution of {sup 137}Cs, (iii) to study the sediment accumulation rates, and (iv) to assess the sediment inventories of {sup 137}Cs. The results show a very high variation in {sup 137}Cs concentrations and an almost 100-fold difference in inventories, showing predominance of Chernobyl derived {sup 137}Cs in the Baltic Proper compared to the western Baltic and the Skagerrak areas. Sediment accumulation rates were highly dependent on sediment types and ranged from 0.05 to 1.8 cm/y.

  18. Evaluating gully erosion using 137Cs and 210Pb/137Cs ratio in a reservoir catchment

    Water erosion in the hilly areas of west China is the main process contributing to the overall sediment of the Yellow River and the Yangtze River. The impact of gully erosion in total sediment output has been mostly neglected. Our objective was to assess the sediment production and sediment sources at both the hillslope and catchment scales in the Yangjuangou reservoir catchment of the Chinese Loess Plateau, northwest China. Distribution patterns in sediment production caused by water erosion on hills and gully slopes under different land use types were assessed using the fallout 137Cs technique. The total sediment production from the catchment was estimated by using the sediment record in a reservoir. Sediment sources and dominant water erosion processes were determined by comparing 137Cs activities and 210Pb/137Cs ratios in surface soils and sub-surface soils with those of sediment deposits from the reservoir at the outlet of the catchment. Results indicated that landscape location had the most significant impact on sediment production for cultivated hillslopes, followed by the terraced hillslope, and the least for the vegetated hillslope. Sediment production increased in the following order: top>upper>lower>middle for the cultivated hillslope, and top>lower>upper>middle for the terraced hillslope. The mean value of sediment production declined by 49% for the terraced hillslope and by 80% for the vegetated hillslope compared with the cultivated hillslope. Vegetated gully slope reduced the sediment production by 38% compared with the cultivated gully slope. These data demonstrate the effectiveness of terracing and perennial vegetation cover in controlling sediment delivery at a hillslope scale. Averaged 137Cs activities and 210Pb/137Cs ratios in the 0-5 cm surface soil (2.22-4.70 Bq kg-1 and 20.70-22.07, respectively) and in the 5-30 cm subsoil (2.60 Bq kg-1 and 28.57, respectively) on the cultivated hills and gully slopes were close to those of the deposited

  19. Radiation doses to frogs inhabiting a wetland ecosystem in an area of Sweden contaminated with 137Cs

    Internal and external radiation doses to frogs living in a wetland ecosystem contaminated with 137Cs were estimated. The external doses were calculated from measured concentrations of 137Cs in soil and in water taking into account changes in the habitat during the frogs' life cycle. The internal dose was estimated from measured concentrations of 137Cs in living frogs (Rana arvalis) using a whole-body counter. The average inventory of 137Cs in the soil was approximately 1000 kBq/m2 of which 86-99 % was found in the top 12 cm. The concentrations of 137Cs in frogs varied between 560 and 3450 Bq/kg ww. The estimated external dose rate was between 21 and 160 mGy/y, while the internal dose of beta and gamma was only between 1 and 6.2 mGy/y. The estimated total dose rate to frogs from 137Cs was below the expected safe level for terrestrial populations but close to the critical dose rate for amphibians suggested in the literature. Therefore, the radiation risk to frogs from radiocaesium in the study area may be one more stressor for an endangered group of animals in this ecosystem. (author)

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

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

    2010-09-15

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

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

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

  2. 137Cs in the western South Pacific Ocean

    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 γ 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 10o latitude by 10 deg. 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 the northern

  3. Stress modification of the kinetic of 137Cs absorption and primary pattern of intercompartments distribution

    The kinetic of 137Cs absorption by pea seedlings and the possibility of alteration of the qualitative and quantitative characteristics of this process were investigated. Gamma irradiation of dry seeds of pea at doses of 25-50 Gy brings about a global change in the kinetic and concentration curves of the active and passive 137Cs uptake by the plant roots. The first and second phases of the kinetic curve, which mirror the passive stage of absorption, and the type of the concentration curve in general, were changed. The level of radionuclide accumulation at this passive stage and the retention for the apoplast-symplast passage increase significantly. Changes in the Michaelis-Menten parameters of the concentration curves were also observed. The changes mirror changes in the radionuclide distribution in the symplast-apoplast system. The time of 137Cs retention for the root-stem transition increased from 0.5 min to 1 min. This investigation suggests that the cation exchange capacity of the parts and structures of a plant is among the main factors which determine the primary intercompartment distribution of 137Cs as nonbiogenous mineral elements

  4. {sup 40}K/{sup 137}Cs discrimination ratios to the aboveground organs of tropical plants

    Sanches, N. [Instituto de Fisica, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza s/n, Gragoata, Niteroi, CEP 24210-346, RJ (Brazil); Anjos, R.M. [Instituto de Fisica, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza s/n, Gragoata, Niteroi, CEP 24210-346, RJ (Brazil)], E-mail: meigikos@if.uff.br; Mosquera, B. [Instituto de Fisica, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza s/n, Gragoata, Niteroi, CEP 24210-346, RJ (Brazil)

    2008-07-15

    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 {sup 137}Cs and {sup 40}K, measured by gamma spectrometry, from five tropical plant species: guava (Psidium guajava), mango (Mangifera indica), papaya (Carica papaya), banana (Musa paradisiaca), 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 {sup 137}Cs and {sup 40}K in their growing parts. However, a significant correlation between activity concentrations of {sup 137}Cs and {sup 40}K was observed in these tropical plants. The {sup 40}K/{sup 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.

  5. Measuring the bioenergetic cost of fish activity in situ using a globally dispersed radiotracer (137Cs)

    The energetic cost of activity is an important component of the bioenergetic budget of fish, yet this parameter has rarely been quantified for wild populations. Using a 137Cs mass balance approach, we estimated the annual bioenergetic budgets for individual age-classes of 19 species of North American freshwater fish. Immature fish have low activity-related metabolic costs that agree with estimates based on swimming speed or integer multipliers. Mature fish have 2- to 4-fold higher activity than immature fish and 2- to 4-fold higher activity than estimates based on swimming speed or integer multipliers. The higher activity in mature fish may be due to reproductive efforts. Underestimation of activity in conventional bioenergetics models leads to underestimation of consumption rates. Thus, our in situ and age-specific estimates of activity costs provide a means to improve bioenergetic predictions. Although our analysis was done on an annual basis, it is possible to use the 137Cs technique over shorter intervals (weeks). The 137Cs method has general applicability to aquatic systems because 137Cs is globally dispersed and can be accurately measured in all aquatic organisms using gamma spectrometry. (author). 62 refs., 4 tabs., 4 figs

  6. 40K/137Cs discrimination ratios to the aboveground organs of tropical plants

    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 137Cs and 40K, measured by gamma spectrometry, from five tropical plant species: guava (Psidium guajava), mango (Mangifera indica), papaya (Carica papaya), banana (Musa paradisiaca), 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 137Cs and 40K in their growing parts. However, a significant correlation between activity concentrations of 137Cs and 40K was observed in these tropical plants. The 40K/137Cs 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

  7. A comparison of measured and calculated values of air kerma rates from 137Cs in soil

    V. P. Ramzaev

    2016-01-01

    Full Text Available In 2010, a study was conducted to determine the air gamma dose rate from 137Cs deposited in soil. The gamma dose rate measurements and soil sampling were performed at 30 reference plots from the south-west districts of the Bryansk region (Russia that had been heavily contaminated as a result of the Chernobyl accident. The 137Cs inventory in the top 20 cm of soil ranged from 260 kBq m–2 to 2800 kBq m–2. Vertical distributions of 137Cs in soil cores (6 samples per a plot were determined after their sectioning into ten horizontal layers of 2 cm thickness. The vertical distributions of 137Cs in soil were employed to calculate air kerma rates, K, using two independent methods proposed by Saito and Jacob [Radiat. Prot. Dosimetry, 1995, Vol. 58, P. 29–45] and Golikov et al. [Contaminated Forests– Recent Developments in Risk Identification and Future Perspective. Kluwer Academic Publishers, 1999. – P. 333–341]. A very good coincidence between the methods was observed (Spearman’s rank coefficient of correlation = 0.952; P<0.01; on average, a difference between the kerma rates calculated with two methods did not exceed 3%. The calculated air kerma rates agreed with the measured dose rates in air very well (Spearman’s coefficient of correlation = 0.952; P<0.01. For large grassland plots (n=19, the measured dose rates were on average 6% less than the calculated kerma rates. The tested methods for calculating the air dose rate from 137Cs in soil can be recommended for practical studies in radiology and radioecology. 

  8. Distribution of naturally occurring radioactivity and 137Cs in the marine sediment of Farasan island, southern red sea, Saudi Arabia

    The present work is a part of a project dedicated to measure the marine radioactivity near the Saudi Arabian coast of the Red Sea and Arabian Gulf for establishing a marine radioactivity database, which includes necessary information on the background levels of both naturally occurring and man-made radionuclides in the marine environment. Farasan Islands is a group of 84 islands (archipelago), under the administration of the Kingdom of Saudi Arabia, in the Red Sea with its main island of Farasan, which is 50 km off the coast of Jazan City. The levels of natural radioactivity of 238U, 235U, 226Ra, 232Thand 40K and man-made radionuclides such as 137Cs in the grab sediment and water samples around Farasan Island have been measured using gamma-ray spectroscopy. The average activity concentrations of 238U, 235U, 226Ra, 232Th, 40K and 137Cs in the sediment samples were found to be 35.46, 1.75, 3.31, 0.92, 34.34 and 0.14 Bq kg-1, respectively. (authors)

  9. 137Cs contaminated waste disposal in cement factory: Environmental problems

    In the course of utilization (May-June '91) of aluminum slags polluted by 137Cs at the cement factory Presacementi in Robilante (Cuneo, Italy) and during the following months, samples were taken in particular points of the plant, at fixed frequencies. Samples were analyzed to determine 137Cs concentration. Collected data were used to study the behaviour of the element throughout the process. Emissions and ground level air concentrations were estimated from the available data. Contamination of the manufactured cement were monitored until negligible values of 137Cs concentration were attained

  10. Attenuation of the gamma rays in tissues

    The mass and lineal attenuation coefficient and of hepatic tissue, muscular, osseous and of brain before gamma rays of 10-3 to 105 MeV were calculated. For the case of the osseous tissue the calculation was made for the cartilage, the cortical tissue and the bone marrow. During the calculations the elementary composition of the tissues of human origin was used. The calculations include by separate the Photoelectric effect, the Compton scattering and the Pair production, as well as the total. For to establish a comparison with the attenuation capacities, the coefficients of the water, the aluminum and the lead also were calculated. The study was complemented measuring the attenuation coefficient of hepatic tissue of bovine before gamma rays of 0.662 MeV of a source of 137 Cs. The measurement was made through of an experiment of photons transmission through samples frozen of hepatic tissue and with a Geiger-Mueller detector. (Author)

  11. 137Cs mobility in soils and its long-term effect on the external radiation exposure

    To predict the external gamma-dose rate of Chernobyl-derived 137Cs for a period of about 100 years after its deposition, the vertical distribution of radiocesium in several meadow soils in the Chernobyl area and in Germany was determined, and the corresponding residence half-times of this radionuclide in the various soil layers were evaluated using a compartment model. The resulting residence half-times were subsequently used to calculate the vertical distribution of 137Cs in the soil as a function of time and finally to predict the external gamma-dose rates in air for these sites at various times. A regression analysis of the data obtained showed that the time dependence of the relative gamma-dose rate in air D(t) at the Chernobyl sites can be described by an exponential equation D(t) = a + b . exp(-t/c), where t is the time after deposition. For the ten German sites the best fit was obtained using the two-exponential equation D(t) = a . exp(-t/b) + c . exp(-t/d). The gamma-dose rate of 137Cs at the Chernobyl sites decreases significantly more slowly with time than at the German sites. This means that after e.g. 30 years the mean relative gamma-dose rate at the German sites will have decreased from 100% (corresponding to an infinite plane source on a smooth surface) to 9% (95% confidence interval 8%-10%), while at the sites in the Chernobyl area it will have decreased only to 21% (20%-23%). This difference is the result of the longer residence half-times of 137Cs in the soils at the Chernobyl sites. All results are compared with estimates from earlier studies. (orig.). With 4 figs., 2 tabs

  12. Accumulation of 137Cs in puddle sediments within urban ecosystem

    The role of puddle sediments as a final depot of 137Cs horizontal migration within the urban landscape is studied using the example of Ekaterinburg city, Russia. Radioactive contamination in the city appeared due to fallout after atmospheric testing of nuclear weapons and nuclear accidents. Contamination density of 137Cs in the region was assessed from archive data to be about 5.1 kBq/m2, of which the maximum activity concentration (137Cs activity concentration in puddle sediments of 80 Bq/kg, with a maximum value of 540 Bq/kg. It is estimated that horizontal migration has led to about a fourfold concentration of 137Cs in puddle sediments.

  13. Long-term behaviour of 137Cs in Finnish lakes

    Deposition of 137Cs from Chernobyl accident was unevenly distributed in Finland. This caused large variation to contents of 137Cs in freshwater fish in Finnish lakes. In the course of time environmental processes like runoff, water flow, hydrological cycling, sedimentation and chemical parameters as e.g., K of lake water, topography of the catchment affect the transfer of 137Cs in water sheds. Most of the Finnish lakes are deficient in nutrients and hence the accumulation of 137Cs into fishes is high. High amount of humic substances is also typical of Finnish lakes. About 6000 freshwater fish samples from 350 Finnish lakes have been analysed for 137Cs in 1986-2003. Sampling was focused on the central parts of Finland with highest deposition of 137Cs, but samples from other areas were also analysed. Large lakes, most important for freshwater fishing in Finland, and small oligotrophic lakes, in which the highest contents of 137Cs were expected to be found, were included in the study. Variation range of 137Cs in fish was still in 2003 large, from 5 Bq/kg to 5000 Bq/kg (fresh weight). Water samples from about 30 lakes were taken in 1998 and 2002 and analysed for 137Cs. Contents of 137Cs in lake waters varied then from 4 to 330 Bq/m3. During the first years after the deposition in 1986, the amount of the deposited 137Cs in the lake was the dominant factor on the distribution of 137Cs in fish and surface water. Later study on regional behaviour of 137Cs in fish revealed differences in decrease rates in the large drainage areas [2]. Temporal changes of 137Cs in water and especially in fish in individual lakes of various types, even in those located close to each other, differ still much. Transfer coefficients of 137Cs from the deposition to water, TFw (Bq/m3 in water/kBq/m2 deposited) of the lakes included in this study varied from 0,40 to 8,7 in 1998. Transfer factors from the deposition to various species of fish from various lakes, TFf (Bq/kg in fish / Bq/m2), varied

  14. 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

    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

  15. In situ gamma-ray spectrometric analysis of radionuclide distributions at a commercial shallow land burial site

    Gamma-ray spectrometric analysis conducted at the Maxey Flats, Kentucky (USA) shallow land burial site confirmed that the waste radionuclides have been retained largely within the restricted area of the burial site. Concentrations of 137Cs and 60Co were comparable with those originating from global fallout and lower than concentrations measured in several other areas having similar rainfall. In-situ spectrometric analyses, corroborated by soil sample and vegetation analyses, indicate that the site has influenced 60Co levels slightly in the west drainage channel, but 137Cs did not originate from the site. Concentrations of 60Co, 90Sr and 137Cs determined in subsurface soils by well logging techniques confirmed that subsurface migration of waste-derived radionuclides to points outside the restricted area has not been a significant source of contamination of the environs adjacent to the site. 8 references, 8 figures

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

    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.

  17. 137Cs radioactive dating of Lake Ontario sediment cores

    The distribution of 137Cs in sediment cores from Lake Ontario provides estimates of the sediment accumulation rates. Geochronology with 210Pb dating and distribution of Ambrosia (ragweed) pollen compare well with 137Cs 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

  18. Migratory capacity of 137Cs in water-containing rocks

    The effects of a number of physicochemical and hydrogeologic factors (sorption capacity of rocks, mechanisms of cesium absorption by these, chemical composition of underground waters) on 137 Cs migration in the case of radioactive contamination of underground water in areas of location of atomic power stations have been studied. Approximate equations of ion-exchange sorption may be applied for predicting 137 Cs migration in rocks within the aeration zone and in water-bearing horizons

  19. Phytodemutation effect on the 137Cs redistribution within Chernobyl urbanized landscapes

    The conception of 'radiometry anticipation' is determined. This one used for estimation of gamma-emitting radionuclide contamination dynamics within Chernobyl urbanized landscapes. Estimation of phytodemutation is conducted by analysis of the spatial distributing of trees crowns serriedness ratio. Comparison of the spatial distributing of contamination of soil by a 137Cs and level of Chernobyl urbanized landscapes phytodemutation is executed for period from 1990 to 2006

  20. Transfer of 137Cs through the food chain to man

    Deposition, concentrations in diet, and body burdens of 137Cs have been measured since 1954 at various sites throughout the world. This report is a compilation and updating of various fallout 137Cs measurements and an interpretation of transfer properties of 137Cs from deposition to diet and from diet to man. An empirical model is used to correlate deposition and diet data. Direct foliar contamination, stored food supplies, and uptake from soil contribute to the dietary levels of 137Cs. The accumulation of 137Cs by man is described by a single exponential model. The inferred biological half-times, 200 to 400 days, are somewhat greater than the half-time of about 100 days obtained from shorter term studies. Differences in body burdens due to sex, age, and weight are discussed. During the period 1954 to 1974, the internal dose from fallout 137Cs, based on average body burdens, is estimated to be 4 to 5 percent of the 21 year radiation dose from 40K

  1. Distribution of 137Cs in water leachates of forest humus

    The distribution of 137Cs in water extracts of organic layers of forest soils was investigated using an ultrafiltration method. Samples were taken from two sites in the Bavarian Alps. The different horizons of the organic layers were extracted by column elution with water and 50 mmol/litre CsCl solution. Water extracts were fractionated using membranes with the molecular weight cutoff of 500, 1000 and 3000 Dalton to determine the molecular weight distribution of dissolved organic carbon (DOC). The activity of 137Cs associated with the different DOC-fractions was measured by direct gammaspectrometry. Cesium-137 in the fraction smaller than 500 Dalton was defined as 'ionic'. The results indicated a change of the binding sites depending on the degree of decomposition and humification in the profile. Organic bound 137Cs was identified in all extracts. High mobilities of DOC and 137Cs were observed in the same horizons, fractionation showed then low-molecular-weight DOC and 137Cs mainly in ionic form. In horizons with high-molecular-weight DOC the portion of organic bound 137Cs ranged up to 40%. (author)

  2. Specific activity 137Cs at fishes of Ukraine current state

    Specific activity of 137Cs at fishes of reservoirs of 30 kilometers ChNPP zone (Pripyat river and its bays, lakes, cool-ing-pond of ChNPP, etc.), water basins of Dneprovsky cascade, Shatsky lakes and Black sea near town Sudak is investigated during 2010 - 2012. Levels of specific activity of 137Cs at fishes in many respects are defined by flowage of the reservoir. Normally, the flowage of the reservoir is more, the levels of specific activity of 137Cs at fishes are less. The greatest specific activity of 137Cs at fishes was registered in the north of Ukraine in closed and half-closed reservoirs of 30 kilometers ChNPP zone - to 32000 Bqk/kg. In the southern direction activity of 137Cs at fishes decreases from 4,8 to 78,5 Bq/kg in Kyiv water basin to 1 - 6 Bq/kg, in the Kahovsky water basin and to 0,6 - 1,9 Bq/kg in the Black sea. In large reservoirs the greatest specific activity of 137Cs, as a rule, is registered in fishes of the higher trophic levels

  3. Rate-capability study of a four-gap phenolic RPC with a 137Cs source

    In this paper, we report on the systematic rate-capability study of four-gap phenolic resistive plate chambers (RPCs), with cosmic muons and gamma rays emitted from a 137Cs source. A prototype four-gap RPC with a gap thickness of 1.06 mm has been constructed with 2-mm thick phenolic high-pressure-laminated (HPL) plates. A 32-channel front-end-electronics board, which has been developed for the operation of the current double-gap RPCs in the CMS experiment, was used to digitize the detector signals of the prototype RPC, with charge thresholds of 80, 130, and 170 fC. The cosmic muons were reliably measured with efficiencies of higher than 95%, at a maximum gamma-hit rate of 5 kHz cm−2. The present research confirms that the use of the current four-gap phenolic RPCs is advantageous to the high-η triggers in CMS, by virtue of the high rate capability

  4. Intensity of transmitted photon spectra as a function of transverse and longitudinal dimensions of soil medium using 137Cs

    Transmitted photon spectra (pulse-height distribution) of 137Cs gamma rays are measured through longitudinal and transverse dimensions of the soil medium. The intensity (photon fluence rate) of the multiple-scattered peak, appearing in the lower energy part of the spectrum, has been studied as a function of longitudinal as well as transverse thickness of the soil medium. The intensity of multiple-scatter peak decreases exponentially with the increase in longitudinal thickness of the soil medium, whereas a reverse trend of multiple-scatter peak intensity with transverse thickness occurs as the longitudinal dimension increases. The soil medium as a whole takes part in multiple scattering affecting the intensities of transmitted photons. (authors)

  5. Quantifying Soil Erosion and Deposition Rates in Tea Plantation Area, Cameron Highlands, Malaysia Using 137Cs

    The soil erosion and deposition in the hilly area is a great concern for the planters. In this study, the tea plantation was chosen to quantify the rates of soil erosion and deposition for it will provide information on the improvement of soil conditions and cost reduction of fertilizer consumption. The aims of this research are to determine the rate of soil erosion and deposition using environmental radionuclide, 137Cs. Soil profile samples were collected by using scrapper plate and two cores soil sample were collected in the undisturbed forests area nearby. The 137Cs activity concentration was measured using low background coaxial hyper pure germanium detector gamma spectrometer based on 137Cs gamma energy peak at 661.66 keV. The highest erosion rate using Proportional Models and Mass Balance Model 1 was found in point HE top area which is 52.39 t ha-1 yr-1 and 95.53 t ha-1 yr-1 respectively while the lowest at location HF top which is 4.78 t ha-1 yr-1 and 4.97 t ha-1 yr-1. The deposition rate was higher in HF center which is 216.82 t ha-1 yr-1 and 97.51 t ha-1 yr-1 and the lowest at HE center which is 0.05 t ha-1 yr-1 for both models used. (author)

  6. Biogeochemical behaviour of 137Cs and 90Sr in the artificial reservoirs of Mayak PA, Russia

    Strand, P.; Brown, J.E.; Amundsen, I. [Norwegian Radiation Protection Authority, Grini naeringspark 13, P.O. Box 55, N-1332 Oesteraas (Norway); Drozhko, E.; Mokrov, Y. [Mayak Production Association, 31, Lenin St, 45065 Chelyabinsk-65 (Russian Federation); Salbu, B.; Oughton, D. [Laboratory for Analytical Chemistry, Agricultural University of Norway, N-1432 Aas (Norway); Christensen, G.C. [Institute for Energy Technology, Health and Safety Department, Institute for Energy Technology, P.O. Box 40, N-2007 Kjeller (Norway)

    1999-10-29

    The Mayak Production Association (PA) in the southern Urals, Russia was the site of the first weapons-grade plutonium production reactor complex in Russia. The site and surrounding area have been significantly contaminated by direct discharges of radionuclides for over 40 years, the Techa River alone having received more than 100 PBq of waste in the period 1949-1956. The aim of this study was to consider the levels of 90Sr and 137Cs in water, sediment and biota samples for two industrial reservoirs in the Mayak PA area, thus allowing a biogeochemical assessment of the behaviour of radionuclides in the system. Four sediment cores were collected and sectioned along with four water samples and seven fish samples (pike, perch and roach). Samples were analysed using (1) standard gamma-spectrometric techniques (HPGe and NaI(Tl) detectors) for 137Cs determination; and (2) radiochemical separation and beta-counting (low-background, anti-coincidence and Geiger-Muller counters) for 90Sr determination. Maximum specific activities (dry weight) of 3350 kBq kg{sup -1} {sup 137}Cs and 720 kBq kg{sup -1} {sup 90}Sr were measured in sediments from Reservoir 10. Activity levels of sediment-bound radionuclides in Reservoir 11 were 403 kBq kg{sup -1} {sup 137}Cs and 670 kBq kg{sup -1} {sup 90}Sr. Water concentrations in Reservoir 10 were as high as 100 Bq l{sup -1} {sup 137}Cs and 8.4-14 kBq l{sup -1} {sup 90}Sr. A dramatic decrease in 137Cs concentrations was observed in Reservoir 11, i.e. 1.1-1.5 Bq l{sup -1}, but 90Sr levels fell to a lesser extent, i.e. 1.9-2.4 kBq l{sup -1}. Sediment and water activity data allowed the calculation of distribution coefficients (K{sub d} values). This parameter fluctuated for both radionuclides reflecting the heterogeneous nature of the sediment deposits in the reservoirs. Caesium-137 Concentration Factors (CFs) as high as 1400 l kg{sup -1} were calculated for pike from Reservoir 10. A pronounced 'trophic level' effect was evident in

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

    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. PMID:10081145

  8. A Monte Carlo simulation to study a design of a gamma-ray detector for neutron resonance densitometry

    Tsuchiya, H.; Harada, H.; Koizumi, M.; Kitatani, F.; Takamine, J.; Kureta, M.; Iimura, H.

    2013-11-01

    Neutron resonance densitometry (NRD) has been proposed to quantify nuclear materials in melted fuel (MF) that will be removed from the Fukushima Daiichi nuclear power plant. The problem is complex due to the expected presence of strong neutron absorbing impurities such as 10B and high radiation field that is mainly caused by 137Cs. To identify the impurities under the high radiation field, NRD is based on a combination of neutron resonance transmission analysis (NRTA) and neutron resonance capture analysis (NRCA). We investigated with Geant4 the performance of a gamma-ray detector for NRCA in NRD. The gamma-ray detector has a well shape, consisting of cylindrical and tube type LaBr3 scintillators. We show how it measures 478 keV gamma rays derived from 10B(n, αγ) reaction in MF under a high 137Cs-radiation environment. It was found that the gamma-ray detector was able to well suppress the Compton edge of 662-keV gamma rays of 137Cs and had a high peak-to-Compton continuum ratio, by using the tube type scintillator as a back-catcher detector. Then, we demonstrate that with this ability, detection of 478-keV gamma rays from 10B is accomplished in realistic measuring time.

  9. Distribution of artificial gamma-ray emitting radionuclide activity concentration in the top soil in the vicinity of the Ignalina Nuclear Power Plant and other regions in Lithuania

    Luksiene, Benedikta, E-mail: bena@ar.fi.lt [Center for Physical Sciences and Technology, Savanoriu ave. 231, LT-02300 Vilnius (Lithuania); Marciulioniene, Danute [Nature Research Centre, Akademijos str. 2, LT-08412 Vilnius (Lithuania); Rozkov, Andrej [PLL ' LOKMIS' Radiometry Department, Visoriu 2, LT-08300 Vilnius (Lithuania); Gudelis, Arunas [Center for Physical Sciences and Technology, Savanoriu ave. 231, LT-02300 Vilnius (Lithuania); Holm, Elis [Department of Medical Radiation Physics, Lund University Hospital, SE-22185 Lund (Sweden); Galvonaite, Audrone [Lithuanian Hydrometeorological Service under the Ministry of Environment, Rudnios str. 6, LT-09300 Vilnius (Lithuania)

    2012-11-15

    The impact of the operating Ignalina Nuclear Power Plant (INPP) on the contamination of top soil layer with artificial radionuclides has been studied. Results of the investigation of artificial gamma-ray emitting radionuclide distribution in soil in the vicinity of the INPP and distant regions in Lithuania in 1996-2008 (INPP operational period) show that nowadays {sup 137}Cs remains the most important artificial gamma-ray emitting radionuclide in the upper soil layer. Mean {sup 137}Cs activity concentrations in the top soil layer in the vicinity of the INPP were found to be significantly lower compared to those in remote regions of Varena and Plunge ({approx} 300 km from INPP). In 1996 and 1998 mean {sup 137}Cs activity concentrations were in the range of 28-45 Bq/kg in the nearest vicinity to the INPP, 103 Bq/kg in Varena and 340 Bq/kg in Plunge region. {sup 137}Cs activity concentrations were 5-20 times lower in meadow soil (4-14 Bq/kg) compared to swamp and forest soil. {sup 60}Co, the INPP origin radionuclide, was detected in samples only in 1996 and 2000, and the activity concentration of {sup 60}Co was found to be in the range from 0.4 to 7.0 Bq/kg at the sampling ground nearest to the INPP. Average annual activity concentrations of the INPP origin {sup 137}Cs and {sup 60}Co in the air and depositions in the INPP region were modeled using Pasquill-Gifford equations. The modeling results of {sup 137}Cs and {sup 60}Co depositional load in the INPP vicinity agree with the experimentally obtained values. Our results provide the evidence that the operation of INPP did not cause any significant contamination in soil surface. -- Highlights: Black-Right-Pointing-Pointer Gamma-emitters in top soil were studied during the operational period of the Ignalina NPP. Black-Right-Pointing-Pointer Only {sup 137}Cs was detected in each sample of the top soil in studied regions every year. Black-Right-Pointing-Pointer The mean {sup 137}Cs activity in the top soil of the INPP

  10. Sorption of 137Cs from Aqueous Waste Solutions using Pottery

    A simple and inexpensive method for sorption of 137Cs from aqueous solutions using a highly available vase shape pottery material has been investigated. Porosity of the used pottery allowed for the penetration of the radioactive solution through its permeable body. Two routes had been investigated for cesium removal from the radioactive solutions. In the first one, pottery bodies were immersed into the radioactive solutions. In the second method; the radioactive solutions were filled the inner volumes of the pottery bodies. Vase shape pottery showed higher sorption capability for 137Cs much more than its powder forms, especially in the alkaline medium. Pottery bodies showed high potential for 137Cs removal. Adsorption isotherms revealed good lit to the Freundlich and Langumir isotherms. During sorption processes outside and inside the pottery body, 137Cs was well captured inside the amorphous microstructure of the pottery body. In this respect, micro filtration of cesium radionuclides through the used pottery could be postulated. Desorption experiments indicated higher immobilization affinity for radiocesium into pottery bodies, which indicates a high containment for 137Cs with an irreversible fixation mechanism

  11. Plant remediation of soil contaminated with 137Cs

    A pot experiment was conducted to evaluate the bio-remediation of soils contaminated with 137Cs. The selected plants are Cucurbita moschata Duchesne, Brassica chinensis L, Chloris virgata, Beta oulgaris L. Hongye, Beta oulgaris L. Dongshengye and Beta oulgaris L. The soils samples were taken from the paddy field, 2 km from the Dayawan nuclear power plant and Qinshan nuclear power plant, respectively, and cinnamon soil from the cultivated land in Beijing. The results show that all the employed species of plant have a higher accumulation to 137Cs with the increased grade of the radioactivity of 137Cs. A good correlation exist with the coefficient (r2) of 0.9989. When the contaminated radioactivity of 137Cs is in the same level the uptake of Cucurbita moschata Duchesne, Brassica chinensis L. and Chloris virgata increased with the decrease of pH value ranged 5.22-7.69. The ability of bioremediation in the orders were Chloris virgata, Brassica chinensis L., Beta oulgaris L. Hongye, Cucurbita moschata Duchesne, Beta oulgaris L. and Beta oulgaris L. Dongshengye, according to the comprehensive evaluation of transfer factor, specific activity of plant in dry weight of biomass and total absorption of 137Cs by the individual plant in the same area. (authors)

  12. Determination of 90Sr, 14C, 134Cs and 137Cs activities in total diet

    Full text: According to the EU Recommendation dated 8 June 2000 On the Application of Article 36 of the EURATOM Treaty Concerning the Monitoring of the Levels of Radioactivity in the Environment for the Purpose of Assessing the Exposure of the Population as a Whole, 2000/473/EURATOM) the level of radioactivity in human diet is necessary to be measured for the assessment of radiological affects. Since there has not been any comprehensive work done on this subject in Turkey until now, we proposed a project for a detailed study, comprising the sampling and measurement of 90Sr, 14C, 134Cs and 137Cs in the human diet. Sr-90 and C-14 will be measured with Liquid Scintillation Spectrometry (LSS) and Cs-134 and Cs-137 with Gamma Ray Spectrometry. The sample preparation for Sr-90 and C-14 is a tedious process and should be investigated thoroughly. Sampling will also be a major concern due to the difficulty of finding suitable test subjects. The diets were collected by using double portion method over a three days period from the volunteer laboratory staff and methods for the radiochemical analysis of the diets for 90-Sr and 14-C were tested. The Sr-90 and C-14 activities founded are good agreement with the spiked activity. Real samples will be analyzed by validated methods for Sr-90, C-14, Cs-134 and Cs-137. Studies are still in progress. (author)

  13. Determination of 131I, 134Cs, 137Cs in plants and cheese after Chernobyl accident in Roumania

    Various samples from the south-east region of Roumania (plants, fodder, cheese) were analyzed for 131I, 134Cs and 137Cs concentrations in May and July 1986 by γ-ray spectrometry. For plants, a considerable decrease was observed for 131I (to 3.0-7.0 nCi.kg-1), 134Cs (to 0.5-2.0 nCi.kg-1) and 137Cs (to 1.0-4.0 nCi.kg-1) from the first half (5-15 May) till the end of May 1986. For cheese, maximum values were measured between 5 and 15 May (sheep cottage cheese: 500-800 nCi.kg-1 for 131I, 25-50 nCi.kg-1 for 134Cs, 40-80 nCi.kg-1 for 137Cs); at the beginning of July a considerable decrease (to 5-10 nCi.kg-1 for 131I, 1.2-2.0 nCi.kg-1 for 134Cs, 2.2-3.0 nCi.kg-1 for 137Cs) was observed. In November 1986 a small increase up to 2.0-3.0 nCi.kg-1 for 134Cs and 3.4-5.0 nCi.kg-1 for 137Cs was reported. (author) 4 refs.; 2 tabs

  14. Household methods to reduce 137Cs contents of mushrooms

    High radiocaesium contents in different species of mushrooms have been observed in areas contaminated by radiocaesium deposition after the Chernobyl accident in 1986. There has been no significant reduction in the 137Cs contents of mushrooms during the past ten years, besides via radioactive decay. The internal radiation dose received via mushrooms can be reduced by processing mushrooms before consumption. Various household methods were studied to find out their efficiency to reduce 137Cs contents of mushrooms. The methods tested were the same as normally used in cooking. The tests were made for the species of edible mushrooms widely consumed. The retention factors for the treatments tested were in most cases 0.2-0.3. The efficiency of treatments in reducing the 137Cs contents increased with larger water volumes and prolonged treatment times

  15. 137Cs transfer coefficients from fodder to cow milk

    The transfer of 137Cs from the components of cows' diets to milk was followed in detail on 10 farms in the north-eastern region of Italy (Friuli-Venezia Giulia) from June to July 1988. Samples of milk, grass and other components of the cows' diet were collected regularly and analysed for radiocaesium content. The transfer factors, calculated for 137Cs after a four-week feeding period with contaminated silage, were higher (0.0064) than those calculated in 1987 in the same area (0.0030). This may be attributable to the fact that the 137Cs associated to the forage administrated to cows in 1988 was completely incorporated in the plant and thus more assimilable to the cattle. (Author)

  16. Household methods to reduce {sup 137}Cs contents of mushrooms

    Kostiainen, E. [Radiation and Nuclear Safety Authority - STUK, Helsinki (Finland)

    2005-09-15

    High radiocaesium contents in different species of mushrooms have been observed in areas contaminated by radiocaesium deposition after the Chernobyl accident in 1986. There has been no significant reduction in the {sup 137}Cs contents of mushrooms during the past ten years, besides via radioactive decay. The internal radiation dose received via mushrooms can be reduced by processing mushrooms before consumption. Various household methods were studied to find out their efficiency to reduce {sup 137}Cs contents of mushrooms. The methods tested were the same as normally used in cooking. The tests were made for the species of edible mushrooms widely consumed. The retention factors for the treatments tested were in most cases 0.2-0.3. The efficiency of treatments in reducing the {sup 137}Cs contents increased with larger water volumes and prolonged treatment times.

  17. Transfer of 137Cs into fish in small forest lakes

    The transfer of 137Cs into fish in seepage and drainage lakes from 1988 to 1992 was analysed using linear regression. Empirical results for 137Cs in lake water and fish were used to calculate concentration factors (CFs). In the drainage lakes the CF decreased during the study period by 9% per year whereas in the seepage lakes the CF increased significantly by 4.3% per year. The transfer of 137Cs into pike was significantly (1.6 times) higher than that into perch. The CF increased on average by 3.4% for each 1-cm increase in the median size of perch. The relationship between the water chemistry and the CF differed between clear-water seepage and brown-water drainage lakes.

  18. Determination of 40K and 137Cs concentration in selected honey samples

    Seventeen honey samples collected at different sites during 1992 have been measured using the method of γ-spectroscopy. Measurements were performed by a low background high purity germanium spectrometer of a relative efficiency of 14.5% and an energy resolution of 1.7.keV. Using natural γ-ray sources to determine efficiency, it has been shown that out of 17 samples of natural honey only two (of meadow type) have specific activity of 137Cs greater than 0.5 Bq kg-1. The remaining samples have the same 137Cs concentrations as before May, 1986. Predominant activity in all samples comes from the 40K radionuclide, indicating natural honey. (author) 5 refs.; 1 tab

  19. Analysis of 210 Pb and 137 Cs in diets of university students

    In this work, 210 P and 137 Cs were determined in the male students diets (age: 19-25) of Sao Paulo University, by gamma spectrometry. The sampling was made using the duplicate portion methodology, which consists in collecting duplicate portions of all food and beverage consumed during three days of a week. The levels obtained for 210 Pb in these samples varied from the Minimum Detectable Concentration (0.43 Bq.kg-1 ) to 1.68 Bq.kg-1 . For 137 Cs, the values ranged from the Minimum Detectable Concentration (0.17 Bq.kg-1 ) to 0.95 Bq.kg-1 . An estimate of the daily ingestion of those radionuclides was made according to the data obtained. The values varied from 78 to 309 mBq.d-1 for 210 Pb, and 53 to 157 mBq.d-1 , for 137 Cs, among the diets analyzed. The data obtained these diets agreed with the data obtained for other authors. (author)

  20. Surface activity of 137Cs, sheet 35 - Trnava

    In the predominantly geomorphologically mountainous terrain the map of surface activity of 137Cs was compiled from the results of exploration activities on scale 1:200 000 and in the Danube upland (between Povazsky Inovec and Little Carpathians) on scale 1:50 000. Surface activities of 137Cs are significantly unevenly distributed. The most widespread surface activity of 137Cs in the interval from 1000 to 2000 Bq · m-2 was mapped on mostly continuous area in the central part of map sheet and represents 68.4% of its area. The exception is only a small increase (10,225 Bq · m-2) in Banovska upland south-east from the village Zlatniky. Higher surface activities of 137Cs were registered in the north part of the map sheet. There from neighbouring map sheet (34 - Znojmo) reaches an area of increased values (3000 to 5000 Bq · m-2, max. 6550 Bq · m-2), geomorphologically falling into the western part of the White Carpathians. Relatively high surface activities of 137Cs were found in the south-east part of the map sheet in the Tribec mountains near Skycov (max. 7426 Bq.m-2), in Zitavska flood-plain south of the Zlate Moravce (max. 13962 Bq · m-2), but mainly in Vtacnik and Stiavnicke Hills, where in Nova Bana was measured the maximal surface activity 16497 Bq · m-2. Considering sizeable areal expansion of lower levels of surface activity of 137Cs, the geometric mean (1338 Bq.m-2) on this map sheet corresponds to the national average. (authors)

  1. Changes in 137Cs transfer to agricultural products

    The food production and food harvesting systems common in the areas contaminated by the Chernobyl accident in Republic of Belarus can be grouped into three major categories: collective farm produce, private farming produce and natural foods collected from natural ecosystems. The collective farm system provided the smallest contribution (8-12 %) to the intake of 137Cs. Natural food was the major contributor to the intake at one study site (73 %), and private produce was the major contributor (60 %) at the other study site. Assessment of the situation just after the accident (one year) shows that collective farming was still a minor contributor to 137CS intake (10 %) whilst private fanning would have been the major contributor wherever private milk production and consumption continued. The extent to which inhabitants consume natural foods from forests has a considerable effect on their 137CS intake. The comparative importance of food products from natural ecosystems increases with time due to the long effective ecological half lives of 137Cs in unimproved pastures and forests. Estimation of the contribution to the fluxes of 137Cs from the different production and harvesting systems showed that the contribution from private farming and food harvesting from natural ecosystems may also be significant, contributing 14-30 % to the total fluxes of 137Cs from an area even if the quantity of food produced in these systems is small. However, the major contributor to the flux exported from an area was the collective farming system, accounting for about 70-86 % of the total. Refs. 12 (author)

  2. Characterization of charge carrier collection in a CdZnTe Frisch collar detector with a highly collimated 137Cs source

    A 4.7 x4.7x9.5 mm3 CdZnTe Frisch collar device was characterized through probing the device with a highly collimated 137Cs 662 keV gamma ray source. In a systematic series of experiments, the detector was probed along the length and width with a 137Cs gamma ray source using a 43.0 mm long Pb-collimator with a 0.6 mm circular hole. The detector was probed along the central line under different operating voltages of 1200, 1000, 800, 600 and 400 V. The experimental results correlated well to charge collection calculations for a modeled device with the same size and operating conditions. It was proved that, unlike the planar configuration, the charge collection efficiency profile along the length of Frisch collar device is considerably improved. The CdZnTe raw materials for this study were acquired from Redlen Technologies, and the Frisch collar device was fabricated and characterized at S.M.A.R.T. Laboratory at Kansas State University.

  3. The behaviour of 137Cs in the aquatic environment

    Through 137Cs concentration profiles in sediments from Rochedo Reservoir, it was possible to estimate the amount of this radionuclide (94 TBq) which has reached the Meia Ponte River system, as a consequence of the Goiania Radiological accident in 1987. Based on in-situ measurements as well as on laboratory studies, the influence of NH4+ concentration on the Kd value was also investigated. The results have shown that for high NH4d+ concentrations there is a clear correlation between both parameters. It was also observed the influence on the ageing effect on the 137Cs release from the sediment, as well as of the illite content on it. (author)

  4. Transfer factor values of 137 Cs from latosoils to vegetables

    Transfer Factor values for black beams, radish and carrot were obtained for soils artificially and accidentally contaminated in Goiania during 1987. Differences of 137 Cs-soil-to-plant transfer were discussed in the light of pedology and crop type. These values were about one order of magnitude higher than mean values reported by IUR for temperature climate for the same crops. These results advertising for the peculiar dynamics of 137 Cs in tropical soils and for needs to obtain regional data to be used in assessment dose models. (author)

  5. Declassification of 137Cs liquid wastes by reverse osmosis

    In June 1998, a 137Cs source was accidentally melted in one of the furnaces of a stainless steel production company located in Spain. As a result of this incident, the furnace and its cooling circuit were radioactively contaminated. LAINSA (Logistica y Acondicionamientos Industriales S.A.) company took charge of the plant decontamination process, in which 40 m3, approximately, of 137Cs contaminated water with a mean activity of 300 kBq/L were generated. This company contacted the Chemical and Nuclear Engineering Department of the Polytechnic University of Valencia (UPV) to develop a project for radioactive liquid wastes treatment

  6. Mathematical model of 137Cs dynamics in the deciduous forest

    A mathematical model of 137Cs behaviour in the forest ecosystem is presented. The behaviour of this radionuclide is assumed to obey the same regularities as the behaviour of its stable chemical analogue, potassium. Radionuclide dynamics are considered in parallel with the dynamics of the phytomass. Radionuclides contained in the vegetation are pooled into two basic compartments: external and internal contamination, with separate analysis of each. The model was verified using the data obtained in the 30-km zone of the Chernobyl NPP in 1986-1994. The algorithm described was found to be the most efficient in terms of 137Cs behaviour in the forest environments

  7. Determination of 131I, 134Cs, 137Cs in grass and cheese after Chernobyl accident in Austria

    Various samples from Styria (grass) and Salzburg (cheese) were analyzed for 131I, 134Cs and 137Cs concentration during April - July 1986 by γ-ray spectroscopy. The concentrations are reported in nCi kg-1 wet weight. The values found for 131I were 0.2-17.2 (grass), 0.1-0.5 (cheese), for 134Cs 1.1-6.2 (grass), 0.2-1.3 (cheese), for 137Cs 1.6-15.7 (grass), 0.3-2.2 (cheese). While radioactivity of 131I, 134Cs and 137Cs in cheese samples increased from May to June, it decreased in grass samples from May to July. (author) 5 refs

  8. Digital Logarithmic Airborne Gamma Ray Spectrometer

    Zeng, GuoQiang; Li, Chen; Tan, ChengJun; Ge, LiangQuan; Gu, Yi; Cheng, Feng

    2014-01-01

    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. The spectrometer can clearly distinguish the photopeaks at 239, 352, 583, and 609keV in the low-energy spectral sections after the energy calibration. 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, effectively measuring energy from 20keV to 10MeV is possible.

  9. Reconstruction of 137Cs signal in cuba using 7be as a Tracer of vertical transport processes in the Atmosphere

    The goal of this study is to estimate the 137Cs signal in Cuba using the relation 137Cs/7Be for Miami and Cienfuegos City's obtained for four year and data base of 137Cs concentration in aerosols for Miami since 1957. The temporal behaviour of 137Cs and 7Be in aerosols in the Central and Southern region of Cuba are shown too. Sampling of aerosols was carried out in the Environmental Study Centre (22 grade 03'N, 80 grade 29'W) facilities during June/1994 - December/1998 in Cienfuegos Province. Aerosols were collected by an integral method using the facility Primus I, with 0.65 m2 collection area, 1200 m3h-1 air flux during 7 days collection time. Petrianov filter FPP-15-1.5 was used (efficiency collection of 99% to aerosols 0.3-1.5 mm diameter). After collection, the filters were ashed at 350 grade for 72 hours, put in appropriate geometry and analysed by gamma spectrometry. 137Cs mean concentration in aerosols was 1.09 mBqm-3 and the range of variations was 0.18-3.24 mBqm-3 ; while the 7Be was 4.10 mBqm-3 with 0.96-10.46 mBqm-3 variation range. These results allow to establish a relationship between 137Cs concentrations in aerosols from Cienfuegos and Miami in the same period, normalising in both cases with 7Be values; this normalisation allows to discriminate the variations due to local meteorological conditions and latitudinal position

  10. Time-dependence of 137Cs activity concentration in wild game meat in Knyszyn Primeval Forest (Poland)

    Wild game meat samples were analysed from the region of the Podlasie province (Knyszyn Primeval Forest). 137Cs content in meat was determined by gamma spectrometry in 2003 (33 samples), 2009 (22 samples) and 2012 (26 samples). The samples were collected in the autumn of 2003, 2009 and 2012 and were compared with data from 1996. Mean concentrations of 137Cs in the respective years were as follow: 42.2 Bq kg−1, 33.7 Bq kg−1 and 30.5 Bq kg−1, respectively. On the basis of mean values of 137Cs in the meat samples of red deer (Cervus elaphus), roe deer (Capreolus capreolus) and wild boars (Sus scrofa) between 1996/2012, the effective half-life of 137Cs was determined for specific species. For red deer equaled 8.9 years, for roe deer 11.6 years while for wild boar it exceeded the physical half-life and equaled 38.5 years. Mean value CR obtained for all three species equaled 1.7 ± 1.5 out of 102 measurements in animals muscles. - Highlights: • 137Cs activity concentrations in wild game meat from North-east Poland are presented. • The determined T1/2eff for 137Cs for red deer, wild boar and roe deer. • The results of 16 years of observation are presented. • Significant scattering of results for wild boars was observed. • Concentration ratio (CR) values were calculated out of the results for three species

  11. A long-term performance evaluation of the gamma-ray activity measurement laboratory in CPST, Lithuania.

    Gudelis, A; Gorina, I; Butkus, P; Nedveckaitė, T

    2014-05-01

    The quality control procedures used for two HPGe detectors (a well-type and a GAMMA-X coaxial) are described. Since 2001, check sources containing (137)Cs have been measured weekly for 7200s each, and the gamma-ray spectrometry system background was determined once per month for an acquisition time of 100,000 s. The laboratory participated in the international comparisons at environmental radioactivity level organized by the IAEA, Risø National Laboratory and NPL. PMID:24315285

  12. Coefficients of leaf-fruit translocation for 60Co, 90Sr and 137Cs in bean plant (Phaseolus vulgaris)

    Due to the increasing use of nuclear fission for the generation of electrical energy, the safety aspects of power plants must be minutely appraised. In case of an accident, with liberation of radioactive material into the atmosphere, knowledge about the behavior of plant species when in contact with radionuclides is indispensable. An important route through which agricultural products are contaminated by radionuclides is leaf-fruit translocation. This phenomenon can be evaluated by simulating a fallout contamination in a controlled atmosphere using as a tracer man-made radionuclides. In order to quantity the leaf-fruit translocation coefficients for 60Co, 90Sr and 137Cs in the common bean (Phaseolus vulgaris), variety black diamond, an experiment was carried out in a greenhouse with completely randomized blocks design with six treatments and four blocks. A mixture of these three radionuclides was prepared and used to determine their translocation coefficients. The bean plants were contaminated inside a device especially designed to avoid environmental contamination. In each treatment four vases were sprinkled and one was used to estimate the initial activity of the other three vases. High-resolution gamma-ray spectrometry was used for 60Co and 137Cs activity determinations and chemical separation followed by beta counting of 90Y was used for 90Sr determinations. The number of treatments was reduced from six to four sprayings corresponding to 30, 45, 60 and 75 days after planting. This reduction was due to the attack of common and gold mosaic viroses. Symptoms were observed on the diseased bean plants 50 days after planting. It was possible, however, to verify a functional dependence between instant of tracer application and the level of physiological development of the bean plant. It was verified that the temporal relationship values for leaf-fruit translocation were similar for 60Co and 137Cs. For the 90Sr, the translocation was below 2,5 mBq kg-1/Bq kg-1, 0

  13. Determination of mass attenuation coefficients of soils and water, using a two in-line gamma ray (Cs-137 and Am-241) for three different detection systems

    The monoenergetic gamma ray attenuation technique was used as non-destructive method to determine the bulk density and water content of soils, under laboratory conditions. For simultaneous determination it is necessary to use two sources emitting different gamma ray energy, which requires therefore a greater knowledge of the radiation detection technique. To avoid interference from the source with the greater gamma ray energy in the detection of the lower energy, the two sources can be placed side by side (2 parallel γ-beam) or in such a way that the rays intersect at a 900 angle (2 crossed γ-beam) but do not have the same track in the sample. When two in-line gamma ray sources (2 γ-line) placed in the same shielding are used, in spite of the disadvantage of interference in the detection, the bulk density and water content of the soil are simultaneously evaluated in the same track. The objective of the present work was to instal a double gamma ray beam in line (137Cs - 662 KeV and 241Am - 60 KeV) and to study the interference (by 137Cs on 241Am) detection with three different detectors, and also to estimate the mass attenuation coefficients for soils and water for each gamma ray energy. The interference caused by 137Cs was around 3%, not exceeding 5%, and the mass attenuation coefficient values agreed with those reported in the literature for a single gamma ray (monoenergetic) beam. (Author)

  14. The extraction of 137Cs and 89Sr from waste simulants using pillared montmorillonite

    Two samples of a silica-pillared montmorillonite produced using 3-aminopropyltrimethoxy silane and an alumina-pillared montmorillonite were evaluated for the removal of 137Cs and 89Sr from a simulated nuclear waste solution and a simulated groundwater, and the results were compared to the parent montmorillonite and two zeolites, AW500 (chabazite) and clinoptilolite. The parent and pillared clays were characterized using x-ray powder diffraction and surface area analysis by nitrogen adsorption/desorption studies. The pillared clays exhibited d-spacings of between 17.43 and 18.32 angstrom after calcination, and surface areas ranging from 71.3 to 264.4 m2/g. Both of the silica-pillared clays and the alumina-pillared clay exhibited excellent Kds for 137Cs from simulated groundwater with values of 23,650, 23,260 and 144,570 mL/g, respectively. These were far better than the Kds obtained by clinoptilolite and AW500 which had Kds of only 14,560 and 9,650 mL/g, respectively. None of the pillared clays showed a high selectivity for 89Sr from groundwater or 137Cs from simulated alkaline tank waste. They did, however, show a slight selectivity for 89Sr in the simulated Hanford tank wastes, but this is thought to be due to a precipitation mechanism rather than to ion exchange

  15. Standard test method for determining the content of cesium-137 in irradiated nuclear fuels by high-resolution gamma-ray spectral analysis

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This test method covers the determination of the number of atoms of 137Cs in aqueous solutions of irradiated uranium and plutonium nuclear fuel. When combined with a method for determining the initial number of fissile atoms in the fuel, the results of this analysis allows atom percent fission (burn-up) to be calculated (1). The determination of atom percent fission, uranium and plutonium concentrations, and isotopic abundances are covered in Test Methods E 267 and E 321. 1.2 137Cs is not suitable as a fission monitor for samples that may have lost cesium during reactor operation. For example, a large temperature gradient enhances 137Cs migration from the fuel region to cooler regions such as the radial fuel-clad gap, or, to a lesser extent, towards the axial fuel end. 1.3 A nonuniform 137Cs distribution should alert the analyst to the potential loss of the fission product nuclide. The 137Cs distribution may be ascertained by an axial gamma-ray scan of the fuel element to be assayed. In a mixed-oxide fu...

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

    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%

  17. 137Cs in the fungal compartment of Swedish forest soils

    The 137Cs activities in soil profiles and in the mycelia of four ectomycorrhizal fungi were studied in a Swedish forest in an attempt to understand the mechanisms governing the transfer and retention of 137Cs in forest soil. The biomass of four species of fungi was determined and estimated to be 16 g m-2 in a peat soil and 47-189 g m-2 in non-peat soil to the depth of 10 cm. The vertical distribution was rather homogeneous for two species (Tylospora spp. and Piloderma fallax) and very superficial for Hydnellum peckii. Most of the 137Cs activity in mycelium of non-peat soils was found in the upper 5 cm. Transfer factors were quite high even for those species producing resupinate sporocarps. In the peat soil only approximately 0.3% of the total 137Cs inventory in soil was found in the fungal mycelium. The corresponding values for non-peat soil were 1.3, 1.8 and 1.9%

  18. Radiobiological studies using gamma and x rays.

    Potter, Charles Augustus; Longley, Susan W.; Scott, Bobby R. [Lovelace Respiratory Research Institute, Albuquerque, NM; Lin, Yong [Lovelace Respiratory Research Institute, Albuquerque, NM; Wilder, Julie [Lovelace Respiratory Research Institute, Albuquerque, NM; Hutt, Julie A. [Lovelace Respiratory Research Institute, Albuquerque, NM; Padilla, Mabel T. [Lovelace Respiratory Research Institute, Albuquerque, NM; Gott, Katherine M. [Lovelace Respiratory Research Institute, Albuquerque, NM

    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.

  19. Temporal evolution of 137Cs+, K+ and Na+ in fruits of South American tropical species

    Concentrations of 137Cs, K and Na in fruits of lemon (Citrus limon B.) and of K and Na in fruits of coconut (Cocos nucifera L.) trees were measured by both gamma spectrometry and neutron activation analysis, with the aim to understand the behaviour of monovalent inorganic cations in tropical plants as well as the plant ability to store these elements. Similar amounts of K+ were incorporated by lemon and coconut trees during the growth and ripening processes of its fruits. The K concentration decreased exponentially during the growth of lemons and coconuts, ranging from 13 to 25 g kg−1 dry weight. The incorporation of Na+ differed considerably between the plant species studied. The Na concentration increased linearly during the lemon growth period (0.04 to 0.70 g kg−1 d.w.) and decreased exponentially during the coconut growth period (1.4 to 0.5 g kg−1 d.w.). Even though radiocaesium is not an essential element to plants, our results have shown that 137Cs incorporation to vegetable tissues is positively correlated to K distribution within the studied tropical plant species, suggesting that the two elements might be assimilated in a similar way, going through the biological cycle together. A mathematical model was developed from the experimental data allowing simulating the incorporation process of monovalent inorganic cations by the fruits of such tropical species. The agreement between the theoretical approach and the experimental values is satisfactory along fruit development. - Highlights: ► Concentrations of 137Cs, K and Na in fruits of lemon (Citrus limon B.) are presented. ► Concentrations of K and Na in fruits of coconut (Cocos nucifera L.) are also showed. ► We investigated the use of 137Cs as a tracer for the plant absorption of macronutrients. ► A model was developed to simulate the temporal evolution of 137Cs, K and Na by fruits. ► This model exhibited close agreement with our results along the fruit development

  20. Results of an IAEA inter-comparison exercise to assess 137Cs and total 210Pb analytical performance in soil.

    Shakhashiro, A; Mabit, L

    2009-01-01

    Fallout radionuclides (FRNs) such as (210)Pb and (137)Cs have been widely used to assess soil erosion and sedimentation processes. It is of major importance to obtain accurate analytical results of FRNs by gamma analysis before any data treatment through conversion model and to allow subsequent comparison of erosion and sedimentation rates from different case studies. Therefore, IAEA organized an inter-comparison exercise to assess the validity and reliability of the analytical results of (137)Cs and total (210)Pb using gamma-spectrometry in the various laboratories participating in the IAEA Co-ordinated Research Project on "Assess the effectiveness of soil conservation measures for sustainable watershed management using fallout radionuclides". Reference materials were distributed to 14 participating laboratories and, using a rating system, their analytical results were compared to the reference values assigned. In the case of (137)Cs, the analytical results were satisfactory with 66% of the laboratories producing acceptable results. Only the sample with low (137)Cs activity (2.6+/-0.2Bqkg(-1)) gave less accurate results with more than 25% not acceptable results. The total (210)Pb analysis indicated a clear need for corrective actions in the analysis process as only 36% of the laboratories involved in the proficiency test was able to access total (210)Pb with occurrence (bias 10%). This inter-laboratory test underlines that further inter-comparison exercises should be organized by IAEA or regional laboratories to ensure the quality of the analytical data produced in Member States. As a result of the above-mentioned proficiency test, some recommendations have been provided to improve accurate gamma measurement of both (137)Cs and total (210)Pb. PMID:18760612

  1. Transport of 137Cs to the Southern Hemisphere in an ocean general circulation model

    Tsumune, Daisuke; Aoyama, Michio; Hirose, Katsumi; Bryan, Frank O.; Lindsay, Keith; Danabasoglu, Gokhan

    2011-04-01

    137Cs originating from global fallout is transported into the ocean interior by advection and diffusion, and the 137Cs concentration is reduced by radioactive decay. 137Cs concentrations in the global ocean can be simulated by global integration of the coarse-resolution Parallel Ocean Program to understand the mechanism of material transport in the ocean. We investigated the transport mechanism of 137Cs to the Southern Hemisphere using an ocean general circulation model (OGCM) and compared the simulated results with observations of 137Cs concentrations in the Southern Hemisphere. 137Cs was deposited on the ocean surface mainly as global fallout originating from atmospheric nuclear weapons testing since 1945, and the global distribution of cumulative 137Cs deposition has been reconstructed from global measurements of 137Cs in rain, seawater, and soil. We estimated the global distribution of 137Cs deposition from 1945 to 2003 using these distribution data, 137Cs deposition data observed at the Meteorological Research Institute, Tsukuba, Japan, from 1958 to 2003, and 137Cs deposition data for 1945-1957 estimated from ice-core data. We compared the simulated results with 137Cs sections from the South Pacific, Indian, and South Atlantic Oceans obtained during the BEAGLE2003 cruise in 2003. The simulated 137Cs sections were in good agreement with the observations, except for the effects of mesoscale eddies, which not be simulated by the model because of its coarse resolution. OGCMs can simulate the general pattern of 137Cs distribution in the world’s oceans and improve our understanding of the transport mechanism leading to those 137Cs distributions on a time scale of several decades. The model simulation results suggest that the 137Cs deposited in the North Pacific advected to the South Pacific and Indian Ocean, and then to the South Atlantic over about four decades. The North Pacific is thus an important source area of 137Cs to the Southern Hemisphere.

  2. Deposition of 7Be and 137Cs in Sweden 2001 - 2008. With Radionuclides in ground level air in Sweden. Yearly report 2008

    Deposition of 7Be and 137Cs for four stations in Sweden are reported for the period 2001- 2008. For 7Be a correlation with total precipitation is seen. For 137Cs there is no correlation with precipitation and no correlation with surface air concentrations of 137Cs. The overall levels of 137Cs fallout is higher in areas that were largely affected by the Chernobyl fallout in 1986. The 137Cs deposition seen in the Gaevle area are mostly due to resuspension of this 137Cs fallout, but for other areas the total yearly deposition and resuspension are down to pre Chernobyl levels. Filtering of ground level air is performed continuously at six different locations in Sweden: Kiruna, Umeaa, Gaevle, Kista, Visby and Ljungbyhed. The filters are pressed into weekly samples and the contents of different radionuclides are measured by gamma spectroscopy. Precipitation is also collected at four of the stations: Kiruna, Gaevle, Kista and Ljungbyhed, the samples are ashed and the contents of radionuclides are measured. The levels of Be-7 and Cs-137 during 2008 in air and precipitation are presented for the different stations. Other anthropogenic radionuclides detected, if any, are also presented

  3. Contribution of Asian dust to atmospheric deposition of radioactive cesium (137Cs)

    Both Asian dust (kosa) transported from the East Asian continent and locally suspended dust near monitoring sites contribute to the observed atmospheric deposition of 137Cs in Japan. To estimate the relative contribution of these dust phenomena to the total 137Cs deposition, we monitored weekly deposition of mineral particles and 137Cs in spring. Deposition of 137Cs from a single Asian dust event was 62.3 mBq m-2 and accounted for 67% of the total 137Cs deposition during the entire monitoring period. Furthermore, we found high 137Cs specific activity in the Asian dust deposition sample. Although local dust events contributed to 137Cs deposition, their contribution was considerably smaller than that of Asian dust. We conclude that the primary source of atmospheric 137Cs in Japan is dust transported from the East Asian continent

  4. Distribution of 137Cs radionuclide in industrial wastes effluents of Gresik, East Java, Indonesia

    The distribution of anthropogenic radionuclides 137Cs was measured from industrial waste effluent of Gresik to Gresik Sea in east Java, Indonesia. The activity of 37Cs detected at all stations was much lower than in northeast Japan both before and after NPP Fukushima accident. This indicated that in Gresik industrials waste did not consist of 137Cs. The lowest activity 137Cs occurred at the station nearest to the industrial waste effluent that contained some particle ions that were able to scavenge 137Cs and then precipate this radionuclide. Furthermore, the greatest 137Cs occurred at the station that has high current speeds that stirred up sediment to release 137Cs in seawater as a secondary source. The lowest salinity did not effect on the activity of 137Cs even though the lowest salinity and activity 137Cs occurred at the same station. (author)

  5. Distribution of 137Cs Radionuclide in Industrial Wastes Effluents of Gresik, East Java, Indonesia

    Muslim

    2015-04-01

    Full Text Available The distribution of anthropogenic radionuclides 137Cs was measured from industrial waste effluent of Gresik to Gresik Sea in east Java, Indonesia. The activity of 37Cs detected at all stations was much lower than in northeast Japan both before and after NPP Fukushima accident. This indicated that in Gresik industrials waste did not consist of 137Cs. The lowest activity 137Cs occurred at the station nearest to the industrial waste effluent that contained some particle ions that were able to scavenge 137Cs and then precipate this radionuclide. Furthermore, the greatest 137Cs occured at the station that has high current speeds that stirred up sediment to release 137Cs in seawater as a secondary source. The lowest salinity did not effect on the activity of 137Cs even though the lowest salinity and activity 137Cs occured at the same station

  6. Application of the Monte Carlo code DETEFF to efficiency calibrations for in situ gamma-ray spectrometry

    Carrazana Gonzalez, J.; Cornejo Diaz, N. [Centre for Radiological Protection and Hygiene, P.O. Box 6195, Habana (Cuba); Jurado Vargas, M., E-mail: mjv@unex.es [Departamento de Fisica, Universidad de Extremadura, 06071 Badajoz (Spain)

    2012-05-15

    We studied the applicability of the Monte Carlo code DETEFF for the efficiency calibration of detectors for in situ gamma-ray spectrometry determinations of ground deposition activity levels. For this purpose, the code DETEFF was applied to a study case, and the calculated {sup 137}Cs activity deposition levels at four sites were compared with published values obtained both by soil sampling and by in situ measurements. The {sup 137}Cs ground deposition levels obtained with DETEFF were found to be equivalent to the results of the study case within the uncertainties involved. The code DETEFF could thus be used for the efficiency calibration of in situ gamma-ray spectrometry for the determination of ground deposition activity using the uniform slab model. It has the advantage of requiring far less simulation time than general Monte Carlo codes adapted for efficiency computation, which is essential for in situ gamma-ray spectrometry where the measurement configuration yields low detection efficiency. - Highlights: Black-Right-Pointing-Pointer Application of the code DETEFF to in situ gamma-ray spectrometry. Black-Right-Pointing-Pointer {sup 137}Cs ground deposition levels evaluated assuming a uniform slab model. Black-Right-Pointing-Pointer Code DETEFF allows a rapid efficiency calibration.

  7. Dietary items as possible sources of (137)Cs in large carnivores in the Gorski Kotar forest ecosystem, Western Croatia.

    Šprem, Nikica; Piria, Marina; Barišić, Domagoj; Kusak, Josip; Barišić, Delko

    2016-01-15

    The mountain forest ecosystem of Gorski Kotar is distant from any significant sources of environmental pollution, though recent findings have revealed that this region is among the most intense (137)Cs contaminated area in Croatia. Therefore, the aim of this study was to investigate (137)Cs and (40)K load in three large predator species in the mountain forest ecosystem. Radionuclides mass activities were determined by the gamma-spectrometric method in the muscle tissue of brown bear (47), wolf (7), lynx (1) and golden jackal (2). The highest (137)Cs mass activity was found in lynx (153 Bq kg(-1)), followed by brown bear (132 Bq kg(-1)), wolf (22.2 Bq kg(-1)), and golden jackal (2.48 Bq kg(-1)). Analysis of 63 samples of dietary items suggests that they are not all potentially dominant sources of (137)Cs for wildlife. The most important source of radionuclides for the higher parts of the food-chain from the study area were found to be the mushroom species wood hedgehog (Hydnum repandum), with a transfer factor TF of 5.166, and blueberry (Vaccinium myrtillus) as a plant species (TF=2.096). Food items of animal origin indicated higher mass activity of radionuclides and therefore are possible moderate bioindicators of environmental pollution. The results also revealed that possible unknown wild animal food sources are a caesium source in the study region, and further study is required to illuminate this issue. PMID:26556746

  8. Results of an IAEA inter-comparison exercise to assess 137Cs and total 210Pb analytical performance in soil

    Fallout radionuclides (FRNs) such as 210Pb and 137Cs have been widely used to assess soil erosion and sedimentation processes. It is of major importance to obtain accurate analytical results of FRNs by gamma analysis before any data treatment through conversion model and to allow subsequent comparison of erosion and sedimentation rates from different case studies. Therefore, IAEA organized an inter-comparison exercise to assess the validity and reliability of the analytical results of 137Cs and total 210Pb using γ-spectrometry in the various laboratories participating in the IAEA Co-ordinated Research Project on 'Assess the effectiveness of soil conservation measures for sustainable watershed management using fallout radionuclides'. Reference materials were distributed to 14 participating laboratories and, using a rating system, their analytical results were compared to the reference values assigned. In the case of 137Cs, the analytical results were satisfactory with 66% of the laboratories producing acceptable results. Only the sample with low 137Cs activity (2.6±0.2 Bq kg-1) gave less accurate results with more than 25% not acceptable results. The total 210Pb analysis indicated a clear need for corrective actions in the analysis process as only 36% of the laboratories involved in the proficiency test was able to access total 210Pb with occurrence (bias ≤10%). This inter-laboratory test underlines that further inter-comparison exercises should be organized by IAEA or regional laboratories to ensure the quality of the analytical data produced in Member States. As a result of the above-mentioned proficiency test, some recommendations have been provided to improve accurate gamma measurement of both 137Cs and total 210Pb

  9. Behaviour of 137Cs in the Boreal forest ecosystem of central Sweden

    Behaviour of Chernobyl fallout 137Cs in a coniferous forest ecosystem in central Sweden was investigated between 1990 and 1994. Results demonstrated that forest soil belongs to nutrient deficient type, and deposited fallout 137Cs from Chernobyl nuclear accident (CNA) was retained (85%) in the upper 5 cm of humic forest soil layer, with a venial migration deeper into soil profile. No correlation between forest soil exchangeable and total potassium (K+) and 137Cs transfer parameters was observed. However, addition of K+, found to efficiently reduce 137Cs uptake by sheep's fescue and the addition of stable caesium (133Cs+) enhanced it. The addition of ammonium (NH4+) was slightly stimulating the uptake of 137Cs by sheep's fescue in the first cut only. Field plants showed a considerably reduction in their 137Cs activity concentrations. Relative to their 137Cs levels of 1986-89, a little reduction in heather (16%) occurred eight years after CNA. In contrast the reductions in lingonberry and bilberry were 87% and 68%, respectively. Three fractions of forest soil bound 137Cs were observed due to sequential extraction procedure (SEP). The first, is easily extractable 137Cs fraction (F1+F2), it comprises 22% of total forest soil 137Cs inventory in the upper 5 cm layer. The second, is soil organically and biologically bound 137Cs (F3+F4) comprises about 30% of soil bound 137Cs. This fraction might be accounted for long-term soil available 137Cs for plant uptake after bio-degradation processes by soil microorganisms. The third, is the residual fraction (F5), it comprises more than 35% of total forest soil 137Cs inventory, and may be associated with soil components which are probably of organic nature. Sorption of 137Cs by zeolite (Mordenite) revealed that soil bound 137Cs is to some extent more mobile in forest soils with high OM% and low pH than those with low OM%. 99 refs

  10. Geographic zones with increased migration of 137Cs from environment into food stuffs

    Increased 137Cs migration from the environment into the human organism through the biological lichen-deer-man chain in the arctic region is considered. Levels of 137Cs content in lichen and deer meat are presented. The degree of 137Cs migration in the wooded district on food stuffs of local production (milk, mushrooms, meat) is presented. The increased 137Cs content is found in food stuffs of animal and vegetable origin in the wooded district due to peculiarities of natural conditions

  11. Fractionation of caesium (137Cs) in coniferous forest soil in central Sweden

    Sequential extraction procedure (SEP) was applied for fractionation of Chernobyl fallout 137Cs bound onto soils of a coniferous forest ecosystem located in central Sweden. Results of sequentially extracted 137Cs fractions demonstrated that 8% (mean value) of the total deposited 137Cs was water soluble (F1) and 13% was NH4OAc extractable (F2). Oxidation of F2 residuals by H2O2 led to a release of 15% of soil-bound 137Cs (F3). Acid digestion of F3 residuals showed a possibility of releasing an extra amount of soil-bound 137Cs, 22% of the total soil 137Cs inventory (F4). These two fractions (F3 and F4) include strongly bound 137Cs that seems to require longer biodegradation processes by soil microflora and microfauna before becoming available for uptake by plants and fungi. More than 37% of the total soil 137Cs inventory was bound onto soil residuals in a non-extractable form that includes slowly degradable organic matter and other soil residual compartments. The distribution coefficient (Kd) was rather low and shows an inverse relation with the increase of percentage of soil organic matter, which indicates a week binding of 137Cs onto forest soil. In contrast, chemical fractionation of soil bound 137Cs showed a substantial fraction of 137Cs was strongly bound onto soil as organically bound 137Cs. Apparently, the binding processes of radiocaesium onto forest soil seems to be time dependent

  12. Radioactivity Levels and Gamma-Ray Dose Rate in Soil Samples from Kohistan (Pakistan) Using Gamma-Ray Spectrometry

    Hasan M. Khan; M. Ismail; K. Khan; P. Akhter

    2011-01-01

    The analysis of naturally occurring radionuclides (226Ra, 232Th and 40K) and an anthropogenic radionuclide 137Cs is carried out in some soil samples collected from Kohistan district of N.W.F.P. (Pakistan), using gamma-ray spectrometry. The gamma spectrometry is operated using a high purity Germanium (HPGe) detector coupled with a computer based high resolution multi channel analyzer. The speciSc activity in soil ranges from 24.72 to 78.48Bq·kg-1 for 226Ra, 21.73 to 75.28Bq·kg-1 for 232Th, 7.06 to 14.9Bq·kg-1 for l37Cs and 298.46 to 570.77Bq·kg-1 for 40K with the mean values of 42.11, 43.27, 9.5 and 418.27Bq·kg-1, respectively. The radium equivalent activity in all the soil samples is lower than the safe limit set in the OECD report (370Bq·kg-1). Man-made radionuclide 137Cs is also present in detectable amount in all soil samples. Presence of 137Cs indicates that the samples in this remote area also receive some fallout from nuclear accident in Chernobyl power plant in 1986. The internal and external hazard indices have the mean values of 0.48 and 0.37 respectively. Absorbed dose rates and effective dose equivalents are also determined for the samples. The concentration of radionuclides found in the soil samples during the present study is nominal and does not pose any potential health hazard to the general public.

  13. Uncertainty in the modelling of 137Cs turnover in lakes

    In the context of the IAEA-CEC co-ordinated research programme on Validation of Environmental Model Predictions (VAMP), a generic model for lake ecosystems has been tested under a variety of environmental conditions. The main emphasis has been placed on predicting the levels of 137Cs in water and predatory fish, which are of most concern from a radiological point of view. 2 figs

  14. Activity of 137Cs in mushrooms from Slovak Republic

    In this paper, activity concentrations of radiocesium in mushrooms from various locations in the Slovak Republic during the year 2001 are presented. The highest activity concentration of 137Cs measured was 966 Bq/kg, for Suillus luteus from Senica. Mushrooms belonging to Boletaceae which grow in Central Europe are not only bio-indicators of the environmental contamination with radiocesium, but might also represent depending on their actual radiocesium contamination - some risk factor if consumed too extensively. (authors)

  15. Standardization of 137 Cs+137m Ba by Liquid Scintillation

    A procedure for the preparation of a stable, homogeneous solution of ''137 Cs+''137m Ba, for use in liquid scintillation measurements, is described. Its count rate stability and spectral time evolution has been followed for several weeks. The solution has been standardised by the CIEMAT/NIST method in both Ultima-Gold and Insta-Gel, to a combined uncertainty lower than 0,51% (k=1)

  16. 137Cs and 210Pb distribution in Manila Bay sediment

    Two radionuclides were measured in surface sediment samples taken from geographically distributed sections of Manila Bay, namely cesium-137 (137Cs) and lead-210 (210Pb). Results indicated a noticeable change in the radioactivity concentration levels in sediments collected in 2005 and 2010, with a median concentration of 1.0 and 2.64 Bq kg-1, respectively. Higher levels of 137Cs radioactivity were measured in the northern and inner portion of the bay adjacent to major river systems, agricultural and highly industrialized urban areas. 137Cs isotope increased in activity in most of the samples especially in the northwestern areas of Bataan and Pampanga with five times more than the activity from the first sampling measurements. Nevertheless, radioactivity concentrations observed in surface sediments along the bay are within the range of radioactivity in several areas monitored in the Northern Hemisphere. The country has been frequented by tropical cyclones and storms that have caused erosion, which may have introduced elevated material input in the bay. In addition, wind-driven circulation especially in the shallower areas of the bay is a possibility for the substantial sediment movement and accumulation along this coast. Conversely, areas with higher 137Cs have lower values of 210Pb. In an undisturbed environment, 210Pb deposition values are assumed nearly constant. Hence, changes in the radioactivity concentration levels of these radionuclides can be an indicator of pollution input from land-based sources, sediment movement and reworking in the coastal areas. At present, there is very limited information on the radioactivity level of various radioisotopes in Manila Bay.The data obtained are benchmark values against which changes that will be occurring in the bay can be assessed. (author)

  17. Study on accumulation of 137Cs in aquatic organisms

    FengDing-Hua; CheungT

    1998-01-01

    The organisms were cultivated for 7d in well water contaminated with 137Cs,The experimental results show that the accumulation level of tissues of carassius auratus had the order of gill>viscera>epidermis(including scales)>bone(including head and tail)>flesh.The concentration capability of them had the order of shrimp>carassius auratus>ophiocephalus argus,The concentration factors(CF) of shrimp was 12.6 times of that of ophiocephalus argus.

  18. Leaching of /sup 137/Cs from an epoxide resin

    Leaching of /sup 137/Cs has been found to be independent of surface-area-to-volume ratio and leachant renewal frequency. Short-term leaching can be satisfactorily described by a simple diffusion model. Longer-term data are better explained by including a first-order reaction combined with diffusion. γ-irradiation to 10/sup 7/ Gy has little effect on leaching behaviour of samples containing IX resin

  19. 137Cs, trace and toxic elements distribution in Austrian mushrooms

    Various mushroom species have been analyzed for their elemental composition (i.e., Al, B, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, P, Sr and Zn) by means of ICP-AES. The accuracy of the measurements was confirmed by analyzing a series of the same samples by short time activation analysis. The data were evaluated statistically including the values of 137Cs. The results denote that the distribution of these elements and their correlation coefficients are highly distinctive for each mushroom species. K, Na and P were found to correlate negatively with 137Cs in most species. Suillus grevillei and Cantharellus cibarius show high Be values (0.27 and 0.30 μg g-1, respectively), while Pb was high in Suillus grevillei (16.3 μg g-1) and Amanita rubescens (9.3 μg g-1). Higher levels of Cd were found in Rozites caperata and Russula vesca with a mean of 9.2 and 16.1 μg g-1, respectively. Cluster analysis was applied to classify these samples according to their botanical species using their elemental composition . The concentrations of Al, Cr, Mn, Na and 137Cs have no influence on the classification of these samples. (author) 9 refs.; 3 figs.; 3 tabs

  20. Natural radionuclides and 137Cs in commercialized edible mushrooms in Sao Paulo-Brazil

    Artificial and natural radionuclides are commonly found in several compartments of the earth's crust. Some mushroom species have a high capacity to absorb radionuclides and toxic elements from the soil. Diet is considered as one of the main routes of radioactive contamination. Therefore, radioactivity measurements in the environment and in food are extremely important to monitor the radiation levels that human can be exposed to either directly or indirectly. Environmental bio monitoring has demonstrated that diverse organisms such as crustaceans, fish and mushrooms are useful when evaluating both the contamination and the quality of the ecosystems. There are actually several radionuclides that can be accumulated in mushrooms, including 40K, 137Cs, 232Th and 238U. There are few studies in the Southern hemisphere countries, on the natural and artificial radioactivity levels in mushrooms. The present study evaluated 40K, 137Cs, 232Th and 238U in commercialized edible mushrooms in the state of Sao Paulo, Brazil. The edible mushroom samples were acquired in different commercial establishments in the Sao Paulo metropolitan region, specifically in Municipal Markets. Some samples were acquired directly from producers located in the cities of Mogi das Cruzes, Mirandopolis, Suzano and Juquitiba. About 400g were collected for each edible mushroom species, which included Agaricus sp, Pleurotus sp and Lentinula sp species. All the samples were prepared and stored in polyethylene bottles for approximately 35 days, so that secular equilibrium could be established before counting. The 40K, 137Cs, 232Th and 238U gamma activities were measured by gamma spectrometry. The equipment consisted of a Hyper pure Germanium detector connected to an electronic system. The detector efficiency was obtained from measurements of reference materials: IAEA-300, IAEA-327 and IAEA-375. The results for the specific activities in edible mushrooms samples ranged fi-om 461 to 1535 Bq kg-1, 1.4 to 10.6 Bq

  1. Comparative study of neutron and gamma-ray pulse shape discrimination of anthracene, stilbene, and p-terphenyl

    Solid state organic scintillators, such as anthracene, stilbene, and p-terphenyl were investigated on their basic scintillation properties and neutron–gamma discrimination capabilities. Scintillation wavelengths under X-ray irradiation of anthracene, stilbene, and p-terphenyl were 445–525, 400–500, and 350–450 nm, respectively. Scintillation light yields of anthracene, stilbene, and p-terphenyl under 137Cs gamma-ray irradiation were 20100, 16000, and 19400 ph/MeV, respectively. Neutron and gamma-ray events discrimination capabilities were examined and anthracene exhibited the best figure of merit among three organic scintillators

  2. Comparative study of neutron and gamma-ray pulse shape discrimination of anthracene, stilbene, and p-terphenyl

    Yanagida, Takayuki, E-mail: yanagida@lsse.kyutech.ac.jp [Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu, Kitakyushu, Fukuoka 808-0196 (Japan); Watanabe, Kenichi [Nagoya University, Furocho, Chikusa, Nagoya 464-8603 (Japan); Fujimoto, Yutaka [Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu, Kitakyushu, Fukuoka 808-0196 (Japan)

    2015-06-01

    Solid state organic scintillators, such as anthracene, stilbene, and p-terphenyl were investigated on their basic scintillation properties and neutron–gamma discrimination capabilities. Scintillation wavelengths under X-ray irradiation of anthracene, stilbene, and p-terphenyl were 445–525, 400–500, and 350–450 nm, respectively. Scintillation light yields of anthracene, stilbene, and p-terphenyl under {sup 137}Cs gamma-ray irradiation were 20100, 16000, and 19400 ph/MeV, respectively. Neutron and gamma-ray events discrimination capabilities were examined and anthracene exhibited the best figure of merit among three organic scintillators.

  3. Whole-body 137Cs and 137Cs levels in the Greek population following the 1986 Chernobyl accident

    One of the consequences of the reactor accident at Chernobyl was the contamination of foodstuffs with 134Cs and 137Cs. Whole-body measurements were carried out over a four year period to determine the committed effective dose to the Greek population from internal contamination with 134Cs and 137Cs. The mean 50 year committed effective dose in residents of Ioannina was found to be 495 μSv for men, 330 μSv for women and 300 μSv for children. Measurements on subjects living in other parts of Greece showed that the average level of internal contamination over the country was about 10% higher than Ioannina, resulting in a 4.5 kSv collective effective dose to the Greek population. (author)

  4. Dissolution behavior of 137Cs absorbed on the green tea leaves

    The green tea leaf was dipped in the 137CsCl solution to elucidate the dissolution behavior of 137Cs. The IP observation showed that 137Cs was not uniformly adsorbed on the tea leaf, even if the tea leaf was dipped in the homogeneous solution. The activation energy of 137Cs dissolution was estimated to be 0.045 eV, indicating that most of 137Cs would exist as the adsorbed state. The dissolution behaviors as a function of cesium and potassium concentrations and pH, were also studied. (author)

  5. Dissolution behavior of 137Cs absorbed on the green tea leaves

    The green tea leaves was dipped in the 137CsCl solution to elucidate the dissolution behavior of 137Cs contaminated on the green tea leaves. It was found that the amount of 137Cs dissolved into tea water was controlled by the temperature of water, and the activation energy of 137Cs dissolution was estimated to be 0.045 eV, indicating that most of 137Cs would exist as the adsorbed state. In addition, the dissolution behavior was controlled by the concentration of stable Cs dissolved in water, although no large correlation with pH was observed. (author)

  6. Effect of deposit feeders on migration of 137Cs in lake sediments

    Illite clay particles with adsorbed 137Cs were added as a submillimeter layer to the surface of silt-clay sediments contained in rectangular Plexiglas cells stored in a temperature-regulated aquarium, in order to trace the effect of the oligochaete, Tubifex tubifex, and the amphipod, Pontoporeia hoyi, on mass redistribution near the sediment-water interface. A well-collimated NaI gamma detector scanned each sediment column (approximately 10 cm deep) at daily or weekly intervals of six months, depicting the time evolution of radioactivity with and without added benthos. In a cell with tubificids (approximately 5 X 104 m-2), which feed below 3 cm and defecate on surface sediments, the labeled layer was buried at a rate of 0.052 +- 0.007 cm/day (200C). When labeled particles entered the feeding zone, 137Cs reappeared in surface sediments creating a bimodal activity profile. In time, the activity tended toward a uniform distribution over the upper 6 cm, decreasing exponentially below to undetectable levels by 9 cm. In a cell with amphipods (approximately 1.6 X 104 m-2) uniform activity developed rapidly (approximately 17 days) down to a well-defined depth (1.5 cm). The mixing of sediments by Pontoporeia is described by a simple quantitative model of eddy diffusive mixing of sediment solids. The value of the diffusion coefficient, 4.4 cm2/yr (70C) was computed from a least squares fit of theoretical to observed profile broadening over time. In a cell without benthos, small but measurable migration of 137Cs indicated an effective molecular diffusion coefficient of 0.02 cm2/yr. (Auth.)

  7. Gamma-ray methods

    Bulk analysis techniques using gamma radiation are described. The methods include gamma-ray induced reactions, selective gamma-ray scattering and methods which rely on natural radioactivity. The gamma-ray resonance scattering technique can be used for the determination of copper and nickel in bulk samples and drill cores. The application of gamma-gamma methods to iron ore analysis is outlined

  8. Relationship between 137Cs concentration and cultivated history on loessial hillslopes

    There are close linkages between soil loss degree and soil disturbance degree by human. So it is a key problem to know that how human activity affects soil loss. To analyse the correlation of 137Cs loss degree with hillslopes' cultivated histories, the concentrations of 137Cs on different kinds of loessial hillslopes with different cultivated histories, abandoned ages and different patterns of reforestation are studied. The result shows that there is a linear relationship among 137Cs areal concentrations, cultivation ages and slope gradients. the regressive equation is as follows: X=2356.79-22.77 t-35.53 S. Variant coefficient of 137Cs areal concentration is 80.11% among hillslopes with different abandonment ages. It is also deduced that 137Cs areal concentration is affected primarily by abandonment ages of hillslopes. The 137Cs loss rates of hillslopes with different vegetation restoration manners show significant differences, as a whole, autogenic restoration 137Cs area concentrations on hillslopes. (authors)

  9. The Danish airborne gamma-ray surveying results

    Hovgaard, J. [Danish Emergency Management Agency, Birkeroed (Denmark)

    1997-12-31

    The Danish Emergency Management Agency (DEMA) in co-operation with the Technical University of Denmark (TUD), Department of Automation, participated in the international exercise RESUME-95 arranged in Finland in August 1995. DEMA performed measurement with their airborne gamma-ray surveying system. Surveys were done in the three areas known as AREA I, II, III. Results from AREA II (3 km x 6 km) show that the apparent {sup 137}Cs deposition assuming a deposition profile equal to the profile in AREA I based on soil samples varies from a few 10th kBqm{sup -2} up to 110 kBqm{sup -2}. However, a detailed analysis using a new method, Noise Adjusted Singular Value Decomposition (NASVD), shows that the true variations probably are smaller and that the observed differences to some extend are due to major variations in the depth distribution of the cesium. For example agricultural areas appears to have cesium much deeper deposit than the undisturbed areas. Another interesting result is that the NASVD analysis shows that the ration of {sup 134}Cs to {sup 137}Cs is fixed and approximately 0.03 (August 1995) a number in good agreement with the expected ratio from the Chernobyl accident. No true real-time software for source detection is yet integrated in the Danish system. Results from AREA III, however, show that the implemented software for rapid post processing of data worked excellent for detection of radioactive sources. Post analysis using NASVD demonstrates that all sources except for a small {sup 137}Cs source can be localized. (au).

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

    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.

  11. Monitoring of Chernobyl fallout 137Cs in semi-natural coniferous forest of central Sweden

    Monitoring the behaviour of 137Cs in semi-natural coniferous forest ecosystem of central Sweden was investigated between 1990 and 1994. Results demonstrated that soil in the area of study is thin layer characterised with high organic matter fraction and acidic pH. Most of Chernobyl fallout deposited 137Cs retained in the upper 5 cm with venial migration into deeper layers of soil profile The activity concentration of 137Cs in the dominant plants showed some variation, which presumed to be due to high variations in the different soil parameters and species-specificity of plants in 137Cs uptake. Fractionation of soil bound 137Cs using sequential extracted procedure predicted that easily extractable 137Cs fraction that includes water soluble and NH4OAc exchangeable comprises ∼25% of total soil radiocaesium inventory in the upper 5 cm layer of forest soil. These fractions, represent the soil mobile 137Cs in the forest ecosystem. About 37% of total forest soil 137Cs inventory could be accounted for soil organically bound 137Cs that include oxidizable and acid digestible organic matter. These fractions require a long term big-degradation process by soil micro-organisms, before becoming available for plant uptake. More over a substantial fraction Of 137Cs was firmly bound onto soil compartments of organic and/or mineral nature as a residual (36%). This means that binding processes of 137Cs onto humic forest soil with high fraction of organic matter and acidic reaction is time dependent. The most distinguished soil parameters that might influenced 137Cs transfer to and/or uptake by natural plants in the area of study were soil OM%, and soil pH. Soil biological activity might also be considered, (although it was not determined in this study). The long term 137Cs availability in this type of forest soil must be related to the organically bound 137Cs fractions. (author)

  12. Incorporation of {sup 137}Cs by tropical tree species and its correlation with plant physiology

    Cid, Alberto Silva; Anjos, Roberto Meigikos dos; Macario, K.D.; Veiga, R.; Ayubi, J. Juri; Lacerda, T. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Instituto de Fisica; Zamboni, C.B.; Medeiros, I.M.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN- SP), Sao Paulo, SP (Brazil); Velasco, H.; Rizzotto, M. [Universidad Nacional de San Luis (UNSL) (Argentina). Instituto de Matematica Aplicada San Luis; Audicio, P. [Facultad de Ciencias (UDELAR), Montevideo (Uruguay). Centro de Investigaciones Nucleares

    2011-07-01

    Environmental phenomena associated with potential releases of radionuclides to terrestrial ecosystems have attracted the interest of several researches around the world. However, such interest has not been focused exclusively in its effects on human health. Several radionuclides have also been used as tracers of physicochemical or biological phenomena. These studies depend on both the development of auxiliary analysis techniques, which help to improve the results of traditional methods, and the production of additional data, so that a wide variety of natural processes can be understood. In this sense, the same radiometric results can be analyzed or interpreted from different viewpoints, allowing the interdisciplinary understanding of the overall structure of terrestrial ecosystems. {sup 137}Cs, for example, is one of the main fission products of nuclear reactors and atmospheric nuclear testing that is persistent in the biosphere because of its half-life of 30.2 years and biological mobility. This radionuclide remains in the top soil due to fixation and adsorption to clay minerals and organic matter, persisting in the root zone of plant for a long period of time. As its chemical behavior is similar to other monovalent inorganic cations (such as NH{sup +}{sub 4} , Na{sup +} and K{sup +}), Cs{sup +} can be readily absorbed by roots and translocated to the aboveground parts of plant. In this work, concentrations of {sup 137}Cs{sup +}, K{sup +} and Na{sup +} in fruits of lemon (Citrus limon B.) and coconut (Cocos nucifera L.) were measured by both gamma spectrometry and neutron activation analysis, with the aim to understand the behavior of monovalent inorganic cations in tropical plants as well as the plant ability to store these elements. In contrast to K{sup +} and Na{sup +}, Cs{sup +} is not an essential element to plants. However, our results have shown that {sup 137}Cs{sup +} incorporation to vegetal tissues is positively correlated to K{sup +} distribution inside

  13. Time-dependent modelling of 137Cs migration in Estonian soil profiles

    Our first countrywide study carried out in 1991-1993 determined both geographical and depth distributions of the deposited 134Cs and 137Cs in the Estonian soil. According to the results of this study and an independent air-borne scanning, radiocaesium originating from the 1986 Chernobyl accident with the mean deposition of 2 kBq m-2 was extremely unevenly distributed over the country . The mapped distribution is presented in Fig. 1. Our estimates demonstrated that about 2/3 of the total 137Cs inventory in Estonia was deposited in Ida-Virumaa County, NE Estonia, where the maximum depositions reached 40 kBq m-2. The region was revisited for soil sampling in 1998-2001. Undisturbed soil profiles down to a depth of ∼ 20 cm were collected and the 2-3 cm sample core slices analyzed using a low-background HPGe gamma spectrometer (42% efficiency and 1.7 keV resolution). As in the previous study, both total depositions and depth distributions of the deposited 134Cs (where possible) and 137Cs activity concentrations were determined. Depth distributions of the deposited activity showed considerable site-specific variations. In addition, it appeared that in comparison with our previous study, clear features of time-dependent migration to deeper soil layers were evident. The preliminary modeling has demonstrated that a lognormal distribution with varying parameters fits satisfactorily the determined depth-distributions of the Chernobyl radiocaesium activity concentration. An attempt was made to apply a single model to describe the observed time-dependent depth-distribution pattern over the time period of 1986-2001. We started from the multi-compartmental migration model for undisturbed soil (here Model RP72), presented in Fig. 2. This model has been elaborated basing on experimental migration results for Pu for a time period up to 30 y. For our application, the model is modified to account for the radioactive decay of 137Cs. The results of modeling using the original transfer

  14. Application of a CdTe gamma-ray spectrometer to remote characterization of high-level radioactive waste tanks

    Keele, B.D.; Addleman, R.S.; Blewett, G.R.; McClellan, C.S.; Subrahmanyam, V.B.; Troyer, G.L.

    1991-10-01

    Small, shielded cadmium telluride (CdTe) semiconductor gamma-ray detectors have been used for in situ radiological characterization of underground high-level radioactive waste tanks. Remote measurements up to 700 R/h have been made in gamma radiation fields. Spectral data have been used to generate qualitative and quantitative radionuclide profiles of high-level radioactive waste tanks. Two electronic spectral enhancement techniques (pulse risetime discrimination and pulse risetime compensation) have been used in order to measure trace isotopes in the presence of large amounts of {sup 137}Cs. Spectral resolution better than 1.5% FWHM for the {sup 137}Cs 662 keV photopeak has been obtained. 4 refs., 7 figs.

  15. A long-term performance evaluation of the gamma-ray activity measurement laboratory in CPST, Lithuania

    The quality control procedures used for two HPGe detectors (a well-type and a GAMMA-X coaxial) are described. Since 2001, check sources containing 137Cs have been measured weekly for 7200s each, and the gamma-ray spectrometry system background was determined once per month for an acquisition time of 100,000 s. The laboratory participated in the international comparisons at environmental radioactivity level organized by the IAEA, Risø National Laboratory and NPL. - Highlights: • Check sources and background measurements support quality control. • Results obtained in 2001–2013 are presented. • No traces of 137Cs peak at 661.7 keV were observed in the background spectra. • Participation in proficiency-testing programmes is an endeavour of perfection

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

    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. PMID:26760221

  17. Adsorption models of {sup 137}Cs radionuclide and Sr (II) on some Egyptian soils

    Kamel, Nariman H.M., E-mail: Narimankamel@hotmail.co [Radiation Protection Department, Nuclear Research Center, Atomic Energy Authority, P.O. Box 13759, Cairo (Egypt)

    2010-04-15

    Distribution of cesium ({sup 134}Cs and {sup 137}Cs) and strontium (Sr-II) between soil/water phases depends on many factors such as concentration of these ions between phases, the cation exchange capacity (CEC) of the soil as well as its clay content, chemical composition (especially Na, K, Ca, and Mg ions), grain size distribution, calcite, iron oxide content, and organic coatings. Distribution coefficients (Kd) of cesium (labeled with {sup 137}Cs) and strontium were measured on the grain size distributions >=32 mum of four soil samples. These soils were obtained from four different locations within Inshas site in Egypt and three groundwater samples were obtained from the same site locations. X-ray diffraction showed that the soil samples consisted mainly of quartz mixed with the minor amounts of kaolonite and clay minerals. Sorption experiments were carried out at strontium aqueous concentrations range 10{sup -7} to 10{sup -4} mol l{sup -1}. The CEC and Kds for cesium and strontium were measured at the same metal concentrations range. Distribution coefficients of cesium were found to be influenced by the composition of the soil, while the distribution coefficients of strontium were found to depend on calcium concentrations in the soil/groundwater system. The aim of this study was to determine the safety assessment of disposal {sup 137}Cs radionuclide and Sr(II) in the aquifer regions inside the Inshas site. Sequential extraction tests showed that, strontium was associated with the carbonate fractions and majority of cesium was sorbed on the iron oxides and the residue.

  18. Attenuation of the gamma rays in tissues; Atenuacion de los rayos gamma en tejidos

    Arcos P, A.; Rodriguez N, S.; Pinedo S, A.; Amador V, P.; Chacon R, A.; Vega C, H.R. [Unidad Academica de Estudios Nucleares, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2005-07-01

    The mass and lineal attenuation coefficient and of hepatic tissue, muscular, osseous and of brain before gamma rays of 10{sup -3} to 10{sup 5} MeV were calculated. For the case of the osseous tissue the calculation was made for the cartilage, the cortical tissue and the bone marrow. During the calculations the elementary composition of the tissues of human origin was used. The calculations include by separate the Photoelectric effect, the Compton scattering and the Pair production, as well as the total. For to establish a comparison with the attenuation capacities, the coefficients of the water, the aluminum and the lead also were calculated. The study was complemented measuring the attenuation coefficient of hepatic tissue of bovine before gamma rays of 0.662 MeV of a source of {sup 137} Cs. The measurement was made through of an experiment of photons transmission through samples frozen of hepatic tissue and with a Geiger-Mueller detector. (Author)

  19. 137Cs and 226Ra determination in soil and land snails from a radioactive waste site

    Environmental radioactivity studies related to nuclear facilities can provide information concerning the transfer of radionuclides to the surrounding soils, water and the local biota. A study of 226Ra, 137Cs and 40K content in soils and in land snails, Helix aspersa Mueller, has been performed at the confined Storage Centre for Radioactive Waste (Maquixco, Mexico). At this site, solid and liquid radioactive waste has been stored for two decades; tailing piles of radiometric ore also stood for some time before being buried in specific containers. The nuclear technique used was gamma spectrometry. Atomic absorption spectrophotometry was used for soil and land snails chemical analysis. The preliminary results obtained in soil samples show 226Ra and 137Cs values ranging from 88 to 19979? and from 89 to 4961 Bq/kg (dry wt.), respectively, depending on the sampling region. For the snails, 226Ra levels in shell samples up to a factor of 9 greater were obtained for the site samples as compared with reference samples collected 100 km away. The results are discussed as a function of the uranium ore tailings localization at the site; a preliminary estimation of concentration factors (soil/snail) is also intended

  20. 137Cs and 90Sr behaviour in contaminated soils of the Chernobyl area

    The improvement of the understanding of the mechanisms which generate radionuclides retention in soils are of main importance for radioactivity transport models, especially for long time assessments. In this context, the objectives of this thesis were to identify the mechanisms responsible for 137Cs and 90Sr behaviour in non cultivated soils and to quantify their influence. We studied radiocaesium and radiostrontium availability in different soils of the Chernobyl area (chernozem), sand, gley, peat), whose contamination took several physico-chemical forms (fuel particles, condensed forms, mixed deposits). The migration profiles obtained by gamma spectrometry and liquid scintillation show that the majority of the activity is contained in the ten first centimeters of soil, except for one site. The profiles are varied and don't allow to classify the radionuclides availability according to the pedology or to the contamination type. A selective extraction protocol applied on several soil layers has been adopted as an indirect approach. Although radionuclides availability is increasing with depth, the selective extraction protocol shows that a non negligible fraction of activity remain not mobile. 137Cs is associated to interstratified clay minerals in a non reversible way and 90Sr is strongly bound to fuel particles. The existence of these retention mechanisms calls into question the use of the Kd distribution coefficient in transport models because they disabled reversibility and instantaneous desorption notions. (author)

  1. Immobilization of 137Cs on cement-zeolite composites

    The research has been mainly concerned with the solidification of radioactive waste in cement based matrices to reduce the mobility of cesium in the solid form. Zeolite was fixed in a cement based matrix and exposed to synthetic ground water. The zeolite can replace sand materials that are used in the cement formulations. The influences of different weights of zeolite and sand on the diffusion coefficients for 137Cs were studied using the solid waste form treated in ground water. (author). 3 refs, 3 figs, 8 tabs

  2. A review: study on the behavior of 137Cs in agricultural environment of China

    In China, study on the behavior of137Cs in agricultural environment was begun in 1960. Many papers on the behavior of 137Cs in soil-plant system and the estimation of 137Cs radioactivity in soil and food were published. The absorption, accumulation and distribution of 137Cs in plant, the relationship between absorption of 137Cs by plant and contaminating way and form, the 137Cs radioactivity in soil and food and its transfer coefficient in soil-plant system, the effects of the characters of soil and plant as well as the living stages on the transfer are concerned. The results show that the average radioactivity of 137Cs in soil of China is 10.45 Bq/kg, and the deposition densities decrease with the latitude decreasing. The transfer coefficient of 137Cs from soil to the agricultural products is about 0.12∼8.19 x 10-3. The distribution of 137Cs in rice plant is in the order of the root>glume>leaf>stem>rice. The radioactivity of aerial part accumulates mainly in the glume. The countermeasures to alleviate the adverse effects of 137Cs contamination need further study

  3. Dose rate levels around industrial gamma sources

    Dose rate levels around two gamma ray sources utilized in a mining corporation have been determined. Both gamma ray sources are 137Cs and are installed in a mining corporation to measure on-line the density of mine products. Dose rate levels were calculated in several sites around the 137Cs sources using two active and several passive thermoluminescent dosemeters. Using the 137Cs' gamma factor dose rates were calculated in all the points. A comparison between the measured and calculated dose rate levels was carried out. Calculated dose rate levels was obtained for three cases: first, assuming the sources were bare, second, assuming the sources inside their shielding and the third, adding an extra shield to reduce the dose rate levels to those similar to local background. (author)

  4. 137Cs inventory in semi-isolated basins of the western South Pacific

    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.

  5. {sup 137}Cs applicability to soil erosion assessment: theoretical and empirical model; Aplicabilidade do {sup 137}Cs para medir erosao do solo: modelos teoricos e empiricos

    Andrello, Avacir Casanova

    2004-02-15

    The soil erosion processes acceleration and the increase of soil erosion rates due to anthropogenic perturbation in soil-weather-vegetation equilibrium has influenced in the soil quality and environment. So, the possibility to assess the amplitude and severity of soil erosion impact on the productivity and quality of soil is important so local scale as regional and global scale. Several models have been developed to assess the soil erosion so qualitative as quantitatively. {sup 137}Cs, an anthropogenic radionuclide, have been very used to assess the superficial soil erosion process Empirical and theoretical models were developed on the basis of {sup 137} Cs redistribution as indicative of soil movement by erosive process These models incorporate many parameters that can influence in the soil erosion rates quantification by {sup 137} Cs redistribution. Statistical analysis was realized on the models recommended by IAEA to determinate the influence that each parameter generates in results of the soil redistribution. It was verified that the most important parameter is the {sup 137} Cs redistribution, indicating the necessity of a good determination in the {sup 137} Cs inventory values with a minimum deviation associated with these values. After this, it was associated a 10% deviation in the reference value of {sup 137} Cs inventory and the 5% in the {sup 137} Cs inventory of the sample and was determinate the deviation in results of the soil redistribution calculated by models. The results of soil redistribution was compared to verify if there was difference between the models, but there was not difference in the results determinate by models, unless above 70% of {sup 137} Cs loss. Analyzing three native forests and an area of the undisturbed pasture in the Londrina region, can be verified that the {sup 137} Cs spatial variability in local scale was 15%. Comparing the {sup 137} Cs inventory values determinate in the three native forest with the {sup 137} Cs inventory

  6. Distribution of 226 Ra, 232 Th, 40 K and 137 Cs in soils of Province of Camaguey, Cuba

    A survey programme aimed at studying the environmental radioactivity in the Province of Camaguey in the eastern region of Cuba was undertaken. The average concentrations of 226 Ra, 232 Th, and 40 K in the surveyed soils were 26.4, 11.5 and 210 Bq.kg-1, respectively. The man-made radionuclide found was 137 Cs and its concentration was similar to those reported in regions affected only by global radioactive fallout, (7.9 Bq.kg-1). Radiological measurements carried out with a portable ionization chamber RSS-112 at the sampled sites revealed an average outdoor absorbed dose rate of 59.0 nGy.h-1 due to cosmic rays and terrestrial gamma radiation. Computed dose rates obtained through the UNSCEAR(1993) dose coefficients range from 4-182 nGy.h-1, with a mean value of 27.8 nGy.h-1, due to natural terrestrial gamma radiation. Ratio of Indoor to Outdoor absorbed dose rates in air was 1.75. The average value of absorbed dose rate in air for the ionizing component of cosmic rays was 31.8 nGy.h-1 at sea level. Because of the 95% of the Camaguey population lives at altitudes close to sea level (10-100 m), the absorbed dose rate in outdoor air from ionizing component of cosmic rays was estimated to be 32.3 nGy.h-1. An annual average effective dose equivalent of 510 μSv was estimated for Camaguey population due to the ionizing component of cosmic and gamma terrestrial radiation. This value is lower than the 760 μSv.year-1 estimated as a world average by UNSCEAR (1993). (author)

  7. Determination of photon attenuation coefficient, porosity and field capacity of soil by gamma-ray transmission for 60, 356 and 662 keV gamma rays

    Gamma-ray transmission methods have been used accurately for the study of the properties of soil in the agricultural purposes. In this study, photon attenuation coefficient, porosity and field capacity of soil are determined by using gamma-ray transmission method. To this end, the soil sample was collected from Erzurum and a 2x2 in NaI (Tl) scintillation detector measured the attenuation of strongly collimated monoenergetic gamma beam through soil sample. The radioactive sources used in the experiment were 241Am, 133Ba and 137Cs. The mass attenuation coefficients of dry soil samples were calculated from the transmission measurements. The soil samples were irrigated by adding known quantities of water and the soil-water properties were examined. It was observed that gamma-ray transmission method for determination of the soil parameters has advantages such as practical, inexpensive, non-destructive and fast analysis

  8. Determination of photon attenuation coefficient, porosity and field capacity of soil by gamma-ray transmission for 60, 356 and 662 keV gamma rays.

    Demir, D; Un, A; Ozgül, M; Sahin, Y

    2008-12-01

    Gamma-ray transmission methods have been used accurately for the study of the properties of soil in the agricultural purposes. In this study, photon attenuation coefficient, porosity and field capacity of soil are determined by using gamma-ray transmission method. To this end, the soil sample was collected from Erzurum and a 2 x 2 in NaI (Tl) scintillation detector measured the attenuation of strongly collimated monoenergetic gamma beam through soil sample. The radioactive sources used in the experiment were (241)Am, (133)Ba and (137)Cs. The mass attenuation coefficients of dry soil samples were calculated from the transmission measurements. The soil samples were irrigated by adding known quantities of water and the soil-water properties were examined. It was observed that gamma-ray transmission method for determination of the soil parameters has advantages such as practical, inexpensive, non-destructive and fast analysis. PMID:18554919

  9. Rapid determination of soil contamination by helicopter gamma ray spectrometry

    The paper describes aerial nuclide specific measurements of surface contamination that were performed after the Chernobyl reactor accident in the southern region of the Federal Republic of Germany in August 1989. For these measurements, a helicopter equipped with a gamma ray spectrometer system including an HPGe detector with a relative efficiency of 50% was used. Soil contamination due to 134Cs and 137Cs was measured during a number of flights covering a total distance of about 300 km. The average flying altitude measured by a laser altimeter was about 70 m above ground level and the speed was about 130 km/h. The measuring time was chosen to be 60 s for each spectrum, corresponding to a flight path distance of about 2.2 km over which the average soil contamination was determined. The measured 137Cs values of up to 25 kBq/m2 are in good agreement with the results of measurements obtained by other methods. The values measured for 134Cs were lower by a factor of 5. (author). 5 refs, 4 figs

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

    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

  11. Analysis of 137Cs in fission based neutron dosimetry

    137Cs analysis is based on dissolving an irradiated fission dosimeter and chemically separating the cesium from the rest of the fission material. The samples consisted of uranium and neptunium in the form of metal or oxide. The uranium samples were dissolved in nitric acid and the neptunium samples in a mixture of nitric acid and chloric acid with addition of hydrogen peroxide. Cs was precipitated into a mixture of ammonium molyndophoshate and cellulose powder. A preparate for measurement was made from the precipitate and covered with polyethen plastic. Since other fission products than cesium were precipitated as well from the more recently irradiated samples, the activity measurements could not be carried out with a NaI(Tl) cavity crystal, but had to be made with a less efficient but more selective germanium semiconductor crystal. The method is well suited for 137Cs determination, especially for older dosimeters where the more short-lived fission products have decayed. (orig.) (6 refs., 7 figs., 7 tabs.)

  12. Fractionation of 137Cs and Pu in natural peatland

    High Cs-137 concentrations in plants growing on peatland inspired us to investigate the quantity of its bioavailable fraction in natural peat. Our investigation aims to: a) estimate the quantity of bioavailable Cs-137 and Pu present in peat, b) verify the similarity of Cs-137 and K-40 behaviours, and c) perform a quantification of Cs-137 and Pu transfer from peat to plants. We analysed the vertical distribution of Cs-137 and Pu isotopes in the peat and their concentrations in plants growing on these places. Bioavailability of radionuclides was investigated by sequential extraction. Sequential analyses revealed that it was the upper layer which contained the majority of Cs-137 in an available form while deeper layers retained Cs-137 in immobile fractions. We can conclude that 18% of all Cs-137 in the peat is still bioavailable. Despite of the low quantity of bioavailable fraction of Cs-137 its transfer factor reached extremely high values. In the case of Pu, 64% of its total amount was associated with fulvic/humic acids which resulted in the high transfer factor from peat to plants. 27 years after the Chernobyl nuclear accident, the significant part of radionuclides deposited in peatland is still bioavailable. - Highlights: • Decrease of exchangeable 137Cs and its increase in residual fraction with depth. • High 137Cs transfer factor contrary to its low quantity in bioavailable fractions. • Fulvic/humic acids are a more effective carrier for Pu than for Cs

  13. Body burden and distribution of 137Cs in reindeer

    The whole body was collected from 6 reindeer that had been grazing contaminated pasture and from 6 reindeer that had been fed uncontaminated feed the last weeks before slaughter. The body was emptied from in-gesta and weighed. Samples were taken from skeletal muscle, kidneys, heart, liver, lungs, rumen wall, bone and blood. The total activity of 137Cs in the ingesta-free body and the activity concentration of l37Cs in the different tissues were determined. The highest acitivity concentrations of l37Cs were found in skeletal muscle and in kidneys. Activity concentrations in kidneys, heart, liver, lungs and rumen wall, relative to skeletal muscle, were lower in reindeer with decreasing radiocaesium levels, compared to reindeer with continuous intake of radiocaesium, indicating a more rapid elimination in these tissues than in muscle. The ratios between average activity concentration of 137Cs in whole body and acitivity concentration in muscle from the same animal, ranged from 0.51 to 0.62. A factor of 0.57 is suggested for calculating average body activity concentration of radiocaesium from known activity concentration in muscle

  14. Absolute measurement of the desintegration rate of 137 Cs by 4Π (BS) e--X coincidence method

    The method developed by the Nuclear Metrology Laboratory for the absolute measurement of the desintegration rate of 137Cs by 4Π(BS)e--X is described. The conversion electron are measured by a pair of surface barrier detectors with 200mm2 of active area and 1000μm of depletion depth. The X-rays are measured by two 50.8mm diameter and 1.0mm thick NaI (Tl) scintillation counters. (author)

  15. The use of tree bark as long term biomonitor of (137)Cs deposition.

    Cosma, Constantin; Iurian, Andra-Rada; Incze, Reka; Kovacs, Tibor; Žunić, Zora S

    2016-03-01

    Airborne (137)Cs originated from the nuclear tests in the atmosphere and from the Chernobyl nuclear disaster was retained by the trees biomass and nowadays it can still be found in various concentrations in tree barks from Romania and other European countries. This study brings the first results of (137)Cs presence in tree bark from Romania on different considerations: (i) data dispersion in spruce and oak bark from NW, SW and central Romania, and the spatial variability of (137)Cs within oak and spruce bark from a natural protected forest area from Balvanyos area (Covasna County), known to be highly affected by the Chernobyl nuclear release; (ii) comparison of (137)Cs content in different tree bark species (oak, spruce, poplar and cherry); (iii) differences in (137)Cs concentrations with the bark depth layers and around the tree trunk; and (iv) comparison of mean (137)Cs values in spruce/oak bark from Romania with data from other European countries. PMID:26771244

  16. Uptake of 137Cs in cultured fresh water fish (Cyprinus carpio): physiological and histological effects

    An experiment was conducted in fresh-water fish (Cyprinus carpio) cultured, in small water tanks, artificially contaminated with radioactive 137Cs (3000 Bq/1) to determine the uptake of 137Cs and its physiological and histological effects in different fish organs. It was found that 137Cs was located in muscular tissues, gills, head muscles, liver and kidneys. Moderate amounts were found in spleen, eyes, gonads, intestine and urinary bladder. It seems that sorption was of much less importance than ingestion in the uptake of 137Cs. The histological examination in musculature tissue, revealed an acute hyperemia with focal haemorrages which may be due to allergic effects of 137Cs. Hyperemia and focal fatty degeneration of hepatic cells was also noted in the liver which may be due to toxic effects of 137Cs. Diffused hyperemia has also occurred in the brain and focal degeneration of epithelial cells of renal tubules. (Author)

  17. Distribution of Na, K, Rb, Cs, and 137Cs in some Austrian higher fungi

    The level of 137Cs in 28 species of mushroom collected and analyzed between 1986 and 1992, after the Chernobyl accident, are reported. Xerocomus badius was found to accumulate 137Cs (the median value of 58 samples is 3667 Bq/kg). The 137Cs content of Rozites caperata, Scleroderma vulgare, and Tylopilus felleus exceeded 600 Bq/kg. Some of these samples collected in August 1992 were investigated for their 134Cs and 137Cs content as well as their Na, K, Rb, and Cs levels by applying instrumental neutron activation analysis (INAA). The results show a high correlation coefficient (0.80) between the contents of 137Cs and Na, but none between 137Cs and K

  18. Distribution of 137Cs in sediments in Xiangshan, Xiamen and Yangpu harbours, China

    Xiangshan Harbour (Zhejing Province), Xiamen Harbour (Fujian Province) and Yangpu Harbour (Hainan Province) are tide-channel type bays, located on the southeast coast of China. Six sediment cores were collected in the Harbours in several projects respectively. Sediment samples were collected with a Lehigh gravity corer which utilized a 10.3 cm diameter, PVC core barrel. Styrofoam sediment core retainers were fitted into the top of the core barrel following core recovery to facilitate core sampling without loss of sediment from the barrel. The core barrels were split lengthwise using a circular saw. Following visual inspection for geological parameters (colour, texture, etc.) and photography of the cores, they were subsampled at 1-2 cm or 5 cm intervals for the entire length of the core. The sediment samples were stored in air-tight, plastic containers and returned to Nanjing University for 137Cs and other types of analysis. The sediment samples were oven dried at approximately 100 deg. C. at the Nanjing University isotope laboratory and the % loss of water used to determine the wet and dry densities. The contents of 137Cs were counted using an n-type HPGe γ-ray spectrometry system. The coaxial detector has an efficiency of 25%, with a lead shield 12 cm thick. Each sample was measured for 12h

  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.

    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. PMID:26990074

  20. The organic matter of forest soil as an incorporator of 137Cs

    The decomposition of a forest litter in forest ecosystems contaminated by radionuclides is accompanied by the accumulation of organomineral compounds associated with 137Cs in deeper soil layers. The highest level of 13Cs in the upper organic-reach soil layers was found in the insoluble fraction of organic matter, hemicellulose and cellulose. Due to a high level of the 137Cs accumulation in a forest litter, the last generates a substantial part of the 137Cs background in forests

  1. Possibility of soil clean-up from 137Cs in coast part of drainage system

    The net of drainage canals is used for the collection of the surface ground waters on the radioactive waste storage at the MosNPO RADON. The soils of the drainage system were contaminated by 137-Cs migrating in the direction of the common flow. A unique technology was elaborated permitting to extract 137Cs from soil 90% and to concentrate 137-Cs on the selective inorganic sorbent (nickel ferrocyanide). This technology combines electrokinetics, membrane and sorption methods of the contaminated media cleaning

  2. 137Cs and 90Sr concentration in the Baltic Sea coastal zone

    The results of the 137Cs and 90Sr concentration measurements in the Baltic Sea coastal zone (near the settlement of Juodkrante) are presented. The concentration variation range is from 0.3 to 1.2 nCi/m3. The maximum 137Cs concentration is observed in autumn and the minimum one - in summer. 137Cs/90Sr concentration ratio in summer and autumn of 1977 was over 1, and that of April 1976 was less than 0.5

  3. {sup 137}Cs contaminated waste disposal in cement factory: Environmental problems; Smaltimento di scorie contaminate da {sup 137}Cs in un cementificio: problematiche ambientali

    Bianchi, D.; Cammarata, E.; Marzolla, N.; Rabbia, G.; Vescovi, A.; Astori, E. [Alessandria USL 20, Alessandria (Italy). Lab. di sanita` pubblica; Cagliero, S. [Cuneo USL 15, Cuneo (Italy). Lab. di sanita` pubblica

    1995-09-01

    In the course of utilization (May-June `91) of aluminum slags polluted by {sup 137}Cs at the cement factory Presacementi in Robilante (Cuneo, Italy) and during the following months, samples were taken in particular points of the plant, at fixed frequencies. Samples were analyzed to determine {sup 137}Cs concentration. Collected data were used to study the behaviour of the element throughout the process. Emissions and ground level air concentrations were estimated from the available data. Contamination of the manufactured cement were monitored until negligible values of {sup 137}Cs concentration were attained.

  4. Transfer of 137Cs from soil to plants in a wet montane forest in subtropical Taiwan

    The distribution of 137Cs in an undisturbed, multistoried, subtropical wet montane forest ecosystem surrounding Yuanyang Lake (lake surface level ca. 1670 m, in northeastern Taiwan), was investigated. The mossy forest here represents a currently-rare perhumid temperate environment in subtropical region. The radioactivity concentration of 137Cs was determined by γ-spectroscopy with a Ge(Li) detector. Although the soil is extremely acidic (pH 3.3 to 3.6) and the rainfall is high, 137Cs is evidently retained in the organic layer. The radioactivity concentration of 137Cs in surface soil ranges from 28 to 71 Bq x kg-1. The concentrations of 137Cs in the ground moss layer and litter were much lower than that in the soil organic layer; this suggests that 137Cs detected is not from the newly deposited radioactive fallout. The radioactivity concentration and transfer factor (TF) of 137Cs varied with plant species. Shrubs and ferns have higher values than a coniferous tree (Taiwan cedar). The TF in this ecosystem is as high as 0.21 to 1.88. The high values of TF is attributed to the abundance of the organic matter in the forest soils. The rapid recycling of 137Cs through the soil-plant system of this undisturbed multistoried ecosystem suggests the existence of an internal cycling that help the accumulation of 137Cs in this ecosystem. (author)

  5. 137Cs radiation burden on children from a highly contaminated area of Belarus

    The radiation burden from 137Cs sources on 22 children from a small Byelorussian village was studied from 1992 to 1994. Foodstuff, whole body burden and urinary excretion of 137Cs were measured, intake rates, biological half-lives and doses were calculated. The median value for the 137Cs whole body incorporation level was found to be 124 Bq, the biological half life was calculated as 68 d for girls and 50 d for boys. The internal dose caused by 137Cs was found to be negligible in comparison to that from external sources. No deviation from normal values could be shown in simultaneously studied clinico-chemical parameters

  6. The effect of fertilizer applications on 137Cs uptake by different plant species and vegetation types

    A trial carried out in a greenhouse over a two-year period is discussed. The effects on 137Cs concentration in plants, roots and soil have been investigated versus the grassland species composition (legume, grass and mixture) and eight combinations of mineral fertilizers (NPK). The results indicate: (a) the effect of K fertilizer in reducing 137Cs plant absorption; (b) the effect of N fertilizer in favouring grass growth and radiocaesium absorption; (c) for all fertilizer combinations, a higher 137Cs storage in the root system of the legumes and a lower 137Cs absorption in the plants. (author)

  7. The 137Cs activity and its geographical significance in terrestrial ecosystem of Great Wall Station, Antarctica

    2000-01-01

    The radioactive isotope——137 Cs is one of the important tracers for studying the physical processes and the human impacts on the environment. Based on the investigation results of the terrestrial ecosystem of Great Wall Station, Antarctica, it was shown that there are some artificial radioactive elements——137Cs in Antarctic terrestrial ecosystem. The sequence of 137Cs specific activities is as follows: crustaceous lichen>fruticose lichen>surface-moss>surface soil, and the crustaceous lichen is one of the most sensitive ways in monitoring the impact of the long-term diffusion of 137Cs on the environment.

  8. 137Cs contamination of Techa river flood plain in Brodokalmak settlement

    137Cs contamination of the Techa river flood plain inside the Brodokalmak settlement has been mapped. The collimated scintillated detector technique was used for 137Cs deposit measurements. The 137Cs contamination is very heterogeneous. A comparison of this technique with the traditional sample method was performed at selected locations. The sampling data are in good agreement with in-situ data. Soil surface activity of 90Sr was determined from the samples. It was shown that 137Cs contamination correlates with 90Sr contamination within the flood plain of the settlement

  9. Effect of arbuscular mycorrhizal (AM) fungi on 137Cs uptake by plants grown on different soils

    The potential use of mycorrhiza as a bioremediation agent for soils contaminated by radiocesium was evaluated in a greenhouse experiment. The uptake of 137Cs by cucumber, perennial ryegrass, and sunflower after inoculation with a commercial arbuscular mycorrhizal (AM) product in soils contaminated with 137Cs was investigated, with non-mycorrhizal quinoa included as a “reference” plant. The effect of cucumber and ryegrass inoculation with AM fungi on 137Cs uptake was inconsistent. The effect of AM fungi was most pronounced in sunflower: both plant biomass and 137Cs uptake increased on loamy sand and loamy soils. The total 137Cs activity accumulated within AM host sunflower on loamy sand and loamy soils was 2.4 and 3.2-fold higher than in non-inoculated plants. Although the enhanced uptake of 137Cs by quinoa plants on loamy soil inoculated by the AM fungi was observed, the infection of the fungi to the plants was not confirmed. - Highlights: ► Effect of soil inoculation on 137Cs uptake by crops was studied in greenhouse. ► 137Cs uptake by inoculated sunflower plants was most pronounced. ► The higher 137Cs uptake by inoculated sunflower due to presence of mycorrhiza. ► Studies suggest potential for use of mycorrhiza on contaminated sites.

  10. Effect of application timing of potassium fertilizer on root uptake of 137Cs in brown rice

    We investigated the optimal timing and quantity of K to reduce radiocesium in brown rice. The concentration of 137Cs in brown rice was reduced from 32 Bq kg-1 without K fertilizer to 2.0 Bq kg-1 with 16 g m-2 of basal K. The concentration of exchangeable 137Cs in the soil decreased from 234 to 25 Bq kg-1 with increasing application of K fertilizer from 0 to 57 g m-2. Hence, heavy application of K fertilizer in the early growing period can decrease the uptake of 137Cs by rice plants and the concentration of exchangeable 137Cs in the soil. (author)

  11. Concentrations of 137Cs in soils and selected forest plants in Taiwan

    Fallout 137Cs activities in soils and trees were measured from samples taken in mountainous areas and along three cross-island highways in Taiwan. Typical concentration in near-surface samples is about 5 Bq kg-1 depending on soil density. No correlation was found between the concentrations of 137Cs and stable elements in soils. Mechanical disturbance and soil density were identified as major causes for redistribution of 137Cs in both forest soils and trees. The transfer coefficient of 137Cs from soil to bastard banian estimated is 0.23. (author)

  12. 137Cs in carpets of the forest moss Pleurozium schreberi, 1961-1973

    Accumulation, retention and internal cycling of the fallout radionuclide 137Cs (physical half-life=30.2 a) were studied in forest moss Pleurozium schreberi (Brid.) Mitt. collected in southern Sweden during the period 1961-1973. The highest 137Cs concentrations occurred in the green top parts of the living moss. A major part of the deposited 137Cs is available for transport from the dying to growing parts of the moss.Elimination of 137Cs from living moss, as well as from dead moss, throughout 1968-1973, can be characterized by the same mean residence time (4+-1 a). 137Cs and naturally occurring stable K show different behaviour in the moss, so that the 137Cs/K ratio is higher by a factor of approximately 2 in the dead parts of the moss than in the living parts. The vertical distribution of 137Cs in the moss-covered ground has been described theoretically. Relative penetration of 137Cs is about 5 times higher in ground covered by moss-carpets than in ground covered by lichen-carpets. Throughout 1969-1973, the total amount of 137Cs retained in the moss-carpet was 64.2+-2.2 nCi.m-2. (author)

  13. Soil-dependent uptake of 137Cs by mushrooms: experimental study in the Chernobyl accident areas

    The influence of agrochemical properties of forest soils and growth conditions on 137Cs aggregated transfer factors from soil to different species of forest mushrooms have been analysed. Statistically significant correlations between 137Cs soil to mushroom aggregated transfer factors and agrochemical soil properties have been revealed. The experimental data show that 137Cs aggregated transfer factors depend on the mushroom's trophic group, biological family, genus and species. They also strongly depend on forest soil properties and their values can be estimated with the use of multiple regression equations constructed from agrochemical soil parameters which most closely correlate with the 137Cs transfer parameters for particular mushroom groups

  14. Distribution characteristics of 137Cs in soil profiles under different land uses and its implication

    This paper presents a study of the distribution of 137Cs in soils under three different land uses in a semiarid watershed. The results showed the average inventory of 137Cs in the cultivated land, woodland and grassland was 888, 1489 and 1650 Bq/m2, respectively. The pattern of depth distribution of 137Cs in the soil profiles with cultivated land, woodland and grassland was disturbed, eroding and aggrading, and normal profiles, respectively. The coefficient of variation of 137Cs inventory varied from 8.9 to 38.8 % for different land uses. (author)

  15. Arbuscular mycorrhizal fungi mediated uptake of 137Cs in leek and ryegrass

    In a first experiment of soil contaminated with 137Cs, inoculation with a mixture of arbuscular mycorrhizae enhanced the uptake of 137Cs by leek under greenhouse conditions, while no effect on the uptake by ryegrass was observed. The mycorrhizal infection frequency in leek was independent of whether the 137Cs-contaminated soil was inoculated with mycorrhizal spores or not. The lack of mycorrhizae-mediated uptake of 137Cs in ryegrass could be due to the high root density, which was about four times that of leek, or due to a less well functioning mycorrhizal symbiosis than of leek. In a second experiment, ryegrass was grown for a period of four cuts. Additions of fungi enhanced 137Cs uptake of all harvests, improved dry weight production in the first cut, and also improved the mycorrhizal infection frequencies in the roots. No differences were obtained between the two fungal inoculums investigated with respect to biomass production or 137Cs uptake, but root colonization differed. We conclude that, under certain circumstances, mycorrhizae affect plant uptake of 137Cs. There may be a potential for selecting fungal strains that stimulate 137Cs accumulation in crops. The use of ryegrass seems to be rather ineffective for remediation of 137Cs-contaminated soil

  16. 137Cs use in estimating soil erosion: 30 years of research

    Significant amounts of fallout 137Cs from nuclear weapons tests were introduced to the landscape during the 1950s and 1960s. Once 137Cs reaches the soil surface it is strongly and quickly adsorbed by clay particles, and is essentially nonexchangeable in most environments. Thus, 137Cs becomes and effective tracer of the movement of soil particles across the landscape. Over the past 30 years, researchers have shown that 137Cs can be used to study soil movement. Early work used empirical relationships between soil loss and 137Cs loss to estimate erosion. This was followed by the development of proportional and theoretical models to relate 137Cs movement and soil redistribution. Most of the problems related to the 137Cs technique are the same as those encountered with other techniques (i.e., sampling, measurement). The 137Cs technique can make actual measurements of soil loss and redeposition in fields, fostering the formulation of better plans to conserve the quality of the landscape. This paper reviews the development of the 137Cs technique to show how it can be used to understand erosion and soil movement on the landscape. (author)

  17. Rates of leaching of 137Cs and potassium from different plant litters

    Mature plants of Calluna vulgaris, Trifolium repens and Agrostis capillaris were labelled with 137Cs by uptake through the roots. Shoot material was allowed to dry to give plant litters adequately labelled for leaching experiments, using microcosms subjected to a number of applied treatments. Measurements were made of 137Cs activity, potassium content and pH on the leachates from each microcosm obtained every 2 weeks over a 3-month period. The respiration rate of the litter was also measured to give an index of microbial activity. At the end of the experiment, 137Cs and K contents of the residual litter were measured. Generally, the rate of release of 137Cs from Calluna litter was slower than that from Trifolium or Agrostis. After 3 months, the loss of 137Cs from Calluna litter had stabilised at about 30-40% of the original. Trifolium had lost 60% of the initial 137Cs over the same period, whilst Agrostis had lost about 70%. Repeated drying and rewetting treatment, compared to a continuous moistened state, resulted in the stabilisation of 137Cs within Trifolium and Agrostis litters. In Agrostis and Trifolium, the release of potassium was greater and more rapid than the release of 137Cs, with only 10% of the original K remaining in the litter after 2 months. In Calluna, the release of K resembled the release of 137Cs more closely. (author)

  18. Arbuscular mycorrhizal fungi mediated uptake of {sup 137}Cs in leek and ryegrass

    Rosen, Klas; Weiliang, Zhong; Maertensson, Anna [Department of Soil Sciences, Swedish University of Agricultural Sciences P.O. Box 7014, SE-750 07 Uppsala (Sweden)

    2005-02-15

    In a first experiment of soil contaminated with {sup 137}Cs, inoculation with a mixture of arbuscular mycorrhizae enhanced the uptake of {sup 137}Cs by leek under greenhouse conditions, while no effect on the uptake by ryegrass was observed. The mycorrhizal infection frequency in leek was independent of whether the {sup 137}Cs-contaminated soil was inoculated with mycorrhizal spores or not. The lack of mycorrhizae-mediated uptake of {sup 137}Cs in ryegrass could be due to the high root density, which was about four times that of leek, or due to a less well functioning mycorrhizal symbiosis than of leek. In a second experiment, ryegrass was grown for a period of four cuts. Additions of fungi enhanced {sup 137}Cs uptake of all harvests, improved dry weight production in the first cut, and also improved the mycorrhizal infection frequencies in the roots. No differences were obtained between the two fungal inoculums investigated with respect to biomass production or {sup 137}Cs uptake, but root colonization differed. We conclude that, under certain circumstances, mycorrhizae affect plant uptake of {sup 137}Cs. There may be a potential for selecting fungal strains that stimulate {sup 137}Cs accumulation in crops. The use of ryegrass seems to be rather ineffective for remediation of {sup 137}Cs-contaminated soil.

  19. Uptake and translocation of {sup 137}Cs by Houttuynia cordata (in water culture)

    Kimura, Shojiro; Yamaoki, Rumi [Osaka Univ. of Pharmaceutical Sciences, Takatsuki (Japan)

    2001-08-01

    The water culture experiment of Houttuynia cordata of the medicinal plant was carried out, and basic study on {sup 137}Cs accumulation characteristic and internal circulation in H. cordata in the fruiting stage was investigated since the flowering season. H. cordata accumulated 80% of {sup 137}Cs absorbed unlike K to the root, rhizome, terminal bud of the underground part for the rhizome reproduction. {sup 137}Cs content to the young leaf, spike, involucre increased in the flowering season. Thereafter, {sup 137}Cs was recirculated to the developing organs in second generations such as the rhizome and bud. (author)

  20. Uptake and translocation of 137Cs by Houttuynia cordata (in water culture)

    The water culture experiment of Houttuynia cordata of the medicinal plant was carried out, and basic study on 137Cs accumulation characteristic and internal circulation in H. cordata in the fruiting stage was investigated since the flowering season. H. cordata accumulated 80% of 137Cs absorbed unlike K to the root, rhizome, terminal bud of the underground part for the rhizome reproduction. 137Cs content to the young leaf, spike, involucre increased in the flowering season. Thereafter, 137Cs was recirculated to the developing organs in second generations such as the rhizome and bud. (author)

  1. Long-term behaviours of 137Cs in simulated crop fields

    In order to understand the long-term behaviour of 137Cs in crop fields, root uptake and underground distribution of 137Cs were investigated through a greenhouse experiment where 137Cs was mixed with topsoil in culture boxes and rice, soybean and Chinese cabbage were grown for 4 years. Soil-to-plant transfer factors of 137Cs for hulled rice, rice straw, soybean seed and Chinese cabbage reduced by factors of 3-10 depending on crops, and leaching of 137Cs from the rice culture box decreased by a factor of about 7, in 3 years. The 137Cs transfer factor for soybean seed were several times higher than that for hulled rice. The amount of 137Cs leaching during the growing season of rice was as low as 0.025% of applied activity even in the 1st year. The uniformity of 137Cs distribution in topsoil tended to improve year by year. The present results may be utilized as basic information for the environmental impact assessment and the counter-measure decision when crop fields are contaminated with 137Cs

  2. Some biological factors related to the 137Cs concentration of marine organisms

    Marine Ecology Research Institute has been studying the factors controlling the concentration of radionuclides in marine biota. Weight of fish seemed to be an important factor controlling the concentration of 137Cs because of the good correlation observed between the weight and the concentration of 137Cs. Food habits also seemed to be an important factor because fishes in higher trophic levels tended to indicate higher concentration factors and a positive correlation was observed between the concentrations of predator fishes and those of the foodstuff. Gender could be another factor controlling the concentration of 137Cs because the difference of 137Cs between gender was observed in rockfish and marbled sole. (author)

  3. Standardization of radionuclides 45Ca, 137Cs, 204Tl by tracing method using 4πβ-γ coincidence system

    The procedure followed for the standardization of 45Ca, 137Cs and 204Tl is described. The activity measurements was carried out in a 4πβ-γ coincidence system by the tracing method. The radionuclides chosen as the P-y emitting tracer nuclide were 60Co for the 45Ca and 134Cs for 137Cs and 204TL because their end-point beta-ray energy are close to the respective beta emitters. The radioactive sources were prepared using two different techniques: one was the drops technique and the other was the solution technique. In the drop technique the sources were prepared by dropping directly on the subtract both solutions (tracer and beta pure). In the other technique a solution of tracer plus beta pure was mixed previously before making the radioactive sources. The activities of the radionuclides obtained with these technique were compared and the values are in agreement within the experimental uncertainties. (author)

  4. Evaluation of environmental radiological impact of 137 Cs repository area, site of Abadia de Goias, using the RESRAD model

    Radiological impacts under a conservative approach were assessed for the final deposition of 137 Cs at the repository site of Abadia de Goias, in the State of Goias. This site was selected as the definitive storage location for the wastes generated in the radiological accident occurred in the definitive storage location for the wastes generated in the radiological accident occurred in the nearby city of Goiania, in September of 1987. The wastes are composed of various different materials, with an estimated radioactive inventory of about 1250 Ci of 137 Cs, and will be deposited definitively in a repository box of concrete with a volume of 3900 m3 approximately. A conservative approach was considered in this study and the contaminated zone was simplified as an isotropic block of soil, of 3900 m3 of volume, containing 1250 Ci of 137 Cs homogeneously distributed within the whole volume. Several potential exposure scenarios were considered for the assessment of the future radiological impacts predicted at the repository site, depending on the level of institutional control maintained at the site, its future use, the time spent at the site and the sources of food. A comparative analysis of the resulting radiological impacts from all these future potential scenarios was performed using a microcomputer program named RESRAD. The simulated results indicated that the external exposure to gamma radiation, directly from the contaminated soil, is the most significant exposure pathway. The maximum predicted annual dose was below 7 mrem. (author). 5 refs, 6 figs, 3 tabs

  5. Comparison of transfer factors of 137Cs from soil to leafy vegetables in pot experiment and ambient environment

    The paper deals with the transfer factors (TF) generated for a few varieties of leafy vegetables (spinach, fenugreek, and amaranths) consumed by the locals around Tarapur atomic power station environment in India. The soil and leafy vegetable samples collected from the ambient environment of nuclear site were used for the determination of the TFs and they were compared with TFs generated from pot experiments under controlled conditions for 137Cs. The activity of 137Cs in soil and each vegetable was determined by gamma spectrometry using HPGe detector (35 and 160% relative efficiency) and was reported on dry weight basis for both ambient environment and pot samples. The radioactive effluent containing 137Cs (pH ∼7) from nuclear power station was used to spike the soil for pot (size 90 cm x 45 cm x 42 cm) experiment. The TFs obtained for ambient environment and pot experiment were found to be in the range of 0.035-0.592 and 0.0054-0.29, respectively. It is observed that TFs of ambient environment are in good agreement with those obtained in the pot experiment conducted under controlled conditions. Further, the observed TF values at Tarapur nuclear site are comparable with the range of typical IAEA transfer factor values for general leafy vegetation (0.11-2.9) for tropical environment. (author)

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

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

    2016-01-01

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

  7. Uptake of {sup 137}Cs by fresh water fish

    Man, C.K.; Kwok, Y.H

    2000-02-01

    The uptake and discharge rates of {sup 137}Cs by fresh water fish at different radionuclide concentrations have been studied. A dual compartment model was used to fit the experimental data. The discharge rates have been found to be negligible for the duration of the experiment of 10 days. The uptake rates were independent of radionuclide concentrations for a particular type of fresh water fish and were different for different types of fish. The uptake rates of carp, tilapia and snakehead were 1.58, 1.66 and 2.23, in unit of 10{sup -6} h{sup -1}, respectively. It was also estimated that the consumption of fresh water fish, even if the water were contaminated as much as that in the Chernobyl accident, leads to negligible latent cancer fatality to the Hong Kong population.

  8. Uptake of 137Cs by fresh water fish

    The uptake and discharge rates of 137Cs by fresh water fish at different radionuclide concentrations have been studied. A dual compartment model was used to fit the experimental data. The discharge rates have been found to be negligible for the duration of the experiment of 10 days. The uptake rates were independent of radionuclide concentrations for a particular type of fresh water fish and were different for different types of fish. The uptake rates of carp, tilapia and snakehead were 1.58, 1.66 and 2.23, in unit of 10-6 h-1, respectively. It was also estimated that the consumption of fresh water fish, even if the water were contaminated as much as that in the Chernobyl accident, leads to negligible latent cancer fatality to the Hong Kong population

  9. 137Cs leaching through cement-radwaste matrix

    To assess the safety for disposal of radioactive mortar-waste composition, the leaching of 137Cs from a waste composite into a surrounding fluid has been studied. Leaching tests were carried out in accordance with a method recommended by IAEA. Determination of retardation factors, KF and coefficients of distribution, kd, using a simplified mathematical model for analyzing the migration of radionuclides, has been developed. In our experiment we have achieved the lowest leaching values after 120, days for each samples. Results presented in this paper are examples of results obtained in a 30 year mortar and concrete testing project, which will influence the design of the engineered trenches system for a future central Serbian radioactive waste storage center. (author)

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

    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 210Pb profile was 6.7 mm/year from 1965 to 2005. A 3.5-fold increase in 137Cs 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.

  11. 137Cs penetration through concrete in radioactive waste management

    To assess the safety for disposal of radioactive waste-concrete composition, the leaching of 137Cs from a waste composite into a surrounding fluid has been studied. Leaching tests were carried out in accordance with a method recommended by IAEA. Determination of retardation factors, KF and coefficients of distribution, kd, using a simplified mathematical model for analyzing the migration of radionuclides, has been developed. In our experiment we have achieved the lowest leaching values after 60 days in samples. Results presented in this paper are examples of results obtained in a 20 year mortar and concrete testing project, which will influence the design of the engineered trenches system for a future central Serbian radioactive waste storage center. (author)

  12. Quality assurance of 137Cs Photons for Vivo Mouse Irradiation System

    The multi-purpose irradiation apparatus using a 137Cs, which can be used for the blood test, can be affected by the other components of the experiments such as the size and shape of the beaker and the maximum variation of more than 35% has been reported. The mount of the absorbed dose is determined by the distance between irradiation target and the source and the irradiation time with the irradiator (Gamma Irradiator, Chiyoda Technol Co, Japan) for this experiment. The low-dose irradiation has been used in this study is advantageous for irradiating the cell culture vessel or the small animal. However, radiation is performed by placing the 3-5 mice in each mouse cage (polycarbonate cage). In this case, overlapping often happens to the target during irradiation. Irradiating without considering the geometrical aspect of the irradiation device can occur as well. To solve the problems, the mouse apartment with the 45 mouse cages is built and the device is assessed by being compared with the conventional method in 2 different ways. Firstly, the glass dosimeters were inserted into the head and the body of the lab mice for 2 methods. Secondly, MCNP simulation was performed for absorbed dose and air kerma measurements in each mouse apartment chamber. In this study, the system that allows the accurate irradiation using the 137Cs gamma irradiator mainly used in Radiation Biology was developed and the accuracy of the system has been confirmed by the experiments. The dose delivery using the conventional system had the variation of 42% at most whereas the variation was less than 6% for the mouse apartment. From the MCNP simulation, the difference between each chamber was less than 0.1% and 0.4% for the air kerma and the absorbed dose respectively. Considering the statistical error of MCNP and the assumption from the simulation, the accuracy of the simulation was matched well with the measurements with the glass dosimeters

  13. Quality assurance of {sup 137}Cs Photons for Vivo Mouse Irradiation System

    Noh, S. J. [Inje Univ., Kimhae (Korea, Republic of); Kim, H. J.; Jeong, D. H.; Yang, K. M.; Son, T. G.; Kang, Y. R. [Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of); Shin, S. G.; Kye, Y. U. [Pohang University of Science and Technology, Pohang (Korea, Republic of)

    2014-10-15

    The multi-purpose irradiation apparatus using a {sup 137}Cs, which can be used for the blood test, can be affected by the other components of the experiments such as the size and shape of the beaker and the maximum variation of more than 35% has been reported. The mount of the absorbed dose is determined by the distance between irradiation target and the source and the irradiation time with the irradiator (Gamma Irradiator, Chiyoda Technol Co, Japan) for this experiment. The low-dose irradiation has been used in this study is advantageous for irradiating the cell culture vessel or the small animal. However, radiation is performed by placing the 3-5 mice in each mouse cage (polycarbonate cage). In this case, overlapping often happens to the target during irradiation. Irradiating without considering the geometrical aspect of the irradiation device can occur as well. To solve the problems, the mouse apartment with the 45 mouse cages is built and the device is assessed by being compared with the conventional method in 2 different ways. Firstly, the glass dosimeters were inserted into the head and the body of the lab mice for 2 methods. Secondly, MCNP simulation was performed for absorbed dose and air kerma measurements in each mouse apartment chamber. In this study, the system that allows the accurate irradiation using the {sup 137}Cs gamma irradiator mainly used in Radiation Biology was developed and the accuracy of the system has been confirmed by the experiments. The dose delivery using the conventional system had the variation of 42% at most whereas the variation was less than 6% for the mouse apartment. From the MCNP simulation, the difference between each chamber was less than 0.1% and 0.4% for the air kerma and the absorbed dose respectively. Considering the statistical error of MCNP and the assumption from the simulation, the accuracy of the simulation was matched well with the measurements with the glass dosimeters.

  14. Estimation of vertical migration velocity of 137Cs in the Mount IDA/Kazdagi, Turkey

    This paper presents the results obtained from a radioecological study carried out in the forest sites of Mount IDA (Kazdagi)/Edremit, Turkey. For 118 soil profiles, the depth distribution of 137Cs activity was established by fitting the experimental points to an exponential, a gaussian or a log-normal function. The relaxation lengths were in the range of 1.09–16.7 cm with a mean of 5.73 cm, showing a slow transport and a strong retention capacity of 137Cs even after the 26-y period of Chernobyl accident. From the data for the vertical distribution of 137Cs in soil profiles, the mean annual migration velocity of 137Cs was in the range of 0.11–0.62 cm year−1 with a mean of 0.30 cm year−1. Statistically significant correlations between the thickness of the humus layer and the mean annual velocity of 137Cs were found for both coniferous and mixed forest sites. The mean annual velocity of 137Cs in the forests sites with Pinus nigra var pallasiana was significantly higher than sites with Pinus brutia. External dose-rates from the 137Cs in forest soils were estimated using a conversion factor used in many studies and comprised with the external dose-rates determined according to the vertical distribution of 137Cs within the soil depth profiles. It is clearly seen that both levels and spatial distribution patterns of the external dose-rates from 137Cs were influenced considerably with the vertical migration rate and the vertical distribution of 137Cs. - Highlights: • The vertical migration of 137Cs was investigated in the forests at the Mount IDA. • The relaxation lengths of 137Cs are found in the range of 1.09–16.67 cm. • The mean annual velocity of 137Cs is found in the range of 0.11–0.62 cm year−1. • External dose-rates determined using the vertical distribution of 137Cs. • The external dose-rates were influenced with the vertical distribution of 137Cs

  15. Atmospheric deposition of radioactive cesium (137Cs) associated with dust events in East Asia

    Since the cessation of atmospheric nuclear testing in 1980, there has been no known serious atmospheric contamination by radioactive cesium (sup(137)Cs) apart from the Chernobyl nuclear reactor accident in 1986. There now remain only small amounts of anthropogenic radionuclides in the atmosphere that can be directly related to past testing. However, sup(137)Cs is still regularly found in atmospheric deposition samples in Japan. In this study, we analyzed sup(137)Cs monitoring data, meteorological data, and field survey results to investigate the recent transport and deposition of sup(137)Cs associated with dust phenomena. Monthly records of nationwide sup(137)Cs deposition in Japan during the 1990s show a consistent seasonal variation, with higher levels of deposition occurring in spring. In March 2002, an unexpectedly high amount of sup(137)Cs was deposited in the northwestern coastal area of Japan at the same time as an Asian dust event was observed. Analysis of land-based weather data showed that sandstorms and other dust-raising phenomena also occurred in March 2002 over areas of Mongolia and northeastern China where grassland and shrubs predominated. Furthermore, radioactivity measurements showed sup(137)Cs enrichment in the surface layer of grassland soils in the areas affected by these sandstorms. These results suggest that grasslands are potential sources of sup(137)Cs-bearing dust. Continued desertification of the East Asian continent in response to recent climate change can be expected to result in an increase in sup(137)Cs-bearing soil particles in the atmosphere, and their subsequent re-deposition in Japan. However, soil dust is also raised around Japanese monitoring sites by the strong winds that are common in Japan in spring, and this local dust might also contribute to sup(137)Cs deposition in Japan. To estimate the relative contributions of local and distant dust events to the total sup(137)Cs deposition, we monitored deposition of mineral particles

  16. Uptake, retention and organ/tissue distribution of 137Cs by Japanese catfish (Silurus asotus Linnaeus)

    The work describes the uptake, retention/biological elimination and organ/tissue distribution of 137Cs by freshwater Japanese catfish (Silurus asotus Linnaeus) under laboratory conditions. The fish were divided into three groups based on their size and age and reared in 137Cs-spiked water. The concentration of 137Cs in the whole body of the live fish was measured at regular intervals up to 60 days. A significant accumulation of 137Cs was found, but a steady state condition was not achieved by the end of the experiment. The bioaccumulation factors at steady state and the required time to reach steady state were estimated to be 1.55 and 255 days, 1.76 and 180 days and 1.99 and 160 days for large, medium and small size fish, respectively. To determine the effective half-life of 137Cs, the fish were transferred and reared in the non-contaminated host water. The concentration of the remaining 137Cs in the whole body of the live fish was measured up to 66 days. The average effective half-life of 137Cs in the fish species was found to be ∼142 days for fish of all sizes. The distribution of 137Cs in different organs/tissues of the fish was determined. Accumulation of 137Cs in muscle/flesh of the fish was found to be ∼75% of whole body accumulation. The uptake rate and the retention capability of juvenile fish were found to be higher and therefore, these were more susceptible to 137Cs than adult and old fish, and could be an important source of 137Cs in the human food chain

  17. Uptake, retention and organ/tissue distribution of 137Cs by Japanese catfish (Silurus asotus Linnaeus)

    The work describes the uptake, retention/biological elimination and organ/tissue distribution of 137Cs by Japanese Catfish (Silurus asotus Linnaeus) under laboratory conditions. The fish were divided in to three groups viz. large, medium and small based on their size and age and reared into the 137Cs spiked water. The concentration of 137Cs in the whole body of the live fish was measured at certain intervals up to 60 days. A significant accumulation of 137Cs was found but a steady state condition was not achieved by the end of the experiment. The Bfs at steady state condition and the required time were estimated to be 1.55 and 255 d, 1.76 and 180 d and 1.99 and 160 d for large, medium and small size fish respectively. To determine the effective halflife of 137Cs, the fish were transferred and reared into the non contaminated host water. The concentration of the remaining 137Cs in the whole body of the live fish was measured up to 66 days. The average effective half-life of 137Cs in the fish species was found to be ∼ 142 days for all size of fish. The uptake rate and the retention capability of juvenile fish were found to be higher and therefore, more susceptible to 137Cs than adult and old fish and could be an important source of 137Cs in the human food chain. The distribution of 137Cs in different organs/tissues of the fish were determined. Accumulation of 137Cs in muscle/flesh of the fish was found to be ∼ 75% of whole body accumulation. (author)

  18. Fire as an agent in redistributing fallout 137Cs in the Canadian boreal forest

    The presence of fallout 137Cs in the boreal forest and the effect of fire in redistributing 137Cs were studied in the remote region of Wood Buffalo National Park, N.W.T., Canada. Results of a preliminary study of five burned (the fire occurred in 1981) and five unburned stands conducted in 1986 revealed that 137Cs concentrations were higher in the surface soil of the burned stands than in the unburned ones. In 1989, a comprehensive study was conducted, in which one burned and one unburned white spruce stand were sampled in greater detail. The latter investigation also revealed a difference in the distribution of 137Cs within the burned stand compared to the unburned one. Specifically, in the unburned stand, the highest 137Cs concentration was identified in the epiphytic lichens and in the mosses, whereas in the burned stand, the highest concentration was measured in the surface organic soil. These results indicate that fire caused the mobilization of part of the 137Cs bound to the above-ground matter and concentrated it in the ash layer of the burned surface soil. An additional ecologically important finding in our study was that significantly lower total 137Cs load was observed in the burned stand compared to the unburned one. Hence, our data not only provide evidence that 137Cs is being redistributed within the burned stand to the surface soil, but also that part of the 137Cs is lost due to fire, presumably contaminating other ecosystems. Volatilization and fly-ash during the fire, and runoff (e.g. from snow melt) after the fire are the most likely mechanisms for the 137Cs removal. These findings point to fire as an agent of 137Cs secondary contamination for initially unaffected systems, as well as for those previously contaminated

  19. Study on separation of 137Cs from 235U fission process waste - utilization of silica gel-supported ferrocyanide complex salt for 137Cs picking

    In connection with the potential domestic demand especially in the fields of industry and nuclear medicine, the separation of 137Cs from 235U fission process waste is to be of interest although its economic value could be a polemic. A preliminary study on the separation of 137Cs from the 235U fission process waste generated in the production of 99Mo in P.T. BATAN Teknologi, Serpong, was performed through experiments on 137Cs picking from sample solution of the radioactive fission waste (RFW). The presented study is aimed to gain experimental data supporting utilization of the matrix of silica gel-supported ferrocyanide complex salt for the separation of 137Cs from RFW. Subsequent step would be the recovery and purification of 137Cs as part of production technology of 137Cs. The RFW sample was batch-treated with the matrix of silica gel-supported ferrocyanide complex salt which was synthesized from silica gel, potassium hexacyanoferrate(II) and copper(II) chloride. The binding of radioisotopes in RFW on the matrix was observed by γ-spectrometry of the RFW solution before and during the treatment. The results showed that approximately 85% of 137Cs could be picked from the RFW sample into the matrix. Less amount of 95Zr and 95Nb was bound into the matrix. 103Ru was slightly bound into the matrix whereas 141/144Ce and 129mTe were not. It was observed that by using 0.2 and 0.4 g of matrix for 10 ml of RFW, the amount of matrix influenced the binding quantity of 95Zr and 95Nb but not that of 137Cs. (author)

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

    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 137Cs, 60Co, 235U, 238U, and 154Eu were identified on spectral gamma logs from boreholes monitoring the PUREX specific retention facilities; the isotopes 137Cs, 60Co, 125Sb, and 154Eu were identified on the logs from boreholes at the BC Controlled Area cribs and trenches; and 137Cs, 60Co, and 125Sb 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 137CS and/or 60Co 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 106Ru and 125Sb, and the much slower decay of shallower and longer-lived isotopes such as 137Cs. The radionuclides 137Cs and 60Co 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 99Tc, NO3, or 129I, all of which can be highly mobile in the vadose zone and, for the radionuclides, have long half-lives

  1. Thorium determination in intercomparison samples and in some Romanian building materials by gamma ray spectrometry

    Pantelica, A.; Georgesecu, I.I.; Murariu-Magureanu, M.D.; Margaritescu, I.; Cincu, E

    2001-07-01

    Thorium content in zircon sand, thorium ore and thorium liquid sample (EU Laboratories Network Intercomparison), as well as in some Romanian building materials: sand, wood, tufa, asbestos-cement, cement mill dust, coal fly ash, bricks, and tile (28 samples) were determined by gamma ray spectrometry. For the building materials, {sup 226}Ra, {sup 40}K and {sup 137}Cs specific activities were also measured. The results were compared with the Romanian legal norms concerning the highest admissible levels for {sup 232}Th, {sup 226}Ra, and {sup 40}K radioactivity, and to Th, U, and K concentration values previously determined in our laboratory on similar types of samples. (author)

  2. Thorium determination in intercomparison samples and in some Romanian building materials by gamma ray spectrometry

    Thorium content in zircon sand, thorium ore and thorium liquid sample (EU Laboratories Network Intercomparison), as well as in some Romanian building materials: sand, wood, tufa, asbestos-cement, cement mill dust, coal fly ash, bricks, and tile (28 samples) were determined by gamma ray spectrometry. For the building materials, 226Ra, 40K and 137Cs specific activities were also measured. The results were compared with the Romanian legal norms concerning the highest admissible levels for 232Th, 226Ra, and 40K radioactivity, and to Th, U, and K concentration values previously determined in our laboratory on similar types of samples. (author)

  3. Gamma-ray attenuation coefficients of some building materials available in Egypt

    Mass attenuation coefficients of various types of building materials were measured using a high-resolution HPGe spectrometer detector. Samples were irradiated by gamma-rays emitted from point sources of 241Am, 133Ba, 60Co and 137Cs. The results are in good agreement with the theoretical calculations of XCOM code. The effectiveness of building materials in shielding were determined over the range 50-3000 keV. Finally, the protection efficiency of walls and roofs from radiation exposure were determined. The effectiveness of all tested building materials was better than the internationally accepted limit, and they are therefore acceptable for use.

  4. Study of Naturally Occurring Radioactive Material (NORM) in soil using low background gamma ray spectrometry

    There has been an increasing concern in the state of Punjab arising due to naturally occurring radioactive material (NORM) after high concentration levels of uranium was observed in ground water besides nails and hair of children. The concentration levels of 238U, 232 Th and 40K in top soil were measured using low background gamma ray spectrometric setup. The concentration of NORM was found to be similar to what is expected as a result of their normal abundance but was found to be lower than what has been observed in the state of Jharkhand. In addition to NORM the fall out radionuclide 137Cs was also observed in soil samples. (author)

  5. Application of a field-portable scintillation detector for studying the distribution of 137Cs inventories in a small basin in Central Russia

    Information relating to the spatial variability of 137Cs inventories within small areas is an important requirement both for assessing environmental contamination associated with the Chernobyl accident and for use in geomorphological applications where 137Cs measurements can provide a basis for estimating rates of erosion and sedimentation. Collection of such information using traditional techniques is, however, hampered by the need to collect soil cores and to analyse these in the laboratory using gamma spectrometry, which commonly involves lengthy count times. The use of field-portable in situ detectors offers many potential advantages over conventional field sampling. However, in order to assess this potential, there is a need for rigorous comparisons of the results obtained using the two approaches. This contribution reports the results of such a comparison undertaken in the small Lapki Balka catchment (2.18 km2) located near the town of Plavsk in Russia. The study area, which is located ca. 550 km northeast of Chernobyl, received high inputs of Chernobyl fallout and 137Cs inventories immediately after the accident were in excess of 200 kBq m-2. Parallel measurements of 137Cs inventories were made at more than 120 points using a 'CORAD' portable detector and conventional soil sampling. The sampling points were selected to be representative of the range of land use and geomorphological features within the study catchment. The results generally showed close agreement between the values of 137Cs inventory provided by the two approaches, but it is necessary to take account of the fact that the 'CORAD' results represent spatially averaged values, whereas the analysis of soil cores provides essentially point values. The interaction of the spatial properties of the two sets of measurements with the microvariability of soil 137Cs inventories must be considered when interpreting differences in both magnitude and dispersion. The results obtained indicate that in situ

  6. Gamma-ray astronomy

    Pohl, Martin

    2001-01-01

    This paper summarizes recents results in gamma-ray astronomy, most of which were derived with data from ground-based gamma-ray detectors. Many of the contributions presented at this conference involve multiwavelength studies which combine ground-based gamma-ray measurements with optical data or space-based X-ray and gamma-ray measurements. Besides measurements of the diffuse emission from the Galaxy, observations of blazars, gamma-ray bursts, and supernova remnants this paper also covers theo...

  7. 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

    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.

  8. Behavior of 137Cs concentrations in the North Pacific in an ocean general circulation model

    Tsumune, Daisuke; Aoyama, Michio; Hirose, Katsumi

    2003-08-01

    We have carried out a first simulation of the spatial distributions and the temporal variations of 137Cs concentrations in the North Pacific in off line calculations by using archived output of an ocean general circulation model (OGCM) developed by the National Center of Atmospheric Research (NCAR). Artificial radionuclides including 137Cs are introduced into ocean surface due to global fallout originating from the large-scale atmospheric nuclear weapons tests in 1961-1962. The distribution of radioactive deposition used as forcing for this simulation is estimated from global precipitation data and observed values of annual deposition of radionuclides at the Meteorological Research Institute (MRI) in Japan. 137Cs originating from global fallout have been transported into the ocean interior by advection and diffusion, and the 137Cs concentrations reduced by radioactive decay. We assess the skill of the model calculations by comparing simulated values of 137Cs in seawater with the observed values included in the database compiled by MRI because 137Cs is one of the most useful tracers regarding water motion in the ocean. The vertical and horizontal distributions of the calculated 137Cs concentrations were in good agreement with those of the observed 137Cs concentrations, except in the deep layer.

  9. 137Cs in Finnish wild berries, mushrooms and game meat in 2000-2005

    Activity concentrations of 137Cs in wild berries, mushrooms and game meat were measured in samples collected during 2000-2005 in areas with varying 137Cs deposition levels in Finland. Depending on the 137Cs deposition levels in the sampling areas, the areal-mean activity concentrations of 137Cs were 10-230 Bq kg-1 in wild berries, 20-240 Bq kg-1 in moose meat and 10-3000 Bq kg-1 in all mushroom species. Compared with the 137Cs level of samples collected in 1986 in the corresponding areas, the reduction in the 137Cs level was about one third for wild berries, equal to the rate of radioactive decay of 137Cs. More reduction was observed in the activity concentrations of 137Cs in moose meat, on average up to 50% since 1986. The aggregated transfer coefficients from soil to wild berries showed no change since 1986-1988, while there was about one third reduction in those from soil to game meat. (orig.)

  10. Effect of some chemical compounds on assimilation of 137Cs by hens

    Data on the decrease of 137Cs transition to the organism of laying hens after introduction of ferrocyanide and certain minerals into their ration are presented.It is established that introduction of any high capacity substances into gastrointestinal tract decreases 137Cs contact with its wall decreasing its assimilation by organism

  11. 137Cs vertical distribution at the deep basins of the North and Central Aegean Sea, Greece

    Large volume seawater samples were collected for the determination of 137Cs concentration along with depth in the deep basins of North and Central Aegean Sea. The vertical 137Cs distribution showed maximum concentration at the bottom of the basins, while the minimum values corresponded to the intermediate layer, where Levantine water exists. The surface 137Cs activity is found to lie between the two limits and is originated from the Black Sea waters. The typical oceanographic advection–diffusion balance model is modified to a diffusion-settling-decay balance model to better understand the vertical distribution and variation of the 137Cs concentration in the deep basins. In addition, the diffusivity of each basin, as well as the settling speed of particulate 137Cs is also estimated. The results are compared with theoretical approach as well as with previous data. - Highlights: • Three deep basins were studied using 137Cs as a tracer. • Deep waters constitute 137Cs repositories due to deep water formation followed Chernobyl accident. • Diffusivities, as well as particulate 137Cs settling speeds are estimated

  12. Global distribution of 137Cs inputs for soil erosion and sedimentation studies

    A global distribution of 137Cs deposition from the atmospheric nuclear tests, with estimates for 1996, excluding Chernobyl contribution, is presented, based on the global deposition data for 90Sr. The data can be used to identify areas and countries, especially in the southern hemisphere, where the 137Cs inventories are appropriate for soil erosion and sedimentation studies. (author)

  13. Investigation of radionuclide 137Cs sorption by natural and synthetic zeolites

    Sorption-selective properties of natural zeolite-clinoptilolite, from the Sokirnitsky deposit of Ukraine, and synthetic zeolites relatively to radionuclide 137Cs and depending on pH and temperature were studied. A high sorption ability of clinoptilolite relatively to 137Cs was determined

  14. Uptake of 137Cs from acidic solution by ammonium molybdophosphate (AMP) immobilized in calcium alginate

    The uptake rate for Cs+ for AMP-Ca ALG was fairly fast and the uptake attained an equilibrium within 3 hours. The observed uptake varies between 80-96% depending on the concentration of 137Cs. 137Cs is one of the major radionuclide in the effluent generated at the middle and back end of nuclear fuel cycles

  15. Volatility of 137Cs and 90Sr from high-level waste glass

    Volatility of 137Cs and 90Sr from simulated high-level waste glass was examined in a closed system. The sample containing 137Cs or 90Sr was placed in a double-crucible, heated at a given temperature for 3 days and cooled to room temperature. Then the activity of 137Cs or 90Sr of the crucible was measured. Volatility of 137Cs at 8000C was measured to be about 2 x 10-2 g/cm2.day. The amount of the leakage of 137Cs from the inner crucible to the outer crucible was very small. Volatility of 137Cs at 4000C was about 1.6 x 10-6 g/cm2.day, which was almost the same as that of 90Sr at 4000C. This may indicate that fine particles adhering to the surface of the sample are the main cause of air contamination when the temperature is less than 4000C. Part of the 137Cs that was deposited on the surface of the outer crucible (stainless steel) dissolved in water at room temperature, which means that 137Cs deposited on a stainless steel surface may be easily removed by a decontamination process

  16. Field measurements of 137Cs behaviour in the litter layers of a pine forest in Ireland

    The migration of 137Cs down the forest soil profile is complex and governed by both physical and biological processes. In this forest study, two physic migration processes (137Cs leaching and little accumulation) have been evaluated and their contribution to the migration of the Chernobyl contamination compared. 1 ref., 3 figs

  17. Regularities of 137Cs distribution for the Mozyr' Poles'e landscapes

    Long-term investigations revealed lateral redistribution of 137Cs in geochemical conjugation of elementary landscapes of the Mozyr Poles'e. The systematic study allowed to separate the zones of accumulation and of prevalently biogenic and mechanical transport of 137Cs and to establish their correlation with landscape- geochemical structure of territory

  18. Distribution of the radionuclide 137Cs in the soils of a wet mountainous forest in Taiwan

    The behavior of 137Cs was studied in the Yuanyang lake ecosystem, a wet mountainous forest in subtropical Taiwan. Soils investigated are either partially podzolic soils or nearly pure peats with a high organic matter concentration in the surface layer. Concentration of 137Cs was highest in the organic surface layers, particularly in the Oe horizon or in the underlying A horizon. The downwards migration to the mineral horizons is limited, in spite of the high rainfall. Topography is a critical factor for the distribution of 137Cs. It is shown that the concentration of 137Cs is highest at the foot of the slope and lower near the summit and near the lakeshore. The variation of the concentration along the landscape has been attributed to erosion-deposition in combination with surface run-off of the undisturbed forest. The amount of 137Cs in the site studied is significantly higher than at any other place in Taiwan. The accumulation of 137Cs is attributed to the high rainfall, which brought large amounts of 137Cs with the precipitation in the early 1960s. A very remarkable feature of the ecosystem is that 137Cs is not leached to the subsoils, but is stored in the biomass. Due to permanent recycling it remains available, without being leached downward

  19. Vertical distribution of 137Cs in the native forest soil at Londrina region (Parana, Brazil)

    The 137 Cs depth distribution has been studied in several areas in the world and its knowledge is very important to verify its behavior in the soil matrix. The form of 137 Cs depth distribution more observed in an undisturbed soil it is exponential type. In this work, the study of 137 Cs depth distribution was accomplished at three native forests and a coffee yard, built before the 137 Cs fallout, in the region of Londrina (Parana). The sampling was conducted in 1 cm, 2 cm, 4 cm and 5 cm increment depth. The 137 Cs inventory observed for the forests was 248 Bq m-2 (Mata1), 338 Bq m-2 (Mata2) and 325 Bq m-2 (MataUEL). No 137 Cs activity was detected in the coffee yard. The 137 Cs depth distribution for the three forests presented the exponential type. For the soil class of the forests, 137 Cs adsorbed on the soil particles can be considered fixed or slowly exchangeable. (author)

  20. Foliar leaching of 137Cs from Eriophorum vaginatum L., Scirpus caespitosus L. and Erica tetralix L

    Evidence of extensive leaching losses of nutrients, particularly of K, suggest that loss of 137Cs by foliar leaching could be considerable and could stimulate further root uptake and redistribution of 137Cs in plants. This study investigated the foliar leaching of 137Cs from two deciduous graminoid species, Eriophorum vaginatum and Scirpus caespitosus and one evergreen shrub, Erica tetralix. Plants were labelled with 137Cs via the roots and subjected to a leaching treatment in August and November and changes in both leachate and plant 137Cs activity were determined. Leaching losses were significantly reduced in November compared with August in the deciduous species, but not in the evergreen E. tetralix. A reduction in the total activity of 137Cs of leached plants was observed not only in leaves but also in stems and roots in some instances, suggesting that 137Cs from these organs had been redistributed to replenish that lost by leaching from the leaves. The data suggest that leaching losses were greater from older and senescent leaves than from younger leaves of E. vaginatum. The extent to which this is an accurate representation of foliar leaching of field-grown plants by rainfall, and the likely fate of 137Cs lost by foliar leaching are discussed. (author)

  1. Long-term ingestion dose monitoring in a population group with increased 137Cs intake

    137Cs amounts and ingestion doses in Czech population have been monitored by whole-body counting since the Chernobyl accident. Indirect estimation of the retention through measurement of 137Cs excreted with urine in 24 hours has also been performed since 1987. The 137Cs content in human body can be calculated from the urine data provided that the intake of 137Cs during the period of interest is constant. In a semi-natural environment, the 137Cs content in mushrooms, wild berries and game decreases due to its natural decay solely. The 137Cs content in people who mostly consume venison and have been living in an area with elevated contamination has been monitored, mostly through measurement of 137Cs in urine. In parallel, measurements with a mobile whole-body counter have also been performed. Currently, annual doses from the ingestion of 137Cs in the inhabitants are very low (0.001 to 0.002 mSv.year-1). In a group of hunters in the Jeseniky Mountains (Northern Moravia) the doses were estimated to 0.10 mSv.year-1. (orig.)

  2. Rapid determination of soil contamination by helicopter gamma ray spectroscopy

    Specific aerial nuclide measurements of surface soil contamination were performed after the Chernobyl accident in the southern part of Germany. A helicopter equipped with a gamma ray spectroscopic system including a HPGe detector (50% relative efficiency) and 3 NaI(Tl)-detectors (volume 12 l) was used. A detailed description is given of the complete measuring system which can also be used for detection of gamma sources, e.g. radioactive fragments of nuclear powered satellites. At an altitude of 100 m, a soil contamination of several kBq/m2 for 134Cs and 137Cs can be measured for 60 s at a helicopter speed of 100 km/h. For detection of point gamma sources, the NaI(Tl)-detector was used. Assuming a line spacing of 300 m and a speed of 100 km/h, an area of about 30 km2 can be surveyed per hour. Thus 60Co-sources of some GBq activity can be detected. The system was practically applied for the first time for measuring the man-made radionuclides. The chosen distance between the routes was 10 km, and measuring time - 60 s for each spectrum corresponding to a flight path distance of about 2.2 km over which the average soil contamination was determined. The measured 137Cs values of up to 25 kBq/m2 are in good agreement with the results obtained by other methods (in-situ-spectrometry, measurements of soil samples). The aerial measuring system was also tested in the former USSR, in a region north of Chernobyl, with nuclide deposition values of up to 2 MBq/m2. 7 figs., 2 refs. (orig.)

  3. Accumulation and Elimination of 137Cs Radionuclide by gold fish (Cyprinus Carpio)

    A study to estimate accumulation and elimination of 137Cs radionuclide by gold fish (Cyprinus Carpio) has been carried out. The experiment used aquarium as a cultivating media. Gold fish was placed into aquarium filled with 70 liter of water and 137Cs concentration of 10 Bq/ml. From the observing time of 40 days it was found that activity concentration in fish became saturated in 30th day. Saturation after the 30th day was confined by additional observation using 137Cs concentration of 5 and 15 Bq/ml. Saturated concentration fish was then transfered to inactive aquarium to determine is elimination rate. Transfer factor, i.e. the ratio of 137Cs concentration in fish to that in water, was found to be (12.99+0.28) ml/g, whereas the elimination rate of 137Cs was found to be 0.046 day, which correspond to a biological half life of 15 days

  4. Intake estimation and dose assessment of 90Sr, 137Cs around QNPP base

    90Sr and 137Cs are important radionuclides in environmental investigation related to nuclear power stations. A mode of intake estimation and dose assessment via various food chains is made in this paper. Based on daily food consumption and dietary composition for Chinese reference man and for man of Zhejiang province and the concentration of 137Cs and 90Sr around QNPP Base, the intake estimation and dose of 90Sr and 137Cs around QNPP Base are calculated. It shows that the main food sources of intake of 90Sr and 137Cs are rice,vegetable and aquatic product. Also the public average annual committed effective dose of 90Sr(2.5 μSv)is obviously higher than the contribution of dose of the 137Cs(0.36 μSv). A practical estimation method was made by taking QNPP Base as an example in this paper, while no background change occurs after its commercial operation. (authors)

  5. Uptake of 90Sr and 137Cs by mushrooms following the Chernobyl accident

    After the Chernobyl accident high concentrations of radionuclides were found in Sweden in mushrooms and the contents of 90Sr and 137Cs were measured. The level of 90Sr was generally low and, in proportion to 137Cs, 2-3 orders of magnitude lower than in the fallout. The contents of 137Cs varied among species, while the geographical distribution of the radioactivity largely followed the soil deposition. Extreme local variation occurred and the ratio 134Cs/137Cs diverged from other biological samples leading to the conclusion that old fallout was involved in the uptake. Transfer factors calculated for the uptake of 137Cs exhibited no correlation with the fallout levels, being mainly correlated with the different species. The problems associated with the definition of transfer factors for mushrooms were discussed. (author)

  6. Seasonality of 137Cs in roe deer from Austria and Germany

    Empirical data on the 137Cs activity concentration in meat of roe deer (Capreolus capreolus) roaming in 3 spruce forest areas and one peat bog area are presented and compared. They cover time series of nearly 20 years after a spike contamination in 1986 originating from Chernobyl. A model is presented which considers three soil compartments to describe the change of the availability of 137Cs with time. The time-dependency of the 137Cs activity concentration in meat of roe deer is a combination of two components: (1) an exponential decay and (2) a peak in the second half of each year during the mushroom season. The exponential decay over the years can be described by a sum of two exponential functions. The additional transfer of 137Cs into roe deer during the mushroom season depends on precipitation. On the peat bog the 137Cs activity concentration in roe deer is higher and more persistent than in spruce forest

  7. Translocation, accumulation and distribution of 137Cs in rice after foliage contamination

    The single leaf of rice stem was artificially contaminated with 137Cs at different growth stages to study its foliage absorption and translocation. The results showed that the translocation rate of 137Cs to non-contaminated parts of the plant was related with the phyllo-taxis of the contaminated leaf and the majority of 137Cs in the plant was distributed in leaves and stems. For rice being contaminated, there was a positive linear relationship between the accumulation of 137Cs in each non-contaminated part of the plant and the amount of the contamination. The order of the specific activity of 137Cs was: Leaf>Stem>root>ear in non-contaminated parts of the plant

  8. Re-distribution of 137Cs Chernobyl signal in the Aegean Sea

    The present levels of 137Cs in the water column of the Aegean Sea are at all depths, significantly higher than in the pre-Chernobyl period. The concentrations in surface and intermediate water show a linear relationship to salinity, indicating that mixing of Black Sea Water with highly saline waters of Levantine origin is the main process controlling 137Cs levels. The present 137Cs concentrations in deep basins of the North and South Aegean (3.7 - 5.5 Bq m-3) are the highest in the deep waters of the Mediterranean Sea. In the North Aegean the transfer of 137Cs from the surface layers to the bottom took place through the dense water formation events in 1987 and 1993. The 137Cs levels in the deep South Aegean are higher than expected, possibly in relation to a contribution of N-Aegean deep waters. (author)

  9. The effect of gamma rays on carrots

    The effects of several doses (5-400 Gy) of gamma rays from a 137Cs source were studied on several biological indices in carrots. Doses higher than 50 Gy reduced the wet weight of the cells in the suspension medium whereas the doses of 5 and 10 Gy affected the wet weight positively and to a lesser extent the dry weight. This may be due to higher water absorption of the irradiated cells since their number was less than that of the control. The different doses did not affect the chromosome number of the cells but reduced the cell division rates. At doses higher than 200 Gy no singel cell was recorded as dividing after two days of irradiation. A week later, however, the cells seemed to have recovered some ability for division, but with an increase of prophase stage in mitosis and also in the mitotic division abnormalities. Cells irradiation with 10 Gy caused the cells to differentiate and to form somatic embryos due to halting the effect of 2,4-D hormon. Higher doses, however, prohibited or reduced cells differentiation, probably due to higher mitotic division abnormalities. Nevertheless, it has been possible to attain mature plants from all treatments except for the 400 Gy. The low doses of 5 and 10 Gy, contrary to the higher ones, affected positively the speed of seed germination, increased the plant height, and also increased the root weight. 11 refs. (author)

  10. 137Cs vertical migration in a deciduous forest soil following the Fukushima Dai-ichi Nuclear Power Plant accident

    The large amount of 137Cs deposited on the forest floor because of the Fukushima Dai-ichi Nuclear Power Plant accident represents a major potential long-term source for mobile 137Cs. To investigate 137Cs mobility in forest soils, we investigated the vertical migration of 137Cs 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 137Cs in the litter layer moved into the mineral soil within one year after the accident. On the other hand, the topsoil prevented migration of 137Cs, and only 2% of 137Cs 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 137Cs inventory. Therefore, the migration of 137Cs by seepage water comprised only a very small part of the total 137Cs inventory in the mineral soil, which was undetectable from the vertical distribution of 137Cs in the soil profile. In the present and immediate future, most of the 137Cs deposited on the forest floor will probably remain in the topsoil successively, although a small but certain amount of bioavailable 137Cs exists in forest surface soil. -- Highlights: • Lysimeter captured 137Cs mobility in a forest soil after the Fukushima accident. • Major part of 137Cs in the litter layer moved into the mineral soil within a year. • Litter-leachate 137Cs was predominantly adsorbed within the topsoil. • The annual migration below a 10 cm depth was 0.1% of the total 137Cs inventory

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

    To investigate the behavior of nuclear accident-derived 137Cs in river water under base-flow conditions, concentrations of dissolved and particulate 137Cs were measured at 16 sampling points in seven rivers of Fukushima Prefecture, Japan, in 2012 and 2013. The concentration of dissolved 137Cs was significantly correlated with the mean 137Cs inventory in the catchment area above each sampling point in both sampling years. These results suggest that the concentration of dissolved 137Cs under base-flow conditions is primarily determined by the 137Cs inventory of the catchment area above the sampling point. However, the concentration of particulate 137Cs did not show a clear relationship with either the mean 137Cs inventory or the dissolved 137Cs concentration, thus indicating that particulate and dissolved forms do not effectively interact in rivers. To evaluate the contribution of the 137Cs inventory within catchment areas, we analyzed relations between the 137Cs concentration and the mean 137Cs 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 137Cs 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 137Cs 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 137Cs can originate from a larger area of the catchment even under base-flow conditions; however, particulate 137Cs did not show such behavior. The results also show that under base-flow conditions, dissolved and particulate 137Cs behave independently during their transport from river catchments to the ocean. - Highlights: • 137Cs in river water under base-flow conditions was investigated in Fukushima. • Dissolved 137Cs was significantly correlated with 137

  12. 137Cs applicability to soil erosion assessment: theoretical and empirical model

    The soil erosion processes acceleration and the increase of soil erosion rates due to anthropogenic perturbation in soil-weather-vegetation equilibrium has influenced in the soil quality and environment. So, the possibility to assess the amplitude and severity of soil erosion impact on the productivity and quality of soil is important so local scale as regional and global scale. Several models have been developed to assess the soil erosion so qualitative as quantitatively. 137Cs, an anthropogenic radionuclide, have been very used to assess the superficial soil erosion process Empirical and theoretical models were developed on the basis of 137 Cs redistribution as indicative of soil movement by erosive process These models incorporate many parameters that can influence in the soil erosion rates quantification by 137 Cs redistribution. Statistical analysis was realized on the models recommended by IAEA to determinate the influence that each parameter generates in results of the soil redistribution. It was verified that the most important parameter is the 137 Cs redistribution, indicating the necessity of a good determination in the 137 Cs inventory values with a minimum deviation associated with these values. After this, it was associated a 10% deviation in the reference value of 137 Cs inventory and the 5% in the 137 Cs inventory of the sample and was determinate the deviation in results of the soil redistribution calculated by models. The results of soil redistribution was compared to verify if there was difference between the models, but there was not difference in the results determinate by models, unless above 70% of 137 Cs loss. Analyzing three native forests and an area of the undisturbed pasture in the Londrina region, can be verified that the 137 Cs spatial variability in local scale was 15%. Comparing the 137 Cs inventory values determinate in the three native forest with the 137 Cs inventory value determinate in the area of undisturbed pasture in the

  13. 137Cs and 40K partitioning in the system soil-plant under different ecological conditions

    In the environment 137Cs is exclusively of the anthropogenic origin. Among different released fission radionuclides, 137Cs is the most significant one as it contributes to long-term doses to population. It belongs to the group of radionuclides which under accidental situations can disperse worldwide because of air mass transport. 137Cs deposition in the Lithuanian terrestrial and aquatic ecosystems is basically related to the global fallout and contaminated air masses from the Chernobyl NPP accident. An extra load of 137Cs to the Lithuanian terrestrial ecosystems was determined after the Fukushima Daiichi NPP accident as well. Over the recent decades evident changes in the approach to the radiation protection of non-human species from ionizing radiation have taken place. Furthermore, long-term predictions of the mobility and bioavailability of 137Cs are required because of its penetration into the food chain. 40K is a typical lithophilic element and its geochemistry could be similar to that of 137Cs because they both are of the same valence state, +1. Investigation results of 137Cs and 40K behavior in the environmental systems in the literature are rather contradictory. Therefore, the aim of the present study is to assess 137Cs and 40K activity concentration in soil and various plants of a different root system and to compare bioavailability of these radionuclides under different environmental ecological conditions. 137Cs deposition distribution in the upper soil layer is different in the studied territory. The mean 137Cs activity concentrations in soil and plants in the post-Chernobyl period varied in a wide range. 137Cs activity concentrations in soil varied from about 30 Bq/kg to 340 Bq/kg, while in various plants and grasses the range was 45-119 Bq/kg. Mean values of the 137Cs transfer factor ranged from 0.1 to 1.4. The discrimination factor was determined to evaluate the effect of 40K activity concentration in soil and plants on distribution of 137Cs in plants

  14. Determination of radionuclides for river sediment CRM with HPGe gamma-ray spectrometer

    The authors described the method and results for determination of seven radionuclides: 238U, 235U, 226Ra, 232Th, 40K, 60Co and 137Cs in the river sediment Certified Reference Material (CRM) using a HPGe gamma-ray spectrometer. The accuracy and reliability of measurement results were improved through varieties of techniques, which include: precise calibration of the gamma-ray spectrometer, coincidence summing correction and interference peak correction, two kinds of peak analysis methods (TPA and function fit), and utilization of as many as possible characteristic gamma-rays. Present measurement results for the seven radionuclides were in agreement with the verification results of the CRM with 1 σ or 2σ uncertainty, and its relative deviation were in the range of +1.0%--6.5%

  15. 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

    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 134Cs, 137Cs, 131I, 129mTe and 110mAg. The radioactivity ratio of 134Cs–137Cs was almost constant at 0.91 regardless of the locations of soil sampling. The radioactivity ratios of 131I and 129mTe–137Cs 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. - Highlights: • Soil deposition density maps of gamma-ray emitting radioactive nuclides from the Fukushima Daiichi Nuclear Power Plant (NPP) accident were constructed for 134Cs, 137Cs, 131I, 129mTe and 110mAg. • The radioactivity ratios for the observed radioactive radioactive nuclides indicated specific regional features. • The radiation doses from radioactive cesium were found to be much higher than those from the other radioactive nuclides

  16. Soil to plant 137Cs transfer factors in Zea mays and Phaseolus vulgaris in a semi-arid ecosystem from a radioactive waste site

    A study of 137Cs in soil, maize plants, (Zea mays) and beans (Phaseolus vulgaris) has been performed at the confined Storage Centre for Radioactive Waste from Mexico. Under field conditions the site was divided in four zones with different soil contamination characteristics. The plants were grown 'in situ' reproducing the local agricultural practices without fertilizers, pesticides or artificial irrigation.The 137Cs determinations were performed using a low background gamma spectrometry system with an HPGe detector. The results indicate that one of the zones had a striking 137Cs contamination in the soil and the uptake by the grown plants showed the highest specific activities at the root. For the edible parts of the plants the amount of 137Cs in the maize grains was one order of magnitude lower than for the beans. The transfer factors ranges for the different parts of the maize plants was from 0.001 in the grain to 0.6 in the root. (author)

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

    NONE

    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.``

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

    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.''

  19. Modeling 137CS dispersion from a radiological dispersion device

    This analysis reveals that, if terrorists detonate a RDD containing a relatively small amount of 137Cs (approximately 12-35g), the resulting dispersion can contaminate a relatively large area. The actual magnitude of a terrorist incident involving the release of radioactive material by a dirty bomb depends on the dimensions of the contaminated area and the accompanying contamination density (i.e., radioactivity) distributed within that area. Applying a semiempirical model indicates that the spatial extent of the contaminated area and the level of activity within that area are dependent primarily on local scale meteorological conditions, especially whether rainfall occurs, as well particle size and effective release height. As a result, the magnitude of the consequences of terrorists acquiring non-weapons grade nuclear materials and releasing those materials with a dirty bomb is contingent on a number of factors beyond the scope of active countermeasures, especially the RDD's design elements and local-scale meteorological conditions. Modeling the dispersion of radioactive aerosols throughout an urban landscape, especially with accurate 3-D representation of its complex geometry and meteorology, is indispensable for assessing the potential consequences of a terrorist incident and implementing effective emergency response, health services, and decontamination decisions. (orig.)

  20. Gamma ray attenuation in a developed borate glassy system

    Saeed, Aly; El shazly, R. M.; Elbashar, Y. H.; Abou El-azm, A. M.; El-Okr, M. M.; Comsan, M. N. H.; Osman, A. M.; Abdal-monem, A. M.; El-Sersy, A. R.

    2014-09-01

    Measurements and calculations of gamma ray attenuation coefficients in glass barriers of xBaO-5ZnO-5MgO-14Na2O--1Li2O-(75-x)B2O3, previously prepared by the melt-quenching technique [1], were performed for γ-ray of energies 121.8, 244.7, 344.14, 661.66, 778.7, 974, 1086.7, 1173.24, 1332.5, and 1407.9 keV; which emitted from 152Eu, 137Cs, and 60Co radioactive gamma ray sources. The transmitted γ-rays were detected by 3″×3″ and 5″×5″ NaI (Tl) scintillation γ-ray spectrometers, and a highly calibrated survey meter. The mass attenuation coefficients of γ-rays (σ(E) were deduced from the attenuation curves, while the WinXCom computer program (version 3.1) was used to calculate the mass attenuation coefficients of γ-rays for such energies at different barium concentrations of a glassy system. A good agreement between both experimental and theoretical results was achieved as well as results obtained by other workers in similar field.

  1. 137Cs dynamics within a reactor effluent stream in South Carolina

    Radiocesium dynamics are being studied in a blackwater creek which had received production reactor releases from the Savannah River Plant in South Carolina. Most 137Cs in the water column is dissolved or in colloidal form and is believed to originate primarily through outflow from an upstream ''contaminated'' reservoir. All ecosystem components in the stream have high 137Cs concentration factors. Radiocesium concentrations are highest in filamentous algae (332 pCi/g-dry) and suspended particulate matter (100 to 200 pCi/g). Other food chain bases had much lower 137Cs levels. Most consumer populations averaged 10 to 50 pCi/g. Radiocesium concentrations decreased in transfers between food chain bases and primary consumers or filter feeders. Omnivores and small predators have similar 137Cs concentrations with bioaccumulation occurring by top-carnivores. Radiocesium levels are around 100 pCi/g in largemouth bass and water snakes. Foodweb components in the stream have reached a dynamic equilibrium in 137Cs concentrations despite a 10 yr absence of reactor operations. Radiocesium levels are apparently being maintained through long-term 137Cs cycling in the upstream reservoir and surrounding flood plain forest systems. Rainfall and other physical processes influence the seasonal 137Cs fluctuations in stream components

  2. Availability and immobilization of 137Cs in subtropical high mountain forest and grassland soils

    To understand the behavior of 137Cs in undisturbed soils after nuclear fallout deposition between the 1940s and 1980s, we investigated the speciation of 137Cs in soils in forest and its adjacent grassland from a volcano and subalpine area in Taiwan. We performed sequential extraction of 137Cs (i.e., fractions readily exchangeable, bound to microbial biomass, bound to Fe-Mn oxides, bound to organic matter, persistently bound and residual). For both the forest and grassland soils, 137Cs was mainly present in the persistently bound (31-41%) and residual (22-62%) fractions. The proportions of 137Cs labile fractions - bound to exchangeable sites, microbial biomass, Mn-Fe oxides, and organic matter - were lower than those of the recalcitrant fractions. The labile fractions in the forest soils were also higher than those in the grassland soils, especially in the volcanic soil. The results suggest that the labile form of 137Cs was mostly transferred to the persistently bound and resistant fractions after long-term deposition of fallout. The readily exchangeable 137Cs fraction was higher in soils with higher organic matter content or minor amounts of 2:1 silicate clay minerals

  3. The occurrence and bioavailability of radioactive 137Cs in small forest lakes in southern Finland

    Following the Chernobyl accident in late April 1986, central Finland was subjected to considerable radioactive fallout. The radioactive isotope of caesium, 137Cs, was potentially the most harmful isotope in the fallout because of its long half-life (30 years). 137Cs activities remained unexpectedly low within the biota (algae, zooplankton, aquatic moss, fish) of some humic forest lakes in southern Finland compared to the clear water lakes within the same district. This observation suggested that humic substances, by binding 137Cs chemically, may reduce its bioavailability in lake water. Our laboratory experiments (throughflow systems; gel chromatography) demonstrated that binding of 137Cs by humic substances was negligible in untreated lake waters; only when most of the alkali metals had been removed with an ion exchange resin was any binding of 137Cs by low molecular humic fractions apparent. Instead, the concentrations of cations (especially potassium) were of overwhelming importance for the bioavailability of 137Cs within the lacustrine ecosystems. The concentrations of 137Cs within food chains are expected to stay at a high level for many years especially in lakes with long water renewal times. (Author)

  4. Variability of 137Cs inventories in undisturbed soils across the territory of Viet Nam

    Inventories of 137Cs were measured in putatively undisturbed soils at 292 locations throughout the territory of Viet Nam. Logarithms of these values were regressed against characteristics of the sampling sites, such as geographical co-ordinates, annual rainfall and physico-chemical parameters of soil. The regression model containing latitude and annual rainfall, as explanatory variables, could explain 76% of the variation in logarithmic inventory values. The model was interpreted to represent the spatial distribution of 137Cs deposition density while the regression residuals were assigned to the loss or gain of 137Cs due to soil erosion or accretion at the sampling sites. Depth-distribution profiles of 137Cs, measured at eight selected sites, provided support for this interpretation. In particular, a linear relationship was found between the residual and the 137Cs-penetration depth. Although, on average, the measured inventories differed from the deposition values by 31%, the 137Cs deposition density could be predicted by the regression model with a ±7% relative uncertainty at a 95% confidence level. The model has, therefore, been used to provide 137Cs baseline values in soil-erosion studies. These results are in general agreement with the global pattern published in 1969 by the United Nations Scientific Committee on the Effects of Atomic Radiation, and provide further insights into the spatial distribution of nuclear-test fallout deposition in East Asia. (author)

  5. Physical and chemical parameters affecting transport of 137Cs in arid watersheds

    The occurrence and amount of fallout 137Cs were determined in 12 watersheds in the arid southwestern United States. The factors believed to influence the distribution of 137Cs in the watershed soils and in the reservoir sediments were investigated by using stepwise regression techniques. Seventeen parameters, in the case of soils, and 21 parameters, in the case of sediments, were used in the study. Ninety percent of the variation in the 137Cs content of soils, per unit weight, could be predicted in terms of the percentage of soil nitrogen, the R factor (rainfall intensity) of the universal soil loss equation, the percentage of sand in the soils, and the soil cation exchange capacity. Also, 90% of the variation in the content of 137Cs in the watershed soils, per unit area, could be predicted in terms of the fallout intensity, the percentages of silt and clay, and the cation exchange capacity. For reservoir sediments the equivalent predictors of 137Cs accumulation in the sediment profile, per unit weight, were the soil cation exchange capacity, the January-March average precipitation, and the soil contents of total P and N. The distribution of 137Cs in sediments per unit area was similarly predicted by watershed area, percentage of total soil C, reservoir surface area, areal concentration of 137Cs in the watershed soils, and soil organic matter

  6. Uptake of 137Cs from coniferous forest soil by sheep's fescue in pot experiment

    The uptake of Chernobyl fallout radiocaesium (137Cs) from forest soils with low nutrients, high organic matter content, and acidic pH were examined in pot experiments. Results of sheep's fescue (Festuca ovina) two harvests after growing period of 13 weeks each, showed a slight variation in the 137Cs uptake. Transfer factor (TF) for 137Cs based upon soil-to-plant relationships calculated, (Bqkg-1 plant DW/Bqkg-1 soil DW). The ranges were from 0.03 to 3.43 with a mean of 0.34 ± 0.31 for first cut and from 0.03 to 2.28 with a mean of 0.36 ± 0.33 for second cut. Variation in the uptake of 137Cs by sheep's fescue grass might be due to the influence of soil pH and OM % in conjunction with soil moisture. The effect of potassium (K+), stable caesium (Cs+), and ammonium (NH4+) that were added as chlorides on 137Cs uptake by sheep's fescue were also tested in pot experiment under the same conditions of previous set-up. Results from three harvests after growing period of 13 weeks each, demonstrated that K+ reduced the uptake of 137Cs. In contrast the addition of both stable Cs+ and NH4+ found to enhance 137Cs uptake by sheep's fescue. (author)

  7. The latitudinal inventory of sup(137)Cs in vegetation and topsoil in northern Canada, 1980

    The latitudinal distribution of fallout sup(137)Cs in Canada has been determined along a transect extending from 50 degrees to 82 degrees N in 1980. The sup(137)Cs content of lichens, bryophytes, and cushionlike vascular species was measured at 16 sites between Brandon, Manitoba, and Alert, Ellesmere Island. Lichen species were shown to be the most effecive biological monitors of sup(137)Cs deposition because of their specific morphology, longevity, and slow growth rates. Dry, exposed ridges were the sites of the highest sup(137)Cs retention by plants. sup(137)Cs levels in vegetation followed a bell-shaped distribution along the transect and the maximum accumulation was measured in samples collected between 60 degrees and 70 degrees N ((10 nCi msup(-2) at 63 degrees N) (1 Ci = 37 GBq). This distribution is the combined results of the original latitudinal deposition of sup(137)Cs, the expired portion of its physical half-life, and the efficiency of biotic and abiotic removal processes along the studied corridor. It is suggested that the long-term implications of sup(137)Cs in the northern food chain ought to be followed and studied more closely in the light of the data presented

  8. 137Cs in the Danish Wadden Sea: contrast between tidal flats and salt marshes

    The 137Cs activity of salt marsh and tidal flat sediments of the northern part of the European Wadden Sea was studied based on a comprehensive dataset of 210Pb dated cores. The 137Cs inventory of salt marsh sediments shows a major peak corresponding to the Chernobyl accident in 1986, and a minor peak located in the late 1960s interpreted as the combined effect of atmospheric testing of nuclear weapons. Emissions from the nuclear reprocessing plant Sellafield are not reflected as peaks in 137Cs activity, but may contribute to the rising 137Cs activity in the years prior to 1986. The 137Cs activity of tidal flat sediments differs from salt marsh sediment in two respects. First, the activity is much lower and, second, the major peak in the 1980s is located in the beginning instead of in the middle of the decade. The differences in 137Cs inventory between the two environments are interpreted to result from repeated cycles of deposition/resuspension and mixing on tidal flats. A simple model illustrating the consequence of mixings returns an apparent shift of major peaks in 137Cs activities backwards in time corresponding to the mixing depth divided by the deposition rate

  9. Concentration ratios for small mammals collected from the exposed sediments of a 137Cs contaminated reservoir

    137Cs concentration ratios were computed for small mammals collected from the dried sediments of a partially drained, contaminated reservoir. Soil 137Cs activity concentrations were heterogeneous on small and large spatial scales and had a geometric mean of 253 (range 23-2110) Bq/kg dry weight. Mean 137Cs activity concentrations in composite cotton rat Sigmodon hispidus and cotton mouse Peromyscus gossypinus samples averaged 2480 (range 556-6670) and 471 (range 96-1000) Bq/kg whole body dry weight, respectively. About 50% of the variance in cotton rat tissue 137Cs activity was explained by variation in soil 137Cs activity. Soil-to-animal dry weight concentration ratios averaged 6.0 for cotton rats and 1.2 for cotton mice and were generally similar to 137Cs concentration ratios for herbivorous, homeothermic animals from other contaminated ecosystems. In the RESRAD-BIOTA dose model, the default wet-weight concentration ratio for 137Cs in terrestrial animals is 110 resulting in an estimate of internal and external radiation doses to terrestrial biota that is 44 times more than the dose calculated with the actual measured wet-weight concentration ratio for cotton rats (1.6). These results show that site-specific concentration ratios can significantly affect the estimation of dose

  10. Transfer of 137Cs and stable Cs in soil-grass-milk pathway in Aomori, Japan

    The soil-to-grass transfer factors and grass-to-milk transfer coefficients were determined for 137Cs and stable Cs in soil, grass and milk samples collected in Aomori Prefecture, Japan. The concentrations of 137Cs in the soil and grass samples collected from 25 sampling sites were 13 ± 12 Bq x kg-1 and 2.0 ± 2.1 Bq x kg-1 dry wt., respectively. The geometric mean of soil-to-grass transfer factor of 137Cs was 0.13 and its 95% confidence interval was 0.017-0.98. The transfer factor of 137Cs was higher than that of stable Cs, and they had a positive correlation. The concentration of K in the soil affected both transfer factors. The concentration of 137Cs in milk samples collected from 16 sites was 76 ± 43 mBq x kg-1 fresh wt. and had a good correlation with that of stable Cs. The geometric mean of grass-to-milk transfer coefficient of 137Cs was 0.0027, assuming that a cow's total daily intake was 20 kg of dry grass. The transfer coefficient of 137Cs was positively correlated with that of stable Cs. (author)

  11. Uptake of 137Cs from coniferous forest soil by sheeps' fescue in pot experiment

    The uptake of the post-Chernobyl 137Cs fallout from forest soils with low nutrients, high organic matter content and acidic pH was examined in pot experiments. Results of sheep's fescue (Festuca ovina) two harvests (after growing period of 13 weeks) showed a considerable variations in 137Cs uptake. Transfer factor (TF) for 137Cs based upon soil-to-plant relationships was calculated: Bqkg-1 plant DW / Bqkg-1 soil DW. A considerable fluctuations in the values were also observed. The ranges were: from 0.03 to 3.43 with a mean of 0.35±0.43 for the first cut and from 0.03 to 2.28 with a mean of 0.36±0.42 for the second cut. This variation in the 137Cs uptake by sheep's fescue grass might be due to the influence of high soil OM% and soil pH in conjunction with soil moisture. The effect of potassium (K+), stable caesium (Cs+), and ammonium (NH4+) that were added as chlorides on 137Cs uptake by sheep's fescue were also tested in a pot experiment under the same conditions of previous set-up. Results of three harvests demonstrated that K+ reduced the uptake of 137Cs. In contrast an addition of both Cs+ and NH4+ seams to enhance the uptake of 137Cs by sheep fescue. (author)

  12. Fallout 137Cs in cultivated and noncultivated north central United States watersheds

    The cesium (137Cs) concentrations were measured in the soils and sediments of 14 watersheds, 7 cultivated and 7 noncultivated, in the North Central United States. The 137Cs concentration in watershed soils ranged from 56 to 149 nCi/m2, with cultivated watersheds averaging 75 nCi/m2 and noncultivated watersheds averaging 104 nCi/m2. The 137Cs concentration in the reservoir sediments ranged from 74 to 1,280 nCi/m2, with a mean of 676 nCi/m2 for the cultivated watersheds and 365 nCi/m2 for the noncultivated watersheds. The 137Cs concentrations per unit area in sediments were 0.8 to 18.7 times greater than those found in the contributing watershed soils. This indicated that some 137Cs is moving within the watersheds and that the reservoirs are acting as ''traps'' or ''sinks.'' The factors accounting for the variation in 137Cs concentration in the soils and sediments of the watersheds are (i) the erosion potential of the watershed, (ii) the sites for adsorption of 137Cs, and (iii) the input of radioactivity into the watershed

  13. Foliar absorption and translocation of 137cs in egyptian olive plants

    Foliar absorption and translocation of 137Cs by olive leaves were studied. Olive seedlings were transferred to the greenhouse in pots containing fine Nile silt.. Two seriies of pot experiments were conducted at the Nuclear Research Center site at Inshas. The treatments were conducted on leaves at the two middle nodes of the selected shoots. The lower surface of the olive leaf absorbed more 137Cs at the studied pH values as compared with the upper surface. The results show that changing the pH from 2 to 3 had no have any effect on the foliar absorption of 137Cs. Further increase of pH value caused the 137Cs foliar absorption to show a minimum at pH 5 then a maximum at pH 7. At pH 8 the foliar absorption of 137Cs started to decrease again. The concentration of translocated 137Cs was found to decrease gradually in the leaves above and below the treated ones. Absorption of 137Cs increased with time in the first 24 hours followed by lower absorption rates till the end of the experiment after 148 hours

  14. Uptake, retention and organic/tissue distribution of 137Cs by Japanese catfish (Silurus asotus linnaeus)

    Full text: This works describes the uptake, retention/biological elimination of 137Cs by Japanese Catfish (Silurus asotus linnaeus) under laboratory conditions. The fish were divided in to three groups viz. large, medium and small and reared in to the host water contaminated by 137Cs. The accumulated 137Cs concentration in the whole body of the fish was measured at certain intervals up to 60 days. 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 different organs/tissues of the fish were determined. To determine the effective half-life, the fish were transferred and reared into the non contaminated host water. The concentration of the radionuclide in the whole body of the fish was measured up to 66 days. Neglecting the small first compartment for a few days, the average effective half-life of 137Cs in the fish species was found to be ∼ 30 days for all size of fish. Accumulation of 137Cs in muscle/flesh of the fish was found to be ∼ 75% of whole body accumulation. (author)

  15. Evaluation of radioactive exposure from 137Cs in contaminated areas of Northern Ukraine.

    Handl, J; Beltz, D; Botsch, W; Harb, S; Jakob, D; Michel, R; Romantschuk, L D

    2003-04-01

    The paper gives averages of 137Cs deposition densities in soils from three areas in Northern Ukraine measured 12 to 15 y following the Chernobyl accident: in an area near Narodici (75 km west of the Chernobyl nuclear power plant in the so-called zone II) heavily contaminated by the Chernobyl fall-out and in areas around Korosten and Zhitomir showing contamination levels to be much lower. The three areas exhibited very different 137Cs deposition densities of 2.2 MBq m(-2), 400 kBq m(-2), and 5 kBq m(-2), respectively. During a 1-y observation, measurements of the 137Cs transfer in the food chain to humans and 137Cs whole body contents dependent on the 137Cs daily intake were carried out under realistic conditions of the rural inhabitants who lived in settlements within zone II. Detailed investigations of components of the daily diet showed that the high 137Cs contamination levels found in soils of zone II do not affect in any way low 137Cs concentrations of all important agricultural products harvested and consumed by villagers. With regard to consumption habits of the population of zone II, mushrooms and wild berries were found to contribute more than 95% of the 137Cs daily intake to the 137Cs whole body content of about 12 kBq (with maximum values up to 760 kBq) measured in a group of inhabitants of zone II during a period from July 1998 to July 1999. The median of the annual dose of these inhabitants from external and internal exposures was 1.2 mSv y(-1) with a geometric standard deviation of 2.6. Excluding extreme habits, the geometric mean of the total exposure was 1.0 mSv y(-1) with a geometric standard deviation of 1.3. PMID:12705449

  16. Spatial distribution of 40K, 228Ra, 226Ra, 238U and 137Cs in surface soil layer observed at small areas

    The main goal of this study is to give a more detailed insight into spatial radionuclide distribution in soils. It has been necessary in order to plant the future soil sampling procedure that would assure the representative soil samples for broader areas that are usually covered by in situ gamma-spectrometry measurements or aerial gamma-ray spectrometry. The spatial distributions of natural radionuclides and 137Cs activity in surface soil layer were studed in five regular grids, consisting of 9 points each. The distances between sampled points were 30 cm (A grid), 2.45 m (B grid), 19.5 m (C grid), 156 m (D grid) and 213 m (E grid), respectively. Soil samples were dominantly taken at agricultural ploughed fields from areas of ca. 315 cm2 (circle of a. 20 cm diameter), from surface up to 15 cm depth. The results indicate that representative soil sample must cover the broader area to provide data that could be compared with data collected by aerial gamma-spectrometry. The average sample on each locality must be prepared from several point samples. It seems that the central point and four points, each at approximately 50-100 m N, S, E, and W from the central point, could be enough

  17. Natural radionuclides and {sup 137}Cs in commercialized edible mushrooms in Sao Paulo-Brazil; Radionuclideos naturais e {sup 137}Cs em cogumelos comestiveis comercializados em Sao Paulo - Brasil

    Castro, Lilian Pavanelli de

    2008-07-01

    Artificial and natural radionuclides are commonly found in several compartments of the earth's crust. Some mushroom species have a high capacity to absorb radionuclides and toxic elements from the soil. Diet is considered as one of the main routes of radioactive contamination. Therefore, radioactivity measurements in the environment and in food are extremely important to monitor the radiation levels that human can be exposed to either directly or indirectly. Environmental bio monitoring has demonstrated that diverse organisms such as crustaceans, fish and mushrooms are useful when evaluating both the contamination and the quality of the ecosystems. There are actually several radionuclides that can be accumulated in mushrooms, including {sup 40}K, {sup 137}Cs, {sup 232}Th and {sup 238}U. There are few studies in the Southern hemisphere countries, on the natural and artificial radioactivity levels in mushrooms. The present study evaluated {sup 40}K, {sup 137}Cs, {sup 232}Th and {sup 238}U in commercialized edible mushrooms in the state of Sao Paulo, Brazil. The edible mushroom samples were acquired in different commercial establishments in the Sao Paulo metropolitan region, specifically in Municipal Markets. Some samples were acquired directly from producers located in the cities of Mogi das Cruzes, Mirandopolis, Suzano and Juquitiba. About 400g were collected for each edible mushroom species, which included Agaricus sp, Pleurotus sp and Lentinula sp species. All the samples were prepared and stored in polyethylene bottles for approximately 35 days, so that secular equilibrium could be established before counting. The {sup 40}K, {sup 137}Cs, {sup 232}Th and {sup 238}U gamma activities were measured by gamma spectrometry. The equipment consisted of a Hyper pure Germanium detector connected to an electronic system. The detector efficiency was obtained from measurements of reference materials: IAEA-300, IAEA-327 and IAEA-375. The results for the specific activities

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

    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

  19. 137Cs in small forest lakes of Finland after the Chernobyl accident

    A joint monitoring study between the Radiation and Nuclear Safety Authority (STUK) and the Finnish Game and Fisheries Research Institute (FGFRI) on the radioactivity of forest lakes in Evo, Southern Finland, was started in summer 1987. Besides fish, lake water and other biota, such as zooplankton, larvae of various insects and aquatic plants, were analysed from these lakes. Soil samples from the lake catchments were also analysed in 1988 - 1989. In 1992, samples of bottom sediment were analysed from one lake for 137Cs. In addition, fish from the Finnish Acidification Research Project of FGFRI from several small forest lakes in 1986 - 1989 were analysed for 137Cs. The results obtained in the joint study of STUK and FGFRI are gathered in this report. The highest activity concentrations of 137Cs in fish were about 30 000 Bq / kg (w.w.) in 1987 in pike from Lake Iso Valkjaervi, which is a clear-water seepage lake having no natural inlet or outlet. Variation in the activity concentrations of 137Cs in fishes in small forest lakes in the area receiving the highest deposition in Finland has remained large since the Chernobyl deposition. Interspecific differences in 137Cs levels of fish were consistent with their trophic position in the food webs. Ten-fold interlake differences in 137Cs contents of lake water were noted within the same municipality in 1987. In the bottom sediment of Lake Iso Valkjaervi, 95% of 137Cs was present in the uppermost 10 cm and about 70% in the uppermost 3 cm in 1992. The total amount of 137Cs detected in the sediment profile was only a quarter of the average deposition in the municipality of Lammi measured by Arvela et al. (1990). Average values for 137Cs in soil in the catchments of five lakes as Becquerels per unit area were clearly higher than the average value for the deposited 137Cs in the municipality of Lammi determined by Arvela et al. (1990). An aquatic plant, the yellow iris, was the most effective 137Cs accumulator of all the organisms

  20. The spread of 137Cs by resuspension of contaminated soil in the urban area of Goiania

    Measurements regarding the population exposure were performed in Goiania after the radiological accident as well as studies on resuspension and redeposition of 137Cs in urban areas, on the contribution of soil splash to the 137Cs uptake by leafy vegetables and on the transfer of 137Cs from soil to chicken meat and eggs. Periodical street dust sampling was used to follow-up the spreading of the radionuclide in the city. The results do not indicate a measurable spreading of this radionuclide throughout the city from the contaminated areas, but resuspension can lead to significant local contamination of agricultural products, equipment, structures, etc. (author)

  1. Coefficients of leaf-fruit translocation for {sup 60}Co, {sup 90}Sr and {sup 137}Cs in bean plant (Phaseolus vulgaris); Coeficientes de translocacao folha-fruto de {sup 60}Co, {sup 90}Sr e {sup 137}Cs em feijoeiro (Phaseolus vulgaris)

    Macacini, Jose Flavio

    2000-01-15

    Due to the increasing use of nuclear fission for the generation of electrical energy, the safety aspects of power plants must be minutely appraised. In case of an accident, with liberation of radioactive material into the atmosphere, knowledge about the behavior of plant species when in contact with radionuclides is indispensable. An important route through which agricultural products are contaminated by radionuclides is leaf-fruit translocation. This phenomenon can be evaluated by simulating a fallout contamination in a controlled atmosphere using as a tracer man-made radionuclides. In order to quantity the leaf-fruit translocation coefficients for {sup 60}Co, {sup 90}Sr and {sup 137}Cs in the common bean (Phaseolus vulgaris), variety black diamond, an experiment was carried out in a greenhouse with completely randomized blocks design with six treatments and four blocks. A mixture of these three radionuclides was prepared and used to determine their translocation coefficients. The bean plants were contaminated inside a device especially designed to avoid environmental contamination. In each treatment four vases were sprinkled and one was used to estimate the initial activity of the other three vases. High-resolution gamma-ray spectrometry was used for {sup 60}Co and {sup 137}Cs activity determinations and chemical separation followed by beta counting of {sup 90}Y was used for {sup 90}Sr determinations. The number of treatments was reduced from six to four sprayings corresponding to 30, 45, 60 and 75 days after planting. This reduction was due to the attack of common and gold mosaic viroses. Symptoms were observed on the diseased bean plants 50 days after planting. It was possible, however, to verify a functional dependence between instant of tracer application and the level of physiological development of the bean plant. It was verified that the temporal relationship values for leaf-fruit translocation were similar for {sup 60}Co and {sup 137}Cs. For the {sup 90

  2. Effects of ash recycling on the migration rate of 137Cs in forest soils

    Large areas of the eastern parts of central Sweden received as a result of the Chernobyl fallout considerable amount of radioactive caesium (137Cs) . From a physical and chemical point of view potassium (K) and Cs are rather similar, and uptake Of 137Cs from the soil by the plants is restricted because of high of K availability. This leads to that most of the 137Cs the soil is the large storage, only a small portion of the available 137Cs is circulated in the vegetation. Since only minute part of the total pool of 137Cs of the ecosystem is stored in the above ground part of the vegetation, extraction of bio-fuels only marginally relive the system from 137Cs. Recycling of wood-ash could in the future become a common feature in Swedish forestry. However, the use of bio-fuel leads to an increased concentration of 137Cs in the produced wood-ash by c. 40 times. This question, how wood-ash recycling affects the radiation climate in the forest is an aspect on wood-ash recycling have been recognised during recent years. The Swedish Radiation Protection Authority (SSI) has stated that the highest radioactivity that could be spread onto the forests is 5 kBq/ha. The effect on the vegetation content of 137Cs is an intricate interaction between the properties of the ash and the soil. The form in which 137Cs and K is stored in the ash could affect the release. In addition, soil pH and differences in turnover time between the two constituents affects the content of 137Cs in the vegetation. In case large amounts of K are released the uptake of 137Cs be blocked. It has been demonstrated that addition of KCl reduced the concentrations of 137Cs fungal fruit bodies by two thirds a lower effect was found after addition of 3 tonnes wood-ash. In another investigation showed that the activity of 137Cs did not increase the activity in vegetation, and in one case also lowered the activity, this despite the fact that the wood-ash contained 137Cs. In the present study the objective was to

  3. Gamma ray spectrometry results from core samples collected for resume 95

    Field sampling of an airfield at Vesivehmaa, near Vaaksy, Finland (Area 1) was carried out between 26-29 May 1995, to establish the radionuclide deposition and inventory of Chernobyl derived 137Cs, and natural radio radionuclides. The objective was to establish a common calibration site for in-situ and airborne gamma spectrometers, for Exercise RESUME 95 conducted in August 1995. The report presents the sampling details, handling and treatment. The analyses are discussed with particular emphasis given to 137Cs, 134Cs, 40K, 214Tl radionuclides, and the quantification of their respective deposition and inventories. The calibration site was based upon a hexagonal sampling pattern developed by The Scottish Universities Research and Reactor Centre (SURRC). This sampling scheme enables ground level deposition to be related to gamma-ray spectrometers at different heights, taking account of differences in fields of view. More than 50 soil cores were collected in May, split vertically, and taken to Sateilyturvakeskus (STUK) for drying prior to gamma spectrometry. Some 160 individual samples were counted between SURRC and STUK, with 5 samples measured in both laboratories and two IAEA reference materials. Results from common samples and reference materials confirm both compatibility between the two laboratories and traceability to recognised standards. (author)

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

    We used numerical simulations to investigate major controls on spatiotemporal variations of 137Cs 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 137Cs 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 137Cs activities in sediments. The spatial pattern of 137Cs in sediments, which mainly reflected the history of 137Cs 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 137Cs activity in the sediments was due to adsorption of 137Cs onto the sediment mineral fraction having a long desorption timescale of 137Cs. The simulated total 137Cs inventory in sediments integrated over the offshore area, where most of the monitoring stations were located, was on the order of 1013 Bq; this value is consistent with a previous estimate based on observed data. Taking into account 137Cs activities in sediments in both the coastal area and in the vicinity of the power plant, the simulated total inventory of 137Cs in sediments off the Fukushima coast increased to a value on the order of 1014 Bq. - Highlights: • Variations of 137Cs in seabed sediments off the Fukushima coast are investigated. • Sediments record the history of 137Cs activities in the overlying bottom water. • Distribution of sediment grain size affects 137Cs activities in sediments. • Estimated total inventory of 137Cs in the sediments is on the order of 1014 Bq

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

    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).

  6. Determination of gamma ray attenuation coefficients of Al–4% Cu/B4C metal matrix composites at 662, 1173 and 1332 keV

    I Akkurt; K Günoğlu; A Çalik; M S Karakas

    2014-08-01

    Gamma ray attenuation coefficients of metal matrix composites have been investigated. For this purpose, the linear attenuation coefficients of composites containing boron carbide (B4C) at different rates have been measured using a gamma spectrometer that contains a NaI(Tl) detector and MCA at 662, 1173 and 1332 keV, which are obtained from 137Cs and 60Co sources. The measured results were compared with the calculation obtained using computer code of XCOM for 1 keV–1 GeV gamma energies.

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

    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. PMID:26895593

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

    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

  9. 137Cs in fishes of the cooling-pond after the decommissioning the ChNPP

    Content of 137Cs in fishes of the ChNPP cooling-pond was studied during 1999 - 2006. It is established, that in the main fishes species of the cooling-pond there was no essential decrease of content of 137Cs. In Abramis brama (L.), Blicca bjoerkna (L.) and Ictalurus punctatus (Raf.) the contents of 137Cs to 2006 has not decreased in comparison to 1999 - 2000. In Alburnus alburnus (L.) the content of 137Cs in 2006 authentically exceeds those in 2000. Probably, the given phenomenon is caused by the reorganization of trophic circuits due to the change of temperature and hydrological parameters of the cooling-pond ecosystem as the result of decommissioning of ChNPP

  10. Soil 137Cs activity in a tropical deciduous ecosystem under pasture conversion in Mexico

    Soil profiles of 137Cs were measured in a tropical deciduous ecosystem under pasture conversion on the Pacific Coast of Mexico. Soil samples were taken from unperturbed forest, and from pasture plots following forest conversion. The average total 137Cs areal activity of non-eroded forest sites indicated a base level of 5 315 ± 427 Bq m-2. On average, total areal activity on hill-tops was significantly higher (range 10-47%) in the forest than in the pastures. A significant correlation was found between the total 137Cs areal activity and soil organic matter content (r2 = 0.16). This correlation can be explained by a soil physical-protection hypothesis. The redistribution of 137Cs in the landscape is explained by soil erosion processes. (author)

  11. A case study of the transfer of 137Cs to the human fetus and nursing infant

    A four-months pregnant woman was contaminated during an accident involving 137Cs from a teletherapy source that occurred in Brazil in September 1987. In vivo monitoring and analysis of 137Cs concentration in excreta samples (both urine and faeces) of the mother was performed. In vivo monitoring of the infant was conducted after birth. After birth, for about 90 days, which corresponds to most of the period of measurement, the infant was exclusively fed by mother's milk, which was also measured. Estimates of parameters associated with the retention and distribution of 137Cs relating to the metabolism of mother and infant were made. The results provide useful information for age-specific models describing the metabolism of 137Cs. (author)

  12. Floodplain data: ecosystem characteristics and /sup 137/Cs concentrations in biota and soil. [ORNL

    Van Voris, P.; Dahlman, R.C.

    1976-11-01

    Radiocesium (/sup 137/Cs) distribution was determined in soil, roots, ground vegetation, overstory, litter, mammals, feces, and insects for a floodplain ecosystem contaminated by radioactive wastes from Manhattan Project operations in 1944. The 2-ha research site was located on the ERDA reservation, Oak Ridge, Tennessee, in a drained holding pond between Oak Ridge National Laboratory and White Oak Lake. Maximum /sup 137/Cs concentrations in soil occurred near the old retention pond dam (84,400 pCi/g) and at the upper portion of the floodplain boundary (70,500 pCi/g). This bimodal distribution pattern of /sup 137/Cs was evident for all samples collected. Large amounts of data have been collected since the summer of 1974. This report documents the data on ecosystem characteristics and /sup 137/Cs concentrations in biota and soil.

  13. 137CS-determination in game meat from some hunting areas in lower Austria

    In 1986, the contamination of some regions in Austria by 137Cs, due to the Chernobyl accident was relatively high. Among other 137Cs is taken up by people by the consumption of game. In an area of Lower Austria which is relatively heavily contaminated by Chernobyl fallout since 1986 the 137Cs-contamination of meat of game-animals was measured every year. Clear differences arose in the load of the single game species whose causes just like the temporal changes are discussed. The highest 137Cs activity concentration was with 5243 Bq/kg measured on a wild boar. With this activity concentration an annual effective dose of only 0,06 mSv can be estimated for an annual average consumption of one kilogram meat of wild boar. (orig.)

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

    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.

  15. Effect of application timing of potassium fertilizer on root uptake of 137Cs in brown rice

    We have already reported that potassium fertilizer is effective to reduce radiocesium in brown rice. In this study, we tried to find the most appropriate timing for potassium fertilizer application during the rice cultivation period in terms of 137Cs concentrations in brown rice. The concentration of 137Cs in brown rice cultivated without application of potassium fertilizer was 32 Bq kg-1, while that with application of basal fertilizer including potassium was 5 Bq kg-1. The concentration of 137Cs in brown rice was increased with the late application timing. Therefore, application of potassium fertilizer in the early growing period reduced the uptake of 137Cs by rice plant from contaminated soils effectively. (author)

  16. A comparison of 137Cs radioactivity in localized evergreen and deciduous plant species

    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 137Cs concentrations between broadleaf and evergreen foliage at CPSES. Soil 137Cs concentrations from each vegetation location were also compared to the foliage 137Cs concentrations. The study's objective was to determine if the deciduous and evergreen vegetation 137Cs concentrations are statistically the same

  17. Body burden of fallout 137Cs in the inhabitants of Moscow in 1980-1983

    Several groups of people living in Moscow were measured for fallout 137Cs in 1980-1983. In vivo measurements of incorporated 137Cs were made with use of a whole-body counter. The minimum measurable activities of 137Cs were 37 and 17 Bq consequently for time of measurement 15 and 30 min. All persons measured were classified into four groups, personnel of whole-body counters laboratory, teenagers-sportsman, patients of a Moscow hospital (with heart and kidneys diseases) and normal adults-inhabitants of Moscow. The activity of 137Cs in the normal adults and patients was observed to decrease during the period of investigation. It was shown that by the end of 1983 the great majority of the results were similar and below the minimum measurable activity (for time of measurement 15 min)

  18. Modelling the distribution of 90Sr and 137Cs in the Mediterranean Sea (MTPII-MATER)

    Within the frame of the MTPII-MATER project (MAST), the distribution of 90Sr and 137Cs in the Mediterranean Sea was modelled, as these radionuclides are useful tracers of water circulation. The Mediterranean Sea was divided into 81 boxes, corresponding to 21 regions, taking into account water mass circulation, bathymetry and data availability. Transfer rates were obtained from the MOM model run under MEDMEX conditions. The model was run with realistic inputs, which included weapons global fallout, Chernobyl 137Cs, nuclear industry and river runoff. It was observed that existing data are scarce, especially in the eastern Mediterranean. In general, model predictions agreed well with observations, showing maximum concentrations in surface waters and maxima due to global fallout (137Cs and 90Sr) and to the Chernobyl accident (137Cs only). (author)

  19. Floodplain data: ecosystem characteristics and 137Cs concentrations in biota and soil

    Radiocesium (137Cs) distribution was determined in soil, roots, ground vegetation, overstory, litter, mammals, feces, and insects for a floodplain ecosystem contaminated by radioactive wastes from Manhattan Project operations in 1944. The 2-ha research site was located on the ERDA reservation, Oak Ridge, Tennessee, in a drained holding pond between Oak Ridge National Laboratory and White Oak Lake. Maximum 137Cs concentrations in soil occurred near the old retention pond dam (84,400 pCi/g) and at the upper portion of the floodplain boundary (70,500 pCi/g). This bimodal distribution pattern of 137Cs was evident for all samples collected. Large amounts of data have been collected since the summer of 1974. This report documents the data on ecosystem characteristics and 137Cs concentrations in biota and soil

  20. Influence of the Chernobyl fallout on 137Cs wine activities on the Rhone valley

    Influence of the Chernobyl fallout on 137CS wine activities on the Rhone valley. Some parts of the Rhone valley have been quite strongly, affected by the Chernobyl fallout, with 137Cs deposits sometimes higher than 20 000 Bq m-2. In those regions, most of agricultural surfaces are devoted to vineyards for famous vintages. This study shows that the consequences of the Chernobyl fallout in wine were visible but very weak. 137CS wine activities did not reached 1 Bq 1-1. Such limited consequences are linked to the date of the deposit, the first week of May 1986, at the beginning of vineyard plant foliar development. Since 1986, this activity has strongly decreased to be in 2000 close to those existing before the accident: some milli-becquerel per litre. 137Cs activities in soil, mainly contained within the 20 first centimeters, are weakly available for vineyard roots. (authors)

  1. Detritivores enhance the mobilization of 137Cs from leaf-litter

    A large amount of radioactive material was released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident after the disastrous earthquake and subsequent tsunami of March 2011. Since most of the Japanese land area is covered by forest ecosystems, 137Cs was mostly deposited and accumulated on the land surface of forest. The fate of radioactive materials accumulated on the leaf litters should be conscientiously monitored to understand the future distribution and the spread to the surrounding landscapes. Because the accident took place on 11 March 2011, just before the bud-break of deciduous trees, the 137Cs are highly accumulated on the surface of leaf litter on the forest floor. This accumulated 137Cs had transferred to higher trophic organisms mainly through the detritus food chain. However, on the litter surface, 137Cs considered to be strongly and immediately fixed and highly immobilized. Decomposition processes in the forest floor can re-mobilise the nutritional elements which are contained within detritus and make them available for the organisms. In the present study, the feeding effect of detritivore soil arthropods on the mobilization of 137Cs from leaf litter was experimentally examined. Furthermore, the effect of detritivores on the plant uptake of 137Cs was examined by small-scale nursery experiment. Decomposition experiment in the small microcosms was performed using a larvae of Trypoxylus dichotomus, whichis a detritivores feeding on dead plant materials such as wood debris and leaf litters. Contaminated leaf litters were collected in a forest of the Kami-Oguni River catchment in the northern part of Fukushima Prefecture. The leaf litters at A0 layers which are highly contaminated by 137Cs were utilized for the experiment. The contaminated leaf litter was fed to the larvae for ten days. The litter with larvae excreta was washed by 2 M KCl and deionized water. The 137Cs concentration was measured by germanium detectors (Seiko EG and G). As a

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

    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. PMID:27085039

  3. Detritivores enhance the mobilization of {sup 137}Cs from leaf-litter

    Murakami, Masashi; Suzuki, Takahiro [Community Ecology Lab., Biology Course, Faculty of Science, Chiba University, Chiba, 263-8522 (Japan); Ishii, Nobuyoshi [National Institute of Radiological Sciences, Chiba, 263-8555 (Japan); Ohte, Nobuhito [Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 (Japan)

    2014-07-01

    A large amount of radioactive material was released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident after the disastrous earthquake and subsequent tsunami of March 2011. Since most of the Japanese land area is covered by forest ecosystems, {sup 137}Cs was mostly deposited and accumulated on the land surface of forest. The fate of radioactive materials accumulated on the leaf litters should be conscientiously monitored to understand the future distribution and the spread to the surrounding landscapes. Because the accident took place on 11 March 2011, just before the bud-break of deciduous trees, the {sup 137}Cs are highly accumulated on the surface of leaf litter on the forest floor. This accumulated {sup 137}Cs had transferred to higher trophic organisms mainly through the detritus food chain. However, on the litter surface, {sup 137}Cs considered to be strongly and immediately fixed and highly immobilized. Decomposition processes in the forest floor can re-mobilise the nutritional elements which are contained within detritus and make them available for the organisms. In the present study, the feeding effect of detritivore soil arthropods on the mobilization of {sup 137}Cs from leaf litter was experimentally examined. Furthermore, the effect of detritivores on the plant uptake of {sup 137}Cs was examined by small-scale nursery experiment. Decomposition experiment in the small microcosms was performed using a larvae of Trypoxylus dichotomus, whichis a detritivores feeding on dead plant materials such as wood debris and leaf litters. Contaminated leaf litters were collected in a forest of the Kami-Oguni River catchment in the northern part of Fukushima Prefecture. The leaf litters at A0 layers which are highly contaminated by {sup 137}Cs were utilized for the experiment. The contaminated leaf litter was fed to the larvae for ten days. The litter with larvae excreta was washed by 2 M KCl and deionized water. The {sup 137}Cs concentration was measured

  4. Gamma-ray Astronomy

    Hinton, Jim

    2007-01-01

    The relevance of gamma-ray astronomy to the search for the origin of the galactic and, to a lesser extent, the ultra-high-energy cosmic rays has long been recognised. The current renaissance in the TeV gamma-ray field has resulted in a wealth of new data on galactic and extragalactic particle accelerators, and almost all the new results in this field were presented at the recent International Cosmic Ray Conference (ICRC). Here I summarise the 175 papers submitted on the topic of gamma-ray astronomy to the 30th ICRC in Merida, Mexico in July 2007.

  5. Factors Effecting Adsorption of 137 Cs in Marine Sediment Samples in Marine Sediment Samples from the Upper Gulf of Thailand

    Contamination of 137Cs in sediment is a far more serious problem than in water because sediment is a main transport factor of 137Cs to the aquatic environmental. Most of 137Cs in water could be accumulated in sediment which has direct effect to benthos. This study focused on factors effecting the adsorption of 137Cs in marine sediment samples collected from four different estuary sites to assess the transfer direction of 137Cs from water to sediment that the study method by treat 137Cs into seawater and mixed with different sediment samples for 4 days. The result indicated that properties of marine sediment (cation exchange capacity (CEC), organic matter, clay content, texture, type of clay mineral and size of soil particle) had effects on 137Cs adsorption. CEC and clay content correlated positively with the accumulation of 137Cs in the marine sediment samples. On the other hand, organic matter in sediment correlated negatively with the accumulation of 137Cs in samples. The study of environmental effects (pH and potassium) found that the 137Cs adsorption decreased when concentration of potassium increased. The pH effect is still unclear in this study because the differentiation of pH levels (6, 7, 8.3) did not have effects on 137Cs adsorption in the samples.

  6. Modelling of 137Cs behaviour in the soil-plant system following the application of ameliorants

    A set of countermeasures aimed at reducing 137Cs uptake by plant products includes agrochemical measures based on changes in the soil properties after the application of ameliorants. The dynamic models for studying the effect of the application of potassium fertilizers and dolomite powder on 137Cs accumulation in plants are presented. Conceptual approaches to the development of models are based on the identification of mechanisms governing a complex of physico-chemical processes in soil after the use of ameliorants. The following assumptions were used in the development of models: - dynamics of 137Cs distribution in each soil layer depends on the sorption processes characterized by different time to achieve quasi-equilibrium (exchangeable uptake and fixation by clay minerals) as well as on vertical migration process; - change in 137Cs content in soil solution results from the radionuclide sorption on selective and nonselective exchange sites; - uptake of extra amounts of K+ and Ca2+ in soil solution produces effect on processes of 137Cs exchangeable sorption and initiate specific processes responsible for 137Cs fixation in the crystal lattice of clay minerals; - Ca2+ and K+ cations have a competing effect on 137Cs uptake by plants from soil solution, which along with the fixation processes, causes lower accumulation of this radionuclide by plants during the application of ameliorants. The developed models were parameterized for soils of the coniferous forest located in the Bryansk region in area suffered from the radioactive fallout after the Chernobyl accident. Effects of ameliorants and time of their application on 137Cs behaviour in the soil-plant system are assessed. The contribution of soil chemical and biological processes to the decrease in the radionuclide uptake by plants is estimated. (author)

  7. 137 Cs soil contamination of Techa river flood plain near village Muslyumovo

    The results of measuring soil contamination with 137 Cs in 16-km zone of the Techa river flood plain near the Muslyumovo village of the Chelyabinsk region are presented. The measurements are performed in 1995-1996. Maps for the 137 Cs buildup distribution in soils of the half-kilometer areas along the river branch are plotted. Total amount and area of contaminated flood plain are estimated for these zones

  8. Accumulation of 137Cs in Brazilian soils and its transfer to plants under different climatic conditions

    The spatial distribution and behaviour of the global fallout 137Cs in the tropical, subtropical and equatorial soil-plant systems were investigated at several upland sites in Brazil selected according to their climate characteristics, and to the agricultural importance. To determine the 137Cs deposition density, undisturbed soil profiles were taken from 23 environments situated between the latitudes of 02oN and 30oS. Sampling sites located along to the equator exhibited 137Cs deposition densities with an average value of 219 Bq m-2. Extremely low deposition densities of 1.3 Bq m-2 were found in the Amazon region. In contrast, the southern part of Brazil, located between latitudes of 20oS and 34oS, exhibited considerably higher deposition densities ranging from 140 Bq m-2 to 1620 Bq m-2. To examine the 137Cs soil-to-plant transfer in the Brazilian agricultural products, 29 mainly tropical plant species, and corresponding soil samples were collected at 43 sampling locations in nine federal states of Brazil. Values of the 137Cs concentration factor plant/soil exhibited a large range from 0.020 (beans) to 6.2 (cassava). Samples of some plant species originated from different collecting areas showed different concentration factors. The 137Cs content of some plants collected was not measurable due to a very low 137Cs concentration level found in the upper layers of the incremental soils. Globally, the soil-to-plant transfer of 137Cs can be described by a logarithmic normal distribution with a geometric mean of 0.3 and a geometric standard deviation of 3.9

  9. 137Cs and 90Sr aerosol-carriers origination when welding radioactively contaminated metal structures

    The results of research of main parameters of welding process influence to 137Cs and 90Sr radionuclides transition regularity in a welding aerosol are demonstrated. The 137Cs specific activity in welding aerosol decreases according to power law with lessening of surface activity of plates being welded on, and depends on content of electrode cover and does not depend on welding heat input. Respirable fraction activity of welding aerosol exceeds at 20 - 30 % the welding aerosol activity as a whole.

  10. Inventory and vertical migration of 137Cs in Spanish mainland soils

    In this study the total activity of 137Cs deposited per unit area over the Spanish peninsular territory was analysed using a 150 x 150 km2 mesh grid, with samples taken from 29 points. The deposited activities ranged between 251 and 6074 Bq/m2. A linear relationship was obtained between these values and the mean annual rainfall at each sampling point which allowed a map to be drawn, using GIS software, which shows the distribution of total deposited 137Cs activity across the Spanish mainland. At twelve of these sampling points the vertical migration profile of 137Cs was obtained. These profiles are separated into two groups with different behaviour, one of which includes clay and loam soils and the other containing sandy soils. For both groups of profiles the parameters of the convective-diffusive model, which describes the vertical migration of 137Cs in the soil, v (apparent convection velocity) and D (apparent diffusion coefficient) were calculated. - Highlights: → Measured the 137Cs activity in Spanish mainland, being within a range of [251, 6074] Bq/m2, with a mean value of 1726 Bq/m2. → Establishment of the 137Cs background by means of a 137Cs inventory map showing its distribution in the Spanish mainland. → 137Cs shows two different behaviour tendencies in soil depending on it. → The parameters which govern the applied model have been obtained for the analysed profiles. → Analysed those parameters, the two tendencies have been reflected in the obtained values.

  11. 90Sr and 137Cs in higher aquatic plants of the Chernobyl NPP exclusion zone

    The content of 90Sr and 137Cs radionuclides in higher aquatic plants of water object within Chernobyl NPP exclusion zone has been analysed. Biodiversity of phytocenose was studied and species-indicators of radioactive contamination were revealed. The seasonal dynamics of radionuclide content in macrophytes was studied and the role of main aquatic plant clumps in processes of 90Sr and 137Cs distribution in abiotic component of biohydrocenose was demonstrated

  12. [90Sr and 137Cs in higher aquatic plants of the Chernobyl nuclear plant exlusion zone

    Gudkov, D I; Derevets, V V; Kuz'menko, M I; Nazarov, A B

    2001-01-01

    The content of radionuclides 90Sr and 137Cs in higher aquatic plants of water objects within Chernobyl NPP exclusion zone has been analysed. Biodiversity of phytocenose was studied and species-indicators of radioactive contamination were revealed. The seasonal dynamics of radionuclide content in macrophytes was studied and the role of main aquatic plant clumps in processes of 137Cs and 90Sr distribution in abiotic component of biohydrocenose was demonstrated. PMID:11402559

  13. Toxicity of injected 137CsCl in beagle dogs. IX

    Studies on the metabolism, dosimetry and effects of intravenously administered 137CsCl in the Beagle dog are being conducted to aid in assessing the biologic consequences of exposure to 137Cs such as occurs in the event of certain nuclear accidents. Effects of the chronic, relatively uniform whole-body exposure produced by 137Cs are being compared with other diverse radiation dose patterns resulting from inhalation of radioactive aerosols. Sixty-six dogs were entered into the study: six with a mean initial 137Cs body burden of 3780 μCi/kg and five groups of 12 dogs each with mean initial 137Cs body burdens of 2820, 1940, 1420, 970 and 0 μCi/kg. Seventeen of the dogs injected with 137CsCl have died: 11 at 19 to 81 days after injection and cumulative whole-body doses of 860 to 1400 rads died with severe bone marrow damage and resultant pancytopenia; two at 2471 and 2707 days after injection and cumulative doses of 690 and 1800 rads with a neurofibrosarcoma of the liver and a mast cell tumor of the skin; four at 693 to 2148 days after injection and cumulative doses of 840 to 2000 rads with shock, aspiration pneumonia, severe arthritis and renal amyloidosis. Two control dogs died; one at 647 days with auto-immune hemolytic anemia and one at 2442 days with renal amyloidosis. Serial observations are continuing on the 37 137CsCl dogs and 10 control dogs. The 137CsCl dogs now alive have cumulative whole-body doses of 550 to 2200 rads at 2777 to 3031 days after injection

  14. Toxicity of injected 137CsCl in beagle dogs. X

    Studies on the metabolism, dosimetry and effects of intravenously administered 137CsCl in the Beagle dog are being conducted to aid in assessing the biologic consequences of exposure to 137Cs such as occurs in the event of certain nuclear accidents. Effects of the chronic, relatively uniform whole-body exposure produced by 137Cs are being compared with other diverse radiation dose patterns resulting from inhalation of radioactive aerosols. Sixty-six dogs were entered into the study: six with a mean initial 137Cs body burden of 3780 μCi/kg and five groups of 12 dogs each with mean initial 137Cs body burdens of 2820, 1940, 1420, 970 and 0 μCi/kg. Eighteen of the dogs injected with 137CsCl have died: 11 from 19 to 81 days after injection and cumulative whole-body doses of 860 to 1400 rads died with severe bone marrow damage and resultant pancytopenia; two at 2471 days and at 2707 days after injection and cumulative doses of 690 and 1800 rads with a neurofibrosarcoma of the liver and a mast cell tumor of the skin; five from 693 to 3162 days after injection and cumulative doses of 840 to 2000 rads with shock, aspiration pneumonia, severe arthritis, renal amyloidosis and congestive heart failure. Three control dogs died; one at 647 days with auto-immune hemolytic anemia, one at 2442 days with renal amyloidosis and one at 3088 days with disseminated complex mammary adenocarcinoma. Serial observations are continuing on the 36 137CsCl dogs and nine control dogs. The 137CsCl dogs now alive have cumulative whole-body doses of 550 to 2200 rads from 2777 to 3031 days after injection

  15. 137Cs: A Widely Used and Validated Medium Term Soil Tracer

    Radioactive Caesium-137 (137Cs) is found globally in the environment due to fallout after nuclear weapon testing in the fifties and sixties, and nuclear accidents in the more recent past. The properties and particular features of 137Cs (half-life of about 30 years), such as its strong adsorption to soil particles, make it an exceptional and the most widely used soil tracer for studying soil movement processes. The 137Cs method that possesses a number of major advantages over traditional approaches to document erosion and deposition rates, provides estimates of soil redistribution averaged over a period of several decades. It has been employed to study soil redistribution under different agro-ecological conditions in many different areas of the world. 137Cs has been also used in soil erosion investigations over a wide range of geographic scales, extending from experimental plots, through fields of a few hectares to small watersheds of several km2. This method has been validated by many international peer-reviewed studies that compared erosion rates obtained with 137Cs, other tracers, direct measurements at various scales and/or traditional soil erosion modelling. Significant progress has been made in harmonizing protocols for application of 137Cs-based soil erosion research through cooperation of specialist teams and coordination by the International Atomic Energy Agency (IAEA). The development, refinement and calibration of the 137Cs method have provided a universal and mature tool to quantify soil redistribution rates in a range of natural and agro-ecosystems, and have paved the way for a wider application of the technique, particularly in assessing the effectiveness of soil conservation technologies in controlling or mitigating soil erosion and associated degradation processes. This paper explains the fundamental principles of the use of fallout radionuclides for soil erosion assessments based on the example of 137Cs. (author)

  16. Peculiarities of 137Cs translocation in higher plants under environmental and laboratory conditions

    Accumulation of technogenic 137Cs in higher plant roots and above-ground part and comparison of 137Cs and 40K transfer from roots to the above-ground part of plant as well as distribution within above-ground part of plant under environmental conditions were investigated. Parallely, the results of the investigations of 137Cs accumulation in the roots and shoots of test-organism Lepidium sativum L. in the model hydroponic system aqueous solution-solid phase-plant were analyzed. Peculiarities of transfer of this radionuclide from roots to shoots during the entire plant growing period under experimental conditions were determined. 137Cs activity in the tested plants of meadow ecotop was on an average 6-fold lower than in the plants of swamp and 10-fold lower than in the plants of forest ecotop. Differences in 137Cs and 40K transfer from roots to the above-ground part of plant and their distribution in plants indicate particular biological metabolism of these radionuclides in plants. Increased levels of 137Cs in soil practically did not affect the 40K transfer from roots to the above-ground part of plants. The results of investigations under natural and laboratory conditions show that increasing contamination of growth medium with 137Cs caused higher accumulation of this radionuclide in roots but its transfer from roots to the above-ground part of plant decreased or changed insignificantly. 137Cs transfer from roots to above-ground part under natural (Artemisia vulgaris) and laboratory (Lepidium sativum) conditions was rather similar. (authors)

  17. Toxicity of injected 137CsCl in Beagle dogs. XI

    Studies of the metabolism, dosimetry and effects of intravenously administered 137CsCl in the Beagle dog are being conducted to aid in assessing the biologic consequences of exposure to 137Cs that might occur in the event of certain nuclear accidents. Effects of the chronic, relatively uniform whole-body exposure produced by 137Cs are being compared with other diverse radiation dose patterns resulting from inhalation of radioactive aerosols. Sixty-six dogs were entered into the study: six with a mean initial 137Cs body burden of 3780 μCi/kg and five groups of 12 dogs each with mean initial 137Cs body burdens of 2820, 1940, 1420, 970 and 0 μCi/kg. Twenty-two of the dogs injected with 137CsCl have died: 11 with cumulative whole-body doses of 860 to 1400 rads died from 19 to 81 days after injection with severe bone marrow damage and resultant pancytopenia; four with cumulative whole-body doses of 690 to 1900 rads have died between 2471 and 3386 days post injection with neurofibrosarcoma of the liver, dermal mast cell tumor, hemangiosarcoma of the right atrium, and squamous cell carcinoma of the maxillary sinus and soft palate; seven with cumulative doses of 840 to 2200 rads from 693 to 3529 days after injection with shock, aspiration pneumonia, severe arthritis, renal amyloidosis, congestive heart failure, leiomyoma of bladder and urethra, and brain and spinal cord edema. Four control dogs have died: one at 647 days with auto-immune hemolytic anemia, one at 2442 days with renal amyloidosis, one at 3088 days with disseminated complex mammary adenocarcinoma and one at 3265 days with chronic interstitial nephritis. Serial observations are continuing on the 32 137CsCl injected dogs and eight control dogs. The 137CsCl injected dogs now alive have cumulative whole-body doses of 550 to 1500 rads from 3508 to 3762 days after injection

  18. Study of relation between 137Cs soil-to-plant transfer factor and basic soil properties

    Experiments are reviewed in which along with the determination of the 137Cs soil-to-plant transfer factors, the basic properties of soils were determined. The basic properties of soils were completely determined only in a small number of experimental studies. In the said experiments, a multi-parameter regression analysis was used to find a regression equation suitable for reliable forecast of 137Cs content in plants according to the properties of soils. (author). 7 tabs., 34 refs

  19. Phytoremediation of 137Cs from low level nuclear waste using Catharanthus roseus

    Remediation of radionuclides has been carried out using the phytoremediation technology. The green plants have been screened for the uptake potential of radionuclide and found that Catharanthus roseus has the high potential for radionuclides in particular 137Cs. Low level nuclear waste (LLNW) collected from effluent treatment plant, BARC has been characterized for physico-chemical and the presence of traces of radionuclides. LLNW was spiked with 3.7 x 104 kBqL-1 activity level of 137Cs. The plants of C. roseus were grown in (i) LLNW, (ii) 137Cs spiked LLNW and (iii) with the control. The radio activities were measured in the solution at the intervals of 0, 1, 2, 3, 6, 8 and 15 days in triplicate set of the experiment. The plants were harvested after the growth. The depletion of 137Cs in LLNW was found to be 19, 21, 24, 38, 60 and 76% at intervals of 1, 2, 3, 6, 8 and 15 days, respectively. The bio-accumulation of 137Cs has been measured in the roots and shoots of the harvested plants. The activity of 137Cs was found higher in shoots (998 kBq g-1 dw) as compared to the roots (735 kBq g-1 dw). The uptake of radionuclide-137Cs, bio-accumulation in the shoot via the active transport from the root, shows the high efficiency and potentiality of C. roseus for the remediation of radionuclide. The bio-accumulation of 137Cs in the shoot will remediate the radionuclide contamination from LLNW. C. roseus can also be made applicable for effective remediation of radionuclides present in the LLNW. (author)

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

    Highlights: • In response to the Japan Fukushima Daiichi nuclear accident. • The monitoring have been carried out in some Indonesia coasts. • 137Cs in the eastern and western Indonesia coasts originated from global fallout. - Abstract: 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 137Cs 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 137Cs 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 137Cs concentrations in the fish from several Indonesian coasts were 137Cs concentrations in mollusk, crab and prawn were 10.65–38.78, 4.02 and 6.16 mBq kg−1, respectively. 134Cs was not detected in the seawater, sediments or biota. Thus, it was concluded that 137Cs on the eastern and western Indonesian coasts originated from global fallout

  1. Sampling soils for 137Cs using various field-sampling volumes

    The sediments from a liquid effluent receiving area at the Los Alamos National Laboratory and soils from intensive study area in the fallout pathway of Trinity were sampled for 137Cs using 25-, 500-, 2500-, and 12 500-cm3 field sampling volumes. A highly replicated sampling program was used to determine mean concentrations and inventories of 137Cs at each site, as well as estimates of spatial, aliquoting, and counting variance components of the radionuclide data. The sampling methods were also analyzed as a function of soil size fractions collected in each field sampling volume and of the total cost of the program for a given variation in the radionuclide survey results. Coefficients of variation (CV) of 137Cs inventory estimates ranged from 0.063 to 0.14 for Mortandad Canyon sediments, where CV values for Trinity soils were observed from 0.38 to 0.57. Spatial variance components of 137Cs concentration data were usually found to be larger than either the aliquoting or counting variance estimates and were inversely related to field sampling volume at the Trinity intensive site. Subsequent optimization studies of the sampling schemes demonstrated that each aliquot should be counted once, and that only 2 to 4 aliquots out of an many as 30 collected need be assayed for 137Cs. The optimization studies showed that as sample costs increased to 45 man-hours of labor per sample, the variance of the mean 137Cs concentration decreased dramatically, but decreased very little with additional labor

  2. Effect of 137Cs on spring wheat and transfer in soil-wheat systems

    The study emphasized on the effect of 137Cs on spring wheat and transfer factors in soil-wheat system. The results show that the spring wheat grown normally under the experimental conditions and no adverse effects appeared; the absorption trends of 137Cs by spring wheat were in the order of Dayawan soil > Qinshan soil > Beijing soil; the specific radioactivity of 137Cs in wheat increased in the magnitude order varying with the radioactivity of 137Cs applied in the soils and the relationship was significant difference in positive; the transfer factor (TF) of 137Cs in the soil-plant systems varied with the characteristic of soil and the range was within n x 10-2- n x 100 in the same activity of contamination; in the same soil-plant system the TF value increased varying with the radioactivity of 137Cs contamination in the range of 2.2 x 10-2 - 5.4 x 10-2 for Beijing soil plant system, 1.04 - 2.09 for Dayawan soil-plant system and 0.51 - 1.21 for Qinshan soil-plant system

  3. Distribution of {sup 137}Cs in water leachates of forest humus

    Passeck, U.; Zech, W. [Bayreuth Univ. (Germany); Lindner, G. [Fachhochschule Coburg (Germany)

    1995-12-31

    The distribution of {sup 137}Cs in water extracts of organic layers of forest soils was investigated using an ultrafiltration method. Samples were taken from two sites in the Bavarian Alps. The different horizons of the organic layers were extracted by column elution with water and 50 mmol/litre CsCl solution. Water extracts were fractionated using membranes with the molecular weight cutoff of 500, 1000 and 3000 Dalton to determine the molecular weight distribution of dissolved organic carbon (DOC). The activity of {sup 137}Cs associated with the different DOC-fractions was measured by direct gammaspectrometry. Cesium-137 in the fraction smaller than 500 Dalton was defined as `ionic`. The results indicated a change of the binding sites depending on the degree of decomposition and humification in the profile. Organic bound {sup 137}Cs was identified in all extracts. High mobilities of DOC and {sup 137}Cs were observed in the same horizons, fractionation showed then low-molecular-weight DOC and {sup 137}Cs mainly in ionic form. In horizons with high-molecular-weight DOC the portion of organic bound {sup 137}Cs ranged up to 40%. (author).

  4. The feature and distribution of 137Cs in the forest soil

    The 137Cs concentration in an undisturbed upper layer of naked land in Fukuoka Prefecture decreased exponentially from 1969 to 1999 with the apparent half-life of 7 years. The ratio of 137Cs concentration in the lower layer of the soil to that in the upper layer was about 1/5. The concentration of 137Cs, 40K, and stable Cs and the soil profile consisting of loss on ignition, pH, and electric conductivity were determined in the 48 samples collected in the forests and the neighboring naked land from 1991 to 1998. The 137Cs concentration in the forest soils ranged from 1 to 424 Bq/kg dry wt, 131 Bq/kg dry wt on average, although 137Cs was hardly detected in the naked soil around the forest. There was no regional difference in the distribution of the 137Cs concentration, and it varied with pH and electric conductivity in the soil. Further, it tended to be higher in the deciduous woodland than in the evergreen woodland. (author)

  5. 137Cs and 40K in the flesh of Pacific albacore, 1964-1974

    Concentrations of 137Cs in the flesh of albacore tuna caught off the California coast during the last 10 yr decreased by a considerably smaller factor than did corresponding values reported for atmospheric fallout. Between 1965 and 1974, average tissue concentrations decreased steadily from 90 to approx. 40pCi/wet kg, which suggests an effective half-time for 137Cs in the upper layer of the eastern North Pacific of about 1 decade. Values for natural 40K, which was measured at the same time, averaged 3300pCi/wet kg. The 1965 mean concentrations of 137Cs in albacore from four widely separated fisheries in the Northern Hemisphere agreed within a factor of two, ranging from 50 to 90pCi/wet kg. In contrast, specimens from South Pacific fishery based at American Samoa averaged only 14pCi/wet kg. Surface seawater collected around Tutuila Island averaged 0.085pCi/l. 137Cs, in good agreement with measurements made a year later over a much wider area of the South Pacific. No larger variations in flesh concentrations of 137Cs or 40K were observed as a function of tuna size, species, portion of the body sampled or cooking. Thus, radioanalysis of canned tuna may be an efficient method of following major changes in 137Cs contamination of upper layers of the world ocean. (author)

  6. Dietary 137Cs and 90Sr in Finland in 1960 - 2000

    Domestic animal products dominated dietary intake of 137 Cs in 1960 2000. Freshwater fish and vegetable products of agricultural origin were almost equal contributors of 137 Cs to the diet. Wild foods received from forests, assessed using a simple approach, were also non-negligible sources of 137 Cs. Marine and brackish-water fishes, although of low activity concentration of 137 Cs compared to freshwater fishes, added to the ingestion dose through a higher consumption rate. Sources of dietary 137 Cs during the period of atmospheric nuclear fallout from weapon tests differed from the post-Chernobyl time. Agricultural produce then seemed to dominate the 137 Cs received via the Finnish diet more than after the Chernobyl accident. Subsequent growth periods of considerable stratospheric fallout made the pathways from vegetation to human diet important in the 1960s. Strontium 90 is mobile in soils for long periods of time. However, it has not been a significant dietary nuclide for Finns during the history of environmental radioactive contamination. In the years of maximum deposition rates in early 1960s the doses exceeded more than tenfold the doses in the following decades, and also the doses received after the Chernobyl accident (Rajama and Rantavaara 1982). The wild foods from forests are not likely to contribute to ingestion of 90 Sr essentially more than similar types of agricultural and garden products replacing wild foods in the diets of non-pickers and non-hunters. (AU)

  7. 137Cs in puddle sediments as timescale tracer in urban environment

    The 137Cs-based chronological approach is suggested to identify the age of urban landscapes and the chronology of pollution of soil in residential areas. Three main pivot points constitute the basis of the chronological approach: beginning of the Atomic Era in 1945, the maximum input in 1963 and the Chernobyl accident in 1986. Application of 137Cs as a timescale tracer was tested on the example of Ekaterinburg, a city in the Middle Urals region of Russia. The sampling of recent urban sediments of micro water bodies (puddles) was carried out in 210 locations in 2007–2010. The concentrations of Pb, Zn, Cu, Ni, Co, Mn and Fe, and activity concentrations of 137Cs were measured. It was found that the 137Cs concentrations in the puddle sediments correlated with the age of surrounding buildings determined by the year of construction. The correlations between the concentrations of metals and 137Cs in the puddle sediments identified the major pollutants of the urban area, assessing their background concentrations and obtaining the average annual inputs. - Highlights: • The approach to assess age of landscape and chronology of heavy metal pollution of urban environment is suggested. • Technogenic isotope 137Cs is used as a timescale tracer. • The puddle sediments reflect the recent pollution of urban soil. • The approach allows identifying the pollutants, assessing their background values, and obtaining the average annual input of pollutants

  8. Influence on the mouse immune system of chronic ingestion of 137Cs

    The aim of this work was to determine the possible occurrence of damage to the immune system during the course of chronic ingestion of 137Cs. BALB/C mice were used, with 137Cs intake via drinking water at a concentration of 20 kBq l-1. Adults received 137Cs before mating and offspring were sacrificed at various ages between birth and 20 weeks. Phenotypic analysis of circulating blood cells and thymocytes did not show any significant modification of immune cell populations in animals ingesting 137Cs as compared with control animals, with the exception of a slight increase in Treg percentage at the age of 12 weeks. Functional tests, including proliferative response to mitogens such as phytohaemagglutinin, response to alloantigens in mixed lymphocyte reaction and immunoglobulin response to vaccine antigens such as tetanus toxin and keyhole limpet haemocyanin did not show any significant functional modification of the immune system in 137Cs-ingesting animals as compared with control animals. Overall, our results suggest that chronic ingestion of a low concentration of 137Cs in drinking water in the long term does not have any biologically relevant effect on the immune system.

  9. The 137Cs accumulation by forest-derived products in the Gomel region

    This paper reports basic features of the 137Cs uptake by forest-derived products in the Gomel region. Even with the soil contamination density of 37 kBq m−2 the radionuclide contents in 20–30% of mushrooms and berries were found to be higher than the admissible levels. The 137Cs contamination density of soil, site type and meteorological parameters were observed as the major factors which govern the radiocaesium uptake by mushrooms and berries. The 137Cs contents in forest-derived products were found to increase directly with the soil contamination density. Bilberries (Vaccinium myrtillus) growing on different site types differed significantly in the 137Cs content. It was also determined that statistically significant differences in the 137Cs radioactivity of forest foods growing on different natural sites were governed by the factor designated in the current study by “territorial”. The differences are to be accounted for both by forms of the Chernobyl fallout and by the natural and climatic conditions determining variations in the availability of radionuclides in the soil. In dry years the 137Cs concentrations in some mushroom species were higher than in normal years

  10. Influence on the mouse immune system of chronic ingestion of {sup 137}Cs

    Bertho, Jean-Marc; Faure, Marie-Cecile; Louiba, Sonia; Tourlonias, Elie; Stefani, Johanna; Siffert, Baptiste; Paquet, Francois; Dublineau, Isabelle, E-mail: Jean-marc.bertho@irsn.fr [IRSN, Laboratoire de Radiotoxicologie Experimentale, Fontenay aux Roses (France)

    2011-03-01

    The aim of this work was to determine the possible occurrence of damage to the immune system during the course of chronic ingestion of {sup 137}Cs. BALB/C mice were used, with {sup 137}Cs intake via drinking water at a concentration of 20 kBq l{sup -1}. Adults received {sup 137}Cs before mating and offspring were sacrificed at various ages between birth and 20 weeks. Phenotypic analysis of circulating blood cells and thymocytes did not show any significant modification of immune cell populations in animals ingesting {sup 137}Cs as compared with control animals, with the exception of a slight increase in Treg percentage at the age of 12 weeks. Functional tests, including proliferative response to mitogens such as phytohaemagglutinin, response to alloantigens in mixed lymphocyte reaction and immunoglobulin response to vaccine antigens such as tetanus toxin and keyhole limpet haemocyanin did not show any significant functional modification of the immune system in {sup 137}Cs-ingesting animals as compared with control animals. Overall, our results suggest that chronic ingestion of a low concentration of {sup 137}Cs in drinking water in the long term does not have any biologically relevant effect on the immune system.

  11. Deposition of atmospheric (137)Cs in Japan associated with the Asian dust event of March 2002.

    Fujiwara, Hideshi; Fukuyama, Taijiro; Shirato, Yasuhito; Ohkuro, Toshiya; Taniyama, Ichiro; Zhang, Tong-Hui

    2007-10-01

    Considerable deposition of (137)Cs was observed in the northwestern coastal area of Japan in March 2002. Since there were no nuclear explosions or serious nuclear accidents in the early 2000s, transport of previously contaminated dust appears to be the only plausible explanation for this event. In March 2002, there was a massive sandstorm on the East Asian continent, and the dust raised by the storm was transported across the sea to Japan. This dust originated in Mongolia and northeastern China, in an area distant from the Chinese nuclear test site at Lop Nor or any other known possible sources of (137)Cs. Our radioactivity measurements showed (137)Cs enrichment in the surface layer of grassland soils in the area of the sandstorm, which we attributed to accumulation as a result of past nuclear testing. We suggest that the grassland is a potential source of (137)Cs-bearing soil particles. Since the late 1990s, this area has experienced drought conditions, resulting in a considerable reduction of vegetation cover. We attribute the prodigious release of (137)Cs-bearing soil particles into the atmosphere during the sandstorm and the subsequent deposition of (137)Cs in Japan to this change. PMID:17604085

  12. A new approach to analysis of relationships between 137Cs activity concentrations in forest soil horizons

    The measurements results of 137Cs activity concentrations in forest soil profiles are discussed. In studies some simplifications were considered. First of them concerns disregarding of soil subtype in data analysis. However initially this parameter was considered in data analysis, it was finally ignored. The second assumption drops information about specific soil horizon. Description of 137Cs accumulation is based on relationships between its relative activity concentrations in soil layers. The model formulation was based on the results of exploratory data analysis of the relative 137Cs activity concentrations. In studies the methods designed for compositional data analysis were used. The results of analysis showed that the relationships between the relative activity concentrations of 137Cs in soil layers, due to their nature, might be divided into two groups. The first of them concerns layers located close to soil surface. The relative activity concentrations of 137Cs in these layers are proportional to each other, and distribution mechanism of cesium within them has the characteristics of the process leading to thermodynamic equilibrium. The second group is related to layers that are located deeper. The calculation results suggest lack of thermodynamic equilibrium between these layers and layers situated above. Utilization of a linear model for description of changes in relative activity concentrations of 137Cs in deeper layers supposes that these changes occur much slower than in layers lying above. (author)

  13. Gamma-ray sources

    Results are presented from an analysis of the celestial gamma-ray fine-scale structure based on over half of the data which may ultimately be available from the COS-B satellite. A catalogue consisting of 25 gamma-ray sources measured at energies above 100 MeV is presented. (Auth.)

  14. Accumulation of 137Cs after potassium fertilization in plant organs of Salix viminalis L. and in combusted ash

    The effect of potassium (K) application at a common rate on 137Cs uptake and distribution within basket willow (Salix viminalis L.) and 137Cs activity in willow ash was studied in a three-year field experiment on a sandy soil. Experimental plots fertilized with 60 kg N and 48 kg K per ha were compared with a control with similar N but no K fertilization. There was no significant difference in 137Cs activity concentrations in plants growing on plots with or without fertilizer K. Higher concentrations of 137Cs activity were found in roots and leaves of willow than in stems and cuttings. The highest 137Cs activity concentration was detected in the fine roots (size 0-1 mm). The transfer factor (TFg) of 137Cs in different plant organs varied between 0.1 x 10-3 and 2.6 x 10-3 m2 kg-1. After combustion, 137Cs activity concentrations in ash produced from wood chips from K-fertilized plots were significantly lower than those in ash originating from plots without K fertilization. Fly ash had higher 137Cs concentrations than bottom ash and all ash samples had 137Cs concentrations that were well below the 10 000 Bq kg-1 Swedish limit for spreading on land. -- Highlights: → We studied effect of potassium on 137Cs uptake by basket willow (Salix viminalis). → No significant difference in 137Cs activity in plants was found. → Higher 137Cs activity was found in roots and leaves than in stems and cuttings. → Highest 137Cs activity was detected in fine roots (size 0-1 mm). → Transfer factors of 137Cs in plant organs were 0.1 x 10-3 and 2.6 x 10-3 m2 kg-1.

  15. Concentration and speciation of plutonium, americium, uranium, thorium, potassium and 137Cs in a venice canal sediment sample

    Testa, C.; Desideri, D.; Guerra, F.; Meli, M. A.; Roselli, C.; Degetto, S.

    1999-01-01

    A sequential extraction method consisting of six operationally-defined fractions has been developed for determining the geochemical partitioning of natural (U, Th, 40K) and antropogenic (Pu, Am, 137Cs) radionuclides in a 40-50 cm deep sediment sample collected in a Venice canal. Extraction chromatography with Microthene-TOPO (U, Th), Microthene-TNOA (Pu) and Microthene-HDEHP (Am) column was used for the chemical separation of a single radionuclide; the final recoveries were calculated by adding 236U, 229Th, 242Pu and 243Am as the yield tracers. After electrodeposition the alpha spectrometry was carried out. 137Cs and 40K were measured by gamma spectrometry. The total concentrations in the wet sample (Bq/kgd), obtained by a complete disgregation of the matrix by wet and dry treatment, were the following: 239+240Pu=1.03±0.07, 238Pu=0.022±0.005, 241Am=0.337±0.027, 137Cs=9.78±0.78, 238U=28.84±1.62, 232Th=21.42±1.93, 40K=376.05±12.78. The mean ratio 238Pu/239+240Pu (0.02) shows a contamination due essentially to fall-out and U and Th alpha spectra indicate the natural origin of two elements. The absence of 134Cs in the sample proves that at 40-50 cm depth the sediment was not affected by the Chernobyl fall-out. As far as the speciation is concerned the following fractions were considered: water soluble, carbonates, Fe-Mn oxides, organic matter, acid soluble, residue. Pu (˜67%) an Am (˜95%) were present principally in the carbonate fraction; U was more distributed and about 30% and 45% appeared in the carbonate fraction and in the residue respectively; the majority of Th was present in the residue (˜60%); 40K was totally present in the residue; finally 137Cs was found mostly in the acid soluble fraction (˜53%) and in the residue (˜47%). Some stable elements (Fe, Mn, Al, Ti, Ca, Pb, Ba) were also determined in the different fractions to get more information about the chemical association of the single radionuclides.

  16. {sup 137}Cs and {sup 90}Sr behaviour in contaminated soils of the Chernobyl area; Etude du comportement du {sup 137}Cs et du {sup 90}Sr dans les sols contamines de la region de Tchernobyl

    Gri, N. [CEA/Fontenay-aux-Roses, Inst. de Protection et de Surete Nucleaire (IPSN), 92 (France)]|[Paris-11 Univ., 91 - Orsay (France)

    2000-07-01

    The improvement of the understanding of the mechanisms which generate radionuclides retention in soils are of main importance for radioactivity transport models, especially for long time assessments. In this context, the objectives of this thesis were to identify the mechanisms responsible for {sup 137}Cs and {sup 90}Sr behaviour in non cultivated soils and to quantify their influence. We studied radiocaesium and radiostrontium availability in different soils of the Chernobyl area (chernozem, sand, gley, peat), whose contamination took several physico-chemical forms (fuel particles, condensed forms, mixed deposits). The migration profiles obtained by gamma spectrometry and liquid scintillation show that the majority of the activity is contained in the ten first centimeters of soil, except for one site. The profiles are varied and don't allow to classify the radionuclides availability according to the pedology or to the contamination type. A selective extraction protocol applied on several soil layers has been adopted as an indirect approach. Although radionuclides availability is increasing with depth, the selective extraction protocol shows that a non negligible fraction of activity remain not mobile. {sup 137}Cs is associated to interstratified clay minerals in a non reversible way and {sup 90}Sr is strongly bound to fuel particles. The existence of these retention mechanisms calls into question the use of the K{sub d} distribution coefficient in transport models because they disabled reversibility and instantaneous desorption notions. (author)

  17. Deposition, transfer and migration of 137Cs and 90Sr in Swedish agricultural environments, and use of 137Cs for erosion studies

    Intensive atmospheric tests of nuclear bombs in the late 1950s and early 1960s resulted in fallout on Sweden of 3 kBq/m2137Cs and 2 kBq/m290Sr. To determine how soil characteristics influence radionuclide transfer to red clover, pot experiments with 137Cs and 90Sr were made with 178 Swedish mineral soils; significant negative correlations were obtained the with levels of P, K and Ca. To quantify impact in field conditions, experiments with artificial depositions on microplots were started in 1961. Transfer to barley on 12 topsoils combined with sandy and clay subsoils, and to grass on two contrasting pastures, was followed over two decades. The subsoil type was found to be important. Fallout of 137Cs from the Chernobyl accident, up to 200 kBq/m2 in some areas of Sweden, was studied between 1986 and 1994. As in the microplot experiments, transfer of 137Cs to grass was higher than to arable crops. Transfer rates were high in the first year(s), and then decreased differently from year to year, as shown by a new Tar (i.e. annual reduction rate in nuclide transfer) concept. The use of Chernobyl fallout to investigate soil redistribution on arable fields is briefly discussed; a frame-scrape soil-sampling procedure is proposed to improve the accuracy and precision of the 137Cs technique for evaluation of soil erosion. (author)

  18. Activities of \\gamma-ray emitting isotopes in rainwater from Greater Sudbury, Canada following the Fukushima incident

    Cleveland, B T; Lawson, I T; Smith, N J T; Vazquez-Jauregui, E

    2012-01-01

    We report the activity measured in rainwater samples collected in the Greater Sudbury area of eastern Canada on 3, 16, 20, and 26 April 2011. The samples were gamma-ray counted in a germanium detector and the isotopes 131I and 137Cs, produced by the fission of 235U, and 134Cs, produced by neutron capture on 133Cs, were observed at elevated levels compared to a reference sample of ice-water. These elevated activities are ascribed to the accident at the Fukushima Dai-ichi nuclear reactor complex in Japan that followed the 11 March earthquake and tsunami. The activity levels observed at no time presented health concerns.

  19. Effective half-lives of 137Cs in giant butterbur and field horsetail, and the distribution differences of potassium and 137Cs in aboveground tissue parts

    Concentrations of 137Cs and 40K in different tissues of edible wild herbaceous plants, that is, leaf blade and petiole for giant butterbur (Petasites japonicas (Siebold et Zucc.) Maxim.), and leaf, stem and strobilus for fertile shoot of field horsetail (Equisetum arvense L.) were measured in 2012–2014 to clarify the effect in Japan from the Fukushima Daiichi Nuclear Power Plant accident. The concentrations of 137Cs decreased with time with effective half-lives of ca. 450 d and 360 d for giant butterbur and field horsetail, respectively. The ANOVA test revealed that 40K and 137Cs distributions in leaf blade and petiole for giant butterbur and leaf and stem for field horsetail were different. Therefore, other plants, leaf and stem for Japanese knotweed (Fallopia japonica (Houtt.) Ronse Decr.) and Canada goldenrod (Solidago canadensis L.), and leaf blade and petiole for gingko (Ginkgo biloba L.) and Someiyoshino cherry (Cerasus × yedoensis (Matsum.) A.V.Vassil. ‘Somei-yoshino’) were collected from the same sampling field and their 137Cs and 40K concentrations were compared to those in the giant butterbur and field horsetail parts. For 137Cs, concentrations in leaf blade and leaf parts were 1.1–6.0 times higher than those in petiole and stem parts for all six plants. On the other hand, 40K concentrations in leaf blade and leaf parts were 0.40–0.97 of those observed in petiole and stem parts. Discrimination ratios of 40K/137Cs of leaf blade to petiole or leaf to stem were then calculated and they ranged from 0.09 to 0.57. These results suggested that Cs and K did not behave similarly in these plants. Thus, to understand the radiocesium fate in plants, K measurement results should not be used as an analog for Cs behavior although Cs is known to have a similar chemical reactivity to that of K. - Highlights: • 137Cs amounts in leaf blade and leaf were higher than those in petiole and stem in plants. • 40K amounts in leaf blade and leaf were lower than

  20. Determination of Ore Concentration in Exploration Holes by the Gamma-Ray Backscattering Technique

    The gamma-ray backscattering technique was applied to the determination of zinc concentration in exploration holes in a zinc-lead mine. The special geological situation allowed the calculation of calibration curves for different sources and source detector geometries. 60Co, 137Cs and 75Se were used as gamma-sources, the best results being obtained using 137Cs. Different probe lengths were investigated, and the optimal configuration was determined in test measurements in the mine. Measurements were carried out with the optimized probe in drill holes, for which the zinc concentration had already been determined by core sampling techniques and chemical analyses. The measurements from the backscattering technique were evaluated by calculated calibration curves. Very good agreement of the results was obtained in comparison with the chemical drill analyses. The mean deviation for a typical borehole of 50 m length was 1%. The backscatter probe was used in connection with a portable ratemeter. The time constant used was 15 s. The statistical accuracy of the count-rate measurement was better than 0 5%. The speed of the measurements was about 25 m/h. The total length of investigated boreholes was 940 m. (author)

  1. A new FSA approach for in situ $\\gamma$-ray spectroscopy

    Caciolli, A; Bezzon, G P; Broggini, C; Buso, G P; Callegari, I; Colonna, T; Fiorentini, G; Guastaldi, E; Mantovani, F; Massa, G; Menegazzo, R; Mou, L; Alvarez, C Rossi; Shyti, M; Zanon, A; Xhixha, G

    2011-01-01

    An increasing demand of environmental radioactivity monitoring comes both from the scientific community and from the society. This requires accurate, reliable and fast response preferably from portable radiation detectors. Thanks to recent improvements in the technology, $\\gamma$-spectroscopy with sodium iodide scintillators has been proved to be an excellent tool for in-situ measurements for the identification and quantitative determination of $\\gamma$-ray emitting radioisotopes, reducing time and costs. Both for geological and civil purposes not only $^{40}$K, $^{238}$U, and $^{232}$Th have to be measured, but there is also a growing interest to determine the abundances of anthropic elements, like $^{137}$Cs and $^{131}$I, which are used to monitor the effect of nuclear accidents or other human activities. The Full Spectrum Analysis (FSA) approach has been chosen to analyze the $\\gamma$-spectra. The Non Negative Least Square (NNLS) and the energy calibration adjustment have been implemented in this method f...

  2. Activity concentrations of 137Cs in meat of broiler chicken after single and continuous application

    Previously we examined the transfer, distribution and half-live of radiocaesium in broiler chicken after the application of artificially contaminated feed mixture or wheat wheat contaminated from the Chernobyl accident. Our results pointed to a different dynamics of radiocaesium in breast meat compared to leg meat in the chicken after short-time application (3 oral applications in 1 day). The aim of the present study was to find if the results are similar also after single and repeated (long-time) applications of an artificially contaminated feed mixture. Two experiments were carried out with broiler chickens (White Leghorn hybrid, race ISA VEDETTE). In experiment 1, one artificially contaminated oral dose of 5160 Bq of 137Cs (activity concentration 1664 Bq/g) was administered to 18-day-old chickens. In experiment 2, artificially contaminated oral doses of 500 Bq of 137Cs (activity concentration 161.3 Bq/g) were administered to 14-day-old chickens twice a day (at 8:00 and 20:00 h.) for 10 days. In either experiment, four chickens were slaughtered for activity determination in meat (breast and leg muscles) 6, 12, 24, 48 and 96 hours and 2, 4, 8, 10 days, respectively, after the first application of 137Cs. The uptake of the single oral 137Cs was rapid and the maximum 137Cs activity concentrations were found in breast meat (0.783 Bq/g) 24 hours and in leg meat (1.005 Bq/g) 6 hours after 137Cs application. From the 24th hour of the experiment, radiocaesium activity concentrations in breast and leg meat decreased with the biological half-life (T1/2b) of 84 and 66 hours, respectively. During a 10-day application of continuous doses of 137Cs, the Cs activity concentrations increased and were 3.988 Bq/g in breast meat and 5.610 Bq/g in leg meat on day 2, and 7.427 Bq/g and 7.698 Bq/g, respectively, on day 10. Immediately after the administration of radiocaesium was stopped, the 137Cs activity concentrations decreased rapidly with T1/2b = 4.5 and 3.8 days in breast and leg

  3. {sup 137}Cs and {sup 40}K estimate in edible mushrooms in Sao Paulo, Brazil

    Castro, Lilian Pavanelli de; Maihara, Vera A.; Moura, Patricia L.C. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: lilian.pavanelli@terra.com.br; vmaihara@ipen.br; patricialandim@ig.com.br; Figueira, Rubens C.L. [Universidade Cruzeiro do Sul, Sao Paulo, SP (Brazil); E-mail: figueiraru@yahoo.com.br

    2007-07-01

    After the Chernobyl accident in 1986, high levels of the radionuclide accumulation in different foodstuffs and the environment have being reported. The potential of mushrooms to accumulate fallout radionuclides in their fruit bodies have been well recognized. Mushrooms can also accumulate toxic elements in general, including natural radionuclides. In Southern Hemisphere countries, especially in Latin America, there are a few studies on this subject. In Brazilian literature, there are no studies that determine the composition of natural and artificial radionuclides in edible mushrooms. The objective of this study was to measure of {sup 137} Cs and {sup 40}K activity in commercialized edible mushrooms in Sao Paulo, Brazil. The activity measurements were carried out by spectrometry gamma. The system detection efficiency was measured using the certified reference materials IAEA- 300 Marine Sediment and IAEA-375 Soil. The activities of {sup 13}'7Cs in the mushroom samples varied from 2.2 to 6.5 Bq kg{sup -1} for Pleurotus osteatus and Agaricus bisporus respectively. The {sup 40}K activities varied from 150 to 907 Bq kg{sup -1} for Pleurotus ostreatus and Lentinula edodes, respectively. (author)

  4. Moisture profile measurements of concrete samples in vertical water flow by gamma ray transmission method

    Samples of concrete for popular habitation (0.1x0.03x0.1 m) and cellular concrete (0.1x0.05x0.1 m) were submitted to water vertical ascending infiltration. The moisture content spatial and temporal evolution of each sample it was monitored in three halfway positions in a same horizontal line, applying the gamma rays transmission method. The data were taken with a 137Cs (3.7x1010 Bq, 0662 MeV) source, NaI (Tl) of 2x2'' detector coupled to gamma ray spectrometry standard electronic with multichannel analyzer and a micrometric table. For the popular habitation concrete, there was a clear correlation between wetting profiles and concrete strength. The cellular concrete showed a wetting profile compatible to its greater porosity. (author)

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

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

    2013-03-01

    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 137Cs 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° (horizontal) to 90° (vertical).

  6. Moisture profile measurements of concrete samples in vertical water flow by gamma ray transmission method

    da Rocha, M. C.; da Silva, L. M.; Appoloni, C. R.; Portezan Filho, O.; Lopes, F.; Melquíades, F. L.; dos Santos, E. A.; dos Santos, A. O.; Moreira, A. C.; Pötker, W. E.; de Almeida, E.; Tannous, C. Q.; Kuramoto, R.; Cavalcante, F. H. de M.; Barbieri, P. F.; Caleffi, A. F.; Carbonari, B. T.; Carbonari, G.

    2001-06-01

    Samples of concrete for popular habitation (0.1×0.03×0.1 m) and cellular concrete (0.1×0.05×0.1 m) were submitted to water vertical ascending infiltration. The moisture content spatial and temporal evolution of each sample it was monitored in three halfway positions in a same horizontal line, applying the gamma rays transmission method. The data were taken with a 137Cs (3.7×1010 Bq, 0662 MeV) source, Nal (Tl) of 2×2″ detector coupled to gamma ray spectrometry standard electronic with multichannel analyzer and a micrometric table. For the popular habitation concrete, there was a clear correlation between wetting profiles and concrete strength. The cellular concrete showed a wetting profile compatible to its greater porosity.

  7. Patterns of 137Cs accumulation in bullhead catfish inhabiting an abandoned reactor reservoir

    The author assayed muscle 137Cs concentrations of bullhead catfish (Ameiurus natalis) in order to determine factors contributing to the bioconcentration of this fission product. Bullhead catfish (N = 173) were obtained from the Pond B reservoir, Savannah River Site, SC. Muscle 137Cs concentration did not differ between sexes (ANOVA, P = 0.631). Age of fish (1--6 yr) appeared to explain variation in 137Cs concentration (P = 0.005), but not when mass of fish was included as a model covariate (P = 0.086). Least-square means, adjusted for the covariate, suggested that 1 and 2 yr old fish (71.09 and 81.38 mean pCi/g, respectively) differed from 3, 4, 5, and 6 yr old fish (94.94, 92.34, 97.27, 90.25 mean pCi/g, respectively). Therefore, the effects of age and mass were evaluated by partitioning the data into young (1--2 yr) and older (3, 4, 5, and 6 yr) age classes. When adjusted for mass, age (young vs. old) significantly accounted for differences in 137Cs concentration (78.98 vs. 94.33 mean pCi/g; P = 0.005). Within older fish, neither age (P = 0.870) or mass (P = 0.361) significantly influenced 137Cs concentration. The effect of age within young fish was nonsignificant (P = 0.971) in contrast to the influence of mass (P = 0.044). This suggests that the contribution of 'size' (mass) to 137Cs body burden is related to early growth and that these fish reach an asymptotic 'steady-state' 137Cs concentration by 3 years of age

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

    We performed a simulation of sediment and 137Cs 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 137Cs 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 137Cs in sediment-sorbed form at the exit of reservoir satisfactorily reproduced the observational data. We also performed sediment and 137Cs behavioral simulation by changing the water level of the reservoir, because such a dam operation could control the quantities of sediment and 137Cs 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 137Cs to the lower river at a later stage of rainfall events. - Highlights: • We simulated sediment and 137Cs behavior in a reservoir in the Fukushima area. • The simulation reproduced the measured values during a heavy rainfall event. • It clarified the reservoir buffers contamination movement in heavy rainfall events

  9. 137Cs and 9Sr uptake by sunflower cultivated under hydroponic conditions

    The 9Sr and 137Cs uptake by the plant Helianthus annuus L. was studied during cultivation in a hydroponic medium. The accumulation of radioactivity in plants was measured after 2, 4, 8, 16 and 32 days of cultivation. About 12% of 137Cs and 20% of 9Sr accumulated during the experiments. We did not find any differences between the uptake of radioactive and stable caesium and strontium isotopes. Radioactivity distribution within the plant was determined by autoradiography. 137Cs was present mainly in nodal segments, leaf veins and young leaves. High activity of 9Sr was localized in leaf veins, stem, central root and stomata. The influence of stable elements or analogues on the transfer behaviour was investigated. The percentage of non-active caesium and strontium concentration in plants decreased with the increasing initial concentration of Cs or Sr in the medium. The percentage of 9Sr activity in plants decreased with increasing initial activity of the nuclide in the medium, but the activity of 137Cs in plants increased. The influence of K+ and NH4+ on the uptake of 137Cs and the influence of Ca2+ on the uptake of 9Sr was tested. The highest accumulation of 137Cs (24-27% of the initial activity of 137Cs) was found in the presence of 10 mM potassium and 12 mM ammonium ions. Accumulation of about 22% of initial activity of 9Sr was determined in plants grown on the medium with 8 mM calcium ions

  10. {sup 137}Cs and {sup 9}Sr uptake by sunflower cultivated under hydroponic conditions

    Soudek, Petr [Department of Plant Tissue Cultures, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-166 10 Prague 6 (Czech Republic); Valenova, Sarka [Department of Plant Tissue Cultures, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-166 10 Prague 6 (Czech Republic); Vavrikova, Zuzana [Department of Plant Tissue Cultures, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-166 10 Prague 6 (Czech Republic); Vanek, Tomas [Department of Plant Tissue Cultures, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-166 10 Prague 6 (Czech Republic)]. E-mail: vanek@uochb.cas.cz

    2006-07-01

    The {sup 9}Sr and {sup 137}Cs uptake by the plant Helianthus annuus L. was studied during cultivation in a hydroponic medium. The accumulation of radioactivity in plants was measured after 2, 4, 8, 16 and 32 days of cultivation. About 12% of {sup 137}Cs and 20% of {sup 9}Sr accumulated during the experiments. We did not find any differences between the uptake of radioactive and stable caesium and strontium isotopes. Radioactivity distribution within the plant was determined by autoradiography. {sup 137}Cs was present mainly in nodal segments, leaf veins and young leaves. High activity of {sup 9}Sr was localized in leaf veins, stem, central root and stomata. The influence of stable elements or analogues on the transfer behaviour was investigated. The percentage of non-active caesium and strontium concentration in plants decreased with the increasing initial concentration of Cs or Sr in the medium. The percentage of {sup 9}Sr activity in plants decreased with increasing initial activity of the nuclide in the medium, but the activity of {sup 137}Cs in plants increased. The influence of K{sup +} and NH{sub 4} {sup +} on the uptake of {sup 137}Cs and the influence of Ca{sup 2+} on the uptake of {sup 9}Sr was tested. The highest accumulation of {sup 137}Cs (24-27% of the initial activity of {sup 137}Cs) was found in the presence of 10 mM potassium and 12 mM ammonium ions. Accumulation of about 22% of initial activity of {sup 9}Sr was determined in plants grown on the medium with 8 mM calcium ions.

  11. Precipitation scavenging of 7Be and 137Cs radionuclides in air

    Atmospheric depositional fluxes of the naturally occurring 7Be of cosmogenic origin and 137Cs from fallout of the Chernobyl accident were measured over a 6-year period (January 1987-December 1992) at Thessaloniki, Greece (40o38'N, 22o58'E). Total precipitation accumulation during 1987-1992 varied between 33.7 cm and 65.2 cm, reflecting a relatively dry (precipitation-free) climate. The activity concentrations of 7Be and 137Cs in rainwater depended on the precipitation rate, being higher for low precipitation rates and lesser for high precipitation rates. 137Cs was removed by rain and snow more efficiently than 7Be. Snowfall was more efficient than rainfall in removing the radionuclides from the atmosphere. The annual bulk depositional fluxes of 7Be varied between 477 and 1133 Bq m-2 y-1 and this variability was attributed to the amount of precipitation and the variations of the atmospheric concentrations of 7Be. The annual bulk depositional fluxes of 137Cs showed a significant decrease over time from 1987 to 1992, resulting in a removal half-life of 1.33 years. The presence of 137Cs in air, and therefore in rainwater and snow, long after the Chernobyl accident (26 April 1986) was mainly due to the resuspension process. The normalized depositional fluxes of both radionuclides showed maximal values during the spring season where the maximum amount of precipitation occurred. The relatively high positive correlation between 7Be and 137Cs normalized depositional fluxes indicates that the scavenging process of local precipitation controlled the fluxes of both radionuclides. The dry depositional flux of 7Be was less than 9.37% of total (wet and dry) depositional flux. The fraction of dry-to-total depositional flux of 137Cs was much higher than that of 7Be, due to the resuspended soil

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

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

  13. Distribution of {sup 226} Ra, {sup 232} Th, {sup 40} K and {sup 137} Cs in soils of Province of Camaguey, Cuba

    Flores, Osvaldo Brigido; Barreras Caballero, Aldo A.; Montalvan Estrada, Adelmo; Queipo Garcia, Maite [Ministerio da Ciencia, Tecnologia y Medio Ambiente, Camaguey (Cuba). Centro de Atencion a la Actividad Nuclear. Lab. de Vigilancia Radiologica Ambiental]. E-mail: sean@caonao.cmw.inf.cu; Zerquera, Juan Tomas [Centro de Proteccion y Higiene de las Radiaciones, La Habana (Cuba)

    2001-07-01

    A survey programme aimed at studying the environmental radioactivity in the Province of Camaguey in the eastern region of Cuba was undertaken. The average concentrations of {sup 226} Ra, {sup 232} Th, and {sup 40} K in the surveyed soils were 26.4, 11.5 and 210 Bq.kg{sup -1}, respectively. The man-made radionuclide found was {sup 137} Cs and its concentration was similar to those reported in regions affected only by global radioactive fallout, (7.9 Bq.kg{sup -1}). Radiological measurements carried out with a portable ionization chamber RSS-112 at the sampled sites revealed an average outdoor absorbed dose rate of 59.0 nGy.h{sup -1} due to cosmic rays and terrestrial gamma radiation. Computed dose rates obtained through the UNSCEAR(1993) dose coefficients range from 4-182 nGy.h{sup -1}, with a mean value of 27.8 nGy.h{sup -1}, due to natural terrestrial gamma radiation. Ratio of Indoor to Outdoor absorbed dose rates in air was 1.75. The average value of absorbed dose rate in air for the ionizing component of cosmic rays was 31.8 nGy.h{sup -1} at sea level. Because of the 95% of the Camaguey population lives at altitudes close to sea level (10-100 m), the absorbed dose rate in outdoor air from ionizing component of cosmic rays was estimated to be 32.3 nGy.h{sup -1}. An annual average effective dose equivalent of 510 {mu}Sv was estimated for Camaguey population due to the ionizing component of cosmic and gamma terrestrial radiation. This value is lower than the 760 {mu}Sv.year{sup -1} estimated as a world average by UNSCEAR (1993). (author)

  14. Gamma ray optics

    Jentschel, M.; Guenther, M. M.; Habs, D.; Thirolf, P. G. [Institut Laue-Langevin, F38042 Grenoble (France); Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany); Max-Planck-Institut fuer Quantenoptik, D-85748 Garching, Germany and Ludwig-Maximilians-Universitaet Muenchen, D-85748 Garching (Germany); Ludwig-Maximilians-Universitaet Muenchen, D-85748 Garching (Germany)

    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.

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

    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.

  16. Gamma-ray astronomy

    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.

  17. Gamma ray camera

    An improved Anger-type gamma ray camera utilizes a proximity-type image intensifier tube. It has a greater capability for distinguishing between incident and scattered radiation, and greater spatial resolution capabilities

  18. Total beta activity, 137Cs and 90Sr in surface air in northern Finland in 1963

    Air filter samples collected at Sodankylae(67 22' N, 26 39' E) were analyzed to determine concentrations of 137Cs and 90Sr in surface air in northern Finland in 1963. Previously, activity concentrations of Pu isotopes have been determined from the same filters. Activity concentrations of 137Cs and 90Sr in surface air were 3-13800 ± 2700 μBq/m3 and 3-5340 ± 290 μBq/m3, respectively. Air concentrations of 137Cs and 90Sr varied seasonally with a maximum in spring due to the springtime enhanced transportation of air masses with radioactive aerosols from the stratosphere to the troposphere. Activity ratios 90Sr/239+240Pu and 90Sr/137Cs were 6.9 ± 0.8-75 ± 5 and 0.08 ± 0.03-1.46 ± 0.51, respectively. The median value for the 90Sr/137Cs ratio (0.508) indicates contamination from global nuclear test fallout. An air mass back trajectory analysis suggests that no direct transport of radioactivity from the Novaya Zemlya test site to northern Finland occurred in 1963. (orig.)

  19. Isolation of 137-Cs in tuna fish by ammonium phosphomolybdate (AMP)

    The isolation of 137-Cs in tuna fish (Neithunnus macroptenus) has been carried out using AMP. The energy of 137-Cs was measure using NaI(T1) detector connected to a Multi Channel Analyzer (MCA). In standard solution of 137-Cs with activity 160.74 and 80.37 pCi, the addition of 120 mg AMP and 7 hours of absorption time, caused 97% of 137-Cs in the solution was absorbed. The destruction of tuna fish was carried out using two methods namely by wet destruction with sulfuric acid, nitrit acid and hydrogen peroxid mixture and by wet destruction with hydrogen peroxide. The applications of this technique of tuna fish was carried out by spiking 137-Cs standard into the fish before being destructed. The recovery obtained from wet destruction with H2O2 was about 80%, while from destruction with acid mixtures and H2O2 was only about 47%. (authors). 3 refs, 3 tabs

  20. Specific activity and concentration model applied to 137Cs movement in a eutrophic lake

    A linear systems-analysis model which simulates time-dependent dynamics of specific activity and concentration of radiocesium in lake ecosystems was applied to a shallow, eutrophic lake that had received a pulse input of 137Cs. Best estimates of transfer coefficients for abiotic compartments (sediment, interstitial water and lake water) and the macrophyte compartment which controlled the mass balance of cesium in water were determined by ''tuning'' our initial estimates of the transfer coefficients to observed data on 137Cs concentrations and contents of these compartments. In most cases, the optimized transfer coefficients for the abiotic compartments were not greatly different from our independently derived initial estimates, and the simulations for optimized coefficients were close to those based on initial estimates. The 137Cs concentrations in water as predicted by the optimized transfer coefficients were then used to calculate 137Cs kinetics in biota other than macrophytes. In general, model simulations were close to concentrations observed in the biota. The agreement between 137Cs concentrations and simulations in bottom invertebrates supported our assumption that bottom sediments are not a major source of Cs to the biota. Our specific activity and concentration model was compared to the radionuclide content model, the model used in terrestrial ecosystems. For biotic components of aquatic ecosystems, values of α/sub ij/, the transfer coefficients of our model, are easily estimated from turnover rates of radiocesium in individual organisms in the laboratory

  1. Temporal change in fallout 137Cs in terrestrial and aquatic systems: a whole ecosystem approach

    During the years after a nuclear accident, the bioavailability and environmental mobility of radiocesium declines markedly, resulting in large changes in contamination of foodstuffs, vegetation, and surface waters. Predicting such changes is crucial to the determination of potential doses to affected populations and therefore to the implementation of radiological countermeasures. We have analyzed 77 data sets of radiocesium (137Cs) activity concentrations in milk, vegetation, and surface waters after the Chernobyl accident. Our results show that the rate of decline in 137Cs during the years after Chernobyl is remarkably consistent in all three ecosystem components, having a mean effective half-life, Teff ≈ 2 years. By comparing changes in 137Cs availability with rates of diffusion of 40K (a close analogue) into the lattice of an illitic clay (1) we have, for the first time, directly linked changes in the environmental availability of 137Cs to fixation processes at a mechanistic level. These changes are consistent with declines in the exchangeable fraction of 137Cs in soils (2, 3)

  2. 137Cs-uptake into wheat (Triticum vulgare) plants from five representative soils of Bangladesh.

    Monira, B; Ullah, S M; Mollah, A S; Chowdhury, N

    2005-05-01

    A pot experiment was conducted to study the uptake of 137Cs by wheat grown in five representative soils of Bangladesh having different soil characteristics. Artificial application of 137Cs increased the activity in soils up to 45.9 Bq/kg soil, measured at the end of the harvest of wheat crop. Different plant parts had different ability to accumulate 137Cs. Grains had the least activity and transfer factor, while the highest activity and lowest transfer factor were measured in roots, which restricted translocation of 137Cs to wheat straw. The result showed that the transfer factors (mean value) varied from 0.05 to 0.114 in wheat straw, 0.066-0.133 in roots and 0.011-0.043 in wheat grains. The activity and transfer factor of radioactive cesium in wheat plants were found to be greatly influenced by soil properties, i.e. clay content, K, organic matter, CEC, pH, exchangeable ions, etc. Cation exchange capacity and calcium in soils influenced positively, while clay minerals, exchangeable K and organic matter, negatively affected the 137Cs activity concentrations in wheat plants. PMID:15931978

  3. ESTIMATION OF SOIL EROSION IN A RESERVOIR WATERSHED USING 137CS FALLOUT RADIONUCLIDE

    Y. J. CHIU; A. M. BORGHUIS; H. Y. LEE; K. T. CHANG; J. H. CHAO

    2007-01-01

    Sedimentation from soil erosion is a critical reservoir watershed management issue. Due to the difficulty of field investigations, empirical formulas are commonly used to estimate the soil erosion rate. However, these estimations are often far from accurate. An effective alternative to estimating soil erosion is to analyze the spatial variation of 137Cs inventory in the soil. 137Cs can be adsorbed by the soil and is widely assumed to change its distribution only when disturbed by rainfall and human activities. Thus, 137Cs distributed in soils can be a useful environmental tracer to estimate soil erosion. In this study, the net soil loss estimate is 108,346 t/yr and the gross erosion and net erosion rates are 10.1 and 9 t/ha yr respectively. The sediment delivery ratio is therefore estimated to be 0.9 based on the two erosion rates. Because of the steep hillsides in the watershed, only 10% of the sediment yield stayed in the deposition sites and 90% was transported to the river as the sediment output. Soil erosion estimates from spatial variations of the 137Cs activity in the Baishi river watershed showed satisfactory accuracy when compared to sediment yield data. Using soil 137Cs concentrations is therefore a feasible method for estimating soil loss or deposition in Taiwan. Data sampling, analysis and result of this approach are given in this paper.

  4. Spatial distribution of fallout 137Cs in coastal marine water of Tamil Nadu coast

    Very little information on the fallout 137Cs activity exists for the Bay of Bengal. Normally the volume of sea water required for detecting fall out level of 137Cs in coastal marine environment ranges from 100 litres to 1000 litres. The studies on distribution of 137Cs in surface seawater of Tamil Nadu in Bay of Bengal were carried out in April 2009. On the eastern coastal lines of Bay of Bengal in Tamil Nadu, seven offshore locations were selected namely Chennai, Pondicherry, Karaikal, Rameshwaram, Tuticorin, Nagercoil and Kanyakumari. In situ preconcentration method was adopted and the experiments were carried out using motor boats well equipped to carry the instruments and provide power supply to operate the pump. 1000 litres of seawater was passed each time through CFCN filters at all the locations at a flow rate of 8 litres per minute. The activity concentrations of 137Cs was in the range of 0.90 to 2.2 Bq/m3. These data represents reference values for coastal environment of Tamil Nadu and will be used to estimate radionuclide inventory in Indian marine environment, particularly of East Coast. The 137Cs activity indicates that there are no new inputs of these radionuclides into the area. (author)

  5. Influence of urea and of chlorocholine chloride on accumulation of 137Cs in spring wheat crops

    The influence of leaf feeding with nitrogen in urea solution and application of chlorocholine chloride (CCC) on the uptake of 137Cs by spring wheat from the investigated soil samples and through leaves was studied in pot experiments. Spray application of nitrogenous fertilizer in urea solution with additional use of growth retardant were found to have brought about an increased accumulation in the grain of 137Cs taken up by the plants from the contaminated soil. It was found that the 2-4 times more 137 Cs accumulated in the wheat grain from the leaves contaminated in the flowering stage in the comparison with that found in the grain of plants contaminated in the propagation stage. The application of leaf feeding with urea and chlorocholine exerted no influence on the accumulation of 137Cs in grain if the plants had been contaminated superficially in their earlier development stages. Contamination with 137Cs sprayed upon the plants after application of chlorocholine chloride appeared to pass to the spring wheat crops more readily. (author)

  6. Migration of 137Cs in the soil of sloping semi-natural ecosystems in Northern Greece

    In the present study, the 137Cs concentration in the soil of sloping semi-natural ecosystems at four different regions of Western Macedonia in Greece was measured 10 years after the Chernobyl accident. These regions were highly polluted due to the deposition of radionuclides escaped during the accident. The concentrations of 137Cs measured were found to differ significantly among the four regions. The rates of both horizontal and vertical migration in the soil were also evaluated. The vertical migration velocity of 137Cs was found to range from 0.1 to 0.3 cm per year, in the most contaminated areas. Consequently, 10 years following the Chernobyl accident, the bulk of 137Cs deposited over the surface of the studied areas in Greece was found to be restricted in the upper 5 cm layer of soil. Regarding the horizontal migration, in most of the sampling sites, we did not detect any displacement or trend to movement of radiocaesium on the surface from the upper to the lower levels of the slopes. Instead, we recorded decreased concentrations of 137Cs with the decrease of altitude

  7. 137Cs contamination of the Techa river flood plain near the village of Muslumovo

    The results of a radiometric survey of the Techa river flood plain near the village of Muslumovo in the Chelyabinsk region of Russia are presented. The observed territory extended 16.6 km along the riverbed, with a total area of 2.5 km2. The collimated scintillation detector technique was applied to in situ field measurements of 137Cs deposition on the soil. Maps of 137Cs deposition and soil penetration depth were developed on the basis of approximately 5000 measurements. The total 137Cs deposition within the surveyed territory has been estimated at 6.6 TBq. The means of the total 137Cs soil depositions at half-kilometer sites on the flood plain and its distribution along the river have also been calculated. A maximum 137Cs contamination above 7.5 MBq/m2 is associated with a bank height up to 1 m above the usual water level. The data identify zones of intensive radionuclide sedimentation and transit zones

  8. Peculiarities of 137Cs accumulation by macromycetes in dry bors of Ukrainian Polessye

    The main ecological peculiarities of dry bor in Ukrainian Polessye were given. Research were carried out in Central Polessie of Ukraine during 1997 - 1999. Results were obtained due to spectrometric measurement of specific activity of 137Cs in fruit bodies of mushrooms and in the soil. Species composition of macromycetes was divided on homogeneous groups on intensity of 137Cs accumulation. Amanita porphyria, A. muscaria and Tricholoma portentosum belong to the group of weak 137Cs accumulation from the soil (TF = 15 - 20); Amanita pantherina, A. phalloides, Cantharellus cibarius, Boletus edulis, Tricholoma flavovirens and Laccaria laccata - to the group of moderate radionuclide accumulation (TF = 30 - 55). The group of strong 137Cs accumulation (TF = 100 - 180) consists of Suillus variegates, S. bovines and Hydnum imbricatum; and group of very strong accumulation (TF 200 - 280) - of Xerocomus badius, Lactarius rufus, Russula xerampelina, Cortinarius varius and Paxillus involutus. Cortinarius sanguineus (with TF 400) is an accumulator of 137 Cs. Comparative evaluation of dry bor was given from the point of view of purchase of edible macromycetes in it

  9. 137Cs availability for soil to understory transfer in different types of forest ecosystems

    A quantitative analysis of 137Cs bioavailability in forest soils in the long term after the Chernobyl NPP accident based on a 3-year (1996-1998) investigation is presented. Five forest sites with different trees, composition and properties of soil were studied to identify factors determining radiocaesium transfer to different understory species. The following parameters were investigated: 137Cs activity concentrations and its speciation in various horizons of forest soil, accumulation of this radionuclide by different species of understory vegetation and distribution of root biomass in the soil profile. It has been shown that one decade after the deposition maximum 137Cs activity in soil of the experimental sites considered is located in different soil layers dependent on moisture regime, characteristics of litter and soil properties. A linear dependence between aggregated transfer factors for different species and groups of species of understory vegetation and exchangeable and available fractions of radiocaesium in soil was found. The vertical distribution of 137Cs activity, percentage of exchangeable radiocaesium in each horizon of litter and soil, as well as distribution of root systems (mycelia) over the soil profile are key factors governing variations in the availability of 137Cs for transfer to all forest understory components

  10. GIS supported calculations of 137Cs deposition in Sweden based on precipitation data

    137Cs deposition maps were made using Kriging interpolation in a Geographical Information System (GIS). Quarterly values of 137Cs deposition density per unit precipitation (Bq/m2/mm) at three reference sites and quarterly precipitation at 62 weather stations distributed over Sweden were used in the calculations of Nuclear Weapons Fallout (NWF). The deposition density of 137Cs, resulting from the Chernobyl accident, was calculated for western Sweden using precipitation data from 46 stations. The lowest levels of NWF 137Cs deposition density were noted in the northeastern and eastern Sweden and the highest levels in the western parts of Sweden. The Chernobyl 137Cs deposition density is highest along the coast in the selected area and the lowest in the southeastern part and along the middle. The sum of the calculated deposition density from NWF and Chernobyl in western Sweden was compared to accumulated activities in soil samples at 27 locations. Comparisons between the predicted values of this study show a good agreement with measured values

  11. The characteristics of a low background germanium gamma ray spectrometer at China JinPing underground laboratory

    A low background germanium gamma ray spectrometer, GeTHU, has been installed at China JinPing Underground Laboratory (CJPL). The integral background count rate of the spectrometer was 0.629 cpm between 40 and 2700 keV, the origins of which were studied by Monte Carlo simulation. Detection limits and efficiencies were calculated for selected gamma peaks. Some samples of rare event experiments were measured and 137Cs contamination was found in boric acid. GeTHU will be mainly used to measure environmental samples and screen materials in dark matter and double beta decay experiments. - Highlights: • The first low background gamma ray spectrometer (GeTHU) was developed at CJPL. • It has a large inner chamber which can host large samples for different purposes. • The background characteristics are presented and the origin is studied. • Detection limits are given for selected radionuclides and efficies are calculated. • Some samples were measured and 137Cs contamination was found in boric acid

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

    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

  13. Migration of 137Cs from air to soil and plants in the Gulsvik area, Norway after the Chernobyl reactor accident

    The migration of 137Cs from air to soil and vegetation after the Chernobyl accident has been studied using the concentrations measured in the Gulsvik area in Norway. The major part of the 137Cs deposition seems to be in the soil. An uptake of 137Cs from soil to plants through their root system is not a rapid process. Only a few percent of the deposition can be traced in plants. This seems to suggest that as far as 137Cs is concerned, an effect of the Chernobyl releases is not an acute but a long-term phenomenon. The 137Cs accumulation in soils is rather high, but doses not result in 137Cs levels in plants and diet higher than acceptable in Norway

  14. Simulation study on 137Cs distribution in the each component of irrigation-farmed gray-brown desert soil humus

    The components and characters of humus in irrigation-farmed gray-brown desert soil were studied and gel filtration method is used at indoor experiment to study the bond properties of the foreign source 137Cs and soil humus' components. Results show that the bonding rate of 137Cs was the highest in clay mineral, 78.37% of total. 21.63% of 137Cs was accumulated in the humus, the bonding rate of 137Cs with humic acid, fulvic acid, and humin were 5.78%, 6.60% and 9.25%, respectively. The humic acid and 137Cs formed four low weight complex molecules, their average molecular weights are > 700, 392, 168 and 137Cs can not only be bonded into the stable organic-inorganic composite, but also into humus-metal ion complex with very high stability. (authors)

  15. Post-depositional redistribution and gradual accumulation of 137Cs in a riparian wetland ecosystem in Sweden

    After the Chernobyl accident, high activity concentrations of 137Cs (>1 MBq m-2) were detected in a riparian swamp in the central-eastern part of Sweden. The objective of this study was to clarify the redistribution processes behind the accumulation of 137Cs in the wetland. A mass balance budget of 137Cs was calculated based on soil and sediment samples and reports in the literature. Results showed that accumulation occurred over several years. Of all the 137Cs activity discharged between 1986 and 2002 from the upstream lake, 29% was estimated to be retained in the wetland. In 2003, measurements showed that 17 kBq m-2 sedimented on the stream banks of the wetland. Continuing overbank sedimentation by spring flooding prolongs the time that the wetland will contain high activity concentrations of 137Cs. Consequently, organisms living in wetlands serving as sinks for 137Cs may become exposed over long time periods to high activity concentrations

  16. Evaluation of Transmutation of 137Cs(r,n) 136Cs Using Ultra-Intense Lasers in Solid Targets

    R. Sadighi-Bonabi; O. Kokabee

    2006-01-01

    Relativistic electrons produced in ultra-intense laser-solid interaction generate highly collimated γ-ray beams through Bremsstrahlung that can be used to induce photonuclear reactions. Photonuclear transmutation (of (γ, n) type) of 137Cs, one of the hazardous nuclear wastes with half-life of 30.17 years which cannot be transmuted practically with neutron bombardment due to its very low neutron capture cross section, has been considered. Nuclear activity of produced 136Cs with half-life of 13.16 days has been evaluated analytically using available experimental data. With irradiating a 137Cs sample by p-polarized laser light of 1020 Wcm-2 and the repetition rate of 10 Hz for 30mm, the activity of 0.24 Bq is obtained. It is found that intensity has a large effect in yield around 1021 Wcm-2. For similar laser with intensity of 5×1021 Wcm-2, the activity increases with a factor of 105.

  17. Experimental investigation of γ-ray attenuation coefficients for granites

    Highlights: ► Radiation shielding properties of granites have been investigated. ► This is done by measuring linear attenuation coefficients. ► Measurement was performed using 137Cs and 60Co sources. - Abstract: The linear attenuation coefficients of γ-rays for some granite samples have been measured at 662, 1773 and 1332 keV. The γ-rays have been obtained from 137Cs and 60Co sources respectively and the measurement have been performed using a gamma spectrometer which contains 3” × 3” NaI(Tl) detector connected to 16384 channel Multi-Channel-Analyser (MCA).

  18. Development of transportable gamma-ray tomographic system for industrial application

    Kim, Jongbum; Jung, Sung-hee; Moon, Jinho; Guen Park, Jang; Jin, Joonha; Cho, Gyuseong

    2012-11-01

    This paper introduces a gamma-ray tomographic system which is transportable and can be used for on-line systems such as a pipeline operation. In a previous study, a feasibility study on a gamma-ray tomographic system with a scanning geometry of Electron Beam CT was carried out by Monte Carlo simulation. This paper contains a successive work on a previous study by developing and evaluating a real system. To construct a gamma-ray CT, 137Cs was used as a gamma-ray source and radiation measurement system with 72 channel CsI detectors whose crystal is a 12 mm×12 mm×20 mm rectangular parallelepiped was developed to operate jointly with a motion control system. ML-EM algorithm was used for image reconstruction of experimental data. Using the developed transportable gamma-ray system, laboratory and field experiments were carried out successfully. The field experiment results show that a gamma-ray CT with an Electron Beam CT scanning geometry can be a transportable gantry for objects which are parts of processes.

  19. Development of transportable gamma-ray tomographic system for industrial application

    This paper introduces a gamma-ray tomographic system which is transportable and can be used for on-line systems such as a pipeline operation. In a previous study, a feasibility study on a gamma-ray tomographic system with a scanning geometry of Electron Beam CT was carried out by Monte Carlo simulation. This paper contains a successive work on a previous study by developing and evaluating a real system. To construct a gamma-ray CT, 137Cs was used as a gamma-ray source and radiation measurement system with 72 channel CsI detectors whose crystal is a 12 mm×12 mm×20 mm rectangular parallelepiped was developed to operate jointly with a motion control system. ML-EM algorithm was used for image reconstruction of experimental data. Using the developed transportable gamma-ray system, laboratory and field experiments were carried out successfully. The field experiment results show that a gamma-ray CT with an Electron Beam CT scanning geometry can be a transportable gantry for objects which are parts of processes.

  20. The uptake of 90Sr, 137Cs and 144Ce by leaves of spring wheat and rape

    The distribution and accumulation of 90Sr, 137Cs, 144Ce through the leaf surface into the plant have been studied. The results show that the uptake rate of 137Cs by crop plant is about 53%, while the uptake rate for 90Sr and 144Ce is about 0.4%. However 90Sr is absorbed in significant amount from soil whereas 137Cs is absorbed in negligible amount

  1. 3D modeling technique of time-series 137Cs concentration in coastal organisms in case of short term introduction

    Short term estimation of released radionuclides behavior is necessary for decision-making in emergent action. To predict radionuclide concentrations in marine organisms under short term radionuclide introduction to coastal water, the simple time series 137Cs transfer both from seawater and food chain to marine organisms were studied. The model was developed for typical Japanese coastal water including benthic food chain and planktonic food chain, with transfer parameter data set, such as uptake rate constant, excretion rate constants, gut transfer rates, food ingestion rates of 137Cs, those collected by many tracer experiment studies. For the development of the modeling technique in prediction of the temporal 137Cs concentrations in marine biota, the time and space distributions of 137Cs concentrations in marine organisms are important especially in case of short term introduction to coastal area. We developed a 3-dimension model being composed of nuclide transfer both from seawater and food chain in imaginary coastal area, expressing the temporal 137Cs concentrations in marine organisms accompanied with the habitat location. The result of 3D modeling in case of short term introduction to exhibit the following information: 1) The introduced 137Cs in seawater is diluted and disappeared quickly under normal current conditions, while 137Cs in organisms slowly increased even after the seawater is cleared, mainly from the contribution from 137Cs transfer through food chain. 2) The 137Cs concentration in fish of higher trophic level appears approximately 100 days later, and the concentration ratio (137Cs in organism/137Cs in seawater) reaches only 1-10 even using the maximum 137Cs concentrations in organism and seawater

  2. An aerial gamma ray survey of Hunterston Nuclear Power Station on 14th-15th April and 4th May 1994

    An aerial gamma ray survey of a 31 km square area surrounding the Hunterston Nuclear Power station in Scotland was carried out in 1994. The recorded spectral data were analysed for 137Cs, 60Co, 40K, 214Bi and 208Tl and maps produced of the distribution of these nuclides. The recorded 137Cs arises largely from weapons and Chernobyl fallout which had been mapped in earlier surveys but not in such detail. Local enhancements were observed at the Hunterston site, but at a lower level than previously, and at a salt marsh. The latter, is attributed to past discharges from the Sellafield nuclear plant. There was an enhanced 60Co signal associated with the 137Cs at the Hunterston site but elsewhere the 60Co count-rate was at minimum detectable levels and showed a slight correlation with the natural radionuclides. The natural radioniclides, 40K, 214Bi and 208Tl, are strongly correlated with each other. Their distribution reflects underlying geological and geomorphological features of the area. The survey results have established a reference set from which future environmental changes can be assessed. (11 figures; 1 table; 30 references) (UK)

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

    This second part of the study reports the development of a model to describe the vertical migration of the artificial radioisotope 137Cs 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 137Cs 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

  4. Gamma ray attenuation in a developed borate glassy system

    Measurements and calculations of gamma ray attenuation coefficients in glass barriers of xBaO–5ZnO–5MgO–14Na2O–-1Li2O–(75−x)B2O3, previously prepared by the melt-quenching technique [1], were performed for γ-ray of energies 121.8, 244.7, 344.14, 661.66, 778.7, 974, 1086.7, 1173.24, 1332.5, and 1407.9 keV; which emitted from 152Eu, 137Cs, and 60Co radioactive gamma ray sources. The transmitted γ-rays were detected by 3″×3″ and 5″×5″ NaI (Tl) scintillation γ-ray spectrometers, and a highly calibrated survey meter. The mass attenuation coefficients of γ-rays (σ(E)) were deduced from the attenuation curves, while the WinXCom computer program (version 3.1) was used to calculate the mass attenuation coefficients of γ-rays for such energies at different barium concentrations of a glassy system. A good agreement between both experimental and theoretical results was achieved as well as results obtained by other workers in similar field. - Highlights: • Design new glass system can be used as nuclear radiation shielding material. • Three different systems were used to measure γ-ray attenuation coefficients. • The γ-ray attenuation coefficients in this glass system were measured for 10 γ-energy lines. • Good agreement between experimental, theoretical, and results by other workers have been achieved. • Improvement of σ and HVL by increasing BaO concentration up to 50% in our glassy system

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

    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%.

  6. The influence of the sorptive properties of organic soils on the migration rate of 137Cs

    Using a compartment model, the migration rates of 137Cs were calculated for two types of organic soils: a low peat-muck soil and a black earth. The migration rates of 137Cs in the tested soils turned out to be significantly higher than in mineral types examined earlier and ranged from 0.6 to 12.3 cm/year. The partition coefficients (Kd) were also determined for samples with varying organic matter content (OM) that were taken from different layers of the studied soils. The experimental results indicate that there is a clear relationship between Kd values and OM. The investigation was widened by microcalorimetric measurements which confirmed that the adsorption of 137Cs on the organic soils is low

  7. Estimation of radiation doses from 137Cs to frogs in a wetland ecosystem

    Currently, there is no established methodology to estimate radiation doses to non-human biota. Therefore, in this study, various dose models were used to estimate radiation doses to moor frogs (Rana arvalis) in a wetland ecosystem contaminated with 137Cs. External dose estimations were based on activity concentrations of 137Cs in soil and water, considering changes in habitat over a life-cycle. Internal doses were calculated from the activity concentrations of 137Cs measured in moor frogs. Depending on the dose model used, the results varied substantially. External dose rates ranged from 21 to 160 mGy/y, and internal dose rates varied between 1 and 14 mGy/y. Maximum total dose rates to frogs were below the expected safe level for terrestrial populations, but close to the suggested critical dose rate for amphibians. The results show that realistic assumptions in dose models are particularly important at high levels of contamination

  8. Alkaline extraction: can it be used for the removal of 137Cs from soil?

    A titration extraction procedure was applied to a silty clay which was spiked with 137Cs. At least 20% of spiked 137Cs silty clay was found to be associated with the humic acid (HA) fraction. This shows that HA contributes significantly to cesium fixing in soil and cesium is not only fixed between regular ion exchange complexes (REC) and specific sites in the frayed edges of clay minerals (FES). About 85% of 137Cs was found in the 12M HCl extract. The titration extraction procedure was found useful for investigation of the impact of the soil pH on the radiocesium mobility. Only trace amounts of cesium were found between pH 1 to 7, demonstrating a high immobility of cesium over this pH range. If the alkaline digestion is applied to soil for the removal of radiocesium, then these can be significantly separated from the extract by protonation of the extracted HA. (P.A.)

  9. 90Sr and 137Cs accumulation by live and dead lichens

    Experimental data on the accumulation and fixation strength of two long-living fragment radionuclides (90Sr and 137Cs) in live and dead lichens are given. It is shown that the mechanisms of 90Sr absorption by lichens from aqueous solutions are based mainly on physico-chemical sorption, whereas the 137Cs absorption depends largely on the physiological-biochemical processes related to metabolic plant activity. The long confinement of 90Sr and 137Cs in lichens is explained by the extremely instable water regime resulting in a rather long dehydration of lichens when leaching of radionuclides from plants with the weakly-mineralized waters is retarded. It is indicated that the liberation of lichens from radionuclides with thallome parts dying off annually can not be essential due to the longevity of these plant forms, their slow growth and dying off

  10. Airborne fallout mapping of {sup 137}Cs Finnish defence forces team

    Kettunen, M.; Heininen, T. [Finnish Defence Forces Research Centre, Lakiala (Finland); Pulakka, M. [Finnish Air Force Depot, Tampere (Finland)

    1997-12-31

    The main task of the team was to create a fallout map of {sup 137}Cs in a specified area in Padasjoki Auttoinen village. The team used an MI-8 helicopter of the Finnish Air Force. The team had an HPGe system (relative efficiency 70%) to measure nuclide specific ground contamination level. For navigation the team took advantage of the DGPS service provided by Finnish Broadcasting company utilizing the RDS-channel to get position accuracy within 2 meters. The correction signal is reachable nationwide on the FM transmitter network. The system produced a distribution map for {sup 40}K and fallout maps for {sup 134,137}Cs using a Micro Station Program with TerraModeler application. The maximum measured {sup 137}Cs ground contamination exceeded 130-140 kBqm{sup -2}. (au).

  11. Soil to plant transfer of 137Cs and 60Co in Ferralsol, Nitisol and Acrisol

    In this study, soil to plant transfer factor values were determined for 137Cs and 60Co in radish (Raphanus sativus), maize (Zea mays L.) and cabbage (Brassica oleracea L. var. capitata) growing in gibbsite-, kaolinite- and iron-oxide-rich soils. After 3 years of experiment in lysimeters it was possible to identify the main soil properties able to modify the soil to plant transfer processes, e.g. exchangeable K and pH, for 137Cs, and organic matter for 60Co. Results of sequential chemical extraction were coherent with root uptake and allowed the recognition of the role of iron oxides on 137Cs behaviour and of Mn oxides on 60Co behaviour. This information should provide support for adequate choices of countermeasures to be applied on tropical soils in case of accident or for remediation purposes

  12. Bioaccumulation of 137Cs in pelagic food webs in the Norwegian and Barents Seas

    Knowledge and documentation of the levels of radioactive contamination in fish stocks important to Norwegian fisheries is of major importance to Norwegian consumers and fish export industry. In the present study, the bioaccumulation of caesium-137 (137Cs) has been investigated in marine food webs in the Barents and Norwegian Seas. The contents of 137Cs in the different organisms were generally low (-1 wet weight), but a marked bioaccumulation was apparent: The concentration of 137Cs was about 10-fold higher in the harbour porpoise Phocoena phocoena, representing the upper level of the food web, than in the amphipod Themisto sp., representing the lower level of the food web. The Concentration Factors (CF=Bq kg-1 wet weight/Bq l-1 seawater) increased from 10±3 for a mixed sample of krill and amphipods to 165±5 for harbour porpoises

  13. 137Cs distribution in soil as a function of erosion and other processes

    Nuclear weapons tests have deposited upon the Saskatoon area considerable amounts of the fission product 137Cs. The average concentration for the area was found to be 67,3 nCi/m2 and its distribuition upon the area as a whole is quite uniform. The above figure is high enough to allow the evaluation of deviations from it, caused by erosion and deposition processes; 137Cs losses as high as 34% were observed in knolls of cultivated fields, whereas an increase of 95% over the average for the region was found in depressions. Such results favour the use of fallout 137Cs as a tracer in the study of physical processes in the soil of the Saskatoon region. (Author)

  14. Plate-out distribution of 137Cs in the OGL-1 primary loop

    In order to reflect on safety evaluation of HTTR (High Temperature Engineering Test Reactor), measurements of fission products plate-out distribution have been done on the primary circuit of OGL-1 (Oarai Gas Loop No.1) which has been operated in the simular gas flow condition with the HTTR. The measurements have been performed since 46th till 73rd operation cycles of the JMTR (Japan Materials Testing Reactor) in which from 3rd to 9th fuel specimens of OGL-1 were irradiated. It became clear that 137Cs plated-out well on the piping at 400 ∼ 500 deg C. It was also observed that 137Cs released from the pipe at higher than 500 deg C and deposited again on the pipe at lower than 400 deg C when the release rate of 137Cs from irradiation fuel decreased. (author)

  15. Resuspension and spreading of 137 Cs in urban areas: the Goiania experience

    The characteristics of the Goiania accident (a restricted and local contamination) together with the fact that the region has received no contribution from the Chernobyl accident, neither from the atomic tests represents an unique opportunity to study the behaviour of 147 Cs at an urban area. The study of the resuspension and deposition processes of the 137 Cs associated to surface soil was performed at a house at the 57th. street near the main primary focus. It was decided to use the two gardens of the house, where continuous measurements of aerosol and total deposition took place. Impactor measurements were also performed to evaluate the size distribution of particles in the air. The results as a whole suggests a very complex pattern for the 137 Cs resuspension and deposition in Goiania, indicating to be these mechanisms local,phenomena and without evidences of a significant spreading of 137 Cs from the places of primary contamination. (author). 63 refs., 14 figs., 9 tabs

  16. Levels of 137Cs and 40K in edible parts of some vegetables consumed in Egypt

    The concentrations of 137Cs and 40K in some Egyptian foodstuffs have been measured. The results of this study can be considered as a first step towards calculating the baseline levels of radioactivity in foodstuffs in Egypt. Furthermore, the data presented herein can be used as a reference level for future food radioactivity monitoring after the possible operation of the planned nuclear power plants, as well as to screen imported foodstuffs that are suspected of being contaminated. The overall intake of 137Cs is quite low and no significant radionuclide contamination was found. The highest contents of 137Cs and 40K among the tested foodstuffs were in Jew's mallow and roquette. Calculations were also made to determine the potential dose to an individual consuming vegetables

  17. Transfer of 137Cs in Zea mays and Phaseolus vulgaris in a semi-arid ecosystem

    With the objective to analyse the transference of 137 Cs from soil to plants, it is realized a study in maize and bean plants in the Radioactive Waste Storage Center (CADER). This site is located in a semi-arid region with a characteristic vegetation of a sub humid temperature zone. So those plants maize and beans were cultivated in four zones near CADER during a four years period. The obtained results for 1991 to 1994 for 137 Cs in soil samples for those zones showed an evident contamination in zone 1, due to a rupture of an industrial source. In 1994 the effect of decontamination was evident since the values of specific activity found in roots were around magnitude lesser than found in 1992. In spite of exhaustive studies have been reported about the transference factors for 137 Cs in different agricultural foods, relatively few of them have paid attention to the interactions between cereals and leguminous associated in semiarid ecosystems. (Author)

  18. Peculiarities of 90 Sr and 137 Cs behavior in the atmosphere and the hydrosphere

    Physical and chemical forms of 137 Cs, 90 Sr carriers were investigated in the atmosphere, river and sea water and bottom sediments. The physico-chemical forms of aerosol-radionuclide carriers of artificial radionuclides (137 Cs and 90 Sr), having arrived to the territory of Lithuania after the Chernobyl accidents, were also investigated. Considerable differences were detected in the properties of carriers of radionuclides of secondary pollution, which resulted from the wind transport of dust and combustion products from forests and peat-bogs fires and dust storms in the greatly polluted territories of the Ukraine and Belarus. The time-course of physico-chemical forms of 137 Cs shows properties and concentration variations in the atmosphere in 1994-1995. (author)

  19. The level of 137Cs concentration in Greek soils one decade after the Chernobyl accident

    One of the most serious consequences of the Chernobyl accident was the greatest radioactive contamination of the biosphere including the soil cover. It is well known that a soil analysis is a principal systematic method to estimate the radioactivity level in the particular area since deposition pattern is determined by measuring activity in grass and soil. The aim of the present work is first to identify the level of the existing 137Cs contamination over Greece ten years after the Chernobyl accident. Secondly, a comparison between the 1986 137Cs - distribution and the present measured one in more - less the same areas of Greece, has been attempted. The 40k (0.0118% of natural K) concentration in soils as ratio 137Cs/ 40k has been, examined, even this ratio is not as constant in biological systems as the ratio Sr/Ca

  20. Modelling of 137Cs behaviour in forest ecosystems and prediction of its accumulation in forest products

    A mathematical model of 137Cs migration in forest ecosystem contaminated due to the Chernobyl accident presented, which describes the behaviour of this radionuclide in the forest litter-soil system, tress, and forest animals. The model's parameters for different types of forest ecosystems are estimated and model's adequacy is tested through the use of independent experimental data. The sensitivity of the model's output variables is analyzed to variations in the most significant parameters. The differences in the seasonal and mean annual dynamics of 137Cs concentration in muscles of roe deers and mooses are shown to be defined by specific features of the diets of these animals and variations in 137Cs content in the main diet components

  1. 131I and 137Cs removal from cheese, upon immersion in a sodium chloride solution

    Cheese samples have been ripened, using milk artificially contaminated with radioactive 137Cs and 131I. Tests have been carried out to investigate the effect of brine (18%W/V NaCl) on the radionuclide concentration in the cheese. The removal percent of both radionuclides is 45% at least for the first 24 hours of immersion and it was increased at about 5% in the next 48 hours. An attempt was made to examine the reverse situation. Cheese curd from uncontaminated milk was immersed in the brine which had been injected with 131I or 137Cs. It may be concluded that brine may act as a ''purifier'' of cheese curd in the case of 131I and 137Cs removal. (Author)

  2. In situ measurements of density of 137Cs contamination of the forest system in Ukraine

    The Chernobyl accident resulted in significant contamination of Ukrainian territory by various radionuclides. The activity of the main dose forming radionuclide released into the environment, 137Cs, was estimated to be approximately 3.1 x 1016 Bq. The density of surface contamination of different natural systems by 137Cs is the characteristic used for assessment and prediction of the radioecological situation. For validation of the in situ method and study of migration processes, the inventory of 137Cs (activity per unit area) was determined through a combination of in situ spectrometry using a NaI(Tl) detector and of soil samples analyses of numerous Ukrainian forest sites for the past 3 years. 5 refs, 2 figs, 2 tabs

  3. In-situ gamma-ray spectrometry with the K-A-TE-RINA submersible detector

    Full text: A new detection system, named K-A-TE-RINA (Innovative Sensor for Artificial Radioactivity), has been developed for radioactivity measurements in the marine environment. The system is based on a γ aI scintillator housed in a tube made of special plastic material capable for operation in open sea. The efficiency of the detection system is measured in the laboratory using two reference gamma-ray sources: 40K and 137Cs. The developed electronics offer proper adjustment of the maximum detection energy in order to apply the system in different key-environments, focusing on a requested radionuclide. The low power consumption and the gain stabilization of the output voltage make the developed system reliable for long term measurements. Many tests were also made in order to check the linearity of electronics in case of long term measurements. The system was deployed in open sea in order to measure background and volumetric activity variation of 137Cs and 222Rn decay products. The field measurements in the Aegean Sea offer very promising results concerning the use of the whole system in the marine environment. In future, the system will be installed on a specific application buoy together with other sensors (such as salinity, rain gauge, temperature and wind direction), for investigations of the correlation of natural and man-made radioactivity with oceanographic and atmospheric measurements. (author)

  4. Chernobyl case study: modelling the dynamics of long-term cycling and storage of 137Cs in forested ecosystems

    A microcomputer digital simulation model (RADFORET) was developed to predict long-term (∼ 250 y) cycling of radiocesium (137Cs) in forested ecosystems using detailed 137Cs distribution data from two ecosystems in North America. Primary forcing functions for the model were concentration of 137Cs in the soil compartment and the rate of forest growth. Parameters were set for controlling the movement of 137Cs from soil into, and subsequent cycling within, the biotic compartments for each ecosystem. The amount of the 137Cs available for uptake from the soil was inversely correlated with clay content in the soil from each site and positively correlated with cation exchange capacity (CEC) and soil organic matter. The effect of forest growth on the 137Cs cycling model was simulated by coupling output of a forest growth succession model to the RADFORET cycling model. Forecasts of 137Cs distribution in the donor-controlled model favorably compared with 137Cs distributions in forests at Oak Ridge, Tennessee, and Savannah River, Georgia. This provided a measure of model validity for additional simulations of projected 137Cs cycling in forests around the Chernobyl site. (author)

  5. Temporal variations of 90Sr and 137Cs concentrations in Japanese coastal surface seawater and sediments from 1974 to 1998

    Ikeuchi, Yoshihiro

    2003-09-01

    90Sr and 137Cs concentrations were determined in surface water and bottom sediments collected at 11 sites offshore from Japan during the period 1974-1998, to investigate their temporal variations and behaviour in the coastal marine environment. The concentrations of 90Sr and 137Cs in surface water have decreased with time since 1974. After the period of atmospheric nuclear weapons tests, the mean residence times of 90Sr and 137Cs were about 41 and 51 years, respectively. The 137Cs/ 90Sr activity ratios in coastal seawater during the atmospheric nuclear weapons tests (up until 1980) were lower than those after the tests due to the inflow of 90Sr in river water. A sharp increase in 137Cs levels was observed in airborne dust, in precipitation on the Japanese islands, and in coastal surface seawater in 1986 following the Chernobyl accident. However, the 137Cs levels in surface water returned to pre-1986 levels quickly, indicating rapid removal of Cs from the surface to deeper water. Concentrations of 90Sr in sediments were generally much lower than those for 137Cs, reflecting the more effective scavenging of Cs from the water column. In Ca-rich sediments, consisting of corals and shells, higher 90Sr levels and 90Sr/ 137Cs activity ratios were found, reflecting higher accumulation of Sr than Cs in marine organisms. Higher accumulation of 90Sr than 137Cs was also found in seaweed (gulfweed and wakame).

  6. Concentration of 137Cs and 40K in meat of omnivore and herbivore game species in mountain forest ecosystems of Gorski Kotar, Croatia

    The aim of this study was to investigate 137Cs and 40K load in large mammal game species in the mountain forest region of Gorski Kotar in Croatia approximately a quarter of century after the Chernobyl accident. 137Cs and 40K activity were determined by the gamma-spectrometric method in 49 meat samples of five large game species: brown bear (Ursus arctos), wild boar (Sus scrofa), roe deer (Capreolus capreolus), red deer (Cervus elaphus), and chamois (Rupicapra rupicapra). The results indicated that herbivore game species (roe deer, red deer and chamois) show significantly lower 137Cs concentrations than omnivore species (brown bear, wild boar), thereby confirming the hypothesis that different dietary strategy impact caesium concentrations in meat. The measured caesium load in brown bear meat was in the range of two orders of magnitude, while caesium load in wild boar meat was found in the range of one order of magnitude. The estimated effective equivalent dose showed that uptake of the highest caesium doses would be from consumption of omnivore species meat, while much lower doses could be taken in with the consumption of meat from herbivore species. (author)

  7. A preliminary study on 226Ra, 232Th, 40K and 137Cs activity concentrations in vegetables and fruits frequently consumed by inhabitants of Elazig Region, Turkey

    Determining radioactivity levels in foodstuffs is of great importance for the protection of human health. In addition, the literature includes few studies related to this subject in Turkey. In this study, gamma spectroscopic system was used in order to measure 226Ra, 232Th, 40K and 137Cs activity concentrations in vegetables and fruits produced in Elazig( Region. The average activity concentrations in vegetables was calculated as 0.64 ± 0.26 Bq kg-1 for 226Ra, 0.65 ± 0.14 Bq kg-1 for 232Th, 13.98 ± 1.22 Bq kg-1 for 40K, and 0.54 ± 0.04 Bq kg-1 for 137Cs. The average activity concentrations in fruits were 1.52 ± 0.34, 0.98 ± 0.23, 18.66 ± 1.13 and 0.59 ± 0.16 Bq kg-1, respectively for 226Ra, 232Th, 40K and 137Cs. Total committed effective dose value was determined as 20 and 30.55 μSv y-1, respectively for vegetables and fruits. The findings were compared with previous data reported for Turkey and other regions of the world. (author)

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

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

    1999-03-01

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

  9. Surface radiological investigations at environmental research area 11, 137Cs- and 60Co-contaminated plots at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    A surface radiological investigation at the 137Cs- and 6OCo-contaminated forest area (Chestnut Ridge east and west plots) was conducted from January 1992 through August 1992. Results of the survey revealed numerous spots and small areas of surface contamination that followed the original placement of feeders used for 6OCo- and 137Cs-labeled seeds in a 1969--1970 study. Surface gamma exposure rates reached 380 μR/h at the east plot and 400 μR/h at the west plot, but approximately one-half and one- third, respectively, of the identified anomalies did not exceed 39 μR/h. Results of soil sample analyses demonstrated that 137Cs and 6OCo were responsible for the elevated radiation levels. Radionuclides were found below the surface at soil sample locations, in some cases at depths below 18 in. The same pattern of subsurface contamination may be present at other elevated surface spots at both plots. These survey results show that current radiological conditions at the site remain an environmental problem. Recommendations for corrective actions are included

  10. Sediment transport in a small stream based on 137Cs inventories of the bed load fraction

    The authors report on sediment transport in White Oak Creek, a small third-order stream in eastern Tennessee, whose sediments have been contaminated by the irreversible adsorption of 137Cs. Sediment cores taken downstream from a point contamination source record the recent history of sedimentation and contamination in the creek. Sediment size distinguishes between different sedimentation events. The contamination profile developed since the last sedimentation event is used to estimate the time of the most recent sedimentation event which agrees with higher-than normal periods of discharge measured by weirs on the creek. It is likely that at least seven major bed load transport events occurred during 1985 and 1986. Total inventories of 137Cs in the bed load fraction were measured for six different size fractions for cores taken downstream from the point contamination source. The 137Cs concentration at any point in the creek is due to contaminated sediment transported to that location and subsequent contamination by 137Cs adsorbed directly from stream-water. The irreversible nature of 137Cs adsorption onto the sediments of White Oak Creek means that 137Cs can be used as a particle tracer in this system. Sediment transport in White Oak Creek was modeled by using a general transport model that has terms for dispersion, velocity, adsorption, and radioactive decay. For White Oak Creek, maximum velocities of 265, 215, 170, and 160 m y-1 are estimated for the 1-2, 2-4, 4-8, and 8-16 mm size fractions, respectively

  11. A comparative study on radiocaesium (137Cs) uptake from coniferous forest soil

    Radiocaesium (137Cs) uptake from a coniferous forest ecosystem with soil characterized by a high fraction of organic matter and low pH was studied using sheep's fescue (Festuca ovina) as indicator in a pot experiment and compared with bilberry (Vaccinium myrtillus), lingonberry (Vaccinium vitis-idaea), and heather (Calluna vulgaris) taken from an area of coniferous forest. Results obtained on an average basis showed a slight variation within 137Cs uptake values in all tested plants. Based upon the soil-plant relationship (Bq kg−1 plant DM/Bq kg−1 soil DM), 137Cs transfer factors (TF) were calculated. Sheep's fescue TF in the two harvests (growing periods of 13 weeks each) ranged from 0.03 to 3.45, with a mean of 0.35 ± 0.42. Field plants showed higher 137Cs TF when compared with sheep's fescue. Bilberry TF ranged from 0.28 to 2.30, with a mean of 0.85 ± 0.49. Lingonberry TF ranged from 0.57 to 4.46 with a mean of 1.35 ± 0.78. Heather TF ranged from 1.80 to 8.89 with a mean of 3.31 ± 1.53. Radiocaesium transfer coefficients (TC, Bq kg−1 plant DM/Bq m−2) of field plants were also calculated. Heather 137Cs TC was the highest among all tested plants and ranged from 0.38 to 0.64 with a mean of 0.49 ± 0.05. The results demonstrated that 137Cs transfer parameters of pot experiment with sheep's fescue show no significant differences between the obtained transfer factors, using soils from bilberry, lingonberry, and heather sites. (author)

  12. A comparative study on radiocaesium (137Cs) uptake from coniferous forest soil

    Radiocaesium (137Cs) uptake from a coniferous forest ecosystem with soil characterized by a high fraction of organic matter and low pH was studied using sheep's fescue (Festuca ovina) as indicator in a pot experiment and compared with bilberry (Vaccinium myrtillus), lingonberry (Vaccinium vitis-idaea), and heather (Calluna vulgaris) taken from an area of coniferous forest. Results obtained on an average basis showed a slight variation within 137Cs uptake values in all tested plants. Based upon the soil-plant relationship (Bq kg-1 plant DM/Bq kg-1 soil DM), 137Cs transfer factors (TF) were calculated. Sheep's fescue TF in the two harvests (growing periods of 13 weeks each) ranged from 0.03 to 3.45, with a mean of 0.35 ± 0.42. Field plants showed higher 137Cs TF when compared with sheep's fescue. Bilberry TF ranged from 0.28 to 2.30, with a mean of 0.85 ± 0.49. Lingonberry TF ranged from 0.57 to 4.46 with a mean of 1.35 ± 0.78. Heather TF ranged from 1.80 to 8.89 with a mean of 3.31 ± 1.53. Radiocaesium transfer coefficients (TC, Bq kg-1 plant DM/Bq m-2) of field plants were also calculated. Heather 137Cs TC was the highest among all tested plants and ranged from 0.38 to 0.64 with a mean of 0.49 ± 0.05. The results demonstrated that 137Cs transfer parameters of pot experiment with sheep's fescue show no significant differences between the obtained transfer factors, using soils from bilberry, lingonberry, and heather sites. (author)

  13. Influence of biologically-active substances on 137Cs and heavy metals uptake by Barley plant

    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 137Cs 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 137Cs activity in harvest (40- 50%), increase in K concentration and significant reduction in Ca concentration. Increased Cd content in soil reduced 137Cs transfer to barley plants by 30-60% (p137Cs 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 137Cs absorption by plants directly with their influence on HM phyto-toxicity. The dependence of Concentration Ratio of 137Cs 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)

  14. Using {sup 137}Cs to quantify the sediment delivery ratio in a small watershed

    Li Mian, E-mail: hnli-mian@163.com [Yellow River Institute of Hydraulic Research, Key Laboratory of Sediment Research of Yellow River of Ministry of Water Resources, Zhengzhou, Henan 450003 (China); Yao Wenyi [Yellow River Institute of Hydraulic Research, Key Laboratory of Sediment Research of Yellow River of Ministry of Water Resources, Zhengzhou, Henan 450003 (China); Li Zhanbin [Xi' an University of Technology, Xi' an, Shaanxi 710048 (China); Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi 712100 (China); Liu Puling [Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi 712100 (China); Yang Er; Shen Zhenzhou [Yellow River Institute of Hydraulic Research, Key Laboratory of Sediment Research of Yellow River of Ministry of Water Resources, Zhengzhou, Henan 450003 (China)

    2012-01-15

    Understanding the sediment delivery ratio (SDR) is important in controlling sediments for the sustainable development of natural resources and in the design of the construction such as dams and reservoirs. The purpose of this investigation is to determine the SDR by the {sup 137}Cs tracing method in a small watershed in the Sichuan Hilly Basin of China. In the study watershed, different land plots are divided according to the land use type, and 97 sampling sites were selected from these plots. The results show that the average net soil loss rates from the forest land and sloping cultivated land are 1759 and 4468 t/km{sup 2} a, respectively. No {sup 137}Cs was detectable on the bare rock surfaces and previous work showed that the erosion rate from the bare rock area was 14,260 t/km{sup 2} a. In the depositional zone, the sedimentation rates in the Caoto (a kind of cultivated land located at the foot of hills) and paddy field are 3113 and 3562 t/km{sup 2} a, respectively. Combining the area of each land use in the small watershed, the SDR of 0.40 is obtained in the past four decades. The {sup 137}Cs technique was shown to provide an effective and rapid means of estimating the SDR within the small watershed. - Highlights: Black-Right-Pointing-Pointer The erosion and deposition rates can be easily obtained by the {sup 137}Cs tracing method. Black-Right-Pointing-Pointer The {sup 137}Cs method provides an effective means for estimating the SDR. Black-Right-Pointing-Pointer The {sup 137}Cs method is more convenient and rapid than other methods for the SDR research.

  15. Using 137Cs to quantify the sediment delivery ratio in a small watershed

    Understanding the sediment delivery ratio (SDR) is important in controlling sediments for the sustainable development of natural resources and in the design of the construction such as dams and reservoirs. The purpose of this investigation is to determine the SDR by the 137Cs tracing method in a small watershed in the Sichuan Hilly Basin of China. In the study watershed, different land plots are divided according to the land use type, and 97 sampling sites were selected from these plots. The results show that the average net soil loss rates from the forest land and sloping cultivated land are 1759 and 4468 t/km2 a, respectively. No 137Cs was detectable on the bare rock surfaces and previous work showed that the erosion rate from the bare rock area was 14,260 t/km2 a. In the depositional zone, the sedimentation rates in the Caoto (a kind of cultivated land located at the foot of hills) and paddy field are 3113 and 3562 t/km2 a, respectively. Combining the area of each land use in the small watershed, the SDR of 0.40 is obtained in the past four decades. The 137Cs technique was shown to provide an effective and rapid means of estimating the SDR within the small watershed. - Highlights: ► The erosion and deposition rates can be easily obtained by the 137Cs tracing method. ► The 137Cs method provides an effective means for estimating the SDR. ► The 137Cs method is more convenient and rapid than other methods for the SDR research.

  16. Assessment of the mobility and bioavailability of 60 Co and 137 Cs in contaminated soils

    Results of a classical sequential chemical extraction procedure for 137 Cs in an acid Oxisol showed that after 3 years of contamination radiocesium remains potentially available for transfer processes: 40% bio-available, 20% mobile under oxidizing conditions and 40% bound to Fe and Mn oxides (available under reducing conditions). At this time, the transfer factor obtained in this soil was higher than values obtained in basic Oxisol and was higher than values obtained in soils from temperate climate areas. Seven years after the contamination, the 137 Cs distribution in this acid Oxisol have been changed as consequence of changes in soil properties: 8% bioavailable, 16% mobile under oxidizing conditions, 43% bound to Fe and Mn oxides and 33% strongly bound to soil compounds. Changes in the 137 Cs distribution in this soil were followed by reductions in soil to plant transfer factor. Between 1996 and 2000, the 137 Cs distribution, 137 Cs soil to plant transfer factor and soil properties in the basic Oxisol remained almost the same. The 60 Co distribution showed that Mn oxides is the main sink for this element and four years after contamination no 60 Co was detected as bioavailable or detectable in plants. In this study the use of an alternative sequential chemical extraction protocol to evaluate 60 Co and 137 Cs mobility under a large range of physico-chemical soil properties has shown to be very consistent with soil to plant transfer factors data for maize. The knowledge of bio-geochemical behavior of radionuclides in soil system can be used for the risk assessment in the case of nuclear accident or contamination scenarios. (author)

  17. GIS supported calculations of (137)Cs deposition in Sweden based on precipitation data.

    Almgren, Sara; Nilsson, Elisabeth; Erlandsson, Bengt; Isaksson, Mats

    2006-09-15

    It is of interest to know the spatial variation and the amount of (137)Cs e.g. in case of an accident with a radioactive discharge. In this study, the spatial distribution of the quarterly (137)Cs deposition over Sweden due to nuclear weapons fallout (NWF) during the period 1962-1966 was determined by relating the measured deposition density at a reference site to the amount of precipitation. Measured quarterly values of (137)Cs deposition density per unit precipitation at three reference sites and quarterly precipitation at 62 weather stations distributed over Sweden were used in the calculations. The reference sites were assumed to represent areas with different quarterly mean precipitation. The extent of these areas was determined from the distribution of the mean measured precipitation between 1961 and 1990 and varied according to seasonal variations in the mean precipitation pattern. Deposition maps were created by interpolation within a geographical information system (GIS). Both integrated (total) and cumulative (decay corrected) deposition densities were calculated. The lowest levels of NWF (137)Cs deposition density were noted in north-eastern and eastern parts of Sweden and the highest levels in the western parts of Sweden. Furthermore the deposition density of (137)Cs, resulting from the Chernobyl accident was determined for an area in western Sweden based on precipitation data. The highest levels of Chernobyl (137)Cs in western Sweden were found in the western parts of the area along the coast and the lowest in the east. The sum of the deposition densities from NWF and Chernobyl in western Sweden was then compared to the total activity measured in soil samples at 27 locations. Comparisons between the predicted values of this study show a good agreement with measured values and other studies. PMID:16647743

  18. SVOM gamma ray monitor

    2010-01-01

    The space-based multi-band astronomical Variable Object Monitor(SVOM) mission is dedicated to the detection,localization and broad-band study of gamma-ray bursts(GRBs) and other high-energy transient phenomena.The gamma ray monitor(GRM) onboard is designed to observe GRBs up to 5 MeV.With this instrument,one of the key GRB parameters,Epeak,can be easily measured in the hard X-ray band.It can achieve a detection rate of 100 GRBs per year which ensures the scientific output of SVOM.

  19. Erosion and sediment deposition evaluation on slopes under different tillage systems in the Cerrado region using the 137Cs fallout technique

    In Brazil, the expansion of agricultural areas causes several problems on natural resources. With the increasing occupation of the Cerrado region by agriculture, a series of environmental problems like deforestation, soil erosion and soil compaction are appearing and causing radical transformations in the natural landscape due to removing almost all native vegetation. The conventional tillage system (CTS) is considered an inadequate form of soil management for its frequently irremediable consequences of soil compaction and soil erosion, and the no till system (NTS) makes the maintenance of the soil conditions possible, letting them close to the natural environment, thus reducing rates of soil erosion. The objective of this work was to evaluate the efficiency of riparian forests in the retention of sediments originated for three different tillage systems, through the fallout 137CS redistribution technique, the Universal Soil Loss Equation (USLE) and some physical and chemical parameters that indicate the structural conditions of the soils of Goiatuba and Jandaia-GO. In the three areas, soil profiles were collected in three layers of 20 cm (0-20, 20-40 and 40-60 cm) at distinct points located along linear transects in the direction of the maximum slope until the riparian forest. In the riparian forest of each area, trenches were opened and soil was sampled to evaluate the activity of 137Cs and the physical and chemical parameters of soil. Detection of the activity of 137Cs was made with a gamma ray detector model (GEM-20180P, EG and ORTEC) connected to a multichannel analyzer. The comparison of averages was made using the Tukey test at 5% level of significance. The. results indicated that, the three soil tillage systems presented high rates of soil erosion and deposition of sediments and the riparian forest of the areas under CTS, NTS and pasture, located downstream received great amounts of sediments, and that only the riparian forest of CTS was capable to trap the

  20. Predicting the burial rate of PCB contaminated sediments using 137Cs dating

    The historical rate of sediment accumulation behind three dams along the Kalamazoo River in Michigan was used to predict how rapidly existing PCB contaminated bottom sediments will be buried by relatively clean sediments derived from the watershed at large. Average annual sedimentation rates were determined from the distribution of 137Cs in predominantly sandy to coarse grained sediments were observed. Using the 137Cs method to calculate sedimentation rates appears to be more successful in environments where the depositional materials contain a high percentage of silts, clay or other fine particles