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Sample records for radionuclide 226ra 238u

  1. 226Ra/238U disequilibrium in an upland organic soil exhibiting elevated natural radioactivity

    International Nuclear Information System (INIS)

    Dowdall, M.; O'Dea, J.

    2002-01-01

    This paper presents the results of a study into the anomalous 226 Ra/ 238 U disequilibrium ( 226 Ra/ 238 U of 0.5-9) exhibited by an upland organic soil in Co. Donegal, Ireland. Radiochemical speciation of 226 Ra, 238 U and 228 Ra indicates that in this organic soil the high 226 Ra/ 238 U ratio is due to loss of 238 U relative to 226 Ra via oxidation and mobilisation of 238 U in the upper layers of the soil and subsequent loss in solution. At the lower, more reducing depths of the soil profile, 238 U and 226 Ra are essentially in equilibrium. Loss of 238 U appears to occur primarily from the easily oxidised organic and iron oxide fractions of the soil, samples exhibiting high 226 Ra/ 238 U ratios displaying significantly lower 238 U levels in these fractions than samples whose ratio is below the average value for the soil of the valley. Selective enrichment of 226 Ra by plants or preferential leaching of 226 Ra from the underlying rock is not supported by the results of this study

  2. Estimation of radionuclide concentration of 238U, 226Ra, 232Th in air in Wuhan city

    International Nuclear Information System (INIS)

    Shi Jinhua; Chen Changhua

    1989-01-01

    The concentrations of 238 U, 226 Ra and 232 Th in air in Wuhan area were estimated by assuming that they originate from resuspended particles of soil and investigating the dust content in air and the concentrations of these radionuclides in soil. 60 soil samples were collected from April to October, 1984, and 7346 air dust samples during 1981-1985. The estimated mean air concentrations of 238 U, 226 Ra and 232 Th were 24.0 x 10 -9 , 18.9 x 10 -9 and 28.7 x 10 -9 , Bq/L, respectively. Their highest values were observed of 30.4 x 10 -9 , 23.9 x 10 -9 and 36.2 x 10 -9 Bq/L in 1983. Seasonal change of the concentrations was clear as shown in the data of 1984 and 1985, which was related to the meterological conditions. Among the 6 districts of Wuhan city, the highest concentration was in Qingshan and the lowest in Wuchang

  3. Study on the radioactivity and soil-to-plant transfer factor of 226Ra, 234U and 238U radionuclides in irrigated farms from the northwestern Saudi Arabia

    International Nuclear Information System (INIS)

    Al-Hamarneh, Ibrahim F.; Alkhomashi, N.; Almasoud, Fahad I.

    2016-01-01

    The present study addresses the soil-to-plant transfer factors (TFs) of 226 Ra, 234 U and 238 U for 13 types of vegetables and agricultural crops planted under semi-arid environment in the northwestern part of Saudi Arabia. Crop plants along with plant-growing soils were collected from selected farms, which are irrigated from the non-renewable Saq aquifer, and investigated for their radioactivity content by means of alpha spectrometry after applying a radiochemical separation procedure. Hence, TF data for plant roots, green parts (stem and leaves) and fruits were calculated and contrasted to those reported in the literature. Substantial differences were observed in the TFs of Ra and U radioisotopes among plant species. In crop fruits, eggplant exhibited the highest uptake of 226 Ra (TF value of 0.11), while beans (0.16) have the highest TF for 234 U and 238 U. The geometric mean TF values indicated that the crop roots tend to accumulate Ra and U about four to six-folds higher than fruits. The relation between TF values and soil concentrations showed a weak correlation. Activity ratios between radionuclides in crop plants indicated the preferential translocation of U in fruits than Ra even though Ra is more available for root uptake. The fruit/root (F/R) ratios obtained for the investigated plants shown that pepper had the smallest F/R ratios (0.07 ± 0.01, 0.12 ± 0.02 and 0.11 ± 0.02 for 226 Ra, 234 U and 238 U, respectively), while the highest F/R ratios were observed in potatoes (0.71 ± 0.15, 0.44 ± 0.10 and 0.40 ± 0.08 for 226 Ra, 234 U and 238 U, respectively). The TF and F/R ratios data of natural radionuclides in the study region can hopefully improve the scientific knowledge for future studies. - Highlights: • Ra and U isotopes were measured in soils and plant crops in farms in Saudi Arabia. • Ra and U activities in plant roots (R) slightly exceeded that in their fruits (F). • Ra/U activity ratios showed preferential translocation of U

  4. Activity concentrations of 238U and 226Ra in scales formed on pipes of industrial boilers in the state of Pernambuco, Brazil

    International Nuclear Information System (INIS)

    Poggi, Claudia M.B.; Farias, Emerson E.G. de; Gazineu, Maria H.P.

    2015-01-01

    The procedures employed in the industry can generate significant amounts of solid, liquid and gaseous wastes that usually contain toxic or materials of difficulty degradation. One of the facts that contribute to the formation of such wastes is the generation of steam used in operating processes and industry segments. Currently, steam supplied by boilers is the most economical and practical mode of heat transfer in industrial processes. Due to the high temperature of water used in these processes, compounds which were previously soluble become insoluble, generating residues called scales. This material, which contains stable ions, can also present naturally occurring radionuclides such as 238 U and 226 Ra, which concentrate over time in piping and equipment surfaces. If not disposed correctly, this material also can contaminate the environment. The main origin of these radionuclides is the use of groundwater in industrial processes. Thus, in regions of naturally enriched in radionuclides such as the Region of Pernambuco, including the municipalities of Paulista and Goiana, there is a greater possibility of radioactive scale formation. Therefore, this study aimed to determine the activity concentrations of 238 U and 226 Ra present in the solid wastes generated by industries situated in Paulista and Goiana, in order to assess radionuclide disequilibrium. For the sake of comparison, scale samples collected from industries located in the municipality of Caruaru, far from the previous municipalities, were also analyzed. The determination of the activity concentrations for 238 U and 226 Ra was performed by High Resolution Gamma-Ray Spectrometry. Samples were collected, prepared, packed in plastic containers and set aside for a minimum time of 21 days, for the secular equilibrium to occur between 226 Ra and its short lived descendants. The counting time was 80,000 seconds. Gamma energies used for determination of activity concentrations were 1001 keV for 238 U, and 352 ke

  5. Temporal evolution of natural radionuclides distributions 238U, 234Th, 226Ra, 228Ra, 210Pb and 210Po in the Bransfield strait, Antarctica peninsula

    International Nuclear Information System (INIS)

    Lapa, Flavia Valverde

    2013-01-01

    Research on the distribution of natural radionuclides in Antarctica is rare and thus, there is great interest in to know their occurrence and factors related to its mobilization, transference and accumulation in this extremely fragile environment. Natural radionuclides have been used intensively as tracers in the ocean, helping to better understand processes as sinking and particle resuspension, water masses mixture and oceanic circulation. 234 Th (t½ = 24.1 days) is a particle-reactive radionuclide produced continuously in seawater by the decay of its soluble precursor conservative with salinity 238 U (t½ = 4.5 10 9 years). Since 234 Th presents relatively short half-life, it is used to quantify processes that occur in temporal scale varying from days to weeks. The disequilibrium 234 Th/ 238 U in the surface ocean has been applied to estimate carbon fluxes exported via sinking material. The flux of particles biologically productive out of the euphotic zone in the Southern Ocean has special attention due to its importance in the control of CO 2 atmospheric concentrations. The radionuclides 210 Pb (t½ = 22.3 years) and 210 Po (t½ = 138 days) are also particle-reactive. The disequilibrium 210 Po/ 210 Pb has been used to estimate fluxes of particles exported in the ocean in the time scale of weeks. The long-lived Ra isotopes, 226 Ra (t½ = 1,600 years) and 228 Ra (t½ = 5.75 years) are soluble in seawater, presenting unique properties that make them excellent tracers of water masses. This research work had the aim to study the distributions of natural radionuclides 238 U, 234 Th, 22 '6Ra, 22 '8Ra, 210 Pb and 210 Po in the Bransfield Strait during 2 samplings carried out in the 2011 Austral Summer (OPERANTAR XXIX and XXX). (author)

  6. Assessment of annual effective dose from 238U and 226Ra due to consumption of foodstuffs by inhabitants of Tehran city (IR)

    International Nuclear Information System (INIS)

    Hosseini, T.; Fathivand, A. A.; Abbasisiar, F.; Karimi, M.; Barati, H.

    2006-01-01

    The concentrations of 238 U and 226 Ra were determined in different foodstuffs purchased from markets in Tehran. Determinations of the radionuclides have been carried out using alpha spectrometry technique, on samples of egg, lentil, potato, rice, soya, spinach, tea and wheat. Average concentrations of natural radionuclides and foodstuff consumption rate were used to assess annual intake and based on intake values, the annual effective ingestion dose has been estimated for Tehran city residents. The measurement results show that soya has the maximum concentration of 238 U equal to 15.6 ± 2.6 mBq kg -1 and tea has the maximum concentration of 226 Ra equal to 1153.3 ± 265.3 mBq kg -1 . Besides, the maximum annual effective dose from 238 U and 226 Ra were assessed to be 2.88 x 10 -2 ±7.20 x 10 -3 and 2.15 ± 0.54 μSv, respectively, from wheat samples. (authors)

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

    International Nuclear Information System (INIS)

    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 sites

  8. Activity concentrations of {sup 238}U and {sup 226}Ra in scales formed on pipes of industrial boilers in the state of Pernambuco, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Poggi, Claudia M.B.; Farias, Emerson E.G. de, E-mail: claudiapoggi04@gmail.com, E-mail: emersonemiliano@yahoo.com.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Franca, Elvis J.; Hazin, Clovis A., E-mail: chazin@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Gazineu, Maria H.P., E-mail: helena@unicap.br [Universidade Catolica de Pernambuco (UNICAP), Recife, PE (Brazil). Centro de Ciencias e Tecnologia

    2015-07-01

    The procedures employed in the industry can generate significant amounts of solid, liquid and gaseous wastes that usually contain toxic or materials of difficulty degradation. One of the facts that contribute to the formation of such wastes is the generation of steam used in operating processes and industry segments. Currently, steam supplied by boilers is the most economical and practical mode of heat transfer in industrial processes. Due to the high temperature of water used in these processes, compounds which were previously soluble become insoluble, generating residues called scales. This material, which contains stable ions, can also present naturally occurring radionuclides such as {sup 238}U and {sup 226}Ra, which concentrate over time in piping and equipment surfaces. If not disposed correctly, this material also can contaminate the environment. The main origin of these radionuclides is the use of groundwater in industrial processes. Thus, in regions of naturally enriched in radionuclides such as the Region of Pernambuco, including the municipalities of Paulista and Goiana, there is a greater possibility of radioactive scale formation. Therefore, this study aimed to determine the activity concentrations of {sup 238}U and {sup 226}Ra present in the solid wastes generated by industries situated in Paulista and Goiana, in order to assess radionuclide disequilibrium. For the sake of comparison, scale samples collected from industries located in the municipality of Caruaru, far from the previous municipalities, were also analyzed. The determination of the activity concentrations for {sup 238}U and {sup 226}Ra was performed by High Resolution Gamma-Ray Spectrometry. Samples were collected, prepared, packed in plastic containers and set aside for a minimum time of 21 days, for the secular equilibrium to occur between {sup 226}Ra and its short lived descendants. The counting time was 80,000 seconds. Gamma energies used for determination of activity concentrations

  9. Influence of soil texture on the distribution and availability of 238U, 230Th, and 226Ra in soils

    International Nuclear Information System (INIS)

    Blanco Rodriguez, P.; Vera Tome, F.; Lozano, J.C.; Perez-Fernandez, M.A.

    2008-01-01

    The influence of soil texture on the distribution and availability of 238 U, 230 Th, and 226 Ra in soils was studied in soil samples collected at a rehabilitated uranium mine located in the Extremadura region in south-west Spain. The activity concentration (Bq kg -1 ) in the soils ranged from 60 to 750 for 238 U, from 60 to 260 for 230 Th, and from 70 to 330 for 226 Ra. The radionuclide distribution was determined in three soil fractions: coarse sand (0.5-2 mm), medium-fine sand (0.067-0.5 mm), and silt and clay ( 238 U, 230 Th, and 226 Ra between the activity concentration per fraction and the total activity concentration in the bulk soil. Thus, from the determination of the activity concentration in the bulk soil, one could estimate the activity concentration in each fraction. Correlations were also found for 238 U and 226 Ra between the labile activity concentration in each fraction and the total activity concentration in bulk soil. Assuming that there is some particle-size fraction that predominates in the process of soil-to-plant transfer, the parameters obtained in this study should be used as correction factors for the transfer factors determined from the bulk soil in previous studies

  10. The transport characteristics of {sup 238}U, {sup 232}Th, {sup 226}Ra, and {sup 40}K in the production cycle of phosphate rock

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yoon Hee; Lim, Jong Myoung; Ji, Young Yong; Chung, Kun Ho; Kang, Mun Ja [Environmental Radioactivity Assessment Team, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-03-15

    Phosphate rock and its by-product are widely used in various industries to produce phosphoric acid, gypsum, gypsum board, and fertilizer. Owing to its high level of natural radioactive nuclides (e.g., 238U and 226Ra), the radiological safety of workers who work with phosphate rock should be systematically managed. In this study, 238U, 232Th, 226Ra, and 40K levels were measured to analyze the transport characteristics of these radionuclides in the production cycle of phosphate rock. Energy dispersive X-ray fluorescence and gamma spectrometry were used to determine the activity of 238U, 232Th, 226Ra, and 40K. To evaluate the extent of secular disequilibrium, the analytical results were compared using statistical methods. Finally, the distribution of radioactivity across different stages of the phosphate rock production cycle was evaluated. The concentration ratios of 226Ra and 238U in phosphate rock were close to 1.0, while those found in gypsum and fertilizer were extremely different, reflecting disequilibrium after the chemical reaction process. The nuclide with the highest activity level in the production cycle of phosphate rock was 40K, and the median 40K activity was 8.972 Bq·g−1 and 1.496 Bq·g−1, respectively. For the 238U series, the activity of 238U and 226Ra was greatest in phosphate rock, and the distribution of activity values clearly showed the transport characteristics of the radionuclides, both for the byproducts of the decay sequences and for their final products. Although the activity of 40K in k-related fertilizer was relatively high, it made a relatively low contribution to the total radiological effect. However, the activity levels of 226Ra and 238U in phosphate rock were found to be relatively high, near the upper end of the acceptable limits. Therefore, it is necessary to systematically manage the radiological safety of workers engaged in phosphate rock processing.

  11. Daily ingestion of 232Th, 238U, 226Ra, 228Ra and 210Pb in vegetables by inhabitants of Rio de Janeiro City

    International Nuclear Information System (INIS)

    Santos, E.E.; Lauria, D.C.; Amaral, E.C.S.; Rochedo, E.R.

    2002-01-01

    The concentrations of the naturally occurring radionuclides 232 Th, 238 U, 210 Pb, 226 Ra and 228 Ra were determined in the vegetables (leafy vegetables, fruit, root, bean and rice) and derived products (sugar, coffee, manioc flour, wheat flour, corn flour and pasta) consumed most by the adult inhabitants of Rio de Janeiro City. A total of 88 samples from 26 different vegetables and derived products were analyzed. The highest contribution to radionuclide intake arises from bean, wheat flour, manioc flour, carrot, rice, tomato and potato consumption. The estimated daily intakes due to the consumption of vegetables and derived products are 1.9 mBq of 232 Th (0.47 μg), 2.0 mBq of 238 U (0.17 μg), 19 mBq of 226 Ra, 26 mBq of 210 Pb and 47 mBq of 228 Ra. The estimated annual effective dose due to the ingestion of vegetables and their derived products with the long-lived natural radionuclides is 14.5 μSv. Taking into account literature data for water and milk from Rio de Janeiro the dose value increases to 29 μSv, with vegetables and derived products responsible for 50% of the dose and water for 48%. 210 Pb (62%) and 228 Ra (24%) were found to be the main sources for internal irradiation

  12. 238U-230Th-226Ra radioactive disequilibria in the products from 1707 eruption of Fuji volcano, Japan

    International Nuclear Information System (INIS)

    Kurihara, Yuichi; Takahashi, Masaomi; Sato, Jun

    2008-01-01

    Time scale of magmatic processes in the 1707 eruptive activity of Fuji volcano, Japan, was estimated by the 238 U- 230 Th- 226 Ra disequilibria observed in the 1707 volcanic products. The activity ratios of 226 Ra/ 230 Th in the products were larger than unity, being enriched in 226 Ra relative to 230 Th. The decay-corrected 226 Ra/ 230 Th activity ratio to the time of the eruption versus 238 U/ 230 Th activity ratio diagram for the 1707 volcanic products showed a positive correlation, suggesting that the 238 U/ 230 Th- 226 Ra disequilibria occurred during the magma genesis of Fuji volcano. The 230 Th- 226 Ra disequilibria in the 1707 volcanic products suggested that the time scale from the magma genesis to the eruption, including the melting of the mantle wedge, magma storage and magmatic differentiation from basalt to andesite, was less than 8000 years. (author)

  13. The transport characteristics of "2"3"8U, "2"3"2Th, "2"2"6Ra, and "4"0K in the production cycle of phosphate rock

    International Nuclear Information System (INIS)

    Jung, Yoon Hee; Lim, Jong Myoung; Ji, Young Yong; Chung, Kun Ho; Kang, Mun Ja

    2017-01-01

    Phosphate rock and its by-product are widely used in various industries to produce phosphoric acid, gypsum, gypsum board, and fertilizer. Owing to its high level of natural radioactive nuclides (e.g., 238U and 226Ra), the radiological safety of workers who work with phosphate rock should be systematically managed. In this study, 238U, 232Th, 226Ra, and 40K levels were measured to analyze the transport characteristics of these radionuclides in the production cycle of phosphate rock. Energy dispersive X-ray fluorescence and gamma spectrometry were used to determine the activity of 238U, 232Th, 226Ra, and 40K. To evaluate the extent of secular disequilibrium, the analytical results were compared using statistical methods. Finally, the distribution of radioactivity across different stages of the phosphate rock production cycle was evaluated. The concentration ratios of 226Ra and 238U in phosphate rock were close to 1.0, while those found in gypsum and fertilizer were extremely different, reflecting disequilibrium after the chemical reaction process. The nuclide with the highest activity level in the production cycle of phosphate rock was 40K, and the median 40K activity was 8.972 Bq·g−1 and 1.496 Bq·g−1, respectively. For the 238U series, the activity of 238U and 226Ra was greatest in phosphate rock, and the distribution of activity values clearly showed the transport characteristics of the radionuclides, both for the byproducts of the decay sequences and for their final products. Although the activity of 40K in k-related fertilizer was relatively high, it made a relatively low contribution to the total radiological effect. However, the activity levels of 226Ra and 238U in phosphate rock were found to be relatively high, near the upper end of the acceptable limits. Therefore, it is necessary to systematically manage the radiological safety of workers engaged in phosphate rock processing

  14. Accumulation of 226Ra, 238U and 230Th by wetland plants in a vicinity of U-mill tailings at Zirovski vrh (Slovenia)

    International Nuclear Information System (INIS)

    Marko Cerne; Borut Smodis; Marko Strok; Radojko Jacimovic

    2010-01-01

    The impact of a U-mill tailing on radionuclide accumulation by plants was assayed. In particular, a preliminary screening of 226 Ra, 238 U and 230 Th in Marsh marigold (Caltha palustris L.), soft rush (Juncus effusus L.) and Tall Moor grass (Molinia arundinacea (L.) Moench) grown in a marsh habitat is presented. Activity concentrations for the studied radionuclides and their transfer factors for the particular plants are shown and discussed. (author)

  15. Internal radiation due to bioaccumulated natural radionuclides ({sup 238}U and {sup 226}Ra) in some wild plants sampled from Singhbhum Thrust Belt

    Energy Technology Data Exchange (ETDEWEB)

    Singh, V K [Co-operative College, Jamshedpur (India). Botany Dept.; Geeta, [Jamshedpur Women` s College, Jamshedpur (India). Botany Dept.

    1995-01-01

    Estimation of radioactivity (Bq/Kg dry Wt.) due to bioaccumulated {sup 238}U,{sup 226}Ra was carried out in six species of native plants growing in the non-occupational settings of Singhbhum Thrust Belt (STB). Due to medicinal and other economic values, these plants are used by the local people in their day to day life. Among the six species, Echinops echinatus excelled in the pick-up process of radionuclides. The rank decreased in the order: Echinops>Vitex>Cleistanthus>Ocimum>Holorrhoena>Lantana. (author). 14 refs., 2 tabs.

  16. Radioactive Contamination of Alluvial Soils in the Taiga Landscapes of Yakutia with 137Cs, 226Ra, and 238U

    Science.gov (United States)

    Chevychelov, A. P.; Sobakin, P. I.

    2017-12-01

    The concentrations and distribution of 137Cs in alluvial soils (Fluvisols) of the upper and middle reaches of the Markha River in the northwest of Yakutia and 226Ra and 238U in alluvial soils within the El'kon uranium ore deposit in the south of Yakutia have been studied. It is shown that the migration of radiocesium in the permafrost-affected soils of Yakutia owing to alluviation processes extends to more than 600 km from the source of the radioactive contamination. The migration of 137Cs with water flows is accompanied by its deposition in the buried horizons of alluvial soils during extremely high floods caused by ice jams. In the technogenic landscapes of southern Yakutia, active water migration of 238U and 226Ra from radioactive dump rocks. The leaching of 238U with surface waters from the rocks is more intense than the leaching of 226Ra. The vertical distribution patterns of 238U and 226Ra in the profiles of alluvial soils are complex. Uranium tends to accumulate in the surface humus horizon and in the buried soil horizons, whereas radium does not display any definite regularities of its distribution in the soil profiles. At present, the migration of 238U and 226Ra with river water and their accumulation in the alluvial soils extend to about 30 km from the source.

  17. Influence of soil structure on the "Fv approach" applied to 238U and 226Ra.

    Science.gov (United States)

    Blanco Rodríguez, P; Vera Tomé, F; Lozano, J C

    2017-02-01

    The soil-to-plant transfer factors were determined in a granitic area for the two long-lived uranium series radionuclides 238 U and 226 Ra. With the aim to identify a physical fraction of soil whose concentration correlates linearly with the plant concentration, the soil compartment was analyzed in various stages. An initial study identified the soil compartments as being either bulk soil or its labile fraction. The bulk soil was subsequently divided into three granulometric fractions consisting of: coarse sand, fine sand, and silt and clay. The soil-to-plant transfer of radionuclides for each of these three texture fractions was analyzed. Lastly, the labile fraction was extracted from each textural part, and the activity concentration of the radionuclides 238 U and 226 Ra was measured. In order to assess the influence of soil texture on the soil-to-plant transfer process, we sought to identify possible correlations between the activity concentration in the plant compartment and those found in the different fractions within each soil compartment. The results showed that the soil-to-plant transfer process for uranium and radium depends on soil grain size, where the results for uranium showed a linear relationship between the activity concentration of uranium in the plant and the fine soil fraction. In contrast, a linear relation between the activity concentration of radium in the plant and the soil coarse-sand fraction was observed. Additionally, the presence of phosphate and calcium in the soil of all of the compartments studied affected the soil-to-plant transfer of uranium and radium, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Temporal evolution of natural radionuclides distributions {sup 238}U, {sup 234}Th, {sup 226}Ra, {sup 228}Ra, {sup 210}Pb and {sup 210}Po in the Bransfield strait, Antarctica peninsula; Evolucao temporal das distribuicoes dos radionuclideos naturais {sup 238}U, {sup 234}Th, {sup 226}Ra, {sup 228}Ra, {sup 210}Pb and {sup 210}Po no estreito de Bransfiel, peninsula Antartica

    Energy Technology Data Exchange (ETDEWEB)

    Lapa, Flavia Valverde

    2013-07-01

    Research on the distribution of natural radionuclides in Antarctica is rare and thus, there is great interest in to know their occurrence and factors related to its mobilization, transference and accumulation in this extremely fragile environment. Natural radionuclides have been used intensively as tracers in the ocean, helping to better understand processes as sinking and particle resuspension, water masses mixture and oceanic circulation. {sup 234}Th (t½ = 24.1 days) is a particle-reactive radionuclide produced continuously in seawater by the decay of its soluble precursor conservative with salinity {sup 238}U (t½ = 4.5 10{sup 9} years). Since {sup 234}Th presents relatively short half-life, it is used to quantify processes that occur in temporal scale varying from days to weeks. The disequilibrium {sup 234}Th/{sup 238}U in the surface ocean has been applied to estimate carbon fluxes exported via sinking material. The flux of particles biologically productive out of the euphotic zone in the Southern Ocean has special attention due to its importance in the control of CO{sub 2} atmospheric concentrations. The radionuclides {sup 210}Pb (t½ = 22.3 years) and {sup 210}Po (t½ = 138 days) are also particle-reactive. The disequilibrium {sup 210}Po/{sup 210}Pb has been used to estimate fluxes of particles exported in the ocean in the time scale of weeks. The long-lived Ra isotopes, {sup 226}Ra (t½ = 1,600 years) and {sup 228}Ra (t½ = 5.75 years) are soluble in seawater, presenting unique properties that make them excellent tracers of water masses. This research work had the aim to study the distributions of natural radionuclides {sup 238}U, {sup 234}Th, {sup 22}'6Ra, {sup 22}'8Ra, {sup 210}Pb and {sup 210}Po in the Bransfield Strait during 2 samplings carried out in the 2011 Austral Summer (OPERANTAR XXIX and XXX). (author)

  19. Behaviour of {sup 238}U, {sup 234}U, {sup 228}Ra and {sup 226}Ra in rock alterations: study of Morungaba granitoids, SP-Brazil and ground water in its fractures; Comportamento de {sup 238}U, {sup 234}U, {sup 228}Ra e {sup 226}Ra na alteracao de rochas: estudo dos granitoides de Morungaba (SP) e aguas subterraneas de suas fraturas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Rosana N. dos [Pontificia Univ. Catolica de Sao Paulo, SP (Brazil). Dept. de Fisica]. E-mail: rosana@pucsp.br; Marques, Leila S. [Sao Paulo Univ., SP (Brazil). Inst. de Astronomia, Geofisica e Ciencias Atmosfericas. Dept. de Geofisica]. E-mail: leila@iag.usp.br

    2005-07-01

    This work presents the first results obtained on the investigation of the behavior of uranium and radium radioisotopes in the processes of weathering and rock-water interaction of Morungaba granitoids belonging to Meridional Pluton (Valinhos Town-SP-Brazil). Specific activities of {sup 238}U, {sup 234}U, {sup 228}Ra and {sup 226}Ra were determined in non altered granitoids (Group A), as well as in those affected by different degrees of weathering (Groups B, C and D). The uranium specific activities were determined by alpha spectrometry method, whereas for the determination of radium isotopes high resolution gamma-ray spectrometry technique was employed. The data indicate that {sup 238}U and {sup 234}U are in radioactive equilibrium in the fresh analyzed granitoids, but show a slight depletion of {sup 234}U in relation to {sup 238}U in the weathered rocks. The ({sup 226}Ra/{sup 238}U) and ({sup 226}Ra/{sup 234}U) activity ratios of all investigated rocks are similar, showing a significant {sup 226}Ra depletion, which is probably caused by its preferential leaching. These results indicate that even samples macroscopically classified as fresh rocks, their systems have been opened for some geochemical changes. The high ({sup 234}U/{sup 238}U) activity ratios of groundwaters which are found in the fractures of these granitoids suggest their prolonged residence times in the aquifer and/or their percolation by other rocks presenting different geochemical properties. (author)

  20. 230Th/238U and 226Ra/230Th fractionation in young basaltic glasses from the East Pacific Rise

    International Nuclear Information System (INIS)

    Reinitz, I.; Turekian, K.K.

    1989-01-01

    Mid-ocean ridge basalt (MORB) glasses treated to remove manganese and iron oxyhydroxide coatings containing U and Th decay chain nuclides sequestered from the ambient aqueous environment show little fractionation of ( 230 Th) from ( 238 U), but extensive enrichment of ( 226 Ra) over ( 230 Th). Chronometry based on ( 230 Th)-( 238 U) disequilibrium yields a mean age of 151,000 ± 55,000 (2σ) years ago for Th-U fractionation, from a source region with Th/U (atom ratio) = 1.58 ± 0.43 (2σ). ( 226 Ra) excesses over ( 230 Th) indicate an enrichment event more recent than the fractionation of Th from U. ( 226 Ra/ 230 Th) correlates well with K/U, providing a rough means of estimating the age since eruption of MORB glasses. (orig.)

  1. Determination of 238U, 226Ra, 228Ra and 40K in grapes and wines of Valley of the Sao Francisco

    International Nuclear Information System (INIS)

    Silveira, Patricia Brandao da

    2007-01-01

    0.05 and 0.16 ± 0.01 to 0.45 ± 0.08 Bq L-1, respectively. The values of 238 U, on the other hand, ranged from 8.7 ± 1 to 10 ± 1 and 1.4 ± 0.4 to 3.2 ± 0.9 Bq L-1 for samples of pulp and wine, respectively. Concentrations obtained for 40 K stayed between 43 ± 1 to 56 ± 2 for pulp and 85 ± 2 to 94 ± 1 Bq L-1 for wine. 238 U presented the greatest activity concentration in the samples of pulp and wine. The levels of 226 Ra and 40 K are in agreement with the values found in the literature for both pulp and wine. In soil samples, on the other hand, 226 Ra and 228 Ra have activity concentrations above the reference values recommended by UNSCEAR. (author)

  2. Ground water contamination with (238)U, (234)U, (235)U, (226)Ra and (210)Pb from past uranium mining: cove wash, Arizona.

    Science.gov (United States)

    Dias da Cunha, Kenya Moore; Henderson, Helenes; Thomson, Bruce M; Hecht, Adam A

    2014-06-01

    The objectives of the study are to present a critical review of the (238)U, (234)U, (235)U, (226)Ra and (210)Pb levels in water samples from the EPA studies (U.S. EPA in Abandoned uranium mines and the Navajo Nation: Red Valley chapter screening assessment report. Region 9 Superfund Program, San Francisco, 2004, Abandoned uranium mines and the Navajo Nation: Northern aum region screening assessment report. Region 9 Superfund Program, San Francisco, 2006, Health and environmental impacts of uranium contamination, 5-year plan. Region 9 Superfund Program, San Franciso, 2008) and the dose assessment for the population due to ingestion of water containing (238)U and (234)U. The water quality data were taken from Sect. "Data analysis" of the published report, titled Abandoned Uranium Mines Project Arizona, New Mexico, Utah-Navajo Lands 1994-2000, Project Atlas. Total uranium concentration was above the maximum concentration level for drinking water (7.410-1 Bq/L) in 19 % of the water samples, while (238)U and (234)U concentrations were above in 14 and 17 % of the water samples, respectively. (226)Ra and (210)Pb concentrations in water samples were in the range of 3.7 × 10(-1) to 5.55 × 102 Bq/L and 1.11 to 4.33 × 102 Bq/L, respectively. For only two samples, the (226)Ra concentrations exceeded the MCL for total Ra for drinking water (0.185 Bq/L). However, the (210)Pb/(226)Ra ratios varied from 0.11 to 47.00, and ratios above 1.00 were observed in 71 % of the samples. Secular equilibrium of the natural uranium series was not observed in the data record for most of the water samples. Moreover, the (235)U/(total)U mass ratios ranged from 0.06 to 5.9 %, and the natural mass ratio of (235)U to (total)U (0.72 %) was observed in only 16 % of the water samples, ratios above or below the natural ratio could not be explained based on data reported by U.S. EPA. In addition, statistical evaluations showed no correlations among the distribution of the radionuclide concentrations

  3. Determination of the concentration of 238U, 234U, 232Th, 228Th, 228Ra, 226Ra and 210Pb in the feces of workers from a mining company of niobium and their families

    International Nuclear Information System (INIS)

    Oliveira, Roges de; Lopes, Ricardo T.; Melo, Dunstana R.; Juliao, Ligia M.Q.C.

    2005-01-01

    The object of this study consists of an open mine from which Niobium ore (pyrochlore) is extracted and a metallurgy company, where Fe-Nb alloys are produced for export. For geological reasons, the main ore is associated to natural radionuclides U and Th, and its decay products. The concentration of 234 U, 238 U, 232 Th, 226 Ra and 228 Ra, 228 Th, including 210 Pb in fecal excretion of 12:0 am, 29 workers and 13 family members were determined. The technique employed for the determination of the elements was the sequential method of radiochemical separation, followed by alpha spectrometry and counting α and β in proportional detector. Statistically significant difference was observed in the concentration of 234 U and 238 U, in feces samples, among the group of mining workers and family members; as well as for 232 Th in the feces of workers of crushing and metallurgy groups when compared with the Family Group. No statistically significant difference was detected at a concentration of 226 Ra, 228 Ra and 210 Pb, in feces of any group of workers of the installation in relation to the family group

  4. Sorption study of 226Ra(II) et 238U(VI) on to peat organic matter, in mining environment

    International Nuclear Information System (INIS)

    Bordelet, Gabrielle

    2014-01-01

    The environmental footprint of former uranium mining sites is a major concern for society. In order to guarantee the protection of ecosystems and thus a minimal radiological impact on the biosphere, it is important to understand and to be able to model the phenomena controlling the migration of uranium and its decay products, specially radium ( 226 Ra) (AREVA's Envir-at-Mines project). In the environment, among solid phases which can retain 238 U(VI) and 226 Ra(II), peat is known to have relevant affinity for U(VI). Because peat is usually composed at 90% dry weight of organic matter, the aim of this study was to qualify and quantify peat organic matter affinity for 238 U(VI) and 226 Ra(II). Peat samples extracted from Les Sagnes (close to a former uranium mining site in Limousin area, France) was characterised and batch adsorption/desorption experiments were conducted. The results indicate that 226 Ra(II) adsorption onto that peat is higher than 97% for pH ≥ 4-6 (depending on the organic/mineral ratio in dry peat) corresponding to K d values about 4500 ± 500 mL/g and 238 U(VI) adsorption is higher than 80% at pH ≥ 3 with K d maximal values reaching 11000 mL/g around pH 4.5. Only a little desorption was measured after one month. An ion exchange modelling for radium adsorption onto one type of organic matter sorption site was enough to fit the experimental adsorption K d for the peat over the whole range of pH. However, uranium sorption on peat can be modelled on that organic sorption site only from pH 1 to 5. From pH 5 to 10, to explain the experimental uranium adsorption K d values (close to 1500 mL/g), uranium sorption onto mineral phases (such as smectite and iron oxide in this study) has to be considered. An operational data set is given for both 238 U(VI) and 226 Ra(II) sorption onto Les Sagnes peat. Unlike usual peat, peat from Les Sagnes contains more than 10% dry weight of mineral matter. That is why it is necessary to model sorption of those two

  5. Transfer of 238U, 230Th, 226Ra, and 210Pb from soils to tree and shrub species in a Mediterranean area

    International Nuclear Information System (INIS)

    Blanco Rodriguez, P.; Vera Tome, F.; Lozano, J.C.; Perez Fernandez, M.A.

    2010-01-01

    The soil-to-plant transfer factors of natural uranium isotopes ( 238 U and 234 U), 230 Th, 226 Ra, and 210 Pb were studied in a disused uranium mine located in the Extremadura region in the south-west of Spain. The plant samples included trees (Quercus ilex, Quercus suber, and Eucalyptus cameldulensis) and one shrub (Cytisus multiflorus). All of them are characteristic of Mediterranean environments. The activity concentrations in leaves and fruit were determined for the tree species at different stages of growth. For the shrub, the total above-ground fraction was considered in three seasons. For old leaves and fruit, the highest activity concentrations were found in Eucalyptus cameldulensis for all the radionuclides studied, except in the case of 230 Th that presented similar activity concentrations in all of the tree species studied. In every case, the transfer to fruit was less than the transfer to leaves. In the shrub, the results depended on the season of sampling, with the highest value obtained in spring and the lowest in autumn. Important correlations were obtained for 238 U and 226 Ra between the activity ratio in soils with that in leaves or fruit.

  6. 226Ra and other radionuclides in water, vegetation, and tissues of beavers (Castor canadensis) from a watershed containing U tailings neat Elliot Lake, Canada

    International Nuclear Information System (INIS)

    Clulow, F.V.; Mirka, M.A.; Dave, N.K.; Lim, T.P.

    1991-01-01

    Radionuclide levels were measured in tissues, gut contents, diet items, and water at site of capture, of adult beavers from the Serpent River drainage basin which contains U tailings at Elliot Lake, Ontario, and from nearby control sites. Levels of 226 Ra in beaver bone, muscle and kidney were highest in animals from locations close to U tailing; liver levels did not vary by site. Environmental 226 Ra levels were within ranges previously reported at these or similar locations elsewhere; levels in beaver gut contents reflected levels in diet items. Concentration ratios exceeded unity only between some vegetation items and beaver bone at the Elliot Lake site and were less than 0.19 between vegetation and other tissues. In two beavers with tissue levels of 226 Ra higher than others sampled, neither 232 Th nor 230 Th were detected in bone, muscle or liver tissues. U-238 was measurable in bone, muscle and liver; 228 Th in bone, 210 Po bone, muscle and liver; and 210 Pb was measurable only in bone. Estimated yearly intakes of radionuclides by people eating beavers were calculated to be below current allowable levels set by the Canadian regulatory authorities. (author)

  7. 226Ra, 228Ra and 228Ra/226Ra in surface marine sediment of Malaysia

    International Nuclear Information System (INIS)

    Mei-Wo Yii; Zal Uyun Wan-Mahmood

    2013-01-01

    Surface sediment samples were collected at the West (east coast and west coast of Peninsular Malaysia) and East (Sabah and Sarawak) Malaysia in several expeditions within August 2003 until June 2008 for determining the level of natural radium isotopes. Activity concentrations of 226 Ra and 228 Ra in surface marine sediment at 176 sampling stations were measured. The activity concentrations of both radionuclides in Malaysia (East and West Malaysia) display varied with the range from 9 to 158 Bq/kg dry wt. and 13 to 104 Bq/kg dry wt., respectively. Meanwhile, the ratio distributions of 228 Ra/ 226 Ra were ranged from 0.62 to 3.75. This indicated that the ratios were slightly high at west coast of Peninsular Malaysia compared to other regions (east coast of Peninsular Malaysia, Sabah and Sarawak). The variation of activity concentrations of 226 Ra and 228 Ra and its ratios were also supported by the statistical analyses of one-way ANOVA and t test at 95 % confidence level, whereby there were proved that the measured values were different between the regions. These different were strictly related to their half-life, potential input sources (included their parents, 238 U and 232 Th), parent's characteristic, the geological setting/formation of the study area, environment origin and behavior. (author)

  8. Development and validation of a fast combined analysis method for the determination of the natural radioisotopes Pb-210, Po-210, Ra-226, Ra, 228, U-234 and U-238 in drinking water

    International Nuclear Information System (INIS)

    Schuster, Martina

    2015-01-01

    The guiding value of the effective dose for the consumption of drinking water is 0.1 mSv per calendar year. For the purpose of dose assessment the intake of all relevant radio nuclides via drinking water has to be determined. Some analysis methods for the determination of relevant natural occurring radio nuclides are published but they need complete different and time consuming analysis methods for each radionuclide. This study shows an analysis method which is able to determine the radio nuclides 210 Pb, 210 Po, 226 Ra, 228 Ra, 238 U and 234 U quantitatively within a justifiable time scale. It is based on a chromatography method which has been validated for determination of 90 Sr and 89 Sr in milk, vegetable food and human and animal bones respectively. Applying this method the elution ranges for lead and polonium are so different from uranium and radium that a combined separation with high chemical yield is possible, even by miniaturization the chromatography column which means significant time saving. The activity concentration of 228 Ra and 226 Ra is determined applying gamma-spectrometry and that of 210 Pb, 210 Po, 234 U and 238 U by LSC. The chemical yield of 210 Pb is calculated with a stable lead applying AAS and that of the radium isotopes with 223 Ra. Therefor 223 Ra is separated of a 227 Ac standard solution. The method is validated by a interlaboratory test for the determination of natural radio nuclides in drinking water which was released by the Bundesamt fuer Strahlenschutz. For the analysis only about four litres of drinking water are necessary to realize the required limit of detection. The method is very efficient, enough specific and allows the determination of dose relevant radio nuclides.

  9. Development of sequential analytical method for the determination of U-238, U-234, Th-232, Th-230, Th-228, Ra-226 and Ra-228 and its application in mineral waters

    International Nuclear Information System (INIS)

    Costa Lauria, D. da.

    1986-01-01

    A sequential analytical method for the determination of U-238, U-234, Th-232, Th-230, Th-228, Ra-226 and Ra-228 in environmental samples and applied to the analysis of mineral waters is studied. Thorium isotopes are coprecipitated with lanthanium fluoride before counting in alpha spectrometer, the uranium isotopes are determined by alpha spectrometry following extraction with TOPO onto a polymenic membrane. Radium-226 is determined with the radom emanation technique. (M.J.C.) [pt

  10. U-isotopes and "2"2"6Ra as tracers of hydrogeochemical processes in carbonated karst aquifers from arid areas

    International Nuclear Information System (INIS)

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

    2016-01-01

    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 ("2"3"8U, "2"3"5U and "2"3"4U) and "2"2"6Ra by alpha spectrometry were determined. The activity concentration of "2"3"8U 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 "2"3"4U/"2"3"8U 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. "2"2"6Ra 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 "2"2"6Ra/"2"3"4U 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). "2"2"6Ra 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 "2"3"4U/"2"3"8U activity ratios, probably due to fast uniform bulk

  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. Determination of natural radionuclides, U, Th-232, Ra-226, Ra-228, Pb-210 and K-40 in sediments from CananÉIa-Iguape System, Brazil

    International Nuclear Information System (INIS)

    Jesus, Gleyka J.D.; Chiozzini, Vitor G.; Saueia, Cátia H.R.; Nisti, Marcelo B.; Braga, Elisabete S.; Fávaro, Deborah I.T.; Universidade de São Paulo

    2017-01-01

    The Cananéia-Iguape estuarine-lagoon complex, located in the south of São Paulo State, Brazil, is a protected area recognized by UNESCO as part of the Biosphere Reserve, due to its importance as a natural ecosystem. However, along the years, the mining activities in the region affected the river basin, to such an extent that contamination was observed for As, Cu, Pb and Zn. Since the mining activities can also enhance the levels of natural radioactivity in the sediments, this study aimed to determine the activity concentration of the natural radionuclides (K-40, U, Ra-226, Pb-210, Th-232 and Ra-228) in 34 bottom sediments samples collected in the Cananéia-Iguape system. The samples were measured by gamma spectrometry, using a HPGe for the determination of K-40, Ra-226, Pb-210 and Ra-228. The concentration of U and Th-232 was determined by instrumental neutron activation analysis. The activity concentration of K-40 varied from 119 ± 17 to 522 ± 74 Bq kg"-"1; U-238 varied from 0.31 ± 0.05 to 5.8 ± 0.3 mg kg"-"1; Ra-226 varied from 3.7 ± 0.3 to 43.3 ± 1.5 Bq kg"-"1; Pb-210 varied from 5.8 ± 2.6 to 118 ± 12 Bq kg"-"1; Th-232 varied from 0.67 ± 0.02 to 16.6 ± 0.4 mg kg"-"1 and Ra-228 varied from 3.5 ± 0.6 to 64.9 ± 2.4 Bq kg"-"1. These results were compared with literature values for the region, indicating that they are the background of the region and no contamination was observed from NORM (Naturally Occurring Radioactive Material) industries. (author)

  13. Determination of natural radionuclides, U, Th-232, Ra-226, Ra-228, Pb-210 and K-40 in sediments from CananÉIa-Iguape System, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, Gleyka J.D.; Chiozzini, Vitor G.; Saueia, Cátia H.R.; Nisti, Marcelo B.; Braga, Elisabete S.; Fávaro, Deborah I.T., E-mail: gjdjesus@ipen.br, E-mail: chsaueia@ipen.br, E-mail: mbnisti@ipen.br, E-mail: defavaro@ipen.br, E-mail: vitor.chio@usp.br, E-mail: edsbraga@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Universidade de São Paulo (USP), SP (Brazil). Instituto Oceanográfico

    2017-07-01

    The Cananéia-Iguape estuarine-lagoon complex, located in the south of São Paulo State, Brazil, is a protected area recognized by UNESCO as part of the Biosphere Reserve, due to its importance as a natural ecosystem. However, along the years, the mining activities in the region affected the river basin, to such an extent that contamination was observed for As, Cu, Pb and Zn. Since the mining activities can also enhance the levels of natural radioactivity in the sediments, this study aimed to determine the activity concentration of the natural radionuclides (K-40, U, Ra-226, Pb-210, Th-232 and Ra-228) in 34 bottom sediments samples collected in the Cananéia-Iguape system. The samples were measured by gamma spectrometry, using a HPGe for the determination of K-40, Ra-226, Pb-210 and Ra-228. The concentration of U and Th-232 was determined by instrumental neutron activation analysis. The activity concentration of K-40 varied from 119 ± 17 to 522 ± 74 Bq kg{sup -1}; U-238 varied from 0.31 ± 0.05 to 5.8 ± 0.3 mg kg{sup -1}; Ra-226 varied from 3.7 ± 0.3 to 43.3 ± 1.5 Bq kg{sup -1}; Pb-210 varied from 5.8 ± 2.6 to 118 ± 12 Bq kg{sup -1}; Th-232 varied from 0.67 ± 0.02 to 16.6 ± 0.4 mg kg{sup -1} and Ra-228 varied from 3.5 ± 0.6 to 64.9 ± 2.4 Bq kg{sup -1}. These results were compared with literature values for the region, indicating that they are the background of the region and no contamination was observed from NORM (Naturally Occurring Radioactive Material) industries. (author)

  14. Transfer of {sup 238}U, {sup 230}Th, {sup 226}Ra, and {sup 210}Pb from soils to tree and shrub species in a Mediterranean area

    Energy Technology Data Exchange (ETDEWEB)

    Blanco Rodriguez, P. [Natural Radioactivity Group, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas s/n, 06071 Badajoz (Spain); Vera Tome, F. [Natural Radioactivity Group, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas s/n, 06071 Badajoz (Spain)], E-mail: fvt@unex.es; Lozano, J.C. [Natural Radioactivity Group, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas s/n, 06071 Badajoz (Spain); Laboratorio de Radiaciones Ionizantes, Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca (Spain); Perez Fernandez, M.A. [Natural Radioactivity Group, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas s/n, 06071 Badajoz (Spain); Area de Ecologia, Universidad Pablo Olavide, Carretera de Utrera km. 1, 41013 Sevilla (Spain)

    2010-06-15

    The soil-to-plant transfer factors of natural uranium isotopes ({sup 238}U and {sup 234}U), {sup 230}Th, {sup 226}Ra, and {sup 210}Pb were studied in a disused uranium mine located in the Extremadura region in the south-west of Spain. The plant samples included trees (Quercus ilex, Quercus suber, and Eucalyptus cameldulensis) and one shrub (Cytisus multiflorus). All of them are characteristic of Mediterranean environments. The activity concentrations in leaves and fruit were determined for the tree species at different stages of growth. For the shrub, the total above-ground fraction was considered in three seasons. For old leaves and fruit, the highest activity concentrations were found in Eucalyptus cameldulensis for all the radionuclides studied, except in the case of {sup 230}Th that presented similar activity concentrations in all of the tree species studied. In every case, the transfer to fruit was less than the transfer to leaves. In the shrub, the results depended on the season of sampling, with the highest value obtained in spring and the lowest in autumn. Important correlations were obtained for {sup 238}U and {sup 226}Ra between the activity ratio in soils with that in leaves or fruit.

  15. Characterization of {sup 238}U, {sup 232}Th, {sup 40}K, and {sup 226}Ra in NORM and Air Particulate Occurring from Phosphate Processing Facility

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yoon Hee; Lim, Jong Myoung; Ji, Young Yong; Kim, Hyun Cheol; Kim, Chang Jong; Park, Ji Yong; Chung, Kun Ho; Kang, Mun Ja [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    In this study, radio-activities of {sup 238}U, {sup 232}Th, {sup 40}K, and {sup 226}Ra occurring in raw materials and by-products at phosphate processing facility were complementally determined using ED-XRF, γ-spectrometry and ICP-MS method. Although the degree of immersion in the human body varies depending on the particle size and density, the particle size is especially used as a key factor in assessing dose. Thus, size distribution characteristics of {sup 238}U concentrations in airborne particulates collected at the phosphate processing facility were also evaluated. The naturally occurring radioactive materials (NORM) are widely spread throughout the environment, it occupies the largest part of public radioactivity exposure. According to report of the US National Academy of Sciences, 82% of the human radiation dose received annually comes from the natural radionuclides. Radiation exposure doses from natural radionuclides is not significantly concerned level compared to those from artificial radionuclides which could be released into the environment by nuclear tests and power plant accident. It could make a serious risk problem to unspecific public when exposed to the natural radionuclides during long-term period at high activity concentration levels. Therefore, it is essential to make a professional and systematic approach for the proper handling and diminution.

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

    International Nuclear Information System (INIS)

    Russo, Ana Carolina

    2013-01-01

    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 226 Ra, 228 Ra and 210 Pb 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 210 Pb, from 0.5% to 1.4% for 226 Ra and from 0.1% to 1.0% for the 228 Ra 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 226 Ra, less than 10% for '2 28 Ra and less than 10% for 210 Pb. 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 226 Ra, 1.2% for 228 Ra and 11.3% for 210 Pb. 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)

  17. Evaluating the distribution of the radioactive isotopes 226 Ra and 238 U in the ground water

    International Nuclear Information System (INIS)

    Bragea, M.

    2006-01-01

    By closing the mining activities huge quantities of waste rock stored in unprotected dump remained abandoned. As a result of the process of ore extraction, the waste rock and a very low percentage of metallic minerals were stored in tailing ponds, with a clay liner necessary to isolate the tailing from the rest of the aquifer. The migration of hazardous elements and radionuclides in groundwaters depends on the degree of their interaction with the surrounding rock material. This paper describes some of the experimental clay formations, to identify the main factors influencing the radioisotopes concentration and in a first approach to estimate the natural radionuclide intake levels by adult inhabitants of Ciudanovita region, Romania. Therefore we tried to study the extractive power of natural water in the existing depositing places. Several natural analogue laboratory models were set up, to study the dependence of washed quantity of radionuclides on the water amount washing the sample and mass of the samples. The effect of sorption on travel time was determined by comparing groundwater travel time (no sorption) with radionuclide travel time (includes sorption) The mechanism of releasing 226 Ra and 238 U from the minerals that compose the waste rock is influenced by the duration of the contact between the water and the waste rock, the composition of the water phase. Further on, the necessity of the paper is connected to the fact that the exchanges water-waste rock are complex processes, that depend on the environment conditions, each case can be a particular case. (author)

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

    International Nuclear Information System (INIS)

    Silva Amaral, E.C. da.

    1979-08-01

    A sampling and analytical program for 238 U, 226 Ra and 210 Pb was started, at first, in the uranium mine region, at Pocos de Caldas, MG, Brazil. Afterwards, the interaction was studied between 226 Ra and local river sediments and waters. Peliminary studies were also done on the mobility of 226 Ra retained on solid matter or soil, induced by local waters. Above normal concentrations of 238 U, 226 Ra and 210 Pb were found in local waters, sediments and plants collected on the imediate vicinity of the mine. 226 Ra distribution coefficients are on the order of 10 3 for the different samples assayed. It was concluded that, in the future, 226 Ra discharged into liquid environment should be only temporarily retained by sediments. Its transport by surface waters should be predominantly in the soluble form. 226 Ra should become the critical radionuclide in terms of internal radiation dose on the local population, due to its ingestion with water. 226 Ra retained on solid supports is mobilized by local waters and its solubilization is dependent on the volume of water passed through. (M.A.) [pt

  19. 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)

    Perianez, R.; Abril, J.M.; Garcia-Leon, M.

    1997-01-01

    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 226 Ra, 238 U and 232 Th in water, suspended matter, distribution coefficients and Th/U mass rations. (author)

  20. Natural radionuclides, 226Ra, 228Ra and 210Pb, determined in mineral water springs from Parque das Águas de Caxambu, and assessment of the committed effective doses

    International Nuclear Information System (INIS)

    Meneghini, Arthur A.; Damatto, Sandra R.; Oliveira, Joselene; Prilip, Amanda

    2017-01-01

    The increase of mineral water consumption and its medicinal use results in the necessity of characterization of these waters sources, once that water is a vital part of human diet. In the mineral waters, besides stable elements, responsible of the chemical composition, the presence of natural radionuclides from the 238 U, 232 Th, 235 U series and 40 K gives the radiation property. The incorporation of these radionuclides through the ingestion and external treatment of mineral waters are a very important point, due the ionizing radiation of these radionuclides are harmful to the organism. The largest mineral water park of the world is situated in Brazil, in the city of Caxambu, called Parque das Águas de Caxambu. In this park are 12 fountains distributed in the park, also a tubular well of 60 meters of depth which regularly provide water spouts, geyser, and another spring located inside the Gloria Hotel. Therefore, the aim of this work was to evaluate the activity concentrations of the radionuclides 226 Ra, 228 Ra and 210 Pb in the mineral waters springs collected at the 'Parque das Águas de Caxambu' and in the Gloria Hotel, as well as to estimate the committed effective doses due to the consumption of these waters. In six campaigns, the radionuclides with the highest concentrations were 226 Ra and 228 Ra in the springs D. Ernestina, Beleza and Venâncio. These springs also presented the highest values of the committed effective dose. (author)

  1. Natural radionuclides, {sup 226}Ra, {sup 228}Ra and {sup 210}Pb, determined in mineral water springs from Parque das Águas de Caxambu, and assessment of the committed effective doses

    Energy Technology Data Exchange (ETDEWEB)

    Meneghini, Arthur A.; Damatto, Sandra R.; Oliveira, Joselene; Prilip, Amanda, E-mail: ameneghini@usp.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-07-01

    The increase of mineral water consumption and its medicinal use results in the necessity of characterization of these waters sources, once that water is a vital part of human diet. In the mineral waters, besides stable elements, responsible of the chemical composition, the presence of natural radionuclides from the {sup 238}U, {sup 232}Th, {sup 235}U series and {sup 40}K gives the radiation property. The incorporation of these radionuclides through the ingestion and external treatment of mineral waters are a very important point, due the ionizing radiation of these radionuclides are harmful to the organism. The largest mineral water park of the world is situated in Brazil, in the city of Caxambu, called Parque das Águas de Caxambu. In this park are 12 fountains distributed in the park, also a tubular well of 60 meters of depth which regularly provide water spouts, geyser, and another spring located inside the Gloria Hotel. Therefore, the aim of this work was to evaluate the activity concentrations of the radionuclides {sup 226}Ra, {sup 228}Ra and {sup 210}Pb in the mineral waters springs collected at the 'Parque das Águas de Caxambu' and in the Gloria Hotel, as well as to estimate the committed effective doses due to the consumption of these waters. In six campaigns, the radionuclides with the highest concentrations were {sup 226}Ra and {sup 228}Ra in the springs D. Ernestina, Beleza and Venâncio. These springs also presented the highest values of the committed effective dose. (author)

  2. Environmental evolution records reflected by radionuclides in the sediment of coastal wetlands: A case study in the Yellow River Estuary wetland.

    Science.gov (United States)

    Wang, Qidong; Song, Jinming; Li, Xuegang; Yuan, Huamao; Li, Ning; Cao, Lei

    2016-10-01

    Vertical profiles of environmental radionuclides ( 210 Pb, 137 Cs, 238 U, 232 Th, 226 Ra and 4 0 K) in a sediment core (Y1) of the Yellow River Estuary wetland were investigated to assess whether environmental evolutions in the coastal wetland could be recorded by the distributions of radionuclides. Based on 210 Pb and 137 Cs dating, the average sedimentation rate of core Y1 was estimated to be 1.0 cm y -1 . Vertical distributions of natural radionuclides ( 238 U, 232 Th, 226 Ra and 40 K) changed dramatically, reflecting great changes in sediment input. Concentrations of 238 U, 232 Th, 226 Ra and 40 K all had significant positive relationships with organic matter and clay content, but their distributions were determined by different factors. Factor analysis showed that 238 U was determined by the river sediment input while 226 Ra was mainly affected by the seawater erosion. Environmental changes such as river channel migrations and sediment discharge variations could always cause changes in the concentrations of radionuclides. High concentrations of 238 U and 226 Ra were consistent with high accretion rate. Frequent seawater intrusion decreased the concentration of 226 Ra significantly. The value of 238 U/ 226 Ra tended to be higher when the sedimentation rate was low and tide intrusion was frequent. In summary, environmental evolutions in the estuary coastal wetland could be recorded by the vertical profiles of natural radionuclides. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. A sequential extraction procedure to determine Ra and U isotopes by alpha-particle spectrometry in selective leachates

    International Nuclear Information System (INIS)

    Aguado, J.L.; Bolivar, J.P.; San-Miguel, E.G.; Garcia-Tenorio, R.

    2003-01-01

    A radiochemical sequential extraction procedure has been developed in our laboratory to determine 226 Ra and 234,238 U by alpha spectrometry in environmental samples. This method has been validated for both radionuclides by comparing in selected samples the values obtained through its application with the results obtained by applying alternative procedures. Recoveries obtained, counting periods applied and background levels found in the alpha spectra give suitable detection limits to allow the Ra and U determination in operational forms defined in riverbed contaminated sediments. Results obtained in these speciation studies show that 226 Ra and 234,238 U contamination tend to be associated to precipitated forms of the sediments. (author)

  4. 238U-series radionuclides in Finnish groundwater-based drinking water and effective doses

    International Nuclear Information System (INIS)

    Vesterbacka, P.

    2005-09-01

    The thesis deals with the occurrence of 238 U-series radionuclides and particle-bound 210 Pb and 210 Po in Finnish groundwater-based drinking water, methods used for removing 234 U, 238 U, 210 Pb and 210 Po, and the annual effective doses caused by 238 U-series radionuclides in drinking water. In order to reduce radiation exposure and avoid high doses, it is important to examine the activity levels of natural radionuclides in groundwater. In this work, the activity concentrations of radon ( 222 Rn), radium ( 226 Ra), uranium ( 238 U and 234 U), lead ( 210 Pb) and polonium ( 210 Po) were determined from 472 private wells, which were selected randomly from across Finland. On the basis of the results, the activity concentrations in groundwater and the radiation exposure from drinking water of people living outside the public water supply in Finland was specified. The efficiency of 238 U, 234 U, 210 Pb and 210 Po removal from drinking water was examined at ten private homes. In order to obtain accurate results and correct estimates of effective doses, attention was paid to the sampling of 222 Rn and 210 Pb, and the determination of 210 Pb. The results revealed that the median activity concentrations of natural radionuclides were as much as ten times higher in drilled wells than in wells dug in soil. The average activity concentration of 222 Rn in drilled wells was 460 Bq/l and in dug wells 50 Bq/l. The highest activity concentrations were found in Southern Finland. In addition, occasional high activity concentrations were found all over Finland. The average activity concentrations of 234 U and 238 U in drilled wells were 0.35 and 0.26 Bq/l and in dug wells 0.020 and 0.015 Bq/l, respectively. The spatial distribution of 234 U, 238 U, 210 Pb and 210 Po was essentially similar to that of 222 Rn. In contrast to other natural radionuclides, the highest 226 Ra activity concentrations were found in coastal areas, since drilled well water near the sea has a higher salinity

  5. Radionuclides concentration in foods in Peninsular Malaysia

    International Nuclear Information System (INIS)

    Zalina Laili; Muhamat Omar; Mohd Nahar Othman; Md Suhaimi Elias; Esther Philip, Mohd Zaidi Ibrahim; Faizal Azrin Abdul Razalim; Azmi Hassan

    2006-01-01

    The concentrations of natural radionuclides (U-238, Th-232, Ra-226, Ra-228 and K-40) and artificial radionuclides (Cs-137) in fresh, dried and cooked foodstuffs from 30 major towns in Peninsular Malaysia were determined by gamma spectrometry system and Instrumental Neutron Activation Analysis (INAA) technique. A total of 232 samples representing a typical Malaysian community diet were analysed. The results showed that most of the samples contained only natural radionuclides. The percentage of radionuclides detected in the samples were found about 2% for U-238, 9% for Th-232, 49% for Ra-226, 77% for Ra-228, 99% for K-40 and 15% for Cs-137. The radionuclide concentrations were in the ranges of <6.1 - 29.3, <2.0 - 55.8, <0.1 - 34.4, <0.1 - 41, <0.1- 2552.3 and < 0.1 - 6.6 Bq/Kg dry weight for U-238, Th-232, Ra-226, Ra-228 and K-40 and Cs-137 respectively. The study revealed that most of the foodstuffs did not contain U-238. Lentils were found to contain significant concentration of Th-232 (4 - 49 Bq/kg) and can be considered as thorium accumulators. The concentrations of Ra-226 and Ra-228 in leafy vegetables were higher than the fruit and root vegetables. These data can be used as a reference for future food radioactivity monitoring. As edible mushroom and fern had high concentrations of Cs-137, indicating their high ability to accumulate Cs-137, they could be used as indicator plants in the event of radioactive fall outs

  6. Ingestion dose from 238U, 232Th, 226Ra, 40K and 137CS in cereals, pulses and drinking water to adult population in a high background radiation area, Odisha (India)

    International Nuclear Information System (INIS)

    Lenka, P.; Sahoo, S. K.; Mohapatra, S.; Patra, A. C.; Dubey, J. S.; Vidyasagar, D.; Tripathi, R. M.; Puranik, V. D.

    2013-01-01

    A natural high background radiation area is located in Chhatrapur, Odisha in the eastern part of India. The inhabitants of this area are exposed to external radiation levels higher than the global average background values, due to the presence of uranium, thorium and its decay products in the monazite sands bearing placer deposits in its beaches. The concentrations of 232 Th, 238 U, 226 Ra, 40 K and 137 Cs were determined in cereals (rice and wheat), pulses and drinking water consumed by the population residing around this region and the corresponding annual ingestion dose was calculated. The annual ingestion doses from cereals, pulses and drinking water varied in the range of 109.4-936.8, 10.2-307.5 and 0.5-2.8 μSv y -1 , respectively. The estimated total annual average effective dose due to the ingestion of these radionuclides in cereals, pulses and drinking water was 530 μSv y -1 . The ingestion dose from cereals was the highest mainly due to a high consumption rate. The highest contribution of dose was found to be from 226 Ra for cereals and drinking water and 40 K was the major dose contributor from the intake of pulses. The contribution of man-made radionuclide 137 Cs to the total dose was found to be minimum. 226 Ra was found to be the largest contributor to ingestion dose from all sources. (authors)

  7. Migration of 226 Ra, 228 Ra, 210 Pb, U and Th from phosphogypsum

    International Nuclear Information System (INIS)

    Silva, Nivaldo Carlos da; Cipriani, Moacir; Taddei, Maria Helena T.

    2002-01-01

    The physico-chemical availability of radioactive elements ( 210 Pb, 226 Ra, 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 ( 226 Ra, 228 Ra and 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 -1 , 70±50 mBqL -1 , 100±60 mBqL -1 and 110±55 mBqL -1 for U, 226 Ra, 228 Ra and 210 Pb, respectively. Thorium activities were below detection limit. (author)

  8. Effects on elevating cancer risk in population exposed to natural radionuclide 226Ra if parent radionuclide 238U is entered the body by inhalation or ingestion

    International Nuclear Information System (INIS)

    Zupunski, Lj.; Trobok, M.; Gordanic, V.; Spasic-Jokic, V.; Sovilj, P.

    2009-01-01

    People have always been exposed to ionizing radiation originating from natural radionuclides including 238 U, 40 K, 232 Th that exist in earths crust. Although received doses are small, due to the fact that threshold does not exist, there is a certain risk of developing cancer. Purpose of this study was to measure 238 U concentrations in soil of Bela Crkva territory. Based on these measurements, risks of developing cancers are calculated using Monte Carlo method.(author) [sr

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

    International Nuclear Information System (INIS)

    Silva, Carolina Fernanda da

    2015-01-01

    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 238 U, 234 U, 230 Th, 22 '6Ra, 210 Pb and 210 Po, members from the 238 U decay series, and the radionuclides 232 Th and 228 Ra members of the 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 210 Po determination, and gross alpha and beta counting, 228 Ra, 226 Ra and 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 radionuclides 226 Ra, 228 Ra, 210 Pb, and 210 Po, were determined in most

  10. Extensive radioactive characterization of a phosphogypsum stack in SW Spain: {sup 226}Ra, {sup 238}U, {sup 210}Po concentrations and {sup 222}Rn exhalation rate

    Energy Technology Data Exchange (ETDEWEB)

    Abril, Jose-Maria, E-mail: jmabril@us.es [Dpto. Fisica Aplicada I, Universidad de Sevilla, EUITA, Ctra Utrera Km 1, 41013 Seville (Spain); Garcia-Tenorio, Rafael, E-mail: gtenorio@us.es [Dpto. Fisica Aplicada II, Universidad de Sevilla, ETSA, Avda. Reina Mercedes s/n, 41012 Seville (Spain); Manjon, Guillermo, E-mail: manjon@us.es [Dpto. Fisica Aplicada II, Universidad de Sevilla, ETSA, Avda. Reina Mercedes s/n, 41012 Seville (Spain)

    2009-05-30

    Phosphogypsum (PG) is a by-product of the phosphate fertilizer industries that contains relatively high concentrations of uranium series radionuclides. The US-EPA regulates the agriculture use of PG, attending to its {sup 226}Ra content and to the {sup 222}Rn exhalation rate from inactive stacks. Measurements of {sup 222}Rn exhalation rates in PG stacks typically show a large and still poorly understood spatial and temporal variability, and the published data are scarce. This work studies an inactive PG stack in SW Spain of about 0.5 km{sup 2} from where PG can be extracted for agriculture uses, and an agriculture soil 75 km apart, being representative of the farms to be amended with PG. Activity concentrations of {sup 226}Ra, {sup 238}U and {sup 210}Po have been measured in 30 PG samples (0-90 cm horizon) allowing for the construction of maps with spatial distributions in the PG stack and for the characterization of the associated PG inputs to agriculture soils. Averaged {sup 226}Ra concentrations for the stack were 730 {+-} 60 Bq kg{sup -1} (d.w.), over the US-EPA limit of 370 Bq kg{sup -1}. {sup 222}Rn exhalation rate has been measured by the charcoal canister method in 49 sampling points with 3 canisters per sampling point. Values in PG stack were under the US-EPA limit of 2600 Bq m{sup -2} h{sup -1}, but they were one order of magnitude higher than those found in the agriculture soil. Variability in radon emissions has been studied at different spatial scales. Radon exhalation rates were correlated with {sup 226}Ra concentrations and daily potential evapotranspiration (ETo). They increased with ETo in agriculture soils, but showed an opposite behaviour in the PG stack.

  11. Bioavailability of radionuclides {sup 226}Ra, {sup 228}Ra and {sup 210}Pb present in the brazilian phosphate fertilizers and phosphogypsum; Avaliacao da biodisponibilidade dos radionuclideos {sup 226}Ra, {sup 228}Ra e {sup 210}Pb presentes nos fertilizantes fosfatados e no fosfogesso de procedencia nacional

    Energy Technology Data Exchange (ETDEWEB)

    Russo, Ana Carolina

    2013-08-01

    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 {sup 226}Ra, {sup 228}Ra and {sup 210}Pb 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 {sup 210}Pb, from 0.5% to 1.4% for {sup 226}Ra and from 0.1% to 1.0% for the {sup 228}Ra 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 {sup 226}Ra, less than 10% for '2{sup 28}Ra and less than 10% for {sup 210}Pb. 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 {sup 226}Ra, 1.2% for {sup 228}Ra and 11.3% for {sup 210}Pb. 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)

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

    International Nuclear Information System (INIS)

    Mora, Tamires de Araujo

    2015-01-01

    The natural radionuclides from radioactive series of 238 U, 235 U and 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 226 Ra, 228 Ra and 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 226 Ra and 228 Ra by co-precipitation with Ba(Ra)SO 4 and 210 Pb by co-precipitation with PbCrO 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 226 Ra and 210 Pb were used to estimate the unsupported 210 Pb activities present in sediment profile 1 B. Based on unsupported 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)

  13. Modelling of the radioactive daughter elements in soil to assess radiation impact due to contaminated irrigation water by parents of 231Pa, 226Ra, 238U, 237Np and 239Pu

    International Nuclear Information System (INIS)

    Bela Kanyar; Katalin Eged; Tunde Katona; Gerhard Proehl; Ulla Bergstroem; Bengt Hallberg; Shelly Mobbs; Geert Olyslaegers; Theo Zeevaert; Palome Pinedo; Inmaculade Simon

    2004-01-01

    Radioactive wastes may contain both parent and daughter radionuclides. In some cases the transfer parameters of the daughter radio-elements differ significantly from that of the parent ones and therefore the dose contributions in the different pathways might be important to assess separately. The present work has compared 5 different site specific models by a scenario, using contaminated water for drinking and irrigation. Altogether 5 radionuclides from the investigated 10 ones contained radioactive daughter elements. In general, for long term studies in biosphere the steady-state formulations of processes are adequate to assess the contamination, except the infiltration into the deeper soil and sediment layers. According to the results of the modelling and computer simulations, the following daughters are to be assessed separately from their parents with respect to the radiation impact: for parent 231 Pa the daughter 227 Ac, for parent 226 Ra the daughters 222 Rn, 210 Pb and 210 Po and for parent 237 Np the daughter 233 Pa. The dose contributions of the daughters from parents 238 U and 239 Pu are less significant during the considered 100-10000 years. In case of contamination of irrigation water with 1 Bq x m -3 of the parent radionuclide 231 Pa, more than 90% of the external dose from soil exposure comes from the daughter 227 Ac (annually 15 nSv). By a similar contamination with 226 Ra as a parent radionuclide, 60% of the ingestion dose is due to food contamination with the daughters 210 Pb and 210 Po (approximately 150 nSv x a -1 ). (author)

  14. Radionuclide analysis in the soil of Kumaun Himalaya, India, using gamma ray spectrometry

    International Nuclear Information System (INIS)

    Ramola, R.C.; Prasad, Ganesh; Gusain, G.S.; Choubey, V.M.; Tosheva, Z.; Kies, A.

    2011-01-01

    Environmental release of low levels of radioactivity can occur as a consequence of normal radionuclides present in the earth's crust. We present here the results of a survey undertaken in 2003 on the radionuclide concentration in different rock formations in the eastern part of Kumaun Himalaya. The activity concentration and gamma-absorbed dose rates of the terrestrial radionuclides caused by 226 Ra, 232 Th and 40 K were determined in the soil samples collected from the eastern part of Kumaun Himalaya. The mean concentration of 238 U and 232 Th in the earth's crust varied from 0.5 to 5 ppm (6 to 60 Bq/kg) and 2 to 20 ppm (8 to 80 Bq/kg) respectively. The reported activity concentration for the different rock formations varied from 32.6 to 1305.5 Bq/kg for 238 U, 16.3 to 136.3 Bq/kg for 232 Th and 124.6 to 1758.0 Bq/kg for 40 K. The distribution of the radionuclides varied with rock type due to different chemical properties of the measured radionuclides and the rocks. The result shows that high activity levels were found in Saryu Formation consisting of augen-gneiss, granite interbedded with schists and flaggy quartzite. The total air-absorbed dose rate in air above 1 m height was calculated from the three radionuclides ( 226 Ra, 232 Th and 40 K), which varied from 39.1 to 226.8 nGy h -1 . The internal and external health-hazard indices were calculated based on the concentration of 226 Ra, 232 Th and 40 K. Strong positive correlations were observed between 235 U and 226 Ra, 232 Th and 226 Ra, 40 K and 232 Th as well as 40 K and 226 Ra. However, no significant correlation was observed between 238 U and 226 Ra because of radioactive disequilibrium between them. (author)

  15. 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)

  16. Spatial distribution of natural and fallout level of 226Ra, 228Ra, 40K and 137Cs in grab sediments of Mumbai Harbour Bay

    International Nuclear Information System (INIS)

    Kumar, Ajay; Rout, Sabyasachi; Joshi, V.M.; Karpe, Rupali; Ravi, P.M.; Singhal, R.K.

    2012-01-01

    Radionuclides introduced from fall-out and nuclear installations into the marine surface water subjected to movement and mixing with tides and current, undergo horizontal dispersion, dilution and get bound to suspended particles by various physical, chemical, and biological processes. For this study, about 250 g of meshed grab sediments of eight sampling locations were transferred to a suitable cylindrical acrylic container, sealed and kept for 30 days to allow for in-growth of radon gas in order to achieve secular equilibrium between 226 Ra, 214 Pb and 214 Bi in the 238 U decay chain and between 212 Pb, 208 TI and 228 Ac in the 232 Th decay chain. The activity concentrations of 226 Ra, 228 Ra, 40 K and 137 Cs were measured using Gamma spectrometry system

  17. Preparation of 227Ac by neutron irradiation of 226Ra

    International Nuclear Information System (INIS)

    Kukleva, E.; Kozempel, J.; Vlk, M.; Micolova, P.; Vopalka, D.

    2015-01-01

    Radium-223 is prospective alpha-emitting therapeutic radionuclide for targeted radionuclide therapy. Although 223 Ra is formed naturally by the decay of 235 U, for practical reasons its preparation involves neutron irradiation of 226 Ra. The α-decay of the 227 Ra (T 12 = 43 min.) produced via 226 Ra(n,γ) 227 Ra reaction leads to 227 Ac, a mother nuclide of 227 Th and 223 Ra subsequently. Irradiation target radium material is generally available in multi-gram quantities from historical stock. Main aim of this study was to experimentally and theoretically evaluate and verify available literature data on production of 223 Ra. According to data obtained from γ-spectra, the approximate yield values were determined and effective cross-section for the 223 Ra production was calculated. (authors)

  18. Plant/soil concentration ratios of 226Ra for contrasting sites around an active U mine-mill

    International Nuclear Information System (INIS)

    Ibrahim, S.A.; Whicker, F.W.

    1988-01-01

    Concentrations of 226Ra were determined in native vegetation and underlying substrate (soil and tailings) at various sites around a conventional open-pit, acid leach U production operation in Wyoming. Plant/soil concentration ratios (CRs) for 226Ra were estimated for various sites, including weathered tailings; a tailings impoundment shoreline; downwind from exposed tailings; a mine overburden reclamation area; and several background locations. Radium-226 concentrations for vegetation and substrate and CR values from the perturbed sites were elevated above background. The highest vegetation concentration (1.3 Bq g-1) was found in a grass which had invaded exposed, weathered tailings. Levels of 226Ra in soil and vegetation and CR values decreased with distance from the tailings impoundment edge. CR values varied significantly among sites, but few differences were found between plant species groups. The observed CR values ranged from 0.07 at the background and reclamation areas to 0.4 downwind from the tailings area. Average CR values for plants growing on exposed tailings and within one meter from the impoundment edge were 0.15 and 0.3, respectively. CR values of 226Ra for plants on tailings substrates were comparatively low in contrast to other radionuclides in the U chain. We speculate that in the case of sulfuric acid leached tailings-derived material, 226Ra is sequestered as sulfate, which is highly insoluble relative to the sulfates of the other elements (e.g., U and Th) resulting in reduced availability for plant uptake

  19. Biomass selection for biosorption study of 226 Ra and 137 Cd radionuclides

    International Nuclear Information System (INIS)

    Costa, Wilson Cervi da

    2003-01-01

    The main goal of this work was to verify the potentialities to apply the biosorption technique to synthetic and real solution containing 226 Ra and 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. 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 2+ and Ca 2+ , two essential nutrients. On the other hand, the selection of 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 + and K + . (author)

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

    International Nuclear Information System (INIS)

    Daoh, Murnee; Kessaratikoon, Prasong; Udomsomporn, Suchin

    2011-06-01

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

  1. Study of natural radionuclides - {sup 226}Ra, {sup 228}Ra and {sup 210}PB - in marine sediment cores from Southwest Atlantic during the Holocene; Estudo dos radionuclideos naturais - Ra226, Ra-228 e Pb-210 - em alguns registros sedimentares do Atlantico sudoeste ao longo do holoceno

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Alice Miranda Ribeiro

    2016-07-01

    Natural radionuclides from {sup 238}U and {sup 232}Th series have been successfully applied as tracers of environmental process and climate changes. The {sup 210}Pb (half-life of 22.2 years) is used in the geochronological dating technique of sediment cores of the last 100-150 years, and its respective sedimentation rate determination. The study of {sup 226}Ra and {sup 228}Ra concentrations (half-lives of 1,600 years and 5.75 years, respectively) helps calculate the activity of {sup 210}Pb in excess in the environment, besides being important tracers of marine processes, as ground water discharge. In this work it was determined the activity concentrations of {sup 226}Ra, {sup 228}Ra and {sup 210}Pb in four short marine cores collected since the continental platform to upper slope of Southwest Atlantic Ocean. Taking into account the results obtained, sedimentation rates and the ages of each sediment layer were determined using the geochronological dating method with {sup 210}Pb. All sediment samples were total acid digested in microwave. The sequential radiochemical separation of {sup 226}Ra, {sup 228}Ra, {sup 210}Pb were performed, obtaining in the end the precipitation of Ba(Ra)SO{sub 4} and PbCrO{sub 4}. The gross α measurements of {sup 226}Ra and gross β measurements of {sup 228}Ra and {sup 210}Pb from the precipitates were carried out in a gas-flow low background proportional counter. Concerning all cores analyzed, the activities concentrations of {sup 226}Ra ranged from 14 Bq.kg{sup -1} to 154 Bq.kg{sup -1}; the concentrations of {sup 228}Ra ranged from 17 Bq.kg{sup -1} to 45 Bq.kg{sup -1}; and the concentrations of {sup 210}Pb ranged from 20 Bq.kg{sup -1} to 2,073 Bq.kg{sup -1}. High values of {sup 210}Pb were observed on the top of all the cores studied, mainly related to atmospheric deposition. The results obtained in this work were of the same order of magnitude of those reported in the literature available on non contaminated areas of Southeast

  2. 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

  3. 226Ra measurement by thermal ionisation mass spectrometry: Use of 226Ra and 14C for groundwater dating

    International Nuclear Information System (INIS)

    Dever, L.

    1997-01-01

    Recent developments in thermal ionisation mass spectrometry (TIMS) and in chemical separation Ra and Ba allow to analyse 226 Ra on smaller water samples ( 3 litres). The sampling has been realised on the Chalk aquifer of the Paris basin. The water samples have been collected in the unsaturated zone using in situ filtering devices and in the unconfined and confined parts of the aquifer in the boreholes used for public water supply. 226 Ra contents vary from 0.064±0.02 dpm/kg (n=6) in the unsaturated zone to 0.119±0.069 dpm/kg (n=7) in the unconfined aquifer and 0.319±0.057 dpm/kg (n=9) in the confined aquifer. For all the samples the 226 Ra/ 238 U activity ratios are much lower than the secular equilibrium. This points out that the two isotopes have different input function in the water during the mineralisation of the solution. The good correlation (r 2 =0.9) between the 226 Ra and Sr indicates that dissolution of Chalk is the dominant mechanism of mineralisation in 226 Ra of the solution. In the Chalk the mineralisation of the water occurs in the first metres of the unsaturated zone, during the water percolation the water rock interaction takes place through dissolution and precipitation of calcite in a non steady state. According to his distribution coefficient Sr is then a better tracer of dissolution/precipitation process than Ba. Using a geochemical model based on 226 Ra/Sr and Sr/Ca ratios an 'age' of the water could be determined. With 226 Ra half life of 1620 years we obtain 'ages' varying from 150 years to 1950 years in the unconfined aquifer. For the confined part of the aquifer where the redox condition is different it is necessary to use a geochemical model based on the U concentration in the water, the 226 Ra gives in such case ages varying from 1.8ka to 12.8ka. The radiocarbon ages obtained through usual chemical and/or isotopic models are quite similar and an isochrome between 226 Ra and 14 C ages can be calculated between 0 and 8ka

  4. Certified reference materials for radionuclides in Bikini Atoll sediment (IAEA-410) and Pacific Ocean sediment (IAEA-412)

    DEFF Research Database (Denmark)

    Pham, M. K.; van Beek, P.; Carvalho, F. P.

    2016-01-01

    The preparation and characterization of certified reference materials (CRMs) for radionuclide content in sediments collected offshore of Bikini Atoll (IAEA-410) and in the open northwest Pacific Ocean (IAEA-412) are described and the results of the certification process are presented. The certified...... radionuclides include: 40K, 210Pb (210Po), 226Ra, 228Ra, 228Th, 232Th, 234U, 238U, 239Pu, 239+240Pu and 241Am for IAEA-410 and 40K, 137Cs, 210Pb (210Po), 226Ra, 228Ra, 228Th, 232Th, 235U, 238U, 239Pu, 240Pu and 239+240Pu for IAEA-412. The CRMs can be used for quality assurance and quality control purposes...

  5. Forage uptake of uranium series radionuclides in the vicinity of the anaconda uranium mill

    International Nuclear Information System (INIS)

    Rayno, D.R.; Momeni, M.H.; Sabau, C.

    1980-01-01

    Radiochemical analysis was performed on samples of soil and eight species of common vegetation growing on the Anaconda uranium mill site, located in New Mexico. The concentrations of the long-lived radionuclides U-238, U-234, Th-230, Ra-226, and Pb-210 in these forage plants were determined. The sampling procedures and analytical laboratory methods used are described. The highest radionuclide concentration found in a forage species was 130 pCi of Ra-226 per gram dry weight for grass growing on the main tailings pile at Anaconda, where the surface soil activity of Ra-226 was 236 pCi/g. A comparison of shoots activity with that of roots and soil was used to determine a distribution index and uptake coefficient for each species. The distribution index, the ratio of root activity to shoot activity, ranged from 0.30 (Th-230) in galleta grass (Hilaria jamesii) to 38.0 (Ra-226) in Indian ricegrass (Oryzopsis hymenoides). In nearly all instances, the roots contained higher radionuclide concentrations. The uptake coefficient, the ratio of vegetation activity to soil activity, ranged from 0.69 (U-238) in Indian ricegrass roots to 0.01 (U-238) in four-wing saltbush (Atriplex canescans) shoots. The range of radionuclide concentrations in plants growing on the Anaconda mill site is compared to that in vegetation from a control site 20 km away

  6. Preparation of 227Ac/223Ra by neutron irradiation of 226Ra

    International Nuclear Information System (INIS)

    Ekaterina Kukleva; Jan Kozempel; Martin Vlk; Petra Micolova; Dusan Vopalka

    2015-01-01

    Radium-223 is a prospective alpha-emitter for targeted radionuclide therapy. Although 223 Ra is formed naturally by the decay of 235 U, for practical reasons its preparation involves neutron irradiation of 226 Ra. The β - decay of the 227 Ra (T ½ = 43 min) produced via 226 Ra(n,γ) 227 Ra reaction leads to 227 Ac, a mother nuclide of 227 Th and subsequently 223 Ra. Radium target material is generally available in multigram quantities from historical stock. The main aim of this study was to experimentally as well as theoretically evaluate and verify the available literature data on production of 227 Ac/ 223 Ra. According to the data obtained from the γ-spectra, the approximate yield values were determined and effective cross section value for the 227 Ac production was calculated to 14 ± 4 b. (author)

  7. Study of natural radionuclides - "2"2"6Ra, "2"2"8Ra and "2"1"0PB - in marine sediment cores from Southwest Atlantic during the Holocene

    International Nuclear Information System (INIS)

    Costa, Alice Miranda Ribeiro

    2016-01-01

    Natural radionuclides from "2"3"8U and "2"3"2Th series have been successfully applied as tracers of environmental process and climate changes. The "2"1"0Pb (half-life of 22.2 years) is used in the geochronological dating technique of sediment cores of the last 100-150 years, and its respective sedimentation rate determination. The study of "2"2"6Ra and "2"2"8Ra concentrations (half-lives of 1,600 years and 5.75 years, respectively) helps calculate the activity of "2"1"0Pb in excess in the environment, besides being important tracers of marine processes, as ground water discharge. In this work it was determined the activity concentrations of "2"2"6Ra, "2"2"8Ra and "2"1"0Pb in four short marine cores collected since the continental platform to upper slope of Southwest Atlantic Ocean. Taking into account the results obtained, sedimentation rates and the ages of each sediment layer were determined using the geochronological dating method with "2"1"0Pb. All sediment samples were total acid digested in microwave. The sequential radiochemical separation of "2"2"6Ra, "2"2"8Ra, "2"1"0Pb were performed, obtaining in the end the precipitation of Ba(Ra)SO_4 and PbCrO_4. The gross α measurements of "2"2"6Ra and gross β measurements of "2"2"8Ra and "2"1"0Pb from the precipitates were carried out in a gas-flow low background proportional counter. Concerning all cores analyzed, the activities concentrations of "2"2"6Ra ranged from 14 Bq.kg"-"1 to 154 Bq.kg"-"1; the concentrations of "2"2"8Ra ranged from 17 Bq.kg"-"1 to 45 Bq.kg"-"1; and the concentrations of "2"1"0Pb ranged from 20 Bq.kg"-"1 to 2,073 Bq.kg"-"1. High values of "2"1"0Pb were observed on the top of all the cores studied, mainly related to atmospheric deposition. The results obtained in this work were of the same order of magnitude of those reported in the literature available on non contaminated areas of Southeast Brazilian Coast. Sedimentation rates fall with the increase of water column depth and ranged from 0

  8. Investigation of natural radionuclide contents in soil in China

    International Nuclear Information System (INIS)

    Pan Sanming; Liu Ruye

    1992-01-01

    The survey of natural radionuclide contents in soil in China (1983-1990) is a part of investigation of environmental natural radioactivity level on China. The results of the investigation area as follows: (1) The average content of natural radionuclides 238 U, 226 Ra, 232 Th and 40 K(area weighted) and its standard deviation for single measurement is 39.5 and 34.4,36.5 and 22.0, 49.1 and 27.6, 580.0 and 202.0 Bq.kg -1 ,respectively.(2) The content of natural radionuclides is apparently correlated to the types of soil-forming rock. The analysis results from 1552 soil samples of soil-forming rock show that: the content of 238 U, 226 Ra, 232 Th and 40 K for magmatic rock type is the highest, 238 U, 226 Ra and 232 Th of metamorphic rock type higher, sedimentary rock type the lowest. However, the content of 40 K of sedimentary rock type is more higher, magmatic rock type the lowest. In magmatic rock type, the content of 238 U, 226 Ra, 232 Th of granite and acidic magmatic rock type, and the content of 40 K of acidic and alkaline magmatic rock type are higher. (3) The analysis results from 9613 various types of soil samples show that for crimson soil of ferralsol wind soil of rock soil-forming order at northern part is lower. For frigid dessert soil of alpine soil order, alpine dessert soil, and the burozem, dark burozem and drab soil of alfisol order and semialfisol order, the content of 40 K is shown to be higher, and it is lower for latosol of ferralsol order, crimson soil, yellow soil and various lime soil. (4) The geographical distribution of the natural radionuclide content in soil appears apparently regional

  9. Content of Natural Radionuclides in Sediments in the Vicinity of a Former Uranium Mine

    International Nuclear Information System (INIS)

    Strok, M.; Planinsek, P.; Smodis, B.

    2011-01-01

    Former Slovenian uranium mine Zirovski vrh lies in the subalpine environment with relative high rainfall and population density. As a legacy of uranium mining, Jazbec and Borst waste piles were constructed in the vicinity of a former uranium mine. On the Jazbec waste pile, about 2.5 millions of tons of spoil, and 0.05 millions of tons of red mud were deposited. Average activity concentrations in spoil are 750 Bq/kg for 238U, 226Ra and 230Th, and in red mud 495 Bq/kg for 238U, 190 Bq/kg for 226Ra and 65100 Bq/kg for 230Th. On the Borst waste pile, about 0.6 millions of tons of uranium mill tailings (UMT) were deposited. Average activity concentrations in UMT are 995 Bq/kg for 238U, 8630 Bq/kg for 226Ra and 3930 Bq/kg for 230Th. Seepage waters with elevated radionuclide concentrations from both waste piles flow in the nearby streams Brebovscica and Todrascica. Todrascica outfalls into the Brebovscica and Brebovscica into the Poljanska Sora River. Due to the different biogeochemical processes, natural radionuclides from both waste piles can be transferred to the sediments of the affected streams. These processes are mainly driven by the sorption onto the particles and particles settling or by the direct diffusion to sediments. Therefore the aim of this work was to find out at which extent these processes occur in the specific case by comparing activity concentrations in sediments before and after inflow of seepage waters from both waste piles. In sediment samples, 238U, 234U, 230Th, 226Ra, 210Pb and 210Po activity concentrations were determined, using radiochemical separations followed by either alpha spectrometry or proportional counting. Results of the content of natural radionuclides in sediments in the vicinity of a former uranium mine showed that activity concentrations of all analyzed radionuclides were higher in sediments after the inflow of seepage waters from waste piles in Brebovscica and Todrascica stream. This was not the case for Poljanska Sora River

  10. Estimation of 226Ra and U(Nat) in sediment off Mumbai coast

    International Nuclear Information System (INIS)

    Sugandhi, S.; Ravi, P.M.; Wankhede, Sonal

    2012-01-01

    Bottom sediment in a marine system is formed from organic and inorganic particles which settle from water of aquatic media. The sediment compartment is the receptor of radionuclides and it indicates the impact of pollution. Radioactive materials like Ra and U are normal constituents of earths crust. The present study was done to estimate 226 Ra and U(Nat) from various locations in sediment off Mumbai coast. The levels of 226 Ra in sediments of Mumbai coast has been observed to be between 3.8 to 26.0 Bq/kg with a mean averaged value of 13.3 Bq/kg which is similar to the sediment at Bay of Bengal (13.9 to 25.9 Bq/kg), Indian Ocean (13.8 Bq/kg), Arabian Sea (16.9 to 31.7 Bq/kg), Egyptian Red sea coast (27.4 Bq/kg). Uranium content in sediment was found to be in the range of 16.3 to 56.3 Bq/kg with an averaged mean of 32.2 Bq/kg. It is observed that, uranium concentration is higher than radium concentration in sediment. This may be attributed to the relatively higher mobility of radium as compared to uranium in an aquatic environment

  11. The transport of natural radionuclides from soil to plants

    International Nuclear Information System (INIS)

    Bikit, I.; Conkic, Lj.; Slivka, J.; Krmar, M.

    1995-01-01

    The transport and accumulation processes of Ra-226, U-238, Th-232 and K-40 from soil to plants have been studied. Plant samples with consumable parts grown below surface have been bred in natural conditions on soil with enhanced levels of natural radioactivity (barren soil of the uranium mine Gabrovnica-Kalna). An intensive transport of heavy natural radionuclides from soil to the roots was established. The transfer factors for U-238 and Ra-226 have been much bigger than for Th-232. The most intensive uptake was registered for beet root. (author)

  12. Behavior and environmental impacts of radionuclides during the hydrometallurgy of calcareous and argillaceous rocks, southwestern Sinai, Egypt

    Energy Technology Data Exchange (ETDEWEB)

    El Aassy, Ibrahim E. [Nuclear Materials Authority (Egypt); Nada, Afaf A., E-mail: afafhero_nada@yahoo.com [Faculty of Women for Arts, Science and Education (Egypt); El Galy, Mohamed M.; El Feky, Mohamed G. [Nuclear Materials Authority (Egypt); Abd El Maksoud, Thanaa M.; Talaat, Shadia M. [Faculty of Women for Arts, Science and Education (Egypt); Ibrahim, Eman M. [Nuclear Materials Authority (Egypt)

    2012-06-15

    The hydrometallurgy of radionuclides means getting the radioelements from the rocks into solution by leaching, getting the radionuclides from the solution by extraction process, and then precipitation of the desired elements to obtain concentrate. The follow-up of the radionuclides during these processes is the main target of this work to identify the identity of the original samples, pregnant solutions (leachates), residuals and the concentrate. Six samples were chosen to achieve this work. The leaching process was carried out under the conditions; 20-30% acid (H{sub 2}SO{sub 4}) concentration, 1:3 solid/liquid ratios, 60 min stirring time at room temperature. The activity concentrations of {sup 238}U, {sup 235}U, {sup 234}U, {sup 226}Ra, {sup 214}Pb, {sup 214}Bi, {sup 232}Th and {sup 40}K were measured in the original samples, residuals and U-concentrate (Bq/kg), and leachates (Bq/ Script-Small-L). The results indicate that, the radionuclides before {sup 226}Ra in the {sup 238}U decay series are more leachable (released) than those from {sup 226}Ra to {sup 214}Bi in the order; {sup 234}U>{sup 238}U={sup 235}U Much-Greater-Than {sup 226}Ra>{sup 214}Pb>{sup 214}Bi. {sup 232}Th and {sup 40}K are immobile under the present conditions. The radiological hazards of natural radioactivity in the original samples, leachates, residuals and U-concentrate were calculated and compared with the internationally recommended values and were found to be much higher than the world average values. - Highlights: Black-Right-Pointing-Pointer Original rocks, leachates, residuals and concentrate were studied. Black-Right-Pointing-Pointer Radionuclides concentrations were examined through different phases. Black-Right-Pointing-Pointer Radionuclides are more leachable before than that after {sup 226}Ra series. Black-Right-Pointing-Pointer Radiological hazards were compared with the international values. Black-Right-Pointing-Pointer Cautions should be taken in considerations during mining

  13. Radionuclide activities and radiological impact from the intake of milk, wheat flour, tea and coffee

    International Nuclear Information System (INIS)

    Nik Nadia Hazwani Nek Kamal; Amran Abdul Majid

    2013-01-01

    Full-text: The annual intake of four naturally occurring radionuclides 226 Ra, 238 U, 232 Th and 40 K from powdered milk, wheat flour, tea and coffee for Malaysian population were estimated using gamma spectrometry system. The radionuclides annual intake of 226 Ra ranged from 6 to 35.7 Bq, 232 Th ranged from 7.6 to 57.7 Bq, 238 U ranged from 6.3 to 63.7 Bq and 40 K ranged from 771.8 to 1707.5 Bq for adults. The means of these intakes were 28.8 Bq for 226 Ra, 38.5 Bq for 232 Th, 28.1 Bq for 238 U and 2921.1 Bq for the 40 K. The annual intake of radionuclide for infants were found to be 66.2 Bq for 226 Ra, 71.6 Bq for 232 Th, 23 Bq for 238 U and 7774.8 Bq for 40 K. the annual internal dose for infants from the intake of powdered milk were 63.5 μSv for 226 Ra, 32.2 μSv for 232 Th, 2.8 μSv for 238 U and 326.5 μSv for 40 K. The measured values also gives annual internal dose of 13.7 μSv 226 Ra, 19 μSv for 232 Th, 4 μSv for 238 U and 24.2 μSv for 40 K for adult population. The net radiological impact of these radionuclides is 425 μSv for infants and 60.9 μSv for adults. This value gives cancer risk factor of 1.8 x 10 -3 for infants and 1.7 x 10 -4 for adults. The probability of cancer risk increment is estimated as 0.18 % for infants (18 person in 10000) and 0.017 % for adults (1.7 person in 10000). Whereas ICRP cancer risk factor for general public is 2.5 x 10 -3 nd the total risk involved from all natural radiation sources based on global average radiation dose of 2.4 mSv is of 6 x 10 -3 . The estimated cancer risk shows that probability of increase of cancer risk from intake of milk, wheat flour, tea and coffee is only a minor fraction of ICRP values. Therefore, the diet does not pose any significant health hazard and is considered safe for human consumption. (author)

  14. Soil-to-plant transfer factors for natural radionuclides in grass in the vicinity of a former uranium mine

    Energy Technology Data Exchange (ETDEWEB)

    Štrok, Marko, E-mail: Marko.Strok@ijs.si; Smodiš, Borut, E-mail: Borut.Smodis@ijs.si

    2013-08-15

    Highlights: • Soil and grass samples were collected from sites at the uranium mill tailings pile. • {sup 238}U, {sup 230}Th, {sup 226}Ra and {sup 210}Pb activity concentrations were determined. • Soil-to-plant transfer factors were determined and are comparable with literature. • Potential use of grass as a monitor of radionuclide migration was evaluated. • Grass has potential in predicting {sup 238}U and {sup 226}Ra migration. -- Abstract: The activity concentrations of {sup 238}U, {sup 230}Th, {sup 226}Ra and {sup 210}Pb were determined in soil and grass samples collected from sites at the uranium mill tailings waste pile, which lies near the former uranium mine at Žirovski vrh in Slovenia. Soil-to-plant transfer factors were determined and the potential use of grass as a monitor of radionuclide migration from the waste pile was evaluated. It was found that grass was not suitable for monitoring {sup 230}Th and {sup 210}Pb migration (no linear correlation between soil and grass activity concentrations) but has potential in predicting {sup 238}U and {sup 226}Ra migration (linear correlation between soil and grass activity concentrations). Soil-to-plant transfer factors for grass were in the range from 0.0014 to 0.015 kg/kg DM for {sup 238}U, 0.0039 to 0.012 kg/kg DM for {sup 230}Th, 0.035 to 0.46 kg/kg DM for {sup 226}Ra and 0.098 to 1.5 kg/kg DM for {sup 210}Pb.

  15. Naturally occurring radionuclides in food

    International Nuclear Information System (INIS)

    Djujic, I.

    1995-01-01

    The naturally occurring radionuclides are the major source of radiation exposure to humans. The principal way of natural radiation exposure is the inhalation of 222 Rn decay products (about 85% of the total). The remainder is equally divided between internally deposited radionuclides, cosmic and terrestrial sources. In the present study, the content of 40 K, 210 Pb, 226 Ra, 230 Th, 232 Th and 238 U in representative food samples (milk, pork, beef, potatoes, wheat and corn flour) and samples of different food items that do not represent entire national production but provide interesting additional data for approximative calculation of naturally occurring radionuclide intake is presented. Daily weight of food eaten, participation of food groups, as well as daily intake by food of mentioned naturally occurring radionuclides in the Serbian diet was obtained on the base of house hold budget surveys. The result obtained for daily intake estimates in mBq for Serbian population are 78.1 ( 40 K), 38.2( 210 Pb), 52.3( 226 Ra), 2.0( 230 Th) and 12.5( 238 U). (author)

  16. Uptake of radionuclides by vegetation at a High Arctic location

    International Nuclear Information System (INIS)

    Dowdall, M.; Gwynn, J.P.; Moran, C.; O'Dea, J.; Davids, C.; Lind, B.

    2005-01-01

    Radionuclide levels in vegetation from a High Arctic location were studied and compared to in situ soil concentrations. Levels of the anthropogenic radionuclide 137 Cs and the natural radionuclides 40 K, 238 U, 226 Ra and 232 Th are discussed and transfer factor (TF) values and aggregated transfer (Tag) values are calculated for vascular plants. Levels of 137 Cs in vegetation generally followed the order mosses > lichen > vascular plants. The uptake of 137 Cs in vascular plants showed an inverse relationship with the uptake of 40 K, with 137 Cs TF and Tag values generally higher than 40 K TF and Tag values. 40 K activity concentrations in all vegetation showed little correlation to associated soil concentrations, while the uptake of 238 U, 226 Ra and 232 Th by vascular and non-vascular plants was generally low. - Uptake of the anthropogenic radionuclide 137 Cs is highest for moss species

  17. Determination of 226Ra by alpha spectrometry of liquid scintillation

    International Nuclear Information System (INIS)

    Nobrega, A.W.; Sachett, I.A.; Hespanhol, E.C.B.

    1987-01-01

    The determination of 226 Ra in environmental samples using alpha spectrometry in liquid scintilation is studied. The Radon 1-2 emanation method and 226 Ra separation process of other radionuclides alpha emissors are analyzed. The use of 226 Ra coprecipitation with barium sulphate is evaluated. (M.J.C.) [pt

  18. U-Th-Ra disequilibria at the Masaya (Nicaragua); Desequilibres U-Th-Ra au Masaya (Nicaragua)

    Energy Technology Data Exchange (ETDEWEB)

    Sigmarsson, O; Condomines, M [Centre de Recherches Volcanologiques, CNRS URA-10, 63 - Clermont Ferrand (France)

    1997-12-31

    {sup 238}U-{sup 230}Th-{sup 226}Ra radioactive disequilibria were measured in several basalt samples of the post-caldera flows of the Masaya volcano (Nicaragua). {sup 230}Th/{sup 232}Th ratios are from the highest known in the world (about 2.53) with {sup 230}Th/{sup 238}U ratios close to 1. These exceptionally high isotopic thorium ratios from the Masaya and other neighboring volcanoes (Conception, Cerro Negro, Momotombo) are followed by very high {sup 10}Be/{sup 9}Be ratios (60 10{sup -11} for the 1722 flow). These geochemical characteristics with {delta}{sup 18}O of typical mantle origin (5.55) suggest an influence of the subducted sediments fluids in the magma source. The age of the metasomatism ranges from 10 to 0.3 Ma. Initial {sup 226}Ra/{sup 230}Th ratios measured in four historical flows vary from 1.3 to 1.4 and are anti-correlated with the Th content. These variations are probably linked to the fractionated crystallisation of plagioclase minerals. The initial {sup 226}Ra/Ba ratio remains constant and suggests the existence of a huge stationary magmatic reservoir. This hypothesis is also confirmed by the disproportion between the SO{sub 2} quantity emitted by the volcano and by the degassing of lavas on the ground. The {sup 226}Ra excess observed in the Masaya lavas can be the result of a second stage of metasomatism which occurred less than 8000 years B.P. during partial fusion. Abstract only. (J.S.).

  19. U-Th-Ra disequilibria at the Masaya (Nicaragua); Desequilibres U-Th-Ra au Masaya (Nicaragua)

    Energy Technology Data Exchange (ETDEWEB)

    Sigmarsson, O.; Condomines, M. [Centre de Recherches Volcanologiques, CNRS URA-10, 63 - Clermont Ferrand (France)

    1996-12-31

    {sup 238}U-{sup 230}Th-{sup 226}Ra radioactive disequilibria were measured in several basalt samples of the post-caldera flows of the Masaya volcano (Nicaragua). {sup 230}Th/{sup 232}Th ratios are from the highest known in the world (about 2.53) with {sup 230}Th/{sup 238}U ratios close to 1. These exceptionally high isotopic thorium ratios from the Masaya and other neighboring volcanoes (Conception, Cerro Negro, Momotombo) are followed by very high {sup 10}Be/{sup 9}Be ratios (60 10{sup -11} for the 1722 flow). These geochemical characteristics with {delta}{sup 18}O of typical mantle origin (5.55) suggest an influence of the subducted sediments fluids in the magma source. The age of the metasomatism ranges from 10 to 0.3 Ma. Initial {sup 226}Ra/{sup 230}Th ratios measured in four historical flows vary from 1.3 to 1.4 and are anti-correlated with the Th content. These variations are probably linked to the fractionated crystallisation of plagioclase minerals. The initial {sup 226}Ra/Ba ratio remains constant and suggests the existence of a huge stationary magmatic reservoir. This hypothesis is also confirmed by the disproportion between the SO{sub 2} quantity emitted by the volcano and by the degassing of lavas on the ground. The {sup 226}Ra excess observed in the Masaya lavas can be the result of a second stage of metasomatism which occurred less than 8000 years B.P. during partial fusion. Abstract only. (J.S.).

  20. Simultaneous determination of Ra-226, natural uranium and natural thorium by gamma-ray spectrometry INa(Ti), in solid samples.; Determinacion de U (Natural), Th (Natural) y Ra-226 en diversos materiales, mediante espectrometria con INa (TI)

    Energy Technology Data Exchange (ETDEWEB)

    Salvador, S.; Navarro, T.; Alvarez, A.

    1991-07-01

    A method has been developed to determine activities of Ra-226, natural uranium and natural thorium by gamma-ray spectrometry. The measurement system has been calibrated using standards specially prepared at the laboratory. It is necessary to assume secular equilibrium in the samples, between Ra-226 and Th-232 and its daughters nuclides, and between U-238 and its immediate daughter Th-234, as the photo peaks measured are those of the daughters. The results obtained indicate that this method can of ter replace the radiochemical techniques used to measure activities in this type of sample. The method has been successfully used to determine these natural isotopes in samples from uranium mills. (Author) 9 refs.

  1. Sequential determination of U and Th isotopes, 226Ra, 228Ra, 210Pb, and 210Po in mushroom

    International Nuclear Information System (INIS)

    Rosa, Mychelle M.L.; Taddei, Maria Helena T.; Dias, Fabiana F.; Maihara, Vera A.

    2009-01-01

    For this study, mushroom samples were collected in Brazil at the Sao Paulo Metropolitan Region and at the Pocos de Caldas Plateau (PC; a region of elevated natural radioactivity, which houses the first Brazilian uranium mine). This paper discusses a sequential methodology to determine natural series radionuclides in mushrooms, such as uranium ( 238 U and 234 U) and thorium ( 232 Th, 230 Th, and 228 Th) isotopes, radium-226, radium-228, as well as lead-210 and polonium-210; using Alpha Spectrometry, Gamma Spectrometry, and Total Alpha and Beta Counting. The method involves total sample dissolution in a closed system in order to avoid loss of Polonium and employment of specific chromatographic resins for radionuclide purification. A subsequent interpretation of the results can provide information on pollutants present in mushrooms and infer possible contamination in the areas sampled as well as allow an association of measured concentrations to radioactive anomalies in the Plateau. (author)

  2. Natural radionuclide dose and lifetime cancer risk due to ingestion of fish and water from fresh water reservoirs near the proposed uranium mining site.

    Science.gov (United States)

    Annamalai, Sathesh Kumar; Arunachalam, Kantha Deivi; Selvaraj, Rajaram

    2017-06-01

    Ten sampling locations in Nagarjuna Sagar Dam have been selected to assess the suitability of the reservoir water for human consumption. The sediment, water, and fish samples were collected and analyzed for radionuclide ( 238 U, 232 Th, 210 Po, 226 Ra, 210 Pb) and physicochemical parameters like pH, TOC, total hardness, alkalinity, DO, cation exchange capacity, and particle size. The spatial variations among the radionuclides ( 238 U, 232 Th, 210 Po, 226 Ra, 210 Pb) in water and bottom sediments of Nagarjuna Sagar Dam were determined. The uranium concentration in the sediment and water was in BDL (water samples of the analyzed radionuclides are 238 U-10 Bq/l, 210 Po-0.1 Bq/l, 226 Ra-1 Bq/l, and 210 Pb-0.1 Bq/l. The radionuclides in our water samples were approximately 50 times far below the recommended limit. The ingestion of water and fish would not pose any significant radiological impact on health or cancer risk to the public, implicating that the fishes from Nagarjuna Sagar Dam reservoir are safe for human consumption except the fisherman community.

  3. Determination of distribution coefficients of some natural radionuclides (U, Ra, Pb, Po) between different types of Syrian soils and their solutions

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Al-Hamwi, A.; Amin, Y.; Al-Akel, B.

    2009-11-01

    In this study, distribution coefficients of some natural radionuclides ( 226 Ra, U, 210 Pb and 210 Po) between different types of soils in Syria and their solutions were determined. The distribution coefficients values ranged from (164-1933, 280-1722, 350-4749 and 101-117) l kg - 1 for 226 Ra, U, 210 Pb and 210 Po, respectively at pH = 4.0. While, the distribution coefficients values ranged from (207-6706, 673-2397, 149-2147 and 103- 292) l kg - 1 for 226 Ra, U, 210 Pb and 210 Po, respectively at pH = 5.5. In addition, the distribution coefficients values ranged from (167-1707, 126- 1239, 44-1122 and 125-1475) l kg - 1 for 226 Ra, U, 210 Pb and 210 Po, respectively at pH = 7.0. Moreover, the results showed that 210 Po distribution coefficients had the maximum values at pH 7. While 210 Pb distribution coefficients had the minimum values at same pH. In addition to, U distribution coefficients had the maximum values at pH 5.5. On the other hand, the effect of soil mineral content, CEC, ECE, pH and soluble ions on the distribution coefficients were investigated. In general, the results showed that there are logarithmic relationships between studied radionuclide activity in the soil and their distribution coefficients in all soil types (R 2 ranged from 0.59 to 1.00 at pH 4.0). On the other hand, there were no relationships between the distribution coefficients and soil pH. (authors)

  4. Field measurements of radon exhalation and Ra-226 content in soil using the can-technique

    International Nuclear Information System (INIS)

    Hafez, A.F.; El-Khatib, A.M.; Moharram, B.M.; Kotb, M.A.; Abdel-Naby, A.

    1991-01-01

    CR-39 and LR-115 plastic nuclear track detectors in the can-technique have been employed in the field measurements of radon exhalation, Ra-226 and U-238 content in dry-soil air at numerous regions in Sudan (the Blue and White Nile and Mogran regions). Measurements gave an average radon exhalation from the soil to the atmosphere and Ra-226 content of (23.4±2.60) kBq.m -2 and (123±13.65) Bq.kg -1 respectively. A polyethylene permeable memebrane cover was used to eliminate the contribution of thoron activity inside the can. Assuming a radioactive equilibrium between the U-series, the average U-238 content in the soil was found to be (9.92±1.01) ppm. This survey may be used for uranium prospection in soil. (orig.) [de

  5. Applying a method of chemical separation and mass spectrometry for the determination of radium-226 in surface water

    International Nuclear Information System (INIS)

    Sibello Hernandez, Rita Y; Cozzella, Maria Letizia; Guillen Arruebarrena, Aniel

    2014-01-01

    Radium-226 ( 226 Ra) is a naturally occurring radionuclide, alpha emitter with half-life of 1 622 years originating from uranium-238 ( 238 U). Its presence in drinking water is a major radiological hazards, which requires constant monitoring. The analytical techniques used in the determination of 226 Ra generally require the establishment of secular equilibrium and/or tedious separation of other elements. The main objective of this paper is to demonstrate the efficiency and speed of a method of preconcentration and separation of 226 Ra in natural water samples using coprecipitation with MnO 2 radius and purification by cation exchange resin Dowex 50WX8. Measurement technique was Quadrupole Mass Spectrometry and associated induced plasma ICP-Q-MS. The 226 Ra values obtained are in the range of 0,010-0,219 pg/L in natural waters analyzed

  6. Health implications of radionuclide levels in cattle raised near U mining and milling facilities in Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    Lapham, S.C.; Millard, J.B.; Samet, J.M.

    1989-01-01

    This study was conducted to determine radionuclide tissue levels in cattle raised near U mining and milling facilities. Ambrosia Lake, New Mexico, has been the site of extensive U mining for 30 y and contains several underground U mines, a processing mill, and two large U tailings piles. Ten cows were purchased from two grazing areas in Ambrosia Lake and ten control animals were purchased from Crownpoint, New Mexico. Muscle, liver, kidney, and bone tissue taken from these animals, and environmental samples, including water, grasses and soil collected from the animals' grazing areas, were analyzed for 238 U, 234 U, 230 Th, 226 Ra, 210 Pb, and 210 Po. Mean radionuclide levels in cattle tissue and environmental samples from Ambrosia Lake were higher in almost every comparison than those found in respective controls. Liver and kidney tissues were particularly elevated in 226 Ra and 210 Po. Radiation dose commitments from eating cattle tissue with these radionuclide concentrations were calculated. We concluded that the health risk to the public from eating exposed cattle is minimal, unless large amounts of this tissue, especially liver and kidney, are ingested

  7. Determination of /sup 226/Ra by alpha spectrometry of liquid scintillation

    Energy Technology Data Exchange (ETDEWEB)

    Nobrega, A W; Sachett, I A; Hespanhol, E C.B.

    1987-07-01

    The determination of /sup 226/Ra in environmental samples using alpha spectrometry in liquid scintilation is studied. The Radon/sup 1-2/ emanation method and /sup 226/Ra separation process of other radionuclides alpha emissors are analyzed. The use of /sup 226/Ra coprecipitation with barium sulphate is evaluated. (M.J.C.).

  8. Radiochemical determination of 210 Pb and 226Ra in petroleum sludges and scales

    International Nuclear Information System (INIS)

    Araujo, Andressa Arruda de

    2005-01-01

    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 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 238 U series. This work, therefore, focuses on the radiochemical determination of the concentration of 210 Pb, and 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 210 Pb varied from 1,14 to 507,3 kBq kg -1 . The values for 226 Ra were higher, varying from 4,36 to 3.445 kBq kg -1 . The results for 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)

  9. Ra-226 and Rn-222 in saline water compartments of the Aral Sea region

    International Nuclear Information System (INIS)

    Schettler, Georg; Oberhänsli, Hedi; Hahne, Knut

    2015-01-01

    analysis of the radionuclide using an ICP sector field mass spectrometer. The 226 Ra concentration of 17 unconfined groundwater samples ranged between 0.2 and 5 ppq, and that of 28 artesian waters between <0.2 and 13 ppq. The ICP-MS results conformed satisfactorily to analytical results based on γ-measurements of the 222 Rn ingrowth after purging and trapping on super-cooled charcoal. The 226 Ra concentrations were positively correlated with the salinity and the dissolved NaCl concentrations. The occurrence of unusually high 226 Ra activities is explained by radium release from adsorption sites with increasing salinity. The inferred spatial variability of 222 Rn in the Aral Sea and of 222 Rn and 226 Ra in the groundwater of the Amu Darya Delta is discussed in the context of our own previous hydrochemical studies in the study sites. Relatively low 222 Rn activities in the unconfined GW (1–9.5 Bq/l) indicate the alluvial sediments hosting the GW to be a low- 238 U( 226 Ra) substrate. Positive correlations between U and 226 Ra, and U and 222 Rn are likely related to locally deposited Fe(Mn)OOH precipitates. The 222 Rn activity of the GW, however, distinctly exceeds the 222 Rn concentration in the Aral Sea (10 mBq/l), in principle, making 222 Rn a sensitive tracer for the inflow of GW. The high water volume of the Large Aral Sea and wind induced mixing of its water body, however, hamper the detection of local groundwater inflow

  10. 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)

  11. Distribution and correlation of the natural radionuclides in a coal mine of the West Macedonia Lignite Center (Greece).

    Science.gov (United States)

    Tsikritzis, L I; Fotakis, M; Tzimkas, N; Kolovos, N; Tsikritzi, R

    2008-02-01

    The distribution and correlation of six natural nuclides in the West Macedonia Lignite Center, Northern Greece were studied. Fifty-five samples of lignite, aged from 1.8 to 5 million years, and corresponding steriles, beds of marls, clays and sands alternating with the lignite, were collected perpendicular to the mine benches and measured spectroscopically. The mean concentrations of (238)U and (226)Ra in lignites were found to be higher than that in steriles since these nuclides are associated with the organic material of lignite, whereas (238)U/(226)Ra equilibrium was not observed in either lignites or steriles. Finally, the ratio (226)Ra/(228)Ra in lignites was approximately double of that in steriles, confirming the affinity of the (238)U series with the coal matrix in contrast to the (232)Th series. No correlation was found between radionuclide concentrations and the depth of the sample, nor with the ash content of lignite.

  12. The enrichment of natural radionuclides in oil shale-fired power plants in Estonia – The impact of new circulating fluidized bed technology

    International Nuclear Information System (INIS)

    Vaasma, Taavi; Kiisk, Madis; Meriste, Tõnis; Tkaczyk, Alan Henry

    2014-01-01

    Burning oil shale to produce electricity has a dominant position in Estonia's energy sector. Around 90% of the overall electric energy production originates from the Narva Power Plants. The technology in use has been significantly renovated – two older types of pulverized fuel burning (PF) energy production units were replaced with new circulating fluidized bed (CFB) technology. Additional filter systems have been added to PF boilers to reduce emissions. Oil shale contains various amounts of natural radionuclides. These radionuclides concentrate and become enriched in different boiler ash fractions. More volatile isotopes will be partially emitted to the atmosphere via flue gases and fly ash. To our knowledge, there has been no previous study for CFB boiler systems on natural radionuclide enrichment and their atmospheric emissions. Ash samples were collected from Eesti Power Plant's CFB boiler. These samples were processed and analyzed with gamma spectrometry. Activity concentrations (Bq/kg) and enrichment factors were calculated for the 238 U ( 238 U, 226 Ra, 210 Pb) and 232 Th ( 232 Th, 228 Ra) family radionuclides and for 40 K in different CFB boiler ash fractions. Results from the CFB boiler ash sample analysis showed an increase in the activity concentrations and enrichment factors (up to 4.5) from the furnace toward the electrostatic precipitator block. The volatile radionuclide ( 210 Pb and 40 K) activity concentrations in CFB boilers were evenly distributed in finer ash fractions. Activity balance calculations showed discrepancies between input (via oil shale) and output (via ash fractions) activities for some radionuclides ( 238 U, 226 Ra, 210 Pb). This refers to a situation where the missing part of the activity (around 20% for these radionuclides) is emitted to the atmosphere. Also different behavior patterns were detected for the two Ra isotopes, 226 Ra and 228 Ra. A part of 226 Ra input activity, unlike 228 Ra, was undetectable in the solid

  13. Reference material for radionuclides in sediment IAEA-384 (Fangataufa Lagoon sediment)

    DEFF Research Database (Denmark)

    Povinec, P.P.; Pham, M.K.; Sanchez-Cabeza, J.A.

    2007-01-01

    A reference material designed for the determination of anthropogenic and natural radionuclides in sediment, IAEA-384 (Fangataufa Lagoon sediment), is described and the results of certification are presented. The material has been certified for 8 radionuclides (K-40, Co-60, Eu-155, Th-230, U-238, ...... management of radioanalytical laboratories engaged in the analysis of radionuclides in the environment, as well as for the development and validation of analytical methods and for training purposes. The material is available from IAEA in 100 g units.......A reference material designed for the determination of anthropogenic and natural radionuclides in sediment, IAEA-384 (Fangataufa Lagoon sediment), is described and the results of certification are presented. The material has been certified for 8 radionuclides (K-40, Co-60, Eu-155, Th-230, U-238, Pu......-238, Pu239+240 and Am-241). Information values are given for 12 radionuclides (Sr-90, Cs-137, Pb-210 (Po-210), Ra-226, Ra-228, Th-232, U-234, U-235, Pu-239, Pu-240 and Pu-241). Less reported radionuclides include Th-228, U-236, Np-239 and Pu-242. The reference material may be used for quality...

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

    DEFF Research Database (Denmark)

    Pham, M.K.; Benmansour, M.; Carvalho, F.P.

    2014-01-01

    A Certified Reference Material (CRM) for radionuclides in seaweed (Fucus vesiculosus) from the Baltic Sea (IAEA-446) is described and the results of the certification process are presented. The 40K, 137Cs, 234U and 239þ240Pu radionuclides were certified for this material, and information values...... for 12 other radionuclides (90Sr, 99Tc, 210Pb (210Po), 226Ra, 228Ra, 228Th, 230Th, 232Th, 235U, 238U, 239Pu and 240Pu) are presented. The CRM can be used for Quality Assurance/Quality Control of analysis of radionuclides in seaweed and other biota samples, as well as for development and validation...

  15. A rapid analysis of {sup 226}Ra in raw materials and by-products using gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Chung Sup; Chung, Kun Ho; Kim, Chang Jong; Ji, Young Yong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-03-15

    A gamma-ray peak of {sup 226}Ra (186.2 keV) overlaps with one of {sup 235}U (185.7 keV) in a gamma-ray spectrometry system. Though reference peaks of {sup 235}U can be used to correct the peak interference of {sup 235}U in the analysis of {sup 226}Ra, this requires a complicated calculation process and a high limit of quantitation. On the other hand, evaluating {sup 226}Ra using the correction constant in the overlapped peak can make a rapid measurement of {sup 226}Ra without the complicated calculation process as well as overcome the disadvantage in the indirect measurement of {sup 214}Bi, which means the confinement of {sup 222}Rn gas in a sample container and a time period to recover the secular equilibrium. About 93 samples with 6 species for raw-materials and by-products were prepared to evaluate the activity of {sup 226}Ra using the correction constant. The results were compared with the activity of {sup 214}Bi, which means the indirect measurement of {sup 226}Ra, to validate the method of the direct measurement of {sup 226}Ra using the correction constant. The difference between the direct and indirect measurement of {sup 226}Ra was generally below about ± 20%. However, in the case of the phospho gypsum, a large error of about 50% was found in the comparison results, which indicates the disequilibrium between {sup 238}U and {sup 226}Ra in the materials. Application results of the contribution ratio of {sup 226}Ra were below about ± 10% . The direct measurement of {sup 226}Ra using the correction constant can be an effective method for its rapid measurement of raw materials and by-products because the activity of {sup 226}Ra can be produced with a simple calculation without the consideration of the integrity of a sample container and the time period to recover the secular equilibrium.

  16. U-series radioactive disequilibria 238U-230Th-226Ra: discussions on sources and processes responsible for volcanism of the Andean cordillera and on the deglaciation in Iceland

    International Nuclear Information System (INIS)

    Chmeleff, J.

    2005-10-01

    Thanks to precise analyses of uranium series radioactive disequilibria, permitted by improvements of mass spectrometry data acquisition and optimization of chemistry, two questions were tackled and answers about the periods of glaciation in Iceland and the petrogenesis of Andean lavas were proposed. Two methods were used to date lava flows from the Reykjanes peninsula and the island of Heimaey, in Iceland, directly linked to the periods of deglaciation or reheating around the last ice age. An original method based on the use of segregation veins present in the lava flows has been developed. Thanks to the formation of this particular geological object this methods permits to be freed from xeno-crystals when using the internal isochron method in the 238 U- 230 Th system. Using this method some constraints are brought both on the quaternary geology of the area of Reykjavik and on the age of the end of the Wurm glaciation on Heirnaey. In parallel, due to the homogeneity of the historical and Holocene lavas of the Reykjanes peninsula, regarding the ( 230 Th/ 232 Th) and Th/U ratios, it is possible to derive the ( 230 Th/ 232 Th) ratio in time to determine the age of lava flows installed during the ice age. Thus we confirmed that the magnetic excursion recorded in the Skalamaelifell lava flow is most probably the same one as that of Laschamp-Olby and that at this time (approximately 48.000 years) the Reykjanes peninsula was entirely covered with a glacier. Thanks to this method the extent of the glacier was also constrained by dating of a picritic shield around 22.000 years, thus the peninsula has to be free of any ice cap despite the fact that glaciation is the most intense around this time.Then Andean arc magmas petrogenesis was constrained in time and space. Almost systematic excesses of 226 Ra compared to 230 Th in lavas of austral, southern and northern volcanic zones of the Andes (AVZ, SVZ and NVZ) constrain the ascending time from the source to the surface after

  17. Assessment of radionuclide contents in food in Hong Kong

    International Nuclear Information System (INIS)

    Yu, K.N.; Mao, S.Y.

    1999-01-01

    Baseline values of concentrations of the natural radionuclides ( 238 U, 226 Ra, 228 Ra/ 232 Th, 210 Pb) and artificial radionuclides ( 137 Cs, 60 Co) in food and drinks (tap water, milk, and water-based drinks) were determined by gamma spectroscopy. All food and drinks were found to contain detectable 40 K contents: 0.1 to 160 Bq Kg -1 for food and 0.006 to 61 Bq L -1 for drinks. Most of the other natural radionuclides in solid food were found to have contents below the minimum detectable activities (MDA). More samples in the leafy vegetable, tomato, carrot and potato categories contained detectable amounts of 228 Ra than the meat, cereal, and fish categories, with concentrations up to 1.2 Bq kg -1 for the former categories and 0.35 Bq kg -1 for the latter categories. The 238 U and 226 Ra radionuclides were detectable in most of the water-based drink samples, and the 228 Ra and 210 Pb radionuclides were detectable in fewer water-based drink samples. The 137 Cs contents in solid food were detectable in most of the solid food samples (reaching 0.59 Bq kg -1 ), but in drinks the 137 Cs contents were very low and normally lower than the MDA values. Nearly all the 60 Co contents in food and drinks were below the MDA values and their contents were below those of 137 Cs

  18. Distribution of radionuclides and elements in Cubatao River sediments

    International Nuclear Information System (INIS)

    Silva, P.S.C.; Mazzilli, B.P.; Favaro, D.I.T.

    2006-01-01

    Cubatao River is located in Santos Basin, Sao Paulo State, Brazil. This region is characterized by the occurrence of estuaries and mangrove. Due to its location, near the coastal line, it is also an important industrial area, where phosphate fertilizer plants, petrol refineries, and chemical and steel industries are present. Such human activities contribute to the enhancement of elemental composition in sediments and, in some cases, also increase the radionuclide concentrations, the so called Technologically Enhanced Natural Occurring Radioactive Materials (TENORM). The contamination of land and sediments by TENORM is of major concern. The activity concentration of U and Th series radionuclides was determined in five sediment samples from Cubatao River. The activity concentration ratio was also determined. Equilibrium was observed for the ratio 234 U/ 238 U. The activity ratios of Th/ 238 U, 228 Ra/ 226 Ra and 210 Pb/ 226 Ra were higher than the unity. In the first two cases, the observed values are due to the higher activity of Th in the sediment and in the last case are probably due to the atmospheric deposition of 210 Pb. (author)

  19. 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)

  20. Bioavailability pf radionuclides 226Ra, 228Ra and 210Pb present in Brazilian phosphogypsum and phosphate fertilizers

    International Nuclear Information System (INIS)

    Russo, Ana Carolina; Saueia, Catia H.R.; Mazzilli, Barbara P.

    2011-01-01

    Phosphogypsum (PG) is a by-product of phosphate fertilizers industries. The USEPA classified PG as a - Technologically Enhanced Naturally Occurring Radioactive Material (TENORM). Its worldwide production on 2006 was estimated in 150 million tons. Annually the three main phosphate industries in Brazil are responsible for 5.5x106 tons of phosphogypsum, which is stored in stacks. The level of radionuclides present in phosphogypsum is well-known and makes its disposal or reutilization an environmental concern. Part of this byproduct can be reused, for example, to improve fertility of agricultural soils. To assess the long term environmental impact of radioactive contamination of ecosystems, information on source term including radionuclide speciation, mobility and biological uptakes have high importance. This paper intends to evaluate the bioavailability of the radionuclides 226 Ra, 228 Ra and 210 Pb to the environment by following a procedure established by the EC (European Community), which includes a single EDTA-NH 4 0.05M extraction at pH 7.0 prior to the analyses. These results is compared with the total activity concentration of these radionuclides in Brazilian PG and the most used phosphate fertilizers (SSP, TSP, MAP and DAP). This procedure intends to represent on a more realistic way the leaching of radionuclides from PG and fertilizers to soil and agricultural products. (author)

  1. 226Ra chronology of a coastal marine sediment

    International Nuclear Information System (INIS)

    Koide, M.; Bruland, K.; Goldberg, E.D.

    1976-01-01

    Unsupported 226 Ra (tsub (1/2) = 1620 years) in marine sediments can provide a basis for measuring rates of accumulation of the order of centimeters per thousand years. The excess radium apparently enters the sediments incorporated in phytoplankton. The sensitivity of the method depends upon the initial value of the unsupported 226 Ra and of the value of 230 Th, a parent of 226 Ra, in the sedimentary components. 226 Ra dating was applied to a sediment taken from the slope of the San Clemente Basin in the Southern California coastal region. Rates of sedimentation over two half-lives of the nuclide were found to be either 5.2 or 5.3 cm/1000 years depending upon which of two models for the geochronology is used. One model assumes that the 230 Th brings to the deposit an amount of 226 Ra in equilibrium with it. The other is based upon the growth of the 226 Ra from the 230 Th in the sedimentary components. 238+239 Pu and 210 Pb levels in the upper strata indicated sedimentation rates of the order of 100-500 cm/1000 years, i.e. much faster accumulations. It is suggested that these derived rates are spurious and reflect bioturbative activities of surface-living organisms. (Auth.)

  2. Report on the intercomparison run IAEA-306 radionuclides in Baltic Sea sediment

    International Nuclear Information System (INIS)

    Ballestra, S.; Vas, D.; Lopez, J.J.; Noshkin, V.

    1989-10-01

    The results of an intercomparison exercise on a Baltic Sea sediment sample, coded as IAEA-306, designed for the determination of artificial and natural radionuclide levels, are reported. This sample was collected in the fall 1986. It was anticipated that the concentrations of the artificial radionuclides in this sediment would be higher than the environmental levels usually found and, therefore, would constitute an excellent intercomparison sample. The data from 84 laboratories representing 34 countries have been evaluated. The most frequently measured radionuclides are: 90 Sr, 125 Sb, 134 Cs, 137 Cs, 238 Pu, 239+240 Pu, 241 Am, 40 K, 210 Pb- 210 Po, 226 Ra, 228 Ra, 228 Th, 230 Th, 232 Th, 234 U and 238 U. 6 refs, 13 tabs

  3. Determination of radioactivity levels in phosphate-containing fertilizers, copper and gold ores by direct gamma-ray spectroscopy. U-238, Th-232, K-40, and Ra-226 in fertilizers and ores

    International Nuclear Information System (INIS)

    Constantinescu, B.; Constantin, F.; Dusoiu, N.; Pascovoici, G.

    1996-01-01

    Two particular sources from the natural radiation background which may be encountered in Romanian industry are here presented: the phosphate containing fertilizers and the gold and copper ores, respectively. U-238, Th-232, K-40, and Ra-226 activity levels for several imported phosphorites, superphosphates and also for concentrated Cu and Au indigenous ores are reported. A simple and efficient radioactivity determination procedure based on a large volume NaI(Tl) detector, coupled to a Romanian design portable multichannel analyzer is described. Potential radiological impacts for the specialized workers are also discussed. (author) 1 fig., 4 tabs. 6 refs

  4. Intercomparison of radionuclide measurements in marine sediment sample IAEA-367

    International Nuclear Information System (INIS)

    Ballestra, S.; Lopez, J.J.; Gastaud, J.; Vas, D.; Noshkin, V.

    1991-08-01

    The results of an intercomparison exercise on a Pacific Ocean sediment sample, IAEA-367, designed for the determination of artificial and natural radionuclides levels, are reported. The data from 81 laboratories representing 37 countries have been evaluated. The following are the recommended values, with confidence intervals, for 60 Co, 90 Sr, 137 Cs, 239+240 Pu (Reference date: 1 January 1990). Information values for 155 Eu, 238 Pu, 241 Am, and 241 Pu are reported. Information values for the following natural radionuclides 40 K, 226 Ra, 228 Th, 230 Th, 234 U, 235 U and 238 U are also reported. (author)

  5. Committed effective dose from naturally occuring radionuclides in shellfish

    International Nuclear Information System (INIS)

    Khandaker, Mayeen Uddin; Wahib, Norfadira Binti; Amin, Yusoff Mohd.; Bradley, D.A.

    2013-01-01

    Recognizing their importance in the average Malaysian daily diet, the radioactivity concentrations in mollusc- and crustacean-based food have been determined for key naturally occuring radionuclides. Fresh samples collected from various maritime locations around peninsular Malaysia have been processed using standard procedures; the radionuclide concentrations being determined using an HPGe γ-ray spectrometer. For molluscs, assuming secular equilibrium, the range of activities of 238 U ( 226 Ra), 232 Th ( 228 Ra) and 40 K were found to be 3.28±0.35 to 5.34±0.52, 1.20±0.21 to 2.44±0.21 and 118±6 to 281±14 Bq kg −1 dry weight, respectively. The respective values for crustaceans were 3.02±0.57 to 4.70±0.52, 1.38±0.21 to 2.40±0.35 and 216±11 to 316±15 Bq kg −1 . The estimated average daily intake of radioactivity from consumption of molluscs are 0.37 Bq kg −1 for 238 U ( 226 Ra), 0.16 Bq kg −1 for 232 Th ( 228 Ra) and 18 Bq kg −1 for 40 K; the respective daily intake values from crustaceans are 0.36 Bq kg −1 , 0.16 Bq kg −1 and 23 Bq kg −1 . Associated annual committed effective doses from molluscs are estimated to be in the range 21.3 to 34.7 μSv for 226 Ra, 19.3 to 39.1 μSv for 228 Ra and 17.0 to 40.4 μSv for 40 K. For crustaceans, the respective dose ranges are 19.6 to 30.5 μSv, 22.0 to 38.4 μSv and 31.1 to 45.5 μSv, being some several times world average values. - Highlights: ► Activity concentrations of naturally occuring radionuclides were assessed for shellfish. ► 238 U, 232 Th, 40 K intake via shellfish showed several times higher than world averages. ► Committed effective doses due to the ingestions of 238 U, 232 Th, 40 K are the first report in Malaysia. ► Estimated committed effective dose also showed higher values than the world average

  6. 226Ra determination in phosphogypsum by alpha-particle spectrometry

    International Nuclear Information System (INIS)

    Aguado, J.L.; Bolivar, J.P.; Garcia-Tenorio, R.

    1999-01-01

    A radiochemical method for 226 Ra 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 226 Ra behaviour in phosphogypsum (the main by-product of producing phosphoric acid from phosphate rocks). (author)

  7. Natural radionuclides from U-238 and Th-232 series and inorganic chemical characterization of soil profiles and sediment cores of the TaiaÇUpeba Reservoir, SÃO Paulo, Brazil

    International Nuclear Information System (INIS)

    Souza, J.M.; Damatto, S.R.; Surkov, A.M.; Silva, A.R.; Maduar, M.F.; Gonçalves, P.N.; Leonardo, L.

    2017-01-01

    Taiaçupeba reservoir, located in the state of São Paulo, Brazil, belongs to Producer System of Alto Tietê (Sistema Produtor Alto Tietê) and it is responsible for water supply for about 3.1million of people. The water quality of a reservoir is very important, but this is reduced by the increase of environmental degradation of the soil around the reservoir and its different uses. The study of soil profiles and sediment cores is an important tool for understanding the geophysical and geochemical aspects of an aquatic ecosystem. The objective of this work was to present the natural radionuclides 238 U, 226 Ra, 210 Pb, 232 Th, 228 Th, 228 Ra and 40 K activity concentrations and also the inorganic chemical characterization of four soil profiles and four sediment cores collected in the area of influence area of Taiaçupeba reservoir. The analytical techniques, gamma spectrometry and instrumental neutron activation analysis were used in the determination. In the soil profiles the highest activity concentrations were obtained for the radionuclides 40 K and 228 Th and the lowest for 210 Pb; in the sediment cores the highest activity concentrations were obtained for the radionuclide 210 Pb and the lowest for 226 Ra and 228 Ra. For the inorganic chemical characterization the highest values obtained were for Na, As and Sb; in a sediment core a very high concentration was obtained for the element Zn indicating a probable accumulation of this element inside the reservoir; enrichment factor was used to evaluate a possible anthropic contamination in the soil and sediment at the margins of Taiaçupeba reservoir. (author)

  8. Determination of radioactivity in Chinese phosphate rock and fertilizer

    International Nuclear Information System (INIS)

    Chen Jingjian; Zhu Yongyi; Yang Juncheng

    1993-01-01

    The presented paper reported the radioactivity of U-238, Ra-226, Th-232 and K-40 in Chinese phosphate rocks by gamma spectrographic analysis during 1985-1990. The results showed that the decay chain of U-238-Ra-226 was the main source of radionuclides in phosphate rocks. The radionuclides in phosphate fertilizer differed from the forms of phosphate fertilizer. U-238 was the most important radionuclide in phosphoric compound fertilizer. The transfer rate of radionuclides was also estimated. (2 figs., 1 tab.)

  9. Research over the extraction process in order to simulate 226Ra and Unat radionuclides migration in uranium waste dumps

    International Nuclear Information System (INIS)

    Bragea, Mihaela; Toro, Laszlo; Cristache, Carmen

    2008-01-01

    To simulate the phenomenon of migration availability of radioactive elements in uranium waste product from waste dump into the environment it was taken into account the Ciudanovita, Romania area with its uranium waste dumps. It were made studies through experiments of static extraction in agitation pot (static regime), which allow to pursue the evolution of contaminants along a specific period of time. It was accomplish a study about sorption and adsorption process on the geological environment (clay). It was observed that 226 Ra and U nat transition through the sorption and adsorption processes were induced by the type of clay (due to variable solubility of clay and the physics and chemical status of 226 Ra and U nat into the clay) and the time interval until the water contacts the clay. The concentration measurements of radionuclides into different dimension of clay particles were made to give pertinent information about the way of chosen the repair strategies for the studied site. The present work is based mainly on this research direction: optimization and improvement of the performances obtained from the geo-chemical processes investigation methods in the waste dumps and the surrounding geological structures to isolate them, in order to reduce the negative environmental impact. Measurements of the two radionuclides concentrations in particles with different dimensions were made to supply accurate information regarding the selection of remediation strategies for the dumpsite in study. (author)

  10. Concentration Of 228Th, 226Ra, And 40K Radionuclides In Drinking Water In Southern Sumatera

    International Nuclear Information System (INIS)

    Sutarman; Warsono, Asep; Wahyudi

    2000-01-01

    Measurements of 228 Th, 226 Ra, and 40 K concentrations in drinking water on several places in Southern Sumatera (1997-1999) have been carried out. The sample were collected from the Province of Lampung (Kalianda, Bandar Lampung, Kotabumi, Talangpadang, Kotaagung, Liwa, Manggala, and Pakuanratu), and the Province of Southern Sumatera (Palembang-1, Palembang-2, Plaju, Lahat, and Sekayu). Measurements of 228 Th, 226 Ra, and 40 K concentrations in drinking water using the gamma spectrometer with the HP-Ge detector. The results of measurement showed that the concentration was the range of undetectable ( 228 Th concentration, the range of undetectable ( 226 Ra, radionuclide and the range of undetectable (< 128.96 mBq/l) to (880.54 n 22.75) mBq/l with average of (412.12 n 5.02) mBq/l, and the data mentioned above were still far under the maximum permissible concentration. The estimated of annual dose equivalent effective in drinking water was 0.03 mSv/year for public (5 mSv/year)

  11. Contents of natural and anthropological radionuclides in uncultivated soils in the eastern part of Bulgaria

    International Nuclear Information System (INIS)

    Todorov, P.; Georgieva, D.; Yaneva, B.

    2006-01-01

    Bulgaria is a country which is located in the Eastern part of Europe. The lay shape of Bulgaria is very various, regarding to the lay shape, rock types and some human activities it defines content of radionuclides in uncultivated soils. Natural radionuclides in these soils are: U 238, Ra 226, Th 232 and K 40. The main anthropological source of radionuclides in these soils is Cs 137. There are no normative documents about limit concentrations of these radionuclides in uncultivated soils. So the actual concentrations are compared with some background concentrations, as a result from a lot of studies in the past. Valuation of natural and anthropological radionuclides is made by determination of their special activity in soil samples from the 0 - 20 cm layer by using the nondestructive gamma spectro metrological analysis. Specific activity of U 238 is defined by its daughter product - Th 234, specific activity of Ra 226 by Pb 214 and Bi 214, of Th 232 by Ac 228 and Pb 212, and specific activity of K-40 and Cs 137 by gamma spectro metrological analysis. In the last years there was made a systematic and valuation of concentrations of these radionuclides. There were examined more than 500 samples each year in the investigated area. Concentrations for U 238 vary from 4 to 64 Bq/kg, for Ra 226 from 7 to 54 Bq/kg, for Th 232 from 12 to 67 Bq/kg, for K 40 from 72 to 1106 Bq/kg. For Cs 137, the concentrations vary from 2 to 234 Bq/kg. During this analysis there were no indices of natural radionuclides above the limit concentrations - background concentrations typical for the different regions

  12. Vegetation-derived insights on the mobilization and potential transport of radionuclides from the Nopal I natural analog site, Mexico

    International Nuclear Information System (INIS)

    Leslie, B.W.; Pickett, D.A.; Pearcy, E.C.

    1999-01-01

    The Nopal I uranium (U) deposit, Pena Blanca, Mexico is a source term and contaminant transport natural analog to the proposed high-level nuclear waste repository at Yucca Mountain, Nevada. In an attempt to characterize the mobilization and potential transport of radionuclides in the unsaturated zone at the Nopal I deposit, vegetation growing on ore piles was analyzed for 238 U, 235 U, and 232 Th decay-series isotopes. Specimens of Phacelia robusta growing on high-grade piles of U ore were collected and analyzed by alpha autoradiography, and by alpha and gamma spectrometry. Activities for U, thorium (Th), and radium (Ra) isotopes (Bq/kg dried plant) were 300, 1,000, and 7,000 for 238 U, 230 Th, and 226 Ra, respectively. The 226 Ra activities in these specimens are among the highest ever measured for plants; furthermore, the plant-to-soil 226 Ra concentration ratio is higher than expected. These results demonstrate the large mobility and bio-availability of Ra in the Nopal I environment, and support previous indications of recent loss of 226 Ra from the ore body. Comparison between the activities of 238 U and 232 Th decay-chain Th isotopes in the plants and in the ore substrate indicate that relative mobilization into pore solutions of 228 Th > 230 Th > 232 Th, in a ratio of about 50--25:4:1, respectively. The similarity of the plant's 234 U/ 238 U activity ratio (∼1.2) to that of a caliche deposit that formed adjacent to the Nopal ore body around 54 ka suggests the 234 U/ 238 U activity ratio of U released from the ore is approximately 1.2. The U and 226 Ra isotope activities of the plants and ore substrate, and solubility considerations, are used to assess a source term model of the potential Yucca Mountain repository. These results suggest the use of a natural analog source term model in performance assessments may be non-conservative

  13. Determination of 226 Ra and 228 Ra in mineral spring waters of the Aguas da Prata region

    International Nuclear Information System (INIS)

    Oliveira, J. de.

    1993-01-01

    Concentration levels of 226 Ra and 228 Ra have been analysed in most of the mineral spring waters available in the Aguas da Prata region. The 226 Ra and 228 Ra were determined by coprecipitation with barium sulphate. The 226 Ra was determined by gross alpha counting of the Ba(Ra)SO 4 precipitate. The determination of 228 Ra was done by measuring the gross beta activity of the same precipitate. Both measurements were carried out in a low background gas flow proportional counter. Dose calculations were performed in order to evaluate the relative importance of such radionuclides to the radiation exposure due to the ingestion of these waters. Based upon measured concentrations, committed effective doses up to 5.5 x 10 -1 mSv/y and 1.0 x 10 -2 mSv/y were observed for 226 Ra and 228 Ra, respectively. These results show that 226 Ra is the main contributor to radiation exposure. (author)

  14. Natural Radionuclides in Slag/Ash Pile from Coal-Fired Power Plant Plomin

    International Nuclear Information System (INIS)

    Barisic, D.; Lulic, S.; Marovic, G.; Sencar, J.

    2001-01-01

    Full text: The coal slag/ash pile contains about one million tons of different (bottom ash, filter ash, gypsum) waste material deposited in vicinity of Plomin coal-fired power plant. Activities of 40 K, 228 Ra, 226 Ra and 238 U in materials deposited on slag/ash pile as well as in used coals were occasionally measured during past more than two and half decades of Plomin coal-fired plant operation. The radionuclides content in deposited bottom and filter ash material are related with radionuclide activities and mineral matter fraction in coals used. Up to the middle of nineties, the majority of coal used was anthracite from Istrian local mines. In that period, deposited waste material was characterised with relatively high 226 Ra and 238 U activities while potassium and thorium content was very low. When Istrian coal has been completely substituted with imported coal, uranium series radionuclide concentrations in deposited waste materials decreased significantly. Meanwhile, potassium and thorium activities in slag/ash pile material increased. It seems that slag/ash pile material generated in the last several years of Plomin coal-fired power plant operation could be generally used in cement industry without any special restriction. (author)

  15. The detailed analysis of natural radionuclides dissolved in spa waters of the Kłodzko Valley, Sudety Mountains, Poland

    International Nuclear Information System (INIS)

    Walencik-Łata, A.; Kozłowska, B.; Dorda, J.; Przylibski, T.A.

    2016-01-01

    A survey was conducted to measure natural radioactivity in spa waters from the Kłodzko Valley. The main goal of this study was to determine the activity concentration of uranium, radium and radon isotopes in the investigated groundwaters. Samples were collected several times from 35 water intakes from 5 spas and 2 mineral water bottling plants. The authors examined whether the increased gamma radiation background, as well as the elevated values of radium and uranium content in reservoir rocks, have a significant impact on the natural radioactivity of these waters. The second objective of this research was to provide information about geochemistry of U, Ra, Rn radionuclides and the radiological and chemical risks incurred by ingestion of isotopes with drinking water. On the basis of results obtained, it is feasible to assess the health hazard posed by ingestion of natural radioactivity with drinking waters. Moreover, the data yielded by this research may be helpful in the process of verification of the application of these waters in balneotherapy. In addition, annual effective radiation doses resulting from the isotopes consumption were calculated on the basis of the evaluated activity concentrations. In dose assessment for uranium and radium isotopes, the authors provided values for different human age groups. The obtained uranium content in the investigated waters was compared with the currently valid regulations concerning the quality of drinking water. Based on the activity concentrations data, the activity isotopic ratios 234 U/ 238 U, 226 Ra/ 238 U, 222 Rn/ 238 U, 222 Rn/ 226 Ra and the correlations between radionuclides content were then examined. In brief, it may be concluded on the basis of the obtained results that radon solubility is inversely proportional to radium and uranium dissolution in environmental water circulation. The presented study allows conclusions to be drawn on the radionuclide circulation among different environmental biota: from

  16. Quantification of 235 U and 226 Ra in soil samples by means of Gamma spectroscopy

    International Nuclear Information System (INIS)

    Quintero P, E.; Rojas M, V.P.; Montes M, F.R.; Gaso P, M.I.; Cervantes N, M.L.

    2000-01-01

    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 235 U and 226 Ra; also is presented the method for the 226 Ra correction activity. (Author)

  17. Radionuclide content and state of isotopic disequilibrium in some utilized smoking pastes

    Energy Technology Data Exchange (ETDEWEB)

    Shabana, El-Said Ibrahim; Yahya, Ahmad Abu Bakre [King Abdulaziz Univ., Jeddah (Saudi Arabia). Faculty of Engineering, Radiation Protection and Training Centre; Kinsara, Abdulraheem Abdulrahman [King Abdulaziz Univ., Jeddah (Saudi Arabia). Faculty of Engineering, Nuclear Engineering Dept.

    2014-10-01

    {sup 238}U, {sup 234}U, {sup 226}Ra, {sup 210}Pb and {sup 210}Po were measured in some jurak and mehassel samples collected from the local market. Jurak is a paste mixture composed of 30% tobacco, 50% molasses and 20% spices and minced fruits. Mehassel is a local trade-name of a paste mixture of unknown ratios of tobacco to spices and minced fruits. Both jurak and mehassel are used for smoking by Shisha (a pipe used for smoking and has a water filter). Just for comparison, these radionuclides were measured in some cigarette tobacco samples. In cigarette tobacco samples, the average activity concentrations were 0.32 ± 0.10, 0.51 ± 0.11, 3.6 ± 1.0, 16.1 ± 2.4 and 15.8 ± 2.2 Bq/kg for {sup 238}U, {sup 234}U, {sup 226}Ra, {sup 210}Pb and {sup 210}Po, respectively. These values for the same isotopes were 1.01 ± 0.25, 1.04 ± 0.27, 1.2 ± 0.4, 4.4 ± 1.0 and 4.2 ± 0.9 Bq/kg in jurak samples and 0.17 ± 0.07, 0.24 ± 0.08, 1.8 ± 0.7, 7.5 ± 1.7 and 7.0 ± 1.6 Bq/kg in mehassel samples, respectively. Generally, the mean values of the results indicated that, except for uranium in jurak, the activity concentration for all the analyzed radionuclides in the different samples followed the sequence: {sup 210}Po ∼ {sup 210}Pb > {sup 226}Ra >> {sup 234}U > {sup 238}U, whereas for each radionuclide, its activity concentration followed the sequence: cigarette tobacco > mehassel > jurak. Molasses contributed to the enhanced uranium content in jurak samples. The obtained results are discussed in detail.

  18. Transfer factor of the radionuclides in food crops from high-background radiation area of south west India

    International Nuclear Information System (INIS)

    Shanthi, G.; Thampi Thanka kumaran, J.; Allen Gnana raj, G.; Maniyan, C. G.

    2012-01-01

    It is necessary to obtain the transfer factor (TF) of long-lived radionuclides because soil type and vegetation can affect TF. We studied the food crops commonly consumed by the general public of Kanyakumari district of south India. The main focus was on rice, fruits, vegetables and tapioca because the consumption of these is high. The soil to rice TF for the radionuclides, 226 Ra, 232 Th, 238 U and 40 K are 8.8 x 10. -2 , 14.2 x 10. -2 , 5.8 x 10. -2 and 6.3 x 10. -2 , respectively. The TF of tapioca for 226 Ra, 232 Th, 238 U and 40 K are 6.2 x 10 -2 , 11 x 10 -2 , 1.9 x 10 -2 and 8.9 x 10 -2 , respectively. For fruits and vegetables, the TFs are low. In the majority of the crops the non-edible parts accumulate more radionuclides than the edible parts. (authors)

  19. Determination of specific activities of U-238, Ra-226, Ra-228 e Th-228 in samples of mineral fertilizers with phosphorus; Determinacao das atividades especificas de U-238, Ra-226, Ra-228 e Th-228 em amostras de fertilizantes minerais com fosforo

    Energy Technology Data Exchange (ETDEWEB)

    Garcez, R.W.D.; Lopes, J.M.; Silva, A.X. da, E-mail: rgarcez@nuclear.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharoa (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Domingues, A.M.; Lima, M.A.F. [Universidade Federal Fluminense (UFF),Niteroi, RJ (Brazil)

    2016-07-01

    Samples were analyzed by gamma spectrometry mineral fertilizers with the HPGe detector and aid LabSOCS software for calculating the detection efficiency curve. Specific activities found for Pa-234m, Ra-226, Ra-228 and Th-228 in samples of phosphate fertilizers were 505 Bq.kg{sup -1}, 458 Bq.kg{sup -1}, 450 Bq.kg{sup -1} and 394 Bq.kg{sup -1}, respectively. And for the NPK fertilizer samples were found average values of 390 Bq.kg{sup -1}, 252 Bq.kg{sup -1}, 280 Bq.kg{sup -1} and 268 Bq.kg{sup -1}, respectively. (author)

  20. Studies of transport pathways of Th, U, rare earths, Ra-228, and Ra-226 from soil to plants and farm animals: Final progress report, 1983-1988

    Energy Technology Data Exchange (ETDEWEB)

    Linsalata, P

    1988-07-01

    This report consists of three parts. Part 1 discusses a field study conducted in an area of enhanced, natural radioactivity to assess the soil to edible vegetable concentration ratios (CR = concentration in dry vegetable/concentration in dry soil) of Th-232, Th-230, Ra-226, Ra-228, and the light rare earth elements (REE's), La, Ce, and Nd. Twenty-eight soil, and approximately 42 vegetable samples consisting of relatively equal numbers of seven varieties, were obtained from 11 farms on the Pocos de Caldas Plateau in the state of Minas Gerais, Brazil. This region is the site of a major natural analogue study to assess the mobilization and retardation processes affecting thorium and the REE's at the Morro do Ferro ore body, and uranium series radionuclides at the Osamu Utsumi open pit uranium mine. Thorium (IV) serves as a chemical analogue for quadrivalent plutonium, the light REE's (III) as chemical analogues for trivalent americium and curium, and uranium (VI) as an analogue for transuranics with stable oxidation states above IV, e.g., Pu(VI). Part 2 includes our final measurement results for naturally occurring light rare earth elements (REE's include La, Ce, Nd, and SM), U-series and Th-series radionuclides in adult farm animal tissues, feeds and soils. Our findings on soil-to-tissue concentration ratios (CR's) and the comparative behavior of these elements in farm animals raised under natural conditions by local farmers are presented. Part 3 summarizes our findings to date on the distribution and mobilization of Th-232, light rare earth elements (LREE), U-238 and Ra-228 in the MF basin. Estimates of first order, present day, mobilization rate constants resulting from ground water solubilization and seepage/stream transport are calculated using revised inventory estimates for the occurrence of these elements in the ore body and annual flux estimates for the transport of these elements away from the ore body. 151 refs., 20 figs., 40 tabs.

  1. Natural radionuclides from U-238 and Th-232 series and inorganic chemical characterization of soil profiles and sediment cores of the TaiaÇUpeba Reservoir, SÃO Paulo, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Souza, J.M.; Damatto, S.R.; Surkov, A.M.; Silva, A.R.; Maduar, M.F.; Gonçalves, P.N., E-mail: jmarques@ipen.br, E-mail: damatto@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Leonardo, L. [Centro Universitário São Camilo (Campus Ipiranga), São Paulo, SP (Brazil)

    2017-07-01

    Taiaçupeba reservoir, located in the state of São Paulo, Brazil, belongs to Producer System of Alto Tietê (Sistema Produtor Alto Tietê) and it is responsible for water supply for about 3.1million of people. The water quality of a reservoir is very important, but this is reduced by the increase of environmental degradation of the soil around the reservoir and its different uses. The study of soil profiles and sediment cores is an important tool for understanding the geophysical and geochemical aspects of an aquatic ecosystem. The objective of this work was to present the natural radionuclides {sup 238}U, {sup 226}Ra, {sup 210}Pb, {sup 232}Th, {sup 228}Th,{sup 228}Ra and {sup 40}K activity concentrations and also the inorganic chemical characterization of four soil profiles and four sediment cores collected in the area of influence area of Taiaçupeba reservoir. The analytical techniques, gamma spectrometry and instrumental neutron activation analysis were used in the determination. In the soil profiles the highest activity concentrations were obtained for the radionuclides {sup 40}K and {sup 228}Th and the lowest for {sup 210}Pb; in the sediment cores the highest activity concentrations were obtained for the radionuclide {sup 210}Pb and the lowest for {sup 226}Ra and {sup 228}Ra. For the inorganic chemical characterization the highest values obtained were for Na, As and Sb; in a sediment core a very high concentration was obtained for the element Zn indicating a probable accumulation of this element inside the reservoir; enrichment factor was used to evaluate a possible anthropic contamination in the soil and sediment at the margins of Taiaçupeba reservoir. (author)

  2. 238U, 234U and 230Th in uranium miners' lungs

    International Nuclear Information System (INIS)

    Singh, M.P.; Wrenn, M.E.; Archer, V.E.; Saccomanno, G.

    1981-01-01

    Fourteen uranium miners' lungs from Colorado plateau were collected at autopsy and the concentrations of 238 U, 234 U and 230 Th were determined by radiochemical procedures utilizing solvent extraction - alpha spectrometric techniques. The uranium and thorium isotopes are in near equilibrium with average concentrations of 238 U, 234 U and 230 Th being 89.3, 95.2 and 91.1 pCi/kg respectively. The combined average radiation dose rate to lung from these three isotopes is about 24.2 mrad/year at death excluding the unmeasured contribution from the 226 Ra and daughters. The average concentration of 230 Th is about 65 times higher than the mean concentration of 230 Th in lungs of non-miners dying at comparable ages from the same region

  3. Effect of alteration processes on the distribution of radionuclides in uraniferous sedimentary rocks and their environmental impact, southwestern Sinai, Egypt

    International Nuclear Information System (INIS)

    El Aassy, I.E.; El Galy, M.M.; El Feky, M.G.; Ibrahim, E.M.; Nada, A.A.; Abd El Maksoud, T.M.; Talaat, S.M.

    2011-01-01

    The contents of natural radionuclides in various types of sedimentary rocks in Um Bogma Formation and base of El Hashash Formation were determined by gamma-ray spectrometry. Three types of lower Carboniferous sedimentary rocks were investigated; sandstone (El Hashash Formation), dolostone and argillaceous sediments (Um Bogma Formation). The alteration processes are dolomitization, dedolomitization, karstification and lateritization. The specific radioactivity of 238 U, 226 Ra, 232 Th and 40 K determined in different samples, indicate that 238 U and its decay products contribute primarily to the high natural radioactivity of rocks. The maximum concentration of 238 U reached up to 2129.36 ppm in argillaceous sediments. The average concentrations of determined radionuclides ( 238 U, 226 Ra, 232 Th and 40 K) are 8.34 ppm, 7.88 ppm, 4.68 ppm and 0.3%, respectively in sandstone. In dolostones the average concentrations are 418.69 ppm, 808.75 ppm, 3.14 ppm and 0.29%, respectively. For argillaceous sediments are 276.88 ppm, 419.49 ppm, 11.47 ppm and 0.93%, respectively. The 238 U/ 226 Ra ratio in sandstone ranges between 0.89 and 1.25, while in dolostones and argillaceous sediments are 0.27-2.63 and 0.27-1.83, respectively. These variations in the concentrations of radioelements and their ratios are due to the action of the alteration processes affected these different sedimentary rocks in different times. Environmentally, the Raeq in dolostones and argillaceous sediments exceeds the permitted limits, while in the sandstone samples; it is within the permissible levels. (author)

  4. Leaching of 60Co, 137Cs and 226Ra in lysimeter experiments

    International Nuclear Information System (INIS)

    Gerzabek, M.H.; Mueck, K.; Steger, F.; Algader, S.M.

    1996-10-01

    The present report describes the first results obtained from lysimeter experiments started in 1990. The lysimeter plant consists of twelve soil monoliths from four different sites (three replicates each). Since 1990 the following agricultural crops were grown: endive, corn, winter wheat, mustard, sugar beet and potato. Gravitational water ranged from 3.9 % to 18.3 % of precipitation plus irrigation water, calculated as half years average values excluding the first six months of operation. The two Cambisols on sediments exhibited a mean percentage of approx. 10 %. The Dystric Cambisol on silicate rock and the Gleysol showed average values of 20 %. In 1990 the top layers (20 cm) were contaminated with three radionuclides. The leaching of the contaminants 60 Co, 137 Cs and 226 Ra differed distinctly between the elements. The lowest leaching rates were observed for 137 Cs, followed by 60 Co. The 226 Ra-concentrations in the gravitational water were clearly highest of all. However, the comparison of the 226 Ra/ 22 2 8 Ra ratios in deep soil layers and in gravitational water showed that the 226 Ra measured in the leachate originates from the natural contents in the subsoil and not from the artificial 226 Ra contamination of the topsoil. The mobility of the artificial radionuclides decreased therefore in the following order: 60 Co > ( 226 Ra) > 137 Cs. (author)

  5. 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)

  6. Solubility of 238U radionuclide from various types of soil in synthetic gastrointestinal fluids using "US in vitro" digestion method

    Science.gov (United States)

    Rashid, Nur Shahidah Abdul; Sarmani, Sukiman; Majid, Amran Ab.; Mohamed, Faizal; Siong, Khoo Kok

    2015-04-01

    238U radionuclide is a naturally occuring radioactive material that can be found in soil. In this study, the solubility of 238U radionuclide obtained from various types of soil in synthetic gastrointestinal fluids was analysed by "US P in vitro" digestion method. The synthetic gastrointestinal fluids were added to the samples with well-ordered, mixed throughly and incubated according to the human physiology digestive system. The concentration of 238U radionuclide in the solutions extracted from the soil was measured using Induced Coupling Plasma Mass Spectrometer (ICP-MS). The concentration of 238U radionuclide from the soil samples in synthetic gastrointestinal fluids showed different values due to different homogenity of soil types and chemical reaction of 238U radionuclide. In general, the solubility of 238U radionuclide in gastric fluid was higher (0.050 - 0.209 ppm) than gastrointestinal fluids (0.024 - 0.050 ppm). It could be concluded that the US P in vitro digestion method is practicle for estimating the solubility of 238U radionuclide from soil materials and could be useful for monitoring and risk assessment purposes applying to environmental, health and contaminated soil samples.

  7. An assessment of natural radionuclides in water of Langat River estuary, Selangor

    Energy Technology Data Exchange (ETDEWEB)

    Hamzah, Zaini, E-mail: tengkuliana88@gmail.com; Rosli, Tengku Nurliana Tuan Mohd, E-mail: tengkuliana88@gmail.com; Saat, Ahmad, E-mail: tengkuliana88@gmail.com; Wood, Ab. Khalik, E-mail: tengkuliana88@gmail.com [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)

    2014-02-12

    An estuary is an area that has a free connection with the open sea and it is a dynamic semi-enclosed coastal bodies. Ex-mining, aquaculture and industrial areas in Selangor are the sources of pollutants discharged into the estuary water. Radionuclides are considered as pollutants to the estuary water. Gamma radiations emitted by natural radionuclides through their decaying process may give impact to human. The radiological effect of natural radionuclides which are {sup 226}Ra, {sup 228}Ra, {sup 40}K, {sup 238}U and {sup 232}Th, were explored by determining the respective activity concentrations in filtered water along the Langat estuary, Selangor. Meanwhile, in- situ water quality parameters such as temperature, dissolve oxygen (DO), salinity, total suspended solid (TSS), pH and turbidity were measured by using YSI portable multi probes meter. The activity concentration of {sup 226}Ra, {sup 228}Ra and {sup 40}K were determined by using gamma-ray spectrometry with high-purity germanium (HPGe) detector. The activity concentrations of {sup 226}Ra, {sup 228}Ra and {sup 40}K in samples are in the range of 0.17 - 0.67 Bq/L, 0.16 - 0.97 Bq/L and 1.22 - 5.57 Bq/L respectively. On the other hand, the concentrations of uranium-238 and thorium-232 were determined by using Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF). The thorium concentrations are between 0.17 ppm to 0.28 ppm and uranium concentrations were 0.25 ppm to 0.31 ppm. The results show activity concentrations of radionuclides are slightly high near the river estuary. The Radium Equivalent, Absorbed Dose Rate, External Hazard Index, and Annual Effective Dose of {sup 226}Ra, {sup 228}Ra and {sup 40}K are also studied.

  8. Availability of U-238 and Th-232 present in phosphogypsum used in agriculture: precision and accuracy of the methodology

    International Nuclear Information System (INIS)

    Malheiro, Luciano H.; Saueia, Catia H.R.; Mazzilli, Barbara P.

    2013-01-01

    Phosphogypsum (PG) can be classified as Technologically Enhanced Naturally Occurring Radioactive Material (TENORM), and it is obtained as a residue of the phosphate fertilizer industry. PG presents in its composition radionuclides of the natural U and Th series: mainly Ra-226, Ra-228, Th-232, Pb-210 and Po-210. The Brazilian producers stock the PG in dry stacks, posing risks to the surrounding environment. A possible solution to this problem is to reuse PG in agriculture; however, it is necessary to ensure that the radionuclides present in the PG will not be available to the agricultural products. This study is part of a research project sponsored by Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP - 2010-10587-0) entitled 'Availability of metals and radionuclides in tropical soils amended with phosphogypsum', and its objective is to evaluate the reliability of an optimal methodology to determine U-238 and Th-232 in samples of soils amended with PG through percolation with water. The methodology comprises a sequential radiochemical separation of the radionuclides present in the leachate. The UTEVA resin was used for the purification and separation of U-238 and Th-232, and the final activity concentrations were determined by alpha spectrometry. The precision and accuracy of the methodology were checked by measuring standard reference material. The results obtained for the relative error and relative standard deviation varied respectively from 2.34 % to 5.92 % and 6.10 % to 6.21 % for uranium, and from 0.42 % to 3.13 % and 9.68 % to 10.97 % for thorium. (author)

  9. Intercomparison of radionuclide measurements in marine sediment sample IAEA-368

    International Nuclear Information System (INIS)

    Ballestra, S.; Lopez, J.J.; Gastaud, J.; Parsi, P.; Vas, D.; Noshkin, V.

    1991-08-01

    The results of an intercomparison exercise on a Pacific Ocean sediment sample, IAEA-368, designed for the determination of artificial and natural radionuclides levels, are reported. The data from 89 laboratories representing 37 countries have been evaluated. The following are the recommended values, with confidence intervals, for 60 Co, 155 Eu, 210 7Pb, 226 Ra, 238 U, 238 Pu and 239+240 Pu (Reference date: 1 January 1990). Information values for 40 K, 90 Sr, 137 Cs, 228 Th, 230 Th, 232 Th, 234 U, 235 U and 241 Am are also reported. (author)

  10. Intercomparison of radionuclide measurements in marine sediment sample IAEA-135

    International Nuclear Information System (INIS)

    Ballestra, S.; Gastaud, J.; Lopez, J.J.; Parsi, P.; Vas, D.

    1993-08-01

    The results of an intercomparison exercise on a marine sediment from Irish Sea, IAEA-135, designed for the determination of artificial and natural radionuclides levels, are reported. The data from 151 laboratories representing 51 countries have been evaluated. The following are the recommended values, with confidence intervals, for 40 K, 60 Co, 134 Cs, 137 Cs, 154 Eu, 155 Eu, 226 Ra, 228 Ra, 232 Th, 238 Pu, 239+240 Pu (Reference date: 1 January 1992). Information values for 57 Co, 90 Sr, 106 Ru, 125 Sb, 210 Pb, 210 Po, 228 Th, 230 Th, 234 U, 235 U, 238 U and 241 Am are also reported. All values are expressed in Bq kg -1 dry weight. (author)

  11. Intercomparison of radionuclide measurements on marine sediment sample IAEA-300

    International Nuclear Information System (INIS)

    Ballestra, S.; Gastaud, J.; Lopez, J.J.; Parsi, P.; Vas, D.

    1994-09-01

    The results of an intercomparison exercise on a sediment from Baltic Sea, IAEA-300, designed for the determination of artificial and natural radionuclides' levels, are reported. The data from 159 laboratories representing 51 countries have been evaluated. The following are the recommended values, with confidence intervals, 40 K, 60 Co, 125 Sb, 134 Cs, 137 Cs, 155 Eu, 210 Pb, 210 Po, 228 Ra, 234 U, 238 U, 239+240 Pu and 241 Am. Information values for 54 Mn, 90 Sr, 226 Ra, 228 Th, 230 Th, 232 Th, 235 U and 238 Pu are also reported. All values are given on the reference date of 1 January 1993 and expressed in Bq kg -1 dry weight. (author)

  12. A Procedure for the Sequential Determination of Radionuclides in Phosphogypsum Liquid Scintillation Counting and Alpha Spectrometry for 210Po, 210Pb, 226Ra, Th and U Radioisotopes

    International Nuclear Information System (INIS)

    2014-01-01

    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 analytical data. For maximum utility, such procedures should be comprehensive, clearly formulated, and readily available to both the analyst and the customer for reference. In this publication, a combined procedure for the sequential determination of 210Po, 210Pb, 226Ra, Th and U radioisotopes in phosphogypsum is described. The method is based on the dissolution of small amounts of phosphogypsum by microwave digestion, followed by sequential separation of 210Po, 210Pb, Th and U radioisotopes by selective extraction chromatography using Sr, TEVA and UTEVA resins. Radium-226 is separated from interfering elements using Ba(Ra)SO4 co-precipitation. Lead-210 is determined by liquid scintillation counting. The alpha source of 210Po is prepared by autodeposition on a silver plate. The alpha sources of Th and U are prepared by electrodeposition on a stainless steel plate. A comprehensive methodology for the calculation of results, including the quantification of measurement uncertainty, was also developed. The procedure is introduced as a recommended procedure and validated in terms of trueness, repeatability and reproducibility in accordance with ISO guidelines

  13. Intercomparison of radionuclide measurements in marine sediment sample IAEA-367

    Energy Technology Data Exchange (ETDEWEB)

    Ballestra, S; Lopez, J J; Gastaud, J; Vas, D; Noshkin, V

    1991-08-01

    The results of an intercomparison exercise on a Pacific Ocean sediment sample, IAEA-367, designed for the determination of artificial and natural radionuclides levels, are reported. The data from 81 laboratories representing 37 countries have been evaluated. The following are the recommended values, with confidence intervals, for {sup 60}Co, {sup 90}Sr, {sup 137}Cs, {sup 239+240}Pu (Reference date: 1 January 1990). Information values for {sup 155}Eu, {sup 238}Pu, {sup 241}Am, and {sup 241}Pu are reported. Information values for the following natural radionuclides {sup 40}K, {sup 226}Ra, {sup 228}Th, {sup 230}Th, {sup 234}U, {sup 235}U and {sup 238}U are also reported. (author)

  14. 238U, 234U and 230Th in uranium miners' lungs

    International Nuclear Information System (INIS)

    Singh, N.P.; Wrenn, M.E.; Bennett, D.B.; Archer, V.; Saccomanno, G.

    1982-01-01

    Fourteen uranium miners' lungs from the Colorado Plateau were collected at autopsy and the concentrations of 238 U, 234 U and 230 Th were determined by radiochemical procedures utilizing solvent extraction and alpha spectrometric techniques. The uranium and thorium isotopes are in near equilibrium with average concentrations of 238 U, 234 U and 230 Th being 89.3, 95.2, and 91.1 pCi/kg respectively. The combined average radiation dose rate to lung from these three isotopes is about 24.1 mrad/year at death excluding the unmeasured contribution from the 226 Ra and daughters. The average concentration of 230 Th is about 65 times higher than the mean concentration of 230 Th in lungs of non-miners from the same region dying at comparable ages

  15. Vegetation-derived insights on the mobilization and potential transport of radionuclides from the Nopal I natural analog site, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Leslie, B.W.; Pickett, D.A.; Pearcy, E.C.

    1999-07-01

    The Nopal I uranium (U) deposit, Pena Blanca, Mexico is a source term and contaminant transport natural analog to the proposed high-level nuclear waste repository at Yucca Mountain, Nevada. In an attempt to characterize the mobilization and potential transport of radionuclides in the unsaturated zone at the Nopal I deposit, vegetation growing on ore piles was analyzed for {sup 238}U, {sup 235}U, and {sup 232}Th decay-series isotopes. Specimens of Phacelia robusta growing on high-grade piles of U ore were collected and analyzed by alpha autoradiography, and by alpha and gamma spectrometry. Activities for U, thorium (Th), and radium (Ra) isotopes (Bq/kg dried plant) were 300, 1,000, and 7,000 for {sup 238}U, {sup 230}Th, and {sup 226}Ra, respectively. The {sup 226}Ra activities in these specimens are among the highest ever measured for plants; furthermore, the plant-to-soil {sup 226}Ra concentration ratio is higher than expected. These results demonstrate the large mobility and bio-availability of Ra in the Nopal I environment, and support previous indications of recent loss of {sup 226}Ra from the ore body. Comparison between the activities of {sup 238}U and {sup 232}Th decay-chain Th isotopes in the plants and in the ore substrate indicate that relative mobilization into pore solutions of {sup 228}Th > {sup 230}Th > {sup 232}Th, in a ratio of about 50--25:4:1, respectively. The similarity of the plant's {sup 234}U/{sup 238}U activity ratio ({approximately}1.2) to that of a caliche deposit that formed adjacent to the Nopal ore body around 54 ka suggests the {sup 234}U/{sup 238}U activity ratio of U released from the ore is approximately 1.2. The U and {sup 226}Ra isotope activities of the plants and ore substrate, and solubility considerations, are used to assess a source term model of the potential Yucca Mountain repository. These results suggest the use of a natural analog source term model in performance assessments may be non-conservative.

  16. Solubility of 238U radionuclide from various types of soil in synthetic gastrointestinal fluids using “US in vitro” digestion method

    International Nuclear Information System (INIS)

    Rashid, Nur Shahidah Abdul; Sarmani, Sukiman; Majid, Amran Ab.; Mohamed, Faizal; Siong, Khoo Kok

    2015-01-01

    238U radionuclide is a naturally occuring radioactive material that can be found in soil. In this study, the solubility of 238U radionuclide obtained from various types of soil in synthetic gastrointestinal fluids was analysed by “US P in vitro” digestion method. The synthetic gastrointestinal fluids were added to the samples with well-ordered, mixed throughly and incubated according to the human physiology digestive system. The concentration of 238U radionuclide in the solutions extracted from the soil was measured using Induced Coupling Plasma Mass Spectrometer (ICP-MS). The concentration of 238U radionuclide from the soil samples in synthetic gastrointestinal fluids showed different values due to different homogenity of soil types and chemical reaction of 238U radionuclide. In general, the solubility of 238U radionuclide in gastric fluid was higher (0.050 – 0.209 ppm) than gastrointestinal fluids (0.024 – 0.050 ppm). It could be concluded that the US P in vitro digestion method is practicle for estimating the solubility of 238U radionuclide from soil materials and could be useful for monitoring and risk assessment purposes applying to environmental, health and contaminated soil samples

  17. Bioavailability pf radionuclides {sup 226}Ra, {sup 228}Ra and {sup 210}Pb present in Brazilian phosphogypsum and phosphate fertilizers

    Energy Technology Data Exchange (ETDEWEB)

    Russo, Ana Carolina; Saueia, Catia H.R.; Mazzilli, Barbara P., E-mail: chsaueia@ipen.br [Instituto de Pesquisas Energeticas e Nucleares(IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Phosphogypsum (PG) is a by-product of phosphate fertilizers industries. The USEPA classified PG as a - Technologically Enhanced Naturally Occurring Radioactive Material (TENORM). Its worldwide production on 2006 was estimated in 150 million tons. Annually the three main phosphate industries in Brazil are responsible for 5.5x106 tons of phosphogypsum, which is stored in stacks. The level of radionuclides present in phosphogypsum is well-known and makes its disposal or reutilization an environmental concern. Part of this byproduct can be reused, for example, to improve fertility of agricultural soils. To assess the long term environmental impact of radioactive contamination of ecosystems, information on source term including radionuclide speciation, mobility and biological uptakes have high importance. This paper intends to evaluate the bioavailability of the radionuclides {sup 226}Ra, {sup 228}Ra and {sup 210}Pb to the environment by following a procedure established by the EC (European Community), which includes a single EDTA-NH{sub 4} 0.05M extraction at pH 7.0 prior to the analyses. These results is compared with the total activity concentration of these radionuclides in Brazilian PG and the most used phosphate fertilizers (SSP, TSP, MAP and DAP). This procedure intends to represent on a more realistic way the leaching of radionuclides from PG and fertilizers to soil and agricultural products. (author)

  18. Leaching of RA-226 contaminated gravel using different aqueous treatments

    Energy Technology Data Exchange (ETDEWEB)

    Mamoon, A; Abulfaraj, W H; Sohsah, M A [King Abdulaziz University, Jeddah, Saudi Arbabia (Saudi Arabia)

    1997-12-31

    Investigation of the efficiencies of different aqueous leaching treatments was carried out on gravel artificially contaminated with Ra-226. The extent of leaching efficiency was determined in terms of Ra-226 and its daughter Rn-222. Liquid scintillation counting using high efficiency mineral oil based liquid scintillator was the technique adopted for measuring Ra-226 and Rn-222 leached off the contaminated gravel. Water, dilute solutions of barium chloride and HCl were used as leachants. Different masses of gravel were leached with 200 mL of leachant for various contact time periods. The leached Rn-222 activity measured was plotted vs the decay factor e; from which Rn-222 and Ra-226 originally present in the sample were determined. Several leaching parameters were tested; namely type of leachant, leachant volume/gravel mass ratio, leachant contact time, effect of varying Ba Cl{sub 2} concentration, and successive leaching. Optimization of the leaching parameters for desorption of Ra-226 off the contaminated gravel under laboratory conditions may help determine the ideal conditions for remediating soil contaminated with radium or chemically similar radionuclides. 7 figs.

  19. The detailed analysis of natural radionuclides dissolved in spa waters of the Kłodzko Valley, Sudety Mountains, Poland

    Energy Technology Data Exchange (ETDEWEB)

    Walencik-Łata, A., E-mail: agata.walencik@us.edu.pl [University of Silesia, Institute of Physics, Department of Nuclear Physics and Its Applications, Uniwersytecka 4 St., 40-007 Katowice (Poland); Kozłowska, B.; Dorda, J. [University of Silesia, Institute of Physics, Department of Nuclear Physics and Its Applications, Uniwersytecka 4 St., 40-007 Katowice (Poland); Przylibski, T.A. [Wrocław University of Technology, Faculty of Geoengineering, Mining and Geology, Division of Geology and Mineral Waters, Wybrzeże S. Wyspiańskiego 27, 50-370 Wrocław (Poland)

    2016-11-01

    A survey was conducted to measure natural radioactivity in spa waters from the Kłodzko Valley. The main goal of this study was to determine the activity concentration of uranium, radium and radon isotopes in the investigated groundwaters. Samples were collected several times from 35 water intakes from 5 spas and 2 mineral water bottling plants. The authors examined whether the increased gamma radiation background, as well as the elevated values of radium and uranium content in reservoir rocks, have a significant impact on the natural radioactivity of these waters. The second objective of this research was to provide information about geochemistry of U, Ra, Rn radionuclides and the radiological and chemical risks incurred by ingestion of isotopes with drinking water. On the basis of results obtained, it is feasible to assess the health hazard posed by ingestion of natural radioactivity with drinking waters. Moreover, the data yielded by this research may be helpful in the process of verification of the application of these waters in balneotherapy. In addition, annual effective radiation doses resulting from the isotopes consumption were calculated on the basis of the evaluated activity concentrations. In dose assessment for uranium and radium isotopes, the authors provided values for different human age groups. The obtained uranium content in the investigated waters was compared with the currently valid regulations concerning the quality of drinking water. Based on the activity concentrations data, the activity isotopic ratios {sup 234}U/{sup 238}U, {sup 226}Ra/{sup 238}U, {sup 222}Rn/{sup 238}U, {sup 222}Rn/{sup 226}Ra and the correlations between radionuclides content were then examined. In brief, it may be concluded on the basis of the obtained results that radon solubility is inversely proportional to radium and uranium dissolution in environmental water circulation. The presented study allows conclusions to be drawn on the radionuclide circulation among

  20. Study on natural radionuclide activities in meat samples consumed in Sao Paulo City, Brazil

    International Nuclear Information System (INIS)

    Rosa, Mychelle M.L.; Taddei, Maria HelenaT.

    2015-01-01

    Consumption of food is usually the most important route by which natural and artificial radionuclides can enter the human body. An assessment of radionuclide levels in different foods and diets is therefore important to estimate the intake of these radionuclides by man. The contamination by radionuclides can occur via the food chain (soil, root, plant and animal), with emphasis to the long half-life radionuclides, which can also have their transfer through the animal meat. The inclusion of meat in human nutrition is important because it is an excellent source of high quality protein, nutrient related to construction and cell regeneration. This work aims the determination of natural radionuclides ( 234 U, 235 U, 238 U, 228 Th, 230 Th, 232 Th, 226 Ra, 228 Ra, and 210 Pb) in meat samples. Five groups of samples were analyzed, such as cattle meat (beef), fish, pork, poultry, and processed meat, after radiochemical separation followed by alpha or alpha beta spectrophotometry, and total count quantification. The determination of these radionuclides is very important because they are products of the natural decay series of 238 U and 232 Th, being easily found in meat samples. (author)

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

    International Nuclear Information System (INIS)

    Canete, Socrates Jose P.; Palad, Lorna Jean H.; Enriquez, Eliza B.; Garcia, Teofilo Y.; Yulo-Nazarea, Teresa

    2007-01-01

    Phosphogypsum (PG), the major waste material in phosphate fertilizer processing, has been known to contain enhanced levels of naturally-occurring radionuclides especially 226 Ra. 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 226 Ra from phosphogypsum and through local soil was quantified. Level of 226 Ra in groundwater samples in Isabel, Leyte, Philippines was also quantified to address the primary concern. It was found that the 226 Ra activity in Philippine phosphogypsum is distributed in a wide range from 91.5 to 935 Bq/kg. As much as 5% of 226 Ra 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 226 Ra into the water table. Compared to reported values of natural groundwater levels of 226 Ra, the concentration of this radionuclide in Isabel, Leyte groundwater suggest that there is no 226 Ra intrusion brought about by the presence of phosphogypsum ponds in the area. (Authors)

  2. Natural radionuclides in Austrian bottled mineral waters

    International Nuclear Information System (INIS)

    Gabriele Wallner; Tania Jabbar

    2010-01-01

    All commercially available mineral waters of Austrian origin were investigated with regard to the natural radionuclides 228 Ra, 226 Ra, 210 Pb, 210 Po, 238 U and 234 U. From 1 to 1.5 L of sample the nuclides were extracted and measured sequentially: the radium isotopes as well as 210 Pb were measured by liquid scintillation counting after separation on a membrane loaded with element-selective particles (Empore Radium Disks), 210 Po was determined by α-particle spectroscopy after spontaneous deposition onto a copper planchette and uranium was determined also by α-particle spectroscopy after anion separation and microprecipitation with NdF 3 . The calculated committed effective doses for adults, teens and babies were compared to the total indicative dose of 0.1 mSv/year given in the EC Drinking Water Directive. The dominant portion of the committed effective dose was due to 228 Ra. Highly mineralised waters showed also higher 226 Ra and 228 Ra levels. (author)

  3. Report on the intercomparison run IAEA-312 Ra-226, Th and U in soil

    International Nuclear Information System (INIS)

    Strachnov, V.; Valkovic, V.; Zeisler, R.; Dekner, R.

    1991-01-01

    This report contains the results of the intercomparison IAEA-312 on the determination of uranium, thorium and Ra-226 in an Indonesian soil sample. The participants included 39 laboratories located in 17 countries, and statistical evaluation of their data yield recommended values for these elements. The elements, their recommended values and confidence intervals are: Ra-226, 269 Bq/kg (250-287); Th, 91.4 microg/g (81.3-101.5); U, 16.5 microg/g (15.7-17.4). Tabs

  4. Measurement of 226Ra, 232Th and 40K radioactivity contents in by-product phosphogypsum from phosphate fertilizer industry using gamma ray spectrometric method

    International Nuclear Information System (INIS)

    Demirel, H.; Parmaksiz, A.; Vural, M.; Cakir, I.T.; Demircioglu, B.; Yucel, H.

    2004-01-01

    Full text: Phosphatic fertilizers are produced from the industrial processing of rock phosphate ores which are known to contain naturally occurring radionuclides such as 238 U and its daughter products. A high volume by-product known as phosphogypsum (PG) from the production of phosphoric acid and phosphate fertilizer causes serious storage and environmental problems in phosphoric acid industries. During the phosphoric acid production process, 226 Ra (t 1/2 =1600 y) ends up in PG which has chemical analogous to calcium element. Since the stockpiles of PG near the phosphatic fertilizer plants are huge amounts, the radioactivity contained in PG has measured in view of environmental radioactivity problem. In this work, the natural radioactivity in eighty PG samples taken from a stock near Samsun phosphoric fertilizer plant was measured by a high resolution gamma ray spectrometer. The mean activity of 226 Ra in PG samples has been found to be 546 Bq.kg -1 . However, the activities of 232 Th and 40 K measured in PG samples are negligibly small. In the presented paper, the gamma spectrometric method employed for this work is discussed and the radiological risk impact of radon gas emanation from 226 Ra mainly contained in PG, has been assessed

  5. Natural radionuclides in Italian diet and their annual intake

    International Nuclear Information System (INIS)

    Donatella Desideri; Maria Assunta Meli; Carla Roselli; Laura Feduzi; Nevio Forini; Alba Rongoni

    2014-01-01

    This study was dedicated to the evaluation of the background activity concentration of natural radionuclides as 228 Ra and 228 Th of 232 Th family, 226 Ra of 238 U family and 40 K in the Italian daily diet. These radionuclides were determined by gamma spectrometry. 40 K activity concentration, in the samples taken into account in the present paper, ranged between 70.5 (milk) and 181.1 Bq kg ww -1 (pasta), 226 Ra activity concentration ranged between 1.1 (milk) and 5.7 Bq kg ww -1 (pasta), 228 Ra and 228 Th activity concentration, in the same samples, ranged between 0.7 (milk) and 3.7 Bq kg ww -1 (pasta) and between 1.4 (milk) and 6.1 Bq kg ww -1 (flours) respectively. The annual intake of every radionuclide from foodstuffs ingestion was also calculated. The 94-95 % of the total intake comes from 40 K. For adults and children, the highest activity intake of all radioisotopes was from grain products, for infants it was from milk products. (author)

  6. The measurement of activities of 226Ra, 232Th, 40K in phosphogypsum by gamma ray spectrometry

    International Nuclear Information System (INIS)

    Parmaksiz, A.

    2004-06-01

    Phosphatic fertilizers are produced from the industrial processing of rock phosphate ores which are known to contain naturally occuring radionuclides such as 238 U and its daughter products. A high volume by-product known as phosphogypsum (PG) from the production of phosphoric acid and phosphate fertilizer causes serious storage and environmental problems in phosphoric acid industries. During the phosphoric acid production process, 226 Ra (t 1/2 =1600 y) ends up in PG which has chemical analogous to calcium periodical table. Since the stockpiles of PG near the phosphatic fertilizer plants are huge amounts, the radioactivity contained in PG has to measured in view of environmental radioactivity problem. In this work, the natural radioactivity in eighty PG samples, issued from a stock of about 60.000 tones was measured by a high resolution gamma ray spectrometer with a HPGe detector. The averaged activity of 226 Ra in PG has been found to be 546 Bq.kg -1 . However, the activities of 232 Th and 40 K measured in PG samples are negligibly small. The extra gamma radiation dose rate arising from 1 - 1.5 kg of PG is estimated to be about 241 nGy/h from 1 m ground level applied in 1 m 2 surface area of field

  7. Solubility of {sup 238}U radionuclide from various types of soil in synthetic gastrointestinal fluids using “US in vitro” digestion method

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Nur Shahidah Abdul; Sarmani, Sukiman; Majid, Amran Ab.; Mohamed, Faizal; Siong, Khoo Kok, E-mail: khoo@ukm.edu.my [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor (Malaysia)

    2015-04-29

    238U radionuclide is a naturally occuring radioactive material that can be found in soil. In this study, the solubility of 238U radionuclide obtained from various types of soil in synthetic gastrointestinal fluids was analysed by “US P in vitro” digestion method. The synthetic gastrointestinal fluids were added to the samples with well-ordered, mixed throughly and incubated according to the human physiology digestive system. The concentration of 238U radionuclide in the solutions extracted from the soil was measured using Induced Coupling Plasma Mass Spectrometer (ICP-MS). The concentration of 238U radionuclide from the soil samples in synthetic gastrointestinal fluids showed different values due to different homogenity of soil types and chemical reaction of 238U radionuclide. In general, the solubility of 238U radionuclide in gastric fluid was higher (0.050 – 0.209 ppm) than gastrointestinal fluids (0.024 – 0.050 ppm). It could be concluded that the US P in vitro digestion method is practicle for estimating the solubility of 238U radionuclide from soil materials and could be useful for monitoring and risk assessment purposes applying to environmental, health and contaminated soil samples.

  8. 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)

    Taddei, M.H.T.; Taddei, J.F.A.C.

    2005-01-01

    Due to biological risk and long half lives, the radionuclides 228 Ra, 226 Ra, 210 Pb and 210 Po 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 210 Pb and 226 Ra 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, 226 Ra, 228 Ra, 210 Pb, 210 Po, in water and effluent samples

  9. 226Ra, 228Ra and 40K in scales formed in boilers of industrial installations

    International Nuclear Information System (INIS)

    Poggi, Claudia M. Braga; Farias, Emerson Emiliano G. de; Hazin, Clovis A.; Gazineu, Maria Helena P.; Universidade Catolica de Pernambuco

    2011-01-01

    Many industrial processes involve the production of steam in boilers, which is sent through pipes to machines and other equipment used in different sectors of the installations. The water commonly used in these processes is groundwater, which generally has high concentrations of calcium and magnesium salts, that can co-precipitate with naturally occurring radioactive elements such as 226 Ra and 228 Ra creating radioactive scales, which are deposited in pipes, thus decreasing the efficiency of steam production. In addition, 40 K that is present in all soils and rocks with a concentration of about 0.012% of natural potassium can also be concentrated in these scales. No data was found in literature relating to radionuclides present in the scales formed on boilers in general. In this context, the purpose of this work was to determine concentrations of 226 Ra, 228 Ra and 40 K, in scales generated inside boilers from different industries in the cities of Caruaru, Paulista and Goiana, Pernambuco. Determination of the radionuclides concentration was performed by gamma spectrometry with an HPGe detector, calculating their specific activities. Activity concentrations of 226 Ra were in the range of -1 and 228 Ra activity concentrations varied from 1 . Activity concentrations of 40 K were in the range of -1 . All these activity concentrations were lower than the limits established by the Brazilian Nuclear Energy Commission of for this type of matrix. (author)

  10. 226 Ra in food

    International Nuclear Information System (INIS)

    Toader, M.

    1993-01-01

    Between 1986 and 1992 the author has evaluated natural levels of 226 Ra in some foods representing the major components of the diet in Bucharest population. The estimated daily intake by an adult was 72.5 mBq 226 Ra/day or 65.9 mBq 226 Ra/g.Ca. (Author)

  11. Uranium Series Radionuclides in the Water Column of the Northeast Atlantic Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, F. P. [Nuclear and Technological Institute, Department of Radiological Protection and Nuclear Safety, Sacavem (Portugal)

    2013-07-15

    Naturally occurring radionuclides, namely {sup 238}U, {sup 234}U, {sup 230}Th, {sup 226}Ra, {sup 210}Pb, {sup 210}Po and {sup 232}Th, were analysed in water samples from ocean vertical profiles in three major abyssal basins of the NE Atlantic (Porcupine, Iberia and Tejo Basins), from the surface to the deep sea water layer. Concentrations were determined in the dissolved and particulate phases. The profiles of uranium isotopes in the water column, mostly in dissolved phase, showed nearly homogenized concentrations with {sup 238}U averaging 37{+-}4 mBq/Land {sup 234}U/{sup 238}U activity ratios averaging 1.13{+-}0.04, while {sup 226}Ra concentrations were 2-3 times higher in the bottom than at the ocean surface. {sup 230}Th activity concentrations were four orders of magnitude lower than {sup 234}U, confirming rapid Th scavenging from solution by the particulate matter. {sup 210}Pb and {sup 210}Po activity concentrations in the soluble phase were much lower than dissolved {sup 226}Ra. Modelling the distribution of these radionuclides in the water column leads to an average residence time of dissolved {sup 210}Pb and {sup 210}Po in the upper layer of 5 a and 1 a, respectively, and 0.6 a in the particulate phase for both radionuclides. In the deep water layer, soluble {sup 210}Pb and {sup 210}Po mean residence times were 42{+-}20 a and 2 a, respectively. The calculated {sup 210}Pb deposition flux at the abyssal sea floor is comparable with the flux derived from the {sup 210}Pb-excess inventory measured in sediments, and about 100 Bq.m-2.a{sup -1}. The {sup 210}Pb atmospheric deposition flux at the ocean surface in this region was estimated at about 74 Bq.m{sup -2}a{sup -1} and the {sup 210}Pb sink in the Northeast Atlantic is discussed. (author)

  12. Natural radioactivity (226Ra, 232Th and 40K) and assessment of radiological hazards in the Kestanbol granitoid, Turkey.

    Science.gov (United States)

    Canbaz, Buket; Cam, N Füsun; Yaprak, Günseli; Candan, Osman

    2010-09-01

    The surveys of natural gamma-emitting radionuclides in rocks and soils from the Ezine plutonic area were conducted during 2007. Direct dose measurement using a survey meter was carried out simultaneously. The present study, which is part of the survey, analysed the activity concentrations of (238)U, (232)Th and (40)K in granitoid samples from all over the region by HPGe gamma spectrometry. The activity concentrations of (226)Ra ranged from 94 to 637 Bq kg(-1), those of (232)Th ranged from 120 to 601 Bq kg(-1)and those of (40)K ranged from 1074 to 1527 Bq kg(-1) in the analysed rock samples from different parts of the pluton. To evaluate the radiological hazard of the natural radioactivity in the samples, the absorbed dose rate (D), the annual effective dose rate, the radium equivalent activity (Ra(eq)) and the external (H(ex)) hazard index were calculated according to the UNSCEAR 2000 report. The thorium-to-uranium concentration ratios were also estimated.

  13. /sup 226/Ra in phosphate nodules from the Peru/Chile seafloor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K H; Burnett, W C [Florida State Univ., Tallahassee (USA). Dept. of Oceanography

    1985-04-01

    /sup 226/Ra and other uranium-series radionuclides have been measured in a suite of marine phosphorite samples from the upwelling area off Peru/Chile by gamma-ray spectrometry and radiochemical techniques. Our results lead to the following conclusions: (1) phosphorite nodules typically show unidirectional growth at rates of 1 to 10 mm/Kyr; (2) very young samples (less than a few thousand years) contain slight excess amounts of /sup 226/Ra probably derived from pore fluids; and (3) slow but persistent leakage of /sup 226/Ra out of phosphate nodules occurs resulting in systematically lower /sup 226/Ra ages compared to /sup 230/Th ages for samples older than about twenty thousand years. Radium fluxes from these phosphate nodules appear to be 1 to 3 orders of magnitude less than those calculated for deep-sea sediments and ferromanganese nodules.

  14. Interactions between surface runoff, hydro sediments and radionuclides (210Pb, 226Ra, 228Ra, Th e U) at Alto Ribeirão das Antas, Poços de Caldas, MG, Brazil

    International Nuclear Information System (INIS)

    Moreira, Flavio Henrique de Souza

    2017-01-01

    Knowledge about hydrological and sedimentological dynamics of a river basin is fundamental to the adequate management of water resources, and it can support the identification of contaminants in the water, the estimation of water erosion, the estimation of reservoir siltation, and even the reduction of water treatment costs. The study carried out in Alto Ribeirão das Antas River Basin assessed, throughout seasons, all interactions between the surface runoff and the transport of suspended and underwater hydro-sediments, through direct monitoring of two sites at the Ribeirão das Antas channel. Concurrently, the potential of the indirect monitoring of suspended solids concentration was evaluated using an optical turbidity sensor. The hydrological results point to a high precipitation in the region, however with a well balanced distribution among the humid months, allowing the basin’s high capacity to transform precipitation into surface runoff. Sediment transport rates characterize the studied area as a low sediment production region. The sedimentological regime was found to be in accordance with the surface runoff regime, reflected by the seasonality of the transported masses. The estimation of transport of sediment in suspension through optical turbidity sensor presented promising results. Most of the results of radionuclides 210 Pb, 226 Ra, 228 Ra, Th and U observed in water and in suspended hydro-sediment were below the detection limit of the methodology, whereas in the riverbed hydro-sediments quantification of radionuclides was possible. The radiometric results indicate absence of radionuclide carriage from the Águas Claras Dam at INB Caldas to Ribeirão das Antas. The low concentration values of radioactive elements observed in the study may be of natural origin, once the Poços de Caldas Plateau region presents a geological constitution endowed with anomalies associated to radionuclides. (author)

  15. Simple method for the determination of 210Pb and 226Ra in waters

    International Nuclear Information System (INIS)

    Canoba, Analia C.; Gnoni, Gabriela A.

    2006-01-01

    In this work a method for the separation is described and the determination of the radionuclides 226 Ra and 210 Pb in samples of environmental waters. The determination of 210 Pb consists in how the precipitation of PbSO 4 (lead sulfate) and the measurement by liquid scintillation. The determination of 226 Ra is made for co-precipitation with BaSO 4 (barium sulfate), emanation of 222 Rn in toluene and its measurement by liquid scintillation. Both processes are fast, simple and they utilize accessible reagents and of low cost. In the case of the determination of 210 Pb, the parameters related to the separation and measurement was optimized. In the case of the decision of 226 Ra, was considered the technique already utilized by the laboratory for the measurements of this radionuclide. (author) [es

  16. U isotopes distribution in the Lower Rhone River and its implication on radionuclides disequilibrium within the decay series.

    Science.gov (United States)

    Zebracki, Mathilde; Cagnat, Xavier; Gairoard, Stéphanie; Cariou, Nicolas; Eyrolle-Boyer, Frédérique; Boulet, Béatrice; Antonelli, Christelle

    2017-11-01

    The large rivers are main pathways for the delivery of suspended sediments into coastal environments, affecting the biogeochemical fluxes and the ecosystem functioning. The radionuclides from 238 U and 232 Th-series can be used to understand the dynamic processes affecting both catchment soil erosion and sediment delivery to oceans. Based on annual water discharge the Rhone River represents the largest river of the Mediterranean Sea. The Rhone valley also represents the largest concentration in nuclear power plants in Europe. A radioactive disequilibrium between particulate 226 Ra (p) and 238 U (p) was observed in the suspended sediment discharged by the Lower Rhone River (Eyrolle et al. 2012), and a fraction of particulate 234 Th was shown to derive from dissolved 238 U (d) (Zebracki et al. 2013). This extensive study has investigated the dissolved U isotopes distribution in the Lower Rhone River and its implication on particulate radionuclides disequilibrium within the decay series. The suspended sediment and filtered river waters were collected at low and high water discharges. During the 4-months of the study, two flood events generated by the Rhone southern tributaries were monitored. In river waters, the total U (d) concentration and U isotopes distribution were obtained through Q-ICP-MS measurements. The Lower Rhone River has displayed non-conservative U-behavior, and the variations in U (d) concentration between southern tributaries were related to the differences in bedrock lithology. The artificially occurring 236 U was detected in the Rhone River at low water discharges, and was attributed to the liquid releases from nuclear industries located along the river. The ( 235 U/ 238 U) (d) activity ratio (=AR) in river waters was representative of the 235 U natural abundance on Earth. The ( 226 Ra/ 238 U) (p) AR in suspended sediment has indicated a radioactive disequilibrium (average 1.3 ± 0.1). The excess of 234 Th in suspended sediment =( 234 Th xs

  17. Leaching of U, 230Th and 226Ra from Saskatchewan uranium ore after removing clay

    International Nuclear Information System (INIS)

    Muthuswami, S.V.; Mohd Yunus, M.Z.; Mohamad Nor, M.I.; Kassim, Z.A.; Nirdosh, I.

    1993-01-01

    Distribution of U, 230 Th and 226 Ra in various size fractions in a typical Saskatchewan uranium ore and its resultant mill tailings indicated that less than 4% of these radionuclides were present in the fine ≤ 45 μm) size fraction in the ore whereas their concentration in the similar size fraction in the tailings was > 80%. Removal of clay minerals from the ore by flotation was unsuccessful whereas sedimentation gave nearly complete removal. Leaching of 230 Th from the ore before and after removing clay minerals indicated that dissolution of 230 Th was mproved at higher E h and acidity of the leaching medium and that it was independent of the presence of clay minerals in the ore. (orig.) [de

  18. Determination of specific activities of U-238, Ra-226, Ra-228 e Th-228 in samples of mineral fertilizers with phosphorus

    International Nuclear Information System (INIS)

    Garcez, R.W.D.; Lopes, J.M.; Silva, A.X. da

    2016-01-01

    Samples were analyzed by gamma spectrometry mineral fertilizers with the HPGe detector and aid LabSOCS software for calculating the detection efficiency curve. Specific activities found for Pa-234m, Ra-226, Ra-228 and Th-228 in samples of phosphate fertilizers were 505 Bq.kg"-"1, 458 Bq.kg"-"1, 450 Bq.kg"-"1 and 394 Bq.kg"-"1, respectively. And for the NPK fertilizer samples were found average values of 390 Bq.kg"-"1, 252 Bq.kg"-"1, 280 Bq.kg"-"1 and 268 Bq.kg"-"1, respectively. (author)

  19. Determination of Ra-226 by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Martinez Lobo, A.

    1988-01-01

    This work deals with the method of determination of 226 Ra by low energy photon spectrometry. For this purpose, the interference due to 235 U, that emits a photon with a close energy, has to be considered. The contribution of 235 U to the 186 KeV photopeak is studied through the 63 KeV 234 Th and the 144 KeV 235 U emissions. From the minimum detectable activity of 226 Ra it is discussed the applicability of this method to several kind of samples. (Author)

  20. Study on transfer coefficients of 90Sr, 137Cs, natural U, 226Ra and 239Pu in terrestrial food chains

    International Nuclear Information System (INIS)

    Qin Suyun; Qi Yong; Li Shuqin; Zhou Caiyun; Zhang Jingjuan; Li Jikai; Li Xuequn

    1995-01-01

    The aim of study was to provide values of transfer parameter of 90 Sr, 137 Cs, Natural U, 226 Ra and 239 Pu in terrestrial food chains, more applicable for Chinese socio-natural conditions. Data of radionuclides contents in agricultural crops and in associated soils, in sheep tissues and in associated grasses were collected in couples. The transfer coefficients in terrestrial food chains (soil-crops, grasses-sheep tissues) were calculated. On basis of statistical analysis, the representative values and 95% ranges of transfer coefficient for 5 radionuclides in 7 kind of agricultural products for southern moist areas and north dry areas were given. Regression analysis showed that relation between the transfer coefficients and the radionuclide contents in their associated soils present a negative correlation, it could be described with a equation: Y = aX -b

  1. Uranium and radium-226 in the environment of the post-uranium mining areas in Poland

    Energy Technology Data Exchange (ETDEWEB)

    Kardas, M.; Suplinska, M.; Ciupek, K. [Central Laboratory for Radiological Protection (Poland)

    2014-07-01

    The work carried out under the project NCBiR - 'Technologies Supporting Development of Safe Nuclear Power Engineering'; Task 3: Meeting the Polish nuclear power engineering's demand for fuel - fundamental aspects. Depending on location, environmental components may have different concentration levels of radionuclides. Main source of uranium and radium in the natural environment is atmospheric precipitation of the material resulting weathering and erosion of older rocks, enhanced due to human activity by fertilizers used in agriculture and fossil fuel combustion. The waste heaps and dumps, especially derived from post-uranium mining and phosphate fertilizer industry are the another source of uranium and radium in the environment. Our studies include post-uranium mining areas (inactive mines and waste dumps) and those adjacent meadows and grassland at the area of the Giant Mountains (Karkonosze Mountains) in the south-west Poland. Samples of soil and mineral material from mine shafts, water samples from ponds, streams and small rivers and vegetation samples (grass, alfalfa, birch leaves) were analyzed. Also, similar samples from agricultural regions of Poland were examined as a reference level. Uranium isotopes were determined by radiochemical method (ion exchange and extraction) and activity measurement using alpha spectrometry. Concentration of {sup 226}Ra was determined radiochemically using emanation method. For the validation of the method, determinations of uranium isotopes and radium-226 in reference samples were performed. Depending on location, the different levels of activity concentration of analyzed radionuclides were detected. Samples from the mine shafts and dumps, both water and soil, were characterized by the activity concentrations of {sup 238}U and {sup 226}Ra even by several orders higher than outside of those areas. The concentrations of the radionuclides in the areas located in further distances from mine and dumps are similar to

  2. Intercomparison of radionuclides measurements in marine cockle flesh sample IAEA-134

    International Nuclear Information System (INIS)

    Ballestra, S.; Gastaud, J.; Lopez, J.J.; Parsi, P.; Vas, D.

    1993-08-01

    The results of an intercomparison exercise on a cockle flesh sample from Irish Sea, IAEA-134, designed for the determination of artificial and natural radionuclide levels, are reported. The data from 134 laboratories representing 49 countries have been evaluated. The following are the recommended values, with confidence intervals, for 40 K, 60 Co, 137 Cs, and 2 39+240 Pu (Reference date: 1 January 1992). Information values for 90 Sr, 106 Ru, 125 Sb, 134 Cs, 154 Eu, 155 Eu, 210 Pb, 210 Po, 226 Ra, 228 Ra, 228 Th, 230 Th, 232 Th, 234 U, 235 U, 238 U, 238 Pu and 241 Am are also reported. All the following values are expressed in Bq kg -1 (dry weight). (author)

  3. On alpha activity relationships in 226Ra and U/sub nat/

    International Nuclear Information System (INIS)

    Krejbichova, Z.

    1982-01-01

    A gross alpha activity of 0.1 Bq/l is permitted for drinking and surface waters. If gross activity is higher, it is suitable to determine the 226 Ra content which must not exceed 0.1 Bq/l. The permissible content of natural uranium is 0.05 mg/l. In most samples of ground and surface waters gross alpha activity was below the permissible limit. In some samples with a high content of salts a higher Ra+U activity was found which exceeded gross activity. This was caused by the interference of nonradioactive admixtures. In other samples a higher gross alpha activity was found than was the sum Ra+U which may have been caused by alpha sources from radon decay. It was found that the gross alpha activity of waters is rather caused by uranium than by radium. (E.S.)

  4. Simultaneous determination of RA-226, natural uranium and natural thorioum by gamma-ray spectrometry INa(Tl) in solid samples

    International Nuclear Information System (INIS)

    Salvador, S.; Navarro, T.; Alvarez, A.

    1990-01-01

    A method has been described to determine activities of Ra-226, natural uranium, and natural thorium, by gamma-ray spectrometry. The system was calibrated for efficiency by using synthetic calibrated standards. It is necessary, in the samples, to assume secular equilibrium between Ra-226 and Th-232 and its daughters nuclides, and U-238 and its immediate daughter Th-234, because the photopeaks measured are from these dsaugthers. Our results indicate that a non destructive gamma spectrometric method can ofter replace the radiochemical techniques used in measuring radiactivities in this type of samples. (Author). 9 refs

  5. Distribution of Ra-226 in the Ross Sea, Antarctica

    International Nuclear Information System (INIS)

    Bettoli, M.G.; Cantelli, L.; Queirazza, G.; Roveri, M.; Tositti, L.; Tubertini, O.; Valcher, S.

    1996-01-01

    An improved procedure for the determination of Rn-222 and Ra-226 in seawater developed for easier on-board operations is presented. Data on the radioactive disequilibrium between the mentioned radionuclides as directly determined in the field can be greatly helpful in the study of the gas-exchange processes at the air-sea interface, especially as far as the Antarctic Ocean is concerned. The method employed has been preliminary tested in laboratory on a set of seawater samples collected in the Ross Sea and Ra-226 data collected are discussed and compared to literature data. (UK)

  6. Report on the intercomparison run IAEA-313 Ra-226, Th and U in stream sediment

    International Nuclear Information System (INIS)

    Strachnov, V.; Valkovic, V.; Zeisler, R.; Dekner, R.

    1991-01-01

    This report contains the results of the intercomparison IAEA-313 on the determination of uranium, thorium and Ra-226 in two stream sediments from Indonesia. The participants included 36 laboratories located in 18 countries, and statistical evaluation of their data yield recommended values for these elements. The elements, their recommended values and confidence intervals are: Ra-226, 343 Bq/kg (307-379); Th, 77.1 microg/g (74.8-79.4); U, 18.2 microg/g (17.0-19.3). Tabs

  7. Naturally Occurring Radionuclides and Rare Earth Elements Pattern in Weathered Japanese Soil Samples

    International Nuclear Information System (INIS)

    Sahoo, S.K.; Hosoda, M.; Takahashi, H.; Sorimachi, A.; Ishikawa, T.; Tokonami, S.; Uchida, S.

    2011-01-01

    From the viewpoint of radiation protection, determination of natural radionuclides e.g. thorium and uranium in soil samples are important. Accurate methods for determination of Th and U is gaining importance. The geochemical behavior of Th, U and rare earth elements (REEs) are relatively close to one another while compared to other elements in geological environment. Radioactive elements like 232 Th and 238 U along with their decay products (e.g. 226 Ra) are present in most of the environmental matrices and can be transferred to living bodies by different pathways that can lead to sources of exposure of man. Therefore, it is necessary to monitor these natural radionuclides in weathered soil samples to assess the possible hazards. The activity concentrations of 226 Ra, 228 Th, and 40 K in soils have been measured using a g γ-ray spectroscopy system with high purity germanium detector. The thorium, uranium and REEs were determined from the same sample using inductively coupled plasma mass spectrometry (ICP-MS). Granitic rocks contain higher amounts of Th, U and light REEs compared to other igneous rocks such as basalt and andesites. Therefore, it is necessary to understand the interaction between REEs and nature of soils, as soils are complex heterogeneous mixture of organic and inorganic solids, water and gases. In this paper, we have discussed about distribution pattern of 226 Ra, 232 Th and 238 U along with REEs in soil samples of weathered acid rock (granite and ryolite) collected from two prefectures in Japan: 1. Gifu and 2. Okinawa. (author)

  8. Method Validation for the Gamma-ray Spectrometric Determination of Natural Radioactive Nuclides in NORM Samples - Method Validation for the Gamma-ray Spectrometric Determination of Natural Radionuclides in raw materials and by-products

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Young-Yong; Lim, Jong-Myoung; Jang, Mee; Kim, Chang-Jong; Chung, Kun Ho; Kang, Mun Ja; Choi, Geun-Sik [Environmental Radioactivity Assessment Team, Korea Atomic Energy Research Institute, 111, Daedeok-daero 989, Yuseong, Daejeon, 305-353 (Korea, Republic of)

    2014-07-01

    It has established the 'Act on safety control of radioactive rays around living environment' in Korea, since 2011, to protect the public from natural occurring radioactive materials (NORM) and their by-products. The increasing concerns regarding the radioactivity of those materials therefore dictate many demands for the radioactive analysis for them. There are several methods to determine the concentration of natural radionuclides, such as {sup 235}U, {sup 238}U, {sup 226}Ra, {sup 232}Th, and so on, through a radiochemical analysis using an alpha spectrometer, mass spectrometer and liquid scintillation counter. However, gamma-ray spectroscopy still has an effect on the assessment of radioactive concentration for these nuclides and their progenies. To adapt a gamma spectrometer to the determination of natural radionuclides, the feasibility of their analysis methods should be first verified and validated with respect to accuracy and time and cost constraints. In general, one of the well-known processes in analyzing uranium with a gamma spectrometer is an indirect measurement using the secular equilibrium state with their progenies in a sample. This method, however, demands the time elapsed about 3 weeks to reach the equilibrium state between {sup 226}Ra and {sup 222}Rn and the sufficient integrity of a sample bottle to prevent the leakage of radon isotopes which is a form of noble gas. The simple and quick method is to directly measure a full energy absorption peak of 186.2 keV from {sup 226}Ra without the secular equilibrium state between {sup 226}Ra and {sup 222}Rn in the common sample bottle. However, this direct measurement also has difficulties about the interference with a full energy absorption peak of 185.7 keV from {sup 235}U. In this study, direct measurement with the interference correction technique, which uses several reference peaks for gamma-rays from {sup 235}U and {sup 234}Th, and indirect measurement, which means the identification of {sup

  9. Study on natural radionuclide activities in meat samples consumed in Sao Paulo City, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, Mychelle M.L.; Taddei, Maria HelenaT. [Comissao Nacional de Energia Nuclear (LAPOC/CNEN), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas; Avegliano, Roseane P.; Maihara, Vera A., E-mail: mychelle@cnen.gov.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Consumption of food is usually the most important route by which natural and artificial radionuclides can enter the human body. An assessment of radionuclide levels in different foods and diets is therefore important to estimate the intake of these radionuclides by man. The contamination by radionuclides can occur via the food chain (soil, root, plant and animal), with emphasis to the long half-life radionuclides, which can also have their transfer through the animal meat. The inclusion of meat in human nutrition is important because it is an excellent source of high quality protein, nutrient related to construction and cell regeneration. This work aims the determination of natural radionuclides ({sup 234}U, {sup 235}U, {sup 238}U, {sup 228}Th, {sup 230}Th, {sup 232}Th, {sup 226}Ra, {sup 228}Ra, and {sup 210}Pb) in meat samples. Five groups of samples were analyzed, such as cattle meat (beef), fish, pork, poultry, and processed meat, after radiochemical separation followed by alpha or alpha beta spectrophotometry, and total count quantification. The determination of these radionuclides is very important because they are products of the natural decay series of {sup 238}U and {sup 232}Th, being easily found in meat samples. (author)

  10. Transfer of 226Ra and 137Cs from tea leaves to drinking tea

    International Nuclear Information System (INIS)

    Fathivand, A. A.; Amidi, J.; Heravi, G. H.

    2006-01-01

    Two of the important radionuclides which are entered to environment and human diet are radium-226 ( 226 Ra) and cesium-137( 137 Cs). It is clear that the methods for preparation of foods such as peeling, washing, cooking or frying can affect the dose which is received by human due the to consumption of foodstuffs. An experiment has been performed at the environmental monitoring section of National Radiation Protection Department, aiming to measure the transfer of 226 Ra and 137 Cs from the tea leaves to drinking part of tea. Materials and Methods:Tea samples were pulverized to obtain a homogenous matrix which was weighed and placed In 1000 cm 3 Marinelli beaker. After making tea, the liquid tea and tea-discard were analyzed separately. Measurement of 226 Ra and 137 Cs was performed by gamma spectrometry system using a high purity germanium detector with 40% relative efficiency. The detector was shielded by 10 cm lead all sides with cadmium -copper as liners. Results: It was found that the activity concentration transferred from tea leaves to drinking tea for 137 Cs and 226 Ra are less than 2% and 17% respectively. Conclusion: On the basis of these measurements it seems that no significant levels of radioactivity of 226 Ra and 137 Cs can be found in drinking part of tea. The low concentration of the mentioned radionuclides in drinking tea is mostly due to tea dust and can be removed by its washing before preparing tea

  11. Natural radioactivity determination in samples of Peperomia pellucida commonly used as medicinal herb

    International Nuclear Information System (INIS)

    Sussa, Fabio V.; Silva, Paulo S.C.; Damatto, Sandra R.; Alencar, Marcos M.; Mazzilli, Barbara P.

    2011-01-01

    The radionuclide concentration in different environmental matrixes is reported in literature; however, studies of the distribution of 238 U and 232 Th decay products in plant species are sparse. In this study concentration of naturally occurring radionuclides 238 U, 234 U, 232 Th, 230 Th, 226 Ra, 228 Ra and 210 Pb was determined in sample of Peperomia pellucida and in the surrounding soil. Peperomia pellucida has a rich history of medicinal uses. The content of U and Th isotopes in the leaves, aerial parts, roots and soil was determined by alpha spectrometry after with radiochemical separation by ionic exchange resins and measurement with a silicon surface-barrier detector. The radionuclides measurement of 226 Ra, 228 Ra and 210 Pb were carried out by gross alpha and beta counting after radiochemical separation. The radionuclide activity concentrations mean in samples analyzed ranged from 4.3 to 38 Bq kg -1 for 238 U, from 42 to 129 Bq kg -1 for 234 U, from 2.1 to 38 Bq kg -1 for 230 Th, from 1.7 to 124 Bq kg -1 for 232 Th, from 8.5 to 37 Bq kg -1 for 226 Ra, from 3.2 to 46 Bq kg -1 for 228 Ra, from 39 to 93 Bq kg -1 for 210 Pb. It was also determined the percentage of radionuclides 226 Ra, 228 Ra and 210 Pb in the extraction and infusion of the drug analyzed. The arithmetical mean value recovery was from 23% to 60% in maceration and 24% to 75% in infusion. (author)

  12. Committed effective dose from naturally occuring radionuclides in shellfish

    Science.gov (United States)

    Khandaker, Mayeen Uddin; Wahib, Norfadira Binti; Amin, Yusoff Mohd.; Bradley, D. A.

    2013-07-01

    Recognizing their importance in the average Malaysian daily diet, the radioactivity concentrations in mollusc- and crustacean-based food have been determined for key naturally occuring radionuclides. Fresh samples collected from various maritime locations around peninsular Malaysia have been processed using standard procedures; the radionuclide concentrations being determined using an HPGe γ-ray spectrometer. For molluscs, assuming secular equilibrium, the range of activities of 238U (226Ra), 232Th (228Ra) and 40K were found to be 3.28±0.35 to 5.34±0.52, 1.20±0.21 to 2.44±0.21 and 118±6 to 281±14 Bq kg-1 dry weight, respectively. The respective values for crustaceans were 3.02±0.57 to 4.70±0.52, 1.38±0.21 to 2.40±0.35 and 216±11 to 316±15 Bq kg-1. The estimated average daily intake of radioactivity from consumption of molluscs are 0.37 Bq kg-1 for 238U (226Ra), 0.16 Bq kg-1 for 232Th (228Ra) and 18 Bq kg-1 for 40K; the respective daily intake values from crustaceans are 0.36 Bq kg-1, 0.16 Bq kg-1 and 23 Bq kg-1. Associated annual committed effective doses from molluscs are estimated to be in the range 21.3 to 34.7 μSv for 226Ra, 19.3 to 39.1 μSv for 228Ra and 17.0 to 40.4 μSv for 40K. For crustaceans, the respective dose ranges are 19.6 to 30.5 μSv, 22.0 to 38.4 μSv and 31.1 to 45.5 μSv, being some several times world average values.

  13. Radioactive equilibria and disequilibria of U-series nuclides in the products from Izu arc volcanoes, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Kurihara, Y.; Sato, J. [Meiji Univ., Kawasaki, Kanagawa (Japan). Dept. of Applied Chemistry; Takahashi, M. [Central Research Institute of Electric Power Industry, Tokyo (Japan). Radiation Safety Research Center

    2011-07-01

    Activity ratios among {sup 238}U-{sup 230}Th-{sup 226}Ra in the products from Izu arc volcanoes, Japan, were observed in order to estimate the time scale of magmatic processes and the magma generation for Izu arc volcanism. Activity ratios of {sup 238}U/{sup 230}Th and {sup 226}Ra/{sup 230}Th in the basaltic and andesitic products from Izu arc volcanoes were greater than unity, being enriched in {sup 238}U and {sup 226}Ra relative to {sup 230}Th. The {sup 226}Ra/{sup 230}Th activity ratio versus {sup 238}U/{sup 230}Th activity ratio diagram for these products showed positive correlation, suggesting that the {sup 238}U-{sup 230}Th-{sup 226}Ra disequilibria occurred during the magma genesis by the additions of U- and Ra-rich fluids derived from the subducting slab by dehydration to the mantle wedge. The {sup 230}Th-{sup 226226}Ra radioactive disequilibria observed in the basaltic and andesitic products imply a short period of time (<8000 years) between the magma genesis and the eruption. The majority of rhyolitic products was considered to be almost in equilibrium of {sup 238}U={sup 230}Th={sup 226}Ra. The observation that {sup 238}U-{sup 230}Th-{sup 226}Ra for the rhyolite are in radioactive equilibrium suggested that the rhyolitic magma from Izu arc was generated in the partial melting of the earth crust heated by the basaltic magma of high temperature. (orig.)

  14. Transfer of 226Ra, 228Ra, 210Pb and 210Po in aquatic organisms and food chain

    International Nuclear Information System (INIS)

    Yang Xiaotong; Weng Detong; Chen Wenyin; Chen Xiuyun; Chen Jixi; Zhao Shimin

    1998-01-01

    Objective: To find out the transfer regularities of 226 Ra, 228 Ra, 210 Pb and 210 Po, which are natural radionuclides in the aquatic organisms and food chain. Methods: Large amount of breed of representative aquatic products and their living waters and sediments were collected and treated according to routine experimental procedures. The contents of 226 Ra, 228 Ra, 210 Pb and 210 Po were detected in each sample. Measured data were analyzed statistically and pairwise comparisons were made to determine the differences between groups. Results: 226 Ra, 228 Ra and 210 Pb were mainly deposited in the bones (or shells), their concentration factors (CF) ranged from 10 2 to 10 3 ; the CF ranged only from 10 0 to 10 2 in the flesh. 210 Po was mainly deposited in the soft tissues, CF ranged from 10 2 to 10 4 ; especially in the stomachs and intestines of fishes, the value reached 10 4 . The cooking process did not impinge significantly on the transfer of 226 Ra, 228 Ra and 210 Pb in the food chain (P>0.05), but did significantly influence the transfer of 210 Po, especially in the freshwater fishes and shrimps. Paired comparison test of the activities between raw flesh and cooked flesh showed very significant difference (P 226 Ra, 228 Ra, 210 Pb and 210 Po. Even though the bones (or shells) of aquatic organisms contained relatively higher levels of 226 Ra, 228 Ra and 210 Pb, the cooking process does not significantly increase the radioactive contents in the foodstuffs. However, the cooking process does significantly influence the transfer of 210 Po. It does significantly increase the content of 210 Po in foodstuffs

  15. Radium isotope (223Ra, 224Ra, 226Ra and 228Ra) distribution near Brazil's largest port, Paranaguá Bay, Brazil

    International Nuclear Information System (INIS)

    Dias, Thais H.; Oliveira, Joselene de; Sanders, Christian J.; Carvalho, Franciane; Sanders, Luciana M.; Machado, Eunice C.; Sá, Fabian

    2016-01-01

    This work investigates the 223 Ra, 224 Ra, 226 Ra and 228 Ra isotope distribution in river, estuarine waters and sediments of the Paranaguá Estuarine Complex (PEC). The stratification of the Ra isotopes along water columns indicate differing natural sources. In sediments, the radium isotope activities was inversely proportional to the particle size. The highest concentrations of 223 Ra, 224 Ra, 226 Ra and 228 Ra in the water column were found in the bottom more saline waters and towards the inner of the estuary. These relatively high concentrations towards the bottom of the estuary may be attributed to the influence of tidally driven groundwater source and desorption from particles at the maximum turbidity zone. The apparent river water ages from the radium isotope ratios, 223 Ra/ 224 Ra and 223 Ra/ 228 Ra, indicate that the principal rivers that flow into the estuary have residence times from between 6 and 11 days. - Highlights: • Radium isotope concentrations were evaluated along a large estuarine system. • The radioactivity level in river, estuary and sediments was within a normal range. • Spatial distributions of site specific radionuclides have differing activities and sources.

  16. Intercomparison of radionuclide measurements in marine sediment sample IAEA-368

    Energy Technology Data Exchange (ETDEWEB)

    Ballestra, S; Lopez, J J; Gastaud, J; Parsi, P; Vas, D; Noshkin, V

    1991-08-01

    The results of an intercomparison exercise on a Pacific Ocean sediment sample, IAEA-368, designed for the determination of artificial and natural radionuclides levels, are reported. The data from 89 laboratories representing 37 countries have been evaluated. The following are the recommended values, with confidence intervals, for {sup 60}Co, {sup 155}Eu, {sup 210}7Pb, {sup 226}Ra, {sup 238}U, {sup 238}Pu and{sup 239+240}Pu (Reference date: 1 January 1990). Information values for {sup 40}K, {sup 90}Sr, {sup 137}Cs, {sup 228}Th, {sup 230}Th, {sup 232}Th, {sup 234}U, {sup 235}U and {sup 241}Am are also reported. (author)

  17. Concentration activities of natural radionuclides in three fish species in Brazilian coast and their contributions to the absorbed doses

    International Nuclear Information System (INIS)

    Pereira, Wagner de S.; Py Junior, Delcy de A.; Kelecom, Alphonse

    2009-01-01

    Activity concentrations of U-238, Ra-226, Pb-210, Th-232 e Ra-228 were analysed in three fish species at the Brasilian Coast. The fish 'Cubera snapper' (Lutjanus cyanopterus, Cuvier, 1828), in the region of Ceara and 'Whitemouth croaker' (Micropogonias furnieri, Desmarest, 1823) and 'Lebranche mullet' (Mugil liza, Valenciennes, 1836) in the region of Rio de Janeiro. These concentrations were transformed in absorbed dose rate using a dose conversion factor in unit of gray per year (μGy y -1 ), per becquerel per kilogram (Bq kg -1 ). Only the absorbed dose due to intake of radionuclides was examined, and the contributions due to radionuclides present in water and sediment were disregarded. The radionuclides were considered to be uniformly distributed in the fish body. The limit of the dose rate used, proposed by the Department of Energy of the USA, is equal to 3.65 10 03 mGy y -1 . The average dose rate due to the studied radionuclides is equal to 6.09 10 00 μGy y -1 , a value minor than 0.1% than the limits indicated by DOE, and quite similar to that found in the literature for 'benthic' fish. The most important radionuclides were the alpha emitters Ra-226 having 61 % of absorbed dose rate. U-238 and Th-232, each contributes with approximately 20 % of the absorbed dose rate. These three radionuclides are responsible for almost 100% of the dose rate received by the studied organisms. The beta emitters Ra-228 and Pb-210 account for approximately 1 % of the absorbed dose rate. (author)

  18. The metrological activity determination of 238 U and 230 Th by gamma spectrometry to industrial fuel-cycle application

    International Nuclear Information System (INIS)

    Almeida M, M.C. de; Delgado, J.U.; Poledna, R.

    2006-01-01

    This work describes the difficulty for determining the activity of 238 U and 230 Th using gamma spectrometry due to the low gamma-ray emission probabilities of 92 and 67 keV, and, mainly, the associated high uncertainties about 13 and 11%, respectively. 230 Th is a 238 U daughter and it is product from uranium mills and refineries. 230 Th decays to 226 Ra and this decay has to be measured because these radionuclides are not in secular equilibrium with their daughter products, besides the gamma-energies have high uncertainties in the emission probabilities. These radionuclides, mostly 238 U, are important in the nuclear fuel-cycle, since the mining of uranium ore, where the nominal isotopic content of natural uranium is 99.27% of 238 U, until the irradiated fuel reprocessing, where this isotope, a fertile material, is recovered to be used again. The uranium and thorium are considered safeguarded nuclear materials and the metrology tries to calibrate and standardize these materials to improve the activity determination techniques applied in different fuel-cycle scopes. The essential characteristics of the safeguarded materials are low gamma energies (less than 100 keV) and emission probabilities but with high uncertainties. In this way, the metrology can contribute to homeland security defense against illicit nuclear trafficking with the identification and quantification of the safeguarded radionuclides such as uranium and thorium, using specific gamma window energy and high resolution planar or coaxial germanium detector. The efficiency curve is obtained from the reference source spectrum considering the photopeak areas corresponding the standard activities. This curve depends on radiation energy, sample geometry, photon attenuation (sample absorption and material absorption between sample-detector), dead time and sample-detector position. The metrological activity determinations of 238 U solid sources, and of 230 Th, in solution (5 ml flask), were performed using

  19. Evaluation of radionuclide contamination of soil, coal ash and zeolitic materials from Figueira thermoelectric power plant

    International Nuclear Information System (INIS)

    Fungaro, Denise Alves; Silva, Paulo Sergio Cardoso da; Campello, Felipe Arrelaro; Miranda, Caio da Silva; Izidoro, Juliana de Carvalho

    2017-01-01

    Neutron activation analysis and gamma-ray spectrometry was used to determine 238 U, 226 Ra, 228 Ra, 210 Pb, 232 Th and 40 K contents in feed pulverized coal, bottom ash, fly ash from cyclone and baghouse filters, zeolites synthesized from the ashes and two different soil samples. All the samples used in the study was collected at Figueira thermoelectric power plant, located in the city of Figueira, Paraná State, which coal presents a significant amount of uranium concentration. The natural radionuclide concentrations in pulverized coal were 4216 Bq kg -1 for 238 U, 180 Bq kg -1 for 226 Ra, 27 Bq kg -1 for 228 Ra, 28 Bq kg -1 for 232 Th and 192 Bq kg -1 for 40 K. The ashes fraction presented concentrations ranging from 683.5 to 1479 Bq kg -1 for 238 U, from 484 to 1086 Bq kg -1 for 226 Ra, from 291 to 1891 Bq kg -1 for 210 Pb, from 67 to 111 Bq kg -1 for 228 Ra, from 80 to 87 Bq -1 for 232 Th and from 489 to 718 Bq kg -1 for 40 K. Similar ranges were observed for zeolites. The activity concentration of 238 U was higher than worldwide average concentration for all samples. The concentration of the uranium series found in the ashes were lower than the values observed in similar studies carried out 10 years ago and under the limit adopted by the Brazilian guideline (CNEN-NN-4.01). Nevertheless, the concentrations of this specific area are higher than others coal mines and thermoelectric power plants in and out of Brazil, so it is advisable to evaluate the environmental impact of the installation. (author).

  20. Environmental characterization and radio-ecological impacts of non-nuclear industries on the Red Sea coast

    International Nuclear Information System (INIS)

    El Mamoney, M.H.; Khater, Ashraf E.M.

    2004-01-01

    The Red Sea is a deep semi-enclosed and narrow basin connected to the Indian Ocean by a narrow sill in the south and to the Suez Canal in the north. Oil industries in the Gulf of Suez, phosphate ore mining activities in Safaga-Quseir region and intensified navigation activities are non-nuclear pollution sources that could have serious radiological impacts on the marine environment and the coastal ecosystems of the Red Sea. It is essential to establish the radiological base-line data, which does not exist yet, and to investigate the present radio-ecological impact of the non-nuclear industries to preserve and protect the coastal environment of the Red Sea. Some natural and man-made radionuclides have been measured in shore sediment samples collected from the Egyptian coast of the Red Sea. The specific activities of 226 Ra and 210 Pb ( 238 U) series, 232 Th series, 40 K and 137 Cs (Bq/kg dry weight) were measured using gamma ray spectrometers based on hyper-pure germanium detectors. The specific activities of 210 Po ( 210 Pb) and uranium isotopes ( 238 U, 235 U and 234 U) (Bq/kg dry weight) were measured using alpha spectrometers based on surface barrier (PIPS) detectors after radiochemical separation. The absorbed radiation dose rates in air (nGy/h) due to natural radionuclides in shore sediment and radium equivalent activity index (Bq/kg) were calculated. The specific activity ratios of 228 Ra/ 226 Ra, 210 Pb/ 226 Ra, 226 Ra/ 238 U and 234 U/ 238 U were calculated for evaluation of the geo-chemical behaviour of these radionuclides. The average specific activity of 226 Ra ( 238 U) series, 232 Th series, 40 K and 210 Pb were 24.7, 31.4, 427.5 and 25.6 Bq/kg, respectively. The concentration of 137 Cs in the sediment samples was less than the lower limit of detection. The Red Sea coast is an arid region with very low rainfall and the sediment is mainly composed of sand. The specific activity of 238 U, 235 U and 234 U were 25.3, 2.9 and 25.0 Bq/kg. The average specific

  1. Disequilibria in the disintegration series of U and Th and chemical parameters in thermal spring waters from the Tatun volcanic area (Taiwan)

    International Nuclear Information System (INIS)

    Lin Chunchih; Chu Tiehchi; Huang Yufen

    2003-01-01

    The activity concentrations of 238 U, 234 U, 230 Th, 226 Ra, 232 Th, and 228 Th in thermal spring waters in the Tatun volcanic area were determined. Parameters including acidity, Cl - and SO 4 2- concentrations in spring waters at the sampling sites have been investigated to allow interpretation of the migration of the radionuclides, and to elucidate the influence of these parameters on the variations of radionuclide contents. Radioactive disequilibria were found in uranium and thorium series in thermal spring waters. The contents of uranium and thorium decreased with increasing pH. The ratios of 230 Th/ 234 U, 226 Ra/ 230 Th and 228 Th/ 232 Th show significant disequilibria. The 226 Ra/ 230 Th ratio (0.60-34.8) decreased with the Cl - or SO 4 2- concentration. All 228 Th/ 232 Th ratios (1.01-9.49) deviated from unity due to the co-precipitation of 228 Ra with barium and lead sulfate. (orig.)

  2. Correlations of natural radionuclides in soil with those in sediment from the Danube and nearby irrigation channels

    International Nuclear Information System (INIS)

    Krmar, M.; Varga, E.; Slivka, J.

    2013-01-01

    The correlation between activity concentrations of some natural radionuclides ( 238 U, 226 Ra, 232 Th, 40 K) measured in soil and in sediment taken from the Danube River and nearby irrigation channels was studied. The soil samples were collected from the northern part of Serbia and the sediment from the Serbian part of the Danube River and from the surrounding irrigation channels. The correlation between 238 U and other natural radionuclides in irrigation channel sediments was not as good as in the Danube. One of the possible explanations for this weak correlation can be the different chemical dynamics of 238 U in the irrigation channel sediment or changes of the 238 U activity concentration in irrigation channel sediment due to some human activities. The evaluation of ratios of activity concentrations of some natural radionuclides could be a more sensitive method for the determination of contaminant, rather than the straightforward analysis of activity concentrations. -- Highlights: ► 238 U, 232 Th and 40 K were measured in soil, Danube and surrounding channel sediment. ► Correlation of activity concentrations were observed. ► In cannel sediment natural radionuclides are not well correlated as in Danube one. ► Ratios of 238 U, 232 Th and 40 K can be good indicator for TENORM monitoring

  3. Investigation of the degree of equilibrium of the long-lived uranium-238 decay-chain members in airborne and bulk uranium-ore dusts

    International Nuclear Information System (INIS)

    Jackson, P.O.; Thomas, C.W.

    1982-08-01

    The degree of disequilibrium among 238 U decay chain members in some airborne dusts and typical ores has been established by precise radiochemical analyses. This information is necessary to evaluate the lung dose model currently used for estimating the effect of the inhalation of uranium ore dust. The particle size distributions of airborne decay chain components in dusts at one uranium mill have been investigated. Statistically significant disequilibria were observed for 230 Th, 226 Ra, and 210 Pb in both airborne dusts and composite ore samples. With the exception of ore from one mill in the United States, most of the daughter concentrations in powdered ore composites were within 10% of 238 U. In airborne dusts, the concentration of 226 Ra was typically below 238 U; the minimum 226 Ra concentration observed for airborne ore dusts was 56% of equilibrium. A statistically significant particle size dependence was observed for 226 Ra/ 238 U ratios in several airborne dusts collected at a uranium mill

  4. Soil-to-plant transfer factors of natural radionuclides (226Ra and 40K) in selected Thai medicinal plants.

    Science.gov (United States)

    Saenboonruang, Kiadtisak; Phonchanthuek, Endu; Prasandee, Kamonkhuan

    2018-04-01

    A soil-to-plant transfer factor (TF) is an important parameter that could be used to estimate radionuclides levels in medicinal plants. This work reports concentrations of natural radionuclides ( 226 Ra and 40 K) and TFs in six Thai medicinal plants grown in central Thailand using an HPGe gamma ray spectrometer. Either root, leaf, or flower parts of each medicinal plant were selected for use in the investigation according to their practical uses in traditional medicine. The results showed that due to K being essential in plants, 40 K had higher arithmetic means of activity concentrations and geometric means of TFs (geometric standard deviations in parentheses) of 610 ± 260 Bq kg -1 dry weight (DW) and 2.0 (1.4), respectively, than 226 Ra, which had the activity concentrations and TFs of 4.8 ± 2.6 Bq kg -1 DW and 0.17 (1.8), respectively. The results also showed that the leaves of medicinal plants had higher activity concentrations and TFs than root and flower parts, probably due to higher metabolic activities in leaves. Furthermore, there was good agreement between the results from the current work and other similar reports on medicinal plants. The information obtained from this work could strengthen knowledge of natural radionuclides in plants and particularly increase available TF data on Thai medicinal plants. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Radionuclides in ground water of the Carson River Basin, western Nevada and eastern California, U.S.A.

    Science.gov (United States)

    Thomas, J.M.; Welch, A.H.; Lico, M.S.; Hughes, J.L.; Whitney, R.

    1993-01-01

    Ground water is the main source of domestic and public supply in the Carson River Basin. Ground water originates as precipitation primarily in the Sierra Nevada in the western part of Carson and Eagle Valleys, and flows down gradient in the direction of the Carson River through Dayton and Churchill Valleys to a terminal sink in the Carson Desert. Because radionuclides dissolved in ground water can pose a threat to human health, the distribution and sources of several naturally occurring radionuclides that contribute to gross-alpha and gross-beta activities in the study area were investigated. Generally, alpha and beta activities and U concentration increase from the up-gradient to down-gradient hydrographic areas of the Carson River Basin, whereas 222Rn concentration decreases. Both 226Ra and 228Ra concentrations are similar throughout the study area. Alpha and beta activities and U concentration commonly exceed 100 pCi/l in the Carson Desert at the distal end of the flow system. Radon-222 commonly exceeds 2,000 pCi/l in the western part of Carson and Eagle Valleys adjacent to the Sierra Nevada. Radium-226 and 228Ra concentrations are processes. Thus, U is transported as dissolved and adsorbed species. A rise in the water table in the Carson Desert because of irrigation has resulted in the oxidation of U-rich organic matter and dissolution of U-bearing coatings on sediments, producing unusually high U concentration in the ground water. Alpha activity in the ground water is almost entirely from the decay of U dissolved in the water. Beta activity in ground water samples is primarily from the decay of 40K dissolved in the water and ingrowth of 238U progeny in the sample before analysis. Approximately one-half of the measured beta activity may not be present in ground water in the aquifer, but instead is produced in the sample after collection and before analysis. Potassium-40 is primarily from the dissolution of K-containing minerals, probably K-feldspar and biotite

  6. Evaluation of the environmental radiological impact of Brazilian phosphogypsum and leachability of Ra-226 and Pb-210

    International Nuclear Information System (INIS)

    Santos, Adir Janete Godoy dos

    2002-01-01

    Phosphogypsum is a by-product produced by the phosphoric acid industry, it is formed by precipitation during wet sulphuric acid processing of phosphate rock. Although phosphogypsum is mainly calcium sulphate dihydrate, it contains elevated levels of impurities, which originate from the source phosphate rock used in the phosphoric acid production. Among these impurities, radionuclides from 238 U and 232 Th decay series, particularly 226 Ra, 228 Ra, 210 Pb and Th isotopes are of most concern due to their radiotoxicity. Elemental characterization of stockpiled phosphogypsum from the two main producers of phosphoric acid, Copebras Ltda and Ultrafertil S.A. named A and C respectively, located in Cubatao, was performed by instrumental neutron activation analysis (INAA). Phosphogypsum samples are enriched in rare earths elements, specifically Ce, Eu, La, Nd, Sm, Tb and Yb and the elements Ba and Th. Radiological characterization of stockpiled phosphogypsum was performed by gamma-ray spectrometry. Activity concentrations (2,3 +- 0,5) x 10 2 Bq kg -1 for 228 Ra, (8,5 +- 2,4) x 10 2 Bq kg -1 for 226 Ra and (8,4 +- 2,4) x 10 2 Bq kg -1 for 210 Pb were observed for industry A phosphogypsum. For industry C phosphogypsum, activity concentrations obtained were (1,6 +- 0,6) x 10 2 Bq kg - ''1 for 226 Ra, (3,6 +- 1,2) x 10 2 Bq kg -1 for 226 Ra and (3,4 +- 1,2) x 10 2 Bq kg -1 for 210 Pb. The radiochemical and elemental characterization of the phosphogypsum from industry A and C show that the stacks are quite homogeneous and mainly dependent upon the origin of the phosphatic rock used as raw material. The environmental radiological impact assessment of stockpiled phosphogypsum from industry C was evaluated by taking into account internal and external doses. The critical pathways considered were contamination of groundwater, emanation of radon and direct external exposure due to the radionuclides present in the phosphogypsum. The activity concentrations obtained in the monitor wells

  7. 238U–230Th–226Ra–210Pb–210Po disequilibria constraints on magma generation, ascent, and degassing during the ongoing eruption of Kīlauea

    Science.gov (United States)

    Girard, Guillaume; Reagan, Mark K.; Sims, Kenneth W. W.; Thornber, Carl; Waters, Christopher L.; Phillips, Erin H.

    2017-01-01

    The timescales of magma genesis, ascent, storage and degassing at Kīlauea volcano, Hawai‘i are addressed by measuring 238U-series radionuclide abundances in lava and tephra erupted between 1982 and 2008. Most analyzed samples represent lavas erupted by steady effusion from Pu‘u ‘Ō‘ō and Kūpahianaha from 1983 to 2008. Also included are samples erupted at the summit in April 1982 and March 2008, along the East Rift Zone at the onset of the ongoing eruption in January 1983, and during vent shifting episodes 54 and 56, at Nāpau crater in January 1997, and Kane Nui O Hamo in June 2007. In general, samples have small (∼4%) excesses of (230Th) over (238U) and ∼3 to ∼17% excesses of (226Ra) over (230Th), consistent with melting of a garnet peridotite source at melting rates between 1 × 10–3 and 5 × 10–3 kg m–3 a–1, and melting region porosity between ∼2 and ∼10%, in agreement with previous studies of the ongoing eruption and historical eruptions. A small subset of samples has near-equilibrium (230Th/238U) values, and thus were generated at higher melting rates. Based on U–Th–Ra disequilibria and Th isotopic data from this and earlier studies, melting processes and sources have been relatively stable over at least the past two centuries or more, including during the ongoing unusually long (>30 years) and voluminous (4 km3) eruption. Lavas recently erupted from the East Rift Zone have average initial (210Pb/226Ra) values of 0·80 ± 0·11 (1σ), which we interpret to be the result of partitioning of 222Rn into a persistently generated CO2-rich gas phase over a minimum of 8 years. This (210Pb) deficit implies an average magma ascent rate of ≤3·7 km a–1 from ∼30 km depth to the surface. Spatter and lava associated with vent-opening episodes erupt with variable (210Pb) deficits ranging from 0·7 to near-equilibrium values in some samples. The samples with near-equilibrium (210Pb/226Ra) are typically more

  8. Decision making algorithm of the rehabilitation of agricultural lands contaminated with heavy natural radionuclides

    International Nuclear Information System (INIS)

    Khomutyinyin, Yu.V.; Yivanov, Yu.O.; Kirichenko, V.K.

    2013-01-01

    Problem of rehabilitation of agricultural land contaminated with heavy natural radionuclides ( 210 Pb, 210 Po, 226 Ra, 232 Th, 238 U) was considered. Algorithm of decision making support on advisability of rehabilitation of mentioned land was suggested. Proposed algorithm was tested on the base of agricultural farmlands located in the affected zone of Pridneprovsky Chemicals Plant and its tailing dumps

  9. Intercomparison of radionuclide measurements in marine sediment sample IAEA-135

    Energy Technology Data Exchange (ETDEWEB)

    Ballestra, S; Gastaud, J; Lopez, J J; Parsi, P; Vas, D

    1993-08-01

    The results of an intercomparison exercise on a marine sediment from Irish Sea, IAEA-135, designed for the determination of artificial and natural radionuclides levels, are reported. The data from 151 laboratories representing 51 countries have been evaluated. The following are the recommended values, with confidence intervals, for {sup 40}K, {sup 60}Co, {sup 134}Cs, {sup 137}Cs, {sup 154}Eu, {sup 155}Eu, {sup 226}Ra, {sup 228}Ra, {sup 232}Th,{sup 238}Pu, {sup 239+240}Pu (Reference date: 1 January 1992). Information values for {sup 57}Co, {sup 90}Sr, {sup 106}Ru, {sup 125}Sb, {sup 210}Pb, {sup 210}Po, {sup 228}Th, {sup 230}Th, {sup 234}U, {sup 235}U, {sup 238}U and {sup 241}Am are also reported. All values are expressed in Bq kg{sup -1} dry weight. (author)

  10. Intercomparison of radionuclide measurements on marine sediment sample IAEA-300

    Energy Technology Data Exchange (ETDEWEB)

    Ballestra, S; Gastaud, J; Lopez, J J; Parsi, P; Vas, D

    1994-09-01

    The results of an intercomparison exercise on a sediment from Baltic Sea, IAEA-300, designed for the determination of artificial and natural radionuclides' levels, are reported. The data from 159 laboratories representing 51 countries have been evaluated. The following are the recommended values, with confidence intervals, {sup 40}K, {sup 60}Co, {sup 125}Sb, {sup 134}Cs, {sup 137}Cs, {sup 155}Eu, {sup 210}Pb, {sup 210}Po, {sup 228}Ra, {sup 234}U, {sup 238}U, {sup 239+240}Pu and {sup 241}Am. Information values for {sup 54}Mn, {sup 90}Sr, {sup 226}Ra, {sup 228}Th, {sup 230}Th, {sup 232}Th, {sup 235}U and {sup 238}Pu are also reported. All values are given on the reference date of 1 January 1993 and expressed in Bq kg{sup -1} dry weight. (author)

  11. Soil and vegetation influence in plants natural radionuclides uptake at a uranium mining site

    Science.gov (United States)

    Charro, E.; Moyano, A.

    2017-12-01

    The main objective of this work is to investigate the uptake of several radionuclides by the vegetation characteristic of a dehesa ecosystem in uranium mining-impacted soils in Central-West of Spain. The activity concentration for 238U, 226Ra, 210Pb, 232Th, and 224Ra was measured in soil and vegetation samples using a Canberra n-type HPGe gamma-ray spectrometer. Transfer factors of natural radionuclides in different tissues (leaves, branches, twigs, and others) of native plants were evaluated. From these data, the influence of the mine, the physicochemical parameters of the soils and the type of vegetation were analyzed in order to explain the accumulation of radionuclides in the vegetation. A preferential uptake of 210Pb and 226Ra by plants, particularly by trees of the Quercus species (Quercus pyrenaica and Quercus ilex rotundifolia), has been observed, being the transfer factors for 226Ra and 210Pb in these tree species higher than those for other plants (like Pinus pinaster, Rubur ulmifolius and Populus sp.). The analysis of radionuclide contents and transfer factors in the vegetation showed no evidence of influence of the radionuclide concentration in soils, although it could be explained in terms of the type of plants and, in particular, of the tree's species, with special attention to the tree's rate of growth, being higher in slow growing species.

  12. Estimation of annual effective dose from 226Ra 228Ra due to consumption of foodstuffs by inhabitants of high level natural radiation of Ramsar, Iran

    International Nuclear Information System (INIS)

    Fathivand, A.A.; Asefi, M.; Amidi, A.

    2005-01-01

    Full text: A knowledge of natural radioactivity in man and his environment is important since naturally occurring radionuclides are the major source of radiation exposure to man. Radioactive nuclides present in the natural environment enter the human body mainly through food and water.Besides, measurement of naturally occurring radionuclides in the environment can be used not only as a reference when routine releases from nuclear installation or accidental radiation exposures are assessed, but also as a baseline to evaluate the impact caused by non-nuclear activities. In Iran, measurement of natural and artificial radionuclides in environmental samples in normal and high-background radiation areas have been performed by some investigators but no information has been available on 226 Ra and 228 Ra in foodstuffs. Therefore we have started measurements of 226 Ra and 228 Ra in foodstuffs of Ramsar which is a coastal city in the north part of Iran and has been known as one of the world's high level natural radiation areas, using low level gamma spectrometry measurement system .The results from our measurements and food consumption rates for inhabitants of Ramsar city have been used for the estimation of annual effective dose due to consumption of foodstuffs by inhabitants of Ramsar city. A total of 33 samples from 11 different foodstuffs including root vegetables (beetroot), leafy vegetables (lettuce, parsley and spinach) and tea, meat,chicken, pea,broad bean, rice, and cheese were purchased from markets and were analyzed for their 226 Ra and 228 Ra concentrations. The highest concentrations of 226 Ra and 228 Ra were determined in tea samples with 1570 and 1140 mBq kg -1 respectively and the maximum estimated annual effective dose from 226 Ra and Ra due to consumption foodstuffs were determined to be 19.22 and 0.71 μSv from rice and meat samples respectively

  13. 226Ra bioavailability of plants at urgeirica uranium mill tailings

    International Nuclear Information System (INIS)

    Madruga, M.J.; Brogueira, A.

    2002-01-01

    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 226 Ra 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 226 Ra 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 226 Ra uptake by plants show that 226 Ra concentration ratios for eucalyptus and pines decrease at low 226 Ra concentration in the solid wastes and appear relatively constant at higher radium concentrations. For shrubs, the concentration ratios increase at higher 226 Ra 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 226 Ra 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 226 Ra concentration ratios were obtained when calculated on the basis of available radium than when total radium was considered, for all the dams. (author)

  14. Determination of 226Ra and 228Ra in gypsum

    International Nuclear Information System (INIS)

    Godoy, J.M.

    1989-01-01

    The content of 226 Ra and 228 Ra in different samples of phosphogypsum and three samples of gypsite were determined by gamma spectroscopy. For 226 Ra the 295, 352 and 609 KeV lines and for 228 Ra the 911 and 969 KeV lines were used. The specific activities values ranged from 0.36 to 22.8 pCi/g for 226 Ra and 0.90 to 10.3 pCi/g for 228 Ra. The contribution of a sypsum roof-covering to the 222 Rn concentration in a room was estimated, based on the highest value reported. (author) [pt

  15. Simultaneous determination of Ra-226, natural uranium and natural thorium by gamma-ray spectrometry INa(Ti), in solid samples

    International Nuclear Information System (INIS)

    Salvador, S.; Navarro, T.; Alvarez, A.

    1991-01-01

    A method has been developed to determine activities of Ra-226, natural uranium and natural thorium by gamma-ray spectrometry. The measurement system has been calibrated using standards specially prepared at the laboratory. It is necessary to assume secular equilibrium in the samples, between Ra-226 and Th-232 and its daughters nuclides, and between U-238 and its immediate daughter Th-234, as the photo peaks measured are those of the daughters. The results obtained indicate that this method can of ter replace the radiochemical techniques used to measure activities in this type of sample. The method has been successfully used to determine these natural isotopes in samples from uranium mills. (Author) 9 refs

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

    International Nuclear Information System (INIS)

    Mahiban Ross, E.; Feroz Khan, M.; Lenin Raj, Y.; Godwin Wesley, S.; Kumar, M.; Sundar Rajan, P.

    2007-01-01

    Baseline activity concentration of the natural radio nuclides 40 K, 228 Ra and 226 Ra in vegetables and fruits was determined around Kudankulam. In many of the samples, 228 Ra and 226 Ra was below minimum detection limit. 40 K 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. 228 Ra activity in vegetables and fruits ranged from 0.074 to 1.153 and 0.074 to 0.131 Bq.kg -l fresh respectively. 226 Ra in vegetables and fruits ranged from BDL to 0.07 and BDL-.044 Bq.kg -l fresh respectively. 40 K in vegetables and fruits followed a log normal distribution. (author)

  17. The metrological activity determination of {sup 238} U and {sup 230} Th by gamma spectrometry to industrial fuel-cycle application

    Energy Technology Data Exchange (ETDEWEB)

    Almeida M, M.C. de; Delgado, J.U.; Poledna, R. [Instituto de Radioprotecao e Dosimetria- IRD/SEMRA, CNEN, Av. Salvador Allende s/n, Recreio, CEP 22780-160, Rio de Janeiro (Brazil)]. e-mail: marcandida@yahoo.com.br

    2006-07-01

    This work describes the difficulty for determining the activity of {sup 238} U and {sup 230} Th using gamma spectrometry due to the low gamma-ray emission probabilities of 92 and 67 keV, and, mainly, the associated high uncertainties about 13 and 11%, respectively. {sup 230} Th is a {sup 238} U daughter and it is product from uranium mills and refineries. {sup 230} Th decays to {sup 226} Ra and this decay has to be measured because these radionuclides are not in secular equilibrium with their daughter products, besides the gamma-energies have high uncertainties in the emission probabilities. These radionuclides, mostly {sup 238} U, are important in the nuclear fuel-cycle, since the mining of uranium ore, where the nominal isotopic content of natural uranium is 99.27% of {sup 238} U, until the irradiated fuel reprocessing, where this isotope, a fertile material, is recovered to be used again. The uranium and thorium are considered safeguarded nuclear materials and the metrology tries to calibrate and standardize these materials to improve the activity determination techniques applied in different fuel-cycle scopes. The essential characteristics of the safeguarded materials are low gamma energies (less than 100 keV) and emission probabilities but with high uncertainties. In this way, the metrology can contribute to homeland security defense against illicit nuclear trafficking with the identification and quantification of the safeguarded radionuclides such as uranium and thorium, using specific gamma window energy and high resolution planar or coaxial germanium detector. The efficiency curve is obtained from the reference source spectrum considering the photopeak areas corresponding the standard activities. This curve depends on radiation energy, sample geometry, photon attenuation (sample absorption and material absorption between sample-detector), dead time and sample-detector position. The metrological activity determinations of {sup 238} U solid sources, and of

  18. Natural radionuclides in effluents release by a deactivated uranium mine

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Wagner S.; Kelecom, Alphonse; Silva, Ademir X.; Lopes, José M.; Pinto, Carlos E.C.; Py Júnior, Delcy A.; Antunes, Marcos M., E-mail: pereiraws@gmail.com, E-mail: caerjbr@gmail.com, E-mail: wspereira@inb.gov.br, E-mail: delcy@inb.gov.br, E-mail: Antunes@inb.gov.br, E-mail: lararapls@hotmail.com, E-mail: Ademir@nuclear.ufrj.br, E-mail: marqueslopes@yahoo.com.br [Universidade Veiga de Almeida (UVA), Rio de Janeiro, RJ (Brazil); Indústrias Nucleares do Brasil (COMAP.N/FCN/INB), Resende RJ (Brazil). Fábrica de Combustível Nuclear. Coordenação de Meio Ambiente e Proteção Radiológica Ambiental; Universidade Federal Fluminense (LARARA-PLS/UFF), Niterói, RJ (Brazil). Laboratório de Radiobiologia e Radiometria; Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2017-07-01

    The Ore Treatment Unit (OTU) is a mine and deactivated uranium plant in the city of Caldas, Minas Gerais, Brazil. This facility possesses three points of release of liquid effluents containing radionuclides: point 014, 025 and 076. At these points, the values of activity concentrations (AC) of the radionuclides U{sub nat}, {sup 226}Ra, {sup 210}Pb, {sup 232}Th and {sup 228}Ra were analyzed in 2012. The evaluation of point 014 by univariate statistics pointed four groups. [U{sub nat} > {sup 228}Ra > ({sup 226}Ra = {sup 210}Pb) >{sup 232}Th]. The multivariate statistics separated the radionuclides into two groups: [(U{sub nat} and {sup 232}Th) and ({sup 226}Ra, {sup 228}Ra and {sup 210}Pb)]. At point 025, the univariate statistics described three groups: [Un{sub at} > ({sup 228}Ra = {sup 210}Pb) > ({sup 226}Ra = {sup 232}Th)] and the multivariate analysis also described three but different groups: [(U{sub nat} and {sup 228}Ra), ({sup 226}Ra and {sup 210}Pb) and {sup 232}Th]. In turn, point 076 showed another behavior. The univariate analysis showed only two groups: [(U{sub nat}) > ({sup 226}Ra, {sup 228}Ra, {sup 210}Pb, {sup 232}Th)]. Differently, the multivariate statistics defined three groups: [(U{sub nat} and {sup 232}Th), ({sup 226}Ra and {sup 228}Ra) and {sup 210}Pb].Thus, statistical analysis showed that each point has releases of effluents with different characteristics. Both the behaviors of releases, based on multivariate statistics, and of the AC magnitudes, based on the univariate statistics, are different between the points. The only common features were the greater magnitude of uranium and the smaller magnitude of thorium. (author)

  19. The use of lichens as bioindicators of atmospheric contamination by natural radionuclides and metals in a region impacted by TENORM

    International Nuclear Information System (INIS)

    Leonardo, Lucio

    2010-01-01

    The main aim of this thesis is to study the possibility of using lichen as bioindicator of atmospheric pollution in regions contaminated by radionuclides, metals and rare earth elements. Two regions were chosen, one in Pirapora do Bom Jesus, where a tin and lead industry is located, and a second one in Cubatao, where a phosphate fertilizer industrial complex is located. The two industries chosen are considered as TENORM - Technologically Enhanced Naturally Occurring Radioactive Material, since they can cause a significant increase in the natural radionuclides concentration in the industrial process, and consequently a potential increase in the radiation exposure in products, byproducts and residue. To achieve this aim, the radionuclides 238 U, 226 Ra, 210 Pb, 2' 3 2 Th and 228 Ra, rare earth elements and metals were analyzed in samples of raw material and residues from the installations, lichens and soils. Lichens and soil samples were analyzed by instrumental neutron activation analysis for the determination of uranium, thorium, rare earth elements and metals. The radionuclides 226 Ra, 228 Ra and 2 '1 0 Pb in soil samples were determined by gamma spectrometry and in lichen sample by radiochemical separation and gross alpha and beta counting on a gas flow proportional counter. The concentrations of 238 U (from 19 to 473 Bq kg -1 ), 226 Ra (from 21 to 265 Bq kg -1 ), 210 Pb (from 401 to 1461 Bq kg -1 ), 232 Th (from 15 to 574 Bq kg -1 ), 228 Ra (from 176 to 535 Bq kg'- 1 ), rare earth elements, Hf and Ta determined in lichen samples around the tin and lead industry show an enrichment in these elements. Therefore, the lichens can be used as a fingerprint of the atmospheric contamination. The results obtained for the lichen samples, in the Cubatao region, present a fingerprint mainly of 210 Pb, from industries of the region. The results obtained in this study showed that the lichens can be used as bioindicators of atmospheric pollution by radionuclides and trace

  20. 226Ra intake in the population from Bucharest during the past ten years

    International Nuclear Information System (INIS)

    Toader, M.; Vasilache, R.A.; Tomulescu, V.

    1998-01-01

    During 1986-1996 the content of several radionuclides, including 226 Ra, in the basic foodstuffs and in drinking water was determined. Based on these data and on the data concerning the constituents of the diet in Romania, the 226 Ra intake by the population of Bucharest was estimated for the last ten years, and the doses due to this intake were calculated. The results are presented in graphs and tables, and some general conclusions are drawn. (A.K.)

  1. Natural-series radionuclides in traditional North Australian aboriginal foods

    International Nuclear Information System (INIS)

    Murray, A.S.; Johnston, A.; Hancock, G.J.; Martin, P.

    1997-01-01

    Activity concentrations of the radionuclides 226 Ra, 210 Pb, 210 Po, 238 U, 234 U, 230 Th, 232 Th and 227 Ac were measured in edible flesh of traditional Aboriginal food items from the Magela and Cooper Creek systems in the tropical Northern Territory of Australia. Fish, buffalo, pig, magpie goose, filesnake, goanna, turtle, freshwater shrimp and freshwater crocodile were studied. Activity concentrations in water were also measured to enable the calculation of concentration ratios (CRs).For most edible flesh samples, activity concentrations followed the approximate order: 210 Po>> 226210 [ 234 Usimilar 238 [ 230 Thsimilar 232 Th]. The 210 Po/ 210 Pb activity ratio was particularly high (greater than 100) for pig flesh. CRs for fish species fall into two groups. Group 1 (bony bream and sleepy cod) had CRs about five times higher than for group 2 (eight other species). CRs for turtle flesh were similar to those for fish in group 1, while those for turtle liver were about a factor of 10 higher. CRs for magpie goose, filesnake, freshwater shrimp, goanna and crocodile flesh were also of the same order as for fish in groups 1 or 2.Calculations of dose resulting from release of wastewaters from uranium mining operations in the region show that the dominant pathway would be uptake of radionuclides, especially 226 Ra, by freshwater mussels, followed by radionuclide uptake by fish. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights reserved.)

  2. The 226 Ra, 210 Pb and essential elements bioavailability to pines at Urgeirica uranium mill tailings

    International Nuclear Information System (INIS)

    Madruga, M.J.; Faria, I.

    2006-01-01

    The objective of this study is to correlate the uptake of the natural radionuclides 226 Ra and 210 Pb with the essential elements, potassium, calcium and magnesium in the pines growing at the 'Urgeirica uranium mill tailings. It can be concluded that the potassium, calcium and magnesium mean concentration ratio values are, about two to three orders of magnitude, higher than the values obtained to 226 Ra and 210 Pb for pines growing on the Urgeirica uranium mill tailings. The concentration ratio values higher than 1 obtained to the potassium, calcium and magnesium elements indicate that pines are behaving as accumulators to these elements. Contrarily, the 226 Ra and 210 Pb concentration ratio values lower than 1 indicates that pines are behaving as excluders to these radionuclides. So, it can be concluded that this kind of plants is not suitable to a phyto remediation strategy. In general, a marginally significant correlation was observed between the potassium, calcium and magnesium concentrations, the cation-exchange capacity and the ph in the tailings and the 226 Ra and 210 Pb pines/tailings concentration ratios. (N.C.)

  3. Bioaccumulation of some natural radionuclides in short-antenna grasshoppers (Acrididae family, class Ortoptera)

    International Nuclear Information System (INIS)

    Dimitrova, M.; Markova, E.; Bogdanova, V.

    1996-01-01

    The seasonal accumulation of radioactive elements of the uranium-radium order in representatives of larva stages of different species of of Acrididae family has been examined. The monitoring sites are typical of the region and gave a relevant information about the natural background radiation. The process begins in the end of spring when Acrididae enter on the most intensive phase of their functional development and accumulate lots of radioisotopes not only by food but also through respiratory system and whole-body surface. Among the radioisotopes radium has an average biological absorbability, uranium - a very slight one. This fact explains the high values of radium in the ecosystems examined. Despite its low absorbability coefficient 238 U is found to a considerable extent in the investigated organisms. Because of it high mobility in soil compared to Ra 226, uranium 238 accumulates in plants by water and through trophic chain passes into the living organisms. It is found also that Acrididae accumulate later, during autumn and Bi 214. So they are a reliable bio-indicator for the radionuclides U 238, Ra 226, Pb 214 and Bi 214. It has been found that the ionizing radiation at the natural biocenoses is not only an individual irritant but also has an effect of a radioecological factor of the environment. The examinations show redistribution of the natural radionuclides as a result of economic activities

  4. Transfer-factors for radionuclides in the coal-fired power plants environments in Serbia

    International Nuclear Information System (INIS)

    Todorovic, Dragana; Jankovic, Marija; Joksic, Jasminka; Radenkovic, Mirjana

    2008-01-01

    Full text: During the coal combustion in power plants, radionuclides are distributed in solid and gaseous combustion products and discharged into environment. Radioactivity monitoring of coal-fired power-plants environments (PP Nikola Tesla, PP Kolubara, PP Morava and PP Kostolac) in Serbia was carried out during 2003-2006. Here are presented results concerning the soil-plant and ash-plant systems. Plant samples growing at the soil and ash disposals are analyzed by gamma spectrometry (HPGe detector, relative efficiency 23%) and corresponding transfer factors (TF) for natural isotopes 226 Ra, 232 Th and 40 K were calculated and discussed. Obtained concentrations values of naturally occurring radionuclides are in following ranges: (0.4 - 29) Bq/kg 226 Ra, (0.16 - 23) Bq/kg 232 Th, (245 - 1274) Bq/kg 40 K, (1.7 - 30) Bq/kg 238 U, (0.08 - 4.7) Bq/kg 235 U, (5.6 - 95) Bq/kg 210 Pb; (28 - 288) Bq/kg 7 Be and man-made 137 Cs in range 0.06 - 2.8 Bq/kg. Ash-to-plant and soil-to-plant transfer factors for 226 Ra, 232 Th and 40 K are calculated for several sampling points. Values for both ash-to-plant and soil-to-plant transfer factors are much higher for 40 K than 226 Ra and 232 Th probably due to different assimilation mechanisms of these elements by plants. Analyzed radionuclides have higher concentrations in the ash disposal than soil, and corresponding transfer-factors values obtained for ash-plant systems (ranged from 0,007 to 0,179 for 226 Ra, from 0,015 to 0,174 for 232 Th and from 0,418 to 2,230 for 40 K) are higher, indicating that there is no limit value for absorption in plants. (author)

  5. Radiological characterization of the coal ash and slag from Kastel Gomilica, Croatia

    International Nuclear Information System (INIS)

    Lovrencic, I.; Orescanin, V.; Barisic, D.; Mikelic, L.; Rozmaric Macefat, M.; Lulic, St.; Pavlovic, G.

    2006-01-01

    The objective of this study was radiological characterization of slag and ash produced in a thermo electric unit of the former 'Adriavinil' chemical factory as a by-product of coal combustion and deposited in the Kastel Gomilica region, Croatia. The waste material was deposited in the 'old' regulated and the 'new' unregulated part of the depot. 33 samples were analyzed to obtain a preliminary data on the present state of the new unregulated part of the depot. Activities of the selected radionuclides (40 K, 232 Th, 235 U and 226 Ra) were measured using gamma-spectrometry method. 238 U activity was calculated from the assumed natural 235 U /238 U activity ratio. It is found that there is a dependence of the activities of the selected radionuclides on the activities of the coal used for energy production in the power unit. The content of 232 Th, 226 Ra and 238 U in slag and ash increased several times during the combustion process. Investigated slag and ash showed a significant variability in their activities of selected radionuclides due to a different origin of coal used in the thermoelectric unit of the factory. The waste material was characterized by high activity of naturally occurring 238 U, 235 U and 226 Ra. 226 Ra and 238 U activities were up to 50 times higher than their average activities characteristic for surrounding soils developed on flysch sediments. 40 K and 232 Th showed no elevation compared to soil activities. Mineralogical analysis has been made as well. (authors)

  6. Radiological characterization of the coal ash and slag from Kastel Gomilica, Croatia

    Energy Technology Data Exchange (ETDEWEB)

    Lovrencic, I.; Orescanin, V.; Barisic, D.; Mikelic, L.; Rozmaric Macefat, M.; Lulic, St. [Rudjer Boskovic Institute, Zagreb (Croatia); Pavlovic, G. [Zagreb Univ., Faculty of Science, Dept. of Mineralogy and Petrography (Croatia)

    2006-07-01

    objective of this study was radiological characterization of slag and ash produced in a thermo electric unit of the former 'Adriavinil' chemical factory as a by-product of coal combustion and deposited in the Kastel Gomilica region, Croatia. The waste material was deposited in the 'old' regulated and the 'new' unregulated part of the depot. 33 samples were analyzed to obtain a preliminary data on the present state of the new unregulated part of the depot. Activities of the selected radionuclides (40 K, 232 Th, 235 U and 226 Ra) were measured using gamma-spectrometry method. 238 U activity was calculated from the assumed natural 235 U /238 U activity ratio. It is found that there is a dependence of the activities of the selected radionuclides on the activities of the coal used for energy production in the power unit. The content of 232 Th, 226 Ra and 238 U in slag and ash increased several times during the combustion process. Investigated slag and ash showed a significant variability in their activities of selected radionuclides due to a different origin of coal used in the thermoelectric unit of the factory. The waste material was characterized by high activity of naturally occurring 238 U, 235 U and 226 Ra. 226 Ra and 238 U activities were up to 50 times higher than their average activities characteristic for surrounding soils developed on flysch sediments. 40 K and 232 Th showed no elevation compared to soil activities. Mineralogical analysis has been made as well. (authors)

  7. Transfer of some artificial (226Sr and 137Cs) and natural (40K and 226Ra) radionuclides from milk to its products

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Nashawati, A.; Amin, Y.; Al-Akel, B.

    2005-01-01

    Transfer of some artificial radionuclides ( 137 Cs and 85 Sr) and natural radionuclides ( 226 Ra and 40 K) from milk (cheep and cows) to its products processed according to local manufacturing procedures (home made cheese, kashkawan cheese, shelal cheese, haloom cheese, kareshah cheese, sharkasiah cheese, liquid cheese, yogurt, butter and keshdah) has been studied. The results showed that the retention percent of radium 226 in milk products has reached %100 in the home made cheese and %72 for strontium 85 in the shelal cheese and %40 for cesium 137 in yogurt and %46 for potassium 40 also in yogurt. In addition, most of the retention percent ratios of the studied radionuclides in yogurt were relatively low (about %25 and % 40 in the yogurt processed from the milk of the cows and cheep respectively) with a high processing efficiency, so that making yogurt from the contaminated milk is the best way to reduce the contamination ratio and to make use of the contaminated milk. Furthermore, home made cheese was processed with salty solutions of different concentrations and the results showed that about %90 of cesium and potassium has transferred to the salty solution of %5 soaked for 48 hours, while %40 of the radium and %80 of strontium were removed from the contaminated cheese after 48 hours soaking in a salty solution of %2.5. However, the results of the present work can be used for processing of contaminated milk with artificial radionuclides in order to be utilized. (Authors)

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

    International Nuclear Information System (INIS)

    Pietrzak-Flis, Z.; Chrzanowski, E.; Dembinska, S.

    1997-01-01

    Intake with food and water of 226 Ra, 210 Pb and 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 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 210 Po/ 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 210 Po/ 210 Pb ratio was found to be approximately 10. In central Poland the largest intake of 226 Ra was with flour and vegetables (contribution approx. 60%), the largest intake of 210 Pb was with flour and meat (approx. 50%) and the largest intake of 210 Po was with fish (approx. 34%). From the intake and dose coefficient, annual effective doses were calculated. The dose from 210 Pb and 210 Po was approx. 54 μSv year -1 , and the dose from 226 Ra was approx. 4 μSv year -1

  9. Measurement of 226Ra, 228Ra, 137CS and 40K in edible parts of two types of leafy vegetables cultivated in Tehran province-Iran and resultant annual ingestion radiation dose

    International Nuclear Information System (INIS)

    Changizi, V.; Jafarpoor, Z.; Naseri, M.

    2010-01-01

    The sources of radioactivity in the environment have natural; terrestrial and extraterrestrial. and anthropogenic origins. Plants may get radioactive nuclides in two ways: (i) by the deposition of radioactive fallout, (ii) by absorption from the soil. Materials and Methods: The Concentrations of the natural radionuclides ( 226 Ra, 228 Ra, 40 K) and the artificial radionuclide ( 137 CS) in leek and parsley in Tehran province-Iran were determined using high-purity Ge detectors. Also the effective dose due to the ingestion of such vegetables by the population of Tehran province was studied. Results: The average value of radionuclide concentrations in parsley samples were measured 177.69 ± 12.47 mBq kg -1 fresh for 226 Ra; 349.62 ± 28.42 mBq kg -1 fresh for 228 Ra; 187364.6 mBq kg 1 fresh for 40 K. The average value of radionuclide concentrations in leek samples were measured 94.31 ± 6.46 mBq kg -1 fresh for 226 Ra; 207.47 ± 19.46 mBq kg -1 fresh for 228 Ra; 174555 ± 1704.21 mBq kg -1 fresh for 40 K. The concentrations of 137 Cs in most of Parsley and Leek samples were below the minimum detectable activity. Conclusion: The Average 226 Ra and 228 Ra activities in 29 leek and parsley samples were about 2.63 and 6.78 times the reference values, respectively. The annual effective dose resulting from the studied radionuclides for the adult population in Tehran province were found to be safe in comparison with normal background areas.

  10. Transfer of 226Ra to plants from two types of soil

    International Nuclear Information System (INIS)

    Rosiak, L.; Pietrzak-Flis, Z.

    1998-01-01

    The transfer of 226 Ra to plants used as food (carrot, parsley, wheat) and as fodder (grass, maize) was studied. The plants were grown on two types of soil: sandy soil (l) and sandy loam soil (II) in an open field (exposure to dry and wet deposition, resuspension and soil adhesion) and in polyethylene tent with an underground irrigation system (isolation from wet deposition and from water splash on soil). The plants were grown simultaneously on the open and sheltered fields. The average concentrations of total 226 Ra and of exchangeable 226 Ra were 8.48 ± 0.50 Bq/kg dw was 0.62 ± 0.07 Bq/kg dw , respectively, in Soil I and 12.2 ± 0.56 Bq/kg dw and 0.66 ± 0.05 Bq/kg dw , respectively, in Soil II. 226 Ra was determined in the above-ground parts of the plants after washing in distilled water, in the rinse obtained from washing, in the insoluble residue separated from the rinse, and in the roots. The data obtained allowed us to determine the incorporated radionuclide in the plants and on their surface. Statistical analysis of the data indicates that there is no difference in the incorporated 226 Ra for plants grown on the open field and in the tent. This indicates that Ra enter the plants mainly through the root system, while the pathway via leaves and stems is negligible

  11. Natural radionuclides in Austrian mineral water and their sequential measurement by fast methods

    International Nuclear Information System (INIS)

    Wallner, Gabriele; Wagner, Rosmarie; Katzlberger, Christian

    2008-01-01

    Ten samples of Austrian mineral water were investigated with regard to the natural radionuclides 228 Ra, 226 Ra, 210 Pb, 210 Po, 238 U and 234 U. The radium isotopes as well as 210 Pb were measured by liquid scintillation counting (LSC) after separation on a membrane loaded with element-selective particles (Empore TM Radium Disks) and 210 Po was determined by α-spectroscopy after spontaneous deposition onto a copper planchette. Uranium was determined by ICP-MS as well as by α-spectroscopy after ion separation and microprecipitation with NdF 3 . From the measured activity concentrations the committed effective doses for adults and babies were calculated and compared to the total indicative dose of 0.1 mSv/a given in the EC Drinking Water Directive as a maximum dose. The dominant portion of the committed effective dose was due to the radium isotopes; the dose from 228 Ra in most samples clearly exceeded the dose from 226 Ra

  12. Determination of ''226Ra by Alpha Spectrometry by Using ''225Ra as Yield Tracer

    International Nuclear Information System (INIS)

    Crespo, M. T.; Oller, O.

    1999-01-01

    A method for the determination of low-level ''226 Ra in environmental and geological samples by alpha spectrometry is described. The method is based on the use of ''225 Ra from ''229 Th as yield tracer and has been developed to analyze U, Th and Ra in the same sample. (Author) 12 refs

  13. Estuarine geochemistry of 224Ra, 226Ra, and 222Rn

    International Nuclear Information System (INIS)

    Elsinger, R.J.

    1982-01-01

    Desorption from river borne sediments is the most likely source of the excess 226 Ra. Laboratory mixing experiments on Pee Dee River sediments show an increase in 226 Ra desorption with increasing salinities with maximum desorption occurring at or above 20 0 /oo salinity. Desorption and diffusion are the sources for 226 Ra in the estuarine systems. In Winyah Bay the 228 Ra/ 226 Ra activity ratio does not change significantly with salinity, averaging around 1.4, indicating desorption as the major source of 228 Ra. In the Yangtze River the 228 Ra/ 226 Ra activity ratio is constant (approx.1.90) until increasing linearly above 16 0 /oo. A diffusive flux from regeneration by 232 Th decay in shelf sediments is the source of the increase. In Delaware Bay 228 Ra increases faster than 226 Ra in the less than or equal to22 0 /oo water, indicating a source in addition to desorption. The increase can be balanced by a 0.33 dpm/cm 2 -year flux over the upper part of the Bay where fine grained sediments predominate. 224 Ra behavior is controlled by its 3.64 day half-life. In Winyah Bay a flux of around 0.4 dpm/cm 2 -day is necessary to support the standing crop of non-desorbed 224 Ra in the water column. In Delaware Bay the nearly constant 224 Ra in concentration over the 2.5 0 /oo to 12 0 /oo salinity range are maintained by regeneration from 228 Th in the turbidity maximum zones and diffusion from bottom sediments. Water leaving on ebb tide from a salt marsh on Delaware Bay had increases in all three radium isotopes ( 224 Ra > 228 Ra > 226 Ra) compared to water coming in on the flood tide. Excess 222 Rn concentrations in a fresh water section of the Pee Dee River show a decreasing downstream gradient. Using these gradients to determine evasion rates, stagnant film thicknesses range from 21μ to 62μ

  14. Activity concentrations of 226Ra, 232Th and 40K in brands of fertilisers used in Nigeria

    International Nuclear Information System (INIS)

    Jibiri, N. N.; Fasae, K. P.

    2012-01-01

    The activity concentration of naturally occurring radionuclides 40 K, 226 Ra and 232 Th have been measured in different brands of fertiliser samples sold to farmers in retail markets in six commercial cities in southwestern Nigeria. Gamma ray spectroscopy was employed in the measurements of these radionuclides. The results of measurements showed that the average activity concentration of 40 K in the nitrogen, phosphorus and potassium fertilisers across the cities varied from 3972.0 ±416.9 to 5089.3 ±111.3 Bq kg -1 , 9.9 ±7.3 to 450.6 ±14.3 Bq kg -1 for 226 Ra, while for 232 Th it varied from less than lower limit of detection to 15.1 ±2.8 Bq kg -1 . The activity concentrations of 40 K, 226 Ra and 232 Th in single super phosphate (SSP) fertilisers and phosphate rocks were also determined. However, high activity concentrations of 226 Ra were obtained in the SSP fertiliser and phosphate rocks and in particular, two brands of fertilisers from ITL/TAK and F and C companies. The values of the activity concentration of the radionuclides in the brands of fertilisers used in Nigeria are within the range of values reported in several other countries except 40 K. (authors)

  15. Transfer of 226Ra, 85Sr and 137Cs from milk to milk products

    International Nuclear Information System (INIS)

    Al-Masri, M.S.; Nashawati, A.; Amin, Y.; Al-Akel, B.

    2006-01-01

    Transfer of 226 Ra, 85 Sr and 137 Cs from cow and sheep milk to various Syrian dairy products has been evaluated. Dairy products include Kashkivan cheese, braided cheese, Haloom cheese, Sircassian cheese, liquid cheese, native cheese, cottage, thick yogurt, butter and milk cream. The results showed that the percentage of 226 Ra, 85 Sr and 137 Cs transferred from cow milk to milk cream (P t = food processing retention factor x processing efficiency x 100%) has reached 32%, 16% and 7%, respectively. Butter and liquid cheese were found to have the lowest percentage of transferred 226 Ra, 85 Sr and 137 Cs. Most of the obtained P t values of the studied radionuclides in thick yogurt were relatively low in spite of the high processing efficiencies of thick yogurt. Moreover, the transfer, P t , of the studied radionuclides from cow milk to the prepared cheese was higher than those values determined for sheep milk. This is due to differences in chemical compositions of each type of milk. On the other hand, the treatment of Native cheese, most commonly consumed cheese in Syria, with different concentrations of NaCl solutions showed that 137 Cs was completely removed from cheese soaking in 5% NaCl solution (soaking time of 48 hours), while 40% of 226 Ra and 80% of 85 Sr were also decontaminated using 0-2.5% NaCl solutions and soaking time of 48 hours. Based on the obtained results, industrialization processes of the dairy products that resulted the removal of radionuclides have been identified. (author)

  16. Direct gamma-ray measurement of different radionuclides in the surface water of Suez Canal

    International Nuclear Information System (INIS)

    Lasheen, Y.F.; El-Zakla, T.; Seliman, A.F.; Abdel-Rassoul, A.A.

    2008-01-01

    The radioactivity levels of naturally-occurring 238 U, 232 Th, 226 Ra and 40 K and anthropogenic 137 Cs in surface water from eight locations in the Suez Canal have been assessed by gamma-ray spectrometry. The samples were further characterized by determination of the common cations and anions using ion chromatography. A comparison of 137 Cs radioactivity levels in surface water from the Suez Canal with those of other sea waters is presented. The radioactivity levels of 238 U, 232 Th, 226 Ra and 40 K from sea water are also reported. The effect of total dissolved solids (T.D.S.), chloride, sulphate ion concentrations on the radioactivity levels of 238 U, 232 Th and 226 Ra is discussed. (authors)

  17. Ra-226 bioaccumulation and growth indices in fish.

    Science.gov (United States)

    Shi, Xiaopei; Smith, Richard; Seymour, Colin; Mothersill, Carmel

    2017-06-01

    To determine the accumulated activity of Ra-226 in fathead minnows fed with environmentally relevant levels of Ra-226 for 5 months in water at 20 °C, and to evaluate the influence of this level of Ra-226 on the growth of fathead minnows. Fathead minnows were fed with fish food containing 10-10,000 mBq/g Ra-226 for 5 months. At the end of the experiment, the fish were sacrificed, flash frozen in liquid nitrogen and kept at -20 °C. Longitudinal sections of 40 μm thickness were cut at the middle of the fish body using a cryostat. The activity of Ra-226 in each section was determined using autoradiography with a nuclear track detector CR-39. According to the weight and the width of the fish, the activity of Ra-226 in the whole fish body could be estimated. In addition, the length and the weight of the fish were measured and the condition factor was calculated to evaluate the growth and fitness of the fish. There is a positive but non-linear relationship between the accumulated activity of Ra-226 in fish body and the concentration of Ra-226 in fish food. The highest activity of Ra-226 accumulated in fish body was found from fish fed with 10,000 mBq/g Ra-226 food. This was calculated as 256.4 ± 49.1 mBq/g, p fish fed with food containing lower concentration of Ra-226 (up to 1000 mBq/g), the bioaccumulation of Ra-226 in the body saturated. The Ra-226 concentration factor (CF) for fish was inversely proportional to the Ra-226 activity in food, and the highest CF value was 2.489, obtained from the lowest dietary Ra-226 activity (10 mBq/g). In addition, condition factors (K) of fish in all Ra-226-treated groups were significantly lower than those of the controls. The results show that the bioaccumulation of Ra-226 in fish is not simply related to the dietary Ra-226 activity, and has a saturation value when the dietary activity is low. In addition, the environmental level of Ra-226 in the fish food has a small adverse effect on the growth and fitness of fathead

  18. Intercomparison of radionuclides measurements in marine cockle flesh sample IAEA-134

    Energy Technology Data Exchange (ETDEWEB)

    Ballestra, S; Gastaud, J; Lopez, J J; Parsi, P; Vas, D

    1993-08-01

    The results of an intercomparison exercise on a cockle flesh sample from Irish Sea, IAEA-134, designed for the determination of artificial and natural radionuclide levels, are reported. The data from 134 laboratories representing 49 countries have been evaluated. The following are the recommended values, with confidence intervals, for {sup 40}K, {sup 60}Co, {sup 137}Cs, and 2{sup 39+240}Pu (Reference date: 1 January 1992). Information values for {sup 90}Sr, {sup 106}Ru, {sup 125}Sb, {sup 134}Cs, {sup 154}Eu, {sup 155}Eu, {sup 210}Pb, {sup 210}Po, {sup 226}Ra, {sup 228}Ra, {sup 228}Th, {sup 230}Th, {sup 232}Th, {sup 234}U, {sup 235}U, {sup 238}U, {sup 238}Pu and {sup 241}Am are also reported. All the following values are expressed in Bq kg{sup -1} (dry weight). (author)

  19. A survey of natural terrestrial and airborne radionuclides in moss samples from the peninsular Thailand.

    Science.gov (United States)

    Wattanavatee, Komrit; Krmar, Miodrag; Bhongsuwan, Tripob

    2017-10-01

    The aim of this study was to determine the activity concentrations of natural terrestrial radionuclides ( 238 U, 226 Ra, 232 Th and 40 K) and airborne radionuclides ( 210 Pb, 210 Pb ex and 7 Be) in natural terrestrial mosses. The collected moss samples (46) representing 17 species were collected from 17 sampling localities in the National Parks and Wildlife Sanctuaries of Thailand, situated in the mountainous areas between the northern and the southern ends of peninsular Thailand (∼7-12 °N, 99-102 °E). Activity concentrations of radionuclides in the samples were measured using a low background gamma spectrometer. The results revealed non-uniform spatial distributions of all the radionuclides in the study area. Principal component analysis and cluster analysis revealed two distinct origins for the studied radionuclides, and furthermore, the Pearson correlations were strong within 226 Ra, 232 Th, 238 U and 40 K as well as within 210 Pb and 210 Pb ex , but there was no significant correlation between these two groups. Also 7 Be was uncorrelated to the others, as expected due to different origins of the airborne and terrestrial radionuclides. The radionuclide activities of moss samples varied by moss species, topography, geology, and meteorology of each sampling area. The observed abnormally high concentrations of some radionuclides probably indicate that the concentrations of airborne and terrestrial radionuclides in moss samples were directly related to local geological features of the sampling site, or that high levels of 7 Be were most probably linked with topography and regional NE monsoonal winds from mainland China. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Evaluation of radionuclide contamination of soil, coal ash and zeolitic materials from Figueira thermoelectric power plant

    Energy Technology Data Exchange (ETDEWEB)

    Fungaro, Denise Alves; Silva, Paulo Sergio Cardoso da; Campello, Felipe Arrelaro; Miranda, Caio da Silva; Izidoro, Juliana de Carvalho, E-mail: dfungaro@ipen.br, E-mail: pscsilva@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-07-01

    Neutron activation analysis and gamma-ray spectrometry was used to determine {sup 238}U, {sup 226}Ra, {sup 228}Ra, {sup 210}Pb, {sup 232}Th and {sup 40}K contents in feed pulverized coal, bottom ash, fly ash from cyclone and baghouse filters, zeolites synthesized from the ashes and two different soil samples. All the samples used in the study was collected at Figueira thermoelectric power plant, located in the city of Figueira, Paraná State, which coal presents a significant amount of uranium concentration. The natural radionuclide concentrations in pulverized coal were 4216 Bq kg{sup -1} for {sup 238}U, 180 Bq kg{sup -1} for {sup 226}Ra, 27 Bq kg{sup -1} for {sup 228}Ra, 28 Bq kg{sup -1} for {sup 232}Th and 192 Bq kg{sup -1} for {sup 40}K. The ashes fraction presented concentrations ranging from 683.5 to 1479 Bq kg{sup -1} for {sup 238}U, from 484 to 1086 Bq kg{sup -1} for {sup 226}Ra, from 291 to 1891 Bq kg{sup -1} for {sup 210}Pb, from 67 to 111 Bq kg{sup -1} for {sup 228}Ra, from 80 to 87 Bq{sup -1} for {sup 232}Th and from 489 to 718 Bq kg{sup -1} for {sup 40}K. Similar ranges were observed for zeolites. The activity concentration of {sup 238}U was higher than worldwide average concentration for all samples. The concentration of the uranium series found in the ashes were lower than the values observed in similar studies carried out 10 years ago and under the limit adopted by the Brazilian guideline (CNEN-NN-4.01). Nevertheless, the concentrations of this specific area are higher than others coal mines and thermoelectric power plants in and out of Brazil, so it is advisable to evaluate the environmental impact of the installation. (author).

  1. Long-lived natural Ra isotopes in mineral, therapeutic and spring waters in Caxambu, Minas Gerais state, Brazil

    International Nuclear Information System (INIS)

    Negrao, Sergio Garcia; Oliveira, Joselene de

    2011-01-01

    In many countries all around the world, there is an increasing tendency to replace surface drinking water by commercially available bottled mineral water from different springs for consumption purposes. These practices involve an increased risk of finding higher activities of natural radionuclides in such waters, predominantly of the uranium-radium decay series. Naturally occurring radionuclides such as 238 U, 226 Ra, 222 Rn, 210 Po and 228 Ra are found frequently dissolved in water supplies and their concentrations vary over an extremely wide range. However, from the point of view of radiation hygiene, results of many worldwide surveys indicate that only 222 Rn, 226 Ra and 228 Ra have been found in concentrations that may be of health concern. 226 Ra and 228 Ra are the most radiotoxic isotopes of radium due to their long half-lives, 1,600 and 5.75 years, respectively. Since their chemical behavior is similar to that of calcium, radium isotopes tend to accumulate mostly in the skeleton after ingestion. For the purposes of this study, samples of mineral spring water were taken in Caxambu, a thermal resort located in the extreme south of Minas Gerais, 370 km south of Belo Horizonte. Caxambu is renowned by its waterpark, which has twelve sources of mineral water already being used in treatment of stomach, liver and kidney diseases, between others. 226 Ra activity concentrations varied from 83 to 3,599 mBq L-1, the highest value determined at Venancio spring. Activity concentrations of 228 Ra ranged from 69 to 4,481 mBq L-1. 228 Ra/ 226 Ra activity ratios varied from 0.079 to 4.2. (author)

  2. Determination of 228Th, 226Ra and 40K in Soil Using In-Situ GammaSpectrometer

    International Nuclear Information System (INIS)

    Bunawas; Wahyudi; Syarbaini; Untara

    2000-01-01

    Determination of natural radionuclide in latosol soil at six locationsaround PPTN Serpong by using Inspector portable gamma spectrometer with highpurity Germanium detector (HPGe) which has 26% relative efficiency had beenobtained. Radionuclides data of 228 Th, 226 Ra and 40 K were obtained in4 hours, shorter than laboratories analysis which needed 3 weeks. Thedifferences between in-situ measurement and laboratory were 3.6% to 56.2% forsix conditions of soil measured. According to the specific activity dataanalysis using statistic hypothesis, the result shows that the activity of 228 Th and 226 Ra are independent on location, but 40 K is dependent onlocation. (author)

  3. Certified reference material for radionuclides in fish flesh sample IAEA-414 (mixed fish from the Irish Sea and North Sea)

    International Nuclear Information System (INIS)

    Pham, M.K.; Sanchez-Cabeza, J.A.; Povinec, P.P.; Arnold, D.; Benmansour, M.; Bojanowski, R.; Carvalho, F.P.; Kim, C.K.; Esposito, M.; Gastaud, J.; Gasco, C.L.; Ham, G.J.; Hegde, A.G.; Holm, E.; Jaskierowicz, D.; Kanisch, G.; Llaurado, M.; La Rosa, J.; Lee, S.-H.; Liong Wee Kwong, L.; Le Petit, G.; Maruo, Y.; Nielsen, S.P.; Oh, J.-S.; Oregioni, B.; Palomares, J.; Pettersson, H.B.L.; Rulik, P.; Ryan, T.P.; Sato, K.; Schikowski, J.; Skwarzec, B.; Smedley, P.A.; Tarjan, S.; Vajda, N.; Wyse, E.

    2006-01-01

    A certified reference material (CRM) for radionuclides in fish sample IAEA-414 (mixed fish from the Irish Sea and North Seas) is described and the results of the certification process are presented. Nine radionuclides ( 4 K, 137 Cs, 232 Th, 234 U, 235 U, 238 U, 238 Pu, 239+24 Pu and 241 Am) were certified for this material. Information on massic activities with 95% confidence intervals is given for six other radionuclides ( 9 Sr, 21 Pb( 21 Po), 226 Ra, 239 Pu, 24 Pu 241 Pu). Less frequently reported radionuclides ( 99 Tc, 129 I, 228 Th, 23 Th and 237 Np) and information on some activity and mass ratios are also included. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in fish sample, for the development and validation of analytical methods and for training purposes. The material is available from IAEA, Vienna, in 100 g units

  4. Radionuclides distribution, properties, and microbial diversity of soils in uranium mill tailings from southeastern China

    International Nuclear Information System (INIS)

    Yan, Xun; Luo, Xuegang

    2015-01-01

    Objective: To collect the radioactive contamination data for environmental rehabilitation in uranium mill tailings in southeastern China. Method: The sample areas were divided into high, moderate and low concentration areas, according to the uranium concentration. For every area, 3 soil samples were collected at 0–15 cm, 15–30 cm and 30–45 cm depth respectively, with 5 repetitions for each. Total 45 (3 × 5 × 3) soil samples were collected. Physicochemical properties and enzyme activities of soils were determined as described by references. The concentrations of the radionuclides 238 U, 232 Th, 226 Ra and 40 K in soils were determined by using HPGe gamma-ray spectrometer. Soil microbial diversity was analyzed via denaturing gradient gel electrophoresis (DGGE). Results: Soil samples were all acidic. Physicochemical properties, like pH, content of total/available N, P and K, as well as enzyme activities were all increased along with decreased uranium concentration. The 232 Th concentration was increased with the decreased uranium concentration and was not influenced by the depth of sample sites. However, uranium concentration and depth of sample showed no significant influence on the concentrations of 226 Ra and 40 K. The concentration of 232 Th was significantly correlated with that of 226 Ra and 40 K, while the concentrations of 226 Ra and 40 K were significantly correlated. However, Pearson correlation coefficients between 238 U and other radionuclides were not significant. The microbial population in different concentration areas was different with four domain strains in low area, and two for both moderate and high areas. Furthermore, in each sample site, Proteobacteria was the most dominant flora, while environmental samples were the second according to GenBank database. Moreover, Serratia sp. of Proteobacteria was the dominant strain. Conclusion: Radionuclides distribution in the uranium mill tailing showed a profound influence on soil properties and

  5. National low-level waste management program radionuclide report series, Volume 15: Uranium-238

    International Nuclear Information System (INIS)

    Adams, J.P.

    1995-09-01

    This report, Volume 15 of the National Low-Level Waste Management Program Radionuclide Report Series, discusses the radiological and chemical characteristics of uranium-238 ( 238 U). The purpose of the National Low-Level Waste Management Program Radionuclide Report Series is to provide information to state representatives and developers of low-level radioactive waste disposal facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the waste disposal facility environment. This report also includes discussions about waste types and forms in which 238 U can be found, and 238 U behavior in the environment and in the human body

  6. In-situ radionuclide transport and preferential groundwater flows at INEEL (Idaho): Decay-series disequilibrium studies

    International Nuclear Information System (INIS)

    Luo, S.; Ku, T.L.; Roback, R.; Murrell, M.; McLing, T.L.

    2000-01-01

    Uranium and thorium-decay series disequilibria in groundwater occur as a result of water-rock interactions, and they provide site-specific, natural analog information for assessment of in-situ, long-term migration of radionuclides in the far field of a nuclear waste disposal site. In this study, a mass balance model was used to relate the decay-series radionuclide distributions among solution, sorbed and solid phases in an aquifer system to processes of water transport, sorption-desorption, dissolution-precipitation, radioactive ingrowth-decay, and α recoil. Isotopes of U and Rn were measured in 23 groundwater samples collected from a basaltic aquifer at the Idaho National Engineering and Environmental Laboratory (INEEL), Idaho. The results show that groundwater activities of Th and Ra isotopes are 2--4 orders lower than those of their U progenitors. Modeling of the observed disequilibria places the following constraints on the time scale of radionuclide migration and water-rock interaction at INEEL: (1) Time for sorption is minutes for Ra and Th; time for desorption is days for Ra and years for Th; and time for precipitation is days for Th, years for Ra, and centuries for U. (2) Retardation factors due to sorption average > 10 6 for 232 Th, approximately10 4 for 226 Ra, and approximately10 3 for 238 U. (3) Dissolution rates of rocks are approximately70 to 800 mg/L/y. (4) Ages of groundwater range from 222 Rn occur near the groundwater recharging sites as well as in the major flow pathways. Decay of the sorbed parent radionuclides (e.g., 226 Ra and 228 Ra) on micro-fracture surfaces constitutes an important source of their daughter ( 222 Rn and 228 Th) activities in groundwater

  7. Natural radionuclides in effluents release by a deactivated uranium mine

    International Nuclear Information System (INIS)

    Pereira, Wagner S.; Kelecom, Alphonse; Silva, Ademir X.; Lopes, José M.; Pinto, Carlos E.C.; Py Júnior, Delcy A.; Antunes, Marcos M.; Indústrias Nucleares do Brasil; Universidade Federal Fluminense; Coordenacao de Pos-Graduacao e Pesquisa de Engenharia

    2017-01-01

    The Ore Treatment Unit (OTU) is a mine and deactivated uranium plant in the city of Caldas, Minas Gerais, Brazil. This facility possesses three points of release of liquid effluents containing radionuclides: point 014, 025 and 076. At these points, the values of activity concentrations (AC) of the radionuclides U_n_a_t, "2"2"6Ra, "2"1"0Pb, "2"3"2Th and "2"2"8Ra were analyzed in 2012. The evaluation of point 014 by univariate statistics pointed four groups. [U_n_a_t > "2"2"8Ra > ("2"2"6Ra = "2"1"0Pb) >"2"3"2Th]. The multivariate statistics separated the radionuclides into two groups: [(U_n_a_t and "2"3"2Th) and ("2"2"6Ra, "2"2"8Ra and "2"1"0Pb)]. At point 025, the univariate statistics described three groups: [Un_a_t > ("2"2"8Ra = "2"1"0Pb) > ("2"2"6Ra = "2"3"2Th)] and the multivariate analysis also described three but different groups: [(U_n_a_t and "2"2"8Ra), ("2"2"6Ra and "2"1"0Pb) and "2"3"2Th]. In turn, point 076 showed another behavior. The univariate analysis showed only two groups: [(U_n_a_t) > ("2"2"6Ra, "2"2"8Ra, "2"1"0Pb, "2"3"2Th)]. Differently, the multivariate statistics defined three groups: [(U_n_a_t and "2"3"2Th), ("2"2"6Ra and "2"2"8Ra) and "2"1"0Pb].Thus, statistical analysis showed that each point has releases of effluents with different characteristics. Both the behaviors of releases, based on multivariate statistics, and of the AC magnitudes, based on the univariate statistics, are different between the points. The only common features were the greater magnitude of uranium and the smaller magnitude of thorium. (author)

  8. Interactions between surface runoff, hydro sediments and radionuclides ({sup 210}Pb, {sup 226}Ra, {sup 228}Ra, Th e U) at Alto Ribeirão das Antas, Poços de Caldas, MG, Brazil; Interações entre escoamento superficial, hidrossedimentos e radionuclídeos ({sup 210}Pb, {sup 226}Ra, 228Ra, Th e U) no Alto Ribeirão das Antas, Poços de Caldas-MG

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Flavio Henrique de Souza

    2017-07-01

    Knowledge about hydrological and sedimentological dynamics of a river basin is fundamental to the adequate management of water resources, and it can support the identification of contaminants in the water, the estimation of water erosion, the estimation of reservoir siltation, and even the reduction of water treatment costs. The study carried out in Alto Ribeirão das Antas River Basin assessed, throughout seasons, all interactions between the surface runoff and the transport of suspended and underwater hydro-sediments, through direct monitoring of two sites at the Ribeirão das Antas channel. Concurrently, the potential of the indirect monitoring of suspended solids concentration was evaluated using an optical turbidity sensor. The hydrological results point to a high precipitation in the region, however with a well balanced distribution among the humid months, allowing the basin’s high capacity to transform precipitation into surface runoff. Sediment transport rates characterize the studied area as a low sediment production region. The sedimentological regime was found to be in accordance with the surface runoff regime, reflected by the seasonality of the transported masses. The estimation of transport of sediment in suspension through optical turbidity sensor presented promising results. Most of the results of radionuclides {sup 210}Pb, {sup 226}Ra, {sup 228}Ra, Th and U observed in water and in suspended hydro-sediment were below the detection limit of the methodology, whereas in the riverbed hydro-sediments quantification of radionuclides was possible. The radiometric results indicate absence of radionuclide carriage from the Águas Claras Dam at INB Caldas to Ribeirão das Antas. The low concentration values of radioactive elements observed in the study may be of natural origin, once the Poços de Caldas Plateau region presents a geological constitution endowed with anomalies associated to radionuclides. (author)

  9. 230Th-238U disequilibrium and the melting processes beneath ridge axes

    International Nuclear Information System (INIS)

    McKenzie, D.

    1985-01-01

    The activity ratio ( 230 Th/ 238 U) is calculated for a simple model of melting, for which the melt fraction in chemical and radioactive equilibrium with the solid residium remains constant as melting proceeds. The activity ratio in the melt is only significantly different from unity if the melting is slow compared with the half-life of 230 Th and if the melt fraction present at any time does not exceed a few percent. The observation that ( 230 Th/ 238 U) is about 1.25 for many ocean ridge basalts is therefore most easily explained if the melt fraction in the source region is less than 2% and if the melting occurs in a broad region more than 100 km wide beneath the ridge axis. These results are compatible with other geophysical observations. Measurements of ( 226 Ra/ 238 U) might provide useful constraints on the time required to reach chemical equilibrium between the melt and the matrix. (orig.)

  10. Natural-series radionuclides in traditional North Australian aboriginal foods

    Energy Technology Data Exchange (ETDEWEB)

    Murray, A.S.; Johnston, A.; Hancock, G.J.; Martin, P. [Environmental Research Institute of the Supervising Scientist (ERISS), Jabiru (Australia)

    1997-07-01

    Activity concentrations of the radionuclides {sup 226}Ra, {sup 210}Pb, {sup 210}Po, {sup 238}U, {sup 234}U, {sup 230}Th, {sup 232}Th and {sup 227}Ac were measured in edible flesh of traditional Aboriginal food items from the Magela and Cooper Creek systems in the tropical Northern Territory of Australia. Fish, buffalo, pig, magpie goose, filesnake, goanna, turtle, freshwater shrimp and freshwater crocodile were studied. Activity concentrations in water were also measured to enable the calculation of concentration ratios (CRs).For most edible flesh samples, activity concentrations followed the approximate order: {sup 210}Po>>{sup 226210}[{sup 234}Usimilar{sup 238}[{sup 230}Thsimilar{sup 232}Th]. The {sup 210}Po/{sup 210}Pb activity ratio was particularly high (greater than 100) for pig flesh. CRs for fish species fall into two groups. Group 1 (bony bream and sleepy cod) had CRs about five times higher than for group 2 (eight other species). CRs for turtle flesh were similar to those for fish in group 1, while those for turtle liver were about a factor of 10 higher. CRs for magpie goose, filesnake, freshwater shrimp, goanna and crocodile flesh were also of the same order as for fish in groups 1 or 2.Calculations of dose resulting from release of wastewaters from uranium mining operations in the region show that the dominant pathway would be uptake of radionuclides, especially {sup 226}Ra, by freshwater mussels, followed by radionuclide uptake by fish. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights reserved.)

  11. Low impact of exposure to environmentally relevant doses of 226Ra in Atlantic cod (Gadus morhua) embryonic cells

    International Nuclear Information System (INIS)

    Olsvik, Pål A.; Berntssen, Marc H.G.; Hylland, Ketil; Eriksen, Dag Ø.; Holen, Elisabeth

    2012-01-01

    The aim of this study was to investigate whether 226 Ra, a radionuclide present in produced water from oil platforms in the North Sea and other offshore drilling areas, could affect vulnerable early life stages of Atlantic cod (Gadus morhua). Blastula-stage embryonic cells (EC) from fertilized eggs of Atlantic cod were isolated and exposed to environmental relevant concentrations of 226 Ra and transcription of selected genes quantified. The results showed a weak, but significant up-regulation of GPx3 and HSP70 transcripts after 48 h of exposure to 2.11 Bq/L. In EC exposed to three 226 Ra concentrations (2.11, 23 and 117 Bq/L) for 12 h, metallothionein, HSP90AA, thioredoxin and caspase 8 were significantly up-regulated in cells exposed to 117 Bq/L, whereas thioredoxin was also significantly up-regulated in EC exposed to 23 Bq/L. When EC were exposed to the same 226 Ra concentrations for 48 h, only heme oxygenase was significantly up-regulated in the 23 Bq/L exposure group. The results suggest that environmentally relevant activities of 226 Ra may induce oxidative stress and apoptosis in fish ECs. Exposure of Atlantic cod EC to Cd, selected as a model toxicant, supported the ability of EC around blastula stage to respond to toxicants by altered transcription. Due to dilution, environmentally relevant concentrations of radionuclides present in produced water would be expected to pose a minor threat to early life stages of fish. - Highlights: ► 226 Ra affects the transcription of genes in Atlantic cod embryonic cells. ► 226 Ra may induce oxidative stress and apoptosis in fish embryonic cells. ► 226 Ra not expected to pose a major threat to early life stages of marine fish.

  12. Absorbed Dose Rate Due to Intake of Natural Radionuclides by Tilapia Fish (Tilapia nilotica,Linnaeus, 1758) Estimated Near Uranium Mining at Caetite, Bahia, Brazil

    International Nuclear Information System (INIS)

    Pereira, Wagner de S; Kelecom, Alphonse; Azevedo Py Junior, Delcy de

    2008-01-01

    The uranium mining at Caetite (Uranium Concentrate Unit--URA) is in its operational phase. Aiming to estimate the radiological environmental impact of the URA, a monitoring program is underway. In order to preserve the biota of the deleterious effects from radiation and to act in a pro-active way as expected from a licensing body, the present work aims to use an environmental protection methodology based on the calculation of absorbed dose rate in biota. Thus, selected target organism was the Tilapia fish (Tilapia nilotica, Linnaeus, 1758) and the radionuclides were: uranium (U-238), thorium (Th-232), radium (Ra-226 and Ra-228) and lead (Pb-210). As, in Brazil there are no radiation exposure limits adopted for biota the value proposed by the Department of Energy (DOE) of the United States of 3.5x10 3 μGy y -1 has been used. The derived absorbed dose rate calculated for Tilapia was 2.51x10 0 μGy y -1 , that is less than 0.1% of the dose limit established by DOE. The critical radionuclide was Ra-226, with 56% of the absorbed dose rate, followed by U-238 with 34% and Th-232 with 9%. This value of 0.1% of the limit allows to state that, in the operational conditions analyzed, natural radionuclides do not represent a radiological problem to biota

  13. A review of the behaviour of U-238 series radionuclides in soils and plants

    International Nuclear Information System (INIS)

    Mitchell, N; Pérez-Sánchez, D; Thorne, M C

    2013-01-01

    The U-238 series of radionuclides is of relevance in a variety of environmental contexts ranging from the remediation of former uranium mining and milling facilities to the deep geological disposal of solid radioactive wastes. Herein, we review what is known concerning the behaviour of radionuclides from the U-238 decay chain in soils and plants. This review is intended to provide a single comprehensive source of information to anyone involved in undertaking environmental impact assessment studies relating to this decay chain. Conclusions are drawn relating to values and ranges of distribution coefficients appropriate to uranium, thorium, radium, lead and polonium in different soil types and under various environmental conditions. Similarly, conclusions are drawn relating to plant:soil concentration ratios for these elements for different plant and soil types, and consideration is given to the distribution of these elements within plants following both root uptake and foliar application. (review)

  14. Uranium-series constraints on radionuclide transport and groundwater flow at the Nopal I uranium deposit, Sierra Pena Blanca, Mexico.

    Science.gov (United States)

    Goldstein, Steven J; Abdel-Fattah, Amr I; Murrell, Michael T; Dobson, Patrick F; Norman, Deborah E; Amato, Ronald S; Nunn, Andrew J

    2010-03-01

    Uranium-series data for groundwater samples from the Nopal I uranium ore deposit were obtained to place constraints on radionuclide transport and hydrologic processes for a nuclear waste repository located in fractured, unsaturated volcanic tuff. Decreasing uranium concentrations for wells drilled in 2003 are consistent with a simple physical mixing model that indicates that groundwater velocities are low ( approximately 10 m/y). Uranium isotopic constraints, well productivities, and radon systematics also suggest limited groundwater mixing and slow flow in the saturated zone. Uranium isotopic systematics for seepage water collected in the mine adit show a spatial dependence which is consistent with longer water-rock interaction times and higher uranium dissolution inputs at the front adit where the deposit is located. Uranium-series disequilibria measurements for mostly unsaturated zone samples indicate that (230)Th/(238)U activity ratios range from 0.005 to 0.48 and (226)Ra/(238)U activity ratios range from 0.006 to 113. (239)Pu/(238)U mass ratios for the saturated zone are 1000 times lower than the U mobility. Saturated zone mobility decreases in the order (238)U approximately (226)Ra > (230)Th approximately (239)Pu. Radium and thorium appear to have higher mobility in the unsaturated zone based on U-series data from fractures and seepage water near the deposit.

  15. Radionuclides in waters and soil near the Lagoa Real uranium mine

    International Nuclear Information System (INIS)

    Souza, Susana Oliveira de; Freire, Fabinara Dantas; Dias, Dario M.; Veiga, Artur Jose Pires

    2015-01-01

    Uranium mining generates fuel for the nuclear power plants and it is the main source of income for the region of Caetite-BA. However, Non-Governmental Organizations claim that mining pollutes the environment and jeopardizes human health and safety. Besides uranium, the ground contains significant concentrations of thorium and of all radionuclides of its family, such as radium isotopes. In this framework, we carried out an independent study analyzing the concentration of the radionuclides activities 226, 228 Ra and 234,238 U in water samples and radionuclides 226 Ra, 232 Th and 40 K in soil samples using different techniques of nuclear spectrometry. The selection criteria for the collection points were their proximity to the uranium processing plant and to affluent rivers. The soil samples presented very low concentration of activity for radionuclides investigated, compared to the limits established of the exclusion, exemption and impartiality for radiation protection requirement given by the Regulator Position established by CNEN. The amount of radioisotopes appears consistent with a natural origin, thus it is not possible to state that the mining process in Caetite increases pollution or radiation exposure in a significant way. (author)

  16. Radionuclides in waters and soil near the Lagoa Real uranium mine

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Susana Oliveira de; Freire, Fabinara Dantas, E-mail: sosouza@ufs.br [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Departamento de Fisica; Kozlowska, Beata; Walencik-Lata, Agata, E-mail: beata.kozlowska@us.edu.pl [University of Silesia, Institute of Physics, Katowice (Poland); Dias, Dario M., E-mail: engenheirodario@gmail.com [Secretaria Municipal de Meio Ambiente e Turismo, Andarai, BA (Brazil); Veiga, Artur Jose Pires, E-mail: tk1@ibest.com [Universidade Estadual do Sudoeste da Bahia (UESB), Itapetinga, BA (Brazil). Departamento de Ciencias Exatas e Tecnologicas

    2015-07-01

    Uranium mining generates fuel for the nuclear power plants and it is the main source of income for the region of Caetite-BA. However, Non-Governmental Organizations claim that mining pollutes the environment and jeopardizes human health and safety. Besides uranium, the ground contains significant concentrations of thorium and of all radionuclides of its family, such as radium isotopes. In this framework, we carried out an independent study analyzing the concentration of the radionuclides activities {sup 226,} {sup 228}Ra and {sup 234,238}U in water samples and radionuclides {sup 226}Ra, {sup 232}Th and {sup 40}K in soil samples using different techniques of nuclear spectrometry. The selection criteria for the collection points were their proximity to the uranium processing plant and to affluent rivers. The soil samples presented very low concentration of activity for radionuclides investigated, compared to the limits established of the exclusion, exemption and impartiality for radiation protection requirement given by the Regulator Position established by CNEN. The amount of radioisotopes appears consistent with a natural origin, thus it is not possible to state that the mining process in Caetite increases pollution or radiation exposure in a significant way. (author)

  17. Absorbed Dose Rate Due to Intake of Natural Radionuclides by Tilapia Fish (Tilapia nilotica,Linnaeus, 1758) Estimated Near Uranium Mining at Caetité, Bahia, Brazil

    Science.gov (United States)

    Pereira, Wagner de S.; Kelecom, Alphonse; Py Júnior, Delcy de Azevedo

    2008-08-01

    The uranium mining at Caetité (Uranium Concentrate Unit—URA) is in its operational phase. Aiming to estimate the radiological environmental impact of the URA, a monitoring program is underway. In order to preserve the biota of the deleterious effects from radiation and to act in a pro-active way as expected from a licensing body, the present work aims to use an environmental protection methodology based on the calculation of absorbed dose rate in biota. Thus, selected target organism was the Tilapia fish (Tilapia nilotica, Linnaeus, 1758) and the radionuclides were: uranium (U-238), thorium (Th-232), radium (Ra-226 and Ra-228) and lead (Pb-210). As, in Brazil there are no radiation exposure limits adopted for biota the value proposed by the Department of Energy (DOE) of the United States of 3.5×103 μGy y-1 has been used. The derived absorbed dose rate calculated for Tilapia was 2.51×100 μGy y-1, that is less than 0.1% of the dose limit established by DOE. The critical radionuclide was Ra-226, with 56% of the absorbed dose rate, followed by U-238 with 34% and Th-232 with 9%. This value of 0.1% of the limit allows to state that, in the operational conditions analyzed, natural radionuclides do not represent a radiological problem to biota.

  18. Cleanup protocol for 226Ra-contaminated cobbly soil at UMTRA Project sites

    International Nuclear Information System (INIS)

    Gonzales, D.E.; Millard, J.B.; Miller, M.L.; Metzler, D.

    1994-01-01

    The nonuniform distribution of 226Ra and other radiological contamination of cobbly soil encountered on several Uranium Mill Tailings Remedial Action Project sites is presented and discussed, and the concomitant challenges to the intent and implementation of the U.S. Environmental Protection Agency's soil cleanup standards are noted. In response to technical assessments and information presented to the U.S. Nuclear Regulatory Commission by the U.S. Department of Energy, the Nuclear Regulatory Commission has recently resolved the dilemma by concluding that compliance with Environmental Protection Agency soil cleanup standards for cobby soil at Uranium Mill Tailings Remedial Action Project sites would be adequately attained using bulk radionuclide concentrations, instead of requiring that the radionuclide concentration of the finer soil fraction passing a No. 4 mesh sieve met the standards. A Nuclear Regulatory Commission-approved procedure developed for cobbly soil remediation is outlined and discussed. The site-specific implementation of this procedure at Uranium Mill Tailings Remedial Action Project sites containing cobbly soil is estimated to save millions of dollars

  19. 210Pb/226Ra disequilibria in otoliths of blue grenadier, (Macruronus novaezelandiae); problems associated with radiometric aging

    International Nuclear Information System (INIS)

    Fenton, G.E.; Ritz, D.A.

    1990-01-01

    Otoliths from blue grenadier (Macruronus novaezelandiae), which had been aged previously by annuli analysis, were analysed for the naturally occurring radionuclides 210 Pb and 226 Ra in an attempt to independently verify their age. It is concluded that the radiometric technique could not be applied to determine age because the results showed that 226 Ra was not incorporated at a constant rate throughout the life of M. novaezelandiae. Uptake of 226 Ra was greater in juveniles than in adult fish. This was probably due to the juvenile phase inhabiting inshore/estuarine waters. 20 refs., 1 tab., 2 figs

  20. Natural radionuclides concentration in underground mine materials

    Energy Technology Data Exchange (ETDEWEB)

    Santos, T.O.; Rocha, Z.; Taveira, N.F.; Takahashi, L.C.; Pineiro, M.M., E-mail: talitaolsantos@yahoo.com.br, E-mail: rochaz@cdtn.br, E-mail: mayarapinheiroduarte@gmail.com, E-mail: lauratakahashi@hotmail.com, E-mail: natyfontaveira@hotmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Borges, P.F.; Cruz, P.; Gouvea, V.A.; Siqueira, J.B., E-mail: vgouvea@cnen.gov.br, E-mail: flavia.borges@cnen.gov.br, E-mail: pcruz@cnen.gov.br, E-mail: jbsiquei@cnen.gov.br [Comissão Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    Natural Radionuclides are present in earth's environment since its origin. The main radionuclides present are {sup 40}K, as well as, {sup 238}U and {sup 232}Th with their decay products. These radionuclides occur in minerals in different activity concentration associated with geological and geochemical conditions, appearing at different levels from point to point in the world. Underground mines may present a high natural background radiation which is due to the presence of these radiogenic heavy minerals. To address this concern, this work outlines on the characterization of the natural radionuclides presence in underground mines in Brazil which are located in many cases on higher radiation levels bed rocks. The radon concentration was measured by using E-PERM Electrets Ion Chamber, AlphaGUARD and CR-39 track etch detectors. The radon progeny was determined by using DOSEman detector. Radon concentration measurement in groundwater was performed by using RAD7 detector. The {sup 238}U and {sup 232}Th activity concentration in ore and soil samples were determined by using Neutron Activation Analysis using TRIGA MARK I IPR-R1 Reactor. Gamma spectrometry was used to determine {sup 226}Ra, {sup 228}Ra and {sup 40}K activity concentrations. The results show that the natural radioactivity varies considerably from mine to mine and that there are not risks of radiological damage for exposed workers in these cases. Based on these data, recommendations for Brazilian regulatory standards are presented. (author)

  1. Natural radionuclides concentration in underground mine materials

    International Nuclear Information System (INIS)

    Santos, T.O.; Rocha, Z.; Taveira, N.F.; Takahashi, L.C.; Pineiro, M.M.; Borges, P.F.; Cruz, P.; Gouvea, V.A.; Siqueira, J.B.

    2017-01-01

    Natural Radionuclides are present in earth's environment since its origin. The main radionuclides present are 40 K, as well as, 238 U and 232 Th with their decay products. These radionuclides occur in minerals in different activity concentration associated with geological and geochemical conditions, appearing at different levels from point to point in the world. Underground mines may present a high natural background radiation which is due to the presence of these radiogenic heavy minerals. To address this concern, this work outlines on the characterization of the natural radionuclides presence in underground mines in Brazil which are located in many cases on higher radiation levels bed rocks. The radon concentration was measured by using E-PERM Electrets Ion Chamber, AlphaGUARD and CR-39 track etch detectors. The radon progeny was determined by using DOSEman detector. Radon concentration measurement in groundwater was performed by using RAD7 detector. The 238 U and 232 Th activity concentration in ore and soil samples were determined by using Neutron Activation Analysis using TRIGA MARK I IPR-R1 Reactor. Gamma spectrometry was used to determine 226 Ra, 228 Ra and 40 K activity concentrations. The results show that the natural radioactivity varies considerably from mine to mine and that there are not risks of radiological damage for exposed workers in these cases. Based on these data, recommendations for Brazilian regulatory standards are presented. (author)

  2. Uranium-series constraints on radionuclide transport and groundwater flow at the Nopal I uranium deposit, Sierra Pena Blanca, Mexico

    International Nuclear Information System (INIS)

    Goldstein, S.J.; Abdel-Fattah, A.I.; Murrell, M.T.; Dobson, P.F.; Norman, D.E.; Amato, R.S.; Nunn, A.J.

    2009-01-01

    Uranium-series data for groundwater samples from the Nopal I uranium ore deposit were obtained to place constraints on radionuclide transport and hydrologic processes for a nuclear waste repository located in fractured, unsaturated volcanic tuff. Decreasing uranium concentrations for wells drilled in 2003 are consistent with a simple physical mixing model that indicates that groundwater velocities are low (∼10 m/y). Uranium isotopic constraints, well productivities, and radon systematics also suggest limited groundwater mixing and slow flow in the saturated zone. Uranium isotopic systematics for seepage water collected in the mine adit show a spatial dependence which is consistent with longer water-rock interaction times and higher uranium dissolution inputs at the front adit where the deposit is located. Uranium-series disequilibria measurements for mostly unsaturated zone samples indicate that 230 Th/ 238 U activity ratios range from 0.005-0.48 and 226 Ra/ 238 U activity ratios range from 0.006-113. 239 Pu/ 238 U mass ratios for the saturated zone are -14 , and Pu mobility in the saturated zone is >1000 times lower than the U mobility. Saturated zone mobility decreases in the order 238 U∼ 226 Ra > 230 Th∼ 239 Pu. Radium and thorium appear to have higher mobility in the unsaturated zone based on U-series data from fractures and seepage water near the deposit.

  3. Determination of 226Ra and 228Ra concentrations in foodstuffs consumed by inhabitants of Tehran city of Iran

    International Nuclear Information System (INIS)

    Asefi, M.; Fathivand, A. A.; Amidi, A.; Najafi, A.

    2005-01-01

    The presence of primordial radionuclide in human habitats has always been a source of prolonged exposure. Measurement of naturally occurring radionuclides in the environment can be used as baseline to evaluate the impact of non-nuclear activities and also routine releases from nuclear installations. Materials and Methods: A total of 56 samples from 18 different foodstuff including root vegetables (beetroot, carrot, onion, potato, radish and turnip), leafy vegetables (lettuce, parsley, spinach and white cabbage) and lentil, kidney bean, Soya, eggs, rice, meat, tomato and cooking oil were purchased and analyzed by low level gamma spectrometry. Results: The 226 Ra concentrations from root vegetables varied from 13-62 mBqkg -1 with turnip of highest concentration, i.e. 62mBqkg -1 . Among leafy vegetables; parsley showed the maximum concentration of 228 Ra equal to 173 mBqkg -1 . 226 Rand 228 Ra contents in the soya, 394 and 578 mBq kg -1 was much higher than those of other samples respectively. Conclusion : Results indicate that foodstuff consumed by Tehran inhabitants have low radium content and are safe, as far as radium concentrations is concerned

  4. Removal of 226Ra from tailings pond effluents and stabilization of uranium mine tailings. Bench and pilot scale studies

    International Nuclear Information System (INIS)

    Schmidtke, N.W.; Averill, D.; Bryant, D.N.; Wilkinson, P.; Schmidt, J.W.

    1978-01-01

    Increased world demand for uranium has resulted in recent expansion of Canadian uranium mining operations. Problems have been identified with the discharge of radionuclides such as 226 Ra from tailings pond effluents and with the stabilization of mine tailings. At Environment Canada's Wastewater Technology Centre (WTC) two projects were undertaken in cooperation with the Canadian Uranium Mining Industry and other federal government agencies to address these problems. The first project reports on the progress of bench and pilot scale process simulations for the development of a data base for the design of a full scale mechanical physical/chemical 226 Ra removal waste treatment system with an effluent target level of 10 pCi 226 Ra total per litre. The second project addresses problems of the leachability of radionuclides and the stabilization of both uranium mine tailings and BaRaSO 4 sediments from the treatment of acid seepages

  5. Determination of sup 226 Ra and sup 228 Ra in gypsum

    Energy Technology Data Exchange (ETDEWEB)

    Godoy, J M [Instituto de Radioprotecao e Dosimetria, Rio de Janeiro, RJ (Brazil)

    1989-01-01

    The content of {sup 226}Ra and {sup 228}Ra in different samples of phosphogypsum and three samples of gypsite were determined by gamma spectroscopy. For {sup 226}Ra the 295, 352 and 609 KeV lines and for {sup 228}Ra the 911 and 969 KeV lines were used. The specific activities values ranged from 0.36 to 22.8 pCi/g for {sup 226}Ra and 0.90 to 10.3 pCi/g for {sup 228}Ra. The contribution of a sypsum roof-covering to the {sup 222}Rn concentration in a room was estimated, based on the highest value reported. (author).

  6. 238U decay series nuclides in the northeastern Arabian Sea: scavenging rates and cycling processes

    International Nuclear Information System (INIS)

    Sarin, M.M.; Krishnaswami, S.; Ramesh, R.; Somayajulu, B.L.K.

    1994-01-01

    The extent of radioactive disequilibrium between 234 Th- 238 U, 210 Po- 210 Pb and 210 Pb- 226 Ra has been measured in four vertical profiles from the northeastern Arabian Sea, a region characterized by oxygen deficient and denitrification layers at intermediate depths. The most common feature of the data is that the dissolved concentrations of the daughter nuclides are considerably less than those of their parents, exceptions being the near equilibrium or excess concentrations of 210 Po (relative to 210 Pb) at ∼ 100 m and that of 210 Pb relative to 226 Ra in surface waters. These results suggest that scavenging of dissolved 234 Th, 210 Po and 210 Pb occurs throughout the water column in the northeastern Arabian Sea. (Author)

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

    International Nuclear Information System (INIS)

    Hollanda Vasconcellos, L.M. de.

    1984-01-01

    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)

  8. Radionuclides in corals of Costa Rica

    International Nuclear Information System (INIS)

    Loria M, L.G.; Banichevich, A.; Cortes, T.

    1998-01-01

    Using Low Level Spectrometry they have evaluated the activity (Kq/kg) of 40 K, the gamma emisor daugther of 238 U and 232 Th and the presence of arificial isotopes due to anthropogenic contamination. The probes used are coral as biodynamic captors. The results show a presence between low and mittel of natural isotopes compared to other accumulation processes like sedimentation in soil and agricultural production. The Caribbean side show a higher activity than the Pacific for 40 K and a similar for 226 Ra. Results show low activity for artificial radionuclides with short lif ( 137 Cs). (author) [es

  9. 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)

    Tomazini da Conceicao, Fabiano; Bonotto, Daniel Marcos; Jimenez-Rueda, Jairo Roberto; Frutuoso Roveda, Jose Arnaldo

    2009-01-01

    The common use of phosphate fertilizers NPK and amendments in sugar cane crops in Brazilian agriculture may increase the 226 Ra, 232 Th and 40 K 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 226 Ra, 232 Th and 40 K in soils and sugar cane crops in the Corumbatai river basin, Sao Paulo State, Brazil. The gamma spectrometry was utilized to measure the 226 Ra, 232 Th and 40 K 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 40 K> 226 Ra> 232 Th. Therefore, under these conditions, radionuclides intake through consumption of sugar is not hazardous to human health.

  10. Adsorption of 241Am and 226Ra from natural water by wood charcoal

    International Nuclear Information System (INIS)

    Miro, C.; Baeza, A.; Salas, A.; Pastor-Valle, J.F.; Pastor-Villegas, J.

    2008-01-01

    The adsorption of 241 Am and 226 Ra from natural water by a granulated wood charcoal was investigated as a function of the solution pH, in the range 4-10, and of the water flow, in the range 3.5-42 cm 3 /min. The percentage adsorption of 241 Am (fairly constant at >80% for all pHs) was greater than that of 226 Ra (which increased with increasing pH from ∼40% up to >80%). The results are explained by considering the different species of each radionuclide present at the pH values of the solution at the end of the adsorbent column, and the pH of the point of zero charge of the adsorbent. At pH 6, the elimination of 241 Am from natural water was independent of the water flow, while the elimination of 226 Ra declined linearly as the flow rate was increased

  11. Activity concentrations of /sup 226/Ra, /sup 228/Ra, /sup 210/Pb, /sup 40/K and /sup 7/Be and their temporal variations in surface air

    Energy Technology Data Exchange (ETDEWEB)

    Hoetzl, H.; Winkler, R.

    1987-01-01

    Activity concentrations of the long-lived natural radionuclides /sup 226/Ra, /sup 228/Ra, /sup 210/Pb, /sup 40/K and of /sup 7/Be in surface air were measured twice monthly at a semi-rural location 10 km north of Munich (FRG) for at least three years. For the time interval 1983-1985, all values were found to be distributed log-normally, with geometric means (in ..mu..Bq m-./sup 3/) of 1.2 for /sup 226/Ra, 0.5 for /sup 228/Ra, 580 for /sup 210/Pb, 12 for /sup 40/K and 3500 for /sup 7/Be. Reflecting their common origin, the activity concentrations of /sup 226/Ra and /sup 40/K are correlated with surface air dust concentrations (geometric mean 59 ..mu..g m/sup -3/). Seasonal variations of /sup 210/Pb and /sup 7/Be air activity concentrations are established for the time interval 1978-1985.. The contribution of local soil activity to the air activity concentrations of these radionuclides and of natural uranium is discussed. Resuspension factors are found to be of the order of 10/sup -9/ m/sup -1/.

  12. Geoquímica de radionuclídeos naturais em solos de áreas circunvizinhas a uma Unidade de Mineração e Atividade de Urânio Geochemistry of natural radionuclide in soils surrounding a Mining and Plant Uranium Concentration

    Directory of Open Access Journals (Sweden)

    Gildevan Viana Cardoso

    2009-12-01

    Full Text Available Os impactos ambientais advindos da exploração e do beneficiamento de U são, em grande parte, idênticos àqueles causados por atividades minero-extrativistas em geral. Este trabalho teve o objetivo de determinar a partição geoquímica dos radionuclídeos naturais 238U, 226Ra e 210Pb em áreas circunvizinhas à Unidade de Mineração e Atividade de Urânio (URA das Indústrias Nucleares do Brasil S.A., localizada na Província Uranífera de Lagoa Real, no município de Caetité, na região sudoeste do Estado da Bahia. Foram coletadas amostras de solo em cinco áreas circunvizinhas à URA, representando as principais classes de solos da região, na profundidade de 0-20 cm. Nas cinco áreas, foram determinados o teor de atividade total e o fracionamento geoquímico nas frações: F1 - levemente ácida, F2 - reduzível, F3 - oxidável, F4 - alcalina e F5 - residual. As atividades totais médias foram, em Bq kg-1 de solo, de 50 para 238U, 51 para 226Ra e 159 para 210Pb. Os extraídos na fase potencialmente biodisponível (F1 foram: 11 % para 238U, 13 % para 226Ra e 3 % para 210Pb. O 238U apresentou maior biodisponibilidade nos solos mais ácidos e maior afinidade pelos óxidos de Fe, o que não ocorreu para o 226Ra, tendo este apresentado a maior biodisponibilidade. O 210Pb apresentouse predominantemente associado a F5. As percentagens elevadas de 238U, 226Ra e 210Pb na fração geoquímica F5 indicam que as atividades observadas nos cinco solos estão, predominantemente, associadas ao material que deu origem a esses solos, e não a um processo de contaminação artificial em função da atividade da URA.The environmental impacts resulting from uranium exploration and processing are to a great extent identical to those caused by extractive mining activities in general. This study aimed to determine the geochemical partitioning of the natural radionuclides 238U, 226Ra and 210Pb in areas surrounding the Uranium Mining and Concentration Plant (URA

  13. Determination of natural radionuclides in lichen samples of Carnoparmelia Texana

    International Nuclear Information System (INIS)

    Alencar, Marcos M.; Damatto, Sandra R.; Mazzilli, Barbara P.

    2009-01-01

    Lichen plays an important role in studies of environmental pollution. It can be used for the evaluation of air contaminants, including heavy metals and radionuclides. The main objective of this study is to verify the possibility of using the lichen species Canoparmelia Texana for the assessment of natural radionuclides of the U and Th decay series in air in the vicinity of Instituto de Pesquisas Energeticas e Nucleares (IPEN) installations. IPEN has as major activity to perform research in the field of the nuclear fuel cycle, and therefore deals with natural radionuclides of the U and Th series. The content of 238 U, 234 U, 230 Th, 210 Po and 232 Th in lichen samples were determined by alpha spectrometry after a radiochemical separation. Ra isotopes and 210 Pb were determined by gross alpha and beta counting after a radiochemical separation and measurement on a low background gas flow proportional detector. The results obtained for 238 U varied from 2.4 ± 0.4 Bq kg -1 to 6.6 ± 0.1 Bq kg -1 and from 4.4 ± 0.3 Bq kg -1 to 12.1 ± 2.6 Bq kg -1 , for 232 Th. For 226 Ra varied from 13 ± 1 Bq kg -1 to 38 ± 2 Bq kg -1 and from 200 ± 13 Bq kg -1 to 351 ± 12 Bqkg -1 for 228 Ra. The results obtained were compared with data obtained for the same radionuclides in lichen samples in an area affected by TENORM industry and can be considered as background for this lichen species. It can be concluded that the control of atmospheric discharges of IPEN facilities has been effective along the years, giving no evidence of radiological environmental impact. (author)

  14. Determinations of 90Sr, 137Cs, 226Ra, 228Ra, 210Pb, 210Po contents in chinese diet and estimations of internal doses due to these radionuclides

    International Nuclear Information System (INIS)

    Zhu Hongda; Wang Shouliang; Meng Wei; Wang Daoping; Zheng Xiujun; Liu Qingfen; Liu Peng

    1993-01-01

    As a part of Chinese Total Diet Survey taken place in 1990, the authors report the determined results on 90 Sr, 137 Cs, 226 Ra, 228 Ra, 210 Pb and 210 Pb and 210 Po contents in various foods of Chinese total diet. Based on obtained dietary composition and the determined contents, the Annual Intakes (AI) and Committed Dose Equivalents (CDE) for the public by ingestion were estimated. It is shown that the total CDE for 6 radionuclides is about 0.24 mSv/a. The food categories and nuclides whose relative contributions to the total are dominant were vegetables, aquatic products and cereal, and 210 Pb, 210 Po, 228 Ra, respectively. The results have updated the data from 1982 survey and have complemented important information for water consumption. The regional difference of dietary compositions and resultant internal doses are discussed as well

  15. Natural radioactivity assessment of surface sediments in the Yangtze Estuary

    International Nuclear Information System (INIS)

    Wang, Jinlong; Du, Jinzhou; Bi, Qianqian

    2017-01-01

    The activities of the natural radionuclides ( 238 U, 232 Th, 226 Ra and 40 K) of the surface sediments in the Yangtze Estuary were determined and used to evaluate radiation hazards in the study area. The of activities of 238 U, 232 Th, 226 Ra and 40 K ranges from 14.1 to 62.3, 26.1 to 71.9, 13.7 to 52.3, and 392 to 898 Bq kg −1 , respectively, which were comparable to values of other regions in China. The activities of 232 Th, 40 K and 226 Ra were clearly different from the global recommended values. The radium equivalent activity was less than the recommended limit of 370 Bq kg −1 ; therefore, the sediment in this area can be safely used for reclamation. The external hazard index values were less than one. The average absorbed gamma dose rate and annual effective dose equivalent values were slightly greater than the world average value. 226 Ra/ 238 U and 232 Th/ 238 U ratios could potentially be applied for tracing sediment source. - Highlights: • The natural radioactivity of surface sediments in the Yangtze Estuary was observed. • The radiological hazards of the sediments are insignificant in this study area. • The ratios of natural radionuclides can potentially be applied for sediment source.

  16. Distribution of radionuclides in different parts of a mushroom: Influence of the degree of maturity

    Energy Technology Data Exchange (ETDEWEB)

    Baeza, Antonio [Department of Physics, Veterinary Faculty, University of Extremadura, Avda de la Universidad s/n, 10071 Caceres (Spain)]. E-mail: ymiralle@unex.es; Guillen, Fco. Javier [Department of Physics, Veterinary Faculty, University of Extremadura, Avda de la Universidad s/n, 10071 Caceres (Spain); Salas, Alejandro [Department of Physics, Veterinary Faculty, University of Extremadura, Avda de la Universidad s/n, 10071 Caceres (Spain); Manjon, Jose Luis [Department of Plant Biology, Faculty of Sciences, University of Alcala, 28871 Alcala de Henares, Madrid (Spain)

    2006-04-15

    Mushrooms are known to be bioaccumulators of radionuclides, but little is known about their distribution within the fruiting bodies or the influence of the degree of maturity on uptake. We carried out a series of cultures of the species Pleurotus eryngii under controlled laboratory conditions to analyze these variables. The maximal uptake of {sup 134}Cs and {sup 85}Sr was found to occur in mature fruiting bodies, and with the growth of the mushroom the distribution of radionuclides within the fruiting bodies became inhomogeneous. In particular, there was an exponential increase in the percentage of the total activity of {sup 134}Cs, {sup 85}Sr, and {sup 6}Co in the cap + gills as the fruiting bodies matured, accompanied by a complementary decrease in the stem. Radiocaesium, potassium, calcium, {sup 239+24}Pu, {sup 234,238}U, {sup 228,230,232}Th, and {sup 226}Ra were assayed in the cap, gills, and stem of fruiting bodies of Tricholoma equestre collected in a natural ecosystem and cultured P. eryngii. Potassium and radiocaesium were mainly located in the cap + gills, and {sup 226}Ra in the gills. There was a disequilibrium between {sup 230,232}Th and {sup 228}Th in the different parts of the fungi, probably due to uptake of {sup 228}Ra and subsequent decay to {sup 228}Th. Finally, the distribution pattern of{sup 239+24}Pu, {sup 234,238}U, and {sup 230,232}Th seemed to be species dependent.

  17. Relation of forms of compounds of heavy natural radionuclides in soils

    International Nuclear Information System (INIS)

    Arkhipov, N.P.; Fedorova, T.A.; Fevraleva, L.T.

    1986-01-01

    Results of studying forms of 238 U, 232 Th, 226 Ra, 210 Po, 210 Pb compounds in nonfertilized soils (under control) and in soils fertilized with ammophos containing increased amount of the mentioned radionuclides are given. The study was performed in main-year field experiment with sandy ashen gray soil and leached chernozemic soil. It is shown that a main share of radionuclides in nonfertilized soils is presened with tightly bound compounds and compounds bound with sesquioxide compounds. After 5 years labelled natural radionuclides introduced into the ammophos composition are in a more mobile state as compared with radionuclides in nonfertilized soil and they are presented with acid-soluble and bound with humus compound forms. Systematical application of fertilizers during along-term period results in the concentration increase of heavy natural radionuclides in soil

  18. Environmental characterization and radiological impacts of non-nuclear industries on the red sea coast

    International Nuclear Information System (INIS)

    Mamoney, M. H. El; Khater, Ashraf E. M.

    2002-01-01

    The Red Sea is a deep semi-enclosed and narrow basin connected to the Indian Ocean by a narrow sill in the south and to the Suez Canal in the north. Oil industries in the Gulf of Suez, phosphate ore mining activities in Safaja- Quseir region and intensified navigation activities are non-nuclear land base pollution sources that could have a serious radiological impacts on the marine environment and the coastal ecosystems of the Red Sea. It is a need and an essential to draw up the radiological base-line data, which is not exist yet and to investigate the radio-ecological impact of non- nuclear industries to protect the coastal environment of the Red Sea. Natural and man- made radionuclides have been measured in shore sediment samples collected from the Egyptian coast of the Red Sea. The specific activities of 226 Ra ( 238 U)series, 232 Th series, 40 K, 137 Cs and 210 Pb (Bq/kg dry weight) were measured using gamma ray spectrometry based on hyper pure germanium detectors. The specific activities of 210 Po ( 210 Pb) and uranium isotopes ( 238 U, 235 U and 234 U), (Bq/kg dry weight) were measured using alpha spectrometry based on surface barrier (PIPS) detectors after radiochemical separation. The absorbed radiation dose rates in air (nGy/h) due to natural radionuclides in shore sediment and radium equivalent activity (Bq/kg) were calculated. The specific activity ratios of 228 Ra/ 226 Ra, 210 Pb/ 226 Ra, 226 Ra/ 238 U and 234 U/ 238 U were calculated for evaluation of geo-chemical behaviour of these radionuclides. These results were represented and discussed. The results gave an indication of the possible radiological impacts of oil industries in the northern region and phosphate mining activities in the Safaja-Quseir region

  19. Radionuclide fluxes at a plant manufacturing dicalcium phosphate for domestic animals

    International Nuclear Information System (INIS)

    Gaefvert, T.; Holm, E.

    2002-01-01

    The objectives of this study is to map out the fluxes of radionuclides from the 238 U decay series as well as estimate doses to workers at a dicalcium phosphate plant. At the studied plant phosphate rock is used for the production of dicalcium phosphate, which is a source of calcium and phosphorous for domestic animals. A by-product in the manufacturing process is calcium chloride which is used in the oil industry, food industry and as road salt. In the phosphate rock, the radionuclides were found in secular radioactive equilibrium with an average activity concentration of 830 Bq·kg -1 . Separation and concentration processes was observed. Most of the 226 Ra was found in the calcium chloride while the major part of 238 U was found in the dicalcium phosphate, about 950 Bq·kg -1 . The annual occupational effective dose to workers was found to be below the 1 mSv limit. The study shows a good example of an important non-nuclear industry with a high input of natural radionuclides and several conceivable pathways to man. (author)

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

    International Nuclear Information System (INIS)

    Vera Tome, F.; Blanco Rodriguez, P.; Lozano, J.C.

    2008-01-01

    The elimination of natural uranium and 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 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 226 Ra from the solution: about 50% of the natural uranium and 70% of the 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. Distribution of 226Ra body burden of workers in an underground uranium mine in India.

    Science.gov (United States)

    Patnaik, R L; Jha, V N; Kumar, R; Srivastava, V S; Ravi, P M; Tripathi, R M

    2014-11-01

    Uranium mine workers are exposed to ore dust containing uranium and its daughter products during different mining operations. These radionuclides may pose inhalation hazards to workers during the course of their occupation. The most significant among these radionuclides is (226)Ra. The measurement of radium body burden of uranium mine workers is important to assess their internal exposure. For this purpose, the radon-in-breath measurement technique has been used in the present paper. Workers at the Jaduguda mine, India, associated with different categories of mining operations were monitored between 2001 and 2007. The measurement results indicate that workers--depending on mining operation category--show (226)Ra body burdens ranging from 0.15 to 2.85 kBq. The maximum body burden was found for workers associated with timbering operations, with an average (226)Ra body burden of 0.85 ± 0.54 kBq. Overall, the average value observed for 800 workers was 0.76 ± 0.51 kBq, which gives rise to an average effective dose of 1.67 mSv per year for inhalation and 0.21 mSv per year for ingestion.

  2. Uranium-series constraints on radionuclide transport and groundwater flow at the Nopal I uranium deposit, Sierra Pena Blanca, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, S.J.; Abdel-Fattah, A.I.; Murrell, M.T.; Dobson, P.F.; Norman, D.E.; Amato, R.S.; Nunn, A. J.

    2009-10-01

    Uranium-series data for groundwater samples from the Nopal I uranium ore deposit were obtained to place constraints on radionuclide transport and hydrologic processes for a nuclear waste repository located in fractured, unsaturated volcanic tuff. Decreasing uranium concentrations for wells drilled in 2003 are consistent with a simple physical mixing model that indicates that groundwater velocities are low ({approx}10 m/y). Uranium isotopic constraints, well productivities, and radon systematics also suggest limited groundwater mixing and slow flow in the saturated zone. Uranium isotopic systematics for seepage water collected in the mine adit show a spatial dependence which is consistent with longer water-rock interaction times and higher uranium dissolution inputs at the front adit where the deposit is located. Uranium-series disequilibria measurements for mostly unsaturated zone samples indicate that {sup 230}Th/{sup 238}U activity ratios range from 0.005-0.48 and {sup 226}Ra/{sup 238}U activity ratios range from 0.006-113. {sup 239}Pu/{sup 238}U mass ratios for the saturated zone are <2 x 10{sup -14}, and Pu mobility in the saturated zone is >1000 times lower than the U mobility. Saturated zone mobility decreases in the order {sup 238}U{approx}{sup 226}Ra > {sup 230}Th{approx}{sup 239}Pu. Radium and thorium appear to have higher mobility in the unsaturated zone based on U-series data from fractures and seepage water near the deposit.

  3. Natural radionuclides in soils of a forest fragment of Atlantic Forest under ecological restoration process

    International Nuclear Information System (INIS)

    Ferreira, F.S.; Lira, M.B.; Souza, E.M.; França, E.J.

    2017-01-01

    The natural radioactive isotopes come from the radioactive series of the 238 U (Uranium Series), the 235 U (Actinium Series) and the 232 Th (Thorium Series) series, or they can occur in isolation as is the case with the 40 K. Primordial radionuclides such as 40 K, 232 Th, 235 U and 238 U exist since the formation of the earth, being found in appreciable amounts in nature and in some cases may present a mass activity above the acceptable of environmental radiation. The objective of this work was to evaluate the mass activity of 40 K, 226 Ra and 228 Ra in the soils of a fragment of Atlantic Forest under ecological restoration process located in the Municipality of Paulista, PE, Brazil. Soil samples (0 - 15 cm) were collected under the projection of the treetops of the most abundant trees in the region. After drying and comminution, analytical portions of 40 g were transferred to polyethylene petri dishes, sealed and stored for 30 days to ensure secular equilibrium. Radioactivity was quantified by High Resolution Gamma Spectrometry - EGAR. The mean physical activities of 40 K, 226 Ra and 228 Ra were 12, 15 and 20 Bq kg -1 , respectively, for the surface soil of the Parque Natural Municipal Mata do Frio. The values found were lower than those found in mangroves in the state of Pernambuco and those considered normal for soils worldwide

  4. Risk assessment of human exposure to Ra-226 in oil produced water from the Bakken Shale.

    Science.gov (United States)

    Torres, Luisa; Yadav, Om Prakash; Khan, Eakalak

    2018-06-01

    Unconventional oil production in North Dakota (ND) and other states in the United States uses large amounts of water for hydraulic fracturing to stimulate oil flow. Most of the water used returns to the surface as produced water (PW) containing different constituents. Some of these contents are total dissolved solids and radionuclides. The most predominant radionuclide in PW is radium-226 (Ra-226) of which level depends on several factors including the content of certain cations. A multivariate regression model was developed to predict Ra-226 in PW from the Bakken Shale based on the levels of barium, strontium, and calcium. The simulated Ra-226 activity concentration in PW was 535 pCi/L supporting extremely limited actual data based on three PW samples from the Bakken (527, 816, and 1210 pCi/L). The simulated activity concentration was further analyzed by studying its impact in the event of a PW spill reaching a surface water body that provides drinking water, irrigation water for crops, and recreational fishing. Using food transfer factors found in the literature, the final annual effective dose rate for an adult in ND was estimated. The global average annual effective dose rate via food and drinking water is 0.30 mSv, while the predicted dose rate in this study was 0.49 mSv indicating that there is potential risk to human health in ND due to Ra-226 in PW spills. This predicted dose rate is considered the best case scenario as it is based on the simulated Ra-226 activity concentration in PW of 535 pCi/L which is close to the low end actual activity concentration of 527 pCi/L. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Natural uranium and 226Ra in bottled potable waters of Argentina

    International Nuclear Information System (INIS)

    Bomben, Ana M.; Palacios, Miguel A.

    2001-01-01

    This paper presents the results obtained of the measurement of the natural uranium and 226 Ra concentrations carried out on 345 drinking water samples coming from different provinces of Argentina. The samples were collected from tap water systems and private wells. Six bottled mineral waters samples, selected from those most extensively consumed, were also analyzed. The natural uranium concentration was determined by a fluorimetric procedure and 226 Ra by the 222 Rn emanation technique and liquid scintillation counting. Values ranging from 0,03 to 50 μg L -1 of natural uranium and concentrations up to 22 mBq L -1 were found in the drinking water samples analyzed. Natural uranium concentrations from 0,04 to 3,8 μg L -1 and 226 Ra concentrations up to 2,4 mBq L -1 were measured in the bottled mineral waters samples. Based on the water intake rate and the measured concentrations of both radionuclides analyzed, an annual collective effective dose of 1,5 man Sv and an average committed effective dose of 0,5 μSv a -1 , were calculated for the City of Buenos Aires inhabitants. (author)

  6. Quantitative Mechanistic Description of Natural Radionuclide and Iron Sorption on phosphate Fertilizer Materials

    International Nuclear Information System (INIS)

    Kamel, N.H.M.

    2008-01-01

    The mean activity values of the radionuclide 226 Ra, 238 U and 232 Th decay series, and the radioactive isotopes of 40 K in Bq/kg dry weight of the phosphate ore (Pho-ore), single super phosphate granules, (SSP-G), single super phosphate powder (SSP-P), triple super phosphate (TSP), and phosphogypsum (CaSO 4 ) samples were determined. CaSO 4 sample was found to contain, 300 Bq/kg of radioactive 238 U which is less than the values found in other studied phosphate samples. CaSO 4 sample was found to contain the highest amount of 226 Ra concentration value of 850 Bq/kg. Phosphate fertilizer components are acidic character, therefore, the solid surfaces will in general acquire a surface electric charge when contact with polar solvent such as water. The net electric charge obtained through uptake or release of potential determining ions (e.g, H + or OH - ). Thus the solid surfaces tend to adsorb and/or release of different ions to maintain neutral. The aim of this study is to determine the electric charge and the surface electric potential at the phosphate fertilizer materials

  7. Monitoring of radionuclides in carbon steel blooms produced by EAF process

    Directory of Open Access Journals (Sweden)

    Sofilić T.

    2011-01-01

    Full Text Available Because natural and artificial isotopes in steel might originate from steel scrap or from the residue of the material that was used in the technological process, thus monitoring especially artificial radionuclides 60Co, 137Cs and 192Ir deserve special attention. The analysis by g-spectrometry has been applied to determine the presence of natural isotopes 40K, 226Ra, 232Th and 238U as well as of the artificial isotope 60Co, 137Cs and 192Ir and their activity in the produced steel round blooms in the Steel Mill of CMC Sisak d.o.o. At the same time the content of radionuclides in the other materials (ferroalloys, bauxite, fluorite, lime, coke, graphite electrodes, refractory blocks used in the same steel making process was investigated. The measured values regarding the presence of individual isotopes and their activity in steel were as follows: 40K all values were less than 1.6 Bqkg-1; 232Th all activities values were less than 0.02 Bqkg-1; 226Ra all activities values were less than 0.01 Bqkg-1; 238U all activities values were less than 1.10 Bqkg-1; 60Co all activities values were less than 0.02 Bqkg-1; 192Ir all activities values were less than 0.02 Bqkg-1 and 137Cs all activities values were less than 0.30 Bqkg-1.

  8. Ra-226, Pb-210, and Po-210 in the Black Forest

    International Nuclear Information System (INIS)

    Schuettelkopf, H.; Kiefer, H.

    1981-01-01

    By measuring Pb-210, Po-210 and Ra 226 in air, water, ground, plants, and food samples the concentration ranges of the radionuclide and the transfer factor important for the calculation of the ingestion dose of man were determined. Po 210 was found to have the lowest radiotoxicity. The highest Po-210 concentrations were found in protein-containing food. (DG) [de

  9. Dose rates as a function of time due to postulated radionuclide releases from the U.S. Yucca Mountain high-level radioactive waste repository

    International Nuclear Information System (INIS)

    Moeller, Dade W.; Sun, Lin-Shen C.; Cherry, Robert

    2008-01-01

    had occurred prior to the year in which the assessment was being made. It was also assumed that the associated dose occurred during the year of the release. Based on these analyses, the dominating radionuclide, from the time of repository closure to slightly more than 10 3 year, will be 241 Am. This will be followed by 239 Pu which will be the highest contributor to dose up to about 2.2 x 10 5 year after repository closure. The dominating radionuclide from that time through 10 6 year will be 226 Ra, due to its production through the continuing decay of the relatively large quantity of 234 U and 238 U in the repository. (author)

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

    International Nuclear Information System (INIS)

    Tan Jinbo; Hao Runlong; Tang Zhenxin

    1994-01-01

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

  11. Skeletal dosimetry of injected 226RA in young adult beagles

    International Nuclear Information System (INIS)

    Lloyd, R.D.; Mays, C.W.; Atherton, D.R.

    1986-01-01

    Revised equations are presented for the skeletal dose to young adult beagles from 226 Ra injection. For 0.1 kg of skel/kg body and given 1 μCi 226 Ra/kg with 210 Pb/ 226 Ra = 0.05, the average skeletal dose in rad at 6 yr is 226 Ra = 1200, 222 Rn -> 214 Po = 1050, injected 210 Pb = 56 and 210 Pb from Rn decay in bone = 22. For a Pb/Ra ratio = 0.4, dose from injected 210 Pb is about 20% of that from 226 Ra -> 214 Po. A similar but not numerically indentical relationship obtains for ingested 226 Ra, so the dose from 210 Pb should be included in any study of 226 Ra effects. (orig.)

  12. The natural radioactivity in Guarani aquifer groundwater, Brazil.

    Science.gov (United States)

    Bonotto, D M; Bueno, T O

    2008-10-01

    The measurements of gross alpha and gross beta radioactivity in groundwater samples from Guarani aquifer in Brazil are reported in this paper together with the activity concentration of the natural dissolved radionuclides (40)K, (238)U, (234)U, (226)Ra, (222)Rn, (210)Po, (210)Pb, (232)Th, (228Th), and (228)Ra. Most of the gross alpha radioactivity values were below the critical level of detection corresponding to 1 mBq/L, however, the whole data set for the gross beta radioactivity and radionuclides (40)K, (238)U, (234)U, (226)Ra, (222)Rn, (210)Po, (210)Pb, and (228)Ra was submitted to a statistical treatment, considering class intervals arranged in geometric progression, because of the great variability of the activity. The analysis indicated lognormal distribution of the data, as usually observed in samples taken from the natural context. An inverse relationship between the gross alpha and gross beta activity has been identified and is related to an increase in the K content in the water. The mobility coefficient has been estimated for (238)U, (226)Ra, (232)Th and (228)Ra in Guarani aquifer and the results indicated that the radioelement solubility in the studied system varies according to the following order: radium>uranium>thorium. The implications of the data obtained in terms of standards established for defining the drinking water quality have also been discussed.

  13. Naturally Occurring Radionuclides of Ash Produced by Coal Combustion. The Case of the Kardia Mine in Northern Greece

    Science.gov (United States)

    Fotakis, M.; Tsikritzis, L.; Tzimkas, N.; Kolovos, N.; Tsikritzi, R.

    2008-08-01

    West Macedonia Lignite Center (WMLC), located in Northwest Greece, releases into the atmosphere about 21,400 tons/year of fly ash through the stacks of four coal fired plants. The lignite ash contains naturally occurring radionuclides, which are deposited on the WMLC basin. This work investigates the natural radioactivity of twenty six ash samples, laboratory produced from combustion of lignite, which was sampled perpendicularly to the benches of the Kardia mine. The concentrations of radionuclides 40K, 235U, 238U, 226Ra, 228Ra and 232Th, were measured spectroscopically and found round one order of magnitude as high as those of lignite. Subsequently the Radionuclide Partitioning Coefficients of radionuclides were calculated and it was found that they are higher for 232Th, 228Ra and 40K, because the latter have closer affinity with the inorganic matrix of lignite. During combustion up to one third of the naturally occurring radioisotopes escape from the solid phase into the flue gases. With comparison to relative global data, the investigated ash has been found to have relatively high radioactivity, but the emissions of the WMLC radionuclides contribute only 0.03% to the mean annual absorbed dose.

  14. Naturally Occurring Radionuclides of Ash Produced by Coal Combustion. The Case of the Kardia Mine in Northern Greece

    International Nuclear Information System (INIS)

    Fotakis, M.; Tsikritzis, L.; Tzimkas, N.; Kolovos, N.; Tsikritzi, R.

    2008-01-01

    West Macedonia Lignite Center (WMLC), located in Northwest Greece, releases into the atmosphere about 21,400 tons/year of fly ash through the stacks of four coal fired plants. The lignite ash contains naturally occurring radionuclides, which are deposited on the WMLC basin. This work investigates the natural radioactivity of twenty six ash samples, laboratory produced from combustion of lignite, which was sampled perpendicularly to the benches of the Kardia mine. The concentrations of radionuclides 40 K, 235 U, 238 U, 226 Ra, 228 Ra and 232 Th, were measured spectroscopically and found round one order of magnitude as high as those of lignite. Subsequently the Radionuclide Partitioning Coefficients of radionuclides were calculated and it was found that they are higher for 232 Th, 228 Ra and 40 K, because the latter have closer affinity with the inorganic matrix of lignite. During combustion up to one third of the naturally occurring radioisotopes escape from the solid phase into the flue gases. With comparison to relative global data, the investigated ash has been found to have relatively high radioactivity, but the emissions of the WMLC radionuclides contribute only 0.03% to the mean annual absorbed dose

  15. Radioactivity of coals and fly ashes

    International Nuclear Information System (INIS)

    Papastefanou, C.

    2008-01-01

    The level and the behavior of the naturally occurring primordial radionuclides 238 U, 226 Ra, 210 Pb, 232 Th, 228 Ra and 40 K in coals and fly ashes are described. The activity concentrations of the examined coals and originated from coal mines in Greece ranged from 117 to 435 Bq x kg -1 for 238 U, from 44 to 255 Bq x kg -1 for 226 Ra, from 59 to 205 Bq x kg -1 for 210 Pb, from 9 to 41 Bq x kg -1 for 228 Ra and from 59 to 227 Bq x kg -1 for 40 K. These levels are comparable to those appeared in coals of different countries worldwide. The activity concentrations of the examined fly ashes and produced in coal-fired power plants in Greece ranged from 263 to 950 Bq x kg -1 for 238 U, from 142 to 605 Bq x kg -1 for 226 Ra, from 133 to 428 Bq x kg -1 for 210 Pb, from 27 to 68 Bq x kg -1 for 228 Ra and from 204 to 382 Bq x kg -1 for 40 K. The results showed that there is an enrichment of the radionuclides in fly ash relative to the input coal during the combustion process. The enrichment factors (EF) ranged from 0.60 to 0.76 for 238 U, from 0.69 to 1.07 for 226 Ra, from 0.57 to 0.75 for 210 Pb, from 0.86 to 1.11 for 228 Ra and from 0.95 to 1.10 for 40 K. (author)

  16. Radiological impact evaluation of an uranium mine in an agricultural soil

    International Nuclear Information System (INIS)

    Szeles, Marlene Sotto-Mayor Flues

    1994-01-01

    The contamination of a soil near an uranium mine exhaust ventilating shaft was evaluated. The methodology adopted proved to be successful even for facilities which do not present any preoperational or operational results. The activity concentration of 210 Pb, 238 U, 226 Ra, 228 Ra, 137 Cs and 40 K was measured along a transect of 200m on a field located in the exhaust air direction. The data showed that the activity increased due to the emissions from the mine. The largest effect was observed for 210 Pb, whereas smaller effects were observed for 238 U and 226 Ra. The activity ratios of 210 Pb/ 238 U and 238 U/ 226 Ra in the soil for distances where the contamination was not detectable anymore, were 1,04 and 1,43 , respectively. These results are in good agreement with other data found in the literature. The semivariograms of the activity concentration of the radionuclides at distances, where the effect of the emissions from the mine was not any longer observable, indicated for 210 Pb and 226 Ra the presence of a range (30m and 40m, respectively) within which the variance attains its maximum value. The semivariogram observed for 40 K, showed a wider range, indicating the influence of an uneven fertilizers application. A sequential extraction procedure was applied to investigate the speciation of the radionuclides and stable Pb in the soil. The following extractions were carried out: fraction I readily exchangeable, fraction II bound to carbonates and fraction III bound to Fe and Mn oxides. In the soil near the exhaust air the extraction was more effective for 210 Pb, 238 U and 226 Ra . The radionuclide 210 Pb was more extracted in fraction I and III, whereas 238 U and 226 Ra were similarly extracted in fraction II and III. The behaviour of 210 Pb was different for the control soil and the agricultural soil. In the control soil 210 Pb was more extracted in fraction II and III, whereas in the the agricultural soil it was more extracted in fraction I and III. Stable Pb

  17. Distribution of 226Ra and 228Ra in drinking water and dose assessment

    International Nuclear Information System (INIS)

    Ajay Kumar; Sugandhi, S.; Usha, N.; Rupali, K.; Gurg, R.P.

    2002-01-01

    The radioactivity concentrations of 226 Ra and 228 Ra have been analysed in 123 drinking water samples received from different regions of India. The maximum concentrations of 226 Ra and 228 Ra in drinking water are 8 mBq/l and 11.5 mBq/l respectively. The higher doses due to intake of 228 Ra through drinking water suggests that 228 Ra should also be measured in the assessment of ingestion dose to the population. The estimated committed effective doses range from 0.082 to 2.45 μSv/year and from 1.53 to 8.81 μSv/year for the ingestion of 226 Ra and 228 Ra respectively. (author)

  18. 224Ra and 226Ra experimentally induced dental changes in rats

    International Nuclear Information System (INIS)

    Reichart, P.A.; Althoff, J.; Eckhardt, W.; Rippel, W.

    1979-01-01

    Sprague-Dawley rats received intragastrically a single dose of 226 Ra or 224 Ra once weekly for 21 weeks. During this period the animals of both groups were thus exposed to comparable doses. After 12 weeks, a shortening of the maxillary incisors was observed, and this progressed during the course of the 55-week experiment. Radiologically, a loss of pulpal transparency and an apical irregular opacity in the maxillary incisors were demonstrable. Histologically, dysplastic changes of the maxillary incisors and multiple resorptions at the cemento-enamel junction of the molars were seen. The observed alterations were more pronounced in the 226 Ra group than in the 224 Ra treated group. The experimentally induced resorptions were comparable to those observed in patients who had incorporated 224 Ra or 226 Ra. Clinical, radiological, histological, γspecrometrical, and autoradiographical findings, as well as dose-estimations, are described. (author)

  19. 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.

  20. Distribution of {sup 226}Ra body burden of workers in an underground uranium mine in India

    Energy Technology Data Exchange (ETDEWEB)

    Patnaik, R.L.; Jha, V.N.; Kumar, R.; Srivastava, V.S.; Ravi, P.M.; Tripathi, R.M. [Bhabha Atomic Research Centre, Health Physics Unit, Jaduguda, Jharkhand (India)

    2014-11-15

    Uranium mine workers are exposed to ore dust containing uranium and its daughter products during different mining operations. These radionuclides may pose inhalation hazards to workers during the course of their occupation. The most significant among these radionuclides is {sup 226}Ra. The measurement of radium body burden of uranium mine workers is important to assess their internal exposure. For this purpose, the radon-in-breath measurement technique has been used in the present paper. Workers at the Jaduguda mine, India, associated with different categories of mining operations were monitored between 2001 and 2007. The measurement results indicate that workers - depending on mining operation category - show {sup 226}Ra body burdens ranging from 0.15 to 2.85 kBq. The maximum body burden was found for workers associated with timbering operations, with an average {sup 226}Ra body burden of 0.85 ± 0.54 kBq. Overall, the average value observed for 800 workers was 0.76 ± 0.51 kBq, which gives rise to an average effective dose of 1.67 mSv per year for inhalation and 0.21 mSv per year for ingestion. (orig.)

  1. A database of radionuclide activity and metal concentrations for the Alligator Rivers Region uranium province.

    Science.gov (United States)

    Doering, Che; Bollhöfer, Andreas

    2016-10-01

    This paper presents a database of radionuclide activity and metal concentrations for the Alligator Rivers Region (ARR) uranium province in the Australian wet-dry tropics. The database contains 5060 sample records and 57,473 concentration values. The data are for animal, plant, soil, sediment and water samples collected by the Environmental Research Institute of the Supervising Scientist (ERISS) as part of its statutory role to undertake research and monitoring into the impacts of uranium mining on the environment of the ARR. Concentration values are provided in the database for 11 radionuclides ( 227 Ac, 40 K, 210 Pb, 210 Po, 226 Ra, 228 Ra, 228 Th, 230 Th, 232 Th, 234 U, 238 U) and 26 metals (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, S, Sb, Se, Sr, Th, U, V, Zn). Potential uses of the database are discussed. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  2. Determination of the 226Ra, 228Ra and 210Pb concentrations in the mineral water springs from water parks of Cambuquira and Marimbeiro, Minas Gerais and assessment of the committed effective doses

    International Nuclear Information System (INIS)

    Santos, Laíssa A.B. dos; Damatto, Sandra R.

    2017-01-01

    Due to the importance of human life, water quality must be controlled and a very important parameter are the limits of the natural radioactivity of the water consumed. In relation to therapeutic practices based on water intake the radionuclides 210 Pb, 226 Ra and 228 Ra when present, are of great importance because they contribute to the internal irradiation of individuals.The study areas of the present work were the Parque das águas of Cambuquira and Marimbeiro, located in Minas Gerais. Hence, the objective of this work was to determine the 226 Ra, 228 Ra and 210 Pb concentrations in the springs of these parks and evaluate the committed effective doses due to its consumption.The radionuclides were determined by a radiochemical procedure in four collections at different seasons of the year. The Concentrations ranged from 4 ± 1 mBq / L to 509 ± 32 mBq / L for 226 Ra, from 3.7 ± 0.1 mBq / L to 631 ± 27 mBq / L for 228 Ra and 5 ± 1 mBq / L to 60 ± 5 mBq / L for 210 Pb. The dose for adults from 1.21 x 10 -01 mSv/y for 226 Ra, 3.18 x 10 -01 mSv/y for 228 Ra and for 210 Pb 3.02 x 10 -02 mSv/y. (author)

  3. 222Rn, 226Ra, and U in drinking water in Hungary

    International Nuclear Information System (INIS)

    Szerbin, P.; Koeteles, G.

    2002-01-01

    Among radionuclides ingested by drinking water the most important ones are radon, radium and uranium, causing radiation exposure of the lungs, bones, and gastro-intestinal organs, mainly kidneys. For this reason, as a part of the National Environmental Health Program to determine the main risk factors of the Hungarian population from environmental substances, 222 Rn, 226 Ra, and U concentrations were measured in domestic water supplies. Water samples were taken from all of the 19 Hungarian counties. Three cities were chosen from each county by the criteria of number of the population. Samples were taken from the communal drinking water supplies. Radon was determined by short lived daughter products using scintillation technique after water degassing into Lucas cells. Radium and uranium were determined after chemical separation, by Lucas scintillation method and by liquid scintillation technique. The obtained results were compared to the available literature data. Radioactivity levels were assessed for conformity with the Hungarian standards, WHO guidelines, and used for dose calculations. It was concluded that the radioactivity of the drinking water in Hungary is in the order of magnitude of the worldwide average. The measured radioactivity levels never exceeded the limits of the valid Hungarian standards for annual intake limits and were adequate to WHO guidelines. It was found that public doses from radon, radium, and uranium ingestion by drinking water were 12.7, 8.8, and 7.3 μSv y -1 , respectively. Summarizing the results of the survey it was concluded that comparing these doses to the public dose from other natural sources of radiation are negligibly small. (author)

  4. Alpha-particle doses to human organs and tissues from internally-deposited 226Ra and 228Ra

    International Nuclear Information System (INIS)

    Keane, A.T.; Schlenker, R.A.

    1981-01-01

    Estimation of radiation doses to the soft tissues from internally-deposited 226 Ra and 228 Ra is relevant to an investigation of soft-tissue malignancies in radium-exposed persons being conducted at the Center for Human Radiobiology. Alpha-particle doses in a 50-year period following a single injection of 226 Ra or 228 Ra are presented for 31 soft tissues and organs of the adult human. The dose estimates were derived from the ICRP alkaline earth model fitted to data on retention of 226 Ra in soft tissues and bone, combined with reported ratios of 226 Ra to Ca in soft tissue and bone at natural levels and the distribution of Ca in the tissues of Reference Man (ICRP23). The median of the 31 organ and tissue doses from the α-particles of 226 Ra itself is 0.08 rad per injected μCi. An additional average dose of 0.01 rad per μCi 226 Ra daughter products produced in soft tissue or transferred from bone to soft tissue. Soft-tissue doses from α-particles of the 228 Ra decay series are about six times those from 226 Ra α-particles for equal injected activities of 228 Ra and 226 Ra, with the assumption that 228 Ra daughter products do not transfer from the organ in which they are produced. The 50-year dose to the red marrow of bone from α-particles originating in bone is 0.55 rad per μCi 226 Ra injected and 1.0 rad per μCi 228 Ra injected. For ingestion by dial painters of luminous compound containg 226 Ra or 228 Ra with a daughter-to-parent activity ratio of 0.5, the dose to the mucosal alyer of the lower large intestine from α-particles originating in the gut contents is about 0.1 rad per μCi systemic intake of 226 Ra or 228 Ra

  5. Natural radionuclides and heavy metals in vegetables of people diet from Rio de Janeiro, RJ, Brazil

    International Nuclear Information System (INIS)

    Santos, Eliane Eugenia dos

    2002-01-01

    The characterization of the population exposure to the natural radiation is of extreme importance to set reference levels as a base to a regulatory system. Foodstuff, particularly of vegetable origin, presents variable contents of chemical products, essentials and not essentials according to soil characteristics, agricultural practices, among others. The present work had the goal to establish a methodology that allows evaluating the incorporation of natural radionuclides and heavy metals by the Brazilian population consuming foodstuff from vegetal origin. The results indicate that doses due to the ingestion of natural radionuclides and heavy metals as well in vegetables and derived products consumed by the Rio de Janeiro population are below the reference values set by international organizations. Regarding U and Th decay chain exposure ( 238 U, 23T h, 228 Ra, 226 Ra, 210 Pb), it was estimated an effective dose of 14,5 μSv/a, being 228 Ra, 226 Ra, 210 Pb responsible by 96%. The K-40 ingestion dose was assessed as 103 μSv/a. The daily intake of metals was assess as 2870 μg/d for Zn, 2499 μg/d for Mn, 1064 μg/d Cu, 96 μg/d Ni, 14,8 μg/d Cr, 11 μg/d Cd e 4,8 μg/d Pb. The most consumed metals by the Rio de Janeiro city inhabitants are Zn, Mn e Cu. The proposed methodology to extend this effective dose to the main Brazilian cities is: 1) to select for special analysis at each region the more consumed fruits at each city, carrots, manioc, tomato and sugar; 2) to use as a base line for all country the results of natural radionuclides and heavy metals obtained in this work for vegetables and derived products at specific locations and/or imported and distributed throughout the country; 3) in relation to natural radionuclides, it is only necessary to analyze 228 Ra, 226 Ra, 210 Pb. (author)

  6. 226Ra, 232Th and 40K analysis in sand samples from some beaches of Great Vitoria, Espirito Santo, Brazil: preliminary results

    International Nuclear Information System (INIS)

    Aquino, Reginaldo R.; Pecequilo, Brigitte R.S.

    2009-01-01

    The natural radioactivity in superficial beach sand samples of 7 beaches of Great Vitoria, metropolitan region of the State of Espirito Santo, southeast Brazil, was determined from the 226 Ra, 232 Th and 4 0 K contents. The assessed beaches were Manguinhos, Camburi, Praia do Canto, Curva da Jurema, Itapua, Setibao and Areia Preta. Three samples of each beach were sealed in standard 100 mL polyethylene flasks and stored in order to obtain secular equilibrium in the 238 U and 232 Th series. All samples were measured by high resolution gamma spectrometry and the spectra were analyzed with the WinnerGamma software. The 232 Th concentration was determined from the average concentrations of 228 Ac, 212 Pb and 212 Bi and the 226 Ra concentration was determined from the average concentrations of 214 Pb and 214 Bi. Preliminary results show concentrations varying from 9 Bq.kg -1 to 6035 Bq.kg -1 for 232 Th, from 4 Bq.kg -1 to 575 Bq.kg -1 for 226 Ra and from 13 Bq.kg -1 to 142 Bq.kg -1 for 40 K. Areia Preta beach shows the highest values for 232 Th, while the highest value for 226 Ra was observed for Camburi beach. High values of 40 K were observed for Curva da Jurema beach. (author)

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

    International Nuclear Information System (INIS)

    Oliveira, J. de; Mazzilli, B.; Oliveira S, M.H de; Bernadete, S.

    1996-01-01

    Concentration levels of 226 Ra and 222 Rn 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 226 Ra was determined by gross alpha counting of a Ba(Ra)SO 4 precipitate. The measurement was carried out in a low background gas flow proportional counter. The 222 Rn 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 226 Ra and 131 Bq/L for 222 Rn 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 226 Ra and 30 Bq/L for 222 Rn. 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

  8. Report on intercomparison IAEA/AG-B-1 of radionuclide measurements in marine algae sample

    International Nuclear Information System (INIS)

    1985-09-01

    This report includes results of the intercomparison exercise organized to enable analysts involved in measurements to check the analytical performance of their measuring methods on homogeneous seaweed material and also to establish reference values for radionuclides 40 K, 54 Mn, 58 Co, 60 Co, 65 Zn, 134 Cs, 137 Cs, 90 Sr, 99 Tc, 238 Pu, 239+240 Pu, 241 Am, 238 U, 230 Th, 226 Ra, 210 Pb, 210 Po, 232 Th, 228 Ra and 228 Th for the advantage of all those who need well-characterized standard material for calibration purposes. The sample of the brown alga Fucus vesiculosus from the coastal area of the Southwest Baltic near the Swedish nuclear plant at Barseback was made available for intercalibration in 47 laboratories in 26 countries. The results were obtained by gamma spectrometry, alpha spectrometry and beta counting

  9. Determination of natural occurring radionuclide and heavy metals in drinking water in Malaysia

    International Nuclear Information System (INIS)

    Nur Suraya Ahmad

    2012-01-01

    The objective of this study is to ascertain the activity concentration of naturally occurring radionuclide and selected heavy metals selected mineral and drinking waters sample in Malaysia. The activity concentration of natural radionuclide (mBq/ L) was determined by Gamma Spectroscopy Systems while the concentration of heavy metal (mg/ L) was determined by the Induces Couple Plasma Mass Spectrometry (ICP-MS). The mineral and drinking water samples used in this study were Segar UKM, Giant, Ice Mountain (600 ml), Ice Mountain (1600 ml), Spritzer, Reverse Osmosis, and fresh tap water. The results of the study found 3 natural occurring radioactive materials (NORM) found for example - U-238, Ra-226 and Ra-228. The activity concentration determined was 0.00 mBq/ L to 1.71 mBq/ L for U-238, 0.00 - 32.46 mBq/ L for Ra-226 and 0.00 - 12.01 mBq/ L for Ra-228 respectively. The concentration of heavy metals Zn, Fe, As, Cl, Mn, Cu and Pb determined in this study were in the range of 0.000 - 0.003 mg/ L, 0.002-0.018 mg/ L, 0.000 - 0.007 mg/ L, 6.152 - 57.724 mg/ L, 0.000 - 0.016 μg/ L, 0.058 - 0.766 μg/ L and 0.000 - 0.380 μg/ L respectively. In general, the result of this study indicate that the activity concentration NORM and selected heavy metals in the studied mineral and drinking water samples were low and not exceed the limit set by World Organization (WHO) and Malaysian Food Regulations 1985. Thus, all the studied water samples complying the Malaysian drinking standard and safe to be consumed. (author)

  10. Distribution of Pa-231 and Ra-226 in rock. An indicator of rock matrix diffusion

    International Nuclear Information System (INIS)

    Saarinen, L.; Suksi, J.

    1995-01-01

    Distribution of Ra-226 and Pa-231 in rock has been studied to find signatures that may be attributed to diffusion. The idea of studying these nuclides originated from the need to obtain interpretative support to the findings of U movement in rock. Concentration profiles of Ra-226 and Pa-231 with other U series nuclides were measured across the secondary U accumulations observed in altered rock close to a fracture in the vicinity of U deposit, and in a radioactivity anomaly. (27 refs., 10 figs., 2 tabs.)

  11. Distribution of "2"2"6Ra body burden of workers in an underground uranium mine in India

    International Nuclear Information System (INIS)

    Patnaik, R.L.; Jha, V.N.; Kumar, R.; Srivastava, V.S.; Ravi, P.M.; Tripathi, R.M.

    2014-01-01

    Uranium mine workers are exposed to ore dust containing uranium and its daughter products during different mining operations. These radionuclides may pose inhalation hazards to workers during the course of their occupation. The most significant among these radionuclides is "2"2"6Ra. The measurement of radium body burden of uranium mine workers is important to assess their internal exposure. For this purpose, the radon-in-breath measurement technique has been used in the present paper. Workers at the Jaduguda mine, India, associated with different categories of mining operations were monitored between 2001 and 2007. The measurement results indicate that workers - depending on mining operation category - show "2"2"6Ra body burdens ranging from 0.15 to 2.85 kBq. The maximum body burden was found for workers associated with timbering operations, with an average "2"2"6Ra body burden of 0.85 ± 0.54 kBq. Overall, the average value observed for 800 workers was 0.76 ± 0.51 kBq, which gives rise to an average effective dose of 1.67 mSv per year for inhalation and 0.21 mSv per year for ingestion. (orig.)

  12. Estimation of Ra-226, Ra-228 and K-40 specific activities in fertilizer samples marketed in the Rio de Janeiro City

    Energy Technology Data Exchange (ETDEWEB)

    Garcêz, R.W.D.; Lopes, J.M.; Silva, A. X. da, E-mail: rgarcez@nuclear.ufrj.br [Universidade Federal do Rio de Janeiro (LAASC/UFRJ), Rio de Janeiro, RJ (Brazil). Departamento de Engenharia Nuclear; Lima, M.A.F. [Universidade Federal Fluminense (LARA/UFF), Niterói, RJ (Brazil). Departeamento de Biologia

    2017-07-01

    The use of fertilizers is a common practice in agriculture and several samples have radionuclides in their composition. This content is natural but some samples may have high concentrations of these radionuclides and this represent a potential radiological risk for plants, animals and water. Therefore, the radiometric analyses of these compounds is important, and the aim of this paper is to determine the specific concentration of K-40, Ra-226 and Ra-228 in fertilizer samples available in market of Rio de Janeiro city and discussing the impacts to agricultural soils caused by this practice. Four types of fertilizer samples were analyzed: nitrogen, potash, phosphate and NPK. They were analyzed through gamma spectroscopy technique with a HPGe detector and with the LabSOCS software for the calculation of the efficiency curve. The specific activities of Ra-226 ranged from 1.48 to 597 Bq/kg, Ra-228 ranged from 2.66 to 832 Bq/kg and K-40 ranged from 16 to 13941 Bq/kg. All samples, except two of nitrogen fertilizer, presented the absorbed dose rate in air, at 1m above the ground level, higher than the estimated average global terrestrial radiation for soil (51 nGy/h) and the phosphate fertilizer samples presented the highest average absorbed dose rate: 532.5 nGy/h, which indicates a greater potential of environmental contamination. (author)

  13. Natural radionuclides in coal and waste material originating from coal fired power plant

    International Nuclear Information System (INIS)

    Marovic, Gordana; Franic, Zdenko; Sencar, Jasminka; Petrinec, Branko; Bituh, Tomislav; Kovac, Jadranka

    2008-01-01

    This paper presents long-term investigations of natural radioactivity in coal, used for power production in the coal-fired power plant (CFPP) situated on the Adriatic coast, and resulting slag and ash. Activity concentrations of 40 K, 232 Th, 226 Ra and 238 U in used coal and resulting waste material have been measured for 25 years. As expected, it was demonstrated that the content of radionuclides in deposited bottom and filter ash material are closely related with radionuclide activity concentrations and mineral matter fraction in used coals. The external hazard index has been calculated and discussed for the slag and ash depository. During the first decade of operation of the CFPP has been used domestic coal produced in nearby area characterized by higher background radiation compared with the rest of Croatia. Therefore, the coal itself had relatively high 226 Ra and 238 U activity concentrations while potassium and thorium content was very low, 40 K activity concentrations being 2-9% and those of 232 Th 1-3% of total activity. As, in addition, the sulphur concentrations in coal were very high use of domestic coal was gradually abandoned till it was completely substituted by imported coal originated from various sources and of low natural radioactivity. Upon this, activity concentrations of uranium series radionuclides in deposited waste materials decreased significantly. Consequently, waste material i.e., slag and ash, generated in the last several years of coal fired power plant operation could be readily used in cement industry and as additive to other building materials, without any special restrictions according to the Croatian regulations dealing with building materials and European directives. (author)

  14. Contamination level of natural 238U and 232Th radionuclides in offshore of coal power plant (assessment at offshore of Panjang Island and Lada Bay, Banten)

    International Nuclear Information System (INIS)

    Sabam Parsaoran Situmorang; Harpasis Selamet Sanusi; June Mellawati

    2011-01-01

    This study had been carried out by collecting sample of the surficial sediments, sea water, seaweeds, anchovies (Stolephorus and Anchoa) and mussels (Codakia) from 4 locations in waters of Pulau Panjang and coastal of Lada Bay (as control/comparison site), Banten in June - July 2010. Natural radionuclides (Th) concentration in samples was measured using neutron activation analysis (NAA) method. The results showed that the total radionuclides concentration in sediment ( 238 U: 18.6160 - 35.0013 Bq/kg; 232 Th: 11.2020 - 35.6685 Bq/kg), seawater ( 238 U: undetected; 232 Th: 0.0790 - 0.1299 Bq/l), cultivation seaweeds ( 238 U: undetected; 232 Th: 3.6735 - 4.8345 Bq/kg), natural seaweeds ( 238 U: 3.6851 - 48.0430 Bq/kg; 232 Th: 3.9941 - 9.0788 Bq/kg), Stolephorus ( 238 U: undetected; 232 Th: 3.3078 Bq/kg) and Codakia ( 238 U: 6.8903 Bq/kg; 232 Th: 3.6023 Bq/kg) in Pulau Panjang, Banten around Suralaya coal power plant higher than control site that were around the Labuan coal power plant, namely in sediments ( 238 U: 10.4253 Bq/kg; 232 Th: 16.5952 Bq/kg), seawater( 238 U: undetected; 232 Th: 0.0671 Bq/l), cultivation seaweeds ( 238 U: undetected; 232 Th: 2.3005 Bq/kg), natural seaweeds ( 238 U: 19.5367 Bq/kg; 232 Th: 2.6729 Bq/kg) and Anchoa ( 238 U: undetected; 232 Th: 2.0603 Bq/kg). (author)

  15. Absorption and removal of Ra-226, Pb-210 and Po-210 by humans and the resulting radiation exposure

    International Nuclear Information System (INIS)

    Gloebel, B.; Berlich, J.; Andres, C.

    1985-01-01

    In over 400 samples (food, water, air, stools and urine), the concentration of Ra-226, Pb-210 and Po-210 was measured. The daily intake for the three nuclides is: Ra-226: 30 mBq; Pb-210: 150 mBq; Po-210: 150 mBq. The table shows intake of individual food and drinking items as well as air. In all but the kidney samples, Pb and Po were present in radioactive equilibrium. The contribution of each radionuclide to radiation exposure is indicated. (orig./HP) [de

  16. Determination of radionuclides and trace elements in marine sediments and biota from the red sea coast

    International Nuclear Information System (INIS)

    Sirelkhatim, Dia Awad

    2002-09-01

    This study presents data on the concentration levels of natural ( 226 Ra, 210 Pb, 210 Po, 238 U, 234 Th and 40 K) and artificial ( 239+240 Pu, 238 Pu, 90 Sr, 137 Cs) radionuclides as well as trace metals (Pb, Sr, Cr, Ni, V, Ba, La, Ce, Rb, Zn, Nb, As, Ti, Mn, Y, Zr, Th, U, and Ga) in multicellular marine algae, molluscs, coral in surface marine sediments collected from the shallower waters of the fringing reefs area and Flamingo Bay near Port Sudan harbour. The analyses were performed using gamma spectrometry, alpha spectrometry, liquid scintillation counting technique, Cerenkov counting technique and X RF.Surface sediments from this coastal region are poor in their trace metals and radionuclide content compared to similar data reported from different coastal areas around the globe and no source of emission has appeared to make any significant contribution. Surface enrichment of 210 Pb and 210 Po with respect to their progenitor 226 Ra is evident from the activity ratios of 210 Pb/ 226 Ra (3.03±1.79) and 210 Po/ 226 Ra (2.23±1.56) indicating sources other than in situ decay of parent nuclide. Activity concentration ranges in mBq/Kg dry weight of the artificial radionuclides studied were found to be from 5.10 to 82 ( 239+240 Pu), from 0.89 to 8.63 ( 238 Pu),and from 29.6 to 389.5 ( 90 Sr). The ratio 239+240 Pu/ 238 Pu which is used for source term identification has confirmed that the origin of anthropogenic radioactivity in the studied area is mainly the global fall-out. 137 Cs was not detected in all samples analysed. Considering 238 U, 234 Th and 40 K, their activity concentration (Bq/Kg dry weight) ranges in sediments are 2.41-6.69, 27.3-79.4 and 462-656, respectively. 234 Th/ 238 U ratio was an order of magnitude higher than unity indicating that the sediments are from high productivity area with a high biogenic flux from the adjacent water. Among marine plants and animals investigated, the coral species, Favites, show substantial concentration of radium at

  17. 226Ra and 228Ra in ground water of the Cambrian-Ordovician Aquifer System in northern Illinois

    International Nuclear Information System (INIS)

    Gilkeson, R.H.; Holtzman, R.B.

    1982-01-01

    Over a large region of Illinois, ground water of the Cambrian-Ordovician Aquifer System exceeds the US EPA drinking water standard of 5 pCi/L for the combined concentration of 226 Ra and 228 Ra. 226 Ra concentrations range from 226 Ra is the geochemistry of uranium in the ground-water flow system, while the 228 Ra activity in ground water which ranges from 232 Th-bearing minerals in the aquifer strata. The comparison of recent analyses to historical data gathered over the last 20 years indicates that, with few exceptions, 226 Ra and 228 Ra activities in ground water have remained constant. The combined concentrations of the two nuclides in ground water of the aquifer system ranged from 226 Ra concentrations were high (greater than or equal to 10 pCi/L), those of 228 Ra were low (less than or equal to 2 pCi/L), but, with few exceptions, in regions where 228 Ra concentrations were high, those of 226 Ra were also high. The range of values raises questions concerning the validity of the US EPA regulation which requires analysis for 228 Ra only when the concentration of 226 Ra exceeds 3.0 pCi/L

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

    International Nuclear Information System (INIS)

    2014-01-01

    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 226 Ra and 228 Ra 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 226 Ra and 228 Ra from interfering elements using PbSO 4 and Ba(Ra)SO 4 coprecipitation steps. The isotopes 226 Ra and 228 Ra 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

  19. Impact of water environmental change and migration of radionuclides on hokutolite conservation in Peito (Taiwan)

    International Nuclear Information System (INIS)

    Lin, C.C.; Tsai, T.L.; Lung, C.C.

    2012-01-01

    Chemical factors (including pH, redox potential, content of total organic compound (TOC) and major ions) and U/Th-series radionuclides in the hot-spring water environment of Peito were determined to investigate the impact of environmental change and migration of radionuclides in water on conserving the precious mineral, hokutolite, in Peito (Taiwan). The activity concentrations of U/Th increased with E h and those of Cl - and SO 4 2- . 234 U/ 238 U ratios were nearly > 1 ascribed to Szilard-Chalmers effect and α-recoil. 230 Th/ 234 U ratios were 228 Ra and 226 Ra activities were governed by pH, E h and SO 4 2- concentration. Disequilibria of 228 Th/ 228 Ra and 228 Ra/ 232 Th were evident attributed to complexation of Th with major anions and co-precipitation of radium with (Ba,Pb)SO 4 . Alpha-recoil caused the enrichment of 228 Ra and apparent disequilibrium of 232 Th/ 228 Th. A mechanism illustrating the radiochemistry involving the formation of hokutolite in Peito was derived accordingly. The water environment of the studied area was found apparently changed in light of the variation of temperature, TOC and concentration ratio of Ba/Pb, which resulted from the channeling of hot spring water and the release of household waste water. The water environmental change can thus hinder the migration of radionuclides as well as the formation of hokutolite so that the performance of hokutolite conservation can be decreased. Immediate enactment of regulations for conserving hokutolite in Peito was therefore suggested in this research. (orig.)

  20. The use of lichens as bioindicators of atmospheric contamination by natural radionuclides and metals in a region impacted by TENORM; Utilizacao de liquens como bioindicadores de contaminacao atmosferica por radionuclideos naturais e metais em regiao impactada por TENORM

    Energy Technology Data Exchange (ETDEWEB)

    Leonardo, Lucio

    2010-07-01

    The main aim of this thesis is to study the possibility of using lichen as bioindicator of atmospheric pollution in regions contaminated by radionuclides, metals and rare earth elements. Two regions were chosen, one in Pirapora do Bom Jesus, where a tin and lead industry is located, and a second one in Cubatao, where a phosphate fertilizer industrial complex is located. The two industries chosen are considered as TENORM - Technologically Enhanced Naturally Occurring Radioactive Material, since they can cause a significant increase in the natural radionuclides concentration in the industrial process, and consequently a potential increase in the radiation exposure in products, byproducts and residue. To achieve this aim, the radionuclides {sup 238}U, {sup 226}Ra, {sup 210}Pb, {sup 2'}3{sup 2}Th and {sup 228}Ra, rare earth elements and metals were analyzed in samples of raw material and residues from the installations, lichens and soils. Lichens and soil samples were analyzed by instrumental neutron activation analysis for the determination of uranium, thorium, rare earth elements and metals. The radionuclides {sup 226}Ra, {sup 228}Ra and {sup 2}'1{sup 0}Pb in soil samples were determined by gamma spectrometry and in lichen sample by radiochemical separation and gross alpha and beta counting on a gas flow proportional counter. The concentrations of {sup 238}U (from 19 to 473 Bq kg{sup -1}), {sup 226}Ra (from 21 to 265 Bq kg{sup -1}), {sup 210}Pb (from 401 to 1461 Bq kg{sup -1}), {sup 232}Th (from 15 to 574 Bq kg{sup -1}), {sup 228}Ra (from 176 to 535 Bq kg'-{sup 1}), rare earth elements, Hf and Ta determined in lichen samples around the tin and lead industry show an enrichment in these elements. Therefore, the lichens can be used as a fingerprint of the atmospheric contamination. The results obtained for the lichen samples, in the Cubatao region, present a fingerprint mainly of {sup 210}Pb, from industries of the region. The results obtained in this

  1. RA-226 concentration in water samples near uranium mines and in marine fishes

    International Nuclear Information System (INIS)

    Porntepkasemsan, B.

    1987-11-01

    Radium-226 and calcium were measured in water samples from the vicinity of three uranium mines and in fish samples collected from Puget sound, Washington State. The radium content of the samples were below the maximum permissible concentration 3 pCi/L for drinking water recommended by the Public Health Service and U.S. Environmental Protection Agency. The mean value of Ra-226 in water was 0.428 pCi/L and ranged from 0.043 to 1.552 pCi/L, whereas calcium content ranged from 3.0 to 190.0 mg/L. Ra-226 concentrations and calcium content in whole fish were 0.833-20.328 pCi/kg wet wt. and 114.1-259.3 mg/g ash, respectively. Results of the study indicated that Ra-226 concentration in water was correlated with calcium concentration but that this correlation was not observed in fish sample except English sole

  2. Distribution and flux of 226Ra and 228Ra in the Amazon River estuary

    International Nuclear Information System (INIS)

    Key, R.M.; Sarmiento, J.L.; Stallard, R.F.; Moore, W.S.

    1985-01-01

    Measurements of 226 Ra and 228 Ra in the Amazon River estuary show that desorption from riverborne suspended particulate matter in the estuary increases the riverine flux of both isotopes to the ocean by a factor of approximately 5 over the flux attributable to radium dissolved in the river water alone. The total Amazon flux supplies approximately 0.20% of the 226 Ra and approximately 2.6% of the 228 Ra standing crops in the near-surface Atlantic (0-200 m). Diffusive flux from estuarine and shelf sediments and desorption from resuspended sediments in the region of the estuary approximately double the estuarine 226 Ra concentration and quadruple the estuarine 228 Ra concentration above that caused by the dissolved and desorbed river components alone

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

    International Nuclear Information System (INIS)

    Holtzman, R.B.; Sha, J.Y.; Markun, F.

    1982-01-01

    The urinary and fecal excretion rates of 226 Ra have been determined for 53 subjects who had been exposed to 226 Ra; 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%

  4. Transfer of radionuclides at the uranium and thorium decay chains in aquatic and terrestrial environments

    International Nuclear Information System (INIS)

    Letourneau, C.

    1987-04-01

    This report examines the transfer of radionuclides from the uranium and thorium decay chains (U-238, Ra-226, Th-232, Th-230, Po-210 and Pb-210) through the aquatic and terrestrial environment. This transfer is characterized by a transfer coefficient; environmental and experimental factors which cause this coefficient to vary are presented and discussed in this report. Furthermore, based on a literature survey, the report indicates the range of coefficients found for the aquatic sector (that is, sediment and freshwater and marine organisms) and for the terrestrial sector (that is, plants and domestic and wild animals). Afterwards, generalisations are formulated on the transfer of the different radionuclides through the multiple environmental compartments. 75 refs

  5. Radiochemical determination and separation or total radium, 226Ra and 224Ra

    International Nuclear Information System (INIS)

    Suarez, J. A.; Gonzalez, J. A.; Pablo, M. A. de

    1987-01-01

    Radiochemical purification and separation of radium has been carried out and the determination of total radium solubilized in aqueous samples has been studied assuming that all the alpha emitters of the sample have their origin in the 226Ra and elements of its desintegration chain. Also, the activities of 22Ra and 226 Ra have been evaluated separately doing a measurement after the chemical separation of the radium and another one 10 days after. (Author) 9 refs

  6. Horizontal distribution of natural radionuclides (Pb-210, Po-210, Ra-226, Th-232, K-40) and of toxic heavy metals (Pb, Co, Ni) in soil samples in the surroundings of a coal-fired power plant

    International Nuclear Information System (INIS)

    Bunzl, K.; Hoetzl, H.; Rosner, G.; Schmidt, W.; Winkler, R.

    1984-01-01

    The spatial distribution of the specific activities of the above radionuclides in the soil within 5 km of the plant as well as the ratios Pb-210/Ra-226 and Po-210/Ra-226 did not reveal any noticeable effects on the natural concentrations of these radionuclides in the soils. The specific activities of the radionuclides in the fly ash of the plant are obviously too small to disturb the natural distribution pattern significantly. A similar behaviour was observed for the concentrations of the heavy metals in the soils around the plant, which were also within the same range of values as observed for largely unpolluted soils. Increased metal concentrations in the soils downwind of the stack of the power plant were not observable. The concentrations of these metals in the fly ash were not sufficiently high to significantly change the local distribution of the elements in the soils in the surroundings of the plant. (orig./HP) [de

  7. Concentrations of 226Ra and 210Pb in agricultural products surrounding the first brazilian mine and mill in Pocos de Caldas, MG

    International Nuclear Information System (INIS)

    Vasconcellos, L.M.H.; Amaral, E.C.S.; Vianna, E.C.M.

    1989-01-01

    As a complement to the pre-operational environmental monitoring program of the Brazilian first uranium mine and mill, a survey of 226 Ra and 210 Pb in agriculture products, and in the corresponding soils, were carried out in the Pocos de Caldas Plateau. The survey intended to determine site specific transfer factors, in order to better estimate radiation doses on the population. Resulting from the plant operation. In local soils, 226 Ra and 210 Pb have similar concentrations. The average contents are comparable to the values found in areas of normal radioactivity, but the maximum values are higher by one order of magnitude. In the vegetables analyzed (beans, carrot, corn and potato), 226 Ra concentrations are slightly higher than those of 210 Pb, and the maximum values are also one order of magnitude greater than in normal regions. For both radionuclides, the average soil-to-plant transfer factors are of the order of 10 -3 and 10 -2 , when related to total and to exchangeable contents in soils, respectively. These results led to the conclusion that 226 Ra and 210 Pb have similar importance, concerning the population exposure via the foodstuff ingestion pathway. Therefore, it was recommended to carry on routine monitoring program for both radionuclides in the main agriculture crops. However, the naturally elevated radionuclide concentrations, in some local vegetables, will decrease the sensitivity for detecting small increments resulting from the plant operation. (author) [pt

  8. Doses from 222Rn, 226Ra, and 228Ra in groundwater from Guarani aquifer, South America

    International Nuclear Information System (INIS)

    Bonotto, D.M.

    2004-01-01

    Groundwater samples were analysed for 222 Rn, 226 Ra, and 228 Ra in Guarani aquifer spreading around 1 million km 2 within four countries in South America, and it was found that their activity concentrations are lognormally distributed. Population-weighted average activity concentration for these radionuclides allowed to estimate a value either slightly higher (0.13 mSv/year) than 0.1 mSv for the total effective dose or two times higher (0.21 mSv/year) than this limit, depending on the choice of the dose conversion factor. Such calculation adds useful information for the appropriate management of this transboundary aquifer that is socially and economically very important to about 15 million inhabitants living in Brazil, Argentina, Uruguay and Paraguay

  9. Doses from 222Rn, 226Ra, and 228Ra in groundwater from Guarani aquifer, South America.

    Science.gov (United States)

    Bonotto, D M

    2004-01-01

    Groundwater samples were analysed for 222Rn, 226Ra, and 228Ra in Guarani aquifer spreading around 1 million km2 within four countries in South America, and it was found that their activity concentrations are lognormally distributed. Population-weighted average activity concentration for these radionuclides allowed to estimate a value either slightly higher (0.13 mSv/year) than 0.1 mSv for the total effective dose or two times higher (0.21 mSv/year) than this limit, depending on the choice of the dose conversion factor. Such calculation adds useful information for the appropriate management of this transboundary aquifer that is socially and economically very important to about 15 million inhabitants living in Brazil, Argentina, Uruguay and Paraguay.

  10. Radioactivity in Orontes river environment

    International Nuclear Information System (INIS)

    Othman, I.; Al-Masri, M. S.; Al-Oudat, M.; Abba, A.; Al-Hishari, M.; Berakdar, I.

    1998-09-01

    Syrian phosphate industry is considered to be one of the main sources of pollutants at the most important water resources of the middle region viz. Orontes river and Quttina lake. The main environmental concern associated with this industry in connection to radioactive contamination is the presence of naturally occurring radionuclides such as 238 U, 226 Ra and their daughters. The impact of this industry on Orontes environment has been investigated. Water, particulates, sediments and plants from seven locations along the Orontes River have been collected and analyzed for radioactivity. The results have shown a clear signal enhancement of natural radionuclides such as 226 Ra, 238 U and 210 Po in those samples collected from sites close to the factory. This enhancement was found to be due to phosphate factory discharges viz. Dust, liquid influents and phosphogypsum piles situated in the area. In addition, an increase in the concentrations of these radionuclides was also observed in other samples where the applications of phosphate fertilizers which contain relatively higher levels of 226 Ra (225 Bq/kg), 238 U (444 Bq/kg) and 210 (220 Bq/kg) being the main source of enhancement. However, the obtained levels of radioactivity are still lower than those reported in other areas in the world where similar source of contamination is presented. (author)

  11. Environmental impacts of heavy metals, rare earth elements and natural radionuclides in marine sediment from Ras Tanura, Saudi Arabia along the Arabian Gulf.

    Science.gov (United States)

    El-Taher, Atef; Alshahri, Fatimh; Elsaman, Reda

    2018-02-01

    Ras Tanura city is one of the most important cities in Saudi Arabia because of the presence of the largest and oldest oil refinery in the Middle East which was began operations in September 1945. Also its contains gas plant and two ports. The concentration of natural radionuclides, heavy metals and rare earth elements were measured in marine sediment samples collected from Ras Tanura. The specific activities of 238 U, 226 Ra, 232 Th, 40 K and 137 Cs (Bq/kg) were measured using A hyper-pure Germanium detector (HPGe), and ranged from (20.4 ± 4.0-55.1 ± 9.9), (6.71 ± 0.7-46.1 ± 4.5), (3.51 ± 0.5-18.2 ± 1.5), (105 ± 4.4-492 ± 13) and from (0.33 ± 0.04-2.10 ± 0.4) for 238 U, 226 Ra, 232 Th, 40 K and 137 Cs respectively. Heavy metals and rare earth elements were measured using ICPE-9820 Plasma Atomic Emission Spectrometer. Also the frequency distributions for all radioactive variables in sediment samples were analyzed. Finally the radiological hazards due to natural radionuclides in marine sediment were calculated to the public and it's diagramed by Surfer program in maps. Comparing with the international recommended values, its values found to be within the international level. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Behavior of 226Ra in the Mississippi River mixing zone

    Science.gov (United States)

    Moore, Daniel G.; Scott, Martha R.

    1986-12-01

    The behavior of 226Ra in the Mississippi River mixing zone is strongly nonconservative and includes desorption similar to that reported for the Hudson, Pee Dee, and Amazon rivers. However, dissolved and desorbed 226Ra concentrations in the Mississippi are 2 to 5 times greater than in the other rivers at the same salinity. Radium concentrations vary inversely with the water discharge rate. The 226Ra desorption maximum occurs at a salinity of 5.0, much lower than the 18 to 28 salinity values for the maxima of the other three rivers. High concentrations of dissolved 226Ra (up to 82 dpm per 100 L) and the low salinity values for the desorption maximum in the Mississippi River result from three major factors. Suspended sediments include a large fraction of montmorillonite, which gives the sediment a high cation exchange capacity, 0.54 meq/g. The average suspended sediment load is large, about 510 mg/L, and contains 1.9 dpm/g desorbable 226Ra. The dissolved 226Ra river water end-member (9.6 dpm per 100 L) is higher than in surface seawater. The annual contribution of 226Ra to the ocean from the Mississippi River is 3.7 × 1014 dpm/yr, based on data from three cruises. Evidence of flux of 226Ra from estuarine and shelf sediments is common in vertical profile sampling of the deltaic waters but is not reflected in calculations made with an "apparent" river water Ra value extrapolated to zero salinity.

  13. Determination of 210Pb e 226Ra in tobacco leaves cultivated in the states of Rio de Grande do Sul e Alagoas - Brazil

    International Nuclear Information System (INIS)

    Brandao, Y.B.; Antonio Filho, J.; Universidade Federal de Pernambuco

    2005-01-01

    The literature has shown that tobacco use causes damage to the health of cigarette users, manifesting itself in diseases with high mortality. Among these diseases include respiratory failure, pulmonary emphysema and lung cancer, among others. On the other hand, smoking contributes significantly to increasing the dose of natural radiation received by man, due to the presence of uranium series radionuclides, such as 226 Ra, 210 Pb and 210 Po, in relatively high concentrations in fresh tobacco leaves. The determination of these radionuclides in this matrix is of great interest, once they can be incorporated not only by the active smoker, but also by the passive smoker. The results of this study confirmed the significant presence of 226 Ra and 210 Pb in tobacco samples collected and analyzed. The average values of activity concentration found in samples from the State of Alagoas were of Bq.kg -1 0.8 to 210 Pb and 183.5 Bq.kg -1 to 226 Ra. For samples coming from the State of Rio Grande do Sul, these values were 4,0 Bq.kg -1 to 210 Pb and 161.3 Bq.kg -1 to 226 Ra

  14. Determination of the {sup 226}Ra, {sup 228}Ra and {sup 210}Pb concentrations in the mineral water springs from water parks of Cambuquira and Marimbeiro, Minas Gerais and assessment of the committed effective doses

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Laíssa A.B. dos; Damatto, Sandra R., E-mail: lbonifacio@ipen.br, E-mail: damatto@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2017-07-01

    Due to the importance of human life, water quality must be controlled and a very important parameter are the limits of the natural radioactivity of the water consumed. In relation to therapeutic practices based on water intake the radionuclides {sup 210}Pb, {sup 226}Ra and {sup 228}Ra when present, are of great importance because they contribute to the internal irradiation of individuals.The study areas of the present work were the Parque das águas of Cambuquira and Marimbeiro, located in Minas Gerais. Hence, the objective of this work was to determine the {sup 226}Ra, {sup 228}Ra and {sup 210}Pb concentrations in the springs of these parks and evaluate the committed effective doses due to its consumption.The radionuclides were determined by a radiochemical procedure in four collections at different seasons of the year. The Concentrations ranged from 4 ± 1 mBq / L to 509 ± 32 mBq / L for {sup 226}Ra, from 3.7 ± 0.1 mBq / L to 631 ± 27 mBq / L for {sup 228}Ra and 5 ± 1 mBq / L to 60 ± 5 mBq / L for {sup 210}Pb. The dose for adults from 1.21 x 10{sup -01} mSv/y for {sup 226}Ra, 3.18 x 10{sup -01} mSv/y for {sup 228}Ra and for {sup 210}Pb 3.02 x 10{sup -02} mSv/y. (author)

  15. Uptake of endogenous and exogenous 226Ra by vegetables from soils of a highly radioactive region

    International Nuclear Information System (INIS)

    Lima, V.T.; Penna-Franca, E.

    1988-01-01

    The Pocos de Caldas Plateau is a weathered alkaline igneous intrusion where several radioactive anomalies (U and Th series) exist. Not only the local soils but also the edible vegetables produced in the region can present 226 Ra concentrations up to 10 times higher than those from areas of normal radioactivity. The aim of this work is to evaluate through greenhouse experiments, the uptake of endogenous and exogenous 226 Ra by carrots, brown beans and kale grown from four paired local natural and contaminated farm soils. Simultaneously, sequential selective extractions were performed to estimate the partitioning of 226 Ra among six geochemical fractions. The results showed that concentration ratios (CRs), related to plant dry weight, for endogenous and exogenous 226 Ra in soils, were of the order of 10 -2 -10 -1 and 10 -2 -10 0 respectively. The averages of 226 Ra exchangeable and residual fractions in soils were: 3.2% and 50.2% for endogenous and 15.4% and 6.0% for exogenous radium. The CRs calculated either in relation to total 226 Ra or to the exchangeable fraction in soils showed about the same variability. (author)

  16. Radium and uranium levels in vegetables grown using different farming management systems

    Energy Technology Data Exchange (ETDEWEB)

    Lauria, D.C. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN), Av. Salvador Allende s/n, Recreio dos Bandeirantes, Rio de Janeiro, RJ, CEP 22780-160 (Brazil)], E-mail: dejanira@ird.gov.br; Ribeiro, F.C.A. [Centro Regional de Ciencias Nucleares (CRCN/CNEN), Av. Prof. Luiz Freire 200, Cidade Universitaria Recife, PE, CEP 50740-540 (Brazil); Conti, C.C. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN), Av. Salvador Allende s/n, Recreio dos Bandeirantes, Rio de Janeiro, RJ, CEP 22780-160 (Brazil); Loureiro, F.A. [Estacao Experimental de Nova Friburgo, Empresa de Pesquisa Agropecuaria do Estado do Rio de Janeiro, Pesagro (Brazil)

    2009-02-15

    Vegetables grown with phosphate fertilizer (conventional management), with bovine manure fertilization (organic management) and in a mineral nutrient solution (hydroponic) were analyzed and the concentrations of {sup 238}U, {sup 226}Ra and {sup 228}Ra in lettuce, carrots, and beans were compared. Lettuce from hydroponic farming system showed the lowest concentration of radionuclides 0.51 for {sup 226}Ra, 0.55 for {sup 228}Ra and 0.24 for {sup 238}U (Bq kg{sup -1} dry). Vegetables from organically and conventionally grown farming systems showed no differences in the concentration of radium and uranium. Relationships between uranium content in plants and exchangeable Ca and Mg in soil were found, whereas Ra in vegetables was inversely correlated to the cation exchange capacity of soil, leading to the assumption that by supplying carbonate and cations to soil, liming may cause an increase of U and a decrease of radium uptake by plants. The soil to plant transfer varied from 10{sup -4} to 10{sup -2} for {sup 238}U and from 10{sup -2} to 10{sup -1} for {sup 228}Ra.

  17. Radium and uranium levels in vegetables grown using different farming management systems

    International Nuclear Information System (INIS)

    Lauria, D.C.; Ribeiro, F.C.A.; Conti, C.C.; Loureiro, F.A.

    2009-01-01

    Vegetables grown with phosphate fertilizer (conventional management), with bovine manure fertilization (organic management) and in a mineral nutrient solution (hydroponic) were analyzed and the concentrations of 238 U, 226 Ra and 228 Ra in lettuce, carrots, and beans were compared. Lettuce from hydroponic farming system showed the lowest concentration of radionuclides 0.51 for 226 Ra, 0.55 for 228 Ra and 0.24 for 238 U (Bq kg -1 dry). Vegetables from organically and conventionally grown farming systems showed no differences in the concentration of radium and uranium. Relationships between uranium content in plants and exchangeable Ca and Mg in soil were found, whereas Ra in vegetables was inversely correlated to the cation exchange capacity of soil, leading to the assumption that by supplying carbonate and cations to soil, liming may cause an increase of U and a decrease of radium uptake by plants. The soil to plant transfer varied from 10 -4 to 10 -2 for 238 U and from 10 -2 to 10 -1 for 228 Ra

  18. Radium and uranium levels in vegetables grown using different farming management systems.

    Science.gov (United States)

    Lauria, D C; Ribeiro, F C A; Conti, C C; Loureiro, F A

    2009-02-01

    Vegetables grown with phosphate fertilizer (conventional management), with bovine manure fertilization (organic management) and in a mineral nutrient solution (hydroponic) were analyzed and the concentrations of (238)U, (226)Ra and (228)Ra in lettuce, carrots, and beans were compared. Lettuce from hydroponic farming system showed the lowest concentration of radionuclides 0.51 for (226)Ra, 0.55 for (228)Ra and 0.24 for (238)U (Bq kg(-1) dry). Vegetables from organically and conventionally grown farming systems showed no differences in the concentration of radium and uranium. Relationships between uranium content in plants and exchangeable Ca and Mg in soil were found, whereas Ra in vegetables was inversely correlated to the cation exchange capacity of soil, leading to the assumption that by supplying carbonate and cations to soil, liming may cause an increase of U and a decrease of radium uptake by plants. The soil to plant transfer varied from 10(-4) to 10(-2) for (238)U and from 10(-2) to 10(-1) for (228)Ra.

  19. The natural radioactivity in Guarani aquifer groundwater, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Bonotto, D.M. [Departamento de Petrologia e Metalogenia, Universidade Estadual Paulista (UNESP), Av. 24-A No. 1515, C.P. 178, CEP 13506-900, Rio Claro, Sao Paulo (Brazil)], E-mail: danielbonotto@yahoo.com.br; Bueno, T.O. [Departamento de Petrologia e Metalogenia, Universidade Estadual Paulista (UNESP), Av. 24-A No. 1515, C.P. 178, CEP 13506-900, Rio Claro, Sao Paulo (Brazil)

    2008-10-15

    The measurements of gross alpha and gross beta radioactivity in groundwater samples from Guarani aquifer in Brazil are reported in this paper together with the activity concentration of the natural dissolved radionuclides {sup 40}K, {sup 238}U, {sup 234}U, {sup 226}Ra, {sup 222}Rn, {sup 210}Po, {sup 210}Pb, {sup 232}Th, {sup 228Th}, and {sup 228}Ra. Most of the gross alpha radioactivity values were below the critical level of detection corresponding to 1 mBq/L, however, the whole data set for the gross beta radioactivity and radionuclides {sup 40}K, {sup 238}U, {sup 234}U, {sup 226}Ra, {sup 222}Rn, {sup 210}Po, {sup 210}Pb, and {sup 228}Ra was submitted to a statistical treatment, considering class intervals arranged in geometric progression, because of the great variability of the activity. The analysis indicated lognormal distribution of the data, as usually observed in samples taken from the natural context. An inverse relationship between the gross alpha and gross beta activity has been identified and is related to an increase in the K content in the water. The mobility coefficient has been estimated for {sup 238}U, {sup 226}Ra, {sup 232}Th and {sup 228}Ra in Guarani aquifer and the results indicated that the radioelement solubility in the studied system varies according to the following order: radium>uranium>thorium. The implications of the data obtained in terms of standards established for defining the drinking water quality have also been discussed.

  20. Automated measurement of 224Ra and 226Ra in water

    International Nuclear Information System (INIS)

    Dimova, N.; Burnett, W.C.; Horwitz, E.P.; Lane-Smith, D.

    2007-01-01

    We present a new simple approach for automated, non-destructive measurement of the alpha-emitting radium isotopes ( 223 Ra, 224 Ra, and 226 Ra) in water based on the emanation of their respective radon daughters ( 219 Rn, 220 Rn, and 222 Rn). The method combines the high adsorption uptake of MnO 2 Resin for radium (K d =2.4x10 4 ml/g) over a wide pH range with the simplicity of the activity registration using a commercial radon-in-air analyzer (RAD7, DURRIDGE Company, Inc). Radium is first adsorbed onto the MnO 2 Resin by passing a water sample through the resin packed in a gas-tight glass cartridge. The same cartridge is then connected to the radon analyzer via a simple tubing system to circulate air through the resin and a drying system. The efficiency of the proposed system is determined by running standards prepared in the same manner. Our results indicate that the efficiency for 226 Ra is >22% if both 218 Po and 214 Po counts are collected. This is comparable with typical efficiencies for alpha spectrometry but with much less sample preparation. We estimate that an MDA of 0.8 pCi/L for 226 Ra may be obtained with this new approach using a 1 L water sample and less than 4 h of counting

  1. Comparison of uranium and radium isotopes activities in some wells and thermal springs samples in Morroco

    International Nuclear Information System (INIS)

    Hakam, O.K.; Choukri, A.; Reyss, J.L.; Lferde, M.

    2000-01-01

    Activities and activity ratios of uranium and radium isotopes ( 234 U, 238 U, 226 Ra, 228 Ra, 234 U/ 238 U, 226 Ra/ 238 U, 228 Ra/ 226 Ra) have been determined, for the first time in Morocco, for 15 well water samples and 12 spring water samples. The obtained results show that, unlike well waters, the thermal spring waters present relatively low 238 U activities and elevated 226 Ra activities and 234 U/ 238 U activity ratios. Uranium and radium activities are similar to those published for other non polluting regions of the world, they are inferior to the Maximum Contaminant Levels and don't present any risk for public health in Morocco. (author) [fr

  2. Study of soil-plant transfer of 226Ra under greenhouse conditions

    International Nuclear Information System (INIS)

    Soudek, Petr; Petrova, Sarka; Benesova, Dagmar; Kotyza, Jan; Vagner, Martin; Vankova, Radomira; Vanek, Tomas

    2010-01-01

    A soil-plant transfer study was performed using soil from a former uranium ore processing factory in South Bohemia. We present the results from greenhouse experiments which include estimates of the time required for phytoremediation. The accumulation of 226 Ra by different plant species from a mixture of garden soil and contaminated substrate was extremely variable, ranging from 0.03 to 2.20 Bq 226 Ra/g DW. We found differences in accumulation of 226 Ra between plants from the same genus and between cultivars of the same plant species. The results of 226 Ra accumulation showed a linear relation between concentration of 226 Ra in plants and concentration of 226 Ra in soil mixtures. On the basis of these results we estimated the time required for phytoremediation, but this appears to be too long for practical purposes.

  3. Radionuclide inventories for the F- and H-area seepage basin groundwater plumes

    Energy Technology Data Exchange (ETDEWEB)

    Hiergesell, Robert A [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Kubilius, Walter P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-05-01

    Within the General Separations Areas (GSA) at the Savannah River Site (SRS), significant inventories of radionuclides exist within two major groundwater contamination plumes that are emanating from the F- and H-Area seepage basins. These radionuclides are moving slowly with groundwater migration, albeit more slowly due to interaction with the soil and aquifer matrix material. The purpose of this investigation is to quantify the activity of radionuclides associated with the pore water component of the groundwater plumes. The scope of this effort included evaluation of all groundwater sample analyses obtained from the wells that have been established by the Environmental Compliance & Area Completion Projects (EC&ACP) Department at SRS to monitor groundwater contamination emanating from the F- and H-Area Seepage Basins. Using this data, generalized groundwater plume maps for the radionuclides that occur in elevated concentrations (Am-241, Cm-243/244, Cs-137, I-129, Ni-63, Ra-226/228, Sr-90, Tc-99, U-233/234, U-235 and U-238) were generated and utilized to calculate both the volume of contaminated groundwater and the representative concentration of each radionuclide associated with different plume concentration zones.

  4. 226Ra concentrations in some Illinois well waters

    International Nuclear Information System (INIS)

    Holtzman, R.B.; Gilkeson, R.H.

    1982-01-01

    226 Ra concentrations are reported for the waters from deep wells in 43 communities in Illinois. The concentrations range from 0.08 to 20.6 pCi/L. The effectiveness of additives (nitric acid or EDTA) in keeping the 226 Ra in solution in the samples is discussed

  5. Distribution of uranium, Ra-226, Pb-210 and Po-21a in the ecological cycle in mountain regions of central Yugoslavia

    International Nuclear Information System (INIS)

    Milosevic, Z.; Horsic, E.; Kljajic, R.; Bauman, A.

    1980-01-01

    The distributions of U, 226 Ra, 210 Pb and 210 Po in the ecological cycle: soil-hay-domestic animals-meat-cheese-milk were investigated. The levels of radioactivity in soil were found to be normal. The highest result found for U in hay was 100 ug/kg. The amount of 226 Ra was highest in beef bones, where the contamination reached 190 pCi/kg. The amount of 210 Pb in bones never exceeded 30 pCi/kg and in meat, 5 pCi/kg. In most samples 210 Po was below the detection level, but one bone sample reached 90 pCi/kg. U, 226 Ra, 210 Pb and 210 Po in milk all vary from 0 - 2.45 pCi/l. Only 210 Pb in cheese was as high as 60 pCi/kg, 226 Ra, 210 Po and U were hardly detectable. (H.K.)

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

    International Nuclear Information System (INIS)

    Hollanda Vasconcellos, L.M. de.

    1984-01-01

    The average concentrations of 226 Ra and 210 Pb 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 226 Ra and 210 Pb content in the soil was determined by gamma spectrometry. The exchangeable fraction was obtained 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 Muller Counter. (M.A.C.) [pt

  7. Natural radionuclides in food in an area with high concentrations of radionuclides

    International Nuclear Information System (INIS)

    Pereira, W.S.; Moraes, S.R.; Cavalcante, J.J.V.; Kelecom, A.; Silva, A.X. da; Lopez, J.M.; Filgueiras, R.; Carmo, A.S.

    2017-01-01

    Areas of high natural radiation expose the local population to doses greater than the world average. One of the routes of exposure is food intake. The activity concentration (AC) of 5 natural radionuclides in 7 types of foods was analyzed. The highest CA measured was 2.40 Bq.kg -1 for the U nat in the potato. The multivariate statistic identified two groups: (U nat e 232 Th) and [( 210 Pb and 228 Ra) and 226 Ra

  8. Analysis of radionuclides in airborne effluents from coal-fired power plants

    Energy Technology Data Exchange (ETDEWEB)

    Rosner, G.; Chatterjee, B.; Hoetzl, H.; Winkler, R.

    1982-01-01

    In order to assess the level of radioactivity emitted by coal-fired power plants in detail, specific activities of several radionuclides have been measured in samples from a coal-fired and a brown coal-fired plant in the Federal Republic of Germany. Samples measured included coal, brown coal, bottom ash, collected fly ash from the various electrostatic precipitator stages and sieve fractions of collected fly ash as well as samples of escaping fly ash taken from the exhaust stream, all taken simultaneously on three operating days. Nuclides measured were U-238, U-234, Th-232, Th-230, Th-228, Ra-226, Pb-210, Po-210 and K-40. Methods applied included (i) direct gamma spectrometry, (ii) radiochemical separation with subsequent alpha spectrometry and (iii) direct alpha spectrometry. Methods are described and discussed. Finally, annual emission rates of airborne radionuclides are calculated for both plants.

  9. Analysis of radionuclides in airborne effluents from coal-fired power plants

    International Nuclear Information System (INIS)

    Rosner, G.; Chatterjee, B.; Hoetzl, H.; Winkler, R.

    1982-01-01

    In order to assess the level of radioactivity emitted by coal-fired power plants in detail, specific activities of several radionuclides have been measured in samples from a coal-fired and a brown coal-fired plant in the Federal Republic of Germany. Samples measured included coal, brown coal, bottom ash, collected fly ash from the various electrostatic precipitator stages and sieve fractions of collected fly ash as well as samples of escaping fly ash taken from the exhaust stream, all taken simultaneously on three operating days. Nuclides measured were U-238, U-234, Th-232, Th-230, Th-228, Ra-226, Pb-210, Po-210 and K-40. Methods applied included (i) direct gamma spectrometry, (ii) radiochemical separation with subsequent alpha spectrometry and (iii) direct alpha spectrometry. Methods are described and discussed. Finally, annual emission rates of airborne radionuclides are calculated for both plants. (orig.)

  10. Naturally occurring radionuclides transfer factor on aquatic flora and fauna in Nagarjuna Sagar Dam near proposed uranium mining site

    International Nuclear Information System (INIS)

    Arunachalam, Kantha Deivi

    2015-04-01

    Naturally occurring radioactive element can be found in low levels within all rock, soil, and water. The present work aims to understand the transfer of naturally occurring radionuclides in different compartments of environment reflecting its behaviour in different tropic levels. The understanding and evaluation of the possible interactions of various naturally occurring radionuclides were done in the world's third largest man-made dam, Nagarjuna Sagar, built on river Krishna located in Andhra Pradesh, India. The naturally occurring radionuclides such as Uranium ( 238 U), Polonium ( 210 Po), Radium ( 226 Ra), and Lead ( 210 Pb) were analyzed in different matrices (i.e) sediment, water, and fish. The measurement of the naturally occurring radionuclides in the environment can be used as a reference baseline for long-term monitoring in the entire aquatic ecosystem

  11. 238U content in soils of Byelorussia

    International Nuclear Information System (INIS)

    Shagalova, Eh.D.

    1986-01-01

    Results of detection in Byelorussian soils of a heavy natural radionuclide 238 U and its content in humus horizons of the soils on map-schemes are presented. 238 U content is determined by complete decomposition of soils by acids, isolation from thorium using EhDEh-10 P anionite and subsequent solution colorimetry. It is shown that the content of uranium-238 in soils decreases from the North to the South. Its maximum amount (>2x10 -4 %) is detected in turfy-podsolic soils in lake-glacier loams; the minimum one ( -4 %)- in peatymarshy soils. The map-scheme of 238 U content is a background base. Using the background base it is possible to trace the change in uranium content in soils under conditions of technogenic effect and to substantiate the efficiency of environment protection measures

  12. Sequential survey of the occurrence and the possible effects of a 226Ra surplus in harbour slurry polder grounds: Definition study

    International Nuclear Information System (INIS)

    Stoop, P.; Lembrechts, J.

    1993-11-01

    Sediments in the harbors of Rotterdam contain relatively large amounts of naturally occurring radionuclides resulting from emissions of the ore-processing industries (88Be, 92Be). Using harbour sludge as a landfill for polders has locally caused the 226 Ra contents of the soil to be a factor of 4 higher than the expected 226 Ra background. In polders where 226 Ra was measured, the 226 Ra surplus was found to be proportional to the cadmium contents (92Mo). Data on cadmium contents are available for many polders and therefore, cadmium may be useful as a tracer for enhanced levels of 226 Ra. Enhanced levels of 226 Ra may cause higher radon concentrations in dwellings that are built on these soils. Therefore, an extensive research programme is started to study the relation between the 226 Ra contents of the soil and radon concentrations in dwellings. The Laboratory of Radiation Research of RIVM has proposed to set up a sub-programme, focusing on the sites where harbour sludges have been dumped, with the following goals: 1) to investigate if there are dwellings with enhanced radon concentrations as a result of a 226 Ra surplus and 2) to investigate if the relation between the 226 Ra-surplus and the cadmium contents found is generally valid and useful. In this report we describe how this sub-programme may be set up and we give specific advice on the answers to various choices. We propose a.o. to use soil samples from 30 polders to investigate the relation between the 226 Ra surplus and the cadmium contents and to study in eight polders the possible consequences of enhanced 226 Ra levels for the radon concentrations in dwellings. Because the radon measurements take one year (four measurements averaged over three month) we propose that simple diagnostic measurements are made simultaneously with the radon measurements. These additional measurements include measurements of the groundwater table and of the effective ventilation pattern in the dwelling. 1 fig., 5 tabs., 16

  13. Assessment of radiation background level of Shandong basin in east line of northward rerouting of southern river

    International Nuclear Information System (INIS)

    Deng Daping; Xu Jiaang; Zhu Jianguo; Chen Yingmin; Lu Feng; Song Gang; Cao Jingli

    2007-01-01

    Objective: To assess the radiation background levels of Shandong basin in east line of northward rerouting of southern river. Methods: The activity concentrations of gross-alpha, gross-beta, 137 Cs, 238 U, 232 Th, 40 K, 226 Ra and 90 Sr in the samples were measured by national standard methods respectively. The values of the dose conversion factor given by UNSCEAR 2000 were adopted for dose estimation. Results: The average activity concentrations of gross-alpha, gross-beta, 137 Cs, 238 U, 232 Th, 40 K, 226 Ra and 90 Sr in the samples were pooled in order to analyze dose estimation. The committed effective doses of the 226 Ra, 238 U, 90 Sr, 232 Th and 137 Cs from lake water for residents are 1.46, 4.95 x 10 -1 , 1.24 x 10 -1 , 2.58 x 10 -2 and 7.93 x 10 -3 μSv per year respectively. The committed effective doses of the 226 Ra, 238 U and 90 Sr from cyprinoid fish are 5.49 x 10 -2 , 3.69 x 10 -2 and 1.77 x 10 -2 μSv per year respectively. Conclusions: The results show that the average activity concentrations of gross-alpha, gross-beta, 137 Cs, 238 U, 232 Th, 40 K, 226 Ra and 90 Sr in the samples from Shandong basin of northward rerouting of southern river are within the background levels. And in the main lake basin, the estimated exposures of public caused by the radionuclide in water and cyprinoid fish are so low that they can be ignored unless there ate some radioactive contamination in the future. (authors)

  14. Determination of {sup 210}Pb e {sup 226}Ra in tobacco leaves cultivated in the states of Rio de Grande do Sul e Alagoas - Brazil; Determinacao de {sup 210}Pb e {sup 226}Ra em folhas de tabaco cultivadas nos estados do Rio de Grande do Sul e Alagoas - Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Y.B. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Valentim, E.; Hazin, C.A. [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Antonio Filho, J. [Universidade Catolica de Pernambuco (UNICAP), Recife, PE (Brazil); Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2005-07-01

    The literature has shown that tobacco use causes damage to the health of cigarette users, manifesting itself in diseases with high mortality. Among these diseases include respiratory failure, pulmonary emphysema and lung cancer, among others. On the other hand, smoking contributes significantly to increasing the dose of natural radiation received by man, due to the presence of uranium series radionuclides, such as {sup 226}Ra, {sup 210}Pb and {sup 210}Po, in relatively high concentrations in fresh tobacco leaves. The determination of these radionuclides in this matrix is of great interest, once they can be incorporated not only by the active smoker, but also by the passive smoker. The results of this study confirmed the significant presence of {sup 226}Ra and {sup 210}Pb in tobacco samples collected and analyzed. The average values of activity concentration found in samples from the State of Alagoas were of Bq.kg{sup -1} 0.8 to {sup 210}Pb and 183.5 Bq.kg{sup -1} to {sup 226}Ra. For samples coming from the State of Rio Grande do Sul, these values were 4,0 Bq.kg{sup -1} to {sup 210}Pb and 161.3 Bq.kg{sup -1} to {sup 226}Ra.

  15. Behavior and distribution of 226Ra and 228Ra in the east coast of Peninsular Malaysia marine environment

    International Nuclear Information System (INIS)

    Nurrul Assyikeen Mohd Jaffary; Zal Uyun Wan Mahmood; Zaharudin Ahmad; Yii, Mei Wo; Kamarozaman Ishak

    2010-01-01

    The present distributions of 226 Ra, 228 Ra and activity ratios of 228 Ra/ 226 Ra covering the east coast of Peninsular Malaysia were studied. Sediment core samples were collected at 10 identified stations with the thickness of water column between 14 - 72 m depth during the cruise conducted in 2008. Activity concentrations of 226 Ra and 228 Ra in sediment cores of the studied area were in the range of 18.95 ±4.25 Bq/ kg to 46.48 ± 6.41 Bq/ kg dry wt. and 35.50 ± 7.50 Bq/ kg to 77.10 ±11.37 Bq/ kg dry wt., respectively. Meanwhile, the calculated activity ratios of 228 Ra/ 226 Ra were varied mostly 1.48 to 2.24. The finding showed that there has relationships between 226 Ra, 228 Ra and oceanographic parameters which are can be attributed for better understanding of its transport processes and behavior in the east coast of Peninsular Malaysia marine environment. (author)

  16. Effective 226Ra-content of some Hungarian building materials

    International Nuclear Information System (INIS)

    Toth, A.; Feher, I.

    1976-01-01

    The aim of the work was to analyse the effective 226 Ra content of building- and back filling materials used in Hungary. The quantity of radon was determined by ionization chambers connected to vibrating-reed electrometers, as well as by a scintillation radon counter. The radon measuring instruments were calibrated by known 222 Rn quantities given off from standard RaCl 2 solutions. The overall uncertainty of the data obtained is estimated as being 25%. The minimum measurable effective 226 Ra concentration due to a 10 4 g building material source is calculated as 16 fCi/g for the ionization chambers and 8 fCi/g for the scintillation counter. 68 building material samples and 11 backfill (concrete made by fly-ashes) samples have been studied and it has been found, that the effective 226 Ra contents of the tested building materials are 2 to 9 times greater than those found in the Soviet Union though none exceeds the recommended 600 fCi/g level. Among the back filling materials made with fly-ash the maximum 226 Ra content was 3300 fCi/g. The effective 226 Ra content measurements are well suited for a priori radon escape qualification of building materials. (K.A.)

  17. The flux of 226Ra from estuarine and continental shelf sediments

    International Nuclear Information System (INIS)

    Li, Y.H.; Mathieu, G.; Biscaye, P.; Simpson, H.J.

    1977-01-01

    A pronounced desorption phenomenon of 226 Ra from sediment was observed in the Hudson River estuary. Mass balance calculations indicate that the desorption of 226 Ra from the river-borne sediment in estuarine environment is an important source of 226 Ra to the oceans. (Auth.)

  18. Distribution and transport of radionuclides in a boreal mire – assessing past, present and future accumulation of uranium, thorium and radium

    International Nuclear Information System (INIS)

    Lidman, Fredrik; Ramebäck, Henrik; Bengtsson, Åsa; Laudon, Hjalmar

    2013-01-01

    The spatial distribution of 238 U, 226 Ra, 40 K and the daughters of 232 Th, 228 Ra and 228 Th, were measured in a small mire in northern Sweden. High activity concentrations of 238 U and 232 Th (up to 41 Bq 238 U kg −1 ) were observed in parts of the mire with a historical or current inflow of groundwater from the surrounding till soils, but the activities declined rapidly further out in the mire. Near the outlet and in the central parts of the mire the activity concentrations were low, indicating that uranium and thorium are immobilized rapidly upon their entering the peat. The 226 Ra was found to be more mobile with high activity concentrations further out into the mire (up to 24 Bq kg −1 ), although the central parts and the area near the outlet of the mire still had low activity concentrations. Based on the fluxes to and from the mire, it was estimated that approximately 60–70% of the uranium and thorium entering the mire currently is retained within it. The current accumulation rates were found to be consistent with the historical accumulation, but possibly lower. Since much of the accumulation still is concentrated to the edges of the mire and the activities are low compared to other measurements of these radionuclides in peat, there are no indications that the mire will be saturated with respect to radionuclides like uranium, thorium and radium in the foreseen future. On the contrary, normal peat growth rates for the region suggest that the average activity concentrations of the peat currently may be decreasing, since peat growth may be faster than the accumulation of radionuclides. In order to assess the total potential for accumulation of radionuclides more thoroughly it would, however, be necessary to also investigate the behaviour of other organophilic elements like aluminium, which are likely to compete for binding sites on the organic material. Measurements of the redox potential and other redox indicators demonstrate that uranium possibly could

  19. Measuring the radium quartet (228Ra, 226Ra, 224Ra, 223Ra) in seawater samples using gamma spectrometry

    International Nuclear Information System (INIS)

    Beek, P. van; Souhaut, M.; Reyss, J.-L.

    2010-01-01

    Radium isotopes are widely used in marine studies (eg. to trace water masses, to quantify mixing processes or to study submarine groundwater discharge). While 228 Ra and 226 Ra are usually measured using gamma spectrometry, short-lived Ra isotopes ( 224 Ra and 223 Ra) are usually measured using a Radium Delayed Coincidence Counter (RaDeCC). Here we show that the four radium isotopes can be analyzed using gamma spectrometry. We report 226 Ra, 228 Ra, 224 Ra, 223 Ra activities measured using low-background gamma spectrometry in standard samples, in water samples collected in the vicinity of our laboratory (La Palme and Vaccares lagoons, France) but also in seawater samples collected in the plume of the Amazon river, off French Guyana (AMANDES project). The 223 Ra and 224 Ra activities determined in these samples using gamma spectrometry were compared to the activities determined using RaDeCC. Activities determined using the two techniques are in good agreement. Uncertainties associated with the 224 Ra activities are similar for the two techniques. RaDeCC is more sensitive for the detection of low 223 Ra activities. Gamma spectrometry thus constitutes an alternate method for the determination of short-lived Ra isotopes.

  20. Kinetic study of the precipitation of radioactive elements in the production process of phosphoric acid

    International Nuclear Information System (INIS)

    Ben Mahmoud, Souha

    2009-01-01

    In this engineering study we determined the activities of gamma emitting radionuclides belonging to the families of 238 U , 232 Th and 40K in phosphate, the acid derivatives and gypsum in Tunisian Chemical Group. The most important activities are those of 238 U and 226 Ra, which are located in the phosphate, gypsum and the precipitates formed in the pipes.

  1. The distribution of 226Ra in the Atlantic Ocean

    International Nuclear Information System (INIS)

    Broecker, W.S.; Goddard, J.; Sarmiento, J.L.

    1976-01-01

    Based on results obtained during the GEOSECS program the primary features of the distribution of 226 Ra in the Atlantic Ocean can be defined. Outside the Antarctic no significant variation has been found in the 226 Ra content of surface waters. Eighty samples yield an average of 7.4 dpm/100 kg (normalized to a salinity of 35.00%). Deep waters in the central Atlantic have 226 Ra contents several dpm/100 kg higher than expected from the mixing of Antarctic Bottom Water (21.3 dpm/100 kg) and basal North Atlantic Deep Water (10.3 dpm/100 kg). These excesses correlate well with deficiencies in O 2 and excesses in SiO 2 . The intermediate water 226 Ra maximum in the South Atlantic is associated with the inflow of low-oxygen Circumpolar Intermediate Water beneath the Antarctic Intermediate Water. (Auth.)

  2. Migration of U-series radionuclides around the Bangombe natural fission reactor (Gabon)

    International Nuclear Information System (INIS)

    Bros, R.; Yanase, N.; Isobe, H.; Sato, T.; Iida, Y.; Ohnuki, T.; Roos, P.; Holm, E.

    1999-01-01

    The Bangombe natural fission reactors has undergone extensive weathering phenomena and continues to be affected by the penetration of meteoric waters. Hence this system provides a model for studying the stability of spent fuel uraninite and the influence of various rock matrices on the mobilization/retardation of various actinides and fission products. The Bangombe uranium deposit has been investigated by drilling on a grid. Radiochemical analysis by alpha- and gamma-spectroscopy of the obtained rocks show significant disequilibria of the 234 U/ 238 U, 230 Th/ 234 U, and 226 Ra/ 230 Th parent-daughter pairs. In this paper, a conceptual model for spatio/temporal evolution of the Bangombe system is proposed. (J.P.N.)

  3. Internal Dosimetry Monitoring- Detection Limits for a Selected Set of Radionuclides and Their Translation Into Committed Effective Dose

    International Nuclear Information System (INIS)

    Brandl, A.; Hrnecek, E.; Steger, F.

    2004-01-01

    To harmonize the practice of internal dosimetry monitoring across the country, the Austrian Standards Institute is currently drafting a new set of standards which are concerned with occupational incorporation monitoring of individuals handling non-sealed radioactive material. This set of standards is expected to consist of three parts discussing the general necessity and frequency, the requirements for monitoring institutions, and the determination and rigorous calculation of committed effective dose after incorporation of radioactive material, respectively. Considerations of the requirements for routine monitoring laboratories have led to an evaluation of the detection limits for routine monitoring equipment. For a selected set of radionuclides, these detection limits are investigated in detail. The main emphasis is placed on the decay chains of naturally occurring radionuclides showing some significant potential for being out of equilibrium due to chemical processes in certain mining industries. The radionuclides considered in this paper are 226Ra, 228Ra, 228Th, 232Th, 234U, 235U, and 238U. Given the routine monitoring intervals of the Austrian Standard, these detection limits are translated into information on committed effective dose. This paper investigates whether routine monitoring equipment is sufficient to ensure compliance with EC directive 96/29/Euratom for this selected set of radionuclides. (Author) 9 refs

  4. Techniques for precise mapping of 226Ra and 228Ra in the ocean

    International Nuclear Information System (INIS)

    Moore, W.S.; Key, R.M.; Sarmiento, J.L.

    1985-01-01

    Improvements in the analyses of 226 Ra and 228 Ra in seawater made possible by better extraction and processing techniques reduce significantly the errors associated with these measurements. These improvements and the extensive sampling for Ra isotopes conducted on the TTO North Atlantic Study should enable us to use the distribution of 228 Ra to study mixing processes on a 3-15 year time scale in both the upper and deep North Atlantic. The 228 Ra profiles already analyzed show a closer resemblance to GEOSECS tritium data than to TTO tritium data in the upper ocean. This is because the transient tracer tritium was responding on a 10-year time scale during GEOSECS and a 20-year time scale during TTO. The steady state tracer 228 Ra should always respond on a time scale of 8 years. Thus the 228 Ra data obtained on TTO should provide a means to extend the features of the GEOSECS tritium field to the regions of the TTO study. The 226 Ra data are of high enough quality to identify features associated with different water masses. Changes in the positions of the deep-water masses since the GEOSECS cruise are revealed by the 226 Radata

  5. Radionuclide concentrations in raw and purified phosphoric acids from Brazil and their processing wastes: implications for radiation exposures.

    Science.gov (United States)

    da Conceição, Fabiano Tomazini; Antunes, Maria Lúcia Pereira; Durrant, Steven F

    2012-02-01

    Radionuclides from the U and Th natural series are present in alkaline rocks, which are used as feedstock in Brazil for the production of raw phosphoric acid, which can be considered as a NORM (naturally occurring radioactive material). As a result of the purification of raw phosphoric acid to food-grade phosphoric acid, two by-products are generated, i.e., solid and liquid wastes. Taking this into account, the main aim of this study was to evaluate the fluxes of natural radionuclide in the production of food-grade phosphoric acids in Brazil, to determine the radiological impact caused by ingestion of food-grade phosphoric acid, and to evaluate the solid waste environmental hazards caused by its application in crop soils. Radiological characterization of raw phosphoric acid, food-grade phosphoric acid, solid waste, and liquid waste was performed by alpha and gamma spectrometry. The (238)U, (234)U, (226)Ra, and (232)Th activity concentrations varied depending on the source of raw phosphoric acid. Decreasing radionuclides activity concentrations in raw phosphoric acids used by the producer of the purified phosphoric acid were observed as follows: Tapira (raw phosphoric acid D) > Catalão (raw phosphoric acids B and C) > Cajati (raw phosphoric acid A). The industrial purification process produces a reduction in radionuclide activity concentrations in food-grade phosphoric acid in relation to raw phosphoric acid produced in plant D and single raw phosphoric acid used in recent years. The most common use of food-grade phosphoric acid is in cola soft drinks, with an average consumption in Brazil of 72 l per person per year. Each liter of cola soft drink contains 0.5 ml of food-grade phosphoric acid, which gives an annual average intake of 36 ml of food-grade phosphoric acid per person. Under these conditions, radionuclide intake through consumption of food-grade phosphoric acid per year per person via cola soft drinks is not hazardous to human health in Brazil

  6. Environmental radioactivity in Turkey, 2007

    International Nuclear Information System (INIS)

    2009-01-01

    In this report, the activity concentrations of natural and artificial radionuclides, gross alpha/beta activities and air gamma dose rates in the environmental and food samples provided from Turkey's seven geographical regions within the environmental radioactivity monitoring program in 2007 are presented. The activity concentrations of the natural ( 238 U, 232 Th, 2 26Ra, 4 :0K and 7 Be) and artificial ( 137 Cs, 134 Cs, 90 Sr, 238-239+240 Pu, 2 41Am) radionuclides and gross alpha/beta activities in the samples were measured by using the gamma spectrometry, the alpha spectrometry, the liquid scintillation counter and the gross alpha /beta counting system. Results show that 137 Cs and 9 0Sr radionuclides originating from the Chernobyl Nuclear Reactor accident in 1986 exist in some of samples even in low levels. The mean activity concentrations of 238 U, 232 Th, 226 Ra and 40 K in the studied surface soil samples were found as 32.1 Bq kg -1 , 35.0 Bq kg -1 , 29.0 Bq kg -1 and 446.7 Bq kg -1 , respectively, while the mean activity concentrations of the fission product 1 37Cs was found as 18.4 Bq kg -1 . While the activity concentrations of 238 U, 232 Th and 226 Ra in the analyzed food samples are lower than the minimum detectable activity (MDA), 134 Cs and 7 Be radionuclides are not observed. The mean activity concentrations of 137 Cs and 90 Sr radionuclides are 0.24 Bq L - 1 and 0.05 Bq L - 1, respectively. (Includes 4 tables and 7 figures)

  7. 226Ra adsorption on active coals from waste waters

    International Nuclear Information System (INIS)

    Panturu, E.; Georgescu, D.P.; Serban, N.; Filip, D.; Radulescu, R.

    2000-01-01

    During the mining and extraction of uranium, the principle means of protection measurement is to prevent uranium and its products diffusing into the environment. The main carriers of radioactive elements in the environment are air and water. Therefore, reduction of the pollution at a uranium mine can be achieved by the treatment of waste waters contaminated with 226 Ra Radium contaminated waste waters represent a major biological risk. This paper presents the results of the study of the sorption of 226 Ra on active coal mechanisme and the influence of the physical and chemical characteristics of fluid. The 226 Ra removal from the residue pond water at the uranium ore processing plant was studied using eight types of indigenous active coals. The experimental results for each type of active coal and their effect on removal of 226 Ra from waste waters are presented in this paper. (author)

  8. Environmental risks due to radionuclide releases Environmental Risks Due To Radionuclide Releases From The Oil And Gas Industry

    International Nuclear Information System (INIS)

    Steinhausler, F.

    2005-01-01

    Full text : Exploration and transport in the oil- and gas industry result in the release of elevated levels of natural radioactivity into the environment. This has the following impact: Due to the large volumes of water needed during the extraction of gas and oil the resulting waste water can contain increased concentration of natural radionuclides, such as radium (Ra 226) and its decay products; At the oil/water interface waste water and sludge precipitate and form scalings, containing elevated levels of radium (Ra 226); At oil- and gas extraction sites tanks and equipment can be coated with long-lived radon (Rn 222) decay products; Along oil- and gas pipelines (e.g., at compressor stations) radon (Rn 222) decay products can be deposited internally on metal surfaces, such as valves. Typical U 238-series concentration values in production water range from 8 to 42 kBq/ m3, respectively in scale from 1 to 1 000 kBq/kg. In addition, oil- and gas extraction results in significant releases of natural radionuclides to the atmosphere (Rn 222) and to the water (Th 228, Ra 226, Rn 222, Pb 210, Po 210); for example, about 0.15 GBq/a of Rn 222 are released to the atmosphere per 106 m3 of oil extracted. The disposal of large amounts of contaminated wastes (scales, sludges) represents an environmental problem for the scrap metal industry (recycling of steel pipes containing scales) and the housing industry (use of sludge for landfill below a residential area). Using data from the oil- and gas industry in Latin America, Europe and the Asia-Pacific region, the various exposure pathways are reviewed. Furthermore, the current efforts in defining a suitable regulatory framework are discussed

  9. Ground water input to coastal salt ponds of southern Rhode Island estimated using 226Ra as a tracer.

    Science.gov (United States)

    Scott, M K; Moran, S B

    2001-01-01

    The naturally occurring radionuclide 226Ra (t1/2 = 1600 years) was used as a tracer to determine ground water input to Point Judith, Potter, Green Hill and Ninigret ponds in southern Rhode Island. Measurements of 226Ra activity were made in samples collected from salt ponds, pore waters, sediments, and local ground water wells during June-August, 1997. These results were combined with a simple box model to derive ground water input fluxes of 0.1-0.3 cm3 cm-2 d-1 (2-5 x 10(7) L d-1), which are comparable to previous estimates of ground water input to these ponds.

  10. Computer simulation of the natural U 238 and U 235 radioactive series decay

    International Nuclear Information System (INIS)

    Barna, A.; Oncescu, M.

    1980-01-01

    The principles of the computer simulation of a radionuclide decay - its decay scheme adoption and codification -, and the adoption principle of a radionuclide chain in a series are applied to the natural U 238 and U 235 series radionuclide decay computer simulation. Using the computer simulation data of these two series adopted chains, the decay characteristic quantities of the series radionuclides, the gamma spectra and the basic characteristics of each of these series are determined and compared with the experimental values given in the literature. (author)

  11. Temporal behavior of 222Radon, 226Radium and 238Uranium in deep water wells which provide Valle de Toluca with drinking water

    International Nuclear Information System (INIS)

    Pena, P.; Tamez, E.; Iturbe, J.L.; Acosta, A.; Segovia, N.; Carrillo, J.; Armienta, M.

    1994-01-01

    The presence of radionuclides in underground waters may be an indication of its origin and also the sign of the hydraulic properties of the aquifers layers where circulate. Additionally, the ingestion by human beings of water with radioactive elements (Radon 222, Radium 226, Uranium 238) can give as a result the accumulation of such elements in several organs of the body producing then health damages. In this work, the concentrations of Radon 222, Radium 226 and Uranium 238, in waters coming from deep wells which provide with drinking water the Toluca Valley, were determined. For this purpose, during a year (june 1991 to August 1992) ten wells were sampled with a tracking of the radionuclides concentration as well as the physical-chemical components of water; it was established the relationship presented by the analyzed waters with the local geology and the local and regional systems. (Author)

  12. Application of the 226Ra-230Th-234U and 227Ac-231Pa-235U radiochronometers to uranium certified reference materials

    International Nuclear Information System (INIS)

    Rolison, J.M.; Treinen, K.C.; McHugh, K.C.; Gaffney, A.M.; Williams, R.W.

    2017-01-01

    Uranium certified reference materials (CRM) issued by New Brunswick Laboratory were subjected to dating using four independent uranium-series radiochronometers. In all cases, there was acceptable agreement between the model ages calculated using the 231 Pa- 235 U, 230 Th- 234 U, 227 Ac- 235 U or 226 Ra- 234 U radiochronometers and either the certified 230 Th- 234 U model date (CRM 125-A and CRM U630), or the known purification date (CRM U050 and CRM U100). The agreement between the four independent radiochronometers establishes these uranium certified reference materials as ideal informal standards for validating dating techniques utilized in nuclear forensic investigations in the absence of standards with certified model ages for multiple radiochronometers. (author)

  13. Mobility of Ra-226 and Heavy Metals (U, Th and Pb) from Pyritic Uranium Mine Tailings under Sub-aqueous Disposal Conditions - 59283

    International Nuclear Information System (INIS)

    Dave, Nand K.

    2012-01-01

    All uranium mines in the Elliot Lake uranium mining district of north-central Ontario, Canada, have been closed due to low ore grade and prevailing market conditions. A majority of the waste management facilities have been rehabilitated and decommissioned with in-situ shallow water covers to minimize sulphide oxidation, and hence acid generation and release of metal enriched effluents. Laboratory lysimeter studies were undertaken to evaluate the leaching characteristics and mobility of Ra-226 and other heavy metals (U, Th and Pb) from pyritic uranium mine tailings under sub-aqueous disposal conditions for assessing the long-term radiological stability of such waste repositories. The experiments were conducted using three types of un-oxidized tailings: fine, coarse and gypsum depleted mill total tailings. Shallow water covers of depth ∼ 0.3 m were established using natural lake water. The leaching characteristics of radium and other major and trace metals were determined by monitoring both surface and pore water qualities as a function of time. The results showed that Ra-226 was leached from surface of the submerged tailings and released to both surface water and shallow zone pore water during initial low sulphate ion concentration of the surface water cover in all three cases. The release of Ra-226 was further enhanced with the onset of weak acidic conditions in the surface water covers of both coarse and gypsum depleted mill total tailings. With additional acid generation and increasing sulphate and iron concentrations, the dissolved Ra-226 concentrations in the water covers of these tailings gradually decreased back to low levels. Pb was also leached and mobilized with the development of moderate acidic conditions at the surface of the submerged coarse and gypsum deplete tailings. No leaching of U and Th was observed. (authors)

  14. Behavior of Ra-226 and Pb-210 in the aquatical environment of the first Brazilian uranium mine and mill

    International Nuclear Information System (INIS)

    Franca, E.P.; Amaval, E.C.S.; Stoffel, M.G.

    1982-01-01

    The first Brazilian uranium mine and mill will start operation in 1981, on the Pocos de Caldas plateau, in the central state of Minas Gerais. The pre-operational environmental survey indicated that the critical radionuclides in the region will be: 226 Ra due to the tailing pond liquid effluent and 21 Pb produced via 222 Rn dispersion, natural fall-out and accumulation on the ground. Sorption and desorption studies of 226 Ra and 210 Pb on their interaction with local water, suspended matter and sediments have been carried out in the laboratory to understand their behavior in the regional aquatic environment. The laboratory experiments gave indications that, in the aquatic environment of Pocos de Caldas, 210 Pb should remain mostly sorbed on bottom sediments. Its transport should occur essentially bound to suspended matter. By contrast, 226 Ra should be transported mostly in the soluble form

  15. Intake of 210Po, 234U and 238U radionuclides with beer in Poland

    International Nuclear Information System (INIS)

    Skwarzec, B.; Struminska, D.I.; Borylo, A.; Falandysz, J.

    2004-01-01

    238 U, 234 U and 210 Po activity concentrations were determined in beer in Poland by alpha-spectrometry with low-level activity silicon detectors. The results revealed that the mean concentrations of 238 U, 234 U and 210 Po in the analyzed beer samples were 4.63, 4.11 and 4.94 mBq x dm -3 , respectively, the highest in Tyskie (5.71 for 210 Po, 5.06 for 234 U and 6.11 for 238 U) and the lowest in Lech (2.49 for 210 Po). The effective radiation dose due to uranium and polonium ingestions by beer was calculated and were compared to the effective radiation dose from drinking water. (author)

  16. Geochemistry and behavior of Natural radionuclides in the Layers Exploitable Phosphate field MerahLahrachOuladAbdoun's Basin - Morocco

    International Nuclear Information System (INIS)

    Fait, E.; Fakhi, S.

    2012-01-01

    The present work is part of research developed on the behavior and the exchange of metals in solid-liquid's interface. It is about clarifying the distribution of stable metals especially radioactive, in this context radiometric analyzes and elementary has been done on all layers exploitable phosphate aged Maastrichtian (-70.6 million years) - Lutetian (-40.4 My) in the center of OuladAbdoun's basin, MerahLahrach's area. The specific activities of 238U, 235U and 232Th and their respective descendants were determined directly by spectrometry gamma and radio-chemically by spectrometry alpha. The results found show an enrichment of radionuclides in the deeper layers who came from the leaching of upper layers. The maximum specific activity of uranium is stored in the deeper layers (layer 3 aged Maastrichtian) who aren't very rich on phosphorus (22.4% P), however the 238U was reached up to 2066144 Bq/kg, equivalent of 16 11 ppm, the layer 1's median presents the low concentrations with 857 39Bq/Kg, equivalent of 703 ppm. The average specific activity of radionuclides identified in the series of exploited phosphates (238U, 232Th, 226Ra, 214Pb and 40K) are respectively (125572Bq/Kg; 309 Bq/Kg; 1285207 Bq/Kg; 102252 Bq/kg and 207 Bq/Kg). The study of mobility and / or accumulation accomplished by exploiting the variation of isotopic ratios 230Th/238U, 234U/238U and 232Th/238U as a function on the depth of phosphate's layers and the lithology of these samples, has allowed to identify the phenomena of exchanging between the layers of the system studied.

  17. A new determination method of 226Ra, 224Ra, and 228Th in water

    International Nuclear Information System (INIS)

    Horiuchi, Kimiko; Murakami, Yukio.

    1981-01-01

    A new method for the determination of 226 Ra, 224 Ra and 228 Th in water samples is described. It consists of extraction of 222 Rn and 220 Rn into a scintillator-toluene solution in equilibrium with 226 Ra and 224 Ra and the application of integral counting techniques with a liquid scintillation counter. One liter water sample, weakly acidified with hydrochloric acid, is transferred to a glass bottle, and vigorously bubbled with a stream of nitrogen to expel any radon or thoron in the water sample. Twenty five ml of the scintillator-toluene solution is added to the bottle (time is recorded). The bottle is stoppered with a Teflon stopper and kept at an upside-down position for a given period of time (usually 4 -- 16 days) to allow radon and thoron in partial equilibrium with their parent nuclides. Then, the sample system is vigorously shaken for 2 m and the organic layer is gently transferred to a counting vial through a specially devised transferring tube which is connected to the bottle. The initial counting time is set at 4 h after the separation of organic layer. The measurements are repeated 3 times each immediately and after 106 h from the initial counting time. From these results, the integral counting rates of radon and thoron at the initial counting time are easily obtained. The activities of 226 Ra, 224 Ra and 228 Th in the water sample are calculated from these integral counting rates by the proposed formulas. Some data on the 226 Ra and 224 Ra contents of mineral springs are presented. The lowest detection limits for 226 Ra and 224 Ra were 1.10 x 10 -12 and 1.47 x 10 -9 Ci, respectively. The present method is rapid, easy and accurate and eliminates a time-consuming sealing of the sample in Curie bottle and tedious procedure to transfer the sample gas through a vacuum system to the detector. (author)

  18. The 226Ra-Ba relationship in the North Atlantic during GEOTRACES-GA01

    Science.gov (United States)

    Le Roy, Emilie; Sanial, Virginie; Charette, Matthew A.; van Beek, Pieter; Lacan, François; Jacquet, Stéphanie H. M.; Henderson, Paul B.; Souhaut, Marc; García-Ibáñez, Maribel I.; Jeandel, Catherine; Pérez, Fiz F.; Sarthou, Géraldine

    2018-05-01

    We report detailed sections of radium-226 (226Ra, T1/2 = 1602 years) activities and barium (Ba) concentrations determined in the North Atlantic (Portugal-Greenland-Canada) in the framework of the international GEOTRACES program (GA01 section - GEOVIDE project, May-July 2014). Dissolved 226Ra and Ba are strongly correlated along the section, a pattern that may reflect their similar chemical behavior. Because 226Ra and Ba have been widely used as tracers of water masses and ocean mixing, we investigated their behavior more thoroughly in this crucial region for thermohaline circulation, taking advantage of the contrasting biogeochemical patterns existing along the GA01 section. We used an optimum multiparameter (OMP) analysis to distinguish the relative importance of physical transport (water mass mixing) from nonconservative processes (sedimentary, river or hydrothermal inputs, uptake by particles and dissolved-particulate dynamics) on the 226Ra and Ba distributions in the North Atlantic. Results show that the measured 226Ra and Ba concentrations can be explained by conservative mixing for 58 and 65 % of the samples, respectively, notably at intermediate depth, away from the ocean interfaces. 226Ra and Ba can thus be considered conservative tracers of water mass transport in the ocean interior on the space scales considered here, namely, on the order of a few thousand kilometers. However, regions in which 226Ra and Ba displayed nonconservative behavior and in some cases decoupled behaviors were also identified, mostly at the ocean boundaries (seafloor, continental margins and surface waters). Elevated 226Ra and Ba concentrations found in deepwater in the West European Basin suggest that lower Northeast Atlantic Deep Water (NEADWl) accumulates 226Ra and Ba from sediment diffusion and/or particle dissolution during transport. In the upper 1500 m of the West European Basin, deficiencies in 226Ra and Ba are likely explained by their incorporation in planktonic calcareous

  19. Report on the intercomparison run IAEA-307 radionuclides in sea plant

    International Nuclear Information System (INIS)

    Veglia, A.; Ballestra, S.; Vas, D.

    1989-10-01

    The results of an intercomparison exercise on a Mediterranean Sea plant sample, coded as IAEA-307, designed for the determination of artificial and natural radionuclide levels, are reported. This sample was collected along the shore from the vicinity of the Principality of Monaco in October 1986. The data from 66 laboratories representing 31 countries have been evaluated. The most frequently measured radionuclides: 106 Ru, 110m Ag, 134 Cs, 137 Cs, 238 Pu, 239+240 Pu, 241 Am, 40 K and 226 Ra. 10 refs, 38 tabs

  20. Radiochemical determination and separation or total radium, 226Ra and 224Ra; Analisis Radioquimico de Radio total, Radio-226 y Radio-224

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, J A; Gonzalez, J A; Pablo, M A. de

    1987-07-01

    Radiochemical purification and separation of radium has been carried out and the determination of total radium solubilized in aqueous samples has been studied assuming that all the alpha emitters of the sample have their origin in the 226Ra and elements of its desintegration chain. Also, the activities of 22Ra and 226 Ra have been evaluated separately doing a measurement after the chemical separation of the radium and another one 10 days after. (Author) 9 refs.

  1. Study of soil-plant transfer of {sup 226}Ra under greenhouse conditions

    Energy Technology Data Exchange (ETDEWEB)

    Soudek, Petr; Petrova, Sarka [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Drnovska 507, 161 06 Prague 6 (Czech Republic); Benesova, Dagmar; Kotyza, Jan [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Drnovska 507, 161 06 Prague 6 (Czech Republic); Faculty of Environment Technology, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic); Vagner, Martin [Laboratory of Biologically Active Compounds, Institute of Experimental Botany AS CR, v.v.i., Rozvojova 263, Prague 6 (Czech Republic); Vankova, Radomira [Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany AS CR, v.v.i., Rozvojova 263, Prague 6 (Czech Republic); Vanek, Tomas, E-mail: vanek@ueb.cas.c [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Drnovska 507, 161 06 Prague 6 (Czech Republic)

    2010-06-15

    A soil-plant transfer study was performed using soil from a former uranium ore processing factory in South Bohemia. We present the results from greenhouse experiments which include estimates of the time required for phytoremediation. The accumulation of {sup 226}Ra by different plant species from a mixture of garden soil and contaminated substrate was extremely variable, ranging from 0.03 to 2.20 Bq {sup 226}Ra/g DW. We found differences in accumulation of {sup 226}Ra between plants from the same genus and between cultivars of the same plant species. The results of {sup 226}Ra accumulation showed a linear relation between concentration of {sup 226}Ra in plants and concentration of {sup 226}Ra in soil mixtures. On the basis of these results we estimated the time required for phytoremediation, but this appears to be too long for practical purposes.

  2. Temporal behavior of {sup 222}Radon, {sup 226}Radium and {sup 238}Uranium in deep water wells which provide Valle de Toluca with drinking water; Comportamiento temporal de {sup 222}Radon, {sup 226}Radio y {sup 238}Uranio en pozos profundos que abastecen de agua potable al Valle de Toluca

    Energy Technology Data Exchange (ETDEWEB)

    Pena, P; Tamez, E; Iturbe, J L; Acosta, A; Segovia, N [Instituto Nacional de Investigaciones Nucleares, Mexico City (Mexico); Carrillo, J; Armienta, M [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Geofisica

    1994-12-31

    The presence of radionuclides in underground waters may be an indication of its origin and also the sign of the hydraulic properties of the aquifers layers where circulate. Additionally, the ingestion by human beings of water with radioactive elements (Radon 222, Radium 226, Uranium 238) can give as a result the accumulation of such elements in several organs of the body producing then health damages. In this work, the concentrations of Radon 222, Radium 226 and Uranium 238, in waters coming from deep wells which provide with drinking water the Toluca Valley, were determined. For this purpose, during a year (june 1991 to August 1992) ten wells were sampled with a tracking of the radionuclides concentration as well as the physical-chemical components of water; it was established the relationship presented by the analyzed waters with the local geology and the local and regional systems. (Author).

  3. Natural radioactivity in drinking water in private wells in Finland

    International Nuclear Information System (INIS)

    Vesterbacka, P.; Maekaeinen, I.; Arvela, H.

    2005-01-01

    Natural radioactivity in drinking water was determined in population-based random study of 472 private wells. The mean concentrations of 222 Rn, 226 Ra, 234 U, 238 U, 210 Pb and 210 Po in drilled wells were 460, 0.05, 0.35, 0.26, 0.04 and 0.05 Bq l -1 , and in wells dug in the soil were 50, 0.016, 0.02, 0.015, 0.013 and 0.007 Bq l -1 , respectively. Approximately 10% of the drilled wells exceeded a radon concentration of 1000 Bq l -1 and 18% a uranium concentration of 15 μg l -1 . The mean annual effective dose from natural radionuclides for a drilled well user was 0.4 mSv and 0.05 mSv for a user of a well dug in the soil. The effective dose arising from 222 Rn was 75% of the total of all natural radionuclides for drilled well users. As regards long-lived radionuclides, 210 Po and 210 Pb caused the largest portion of the effective dose. The dose arising from 238 U, 234 U and 226 Ra was only 8% of the total of all natural radionuclides. (authors)

  4. 226Ra, 232Th and 40K analysis in water samples from Assiut, Egypt

    International Nuclear Information System (INIS)

    El-Gamal, H.; Abdel Mageed, A.I.; El-Attar, A.L; Abdel Hamid, M.

    2013-01-01

    The activity concentrations of 226 Ra, 232 Th and 40 K 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 226 Ra, 0.05 to 0.37 Bq L−1 for 232 Th and 3.25 to 8.72 Bq L−1 for 40 K 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.

  5. Determination of 226Ra and 228Ra in surface seawater around Sagami bay and its vicinity

    International Nuclear Information System (INIS)

    Nakano-Ohta, T.; Kubota, T.; Mahara, Y.; Yoshikawa, M.; Sato, J.

    2006-01-01

    Activity ratios of 228 Ra/ 226 Ra in surface seawaters were observed at 5 ports of Izu-Oshima, Ajiro port of Sagami bay and Umizuri park of Tokyo bay. The 228 Ra/ 226 Ra activity ratio in surface seawaters were from 0.2 to 0.7 for Izu-Oshima, from 0.2 to 0.7 for Ajiro port and from 0.6 to 0.8 for Tokyo bay. The activity ratio in surface seawaters of Izu-Oshima and Atami of Sagami bay showed lower in spring and highly in autumn, while narrow variation pattern was observed in Umizuri park of Tokyo bay. The observed variation patterns of 228 Ra/ 226 Ra in surface seawaters at Izu-oshima, Ajiro park and Umizuri park may be reflected by difference of contribution from amount of seawater far off coast with low 228 Ra concentration. (author)

  6. Determinations of [sup 90]Sr, [sup 137]Cs, [sup 226]Ra, [sup 228]Ra, [sup 210]Pb, [sup 210]Po contents in chinese diet and estimations of internal doses due to these radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Hongda, Zhu; Shouliang, Wang; Wei, Meng; Daoping, Wang; Xiujun, Zheng; Qingfen, Liu; Peng, Liu [Chinese Academy of Medical Sciences, Tianjin, TJ (China). Inst. of Radiomedicine

    1993-03-01

    As a part of Chinese Total Diet Survey taken place in 1990, the authors report the determined results on [sup 90]Sr, [sup 137]Cs, [sup 226]Ra, [sup 228]Ra, [sup 210]Pb and [sup 210]Pb and [sup 210]Po contents in various foods of Chinese total diet. Based on obtained dietary composition and the determined contents, the Annual Intakes (AI) and Committed Dose Equivalents (CDE) for the public by ingestion were estimated. It is shown that the total CDE for 6 radionuclides is about 0.24 mSv/a. The food categories and nuclides whose relative contributions to the total are dominant were vegetables, aquatic products and cereal, and [sup 210]Pb, [sup 210]Po, [sup 228]Ra, respectively. The results have updated the data from 1982 survey and have complemented important information for water consumption. The regional difference of dietary compositions and resultant internal doses are discussed as well.

  7. Distribution of natural and artificial radionuclides in chernozem soil/crop system from stationary experiments.

    Science.gov (United States)

    Sarap, Nataša B; Rajačić, Milica M; Đalović, Ivica G; Šeremešić, Srđan I; Đorđević, Aleksandar R; Janković, Marija M; Daković, Marko Z

    2016-09-01

    The present paper focuses on the determination of radiological characteristics of cultivated chernozem soil and crops from long-term field experiments, taking into account the importance of distribution and transfer of radionuclides in the soil-plant system, especially in agricultural cropland. The investigation was performed on the experimental fields where maize, winter wheat, and rapeseed were cultivated. Analysis of radioactivity included determination of the gross alpha and beta activity as a screening method, as well as the activities of the following radionuclides: natural ((210)Pb, (235)U, (238)U, (226)Ra, (232)Th, (40)K, (7)Be) and artificial ((90)Sr and (137)Cs). The activities of natural and artificial ((137)Cs) radionuclides were determined by gamma spectrometry, while the artificial radionuclide (90)Sr was determined by a radiochemical analytical method. Based on the obtained results for the specific activity of (40)K, (137)Cs, and (90)Sr, accumulation factors for these radionuclides were calculated in order to estimate transfer of radionuclides from soil to crops. The results of performed analyses showed that there is no increase of radioactivity that could endanger the food production through the grown crops.

  8. Uptake of naturally occurring radioisotopes by vegetation in a region of high radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Mahon, D C; Mathewes, R W [Simon Fraser Univ., Burnaby, British Columbia (Canada)

    1983-05-01

    The accumulation of four naturally occurring radionuclides of the sup(238)U series, uranium, sup(226)Ra, sup(210)Pb and sup(210)Po, in 15 species of native plants was investigated. Of the plants sampled some accumulated, but none concentrated uranium or sup(226)Ra. Grouseberry (Vaccinium scoparium Leiberg) appeared to concentrate sup(210)Pb and sup(210)Po. There were marked seasonal variations in the accumulation of uranium by grass (Calamagrostis rubescens Buckl.), and of sup(210)Pb and sup(210)Po by grass and fireweed (Epilobium angustifolium L.). High positive correlations between soil and vegetation radionuclide content were found for uranium in fireweed and grouseberry in spring, sup(226)Ra in willow (Salix scouleriana L.) in spring, and uranium in fireweed in summer.

  9. Determination of technologically enhanced naturally occurring radioactive material (TENORM) in ashes from coal-fired thermal power plants in the Philippines

    International Nuclear Information System (INIS)

    Parami, Vangeline Kinilitan

    2008-04-01

    The activity concentration (AC) of TENORM - 238 U, 226 Ra ( 238 U series), 232 Th, 228 Ra, 228 Th ( 232 Th series) and 40 K in feed coal, bottom ash and fly ash samples from four coal-fired thermal power plants C, M, P and S were determined using two techniques: inductively coupled plasma mass spectrometry (ICP-MS) and high purity germanium (HPGe) gamma spectrometry. For 232 Th and 238 U [determined at National Institute for Radiological Sciences (NIRS) by the ICP-MS)], Plant S feed coal (FC) sample that originated from China had the highest AC (15.77 ± 0.32 Bq/kg and 13.67 ± 0.82 Bq/kg, respectively), followed by Plant M FC sample also from China (8.31 ± 0.33 Bq/kg and 5.84 ± 0.12 Bq/kg, respectively), while Plants C and P FC samples that originated from the Philippines and Indonesia had the lowest ACs of 232 Th and 238 U. Plant S also had the highest bottom ash (BA) AC of 80.86 ± 3.23 Bq/kg and 100.20 ± 4.01 Bq/kg, respectively while Plant P had the highest fly ash (FA) AC of 155.96 ± 6.24 Bq/kg and 268.03 ± 10.72 Bq/kg, respectively. For AC's of 226 Ra, 228 Ra, 228 Th and 40 K determined by NIRS HPGe, Plant C had the highest in the FC sample (11.70 ± 1.39 Bq/kg, 13.65 ± 4.99 Bq/kg, 11.35 ± 3.96 Bq/kg ad 80.23 ± 10.91 Bq/kg, respectuvely). For AC's in the BA samples, Plant M had the highest 226 Ra (106.73 ± 6.74 Bq/kg) and Plant S had the highest 228 Ra and 40 K (66.64 ± 8.16 Bq/kg and 400.93 ± 43.06 Bq/kg, respectively For AC's in the FA samples, Plant S had the highest 226 Ra and 228 Ra AC's (131.13 ± 8.09 Bq/kg and 87.70 ± 10.45 Bq/kg, respectively) while Plant C had the highest 40 K AC (369.08 ± 40.87 Bq/kg). The highest AC enhancement of 238 U, 226 Ra ( 238 U series), 232 Th, 228 Ra, 228 Th ( 232 Th series) 40 K relative to feed coal occurred in Plant P FA sample, with 238 U showing the highest enhancement of 93.72 among the radionuclides. When normalized with 40 K, 238 U in Plant P FA sample also had the highest enrichment factor (EF

  10. Physico-chemical forms of natural radionuclides in drilled well waters and their removal by ion exchange

    International Nuclear Information System (INIS)

    Vaaramaa, K.

    2003-01-01

    Appreciable concentrations of natural uranium and its daughter radionuclides may occur in drinking water obtained from drilled wells when the bedrock contains these nuclides. Effective methods are needed to remove these radionuclides. A wide range of ion exchange materials, both organic and inorganic, were evaluated for the removal of 234,238 U, 226 Ra, 210 Po and 210 Pb from ground waters. Screenin tests were carried out, in which distribution coefficients (KD) were determined for the ion exchangers. The ion exchangers that gave the highest KD's were tested in column-mode experiments for the removal of the radionuclides from drilled well water. The most efficient exchanger for the removal of U from neutral and slightly alkaline waters was the strong base anion resin. The chelating aminophosphonate resin removed uranium very efficiently from slightly acidic water. As well, it was an efficient exchanger for the removal of toxic and harmful transition metals from drilled well waters. The strong and weak acid cation resins and zeolite A removed radium most efficiently. Large fractions of the total activity of polonium and lead were found to adsorb on equipment in the ion exchange studies. In investigation of this, the well waters were filtered through membranes to determine the soluble and particle-bound forms of 234,238 U, 226 Ra, 210 Po and 210 Pb. Eight of the waters were of Ca type and two were of Na-Cl type. Some of the waters also had high concentrations of Fe, Mn and humic substances. Uranium was present entirely in soluble form, probably as uranyl ion in soluble carbonate complexes. 226 Ra was in soluble form in the waters with low concentrations of Fe and Mn, but 10% of the total radium activity was bound to particles in Fe-Mn-rich waters. The speciation of Po is complex in natural waters; polonium was present in both soluble and particle-bound forms. A correlation was observed between the fractions of particle-bound 210 Po and the concentrations of iron in

  11. Incidence of bone cancer in beagles after inhalation of 90SrCl2 or 238PuO2: Implications for estimation of risk to humans

    International Nuclear Information System (INIS)

    Mewhinney, J.A.; Griffith, W.C.; Hahn, F.F.; Snipes, M.B.; Boecker, B.B.; McClellan, R.O.

    1986-01-01

    Among the life-span studies conducted with beagle dogs, bone cancer has been in two studies the predominant effect at death. These studies involved dogs that inhaled 90 SrCl 2 , which is very soluble in body fluids; and dogs that inhaled 238 PuO 2 , which is initially insoluble but eventually becomes fragmented and more soluble. Both radionuclides were deposited in the skeleton after dissolution in the lung and absorption into the bloodstream. All dogs in the 90 Sr study are dead, and all living dogs in the 238 Pu study are at least 7 years postexposure. Results from these two studies were compared to determine the relative biological effectiveness (RBE) of chronic beta and alpha radiation delivered from these two radionuclides. These data also were used to estimate the risk of bone cancer in man by using comparisons with data from the 90 Sr-, 239 Pu-, and 226 Ra-injected dogs at the University of Utah and data on humans who ingested 226 Ra or were injected with 224 Ra. Such comparisons provided a link between studies in laboratory animals and the available human data. In this way risks of bone cancer in humans from inhaled plutonium or strontium were estimated, even though currently no human cases of bone cancer are known to have resulted from the inhalation of either of these radionuclides. 15 refs., 7 figs., 7 tabs

  12. Natural contents of /sup 226/Ra, /sup 210/Pb, and /sup 210/Po in young human bones and teeth

    Energy Technology Data Exchange (ETDEWEB)

    Czegledi, P

    1987-07-01

    /sup 226/Ra, /sup 210/Pb, and /sup 210/Po activity concentrations were determined in tooth and bone samples of children. The children of 0 to 13 years were residents of Budapest and died from various diseases. In respect of both /sup 226/Ra and /sup 210/Pb activity concentrations, calvaria was representative for the whole skeleton. Examining the total sample, the mean activity concentrations were found to be as follows: /sup 226/Ra 1.53 +- 0.66 mBq/g Ca/sub 3/(PO/sub 4/)/sub 2/; /sup 210/Pb 4.34 +- 0.74 mBq/g Ca/sub 3/(PO/sub 4/)/sub 2/, and /sup 210/Po 3.48 +- 0.53 mBq/g Ca/sub 3/(PO/sub 4/)/sub 2/. It is shown that the burden of the skeleton is about one order of magnitude greater in the age group 1 to 13 years for all three radionuclides.

  13. 210Pb and 226Ra distributions in the circumpolar waters

    International Nuclear Information System (INIS)

    Chung, Y.

    1981-01-01

    210 Pb and 226 Ra profiles have been measured at five GEOSECS stations in the Circumpolar region. These profiles show that 226 Ra is quite uniformly distributed throughout the Circumpolar region, with slightly lower activities in surface waters, while 210 Pb varies with depth as well as location or area. There is a subsurface 210 Pb maximum which matches the oxygen minimum in depth and roughly correlates with the temperature and salinity maxima. This 210 Pb maximum has its highest concentrations in the Atlantic sector and appears to originate near the South Sandwich Islands northeast of the Weddell Sea. Concentrations in this maximum decrease toward the Indian Ocean sector and then become fairly constant along the easterly Circumpolar Current. Relative to 226 Ra, the activity of 210 Pb is deficient in the entire water column of the Circumpolar waters. The deficiency increases from the depth of the 210 Pb maximum toward the bottom, and the 210 Pb/ 226 Ra activity ratio is lowest in the Antarctic Bottom Water, indicating a rapid removal of Pb by particulate scavenging in the bottom layer and/or a short mean residence time of the Antarctic Bottom Water in the Circumpolar region. 226 Ra is essentially linearly correlated with silica and barium in the Circumpolar waters. However, close examination of the vertical profiles reveals that Ba and Si are more variable than 226 Ra in this region. (orig.)

  14. Validation of 226Ra, 228Ra and 210Pb measurements in soil and sediment samples through high resolution gamma ray spectrometry

    International Nuclear Information System (INIS)

    Dias, Danila Carrijo da Silva; Silva, Nivaldo Carlos da; Bonifacio, Rodrigo Leandro; Guerrero, Eder Tadeu Zenun

    2013-01-01

    Radionuclides found in ore extraction waste materials are a great source of concern regarding public health and environmental safety. One technique to determine the concentration of substances is high resolution gamma ray spectrometry using HPGe. Validating a measurement technique is essential to warrant high levels of quality to any scientific work. The Laboratory of Pocos de Caldas of the Brazilian Commission for Nuclear Energy partakes into a Quality Management System project, seeking Accreditation under ISO/IEC 17025 through the validation of techniques of chemical and radiometric analysis of environmental samples from water, soil and sediment. The focus of the Radon Laboratory at LAPOC is validation of Ra-226, Ra-228 and Pb-210 concentration determinations in soil and sediment through a gamma spectrometer system. The stages of this validation process included sample reception and preparation, detector calibration and sample analyses. Dried samples were sealed in metallic containers and analyzed after radioactive equilibrium between Ra-226 and daughters Pb-214 and Bi-214. Gamma spectrometry was performed using CANBERRA HPGe detector and gamma spectrum software Genie 2000. The photo peaks used for Ra-226 determination were 609 keV and 1020 keV of Bi-214 and 351 keV of Pb-214. For the Ra-228 determination a photopeak of 911 keV was used from its short half-life daughter Ac-228 (T1/2 = 6.12 h). For Pb-210, the photopeak of 46.5 keV was used, which, due to the low energy, self-absorption correction was needed. Parameters such as precision, bias/accuracy, linearity, detection limit and uncertainty were evaluated for that purpose. The results have pointed to satisfying results. (author)

  15. Doses from {sup 222}Rn, {sup 226}Ra, and {sup 228}Ra in groundwater from Guarani aquifer, South America

    Energy Technology Data Exchange (ETDEWEB)

    Bonotto, D.M. E-mail: dbonotto@rc.unesp.br

    2004-07-01

    Groundwater samples were analysed for {sup 222}Rn, {sup 226}Ra, and {sup 228}Ra in Guarani aquifer spreading around 1 million km{sup 2} within four countries in South America, and it was found that their activity concentrations are lognormally distributed. Population-weighted average activity concentration for these radionuclides allowed to estimate a value either slightly higher (0.13 mSv/year) than 0.1 mSv for the total effective dose or two times higher (0.21 mSv/year) than this limit, depending on the choice of the dose conversion factor. Such calculation adds useful information for the appropriate management of this transboundary aquifer that is socially and economically very important to about 15 million inhabitants living in Brazil, Argentina, Uruguay and Paraguay.

  16. Worldwide Open Proficiency Test: Determination of Naturally Occurring Radionuclides in Phosphogypsum and Water

    International Nuclear Information System (INIS)

    2010-01-01

    A reliable determination of naturally occurring radionuclides in phosphogypsum is necessary to comply with the radiation protection and environmental regulations. This proficiency test (PT) is one of the series of the world wide proficiency tests organised every year by the IAEA Terrestrial Environment Laboratory. This series of PTs is designed to identify analytical problems, to support Member State laboratories to maintain their accreditation and to provide a forum for discussions regarding the analysis of naturally occurring radionuclides. The range of sample types available for analysis has been mainly at environmental levels. In this PT, the test item set consisted of six samples: one phosphogypsum (the IAEA-434 reference material) and five water samples spiked with natural radionuclides. The main task of the participating laboratories was to identify and traceably quantify the activity levels of radionuclides present in these matrices. The tasks of the IAEA were to prepare and distribute the samples to the participating laboratories, to collect and interpret analysis results and to compile a comprehensive report. The certified massic activity values of all radionuclides used in this PT were traceable to international standards of radioactivity. In this PT, 1800 test items (reference materials) were prepared and distributed to 300 laboratories from 76 countries in November 2008. The deadline for receiving the results from the participants was set at 15 May 2009. The participating laboratories were requested to analyse Ra-226, U-234 and U-238 in water samples 01 and 02, and gross alpha/beta in water samples 03, 04 and 05. In the phosphogypsum sample number 06 the participants were asked to analyse Pb-210, Ra-226, Th-230, U-234 and U-238. The analytical results of the participating laboratories were compared with the reference values assigned to the reference materials, and a rating system was applied. Three National Metrology Institutes (NMI) and six expert

  17. 226Ra and 210Pb lixiviation sediments from the region of uranium mine and mill in Pocos de Caldas, contaminated in laboratory by river water and chemical agents, mobility and availability in soils

    International Nuclear Information System (INIS)

    Oliveira, A.E. de.

    1982-01-01

    Leaching experiments of river bottom sediments, contaminated in the laboratory with 226 Ra or 210 Pb, by river waters or solutions of inorganic salts and mobility experiments of these radionuclides added to soil columns and leached by a volume of distilled or river water, equivalent to the average annual rain precipitation in the region, are performed. The determination of 226 Ra and 210 Pb exchangeable fractions in soils contaminated in the laboratory are studied too. The results, as a whole, lead to the conclusion that 226 Ra should be considered, potentially, the radionuclide most able to increase the population radiation dose, through the ingestion of contaminated water and foodstuff. (M.A.C.) [pt

  18. Rapid determination of radionuclide activity concentrations in contaminated drinking water

    International Nuclear Information System (INIS)

    Medley, P.; Ryan, B.; Bollhofer, A.; Martin, P.; International Atomic Energy Agency, Vienna

    2007-01-01

    As a result of an incident at the Ranger Uranium mine in which drinking water was contaminated with process water, it was necessary to perform quick analysis for naturally occurring uranium and thorium series radionuclide activity concentrations, including 226Ra, 210Pb, 210Po, U and Th isotopes. The methods which were subsequently used are presented here. The techniques used were high-resolution gamma spectrometry, Inductively Coupled Plasma Mass Spectrometry (ICPMS) and high-resolution alpha spectrometry. Routine methods were modified to allow for rapid analyses on priority samples in 1-2 days, with some results for highest priority samples available in less than 1 day. Comparison of initial results obtained through standard procedures, is discussed. An emphasis is placed on high-resolution alpha spectrometry of major alpha-emitting nuclides, specifically 226Ra, 230Th and 238U. The range of uranium concentrations in the samples investigated was from background levels to 6.6ppm. Implications for radiological dose assessment in contamination incidents involving process water are presented. The worst-case scenario for the incident at Ranger Uranium Mine indicates that the maximum committed effective dose to workers was well below the ICRP limit for worker-related dose and below the dose limit for a member of the public, with 230Th being the highest contributor

  19. Radionuclide concentration in drinking water from public supplies in the metropolitan area of Recife, Brazil

    International Nuclear Information System (INIS)

    Melo, N.P.; Amaral, R.S.; Silva, C.M.; Hazin, C.A.; Lima, R.A.; Valentim, E.

    2000-01-01

    There has been an increasing concern with the assessment of human exposure to naturally occurring radionuclides as they account for around 70% of the total dose received by the population. Most of the exposure derived from natural terrestrial sources comes from the radionuclides in the uranium series, which is headed by the long-lived isotope 238 U. Radionuclides pertaining to this decay chain, such as, 226 Ra, 222 Ra, 210 Pb and 210 Po are the most important to be studied, as far as the dose to the population is concerned. In order to verify if the levels of radioactive contaminants in the water from public supplies are in compliance with the limits set by the Ministry of Health, a survey has been carried out in the metropolitan area of Recife, Brazil. This paper reports the results of this survey for both, superficial and groundwater supplies. Water samples collected from 107 sampling points were analyzed to determine their content of natural uranium, 226 Ra, 222 Ra, 210 Pb and 210 Po. Uranium concentrations were determined by fluorimetry after extraction with an organic solvent and deposition in LiF/NaF pellets, which were fused at 1000degC. Radium-226 was determined by the emanation technique, whereas 222 Rn was determined by liquid scintillation counting. Polonium-210, on the other hand, was determined by alpha spectrometry, following its spontaneous plating in copper disks immersed in the water samples. Measured concentrations ranged from 43 to 1330 mBq/L for natural uranium, 5.3 to 83.7 Bq/L for 222 Rn and from below the MDL (22 mBq/L) to 337 mBq/L for 210 Po. The annual intake of each radionuclide was calculated by considering an ingestion of 2L of water per day. The dose to each organ considered important to the ingestion pathway was calculated by using the masses given in the ICRP 23 for the standard man and by applying the appropriate dose conversion factors. (author)

  20. Natural radionuclides in rocks and soils of the high-mountain regions of the Great Caucasus

    Science.gov (United States)

    Asvarova, T. A.; Abdulaeva, A. S.; Magomedov, M. A.

    2012-06-01

    The results of the radioecological survey in the high-mountain regions of the Great Caucasus at the heights from 2200 to 3800 m a.s.l. are considered. This survey encompassed the territories of Dagestan, Azerbaijan, Georgia, Chechnya, Northern Ossetia-Alania, Kabardino-Balkaria, Karachay-Cherkessia, and the Stavropol and Krasnodar regions. The natural γ background radiation in the studied regions is subjected to considerable fluctuations and varies from 6 to 40 μR/h. The major regularities of the migration of natural radionuclides 238U, 232Th, 226Ra, and 40K in soils in dependence on the particular environmental conditions (the initial concentration of the radionuclides in the parent material; the intensity of pedogenesis; the intensity of the vertical and horizontal migration; and the geographic, climatic, and landscape-geochemical factors) are discussed.

  1. 226Ra and 228Ra in scale and sludge samples and their correlation with the chemical composition.

    Science.gov (United States)

    Godoy, José Marcus; da Cruz, Rosana Petinatti

    2003-01-01

    In order to contribute to a future waste management policy related to the presence of technologically enhanced natural occurring radioactive material (TENORM) in the Brazilian petroleum industry, the present work presents the chemical composition and the (226)Ra and (228)Ra content of sludge and scales generated during the offshore E and P petroleum activities in the Campos Basin, the primary offshore oil production region in Brazil. The (226)Ra and (228)Ra content on 36 sludge and scales samples were determined by gamma-spectrometry. Based on X-ray diffractometry results, a chemical analysis schema for these samples was developed. The results have shown that scales are 75% barium and strontium sulfates, with a mean (226)Ra and (228)Ra content of 106 kBq kg(-1) and 78 kBq kg(-1), respectively. On the other hand, sludge samples have a much more complex chemical composition than the scales. The (226)Ra and (228)Ra content in sludge also varies much more than the content observed in the scales samples and ranged from 0.36 to 367 kBq kg(-1) and 0.25 to 343 kBq kg(-1), respectively.

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

    International Nuclear Information System (INIS)

    Porntepkasemsan, Boonsom; Srisuksawad, Kanitha

    2008-01-01

    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 226 Ra and to estimate the age-dependent effective dose to humans due to consumption. 226 Ra 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 226 Ra effective doses per year were found for infants and teens. However, the observed levels of calculated 226 Ra 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

  3. Determination of natural radioactivity in irrigation water of drilled wells in northwestern Saudi Arabia.

    Science.gov (United States)

    Alkhomashi, N; Al-Hamarneh, Ibrahim F; Almasoud, Fahad I

    2016-02-01

    The levels of natural radiation in bedrock groundwater extracted from drilled wells in selected farms in the northwestern part of Saudi Arabia were addressed. The investigated waters form a source of irrigation for vegetables, agricultural crops, wheat, and alfalfa to feed livestock consumed by the general public. Information about water radioactivity in this area is not available yet. Therefore, this study strives to contribute to the quality assessment of the groundwater of these wells that are drilled into the non-renewable Saq sandstone aquifer. Hence, gross alpha and beta activities as well as the concentrations of (224)Ra, (226)Ra, (228)Ra, (234)U, (238)U, and U(total) were measured, compared to national and international limits and contrasted with data quoted from the literature. Correlations between the activities of the analyzed radionuclides were discussed. The concentrations of gross alpha and beta activities as well as (228)Ra were identified by liquid scintillation counting whereas alpha spectrometry was used to determine (224)Ra, (226)Ra, (234)U and (238)U after separation from the matrix by extraction chromatography. The mean activity concentrations of gross α and β were 3.15 ± 0.26 Bq L(-1) and 5.39 ± 0.44 Bq L(-1), respectively. Radium isotopes ((228)Ra and (226)Ra) showed mean concentrations of 3.16 ± 0.17 Bq L(-1) and 1.12 ± 0.07 Bq L(-1), respectively, whereas lower levels of uranium isotopes ((234)U and (238)U) were obtained. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. The study of specific activity and effect of gamma ray from natural radionuclide to the environment outside Sultan Abdul Aziz Plant Station, Kapar, Klang, Selangor

    International Nuclear Information System (INIS)

    Wan Amar Fikri Wan Ali

    2012-01-01

    Waste resulting from coal combustion process can result in increasing the specific activity of natural radionuclide such as 238 U, 232 Th , 226 Ra and 40 K. Following combustion, radionuclide focused on fly ash, some escape the filtration system in the chimney that causes the gamma ray exposure dose increases. The objective of this study was to calculate the specific activity of natural radionuclide and identifying the gamma ray exposure dose outside the Stesen Janakuasa Elektric Station of Sultan Abdul Aziz further examine the risk of gamma ray exposure dose and specific activity of natural radionuclide to the ecosystem because the station is located close to residential areas and local residents migratory bird stopover. The samples studied are soil, water and sediment that are outside the station. Samples taken with the correct procedures then treated and stored about a month before counting. Gamma ray exposure dose for the seven stations studied are between 0.330 μSv/ h - 1.20 μSv/ h. While the range of specific activities obtained for the 40 K, 238 U, 232 Th and 226 Ra were 201 Bq/ kg - 468 Bq/ kg, 0.480 Bq/ kg - 2.57 Bq/ kg, 12.9 Bq/ kg - 74.5 Bq/ kg and 6.64 Bq/ kg - 11.7 Bq/ kg. While the sediment samples were 216 Bq/ kg - 465 Bq/ kg, 18.1 Bq/ kg - 4.43 Bq/ kg, 24.8 Bq/ kg - 65.3 Bq/ kg, 8.53 Bq/ kg - 11.2 Bq/ kg. For water samples, the specific range of their specific activities are 10.5 Bq/ L - 12.1 Bq/ L, 1.40 Bq/ L - 1.63 Bq/ L, 1.57 Bq/ L - 1.65 Bq/ L and 0 Bq/ L - 1.14 Bq/ L. (author)

  5. Assessment of the main natural radionuclides, minor and trace elements in soils and sediments of the Shu valley (near the border of Kazakhstan and Kyrgyzstan)

    International Nuclear Information System (INIS)

    Matveyeva, I.; Burkitbayev, M.; Jacimovic, R.; Planinsek, P.; Smodis, B.; Stegnar, P.

    2014-01-01

    New data on the concentrations of the main gamma-emitting radionuclides, minor and trace elements, and isotopes of uranium (with Ra-226 as a daughter product of U-238) and thorium in soils and sediments of the Shu valley (from the river Chon-Kemin to the river Kuragatty downstream the river Shu) are presented, determined by high-resolution gamma-spectrometry, k 0 -instrumental neutron activation analysis and alpha-spectrometry with appropriate radiochemical separations of the samples, respectively. The results obtained showed an aquatic migration pathway of most of the trace elements and radionuclides and predicted water pollution downstream the river Shu. The scandium method showed pollution by As, Br, Ca, Cr, Zr of the Tasotkel dam impoundment and by Ca and Cr of the river Shu below its confluence with the river Kuragatty. According to the disequilibrium isotopic method for uranium (using the isotopic ratio U-234/U-238), areas with accumulation and leaching processes were estimated for soils and sediments of the river Shu and its main inflows. (author)

  6. The NIST natural-matrix radionuclide standard reference material program for ocean studies

    International Nuclear Information System (INIS)

    Inn, K.G.W.; Zhichao Lin; Zhongyu Wu; MacMahon, C.; Filliben, J.J.; Krey, P.; Feiner, M.; Harvey, J.

    2001-01-01

    In 1997, the Low-level Working Group of the International Committee on Radionuclide Metrology met in Boston, MA (USA) to define the characteristics of a new set of environmental radioactivity reference materials. These reference materials were to provide the radiochemist with the same analytical challenges faced when assaying environmental samples. It was decided that radionuclide bearing natural materials should be collected from sites where there had been sufficient time for natural processes to redistribute the various chemically different species of the radionuclides. Over the succeeding years, the National Institute of Standards and Technology (NIST), in cooperation with other highly experienced laboratories, certified and issued a number of these as low-level radioactivity Standard Reference Materials (SRMs) for fission and activation product and actinide concentrations. The experience of certifying these SRMs has given NIST the opportunity to compare radioanalytical methods and learn of their limitations. NIST convened an international workshop in 1994 to define the natural-matrix radionuclide SRM needs for ocean studies. The highest priorities proposed at the workshop were for sediment, shellfish, seaweed, fish flesh and water matrix SRMs certified for mBq per sample concentrations of 90 Sr, 137 Cs and 239 Pu + 240 Pu. The most recent low-level environmental radionuclide SRM issued by NIST, Ocean Sediment (SRM 4357) has certified and uncertified values for the following 22 radionuclides: 40 K, 90 Sr, 129 I, 137 Cs, 155 Eu, 210 Pb, 210 Po, 212 Pb, 214 Bi, 226 Ra, 228 Ra, 228 Th, 230 Th, 232 Th, 234 U, 235 U, 237 Np, 238 U, 238 Pu, 239 Pu + 240 Pu, and 241 Am. The uncertainties for a number of the certified radionuclides are non-symmetrical and relatively large because of the non-normal distribution of reported values. NIST is continuing its efforts to provide the ocean studies community with additional natural matrix radionuclide SRMs. The freeze

  7. Simultaneous determination of Ra-226, Ra-228 and Pb-210 using a successive coprecipitations techniques

    International Nuclear Information System (INIS)

    Vilhena Schayer Sabino, C. de; Kastner, S.M.S.; Amaral, A.M.

    1990-01-01

    Several techniques for determination of Ra-226, Ra228 and Pb-210. were developed and used in routine at CDTN in the laboratories of radiochemistry. The matrixes were: water and industrial wastes. Some problems of these techniques were the time spent for analyses and chemical separations, interferents, among others. Now-a-days the method in routine developed here is the one of successive coprecipitations, followed α and β countings of the Ra-226 and Ra-228 daughters. This method is based on coprecipitation, purification of barium radium sulfate with EDTA in acetic solution. Lead is dissolved, radium remains precipitated and suffers a new purification and the time for growing of their daughters is waited to be performed the simultaneous α and β countings for Ra-226 and Ra-228 determination. Pb-210 is analyzed in the floating of the first purification with a carrier of bismuth, and the time for Bi-210 growing is waited. Then it is precipitated as hydroxid, purified as phosphate and the β counting of Bi-210 is done. (author) [pt

  8. Evaluation of Ra, Th, K and radium equivalent activity in sand samples from Camburi Beach, Vitoria, Espirito Santos, Brazil

    International Nuclear Information System (INIS)

    Barros, Livia F.; Pecequilo, Brigitte R.S.

    2013-01-01

    Camburi beach, in the city of Vitoria, Espirito Santo State. Brazil, is a naturally high background region in Brazil. The beach sands contain monazite, ilmenite and other accessory minerals rich in 226 Ra, 23 '2Th and 40 K. As these radionuclides are the main natural contributors to external exposure from gamma rays, the knowledge of the sands radioactivity content plays an important role in radiation protection. In this work, 226 Ra, 232 Th and 40 K activities concentrations, together with the radium equivalent activity, Ra eq. were determined in some selected sand samples from a single location at Camburi beach, known for the high level of radioactivity. The sand samples collected monthly from January to December 2011, were dried and sealed in standard 100 mL HPDE polyethylene flasks and measured by high resolution gamma-spectrometry after a 4 weeks ingrowth period, in order to allow the secular equilibrium in the 238 U and 23 '2Th series. Preliminary results, without considering samples self-attenuation, show activities concentrations in the range from 12 ± 1 Bq kg -1 to 1022 ± 30 Bq kg -1 for 226 Ra, 35 ± 1 Bq kg -1 to 5731 ± 134 Bq kg -1 for 232 Th and 18 ± 4 Bqkg -1 to 430 ± 21 Bq kg -1 for 40 K. The Ra eq , presented values ranging from 63 Bq kg -1 to 9250 Bq kg -1 . (author)

  9. Distribution of anthropogenic and naturally occurring radionuclides in soils and lakes of Central Spitsbergen (Arctic)

    International Nuclear Information System (INIS)

    Lokas, Edyta

    2017-01-01

    This work provides the first results on activity concentrations, inventories and activity ratios of the artificial and natural fallout ("1"3"7Cs, "2"3"8Pu, "2"3"9"+"2"4"0Pu, "2"4"1Am, "2"1"0Pb) and lithogenic radionuclides ("2"2"6Ra, "2"2"8Ra, "4"0K) in soils and lake sediments of the inland Spitsbergen. The depths of activity peaks of the artificial radionuclides point to accumulation of up to 10 cm thick deposits during last 50 years. The activity ratios of the radionuclides suggest global fallout as their source. Despite low annual precipitation the inventories of fallout radionuclides in sites not affected by the secondary deposition agree with those reported from the more humid areas of Spitsbergen. (author)

  10. Natural-Series Radionuclides in Traditional Aboriginal Foods in Tropical Northern Australia: A Review

    Directory of Open Access Journals (Sweden)

    Paul Martin

    2004-01-01

    Full Text Available This paper gives a review of available information on natural-series radionuclides in traditional Aboriginal foods of northern Australia. Research on this topic has been carried out primarily for radiological impact assessment purposes in relation to uranium mining activities in the region. Many of the studies have concentrated on providing purely concentration data or concentration ratios, although more detailed uptake studies have been undertaken for freshwater mussels, turtles, and water lilies. The most-studied radionuclides are 238U and 226Ra. However, dose estimates based on current data highlight the importance of 210Po, particularly for the natural (nonmining-related dose. Data on uptake by terrestrial flora and fauna are scarce in comparison with aquatic organisms, and this knowledge gap will need to be addressed in relation to planning for uranium minesite rehabilitation.

  11. Absorbed dose rate due to intake of natural radionuclides by Tilapia fish (Tilapia nilotica, Linnaeus, 1758) estimated near uranium anomaly at Santa Quiteria, Ceara, Brazil

    International Nuclear Information System (INIS)

    Pereira, Wagner de; Kelecom, Alphonse; Py Junior, Delcy de Azevedo

    2007-01-01

    The uranium mining at Santa Quiteria (Santa Quiteria Unit - USQ) is in its environmental licensing phase. Aiming to estimate the radiological environmental impact of the USQ, a monitoring program is underway. However, radioprotection of biota is not explicitly mentioned in Brazilian norms. In order to preserve the biota of the deleterious effects from radiation and to behave in a pro-active way as expected by licensing organs, the present work aims to use an environmental protection methodology, based on the calculation of absorbed dose rate in biota. Thus, selected biomarker was the fish tilapia (Tilapia nilotica, Linnaeus, 1758) and the radionuclides were: uranium (U-238), thorium (Th-232), radium (Ra-226 and Ra-228) and lead (Pb-210). Since there are no exposition limits for biota, in Brazil, the value proposed by the Department of Energy (DOE) of the United States of 3.5 x 10 3 μGy/y has been used. The derived absorbed dose rate calculated for tilapia was 2.76 x 10 0 μGy/y, that is less than 0.1 % of the limit established by DOE. The critical radionuclide was U-238, with 99% of the absorbed dose rate. This value of 0.1% of the limit allows to state that in pre-operational conditions analyzed natural radionuclides do not represent a radiological problem to the biota. (author)

  12. Absorbed dose rate due to intake of natural radionuclides by Tilapia fish (Tilapia nilotica, Linnaeus, 1758) estimated near uranium anomaly at Santa Quiteria, Ceara, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Wagner de [Industrias Nucleares do Brasil S.A. (INB), Pocos de Caldas, MG (Brazil). Coordenacao de Protecao Radiologica. Unidade de Tratamento de Minerios], E-mail: wspereira@inb.gov.br; Kelecom, Alphonse [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Programa de Pos-graduacao em Ciencia Ambiental; Py Junior, Delcy de Azevedo [Industrias Nucleares do Brasil S.A. (INB), Caetite, BA (Brazil). Coordenacao de Protecao Radiologica. Unidade de Concentrado de Uranio], E-mail: Delcy@inb.gov.br

    2007-07-01

    The uranium mining at Santa Quiteria (Santa Quiteria Unit - USQ) is in its environmental licensing phase. Aiming to estimate the radiological environmental impact of the USQ, a monitoring program is underway. However, radioprotection of biota is not explicitly mentioned in Brazilian norms. In order to preserve the biota of the deleterious effects from radiation and to behave in a pro-active way as expected by licensing organs, the present work aims to use an environmental protection methodology, based on the calculation of absorbed dose rate in biota. Thus, selected biomarker was the fish tilapia (Tilapia nilotica, Linnaeus, 1758) and the radionuclides were: uranium (U-238), thorium (Th-232), radium (Ra-226 and Ra-228) and lead (Pb-210). Since there are no exposition limits for biota, in Brazil, the value proposed by the Department of Energy (DOE) of the United States of 3.5 x 10{sup 3} {mu}Gy/y has been used. The derived absorbed dose rate calculated for tilapia was 2.76 x 10{sup 0} {mu}Gy/y, that is less than 0.1 % of the limit established by DOE. The critical radionuclide was U-238, with 99% of the absorbed dose rate. This value of 0.1% of the limit allows to state that in pre-operational conditions analyzed natural radionuclides do not represent a radiological problem to the biota. (author)

  13. Research on background neutron of 226Ra γ source

    International Nuclear Information System (INIS)

    Ji Changsong

    1996-01-01

    This work studies the background neutron emission of 226 Ra γ source: the mechanism of resulting in background neutron is studied; a thesis that the (α, n) type reaction on Radium carriers Cl or Br is the main source of creating background neutron emission of 226 Ra γ source has been proposed and certificated; a proposal of substitution of Cl carrier by Br in radium source produced in China in order to reduce background neutron emission is put forward. A result to reduce the background neutron from 96.4 neutrons/4πsmgRa to 6.1 neutrons/4πsmgRa is obtained

  14. Study of the specific activity concentrations of 40K, 226Ra, 228Ra and 232Th in vegetables and their respective covering tissues (peels)

    International Nuclear Information System (INIS)

    Lopes, J.M.; Garcêz, R.W.D.; Silva, A.X.

    2017-01-01

    This work presents an analysis of specific concentrations of 40 K, 226 Ra, 228 Ra and 232 Th in some vegetables that are part of the diet of the population of the state of Rio de Janeiro. Furthermore, was analyzed the concentrations of radionuclides in the same coating tissue that compose the vegetables. It can notice an increase of the specific concentration of 40 K in the peels of vegetables that have little or no contact with the ground. Among the samples examined, only the pumpkin showed measurable amount of 137 Cs both saves and in the skin. (author)

  15. 226Ra and 228Ra activities associated with agricultural drainage ponds and wetland ponds in the Kankakee Watershed, Illinois-Indiana, USA

    International Nuclear Information System (INIS)

    Sidle, W.C.; Shanklin, D.; Lee, P.Y.; Roose, D.L.

    2001-01-01

    Background radioactivity is elevated in many agricultural drainage ponds and also constructed wetland ponds in the Kankakee watershed. During 1995-1999, gross-α and -β activities were measured up to 455 and 1650 mBq L -1 , respectively. 226 Ra and 228 Ra averaged 139 and 192 mBq L -1 in controlled drainage ponds compared to 53 and 58 mBq L -1 for 226 Ra and 228 Ra, respectively, in native wetland ponds. Analyses of applied ammonium phosphate fertilizers near both native and controlled ponds indicate comparable 226 Ra/ 228 Ra and 228 Ra/ 232 Th activity ratios with only the surface waters in the controlled ponds. For example, 226 Ra/ 228 Ra activity ratios in controlled ponds ranged from 0.79 to 0.91 and group with a local fertilizer batch containing FL phosphate compounds with 226 Ra/ 228 Ra activity ratios of 0.83-1.04. Local soils of the Kankakee watershed have 226 Ra/ 228 Ra activity ratios of 0.54-0.70. Calculated Ra fluxes of waters, in drainage ditches associated with these controlled ponds, for 226 Ra ranged from 0.77 to 9.00 mBq cm -2 d -1 and for 228 Ra ranged from 1.22 to 8.43 mBq cm -2 d -1 . Ra activity gradients were measured beneath these controlled ponds both in agricultural landscapes and in constructed wetlands, all being associated with drainage ditches. Ra had infiltrated to the local water table but was below regulatory maximum contaminant limits. Still, measurable Ra activity was measured downgradient of even the constructed wetlands in the Kankakee watershed, suggesting that the attenuation of Ra was low. However, no Ra excess was observed in the riparian zone or the Kankakee River downgradient of the native wetland ponds

  16. 226Ra behavior in the Pee Dee river-Winyah Bay estuary

    International Nuclear Information System (INIS)

    Elsinger, R.J.; Moore, W.S.

    1980-01-01

    Concentrations of dissolved 226 Ra in Winyah Bay, South Carolina, and in the adjacent Atlantic Ocean are augmented by the desorption of radium from sediments in the low-salinity area of the estuary and diffusion from bottom sediments. Desorption of 226 Ra is reflected by lower concentrations in suspended sediments from higher-salinity regions of the estuary. Bottom sediments from the high-salinity region have lower 226 Ra/ 230 Th activity ratios than those from the low-salinity end. (orig./ME)

  17. TRIATHLER: modern and mobile LSC instrument for the detection of radon and other radionuclides in water

    International Nuclear Information System (INIS)

    Frenzel, E.

    2004-01-01

    Rapid and sensitive measurements of radon in water and in drinking water is done with various methods. Liquid Scintillation Counting (LSC) is one of the best and most sensitive methods. This technique is international agreed and accepted. Now, for some years with Triathler(TM) a compact and mobile liquid scintillation counter is available. The Triathler with integrated alpha/beta separation enables both laboratory and in situ measurements of 222 Rn in water (LLoD 222 Rn in water are possible. In addition with simple chemical steps other natural occurring radionuclides can be measured. Due to European regulations, drinking water has to be monitored regarding the 0.1 mSv concept. With Triathler it is possible according to the method of L. Salonen and the modification by S. Wisser, to detect gross alpha activities 222 Rn in water (extractive and non-extractive methods); 234 U/ 238 U in water (extraction of U via modified cocktails); 226 Ra (enrichment by filtering on special 3M RadDisks); 228 Ra (enrichment by filtering on special 3M RadDisks); alpha-gross counting. The special rapid method for 226 Ra and 228 Ra takes benefit of the element-selective filters of 3M. These filters were developed by US research centers (like the Argonne National Laboratories) together with 3M. Up to 5 liters are filtered through the RadDisks and afterwards measured preferable by LSC, or Low Background Counting or gamma spectroscopy. (author)

  18. The content of natural radioactive elements and artificial radioisotopes in Moldova's soils; Continutul unor elemente radioactive naturale si radioizotopi artificiali in solurile Moldovei

    Energy Technology Data Exchange (ETDEWEB)

    Stasiev, Gr. [Univ. de Stat din Moldova, Chisinau (Moldova, Republic of); Nedealcov, S.; Jigau, Gh. [Centrul Republican de Pedologie Aplicata, Chisinau (Moldova, Republic of)

    2013-08-15

    The results of multiyear investigations of natural radionuclide (U-238, Th-232, Ra-226, K-40) and artificial isotopes (Sr-90, Cs-137, I-131) content on soil and plants are presented. Six anomalous polluted areas were detected after Chernobyl nuclear power plant accident. (authors)

  19. Determination of natural and artificial radionuclides in 3 earner ecosystems (Alcocebre; Vinaroz and Vandellos)

    International Nuclear Information System (INIS)

    Navarro, E.; Roldan, C.; Sanchez, E.

    1998-01-01

    The knowledge of the environmental radioactivity level represents one of the main objectives at the moment for the environmental investigation. To check the existence of possible polluting sources and their impact in the population is of high-priority interest. We have intended to check the existence or not of radioactive pollutants in bio-indicators (algae, limpets and mussels) of the marine environment of three towns located in the Mediterranean coast: Alcocebre and Vinaroz in the county of Castellon and Vandellos in the county of Tarragona where a nuclear group is located for electric power production. The specific activity measurement carried out during the biennium 1996-97 of the natural gamma emitters ''228 Ac (''232Th series), ''226Ra (''238U series), ''235U, ''40K and ''7Be, and of the artificial radionuclides ''60Co, and ''137 Cs, it corroborates the character bio-accumulator of these organisms. Natural and artificial radionuclides have been detected in quantities without radiological significance. (Author) 3 Refs

  20. Natural radionuclides in major aquifer systems of the Parana sedimentary basin, Brazil

    International Nuclear Information System (INIS)

    Bonotto, Daniel Marcos

    2011-01-01

    This paper describes the natural radioactivity of groundwater occurring in sedimentary (Bauru and Guarani) and fractured rock (Serra Geral) aquifer systems in the Parana sedimentary basin, South America that is extensively used for drinking purposes, among others. The measurements of gross alpha and gross beta radioactivity as well the activity concentration of the natural dissolved radionuclides 40 K, 238 U, 234 U, 226 Ra, 222 Rn, 210 Po and 210 Pb were held in 80 tubular wells drilled in 21 municipalities located at Sao Paulo State and its border with Mato Grosso do Sul State in Brazil. Most of the gross alpha radioactivity data were below 1 mBq/L, whereas values exceeding the gross beta radioactivity detection limit of 30 mBq/L were found. The radioelement solubility in the studied systems varied according to the sequence radon>radium>other radionuclides and the higher porosity of sandstones relatively to basalts and diabases could justify the enhanced presence of dissolved radon in the porous aquifer. The implications of the data obtained in terms of standards established for defining the drinking water quality have also been discussed. The population-weighted average activity concentration for these radionuclides was compared to the guideline value of 0.1 mSv/yr for the total effective dose and discussed in terms of the choice of the dose conversion factors. - Highlights: → Integration of distinct radiometric data acquired in groundwaters. → Radiation dose in important hydrological resources in South America. → Contribution of 226 Ra for the more accentuated radiation dose in aquifers. → Dose factors for Rn and generation of values exceeding the maximum of 0.1 mSv/yr.

  1. Natural radionuclides in major aquifer systems of the Parana sedimentary basin, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Bonotto, Daniel Marcos, E-mail: danielbonotto@yahoo.com.br [Departamento de Petrologia e Metalogenia, IGCE-Instituto de Geociencias e Ciencias Exatas, UNESP-Universidade Estadual Paulista Julio de Mesquita Filho, Av. 24-A, No. 1515 - CP 178, CEP 13506-900-Rio Claro, SP (Brazil)

    2011-10-15

    This paper describes the natural radioactivity of groundwater occurring in sedimentary (Bauru and Guarani) and fractured rock (Serra Geral) aquifer systems in the Parana sedimentary basin, South America that is extensively used for drinking purposes, among others. The measurements of gross alpha and gross beta radioactivity as well the activity concentration of the natural dissolved radionuclides {sup 40}K, {sup 238}U, {sup 234}U, {sup 226}Ra, {sup 222}Rn, {sup 210}Po and {sup 210}Pb were held in 80 tubular wells drilled in 21 municipalities located at Sao Paulo State and its border with Mato Grosso do Sul State in Brazil. Most of the gross alpha radioactivity data were below 1 mBq/L, whereas values exceeding the gross beta radioactivity detection limit of 30 mBq/L were found. The radioelement solubility in the studied systems varied according to the sequence radon>radium>other radionuclides and the higher porosity of sandstones relatively to basalts and diabases could justify the enhanced presence of dissolved radon in the porous aquifer. The implications of the data obtained in terms of standards established for defining the drinking water quality have also been discussed. The population-weighted average activity concentration for these radionuclides was compared to the guideline value of 0.1 mSv/yr for the total effective dose and discussed in terms of the choice of the dose conversion factors. - Highlights: > Integration of distinct radiometric data acquired in groundwaters. > Radiation dose in important hydrological resources in South America. > Contribution of {sup 226}Ra for the more accentuated radiation dose in aquifers. > Dose factors for Rn and generation of values exceeding the maximum of 0.1 mSv/yr.

  2. New approach and methodology for radionuclide researches of oil industry wastes

    International Nuclear Information System (INIS)

    Humbatov, F.; Lisanova, E.; Suleymanov, B.; Ahmedov, M.

    2005-01-01

    Full text : Oil and gas production and processing operations sometimes accumulate Norm at elevated concentrations in by-product waste streams. The sources of most of the radioactivity are isotopes of uranium-238 (U-238) and thorium-232 (Th-232) naturally present in subsurface formations from which oil and gas are produced. The primary radionuclides of concern in NORM wastes are Ra-226 of the U-238 decay series, and Ra-228 of the Th-232 decay series. Other radionuclides of concern include radionuclides that form from the decay of Ra-226 and Ra-228. The production waste streams most likely to be contaminated by elevated radium concentrations include produced water, scale, and sludge. Spills or intentional releases of these waste streams to the ground can result in NORM-contaminated soils that must also be disposed of. Radium, which is slightly soluble, can be mobilized in the liquid phases of a formation and transported to the surface in the produced water stream. Dissolved radium either remains in solution in the produced water or precipitates out in scales or sludges. Conditions that appear to affect radium solubility and precipitation include water chemistry (primarily salinity), temperature, and pressure. NORM contamination of scale and sludge can occur when dissolved radium co precipitates with other alkaline earth elements such as barium, strontium, or calcium. In the case of scale, the radium co precipitates, primarily with barium, to form hard, insoluble sulfate deposits. Scale typically forms on the inside of piping, filters, injection wellhead equipment, and other water handling equipment, but also can form as a coating on produced sand grains. In the case of sludge, radium can be present in several forms. It can co precipitate with silicates and carbonates that form in the sludge, or it can be present in pieces of barium sulfate scale that become incorporated into the sludge. NORM-contaminated sludges can accumulate inside piping, separators, heater

  3. The Distributions of the Radionuclides Ra-226, Th-232 and K-40 in Various Parts of The Alfalfa Plant

    International Nuclear Information System (INIS)

    Salahel Din, K.; Harb, S.; Abbady, A.; Saad, N.

    2011-01-01

    The distribution of naturally occurring Ra-226, Th-232 and K-40 in different part of alfalfa plant from two different soils of Qena (South Valley University and Qena governorate farms) was studied under natural field conditions. Sixty two samples (alfalfa plant and its soil) were taken from nine sites inside farms. The samples were analyzed for their Ra-226, Th-232 and K-40 activity concentrations using gamma ray spectrometer consists of 3 x 3 NaI (Tl). The daily intakes of these radioisotopes by calves, milking cattle and sheep were calculated by multiplying concentrations in alfalfa and the daily consumption rates of these plants.

  4. Solid phase microextraction sampling of high explosive residues in the presence of radionuclides and radionuclide surrogate metals

    International Nuclear Information System (INIS)

    Duff, M.C.; Crump, S.L.; Ray, R.J.; Beals, D.; Cotham, W.E.; Mount, K.; Koons, R.D.; Leggitt, J.

    2008-01-01

    The Federal Bureau of Investigation (FBI) Laboratory currently does not have on site facilities for handling radioactive evidentiary materials and there are no established FBI methods or procedures for decontaminating high explosive (HE) evidence while maintaining evidentiary value. One experimental method for the isolation of HE residue involves using solid phase microextraction (SPME) fibers to remove residue of interest. Due to their high affinity for organics, SPME fibers should have little affinity for most metals. However, no studies have measured the affinity of radionuclides for SPME fibers. The focus of this research was to examine the affinity of dissolved radionuclide ( 239/240 Pu, 238 U, 237 Np, 85 Sr, 133 Ba, 137 Cs, 60 Co and 226 Ra) and stable radionuclide surrogate metals (Sr, Co, Ir, Re, Ni, Ba, Cs, Nb, Ru, and Nd) for SPME fibers at the exposure conditions that favor the uptake of HE residues. Our results from radiochemical and mass spectrometric analyses indicate these metals have little measurable affinity for these SPME fibers during conditions that are conducive to HE residue uptake with subsequent analysis by liquid or gas phase chromatography with mass spectrometric detection. (author)

  5. Sorption of 226Ra from oil effluents onto synthetic cation exchangers

    International Nuclear Information System (INIS)

    Attar, L.; Safia, M.

    2014-01-01

    Increasing environmental awareness is being urged for the safe disposal of 226 Ra-contaminated production water generated in the oil industry. Brainiest, 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. (author)

  6. Measuring the radium quartet ({sup 228}Ra, {sup 226}Ra, {sup 224}Ra, {sup 223}Ra) in seawater samples using gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Beek, P. van, E-mail: vanbeek@legos.obs-mip.f [LEGOS, Laboratoire d' Etudes en Geophysique et Oceanographie Spatiales (CNRS/CNES/IRD/UPS), Observatoire Midi Pyrenees, 14 Avenue Edouard Belin, 31400 Toulouse (France); Souhaut, M. [LEGOS, Laboratoire d' Etudes en Geophysique et Oceanographie Spatiales (CNRS/CNES/IRD/UPS), Observatoire Midi Pyrenees, 14 Avenue Edouard Belin, 31400 Toulouse (France); Reyss, J.-L. [LSCE, Laboratoire des Sciences du Climat et de l' Environnement (CNRS/CEA/UVSQ), Avenue de la Terrasse, 91198 Gif-sur-Yvette (France)

    2010-07-15

    Radium isotopes are widely used in marine studies (eg. to trace water masses, to quantify mixing processes or to study submarine groundwater discharge). While {sup 228}Ra and {sup 226}Ra are usually measured using gamma spectrometry, short-lived Ra isotopes ({sup 224}Ra and {sup 223}Ra) are usually measured using a Radium Delayed Coincidence Counter (RaDeCC). Here we show that the four radium isotopes can be analyzed using gamma spectrometry. We report {sup 226}Ra, {sup 228}Ra, {sup 224}Ra, {sup 223}Ra activities measured using low-background gamma spectrometry in standard samples, in water samples collected in the vicinity of our laboratory (La Palme and Vaccares lagoons, France) but also in seawater samples collected in the plume of the Amazon river, off French Guyana (AMANDES project). The {sup 223}Ra and {sup 224}Ra activities determined in these samples using gamma spectrometry were compared to the activities determined using RaDeCC. Activities determined using the two techniques are in good agreement. Uncertainties associated with the {sup 224}Ra activities are similar for the two techniques. RaDeCC is more sensitive for the detection of low {sup 223}Ra activities. Gamma spectrometry thus constitutes an alternate method for the determination of short-lived Ra isotopes.

  7. Uranium-thorium series radionuclides in brines and reservoir rocks from two deep geothermal boreholes in the Salton Sea Geothermal Field, southeastern California

    Science.gov (United States)

    Zukin, Jeffrey G.; Hammond, Douglas E.; Teh-Lung, Ku; Elders, Wilfred A.

    1987-10-01

    Naturally occurring U and Th series radionuclides have been analyzed in high temperature brines (~300°C, 25 wt% dissolved solids) and associated rocks from two deep geothermal wells located on the northeastern margin of the Salton Sea Geothermal Field (SSGF). These data are part of a study of the SSGF as a natural analog of possible radionuclide behavior near a nuclear waste repository constructed in salt beds, and permit evaluation of some characteristics of water-rock interaction in the SSGF. Rock/Brine concentration ratios ( Rc = (dpm/ g) rock/(dpm/ g) brine) were found to vary from near unity for isotopes of Ra, Pb and Rn to about 5 × 10 5 for 232Th. The high sorptivity of 232Th is closely followed by that of 238U and 234U ( Rc ~ 5 × 10 4), suggesting that U is retained in the +4 oxidation state by the reducing conditions in the brines. The relatively high solubility of 210Pb and 212Pb is attributed to formation of chloride complexes, while the high Ra solubility is attributed to chloride complexing, a lack of suitable adsorption sites due to the high brine salinity and temperature, and the reducing conditions that prevent MnO 2 and RaSO 4 from forming. The 228Ra /226Ra ratios in the brines are approximately equal to those of their parents ( 232Th /230Th ) in associated rocks, indicating that Ra equilibration in the brine-rock system is achieved within the mean life of 228Ra (8.3 years). The 224Ra /228Ra ratios in these brines are about 0.7, indicating that either (1) brine composition is not homogeneous and 224Ra decays in fracture zones deficient in Ra and Th as the brine travels to the wellhead or (2) Ra equilibration in the brine-host rock system is not complete within the mean life of 224Ra (5.2 days) because the desorption of 224Ra from the solid phase is impeded. The 228Ac /228Ra activity ratio in the SSGF brines studied is <0.1, and from this ratio the residence time of 228Ac in the brine before sorption onto solid surfaces is estimated to be <70

  8. U-234/U-238 ratio: Qualitative estimate of groundwater flow in Rocky Flats monitoring wells

    International Nuclear Information System (INIS)

    Laul, J.C.

    1994-01-01

    Groundwater movement through various pathways is the primary mechanism for the transport of radionuclides and trace elements in a water/rock interaction. About three dozen wells, installed in the Rocky Flats Plant (RFP) Solar Evaporation Ponds (SEP) area, are monitored quarterly to evaluate the extent of any lateral and downgradient migration of contaminants from the Solar Evaporation Ponds: 207-A; 207-B North, 207-B Center, and 207-B South; and 207-C. The Solar Ponds are the main source for the various contaminants: radionuclides (U-238, U-234, Pu-239, 240 and Am-241); anions; and trace metals to groundwaters. The U-238 concentrations in Rocky Flats groundwaters vary from 2 (CO 3 ) 2 2- , because of the predominant bicarbonate medium

  9. Fractionation of chemical elements including the REEs and 226Ra in stream contaminated with coal-mine effluent

    International Nuclear Information System (INIS)

    Centeno, L.M.; Faure, G.; Lee, G.; Talnagi, J.

    2004-01-01

    Water draining from abandoned open-pit coal mines in southeastern Ohio typically has a low pH and high concentrations of Fe, Al and Mn, as well as of trace metals (Pb, Cu, Zn, Ni, Co, etc.) and of the rare earth elements (REEs). The cations of different elements are sorbed selectively by Fe and Al hydroxide precipitates which form with increasing pH. As a result, the trace elements are separated from each other when the hydroxide precipitates are deposited in the channel of a flowing stream. Therefore, the low-energy environment of a stream contaminated by mine effluent is a favorable site for the chemical fractionation of the REEs and of other groups of elements with similar chemical properties. The interpretation of chemical analyses of water collected along a 30-km-stretch of Rush Creek near the town of New Lexington, Perry County, Ohio, indicates that the abundances of the REEs in the water appear to change downstream when they are normalized to the REE concentrations of the mine effluent. In addition, the Ce/La ratios (and those of all REEs) in the water decrease consistently downstream. The evidence indicates that the REEs which remain in solution are enriched La and Ce because the other REEs are sorbed more efficiently. The solid Fe(OH) 3 precipitates in the channel of Rush Creek upstream of New Lexington also contain radioactive 226 Ra that was sorbed from the water. This isotope of Ra is a decay product of 238 U which occurs in the Middle Pennsylvanian (Upper Carboniferous) coal and in the associated shale of southeastern Ohio. The activity of 226 Ra of the Fe(OH) 3 precipitates increases with rising pH, but then declines farther downstream as the concentration of Ra remaining in the water decreases

  10. Study of natural radioactivity and 222Rn exhalation rate in soil samples for the assessment of average effective dose

    International Nuclear Information System (INIS)

    Bangotra, P.; Mehra, R.; Jakhu, R.; Sahoo, B.K

    2016-01-01

    The natural radioactivity in soil is usually determined from the 226 Ra (Radium), 232 Th (Thorium) and 40 K (potassium). 222 Rn and 220 Rn are produced in soil as a result of the presence of these radionuclides. As 226 Ra decay, the newly created 222 Rn radionuclide recoil from the parent grain and then exhale through the soil. Since 98.5% of radiological effects of 238 U series are produced by 226 Ra and its daughter products. The assessment of gamma radiation dose from natural sources is of particular importance as natural radiation is the largest contributor to the external dose of the world population. Authors are advised to maximize the information content utilizing the full space available. The main objective of the present study is to measure the level of natural radioactivity 226 Ra, 232 Th, 40 K and 222 Rn exhalation rate in the soil samples for health risk assessment

  11. The diffusion and deposition of the gaseous and solid alpha radionuclides/aerosols in air

    International Nuclear Information System (INIS)

    Danis, A.; Ciubotariu, M.; Oncescu, M.; Mocsy, I.

    1999-01-01

    The diffusion and deposition of gaseous and solids alpha radionuclides and aerosols in air are processes which implicate low element amounts and therefore their studies require the using of very accurate and sensitive analysis methods. The alpha track method meets these requirements. The used alpha radionuclides were: Rn-222, as gaseous radionuclide and its solid descendants genetically related as solid radionuclides and the descendants attached to different particles from air as alpha aerosols. All these radionuclides were obtained from a calibrated Ra-226 source. The source was included into an air tight device with a well known volume and used after 40 days when the Ra-226 and its alpha descendants were under radioactive equilibrium. The relative amount and activity of each decay product, at any duration, for any initial mass of Ra-226 parent radionuclide, were calculated using a programme for computation of the U-238 radioactive series gamma accumulation, UURASE, adapted for alpha accumulation as ALFAURASE programme. The radon, Rn-222, as well as the solid alpha radionuclides and aerosols were measured using a new alpha monitoring device with or without paper filter for solid radionuclides and aerosols stopping. The track detectors of CR-39 type were incorporated with these monitoring devices. In order to calibrate the CR-39 detectors, a radon intercomparison programme was established with the participation of the SSNTD group from the Institute of Nuclear Research ATOMKI, Debrecen, Hungary, Institute of Public Health, Cluj-Napoca and SSNTD research group from IFIN-HH. We have used for radon calibration a special experimental device and a Ra-226 source. Using an air tight diffusion and deposition device, coupled with the source device, the concentration of radon and solid alpha radionuclides and aerosols were determined using the alpha track method. The alpha monitoring devices were fixed vertically at different distances from the place of radon penetration into

  12. Radioactive equilibria and disequilibria of U-series nuclides in erupting magmas from Izu arc volcanoes

    International Nuclear Information System (INIS)

    Sato, Jun; Kurihara, Yuichi; Takahashi, Masaomi

    2009-01-01

    Radioactive disequilibria among U-series nuclides are observed in the magmas from volcanoes in the world. Basaltic products from Izu arc volcanoes, including Izu-Oshima and Fuji volcanoes, show 230 Th 238 U and 226 Ra> 230 Th disequilibria, indicating that the addition of U-and Ra-rich fluid from the subducting slab to the mantle wedge at the magma genesis. The disequilibria of 226 Ra> 230 Th in the erupting magmas suggest that the timescale from magma genesis to the eruption may be less than 8000 years. (author)

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

    International Nuclear Information System (INIS)

    Al-zahrany, A. A.; Farouk, M. A.; Al-yousef, A. A.

    2012-01-01

    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 238 U, 235 U, 226 Ra, 232 Thand 40 K and man-made radionuclides such as 137 Cs in the grab sediment and water samples around Farasan Island have been measured using gamma-ray spectroscopy. The average activity concentrations of 238 U, 235 U, 226 Ra, 232 Th, 40 K and 137C s 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)

  14. Distribution of naturally occurring radioactivity and ¹³⁷Cs in the marine sediment of Farasan Island, southern Red Sea, Saudi Arabia.

    Science.gov (United States)

    Al-Zahrany, A A; Farouk, M A; Al-Yousef, A A

    2012-11-01

    The present work is a part of a project dedicated to measure the marine radioactivity near the Saudi Arabian coasts 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 (238)U, (235)U, (226)Ra, (232)Th and (40)K and man-made radionuclides such as (137)Cs in the grab sediment and water samples around Farasan Island have been measured using gamma-ray spectroscopy. The average activity concentrations of (238)U, (235)U, (226)Ra, (232)Th, (40)K and (137)Cs 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.

  15. An intercomparison exercise on radionuclides in sediment samples

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, S.P.

    1996-07-01

    An intercomparison exercise on artificial and natural radionuclides in two sediment samples, one from the Baltic Sea and one from the Kattegat, has been carried out under the EKO-1 project or the Nordic Safety Research Programme (NKS) for the period 1996-97. The measurement techniques have included direct gamma-ray spectrometry with Ge and NaI detectors, and radiochemical procedures followed by beta counting and alpha spectrometry. The participants have 21 laboratories. Results were submitted for Cs-137, Cs-134, Co-60, Sb-125, Pu-239,240, Pu-238, Am-241, Sr-90, Ra-226, Th-232 and K-40, Pb-210, Po-210 and U-235. The analytical performance of the participants was evaluated for those radionuclides where six or more data sets were received. Statistical tests were made to see if individual results agreed with overall average radionuclide concentrations in the two sediment materials within target standard deviations. The results of these tests show that for Cs-137, Cs-134, Ra-226, Th-232 and K-40 the analytical performance criteria were not met for 20-40% of the data sets. For plutonium isotopes the tests show that the performance criteria were not met for 13% of the data sets. Tests of overall analytical performance show that 61% of the data sets do not meet the combined performance criteria. This shows that there is room for considerable improvement of analytical quality for most of the laboratories that have participated in this intercomparison. The intercomparison exercise has furthermore demonstrated several elementary problems in analytical work. (au) 57 tabs., 16 ills., 1 ref.

  16. An intercomparison exercise on radionuclides in sediment samples

    International Nuclear Information System (INIS)

    Nielsen, S.P.

    1996-07-01

    An intercomparison exercise on artificial and natural radionuclides in two sediment samples, one from the Baltic Sea and one from the Kattegat, has been carried out under the EKO-1 project or the Nordic Safety Research Programme (NKS) for the period 1996-97. The measurement techniques have included direct gamma-ray spectrometry with Ge and NaI detectors, and radiochemical procedures followed by beta counting and alpha spectrometry. The participants have 21 laboratories. Results were submitted for Cs-137, Cs-134, Co-60, Sb-125, Pu-239,240, Pu-238, Am-241, Sr-90, Ra-226, Th-232 and K-40, Pb-210, Po-210 and U-235. The analytical performance of the participants was evaluated for those radionuclides where six or more data sets were received. Statistical tests were made to see if individual results agreed with overall average radionuclide concentrations in the two sediment materials within target standard deviations. The results of these tests show that for Cs-137, Cs-134, Ra-226, Th-232 and K-40 the analytical performance criteria were not met for 20-40% of the data sets. For plutonium isotopes the tests show that the performance criteria were not met for 13% of the data sets. Tests of overall analytical performance show that 61% of the data sets do not meet the combined performance criteria. This shows that there is room for considerable improvement of analytical quality for most of the laboratories that have participated in this intercomparison. The intercomparison exercise has furthermore demonstrated several elementary problems in analytical work. (au) 57 tabs., 16 ills., 1 ref

  17. Determination of {sup 226}Ra by gamma spectrometry: study of packaging vial of sample for analysis; Determinacao de {sup 226}Ra por espectrometria gama: estudo do recipiente de acondicionamento de amostra para analise

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Andre Cavalcanti

    2015-07-01

    Determination of radioactivity levels of {sup 226}Ra by gamma spectrometry in a sample is based on measurements of {sup 214}Pb and {sup 214}Bi, daughters of {sup 222}Rn. Because radon is a gas, it can leak from the sample vial or accumulate on the upper empty it. If the vial has any crack, there will be loss of gas, which will cause error in determining the {sup 226}Ra concentration. One possible cause of cracks in the vials, that houses standards and samples, is the radiolysis action in the vial material, usually a polymer. As the demand {sup 226}Ra analysis in different matrices (geological samples, food, plants, etc.) is increasing, it was decided to study some polymer vials available on the market, to verify the feasibility to be used when is applied the analysis method using gamma spectrometry. Four types of polymer vials have been studied. The radiation doses in walls of the vials caused by natural radionuclides present in the sample were simulated using gamma irradiation. Tests, such as compressive strength test and tightness, were applied to the irradiated and non-irradiated vials. First, to verify the effect of radiolysis on the vial material and also if there was {sup 222}Rn diffusion in their walls. These preliminary results pointed out that the acrylic vials are the best option of packaging samples for analysis. This study should be repeated in a larger number of samples for a better evaluation. (author)

  18. The enrichment behavior of natural radionuclides in pulverized oil shale-fired power plants

    International Nuclear Information System (INIS)

    Vaasma, Taavi; Kiisk, Madis; Meriste, Tõnis; Tkaczyk, Alan Henry

    2014-01-01

    The oil shale industry is the largest producer of NORM (Naturally Occurring Radioactive Material) waste in Estonia. Approximately 11–12 million tons of oil shale containing various amounts of natural radionuclides is burned annually in the Narva oil shale-fired power plants, which accounts for approximately 90% of Estonian electricity production. The radionuclide behavior characteristics change during the fuel combustion process, which redistributes the radionuclides between different ash fractions. Out of 24 operational boilers in the power plants, four use circulating fluidized bed (CFB) technology and twenty use pulverized fuel (PF) technology. Over the past decade, the PF boilers have been renovated, with the main objective to increase the efficiency of the filter systems. Between 2009 and 2012, electrostatic precipitators (ESP) in four PF energy blocks were replaced with novel integrated desulphurization technology (NID) for the efficient removal of fly ash and SO 2 from flue gases. Using gamma spectrometry, activity concentrations and enrichment factors for the 238 U ( 238 U, 226 Ra, 210 Pb) and 232 Th ( 232 Th, 228 Ra) family radionuclides as well as 40 K were measured and analyzed in different PF boiler ash fractions. The radionuclide activity concentrations in the ash samples increased from the furnace toward the back end of the flue gas duct. The highest values in different PF boiler ash fractions were in the last field of the ESP and in the NID ash, where radionuclide enrichment factors were up to 4.2 and 3.3, respectively. The acquired and analyzed data on radionuclide activity concentrations in different PF boiler ashes (operating with an ESP and a NID system) compared to CFB boiler ashes provides an indication that changes in the fuel (oil shale) composition and boiler working parameters, as well as technological enhancements in Estonian oil shale fired power plants, have had a combined effect on the distribution patterns of natural radionuclides in

  19. Seasonal variations in 228Ra/226Ra ratio within coastal waters of the Sea of Japan: implications for water circulation patterns in coastal areas

    International Nuclear Information System (INIS)

    Inoue, M.; Tanaka, K.; Watanabe, S.; Kofuji, H.; Yamamoto, M.; Komura, K.

    2006-01-01

    In this study, low-background γ-spectrometry was used to determine the 228 Ra/ 226 Ra ratio of 131 coastal water samples from various environments around Honshu Island, Japan (mainly around Noto Peninsula) at 1-3 month intervals from April 2003 until September 2005. Spatial variation in 228 Ra/ 226 Ra ratios was also assessed by analyzing 34 coastal water samples from five areas within the Sea of Japan during May and June 2004. The 228 Ra/ 226 Ra ratio of coastal water from all sites around Noto Peninsula shows seasonal variation, with minimum values during summer ( 228 Ra/ 226 Ra = 0.7) and maximum values during autumn-winter ( 228 Ra/ 226 Ra = 1.7-2). This seasonal variation is similar to that recorded for coastal water between Tsushima Strait and Noto Peninsula. The measured lateral variation in 228 Ra/ 226 Ra ratios within coastal water between Tsushima Strait and Noto Peninsula is only minor (0.5-0.7; May-June 2004). Coastal waters from two other sites (Pacific shore and Tsugaru Strait, north Honshu) show no clear seasonal variation in 228 Ra/ 226 Ra ratio. These measured variations in 228 Ra/ 226 Ra ratio, especially the temporal variations, have important implications for seasonal changes in patterns of coastal water circulation within the Sea of Japan

  20. Determination of technologically enhanced naturally occurring radioactive material (TENORM) in ashes from coal-fired thermal power plants in the Philippines

    Energy Technology Data Exchange (ETDEWEB)

    Parami, Vangeline Kinilitan

    2008-04-15

    , with {sup 238}U showing the highest enhancement of 93.72 among the radionuclides. When normalized with {sup 40}K, {sup 238}U in Plant P FA sample also had the highest enrichment factor (EF). Except for Plant C samples, {sup 228}Ra, {sup 228}Th and {sup 40}K were about equallypartitioned between BA and FA samples; {sup 238}U had consistently higher partitioning in all FA samples than BA samples; {sup 226}Ra and {sup 232}Th had varied partitioning behavior among the Plants' BA and FA samples. The behavior of the radionuclides during combustion was explained to be influenced by their physical and chemical characteristics and their association with the alumino-silicate minerals in the coal. For most samples, positive correlations between NIRS ICP-MS and NIRS HPGe were very high for {sup 226}Ra with {sup 238}U (R{sup 2}=0.98), and {sup 228}Ra with {sup 232}Th (R{sup 2}=0.94). Correspondence between ICP-MS and HPGe results were generally high with slopes of 0.90 and zero intercept for both {sup 226}Ra vs {sup 238}U and {sup 228}Ra vs {sup 232}Th. Correlations between NIRS HPGe and PNRI HPGe were also very high for {sup 226}Ra (R{sup 2}=0.93) and {sup 228}Ra (R{sup 2}=0.91), and high for {sup 40}K (R{sup 2}=0.86). However the slopes of the correlation lines gave only 0.65 to 0.68 correspondence of NIRS HPGe relative to PNRI HPGe. This could be attribute to the slight difference in sample and standard geometry used in PNRI HPGe experiment and different multi-channel analyzer emulation software used by NIRS and PNRI HPGe's. The result of more detailed study in Plant C showed that the ACs of {sup 226}Ra, {sup 228}Ra, and {sup 40}K were similar between two sampling periods in 2005 and 2006; the ACs in the ash pond were generally slightly lower than that in the BA and FA samples; and the ACs showed a slight decreasing trend with ash pond depth. The AC in both BA and FA samples from Plants C, M, P and S were all below the International Atomic Energy Agency (IAEA) and European

  1. Radon in soil gas in Kosovo.

    Science.gov (United States)

    Kikaj, Dafina; Jeran, Zvonka; Bahtijari, Meleq; Stegnar, Peter

    2016-11-01

    An assessment of the radiological situation due to exposure to radon and gamma emitting radionuclides was conducted in southern Kosovo. This study deals with sources of radon in soil gas. A long-term study of radon concentrations in the soil gas was carried out using the SSNTDs (CR-39) at 21 different locations in the Sharr-Korabi zone. The detectors were exposed for an extended period of time, including at least three seasonal periods in a year and the sampling locations were chosen with respect to lithology. In order to determine the concentration of the natural radioactive elements 238 U and 226 Ra, as a precursor of 222 Rn, soil samples were collected from each measuring point from a depth of 0.8 m, and measured by gamma spectrometry. The levels (Bq kg -1 ) of naturally occurring radionuclides and levels (kBq m -3 ) of radon in soil gas obtained at a depth 0.8 m of soil were: 21-53 for 226 Ra, 22-160 for 238 U and 0.295-32 for 222 Rn. With respect to lithology, the highest value for 238 U and 226 Ra were found in limestone and the highest value for 222 Rn was found in metamorphic rocks. In addition, the results showed seasonal variations of the measured soil gas radon concentrations with maximum concentration in the spring months. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Activity concentration and population dose from 226Ra due to consumption of dietary components

    International Nuclear Information System (INIS)

    Wagh, S.S.; Patra, A.K.; Ravi, P.M.; Sarkar, P.K.

    2012-01-01

    226 Ra (T 1/2 = 1620 years, α-energy 4.78 MeV, 4.59 MeV, γ-energy 186 keV), a product of natural uranium decay series, is abundantly observed in natural environment. Radium, along with its homologue calcium, an essential element in the plant system, is absorbed from the soil by plants and gets redistributed. within different parts of the plants. Because of the long half-life of 226 Ra, it gets accumulated in the human body for along time. The hazard due to ingestion of 226 Ra dissolved in water is reported to be about 40 times higher than that of 90 Sr. This paper deals with the concentration of 226 Ra in different dietary components and ingestion dose from 226 Ra due to consumption of dietary components. Internal radiation exposure to non-human biota due to 226 Ra is also discussed

  3. Low level measurements of natural radionuclides in soil samples around a coal-fired power plant

    International Nuclear Information System (INIS)

    Rosner, G.; Bunzl, K.; Hoetzl, H.; Winkler, R.

    1984-01-01

    To detect a possible contribution of airborne radioactivity from stack effluents to the soil radioactivity, several radionuclides in the soil around a coal-fired power plant have been determined. A plant situated in a rural region of Bavaria was selected to minimize contributions from other civilisatory sources. The soil sampling network consisted of 5 concentric circles with diameters between 0.4 and 5.2 km around the plant, 16 sampling points being distributed regularly on each circle. Radiochemical analysis techniques for 210 Pb and 210 Po in soil samples of several grams has to be developed. They include a wet dissolution procedure, simultaneous precipitation of lead and polonium as the sulfides, purification via lead sulfate, counting of the lead as the chromate in a low-level beta counter and alpha spectrometric determination of the 210 Po in a gridded ionization chamber. The 238 U, 226 Ra, 232 Th and 40 K were counted by low level gamma spectrometry. Specific activities found were in the range of 0.7 to 2.0 pCi g -1 for 210 Pb and 0.3 to 1.6 pCi g -1 for 226 Ra. The distribution patterns of 210 Po and 210 Pb around the plant were found to be similar. They were different, however, from that of 226 Ra. The highest 210 Pb/ 226 Ra activity ratio was 3.9 at a distance of 0.76 km SSE from the plant. Nevertheless, the evidence is not considered to be sufficient to attribute these observations unambiguously to plant release. (orig.)

  4. Seasonal variation of 228Ra/226Ra ratio in seaweed: implications for water circulation patterns in coastal areas of the Noto Peninsula, Japan

    International Nuclear Information System (INIS)

    Inoue, M.; Kofuji, H.; Yamamoto, M.; Komura, K.

    2005-01-01

    To examine water circulation patterns of coastal water, 72 seaweed (Sargasso) samples and 27 coastal water samples were collected from coastal areas of the Noto Peninsula, Japan, during the period from December 1998 to June 2002. The 228 Ra and 226 Ra activities of those samples were measured by low-background γ-ray spectrometry. There was a wide range of activities of 228 Ra (0.5-2 Bq/kg-fresh) and 226 Ra (0.5-1.2 Bq/kg-fresh) in the Sargasso samples. The 228 Ra/ 226 Ra activity ratio of Sargasso samples exhibited seasonal variation with minimum values in June ( 228 Ra/ 226 Ra = ∼1) and maximum values in December (1.5-2.5), which was mainly governed by changes in 228 Ra activity. It is also notable that the seasonal variation of the 228 Ra/ 226 Ra ratio of Sargasso is in approximate agreement with that of the ambient coastal water. Sargasso samples appear to have retained the 228 Ra/ 226 Ra ratio of the ambient coastal waters, and the temporal variations in that ratio provide insight into seasonal changes in water circulation in the Noto Peninsula coastal area

  5. Natural radionuclides in bauxitic tailings (Red-Mud) in the Gulf of Corinth, Greece

    International Nuclear Information System (INIS)

    Papatheodorou, G.; Maratou, A.; Ferentinos, G.; Papaefthymiou, H.

    2004-01-01

    A detailed environmental survey was carried out in the central Gulf of Corinth in order to determine radionuclides in the bauxite ed-mud tailings which have been discharged on the sea floor by a Bauxite Processing Plant (Aluminio Ellados A.E). The discharge of bauxitic tailings via two pipelines at a water depth of 100 m, in Antikyra Bay (Northern Gulf of Corinth), has resulted in the formation of two red-mud mound-like deposits. The red-mud deposits at the mouth of the out falls, are not stable and very often red-m