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Sample records for 226ra 232th 137cs

  1. A preliminary study on 226Ra, 232Th, 40K and 137Cs activity concentrations in vegetables and fruits frequently consumed by inhabitants of Elazig Region, Turkey

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)

  3. Quantification of transfer of {sup 238}U, {sup 226}Ra, {sup 232}Th, {sup 40}K and {sup 137}Cs in mosses of a semi-natural ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Dragovic, S., E-mail: sdragovic@inep.co.r [Institute for the Application of Nuclear Energy - INEP, University of Belgrade, Banatska 31b, 11080 Belgrade (Serbia); Mihailovic, N. [Institute for the Application of Nuclear Energy - INEP, University of Belgrade, Banatska 31b, 11080 Belgrade (Serbia); Gajic, B. [Faculty of Agriculture, Institute of Land Management, Laboratory of Soil Physics, University of Belgrade, Nemanjina 6, 11081 Belgrade (Serbia)

    2010-02-15

    There is a lack of appropriate data on transfer of some radionuclides on many terrestrial biota groups. To expand the available data concentration ratios of {sup 238}U, {sup 226}Ra, {sup 232}Th, {sup 40}K and {sup 137}Cs in mosses are presented in this paper. The relationship between concentration ratios of radionuclides and physicochemical characteristics of the underlying soil was also investigated. The data on concentration ratios obtained here will provide a useful addition to the currently used database of transfer parameters, particularly for natural radionuclides.

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

    Directory of Open Access Journals (Sweden)

    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

  5. Concentration in activity of 137 Cs, 40 K, 232 Th, 226 Ra in waste deposits of the benefits of minerals in the State of Zacatecas

    International Nuclear Information System (INIS)

    The necessity to report the changes in the contained radionuclides in the terrestrial crust, or those deposited by the atomic tests around the world, becomes clear when observing the use of material of waste of those mines. With the purpose of quantifying the concentration in activity its were meet a series of waste samples in mines of the municipalities of Zacatecas, Fresnillo, Guadalupe and Veta Grande of the state of Zacatecas, Mexico. The analysis was carried out by gamma spectrometry with a HPGe detector with a resolution of 1.9 keV corresponding to an energy of 1.33 MeV calibrated in efficiency and energy by means of a certified standard multi nuclide in activity with identical geometry to that of the samples. The times of count are of 80000 seconds, with the purpose of to reduce the relative uncertainties and to define well the interest regions. The activity of 226 Ra and 232 Th is obtained through the one 214 Bi and 228 Ac respectively, the concentration was also measured in activity of the one 40 K and the 137 Cs in units of Bq kg-1. (Author)

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  7. Concentration in activity of {sup 137} Cs, {sup 40} K, {sup 232} Th, {sup 226} Ra in waste deposits of the benefits of minerals in the State of Zacatecas; Concentracion en actividad de {sup 137} Cs, {sup 40} K, {sup 232} Th, {sup 226} Ra en depositos de desecho del beneficio de minerales en el Estado de Zacatecas

    Energy Technology Data Exchange (ETDEWEB)

    Leal, B.; Mireles, F.; Quirino, L.; Davila, I.; Ramirez, F. [UAZ, A.P. 579C, 98068 Zacatecas (Mexico)

    2003-07-01

    The necessity to report the changes in the contained radionuclides in the terrestrial crust, or those deposited by the atomic tests around the world, becomes clear when observing the use of material of waste of those mines. With the purpose of quantifying the concentration in activity its were meet a series of waste samples in mines of the municipalities of Zacatecas, Fresnillo, Guadalupe and Veta Grande of the state of Zacatecas, Mexico. The analysis was carried out by gamma spectrometry with a HPGe detector with a resolution of 1.9 keV corresponding to an energy of 1.33 MeV calibrated in efficiency and energy by means of a certified standard multi nuclide in activity with identical geometry to that of the samples. The times of count are of 80000 seconds, with the purpose of to reduce the relative uncertainties and to define well the interest regions. The activity of {sup 226} Ra and {sup 232} Th is obtained through the one {sup 214} Bi and {sup 228} Ac respectively, the concentration was also measured in activity of the one {sup 40} K and the {sup 137} Cs in units of Bq kg{sup -1}. (Author)

  8. Evaluation of 226Ra, 232Th, 137Cs and 40K “Agaricus Bisporus” Activity in Cultivated Edible Mushroom formed in Tehran Province- Iran

    Directory of Open Access Journals (Sweden)

    Vahid Changizi

    2013-03-01

    Full Text Available Introduction Natural and man made radioactive sources exist in our environment they can enter into our food chains. One of these is the soil-mushroom-human chain. High level doses of natural radiation can cause hazards to humans. Materials and Methods Samples of Agaricus bisporus cultivated edible mushroom in Tehran province- Iran were collected from 7 farms. Specific activity of 226Ra, 228Ra, 137Cs, 40K and 235U of the samples were measured by two HPGe detectors. Results Specific activity of 226Ra, 228Ra, 137Cs and 40K in the edible mushroom samples were equal to 0.06 ± 0.03 - 0.7 ± 0.2 Bq kg-1 dry, 1.4 ± 0.7 Bq kg-1 dry, 0.1 ± 0.03- 0.3 ± 0.1 Bq kg-1dry and 920 ± 400 - 1370 ± 900 Bq kg-1dry , respectively. Conclusion As the measured concentrations of the radionuclides of interest are close or lower than MDA (Minimum Detectable Activity. Consumption of the mushrooms would impose no health consequences to the consumers.

  9. 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.

    Science.gov (United States)

    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

  10. Specific Activities and Radioactive Contour Maps of Natural (238U, 232Th, 226Ra and 40K ) and Anthropogenic (137Cs) Radionuclides in Beach Sand Samples Collected from Nai Yang Beach of Phuket Province After Tsunai Disaster

    International Nuclear Information System (INIS)

    Full text: Specific activities of natural (238U, 232Th, 226Ra and 40K) and artificial anthropogenic (137Cs) radionuclides in 50 beach sand samples collected from Nai Yang beach in Phuket province which was effected from 2004 tsunami disaster, have been studied and measured. Experimental results were obtained by using a high-purity germanium (HPGe) detector and gamma spectrometry analysis system and also evaluated by using the standard reference materials IAEA/RGU-1, IAEA/RGTh-1, KCL and SL-2 which were obtained from Department of Physics, Faculty of Science, Prince of Songkhla University Hat Yai Campus. Experimental set-up and measurements were operated and carried out at Nuclear and Material Physics Laboratory in Department of Physics, Faculty of Science, Thaksin University Songkhla Campus. It was found that, the beach sand specific activity ranges from 862.50 to 3,356.35 Bq/kg for 40K, 3.51- 28.58 Bq/kg for 226Ra, 10.15 to 30.22 Bq/kg for 232Th and 0.00 to 2.39 Bq/kg for 137Cs with mean values of 1,843.03 ± 152.49 Bq/kg, 14.88 ± 3.30 Bq/kg, 19.19 ± 2.80 Bq/kg and 0.14 ± 0.11 Bq/kg, respectively. Furthermore, the results were also used to evaluate the absorbed dose rates in air (D), the radium equivalent (Raeq), the external hazard index (Hex) and the annual effective dose rate (AED) in all beach area. Moreover, experimental results were also compared to the Office of Atoms for Peace (OAP) research data, Thailand and global radioactivity measurements and evaluation, the recommended values which were proposed by the Organization for Economic Cooperation and Development (OECD, 1979) and United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR, 1988, 1993, 2000). Specific activities of natural and artificial anthropogenic radionuclides in all of Nai Yang beach sand samples could be also used to create the radioactive contour maps

  11. [Uptake of radionuclides from soil to plant and the discovery of 226Ra, 232Th hyperaccumulator].

    Science.gov (United States)

    Zhang, Zhi-Qiang; Chen, Di-Yun; Song, Gang; Yue, Yu-Mei

    2011-04-01

    11 sorts of plant samples and corresponding soil samples were collected in Conghua and Taishan, Pearl River Delta. The specific activity of 238U, 226Ra, 232Th and 40K of samples were investigated by using HPGe-gamma-ray spectra analysis. The results showed that the average specific activity of 238U, 226Ra, 232Th and 40K in soil samples were 151.8, 146.3, 226.6, 665.5 Bq/kg, which were higher than the average values of China and the world. The concentration of 238U in all sort of plants are very low and most of them are lower than detection limit, while the values of 226Ra, 232Th and 40K were high. The contents of 226Ra and 232Th in Dicranopteris dichotoma were the highest, whose average specific activity is 285.9, 986.2 Bq/kg respectively. The average bioconcentration factors (BFs)of 26Ra, 232Th of Dicranopteris dichotoma were 2.20, 4.23, respectively, the other 10 sort of plants have BFs of 2266Ra, 232Th were in the range of 10(-1)-10(-2). The bioconcentration factors and the translocation factors of 226Ra, 232Th of Dicranopteris dichotoma. were all bigger than 1, so Dicranopteris dichotoma can be defined as hyperaccumulator of 226Ra and 232Th. PMID:21717763

  12. 226Ra, 232Th and 40K analysis in water samples from Assiut, Egypt

    International Nuclear Information System (INIS)

    The activity concentrations of 226Ra, 232Th and 40K were determined in water samples, using 2”x 2” NaI(Tl) scintillation detector. Water activity ranges from 0.07 to 0.59 Bq L−1 for 226Ra, 0.05 to 0.37 Bq L−1 for 232Th and 3.25 to 8.72 Bq L−1 for 40K with mean values of 2.64, 2.22 and 119.50 Bq L−1, respectively. As far as the measured gamma radionuclides is concerned, the mean annual effective doses for all analyzed samples of water are in the range of 0.02–0.08, 0.03-0.17 and 0.03-0.10 mSv yr-1 for infants, children and adults, respectively, all being lower than the reference level of the committed effective dose recommended by the WHO.

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

    International Nuclear Information System (INIS)

    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

  14. Geochemical Speciation of Soil 7Be,137Cs,226Ra and 228Ra as Tracers to Particle Trnsport

    Institute of Scientific and Technical Information of China (English)

    BALZHANGUO; WANGUOJIANG; 等

    1997-01-01

    A brunisolic soil collected from an erosive forest land(HF-1-1) and a yellow soil from and accumulative shallow basin(HF-6-1) in the watershed of Lake Hongfeng (HF) were used for activity measurements of 7Be,137Cs,226Ra and 228Ra in different geochemical speciation.More than 85% of 7Be,137Cs,226Ra and 228Ra in the soils were bound to organic Fe-Mn oxy-hydroxide and residual fractions.They could move with soil particlesw and be used as tracers for the erosion and /or accumulation of soil particles.7Be gohemical specition in the soils agreed with its trace for seasonal particle transport.137Cs geohemial speciaiton was suitable for tracing soil particle accumulation and for sediment aating.226Ra and 228Ra were ombined in crystalline skeleton of clay minerals and mainly remained as residues in the soils and little was bound to the soluble,exchangeable and carbonate fractions.The differentiation of 226 Ra/228Ra activity ratios in different geoheical fractions in the soils could be used as a parameter to trace accumulation and /or erosion of soil particles.

  15. Radioactivity of Natural Nuclides (40K, 238U, 232Th, 226Ra) in Coals from Eastern Yunnan, China

    OpenAIRE

    Xin Wang; Qiyan Feng; Ruoyu Sun; Guijian Liu

    2015-01-01

    The naturally occurring primordial radionuclides in coals might exhibit high radioactivity, and can be exported to the surrounding environment during coal combustion. In this study, nine coal samples were collected from eastern Yunnan coal deposits, China, aiming at characterizing the overall radioactivity of some typical nuclides (i.e., 40K, 238U, 232Th, 226Ra) and assessing their ecological impact. The mean activity concentrations of 238U, 232Th, 40K and 226Ra are 63.86 (17.70–92.30 Bq· kg-...

  16. Soil-to-root vegetable transfer factors for 226Ra, 232Th, 40K, and 88Y in Malaysia

    International Nuclear Information System (INIS)

    Soil-to-plant transfer factors (TFs) are of fundamental importance in assessing the environmental impact due to the presence of radioactivity in soil and agricultural crops. Tapioca and sweet potato, both root crops, are popular foodstuffs for a significant fraction of the Malaysian population, and result in intake of radionuclides. For the natural field conditions experienced in production of these foodstuffs, TFs and the annual effective dose were evaluated for the natural radionuclides 226Ra, 232Th, 40K, and for the anthropogenic radionuclide 88Y, the latter being a component of fallout. An experimental tapioca field was developed for study of the time dependence of plant uptake. For soil samples from all study locations other than the experimental field, it has been shown that these contain the artificial radionuclide 88Y, although the uptake of 88Y has only been observed in the roots of the plant Manihot esculenta (from which tapioca is derived) grown in mining soil. The estimated TFs for 226Ra and 232Th for tapioca and sweet potato are very much higher than that reported by the IAEA. For all study areas, the annual effective dose from ingestion of tapioca and sweet potato are estimated to be lower than the world average (290 μSv y−1). - Highlights: • Transfer factors of 226Ra, 232Th, 40K, and 88Y radionuclides were estimated for widely consumed root vegetables in Malaysia. • An experimental tapioca field was developed for study of the time dependence of plant uptakes. • The estimated TF values of 226Ra and 232Th for tapioca and sweet potato are higher than the IAEA reported values. • These site-specific TFs are of importance for model derivations for tropical regions

  17. [About the contents of 40K, 226Ra and 232Th in forest soils of the Republic of Belarus].

    Science.gov (United States)

    Perevolotskiĭ, A N; Perevolotskaia, T V

    2014-01-01

    The specific activity of 40K, 232Th and 226Ra in forest soil ecotopes (A2-B2-C2-D2) has been investigated. When the fertility of the soil increases from A2 to D2, then the specific activity of 40K increases in the rooting zone of the soil from 275 ± 6.9 up to 499 ± 11 Bq/kg, 232Th--from 11.8 ± 0.5 to 17.1 ± 1.1 Bq/kg, 226Ra- from 19.2 γ 0.8 to 27.9 ± 1.5 Bq/kg. The calculated capacity of the absorbed dose of γ-radiation conditioned by 40K, 232Th and 226Ra increases from A2 to D2 from 27.5 ± 0.5 to 44.1 ± 1.1 nGy / h at the height of 1 m.

  18. Soil to leaf transfer factor for the radionuclides 226Ra, 40K, 137Cs and 90Sr at Kaiga region, India

    International Nuclear Information System (INIS)

    Transfer factors are the most important parameters required for mathematical modeling used for environmental impact assessment of radioactive contamination in the environment. In this paper soil to leaf transfer factor for the radionuclides 40K, 226Ra, 137Cs and 90Sr is estimated for Kaiga region in Karnataka state, India. Among the plants in which study is carried out, 226Ra, 40K, 137Cs and 90Sr activity in leaves of herbaceous plants is higher than that of tree leaves. Soil to leaf transfer factor for 226Ra, 40K, 137Cs and 90Sr was found to be in the range of 0.03-0.65, 0.32-8.04, 0.05-3.03 and 0.42-2.67 respectively. - Highlights: → Study region is Kaiga, Karnataka, India. → 226Ra, 40K, 137Cs and 90Sr activity in soil and leaf samples are reported. → 226Ra, 40K, 137Cs activity is higher in herbaceous plant leaves, than tree leaves. → In most of the plants transfer factor varies in the order K > Sr > Cs > Ra.

  19. Detection efficiencies of 226Ra and 232Th in different modes of counting of the PRIPYAT-2M spectrometer

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    Antović Nevenka M.

    2009-01-01

    Full Text Available Detection efficiencies of 226Ra and 232Th decay products, as well as corresponding minimum detectable activities in different modes of counting of the PRIPYAT-2M spectrometer (integral, when all pulses - coincident and non-coincident, are counted; non-coincident, when only non-coincident pulses are counted; coincident, when coincident pulses of multiplicity from 2 to 6 are counted, in energy ranges of 200 keV to 2000 keV and 300 keV to 3000 keV are presented here. It has been shown that the mode of double coincidences is the optimum one for measuring radium and thorium activity. In this mode of counting, the sensitivity of the spectrometer is the highest.

  20. Biomass selection for biosorption study of {sup 226} Ra and {sup 137} Cd radionuclides; Selecao de biomassas para o estudo da biossorcao dos radionuclideos {sup 226} Ra e {sup 137} Cs

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Wilson Cervi da

    2003-07-01

    The main goal of this work was to verify the potentialities to apply the biosorption technique to synthetic and real solution containing {sup 226} Ra and {sup 137} Cs, utilizing the seaweed Sargassum sp. and the microorganisms Penicillium sp., Saccharomyces cerevisiae and Monoraphidium sp. Indeed, the screening of the most effective biomass to remove the radionuclides was also a central objective. {sup 226} Ra was selected due to its high radiotoxicity and the fact that it can be assimilated and incorporated by living organism through substitution og Mg{sup 2+} and Ca{sup 2+}, two essential nutrients. On the other hand, the selection of {sup 137} Cs, a radionuclide of medium toxicity, was due to its mobility in the environment, which increases the possibility to be assimilated by the organisms as the essential nutrients Na{sup +} and K{sup +}. (author)

  1. Distribution of 226Ra, 232Th and 40K in soils and sugar cane crops at Corumbatai river basin, Sao Paulo State, Brazil

    International Nuclear Information System (INIS)

    The common use of phosphate fertilizers NPK and amendments in sugar cane crops in Brazilian agriculture may increase the 226Ra, 232Th and 40K activity concentrations in soils and their availability for plants and human food chain. Thus, the main aim of this study was to evaluate the distribution of 226Ra, 232Th and 40K in soils and sugar cane crops in the Corumbatai river basin, Sao Paulo State, Brazil. The gamma spectrometry was utilized to measure the 226Ra, 232Th and 40K activity concentration in all samples. The soil-to-sugar cane transfer factors (TF) were quantified using the ratio between the radionuclide activity concentration in sugar cane and its activity concentration in soil. The results show that, although radionuclides incorporated in phosphate fertilizers and amendments are annually added in the sugar cane crops, if utilized in accordance with the recommended rates, their use does not lead to hazards levels in soils. The soil-to-sugar cane transfer of radionuclides occurred in the following order 40K>226Ra>232Th. Therefore, under these conditions, radionuclides intake through consumption of sugar is not hazardous to human health.

  2. Comment on `Update of 40K and 226Ra and 232Th series $\\gamma$-to-dose conversion factors for soil'

    CERN Document Server

    Malins, Alex; Saito, Kimiaki

    2015-01-01

    A letter to the editor of the Journal of Environmental Radioactivity on the article: E. Gasser, A. Nachab, A. Nourreddine, Ch. Roy, and A. Sellam, `Update of 40K and 226Ra and 232Th series $\\gamma$-to-dose conversion factors for soil', J. Environ. Radioactiv. 138, 68-71 (2014), DOI: 10.1016/j.jenvrad.2014.08.002.

  3. The activity concentrations of 40K, 226Ra, 232Th, 238U and 7Be in moss from spas in eastern Serbia in the period 2000-2012

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    Čučulović Ana

    2014-01-01

    Full Text Available In this work we present the activity concentrations of natural radionuclides 40K, 226Ra, 232Th, 238U and 7Be in mosses. One hundred and sixty-seven moss samples were collected between 2001 and 2012 from the territory of the Sokobanja, Banja Jošanica and Gamzigradska Banja spas. They were classified into 23 species. The activity concentrations (Bq/kg in moss from Sokobanja spa were: 40K 25-427; 226Ra 0.3-36; 232Th 1.0-37; 238U 0.4-28 and 7Be 29-210; from Banja Jošanica spa they were: 40K 90-242; 226Ra 2.4-11.7; 232Th 2.0-12.7; 238U 1.6-11.3 and 7Be 142-212; Gamzigradska Banja spa: 40K 95-351; 226Ra 8.0-21; 232Th 5.1-19; 238U 6.7-18 and 7Be 20-144. The activity concentrations of dominant natural radionuclides (potassium, radium, thorium and uranium in the moss samples were within the usual ranges for the territory of Serbia. [Projekat Ministarstva nauke Republike Srbije, br. III 43009

  4. Radionuclides (210Pb, 226Ra, 210Po e 137Cs) in the Cananeia-Iguape coastal system: environmental studies

    International Nuclear Information System (INIS)

    This work was developed in the Cananeia-lguape Coastal System, coast south of the State of Sao Paulo, with the aim of monitoring the levels of some natural radionuclides (210Pb, 210Po, 226Ra ) and artificial (137Cs) and to study the sedimentary dynamics of the area. For this, some studies and determinations were carried out, such as: sedimentation rates, concentration factors, bio-indicators and ingestion for the human population of some of these radionuclides. For the obtaining of the levels of these radionuclides, radiochemical and instrumental methodologies were developed and applied in reference samples of the International Agency of Atomic Energy (IAEA). After this, the methodologies were applied in samples of sediments, aquatic organisms and water of the channels collected in several points. In the sediments, the levels of (210Pb, 226Ra and 137Cs varied from 6.1 to 167.5 Bq.kg-1 from 4.1 to 28.5 Bq.kg-1 and from MDC (0.28) to 6.1 Bq.kg-1 respectively. More significant correlations were observed among the percentage of mud (silt-clay) in the sediments and the levels of these radionuclides. These data were used for sedimentation rate studies in the points of sampling in the System. The sedimentation rates obtained with the values of unsupported (210Pb and 137Cs for the Ponta do Arrozal (T1), Ponta do Frade (T2), Valo Grande (T3) and Carapara-BOCA River (T4) were of 5.02 and 5.00 mm.a-1, 2.30 and 3.82 mm.a-1, 14.59 and 15.74 mm.a-1, 3.41 and 5.00 mm.a-1 respectively. The sedimentation rates obtained with unsupported 210Pb and the 137Cs in the cores(T1, T2, T3 and T4) showed a good agreement. The sedimentation rates obtained along the System reflect the dynamics intern of the channels, that presents general tendency the one accentuated deposition process, with pronounced contribution of sediments of continental origin, for the drainages Mandira and Ribeira of Iguape Rivers, by the high biological production of the System as well as the pronounced erosion of the

  5. Daily intakes of 238U, 234U, 232Th, 230Th, 228Th and 226Ra in the adult population of central Poland

    Energy Technology Data Exchange (ETDEWEB)

    Pietrzak-Flis, Z.; Rosiak, L.; Suplinska, M.M.; Chrzanowski, E.; Dembinska, S. [Central Laboratory for Radiological Protection, Konwaliowa 7, 03-194 Warsaw (Poland)

    2001-06-12

    Activity concentration of the uranium and thorium series radionuclides was determined in foodstuffs and drinking water in central Poland. Annual and daily intake for the adult population was estimated from the concentrations determined and average annual consumption of food and water. The daily intakes (in mBq) were 22.1 (238U), 26.5 (234U), 2.38 (232Th), 4.06 (230Th), 11.2 (228Th) and 42.2 (226Ra). The intake of uranium isotopes occurred mainly with water; the main intake of thorium isotopes was with animal products, vegetables, cereals and potatoes, whereas 226Ra entered mainly with animal products, cereals and vegetables. From the intake and dose coefficients, the annual effective doses for the ingested radionuclides were calculated. The annual effective dose was 5.95 {mu}Sv, of which 72.4% originated from 226Ra.

  6. Daily intakes of 238U, 234U, 232Th, 230Th, 228Th and 226Ra in the adult population of central Poland

    International Nuclear Information System (INIS)

    Activity concentration of the uranium and thorium series radionuclides was determined in foodstuffs and drinking water in central Poland. Annual and daily intake for the adult population was estimated from the concentrations determined and average annual consumption of food and water. The daily intakes (in mBq) were 22.1 (238U), 26.5 (234U), 2.38 (232Th), 4.06 (230Th), 11.2 (228Th) and 42.2 (226Ra). The intake of uranium isotopes occurred mainly with water; the main intake of thorium isotopes was with animal products, vegetables, cereals and potatoes, whereas 226Ra entered mainly with animal products, cereals and vegetables. From the intake and dose coefficients, the annual effective doses for the ingested radionuclides were calculated. The annual effective dose was 5.95 μSv, of which 72.4% originated from 226Ra

  7. Distribution of 226Ra, 232Th, and 40K in rice plant components and physico-chemical effects of soil on their transportation to grains

    Directory of Open Access Journals (Sweden)

    Mohammed Saad Alsaffar

    2015-07-01

    Full Text Available Radioactivity distribution and transfer factor (TF in plants are crucial parameters used to assess radioactive contamination in the environment and its risks to humans. In this study, the activities of 226Ra, 232Th, and 40K were successfully measured via gamma-ray spectrometry on rice plant components (root, straw, husk, and grain and on corresponding soil samples collected from paddy fields in Penang, Malaysia. Soil physico-chemical characteristics (pH, cation exchange capacity, electrical conductivity, organic matter, and soil texture were also analyzed for their estimated effects on soil–grain TF. A major fraction of the total 226Ra and 232Th activities measured as 47% and 57%, respectively, were concentrated in the roots, whereas only about 9% and 8% were distributed in the grains, correspondingly. 40K activity accumulation was about 59% in the straw and 7% in the grains. Rice soil–grain TFs were observed in the ranges of (0.06–0.36 × 10−1 for 226Ra, (0.04–0.14 × 10−1 for 232Th, and (0.74–4.72 × 10−1 for 40K. Results showed that the selected radionuclide distributions in rice are dependent on component type, and their grain concentrations are not linearly related to their soil concentrations. These findings indicated that uptake predominantly depends on soil physico-chemical characteristics.

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

    OpenAIRE

    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...

  9. Speciation analysis of 129I, 137Cs, 232Th, 238U, 239Pu and 240Pu in environmental soil and sediment

    DEFF Research Database (Denmark)

    Qiao, Jixin; Hansen, Violeta; Hou, Xiaolin;

    2012-01-01

    The environmental mobility and bioavailability of radionuclides are related to their physicochemical forms, namely species. We here present a speciation analysis of important radionuclides including 129I (also 127I), 137Cs, 232Th, 238U and plutonium isotopes (239Pu and 240Pu) in soil (IAEA-375...

  10. The dietary intake of 238U, 234U, 230Th, 232Th, 228Th and 226Ra from food and drinking water by inhabitants of the Walbrzych region

    International Nuclear Information System (INIS)

    Intake with food and water of the natural radionuclides of the uranium and thorium series was determined for adult population of the south-western region in Poland, where in the 1950-ies an exploration of uranium ore was conducted. Concentration of the radionuclides was determined in food products and drinking water and their annual intake was estimated on the basis of the average annual consumption. The intake of 238U, 234U and 230Th occurred mainly with water (33% to 68%), whereas the intake of 232Th, 228Th and 226Ra was mainly with vegetables, potatoes, milk and flour. From the intake and dose coefficients the annual effective doses from the ingested radionuclides were calculated. The total dose was 5.6μSv, of which 74% originated from 226Ra. (author)

  11. 210Pb- 226Ra and 228Ra- 232Th systematics in young arc lavas: implications for magma degassing and ascent rates

    Science.gov (United States)

    Turner, Simon; Black, Stuart; Berlo, Kim

    2004-10-01

    New data show that island arc rocks have ( 210Pb/ 226Ra) o ratios which range from as low as 0.24 up to 2.88. In contrast, ( 228Ra/ 232Th) appears always within error of 1 suggesting that the large 226Ra-excesses observed in arc rocks were generated more than 30 years ago. This places a maximum estimate on melt ascent velocities of around 4000 m/year and provides further confidence that the 226Ra excesses reflect deep (source) processes rather than shallow level alteration or seawater contamination. Conversely, partial melting must have occurred more than 30 years prior to eruption. The 210Pb deficits are most readily explained by protracted magma degassing. Using published numerical models, the data suggest that degassing occurred continuously for periods up to several decades just prior to eruption but no link with eruption periodicity was found. Longer periods are required if degassing is discontinuous, less than 100% efficient or if magma is recharged or stored after degassing. The long durations suggest much of this degassing occurs at depth with implications for the formation of hydrothermal and copper-porphyry systems. A suite of lavas erupted in 1985-1986 from Sangeang Api volcano in the Sunda arc are characterised by deficits of 210Pb relative to 226Ra from which 6-8 years of continuous 222Rn degassing would be inferred from recent numerical models. These data also form a linear ( 210Pb)/Pb-( 226Ra)/Pb array which might be interpreted as a 71-year isochron. However, the array passes through the origin suggesting displacement downwards from the equiline in response to degassing and so the slope of the array is inferred not to have any age significance. Simple modelling shows that the range of ( 226Ra)/Pb ratios requires thousands of years to develop consistent with differentiation occurring in response to cooling at the base of the crust. Thus, degassing post-dated, and was not responsible for magma differentiation. The formation, migration and extraction

  12. Estimation of dose contribution from 226Ra, 232Th and 40K radon exhalation rates in soil samples from Shivalik foot hills in India.

    Science.gov (United States)

    Chauhan, R P; Chauhan, Pooja; Pundir, Anil; Kamboj, Sunil; Bansal, Vakul; Saini, R S

    2014-01-01

    The concentration of radium, thorium and potassium and radon exhalation rates in soil samples collected from Shivalik foot hills in the states of Haryana and Himachal Pradesh (India) were experimentally measured. A high-resolution gamma-ray spectroscopic system was used for the measurement of natural radioactivity ((226)Ra, (232)Th and (40)K) at Inter-University Accelerator Center, New Delhi, using a coaxial n-type high-purity germanium detector (EG&G, ORTEC, Oak Ridge, USA). The mass exhalation rates (EM) of radon in soil samples from the study area measured by 'sealed canister technique' using LR-115 type II track detectors varied from 50±1 to 143±6 mBqkg(-1) h(-1). The activity concentrations of (226)Ra, (232)Th and (40)K in various soil samples of the study area varied from 31±1.3 to 63±4.6, 53±1.8 to 78±2.6 and 472±4.8 to 630±7.0 Bq kg(-1) respectively. The results indicated some higher levels of radioactivity in Lal Dhang peak area of the hills compared with other locations under study. PMID:23893776

  13. Distribution of radioactive pollution of 238U, 232Th, 40K and 137Cs in northwestern coasts of Persian Gulf, Iran

    International Nuclear Information System (INIS)

    A reconnaissance study has been made of the distribution of 238U, 232Th, 40K and 137Cs and geochemical features in soils and sediments samples at various locations in the northwestern coast of Persian Gulf. Activity concentration levels due to radionuclides were measured in 30 soil and sediment samples collected from this region. From the measured spectra, activity concentrations were determined for 40K (range from 146 to 500 Bq kg-1), 137Cs (from 5 to 20 Bq kg-1), 238U (from 21 to 65 Bq kg-1) and 232Th (from 15 to 45 Bq kg-1) with lowest limit detection (LLD) of 68, 3.2, 4.3 and 4.3 Bq kg-1, respectively. The dose rate from ambient air at the soil ranges was between 19 and 58 nGy h-1 with an average of 37.41 ± 9.66 nGy h-1

  14. A four phases model to simulate the dispersion of 226Ra, 238U and 232Th in an estuary affected by phosphate rock processing

    International Nuclear Information System (INIS)

    A numerical model to simulate the dispersion of non conservative radionuclides in tidal waters has been developed. The model includes four phases: water, suspended matter and two grain size sediment fractions. Ionic exchanges between water and the solid phases have been formulated in terms of kinetic transfer coefficients instead of distribution coefficients, because the model was developed for nonequilibrium conditions. The model simultaneously solves the shallow water hydrodynamic equations, the suspended matter dispersion equation and the four equations which give the time evolution of specific activity in each phase. The model has been applied to the Odiel river (southwest Spain), where a phosphate complex releases its wastes. It gives good results in predicting concentrations of 226Ra, 238U and 232Th in water, suspended matter, distribution coefficients and Th/U mass rations. (author)

  15. {sup 226}Ra, {sup 232}Th and {sup 40}K concentrations in igneous rocks from eastern desert, Egypt and its radiological implications

    Energy Technology Data Exchange (ETDEWEB)

    El-Arabi, A.M. [Physics Department, Faculty of Science Qena, South Valley University (Egypt)]. E-mail: elarabi21@yahoo.com

    2007-01-15

    By applying high-resolution {gamma}-ray spectroscopic system, the various radionuclides of the granite samples have been identified quantitatively based on the characteristic spectral peaks. The radionuclides {sup 226}Ra, {sup 232}Th and {sup 40}K concentrations measured as well as radiological parameters, for 49 granite samples were calculated. This subject is important in environmental radiological protection, since granites are widely used as building and ornamental stones. The variation in concentration of radionuclides for the Um Taghir area can be classified into two regions of low and high natural radioactivity. In old granite, the measured {gamma}-ray spectra, activity concentrations were determined for {sup 226}Ra (from 2.9+/-1 to 31.8+/-6Bqkg{sup -1}), {sup 232}Th (range from 1.4+/-1 to 14.9+/-4Bqkg{sup -1}) and {sup 40}K (from 132+/-11 to 2080+/-46Bqkg{sup -1}), in younger granite {sup 226}Ra (from 8.9+/-3 to 9087+/-95Bqkg{sup -1}), {sup 232}Th (range from 9.8+/-3 to 3834+/-62Bqkg{sup -1}) and {sup 40}K (from 471+/-22 to 10230+/-101Bqkg{sup -1}). In Wadi Karim area these values were (14.0+/-4-227.0+/-15, 10.5+/-3-183.0+/-14 and 2299+/-48-7356+/-86Bqkg{sup -1}). The highest values of {sup 226}Ra, {sup 232}Th and {sup 40}K concentration (9087+/-95, 3834+/-62 and 10230+/-101Bqkg{sup -1},respectively) were observed in anomalies samples at Um Taghir region. Radium-equivalent activities (Ra{sub eq}) in addition to the internal hazard index (H{sub in}) have also been determined. In Um Taghir samples Ra{sub eq} varies between 15 and 625Bqkg{sup -1} (old granite), 144-13982Bqkg{sup -1} (younger granite) which exceeds the permitted value (370Bqkg{sup -1}) and hazard index (H{sub in}) (0.05-1.74), (0.65-62.34) which is higher than 1, the corresponding values in Wadi Karim samples were 206-685Bqkg{sup -1} and from 0.59 to 2.46, respectively. The total absorbed dose rates in air calculated from the concentrations of the three radionuclides ranged from 8 to 6187n

  16. 228Ra/226Ra ratio and 7Be concentration in the Sea of Japan as indicators for water transport: comparison with migration pattern of Fukushima Dai-ichi NPP-derived 134Cs and 137Cs

    International Nuclear Information System (INIS)

    To assess the migration patterns of radiocesium emitted from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP), we analyzed 228Ra/226Ra ratios and 7Be concentrations and compared them with 134Cs and 137Cs concentrations in seawater samples collected within the Sea of Japan before and after the FDNPP accident (i.e., during the period 2007–2012) using low-background γ-spectrometry. The 228Ra/226Ra ratios in surface waters exhibited lateral and seasonal variations, reflecting the flow patterns of surface water. This indicates the transport patterns of the FDNPP-derived radiocesium by surface water. Cosmogenic 7Be (half-life: 53.3 d) exhibited markedly high concentrations (5–10 mBq/L) at depths shallower than 50 m, with concentrations decreasing steeply (0.2–2 mBq/L) at depths of 50–250 m. The distribution of 7Be concentrations suggests that the downward delivery of the FDNPP-derived radiocesium to below 50 m depth was negligible for a few months prior to its removal from the Sea of Japan. -- Highlights: • We analyzed 7Be and 228Ra/226Ra ratio with 134Cs and 137Cs in the Sea of Japan. • 228Ra/226Ra ratio explained lateral migration of FDNPP-derived radiocesium in surface. • Vertical profile of 7Be concentration indicated minimal downward delivery of radiocesium

  17. Distribution of 238U, 232Th, 40K, and 137Cs concentrations in soil samples nearby a nuclear laboratory, Capao Island, Brazil

    Directory of Open Access Journals (Sweden)

    Oliveira Luciano S.R.

    2015-01-01

    Full Text Available Absolute soil concentrations of 238U, 232Th, 40K, and 137Cs samples were measured using high-resolution gamma spectrometry. The area of interest encompasses an embankment in a mangrove swamp in Guaratiba, Rio de Janeiro, called Capao Island, where nuclear, chemical and biological defense laboratories of the Brazilian Army Technology Center are in operation for more than 30 years. In order to ensure that no significant environmental impact has resulted from neutron physics experiments performed in a graphite exponential pile in addition to the operation of two cesium-driven irradiating facilities, radiation monitoring of the isotopes was carried out. A total of eight 250 ml soil samples were extracted within an area of 300 m x 300 m. No trace of 137Cs was detected and the measured levels of 238U were found to be close to the global mean. However, some data that slightly exceeded the expected normal range for 232Th (60 % of samples and 40K (20 % of samples should be attributed to the construction debris (cement, rocks, and sand used in the embankment at the site. Since there is no handling of those isotopes at that site or adjacent facilities that could affect their presence, it was concluded that no detectable contamination has occurred.

  18. 放射性核素土壤-植物吸收与钍、镭富集植物的发现%Uptake of Radionuclides from Soil to Plant and the Discovery of 226Ra, 232Th Hyperaccumulator

    Institute of Scientific and Technical Information of China (English)

    张志强; 陈迪云; 宋刚; 岳玉美

    2011-01-01

    11 sorts of plant samples and corresponding soil samples were collected in Conghua and Taishan, Pearl River Delta. The specific activity of 238U、226Ra、232Th and 40K of samples were investigated by using HPGe-γ-ray spectra analysis. The results showed that the average specific activity of 238U, 226Ra, 232Th and 40K in soil samples were 151.8, 146. 3, 226. 6, 665.5 Bq/kg, which were higher than the average values of China and the world. The concentration of 238U in all sort of plants are very low and most of them are lower than detection limit, while the values of 226Ra, 232Th and 4OK were high. The contents of 226Ra and 232Th in Dicranopteris dichotoma were the highest, whose average specific activity is 285.9, 986. 2 Bq/kg respectively. The average bioconcentration factors (BFs)of 226Ra,232Th of Dicranopteris dichotoma were 2. 20, 4.23, respectively, the other 10 sort of plants have BFs of 226Ra, 232Th were in the range of 10 -1 -10-2. The bioconcentration factors and the translocation factors of 226Ra, 232Th of Dicranopteris dichotoma were all bigger than 1, so Dicranopteris dichotoma can be defined as hyperaccumulator of 226Ra and 232Th.%对采集珠江三角洲从化、台山等地的11种植物以及对应的土壤样品,采用HPGe-y能谱分析了其中的天然放射性核素U、Ra、Th和K的比活度,结果表明,土壤样品中U、Ra、Th和K的平均含量为151.8、146.3、226.6和665.5Bq/kg,高于我国和世界的平均值,植物样品中的U含量较低,大多数样品低于检出限,而Ra、Th和K的平均含量相对较高.铁芒萁(Dicranopteris dichotoma)样品中Ra、Th含量最高,平均值分别为285.9 Bq/kg、968.5 Bq/kg,对应的生物富集系数(bioconcentration factor)的平均值为2.20、4.23,而其它10种植物Ra、Th的生物富集系数均在10~10的范围.铁芒萁Ra和Th的富集系数和转移系数(translocation factor)都大于1,可以认为是Ra和Th的超富集植物.

  19. {sup 226}Ra, {sup 232}Th and {sup 40}K contents and radon exhalation rate from materials used for construction and decoration in Cameroon

    Energy Technology Data Exchange (ETDEWEB)

    Ngachin, M; Njock, M G Kwato [Center for Atomic, Molecular Physics and Quantum Optics, University of Douala, PO Box 8580, Douala (Cameroon); Garavaglia, M; Giovani, C; Scruzzi, E [Regional Agency for Environmental Protection (ARPA), 91 via Tavagnacco, 33100 Udine (Italy); Nourreddine, A [Institut Pluridisciplinaire Hubert-Curien, UMR7178 CNRS-IN2P3 and Universite Louis Pasteur, 23 rue de Loess, BP 28, F-67037, Strasbourg cedex 02 (France); Lagos, L [Applied Research Center, Florida International University, 10555 W Flagler Street, EC 2100, Miami, FL 33174 (United States)], E-mail: mngachin@yahoo.com

    2008-09-01

    This work deals with the measurement of radioactivity and radon exhalation rate from building materials manufactured in Douala city from geological materials. Nine types of building material were surveyed for their natural radioactivity contents using high-resolution gamma-ray spectrometry. The activity concentrations for {sup 226}Ra, {sup 232}Th and {sup 40}K varied from 11.5 to 49 Bq kg{sup -1}, 16 to 37 Bq kg{sup -1} and 306 to 774 Bq kg{sup -1}, respectively. The absorbed dose rate in the samples investigated at 1 m above ground level ranged from 28.5 to 66.6 nGy h{sup -1}. External and internal hazard indices were also estimated as defined by the European Commission. The Ra equivalents of the materials studied ranged from 57.5 to 133 Bq kg{sup -1} and are much smaller than the recommended limit of 370 Bq kg{sup -1} for construction materials for dwellings. Polycarbonate nuclear track detectors (NTDs), type CR-39, were used for measuring the radon concentration from different materials. In fact, knowledge of the radon exhalation rate from building materials is important for understanding the individual contribution of each material to the total indoor radon exposure. Samples were hermetically closed in glass vessels and the radon growth was followed as a function of time. The radon exhalation rate was therefore derived from the experimental measurement of {alpha}-track densities. The radon exhalation varied from (5.77 {+-} 0.06) x 10{sup -5} to (7.61 {+-} 0.07) x 10{sup -5} Bq cm{sup -2} h{sup -1} in bricks, from (5.79 {+-} 0.05) x 10{sup -5} to (11.6 {+-} 0.12) x 10{sup -5} in tiles, and was (6.95 {+-} 0.03) x 10{sup -5} Bq cm{sup -2} h{sup -1} in concrete. A correlation (correlation coefficient approx. = 0.8) was found between radium concentration measured with a HPGe detector and the radon exhalation rate obtained using nuclear track detectors.

  20. (226)Ra, (232)Th and (40)K contents and radon exhalation rate from materials used for construction and decoration in Cameroon.

    Science.gov (United States)

    Ngachin, M; Garavaglia, M; Giovani, C; Nourreddine, A; Kwato Njock, M G; Scruzzi, E; Lagos, L

    2008-09-01

    This work deals with the measurement of radioactivity and radon exhalation rate from building materials manufactured in Douala city from geological materials. Nine types of building material were surveyed for their natural radioactivity contents using high-resolution gamma-ray spectrometry. The activity concentrations for (226)Ra, (232)Th and (40)K varied from 11.5 to 49 Bq kg(-1), 16 to 37 Bq kg(-1) and 306 to 774 Bq kg(-1), respectively. The absorbed dose rate in the samples investigated at 1 m above ground level ranged from 28.5 to 66.6 nGy h(-1). External and internal hazard indices were also estimated as defined by the European Commission. The Ra equivalents of the materials studied ranged from 57.5 to 133 Bq kg(-1) and are much smaller than the recommended limit of 370 Bq kg(-1) for construction materials for dwellings. Polycarbonate nuclear track detectors (NTDs), type CR-39, were used for measuring the radon concentration from different materials. In fact, knowledge of the radon exhalation rate from building materials is important for understanding the individual contribution of each material to the total indoor radon exposure. Samples were hermetically closed in glass vessels and the radon growth was followed as a function of time. The radon exhalation rate was therefore derived from the experimental measurement of alpha-track densities. The radon exhalation varied from (5.77 +/- 0.06) x 10(-5) to (7.61 +/- 0.07) x 10(-5) Bq cm(-2) h(-1) in bricks, from (5.79 +/- 0.05) x 10(-5) to (11.6 +/- 0.12) x 10(-5) in tiles, and was (6.95 +/- 0.03) x 10(-5) Bq cm(-2) h(-1) in concrete. A correlation (correlation coefficient approximately 0.8) was found between radium concentration measured with a HPGe detector and the radon exhalation rate obtained using nuclear track detectors.

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

    International Nuclear Information System (INIS)

    This work deals with gamma detection of shielded sources of 235U, 238U, 232Th, 137Cs and 60Co by using HpGe and NaI detectors through their main characteristic energies; 185.7 keV, (63, 1001), (583 and 911), 661.6 and (1173 and 1332) KeV respectively. These radioactive sources were individually hidden in containers of aluminum (Al), iron (Fe) and cupper (Cu) of different thicknesses; 3, 6, 9, 12, 15, 18 mm. Thin containers of lead (Pb) were also used with the same sources. The attenuation factor (I/I0), the ratio of radiation intensity with and without container or shield, was calculated for all the investigated γ-energies. The relationship between the attenuation factor and the studied thicknesses of the containers was given, depicted and discussed. Detection of the mixed sources shielded by different materials of different thicknesses was also carried out by using PDR-77 survey meter. The radiation levels were found to be within the natural background at 65cm distance from the shielded sources. Telescopic arm carrying 2x2 NaI and radiometer was also used. Generally, It can be concluded that smuggling of radioactive materials of low radioactivity can be done without detection by hiding them in containers or within scrap of Cu, Fe or even Al rather than using the conventional heavy lead shield. (author)

  2. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  3. Vertical distribution of Th-isotope ratios, 210Pb, 226Ra and 137Cs in sediment cores from an estuary affected by anthropogenic releases

    International Nuclear Information System (INIS)

    In an estuary system highly polluted by mining and industrial activities, the sections of sediment cores affected by anthropogenic inputs of U-series radionuclides (due to fertilizer plants releases) were determined through the vertical profiles of Th-isotopic ratio (230Th/232Th). Also, when possible, a modified version of the 210Pb dating method was applied in the uncontaminated sections of these cores. Using the information provided by the Th-isotopic ratio and 210Pb methods, we were able to establish confident chronologies, covering the last century, in several of the analysed sediment cores. These chronologies will be used in forthcoming research to study the time evolution of pollutant concentrations in the estuary. Additionally, and based on the established chronologies, we have found that sedimentation rates have drastically increased in some zones of the estuary since the commencement of several industrial activities in the surrounding environment and since the construction of two dikes in the area

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

    International Nuclear Information System (INIS)

    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

  5. Vertical distribution of Th-isotope ratios, {sup 210}Pb, {sup 226}Ra and {sup 137}Cs in sediment cores from an estuary affected by anthropogenic releases

    Energy Technology Data Exchange (ETDEWEB)

    San Miguel, E.G.; Bolivar, J.P. [Dpto Fisica Aplicada, E.P.S. La Rabida, Ctra Palos S/N, Huelva 21819 (Spain); Garcia-Tenorio, R. [Dpto Fisica Aplicada, E.T.S. Arquitectura, Avda, Reina Mercedes, 2, Sevilla 41012 (Spain)

    2004-01-05

    In an estuary system highly polluted by mining and industrial activities, the sections of sediment cores affected by anthropogenic inputs of U-series radionuclides (due to fertilizer plants releases) were determined through the vertical profiles of Th-isotopic ratio ({sup 230}Th/{sup 232}Th). Also, when possible, a modified version of the {sup 210}Pb dating method was applied in the uncontaminated sections of these cores. Using the information provided by the Th-isotopic ratio and {sup 210}Pb methods, we were able to establish confident chronologies, covering the last century, in several of the analysed sediment cores. These chronologies will be used in forthcoming research to study the time evolution of pollutant concentrations in the estuary. Additionally, and based on the established chronologies, we have found that sedimentation rates have drastically increased in some zones of the estuary since the commencement of several industrial activities in the surrounding environment and since the construction of two dikes in the area.

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

    Science.gov (United States)

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

    2007-01-01

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

  7. Determination of (226)Ra, (232)Th, (40)K, (235)U and (238)U activity concentration and public dose assessment in soil samples from bauxite core deposits in Western Cameroon.

    Science.gov (United States)

    Mekongtso Nguelem, Eric Jilbert; Moyo Ndontchueng, Maurice; Motapon, Ousmanou

    2016-01-01

    Determination of activity concentrations in twenty five (25) soil samples collected from various points in bauxite ore deposit in Menoua Division in Western of Cameroon was done using gamma spectrometry based Broad Energy Germanium (BEGe6530) detector. The average terrestrial radionuclides of (40)K, (226)Ra, (232)Th, (235)U and (238)U were measured as 671 ± 272, 125 ± 58, 157 ± 67, 6 ± 3 and 99 ± 69 Bq kg(-1), respectively. The observed activity concentrations of radionuclides were compared with other published values in the world. The outdoor absorbed dose rate in air varied from 96.1 to 321.2 nGy h(-1) with an average of 188.2 ± 59.4 nGy h(-1). The external annual effective dose rate and external hazard index were estimated as 0.23 ± 0.07 mSv year(-1) for outdoor, 0.92 ± 0.29 mSv year(-1) for indoor and 1.13 for the external hazard index, respectively. These radiological safe parameters were relatively higher than the recommended safe limits of UNSCEAR. Consequently, using of soil as building material might lead to an increase the external exposure to natural radioactivity and future applications research need to be conducted to have a global view of radioactivity level in the area before any undergoing bauxite ore exploitation. PMID:27536536

  8. Natural radionuclides and 137Cs in moss and lichen in eastern Serbia

    Directory of Open Access Journals (Sweden)

    Čučulović Ana

    2012-01-01

    Full Text Available The paper presents the results of radionuclides determination in moss (Homolothecium sp., Hypnum Cupressiforme sp., and Brachythecium sp. and lichen (Cladonia sp. sampled in the region of Eastern Serbia during 1996-2010. The activities in moss are in the range of 100-500 Bq/kg d. w. for 40K, and 5-50 Bq/kg d. w. for 226Ra and 232Th, while the “soil-to-moss” transfer factors are 0.45 for 40K, 3 for 226Ra, and 0.3 for 232Th. The spatial distribution of the 137Cs activities is highly non-uniform; some values reach 500 Bq/kg d. w., with less than 10% of the samples, mainly the ones taken prior to 2000, with the activity above 1000 Bq/kg d. w. The variations in the content of natural radionuclides among the moss species are not significant. The frequency pattern of the activities of natural radionuclides in lichen is similar to the one in moss, but the activities in lichen are to some extent lower. The mean activity of 137Cs in lichen is below 400 Bq/kg d. w. The mean activities of 7Be in moss and lichen sampled in 2006 and 2008 are in the range of 41-122 Bq/kg d. w., with pronounced variations between the sampling sites.

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

    International Nuclear Information System (INIS)

    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)

  10. Methods for the determination of 234U/230 U, 230Th/232 Th and 228Ra/226Ra in uranium ores by TIMS%TIMS测定铀矿石样品中234U/238U、230Th/232Th、228Ra/226Ra的方法研究

    Institute of Scientific and Technical Information of China (English)

    朱明燕; 郭冬发; 崔建勇; 刘宇昂; 谭靖; 张彦辉

    2009-01-01

    研究了TIMS测定铀矿石样品中234 U/238 U、230 Th/232 Th、228 Ra/226 Ra的方法.建立了铀矿石密闭混酸一次溶样的方法和采用阴离子、阳离子和Sr特效树脂逐级离子交换分离纯化U、Th和Ra的流程,满足了TIMS测量要求.测定结果表明:100~1000 ng的天然铀中234U/238U,其测量精密度从静态多接收的2.34%提高到动态多接收的0.47%;对230Th与232Th丰度接近、质量为1 μg左右的钍,采用三带点样技术和法拉第多接收技术测定230Th/232Th,其内精度平均值为0.0048%,外精度为0.028%;采用单带加钽发射剂,ETP跳峰测定50~100 fg镭-228稀释剂中的228Ra/226Ra,其内精度小于0.10%,外精度小于0.20%.比较TIMS和HR-ICP-MS、α能谱法测定234U/238U、230Th/232Th、228Ra/226Ra结果,三者结果相吻合.TIMS测量法样品用量少、快速、准确、精密度高,是U,Th、Ra同位素比值测定方法的又一补充.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  13. Determination of 238U, 232Th and 40K activity concentrations in riverbank soil along the Chao Phraya river basin in Thailand

    International Nuclear Information System (INIS)

    The activity concentrations of 238U, 232Th and 40K in riverbank soil along the Chao Phraya river basin was determined through gamma-ray spectrometry measurements made using a hyper-pure germanium detector in a low background configuration. The ranges of activity concentrations of 238U, 232Th and 40K were found to be 13.9 ↔ 76.8, 12.9 ↔ 142.9 and 178.4 ↔ 810.7 Bq kg−1, respectively. The anthropogenic radionuclide, 137Cs, was not observed in statistically significant amounts above the background level in the current study. The absorbed gamma dose rate in air at 1 m above the ground surface, the outdoor annual effective dose equivalent, the values of the radium equivalent activity and the external hazard index associated with all the soil samples in the present work were evaluated. The results indicate that the radiation hazard from primordial radionuclides in all soil samples from the area studied in this current work is not significant. - Highlights: • Radioactivity in surface soils from the Chao Phraya river basin in Thailand is evaluated. • Gamma-ray spectrometric analysis is to identify decays associated with 226Ra, 232Th and 40K. • The results provide baseline measurements for any changes in future radioactivity levels

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

    Science.gov (United States)

    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.

  15. Behavior of 210Pb and 226Ra in tailing samples at Jaduguda

    International Nuclear Information System (INIS)

    Several investigation at various parts of the world as well as in different parts of India reported wide variation in activity of 210Pb and 226Ra in environmental matrices. Since 210Pb occurs in decay chain of 226Ra one would expect that in isolated and undisturbed domain the ratio to be nearly unity. However such a ratio is rarely reached. In the actual experience this ratio is influenced to different degree by several environmental parameters such as soil porosity, particle size distribution, and chemical nature of soil and subsurface and surface movement of water. A thorough study on 226Ra and 210Pb ratio can in principle be used as tool to evaluate some environmental parameters in the tailing ponds. A study of natural radioactivity levels including 226Ra and 210Pb in tailing sample around tailing pond area of uranium mining and milling complex located in the Singhbhum regions of Eastern India were undertaken. Tailing pond is covered with the normal background soil known as capping soil. This also reduces the emanation of radon and exposure due 226Ra and its daughter products. Tailings samples were collected after removing the top capping soil. Samples were processed as described by Environmental Measurement Laboratory (EML 1990). Activity concentration of natural 238U series radionuclide like thorium isotopes (234Th and 228Th), lead isotopes (210Pb and 212Pb), radium isotopes (226Ra and 228Ra) and 234mPa were measured using HPGe based high resolution gamma spectrometric technique after attaining secular equilibrium between 226Ra and its daughters. IAEA standard sources RGTh-1 (800 μg/g of 232Th), RGU-1 (400μg/g of 238U), were used for energy and efficiency calibration of the spectrometer in the same geometry (plastic containers of 6.5 cm dia x 7.5 cm ht) as that of the samples. (author)

  16. 137Cs metabolism during pregnancy

    International Nuclear Information System (INIS)

    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)

  17. 238U sbnd 230Th sbnd 226Ra disequilibria in young Mount St. Helens rocks: time constraint for magma formation and crystallization

    Science.gov (United States)

    Volpe, Alan M.; Hammond, Paul E.

    1991-12-01

    We use 238U-series nuclides and 230Th/ 232Th ratios measured by mass spectrometry to constrain processes and time scales of calc-alkaline magma genesis at Mount St. Helens, Washington. Olivine basalt, pyroxene andesites and dacites that erupted 10-2 ka ago show 3-14% ( 230Th) sbnd ( 238U) and 6-54% 226Ra sbnd 230Th disequilibria. Mineral phases exhibit robust ( 226Ra) sbnd ( 230Th) fractionation. Plagioclase has large 65-280% ( 226Ra) excesses, and magnetite has large 65% ( 226Ra) deficits relative to ( 230Th). Calculated partition coefficients for Ba, Th, and U in mineral-groundmass pairs, except Ba in plagioclase, are low (⩽ 0.04). Correlation between ( 226Ra/ 230Th ) activity ratios and rm/BaTh element ratios in the minerals suggests that 226Ra partitions similar to Ba during crystallization. Internal ( 230Th) sbnd ( 238U) isochrons for 1982 summit and East Dome dacites and Goat Rocks and Kalama andesites show that closed Th sbnd U system fractionation occurred 2-6 ka ago. Apparent internal isochrons for Castle Creek basalt (34 ka) and andesite (27 ka) suggest longer magma chamber residence times and mixing of old crystals and young melt. Mineral ( 226Ra) sbnd ( 230Th) disequilibrium on Ba-normalized internal isochron diagrams suggests average magma chamber residence times of 500-3000 years. In addition, radioactive ( 226Ra/ 230Th ) heterogeneity between minerals and groundmass or whole rock is evidence for open-system Ra sbnd Th behavior. This heterogeneity suggests there has been recent, post-crystallization, changes in melt chemical composition that affected 226Ra more than 230Th. Clearly, magma fractionation, residence and transport of crystal-melt before eruption of chemically diverse lavas at Mount St. Helens occurs over geologically short periods.

  18. Simultaneous determination of gross alpha, gross beta and 226Ra in natural water by liquid scintillation counting

    International Nuclear Information System (INIS)

    The determination of gross alpha, gross beta and 226Ra activity in natural waters is useful in a wide range of environmental studies. Furthermore, gross alpha and gross beta parameters are included in international legislation on the quality of drinking water [Council Directive 98/83/EC]. In this work, a low-background liquid scintillation counter (Wallac, Quantulus 1220) was used to simultaneously determine gross alpha, gross beta and 226Ra activity in natural water samples. Sample preparation involved evaporation to remove 222Rn and its short-lived decay daughters. The evaporation process concentrated the sample ten-fold. Afterwards, a sample aliquot of 8 mL was mixed with 12 mL of Ultima Gold AB scintillation cocktail in low-diffusion vials. In this study, a theoretical mathematical model based on secular equilibrium conditions between 226Ra and its short-lived decay daughters is presented. The proposed model makes it possible to determine 226Ra activity from two measurements. These measurements also allow determining gross alpha and gross beta simultaneously. To validate the proposed model, spiked samples with different activity levels for each parameter were analysed. Additionally, to evaluate the model's applicability in natural water, eight natural water samples from different parts of Spain were analysed. The eight natural water samples were also characterised by alpha spectrometry for the naturally occurring isotopes of uranium (234U, 235U and 238U), radium (224Ra and 226Ra), 210Po and 232Th. The results for gross alpha and 226Ra activity were compared with alpha spectrometry characterization, and an acceptable concordance was obtained

  19. 232Th, a rigid rotor

    International Nuclear Information System (INIS)

    We undertake the present work to treat 232Th with a soft rotor formula used recently by C. Bihari et. al for γ-band and modified by J.B. Gupta et. al. It describes energy in terms of moment of inertia and softness parameter

  20. Desorption of 137Cs+ from mosses

    Directory of Open Access Journals (Sweden)

    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.

  1. 226Ra determination in phosphogypsum by alpha-particle spectrometry

    International Nuclear Information System (INIS)

    A radiochemical method for 226Ra determination by alpha-particle spectrometry in environmental samples has been developed in our laboratory. The method has been validated by measurements in samples with known concentrations of this radionuclide and it has been applied in studies related to 226Ra behaviour in phosphogypsum (the main by-product of producing phosphoric acid from phosphate rocks). (author)

  2. Transfer of 137Cs into mother's milk

    International Nuclear Information System (INIS)

    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)

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

    Science.gov (United States)

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

    2013-10-01

    The presence of natural radioactivity and (137)Cs has been investigated in fresh media obtained from South China Sea locations off the coast of peninsular Malaysia. The media include seafood, sea water and sediment. The samples were collected some weeks prior to the devastating 2011 Tōhoku earthquake and associated tsunami, the occurrence of which precipitated the Fukushima incident. All samples showed the presence of naturally occurring (226)Ra, (228)Ra and primordial (40)K, all at typically prevailing levels. The concentrations of natural radioactivity in molluscs were found to be greater than that of other marine life studied herein, the total activity ranging from 337 to 393 Bq kg(-1) dry weight. The total activity in sea water ranged from 15 to 88 Bq l(-1). Sediment samples obtained at deep sea locations more than 20 km offshore further revealed the presence of (137)Cs. The activity of (137)Cs varied from ND to 0.5 Bq kg(-1) dry weight, the activity increasing with offshore distance and depth. The activity concentrations presented herein should be considered useful in assessing the impact of any future radiological contamination to the marine environment. PMID:23584496

  4. Biological availability of (238)U, (234)U and (226)Ra for wild berries and meadow grasses in natural ecosystems of Belarus.

    Science.gov (United States)

    Sokolik, G A; Ovsiannikova, S V; Voinikava, K V; Ivanova, T G; Papenia, M V

    2014-01-01

    This work is devoted to investigation of behavior of (234)U, (238)U and (226)Ra by determining the soil to plant transfer under different natural conditions such as forest or swamped areas and meadow lands with different soil types. The paper summarizes the data on investigation of uranium and radium uptake by wild berries and natural meadow grasses in the typical conditions of Belarus. Parameters characterizing the biological availability of (234)U, (238)U and (226)Ra for bilberry (Vaccinium myrtillus), lingonberry (Vaccinium viti-idaea), blueberry (Vaccinium iliginosum) and cranberry (Vaccinium oxycoccus palustris) as well as for widely occurring mixed meadow vegetation, which belongs to the sedge-grass or grass-sedge associations and forbs, have been established. In the sites under investigation, the deposition levels of (238+239+240)Pu were less than 0.37 kBq m(-2) and (137)Cs deposition ranged between less than 0.37 and 37 kBq m(-2). It was found that activity concentrations of radionuclides in berries varied in the ranges of 0.037-0.11 for (234)U, 0.036-0.10 for (238)U and 0.11-0.43 Bq kg(-1) for (226)Ra, but in the mixed meadow grasses they were 0.32-4.4, 0.24-3.9 and 0.14-6.9 Bq kg(-1) accordingly. The (234)U/(238)U activity ratios were 1.02 ± 0.01 for wild berries, 1.20 ± 0.09 for underground meadow grasses and 1.02 ± 0.02 for proper soils. The concentration ratios (CRs, dry weight basis) of (234)U and (238)U for mixed meadow grasses were 0.036-0.42 and 0.041-0.46 respectively. The correspondent geometric means (GM) were 0.13 and 0.15 with geometric standard deviations (GSD) of 2.4. The CRs of (226)Ra for meadow grasses were 0.031-1.0 with GM 0.20 and GSD 2.6. The CRs of (234)U, (238)U and (226)Ra for wild berries ranged within 0.0018-0.008 (GM is 0.0034, GSD is 1.8), 0.0018-0.008 (GM is 0.0035, GSD is 1.8) and 0.005-0.033 (GM is 0.016, GSD is 2.1) accordingly. The highest CR values of uranium for mixed meadow grasses were found in the

  5. 226Ra in the western Indian Ocean

    Science.gov (United States)

    Chung, Y.

    1987-09-01

    226Ra profiles have been measured in the western Indian Ocean as part of the 1977-1978 Indian Ocean GEOSECS program. These profiles show a general increase in deep and bottom water Ra concentration from the Circumpolar region to the Arabian Sea. A deep Ra maximum which originates in the Arabian Sea and in the Somali basin at about 3000 m depth spreads southward into the Mascarene basin and remains discernible in the Madagascar and Crozet basins. In the western Indian Ocean, the cold Antarctic Bottom Water spreads northward under the possibly southward-flowing deep water, forming a clear benthic front along the Crozet basin across the Southwest Indian Ridge into the Madagascar and Mascarene basins. The Antarctic Bottom Water continues to spread farther north to the Somali basin through the Amirante Passage at 10°S as a western boundary current. The benthic front and other characteristic features in the western Indian Ocean are quite similar to those observed in the western Pacific where the benthic front as a distinctive feature was first described by Craig et al. [15]. Across the Mid-Indian Ridge toward the Ceylon abyssal plain near the triple junction, Ra profiles display a layered structure, reflecting the topographic effect of the mid-ocean ridge system on the mixing and circulation of the deep and bottom waters. Both Ra and Si show a deep maximum north of the Madagascar basin. Linear relationships between these two elements are observed in the deep and bottom water with slopes increasing northward. This suggests a preferential input of Ra over Si from the bottom sediments of the Arabian Sea and also from the flank sediments of the Somali basin.

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

    International Nuclear Information System (INIS)

    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

  7. 226Ra bioavailability of plants at urgeirica uranium mill tailings

    International Nuclear Information System (INIS)

    Large amounts of solid wastes (tailings) resulting from the exploitation and treatment of uranium ore at the Urgeirica mine (north of Portugal) have been accumulated in dams (tailing ponds). To reduce the dispersion of natural radionuclides into the environment some dams were revegetated with eucalyptus (Eucalyptus globolus) and pines (Pinus pinea). Besides, some shrubs (Cytisus s.p.) are growing at some of the dams. The objective of this study is to determine the 226Ra bioavailability from uranium mill tailings through the quantification of the total and available fraction of radium in the solid wastes and to estimate its transfer to the plants growing on the tailing piles. Plants and solid waste samples were randomly collected at dams. Activity concentration of 226Ra in plants (aerial part and roots) and solid wastes were measured by gamma spectrometry. The exchangeable fraction of radium in solid wastes was quantified using one single step extraction with 1 mol dm-3 ammonium acetate (pH=7) or 1 mol dm-3 calcium chloride solutions. The results obtained for the 226Ra uptake by plants show that 226Ra concentration ratios for eucalyptus and pines decrease at low 226Ra concentration in the solid wastes and appear relatively constant at higher radium concentrations. For shrubs, the concentration ratios increase at higher 226Ra solid waste concentrations approaching a saturation value. Percentage values of 16.0±8.3 and 12.9±8.9, for the fraction of radium extracted from the solid wastes, using 1 mol dm-3 ammonium acetate or calcium chloride solutions respectively, were obtained. The 226Ra concentration ratios determined on the basis of exchangeable radium are one order of magnitude higher than those based on total radium. It can be concluded that, within the standard error values, more consistent 226Ra concentration ratios were obtained when calculated on the basis of available radium than when total radium was considered, for all the dams. (author)

  8. Spatial 137Cs distribution in forest soil

    International Nuclear Information System (INIS)

    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)

  9. Late excretion rates of 226Ra and 210Pb following occupational or iatrogenic exposure. I. 226Ra

    International Nuclear Information System (INIS)

    The urinary and fecal excretion rates of 226Ra have been determined for 53 subjects who had been exposed to 226Ra; 25 had been radium dial painters, 16 were iatrogenic (medical) cases and 12 were former radium chemists. The mean coefficient of elimination, CE (fraction of body content excreted annually), was significantly lower for the medical cases than for dial painters. The mean ratio of urinary-to-fecal excretion rates was 3.0 +- 0.7%

  10. 137Cs metabolism in pregnant women

    International Nuclear Information System (INIS)

    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)

  11. Reactive barriers for 137Cs retention.

    Science.gov (United States)

    Krumhansl, J L; Brady, P V; Anderson, H L

    2001-02-01

    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 2.3 x 10(6) 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 desorption 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 clays 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-Ill 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 Cs-doped for 110 days and subjected to an extreme and prolonged rinsing process. All the clays exhibited some capacity for irreversible Cs uptake. However, the residual loading was greatest on K-Mbt (approximately 0.33 wt.% Cs). Thus, this clay would be the optimal material for constructing artifical reactive barriers.

  12. 226Ra i 228Ra in Croatian Rivers

    International Nuclear Information System (INIS)

    Results of 226Ra and 228Ra in Croatian river waters are presented in this paper. The presence of natural radionuclides in the Croatian rivers emphasizes the need for continuous monitoring. 226Ra and 228Ra were chosen as a possible source of human exposure to radioactivity due to their high radio-toxicity. River water samples (50 L) were collected from the Danube, Drava, Sava, Krka and Neretva rivers twice a year from 2002 to 2006. Activity concentrations of 226Ra ranged from 6.54 mBq L-1 to 59.44 mBq L-1 and 228Ra activity concentrations ranged from 2.57 mBq L-1 to 20.76 mBq L-1. The highest values of both 226Ra and 228Ra were measured in the Drava river, and the lowest values in the Sava river. Statistically significant differences were not observed between radium concentrations from two watersheds (the Black Sea and the Adriatic Sea watershed), nor between 226Ra/228Ra ratio in rivers individually. The number of collected samples is insufficient to make statistically significant conclusions. Further investigation is necessary to obtain larger number of samples. However, the data obtained in this study could be the baseline for evaluating possible future changes.(author)

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

    International Nuclear Information System (INIS)

    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

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

    Institute of Scientific and Technical Information of China (English)

    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.

  15. 226Ra and calcium in the human eye

    International Nuclear Information System (INIS)

    The left eye from each of two CHR cases, 01 to 144 (body burden 690 nCi) and 01-017 (body burden 1210 nCi) was analyzed for 226Ra and calcium. The total amounts in the eye were 1.80 pCi of 226Ra and 2.3 mg of Ca in case 01 to 144, and 5.4 pCi of 226Ra and 14.2 mg of calcium in case 01 to 017. For the latter case the eye was dissected and showed the highest concentrations of activity (on a wet basis) in the choroid, 3.8 pCi/g, sclera 3.4 pCi/g and iris 2.9 pCi/g. The radium content of the eye was 2.7 x 10-4 percent to 4.7 x 10-4 percent of the total body content at 50 to 55 yr after first exposure. The 226Ra/Ca ratios in the whole eye were 1/3 to 1/4 those in the whole body, but that for the choroid from the dissected eye was identical to that of the whole body

  16. Determination of {sup 226}Ra, {sup 228}Ra, and {sup 210}Pb in mushroom from a naturally high radioactive region

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, Mychelle M.L.; Custodio, Luis Gustavo; Cheberle, Luan T.V.; Taddei, Maria Helena T., E-mail: mychelle@cnen.gov.br, E-mail: lgcustodio@hotmail.com, E-mail: lt.cheberle@bol.com.br, E-mail: mhtaddei@cnen.gov.br [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas; Maihara, Vera A., E-mail: vmaihara@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (CNEN/IPEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Many studies have shown that mushrooms are organisms which efficiently accumulate radionuclides and can be used as indicators of environmental contamination and ecosystem quality. The Pocos de Caldas plateau, in Minas Gerais, is a region that has elevated natural radioactivity due to the presence of radiological anomalies of volcanic origin. Seventy areas of radioactive anomalies have been identified in this region. From the radiological point of view the determination of {sup 226}Ra, {sup 228}Ra, and {sup 210}Pb is relevant because they are decay products of the natural series of {sup 238}U and {sup 232}Th, mainly responsible for natural radioactive exposures of man. The present paper is part of a broader study conducted in the Pocos de Caldas plateau, in which the concentration activities of {sup 226}Ra, {sup 228}Ra, and {sup 210}Pb in mushroom samples were determined. The mushrooms were collected at different points of the plateau under the influence of radioactive anomalies and away from the influence of anomalies. From statistical studies a correlation between the accumulation of radionuclides in mushrooms and anomalies was established and it was possible to confirm the efficiency that the mushrooms present as environmental contamination indicators. (author)

  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

    Energy Technology Data Exchange (ETDEWEB)

    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. Possibility of rapidly reporting 226Ra activity in 226Ra-222Rn samples with unknown equilibrium factor by γ spectrometer

    Institute of Scientific and Technical Information of China (English)

    SU Qiong; ZHENG Rui; CHEN Yong; CHENG Jian-Ping

    2004-01-01

    This paper reports the observed changes for equilibrium factors between 226Ra and 222Rn with sealing time of the samples. The samples include soil, raw coal, mineral water, cement, rock, etc. Especially the conceptions of "pre-equilibrium time" and "pre-equilibrium factor" have been put forward and methods of measuring and processing data have been given which can be used for rapidly reporting activity of 226Ra in samples with unknown equilibrium factor. It is definitely concluded that, using methods given in the paper, a test report will be completed in 3~7days, instead of one month, after receiving the sample whose activity is not lower than LLD of the spectrometer.

  19. Radon concentration in soil gas and its correlations with pedologies, permeabilities and 226Ra content in the soil of the Metropolitan Region of Belo Horizonte - RMBH, Brazil

    Science.gov (United States)

    Lara, E.; Rocha, Z.; Palmieri, H. E. L.; Santos, T. O.; Rios, F. J.; Oliveira, A. H.

    2015-11-01

    The radon concentration in soil gas is directly dependent on the geological characteristics of the area, such as lithology, pedology and on geochemicals, physicals and mineralogicals parameters of the soil. This paper looks for correlations between radon concentrations in soil gas and its soil permeability, 238U, 232Th and 226Ra contents in the soil groups classified by pedologies of Metropolitan Region of Belo Horizonte (RMBH), Minas Gerais, Brazil. The soil gas radon concentrations were determined by using an AlphaGUARD® monitor at about 150 measurement points. In soil samples of the same measurement points, the concentrations of 226Ra were determined by gamma spectrometry (HPGe), and 238U and 232Th by ICP-MS. The soil permeabilities were determined by using the RADON-JOK® permeameter. The mean concentrations of radon in soil gas ranged from 13.6±3.0 kBq m-3 for Litholic Neosols until 60.6±8.7 kBq m-3 for Perferric Red Latosols. The mean of 226Ra activity concentrations presented variation of 12.4±2.5 Bq kg-1 for Litholic Neosols until 50.3±13 Bq kg-1 for Perferric Red Latosols. Approximately 40% of the soils presented high permeability. The areas of different pedologies were classified by Soil Radon Index (SRI), determined by the soil gas radon concentration and permeability. Approximately 53% of the Perferric Red Latosols measurement site could be classified as "High Risk" (Swedish criteria). The preliminary results may indicate an influence of iron formations present very close to the Perferric Red Latosols in the retention of uranium minerals, and hence an increase in the concentration of radon and radium, whereas the series are in equilibrium in the environment.

  20. Mechanisms of 137Cs migration in coniferous forest soils

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  2. Identification of 137Cs Reference Sites in Southeastern China

    Institute of Scientific and Technical Information of China (English)

    TANG Xiang-Yu; YANG Hao; DU Ming-Yuan; ZHAO Qi-Guo; LI Ren-Ying

    2006-01-01

    The 137Cs vertical distributions in uncultivated and cultivated soils, developed from Quaternary red clay, granite,argillaceous shale, and red sandstone, were studied to develop reliable guidelines for selecting reference sites in southeastern China, which is dominated by strong acidic and/or clay-textured soils, and examine their reliability by comparing them to the reported 137Cs reference inventory data to see whether they agreed with the global distribution pattern. It was observed that a relatively high proportion of 137Cs was concentrated in the surface layers of soils with relatively high clay content. In the paddy soils developed from granite more 137Cs penetrated to depths below the plow layer (about 45.3%),when compared to those from the other three parent materials. The relatively low soil 137Cs inventories on crests excluded using the crest as the 137Cs reference site; instead the paddy field on the hillock plain was selected. Furthermore, within a specific county characterized by great systematic spatial variations of rainfall and topography across the landscape,a significant (P < 0.01) and positive linear relationship (r2 = 0.81) between local 137Cs inventory and corresponding local annual rainfall was observed. Thus, for areas with large variations in rainfall, a single uniform value of local 137Cs reference inventory should be used with caution.

  3. Sediment environmental capacity of 137Cs in Daya Bay

    Institute of Scientific and Technical Information of China (English)

    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.

  4. Efficient, Tightly-Confined Trapping of 226Ra

    CERN Document Server

    Parker, R H; Bailey, K; Greene, J P; Holt, R J; Kalita, M R; Korsch, W; Lu, Z -T; Mueller, P; O'Connor, T P; Singh, J; Sulai, I A; Trimble, W L

    2013-01-01

    We demonstrate a technique for transferring $^{226}$Ra atoms from a 3-dimensional magneto-optical-trap (MOT) into a standing wave optical dipole trap (ODT) in an adjacent chamber. The resulting small trapping volume (120 $\\mu$m in diameter) allows for high control of the electric and magnetic fields applied to the atoms. The atoms are first transferred to a traveling-wave optical dipole trap, which is then translated 46 cm to a science chamber. The atoms are subsequently transferred into an orthogonal standing-wave ODT by application of a 1-dimensional MOT along the traveling-wave axis. For each stage, transfer efficiencies exceeding 60% are demonstrated.

  5. Decay of 226Ra by 14C emission

    International Nuclear Information System (INIS)

    Since the pioneering experiment by Rose and Jones in 1984 demonstrating 14C decay of 223Ra, spontaneous emission of clusters heavier than α particles but lighter than fission products could be found in several cases to be a rare decay mode of heavy nuclei. This new kind of radioactivity has branching ratios relative to α decay well below 10-9. For energetical reasons the emitted fragments are even-even and the daughter nucleus lies close to the doubly magic 208Pb. Polycarbonate track-recording foils which are sensitive to energetic carbon nuclei but not to α particles are very well suited detectors for the study of 14C emission radioactivity. The tracks are made visible under a microscope by etching techniques. Observation of spontaneous emission of 14C from 226Ra claimed by Hourani et al. and Barwick et al. has been confirmed. Since thick sources of 226Ra were used in these experiments the experimental definitions of decay energy and mass were not very accurate. The experiment described in the thesis measured for the first time charge and energy of the emitted fragments by using thin 226Ra sources and polycarbonate track-recording films. The decay mode could thus be identified unambiguously. The track detector was calibrated with tandem-accelerated 14C and 16O ions and tested by observing the now well established 14C emission from 223Ra; for this decay mode a branching ratio of (5,0 ± 1,0).10-10 relative to α decay was found in agreement with values from the literature. In the case of 226Ra the result for 14C/α ratio is (2,3 ± 1,2).10-11. The order of magnitude of the branching ratios can be reproduced by theoretical models. Estimates of partial half-lifes of Ra and other heavy isotopes for rare decay modes are discussed in the theoretical section of the thesis. 100 refs., 3 tabs., 30 figs. (Author)

  6. Distribution of 226Ra in the Arctic Ocean and the Bering Sea and its hydrologic implications

    Institute of Scientific and Technical Information of China (English)

    邢娜; 陈敏; 黄奕普; 蔡平河; 邱雨生

    2003-01-01

    Radium-226 (226Ra) activities were measured in the surface water samples collected from the Arctic Ocean and the Bering Sea during the First Chinese National Arctic Research Expedition. The results showed that 226Ra concentrations in the surface water ranged from 0.28 to 1.56 Bq/m3 with an average of 0.76 Bq/m3 in the Arctic Ocean, and from 0.25 to 1.26 Bq/m3 with an average of 0.71 Bq/m3 in the Bering Sea. The values were obviously lower than those from open oceans in middle and low latitudes, indicating that the study area may be partly influenced by sea ice meltwater. In the Bering Sea, 226Ra in the surface water decreased northward, probably as a result of the exchange between the 226Ra-deficientsea ice meltwater and the 226Ra-rich Pacific water. In the Arctic Ocean, 226Ra in the surface water increased northward and eastward. This spatial distributionof 226Ra reflected the variation of the 226Ra-enriched river component in the water mass of the Arctic Ocean. The vertical profiles of 226Ra in the Canadian Basin showed a concentration maximum at 200 m, which could be attributed to the inputs of the Pacific water or/and the bottom shelf water with high 226Ra concentration. This conclusion was consistent with the results from 2H, 18O tracers.

  7. Ionizable (Thia)calix[4]crowns as Highly Selective 226Ra2+ Ionophores

    NARCIS (Netherlands)

    Leeuwen, van Fijs W.B.; Beijleveld, Hans; Miermans, Cornelis J.H.; Huskens, Jurriaan; Verboom, Willem; Reinhoudt, David N.

    2005-01-01

    The 226Ra2+ selectivity of the ionizable (thia)calix[4]crowns 1-4 was determined in the presence of a large excess of the most common alkali and alkaline earth cations. Selective 226Ra2+ (2.9 × 10-8 M) extraction occurs even at extremely high Mn+/226Ra2+ ratios of 3.5 × 107 [Mn+ = Na+, K+, Rb+, Cs+,

  8. 137Cs contaminated waste disposal in cement factory: Environmental problems

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  10. Estimation of erosion rate using natural isotop 137Cs

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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

  14. Daily intake of /sup 234,235,238/U, /sup 228,230,232/Th and /sup 226,228/Ra by New York City residents

    International Nuclear Information System (INIS)

    The daily intake of long-lived alpha-emitting members of the U, Th and Ac series by New York City residents has been estimated from measurements of diet, water and air samples. The total daily intakes from inhalation, food and water consumption in mBq are 18 (234U), 0.7 (235U), 16 (238U), 6 (230Th), 4 (232Th) and 52 (226Ra). From this, we infer that the total daily intakes of 228Th and 228Ra are 4 and 35 mBq, respectively

  15. Leachable 226Ra in Philippine phosphogypsum and its implication in groundwater contamination in Isabel, Leyte Philippines

    International Nuclear Information System (INIS)

    Phosphogypsum (PG), the major waste material in phosphate fertilizer processing, has been known to contain enhanced levels of naturally-occurring radionuclides especially 226Ra. The lack of radioactivity data regarding Philippine phosphogypsum and its environmental behavior in the Philippine setting has brought concern on possible contamination of groundwater beneath the phosphogypsum ponds in Isabel, Leyte, Philippines. The radioactivity of Philippine phosphogypsum was determined and the leaching of 226Ra from phosphogypsum and through local soil was quantified. Level of 226Ra in groundwater samples in Isabel, Leyte, Philippines was also quantified to address the primary concern. It was found that the 226Ra activity in Philippine phosphogypsum is distributed in a wide range from 91.5 to 935 Bq/kg. As much as 5% of 226Ra can be leached from Philippine PG with deionized water. In vitro soil leach experiments suggest that the soil in the phosphate fertilizer plant area would be able to deter the intrusion of 226Ra into the water table. Compared to reported values of natural groundwater levels of 226Ra, the concentration of this radionuclide in Isabel, Leyte groundwater suggest that there is no 226Ra intrusion brought about by the presence of phosphogypsum ponds in the area. (Authors)

  16. A beta-alpha coincidence counting system for measurement of trace quantities of 238U and 232Th in aqueous samples at the Sudbury Neutrino Observatory.

    Science.gov (United States)

    Dawson, M.; Doucas, G.; Fergani, H.; Jelley, N. A.; Majerus, S.; O'Keeffe, H. M.; Peeters, S. J. M.; Perry, C.

    2016-08-01

    The Sudbury Neutrino Observatory experiment was built to measure the total flux of 8B solar neutrinos via the neutral current disintegration deuterium nuclei. This process can be mimiced by daughter isotopes of 232Th and 238U which can photodisintegrate the deuterium nucleus. Measurement of the concentration of such radioisotopes in the heavy water was critical to the success of the experiment. A radium assay technique using Hydrous Titanium Oxide coated filters was developed for this purpose and it was used in conjunction with a delayed beta-alpha coincidence counting system. The design, calibration and operation of this counting system are described in this paper. The counting efficiency for 232Th (224Ra) and 238U (226Ra) were measured to be 50 ± 5% and 62 ± 7%

  17. Normal dietary levels of 226Ra, 228Ra, 210Pb, and 210Po for man

    International Nuclear Information System (INIS)

    A review of the literature and the results of some recent measurements were presented on the levels in man's diet of the naturally-occurring radionuclides 226Ra, 228Ra, 210Pb, and 210Po. The mean intakes for standard U.S. diets for these nuclides are tabulated. Intakes in other countries are similar to those in the U.S., but in localized populations the 226Ra intake may be 8 or more pCi/day. The contents of 226Ra in diets chosen by individuals ranged from 0.4 to 7 pCi/day. The few data on 228Ra show intake of this nuclide to be about 80% that of 226Ra, except in monazite areas where intakes of up to 160 pCi/day 228Ra are reported, which may be 50 to 100 times that of 226Ra. Drinking water contributes less than 5% of the daily intake, except in special areas

  18. Distribution of 226Ra Radionuclide in Upwelling Event Off Ulsan, Gampo and Pohang, Korea

    Directory of Open Access Journals (Sweden)

    Muslim

    2009-07-01

    Full Text Available Upwelling is an important event in the sea for it makes the area to become more productive. The objective of this study is to determine the distribution of radium-226 as radiotoxic in the upwelling area in the summer season. Measurements of the horizontal and vertical activities of 226Ra in the Ulsan, Gampo and Pohang waters were conducted in June, August 1999 and June 2000 when the upwelling event was expected to occur. Water temperature, salinity and dissolved oxygen (DO were also measured concurrently. The thermocline layer or the layer where the temperature decreased drastically occurred at a depth between 30 m to 100 m for samples dated June 1999 and 30 m to more than 100 m for samples dated August 1999 and June 2000. The salinity decreased with depth but the DO concentration increased in this layer. The condition affected the vertical distribution of 226Ra in the study area, where the 226Ra activities showed to be relatively homogeneous vertically in each station. This indicates that the upwelling which occurred in the study area was capable to distribute the 226Ra activities from the bottom to the surface. Thus, the 226Ra distribution at that time did not increase with depth, opposite to what usually occurs in the ocean at normal condition. The 226Ra activities also did not decrease after elapsed time of one year, in fact, it increased. However, horizontally the 226Ra activities decreased with increasing distance from the coastal zone. Based on these results, it can be concluded that the upwelling event in the Ulsan, Gampo and Pohang was effective for increasing the 226Ra activities and was capable to create homogeneous 226Ra activities from the bottom to the surface in the water column, and the source of 226Ra was likely to originate from outside area (i.e. coastal zone and bottom area.

  19. Evaluation of the activity concentration of 226Ra, 228Ra and 210Pb in sediments from Antarctica in the Admiralty bay region

    International Nuclear Information System (INIS)

    The natural radionuclides from radioactive series of 238U, 235U and 232Th have been applied as tracers in environmental studies for understanding the dynamics that occur in both marine and terrestrial environment, as for example, in research of oceanic processes and management of the coastal region. In the marine environment, these radionuclides can be used to estimate biogeochemical fluxes of marine particles and nutrients that occur in the water column as well as in the sediment. Several research works applied the distribution and the respective disequilibrium degree of natural radionuclides in the environment, including geochronological models for obtaining historical information on samples of certain sediment profile. In this study we performed a radiochemical characterization of the distribution of 226Ra, 228Ra and 210Pb from a sedimentary column called 1B (248 cm long) collected in the Admiralty Bay, Antarctic Peninsula region. The methodology used included the acid leaching of sediment samples followed by the radiochemical sequential separation of 226Ra and 228Ra by co-precipitation with Ba(Ra)SO4 and 210Pb by co-precipitation with PbCrO4. All measurements were carried out by counting of gross alpha and gross beta measures in a low background gas flow proportional detector. The activity concentrations of 226Ra and 210Pb were used to estimate the unsupported 210Pb activities present in sediment profile 1 B. Based on unsupported 210Pb data and the application of the CIC model (Constant Initial Concentration), it was possible to determine the sedimentation rate of 0.59 ± 0.05 cm /year. (author)

  20. High sensitivity measurement of 224Ra and 226Ra in water with an improved hydrous titanium oxide technique at the Sudbury Neutrino Observatory

    CERN Document Server

    Aharmim, B; Dai, X; Doucas, G; Farine, J; Fergani, H; Ford, R; Hahn, R L; Hallman, E D; Jelley, N A; Lange, R; Majerus, S; Mifflin, C; Noble, A J; O'Keeffe, H M; Rodriguez-Jimenez, R; Sinclair, D; Yeh, M

    2008-01-01

    The existing hydrous titanium oxide (HTiO) technique for the measurement of 224Ra and 226Ra in the water at the Sudbury Neutrino Observatory (SNO) has been changed to make it faster and less sensitive to trace impurities in the HTiO eluate. Using HTiO-loaded filters followed by cation exchange adsorption and HTiO co-precipitation, Ra isotopes from 200-450 tonnes of heavy water can be extracted and concentrated into a single sample of a few millilitres with a total chemical efficiency of 50%. Combined with beta-alpha coincidence counting, this method is capable of measuring 2.0x10^3 uBq/kg of 224Ra and 3.7x10^3 uBq/kg of 226Ra from the 232Th and 238U decay chains, respectively, for a 275 tonne D2O assay, which are equivalent to 5x10^16 g Th/g and 3x10^16 g U/g in heavy water.

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    International Nuclear Information System (INIS)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Uptake and transfer factors of 137Cs by mushrooms

    International Nuclear Information System (INIS)

    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.)

  6. The behaviour of 137Cs in the aquatic environment

    International Nuclear Information System (INIS)

    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)

  7. Declassification of 137Cs liquid wastes by reverse osmosis

    International Nuclear Information System (INIS)

    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

  8. /sup 226/Ra in the western Indian Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Y.

    1987-09-01

    /sup 226/Ra profiles have been measured in the western Indian Ocean as part of the 1977-78 Indian Ocean GEOSECS program. These profiles show a general increase in deep and bottom water Ra concentration from the Circumpolar region to the Arabian Sea. A deep Ra maximum which originates in the Arabian Sea and in the Somali basin at about 3000 m depth spreads southward into the Mascarene basin and remains discernible in the Madagascar and Crozet basins. In the western Indian Ocean, the cold Antarctic Bottom Water spreads northward under the possibly southward-flowing deep water, forming a clear benthic front along the Crozet basin across the Southwest Indian Ridge into the Madagascar and Mascarene basins. The Antarctic Bottom Water continues to spread farther north to the Somali basin through the Amirante Passage at 10/sup 0/S as a western boundary current. The benthic front and other characteristic features in the western Indian Ocean are quite similar to those observed in the western Pacific where the benthic front as a distinctive feature was first described by Craig et al. Across the Mid-Indian Ridge toward the Ceylon abyssal plain near the triple junction, Ra profiles display a layered structure, reflecting the topographic effect of the mid-ocean ridge system on the mixing and circulation of the deep and bottom waters. Both Ra and Si show a deep maximum north of the Madagascar Basin. Linear relationships between these two elements are observed in the deep and bottom water with slopes increasing northward. This suggests a preferential input of Ra over Si from the bottom sediments of the Arabian Sea and also from the flank sediments of the Somali basin.

  9. 134Cs: 137Cs and 106Ru: 137Cs ratios in intertidal sediments from the Cumbria and Lancashire coasts England

    Science.gov (United States)

    Stanners, D. A.; Aston, S. R.

    1981-10-01

    The distributions of 134Cs, 137Cs and 106Ru in intertidal surface sediments from the coasts of Cumbria and Lancashire, north-west England, are reported. The ratios of 134Cs: 137Cs and 106Ru: 137Cs activities have been used together with the isotopic composition of the Windscale radioactive effluents to examine the contamination history of sediments. Distinct differences between the activities and time of contamination of muds, silts and sands are found, and the apparent lag times of transport of radioactive wastes to different sediment localities are estimated. The relatively high activities in fine sediments reflect recent discharges indicating a rapid response to discharge, while the sands contain low levels of older contamination. Apparent lag times of up to 6 years are estimated for the study area; the transport to the south is generally more rapid than to the north. These results have consequences for the operation and interpretation of radiological monitoring in coastal areas.

  10. Activity ratios of (234)U/(238)U and (226)Ra/(228)Ra for transport mechanisms of elevated uranium in alluvial aquifers of groundwater in south-western (SW) Punjab, India.

    Science.gov (United States)

    Kumar, A; Karpe, R K; Rout, S; Gautam, Y P; Mishra, M K; Ravi, P M; Tripathi, R M

    2016-01-01

    The concentrations of total dissolved uranium (U), its isotopic composition ((234)U, (235)U, (238)U) and two long lived Ra isotopes ((226)Ra and (228)Ra) in alluvial aquifers of groundwater were determined to investigate the groundwater flow pattern in the south-western (SW) Punjab, India. Particular attention was given to the spatial variability of activity ratios (ARs) of (234)U/(238)U and (226)Ra/(228)Ra to predict the possible sources and supply process of U into the water from the solid phase. The measured groundwater (234)U/(238)U ARs were ∼1 or >1 in the shallow zone (depth  30 m) with relatively low U concentration. The simultaneous elevated U concentration and (234)U/(238)U ARs in waters were possibly due to differences in imprints of rock-water interactions under hydrologic conditions. However, (234)U/(238)U ARs geochemistry of the two isotopes. On the other hand, (226)Ra/(228)Ra ARs in groundwaters varied widely and observed about 50-300 times higher than (238)U/(232)Th ARs in granitic rocks or soils. Such elevation in ARs might be attributed to different dissolution properties of their parents during water-rock interactions or lattice damage during decay or local enrichments of uranium in the aquifers. PMID:26555366

  11. A Study on Sorption of (226)Ra on Different Clay Matrices.

    Science.gov (United States)

    Alhajji, E; Al-Masri, M S; Khalily, H; Naoum, B E; Khalil, H S; Nashawati, A

    2016-08-01

    The sorption of radium 226 ((226)Ra) on different clay materials (bentonite, illite and a mixture of bentonite-illite) was studied. Clay materials are used in the construction of disposal pits for technically enhanced naturally occurring radioactive materials (TENORM) wastes (i.e., contaminated soil and sludge) generated by the oil and gas industry operations. Experimental conditions (pH, clay materials quantity, and activity concentrations of (226)Ra) were changed in order to determine the optimal state for adsorption of (226)Ra. The results showed that the concentration of adsorbed (226)Ra on clay materials increased with time to reach an equilibrium state after approximately 5 h. More than 95 % of the radium was adsorbed. The mixture of bentonite-illite (1/9) exhibited the greatest adsorption of radium under all experimental conditions. PMID:27329110

  12. Assessment of 226Ra age-dependent dose from water intake

    International Nuclear Information System (INIS)

    The radioactivity in canal and ground waters collected in a 2-year long observation from the vicinity of the Rare Earth Research and Development Center (RRDC), Phathumthani Province, Thailand, was measured in order to determine the concentration of 226Ra and to estimate the age-dependent effective dose to humans due to consumption. 226Ra activities in both canal and ground waters were well below the WHO guidance level for drinking water quality of 1 Bq L-1. The highest 226Ra effective doses per year were found for infants and teens. However, the observed levels of calculated 226Ra effective doses for all age groups in both canal and ground waters show satisfactory low values (less than 15 μSv yr-1). These values are acceptable in accordance with the WHO recommended reference dose level of 100 μSv yr-1 from water intake of 2 L day-1

  13. Determination of 226Ra in water samples using sorbent MnO2-PAN

    International Nuclear Information System (INIS)

    The aim of our study was to determine 226Ra using alpha spectrometer in water samples. The method of separation based on the principle of extraction chromatography was applied by the separation of the natural radionuclides 226Ra from samples of natural mineral, spring, natural medicinal and drinking water from the Slovak Republic, the Czech Republic and Slovenia. The proposed method uses a new selective commercial sorbent MnO2-PAN. The advantage of separating of 226Ra on a given sorbent is the speed of separation, simple sample preparation before the analysis and mainly the high efficiency of the proposed method. The sample was adjusted by coprecipitation with Ba2+ for alpha spectrometric measurements of 226Ra. The radiochemical yield was monitored by radionuclide tracer 133Ba.

  14. 137Cs in the fungal compartment of Swedish forest soils

    International Nuclear Information System (INIS)

    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%

  15. 226Ra bioavailability to plants at the Urgeiriça uranium mill tailings site.

    Science.gov (United States)

    Madruga, M J; Brogueira, A; Alberto, G; Cardoso, F

    2001-01-01

    Large amounts of solid wastes (tailings) resulting from the exploitation and treatment of uranium ore at the Urgeiriça mine (north of Portugal) have been accumulated in dams (tailing ponds). To reduce the dispersion of natural radionuclides into the environment, some dams were revegetated with eucalyptus (Eucalyptus globolus) and pines (Pinus pinea). Besides these plants, some shrubs (Cytisus spp.) are growing in some of the dams. The objective of this study is to determine the 226Ra bioavailability from uranium mill tailings by quantifying the total and available fraction of radium in the tailings and to estimate its transfer to plants growing on the tailing piles. Plant and tailing samples were randomly collected and the activity concentration of 226Ra in plants (aerial part and roots) and tailings was measured by gamma-spectrometry. The exchangeable fraction of radium in tailings was quantified using one single step extraction with 1 mol dm-3 ammonium acetate (pH = 7) or 1 mol dm-3 calcium chloride solutions. The results obtained for 226Ra uptake by plants show that 226Ra concentration ratios for eucalyptus and pines decrease at low 226Ra concentrations in the tailings and appear relatively constant at higher radium concentrations. For shrubs, the concentration ratios increase at higher 226Ra solid waste concentrations approaching a saturation value. Percentage values of 16.0 +/- 8.3 and 12.9 +/- 8.9, for the fraction of radium extracted from the tailings, using 1 mol dm-3 ammonium acetate or calcium chloride solutions, respectively, were obtained. The 226Ra concentration ratios determined on the basis of exchangeable radium are one order of magnitude higher than those based on total radium. It can be concluded that, at a 95% confidence level, more consistent 226Ra concentration ratios were obtained when calculated on the basis of available radium than when total radium was considered, for all the dams. PMID:11379070

  16. 226Ra evidence for the ecosystem shift over the past 40 years in the North Pacific Subtropical Gyre

    Institute of Scientific and Technical Information of China (English)

    YANG JunHong; CHEN Min; QIU YuSheng; LI YanPing; MA Qiang; L(U) E; ZHANG Run; HUANG YiPu

    2007-01-01

    Surface seawater was collected for 226Ra measurement in the North Pacific Subtropical Gyre from July to October, 1999 and October to December, 2003. Combined with the historical data reported for this sea area, a declined trend of surface 226Ra concentrations was observed since 1960s, indicating the ecosystem shift in response to global warming. On one side, the enhanced stratification of the upper water column resulting from global warming reduced the 226Ra input from the depth, on the other, the temporal increase of biological production resulting from the climate-related ecosystem structure change strengthened the 226Ra removal from the surface ocean. Both the physical and biological processes resulted in the decrease of surface 226Ra concentrations in the North Pacific Subtropical Gyre. The temporal trend of surface 226Ra concentrations was consistent with the trends of chlorophyll a, silicate, phosphate and primary production previously reported. This study provided 226Ra evidence for the ecosystem shift under global change.

  17. Evaluation of the activity concentration of {sup 226}Ra, {sup 228}Ra and {sup 210}Pb in sediments from Antarctica in the Admiralty bay region; Avaliacao da concentracao de atividade de Ra-226, Ra-228 e Pb-210 em sedimentos provenientes da Antartica na regiao da baia do Almirantado

    Energy Technology Data Exchange (ETDEWEB)

    Mora, Tamires de Araujo

    2015-07-01

    The natural radionuclides from radioactive series of {sup 238}U, {sup 235}U and {sup 232}Th have been applied as tracers in environmental studies for understanding the dynamics that occur in both marine and terrestrial environment, as for example, in research of oceanic processes and management of the coastal region. In the marine environment, these radionuclides can be used to estimate biogeochemical fluxes of marine particles and nutrients that occur in the water column as well as in the sediment. Several research works applied the distribution and the respective disequilibrium degree of natural radionuclides in the environment, including geochronological models for obtaining historical information on samples of certain sediment profile. In this study we performed a radiochemical characterization of the distribution of {sup 226}Ra, {sup 228}Ra and {sup 210}Pb from a sedimentary column called 1B (248 cm long) collected in the Admiralty Bay, Antarctic Peninsula region. The methodology used included the acid leaching of sediment samples followed by the radiochemical sequential separation of {sup 226}Ra and {sup 228}Ra by co-precipitation with Ba(Ra)SO{sub 4} and {sup 210}Pb by co-precipitation with PbCrO{sub 4}. All measurements were carried out by counting of gross alpha and gross beta measures in a low background gas flow proportional detector. The activity concentrations of {sup 226}Ra and {sup 210}Pb were used to estimate the unsupported {sup 210}Pb activities present in sediment profile 1 B. Based on unsupported {sup 210}Pb data and the application of the CIC model (Constant Initial Concentration), it was possible to determine the sedimentation rate of 0.59 ± 0.05 cm /year. (author)

  18. Distribution and retention in bone of 226Ra and comparison with the ICRP 20 model

    International Nuclear Information System (INIS)

    Analyses are presented of the ratios of 226Ra to calcium in over 650 samples of compact and cancellous bone from 66 female and 26 male subjects who had died from less than one to 60 years after first exposure to radium. The 226Ra/Ca ratios were normalized to the terminal 226Ra skeletal content. The 226Ra/Ca ratios for vertebrae were essentialy identical to those for other cancellous bone for a given subject. Comparisons of the data with predictions of the ICRP model of alkaline earth metabolism show that for female cancellous bone the normalized 226Ra/Ca ratios tended to be greater than predicted, while those for female cortical bone (femoral and tibial shaft) tended to be less. The data for males were fitted better by the model. A modification of the model to reduce the amount of radium deposited in soft tissue fitted the data better in some respects. A straight line linear least squares fit to the data appeared to fit as well as, or better than, the models. A radiation effect was suggested in that the normalized 226Ra/Ca ratio for vertebrae relative to the ratio expected increased with skeletal absorbed dose for vertebra. However, no such effect was apparent for compact bone or for the cancellous bone as a whole

  19. Determination of {sup 226}Ra Isotope in the Leachate around Phosphogypsum Stack Using Ethylenediaminetetraacetic Acid (EDTA)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Geun Ho; Kim, Yong Jae; Chang, Byung Uck [University of Science and Tecknology, Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2011-12-15

    Ba is the most useful element to get the Ba(Ra)SO{sub 4} precipitate. However, when the high concentrations of ions such as sulfate, calcium are existed in the leachate of phosphogypsum stack, it is difficult to get the Ba(Ra)SO{sub 4} precipitate. Since this reason, the developed method for the Ba coprecipitate using EDTA was performed to determine the {sup 226}Ra concentration in the high sulfate sample. The average concentration of {sup 226}Ra in a leachate of phosphogypsum using this method was 0.102 Bq{center_dot}kg{sup -1} and the minimal detectable activity is 3.4 mBq{center_dot}kg{sup -1}. The mBq{center_dot}kg{sup -1} method was 0.102 Bq{center_dot}kg{sup -1} and the minimal detectable activity is 3.4 mBq{center_dot}kg{sup -1}. The {sup 226}Ra stock solution and the CRM (Certified Reference Material) were analyzed to verify this method. In analyzed {sup 226}Ra stock solution, bias with added concentration was approximately 1% and the correlation curve between {sup 226}Ra concentration in simulated standard sample and measured {sup 226}Ra concentration showed good agreement with a correlation coefficient (R{sup 2}) of 0.99. In analyzed CRM, maximum bias with reference value was 5.8% (k=1) and the analytical results were in good agreement with the reference value.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    Fukuyama, Taijiro; Fujiwara, Hideshi

    2008-11-01

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

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

    International Nuclear Information System (INIS)

    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)

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

    Directory of Open Access Journals (Sweden)

    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

  4. 运河水系底质泥中~(226)Ra、~(232)Th、~(40)K 和~(137)Cs 含量的测定

    Institute of Scientific and Technical Information of China (English)

    程祺钧; 虎银秀; 巫柱中; 刘瑞源; 朱福敏

    1989-01-01

    通过对河水、底质泥、悬浮物以及生物样品中放射性核素含量的分析测量,可以了解水系放射性的主要来源以及放射性物质在环境介质中的迁移规律。1984年我们在长江水系放射性水平调查中,分别于1月份(枯水期)和7、8月份(丰水期)对运河水系8个站位的底质泥取样分析,用 Ge(Li)γ谱仪测定了底质泥中~(226)Ra (~(238)U)、~(232)Th、~(40)K 和~(137)Cs 含量,其中~(238)U 含量是按~(238)U-~(226)Ra 达放射性平衡推算的。

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  7. 137Cs and 210Pb distribution in Manila Bay sediment

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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

  9. Study on accumulation of 137Cs in aquatic organisms

    Institute of Scientific and Technical Information of China (English)

    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.

  10. Evaluation of the variation of 226Ra and Ca uptake by plant and their relationship

    International Nuclear Information System (INIS)

    The transfer of 226Ra from soil to plant has been studied for wild trees and grasses to identify the site- and the plant-specific variability in relation to the transfer of Ca. Twelve species of plants and soils were sampled from three different forests and one flood plain in Okayama, Japan. The concentrations of 226Ra in plant varied about 60 times by species and sites, while those in soil were not different significantly among sites. The transfer factors defined as the concentration ratio of 226Ra between plant and soil were linearly correlated with that of Ca, implying that the ability of Ca uptake by plant reflect the ability of 226Ra uptake. The Ca concentrations in plant showed species-specific value and varied 22 times. The range of transfer factor (plant/soil) for Ca increased by the variability of the Ca concentration in soil among sites. These results suggest that the wide variability of 226Ra concentration in plant can be ascribed to both the differences in plant and soil factors of Ca concentration. (author)

  11. Sorption of (226)Ra from oil effluents onto synthetic cation exchangers.

    Science.gov (United States)

    Al Attar, Lina; Safia, Bassam

    2013-07-30

    Increasing environmental awareness is being urged for the safe disposal of (226)Ra-contaminated production water generated in the oil industry. Birnessite, antimony silicate and their cationic derivatives were studied for the take-up of (226)Ra using the batch-type method under experimentally determined parameters, viz. contact time, solution-solid ratio and (226)Ra concentration. Data was expressed in terms of distribution coefficients. Sorption experiments were performed in different concentrations of nitric acid in order to speculate the mechanism of (226)Ra uptake. Variation in the magnitude of sorption efficiency of the materials in the presence of the major components of waste streams, i.e. Na(+), K(+) and Ca(2+), revealed that K(+) was the greatest competitor and Na(+) the least. The application of the materials to sorb (226)Ra from actual oil co-production water samples, collected from Der Ezzor and Al Fourat petroleum companies (DEZPC and AFPC), was interpreted in terms of the exchange properties of the materials and water characterisation. Of the parameters studied, the selectivity of materials was shown to be greatly dependent on the pH of wastewater to be treated. PMID:23623032

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)

  14. Systematic study of heavy cluster emission from {210-226}^Ra isotopes

    CERN Document Server

    Santhosh, K P; Priyanka, B; Unnikrishnan, M S

    2012-01-01

    The half lives for various clusters lying in the cold reaction valleys of {210-226}^Ra isotopes are computed using our Coulomb and proximity potential model (CPPM). The computed half lives of 4^He and 14^C clusters from {210-226}^Ra isotopes are in good agreement with experimental data. Half lives are also computed using the Universal formula for cluster decay (UNIV) of Poenaru et al., and are found to be in agreement with CPPM values. Our study reveals the role of doubly magic 208^Pb daughter in cluster decay process. Geiger - Nuttall plots for all clusters up to 62^Fe are studied and are found to be linear with different slopes and intercepts. {12,14}^C emission from 220^Ra; 14^C emission from {222,224}^Ra; 14^C and 20^O emission from 226^Ra are found to be most favourable for measurement and this observation will serve as a guide to the future experiments.

  15. The concentrations of 226 Ra and 210 Pb in food cultivated in Pocos de Caldas

    International Nuclear Information System (INIS)

    The aim of this study is to determine the average concentrations of 226 Ra and 210 Pb in vegetables widely cultivated in the region, mainly potatoes, carrots, beans and corn which are the main agricultural products (considering production and human consume) in the region and estimation of the average transfer factors soil-foodstuff for both radionuclides. The total 226 Ra and 210 Pb content in the soil was determined by gamma spectrometry. The exchangeable fraction was obtained by ammonium acetate solution extraction. The 226 Ra was analysed by the classical radon emanation procedure and the 210 Pb was isolated by a radiochemical procedure and determined by radiometry of its daughter 210 Bi beta emissions with a Geiger Mueller counter. (author)

  16. 238U, 226Ra and 210Pb in some vent waters of the Galapagos spreading center

    International Nuclear Information System (INIS)

    The concentrations of 226Ra, 238U and 210Pb have been measured in waters from the Mussel Bed and the Rose Garden thermal fields at the Galapagos spreading center over a temperature range of approx.2.5--16 0C. The 226Ra-T plots yield slopes of 0.112 and 0.036 dpm/kg 0C for the Mussel Bed and the Rose Garden respectively yielding a global hydrothermal 226Ra flux less than 5% of that required to sustain the oceanic inventory. 238U concentration in waters 0C is the same as that in ambient sea water whereas water hotter than approx.9 0C shows a decreasing trend with temperature to zero 238U at approx.29 0C. 210Pb concentration in Mussel Bed increases with temperature, and extrapolated to approx.350 0C yields a 210Pb concentration considerably less than that expected from 222Rn decay and basalt alteration

  17. 226Ra and 228Ra in the Seawater of the Western Yellow Sea

    Institute of Scientific and Technical Information of China (English)

    MEN Wu; WEI Hao; LIU Guangshan

    2006-01-01

    Radium isotopes 226Ra and 228Ra in seawater of the western Yellow Sea were measured by using the Mn-fiber adsorption- HPGe γ spectrum method.The distribution features of the two isotopes have been studied.The activities of 226Ra and 228Ra are 2.72-5.57 Bq m-3 and 7.51-34.3 Bq m-3, respectively.The activities of 226Ra and 228Ra from surface to bottom for each depth profile station are comparable within the experimental error, but the mean activities decrease with distance from the shore.From the distribution data of 228Ra, the horizontal eddy diffusion coefficient was estimated at 29 × 106 cm2 s 1.

  18. Bioaccumulation of 226Ra by plants growing in fresh water ecosystem around the uranium industry at Jaduguda, India

    International Nuclear Information System (INIS)

    A field study has been conducted to evaluate the 226Ra bioaccumulation among aquatic plants growing in the stream/river adjoining the uranium mining and ore-processing complex at Jaduguda, India. Two types of plant group have been investigated namely free floating algal species submerged into water and plants rooted in stream and riverbed. The highest 226Ra activity concentration (9850 Bq kg-1) was found in filamentous algae growing in the residual water of tailings pond. The concentration ratios of 226Ra in filamentous algae (activity concentration of 226Ra in plant Bq kg-1 fresh weight/activity concentration of 226Ra in water Bq l-1) widely varied i.e. from 1.1 x 103 to 8.6 x 104. Other aquatic plants were also showing wide variability in the 226Ra activity concentration. The ln-transformed filamentous algae 226Ra activity concentration was significantly correlated with that of ln-transformed water concentration (r = 0.89, p 226Ra in stream/riverbed rooted plants and the substrate. For this group, correlation between 226Ra activity concentration and Mn, Fe, Cu concentration in plants were statistically significant.

  19. Life-span studies in 226Ra-injected animals: Effect of low doses, effect of a decorporative treatment

    International Nuclear Information System (INIS)

    A life-span radiation effects study was performed in mice injected with several doses of 226Ra. The study included 788 male C57Bl mice. For the removal of the 226Ra, half the mice were treated daily with a diet 5% of which was sodium-alginate. The experiment revealed that mice that received the lowest dose of 226Ra lived significantly longer than controls, and, despite appreciable skeletal removal of 226Ra as a result of decorporative treatment, no biological benefit was observed in treated animals. 19 refs., 4 figs., 3 tabs

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)

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

    Science.gov (United States)

    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.

  3. 226Ra lovels in surface and drinking waters in selected localities in Slovakia

    International Nuclear Information System (INIS)

    Samples were taken in the West Slovakia region from local water mains, wells and artesian wells. 226Ra was determined from samples immediately following separation from water by coprecipitation with lead sulphate and barium sulphate. From each sample two parallel separations were made with non-active carriers and one with an internal 226Ra standard. The volume activities of the samples were found to be relatively low, 73% within the range of 0 to 10 mBq/l. Activity in samples taken from artesian wells was 30 to 35 mBq/l. (M.D.)

  4. Quantification of {sup 235} U and {sup 226} Ra in soil samples by means of Gamma spectroscopy; Cuantificacion de {sup 235} U y {sup 226} Ra en muestras de suelo por medio de espectrometria gamma

    Energy Technology Data Exchange (ETDEWEB)

    Quintero P, E.; Rojas M, V.P.; Montes M, F.R.; Gaso P, M.I.; Cervantes N, M.L. [Gerencia de Innovacion Tecnologica, A.P. 18-1027, C.P. 11801 Mexico D.F. (Mexico)

    2000-07-01

    In this work it is presented the Gamma Spectroscopy method which is realized in the Environmental Radiological Surveillance Laboratory using the option of deconvolution of a commercial software for the quantification of {sup 235} U and {sup 226} Ra; also is presented the method for the {sup 226} Ra correction activity. (Author)

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

    International Nuclear Information System (INIS)

    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

  6. A new two-phase media method for 226Ra activity measurement in water

    International Nuclear Information System (INIS)

    A new two-phase media method was developed for determination of 226Ra activity in water. The method was calibrated by applying 7 standard 226Ra waters with known activities. The method detects alphas in two media; 80 ml of water in a glass bottle with air or a non-polar liquid such as olive oil on top of the water. Alpha particles from 226Ra, 222Rn and progeny were detected by two polycarbonate track detectors (PCTDs) which were mounted on a holder inserted in the bottle so that one PCTD is placed in water and the other in air or in the non-polar liquid. The bottles were hermetically sealed and kept for 40 or 48 d. The PCTDs in the bottles shaken every other day enhanced the sensitivity of the measurements. The Calibration Factors for the standard 226Ra waters, air and olive oil above water are, respectively, (7.85 ± 0.25) x 10-3, (7.94 ± 0.13) x 10-3 and 3.02 x 10-2 tracks.cm-2 kBq-1 h-1 m3. (authors)

  7. Assessment of {sup 226}Ra age-dependent dose from water intake

    Energy Technology Data Exchange (ETDEWEB)

    Porntepkasemsan, Boonsom [Research and Development Group, Thailand Institute of Nuclear Technology, Vibhavadi Rangsit Road, Bangkok 10900 (Thailand)], E-mail: boonsom@oaep.go.th; Srisuksawad, Kanitha [Research and Development Group, Thailand Institute of Nuclear Technology, Vibhavadi Rangsit Road, Bangkok 10900 (Thailand)

    2008-11-15

    The radioactivity in canal and ground waters collected in a 2-year long observation from the vicinity of the Rare Earth Research and Development Center (RRDC), Phathumthani Province, Thailand, was measured in order to determine the concentration of {sup 226}Ra and to estimate the age-dependent effective dose to humans due to consumption. {sup 226}Ra activities in both canal and ground waters were well below the WHO guidance level for drinking water quality of 1 Bq L{sup -1}. The highest {sup 226}Ra effective doses per year were found for infants and teens. However, the observed levels of calculated {sup 226}Ra effective doses for all age groups in both canal and ground waters show satisfactory low values (less than 15 {mu}Sv yr{sup -1}). These values are acceptable in accordance with the WHO recommended reference dose level of 100 {mu}Sv yr{sup -1} from water intake of 2 L day{sup -1}.

  8. Determination of (226)Ra in produced water by liquid scintillation counting.

    Science.gov (United States)

    Godoy, José Marcus; Vianna, Lucas M; Godoy, Maria Luiza D P; Almeida, Ana Cristina

    2016-08-01

    It is proposed a method for the determination of (226)Ra in offshore platform liquid effluent samples (produced water). The method is based on a two-phase liquid scintillation counting system and allows for the direct and simple determination of (226)Ra content. Samples with high barium content may also have high (226)Ra concentration. Therefore, the sample volume is based on the barium concentration and ranges from 10 mL to 100 mL. Our new method was tested using multiple real samples and was compared with the BaSO4 precipitation method. The results based on the LSC were 30% higher than the precipitation method, which is attributed to the self-absorption of alpha particles in the BaSO4 precipitate. The determination of both (226)Ra and (228)Ra in the liquid effluent of offshore oil platforms is mandatory in Brazil. Thus, a second method of accurately assessing (228)Ra content remains necessary. PMID:27116402

  9. Intake of {sup 226}Ra, {sup 210}Pb and {sup 210}Po with food in Poland

    Energy Technology Data Exchange (ETDEWEB)

    Pietrzak-Flis, Z.; Chrzanowski, E.; Dembinska, S. [Department of Radiation Hygiene, Central Laboratory for Radiological Protection, Warsaw (Poland)

    1997-09-06

    Intake with food and water of {sup 226}Ra, {sup 210}Pb and {sup 210}Po was determined for an adult population in regions of central, northern and northeastern Poland. The content of radionuclides was determined in the daily diet and, in the central region, also in foodstuffs and drinking water. The annual intake with foodstuffs was estimated on the basis of their average annual consumption. The {sup 226}Ra intake in northeastern Poland was approximately 17% higher than the overall average, correlating well with the higher concentration of this radionuclide in the soil. The {sup 210}Po/{sup 210}Pb ratio was close to unity in the continental regions, whereas at the Baltic Sea coast it was approximately 1.5. The latter value can be ascribed to a larger consumption of fish for which the {sup 210}Po/{sup 210}Pb ratio was found to be approximately 10. In central Poland the largest intake of {sup 226}Ra was with flour and vegetables (contribution approx. 60%), the largest intake of {sup 210}Pb was with flour and meat (approx. 50%) and the largest intake of {sup 210}Po was with fish (approx. 34%). From the intake and dose coefficient, annual effective doses were calculated. The dose from {sup 210}Pb and {sup 210}Po was approx. 54 {mu}Sv year{sup -1}, and the dose from {sup 226}Ra was approx. 4 {mu}Sv year{sup -1}.

  10. Selective 226Ra2+ Ionophores Provided by Self-Assembly of Guanosine and Isoguanosine Derivatives

    NARCIS (Netherlands)

    Leeuwen, van Fijs W.B.; Verboom, Willem; Shi, Xiaodong; Davis, Jeffery T.; Reinhoudt, David N.

    2004-01-01

    The self-assembled guanosine (G 1)-based hexadecamers and isoguanosine (isoG 2)-based decamers are excellent 226Ra2+ selective ionophores even in the presence of excess alkali (Na+, K+, Rb+, and Cs+) and alkaline earth (Mg2+, Ca2+, Sr2+, and Ba2+) cations over the pH range 3-11. G 1 requires additio

  11. Intake of 226Ra, 210Pb and 210Po with food in Poland

    International Nuclear Information System (INIS)

    Intake with food and water of 226Ra, 210Pb and 210Po was determined for an adult population in regions of central, northern and northeastern Poland. The content of radionuclides was determined in the daily diet and, in the central region, also in foodstuffs and drinking water. The annual intake with foodstuffs was estimated on the basis of their average annual consumption. The 226Ra intake in northeastern Poland was approximately 17% higher than the overall average, correlating well with the higher concentration of this radionuclide in the soil. The 210Po/210Pb ratio was close to unity in the continental regions, whereas at the Baltic Sea coast it was approximately 1.5. The latter value can be ascribed to a larger consumption of fish for which the 210Po/210Pb ratio was found to be approximately 10. In central Poland the largest intake of 226Ra was with flour and vegetables (contribution approx. 60%), the largest intake of 210Pb was with flour and meat (approx. 50%) and the largest intake of 210Po was with fish (approx. 34%). From the intake and dose coefficient, annual effective doses were calculated. The dose from 210Pb and 210Po was approx. 54 μSv year-1, and the dose from 226Ra was approx. 4 μSv year-1

  12. 226Ra, 210Pb and 210Po in food and in population in Poland

    International Nuclear Information System (INIS)

    Content of 226Ra, 210Pb and 210Po was determined in daily diet, foodstuffs and drinking water in various regions in Poland. The annual intake of the radionuclides with foodstuffs for an adult population was estimated on the basis of the average annual consumption. The 226Ra intake was in all the places similar; variations between the samples from a locality were bigger than the differences between various localities. Slightly higher 226Ra intake was observed in Suwalki, evidently being associated with the higher concentration of this radionuclide in the soil. The average 210Po/210Pb ratios was below and close to unity in the daily diet of continental regions, whereas at the Baltic Sea coast it was about 1.5. The latter value can be ascribed to a larger consumption of fish for which the 210Po/210Pb ratio was close to 10. The calculated body burden for an adult man was 1.6 Bq for 226Ra, 6.8 Bq for210Pb and 6.8 Bq for 210Po. (author)

  13. {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

    Energy Technology Data Exchange (ETDEWEB)

    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

  14. Behavior of 226Ra in the aquatic environment of the uranium mine region of Pocos de Caldas, MG, Brazil

    International Nuclear Information System (INIS)

    A sampling and analytical program for 238U, 226Ra and 210Pb was started, at first, in the uranium mine region, at Pocos de Caldas, MG, Brazil. Afterwards, the interaction was studied between 226Ra and local river sediments and waters. Peliminary studies were also done on the mobility of 226Ra retained on solid matter or soil, induced by local waters. Above normal concentrations of 238U, 226Ra and 210Pb were found in local waters, sediments and plants collected on the imediate vicinity of the mine. 226Ra distribution coefficients are on the order of 103 for the different samples assayed. It was concluded that, in the future, 226Ra discharged into liquid environment should be only temporarily retained by sediments. Its transport by surface waters should be predominantly in the soluble form. 226Ra should become the critical radionuclide in terms of internal radiation dose on the local population, due to its ingestion with water. 226Ra retained on solid supports is mobilized by local waters and its solubilization is dependent on the volume of water passed through. (M.A.)

  15. Volume activity 226Ra mine waters of Ostrava-Karvina coal mines

    International Nuclear Information System (INIS)

    The State Office for Nuclear Safety, Regional Center Kamenna administers, within the framework of supervision, an inspection on workplaces of mines and discharge radionuclides into the environment from mines of Ostrava-Karvina coal mines. Join-stock company OKD exploit coal in next mines Paskov, Darkov, Lazy and CSA. Join -stock company CMD exploit coal in mine CSM. In 2002 DIAMO, state enterprise took over a part of Ostrava-Karvina coal mines and its division ODRA pump mine waters on Water-pumping shaft Jeremenko, Water- pumping shaft Zofie and close Mine Barbora. A water samples were take on main outflow mine water of mine. The presentation summarizes results from monitoring mine waters from 1999 to 2004 years. Volume activity 226Ra mine waters of Mine Lazy-locality Dukla and Water-pumping shaft Zofie are higher then clearance level from Regulation No.307/2002 Coll. On Radiation Protection. They are comparable with mine waters of uranium mines. Volume activity 226Ra surface waters under outflow perform, without stream Petrvaldska struzka under outflow Water-pumping shaft Zofie, guidance level for contamination surface waters from Government regulation No.61/2003 Coll. Volume activity 226Ra surface waters under outflow coal mines are higher then volume in surface waters under uranium mines, because mine waters from uranium mines are decontaminate on decontamination stations. Considering that volume activities 226Ra surface water of Orlovska struzka stream are under guidance level for contamination surface waters from Government regulation No.61/2003 Coll.. don't urgency arrangement to decontamination mine waters. Mass activity 226Ra in bed sediment under outflow Mine Lazy-locality Dukla are comparable with exemption level from Regulation No.307 /2002 Coll. On Radiation Protection. (authors)

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

    Science.gov (United States)

    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

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

    International Nuclear Information System (INIS)

    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)

  18. Correction methodology for the spectral interfering {gamma}-rays overlapping to the analytical peaks used in the analysis of {sup 232}Th

    Energy Technology Data Exchange (ETDEWEB)

    Yuecel, H., E-mail: haluk.yucel@ankara.edu.t [Institute of Nuclear Sciences, Ankara University (Australia), Besevler Yerleskesi, Tandogan, 06100 Ankara (Turkey); Koese, E. [Institute of Nuclear Sciences, Ankara University (Australia), Besevler Yerleskesi, Tandogan, 06100 Ankara (Turkey); Esen, A.N. [Energy Institute, Istanbul Technical University (ITU), Maslak, 34469 Istanbul (Turkey); Bor, D. [Institute of Nuclear Sciences, Ankara University (Australia), Besevler Yerleskesi, Tandogan, 06100 Ankara (Turkey)

    2011-06-15

    In the {gamma}-ray spectrometric analysis of the radionuclides, a correction factor is generally required for the spectral interfering {gamma}-rays in determining the net areas of the analytical peaks because some interfering {gamma}-rays often might contribute to the analytical peaks of interest. In present study, a correction methodology for the spectral interfering {gamma}-rays (CSI) is described. In particular, in the analysis of {sup 232}Th contained in samples, the interfering {gamma}-rays due to {sup 226}Ra, {sup 235}U, {sup 238}U and their decay products often overlap to the peaks of interest from {sup 232}Th decay products, and vise versa. For the validation of the proposed CSI method, several certified reference materials (CRM) containing U and Th were measured by using a 76.5% efficient n-type Ge detector. The required correction factors were quantified for spectral interference, self-absorption and true coincidence summing (TCS) effects for the relevant {gamma}-rays. The measured results indicate that if one ignores the contributions of the interfering {gamma}-rays to the analytical peaks at 583.2 keV of {sup 208}Tl and 727.3 keV of {sup 212}Bi, this leads to a significantly systematic influence on the resulted activities of {sup 232}Th. The correction factors required for spectral interference and TCS effects are estimated to be {approx}13.6% and {approx}15.4% for 583.2 keV peak. For the 727.3 keV peak, the correction factor is estimated to be {approx}15% for spectral interference, and {approx}5% for the TCS effects at the presently used detection geometry. On the other hand, the measured results also indicate that ignoring the contribution of the interfering {gamma}-rays to the areas of the analytical peaks at 860.6 keV of {sup 208}Tl, 338.3 and 911.2 keV of {sup 228}Ac does not lead to any significant systematic influence on the {sup 232}Th analysis. Because these factors are remained generally less than {approx}5%, i.e., within overall uncertainty

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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. 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.

    Science.gov (United States)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Preparation of 232Th Target by Molecule Plating

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>For the cross section measurement of the 232Th(α, 2n)234U reaction, thorium targets plated on the aluminium foil with 2 and 8 μm thickness are required. It was demanded that the mass thickness of the

  4. Benchmarking ~(232)Th Evaluations With KBR and Thor Experiments

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The n+232Th evaluations from CENDL-3.1, ENDF/B-Ⅶ.0, JENDL-3.3 and JENDL-4.0 were tested with KBR series and THOR benchmark from ICSBEP Handbook. THOR is Plutonium-Metal-Fast (PMF) criticality benchmark reflected with metal thorium.

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

    International Nuclear Information System (INIS)

    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)

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    International Nuclear Information System (INIS)

    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.

  8. 137Cs radiation burden on children from a highly contaminated area of Belarus

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Determination of 226Ra Concentration in the Drinking Water and Internal Dose estimation From Several Locations in Java and Sumatra

    International Nuclear Information System (INIS)

    Random samples or drinking water have been collected from 51 locations in Java (27 locations) and Sumatra (24 locations). lndonesia. The samples were counted for 17 hours and analyzed for 226Ra (609 keV and 352KeV) using gamma spectrometry with H P-Ge detector. The data were evaluated by the statistical method with 68% confidence level. The 226Ra concentrations in drinking water were within a range of undetectable to ( 177.6 + 3.1) mBq/l and the average concentration was (34.8 + 8.2) mBq/l. The data of 226Ra concentration in Sumatra area was about 10 times higher than 226Ra concentration in Java area, except 226Ra concentration at the hot spring water area. The maximum permissible concentration (4000 mBq/l). These data were comparatively lower than 226Ra concentration in drinking water generally observed in other countries (USA, India, Brazil and Japan). The annual internal dose of 226Ra for the public was also estimated

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

    International Nuclear Information System (INIS)

    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

    International Nuclear Information System (INIS)

    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)

    International Nuclear Information System (INIS)

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

    International Nuclear Information System (INIS)

    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

  18. Leachability of 226Ra from spiked soil as a function of time

    International Nuclear Information System (INIS)

    The bioavailability of 226Ra for plant uptake may be dependent on its solubility from the soil components. Solubility of radium from soil may change with time due to chemical and physical binding. A laboratory study was designed to provide data on the water leachable fraction of 226Ra from spiked soil as a function of time. A decreasing trend in the percent leachable fraction was observed over time. The data was modeled by non-linear regression to be a decreasing exponential to a constant value. This information may be helpful in providing an understanding of a similar trend observed in plant uptake studies. The value for the available amount of radium determined in this investigation may help to provide a more meaningful measurement of concentration ratios in plants. 22 references, 3 figures, 5 tables

  19. Vegetation composition and 226Ra uptake by native plant species at a uranium mill tailings impoundment in South China

    International Nuclear Information System (INIS)

    A field investigation was conducted for the vegetation composition and 226Ra uptake by native plant species at a uranium mill tailings impoundment in South China. 80 species belonging to 67 genera in 32 families were recorded in the sampling sites. The Poaceae and Asteraceae were the dominant families colonizing the impoundment. The number of the plant species and vegetation community composition in the sampling sites seemed most closely related to the activities of 226Ra and the pH value of the uranium tailings. The plant species in the sampling sites with relatively low activities of 226Ra and relatively high pH value formed a relatively stable vegetation community. The plant species in the sampling sites with medium activities of 226Ra and medium pH value formed the transitional vegetation community. The plant species in the sampling sites with relatively high activities of 226Ra and relatively low pH value formed a simple unstable vegetation community that was similar to that on the unused grassland. The activities of 226Ra and transfer factors (TFs) varied greatly with the plant species. The high activities of 226Ra and TFs were found in the leaves of Pteris multifida (150.6 Bq/g of AW; 9.131), Pteridium aquilinum (122.2 Bq/g of AW; 7.409), and Dryopteris scottii (105.7 Bq/g of AW; 6.408). They satisfied the criteria for a hyperaccumulator for 226Ra. They may be the candidates for phytoremediation of 226Ra in the uranium mill tailings impoundment areas and the contaminated soils around. - Highlights: • Vegetation composition of native plant species at an impoundment was analyzed. • 226Ra uptake by native plant species at the impoundment was investigated. • Poaceae and Asteraceae were the dominated families colonizing this impoundment. • The plant species and composition were related to activities of 226Ra and pH. • Three plant species were found to be hyperaccumulators for 226Ra

  20. Reflection Asymmetric Relativistic Mean Field Approach and Its Application to the Octupole Deformed Nucleus 226Ra

    Institute of Scientific and Technical Information of China (English)

    GENG Li-Sheng; MENG Jie; Toki Hiroshi

    2007-01-01

    A reflection asymmetric relativistic mean field (RAS-RMF) approach is developed by expanding the equations of motion for both the nucleons and the mesons on the eigenfunctions of the two-centre harmonic-oscillator potential.The efficiency and reliability of the RAS-RMF approach are demonstrated in its application to the well-known octupole deformed nucleus 226Ra and the available data, including the binding energy and the deformation parameters, are well reproduced.

  1. 238U, 226Ra and 210Pb in some vent waters of the Galapagos Spreading Center

    Science.gov (United States)

    Krishnaswami, S.; Turekian, K. K.

    1982-08-01

    The concentrations of 226Ra, 238U and 210Pb have been measured in waters from the Mussel Bed and the Rose Garden thermal fields at the Galapagos spreading center over a temperature range of ˜2.5-16°C. The 226Ra-T plots yield slopes of 0.112 and 0.036 dpm/kg°C for the Mussel Bed and the Rose Garden respectively yielding a global hydrothermal 226Ra flux less than 5% of that required to sustain the oceanic inventory. 238U concentration in waters <9°C is the same as that in ambient sea water whereas water hotter than ˜9°C shows a decreasing trend with temperature to zero 238U at ˜29°C. 210Pb concentration in Mussel Bed increases with temperature, and extrapolated to ˜350°C yields a 210Pb concentration considerably less than that expected from 222Rn decay and basalt alteration.

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

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

    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.)

  4. 137Cs vertical distribution at the deep basins of the North and Central Aegean Sea, Greece

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  6. 137Cs in Finnish wild berries, mushrooms and game meat in 2000-2005

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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)

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

    Directory of Open Access Journals (Sweden)

    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

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

    International Nuclear Information System (INIS)

    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)

  12. Using 137Cs Tracer Technique to Evaluate Erosion and Deposition of Black Soil in Northeast China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Soil and water losses through erosion have been serious in the black soil region of Northeast China. Therefore, a sloping cultivated land in Songnen Plain was selected as a case study to: 1) determine the 137Cs reference inventory in the study area; 2) calculate erosion and deposition rates of black soil on different slope locations; 3) conduct a sensitivity analysis of some model parameters; and 4) compare overall outputs using four different models. Three transects were set in the field with five slope locations for each transect, including summit, shoulder-slope, back-slope, foot-slope, and toe-slope. Field measurements and model simulation were used to estimate a bomb-derived 137Cs reference inventory in the study area.Soil erosion and deposition rates were estimated using four 137Cs models and percentage of 137Cs loss/gain. The 137Cs reference value in the study area was 2 232.8 Bq m-2 with 137Cs showing a clear topographic pattern, decreasing from the summit to shoulder-slope, then increasing again at the foot-slope and reaching a maximum at the toe-slope. Predicted soil redistribution rates for different slope locations varied. Among models, the Yang Model (YANG-M) overestimated erosion loss but underestimated deposition. However, the standard mass balance model (MBM1) gave predictions similar to a mass balance model incorporating soil movement by tillage (MBM2). Sensitivity analysis of the proportion factor γand distribution pattern of 137Cs in the surface layer demonstrated the impact of 137Cs enrichment on calculation of the soil erosion rate. Factors influencing the redistribution of fallout 137Cs in landscape should be fully considered as calculating soil redistribution rate using 137Cs technique.

  13. 137Cs vertical migration in a deciduous forest soil following the Fukushima Dai-ichi Nuclear Power Plant accident

    International Nuclear Information System (INIS)

    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

  14. 226Ra contamination of soil and foliage as a function of distance downwind from uranium mill tailings

    International Nuclear Information System (INIS)

    This study concerned 226Ra contamination of soils and foliage as a function of distance downwind from a uranium mill tailings pile. In soils the radium contamination was primarily associated with particle sizes 226Ra contamination in Artemisia tridentata. Internal contamination appeared to be a larger contributor to total contamination at distances less than or equal to 0.16 km downwind from the tailings pile. At distances > 0.16 km, external contamination became a larger contributor to the total 226Ra contamination. In most soil samples 226Ra concentrations approached background levels at a distance of 1.1 km from the tailings pile. Total vegetation contamination approached background at 6.6 km. This study suggested that a combination of root uptake and foliar absorption were responsible for internal contamination and further studies were suggested. 19 references, 5 figures, 2 tables

  15. 利用 HPGe γ谱仪快速测量226 Ra%Rapid Measurement of 226 Ra Using HPGe Gamma Spectrometer

    Institute of Scientific and Technical Information of China (English)

    张轶名; 於国兵; 杜勤; 闻德运; 顾先宝; 潘灵婧

    2014-01-01

    HPGeγ谱分析中,一般通过测量222 Rn的子体来确定样品中226 Ra的含量,这种方法需要对样品密封数周后测量,无法实现样品中226 Ra含量的快速测量。文章分析了样品γ谱中186 keV全能峰的计数来源,对使用186 keV全能峰计算出的226 Ra的含量结果进行修正,得到较好的实验结果,实现了用186 keV全能峰快速测量样品中Ra的含量。%In general , the content of 226 Ra in a sample is deduced from results of 222 Rn progeny in HPGeγspectral analysis .Because the sample should be sealed for several weeks before the measurement , we can not get the results quickly through this method .The paper analyzes the source of the counts of the full -en-ergy peak in 186 keV in the full-energy peak , and modifies the result of 226 Ra content calculated by using the full-energy peak in 186 keV.The study gets good experiment results and realizes the rapid measurement of Ra in samples using the full -energy peak in 186 keV.

  16. 137Cs applicability to soil erosion assessment: theoretical and empirical model

    International Nuclear Information System (INIS)

    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

  17. 137Cs and 40K partitioning in the system soil-plant under different ecological conditions

    International Nuclear Information System (INIS)

    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

  18. Modeling 137CS dispersion from a radiological dispersion device

    International Nuclear Information System (INIS)

    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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.``

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

    International Nuclear Information System (INIS)

    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.''

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

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

    2012-04-01

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

  11. Atmospheric deposition of {sup 137}Cs between 1994 and 2002 at Cienfuegos, Cuba

    Energy Technology Data Exchange (ETDEWEB)

    Alonso-Hernandez, C.M. [Centro de Estudios Ambientales de Cienfuegos, AP 5. Ciudad Nuclear, Cienfuegos (Cuba)]. E-mail: carlos@ceac.perla.inf.cu; Cartas-Aguila, H. [Centro de Estudios Ambientales de Cienfuegos, AP 5. Ciudad Nuclear, Cienfuegos (Cuba); Diaz-Asencio, M. [Centro de Estudios Ambientales de Cienfuegos, AP 5. Ciudad Nuclear, Cienfuegos (Cuba); Munoz-Caravaca, A. [Centro de Estudios Ambientales de Cienfuegos, AP 5. Ciudad Nuclear, Cienfuegos (Cuba); Martin-Perez, J. [Centro de Estudios Ambientales de Cienfuegos, AP 5. Ciudad Nuclear, Cienfuegos (Cuba); Sibello-Hernandez, R. [Centro de Estudios Ambientales de Cienfuegos, AP 5. Ciudad Nuclear, Cienfuegos (Cuba)

    2006-07-01

    Levels of {sup 137}Cs in total atmospheric deposition have been measured in the Cienfuegos region (Cuba) between 1994 and 2002. Samples were collected every three months, evaporated to dryness to obtain residual samples, and measured by gamma spectrometry. The {sup 137}Cs mean concentration in total deposition was 0.24 Bq m{sup -2} and data ranged between <0.05 and 0.62 Bq m{sup -2}. Precipitation rates and raintime have proved to be the most important factors controlling the concentration and depositional flux of {sup 137}Cs in the atmosphere over Cienfuegos, showing a high correlation coefficient (R = 0.93)

  12. Migration of {sup 226} Ra, {sup 228} Ra, {sup 210} Pb, U and Th from phosphogypsum

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Nivaldo Carlos da; Cipriani, Moacir; Taddei, Maria Helena T. [Comissao Nacional de Energia Nuclear (CNEN), Pocos de Caldas, MG (Brazil). Laboratorio; Fernandes, Elisabete A. de Nadai [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)

    2002-07-01

    The physico-chemical availability of radioactive elements ({sup 210} Pb, {sup 226} Ra, {sup 228} Ra, Th and U) in Brazilian phosphogypsum was investigated in a large scale leaching experiment carried out in lysimeters, using phosphogypsum samples (approximately 1.2 tons) from two phosphoric acid industries. Lysimeters were built using cylindrical concrete containers with 0.9 m inner diameter and 2 m depth. The bottom of the lysimeter was filled with a 10 cm layer of gravel covered with geomembrane sheet. Under this layer a pipe was designed to drain the percolated water. Three lysimeters were filled with phosphogypsum from each industry and a mixture of both. As percolated water comes exclusively from the rain, sample was collected daily when available. Samples were then pooled weekly, carefully prepared and submitted to radiochemical analysis. Radiochemical characterization of phosphogypsum and percolated water was performed by radiochemical separation followed by gross alpha and beta counting ({sup 226} Ra, {sup 228} Ra and {sup 210} Pb) and UV-Vis spectrophotometry with Arsenazo III (U and Th). This experiment was carried out from 12/01/1999 to 01/22/2001, with a precipitation of 2,732 mm. It was observed that approximately 40% (534 L) of the rain fall percolated through the lysimeter 1. The analysis of 22 samples of percolated water from lysimeter 1 showed mean radionuclides activities of 70{+-}30 mBqL{sup -1}, 70{+-}50 mBqL{sup -1}, 100{+-}60 mBqL{sup -1} and 110{+-}55 mBqL{sup -1} for U, {sup 226} Ra, {sup 228} Ra and {sup 210} Pb, respectively. Thorium activities were below detection limit. (author)

  13. Radiation-Induced Neoplasms in Beagles after Administrations of 90Sr and 226Ra

    International Nuclear Information System (INIS)

    The comparative carcinogenic efficiency of two bone-seeking radionuclides is under study in a colony of several hundred beagles. The toxicity of internally deposited alpha emitters (226Ra and its daughters) and of beta irradiation (90Sr) at comparable dosage rates indicates marked differences in site of appearance and mode of action in litters studied up to 7 years of age. Radiation carcinogenesis in beagles exposed to 90Sr daily from midgestation to adulthood (1.5 yr) is at present confined to dogs fed 4 μCi 90Sr/d or higher. The 20 cases constitute a spectrum of myeloproliferative disorders characterized by terminal anaemias, and ranging from myeloid metaplasia to granulocytic leukaemia. Continuous high-level 90Sr irradiation to bone and marrow from early life onward causes a thickened hypocellular bone ('pachyostosis'), some instances of myelofibrosis, and persistent mild leukopenia on which the final spectrum of terminal disoideis is superimposed. In contrast, up to 100 μCl 226Ra given intravenously (8 equally spaced injections at 14 to 18 months of age) to young adults is not a potent marrow cell carcinogen. The higher LET, shorter-range alpha particles are efficient in inducing bone cancers (14 cases) and skeletal lesions similar to those documented in watch-dial luminizers exposed to 226Ra in the early 1900's. The incidence of haematopoietic and skeletal neoplasms observed is dose-rate related, and the morphologic characteristics have several analogues in human cancer. The use of identically treated litters rather than individuals affords additional opportunity to study possible familial factors in the distribution of the neoplasms. Pathogenic evaluation at this juncture strongly indicates that continued bone and marrow irradiation in early life is more likely to induce haematopoietic neoplasms than is skeletal irradiation starting in young adulthood, which induces osseous neoplasms. (author)

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

    International Nuclear Information System (INIS)

    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

  15. Modeling 226Ra behaviour in a Spanish estuary affected by the phosphate industry

    International Nuclear Information System (INIS)

    The behaviour of 226Ra in a system like this estuary is complex since radionuclides are affected by tidal actions and interactions with sediments through adsorption/desorption reactions and erosion/deposition processes. A numerical 2D depth-averaged model of the estuary has been developed, including processes mentioned above. It has been applied to reproduce experimental data measured after a release from the industrial complex in the Odiel River and after an accidental release in the Tinto River from the gypsum piles. The model has also been applied to simulate the self-cleaning process observed in the estuary after the direct releases from the fertilizer complex were stopped

  16. Determination of 226Ra and 224Ra in drinking waters by liquid scintillation counting

    International Nuclear Information System (INIS)

    A method for the determination of Ra-isotopes in water samples has been developed. Ra is coprecipitated with Ba as sulphate. The precipitate is then dissolved with EDTA and counted with a liquid scintillation system after mixing with a scintillation cocktail. The study of the temporal evolution of the separated activity gives the isotopic composition of the sample, i.e. the 224Ra and 226Ra contribution to the total activity. The method has been applied to some Spanish drinking waters. (author)

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

    International Nuclear Information System (INIS)

    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

  18. Temporal changes in the distribution of /sup 137/Cs in alluvial soils at Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    Nyhan, J.W.; Hakonson, T.E.; Miera, F.R. Jr.; Bostick, K.V.

    1978-05-01

    The alluvial soils of three liquid-effluent receiving areas at Los Alamos were sampled to determine /sup 137/Cs temporal distributional relationships. Soil radionuclide concentrations were determined as a function of soil depth and distance from the waste outfall, and discussed relative to runoff transport of /sup 137/Cs-contaminated alluvium. The inventories of soil /sup 137/Cs in various segments of each effluent-receiving area were calculated for two sampling periods and compared with amounts of /sup 137/Cs added to the canyons in the liquid wastes. The distribution patterns of soil cesium were compared with the waste-use history of the three study areas and the hydrologic characteristics of the canyons.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

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

    Science.gov (United States)

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

    2016-05-01

    Age-dependent accumulation of (137)Cs in the muscles and bodies of the pike Esox lucius (aged two to seven years) inhabiting a section of the Yenisei River polluted with artificial radionuclides has been studied. The content of (137)Cs in muscles varied from 0.5 to 7.0 Bq/kg of fresh weight. The maximum content of the radionuclide has been found in juveniles. The content of (137)Cs in pike muscles and body decreased considerably with age. The high content of (137)Cs in the muscles of juveniles is probably a consequence of their higher intensity of feeding as compared to older individuals, which is due to the intense growth of juveniles. PMID:27411826

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

    International Nuclear Information System (INIS)

    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)

  3. 137CS-determination in game meat from some hunting areas in lower Austria

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Science.gov (United States)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  14. 137Cs and 90Sr aerosol-carriers origination when welding radioactively contaminated metal structures

    International Nuclear Information System (INIS)

    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.

  15. [90Sr and 137Cs in higher aquatic plants of the Chernobyl nuclear plant exlusion zone

    Science.gov (United States)

    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.

  16. 137Cs: A Widely Used and Validated Medium Term Soil Tracer

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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.

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

    International Nuclear Information System (INIS)

    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)

  19. Self-cleaning in an estuarine area formerly affected by 226Ra anthropogenic enhancements. Numerical simulations

    International Nuclear Information System (INIS)

    A numerical model of the Odiel-Tinto estuary (Spain) has been developed to study the self-cleaning process that was evidenced from 226Ra measurements in water and sediments collected in the period 1999-2002, after direct releases from a fertilizer complex ceased (in 1998). The hydrodynamic model is first calibrated, and standard tidal analysis is carried out to calculate tidal constants required by the dispersion code to determine instantaneous water currents and elevations over the estuary. In this way, long-term simulations may be carried out. The dispersion code includes advective/diffusive transport of radionuclides plus exchanges with bottom sediments described through a kinetic approach. The dispersion model is first tested by comparing computed and measured 226Ra concentrations over the estuary resulting after releases in the Odiel and Tinto rivers. Next, it is applied to simulate the self-cleaning process of the estuary. The time evolution of radium concentrations in bed sediments is in generally good agreement with observations. The computed sediment halving time of the estuary is 510 days, which also is in good agreement with that estimated from measurements

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

    International Nuclear Information System (INIS)

    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.

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2013-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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).

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)

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

    Science.gov (United States)

    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

  10. Surface water mixing estimated from {sup 228}Ra and {sup 226}Ra in the northwestern North Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, Hajime [Mutsu Institute for Oceanography, Japan Agency for Marine-Earth Science and Technology, 690 Aza-kitasekine Oaza-sekine, Mutsu, Aomori 035-0022 (Japan)], E-mail: kawakami@jamstec.go.jp; Kusakabe, Masashi [Department of Ocean Research, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushimacho, Yokosuka 237-0061 (Japan)], E-mail: masashi@nirs.go.jp

    2008-08-15

    We investigated the horizontal distributions of {sup 228}Ra and {sup 226}Ra in surface waters of the northwestern North Pacific Ocean and Okhotsk Sea. Ratios of {sup 228}Ra/{sup 226}Ra were relatively large in the Tsugaru Current (0.6-0.8) and Okhotsk Sea (0.4-0.5), and small in the Western Subarctic Gyre (<0.2) and the Oyashio (0.25-0.3). {sup 228}Ra/{sup 226}Ra ratios in western Subarctic Water (SAW) rose slightly upon mixing with Okhotsk Water (OKW), before becoming the Oyashio Water (OYW). Also, ratios in the OYW increased during mixing with Tsugaru Current Water (TCW). Estimating from {sup 228}Ra/{sup 226}Ra ratios and {sup 226}Ra activities with a simple two-end members-mixing model, we assumed that approximately 23% of the OYW originated from the OKW and the coastal region off northern Honshu (Japan) was strongly influenced by the TCW. From a diagram of {sup 228}Ra activities against salinity, we could roughly divide surface seawater in the study area into the five water masses, which were SAW, OYW, OKW, TCW, and Subtropical Water (STW)

  11. Field analyses of 238U and 226Ra in two uranium mill tailings piles from Niger using portable HPGe detector

    International Nuclear Information System (INIS)

    The radioactivities of 238U and 226Ra in mill tailings from the U mines of COMINAK and SOMAÏR in Niger were measured and quantified using a portable High-Purity Germanium (HPGe) detector. The 238U and 226Ra activities were measured under field conditions on drilling cores with 600s measurements and without any sample preparation. Field results were compared with those obtained by Inductive Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) and emanometry techniques. This comparison indicates that gamma-ray absorption by such geological samples does not cause significant deviations. This work shows the feasibility of using portable HPGe detector in the field as a preliminary method to observe variations of radionuclides concentration with the aim of identifying samples of interest. The HPGe is particularly useful for samples with strong secular disequilibrium such as mill tailings. - Highlights: • A portable HPGe was used in the field to quantify 238U and 226Ra in mill tailings. • 238U and 226Ra quantification was performed on samples with strong radioactive disequilibrium. • HPGe measurements are compared with results obtained on the same samples by ICP-AES and emanometry. • We show the vertical distributions of U and 226Ra measured in two ∼30 m mill tailings piles. • Portable HPGe can be used directly in the field to observe slight variations of content

  12. Distributions of {sup 137}Cs and {sup 90}Sr in the soil of Uljin, South Korea

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ji Yeon; Kim, Wan; Maeng, Seong Jin; Lee, Sang Hoon [Kyungpook National University, Daegu (Korea, Republic of)

    2016-05-15

    For the purpose of baseline data collection and enhancement of environmental monitoring the distribution studies of {sup 137}Cs and {sup 90}Sr in the soil of Uljin province was performed and the relation between surface soil activities and soil properties (pH, TOC and median of the surface soil) was analyzed. For 14 spots within 10 km from the NPP surface soil samples were collected and soils for depth profile were sampled for 3 spots in April 2011. Using γ-ray spectrometry with HPGe detector, the concentrations of {sup 137}Cs were determined and the concentrations of {sup 90}Sr were measured by counting β-activity of {sup 90}Y (in equilibrium with {sup 90}Sr) in a gas flow proportional counter. The concentration ranges of {sup 137}Cs and {sup 90}Sr were <0.479-39.6 Bq (kg-dry)-1 (avg. 7.51 Bq·(kg-dry)-1) and 0.209-1.85 Bq·(kg-dry)-1 (avg. 0.74 Bq·(kg-dry)-1) which were similar to the reported values from other regions in Korea. The activity ratio of {sup 137}Cs to {sup 90}Sr in surface soils was around 9.67, which is much bigger than the initial value of 1.75 for worldwide fallouts because of faster downward movement of {sup 90}Sr after fall-out than that of {sup 137}Cs. For depth profile studies soils were collected down to 40 cm depth for the locations of Deokgu, Hujeong and Maehwa. The {sup 137}Cs concentration distribution of the first two showed maximum values at top soils and decreased rapidly in exponential manner, while {sup 90}Sr showed two local maximum values for soils near top and about 30 cm depth. Through linear fittings between the {sup 137}Cs and {sup 90}Sr concentrations of surface soil and pH, TOC and median of the surface soil, the only probable relationship obtained was between {sup 137}Cs and TOC (determination coefficient R2=0.6). The concentration ranges of {sup 137}Cs and {sup 90}Sr in Uljin were similar to the reported values from other regions in Korea. The only probable relationship obtained between activities and soil properties

  13. 238U, 234U, 226Ra, 210Po concentrations of bottled mineral waters in Italy and their dose contribution

    International Nuclear Information System (INIS)

    Due to the importance of bottled mineral water in human diet with special regard to children in lactation period, a monitoring of natural radioactivity in some bottled mineral waters produced in Italy was performed. Gross alpha and beta activities and 226Ra, 238U, 234U, and 210Po concentrations were measured. Gross alpha and beta activities were determined by standards ISO 9696 and ISO 9697; for 226Ra determination liquid scintillation was used. The 238U and 234U concentrations were determined by alpha spectrometry after their separation from matrix by extraction chromatography and electroplating. 210Po was measured by alpha spectrometry. The results revealed that the concentrations (mBq L-1) of 226Ra, 238U, 234U, and 210Po ranged from -1; for infants (-1

  14. Concentration of natural radionuclides (40K, 228Ra and 226Ra) in vegetables and fruits collected around Kudankulam, South India

    International Nuclear Information System (INIS)

    Baseline activity concentration of the natural radio nuclides 40K, 228Ra and 226Ra in vegetables and fruits was determined around Kudankulam. In many of the samples, 228Ra and 226Ra was below minimum detection limit. 40K was found to be more in leafy vegetables followed by pods, tubers and fleshy fruits. The highest accumulator among the matrices was the leafy vegetables with the geometric mean of 189.47 Bq.kg-1 fresh for vegetables and fruits with the geometric mean of 128.95 Bq.kg-1 fresh. 228Ra activity in vegetables and fruits ranged from 0.074 to 1.153 and 0.074 to 0.131 Bq.kg-l fresh respectively. 226Ra in vegetables and fruits ranged from BDL to 0.07 and BDL-.044 Bq.kg-l fresh respectively. 40K in vegetables and fruits followed a log normal distribution. (author)

  15. An evaluation of 226Ra and 228Ra in drinking water in several counties in Texas, USA

    International Nuclear Information System (INIS)

    Naturally Occurring Radioactive Material (NORM) or Technology Enhanced Naturally Occurring Radioactive Material (TENORM) can be a potential health risk. It is now well known that the underlying geology in many parts of Texas has given rise to levels of 226Ra and 228Ra that often exceed the limits set by the US Environmental Protection Agency. A detailed literature search was undertaken to assess the levels of 226Ra and 228Ra in all of the Texas counties. Several statistical evaluations of the data were performed. The Hickory aquifer in the Llano Uplift region of Texas has consistently had the highest number of 226Ra and 228Ra concentrations above the legal limit. As well many of the affected rural communities may not have the financial resources to rectify the problem

  16. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  17. Magmatic Processes at Loihi Seamount Inferred From 226Ra-230Th-234U-238U Disequilibria

    Science.gov (United States)

    Pietruszka, A. J.; Hauri, E. H.; Garcia, M. O.

    2001-12-01

    We have conducted a detailed study of the U-series isotope geochemistry of young tholeiitic, transitional and alkalic Loihi basalts to examine the melt generation process during the preshield stage of a Hawaiian volcano. A previous study (Sims et al. 1999; GCA, v. 63) of two dredged lavas from the deep flanks of Loihi found a higher (230Th/238U) activity ratio in an alkalic basalt (1.07) compared to a tholeiitic basalt (1.04). This difference suggests that the tholeiitic basalt may have formed at a higher rate of mantle upwelling than the alkalic basalt. Our samples were collected from surface lava flows at Loihi's summit and along the volcano's south rift zone by submersible. Analyses were preformed using high-precision plasma ionization mass spectrometry. The samples display a relatively large range in the amount of excess 226Ra (0-13%) that extends to much lower values than observed at Kilauea Volcano (11-12%). The low (226Ra/230Th) ratios of Loihi lavas probably result from post-eruptive decay of 226Ra and imply eruption ages of 0-12 kyr. All of the Loihi samples (including the 1996 lava) have small amounts of excess 234U (0.2-0.8%). The most likely source for (234U/238U)>1 at Loihi is seawater, which has (234U/238U)=1.14. Since all of the samples were fresh, hand-picked glasses, these elevated (234U/238U) ratios may have resulted from the assimilation of a seawater-derived component within Loihi's magmatic plumbing system rather than post-eruptive U addition. The range of (230Th/238U) that we measured is 1.01-1.07, which is larger than the previous range known for Loihi. Mass balance calculations using the measured (234U/238U) ratios suggest that 1-6% of the U in the samples that we analyzed is ultimately derived from seawater. Correcting the 230Th-238U disequilibria of the Loihi lavas for this seawater-derived U results in a narrower range in the amount of excess 230Th (6-9%) with no significant differences between tholeiitic, transitional or alkalic basalts

  18. Assessment of natural radionuclides concentration from 238U and 232Th series in Virginia and Burley varieties of Nicotiana tabacum L

    International Nuclear Information System (INIS)

    Brazil is the largest exporter and second largest producer of tobacco worldwide, according to the crop production of 2013/2014. The tobacco plant (Nicotiana tabacum L.) is used to manufacture all derivatives and the chemical composition of the resulting tobacco products varies with the type of tobacco leaves, how they are grown, the region where they are cultivated, the characteristics of preparation (compression, filter and paper) and the temperature variations resulting from the incomplete combustion of tobacco. Tobacco products are extensively used throughout the world, and the most consumed are cigarettes, cigars and narghile. The damaging effects that these products cause to human health are discussed globally, and many surveys are performed with the aim of relating the use of these products with various illnesses. There is a lack of information about the radiological characterization of the tobacco plant both in international and Brazilian literature. The objective of this study was to determine the concentration of radionuclides 238U, 234U, 230Th, 22'6Ra, 210Pb and 210Po, members from the 238U decay series, and the radionuclides 232Th and 228Ra members of the 232Th decay series in the varieties Burley and Virginia, which are the most cultivated in Brazil. Plants from these varieties were cultivated in pots with organic substrate and fertilizer and also acquired from the producers and analyzed by alpha spectrometry for U and Th isotopes and 210Po determination, and gross alpha and beta counting, 228Ra, 226Ra and 210Pb determination. The whole plant, from both places, was analyzed; root, stem, leaves, as well as the organic substrate, the fertilizers, and the soil. The results for U and Th isotopes presented values below the detection limits of the methods to the leaves and stems of all plants analyzed, with measurable results only in roots, soil, and substrate. The radionuclides 226Ra, 228Ra, 210Pb, and 210Po, were determined in most parts of the plants

  19. Precise measurement and analysis of neutron transmission through 232Th

    International Nuclear Information System (INIS)

    Three sets of transmission time spectra through up to eight samples of 232Th have been measured for neutron energies from 6.0 MeV to 0.1 MeV by use of a flight-time technique over 22- and 40-m path lengths, the ORELA pulsed neutron source, and a 1-mm-thick lithium glass detector. The resulting total cross section from 0.1 to 20.0 eV seems to be smaller than that contained in the ENDF/B-V evaluation. Least-squares analysis of the transmissions from 9 to 440 eV using a multilevel Breit-Wigner formalism results in neutron widths consistent with those previously reported. An average radiation width of 25.2 MeV is obtained for 19 low-energy s-wave resonances. 3 figures, 5 tables

  20. The average concentrations of 226Ra and 210Pb in foodstuff cultivated in the Pocos de Caldas plateau

    International Nuclear Information System (INIS)

    The average concentrations of 226Ra and 210Pb in vegetables cultivated in the Pocos de Caldas plateau, mainly potatoes, carrots, beans and corn and the estimation of the average transfer factors soil-foodstuff for both radionuclides, were performed. The total 226Ra and 210Pb content in the soil was determined by gamma spectrometry. The exchangeable fraction was obtained by the classical radon emanation procedure and the 210Pb was isolated by a radiochemical procedure and determined by radiometry of its daughter 210Bi beta emissions with a Geiger Muller Counter. (M.A.C.)

  1. Risk of 226 Ra ingestion due to water consumption from phosphatic regions of the Northeast of Brazil

    International Nuclear Information System (INIS)

    Geological survey performed in the coastal region of the Northeast of Brazil showed presence of uranium phosphate deposits in a land strip corresponding to the Pernambuco-Paraiba sedimentary basin. The local population uses the water that crosses phosphate area, with higher than normal concentration of uranium and its progeny. this work is aimed to determine the cancer risk, based on the rate of ingestion the 226 Ra due to water consumption. The results of the analyses showed increments of 7% for head sarcoma and 3% for osteosarcomas occurrences due to 226 Ra ingestion for the local population. (author)

  2. Distribution and uptake of {sup 137}Cs in relation to alkali metals in a perhumid montane forest ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Chao, J.H. [Nuclear Science and Technology Development Center, National Tsing Hua University, Hsinchu 30013, Taiwan (China)], E-mail: jhchao@mx.nthu.edu.tw; Chiu, C.Y. [Research Center for Biodiversity, Academia Sinica, Taipei 11529, Taiwan (China); Lee, H.P. [Nuclear Science and Technology Development Center, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2008-10-15

    We determined the content of radiocesium ({sup 137}Cs) and alkali metals in soils, plants (2 ferns, a shrub and moss) and rainwater collected in an undisturbed forest ecosystem. The {sup 137}Cs activity and the isotopic ratio of {sup 137}Cs/Cs in the samples were used to interpret the distribution and uptake of {sup 137}Cs and the alkali metals in plants. As a whole, the {sup 137}Cs in plants was assimilated together with K but was not dependent on Cs. Different adaptations of fern species collected in ecological niches cause them to have different {sup 137}Cs/Cs ratios. Diplopterygium glaucum is distributed at the edges of the forest; it usually has shallow organic layers, and the root takes up more stable Cs from mineral layers, leading to lower {sup 137}Cs/Cs ratios than that in the understory Plagiogyria formosana and Rhododendron formosanum species. The steady supply of stable Cs through the uptake by D. glaucum from deep soils may gradually dilute the {sup 137}Cs concentration and thus explain the lower {sup 137}Cs/Cs ratio in the fern samples. The {sup 137}Cs is predicted to be proportional to the Cs content across plant species in the biological cycle once isotopic equilibrium is attained.

  3. Patterns of 137Cs accumulation in bullhead catfish inhabiting an abandoned reactor reservoir

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  5. {sup 137}Cs and {sup 9}Sr uptake by sunflower cultivated under hydroponic conditions

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Soil to plant transfer of 226Ra in a marsh area; Modelling application

    International Nuclear Information System (INIS)

    The Odiel river forms an estuarine system which surrounds a large marsh area. A phosphate fertilizer processing complex releases its wastes into the estuary. The presence of 226Ra in soils and plants (Spartina Densiflora) from the marsh has been investigated. Concentrations up to 700 and 15 mBq g-1 have been detected in soil and plant samples, respectively. Soil to plant concentration ratios have been calculated and some activity ratios have also been investigated. A model which is able to simulate the dispersion of radionuclides in the marsh has been applied. The model includes the exchange of radionuclides between water and the solid phase (suspended matter and bottom sediments) and the transfer of radionuclides to the plants. Model results are, in general, in good agreement with measurements. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  7. Laser trapping of 225Ra and 226Ra with repumping by room-temperature blackbody radiation.

    Science.gov (United States)

    Guest, J R; Scielzo, N D; Ahmad, I; Bailey, K; Greene, J P; Holt, R J; Lu, Z-T; O'Connor, T P; Potterveld, D H

    2007-03-01

    We have demonstrated Zeeman slowing and capture of neutral 225Ra and 226Ra atoms in a magneto-optical trap. The intercombination transition 1S0-->3P1 is the only quasicycling transition in radium and was used for laser-cooling and trapping. Repumping along the 3D1-->1P1 transition extended the lifetime of the trap from milliseconds to seconds. Room-temperature blackbody radiation was demonstrated to provide repumping from the metastable 3P0 level. We measured the isotope shift and hyperfine splittings on the 3D1-->1P1 transition with the laser-cooled atoms, and set a limit on the lifetime of the 3D1 level based on the measured blackbody repumping rate. Laser-cooled and trapped radium is an attractive system for studying fundamental symmetries. PMID:17359153

  8. Computer-controlled system for rapid soil analysis of 226Ra

    International Nuclear Information System (INIS)

    A computer-controlled multichannel analysis system has been developed by the Radiological Survey Activities Group at Oak Ridge National Laboratory (ORNL) for the Department of Energy (DOE) in support of the DOE's remedial action programs. The purpose of this system is to provide a rapid estimate of the 226Ra concentration in soil samples using a 6 x 9-in. NaI(Tl) crystal containing a 3.25-in. deep by 3.5-in. diameter well. This gamma detection system is controlled by a mini-computer with a dual floppy disk storage medium. A two-chip interface was also designed at ORNL which handles all control signals generated from the computer keyboard. These computer-generated control signals are processed in machine language for rapid data transfer and BASIC language is used for data processing

  9. Prompt γ-rays emitted in fission of 226Ra by 12 MeV protons

    International Nuclear Information System (INIS)

    The total energy associated with the emission of prompt γ-rays in fission of 226Ra induced by 12 MeV protons was measured in correlation with the fragment mass and kinetic energy. The dependence of the average total γ-ray energy on fragment mass and total kinetic energy resembles the corresponding dependence of the average number of neutrons. Using these results and the results for the average number of neutrons, the excitation energy of the fragments at the scission point was calculated. The results support the view that the scission-point configuration for the symmetric fission mode is more elongated than that for the asymmetric mode. (B.G.)

  10. Spatial variability of 137Cs in the soil of Belgrade region (Serbia

    Directory of Open Access Journals (Sweden)

    Janković-Mandić Ljiljana J.

    2014-01-01

    Full Text Available Among radionuclides in the soil deposited after Chernobyl accident, 137Cs poses considerable environmental and radiological problems because of its relatively long half-life (30.17 y, its abundance in the fallout, high mobility and similarity to potassium as the major plant nutrient. In this study the samples of undisturbed surface soil (n=250 were taken from 70 regions in Belgrade, during 2006-2010. The specific activities of 137Cs were measured by gamma-ray spectrometry. Based on obtained results external effective dose rates were calculated according to the internationally accepted activity to dose rate conversion equations. The specific activities of 137Cs were geographically mapped. The presence of 137Cs has been detected in all soil samples, with high variability of its specific activity, ranging from 3 Bq kg-1 to 87 Bq kg-1. The mean specific activity of 137Cs was 23 Bq kg-1 and the corresponding absorbed dose was 1.5 nSv h-1. The observed range reflects the inhomogeneity of the deposition process following the Chernobyl accident. It could also be attributed to topographic differences and spatial differences in physicochemical and biological soil properties, soil type and vegetation cover. The results of the present study could be valuable database for future estimations of the impact of radioactive pollution.

  11. Spatial distribution of fallout 137Cs in coastal marine water of Tamil Nadu coast

    International Nuclear Information System (INIS)

    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)

  12. ESTIMATION OF SOIL EROSION IN A RESERVOIR WATERSHED USING 137CS FALLOUT RADIONUCLIDE

    Institute of Scientific and Technical Information of China (English)

    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.

  13. Isolation of 137-Cs in tuna fish by ammonium phosphomolybdate (AMP)

    International Nuclear Information System (INIS)

    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

  14. 137Cs availability for soil to understory transfer in different types of forest ecosystems

    International Nuclear Information System (INIS)

    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

  15. GIS supported calculations of 137Cs deposition in Sweden based on precipitation data

    International Nuclear Information System (INIS)

    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

  16. Migration of 137Cs from air to soil and plants in the Gulsvik area, Norway after the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    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

  17. The uptake of 90Sr, 137Cs and 144Ce by leaves of spring wheat and rape

    International Nuclear Information System (INIS)

    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

  18. 3D modeling technique of time-series 137Cs concentration in coastal organisms in case of short term introduction

    International Nuclear Information System (INIS)

    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

  19. 226Ra Concentration of Hungarian Bottled Mineral Waters and Estimation of the Dose Deriving from Their Consumption

    International Nuclear Information System (INIS)

    Full text: The concentration of 226Ra was measured in most of the bottled mineral waters commercially available in Hungary. The 226Ra concentration exceeded the 100 mBqL-1 value in six cases out of the investigated 29 types of mineral waters. In most of the cases, 226Ra concentration does not reach the 100 mBqL-1 value. 100-800 mBqL-1 values were found in five cases and 3 BqL-1 was measured in one case. This concentration means 0.3 mSvyear-1 dose load in case of 1 Lday-1 consumption, but in case of children (12-17 years old populace) it can reach the 1.6 mSvyear-1. When measuring the 226Ra concentration in soft drinks made from this latter mineral water, 2.6 BqL-1 concentration was determined which means 1.4 mSvyear-1 dose load in the 12-17 years age-group when 1 Lday-1 is consumed from these drinks. (author)

  20. Elimination of natural uranium and {sup 226}Ra from contaminated waters by rhizofiltration using Helianthus annuus L

    Energy Technology Data Exchange (ETDEWEB)

    Vera Tome, F. [Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz (Spain)], E-mail: fvt@unex.es; Blanco Rodriguez, P. [Departamento de Fisica, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz (Spain); Lozano, J.C. [Laboratorio de Radiactividad Ambiental, Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca (Spain)

    2008-04-15

    The elimination of natural uranium and {sup 226}Ra from contaminated waters by rhizofiltration was tested using Helianthus annuus L. (sunflower) seedlings growing in a hydroponic medium. Different experiments were designed to determine the optimum age of the seedlings for the remediation process, and also to study the principal way in which the radionuclides are removed from the solution by the sunflower roots. In every trial a precipitate appeared which contained a major fraction of the natural uranium and {sup 226}Ra. The results indicated that the seedlings themselves induced the formation of this precipitate. When four-week-old seedlings were exposed to contaminated water, a period of only 2 days was sufficient to remove the natural uranium and {sup 226}Ra from the solution: about 50% of the natural uranium and 70% of the {sup 226}Ra were fixed in the roots, and essentially the rest was found in the precipitate, with only very small percentages fixed in the shoots and left in solution.

  1. DISTRIBUITION OF 226Ra AND 228Ra IN UNDERGROUND WATER INTO THE SOUTH REGION OF SAO PAULO STATE

    Directory of Open Access Journals (Sweden)

    CARVALHO DE JESUS, Sueli; CHIRINOS, Hugo;

    2011-08-01

    Full Text Available Monitor of natural radionuclides in aquatic raw is very important to guaranty the normal control level inthe environmental medium and the human. In this report were available the concentration of 226Ra and 228Ra inCananeia’s underground water, Iguape and Comprida Island into the south region of Sao Paulo state, by grossalpha and beta counting method. The concentration of 226Ra was variety into the interval 0.80 to 23 mBqL-1 inApril/2009 (rain period and into the interval 0.63 to 12 mBqL -1in August/2009 (dried period. The concentrationof 228Ra was variety into the interval 18 to 39 mBqL-1 in April/2009 and into the interval 15 to 72 mBqL-1 inAugust/2009. The Activities ratio of 228Ra/226Ra was variety into the interval 3.3 to 31.7 at rain period and 1.1 to26.7 at dried period. To compare the yield values of 226Ra and 228Ra these show high activity of the 228Raisotope. The calculate dose no arising the reference of effective dose level available by WHO.

  2. Estimation of radiation doses from 137Cs to frogs in a wetland ecosystem

    International Nuclear Information System (INIS)

    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

  3. Resuspension and spreading of 137 Cs in urban areas: the Goiania experience

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Alkaline extraction: can it be used for the removal of 137Cs from soil?

    International Nuclear Information System (INIS)

    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.)

  6. In situ measurements of density of 137Cs contamination of the forest system in Ukraine

    International Nuclear Information System (INIS)

    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

  7. Transfer of 137Cs in Zea mays and Phaseolus vulgaris in a semi-arid ecosystem

    International Nuclear Information System (INIS)

    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)

  8. Airborne fallout mapping of {sup 137}Cs Finnish defence forces team

    Energy Technology Data Exchange (ETDEWEB)

    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).

  9. The influence of the sorptive properties of organic soils on the migration rate of 137Cs

    International Nuclear Information System (INIS)

    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

  10. Levels of 137Cs and 40K in edible parts of some vegetables consumed in Egypt

    International Nuclear Information System (INIS)

    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

  11. 137Cs and relationships with major and trace elements in edible mushrooms from Mexico

    International Nuclear Information System (INIS)

    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

  12. 137Cs distribution in soil as a function of erosion and other processes

    International Nuclear Information System (INIS)

    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)

  13. Peculiarities of 90 Sr and 137 Cs behavior in the atmosphere and the hydrosphere

    International Nuclear Information System (INIS)

    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)

  14. Temporal variations of 90Sr and 137Cs concentrations in Japanese coastal surface seawater and sediments from 1974 to 1998

    Science.gov (United States)

    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).

  15. A comparative study on radiocaesium (137Cs) uptake from coniferous forest soil

    International Nuclear Information System (INIS)

    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)

  16. A comparative study on radiocaesium (137Cs) uptake from coniferous forest soil

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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

  18. Assessment of the mobility and bioavailability of 60 Co and 137 Cs in contaminated soils

    International Nuclear Information System (INIS)

    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)

  19. Influence of biologically-active substances on 137Cs and heavy metals uptake by Barley plant

    International Nuclear Information System (INIS)

    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)

  20. GIS supported calculations of (137)Cs deposition in Sweden based on precipitation data.

    Science.gov (United States)

    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

  1. Review of the distribution of 210Pb in the world oceans and 210Pb/226Ra ratio as scavenging tracer

    International Nuclear Information System (INIS)

    It was first shown by Rama et al. (1961) that 210Pb has a very short residence time and is remove quickly from the surface waters by suspended particulate matter. Since the first application of the daughter-parent pair in the 238U series (210Pb/226Ra) for deep-scavenging studies by Craig et al (1973), a number of vertical profiles from major ocean basins have been published to investigate the residence time and scavenging rates of 210Pb. The vertical distributions of 210Pb in the deep-ocean vary widely, depending on its supply rates (the atmospheric deposition rate of 210Pb and production from 226Ra) and the intensity of scavenging. The inventories of 210Pb in the 3 distinct zones of the deep ocean (epipelagic, mesopelagic and bathypelagic zones) will be assessed and compared to the total supply rates. The variations in the scavenging intensities in these three zones will be assessed and presented. The inventory of 210Pb in the euphotic zone will be compared to the global atmospheric fallout data and the relative contribution of advection, production from 226Ra and atmospheric depositional input to the 210Pb inventory will be discussed. Evaluation of the distinct differences between different ocean basins in the supply rates as well as the scavenging intensities of 210Pb is assessed and the results will be presented. Using the 210Pb/226Ra ratios in the water column the scavenging residence times obtained for different ocean basins will be compared. The utility of 210Pb-226Ra pair towards studying boundary scavenging, sediment focusing/erosion, and settling velocity of particles based on the water column profiles, sediment trap data and inventories of 210Pb in sediments will also be presented. The utility of 210Pb as a tracer for other lithogenic elements in the marine environment will be discussed and the results will be summarized. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Suseno, Heny, E-mail: henis@batan.go.id [Marine Radioecology Group, Center for Radiation Safety Technology and Metrology - National Nuclear Energy Agency, Jl. Lebak Bulus Raya No. 49, Kotak Pos 7043 JKSKL Jakarta Selatan 12070 (Indonesia)

    2014-10-24

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

  4. 137Cs monitoring in the meat of wild boar population in Slovakia

    Directory of Open Access Journals (Sweden)

    Katarina Beňová

    2016-06-01

    Full Text Available Currently, due to the elapsed time and the nature of the Chernobyl accident, the only artificial radionuclide present in the soil is 137Cs, with a physical half-life conversion of 30.17 years. The 137Cs is quickly integrated into a biological cycle, similar to potassium. Generally, radionuclides are characterized by their mobility in soil. Contamination of materials and food by radionuclides represent a serious problem and has a negative impact on human health. The threat of international terrorism and the inability to forestall the impact of natural disasters on nuclear energetic (Fukushima accident, are also reasons for continuous monitoring of food safety. According screening measurement performed in European countries, high radioactivity levels were reported in the wild boars muscles from Sumava (Czech Republic. Seasonal fluctuation of 137Cs activity in the wild boar meat samples was observed in the forests on the southern Rhineland. Monitoring of 137Cs activity in the wild boar meat samples in the hunting grounds in Slovakia was initiated based on the reports on exceeding limits of the content of radiocaesium in the meat of wild boar from the surrounding countries. The aim of this study was to determine the 137Cs post Chernobyl contamination of wild boars population in different hunting districts of Slovakia during 2013 - 2014. A total of 60 thigh muscle samples from wild boars of different age categories (4 months - 2 years were evaluated. 137Cs activity was measured by gamma spectrometry (Canberra. Despite the fact Slovakia is closer to Chernobyl as Czech Republic and Germany, the 137Cs activity measured was very low and far below the permitted limit. The highest radiocaesium activity level measured in muscle was 37.2 Bq.kg-1 ±4.7%. Wild boar originated from Zlate Moravce district. The measurement results show, that 137Cs contamination levels of game in Slovakia are low. Radiocaesium activity in examined samples was very low and

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

    Indian Academy of Sciences (India)

    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.

  6. Seasonal changes of 137Cs in benthic plants from the southern Baltic Sea

    OpenAIRE

    Zalewska, Tamara

    2011-01-01

    137Cs activity concentrations were determined in samples of macrophytes Polysiphonia fucoides (red algae) and Zostera marina (vascular plant) collected during the entire vegetation season in the Gulf of Gdańsk in the southern Baltic Sea. The measurements showed considerable seasonality of 137Cs activity in both species; an increase of cesium concentrations was observed from spring to autumn with maximal levels 49.1 ± 1.4 Bq kgd.w. −1 (P. fucoides) and 14.5 ± 1.0 Bq kgd.w. −1 (Z. marina) in la...

  7. 137Cs distribution in sod-podzol forest soil of Ukrainian Polissia

    International Nuclear Information System (INIS)

    137Cs distribution in sod-podzol forest soil of Ukrainian Polissia in different types of forest condition is studied. Rates of specific and total radionuclides activity in the layers of forest floor and in the mineral part of soil are analyzed. According to the qualitative study of 137Cs distribution in the soil of pine plantation the forest floor is considered to be the geochemical barrier for the migration of radionuclides into soil. The highest total radionuclide activity in humus-eluvial horizon is observed

  8. Assessment of natural radionuclides concentration from {sup 238}U and {sup 232}Th series in Virginia and Burley varieties of Nicotiana tabacum L; Avaliacao da concentracao dos radionuclideos naturais das series do {sup 238}U e {sup 232}Th nas variedades Burley e Virginia da Nicotiana tabacum L.

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Carolina Fernanda da

    2015-07-01

    Brazil is the largest exporter and second largest producer of tobacco worldwide, according to the crop production of 2013/2014. The tobacco plant (Nicotiana tabacum L.) is used to manufacture all derivatives and the chemical composition of the resulting tobacco products varies with the type of tobacco leaves, how they are grown, the region where they are cultivated, the characteristics of preparation (compression, filter and paper) and the temperature variations resulting from the incomplete combustion of tobacco. Tobacco products are extensively used throughout the world, and the most consumed are cigarettes, cigars and narghile. The damaging effects that these products cause to human health are discussed globally, and many surveys are performed with the aim of relating the use of these products with various illnesses. There is a lack of information about the radiological characterization of the tobacco plant both in international and Brazilian literature. The objective of this study was to determine the concentration of radionuclides {sup 238}U, {sup 234}U, {sup 230}Th, {sup 22}'6Ra, {sup 210}Pb and {sup 210}Po, members from the {sup 238}U decay series, and the radionuclides {sup 232}Th and {sup 228}Ra members of the {sup 232}Th decay series in the varieties Burley and Virginia, which are the most cultivated in Brazil. Plants from these varieties were cultivated in pots with organic substrate and fertilizer and also acquired from the producers and analyzed by alpha spectrometry for U and Th isotopes and {sup 210}Po determination, and gross alpha and beta counting, {sup 228}Ra, {sup 226}Ra and {sup 210}Pb determination. The whole plant, from both places, was analyzed; root, stem, leaves, as well as the organic substrate, the fertilizers, and the soil. The results for U and Th isotopes presented values below the detection limits of the methods to the leaves and stems of all plants analyzed, with measurable results only in roots, soil, and substrate. The

  9. Modeling of 226Ra behavior in a Spanish estuary affected by the phosphate industry

    International Nuclear Information System (INIS)

    The Odiel and Tinto rivers, southwest Spain, form a fully mixed estuary. An industrial area that includes a complex dedicated to the production of phosphate fertilizers is located by the Odiel River. This complex released phosphogypsum wastes directly to the Odiel River and also disposed them on open air piles located by the Tinto River. Due to new EU regulations, wastes are not directly released to the Odiel from 1998 on, although they are still disposed on the open air piles. The behavior of 226Ra in a system like this estuary is complex, since radionuclides are affected by tidal actions and interactions with sediments through adsorption/desorption reactions and erosion/deposition processes. A numerical 2D depth-averaged model of the estuary has been developed, including processes mentioned above. It has been applied to reproduce experimental data measured after a release from the industrial complex in the Odiel River and after an accidental release in the Tinto River from the gypsum piles. The model has also been applied to simulate the self-cleaning process observed in the estuary after the direct releases from the fertilizer complex were stopped. (author)

  10. Determination of 226Ra and 224Ra in sediments samples by liquid scintillation counting

    International Nuclear Information System (INIS)

    An experimental procedure has been developed for a rapid determination of the activity concentration of 226Ra and 224Ra in sediments by liquid scintillation counting. The importance of the method lies in its application to the measurement of sediments where the Ra-isotopes activity concentration has been increased due to an anthropomorphic enhancement based on releases of naturally occurring radioactive material (NORM). A sample pre-treatment, including a digestion with aqua regia and a precipitation of hydroxides, was applied to samples before the radium extraction, which was made by co-precipitation with barium. Measurements were done in a low background scintillation spectrometer Quantulus 1220, which can separate and detect simultaneously α and β particles. Additionally, some improvements are suggested for a better α and β interference correction of the results. The obtaining of radiochemical yields is also improved using 133Ba as tracer, which decays by emission of conversion electrons and γ-rays; the wide range of radiochemical yields obtained confirms the need of this analyses. The procedure has been applied to the measurement of riverbed sediments from an estuary in the south-west of Spain, affected in the past by direct and indirect phosphogypsum discharges

  11. Potential of Chromolaena odorata for phytoremediation of (137)Cs from solution and low level nuclear waste.

    Science.gov (United States)

    Singh, Shraddha; Thorat, Vidya; Kaushik, C P; Raj, Kanwar; Eapen, Susan; D'Souza, S F

    2009-03-15

    Potential of Chromolaena odorata plants for remediation of (137)Cs from solutions and low level nuclear waste was evaluated. When plants were exposed to solutions spiked with three different levels of (137)Cs, namely 1 x 10(3) kBqL(-1), 5 x 10(3) kBqL(-1) and 10 x 10(3) kBqL(-1), 89%, 81% and 51% of (137)Cs was found to be remediated in 15 d, respectively. At the lowest Cs activity (1 x 10(3) kBqL(-1)), accumulation of Cs was found to be higher in roots compared to shoots, while at higher Cs activities (5 x 10(3) kBqL(-1) and 10 x 10(3) kBqL(-1)), Cs accumulation was more in shoots than roots. When plants were incubated in low level nuclear waste, 79% of the activity was removed by plants at the end of 15 d. The present study suggests that C. odorata could be used as a potential candidate plant for phytoremediation of (137)Cs. PMID:18599208

  12. Transfer Factors of 137Cs and 85Sr by Freshwater Fish in Tropical Environment

    International Nuclear Information System (INIS)

    The experiment was set up to determine the radionuclide transfer factors (T.F.) of 137Cs and 85Sr by tropical freshwater fish. Mixed breeding catfish between Thai catfish (Clarias acrocephalus) and African catfish (Clarias garispinus African sharptooth) were exposed to 137Cs and 85Sr in two 1000-L tanks for 42 days during uptake phase. The calculated T.F. at equilibrium, in flesh, bone, skin plus fin and head were 3.2, 2.6, 1.6 and 1.5 L.kg-1 for 137Cs and 0.1, 4, 1 and 17 L.kg-1 for 90Sr, respectively. These results revealed a much lower values than reported elsewhere for temperate environment, however were in accordance with the tropical values as observed by others. The biological half-lives of 137Cs and 85Sr in flesh part were 41 and 4 days respectively. It is then imperative that suitable T.F. values are employed in the models to predict the transport of radionuclides within the particular ecosystem and the potential dose to man. Thus the relationship between routine release of radionuclides and resulting dose to man can be established and corresponding release limits stipulated for that particular nuclear site

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

    Science.gov (United States)

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

    2015-12-15

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

  14. A medical follow-up of 137 Cs Goiania radiation accident: un update (1990-1992)

    Energy Technology Data Exchange (ETDEWEB)

    Brandao-Mello, Carlos Eduardo; Oliveira, Alexandre Rodrigues de [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Farina, Rosana [Industrias Nucleares do Brasil SA, Rio de Janeiro, RJ (Brazil)

    1995-12-31

    The aim of this paper is to describe the main aftereffects of the 137 Cs accident in the last two years, giving emphasis on clinical, hematological, radiological and psychological aspects. A medical follow-up protocol was established by CNEN and the Leide das Neves Ferreira Foundation of the State of Goias, in order to prospectively follow more than 150 victims. (author). 6 refs.

  15. Long term behaviour of 137Cs in the global marine environment: observations and model simulations

    International Nuclear Information System (INIS)

    137Cs concentration surface water time series in 12 latitudinal boxes of the Pacific Ocean are re-investigated for the period from 1970 to 2005. The apparent half-residence times of 137Cs ranged from 11 to 36 years, depending on the position of the box. Generally these revised estimations of the apparent half-residence times are in good agreement with previous estimations. However, in a few boxes in the South Pacific we found longer apparent half-residence times. 137Cs inventories in the water column of the Pacific were also re-investigated for the period from 1970 to 2003. They are much smaller in the north of the subtropical gyre, however, they showed a less decrease in the south edge of the subtropical gyre. In the equatorial areas, 137Cs inventories had increased or been maintained constant. The main processes of these differences are caused by the southward transport of water masses due to subduction, and due to the existence of mid-depth minima at 300-400 m layers which correspond to the central mode water. (author)

  16. The use of honey bees in environmental monitoring of 137Cs

    International Nuclear Information System (INIS)

    Bees are excellent random samplers of relatively defined areas. A bee typically flies up to 1.5 km from the hive, covering an area of approximately 7 km2. Within this area the bee forages from many plants and collects water from various sources. Bee products, such as pollen and honey, therefore reflect the conditions of the immediate environment. In this study we were interested in the transfer of the anthropogenically produced isotope 137Cs from environmental sinks into the bee products. 137Cs originates principally from the atmospheric thermonuclear bomb tests conducted in the late 1950s and early 1960s. Minute quantities could also originate from nuclear establishments (such as ANSTO in Australia) where it is used in scientific research. Once released into the environment 137Cs is known to bind tightly with the clay component and organic fractions in soil and its distribution largely reflects the physical transport of soil. In this work we compared the 137Cs levels from the Sydney region and other parts of NSW against Ireland (which were high as a result of the Chernobyl reactor accident)

  17. Depth distribution of (137)Cs in anthrosol from the experimental field "Radmilovac" near Belgrade, Serbia.

    Science.gov (United States)

    Vukašinović, Ivana; Todorović, Dragana; Dorđević, Aleksandar; Rajković, Miloš B; Pavlović, Vladimir B

    2013-09-01

    This is a preliminary study of the depth distribution of (137)Cs radionuclides in cultivated anthrosol soil of a 15-year old peach tree plantation at the experimental field "Radmilovac" near Belgrade. Before planting, the soil was ploughed at the depth of 1 m. The soil had not been annually ploughed, irrigated and treated with mineral fertilizers for three years before sampling. Activity concentration for (137)Cs ranged from 1.8 Bq kg(-1) to 35 Bq kg(-1). Along the soil depth it varied highly, reaching as high a total variation coefficient as 83 %. Radiocaesium distribution patterns depended on the extent of soil mixing in the plough layer, as it was mechanically transferred from the surface to the lower soil layers during cultivation. (137)Cs was associated with humus content and fixation to clay fractions in the soil. Our results single out soil's hygroscopic water as a valuable parameter for (137)Cs behaviour that could be used commonly if the measurement is standardised. PMID:24084351

  18. Background distributions of 239+240Pu and 137Cs of upland soil in Rokkasho, Japan

    International Nuclear Information System (INIS)

    The background distributions of Pu and 137Cs in soil were investigated in Rokkasho, Aomori Prefecture, where the first commercial nuclear fuel reprocessing plant in Japan is now being constructed. Soil core samples to 1 m depth were collected at 13 upland fields in Rokkasho and control sites in Hachinohe and Hirosaki. Since fields under yam (Dioscorea babatus) cultivation, which is a common crop in Rokkasho, were dug to approximately 1 m depth at harvesting, depth profiles of fallout radionuclides are heavily disturbed for most fields in Rokkasho. The mean inventories of 239+240Pu and 137Cs in three fields with no yam cultivation history were 116 Bq m-2 and 3.4 kBq m-2, respectively and similar to values in Hachinohe. However, the inventories were approximately a half of those in Hirosaki. The mean ratio of 239Pu/240Pu for all studied fields was 0.18±0.04, and similar to that of global fallout. The Pu concentrations correlate very well with 137Cs (r=0.97) in spite of heavy disturbance of soil, and the ratio of 239+240Pu/137Cs was 0.037±0.007, which is a typical value for global fallout. (author)

  19. Potential of Chromolaena odorata for phytoremediation of (137)Cs from solution and low level nuclear waste.

    Science.gov (United States)

    Singh, Shraddha; Thorat, Vidya; Kaushik, C P; Raj, Kanwar; Eapen, Susan; D'Souza, S F

    2009-03-15

    Potential of Chromolaena odorata plants for remediation of (137)Cs from solutions and low level nuclear waste was evaluated. When plants were exposed to solutions spiked with three different levels of (137)Cs, namely 1 x 10(3) kBqL(-1), 5 x 10(3) kBqL(-1) and 10 x 10(3) kBqL(-1), 89%, 81% and 51% of (137)Cs was found to be remediated in 15 d, respectively. At the lowest Cs activity (1 x 10(3) kBqL(-1)), accumulation of Cs was found to be higher in roots compared to shoots, while at higher Cs activities (5 x 10(3) kBqL(-1) and 10 x 10(3) kBqL(-1)), Cs accumulation was more in shoots than roots. When plants were incubated in low level nuclear waste, 79% of the activity was removed by plants at the end of 15 d. The present study suggests that C. odorata could be used as a potential candidate plant for phytoremediation of (137)Cs.

  20. Elimination of 137Cs from Japanese Catfish Acutely Contaminated by Labelled Food

    International Nuclear Information System (INIS)

    The effective half-life of 137Cs in acutely contaminated Japanese catfish was determined. The fish were fed with fish meal incorporated with 137CsCl and then released into aquaria. To assess the 137Cs activity retained in the fish body, the whole body radioactivity of each fish was measured at regular intervals for up to 157 days. The data were plotted with relative counts on the y-axis and corresponding elapsed time on the x-axis. Relative count plotted against elapsed time was found to consist of three components, namely the first fast, second fast and the slow component. The true elimination curves of the first components were calculated by the peeling off method. The effective half-life of the fast components was determined from the slope of the true curves. The effective half-life of 137Cs for the first fast, second fast and the slow component in Japanese catfish was found to be 1.27, 5.76 and 251 days, respectively. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. {sup 137}Cs and {sup 210}Po dose assessment from marine food in Cienfuegos Bay (Cuba)

    Energy Technology Data Exchange (ETDEWEB)

    Alonso-Hernandez, C. E-mail: carlos@ceac.perla.inf.cu; Diaz-Asencio, M.; Munos-Caravaca, A.; Suarez-Morell, E.; Avila-Moreno, R

    2002-07-01

    One part of Radiological Monitoring Programme in central Cuba (1991-1995) was dedicated to study the background levels of natural and anthropogenic radioactivity in Cienfuegos Bay in the vicinity of the first Cuban nuclear power station under construction. {sup 210}Po and {sup 137}Cs concentrations in fish, molluscs and crustaceans collected in Cienfuegos Bay were determined and the committed effective doses (CED) were calculated for two population groups inhabiting this region. The highest values of {sup 210}Po concentrations were found in crustaceans, but significant accumulation was also observed in fish and molluscs. The mean {sup 137}Cs concentrations in organisms are several times lower with respect to {sup 210}Po, a situation that characterises the regions affected by the global fallout only. Values of CED from the consumption of crustaceans and molluscs are very low both from{sup 210}Po and {sup 137}Cs. The mean individual dose from {sup 210}Po in the seafood consumed varies from 39 {mu}Sv for general populations to 2802 {mu}Sv for the 'critical group' consuming 320 kg of fish per year. The dose from {sup 137}Cs is negligible.

  3. Unmixing of 137Cs, Pb, Zn, and Cd records in lake sediments

    International Nuclear Information System (INIS)

    The inverse Berger-Health model to unmix sedimentary records of particle-associated tracers, originally used for 18O records of particle-associated tracers, originally used for 18O records in deep-sea sediments, is extended to include radioactive materials, environmental pollutants, compaction of sediments, and error analysis. The method is applied to the fallout tracer 137Cs, and to Pb, Zn, and Cd in sediment cores from Lake Michigan. The reconstructued 137Cs input records from northern Lake Michigan. The reconstructed 137Cs input records from northern Lake Michigan are in good agreement with 137Cs fallout data. The unmixed influx records of Pb, Zn, and Cd show excellent agreement with input records reconstructed previously by a frequency domain method, thus supporting the validity of the approach. Assuming that tracer concentrations as well as sedimentation and mixing parameters are known with sufficient accuracy, and that the forward model is correct, the ultimate limitation of this or any other reconstruction method lies in the finite depths of the physical sampling intervals

  4. Distribution of 137Cs in surface soils as affected by forest clear-cutting

    International Nuclear Information System (INIS)

    The distribution of 137Cs was studied in podzol soil profiles from a 5 year old forest clear-cut area and an adjacent mature spruce forest in central Norway in order to assess the effects of clear-cutting on the distribution and mobility of radiocaesium in surface soils. A distinctly higher radiocaesium activity observed in the humus layer from the clear-cut compared to the forest area strongly indicates an increase in organic surface soil 137Cs activity within the first 5 years following forest clear-cutting. Such an increase, previously observed for Ca, Mg, Mn and Zn, is explained by increased supply of radiocaesium from decomposing logging residue, such as lichens and needles. Roughly 25% of the activity leached from decomposing residue had been transported into the A-E layer 5 years after clear-cutting. High 137Cs activity in the eluvial (E) horizon and a distinct decrease in deeper horizons indicates a certain leaching of 137Cs from the humus layer into the E horizon, which may act as an effective barrier against further leaching of radiocaesium. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  5. 137Cs deposition in peat profiles on a raised bog in central Sweden; Forests ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, K.; Vinichuk, M.; Galan, P.R.; Johanson, K.J. (Swedish Univ. of Agricultural Sciences, Dept. of Soil Sciences, Uppsala (Sweden))

    2009-06-15

    Distribution of 137Cs depositions within peat profiles in open bog and nearby (low pine) sites in raised bog are shown and discussed. A possible involvement of Sphagnum moss in radionuclide binding and retention in such nutrient poor ecosystem is suggested. (au)

  6. Potential of Chromolaena odorata for phytoremediation of 137Cs from solution and low level nuclear waste

    International Nuclear Information System (INIS)

    Potential of Chromolaena odorata plants for remediation of 137Cs from solutions and low level nuclear waste was evaluated. When plants were exposed to solutions spiked with three different levels of 137Cs, namely 1 x 103 kBq L-1, 5 x 103 kBq L-1 and 10 x 103 kBq L-1, 89%, 81% and 51% of 137Cs was found to be remediated in 15 d, respectively. At the lowest Cs activity (1 x 103 kBq L-1), accumulation of Cs was found to be higher in roots compared to shoots, while at higher Cs activities (5 x 103 kBq L-1 and 10 x 103 kBq L-1), Cs accumulation was more in shoots than roots. When plants were incubated in low level nuclear waste, 79% of the activity was removed by plants at the end of 15 d. The present study suggests that C. odorata could be used as a potential candidate plant for phytoremediation of 137Cs

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

    International Nuclear Information System (INIS)

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

  8. Activities of the {sup 7}Be and {sup 137}Cs nuclides in mushrooms from Southern and Western Finland

    Energy Technology Data Exchange (ETDEWEB)

    Loennroth, T.; Bjoerkholm, A.; Haavisto, T.; Slotte, J.M.K. [Aabo Akademi, Turku (Finland). Dept. of Physics; Lill, J.O. [Aabo Akademi, Turku (Finland). Dept. of Physics; Aabo Akademi, Turku (Finland). Turku PET Centre and Accelerator Lab.

    2011-07-01

    We report the results from activity measurements of {sup 7}Be and {sup 137}Cs nuclides in mushrooms in Southern and Western Finland. Fifty-three samples were studied, and they showed large variations especially in the {sup 137}Cs activity both regionally and between mushroom species. (orig.)

  9. Physicochemical fractionation of {sup 137}Cs from TEPCO Fukushima Daiichi Nuclear Plant in irrigation water

    Energy Technology Data Exchange (ETDEWEB)

    Tsukada, Hirofumi; Ohse, Kenji; Ishii, Hideki; Kitayama, Kyo; Nanba, Kenji; Kawatsu, Kencho [Fukushima University, 1 Kanayagawa, Fukushima, Fukushima 960-1296 (Japan)

    2014-07-01

    Significant quantities of radionuclides were released into the environment due to the TEPCO Fukushima Daiichi Nuclear Power Plant accident. Cesium-137 is the most important radionuclide for the assessment of radiation exposure to the public for the long-term. The physicochemical form of radionuclides is an important factor in determining the fate of radionuclides in the environment. For instance, {sup 137}Cs in soil can be divided into three fractions (such as exchangeable, bound to organic matter, and strongly bound to particles), and their transferability to biota and contacting waters are different. In the present study, the physicochemical fractions in rice irrigation water were determined. Sixty L of the irrigation water was collected in Oguni, Date, Fukushima (northwest 55 km far away from the Plant) in 2013. The collected sample was filtered with a 0.45 μm membrane filter (Merck Millipore, Durapore{sup R} Membrane Filters), and separated into suspended and dissolved fractions. In addition, 2000-4000 L of the irrigation water was treated by a continuous high-speed centrifugation method, and several g of suspended matter were collected. Twenty ml of concentrated nitric acid was added to 20 L of the filtrated sample and the sample was concentrated with heating, which was used to determine the total concentration of {sup 137}Cs in the dissolved fraction. Then, 5 L of the filtrated sample was passed through a Cs disk (3M, Empore{sup TM} Cesium RAD Disks) and the inorganic, cationic fraction that existed as {sup 137}Cs+ was collected. The difference between the total dissolved fraction and the inorganic fraction was defined as the dissolved organic fraction. The suspended matter collected with the centrifugation method was separated into the three solid-phase fractions noted above: exchangeable, bound to organic matter, and strongly bound to particles. Thus, the total {sup 137}Cs inventory in the irrigation water was separated into five fractions: dissolved

  10. Long term simulation of {sup 137}Cs radioactivity in the regional ocean following the Fukushima Daiichi nuclear power plant accident

    Energy Technology Data Exchange (ETDEWEB)

    Tsumune, D.; Tsubono, T.; Misumi, K.; Yoshida, Y.; Hayami, H. [Central Research Institute of Electric Power Industry (Japan); Aoyama, M. [Meteorological Research Institute (Japan); Uematsu, M. [University of Tokyo (Japan); Maeda, Y. [CERES, Inc. (Japan)

    2014-07-01

    A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant following the earthquake and tsunami of 11 March 2011 resulted in the release of radioactive materials to the ocean by two major pathways, direct release from the accident site and atmospheric deposition. A regional-scale simulation of {sup 137}Cs activity in the ocean offshore of Fukushima was carried out, the sources of radioactivity being direct release, atmospheric deposition, and the inflow of {sup 137}Cs deposited on the ocean by atmospheric deposition outside the domain of the model for more than two years. Direct releases of {sup 131}I, {sup 134}Cs, and {sup 137}Cs were estimated for 1 year after the accident by comparing simulated results and measured activities. The estimated total amounts of directly released {sup 131}I, {sup 134}Cs, and {sup 137}Cs were 11.1±2.2 PBq, 3.5±0.7 PBq, and 3.6±0.7 PBq, respectively. The contributions of each source were estimated by analysis of {sup 131}I/{sup 137}Cs and {sup 134}Cs/{sup 137}Cs activity ratios and comparisons between simulated results and measured activities of {sup 137}Cs. Simulated {sup 137}Cs activities attributable to direct release were in good agreement with measured activities close to the accident site, a result that implies that the estimated direct release rate was reasonable, while simulated {sup 137}Cs activities attributable to atmospheric deposition were low compared to measured activities. The rate of atmospheric deposition onto the ocean was underestimated because of a lack of measurements of deposition onto the ocean when atmospheric deposition rates were being estimated. Measured {sup 137}Cs activities attributable to atmospheric deposition helped to improve the accuracy of simulated atmospheric deposition rates. Simulated {sup 137}Cs activities attributable to the inflow of {sup 137}Cs deposited onto the ocean outside the domain of the model were in good agreement with measured activities in the open ocean within the

  11. Seasonal variation of the {sup 137}Cs level and its relationship with potassium and carbon levels in conifer needles

    Energy Technology Data Exchange (ETDEWEB)

    Rantavaara, Aino, E-mail: aino.rantavaara@stuk.fi [Radiation and Nuclear Safety Authority (STUK), Research and Environmental Surveillance, P.O. Box 14, FI-00881 Helsinki (Finland); Vetikko, Virve, E-mail: virve.vetikko@stuk.fi [Radiation and Nuclear Safety Authority (STUK), Research and Environmental Surveillance, P.O. Box 14, FI-00881 Helsinki (Finland); Raitio, Hannu, E-mail: hannu.raitio@metla.fi [Finnish Forest Research Institute (Metla), P. O. Box 18 , FI-01301 Vantaa (Finland); Aro, Lasse, E-mail: lasse.aro@metla.fi [Finnish Forest Research Institute (Metla), Parkano Unit, Kaironiementie 15, FI-39700 Parkano (Finland)

    2012-12-15

    Seasonal variations in foliar {sup 137}Cs levels were examined in Norway spruce (Picea abies (L.) Karst.), and Scots pine (Pinus sylvestris L.) in western Finland. Our aim was to test the occurrence of seasonal variation in contents and concentrations of {sup 137}Cs, potassium and carbon in needles. The study focused on analysing levels of total {sup 137}Cs in the three youngest needle age classes and comparing them to the levels of potassium and carbon. Spruce and pine needles were collected from 50- and 65-year-old stands on 18 sampling occasions between April 1996 and February 1997. Phases of intensive growth, needle elongation and dormancy were apparent in the time series for the needle contents and activity concentration of {sup 137}Cs, both of which varied according to needle age class and tree species. The sequence of phases with a temporal fluctuation of needle contents, activity concentrations of {sup 137}Cs and concentrations of K and carbon varied occasionally, and the efficiency of their translocation revealed some differences in the dynamics of {sup 137}Cs, K and carbon in spruce and pine. The data clearly showed that the needles' K contents responded strongly to changes in K demand from other parts of the tree due to seasonal changes and that these responses were stronger than the associated retranslocations of {sup 137}Cs, particularly in Scots pine. During intensive growth, K was less mobile than {sup 137}Cs in the needles. The uptake of {sup 137}Cs by current-year needles is simultaneously affected by uptake from the soil via the roots and retranslocation from other internal sources, and both of these processes affect the observed transfer rates during the growth period. Our results provided information on the transfer rates and revealed differentiation of root uptake and retranslocation of {sup 137}Cs in needles. The study can support dynamic modelling of atmospheric {sup 137}Cs contamination in forests. -- Highlights: Black

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

    International Nuclear Information System (INIS)

    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

  13. Evaluation of the mobility of {sup 137}CS in soil profiles of the Pantanal region

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Fernanda L. da; Ferreira, Ana C.M., E-mail: fleite@ird.gov.br, E-mail: anacris@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Wasserman, Maria Angelica V.; Lapa, Celso F., E-mail: lapa@ien.gov.br, E-mail: mwasserman@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Perez, Daniel Vidal; Rendeiro, Nilson, E-mail: chpd@cnps.embrapa.br, E-mail: nilson.rendeiro@embrapa.br [Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Rio de Janeiro, RJ (Brazil). Centro Nacional de Pesquisa de Solos; Picanco Junior, Pericles L., E-mail: pericles.picanco@gmail.com [Instituto BioAtlantica (IBIO), Rio de Janeiro, RJ (Brazil); Rochedo, Elaine R.R., E-mail: elainerochedo@gmail.com [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2013-07-01

    Radioactive pollutants can cause impact on the environmental quality of soils and represent a risk to human health. Radioecological studies have shown that soils with low pH, low organic matter content and low fertility are more vulnerable to contamination by {sup 137}Cs, since the transfer to plants is high. In this study, some surface horizons of soils from Jaraguari, situated at Brazilian Pantanal were assessed in order to map their vulnerability to contamination by {sup 137}Cs. It was also proposed some mitigation measures adapted to the regional scenario in order to optimize radiological protection for rural areas. A conceptual model established to detect the vulnerability of radioactively contaminated soils was applied for soils located in the municipality of Jaraguari (Mato Grosso do Sul). This conceptual model was established based on the relationship between reference values of the soil-to-plant transfer factor (TF) for {sup 137}Cs and critical pedological parameters for each radiovulnerability category (pH, CTC and exchangeable K). The application of this conceptual model to a soil data bank using Geographic Information System (GIS) tools generated vulnerability soils maps. This result identified that most of Pantanal soils presented very low radiovulnerability, but it was possible to detect some small areas presenting extreme radiovulnerability. It was possible to conclude that these small areas is not indicated for activities that presents a potential risk for {sup 137}Cs contamination and also it must receive priority actions for remediation in the case of accident, since a superficial contamination with {sup 137}Cs in these areas can lead to a contamination of subsoil and to a significant spread of contamination via groundwater. (author)

  14. Radiological map evolution in the treatment of 137Cs liquid wastes by a reverse osmosis plant

    International Nuclear Information System (INIS)

    As a result of an accidental 137Cs source melting in one of the furnaces of a stainless steel production company located in Spain, a part of the factory was 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. After some preliminary tests in which the efficiency of reverse osmosis (RO) process in the treatment of 137Cs contaminated effluent was proved, the radioactive liquid waste was treated by a reverse osmosis plant designed by the Chemical and Nuclear Engineering Department of the Polytechnic University of Valencia (UPV), and built by LAINSA company. Membrane techniques (microfiltration, ultrafiltration, nanofiltration and reverse osmosis) have become common in the treatment of radioactive effluents having substitute conventional treatments such as evaporation and ionic exchange. The main advantages of membrane processes used for concentrating radioactive wastes are moderate operating conditions, simple apparatus, high decontamination factors and low energy consumption. The treatment was carried out by the research team UPV-LAINSA, and it consisted in the application of reverse osmosis (RO) process with the main objective of reducing the waste volume to be disposed, obtaining a treated liquid with an activity less than the legal discharge limit for 137Cs radioisotope (300 Bq/L). When working with radioactive effluents it is very important the radiological vigilance of working areas because it ensures that neither exposed personnel nor general public receive doses above established limits. Radiological vigilance consists in determining (continuously or periodically) radiation and contamination levels in working areas and even in those places where personnel can temporarily stand. The aim of this paper is to assess the evolution of radiation levels of the systems

  15. 137Cs and 210Po in Pacific Walrus and Bearded Seal from St. Lawrence Island, Alaska

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-02-02

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

  16. 137Cs and 210Po in Pacific walrus and bearded seal from St. Lawrence Island, Alaska

    International Nuclear Information System (INIS)

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

  17. 137Cs and 210Po in Pacific Walrus and Bearded Seal from St. Lawrence Island, Alaska

    International Nuclear Information System (INIS)

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

  18. The role of the Ganges-Brahmaputra mixing zone in supplying barium and [sup 226]Ra to the Bay of Bengal

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, J. (Univ. of South Carolina, Columbia (United States) Univ. of Alaska, Fairbanks (United States)); Falkner, K.K. (Massachusetts Inst. of Technology, Cambridge (United States) CNES, Toulouse (France)); Brown, E.T. (Massachusetts Inst. of Technology, Cambridge (United States)); Moore, W.S. (Univ. of South Carolina, Columbia (United States))

    1993-07-01

    The Ganges-Brahmaputra river system is ranked fourth among world rivers as a source of freshwater to the oceans and is believed to supply more sediment to the ocean than any other; 1.5 [times] 10[sup 12] kg/yr (Milliman and Meade, 1983). Barium and [sup 226]Ra are typically enriched in waters where sediment-laden rivers enter the ocean. As such, the Ganges-Brahmaputra is likely to produce globally significant barium and [sup 226]Ra fluxes to the ocean. Water samples for barium and [sup 226]Ra were collected within four major channels of the Ganges-Brahmaputra mixing zone during a period of low sediment and freshwater discharge. The data suggest that in addition to suspended sediments supplied directly from rivers, river sediments deposited during high discharge in mangroves and on islands are desorbing barium and [sup 226]Ra to seawater. The release of barium and [sup 226]Ra from these sediment deposits is out-of-phase with the direct supply of sediments from the rivers. Estimates of the annual fluxes of barium and [sup 226]Ra from the Ganges-Brahmaputra mixing zone were also derived. The fluxes of barium and [sup 226]Ra are 5.3 [times] 10[sup 8] mol barium/yr and 9.5 [times] 10[sub 14] dpm radium/yr. The first silicate and phosphate mixing profiles for this system are reported. 29 refs., 6 figs., 3 tabs.

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

    Science.gov (United States)

    Zarubina, N

    2016-09-01

    Levels of soil contamination with (137)Cs, the belonging of fungi to a certain ecological group, the localization depth of the main part of mycelium in soil are the primary factors influencing the value of (137)Cs specific activity in higher fungi after the accident at Chernobyl NPP. It has been found that the value of (137)Cs specific activity in fungi of one species could vary by more than 10 times during a vegetation period. A correlation between the changes of (137)Cs content in fungi during the vegetation period and the amount of precipitates during various periods preceding the collection of samples has not been determined. An assumption has been proposed stating dependence between peculiarities of mycelium growth during the vegetation period and the changes of (137)Cs specific activity in fungi. PMID:26690320

  20. Radiochemical analysis of 210Pb e 226Ra in samples of sludges and scales in petroleum industry

    International Nuclear Information System (INIS)

    The exploration and production of oil can generate different types of waste, such as scales, which are formed in the internal surface of pipes and equipment, sludges that is deposited in water/oil separators, storage tanks and valves and water that is removed along with the oil, which bring to the surface some of the radionuclides present in the rock matrix. From a radiological point of view, the most important radionuclides, which appear in sludges and scales are 228Ra, 226Ra, 210Pb and 228Th, since the exposure to these radionuclides can represent a significant dose on workers. The analysis already performed using gamma spectrometry in samples of sludge and scales indicated the presence of high concentrations of radio isotopes, showing the need to enlarge the radiometric survey including other elements of the 238U series. This work focuses on radiochemical determination of 210Pb and 226Ra concentrations in samples of sludge and scales

  1. Bioavailability of radionuclides 226Ra, 228Ra and 210Pb present in the brazilian phosphate fertilizers and phosphogypsum

    International Nuclear Information System (INIS)

    Phosphogypsum, also called gypsum, by-product of the phosphate fertilizer industry, can be used as soil conditioner since it provides improvements in the soil-plant system. However, this by-product concentrates radionuclides of the U and Th series, present in the phosphate rock used as raw material, which can impact the environment. In order to study the bioavailability of radionuclides, samples of phosphogypsum and phosphate fertilizers (monoammonium phosphate and triple superphosphate) were analyzed. The concentration of 226Ra, 228Ra and 210Pb were determined by gamma spectrometry. The samples were leached with a mild EDTA solution and the radionuclides present in the final solution were determined by total alpha and beta counting on a gas flow proportional counter. The percentage of extraction varied from 1.6% to 1.7% for 210Pb, from 0.5% to 1.4% for 226Ra and from 0.1% to 1.0% for the 228Ra in phosphogypsum samples. The low percentage of extraction obtained for the radionuclides can be partly explained by the low solubility of phosphogypsum, which ranged from 7.7% to 16%. For the monoammonium phosphate samples the percentage of extraction were less than 26% for 226Ra, less than 10% for '228Ra and less than 10% for 210Pb. In spite of the high solubility of 77% of monoammonium phosphate in the EDTA solution, low concentrations of radionuclides were observed in the leached solution. For the triple superphosphate samples, the percentage of extraction was 2.3% for 226Ra, 1.2% for 228Ra and 11.3% for 210Pb. In spite of the high solubility of 66% of triple superphosphate in the EDTA solution, low concentrations of radionuclides were observed in the leached solution. (author)

  2. Investigation of $\\alpha$-decay rates of $^{221}$Fr, $^{224}$Ra and $^{226}$Ra in different environments

    CERN Multimedia

    2007-01-01

    It has recently been suggested, and indicated experimentally, that $\\alpha$- decay half-lives are modified by solid state effects in the surrounding environment. We propose here to measure with high accuracy the $\\alpha$-decay half-life of $^{221}$Fr, $^{224}$Ra and $^{226}$Ra in insulators and metals. Furthermore we plan to investigate the temperature dependency of the half-life in these materials (room temperature, 4 K and 10 mK).

  3. Seasonal variation of 226Ra and 222Rn in mineral spring waters of Aguas da Prata-Brazil

    International Nuclear Information System (INIS)

    Concentration levels of 226Ra and 222Rn have been analysed in most of the mineral spring waters available in the Aguas da Prata region, which is located in the Pocos de Caldas plateau, one of the biggest weathered alkaline intrusions of the world. In this plateau can be found many health resorts[based on springs of thermal and mineral waters. The Aguas da Prata spring waters show a large variety of composition. It has been observed bicarbonates, carbonates and sulphates salts in these mineral waters. The 226Ra was determined by gross alpha counting of a Ba(Ra)SO4 precipitate. The measurement was carried out in a low background gas flow proportional counter. The 222Rn concentrations were determined by liquid scintillation method. Water samples were randomly collected at 9 spring sites over a period of one year, in order to evaluate the seasonal variation of these radionuclides. Lower concentrations were found mostly in the rainy season (summer), which presents 80% of the annual rainfall of the region (1500 mm/year). Higher concentrations up to 2223 mBq/L for 226Ra and 131 Bq/L for 222Rn have been observed in waters with low level of soluble salts. Waters which present high levels of carbonate and sulphate salts showed maximum values of 316 mBq/L for 226Ra and 30 Bq/L for 222Rn. This behaviour is mainly due to the physicochemical properties of these radionuclides in water as well as to the lithologic structure of the aquifers. (authors). 6 refs., 2 figs., 1 tab

  4. Concentration factors for 226Ra in the mullet (Mugilidae) species Mugil cephalus from the South Adriatic Sea

    International Nuclear Information System (INIS)

    226Ra activity concentration in the mullet (Mugilidae) species Mugil cephalus whole individuals, and some organs (gills, gastrointestinal system, fins, muscle and bones), was measured by the γ-coincidence spectrometer PRIPYAT-2M. 226Ra transfer parameters [concentration factors (CFs)] from seawater, sediment and mud with detritus to fish tissues, and annual intake by humans consuming this fish species, have been estimated. Minimum detected radium activity concentration in whole M. cephalus individuals was found to be 0.89 ± 0.42 to 3.09 ± 0.41 Bq kg-1, with arithmetic mean of 1.65 ± 0.39 Bq kg-1. An average concentration in muscles is found to be 2.28 ± 0.84 Bq kg-1, in gills - 5.02 ± 1.85 Bq kg-1, in gastrointestinal system - 12.88 ± 1.71 Bq kg-1, and in bones - 14.72 ± 3.75 Bq kg-1. No one fins showed radium activity above minimum detectable one. Annual intake of 226Ra by human consumers of this fish species is estimated to provide an effective dose of 0.006 mSv year-1. CFs for 226Ra indicating transfer from seawater to whole individuals ranged from 8.9 to 30.9, and those indicating transfer from the sediment and mud with detritus - from 0.11 to 0.39 and from 0.08 to 0.3, respectively. The seawater to bones CFs varied from 97.9 to 197.3, to gastrointestinal system - from 59 to 178.8, to gills - from 22.5 to 68.3, to muscles - from 17 to 30.8. (author)

  5. Evaluation of radionuclides content in the Near-Aral inhabited area's soils

    International Nuclear Information System (INIS)

    The soils analysis for radionuclides content determination in three inhabited areas of Near-Aral region (Shiili, Kazalinsk and Zhalagash) is carried out. In capacity of the 226Ra, 232Th, 40K, 137Cs, and radon concentrations analytical parameters were selected. A mean, minimal and maximal values of 226Ra, 232Th, 40K, 137Cs radioisotopes in the selected areas soils are presented. Results of radionuclide content researches testify about 137Cs global fallout typical levels for the Northern Hemisphere. So on the base of these data one can affirm that radiation situation in these regions is normal and radiation background level does not presents threat for human health. The indoor radon content excluding of two points does not exceeds the stated norms

  6. Determination of 226Ra, 224Ra, 223Ra and 228Ra in mineral water samples of the Slovak Republic

    International Nuclear Information System (INIS)

    The Slovak Republic is very rich in mineral water sources. In recent years, it has been discovered that a number of mineral waters in the Slovak Republic contain high levels of 226Ra and 228Ra. Moreover, there is a lack of information on 224Ra and 223Ra concentrations in mineral waters as well. The currently approved techniques for alpha emitting radium isotopes are based on radon emanation methods. Due to the long ingrowth periods required by these techniques, any 224Ra and 223Ra in the sample decay away and go undetected. For this reason, we have used an alpha spectrometric method for the simultaneous determination of 226Ra, 223Ra and 224Ra. Radium was concentrated by a lead sulphate co-precipitation. The precipitate was dissolved in EDTA and the radium isotopes were separated from possible interfering radionuclides using barium sulphate micro precipitation. The radium-barium precipitate was filtered and counted by alpha spectrometry. 133Ba was used to quantify the yield by gamma spectrometry. In our laboratory, gamma spectrometry was also used for the determination of 228Ra in mineral water samples. Radium was concentrated by a lead-barium sulphate co-precipitation. 133Ba was used to quantify the yield, found to be 97 % on the average, by gamma spectrometry. Furthermore, the committed effective doses for 226Ra, 224Ra, 223Ra, 228Ra intake via ingestion of mineral waters for the members of public were calculated. (author)

  7. Chromosome breakage in lymphocytes from humans with body burdens of 226Ra

    International Nuclear Information System (INIS)

    Peripheral lymphocytes from 10 controls and 40 patients with body burdens of 226Ra ranging from below the limit of detection to 8.6 μCi were scored for unstable chromosome aberrations. The patient population was divided into four groups: a group with body burdens below the limit of detection (less than 0.003 μCi, 12 patients); a low-burden group (0.003 to 0.099 μCi, 13 patients); a moderate-burden group (0.1 to 0.99 μCi, 11 patients); and a high-burden group (greater than 1.0 μCi, 4 patients). In none of these groups was the frequency of cells with unstable aberrations significantly elevated above that in the controls. The rate of occurrence of dicentric and ring chromosomes was above the control frequency in only the two patients with the highest burdens (3.55 and 8.6 μCi). Our results are consistent with the expectation derived from a recent calculation of alpha dose delivered to blood by bone-deposited radium and its decay products. Marshall and Hoegerman have estimated that the blood dose for an individual with a radium burden of 1.0 μCi is 0.09 +- 0.03 rad/year. The value is compared with the dose estimate used by Boyd et al. in their study of British radium-dial painters, and the relevance of the blood dose to the lymphocyte dose is discussed

  8. Determination of natural radioactivity levels in Kars- city center, Turkey

    OpenAIRE

    B., CENGİZ G.; REŞİTOĞLU,; De, S.

    2014-01-01

    The objective of this study is to determine the distribution of natural radionuclides in surface soils in the Karscity center, Turkey. The activity concentrations of 238U, 232 Th, 40 K and 137Cs in 38 soil samples collected from the study area were measured through NaI(Tl) gamma spectrometry. The average activities of the samples were determined to be 47.8, 31.2 and 536 Bqkg-1 for the natural radionuclides 226Ra (238U), 232Th, 40K, respectively, and 18 Bqkg-1 for the fission product 137Cs. ...

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  11. U-isotopes and (226)Ra as tracers of hydrogeochemical processes in carbonated karst aquifers from arid areas.

    Science.gov (United States)

    Guerrero, José Luis; Vallejos, Ángela; Cerón, Juan Carlos; Sánchez-Martos, Francisco; Pulido-Bosch, Antonio; Bolívar, Juan Pedro

    2016-07-01

    Sierra de Gádor is a karst macrosystem with a highly complex geometry, located in southeastern Spain. In this arid environment, the main economic activities, agriculture and tourism, are supported by water resources from the Sierra de Gádor aquifer system. The aim of this work was to study the levels and behaviour of some of the most significant natural radionuclides in order to improve the knowledge of the hydrogeochemical processes involved in this groundwater system. For this study, 28 groundwater and 7 surface water samples were collected, and the activity concentrations of the natural U-isotopes ((238)U, (235)U and (234)U) and (226)Ra by alpha spectrometry were determined. The activity concentration of (238)U presented a large variation from around 1.1 to 65 mBq L(-1). Elevated groundwater U concentrations were the result of oxidising conditions that likely promoted U dissolution. The PHREEQC modelling code showed that dissolved U mainly existed as uranyl carbonate complexes. The (234)U/(238)U activity ratios were higher than unity for all samples (1.1-3.8). Additionally, these ratios were in greater disequilibrium in groundwater than surface water samples, the likely result of greater water-rock contact time. (226)Ra presented a wide range of activity concentrations, (0.8 up to about 4 × 10(2) mBq L(-1)); greatest concentrations were detected in the thermal area of Alhama. Most of the samples showed (226)Ra/(234)U activity ratios lower than unity (median = 0.3), likely the result of the greater mobility of U than Ra in the aquifer system. The natural U-isotopes concentrations were strongly correlated with dissolution of sulphate evaporites (mainly gypsum). (226)Ra had a more complex behaviour, showing a strong correlation with water salinity, which was particularly evident in locations where thermal anomalies were detected. The most saline samples showed the lowest (234)U/(238)U activity ratios, probably due to fast uniform bulk mineral dissolution

  12. U-isotopes and (226)Ra as tracers of hydrogeochemical processes in carbonated karst aquifers from arid areas.

    Science.gov (United States)

    Guerrero, José Luis; Vallejos, Ángela; Cerón, Juan Carlos; Sánchez-Martos, Francisco; Pulido-Bosch, Antonio; Bolívar, Juan Pedro

    2016-07-01

    Sierra de Gádor is a karst macrosystem with a highly complex geometry, located in southeastern Spain. In this arid environment, the main economic activities, agriculture and tourism, are supported by water resources from the Sierra de Gádor aquifer system. The aim of this work was to study the levels and behaviour of some of the most significant natural radionuclides in order to improve the knowledge of the hydrogeochemical processes involved in this groundwater system. For this study, 28 groundwater and 7 surface water samples were collected, and the activity concentrations of the natural U-isotopes ((238)U, (235)U and (234)U) and (226)Ra by alpha spectrometry were determined. The activity concentration of (238)U presented a large variation from around 1.1 to 65 mBq L(-1). Elevated groundwater U concentrations were the result of oxidising conditions that likely promoted U dissolution. The PHREEQC modelling code showed that dissolved U mainly existed as uranyl carbonate complexes. The (234)U/(238)U activity ratios were higher than unity for all samples (1.1-3.8). Additionally, these ratios were in greater disequilibrium in groundwater than surface water samples, the likely result of greater water-rock contact time. (226)Ra presented a wide range of activity concentrations, (0.8 up to about 4 × 10(2) mBq L(-1)); greatest concentrations were detected in the thermal area of Alhama. Most of the samples showed (226)Ra/(234)U activity ratios lower than unity (median = 0.3), likely the result of the greater mobility of U than Ra in the aquifer system. The natural U-isotopes concentrations were strongly correlated with dissolution of sulphate evaporites (mainly gypsum). (226)Ra had a more complex behaviour, showing a strong correlation with water salinity, which was particularly evident in locations where thermal anomalies were detected. The most saline samples showed the lowest (234)U/(238)U activity ratios, probably due to fast uniform bulk mineral dissolution

  13. Radioactivity in {sup 137}Cs of the French terrestrial environment: interpretation of OPERA data acquired between 1993 and 2004; Radioactivite en {sup 137}Cs de l'environnement terrestre francais. Interpretation des donnees OPERA acquises de 1993 a 2004

    Energy Technology Data Exchange (ETDEWEB)

    Roussel-Debet, S.; Masson, O.; Salaun, G.

    2005-07-01

    After having indicated the implemented equipment and methods (location of sampling stations, general presentation of results in terms of {sup 137}Cs activity measurement, of {sup 134}Cs activity, and of isotopic {sup 137}Cs /{sup 134}Cs rate), this report presents, analyses and comments detailed measurements performed by the OPERA (Permanent Observatory of Radioactivity) between 1993 and 2004 of {sup 137}Cs and {sup 134}Cs activity in soils, grass, salads, thyme, mushrooms, cow milk, cow cheese, goat milk, goat cheese, and meat (beef muscle)

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

    Science.gov (United States)

    Snow, Mathew S; Snyder, Darin C

    2016-01-01

    (135)Cs/(137)Cs isotopic analyses represent an important tool for studying the fate and transport of radiocesium in the environment; in this work the (135)Cs/(137)Cs isotopic composition in environmental samples taken from across Europe is reported. Surface soil and vegetation samples from western Russia, Ukraine, Austria, and Hungary show consistent aged thermal fission product (135)Cs/(137)Cs isotope ratios of 0.58 ± 0.01 (age corrected to 1/1/15), with the exception of one sample of soil-moss from Hungary which shows an elevated (135)Cs/(137)Cs ratio of 1.78 ± 0.12. With the exception of the outlier sample from Hungary, surface soil/vegetation data are in quantitative agreement with values previously reported for soils within the Chernobyl exclusion zone, suggesting that radiocesium at these locations is primarily composed of homogenous airborne deposition from Chernobyl. Seawater samples taken from the Irish Sea show (135)Cs/(137)Cs isotope ratios of 1.22 ± 0.11 (age corrected to 1/1/15), suggesting aged thermal fission product Cs discharged from Sellafield. The differences in (135)Cs/(137)Cs isotope ratios between Sellafield, Chernobyl, and global nuclear weapons testing fallout indicate that (135)Cs/(137)Cs isotope ratios can be utilized to discriminate between and track radiocesium transport from different nuclear production source terms, including major emission sources in Europe. PMID:26540258

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  16. The 226Ra isotope activities in ground water samples drawn of two wells from the Meridional Pluton, Morungaba Granitoids, eastern Sao Paulo State; Atividades do 226Ra em aguas subterraneas extraidas de dois pocos localizados no pluton meridional, granitoides de Morungaba, SP

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, Fabio de Oliveira; Silva Junior, Mario Goncalves da; Bertolla, Luciana; Ribeiro, Fernando Brenha [Sao Paulo Univ., SP (Brazil). Inst. de Astronomia, Geofisica e Ciencias Atmosfericas. Dept. de Geofisica]. E-mail: brenha@iag.usp.br

    2005-07-01

    The 226Ra activities, both in solution and associated with suspended solids, were measured in ground water samples drawn from two wells drilled in a fractured granitic aquifer from the Meridional Pluton, Morungaba Granitoids, eastern Sao Paulo State. The 226Ra isotope activities were measured in a sequence of samples collected about one month apart between March, 2003 and April 2004. The 226Ra activities were measured by radon gas emanometry. The mean dissolved 226Ra activity concentration activities observed in the two wells were (44.9 {+-} 7.1) mBq/L and (51.6 {+-} 8.8) mBq/L. The 226Ra activity of the suspend solids in a liter of these waters varied between (0,6 {+-} 0,1) mBq and (13 {+-} 1) mBq, respectively. (author)

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

    Science.gov (United States)

    Alava, Juan José; Gobas, Frank A P C

    2016-02-15

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

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

    Science.gov (United States)

    Alava, Juan José; Gobas, Frank A P C

    2016-02-15

    To track the long term bioaccumulation of (137)Cs in marine organisms off the Pacific Northwest coast of Canada, we developed a time dependent bioaccumulation model for (137)Cs in a marine mammalian food web that included fish-eating resident killer whales. The model outcomes show that (137)Cs can be expected to gradually bioaccumulate in the food web over time as demonstrated by the increase of the apparent trophic magnification factor of (137)Cs, ranging from 0.76 after 1 month of exposure to 2.0 following 30 years of exposure. (137)Cs bioaccumulation is driven by relatively rapid dietary uptake rates, moderate depuration rates in lower trophic level organisms and slow elimination rates in high trophic level organisms. Model estimates of the (137)Cs activity in species of the food web, based on current measurements and forecasts of (137)Cs activities in oceanic waters and sediments off the Canadian Pacific Northwest, indicate that the long term (137)Cs activities in fish species including Pacific herring, wild Pacific salmon, sablefish and halibut will remain well below the current (137)Cs-Canada Action Level for consumption (1000 Bq/kg) following a nuclear emergency. Killer whales and Pacific salmon are expected to exhibit the largest long term (137)Cs activities and may be good sentinels for monitoring (137)Cs in the region. Assessment of the long term consequences of (137)Cs releases from the Fukushima aftermath should consider the extent of ecological magnification in addition to ocean dilution. PMID:26657356

  19. Distribution of /sup 137/Cs in surface intertidal sediments from the Solway Firth

    Energy Technology Data Exchange (ETDEWEB)

    Jones, D.G.; Miller, J.M.; Roberts, P.D. (Institute of Geological Sciences, Keyworth (UK))

    1984-05-01

    The distribution of /sup 137/Cs from the Sellafield (Windscale) nuclear fuel reprocessing plant has been examined in detail in the surface intertidal sediments of the inner Solway Firth by means of a hovercraft-borne radiometric survey. With the exception of a belt of relatively active sands to the south of Silloth, caesium distribution is generally consistent with that of fine-grained sediment such that the highest concentrations occur in mud flat and salt marsh sediments which are most extensive in sheltered coastal embayments. /sup 137/Cs activities in July 1980 were typically 2 to 30 pCi g/sup -1/ but locally exceeded 50 pCi g/sup -1/. These levels are considerably lower than those recorded in locations, such as the outer Solway and Ravenglass estuary, which are closer to the Sellafield outfall.

  20. Bioaccumulation of {sup 137}Cs and {sup 57}Co by five marine phytoplankton species

    Energy Technology Data Exchange (ETDEWEB)

    Heldal, H.E. E-mail: hilde.elise.heldal@imr.no; Stupakoff, I.; Fisher, N.S

    2001-07-01

    Under controlled laboratory conditions, we have examined the bioaccumulation of {sup 137}Cs and {sup 57}Co in three prymnesiophytes, the coccolithophorid Emiliania huxleyi and the non-calcareous species Isochrysis galbana and Phaeocystis globosa, and two diatoms Skeletonema costatum and Thalassiosira pseudonana. We measured the uptake in growing and non-growing cells and determined concentration factors on both volume and dry weight bases. For uptake of {sup 57}Co in non-growing cells, volume concentration factors (VCF) at equilibrium ranged from 0.2x10{sup 3} for E. huxleyi to 4x10{sup 3} for T. pseudonana. For uptake of {sup 137}Cs in non-growing cells, the VCFs were low for all species and the uptake pattern seemed unsystematic. The results suggest that, in contrast to Co, the cycling and bioaccumulation of Cs in marine animals are unlikely to be affected by Cs accumulation in primary producers.

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

    Institute of Scientific and Technical Information of China (English)

    LU Xueqiang; MATSUMOTO Eiji

    2009-01-01

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

  2. Estimating Soil Erosion in Northeast China Using 137Cs and 210Pbex

    Institute of Scientific and Technical Information of China (English)

    YANG Yu-Hong; YAN Bai-Xing; ZHU Hui

    2011-01-01

    Evaluation of soil erosion in agricultural fields is valuable to develop conservation practices for reducing agricultural nonpoint source pollution.Soil erosion rates were quantified using the fallout radionuclide tracer technique in Mojiagou Basin located on the outskirts of Changchun in Northeast China.The calculated soil erosion rates in the study area were 1.99 and 1.85 mm year-1 using 137Cs and excess 210Pb (210Pbex) measurements,respectively.Both fallout radionuclides showed a similar tendency at downslope sites.All measured sites have experienced net erosion during the past 50 to 100 years.137Cs and 210Pbex measurements were useful to quantify soil erosion rates on field and small basin scales.At this rate of erosion,the current fertile topsoil layer would be entirely removed within 70 years.

  3. The distribution of 137Cs in surface intertidal sediments from the Solway Firth

    International Nuclear Information System (INIS)

    The distribution of 137Cs from the Sellafield (Windscale) nuclear fuel reprocessing plant has been examined in detail in the surface intertidal sediments of the inner Solway Firth by means of a hovercraft-borne radiometric survey. With the exception of a belt of relatively active sands to the south of Silloth, caesium distribution is generally consistent with that of fine-grained sediment such that the highest concentrations occur in mud flat and salt marsh sediments which are most extensive in sheltered coastal embayments. 137Cs activities in July 1980 were typically 2 to 30 pCi g-1 but locally exceeded 50 pCi g-1. These levels are considerably lower than those recorded in locations, such as the outer Solway and Ravenglass estuary, which are closer to the Sellafield outfall. (author)

  4. 137Cs transfer for forage to milk and its removal by clay treatment

    International Nuclear Information System (INIS)

    Since Apr 29, 1986, the radioactive contamination resulting from the accident of the Chernobyl reactor was measured in various kinds of matrixes, primarily in Northern Italy. Transfer kinetics of 137Cs from forage of known activity to milk was studied over a period of one year and the body Cs absorption was evaluated by measuring the percentages of Cs eliminated with milk as well as with urine and feces. Further, the decay rate of 137Cs in milk was assessed and the results of the kinetic analysis are reported. The efficiacy of various clay materials in removing Cs from milk was also evaluated. The results of adsorption kinetics for the grey clay which resulted the most effective material are reported. (author) 3 refs.; 5 figs

  5. Microbial transmutation of 137Cs and LENR in growing biological systems

    International Nuclear Information System (INIS)

    This article presents the results of long-term investigations of stable and radioactive isotopes transmutation in growing microbiological cultures. It is shown that transmutation during growth of microbiological associations is 20 times more effective than the same process in the form of 'clean' microbiological culture. In this work, the process of controlled decontamination of highly active reactor isotopes (reactor waste) through the process of growing microbiological associations has been studied. The most rapidly increasing decay rate of 137Cs isotope, which occurred with the 'effective' half life τ* ≈ 310 days (involving an increase in rate and decrease in half life by a factor of 35) was observed in the presence of Ca salt in closed flask with active water containing 137Cs solution and optimal microbiological association. (author)

  6. Airborne fallout mapping of {sup 137}Cs - STUK/HUT team

    Energy Technology Data Exchange (ETDEWEB)

    Nikkinen, M.; Aarnio, P. [Helsinki Univ. of Technology, Espoo (Finland); Honkamaa, T.; Tiilikainen, H. [Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland)

    1997-12-31

    The task of the team was to create a fallout map of {sup 137}Cs on a specified area in Padasjoki Auttoinen village. The team used AB-420 helicopter of the Finnish Frontier Guard. The team had two measuring systems: HPGe system (relative efficiency 18%) and NaI system (5`x5`). Both systems produced similar maps. The average {sup 137}Cs fallout within the area (lakes and ponds included) was 88 kBq m{sup -2,} the maximum value being 161 kBq m{sup -2}. In an emergency the HPGe is superior to NaI because of its better energy resolution, giving possibility to obtain nuclide-specific results. (au).

  7. Modelling the Long Term Leaching Behaviour of 137CS from Different Stabilized Waste Matrices

    International Nuclear Information System (INIS)

    Leaching characteristics of ''1''3''7Cs from immobilized waste matrices in different cement-based grouts have been assessed to investigate the influence of the additives on the leaching behavior of the solid waste matrices. The International Atomic Energy's Agency (IAEA) standard leach method has been employed to study the leach pattern of 137Cs radionuclide from the immobilized waste form. The examination of the leaching data revealed that clay additives reduces the leach rate for the studied radionuclide. The controlling leaching mechanism has been studied and the transport parameters were calculated for all studied waste matrices. Simplified analytical models have been derived to predict the Cumulative Leach Fraction (CLF) of radionuclides over the studied experimental period. These simplified research models could be used as a screening tool to assess the performance of the waste matrix under repository conditions. (author)

  8. Ecological half-life of {sup 137}Cs in lichens in an alpine region

    Energy Technology Data Exchange (ETDEWEB)

    Machart, Peter [Division of Physics and Biophysics, Department of Materials Engineering and Physics, University of Salzburg, Hellbrunner Strasse 34, 5020 Salzburg (Austria); Hofmann, Werner [Division of Physics and Biophysics, Department of Materials Engineering and Physics, University of Salzburg, Hellbrunner Strasse 34, 5020 Salzburg (Austria)], E-mail: Werner.Hofmann@sbg.ac.at; Tuerk, Roman [Department of Organismic Biology, University of Salzburg, Hellbrunner Strasse 34, 5020 Salzburg (Austria); Steger, Ferdinand [Austrian Research Centers, 2444 Seibersdorf (Austria)

    2007-09-15

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

  9. Variation of 14C, 137Cs and stable carbon composition in forest soil and its implications

    International Nuclear Information System (INIS)

    In Japan, about 70% of land area is covered by forest. Therefore, forest ecosystem plays a vital role in ultimate fate of radionuclides and carbon cycle in terrestrial environment. Three undisturbed forest soil profiles were collected from Ibaraki Prefecture, Japan. The 137Cs data illustrate that maximum fallout deposition of 137Cs took place around 1964. 14C determination shows that 14C also has peak values in the top 10 cm of the soil profiles ascribed to the highest bomb 14C level in 1960's. The 13C data show that the turnover dynamics of soil organic carbon could be described very well by progressive enrichment values of δ13C. (author)

  10. Evaluation of 137Cs internal contamination in children by means of whole body counter measurements

    International Nuclear Information System (INIS)

    Two series of internal contamination measurements were performed on children from Byelorussia by means of whole body and urine counting. The body contamination was related to 134Cs and 137Cs emitted in the accident at the Chernobyl Nuclear Power Station on April 26, 1986. The data have been analysed in order to have an experimental estimation of the caesium metabolic parameters and make a comparison with those indicated in ICRP 56, point out the effect of sex and age in relation to 137Cs body activity and half-time of caesium long term retention fraction and obtain indications concerning the statistical distributions of internal contamination in children of both sexes living in different areas of Byelorussia. (author)

  11. Cleanup techniques for Finnish urban environments and external doses from 137Cs - modelling and calculations

    International Nuclear Information System (INIS)

    The external doses under various radioactive deposition conditions are assessed and the efficiencies of some simple decontamination techniques (grass cutting, vacuum sweeping, hosing of paved surfaces and roofs, and felling trees) are compared in the study. The present model has been constructed for the Finnish conditions and housing areas, using 137Cs transfer data from the Nordic and Central European studies and models. The compartment model concerns behaviour and decontamination of 137Cs in the urban environment under summer conditions. Doses to man have been calculated for wet (light rain) and dry deposition in four typical Finnish building areas: single-family wooden houses, brick terraced-houses, blocks of flats and urban office buildings. (26 refs.)

  12. The association of 137Cs with various components of tea leaves fermented from Chernobyl contaminated green tea

    International Nuclear Information System (INIS)

    The distribution of137Cs among various components of fermented tea leaves harvested after the Chernobyl accident was investigated by applying a sequential extraction procedure. An association of the radioisotope with the phenolic moiety of a phenylglucoside was detected in black tea infusate using permeation chromatography as well as UV and NMR spectroscopy. The chemical structure of a 137Cs containing compound also isolated from an artificially 137Cs labelled aqueous extract of green leaves was compared to that of fermented tea leaves. The implications of the findings on the chemical forms of the radionuclide are discussed

  13. Accumulation of {sup 137}Cs in trefoil (leaf and stem), ``Mitsuba``, Cryptotaenia japonica Hassk, immersed in hydroponic culture medium

    Energy Technology Data Exchange (ETDEWEB)

    Motegi, Misako; Miyake, Sadaaki; Ohsawa, Takashi; Nakazawa, Kiyoaki [Saitama Institute of Public Health, Urawa (Japan); Izumo, Yoshiro

    1998-11-01

    Accumulation of {sup 137}Cs in trefoil (leaf and stem), ``Mitsuba``, Cryptotaenia japonica Hassk, with or without root was investigated to prepare higher radioactive plant in hydroponic culture medium (140-150 Bq/ml). It was found that {sup 137}Cs concentration in plant tissue was increased with time, as high as 1.6 times of that in the culture medium after 4 days. On the other hand, {sup 137}Cs concentration was affected by carrier element (Cs>6 ppm) and coexistent elements in the medium. Radioactivity of the plant after 4 days was shown to be sufficient for successive experiments. (author)

  14. The inhibitory effects of potassium chloride versus potassium silicate application on (137)Cs uptake by rice.

    Science.gov (United States)

    Fujimura, Shigeto; Yoshioka, Kunio; Ota, Takeshi; Ishikawa, Tetsuya; Sato, Makoto; Satou, Mutsuto

    2016-03-01

    After the accident at the Fukushima Dai-ichi Nuclear Power Plant owned by the Tokyo Electric Power Company on 11 March 2011, potassium fertilizer was applied to agricultural fields in the southern Tohoku and northern Kanto regions of Japan to reduce the uptake of radiocesium by crops. In this study, we examined the effects of two types of potassium fertilizers, potassium chloride (a readily available potassium fertilizer) and potassium silicate (a slow-release potassium fertilizer), as well as a split application of potassium, on the accumulation of (137)Cs by rice plants in two pot experiments. The (137)Cs concentrations in the brown rice and in the above-ground plants were significantly lower after potassium chloride application than after potassium silicate application. The potassium ion (K(+)) concentrations in soil solutions sampled 9 and 21 d after transplanting were significantly higher for the potassium chloride application than for the potassium silicate application. The K(+) concentrations in soil solutions observed in the application of potassium silicate were similar to those in the treatment when no potassium was applied. This finding indicates that the application of potassium silicate did not sufficiently increase the available K(+) for rice plants in the soil, which led to a greater uptake of (137)Cs after the potassium silicate application than after the application of potassium chloride. The (137)Cs concentration in brown rice was higher in the split application of potassium fertilizer with the second application at the full heading stage than that without split application and the split application with the second application before heading. PMID:26773513

  15. 137Cs mobility in soils and its long-term effect on the external radiation exposure

    International Nuclear Information System (INIS)

    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

  16. Retention and removal 137Cs in Japanese catfish (Silurus asotus Linnaeus) in dressing and cooking method

    International Nuclear Information System (INIS)

    Japanese catfish contaminated by 137Cs have been used to investigate how the dressing and cook-ing method affect the removal of radioactivity from the fish. During the dressing, 6.0% of the initial 137Cs activity was removed by washing the live fish, further 30.3% of the activity relative to washed fish was removed by discarding the non-edible body parts (skeletons, fins, visceral mass, liver, kidney etc.) and washing the chopped fish. Fish curry was cooked using various spices, green-stuffs and vegetable oil following a method commonly used in South East and East Asian countries. The cooking process removed a further 61.6% of the 137Cs activity relative to the activity in dressed fish. Taken together, this normal domestic fish dressing and culinary process removed 74.7% of the initial 137Cs activity present in the live fish. During the cook-ing, the radioactivity removed from the fish pieces was found to distributed over the ingredients of the curry. The cooked fish pieces retained an average, 38.5% of the radioactivity present in the dressed raw fish pieces. Among the ingredients, the gravy was found to contain an average of 34.8% of the activity of the dressed fish. The activity in green-stuffs was found to vary from 4.0% (in cauliflower) to 7.2% (in potato). It may be concluded that normal home preparation and culinary processes removed the radio-activity from the fish to a great extent. In addition, discarding the gravy and green-stuffs of the curry further reduce the radioactivity intake into the human body. (author)

  17. Removal of 137Cs in Japanese catfish during preparation for consumption

    International Nuclear Information System (INIS)

    Japanese catfish contaminated by 137Cs have been used to investigate how dressing and cooking methods affect the removal of radioactivity from the fish. During the dressing, 6.0% of the initial 137Cs activity in live fish was removed by washing them, and a further 30.3% of this activity relative to the washed fish was removed by discarding the nonedible body parts (such as the skeleton, fins, visceral mass, liver, and kidney) and by washing the chopped edible remains. Fish curry was cooked with various spices, vegetable oil, and greens and other vegetables following a method commonly used in Southeast Asian and East Asian countries. The cooking process removed a further 61.6% of the 137Cs activity relative to the activity in dressed fish. Taken together, this normal domestic fish dressing and culinary process removed 74.7% of the initial 137Cs activity that had been present in the live fish. During the cooking, the radioactivity removed from the fish pieces was found to be distributed throughout the ingredients of the curry. The cooked pieces retained, on average, 38.5% of the radioactivity present in the raw dressed pieces. Among the ingredients, the gravy was found to contain an average of 34.8% of the activity of the dressed fish. The activity in greens and vegetables was found to vary from 4.0% (in cauliflower) to 7.2% (in potatoes). It may be concluded that normal home preparation and culinary processes removed much of the radioactivity from the fish. (author)

  18. Study on selective sorption of 137Cs on Al-substituted calcium silicate hydroxy hydrate

    International Nuclear Information System (INIS)

    Sorption properties have been investigated by radiometric (tracer) technique at room temperature for aluminium substituted calcium silicate hydroxy hydrate, known as tobermorite. The 137Cs selectivity has been examined in presence of 1000 times concentrated solution of Na+, Ca2+, and Ba2+. The results suggest that the title phase could be used for immobilization of radioactive cesium. Cation exchange reaction takes place mainly from edge and planar surface sites along with interlayer Ca2+ sites. (author)

  19. Transfer of 137Cs from Chernobyl fallout to meat and milk in Hungary

    International Nuclear Information System (INIS)

    Air, soil, forage, milk and meat samples were analysed for 137Cs and 134Cs following the Chernobyl accident. Deposition of fallout varied widely, the heaviest being in northwestern Hungary. Controlled experiments were conducted on State farms at four locations to determine the transfer coefficients from forage to the milk (Fm) of cows, sheep and goats and to the meat (Ff) of cows and sheep, goats and roe deer. Forage contaminated by Chernobyl fallout in late May of 1986 produced lower Fm and Ff values than worldwide fallout in the 1960s because the form of 137Cs deposited on forage was less available to cattle and sheep. The lower transfer has important implications for assessing the dose commitment of the human population. The second cutting of forage in 1986 and all cuttings in 1987 had greatly reduced concentrations of 137Cs but the Fm and Ff values were much higher, thereby suggesting that after removal of the original deposition the 137Cs in plants was in a more soluble form. Roe deer were fed the same hay as sheep for 50 days and the Ff was 0.35 for deer meat and 0.08 for sheep meat. Cattle fed the same hay produced beef with an Ff of 0.007. Potassium ferric hexacyanoferrate was fed at 0.3 or 0.6 g/d to lactating goats for 9 weeks. The Fm and Ff values were reduced to about 20% of those for the controls. (author). 10 refs, 1 fig., 2 tabs

  20. 137Cs sorption onto Fullers' Earth (calcium montmorillonite) -the influence of sulphate reducing bacteria

    International Nuclear Information System (INIS)

    The influences of Desulfovibrio desulfuricans on the sorption of 137Cs onto Fullers' Earth (Calcium montmorillonite) has been studied using batch sorption methods. Results were expressed as distributions ratios (Rd) and as Freundlich and Dubinin-Radushkevich isotherms. They show that microbes present naturally in the Fullers' Earth did not influence sorption data, however the addition of microbes in the aqueous phase alters the sorption properties in a complex manner. (author)

  1. Exercise for laboratory comparison of calibration coefficient in 137Cs beam, radiation protection - 2013/2014

    International Nuclear Information System (INIS)

    This work deals with the preliminary results of the second exercise of comparing the radiation monitors calibration laboratories in Brazil. The exercise involved eight laboratories and the measured quantity is the air kerma in a beam of 137Cs for radioprotection. The exercise was conducted by the LNMRI/IRD, in a star shaped arrangement from October 2013 to July 2015. The largest deviation was 2% of the calibration coefficient that is acceptable for applications in radioprotection. (author)

  2. Ecological half-times of 137Cs and 90Sr in forest and freshwater ecosystems

    International Nuclear Information System (INIS)

    More than 200 data sets from the literature of measured time series of activity concentrations and transfer factors concerning (1) soil, green plants, mushrooms, and game in forests and (2) water, particulate matter, and fish in rivers, reservoirs and lakes in Europe have been analysed. We used a sum of up to 3 exponential functions to evaluate ecological half-times Teco. In fresh water systems we fitted lognormal distributions of Teco for 137Cs e.g. in water of 32 European lakes Teco1 = 0.3*2.2 ± 1, and Teco2 = 5.7*3.9 ± 1 as geometric mean value in years and standard deviation. Pronounced seasonal variations were observed in particulate matter of lake Lugano, reflecting the bio-mass cycle of this lake. In forests ecological half-times Teco for 137Cs can be fitted also by a lognormal distribution. For central Europe Teco 137Cs activity concentrations were observed recently in wild boar in Germany. For eastern Europe the physical half-time is decisive and in some components of the ecosystem the activity concentration is still increasing. Our investigation shows that time-series of at least one decade for Teco2 and another one for Teco3 are needed to achieve a thorough description. Such series are not easily accessible in publications, especially concerning data from Ukraine, Belarus, Russia and Scandinavia, although this knowledge would be very interesting for the public. Main problems concerning data accessibility are the following: misfit of old data base electronic formats, lost data, public data bases are in general not up dated, non-willingness of some researchers to provide data without money. Concerning 90Sr only very few data sets are available. Because of the higher mobility of 90Sr as compared to 137Cs such data sets are urgently needed to give advice to the population in order to minimise doses from 90Sr. (author)

  3. Measuring techniques for the characterisation of 137Cs contaminated river banks, Slovakia

    International Nuclear Information System (INIS)

    In 1990, 137Cs contaminated areas were discovered along 19 km of the banks of the rivers receiving discharged waste waters from the Bohunice NPP. The contamination was the result of uncontrolled releases of drainage water from the radioactive waste treatment unit and two accidents on the CO2 cooled and heavy water moderated NPP-A1 unit in 1976 and 1977. In total, more than 67.000 m2 of bank surfaces (the lower and middle parts of their slopes) have been found to be contaminated with 137Cs at levels exceeding 1 kBq/kg of soil. This paper describes the planning for restoration of these river banks with emphasis on site characterization techniques used for these purposes. The general strategy and application of monitoring techniques for the purposes of characterisation of contaminated river banks is the main topic of the work performed in the context of the IAEA CRP on 'Site Characterisation Techniques for Environmental Restoration'. First results in developing new and more sophisticated measuring techniques, needed for the characterization of discontinuous and spot-contamination found on parts of the banks are given. The technique described is based on a dose rate measurement approach, using ratio of two detector readings at two different distances above ground and Monte-Carlo simulations of the plastic scintillation detector responses. The method will also be useful, for the final, post-remediation survey of residual spots of 137Cs contamination. (author)

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

    Science.gov (United States)

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

    2014-12-01

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

  5. Transfer and mobility of 137 Cs and 60 Co in oxisol and alfisol

    International Nuclear Information System (INIS)

    One manner to assess potential mobility of radionuclides in soils is the use of sequential extraction procedures. These procedures intend to provide the radionuclide partitioning in geochemical phases of soil affected by changes in physico-chemical conditions. In this study a new sequential chemical extraction protocol was choose to evaluate 60 Co and 137 Cs mobility under a large range of physico-chemical soil properties. The results of sequential procedure was further compared with soil to plant transfer factors data for maize and radish and with soil properties, showing rather consistent results. The 137 Cs distribution in soil showed that Fe oxides are the main sink for this element and after 14 years after contamination the 137 Cs was still available for plants. The 60 Co distribution showed that Mn oxides are the main sink for this element in Alfisol and 5 years after contamination no 60 Co was detected as bioavailable neither detectable in maize. The knowledge of the bio-geochemical behavior of radionuclides in soil system can be useful for risk assessment studies, to be applied in the case of nuclear accident or contamination scenarios. (author)

  6. The accumulation of 137Cs in the biological compartment of forest soils

    International Nuclear Information System (INIS)

    Soil samples were collected in various forest stands, located about 40 km north-west from Uppsala. The various stands were: (1) Clear cut area made in 1987, (2) Normal forest with 50-100 old Norway spruce and Scots pine and with a thick humic layer of about 10 cm; (3) Raised bog with 50-year-old Scots pine and Sphagnum moss layer over peat soil. (4) Rocky area with old Scots pine, growing on a shallow soil, mainly of organic origin. (5) Normal forest with nearly 100-year-old spruce and pine, growing a shallow humic layer over sandy soil. Soil blocks of about 20x20 cm and down to a depth of 10-15 cm were collected on each site. The soil samples were mechanically separated into various fractions: bulk, rhizosphere and soil-root interface. The results showed that 137Cs was unevenly distributed between the three soil fractions. The highest activity concentrations -- 3-4 times higher than in the other two fractions -- as well as the highest organic content -- usually more than 95% -- were found in the soil-root interface fraction. Of the total 137Cs activity in the soil, 18% as a mean value was found in the soil-root interface fraction. The results thus show that a substantial fraction of the 137Cs in the soils in some way associated with the biological part of the soil, probably with the fungal component

  7. Radioactivity in food in Belgrade city

    OpenAIRE

    Vitorović Gordana; Mitrović Branislava; Grdović Svetlana; Petrujkić Branko; Vitorović Duško

    2010-01-01

    The activity concentrations of 40K, 238U, 226Ra, 232Th and 137Cs were measured using the gamma spectrometric method in different food chain samples from the area of the City of Belgrade during the periods May-June 2007 and May-June 2008. Relatively high activities of 40K and 137Cs were detected in the soil. These results indicate that 137Cs is present in the area of Belgrade even 20 years after the nuclear accident in the Chernobyl nuclear power plant. However, in the samples of feedstuffs, a...

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

    Science.gov (United States)

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

    2013-01-01

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

  9. Radiochemical determination of {sup 210} Pb and {sup 226}Ra in petroleum sludges and scales; Determinacao radioquimica de {sup 210} Pb e {sup 226}Ra em borras e incrustacoes de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Andressa Arruda de

    2005-07-01

    The oil extraction and production, both onshore and offshore, can generate different types of residues, such as sludge, that is deposited in the water/oil separators, valves and storage tanks and scales, which form i the inner surface of ducts and equipment. Analyses already carried out through gamma spectrometry indicated the existence of high radioisotope concentration. However, radionuclides emitting low-energy gamma-rays, such as {sup 210} Pb, are hardly detected by that technique. Consequently, there is a need to test alternative techniques to determine this and other radionuclides from the {sup 238} U series. This work, therefore, focuses on the radiochemical determination of the concentration of {sup 210}Pb, and {sup 226} Ra in samples of sludge and scale from the oil processing stations of the UN-SEAL, a PETROBRAS unit responsible for the exploration and production of petroleum in Sergipe and Alagoas. The sludge and scale samples went through a preliminary process of extraction of oil, in order to separate the solid phase, where the largest fraction of the radioactivity is concentrated. After oil removal, the samples were digested using alkaline fusion as an option for dissolution. Finally, their activity concentration was determined for the samples of sludge and scales, using and alternative radiochemical method, which is based on ionic exchange. The activity concentration found for {sup 210}Pb varied from 1,14 to 507,3 kBq kg{sup -1}. The values for {sup 226}Ra were higher, varying from 4,36 to 3.445 kBq kg{sup -1}. The results for {sup 226}Ra were then compared with the ones found for the same samples of sludge and scales using gamma spectrometry. The results of the comparison confirm the efficiency of the methodology used int hi work, that is, radiochemical determination by means of ionic exchange. (author)

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

    Science.gov (United States)

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

    2016-09-01

    The nuclear accidents at Chernobyl and Fukushima released large amounts of (137)Cs radionuclides into the atmosphere which spread over large forest areas. We compared the (137)Cs concentration distribution in different parts of two coniferous forest ecosystems (needle litter, stems and at different depths in the soil) over short and long term periods in Finland and Japan. We also estimated the change in (137)Cs activity concentrations in needle and soil between 1995 and 2013 in Southern Finland based on the back-calculated (137)Cs activity concentrations. We hypothesized that if the (137)Cs activity concentrations measured in 1995 and 2013 showed a similar decline in concentration, the (137)Cs activity concentration in the ecosystem was already stable in 1995. But if not, the (137)Cs activity concentrations were still changing in 2013. Our results showed that the vertical distribution of the (137)Cs fallout in the soil was similar in Hyytiälä and Fukushima. The highest (137)Cs concentrations were observed in the uppermost surface layers of the soil, and they decreased exponentially deeper in the soil. We also observed that (137)Cs activity concentrations estimated from the samples in 1995 and 2013 in Finland showed different behavior in the surface soil layers compared to the deep soil layer. These results suggested that the (137)Cs nuclei were still mobile in the surface soil layers 27 years after the accident. Our results further indicated that, in the aboveground parts of the trees, the (137)Cs concentrations were much closer to steady-state when compared to those of the surface soil layers based on the estimated declining rates of (137)Cs concentration activity in needles which were similar in 1995 and 2013. Despite its mobility and active role in the metabolism of trees, the (137)Cs remains in the structure of the trees for decades, and there is not much exchange of (137)Cs between the heartwood and surface layers of the stem. PMID:27158060

  11. 射气闪烁法测定水中226Ra 方法的改进%Improvement of mensuration method of 226Ra in water by emanation-scintillation

    Institute of Scientific and Technical Information of China (English)

    曹娟; 李晓凤; 吴贤海

    2015-01-01

    Background: According to the national standard of “Analytical Determination of Radium-226 in Water (GB/T 11212-1989)”, emanation-scintillation is widely used to monitor the content of 226Ra in water. Purpose: This study aims to optimize the analysis and mensuration conditions of emanation-scintillation method recommended in GB/T 11212-1989. Methods: The related parameters for mensuration of 226Ra, such as recovery rate, measuring moment and measuring instrument were investigated to identify the optimal working state by a series of experimental tests. Results: If the percent recovery indicated pretreatment loss was introduced, the mensuration result would be more accurate. The optimal measuring moment was 3−4 h after the complete collection of the Radon from the samples. The traditional FD-125 radon-thorium analyzer can be replaced by the portable AB-5R radon monitor which will be more convenient and flexible while keep the same performance. Conclusion: The relevant recommendations provide alternative solution for field measurement of 226Ra in water, and a design reference for the developing and updating of the GB/T 11212-1989 standard in future.%从回收率、测量时刻和仪器选择等方面对《水中镭-226的分析测定》(GB/T 11214-1989)中规定的水中226Ra 分析方法的改进进行了探讨。结果表明,在实验中,采用一个能反映前处理中样品损失的回收率可以提高分析结果的准确度;最佳测量时刻为氡气进气完毕后的3−4 h;测量分析了用便携式 AB-5R 型测氡仪替代标准中要求的 FD-125型室内氡钍分析仪的多种样品测试指标,验证了替代的可行性,为现场快速检测和标准的后续更新提供一定的技术参考。

  12. Evaluation of 137Cs mobility in soil profiles from the Pantanal region, Brazil

    International Nuclear Information System (INIS)

    Radioactive pollutants can cause impact on the environmental quality of soils and pose a risk to human health. The release of radioactive materials through nuclear testing or nuclear accidents cause the deposition of radionuclides on the ground,· it may be leached by rain, transported to the sources of natural waters and absorbed by the soil fauna and flora, and thus enter the human food chain. Radioecological studies have shown that soils with low pH, low organic matter content and low fertility are more vulnerable to contamination by 137Cs, since the transfer to plants is high. In this study, we aimed to assess and map the vulnerability to contamination by 137Cs surface horizons of the soils from the Pantanal and propose mitigation measures adapted to the regional scenario to optimize radiological protection of agricultural areas. Therefore, selected soil profiles located in the municipality of Jaraguari, state of Mato Grosso do Sul, and applied the conceptual model developed by Picanco Jr (2012), which was used in the reference values of the factor of soil-plant transfer (FT) for 137Cs in corn, related soil variables (pH, CTC and exchangeable K) and relevance of parameters and variations of amplitudes for each value range of FT. The application of this conceptual model established to detect the vulnerability of soils to radioactive contamination generated maps vulnerability showing that the region is very heterogeneous as this criterion, showing low levels of vulnerability for most of the region and in some areas, extreme vulnerability. This result identified the Pantanal as one of the less vulnerable to the radioactive contamination, but the sparse areas of extreme vulnerability can lead to contamination of subsoil and a significant spread of contamination via groundwater. This conceptual model, which defines vulnerability classification, is a first step for the study and determination of a numerical index of vulnerability to 137Cs soil and can be used in the

  13. Bioavailability of {sup 137}Cs - geographical variability in Swedish forest- and arable soil. Construction of a database using GIS; Biotillgaenglighet av {sup 137}Cs - geografisk variation i svensk skogs- och aakermark. Uppbyggnad av databas med hjaelp av GIS

    Energy Technology Data Exchange (ETDEWEB)

    Heikkilae, Taina; Lindmark, Malin

    2000-12-01

    Soil acts as a sink for long-lived radionuclides such as {sup 137}Cs . The bioavailability and the plant root uptake of {sup 137}Cs are therefore influenced by chemical and physical characteristics of the soil. The aim of this study is to gather information about Swedish soil conditions, focusing on parameters known to influence the bioavailability of {sup 137}Cs and to indicate areas which may have a higher probability of containing persistent bioavailable {sup 137}Cs. This project was carried out in two parts. First, an information database on soil properties in Swedish forest and agricultural landscapes was constructed using GIS (Geographic Information System). Next, Swedish agricultural and forest soils were characterised according to low, intermediate and high estimated bioavailability of {sup 137}Cs. Agricultural soils were ranked according to clay and organic matter content; forest soils according to podzol, cambisol and peat. The physical and chemical properties of agricultural soils are quite different from forest soils. In contrast to forest soils, agricultural soils are characterised by reduced quantities of organic matter and a higher proportion of clay. Several investigations have indicated. a faster decline in {sup 137}Cs levels in agricultural soils when compared to forest soils. Due to these differences, these soil types are dealt with separately in this report.

  14. Reconstruction of {sup 137}Cs signal in Cuba using {sup 7}Be as tracer of vertical transport processes in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Alonso Hernandez, C.M. E-mail: carlos@ceac.perla.inf.cu; Cartas Aguila, H.; Diaz Asencio, M.; Munoz Caravaca, A

    2004-07-01

    Levels of {sup 137}Cs and {sup 7}Be in aerosols have been measured in the region of Cienfuegos (Cuba) during the period 1994-1998. {sup 137}Cs showed the same seasonal trend as {sup 7}Be and the monthly regimes of precipitation seemed to be responsible for the observed pattern. The {sup 137}Cs/{sup 7}Be ratio obtained in Cienfuegos and Miami (FL) in this period was used to calibrate the long-term database of {sup 137}Cs concentrations recorded in Miami (250 km from Cienfuegos). The database was then employed to reconstruct the {sup 137}Cs monthly concentrations in Cienfuegos since 1957.

  15. Development of certified matrix reference materials for quality assurance of screening 134Cs and 137Cs in food

    International Nuclear Information System (INIS)

    A certified reference material using activated alumina powder certified for activity of 134Cs and 137Cs was developed. The results of the verification and the certification are described. The certified reference material can be used for quality assurance of screening activity measurements of 134Cs and 137Cs in food/foodstuffs. Commercially available equipments were experimentally tested using the CRM and another CRM including 40K. The results of these tests are also shown. - Highlights: • CRM of 134Cs and 137Cs using activated alumina was developed. • CRM including 134Cs, 137Cs and 40K was also developed. • Results of experimental performance test of commercial inspection equipments using CRMs were shown

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

    Energy Technology Data Exchange (ETDEWEB)

    Bertelli, L.; Oliveira, C.A.N.; Lipsztein, J.L. (Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil)); Wrenn, M.E. (Utah Univ., Salt Lake City, UT (United States). Environmental Radiation Lab.)

    1992-01-01

    A four-months pregnant woman was contaminated during an accident involving {sup 137}Cs from a teletherapy source that occurred in Brazil in September 1987. In vivo monitoring and analysis of {sup 137}Cs 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 {sup 137}Cs relating to the metabolism of mother and infant were made. The results provide useful information for age-specific models describing the metabolism of {sup 137}Cs. (author).

  17. Studying sorption properties of a mixture of natural and synthetic zeolites in respect of radionuclides 137Cs and 90Sr

    International Nuclear Information System (INIS)

    Sorption properties of a mixture of zeolites (natural and synthetic) in respect of radionuclides 137Cs and 90Sr are studied. The influence of additions on the sorption properties of clinoptilolite and mixture of zeolites (natural and synthetic) is studied

  18. Indication of Erosion At Tea - Plantation - Gunung Mas - Puncak - West Java Using Environmental Isotop of 137Cs

    International Nuclear Information System (INIS)

    Erosion is a natural phenomena as a result of deforestation. Indication of erosion could be investigated by nuclear method that is used a natural radioisotope of 137Cs in the soil. The present of 137Cs in environment is a result of the nuclear weapon testing in the middle of 1950's. The result of this pre study showed that the total activity of 137Cs in the soil of Tea - Plantation - Gunung Mas - Puncak - West Java is between 150 Bq/m2-1872 Bq/m2. The result showed that the activity of 137Cs could be detected, and the erosion or deposition could be seen at the points of the investigation

  19. Effective and ecological half-lives of 90Sr and 137Cs observed in wheat and rice in Japan

    International Nuclear Information System (INIS)

    Published pre-Fukushima food monitoring data from 1963 to 1995 were used to study the long-term presence of 137Cs and 90Sr in rice and wheat. Effective half-lives (Teff) were calculated for rice (137Cs: 5.6 years; 90Sr: 6.7 years) and wheat (137Cs: 3.5 years; 90Sr: 6.2 years), respectively. In rice, 137Cs exhibits a longer Teff because putrefaction processes will lead to the formation of NH4+ ions that are efficient ion exchangers for mineraladsorbed cesium ions, hence making it more readily available to the plant. Knowledge on the long-term behavior of radiocesium and radiostrontium will be important for Japanese food-safety campaigns after the Fukushima nuclear accident. (author)

  20. A Procedure for the Rapid Determination of 226Ra and 228Ra in Drinking Water by Liquid Scintillation Counting

    International Nuclear Information System (INIS)

    Since 2004, the environment programme of the IAEA has included activities aimed at the development of a set of procedures for the determination of radionuclides in terrestrial environmental samples. Reliable, comparable and ‘fit for purpose’ results are essential requirements for any decision based on analytical measurements. For the analyst, tested and validated analytical procedures are extremely important tools for the production of such data. For maximum utility, such procedures should be comprehensive, clearly formulated and readily available to both the analyst and the customer. This publication describes a procedure for the rapid determination of 226Ra and 228Ra in drinking water. The determination of radium in drinking water is important for protecting human health, since the consumption of drinking water containing radium may lead to an accumulation in the body, contributing to the radiological dose. The method is based on the separation of 226Ra and 228Ra from interfering elements using PbSO4 and Ba(Ra)SO4 coprecipitation steps. The isotopes 226Ra and 228Ra are then determined by liquid scintillation counting. The procedure is expected to be of general use to a wide range of laboratories, including the laboratories of the Analytical Laboratories for the Measurement of Environmental Radioactivity (ALMERA) network, both in emergency situations and for routine environmental monitoring purposes. The method was established after an extensive review of papers from the scientific literature, and was tested and validated in terms of repeatability and trueness (relative bias) in accordance with International Organization for Standardization guidelines. Reproducibility tests were performed at expert laboratories. The calculation of massic activities, uncertainty budget, decision threshold and detection limit are also described

  1. MSFIA-LOV system for (226)Ra isolation and pre-concentration from water samples previous radiometric detection.

    Science.gov (United States)

    Rodríguez, Rogelio; Borràs, Antoni; Leal, Luz; Cerdà, Víctor; Ferrer, Laura

    2016-03-10

    An automatic system based on multisyringe flow injection analysis (MSFIA) and lab-on-valve (LOV) flow techniques for separation and pre-concentration of (226)Ra from drinking and natural water samples has been developed. The analytical protocol combines two different procedures: the Ra adsorption on MnO2 and the BaSO4 co-precipitation, achieving more selectivity especially in water samples with low radium levels. Radium is adsorbed on MnO2 deposited on macroporous of bead cellulose. Then, it is eluted with hydroxylamine to transform insoluble MnO2 to soluble Mn(II) thus freeing Ra, which is then coprecipitated with BaSO4. The (226)Ra can be directly detected in off-line mode using a low background proportional counter (LBPC) or through a liquid scintillation counter (LSC), after performing an on-line coprecipitate dissolution. Thus, the versatility of the proposed system allows the selection of the radiometric detection technique depending on the detector availability or the required response efficiency (sample number vs. response time and limit of detection). The MSFIA-LOV system improves the precision (1.7% RSD), and the extraction frequency (up to 3 h(-1)). Besides, it has been satisfactorily applied to different types of water matrices (tap, mineral, well and sea water). The (226)Ra minimum detectable activities (LSC: 0.004 Bq L(-1); LBPC: 0.02 Bq L(-1)) attained by this system allow to reach the guidance values proposed by the relevant international agencies e.g. WHO, EPA and EC. PMID:26893088

  2. Modelling of {sup 137}Cs behaviour in the soil-plant system following the application of ameliorants

    Energy Technology Data Exchange (ETDEWEB)

    Spiridonov, S.; Fesenko, S.; Sanzharova, N. [Russian Institute of Agricultural Radiology and Agroecology, Obninsk (Russian Federation)

    2004-07-01

    A set of countermeasures aimed at reducing {sup 137}Cs 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 {sup 137}Cs 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 {sup 137}Cs 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 {sup 137}Cs content in soil solution results from the radionuclide sorption on selective and nonselective exchange sites; - uptake of extra amounts of K{sup +} and Ca{sup 2+} in soil solution produces effect on processes of {sup 137}Cs exchangeable sorption and initiate specific processes responsible for {sup 137}Cs fixation in the crystal lattice of clay minerals; - Ca{sup 2+} and K{sup +} cations have a competing effect on {sup 137}Cs 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 {sup 137}Cs 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)

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

    International Nuclear Information System (INIS)

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

  4. Ecological half-life of 137Cs in fish from a stream contaminated by nuclear reactor effluents

    International Nuclear Information System (INIS)

    Radiocesium (137Cs) concentrations were determined during 1974, 1981 and 1998 for seven species of fish inhabiting a stream (Steel Creek) contaminated by effluents from a nuclear reactor to examine the decline of this radionuclide in a natural ecosystem. Median 137Cs concentrations were highest in Micropterus salmoides (largemouth bass) during each year of the investigation (1974=6.67 Bq g-1 dry wt. of whole body; 1981=3.72 Bq g-1; 1998=0.35 Bq g-1), but no patterns of differences were observed among Aphredoderus sayanus (pirate perch), Esox americanus (redfin pickerel), Lepomis auritus (redbreast sunfish), L. gulosus (warmouth), L. punctatus (spotted sunfish), and Notropis cummingsae (dusky shiner). Results demonstrated a rapid decline in 137Cs within fish from Steel Creek during the 24-year period. For example, 137Cs concentrations in all fish species declined significantly among years, even after accounting for radioactive decay. The observed percent declines in 137Cs concentrations of individual species were 3-4 times greater between 1974 and 1981 compared to that expected by physical decay alone, and 2-3 times greater during 1981-1998. Ecological half-lives (EHLs) of 137Cs in fish ranged from 4.43 years in A. sayanus to 6.53 years in L. gulosus. The EHL for 137Cs in all fish species combined was 5.54 years. Current levels of 137Cs in fish from Steel Creek (1.16 Bq g-1 dry wt. of whole body to below detection limits) indicate that the consumption of fish from this ecosystem poses little risk to humans and sensitive wildlife species. These results demonstrate the importance of incorporating the concept of ecological half-life into determinations concerning the length and severity of potential risks associated with radiocontaminants

  5. The distribution of {sup 137}Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Vinichuk, M., E-mail: mykhailo.vinichuk@mark.slu.s [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Department of Ecology, Zhytomyr State Technological University, 103 Chernyakhovsky Street, 10005 Zhytomyr (Ukraine); Johanson, K.J. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Rydin, H. [Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Norbyvaegen 18D, SE-752 36 Uppsala (Sweden); Rosen, K. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden)

    2010-02-15

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

  6. A simple method for calibration of Lucas scintillation cell counting system for measurement of 226Ra and 222Rn

    OpenAIRE

    N.K. Sethy; V.N. Jha; P.M. Ravi; Tripathi, R. M.

    2014-01-01

    Known quantity of radium from high grade ore solution was chemically separated and carefully kept inside the cavity of a Lucas Cell (LC). The 222Rn gradually builds up and attain secular equilibrium with its parent 226Ra. This gives a steady count after a suitable buildup period (>25 days). This secondary source was used to calibrate the radon counting system. The method is validated in by comparison with identical measurement with AlphaGuard Aquakit. The radon counting system was used to eva...

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

    International Nuclear Information System (INIS)

    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)

  8. Bioavailability of 137Cs - geographical variability in Swedish forest- and arable soil. Construction of a database using GIS

    International Nuclear Information System (INIS)

    Soil acts as a sink for long-lived radionuclides such as 137Cs . The bioavailability and the plant root uptake of 137Cs are therefore influenced by chemical and physical characteristics of the soil. The aim of this study is to gather information about Swedish soil conditions, focusing on parameters known to influence the bioavailability of 137Cs and to indicate areas which may have a higher probability of containing persistent bioavailable 137Cs. This project was carried out in two parts. First, an information database on soil properties in Swedish forest and agricultural landscapes was constructed using GIS (Geographic Information System). Next, Swedish agricultural and forest soils were characterised according to low, intermediate and high estimated bioavailability of 137Cs. Agricultural soils were ranked according to clay and organic matter content; forest soils according to podzol, cambisol and peat. The physical and chemical properties of agricultural soils are quite different from forest soils. In contrast to forest soils, agricultural soils are characterised by reduced quantities of organic matter and a higher proportion of clay. Several investigations have indicated. a faster decline in 137Cs levels in agricultural soils when compared to forest soils. Due to these differences, these soil types are dealt with separately in this report

  9. Desorption of 137Cs from Cetraria islandica (L. Ach. using solutions of acids and their salts mixtures

    Directory of Open Access Journals (Sweden)

    ANA A. ČUČULOVIĆ

    2009-06-01

    Full Text Available The desorption of 137Cs from Cetraria islandica (L. Ach. lichen was investigated using the solutions: A H2SO4–HNO3–K2SO4, B H2SO4–HNO3–Na2SO4 and C H2SO4–HNO3– (NH42SO4–(NH4NO3 at pH 2.00, 2.58, 2.87, 3.28 and 3.75, similar to acid rain. After five consecutive desorptions using solutions A, B and C, from 44.0 % (solution B, pH 3.75 to 68.8 % (solution C, pH 3.28 of 137Cs had been desorbed from the lichen. In all cases, the most successful 137Cs desorption was the first one. In the presence of K+ (solution A the total amount of desorbed 137Cs did not depend on the pH of the solution and this was confirmed by the analogous reactions of Cs+ and K+, due to their similar ionic radii. The dependencies of the non-desorbed content of 137Cs on the number of desorptions gave curves indicating that at least two types of sorption occur. One of them can be dominant if suitable desorbants are used. The results indicate lichens as secondary sources of environment pollution with 137Cs.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-04-08

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-04-14

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

  12. Deposition of atmospheric {sup 137}Cs in Japan associated with the Asian dust event of March 2002

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, Hideshi [National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604 (Japan)], E-mail: hfuji@affrc.go.jp; Fukuyama, Taijiro [National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604 (Japan); Shirato, Yasuhito [Agriculture, Forestry and Fisheries Research Council, 1-2-1 Kasumigaseki, Chiyoda-ku, Tokyo 100-8950 (Japan); Ohkuro, Toshiya [Laboratory of Landscape Ecology and Planning, Department of Ecosystem Studies, University of Tokyo, 1-1-1 Yayoi, Bunkyou-ku, Tokyo 113-8657 (Japan); Taniyama, Ichiro [National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604 (Japan); Zhang, Tong-Hui [Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Donggang West Road 260, Lanzhou 730000 (China)

    2007-10-01

    Considerable deposition of {sup 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 {sup 137}Cs. Our radioactivity measurements showed {sup 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 {sup 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 {sup 137}Cs-bearing soil particles into the atmosphere during the sandstorm and the subsequent deposition of {sup 137}Cs in Japan to this change.

  13. Calculation of fusion time scales in 11B + 237Np, 12C + 232Th and 16O + 232Th reactions in a dynamical trajectory model

    International Nuclear Information System (INIS)

    There are several theoretical models which treat the fusion process and energy dissipation in heavy ion collision in terms of a fluctuating force represented by the coupling between macroscopic and intrinsic degrees of freedom. One such dynamical model has been developed by Feldmeier (1987), where the properties of the dissipative force are determined from a microscopic picture of particle exchange between two nuclei. The macroscopic shapes of the nuclear system are represented by axially symmetric configuration with sharp surfaces. We have used the above model to calculate the fusion time scales for the systems 11B + 237Np, 12C +232Th and 16O + 232Th at 77, 86 and 104 MeV bombarding energies to examine the effect of mass asymmetry in fusion dynamics. (author). 2 figs

  14. Measurement by liquid scintillation of {sup 226} Ra coprecipitated in BaSO{sub 4}; Medicion por centelleo liquido de {sup 226} Ra coprecipitado en BaSO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Lopez del Rio, H.; Davila R, J.I.; Badillo A, V.E.; Mireles G, F.; Quirino T, L.; Lugo R, J.F.; Pinedo V, J.L.; Rios M, C. [UAEN-UAZ, A.P. 579C, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)]. e-mail: idavila@cantera.reduaz.mx

    2003-07-01

    The {sup 226} Ra is one of the more radio toxic nuclides since when entering to the organism it continues metabolically to the calcium, accumulating mainly in the bone tissue where it becomes in an internal radiation source. For the analysis of radium in water the methods of radon emanation are generally applied and coprecipitation with barium sulfate. This last is quick and efficient, and the radium in the precipitate can be measured by alpha or gamma spectrometry, or liquid scintillation dissolving the precipitate one with EDTA. In this work it is proposed a procedure for the radium measurement in water based on the coprecipitation with barium sulfate and in the detection by liquid scintillation. The precipitate of Ba(Ra)SO{sub 4} it is carried with water and blended with the liquid scintillator OptiPhase Hi Safe 3, avoiding the dissolution with EDTA. A 92{+-} 1.4% of radium it was recovered and it was reached a minimum activity detectable of 4.2 {+-} 0.9 mBq{sup -1}. The procedure was essayed with natural mineral water with a knew activity in concentration of {sup 226} Ra. The analytic result it coincided with the reported value with a relative error of 9%. (Author)

  15. Development and evaluation of a technique for the determination of {sup 226}Ra and {sup 228}Ra by liquid scintillation in biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Paulo Cesar P.; Sousa, Wanderson O.; Dantas, Bernardo M.; Juliao, Ligia M.Q.C. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)], e-mail: pcesar@ird.gov.br

    2009-07-01

    Radium isotopes are dispersed in the environment according to their physicochemical characteristics. Considering their long half-lives and radiological effects, {sup 226}Ra and {sup 228}Ra are very important issues to radiological protection. In Brazil, radium isotopes represent an exposure problem both in the nuclear fuel cycle installations and in high natural radiation background areas. The experimental part of this work includes the development of a technique for the determination of {sup 226}Ra and {sup 228}Ra by liquid scintillation in biological samples. Radium was concentrated and then separated from the others constituents of the sample by coprecipitation/ precipitation with Ba(Ra)SO{sub 4}. The precipitate was filtered and weighted to calculate the chemical yield. The filter containing the precipitate of Ba(Ra)SO{sub 4} was transferred to a scintillation vial. Two methods were used to prepare the sources. The first one consisted gel suspension and the second one, phases method. The solutions obtained were counted in a low background scintillation spectrometry system (Quantulus) suitable for the detection and identification of both alpha and beta particles for the determination of {sup 226}Ra and {sup 228}Ra. The activity values of {sup 226}Ra and {sup 228}Ra calculated by the two methods are in good agreement with the reference value indicating that both methods are suitable for the determination of {sup 226}Ra and {sup 228}Ra. The values of minimum detectable activity (MDA) for the gel suspension method were 2.5 mBq.L{sup -1} for {sup 226}Ra and 53 mBq.L{sup -1} for {sup 228}Ra and for the method of phases were 2.6 mBq.L{sup -1} for {sup 226}Ra and 66 mBq.L{sup -1} for {sup 228}Ra. (author)

  16. Development and evaluation of a technique for the determination of 226Ra and 228Ra by liquid scintillation in biological samples

    International Nuclear Information System (INIS)

    Radium isotopes are dispersed in the environment according to their physicochemical characteristics. Considering their long half-lives and radiological effects, 226Ra and 228Ra are very important issues to radiological protection. In Brazil, radium isotopes represent an exposure problem both in the nuclear fuel cycle installations and in high natural radiation background areas. The experimental part of this work includes the development of a technique for the determination of 226Ra and 228Ra by liquid scintillation in biological samples. Radium was concentrated and then separated from the others constituents of the sample by coprecipitation/ precipitation with Ba(Ra)SO4. The precipitate was filtered and weighted to calculate the chemical yield. The filter containing the precipitate of Ba(Ra)SO4 was transferred to a scintillation vial. Two methods were used to prepare the sources. The first one consisted gel suspension and the second one, phases method. The solutions obtained were counted in a low background scintillation spectrometry system (Quantulus) suitable for the detection and identification of both alpha and beta particles for the determination of 226Ra and 228Ra. The activity values of 226Ra and 228Ra calculated by the two methods are in good agreement with the reference value indicating that both methods are suitable for the determination of 226Ra and 228Ra. The values of minimum detectable activity (MDA) for the gel suspension method were 2.5 mBq.L-1 for 226Ra and 53 mBq.L-1 for 228Ra and for the method of phases were 2.6 mBq.L-1 for 226Ra and 66 mBq.L-1 for 228Ra. (author)

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

    Science.gov (United States)

    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

  18. Effect of wood ash and K-fertilization on {sup 137}Cs uptake by selected forest plants

    Energy Technology Data Exchange (ETDEWEB)

    Mandro, Yrii N. [Zhytomyr State Technological University, P.O. Box 10005 Zhytomyr (Ukraine); Rosen, Klas [Swedish University of Agricultural Sciences P.O. Box 7070 SE-750 07 Uppsala (Sweden); Vinichuk, Mykhailo M. [Zhytomyr State Technological University, P.O. Box 10005 Zhytomyr (Ukraine); Swedish University of Agricultural Sciences P.O. Box 7070 SE-750 07 Uppsala (Sweden)

    2014-07-01

    Accumulation {sup 137}Cs by different forest plants and trees after fertilization of soil with potassium and wood ash ({sup 137}Cs-contaminated and non-contaminated) in forest ecosystems of Ukraine contaminated by radionuclides after Chernobyl accident in 1986 was studied. Experiment is performed in Bazar forestry, Zhytomyr region, Ukraine, located about 70 km (51 deg. 5'35'' N, 29 deg. 18'56'' E) from Chernobyl NPP. Potassium fertilizer (KCl, wooden ash (Ash), and {sup 137}Cs-contaminated ash ({sup 137}CsAsh) in different combinations) were spread on the forest floor in April 2012 at a rate corresponding 100 kg/ha potassium. The experiment layout was as follows: 1- Control (no fertilizers were applied), 2- KCl, 3- Ash + KCl, 4- Ash + {sup 137}CsAsh, 5- Ash, 6- {sup 137}CsAsh + KCl. Samples (leaves and annual shoots) of blueberry (Vaccinium myrtillus), cowberry (Vaccinium vitis-idaea), rowan (Sorbus aucuparia), birch (Betula), buckthorn (Frangula) and oak (Quercus robur) and also mushrooms (fruit bodies of Russula, Lactarius, Cantharellus, Collybia etc.) and berries (blueberry and cowberry) were taken monthly from each treatment. Samples were measured for {sup 137}Cs with calibrated HPGe detectors. The results of the first year studies show variation of Transfer Factors (TF) for different plants and for the same plants on different treatments. The effect of fertilization was found for blueberry on Ash-applicated (TF = 0.0085 ± 0.0025), {sup 137}CsAsh + KCl-applicated (TF = 0.0105 ± 0.0060) and Ash + KCl-applicated (TF = 0.0123 ± 0.0058) treatments compared to Control (TF = 0.0163 ± 0.0092). Also good effect for rowan on Ash + KCl-applicated treatment (TF = 0.0067 ± 0.0024) compared to Control (TF = 0.0100 ± 0.0064). Effect was less obvious for birch on Ash + KCl-applicated treatment and for cowberry on Ash + KCl-applicated treatment. There was not found an obvious effect of fertilization for buckthorn. Positive effect of

  19. Factors affecting the distribution of natural and anthropogenic radionuclides in the coastal Burullus Lake

    International Nuclear Information System (INIS)

    In the present study, measurements of naturally occurring radioactive materials and 137Cs activity in sediment were conducted for locations covering the entire Burullus Lake in order to gather information about radionuclides mobility and distribution. Low-background γ-spectrometry was employed to determine the activity concentrations of water and sediment samples. The activity concentrations of 226Ra and 232Th are close to uniform distribution in the lake environment. Among the different physical and chemical characteristics measured for water and sediment, only salinity and total organic matter content have the potential to affect the mobility of 137Cs and 40K. The results suggest that these two radionuclides are attached to different mobile particulates. Increasing salinity tends to strengthen the adsorption of 137Cs and solubilization of 40K in sediment. On the other hand, sediment with high organic matter content traps 137Cs and 40K associated particulates to bottom sediment. - Highlights: • 226Ra and 232Th are uniformly distributed in Burullus Lake. • Increasing salinity increases the adsorption of 137Cs and solubilization of 40K in sediment. • Sediment with high organic matter content traps 137Cs and 40K. • 137Cs and 40K are not associated with the same particulate material

  20. Soil features and indoor radon concentration prediction: radon in soil gas, pedology, permeability and 226Ra content.

    Science.gov (United States)

    Lara, E; Rocha, Z; Santos, T O; Rios, F J; Oliveira, A H

    2015-11-01

    This work aims at relating some physicochemical features of soils and their use as a tool for prediction of indoor radon concentrations of the Metropolitan Region of Belo Horizonte (RMBH), Minas Gerais, Brazil. The measurements of soil gas radon concentrations were performed by using an AlphaGUARD monitor. The (226)Ra content analysis was performed by gamma spectrometry (high pure germanium) and permeabilities were performed by using the RADON-JOK permeameter. The GEORP indicator and soil radon index (RI) were also calculated. Approximately 53 % of the Perferric Red Latosols measurement site could be classified as 'high risk' (Swedish criteria). The Litholic Neosols presented the lowest radon concentration mean in soil gas. The Perferric Red Latosols presented significantly high radon concentration mean in soil gas (60.6 ± 8.7 kBq m(-3)), high indoor radon concentration, high RI, (226)Ra content and GEORP. The preliminary results may indicate an influence of iron formations present very close to the Perferric Red Latosols in the retention of uranium minerals. PMID:25920786

  1. Soil features and indoor radon concentration prediction: radon in soil gas, pedology, permeability and 226Ra content.

    Science.gov (United States)

    Lara, E; Rocha, Z; Santos, T O; Rios, F J; Oliveira, A H

    2015-11-01

    This work aims at relating some physicochemical features of soils and their use as a tool for prediction of indoor radon concentrations of the Metropolitan Region of Belo Horizonte (RMBH), Minas Gerais, Brazil. The measurements of soil gas radon concentrations were performed by using an AlphaGUARD monitor. The (226)Ra content analysis was performed by gamma spectrometry (high pure germanium) and permeabilities were performed by using the RADON-JOK permeameter. The GEORP indicator and soil radon index (RI) were also calculated. Approximately 53 % of the Perferric Red Latosols measurement site could be classified as 'high risk' (Swedish criteria). The Litholic Neosols presented the lowest radon concentration mean in soil gas. The Perferric Red Latosols presented significantly high radon concentration mean in soil gas (60.6 ± 8.7 kBq m(-3)), high indoor radon concentration, high RI, (226)Ra content and GEORP. The preliminary results may indicate an influence of iron formations present very close to the Perferric Red Latosols in the retention of uranium minerals.

  2. Radionuclide distribution dynamics in skeletons of beagles fed 90Sr: Correlation with injected 226Ra and 239Pu

    International Nuclear Information System (INIS)

    Data for the bone-by-bone redistribution of 90Sr in the beagle skeleton are reported for a period of 4000 d following a midgestation-to-540-d-exposure by ingestion. The partitioned clearance model (PCM) that was originally developed to describe bone-by-bone radionuclide redistribution of 226Ra after eight semimonthly injections at ages 435-535 d has been fitted to the 90Sr data. The parameter estimates for the PCM that describe the distribution and clearance of 226Ra after deposition on surfaces following injection and analogous parameter estimates for 90Sr after uniform deposition in the skeleton as a function of Ca mass are given. Fractional compact bone masses per bone group (mi,COM) are also predicted by the model and compared to measured values; a high degree of correlation (r = 0.84) is found. Bone groups for which the agreement between the model and experimental values of mi,COM was poor had tissue-to-calcium weight ratios about 1.5 times those for bones that agreed well. Metabolically defined surface in PCM is initial activity fraction per Ca fraction in a given skeletal component for intravenously injected alkaline earth (Sae) radionuclides; comparisons are made to similarly defined surface (Sact) values from 239Pu injection studies. The patterns of Sae and Sact distribution throughout the skeleton are similar

  3. Assessment of work environmental hazard and exposure of a worker utilizing 226Ra in an oncological center

    International Nuclear Information System (INIS)

    Our study presents dosimetric evaluation of activities associated with sealing in glass 72 sources of 226Ra prepared for utilization, and of the effect of an absorbed dose on a worker's select laboratory parameters. During 3 h exposure to 226Ra of activity 31 GBq, it was demonstrated that taking the sources from a bunker in portions only for the time of sealing them in glass, decreases the worker's exposure to the obtained dose from 91.5 mSv to 6 mSv, and additionally used 5 cm shield to 2 mSv. Nine days after the worker's absorption of the radiation dose, we observed in laboratory tests disorders expressed by decreased numbers of white blood cells and neutrophils, decreased activity of antioxidative enzymes in erythrocytes, concentrations of protein thiol groups, vascular endothelial growth factors in serum, and an increase of plasma total antioxidant status level, of insulin-like growth factor I level, and urokinase-type plasminogen activator receptor level in blood serum. (authors)

  4. Long-term effects of an intracavitary treatment with californium-252 on normal tissue. [Swine, /sup 226/Ra

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, M.F.; Beamer, J.L.; Mahony, T.D.; Cross, F.T.; Lund, J.E.; Endres, G.W.R.

    1976-01-01

    About one hundred fifty swine were exposed to either radium-226 or californium-252 sources in the uterine cervix to determine an RBE for both acute and long-term effects. That value for early changes in the tissues at risk in the treatment of cervical cancer was between 6.2 and 6.8. The incidence of complications increased with time after exposure, especially among animals treated with /sup 252/Cf. Analysis of rectal injury showed that ulceration occurred frequently within a year postexposure at doses between 1600 and 2400 rad calculated at 2 cm lateral to the source midline. Fat necrosis and smooth muscle atrophy, resulting in a local rectal stricture, were delayed changes observed in some animals. The lower ureter was the site for a greater frequency of complications than the GI tract. Ureteral stricture often occurred at doses of 1200 rad from /sup 252/Cf and 7000 rad from /sup 226/Ra. Observation of delayed effects in the uterine-cervix in animals held up to 4 years postexposure indicate that the RBE for /sup 252/Cf may be increased to a value as high as 18, while repair may have even decreased it to about 5.6 in the rectum. Fifty swine are still being observed for long-term effects after doses above 800 rad from /sup 252/Cf and 5000 rad from /sup 226/Ra.

  5. Flow cytometric DNA analysis of ducks accumulating 137Cs on a reactor reservoir.

    Science.gov (United States)

    George, L S; Dallas, C E; Brisbin, I L; Evans, D L

    1991-06-01

    The objective of this study was to detect red blood cell (rbc) DNA abnormalities in male, game-farm mallard ducks as they ranged freely and accumulated 137Cs (radiocesium) from an abandoned nuclear reactor cooling reservoir. Prior to release, the ducks were tamed to enable recapture at will. Flow cytometric measurements conducted at intervals during the first year of exposure yielded cell cycle percentages of DNA (G0/G1, S, G2 + M phases) of rbc, as well as coefficients of variation (CV) in the G0/G1 phase. DNA histograms of exposed ducks were compared with two sets of controls which were maintained 30 and 150 miles from the study site. 137Cs live wholebody burdens were also measured in these animals in a parallel kinetics study, and an approximate steady-state equilibrium was attained after about 8 months. DNA histograms from 2 of the 14 contaminated ducks revealed DNA aneuploid-like patterns after 9 months exposure. These two ducks were removed from the experiment at this time, and when sampled again 1 month later, one continued to exhibit DNA aneuploidy. None of the control DNA histograms demonstrated DNA aneuploid-like patterns. There were no significant differences in cell cycle percentages at any time point between control and exposed animals. A significant increase in CV was observed at 9 months exposure, but after removal of the two ducks with DNA aneuploidy, no significant difference was detected in the group monitored after 12 months exposure. An increased variation in the DNA and DNA aneuploidy could, therefore, be detected in duck rbc using flow cytometric analysis, with the onset of these effects being related to the attainment of maximal levels of 137Cs body burdens in the exposed animals.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Analysis of the Survival Rate with Cervical Cancer Using 137Cs and 192Ir Aftedoading Brachytherapy

    Institute of Scientific and Technical Information of China (English)

    GuixioZhou; GuoxiongChen; DemeiMa; JianpingSun; LinMa

    2004-01-01

    OBJECTIVE To analyze and compare the survival rate for stages Ⅱ and Ⅲ cervical cancer treated by external irradiation plus 137Cs or 192Ir. METHODS The patients with cervical cancer were treated by external irradiation plus 137Cs (group A, 427 patients) or plus 192Ir (group B, 156 patients). There were 170 stage Ⅱ cases and 413 stage Ⅲ cases. The number of cancer types were as follows: squamous cell carcinoma, 524; adenocarcinoma, 34; and adenosquamous cell carcinoma, 25. The two groups received the same external irradiation using 8 or 10 MV of X-ray. After the whole pelvis received 25-35 Gy, the focus was given a total of 45-55 Gy by four divided fields. Intracavitary irradiation was performed with one fraction of 6-7 Gy in reference dose at A point every week and a total dose of 40-60 Gy with 6-8 fractions for group A; every fraction of 5-6 Gy in reference dose of A point and total dose of 30-42 Gy with 5-7 fractions for group B.RESULTS The 5-year survival rate of stage Ⅱ and Ⅲ, and total were 82.9%, 62.2%, and 67.2% for group A respectively and 85.1%, 61.5% and 69.2% for group B respectively. There were significant differences between stage Ⅱ and Ⅲ in each group (P 0.05). The late complications of the therapy were rectitis and urocystitis and with an incidence rate of 7.3% and 6.3% for group A and 9.6% and 9.0% for group B (P> 0.05). CONCLUSION The long-term survival rate and complications of stages Ⅱ and Ⅲ cervical cancer are similar when treated with external irradiation plus 137Cs or plus 192Ir.

  8. Natural background radiation and 137Cs inventories in southern Nevada. Preliminary report on fallout, December 1980

    International Nuclear Information System (INIS)

    External radiation measurements and soil sampling were performed at 28 sites in southern Nevada as part of an extensive radiological survey to determine residual levels of fission products and transuranic nuclides in Utah and Nevada as a result of nuclear weapons tests at the Nevada Test Site (NTS) during 1951 to 1958. The natural background exposure rate was found to vary by about a factor of two. The 137Cs inventories tended to be lower than expected indicating the effects of wind erosion. Cobalt-60 and 241Am were detected at several sites which were reported to be hotspots in post-shot radiological surveys

  9. Operationally defined availability from sequential extractions compared to plant uptake of 137Cs and 90Sr

    International Nuclear Information System (INIS)

    The operationally defined bioavailable fraction from a commonly used sequential extraction (SE) procedure was compared to biological availability represented by plant uptake of 137Cs and 90Sr. Experiments were conducted at two locations in the Ukraine and at several field locations on the Savannah River Site, South Caroline. A significant regression existed between plant uptake and the ammonium acetate fraction (r2=0.65), however, ratios of predicted uptake from the SE procedure to observed plant uptake ranged from 0.03 to 5.2. Data suggest that the SE procedure was useful for qualitative interpretations of biological availability but lacked sufficient rigor to be useful for quantitative predictions. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, D.I.

    1999-08-11

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

  12. Sorption study of 137Cs on Al-substituted calcium silicate hydroxy hydrate

    International Nuclear Information System (INIS)

    Calcium silicate hydroxy hydrate is also known as tobermorite and it is similar to Ca5AlxSi6-xO18H24.nH2O (where x = 0.025) in composition. Sorption studies have been investigated by radiometric technique at room temperature. The 137Cs selectivity has been examined in presence of 1000 times concentrated solution of Na+, Ca2+ and Ba2+. The data suggests that tobermorite could be used for immobilisation of radioactive caesium. (author)

  13. Raspodjela 137Cs u antrosolu oglednog poljoprivrednog dobra “Radmilovac” kod Beograda

    OpenAIRE

    Vukašinović, Ivana; Todorović, Dragana; Đorđević, Aleksandar; Rajković, Miloš B.; Pavlović, Vladimir B.

    2013-01-01

    Ovo je preliminarno istraživanje dubinske raspodjele radionuklida 137Cs u kultiviranome zemljištu tipa Antrosol 15 godina starog voćnjaka pod zasadom breskvi koje pripada oglednom poljoprivrednom dobru “Radmilovac” u blizini Beograda. Dubokim oranjem do dubine od 1 m zemljište je pripremljeno za postavljanje zasada breskvi. Tri godine prije uzorkovanja zemljišta prekinuta je obrada voćnjaka odnosno godišnje oranje (do 40 cm dubine), navodnjavanje i unos mineralnoga gnojiva. Koncentracija akti...

  14. {sup 134}Cs and {sup 137}Cs in lichen (Cladonia stellaris) in southern Finland

    Energy Technology Data Exchange (ETDEWEB)

    Puhakainen, M.; Rahola, T.; Heikkinen, T.; Illukka, E. [Radiation and Nuclear Safety Authority, Helsinki (Finland)

    2007-07-01

    The variation of the amounts of fallout radionuclides in reindeer lichen Cladonia stellaris (syn. Cladonia alpestris) and the underlying soil below the lichen was investigated in 1986-2004 at three locations in southern Finland. Samples from the lichen carpet were fractionated into three vertical layers and the distribution of radionuclides between the different fractions was investigated. The effective half-lives of {sup 137}Cs in lichen were almost the same in all three layers and, as a whole, the effective half-life of lichen varied from 2.7 to 3.4 years. (orig.)

  15. Investigation of elevated 137Cs concentrations in small game in Luzerne County, Pennsylvania

    International Nuclear Information System (INIS)

    Squirrel flesh, collected in November 1972 as part of the investigation of background radioactvity levels in the environs of the site selected for the Susquehanna Steam Electric Station (SSES), was found to contain elevated concentrations of 137Cs compared to other samples taken from that area. Consequently, since late 1972 further samples - air particulates, squirrels and rabbits, and their preferred diet materials - have been collected and analyzed to determine the source and extent of the elevated concentrations. Continued measurement of these parameters in the SSES area will help to provide data for the evaluation of potential radiation doses resulting from any future environmental contamination as a result of a station operation

  16. Research on Breeding Traits of Turf Bamboo by ~(137)Cs γ-radiation

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    For the purpose of breeding new and fine varieties of turf bamboo, 5 turf bamboo species (Sasa pygmaea, Indocalamus decorus, I. latifolius, Shibataea chinensis, and S. fortune) were radiated through 137Cs γ-ray in tissue cultures at different radiation dose. It was shown that: 1) Four species of turf bamboo were sensitive to radiation, low dose radiation had no effect on bud germination, high dose radiation delayed bud germination; 2) Radiation at 5 and 10 Gy had not impact on shoot emergence, but radiation...

  17. Changes in 137Cs bioavailability under the influence of soil microflora

    International Nuclear Information System (INIS)

    Despite the rising safety standards applicable to the nuclear industry enterprises still occur the huge radiation accidents, the consequences of which are large-scale releases of radionuclides into the environment. The soil is the main depot for radioactive substances in the ecosystem and triggering element for their transition through trophic chains up to the human being. That is why the search for new effective methods of soil decontamination, particularly the soil that is used for agriculture, still remains of a big relevance. Using the properties of microorganisms to affect the availability of mineral compounds in the soil may become one of such methods. 137Cs is one of the main dose-forming radionuclides, introduced into the ecosystem as a result of the nuclear weapons testing and accidents occurring at nuclear power plants. Thus, radionuclide contamination of agricultural land and food is a major problem for the exclusion zones, formed after the accidents at the Fukushima Daiichi and the Chernobyl NPPs. To study the role of soil microorganisms in the migration of 137Cs 5 isolates from Chernobyl exclusion zone were allocated and identified in accordance with 16s RNA: Burkholderia glathei Hg11, Burkholderia sp IMER-B1-53, Bacillus mycides BCHMAC12, Flavobacterium sp TISTR 1602, Pseudomonas frederiksbergensis TPK 2-4 and compared their ability to accumulate radionuclide with collection species, which are used as a bio-agents of microbial fertilizers: Bacillusmegaterium UKM B-5724, Azotobacterchroococcum UKM B-6003-20A, Azotobacterchroococcum UKM B-6003-9T, Agrobacterium radiobacter by transfer of isolates to liquid nutrient medium containing 5 kBq 137Cs. It was found that the strain Bacillusmegaterium UKM B-5724 from the collection of the Institute of Microbiology and Virology of NASU, has a high ability to accumulate radionuclides. Figured out that certain types of microorganisms can either reduce or increase the ratio of 137Cs transfer from the substrate to

  18. Bio-geochemical behavior of 90Sr, 137Cs and 60Co in tropical soil

    International Nuclear Information System (INIS)

    One manner to assess the bio-geochemical behavior of radionuclides in soils is the integration of experimental methods results obtained in the laboratory with results obtained in field experiments. In this work was used an alternative sequential chemical extraction protocol to evaluate mobility of radionuclides as a function of some physico-chemical conditions operationally defined: Slightly acidic phase: CH3COOH + CH3COONa 1:1, pH 4.7, shacked at room temperature; Easily reducible phase: NH2OH.HCl (0.1 M), pH 2, shacked at room temperature;Oxidizable phase: H2O2 (30%) + HNO3, pH 2, CH3COONH4 (1 M);shacked at room temperature; Alkaline phase: NaOH (0.1 M), pH 12, shacked at room temperature; Resistant phase: Aqua regia heated to 50 deg C / 30 min. The results obtained experimentally indicate the vulnerability of some Brazilian soils due to the higher radionuclide transfer to plant. Although it seems clear that it is difficult to identify which soil property will determine a given TF, the results of geochemical partition for 137Cs, 90Sr and 60Co obtained in slightly acidic phase were very consistent with the TF data for reference plants or with some of the soil properties recognized in the specialized literature as related with mechanisms of sorption of Cs (e.g. exchangeable K, organic matter and iron oxides content), Co (e.g. manganese oxide) and Sr (pH and exchangeable Ca). The 137Cs distribution in soil showed that Fe oxides are the main sink for this element in all type of soil and 16 years after contamination the 137Cs the TF remains almost the same in Goiania soil. The 60Co distribution in soil showed that Mn oxides are the main sink for this element in all type of soils and in the Nitisol, 5 years after contamination, the 60Co was not detected as bioavailable (in the slightly acidic phase) neither detected in plant or were detectable with values very close to the detection limit. In the Nitisol, it is possible that reduction in 137Cs transfer is also

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Transfer of Chernobyl-derived {sup 137}Cs into fishes in some Finnish lakes

    Energy Technology Data Exchange (ETDEWEB)

    Saxen, R.; Koskelainen, U.; Alatalo, M

    2000-09-01

    This report summarises STUK's work for the hydrological modelling (WG 4) in RODOS C, a project co-ordinated by the EU, in 1996-1999. The role of STUK in the project was to provide a data set on the radio-caesium contents in different types of fish and lakes in northern European environmental conditions for the development of a dynamic regional model describing radio-caesium transfer into fish. The co-operating institute, Technical Research Centre of Finland (VTT), was responsible for the modelling work in this project. Besides the analysed data on {sup 137}Cs in the various fish species in the lakes, background information was produced on lakes and their drainage areas that might affect radio-caesium transfer into fish, which was needed for the development of fish, lake and drainage basin models. The role of STUK included also providing another, independent data set for the validation of the model. The proposals and needs of the co-operating institute, VTT, were taken into account. One of the factors strongly affecting the transfer of {sup 137}Cs into fish is the nutrition level of the lake. The average transfer of {sup 137}Cs in predators at the time of maximum activity concentrations in oligotrophic lakes was found to be up to 0.10 m{sup 2}/kg, implying that approximately 10% of the amount of {sup 137}Cs deposited on one square metre is transferred into 1 kg of fish. The corresponding transfer in eutrophic lakes was clearly lower,.i.e. 3- 4%, at the time of maximum concentrations, which usually occurred 1- 3 years after the deposition, depending on the fish species. These time-dependent transfer coefficients can be regarded as a kind of a lake-specific model. If deposition to the lake is known, the activity concentrations in fish can be estimated within specific uncertainty limits, by multiplying the deposition value by the transfer coefficient at a certain time point. Temporal changes in annual averages of transfer coefficients with variation for a certain

  1. Changes in {sup 137}Cs bioavailability under the influence of soil microflora

    Energy Technology Data Exchange (ETDEWEB)

    Pareniuk, Olena [Institute of Environmental Radioactivity of Fukushima University, 1 Kanayagawa, Fukushima City, Fukushima Prefecture, 960-1296 (Japan); Ukrainian Institute of Agricultural Radiology of National University of Life and Environmental Sciences of Ukraine, Chabany, Kyivo-Svyatoshin region, 08162, Kyiv (Ukraine); Illienko, Volodymyr; Gudkov, Igor [National University of Life and Environmental Sciences of Ukraine, Heroyiv Oborony st., 15, Kyiv-03041 (Ukraine); Shavanova, Kateryna; Levchuk, Svyatoslav [Ukrainian Institute of Agricultural Radiology of National University of Life and Environmental Sciences of Ukraine, Chabany, Kyivo-Svyatoshin region, 08162, Kyiv (Ukraine)

    2014-07-01

    Despite the rising safety standards applicable to the nuclear industry enterprises still occur the huge radiation accidents, the consequences of which are large-scale releases of radionuclides into the environment. The soil is the main depot for radioactive substances in the ecosystem and triggering element for their transition through trophic chains up to the human being. That is why the search for new effective methods of soil decontamination, particularly the soil that is used for agriculture, still remains of a big relevance. Using the properties of microorganisms to affect the availability of mineral compounds in the soil may become one of such methods. {sup 137}Cs is one of the main dose-forming radionuclides, introduced into the ecosystem as a result of the nuclear weapons testing and accidents occurring at nuclear power plants. Thus, radionuclide contamination of agricultural land and food is a major problem for the exclusion zones, formed after the accidents at the Fukushima Daiichi and the Chernobyl NPPs. To study the role of soil microorganisms in the migration of {sup 137}Cs 5 isolates from Chernobyl exclusion zone were allocated and identified in accordance with 16s RNA: Burkholderia glathei Hg11, Burkholderia sp IMER-B1-53, Bacillus mycides BCHMAC12, Flavobacterium sp TISTR 1602, Pseudomonas frederiksbergensis TPK 2-4 and compared their ability to accumulate radionuclide with collection species, which are used as a bio-agents of microbial fertilizers: Bacillusmegaterium UKM B-5724, Azotobacterchroococcum UKM B-6003-20A, Azotobacterchroococcum UKM B-6003-9T, Agrobacterium radiobacter by transfer of isolates to liquid nutrient medium containing 5 kBq {sup 137}Cs. It was found that the strain Bacillusmegaterium UKM B-5724 from the collection of the Institute of Microbiology and Virology of NASU, has a high ability to accumulate radionuclides. Figured out that certain types of microorganisms can either reduce or increase the ratio of {sup 137}Cs transfer

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

    Science.gov (United States)

    Ota, Masakazu; Nagai, Haruyasu; Koarashi, Jun

    2016-05-01

    A process-based model for (137)Cs transfer in forest surface environments was developed to assess the dynamic behavior of Fukushima-derived (137)Cs in a Japanese forest. The model simulation successfully reproduced the observed data from 3year migration of (137)Cs in the organic and mineral soil layers at a contaminated forest near Fukushima. The migration of (137)Cs from the organic layer to the mineral soil was explained by the direct deposition pattern on the forest floor and the turnover of litter materials in the organic layer under certain ecological conditions. Long-term predictions indicated that more than 90% of the deposited (137)Cs would remain within the top 5cm of the soil for up to 30years after the accident, suggesting that the forest acts as an effective long-term reservoir of (137)Cs with limited transfer via the groundwater pathway. The model was also used to explore the potential impacts of soil organic matter (SOM) interactions on the mobility and bioavailability of (137)Cs in the soil-plant system. The simulation results for hypothetical organic soils with modified parameters of (137)Cs turnover revealed that the SOM-induced reduction of (137)Cs adsorption elevates the fraction of dissolved (137)Cs in the soil solution, thereby increasing the soil-to-plant transfer of (137)Cs without substantially altering the fractional distribution of (137)Cs in the soil. Slower fixation of (137)Cs on the flayed edge site of clay minerals and enhanced mobilization of the clay-fixed (137)Cs in organic-rich soils also appeared to elevate the soil-to-plant transfer of (137)Cs by increasing the fraction of the soil-adsorbed (exchangeable) (137)Cs. A substantial proportion (approximate 30%-60%) of (137)Cs in these organic-rich soils was transferred to layers deeper than 5cm decades later. These results suggested that SOM influences the behavior of (137)Cs in forests over a prolonged period through alterations of adsorption and fixation in the soil. PMID:26897402

  3. 90Sr and 137Cs contamination of polished rice in Japan. Survey and analysis during the years 1959-1995

    International Nuclear Information System (INIS)

    This paper discusses the influences of global-scale radioactive fallout on polished rice in Japan. For this purpose, a set of paddy topsoil and unpolished rice samples was collected annually from experimental paddy fields at seventeen stations across Japan during the years from 1959 to 1995. According to the graph presenting year-to-year variations in the nationwide averages of 90Sr and 137Cs contents (mBq/kg) of the polished rice samples, the year 1963 marked the first and highest peaks with 269 for 90Sr and 4179 for 137Cs. The average fallout levels of the two nuclides were the highest in that year, too. Thereafter, 90Sr and 137Cs contents of the samples continued to decline drastically, the second peaks being in 1975 with 29·192 and the third peaks in 1995 with 5·46, respectively. It can be conceived that 90Sr and 137Cs nuclides are directly taken into rice grains from stems, leaves and husks which are exposed to the atmosphere, or they are indirectly taken into the grains after they are absorbed from paddy topsoil by the roots. Through the analysis of contamination pathways, it was finally confirmed that for both 90Sr and 137Cs, the direct contamination comprised 70-95% in 1963 when the fallout levels were the highest, and that in the years following 1985 when the fallout nuclides ceased to be detected, the rice contamination was produced mainly through the indirect pathway. Discussions also include the regional differences in the contents of polished rice, especially those between the Japan Sea coast and Pacific coast areas, differences in distribution rate of 90Sr and 137Cs between polished and unpolished rice, and relative difficulties of 90Sr and 137Cs being translocated in throughout plants. (author)

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

    Science.gov (United States)

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

    2016-07-01

    The screening of mini-core collection of azuki bean accessions (Vigna angularis (Willd.) Ohwi & Ohashi) for comparative uptake of (137)Cs in their edible portions was done in field trials on land contaminated by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. Ninety seven azuki bean accessions including their wild relatives from a Japanese gene bank, were grown in a field in the Fukushima prefecture, which is located approximately 51 km north of FDNPP. The contamination level of the soil was 3665 ± 480 Bq kg(-1) dry weight ((137)Cs, average ± SD). The soil type comprised clay loam, where the sand: silt: clay proportion was 42:21:37. There was a significant varietal difference in the biomass production, radiocaesium accumulation and transfer factor (TF) of radiocaesium from the soil to edible portion. Under identical agricultural practice, the extent of (137)Cs accumulation by seeds differed between the accessions by as much as 10-fold. Inter-varietal variation was expressed at the ratio of the maximum to minimum observed (137)Cs transfer factor for seeds ranged from 0.092 to 0.009. The total biomass, time to flowering and maturity, and seed yield had negative relationship to (137)Cs activity concentration in seeds. The results suggest that certain variety/varieties of azuki bean which accumulated less (137)Cs in edible portion with preferable agronomic traits are suitable to reduce the (137)Cs accumulation in food chain on contaminated land. PMID:27105146

  5. Accumulation of 137Cs and 90Sr from contaminated soil by three grass species inoculated with mycorrhizal fungi

    International Nuclear Information System (INIS)

    The use of plants to accumulate low level radioactive waste from soil, followed by incineration of plant material to concentrate radionuclides may prove to be a viable and economical method of remediating contaminated areas. We tested the influence of arbuscular mycorrhizae on 137Cs and 90Sr uptake by bahia grass (Paspalum notatum), johnson grass (Sorghum halpense) and switchgrass (Panicum virginatum) for the effectiveness on three different contaminated soil types. Exposure to 137Cs or 90Sr over the course of the experiment did not affect above ground biomass of the three grasses. The above ground biomass of bahia, johnson and switchgrass plants accumulated from 26.3 to 71.7% of the total amount of the 137Cs and from 23.8 to 88.7% of the total amount of the 90Sr added to the soil after three harvests. In each of the three grass species tested, plants inoculated with Glomus mosseae or Glomus intraradices had greater aboveground plant biomass, higher concentrations of 137Cs or 90Sr in plant tissue, % accumulation of 137Cs or 90Sr from soil and plant bioconcentration ratios at each harvest than those that did not receive mycorrhizal inoculation. Johnson grass had greater aboveground plant biomass, greater accumulation of 137Cs or 90Sr from soil and plant higher bioconcentration ratios with arbuscular mycorrhizal fungi than bahia grass and switchgrass. The greatest accumulation of 137Cs and 90Sr was observed in johnson grass inoculated with G. mosseae. Grasses can grow in wide geographical ranges that include a broad variety of edaphic conditions. The highly efficient removal of these radionuclides by these grass species after inoculation with arbuscular mycorrhizae supports the concept that remediation of radionuclide contaminated soils using mycorrhizal plants may present a viable strategy to remediate and reclaim sites contaminated with radionuclides

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

    Science.gov (United States)

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

    2016-01-01

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

  7. Photo fission cross-section of 232Th, 238U and 237Np

    International Nuclear Information System (INIS)

    In the present work, photo fission cross-section of 232Th, 238U and 237Np evaluated with the help of fission fragment angular distribution measurements by using Bremsstrahlung radiation from 7.4 MeV to 9.0 MeV have been carried out by employing high efficiency SSNTD technique

  8. Investigation of the (232)Th Nucleus Excitations at the FEL {gamma} - Nucleus Colliders

    CERN Document Server

    Koru, H; Sultansoy, S F; Sarer, B

    2001-01-01

    The physics search potential of the FEL {gamma} - Nucleus colliders is analysed using excitations of the (232)Th nucleus. It is shown that, due to the monochromacity of FEL {gamma} beam and high statistics, proposed colliders will play an important role in the field of "traditional" nuclear physics.

  9. Feeding of the {sup 232}Th levels from the decay of {sup 236}U

    Energy Technology Data Exchange (ETDEWEB)

    Gehrke, R.J. E-mail: rjg@inel.gov; Baker, J.D.; Riddle, C.L

    2002-03-01

    Population of the 6{sup +} 332 keV level in {sup 232}Th from the decay of {sup 236}U was observed for the first time. The 49, 112, and 171 keV {gamma}-ray energies and relative intensities from the decay of {sup 236}U were measured.

  10. 230,232Th in milk, meat, and grain in Korea

    International Nuclear Information System (INIS)

    The concentrations of natural radioisotopes 230Th and 232Th in Korean foods were measured by the method of calcium oxalate co-precipitation in addition to the conventional anion-exchange method and alpha spectroscopic measurement. The 230Th concentrations (mBq/kg-fresh) in Korean foods were found to be as follows: milk 0.14-2.45, pork 2.98-8.97, beef 1.94-9.80, chicken 1.22-13.0, rice 0.43-2.35, wheat 0.53-14.4, and soybeans, 8.44-91.6. The 232Th concentrations (mBq/kg-fresh) in Korean foods were found to be as follows: milk 0.01-2.46, pork 0.28-9.32, beef 1.02-5.34, chicken 0.56-4.98, rice 0.32-2.54, wheat 0.53-20.0, and soybeans, 2.30-42.2. The annual internal dose of Th was also estimated. The annual internal dose of 230Th and 232Th in milk was about 0.006 μSv/yr and much lower than that of other countries because of the low intake of milk in Korea compared to other countries. The annual internal dose of 230Th and 232Th in the rice was about 0.043 μSv/yr and highest because rice is the staple food of Koreans. (author)

  11. 232Th and 238U neutron emission cross section calculations and analysis of experimental data

    International Nuclear Information System (INIS)

    In this study, pre-equilibrium neutron-emission spectra produced by (n,xn) reactions on nuclei 232Th and 238U have been calculated. Angle-integrated cross sections in neutron induced reactions on targets 232Th and 238U have been calculated at the bombarding energies up to 18 MeV. We have investigated multiple pre-equilibrium matrix element constant from internal transition for 232Th (n,xn) neutron emission spectra. In the calculations, the geometry dependent hybrid model and the cascade exciton model including the effects of pre-equilibrium have been used. In addition, we have described how multiple pre-equilibrium emissions can be included in the Feshbach-Kerman-Koonin (FKK) fully quantum-mechanical theory. By analyzing (n,xn) reaction on 232Th and 238U, with the incident energy from 2 Me V to 18 Me V, the importance of multiple pre-equilibrium emission can be seen cleady. All calculated results have been compared with experimental data. The obtained results have been discussed and compared with the available experimental data and found agreement with each other

  12. {sup 137}Cs and {sup 210}Pb inventories in soils and sediments from Chapala Lake (Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Fernandez, A.C.; Perez-Bernal, L.H. [Unidad Academica Mazatlan, Instituto de Ciencias del Mar y Limnologia, Universidad Nacional Autonoma de Mexico (Mexico); Sanchez-Cabeza, J.A. [Unidad Academica de Procesos Oceanicos y Costeros, Instituto de Ciencias del Mar y Limnologia, Universidad Nacional Autonoma de Mexico (Mexico); Ontiveros-Cuadras, J.F. [Posgrado en Ciencias del Mar y Limnologia, Instituto de Ciencias del Mar y Limnologia, Universidad Nacional Autonoma de Mexico (Mexico)

    2014-07-01

    Chapala Lake is the largest natural freshwater reservoir in Mexico and it is located in Central Mexico, at 1524 m above sea level. The lake is considered to be fairly anthropized and it has experienced periods of extremely low water level as a result of recent climate change and water extraction. The study of recent manifestations of global change in Chapala Lake requires accurate {sup 210}Pb chronological reconstructions, taking into account the expected variability of sediment accumulation rates by using the Constant Flux model. For a reliable application of this dating model, it is important that {sup 210}Pb flux values in the lacustrine sedimentary record are in correspondence with the local atmospheric fluxes. With the aim to estimate the fluxes of the fallout radionuclides {sup 210}Pb and {sup 137}Cs in the region, sediment and soil cores were collected in the Chapala Lake. Sediment profiles were evaluated and estimated fluxes in sediments and soils were compared. Some geochemical properties (e.g. grain size distribution, organic matter concentration, XRF-derived elemental composition and magnetic susceptibility) were also evaluated to understand how diagenesis changes and sediment provenance can affect the {sup 210}Pb and {sup 137}Cs depth profiles and inventories. Document available in abstract form only. (authors)

  13. Use of 137Cs, 210Pbex and 7Be for Documenting Soil Redistribution: The Future

    International Nuclear Information System (INIS)

    Although 137Cs and to some extent 210Pbex based methodologies are well established, there remains a need for further investigations aimed at exploring the optimal use of 7Be. The information generated by the 7Be measurements can provide a useful complement to 137Cs and fallout 210Pb measurements to assess the effectiveness of different soil conservation practices. The conjunctive use of two or even three fallout radionuclides (FRNs) can generate valuable information on the erosional history of a site by generating datasets for different timescales. This approach needs to be developed further and validated under a range of different agro-ecological conditions. Another promising opportunity is the integration of FRNs and compound specific stable isotope techniques (CSSI) as fingerprinting technologies to identify critical agricultural areas of soil loss. An important and logical next step is the up-scaling of FRN-based methodologies from the field to the watershed level. To assist in integrating and interpreting the spatial complexity of the landscape, FRNs should be used more widely and at a larger scale for contributing more directly to decision making. An additional challenge for the users of FRNs will be to promote their transition and evolution from validated research tool to decision support tool. (author)

  14. 137Cs and 90Sr behaviour in contaminated soils of the Chernobyl area

    International Nuclear Information System (INIS)

    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)

  15. Accumulation of 137Cs and 90Sr radionuclides by leguminous plants of various species and varieties

    International Nuclear Information System (INIS)

    Decision of protein problem on territories contaminated with radionuclides as a result of the accident at the Chernobyl NPP is not possible without extension of lands under cultivation of leguminous plants (peas, lupine and soybean). All lupine varieties show high indices of radionuclides accumulation and are restrictedly acceptable for production on contaminated territories. The following varieties of yellow forage lupine are the most acceptable for cultivation on the contaminated territories: Zhemchug, Rannij, Adradzhenne, Mitan. Introduction of varieties with the low level of radionuclides accumulation (peas — Aist, Agat, Gomelskaya; soybean — Mageva, Pina, Severnaya zvezda) into agricultural production will make to possible to obtain agricultural products meeting the requirements of the “Republican permissible levels of 137Cs and 90Sr content in agricultural raw materials and forages” on arable lands with the higher density of radioactive contamination: 137Cs — 925—1110 kBq/m2 (25-30 Ci/km2) and 90Sr 15—18 kBq/m2 (0.40-0.50 Ci/km2)

  16. Characterization of a 137Cs standard source for calibration purposes ar CRCN-NE

    International Nuclear Information System (INIS)

    Radiation protection monitoring instruments should be calibrated by accredited calibration laboratories. To offer calibration services, a laboratory must accomplish all requirements established by the national regulatory agency. The Calibration Service of the Centro Regional de Ciencias Nucleares (CRCN-NE), Comissao Nacional de Energia Nuclear, Recife, Brazil, is trying to achieve this accreditation. In the present work, a 137Cs standard source was characterized following the national and international recommendations and the results are presented. This source is a commercially available single source irradiator model 28-8A, manufactured by JLShepherd and Associates, with initial activity of 444 GBq (05/13/03). To provide different air kerma rates, as required for the calibration of portable radiation monitors, this irradiator have a set of four lead attenuators with different thickness, providing attenuation factors equal to 2, 4, 10 and 100 times (nominally). The performed tests included: size and uniformity of the radiation standard field at calibration reference position, variation of the air kerma rate for different lead attenuators, determination of attenuation factors for each lead attenuator configuration, and determination of the radiation scattering at the calibration reference position. The results showed the usefulness of the 137Cs standard source for the calibration of radiation protection monitoring detectors. (author)

  17. 137Cs and 210Pb inventories in soils and sediments from Chapala Lake (Mexico)

    International Nuclear Information System (INIS)

    Chapala Lake is the largest natural freshwater reservoir in Mexico and it is located in Central Mexico, at 1524 m above sea level. The lake is considered to be fairly anthropized and it has experienced periods of extremely low water level as a result of recent climate change and water extraction. The study of recent manifestations of global change in Chapala Lake requires accurate 210Pb chronological reconstructions, taking into account the expected variability of sediment accumulation rates by using the Constant Flux model. For a reliable application of this dating model, it is important that 210Pb flux values in the lacustrine sedimentary record are in correspondence with the local atmospheric fluxes. With the aim to estimate the fluxes of the fallout radionuclides 210Pb and 137Cs in the region, sediment and soil cores were collected in the Chapala Lake. Sediment profiles were evaluated and estimated fluxes in sediments and soils were compared. Some geochemical properties (e.g. grain size distribution, organic matter concentration, XRF-derived elemental composition and magnetic susceptibility) were also evaluated to understand how diagenesis changes and sediment provenance can affect the 210Pb and 137Cs depth profiles and inventories. Document available in abstract form only. (authors)

  18. 137Cs elimination by chronically-contaminated largemouth bass (Micropterus salmoides)

    International Nuclear Information System (INIS)

    The temperature-dependent 137Cs biological half-times (Tb) of lifetime-exposed largemouth bass (Micropterus salmoides) from a nuclear cooling reservoir at the US Department of Energy's Savannah River Site were calculated from whole-body measurements of live fish and compared with literature records for acutely and chronically-contaminated fish. The Tb's of the bass averaged 322 d, 225 d, and 140 d at 15, 20, and 26 C, respectively. These mean Tb's were 1.7 to 2.5 times longer than would be expected for acutely contaminated fish, and 1.2 to 1.8 times longer than those predicted for fish at steady-state with their environment according to recent models. This slower elimination did not appear to result from slower elimination from skeletal muscle compared with other soft tissues, in that the muscle to whole-body 137Cs concentration ratios after the elimination period were similar to those of freshly-caught bass. Their results suggested that elimination rates estimated from the terminal elimination components of acutely-dosed fish may not reflect the elimination rates of fish exposed to contaminants throughout their lifetime, even when care is taken to allow sufficient time for absorption of the dose

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

    International Nuclear Information System (INIS)

    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

  20. Remediation Strategy and Practice on Agricultural Land Contaminated with 137Cs and 90Sr in Belarus

    International Nuclear Information System (INIS)

    This paper is intended to review existing data on the efficiency and acceptability of agricultural countermeasures for reducing of internal exposures introduced by consumption of foodstuff produced on land contaminated by 137Cs and 90Sr. Currently, there are strongly reduced state budget resources for mitigating the consequences of the Chernobyl accident. No more than 50% of the required agricultural protective measures could be financed in the last years. There is an increased need for an optimal use of available resources. New efforts are needed to identify sustainable ways to make use of the most affected areas that reflect the radiation hazard, but also revive the economic potential for the benefit of the community. For this reason the practical complex assessment and justifying of countermeasure application in the most contaminated rural districts of Belarus are the main directions of rehabilitation activity to ensure the radiation protection of people for long term after Chernobyl accident. Countermeasures have to lead to the profitable or self-sufficient production of harvests with low radionuclide contamination. The complex of the effective countermeasures has been worked out and implemented mostly in public sector of agriculture. However, particular attention must be given to the production of private farms of several hundred settlements, where samples of milk still contain radionuclides of 137Cs and 90Sr in excess relative to the established limits

  1. Values of soil-plant transfer factor of 226Ra and 228Ra: agricultural areas versus areas of high natural radioactivity

    International Nuclear Information System (INIS)

    In this work, soil to plant transfer factor of 226Ra and 228Ra obtained in areas of traditional agricultural practices varied as a function of the considered cultivated species but little variation was observed as a function of the soil type. Beans and soybeans presented more important absorption than cereals (corn, rice and wheat). In our work legumes (bean and soybean) presented transfer factors up to one order of magnitude higher than average values for regions where natural radioactivity is high. On the other hand, the results for cereals did not presented such clear differences. It can be concluded that cultural inputs of 226Ra and 228Ra are occurring in agricultural areas, but few species can concentrate it. The transfer factor values obtained in this work for 226Ra and 228Ra can be applied in risk assessment models. (author)

  2. The Enhancement of 226Ra in a Tidal Estuary due to the Operation of Fertilizer Factories and Redissolution from Sediments: Experimental Results and a Modelling Study

    Science.gov (United States)

    Periáñez, R.

    2002-05-01

    The presence of 226Ra in a tidal estuary formerly affected by direct discharges from a phosphate fertilizer complex has been investigated. In general, activity levels are lower than those detected when direct discharges were carried out. However, there is still a clear contamination that can be attributed, presumably, to the disposal of Ra-containing phosphogypsum to the river and to the redissolution of radionuclides from the contaminated sediments. A numerical model of the estuary has been developed to investigate these hypothesis. The hydrodynamics are first calibrated and standard tidal analysis is carried out. The dispersion model computes instantaneous currents from the so obtained tidal constants to speed up simulations. The exchanges of 226Ra between water and the bottom sediment have been described in terms of kinetic transfer coefficients. Model results are, in general, in agreement with observations. The simulation results support the previous idea of sediments acting as a source of 226Ra to the water column.

  3. Developing 226Ra and 227Ac age-dating techniques for nuclear forensics to gain insight from concordant and non-concordant radiochronometers

    International Nuclear Information System (INIS)

    The model age or 'date of purification' of a nuclear material is an important nuclear forensic signature. In this study, chemical separation and MC-ICP-MS measurement techniques were developed for 226 Ra and 227Ac: grand-daughter nuclides in the 238U and 235U decay chains respectively. The 230Th-234U, 226Ra-238U, 231Pa-235U, and 227Ac-235U radiochronometers were used to calculate model ages for CRM-U100 standard reference material and two highly-enriched pieces of uranium metal from the International Technical Working Group Round Robin 3 Exercise. In conclusion, the results demonstrate the accuracy of the 226Ra-238U and 227Ac-235U chronometers and provide information about nuclide migration during uranium processing

  4. Developing 226Ra and 227Ac age-dating techniques for nuclear forensics to gain insight from concordant and non-concordant radiochronometers

    International Nuclear Information System (INIS)

    The model age or 'date of purification' of a nuclear material is an important nuclear forensic signature. In this study, chemical separation and MC-ICP-MS measurement techniques were developed for 226Ra and 227Ac: grand-daughter nuclides in the 238U and 235U decay chains, respectively. The 230Th-234U, 226Ra-238U, 231Pa-235U, and 227Ac-235U radiochronometers were used to calculate model ages for CRM-U100 standard reference material and two highly-enriched pieces of uranium metal from the International Technical Working Group Round Robin 3 Exercise. Results demonstrate the accuracy of the 226Ra-238U and 227Ac-235U chronometers and provide information about nuclide migration during uranium processing. (author)

  5. 天津市地表水中氡、钍射气与U-226Ra-Th浓度间相关性探讨

    Institute of Scientific and Technical Information of China (English)

    田义宗

    2012-01-01

    目的 为了探讨地表水中氡、钍射气与U-226 Ra-Th浓度之间的相关性.方法 利用专业设备对天津市的河道、水库的地表水中氡、钍射气进行监测,同时对地表水中的U-226Ra-Th进行分析.结果 在对26个水样品分析发现,地表水中氡与水中的U-226 Ra-Th之间不具有相关性.结论 在对地表水中氡、钍射气和U、226 Ra、Th等进行调查时,应当对关注的核素分别进行监测和分析.

  6. On hygiene standardization of combined environmental factors (on the basis of data on rat death in three generations after injection of 226Ra+herbicide TMTD)

    International Nuclear Information System (INIS)

    The toxic effect of a binary mixture of 226Ra and TMTD herbicide has been determined by mathematical treatment of the results. The results of death in three generators of white rats of no breed, which had been subjected to chronical poisoning with the binary mixture of 226Ra and TMTD herbicide, were investigated. A coefficient of the combined effect was calculated. The advantage in determining the error of this coefficient was given to logarythmic calculations and not to differentiation. This permits a detection of antilogarythmic and coalitive changes in the generative functions of rats after a combined effect of 226Ra+TMTD mixture. The indices of rat generations, which have been affected by the combined effect of both substances introduced into the rats, are presented

  7. A sequential and fast method for low level of 226Ra , 228Ra, 210Pb e 210Po in mine effluents and uranium processing plant

    International Nuclear Information System (INIS)

    Due to biological risk and long half lives, the radionuclides 228Ra, 226Ra, 210Pb and 210Po should be frequently monitored to check for any environmental contamination around mines and uranium plants. Currently, the methods used for the determination of these radionuclides take about thirty days to reach the radioactive equilibrium of the 210Pb and 226Ra daughter's. The evaluation of effluent discharges and leakage of deposits to water bodies in monitoring programs, require quick answers to implement corrective measures. Thereby fast determination methods must be implemented. This work presents a fast and sequential method to, in three days, determine accurately and sensitively, 226Ra, 228Ra, 210Pb, 210Po, in water and effluent samples

  8. {sup 137}Cs in irrigation water and its effect on paddy fields in Japan after the Fukushima nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Natsuki [Institute of Science and Technology, Niigata University, 8050 Ikarashi 2-nocho, Nishi-ku, Niigata 950-2181 (Japan); Obara, Hitomi [Oriental Consultants, Sumitomo Fudosan Nishi Shinjuku Bldg. No. 6, 3-12-1 Honmachi, Shibuya-ku, Tokyo 151-0071 (Japan); Ogasa, Marie; Miyazu, Susumu [Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-nocho, Nishi-ku, Niigata 950-2181 (Japan); Harada, Naoki [Institute of Science and Technology, Niigata University, 8050 Ikarashi 2-nocho, Nishi-ku, Niigata 950-2181 (Japan); Nonaka, Masanori [Graduate School for Management of Technology, Niigata University, 8050 Ikarashi 2-nocho, Nishi-ku, Niigata 950-2181 (Japan)

    2014-05-01

    There is concern that radiocesium deposited in the environment after the accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011 will migrate to paddy fields through hydrological pathways and cause serious and long-lasting damage to the agricultural activities. This study was conducted in the Towa region of Nihonmatsu in the northern part of Fukushima Prefecture, Japan, (1) to quantify {sup 137}Cs in stream water used to irrigate paddy fields by separating the dissolved and particulate components in water samples and then fractionating the particulate components bonded in different ways using a sequential extraction procedure, and (2) to determine the amounts of radiocesium newly added to paddy fields in irrigation water relative to the amounts of radiocesium already present in the fields from the deposition of atmospheric fallout immediately after the FDNPP accident. Three catchments were studied, and the {sup 137}Cs activity concentrations in stream water samples were 79–198 mBq L{sup −1} under stable runoff conditions and 702–13,400 Bq L{sup −1} under storm runoff conditions. The residual fraction (F4, considered to be non-bioavailable) was dominant, accounting for 59.5–82.6% of the total {sup 137}Cs activity under stable runoff conditions and 69.4–95.1% under storm runoff conditions. The {sup 137}Cs newly added to paddy fields in irrigation water only contributed 0.03–0.05% of the amount already present in the soil (201–348 kBq m{sup −2}). This indicates that the {sup 137}Cs inflow load in irrigation water is negligible compared with that already in the soil. However, the contribution from the potentially bioavailable fractions (F1 + F2 + F3) was one order of magnitude larger, accounting for 0.20–0.59%. The increase in the dissolved and soluble radiocesium fraction (F1) was especially large (3.0% to infinity), suggesting that radiocesium migration in irrigation water is increasing the accumulation of radiocesium in rice

  9. 137Cs, 239,240Pu and 241Am in boreal forest soil and their transfer into wild mushrooms and berries

    International Nuclear Information System (INIS)

    Profiles of podzolic soil from boreal forests were sampled from eight sites in Finland and the distribution of 137Cs in the soil layers was determined. In addition, 239,240Pu and 241Am were determined from two soil profiles taken at one sampling site. Inventories of 137Cs in the soil profiles varied between 1.7 kBq/m2 and 42 kBq/m2, reflecting known variation in 137Cs fallout from the Chernobyl accident. The highest proportions of the radionuclides were found in the organic layer at a depth of less than 5 cm, which on average contained 47% of 137Cs, 76% of 239,240Pu and 79% of 241Am. In the litter, clearly higher proportions of 137Cs were found compared to 239,240Pu and 241Am, probably indicating its more effective recycling from the organic layer back to the surface. Only very minor proportions of 137Cs were recorded below 20 cm. The concentration of 137Cs in the soil profiles could be approximated with a declining logarithmic trend. The activity concentrations of 137Cs were determined for six wild mushroom species and three wild berry species at two sites, as well as the aggregated transfer factors and the distribution of 137Cs between their various parts. In addition, 239,240Pu and 241Am were determined in one mushroom and three berry species at one site. Very high concentrations of 137Cs, up to 20 kBq/kg (d.w.), were found in mushrooms, and their transfer factors were between 0.1 m2/kg and 1.0 m2/kg. In berries, the transfer factors were an order of magnitude lower. 137Cs accumulated more in the caps of mushrooms and in the fruits of berries than in other parts. Transfer factors for 239,240Pu and 241Am were two to three orders of magnitude lower than those of 137Cs. - Highlights: ► 137Cs, 239,240Pu and 241Am mainly concentrated in organic layer in podzolic soil. ► Distribution of 137Cs in the upper 20 cm soil follows exponential declining trend. ► 137Cs concentrates into mushrooms but varies considerably between species. ► 137Cs concentrates in mushroom

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

    Science.gov (United States)

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

    2014-02-01

    The background radiation level of (137)Cs at the urban atmosphere of Thessaloniki has been increased during the recent decade only due to the Fukushima accident fallout. Since then, no other signal of (137)Cs was observed until the winter period of 2013, when slightly elevated (137)Cs concentrations were measured. The (137)Cs signals observed were up to 12 μBq m(-3), mainly during holidays and weekends followed by lower or even non-detectable activities in the next working days. Those episodes are attributed to the increase of biomass products combustion for residential heating as this year the tax of oil for heating was drastically raised as a consequence of the financial crisis. A preliminary survey of various wood products as well as of bottom ashes from different domestic burning devices is presented. (137)Cs concentrations up to 11 Bq kg(-1) were measured in wood products and up to 500 Bq kg(-1) in ash samples. PMID:24316685

  11. (135)Cs/(137)Cs isotopic ratio as a new tracer of radiocesium released from the Fukushima nuclear accident.

    Science.gov (United States)

    Zheng, Jian; Tagami, Keiko; Bu, Wenting; Uchida, Shigeo; Watanabe, Yoshito; Kubota, Yoshihisa; Fuma, Shoichi; Ihara, Sadao

    2014-05-20

    Since the Fukushima Daiichi nuclear power plant (FDNPP) accident in 2011, intensive studies of the distribution of released fission products, in particular (134)Cs and (137)Cs, in the environment have been conducted. However, the release sources, that is, the damaged reactors or the spent fuel pools, have not been identified, which resulted in great variation in the estimated amounts of (137)Cs released. Here, we investigated heavily contaminated environmental samples (litter, lichen, and soil) collected from Fukushima forests for the long-lived (135)Cs (half-life of 2 × 10(6) years), which is usually difficult to measure using decay-counting techniques. Using a newly developed triple-quadrupole inductively coupled plasma tandem mass spectrometry method, we analyzed the (135)Cs/(137)Cs isotopic ratio of the FDNPP-released radiocesium in environmental samples. We demonstrated that radiocesium was mainly released from the Unit 2 reactor. Considering the fact that the widely used tracer for the released Fukushima accident-sourced radiocesium in the environment, the (134)Cs/(137)Cs activity ratio, will become unavailable in the near future because of the short half-life of (134)Cs (2.06 years), the (135)Cs/(137)Cs isotopic ratio can be considered as a new tracer for source identification and long-term estimation of the mobility of released radiocesium in the environment.

  12. Random and systematic spatial variability of 137Cs inventories at reference sites in South-Central Brazil

    Directory of Open Access Journals (Sweden)

    Correchel Vladia

    2005-01-01

    Full Text Available The precision of the 137Cs fallout redistribution technique for the evaluation of soil erosion rates is strongly dependent on the quality of an average inventory taken at a representative reference site. The knowledge of the sources and of the degree of variation of the 137Cs fallout spatial distribution plays an important role on its use. Four reference sites were selected in the South-Central region of Brazil which were characterized in terms of soil chemical, physical and mineralogical aspects as well as the spatial variability of 137Cs inventories. Some important differences in the patterns of 137Cs depth distribution in the soil profiles of the different sites were found. They are probably associated to chemical, physical, mineralogical and biological differences of the soils but many questions still remain open for future investigation, mainly those regarding the adsorption and dynamics of the 137Cs ions in soil profiles under tropical conditions. The random spatial variability (inside each reference site was higher than the systematic spatial variability (between reference sites but their causes were not clearly identified as possible consequences of chemical, physical, mineralogical variability, and/or precipitation.

  13. A numerical investigation into the long-term behaviors of Fukushima-derived137Cs in the ocean

    Institute of Scientific and Technical Information of China (English)

    ZHAO Chang; WANG Gang; QIAO Fangli; WANG Guansuo; JUNG Kyung-Tae; XIA Changshui

    2015-01-01

    The Fukushima nuclear accident in 2011 released large amounts of radionuclides, including137Cs, into the Pacific Ocean. A quasi-global ocean radioactive transport model with horizontal grid spacing of 0.5°×0.5° and 21 vertical layers was thereafter established to study the long-term transport of the Fukushima-derived137Cs in the ocean. The simulation shows that the plume of137Cs would be rapidly transported eastward alongside the Kuroshio Current and its extensions. Contaminated waters with concentrations lower than 2 Bq/m3 would reach the west coast of North America 4 or 5 years after the accident. The137Cs tends to be carried, despite its very low concentration, into the Indian and South Pacific Oceans by 2016 via various branches of ocean currents. Meanwhile, the137Cs concentrations in the western part of the North Pacific Ocean decrease rapidly with time. Up to now the highly contaminated waters have remained in the upper 400 m, showing no evidence of significant penetration to deeper layers.

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

    Science.gov (United States)

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

    2014-02-01

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

  15. Dynamics of 137Cs in the forests of the 30-km zone around the Chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    Dynamics of the 137Cs content in the components of the forests in the 30-km zone around the Chernobyl nuclear power plant (NPP) in 1986–1994 are associated mainly with such factors as the size of radioactive particles in the fallout, ecosystem humidification and soil type, tree age. The influence of particle size was especially noticable between 1986–1987 and was displayed by low biological availability of radionuclides in the near part of the zone (within the 10-km radius circle around the NPP) in comparison with more distant regions (within the 30-km radius circle). Later, the expression of this influence decreased and transfer factor (the ratio of 137Cs content in overground phytomass to the soil contamination density) became approximately the same for all plots with similar ecological and fallout characteristics. Humidity of landscape and soil type determined the velocity of radionuclide vertical migration in the soil and 137Cs biological availability. These parameters were maximum for the hydromorphic soils of wet landscapes enriched in organic substance and poor clayey minerals. Differences of 137Cs accumulation in overground phytomass of trees caused by tree age are displayed in the higher 137Cs concentration in structural parts of young trees as compared with old ones

  16. Dynamics of 137Cs in the forests of the 30-km zone around the Chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    Dynamics of the 137Cs content in the components of the forests in the 30-km zone around the Chernobyl nuclear power plant (NPP) in 1986-1994 are associated mainly with such factors as the size of radioactive particles in the fallout, ecosystem humidification and soil type, tree age. The influence of particle size was especially noticeable between 1986-1987 and was displayed by low biological availability of radionuclides in the near part of the zone (within the 10-km radius circle around the NPP) in comparison with more distant regions (within the 30-km radius circle). Later, the expression of this influence decreased and transfer factor (the ratio of 137Cs content in overground phytomass to the soil contamination density) became approximately the same for all plots with similar ecological and fallout characteristics. Humidity of landscape and soil type determined the velocity of radionuclide vertical migration in the soil and 137Cs biological availability. These parameters were maximum for the hydromorphic soils of wet landscapes enriched in organic substance and poor clayey minerals. Differences of 137Cs accumulation in overground phytomass of trees caused by tree age are displayed in the higher 137Cs concentration in structural parts of young trees as compared with old ones

  17. Inventory of {sup 226}Ra, {sup 228}Ra and {sup 210}Pb in marine sediments cores of Southwest Atlantic Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Alice M.R.; Oliveira, Joselene de, E-mail: alice.costa@usp.br, E-mail: jolivei@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Metrologia das Radiacoes. Lab. de Radiometria Ambiental; Figueira, Rubens C.L.; Mahiques, Michel M.; Sousa, Silvia H.M., E-mail: rfigueira@usp.br, E-mail: mahiques@usp.br, E-mail: smsousa@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto Oceanografico

    2015-07-01

    {sup 210}Pb (22.3 y) is a radioactive isotope successfully applied as tracer of sediment dating of the last 100-150 years. The application of {sup 226}Ra and {sup 228}Ra as paleoceanographic tracers (half-lives of 1,600 y and 5.7 y, respectively) also gives some information of ocean's role in past climate change. In this work, it was analyzed 2 sediment cores collect at Southwest Atlantic Ocean. The sediments samples were freeze-dried and acid digested in microwave. It was carried out a radiochemical separation of {sup 226}Ra, {sup 228}Ra and {sup 210}Pb and performed a gross alpha and gross beta measurement of both precipitates Ba(Ra)SO{sub 4} and PbCrO{sub 4} in a low background gas-flow proportional counter. Activity concentrations of {sup 226}Ra ranged from 45 Bq kg{sup -1} to 70 Bq kg{sup -1} in NAP-62 and from 57 Bq kg{sup -1} to 82 Bq kg{sup -1} in NAP-63 samples. The concentration of {sup 228}Ra varied between 37 Bq kg{sup -1} and 150 Bq kg{sup -1} in NAP-62 and between 23 Bq kg{sup -1} and 111 Bq kg{sup -1} in NAP-63 samples. The concentration of total {sup 210}Pb ranged from 126 Bq kg{sup -1} to 256 Bq kg{sup -1} in NAP-62 and from 63 Bq kg{sup -1} to 945 Bq kg{sup -1} in NAP-63 samples. Results of {sup 210}Pb{sub uns} varied from 68 Bq kg{sup -1} to 192 Bq kg{sup -1} for NAP-62, while varied from <4.9 Bq kg{sup -1} to 870 Bq kg{sup -1} in NAP-63 profile. Increased values of {sup 210}Pb{sub uns} were found on the top of both NAP-62 and NAP- 63 sediment profile. (author)

  18. Microbial immobilization and recycling of 137Cs in the organic layers of forest ecosystems: Relationship to environmental conditions, humification and invertebrate activity

    International Nuclear Information System (INIS)

    The 137Cs content of the microbial biomass in the organic layers of 10 German forest sites was quantified with a modified fumigation/extraction method. A KCs factor was calculated for biomass 137Cs from the difference between unfumigated and fumigated samples by means of laboratory cultures. The size of the estimated KCs factors varied between 1.54 and 2.90 (mean, 2.17; S.D., 0.48). The microflora at the different forest sites contained between 1 and 56% of the total amount of 137Cs found in the organic layers (mean, 13%). Litterbag experiments showed that 137Cs was actively transported into the L layer by the microflora and that this effect was enhanced by the mesofauna. It is concluded that the immobilization and recycling of 137Cs by the microflora in the organic layer of forest soils is determined by three major factors: 137Cs availability, growth conditions of the microflora and biotic interactions

  19. 226Ra in waters of an estuarine system formerly affected by direct discharges of wastes from a phosphate fertilizer processing complex

    International Nuclear Information System (INIS)

    The presence of 226Ra in an estuaryformerly affected by direct discharges of waste from a phosphate fertilizer complex has been investigated. Specific activities ranging from 3.6 to 45.2 mBq/l have been detected. In general, activity levels are lower than those detected when direct discharges were carried out. However, there is still a clear contamination due to the disposal of phosphogypsum in open air piles by the river. Moreover, it seems that 226Ra is being redissolved from the contaminated bed sediments, which also contributes to an enhancement in the activity levels of the estuary waters. (author)

  20. Short- and long-term patterns of 137Cs in fish and other aquatic organisms of small forest lakes in southern Finland since the Chernobyl accident

    International Nuclear Information System (INIS)

    We summarize the patterns of 137Cs activity concentrations and transfer into fish and other biota in four small forest lakes in southern Finland during a twenty-year period following the Chernobyl accident in April 1986. The results from summer 1986 showed fastest accumulation of 137Cs into planktivorous fishes, i.e. along the shortest food chains. Since 1987, the highest annual mean values of 137Cs have been recorded in fish occupying the highest trophic levels, for perch (Perca fluviatilis) 13,600 Bq/kg (ww) and for pike (Esox lucius) 20,700 Bq/kg (ww). At the same time, activity concentrations of 137Cs in crustacean zooplankton and Asellus aquaticus have ranged between 1000 and 19,500 Bq/kg (dw). In 2006, 5–28% of the 1987 137Cs activity concentration levels were still present in perch and pike. Since 1989 their 137Cs activity concentrations in oligohumic seepage lakes have remained significantly higher than in polyhumic drainage lakes due to the increased transfer of 137Cs into fish in the seepage lakes with lower electrolyte concentrations, longer water retention times and lower sedimentation rate. - Highlights: ► In summer 1986 highest 137Cs levels in planktivore fishes of short food chains. ► Since 1987 highest 137Cs were recorded in predatory fish of highest trophic levels. ► High variation found also in 137Cs of crustacean zooplankton and Asellus aquaticus. ► In long-term fish 137Cs higher in clear seepage lakes than in humic drainage lakes. ► Increased transfer of 137Cs into fish in seepage lakes was the reason suggested.

  1. Mobile gamma-ray scanning system for detecting radiation anomalies associated with 226Ra-bearing materials

    International Nuclear Information System (INIS)

    A mobile gamma-ray scanning system has been developed by Oak Ridge National Laboratory for use in the Department of Energy's remedial action survey programs. The unit consists of a NaI(T1) detection system housed in a specially-equipped van. The system is operator controlled through an on-board mini-computer, with data output provided on the computer video screen, strip chart recorders, and an on-line printer. Data storage is provided by a floppy disk system. Multichannel analysis capabilities are included for qualitative radionuclide identification. A 226Ra-specific algorithm is employed to identify locations containing residual radium-bearing materials. This report presents the details of the system description, software development, and scanning methods utilized with the ORNL system. Laboratory calibration and field testing have established the system sensitivity, field of view, and other performance characteristics, the results of which are also presented. Documentation of the instrumentation and computer programs are included

  2. Rapid Determination of 226Ra and Uranium Isotopes in Solid Samples by Fusion with Lithium Metaborate and Alpha Spectrometry

    Directory of Open Access Journals (Sweden)

    R. Bojanowski

    2002-01-01

    Full Text Available A simple and rapid method has been developed to determine 226Ra in rocks, soils, and sediments. Samples are decomposed by fusion with lithium metaborate and the melt is dissolved in a solution containing sulfates and citric acid. During the dissolution, a fine suspension of mixed barium and radium sulfates is formed. The microcrystals are collected on a membrane filter (pore size 0.1 μm and analysed in an alpha spectrometer. Application of a 133Ba tracer enables us to assess the loss of the analyte, which only rarely exceeds 10%. All analytical operations, beginning from sample decomposition to source preparation for alpha spectrometry, can be accomplished within 1 or 2 h.

  3. Study and Estimation of the Ratio of 137CS and 40K Specific Activities in Sandy and Loam Soils

    Directory of Open Access Journals (Sweden)

    Renata Mikalauskienė

    2011-12-01

    Full Text Available The present article describes changes in specific activities and fluctuations in the ratio of natural 40K and artificial 137Cs radionuclides in soil samples taken from different places of Lithuanian territory. The samples of soil have been selected from the districts polluted after the accident in Chernobyl nuclear plant per