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Sample records for investigations radionuclide distribution

  1. The investigation of radionuclides distributions in beach sand by ...

    African Journals Online (AJOL)

    The investigation of radionuclides distributions in beach sand by means of GIS techniques. ... The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more information about how to print, save, and work ...

  2. The investigation of radionuclides distributions in beach sand by ...

    African Journals Online (AJOL)

    A transportable and robust gamma ray detection system (GISPI) was employed to determine the concentrations of naturally occurring radionuclides on various beaches in and around Saldanha Bay, located on the West Coast of South Africa. Several mathematical techniques were applied to obtain GIS overlay that could be ...

  3. INVESTIGATION OF BASALT-RADIONUCLIDE DISTRIBUTION COEFFICIENTS: FISCAL YEAR 1980 ANNUAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Ames, L. L.; McGarrah, J. E.

    1980-12-01

    The Basalt Waste Isolation Project (Rockwell Hanford Operations) is conducting a safety assessment of nuclear waste storage in a repository on the Hanford Site. Pacific Northwest Laboratory, in support of the assessment effort, is generating radionuclide distribution coefficient data between simulated groundwaters and basalts and their secondary mineral products under the range of physicochemical conditions expected in a repository in basalt. Experimental radionuclide distribution coefficients were determined for crushed Pomona, Flow E, and Umtanum basalts at 23°, 60°, 150°, and 300°C at both normal oxygen partial pressure (~0.2 atm) and lower oxygen partial pressure (~10{sup -7} atm), using a static technique. Little or no changes in distribution coefficients were noted for selenium, uranium, technetium, neptunium, or plutonium over the oxygen partial pressure range noted above. Sodium dithionite and hydrazine are now under study as system additives to lower Eh to -0.3 to -0.5 V, the conditions expected to prevail in the closed repository in basalt. Radium, strontium, cesium, and americium are not expected to change oxidation states under repository conditions, while iodine remains an anion in either oxidation state. Lowering the system Eh to the -0.3 to -0.5 V expected in a repository in basalt should result in an oxidation state change and enhanced removal from solution for selenium, uranium, technetium, neptunium, and plutonium. Sorption of iodine was not affected by the Eh changes. Temperature change effects on most radionuclide distribution coefficient (Kd) values over the 23° to 300°C range were major with the exception of iodine and technetium, neither of which were appreciably sorbed at normal to ~10{sup -7} atm oxygen partial pressure. Uranium Kd values increased with an increase in temperature. In addition, uranium Kd values at 23°C decrease by an order of magnitude in response to added CO{sub 3}{sup 2-} in the solution. Cesium basalt Kd values

  4. Radionuclide distributions and migration mechanisms at shallow land burial sites. 1982 annual report of research investigations on the distribution, migration and containment of radionuclides at Maxey Flats, Kentucky

    International Nuclear Information System (INIS)

    Kirby, L.J.

    1984-02-01

    Subsurface waters at Maxey Flats are anoxic, have a high alkalinity and contain high concentrations of ferrous, sulfide and ammonium ions and organic carbon. The trench leachates are extremely variable in composition. Prominent radionuclides include 3 H, 60 Co, 90 Sr, 137 Cs, 238 239 240 Pu and 241 Am. A wide spectrum of dissolved organic compounds is present in the leachates, including EDTA, polar organics and decomposition products from the waste forms. Cobalt-60 and plutonium are present as EDTA complexes and 90 Sr and 137 Cs are associated with carboxylic acid type compounds. The chemistry of these waters changes drastically as they become oxic and plutonium becomes less mobile under these new conditions. Water enters the trenches by infiltration through the trench caps, through subsidence areas, and through interfaces between new landfill and the original soil. Lateral flow is very complex and slow, and apparently occurs mainly by fracture flow. The plastic infiltration barrier installed in 1981 to 1982 has been effective in reducing soil moisture if cracks and leaks are eliminated. To date, no direct evidence of radionuclide transport to offsite locations by subsurface flow has been confirmed. The offsite distribution of radionuclides, except for tritium, is comparable to the ambient fallout from nuclear weapons testing. Tritium concentrations in water offsite are orders of magnitude below MPC levels. 24 figures, 31 tables

  5. Radionuclide distributions and migration mechanisms at shallow land burial sites. Annual report of research investigations on the distribution, migration and containment of radionuclides at Maxey Flats, Kentucky

    International Nuclear Information System (INIS)

    Kirby, L.J.

    1982-07-01

    Subsurface waters at Maxey Flats are anoxic systems with high alkalinity and high concentrations of dissolved ferrous ion. Americium and cobalt in these trench waters are made more soluble by the presence of EDTA, while strontium and cesium are unaffected under the same conditions. EDTA is the major organic complexing component in waste trench 27 leachate, but other polar, water-soluble organics are also present. Evidence points to the migration of plutonium between waste trench 27 and inert atmosphere wells as an EDTA complex. Polar organic compounds may influence the migration of 90 Sr and 137 Cs. The primary pathway of water entry into the waste burial trenches is through the trench caps, but major increases in water level have occurred in an experimental trench by subsurface flow. The areal distribution of radionuclides at Maxey Flats has been influenced by surface runoff, deposition from the evaporator plume, subsurface flow and the actions of burrowing animals or deep-rooted trees. Vegetal and surface contamination on site and near site are quite low, and only 60 Co exceeds commonly observed fallout levels. Radionuclide concentrations in surface soil at Maxey Flats are comparable to concentrations resulting from normal fallout in other areas of high rainfall

  6. RADIONUCLIDES DISTRIBUTION NEAR FORMER URANIUM MINING

    Directory of Open Access Journals (Sweden)

    D. A. Zaredinov

    2016-01-01

    Full Text Available The paper shows, that radionuclides from the stony rocks of uranium mines can be leached by atmospheric precipitations. In acid conditions, a degree of leaching is greater.Goal. The aim of this investigation was to study the distribution of radionuclides in uranium minings and their impact on the environmental contamination.Materials and methods. The study was carried out in two stages. In the first stage, a blade of rock was mixed with distilled water in proportions of 0,3 kg of gravel and 1 liter of water. After thirty days of soaking, water was sent to the gamma-spectrometric analysis to Canberra’s spectrometer (USA with a high-purity germanium detector. In the second stage, we carried out the similar experiment with water, wich was acidified to pH = 3. Contamination levels of areas near the in-situ leaching mine were determined. Intervention levels were used to estimate risk and possible water consumption by the population. Estimations were carried out taking into account the combined presence of several radionuclides in the water.Results. The results of these studies have shown that the distribution of radionuclides from the source of the contamination is about 360 meters during the 30 y period. The stream, along which samples of soil were collected and studied, was formed by the miner waters that flow along small ruts towards a village, thereby increasing the likelihood of water use by the public.Conclusions. The uranium mines are the source of radioactive contamination. Radionuclides are distributed due to the erosion of rocks and leached out of the stony rock by precipitations. The extent of leaching is significantly increased in an acidic environment, which takes place near the in-situ leaching mines.

  7. Changing patterns of radionuclide distribution in Irish Sea subtidal sediments

    International Nuclear Information System (INIS)

    Jones, David G.; Kershaw, Peter J.; McMahon, Ciara A.; Milodowski, Antoni E.; Murray, Michael; Hunt, G. John

    2007-01-01

    This paper presents new data on the distribution of long-lived radionuclides in Irish Sea subtidal sediments, contaminated as a result of the BNFL Sellafield discharges. The results from different sampling campaigns in 1999 have been combined to assess the extent of radionuclide mobility relative to earlier surveys, in both the eastern and western Irish Sea areas, and to investigate changes in radionuclide distribution over time. The results appear to confirm the trend of continuing re-distribution and transfer of contamination away from the English coast. West of the Isle of Man, radionuclide concentrations and inventories have remained more or less constant. The inventory of radionuclides in sandy sediments in the eastern Irish Sea is still under-represented by current sampling, but could be improved by deeper and more extensive vibrocoring

  8. Investigation of radionuclide distribution using aircraft for surrounding environmental survey from Fukushima Dai-ichi Nuclear Power Plant

    International Nuclear Information System (INIS)

    Torii, Tatsuo; Sanada, Yukihisa; Shikaze, Yoshiaki; Takahashi, Masaki; Ishida, Mutsushi; Nishizawa, Yukiyasu; Urabe, Yoshimi; Sugita, Takeshi; Kondo, Atsuya

    2012-12-01

    We carried out aerial radiation monitoring (ARM) of all Japan area in order to investigate the influence of the radio cesium which was emitted into the atmosphere by disaster of the Fukushima Dai-ichi nuclear power plant of Tokyo Electric Power Co., Inc. AMS can measure a gamma ray quickly by flight from 300 m height above the ground. Moreover, ARM has an advantage which can grasp self-possessed quantity distribution of an air dose rate and radioactive cesium in f ield , and is visually intelligible. Although there were apparatus and the technique of ARM in our country, sufficient preparations for wide area monitoring were not made. Therefore, it fixed based on the method of the U.S. Department of Energy (DOE) about the method of the conversion to all radiation dose, and the conversion method to radiocesium deposition and the method of mapping. It is possible to discriminate from a background (cosmic-ray, self-contamination and natural nuclides) at the time of western-part-of-Japan measurement by improving of the method in parallel to data acquisition. By this monitoring, it was able to check about the distribution situation of the air dose rate of the Japanese whole region, or the radioactive cesium deposition. Here, the measurement technique and a result are described. (author)

  9. Distribution and migration of long lived radionuclides in the environment around the Chernobyl Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Amano, Hikaru; Matsunaga, Takeshi; Ueno, Takashi; Nagao, Seiya; Yanase, Nobuyuki; Watanabe, Miki; Hanzawa, Yukiko [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-03-01

    Characteristics of the distribution and migration of long lived radionuclides in the environment around the Chernobyl Nuclear Power Plant (30 km exclusion zone) has been investigated. Research items are, (i) Distribution of long lived radionuclides in the surface environment, (ii) Speciation of long lived radionuclides in the surface environment, (iii) Characteristics of the migration in the surface environment, (iv) Characteristics of the uptake into the vegetables, (v) Prediction of future radioecological situation in the environment, respectively. (author)

  10. Radionuclide Inventory Distribution Project Data Evaluation and Verification White Paper

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Restoration

    2010-05-17

    Testing of nuclear explosives caused widespread contamination of surface soils on the Nevada Test Site (NTS). Atmospheric tests produced the majority of this contamination. The Radionuclide Inventory and Distribution Program (RIDP) was developed to determine distribution and total inventory of radionuclides in surface soils at the NTS to evaluate areas that may present long-term health hazards. The RIDP achieved this objective with aerial radiological surveys, soil sample results, and in situ gamma spectroscopy. This white paper presents the justification to support the use of RIDP data as a guide for future evaluation and to support closure of Soils Sub-Project sites under the purview of the Federal Facility Agreement and Consent Order. Use of the RIDP data as part of the Data Quality Objective process is expected to provide considerable cost savings and accelerate site closures. The following steps were completed: - Summarize the RIDP data set and evaluate the quality of the data. - Determine the current uses of the RIDP data and cautions associated with its use. - Provide recommendations for enhancing data use through field verification or other methods. The data quality is sufficient to utilize RIDP data during the planning process for site investigation and closure. Project planning activities may include estimating 25-millirem per industrial access year dose rate boundaries, optimizing characterization efforts, projecting final end states, and planning remedial actions. In addition, RIDP data may be used to identify specific radionuclide distributions, and augment other non-radionuclide dose rate data. Finally, the RIDP data can be used to estimate internal and external dose rates. The data quality is sufficient to utilize RIDP data during the planning process for site investigation and closure. Project planning activities may include estimating 25-millirem per industrial access year dose rate boundaries, optimizing characterization efforts, projecting final

  11. Nevada test site radionuclide inventory and distribution: project operations plan

    International Nuclear Information System (INIS)

    Kordas, J.F.; Anspaugh, L.R.

    1982-01-01

    This document is the operational plan for conducting the Radionuclide Inventory and Distribution Program (RIDP) at the Nevada Test Site (NTS). The basic objective of this program is to inventory the significant radionuclides of NTS origin in NTS surface soil. The expected duration of the program is five years. This plan includes the program objectives, methods, organization, and schedules

  12. 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

  13. Dosimetric characterization of radionuclides for systemic tumor therapy: Influence of particle range, photon emission, and subcellular distribution

    International Nuclear Information System (INIS)

    Uusijaervi, Helena; Bernhardt, Peter; Ericsson, Thomas; Forssell-Aronsson, Eva

    2006-01-01

    Various radionuclides have been proposed for systemic tumor therapy. However, in most dosimetric analysis of proposed radionuclides the charged particles are taken into consideration while the potential photons are ignored. The photons will cause undesirable irradiation of normal tissue, and increase the probability of toxicity in, e.g., the bone marrow. The aim of this study was to investigate the dosimetric properties according to particle range, photon emission, and subcellular radionuclide distribution, of a selection of radionuclides used or proposed for radionuclide therapy, and to investigate the possibility of dividing radionuclides into groups according to their dosimetric properties. The absorbed dose rate to the tumors divided by the absorbed dose rate to the normal tissue (TND) was estimated for different tumor sizes in a mathematical model of the human body. The body was simulated as a 70-kg ellipsoid and the tumors as spheres of different sizes (1 ng-100 g). The radionuclides were either assumed to be uniformly distributed throughout the entire tumor and normal tissue, or located in the nucleus or the cytoplasm of the tumor cells and on the cell membrane of the normal cells. Fifty-nine radionuclides were studied together with monoenergetic electrons, positrons, and alpha particles. The tumor and normal tissue were assumed to be of water density. The activity concentration ratio between the tumor and normal tissue was assumed to be 25. The radionuclides emitting low-energy electrons combined with a low photon contribution, and the alpha emitters showed high TND values for most tumor sizes. Electrons with higher energy gave reduced TND values for small tumors, while a higher photon contribution reduced the TND values for large tumors. Radionuclides with high photon contributions showed low TND value for all tumor sizes studied. The radionuclides studied could be divided into four main groups according to their TND values: beta emitters, Auger electron

  14. Distribution of six radionuclides between soluble and particulate phase at the sea-freshwater interface

    International Nuclear Information System (INIS)

    Peres, J.M.

    1984-01-01

    The distribution of the soluble and particulate phases of radionuclides has been studied in water samples of various salinities (0 per mill; 3.8 per mill; 7.6 per mill; 15.2 per mill; 22.8 per mill; 30.4 per mill; 34 per mill). Cesium 137, cobalt 60, manganese 54, zinc 65, chromium 51 and sodium 22 were investigated. The results are expressed as retention percentages or distribution coefficients (Kd). Increased salinities resulted in decreased retention rates varying with the radionuclides; this appeared with the lowest salinities, and the evolution was small beyond 7 per mill. Other parameters were considered beside salinity, viz.: the suspended matter characteristics (mineralogy, particle size distribution); particulate load of water; organic content, whether associated to the soluble or particulate phase; physico-chemical forms of the radionuclides. To determine the particle size spectra of the suspended matter in the experimental samples, a laser granulometer was used [fr

  15. Review of Distribution Coefficients for Radionuclides in Carbonate Minerals

    International Nuclear Information System (INIS)

    Sutton, M.

    2009-01-01

    An understanding of the transport of radionuclides in carbonate minerals is necessary to be able to predict the fate of (and potentially remediate) radionuclides in the environment. In some environments, carbonate minerals such as calciate, aragonite, dolomite and limestone are present and an understanding of the sorption of radionuclides in these carbonate minerals is therefore advantageous. A list of the radionuclides of interest is given in Table 1. The distribution coefficient, K d is defined as the ratio of the contaminant concentration bound on the solid phase to the contaminant concentration remaining in the liquid phase at equilibrium. Some authors report distribution coefficients and other report partition coefficients, the data presented in this work assumes equality between these two terms, and data are presented and summarized in this work as logarithmic distribution coefficient (log K D ). Published literature was searched using two methods. Firstly, the JNC Sorption Database, namely Shubutani et al (1999), and Suyama and Sasamoto (2004) was used to select elements of interest and a number of carbonate minerals. Secondly, on-line literature search tools were used to locate relevant published articles from 1900 to 2009. Over 300 data points covering 16 elements (hydrogen, carbon, calcium, nickel, strontium, technetium, palladium, iodine, cesium, samarium, europium, holmium, uranium, neptunium, plutonium and americium) were used to calculate an average and range of log K d values for each element. Unfortunately, no data could be found for chlorine, argon, krypton, zirconium, niobium, tin, thorium and curium. A description of the data is given below, together with the average, standard deviation, minimum, maximum and number of inputs for radionuclide K d values for calcite, aragonate, limestone, dolomite and unidentified carbonate rocks in Table 2. Finally, the data are condensed into one group (carbonate minerals) of data for each element of interest in

  16. Empirical distributions of radionuclides, from RWMIS data

    International Nuclear Information System (INIS)

    Atwood, C.L.; Schlafman, M.J.

    1993-04-01

    The RWMIS data base gives data on each shipment of waste received at the Transuranic Storage Area, including the total volume of the shipment and the activity (Ci) of each nuclide in the shipment. This report assumes that the RWMIS numbers are correct, and considers the waste containers now retrievably stored at the Transuranic Storage Area. The total decay-corrected activities are summarized for several classes, such as for transuranic (TRU) waste and non-TRU waste, for α-emitters and β/γ-emitters, by waste originator and by current storage location. The total activity for each nuclide is also given. The empirical distributions are then given for a number of classes and individual nuclides, reflecting the variability between waste shipments. They are expressed in terms of mCi/cu-ft; for fissionable nuclides, the same information is also expressed in terms of mg/cu-ft; finally, the distribution is also given for the committed effective dose equivalent from inhalation, expressed in Mrem/cu-ft. The empirical distributions can be used for simulating the contents of a random waste container with a postulated volume. Examples are given illustrating the uses and limitations of the results

  17. 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.

  18. Sources and distribution of anthropogenic radionuclides in different marine environments

    International Nuclear Information System (INIS)

    Holm, E.

    1997-01-01

    The knowledge of the distribution in time and space radiologically important radionuclides from different sources in different marine environments is important for assessment of dose commitment following controlled or accidental releases and for detecting eventual new sources. Present sources from nuclear explosion tests, releases from nuclear facilities and the Chernobyl accident provide a tool for such studies. The different sources can be distinguished by different isotopic and radionuclide composition. Results show that radiocaesium behaves rather conservatively in the south and north Atlantic while plutonium has a residence time of about 8 years. On the other hand enhanced concentrations of plutonium in surface waters in arctic regions where vertical mixing is small and iceformation plays an important role. Significantly increased concentrations of plutonium are also found below the oxic layer in anoxic basins due to geochemical concentration. (author)

  19. Concerning initial and secondary character of radionuclide distribution in elementary landscape geochemical systems

    Science.gov (United States)

    Korobova, Elena; Romanov, Sergey

    2017-04-01

    Specificity of radionuclide distribution in elementary landscape geochemical systems (ELGS) treated as local system of geochemically linked elementary terrestrial units (in toposequence: watershed-slope-closing depression), belongs to one of the less investigated but practically significant problems of current geochemistry. First measurements after the Chernobyl accident showed a considerable variation of Cs-137 distribution in all examined ELGS (Shcheglov et al, 2001; Romanov, 1989; Korobova, Korovaykov, 1990; Linnik, 2008). The results may be interpreted in frames of two alternative hypotheses: 1) irregularity of the initial contamination; 2) secondary redistribution of the initially regular level of fallout. But herewith only a disproof of the first hypothesis automatically justifies the second one. Factors responsible for initial irregularity of surface contamination included: 1) the presence of the so-called "hot" particles in the initial fallout; 2) interception of radionuclides by forest canopy; 3) irregular aerial particles deposition; 4) uneven initial precipitation. Basing on monitoring Cs-137 spatial distribution that has been performed since 2005, we demonstrate that the observed spatial irregularity in distribution of Cs-137 in ELGS reflects a purely secondary distribution of initial reserves of radionuclides in fallout matter due to its migration with water in local geochemical systems. This statement has some significant consequences. 1. Mechanism of migration of matter in ELGS is complicated and could not be reduced solely to a primitive moving from watershed to closing depression. 2. The control of migration of "labeled atoms" (Cs-137) permits to understand common mechanism of migration of water in all systems on the level of ELGS. 3. Understanding formation of the structure of contamination zones in ELGS permits to use mathematical model to solve the inverse problem of restoration of the initially equable level of their contamination. Performed

  20. The Project on the distribution of fallout radionuclide and their transfer through environment by Fukushima Daiichi NPP accident

    Science.gov (United States)

    Onda, Yuichi; Kato, Hiroaki; Yoshimura, Kazuya; Fukushima, Takehiko; Patin, Jeremy

    2013-04-01

    Radioactive contamination has been detected in Fukushima due to the nuclear accident at Fukushima Daiichi Nuclear Power Plant (NPP) following the earthquake and tsunami on 11 March 2011. Following comprehensive investigation (FMWSE project funded by MEXT, Japan; http://fmwse.suiri.tsukuba.ac.jp/) was conducted to confirm migration of radionuclides through natural environment including soils and rivers. Experimental catchments have been established in Yamakiya district, Kawamata Town, Fukushima prefecture, located about 35 km from Fukushima power plant, and designated as the evacuated zone. Approximate Cs-137 fallout in this area is 200 - 600 kBq/m2. (1) Migration study of radionuclides in natural environment including forests and rivers: 1) Depth distribution of radiocaesium in soils within forests, fields, and grassland, 2) Confirmation of radionuclide distribution and investigation on migration in forests, 3) Study on radionuclide migration due to soil erosion under different land use, 4) Measurement of radionuclides entrained from natural environment including forests and soils. (2) Migration study of radionuclides through hydrological cycle such as soil water, rivers, lakes and ponds, ground water: 1) Investigation on radionuclide migration through soil water, ground water, stream water, spring water under different land use, 2) Study on paddy-to-river transfer of radionuclides through suspended sediments, 3) Study on river-to-ocean transfer of radionuclides via suspended sediments, 4) Confirmation of radionuclide deposition in ponds and reservoirs. The main finding is as follows: 1) Migration of radionuclides to soil water, stream water and ground water was confirmed low at present. On the other hand, concentration of radiocaesium was found approximately 50 kBq/kg in the suspended sediments flowing down the river. 2) Amount of sediments deposited in the tank placed at the end of downstream within the USLE plot was confirmed together with the concentrations of

  1. Assessment of the Chernobyl NPP radionuclide distribution at the territory of Kiev industrial-urban agglomeration

    International Nuclear Information System (INIS)

    1993-01-01

    Results were presented of the complex of geological-ecological studies conducted in 1991-1992 with the aim of establishment of radionuclide distribution character in the upper part of geologic medium of the Kiev industrial-urban agglomeration (IUA). Soil, vegetative biomass, surface and underground water, atmospheric precipitations, atmospheric moisture were sampled for study. Distributions of 134,137 Cs, 144 Ce, 106 Ru, 238,239,240 Pu, 90 Sr, 3 H were investigated. Environmental contamination levels were compared with the preaccidental values. Anomaly fields of contamination density with radioisotopes of the Kiev IUA were revealed. 3 figs.; 3 tabs

  2. Distribution functions to estimate radionuclide solid-liquid distribution coefficients in soils: the case of Cs

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez-Guinart, Oriol; Rigol, Anna; Vidal, Miquel [Analytical Chemistry department, Faculty of Chemistry, University of Barcelona, Mart i Franques 1-11, 08028, Barcelona (Spain)

    2014-07-01

    In the frame of the revision of the IAEA TRS 364 (Handbook of parameter values for the prediction of radionuclide transfer in temperate environments), a database of radionuclide solid-liquid distribution coefficients (K{sub d}) in soils was compiled with data coming from field and laboratory experiments, from references mostly from 1990 onwards, including data from reports, reviewed papers, and grey literature. The K{sub d} values were grouped for each radionuclide according to two criteria. The first criterion was based on the sand and clay mineral percentages referred to the mineral matter, and the organic matter (OM) content in the soil. This defined the 'texture/OM' criterion. The second criterion was to group soils regarding specific soil factors governing the radionuclide-soil interaction ('cofactor' criterion). The cofactors depended on the radionuclide considered. An advantage of using cofactors was that the variability of K{sub d} ranges for a given soil group decreased considerably compared with that observed when the classification was based solely on sand, clay and organic matter contents. The K{sub d} best estimates were defined as the calculated GM values assuming that K{sub d} values were always log-normally distributed. Risk assessment models may require as input data for a given parameter either a single value (a best estimate) or a continuous function from which not only individual best estimates but also confidence ranges and data variability can be derived. In the case of the K{sub d} parameter, a suitable continuous function which contains the statistical parameters (e.g. arithmetical/geometric mean, arithmetical/geometric standard deviation, mode, etc.) that better explain the distribution among the K{sub d} values of a dataset is the Cumulative Distribution Function (CDF). To our knowledge, appropriate CDFs has not been proposed for radionuclide K{sub d} in soils yet. Therefore, the aim of this works is to create CDFs for

  3. Radionuclide cisternography: a prudent investigation in diagnosing spontaneous intracranial hypotension

    International Nuclear Information System (INIS)

    Sehgal, Aditi Khurana; Sethi, Ravinder Singh; Namgyal, Padma A.; Raghavan, Samudrala

    2013-01-01

    Spontaneous intracranial hypotension (SIH) is a cause of new persistent headache, which disappears on recumbence and reappears in sitting/standing position (orthostatic headache). We present a case of orthostatic headache, where the patient was suspected to have SIH and was subjected to radionuclide cisternography (RNC) using 99m Technetium Diethylenetriaminepenta acetic acid for confirmation of diagnosis. After due consent from the patient, the radiotracer was injected intra-thecally and serial images were acquired until 24 h. The direct and indirect evidences of Cerebrospinal fluid (CSF) leakage, which were revealed in our study, provided objective evidence to the clinical diagnosis. RNC is an important investigation in diagnosing SIH and also identifying the site of CSF leak, which may aid the management. (author)

  4. Influence of break structures on the distribution of radionuclides in bottom sediments of the Kyiv reservoir

    International Nuclear Information System (INIS)

    Shestopalov, V.M.; Lyal'ko, V.I.; Fedorovskij, A.D.; Sirenko, L.A.; Khodorovskij, A.Ya.

    2000-01-01

    We study the distribution of radionuclides in bottom sediments of the Kyiv reservoir on the basis of research of adjacent territory break - block structures with deciphering space-born images and ground measurements and forecast the occurrence of extreme situations due to the redistribution of bottom water flows and sediments of radionuclides

  5. Study on vertical distribution of radionuclides ({sup 40}K, Th and U) in soil collected from Manjung district

    Energy Technology Data Exchange (ETDEWEB)

    Zainal, Fetri; Hamzah, Zaini; Wood, Khalik [Faculty of Sciences, Universiti Teknologi MARA, 40450, Shah Alam, Selangor (Malaysia); Saat, Ahmad [Faculty of Sciences, Universiti Teknologi MARA, 40450, Shah Alam, Selangor (Malaysia); Institute of Science, Universiti Teknologi MARA, 40450, Shah Alam, Selangor (Malaysia); Alias, Masitah [TNB Research Sdn. Bhd. 43000 Kajang, Selangor (Malaysia)

    2016-01-22

    The accumulation of radionuclides in soil is a greatest concerns due to their toxicity. This study investigated the vertical distribution of radionuclides and radiological assessment in a soil profile were collected in three different directions [North (N), North-East (NE) and South-East (SE)] within 40 km from Manjung district. All profile samples were collected down to 45cm at 7.5cm interval using hand auger. Soil density and radionuclides ({sup 40}K, Th and U) concentrations were determined by gravimetric method and Energy Dispersive X-Ray Fluorescence (EDXRF) technique, respectively. The radionuclides concentrations was in decreasing order of {sup 40}K > Th > U. Soil quality assessment was carried out using Enrichment Factor (EF), Pollution Index (PI) and Geoaccumulation Index (I {sub geo}) where all radionuclides show significant enrichment (5 < EF < 20), PI classified as middle pollution classes and 0 < Igeo < 1, indicating moderately polluted, respectively. From the concentration of radionuclides, the radiological risk was calculated and the present result show external hazard index (H{sub ex}) is below than unity indicate low radiological risk.

  6. New best estimates for radionuclide solid-liquid distribution coefficients in soils. Part 3: miscellany of radionuclides (Cd, Co, Ni, Zn, I, Se, Sb, Pu, Am, and others)

    International Nuclear Information System (INIS)

    Gil-Garcia, C.; Tagami, K.; Uchida, S.; Rigol, A.; Vidal, M.

    2009-01-01

    New best estimates for the solid-liquid distribution coefficient (K d ) for a set of radionuclides are proposed, based on a selective data search and subsequent calculation of geometric means. The K d best estimates are calculated for soils grouped according to the texture and organic matter content. For a limited number of radionuclides this is extended to consider soil cofactors affecting soil-radionuclide interaction, such as pH, organic matter content, and radionuclide chemical speciation. Correlations between main soil properties and radionuclide K d are examined to complete the information derived from the best estimates with a rough prediction of K d based on soil parameters. Although there are still gaps for many radionuclides, new data from recent studies improve the calculation of K d best estimates for a number of radionuclides, such as selenium, antimony, and iodine.

  7. New best estimates for radionuclide solid-liquid distribution coefficients in soils. Part 3: miscellany of radionuclides (Cd, Co, Ni, Zn, I, Se, Sb, Pu, Am, and others)

    Energy Technology Data Exchange (ETDEWEB)

    Gil-Garcia, C. [Departament de Quimica Analitica, Universitat de Barcelona, Marti i Franques 1-11, 3a Planta, 08028 Barcelona (Spain); Tagami, K.; Uchida, S. [Office of Biospheric Assessment for Waste Disposal, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage, Chiba 263-8555 (Japan); Rigol, A. [Departament de Quimica Analitica, Universitat de Barcelona, Marti i Franques 1-11, 3a Planta, 08028 Barcelona (Spain); Vidal, M. [Departament de Quimica Analitica, Universitat de Barcelona, Marti i Franques 1-11, 3a Planta, 08028 Barcelona (Spain)], E-mail: miquel.vidal@ub.edu

    2009-09-15

    New best estimates for the solid-liquid distribution coefficient (K{sub d}) for a set of radionuclides are proposed, based on a selective data search and subsequent calculation of geometric means. The K{sub d} best estimates are calculated for soils grouped according to the texture and organic matter content. For a limited number of radionuclides this is extended to consider soil cofactors affecting soil-radionuclide interaction, such as pH, organic matter content, and radionuclide chemical speciation. Correlations between main soil properties and radionuclide K{sub d} are examined to complete the information derived from the best estimates with a rough prediction of K{sub d} based on soil parameters. Although there are still gaps for many radionuclides, new data from recent studies improve the calculation of K{sub d} best estimates for a number of radionuclides, such as selenium, antimony, and iodine.

  8. Literature review of the studies on uptake, retention and distribution of radionuclides by the foetus

    International Nuclear Information System (INIS)

    Lamothe, E.S.

    1989-10-01

    This report summarizes the available literature from the last 10 years dealing with studies on uptake, retention and distribution of radionuclides by an embryo or foetus following maternal intakes. The review concentrates on isotopes commonly used by Canadian licensees. From the animal studies and from the limited human data, it is evident that after maternal contamination, the embryo or foetus accumulates and retains most radionuclides. Very little human data is available and a large fraction of the quoted values for human foetal dose retention are obtained from extrapolation from animal experiments. The information obtained in animal experiments is useful in determining general patterns of retention and distributions of radionuclides within the foetoplacental unit

  9. Investigation of the effects of tumor size and type of radionuclide on tumor curability in targeted radiotherapy

    Directory of Open Access Journals (Sweden)

    Hassan Ranjbar

    2015-07-01

    Full Text Available Background: Targeted radiotherapy is one of the important methods of radiotherapy that involves the use of beta-emitting radionuclides to deliver a dose of radiation to tumor cells. An important feature of this method is the tumor size and the finite range of beta particles emitted as a result of radionuclide disintegration those have significant effects for the curability of tumors. Material and Methods: Monte Carlo simulations and mathematical models have been used to investigate the relationship of curability to tumors size for tumors treated with targeted 131I and 90Y. The model assumed that radionuclides are distributed uniformly throughout tumors. Results: The results show that there is an optimal tumor size for cure. For any given cumulated activity, cure probability is greatest for tumors whose diameter is close to the optimum value. There is a maximum value of curability that occurs at a diameter of approximately 3.5 mm for 131I. For 90Y maximum curability occurs at a tumor diameter of approximately 3.5 cm. Tumors smaller than the optimal size are less vulnerable to irradiation from radionuclides because a significant proportion of the disintegration energy escapes and is deposited outside the tumor volume. Tumors larger than the optimal size are less curable because of greater clonogenic cell number. Conclusion: With single radionuclide targeted radiotherapy, there is an optimal tumor size for tumor cure. It is suggested that single agent targeted radiotherapy should not be used for treatment of disseminated disease when multiple tumors of differing size may be present. The use of several radionuclides concurrently would be more effective than reliance on single radionuclide. This approach of using combination of radionuclides with complementary properties could hopefully prepare new measures and improve the efficiency of tumor therapy.

  10. Introduction to CRRIS: a computerized radiological risk investigation system for assessing atmospheric releases of radionuclides

    International Nuclear Information System (INIS)

    Baes, C.F. III; Miller, C.W.; Kocher, D.C.; Sjoreen, A.L.; Murphy, B.D.

    1985-08-01

    The CRRIS is a Computerized Radiological Risk Investigation System consisting of eight fully integrated computer codes which calculate environmental transport of atmospheric releases of radionuclides and resulting doses and health risks to individuals or populations. Each code may also be used alone for various assessment applications. Radionuclides are handled by the CRRIS either in terms of the released radionuclides or the exposure radionuclides which consist of both the released nuclides and decay products that grow in during environmental transport. The CRRIS is not designed to simulate short-term effects. 51 refs

  11. A study on distribution of natural radionuclide polonium-210 in a pond ecosystem

    International Nuclear Information System (INIS)

    Shahul Hameed, P.; Shaheed, K.; Somasundaram, S.S.N.

    1997-01-01

    This paper presents the results of an investigation on the distribution of 210 Po in Mutharasanallur pond ecosystem. It has been demonstrated that 210 Po is non-uniformly distributed within the ecosystem. The results of the study show a dissolved 210 Po concentration in pond water of 1.4mBql -1 . The sediment sample recorded a 210 Po activity of 59.9 Bqkg -1 . The aquatic organism showed differential accumulation of the radionuclide with enhanced bioaccumulation in soft tissues and muscle. The 210 Po activity in the biota fell within the range of 1.2-53.3 Bqkg -1 (wet weight). The bivalve mussel, Lamellidens marginalis was identified to accumulate higher concentration of 210 Po in soft tissues, suggesting that these organisms could serve as a bio-monitor of 210 Po radionuclide in a freshwater system. The concentration factors of 210 Po for the biotic components ranged from ∼ 10 2 - ∼ 10 4 . Analyses of the results indicate that prawn and fish represent an important source of supply of 210 Po to humans via dietary intake. Results of 210 Po activity in the abiotic and biotic components of the pond ecosystem were higher when compared with those of Cauvery river system, the primary water source of the pond. (author)

  12. New best estimates for radionuclide solid-liquid distribution coefficients in soils. Part 2. Naturally occurring radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Vandenhove, H. [Belgian Nuclear Research Centre, Biosphere Impact Studies, Boeretang 200, 2400 Mol, Antwerp (Belgium)], E-mail: hvandenh@sckcen.be; Gil-Garcia, C.; Rigol, A.; Vidal, M. [University of Barcelona, Barcelona (Spain)

    2009-09-15

    Predicting the transfer of radionuclides in the environment for normal release, accidental, disposal or remediation scenarios in order to assess exposure requires the availability of an important number of generic parameter values. One of the key parameters in environmental assessment is the solid liquid distribution coefficient, K{sub d}, which is used to predict radionuclide-soil interaction and subsequent radionuclide transport in the soil column. This article presents a review of K{sub d} values for uranium, radium, lead, polonium and thorium based on an extensive literature survey, including recent publications. The K{sub d} estimates were presented per soil groups defined by their texture and organic matter content (Sand, Loam, Clay and Organic), although the texture class seemed not to significantly affect K{sub d}. Where relevant, other K{sub d} classification systems are proposed and correlations with soil parameters are highlighted. The K{sub d} values obtained in this compilation are compared with earlier review data.

  13. Radionuclide distributions in phytocenoses elements of the Chernobyl' NPP 30-km zone

    International Nuclear Information System (INIS)

    Fedotov, I.S.; Mishenkov, N.N.; Arkhipov, N.P.

    1989-01-01

    In order to estimate the radioecological situation in phytocenoses of the 30-km zone consisting in the main of conifer and conifer-foliage forests, the studies, which give, an opportunity to divide the pine forests into five zones according to degrees of radiation injury character revealing, are made. These zones are characterized by total death, strong injury, intermediate injury, weak injury and stimulation. Radionuclides redistribution in the system including wood fier, forest litter and soil, their accumulation in organs and elements if each cenosis component are studied. The characteristics of experimental sections are given. The data on radionuclide distributions in soil profile of forest tracts, radionuclide concentrations in pine organs, radionuclide contents in mushrooms (conifers), contamination distribution (%) in pines under different levels of soil contamination are given. 6 tabs

  14. Macroscopic and spectroscopic investigations on the immobilization of radionuclides by hardened cement paste

    International Nuclear Information System (INIS)

    Wieland, E.; Bonhoure, I.; Tits, J.; Scheidegger, A.M.; Bradbury, M.H.

    2002-01-01

    The uptake of safety-relevant radionuclides was studied using a combination of macroscopic (wet chemistry) and spectroscopic (X-ray absorption fine structure (XAFS) spectroscopy) techniques with the aim of gaining a mechanistic understanding of the uptake processes on hardened cement paste (HCP) and deducing robust sets of sorption values. HCP contains impurities of metal cations in the ppb to ppm concentration range. As a consequence, the inventories of stable isotopes are expected to be significant in a cementitious near-field and may even exceed the radionuclide inventories of the waste matrix for many safety-relevant radioelements. In view of the significant inventories of stable isotopes, it is suggested that isotopic exchange - replacement of stable isotopes by their radioactive counterparts in the cement matrix - is an important immobilisation process in HCP. However, it is not a priori known what proportion of each elemental inventory is available for isotopic exchange. Wet chemistry studies with Cs and Sr show that the total inventory of these elements is reversibly bound and that their partitioning between HCP and pore water can be modelled using the distribution values deduced from studies of the corresponding tracers ( 137 Cs and 85 Sr). This finding corroborates the relevance of isotopic exchange in cementitious systems. Wet chemistry investigations need to be complemented by spectroscopic techniques, e.g., XAFS, in order to gain a mechanistic understanding of the chemical processes by which waste ions become immobilised in cement-based matrices. XAFS can be used to obtain information at the atomic/molecular level, i.e., the type, number and distance of neighbouring atoms. XAFS studies on cementitious systems are still rather rare, and therefore information on the potential and limitations of this technique is sparse. Mechanistic aspects of the immobilisation processes are discussed for some safety-relevant radionuclides (e.g. Ni and Sr) using the

  15. Radionuclide Migration through Sediment and Concrete: 16 Years of Investigations

    Energy Technology Data Exchange (ETDEWEB)

    Golovich, Elizabeth C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mattigod, Shas V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Snyder, Michelle MV [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Powers, Laura [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Whyatt, Greg A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wellman, Dawn M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-11-01

    The Waste Management Project provides safe, compliant, and cost-effective waste management services for the Hanford Site and the U.S. Department of Energy (DOE) complex. Part of these services includes safe disposal of low-level waste and mixed low-level waste at the Hanford Low-Level Waste Burial Grounds in accordance with the requirements of DOE Order 435.1, Radioactive Waste Management. To partially satisfy these requirements, performance assessment analyses were completed and approved. DOE Order 435.1 also requires continuing data collection to increase confidence in the critical assumptions used in these analyses to characterize the operational features of the disposal facility that are relied on to satisfy the performance objectives identified in the order. Cement-based solidification and stabilization is considered for hazardous waste disposal because it is easily done and cost-efficient. One critical assumption is that concrete will be used as a waste form or container material at the Hanford Site to control and minimize the release of radionuclide constituents in waste into the surrounding environment. Concrete encasement would contain and isolate the waste packages from the hydrologic environment and act as an intrusion barrier. Any failure of concrete encasement may result in water intrusion and consequent mobilization of radionuclides from the waste packages. The radionuclides iodine-129, selenium-75, technetium-99, and uranium-238 have been identified as long-term dose contributors (Mann et al. 2001; Wood et al. 1995). Because of their anionic nature in aqueous solutions, these constituents of potential concern may be released from the encased concrete by mass flow and/or diffusion and migrate into the surrounding subsurface environment (Serne et al. 1989; 1992; 1993a, b; 1995). Therefore, it is necessary to assess the performance of the concrete encasement structure and the ability of the surrounding soil to retard radionuclide migration. Each of the

  16. Radionuclide distributions and sorption behavior in the Susquehanna--Chesapeake Bay System

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, C.R.; Larsen, I.L.; Lowry, P.D.; McLean, R.I.; Domotor, S.L.

    1989-01-01

    Radionuclides released into the Susquehanna--Chesapeake System from the Three Mile Island, Peach Bottom, and Calvert Cliffs nuclear power plants are partitioned among dissolved, particulate, and biological phases and may thus exist in a number of physical and chemical forms. In this project, we have measured the dissolved and particulate distributions of fallout /sup 137/Cs; reactor-released /sup 137/Cs, /sup 134/Cs, /sup 65/Zn, /sup 60/Co, and /sup 58/Co; and naturally occurring /sup 7/Be and /sup 210/Pb in the lower Susquehanna River and Upper Chesapeake Bay. In addition, we chemically leached suspended particles and bottom sediments in the laboratory to determine radionuclide partitioning among different particulate-sorbing phases to complement the site-specific field data. This information has been used to document the important geochemical processes that affect the transport, sorption, distribution, and fate of reactor-released radionuclides (and by analogy, other trace contaminants) in this river-estuarine system. Knowledge of the mechanisms, kinetic factors, and processes that affect radionuclide distributions is crucial for predicting their biological availability, toxicity, chemical behavior, physical transport, and accumulation in aquatic systems. The results from this project provide the information necessary for developing accurate radionuclide-transport and biological-uptake models. 76 refs., 12 figs.

  17. Radionuclides distribution in internal organs of wild animals in alienation zone of Chernobyl NPP

    International Nuclear Information System (INIS)

    Gorbatova, T.A.; Kudryashov, V.P.; Mironov, V.P.

    2002-01-01

    Activities of caesium 137, strontium 90, plutonium isotopes and americium 241 are experimentally defined in the internal organs of bearer and wolf alienation zone of Chernobyl NPP. Radionuclides distribution in the internal organs of wild animals is defined by destruction of nuclear fuel particles

  18. Anthropogenic radionuclides in the Arctic Ocean. Distribution and pathways

    International Nuclear Information System (INIS)

    Josefsson, Dan

    1998-05-01

    Anthropogenic radionuclide concentrations have been determined in seawater and sediment samples collected in 1991, 1994 and 1996 in the Eurasian Arctic shelf and interior. Global fallout, releases from European reprocessing plants and the Chernobyl accident are identified as the three main sources. From measurements in the Eurasian shelf seas it is concluded that the total input of 134 Cs, 137 Cs and 90 Sr from these sources has been decreasing during the 1990's, while 129 I has increased. The main fraction of the reprocessing and Chernobyl activity found in Arctic Ocean surface layer is transported from the Barents Sea east along the Eurasian Arctic shelf seas to the Laptev Sea before entering the Nansen Basin. This inflow results in highest 137 Cs, 129 I and 90 Sr concentrations in the Arctic Ocean surface layers, and continuously decreasing concentrations with depth. Chernobyl-derived 137 Cs appeared in the central parts of the Arctic Ocean around 1991, and in the mid 1990's the fraction to total 137 Cs was approximately 30% in the entire Eurasian Arctic region. The transfer times for releases from Sellafield are estimated to be 5-7 years to the SE Barents Sea, 7-9 years to the Kara Sea, 10-11 years to the Laptev Sea and 12-14 years to the central Arctic Ocean. Global fallout is the primary source of plutonium with highest concentrations found in the Atlantic layer of the Arctic Ocean. When transported over the shallow shelf seas, particle reactive transuranic elements experience an intense scavenging. A rough estimate shows that approximately 75% of the plutonium entering the Kara and Laptev Seas are removed to the sediment. High seasonal riverine input of 239 , 240 Pu is observed near the mouths of the large Russian rivers. Sediment inventories show much higher concentrations on the shelf compared to the deep Arctic Ocean. This is primarily due to the low particle flux in the open ocean

  19. Study of near-ground radionuclide concentration distribution in the Ignalina NPP district

    International Nuclear Information System (INIS)

    Yasyulenis, R.Yu.; Krenyavichus, R.I.; Serapinas, A.A.; Morkelyunas, Yu.-L.Yu.; Miloshene, L.V.

    1984-01-01

    In the course of nuclear weapon testing a great amount of fission products has been released into the atmosphere, thus the long-living radionuclides are still present there contributing to the radiation conditions near the NPP. Often the concentrations of radionuclides released during the reactor operation are comparable with the global background levels. The latter were studied in Ignalina NPP district since 1978. Sampling was done via air pumping through filters at 2000 m 3 /h rate. The sample gamma activity after filter incineration was determined with the use of spectrometer with Ge(Li) semiconductor detector. Time dependence of berillium-7 and caesium-137 concentrations over period of three years has been obtained. The evaluations of radionuclide concentration distributions connected with the NPP releases show substantial difference from the background concentrations [ru

  20. Anthropogenic radionuclides in the Arctic Ocean. Distribution and pathways

    Energy Technology Data Exchange (ETDEWEB)

    Josefsson, Dan

    1998-05-01

    Anthropogenic radionuclide concentrations have been determined in seawater and sediment samples collected in 1991, 1994 and 1996 in the Eurasian Arctic shelf and interior. Global fallout, releases from European reprocessing plants and the Chernobyl accident are identified as the three main sources. From measurements in the Eurasian shelf seas it is concluded that the total input of {sup 134}Cs, {sup 137}Cs and {sup 90}Sr from these sources has been decreasing during the 1990`s, while {sup 129}I has increased. The main fraction of the reprocessing and Chernobyl activity found in Arctic Ocean surface layer is transported from the Barents Sea east along the Eurasian Arctic shelf seas to the Laptev Sea before entering the Nansen Basin. This inflow results in highest {sup 137}Cs, {sup 129}I and {sup 90}Sr concentrations in the Arctic Ocean surface layers, and continuously decreasing concentrations with depth. Chernobyl-derived {sup 137}Cs appeared in the central parts of the Arctic Ocean around 1991, and in the mid 1990`s the fraction to total {sup 137}Cs was approximately 30% in the entire Eurasian Arctic region. The transfer times for releases from Sellafield are estimated to be 5-7 years to the SE Barents Sea, 7-9 years to the Kara Sea, 10-11 years to the Laptev Sea and 12-14 years to the central Arctic Ocean. Global fallout is the primary source of plutonium with highest concentrations found in the Atlantic layer of the Arctic Ocean. When transported over the shallow shelf seas, particle reactive transuranic elements experience an intense scavenging. A rough estimate shows that approximately 75% of the plutonium entering the Kara and Laptev Seas are removed to the sediment. High seasonal riverine input of {sup 239}, {sup 240}Pu is observed near the mouths of the large Russian rivers. Sediment inventories show much higher concentrations on the shelf compared to the deep Arctic Ocean. This is primarily due to the low particle flux in the open ocean

  1. A study on the radiation and environmental safety -Studies on radionuclide migration and distribution in terrestrial ecosystem-

    International Nuclear Information System (INIS)

    Lee, Jung Hoh; Lee, Hyun Duk; Kim, Sam Lang; Lee, Chang Woo; Choi, Yong Hoh; Kim, Sang Bok; Lee, Myung Hoh; Hong, Kwang Heui; Lee, Won Yoon; Park, Doo Won; Choi, Sang Doh

    1995-07-01

    In order to investigate the migrational behaviors of radionuclides deposited onto the farm-land during crop cultures, potato and red pepper were cultured on lysimeters installed in a greenhouse and the solution of mixed radionuclides such as Mn-54, Co-60, Sr-85 and Cs-137 was distributed over the land surface on different growth stages of the crops. For rice, soybean, Chinese cabbage and radish, the second or third year's radio-tracer experiments were carried out. Experimental results on Sr-85 and Cs-137 transfer factors for Chinese cabbage and radish were compared with their root-uptake concentrations calculated using existing methods. Samples of farm-land soils and crop plants were collected in the middle part of Korea and concentrations of several γ-emitters were measured. Soil-to-plant transfer factors of Cs-137 measured in outdoor fields were compared with those from greenhouse experiments. 20 figs, 35 tabs, 58 refs. (Author)

  2. RADIONUCLIDE INVENTORY AND DISTRIBUTION: FOURMILE BRANCH, PEN BRANCH, AND STEEL CREEK IOUS

    Energy Technology Data Exchange (ETDEWEB)

    Hiergesell, R.; Phifer, M.

    2014-04-29

    As a condition to the Department of Energy (DOE) Low Level Waste Disposal Federal Facility Review Group (LFRG) review team approving the Savannah River Site (SRS) Composite Analysis (CA), SRS agreed to follow up on a secondary issue, which consisted of the consolidation of several observations that the team concluded, when evaluated collectively, could potentially impact the integration of the CA results. This report addresses secondary issue observations 4 and 21, which identify the need to improve the CA sensitivity and uncertainty analysis specifically by improving the CA inventory and the estimate of its uncertainty. The purpose of the work described herein was to be responsive to these secondary issue observations by re-examining the radionuclide inventories of the Integrator Operable Units (IOUs), as documented in ERD 2001 and Hiergesell, et. al. 2008. The LFRG concern has been partially addressed already for the Lower Three Runs (LTR) IOU (Hiergesell and Phifer, 2012). The work described in this investigation is a continuation of the effort to address the LFRG concerns by re-examining the radionuclide inventories associated with Fourmile Branch (FMB) IOU, Pen Branch (PB) IOU and Steel Creek (SC) IOU. The overall approach to computing radionuclide inventories for each of the IOUs involved the following components: • Defining contaminated reaches of sediments along the IOU waterways • Identifying separate segments within each IOU waterway to evaluate individually • Computing the volume and mass of contaminated soil associated with each segment, or “compartment” • Obtaining the available and appropriate Sediment and Sediment/Soil analytical results associated with each IOU • Standardizing all radionuclide activity by decay-correcting all sample analytical results from sample date to the current point in time, • Computing representative concentrations for all radionuclides associated with each compartment in each of the IOUs • Computing the

  3. Distribution and behavior of radionuclides and stable elements in Lake Obuchi

    International Nuclear Information System (INIS)

    Ueda, Shinji; Hasegawa, Hidenao; Hisamatsu, Shun'ichi; Inaba, Jiro

    2000-01-01

    Distribution and behavior of radionuclides and related stable elements in the lake water of brackish Lake Obuchi were investigated by field observations. Concentrations of 238 U and stable elements were measured at various points in the lake, and compiled to obtain the elemental distributions and variation characteristics. The concentrations of 238 U in the lake water were higher in areas nearer to the Pacific Ocean, and correlated well with those of Na, K, Ca, Mg and Sr (r = 0.86 to 0.92). These observations implied that 238 U in the lake originated from seawater. The bottom layer water was reductive during July and September (stratified period) in deep areas (> 3 m). In this condition, concentrations of PO 4 3- -P, NH 4 + -N, Fe and Mn in the water increased. Concentration ratios of 238 U to those of Na strongly suggested the following conclusions. The concentrations of 238 U in the turn-over period were represented by a simple mixture of seawater and fresh water. However, in the stratified period, part of the 238 U was lost from the seawater near the bottom of the lake due to the reductive condition. (author)

  4. Direct intratumoral infusion of liposome encapsulated rhenium radionuclides for cancer therapy: Effects of nonuniform intratumoral dose distribution

    International Nuclear Information System (INIS)

    Hrycushko, Brian A.; Li Shihong; Goins, Beth; Otto, Randal A.; Bao, Ande

    2011-01-01

    Purpose: Focused radiation therapy by direct intratumoral infusion of lipid nanoparticle (liposome)-carried beta-emitting radionuclides has shown promising results in animal model studies; however, little is known about the impact the intratumoral liposomal radionuclide distribution may have on tumor control. The primary objective of this work was to investigate the effects the intratumoral absorbed dose distributions from this cancer therapy modality have on tumor control and treatment planning by combining dosimetric and radiobiological modeling with in vivo imaging data. Methods: 99m Tc-encapsulated liposomes were intratumorally infused with a single injection location to human head and neck squamous cell carcinoma xenografts in nude rats. High resolution in vivo planar imaging was performed at various time points for quantifying intratumoral retention following infusion. The intratumoral liposomal radioactivity distribution was obtained from 1 mm resolution pinhole collimator SPECT imaging coregistered with CT imaging of excised tumors at 20 h postinfusion. Coregistered images were used for intratumoral dosimetric and radiobiological modeling at a voxel level following extrapolation to the therapeutic analogs, 186 Re/ 188 Re liposomes. Effective uniform dose (EUD) and tumor control probability (TCP) were used to assess therapy effectiveness and possible methods of improving upon tumor control with this radiation therapy modality. Results: Dosimetric analysis showed that average tumor absorbed doses of 8.6 Gy/MBq (318.2 Gy/mCi) and 5.7 Gy/MBq (209.1 Gy/mCi) could be delivered with this protocol of radiation delivery for 186 Re/ 188 Re liposomes, respectively, and 37-92 MBq (1-2.5 mCi)/g tumor administered activity; however, large intratumoral absorbed dose heterogeneity, as seen in dose-volume histograms, resulted in insignificant values of EUD and TCP for achieving tumor control. It is indicated that the use of liposomes encapsulating radionuclides with higher

  5. Distributions of radionuclides among green alga (Ulva pertusa), sea water and marine sediment

    International Nuclear Information System (INIS)

    Nakamura, Ryoichi; Suzuki, Yuzuru; Ueda, Taishi

    1976-01-01

    Distributions of radionuclides ( 60 Co, 137 Cs, 95 Zr- 95 Nb and 106 Ru- 106 Rh) among green alga (Ulva pertusa), sea water and marine sediment were examined by radioisotope tracer experiment in order to estimate the influence of sediment on the accumulation of radionuclides by the alga. By the application of the compartment model to the experimental results, exponential formulas of distributions were obtained. Through comparison of the transfer coefficients of radionuclides calculated from the exponential formulas, the influence of the sediment on the accumulation of the radionuclides by the green alga was determined to be the largest for 60 Co, followed by 95 Zr,- 95 Nb, 106 Ru- 106 Rh and 137 Cs in this order. The activity ratios of 95 Zr- 95 Nb and 106 Ru- 106 Rh calculated from the transfer coefficients are larger for the alga than for the sediment, inversely those of 60 Co and 137 Cs show higher values for the sediment than for the alga. Especially, in the case of 60 Co, the activity ratio for the sediment is approximately 20 times greater than that for the alga. Biological half lives in green alga estimated from the transfer coefficients were 10 days for 60 Co, 7 days for 137 Cs, 26 days for 95 Zr- 95 Nb and 24 days for 95 Zr- 95 Nb and 24 days for 106 Ru- 106 Rh. (auth.)

  6. Radionuclide Distribution in the Soil on the Stabatishkes Site in the Vicinity of the Ignalina NPP

    Directory of Open Access Journals (Sweden)

    Jevgenij Aliončik

    2011-02-01

    Full Text Available A near surface repository for low and intermediate-level short-lived radioactive waste will be built on the Stabatiškės site in the vicinity of Ignalina NPP during decommissioning works. The reservoir can also be used for the waste stored in the temporary repositories of the Ignalina NPP. Engineering and nature protective barriers are used in the repository for radioactive waste, however, radionuclides can spread into the environment, extend in the biosphere and cause (define the external power light exposure of the environment due to the natural and premature (prescheduled degradation of the engineering barriers of the repository. The properties of the soil (acidity, quantity of organic substances, humidity are being investigated for estimating the possible migration and dispersion of radionuclides. The activity of radionuclides in the soil is also estimated before building the repository. Natural and artificial radionuclides make the pollution of the soil, and therefore the accumulation and vertical migration of artificial (137Cs, 60Co and natural (226Ra, 232Th, 40K radionuclides are being researched in the soil on the Stabatiškės site.Article in Lithuanian

  7. Environmental distribution of long-lived radionuclides 90Sr and 137Cs

    International Nuclear Information System (INIS)

    Csupka, S.

    1977-01-01

    Between 1963 and 1974 the content was investigated of 90 Sr and 137 Cs in various parts of human environment. From food chains milk and dairy products, flour and flour products were chosen being the main sources of radioactivity produced by the above mentioned radionuclides to which the human population is exposed. In 1972 90 Sr and 137 Cs in the daily intake of food were responsible for 60 to 70% of total radioactivity in milk and flour products. On a world scale radioactive fallout continues to be the primary source of radioactive contamination with the soil in which radionuclides are accumulated being the secondary source. (author)

  8. Investigations of the Fundamental Surface Reactions Involved in the Sorption and Desorption of Radionuclides

    International Nuclear Information System (INIS)

    Czerwinski, Ken; Heske, Clemens; Moser, Duane; Misra, Mnoranjan; McMillion, Glen

    2011-01-01

    Models for describing solution- and surface-phase reactions have been used for 30 years, but only recently applicable to complex surfaces. Duff et al., using micro-XANES, found that Pu was concentrated on Mn-oxide and smectite phases of zeolitic tuff, providing an evaluation of contaminant speciation on surfaces for modeling. Experiments at Los Alamos demonstrated that actinides display varying surface residence time distributions, probably reflective of mineral surface heterogeneity. We propose to investigate the sorption/desorption behavior of radionuclides from mineral surfaces, as effected by microorganisms, employing isolates from Nevada Test Site deep alluvium as a model system. Characterizations will include surface area, particle size distribution, x-ray diffraction (XRD), microprobe analysis, extractions, and microbiology. Surface interactions will be assessed by electron spectroscopy (XPS), x-ray absorption fine structure spectroscopy (XAFS), X-ray emission spectroscopy, transmission electron microscopy (TEM) and Scanning electron microscopy (SEM). Desert Research Institute (DRI), University of Nevada, Reno (UNR), and University of Nevada, Las Vegas (UNLV) researchers will collaborate to enhance scientific infrastructure and the understanding of contaminant behavior on surfaces, with broader implications for the management of DOE sites.

  9. Investigations of the Fundamental Surface Reactions Involved in the Sorption and Desorption of Radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Czerwinski, Ken; Heske, Clemens; Moser, Duane; Misra, Mnoranjan; McMillion, Glen

    2011-04-20

    Models for describing solution- and surface-phase reactions have been used for 30 years, but only recently applicable to complex surfaces. Duff et al., using micro-XANES, found that Pu was concentrated on Mn-oxide and smectite phases of zeolitic tuff, providing an evaluation of contaminant speciation on surfaces for modeling. Experiments at Los Alamos demonstrated that actinides display varying surface residence time distributions, probably reflective of mineral surface heterogeneity. We propose to investigate the sorption/desorption behavior of radionuclides from mineral surfaces, as effected by microorganisms, employing isolates from Nevada Test Site deep alluvium as a model system. Characterizations will include surface area, particle size distribution, x-ray diffraction (XRD), microprobe analysis, extractions, and microbiology. Surface interactions will be assessed by electron spectroscopy (XPS), x-ray absorption fine structure spectroscopy (XAFS), X-ray emission spectroscopy, transmission electron microscopy (TEM) and Scanning electron microscopy (SEM). Desert Research Institute (DRI), University of Nevada, Reno (UNR), and University of Nevada, Las Vegas (UNLV) researchers will collaborate to enhance scientific infrastructure and the understanding of contaminant behavior on surfaces, with broader implications for the management of DOE sites.

  10. An investigation of electrostatically deposited radionuclides on latex balloons

    International Nuclear Information System (INIS)

    Price, T.; Caly, A.

    2012-01-01

    Use of Canadian Nuclear Society (CNS) education material for a community science education event to promote science awareness, science culture and literacy (Science Rendezvous 2011) lead to investigation of observed phenomena. Experiments are done on balloons that are electrostatically charged then left to collect particulate. Alpha spectroscopy was performed to identify alpha emitting radioisotopes present on the balloons. The time dependent behaviour of the activity was investigated. Additionally, the Alpha activity of the balloon was compared to Beta activity. The grounds for further investigations are proposed. (author)

  11. Experimental studies on the dynamics of radionuclide transport in soils and plants: an investigation of the effects of soil type and chemical form

    International Nuclear Information System (INIS)

    Coughtrey, P.J.; Jones, C.; Jackson, D.; Thorne, M.C.

    1984-10-01

    The dynamics and distribution of radioisotopes of Ce, Ru, I, Sr and Cs have been studied in soils and grass in greenhouse conditions. Two soil types, representative of localities close to existing nuclear installations, have been investigated in combination with two chemical forms of Ce, Ru, Sr and Cs. The effect of administration of iodine at two different periods of growth has been investigated using I-125 and I-131. The time-dependent behaviour of the radionuclides has also been investigated by means of four harvests at various times after administration of the radionuclides. Parameter values for sorption of radionuclides to soil inorganic and organic fractions were determined by means of serial chemical extraction of soils at each harvest, and for transport from soil to root and from root to shoot by means of assay of derived plant material. In addition, the vertical distribution of radionuclides in the soil profile was determined by means of external scanning of undisturbed pots. The data from these scans have been used to calculate transfer coefficients for loss of radionuclides from surface soil for comparison with soil solution and mass transport parameters used in the model. The results are discussed. (author)

  12. Spatial distribution of radionuclides in Lake Michigan biota near the Big Rock Point Nuclear Plant

    International Nuclear Information System (INIS)

    Wahlgren, M.A.; Yaguchi, E.M.; Nelson, D.M.; Marshall, J.S.

    1974-01-01

    A survey was made of four groups of biota in the vicinity of the Big Rock Point Nuclear Plant near Charlevoix, Michigan, to determine their usefulness in locating possible sources of plutonium and other radionuclides to Lake Michigan. This 70 MW boiling-water reactor, located on the Lake Michigan shoreline, was chosen because its fuel contains recycled plutonium, and because it routinely discharges very low-level radioactive wastes into the lake. Samples of crayfish (Orconectes sp.), green algae (Chara sp. and Cladophora sp.), and an aquatic macrophyte (Potamogeton sp.) were collected in August 1973, at varying distances from the discharge and analyzed for 239 240 Pu, 90 Sr, and five gamma-emitting radionuclides. Comparison samples of reactor waste solution have also been analyzed for these radionuclides. Comparisons of the spatial distributions of the extremely low radionuclide concentrations in biota clearly indicated that 137 Cs, 134 Cs, 65 Zn, and 60 Co were released from the reactor; their concentrations decreased exponentially with increasing distance from the discharge. Conversely, concentrations of 239 240 Pu, 95 Zr, and 90 Sr showed no correlation with distance, suggesting any input from Big Rock was insignificant with respect to the atmospheric origin of these isotopes. The significance of these results is discussed, particularly with respect to current public debate over the possibility of local environmental hazards associated with the use of plutonium as a nuclear fuel. (U.S.)

  13. Distribution of radionuclides in urban areas and their removal

    International Nuclear Information System (INIS)

    Roed, J.; Andersson, K.G.; Garger, E.; Sobotovitch, E.; Matveenko, I.I.

    1996-01-01

    The major contamination processes in the urban environment are wet and dry deposition with the former leading to much greater deposition per unit of time. Typical deposition patterns for radiocesium in urban areas have been identified for these processes and recent in situ measurements have been used to verify these relations and to investigate the urban weathering effect over long periods. The results of a recent series of field trials of decontamination methods in urban or suburban Russian areas are reported, and this experience has been incorporated in an example of formation of strategies for clean-up in an urban contamination scenario

  14. Non-destructive investigation of technical plants and processes and natural processes by short-lived radionuclides (radiotracer)

    International Nuclear Information System (INIS)

    Jentsch, Thorsten; Zeuner, Albert

    2009-01-01

    Short lived open radionuclides are very suitable to investigate transport and mixing processes. They do not pollute the product. After decay of the radionuclide, the product can be used without any restrictions. Examples are showed for technical processes investigation by aid of radiotracer. (orig.)

  15. Upscaling the Use of Fallout Radionuclides in Soil Erosion and Sediment Budget Investigations: Addressing the Challenge

    Directory of Open Access Journals (Sweden)

    D.E. Walling

    2014-09-01

    Full Text Available The application of fallout radionuclides in soil erosion investigations and related sediment budget studies has provided a widely used tool for improving understanding of soil erosion and sediment transfer processes. However, most studies using fallout radionuclides undertaken to date have focussed on small areas. This focus on small areas reflects both the issues addressed and practical constraints associated with sample collection and analysis. Increasing acceptance of the important role of fine sediment in degrading aquatic habitats and in the transfer and fate of nutrients and contaminants within terrestrial and fluvial systems has emphasised the need to consider larger areas and the catchment or regional scale. The need to upscale existing approaches to the use of fallout radionuclides to larger areas represents an important challenge. This contribution provides a brief review of existing and potential approaches to upscaling the use of fallout radionuclides and presents two examples where such approaches have been successfully applied. These involve a national scale assessment of soil erosion rates in England and Wales based on 137Cs measurements and an investigation of the sediment budgets of three small/intermediate-size catchments in southern Italy.

  16. Investigations on the effect of grazing intensity on the transfer of radionuclides to cow's milk

    International Nuclear Information System (INIS)

    Voigt, G.; Schotola, C.; Crout, N.M.J.; Absalom, J.

    1997-03-01

    For these investigations two farms were chosen. Farm A carries out a rotational grazing regime with 4 grazed pastures which is the more commonly used farm practice in Bavaria, farm B practises a continuous grazing regime with one grazed pasture only. In farm B a tenfold lower Cs-137 activity concentration was observed in milk though activity concentrations in soil and pasture grass were the same as that at farm A, indicating the same transfer rate soil-plant at both locations. It could be shown under normal agricultural conditions that with a higher grazing pressure lower activity concentrations in milk (in this case a factor of about 2 to 3) were obtained. Therefore changing stock density in combination with a continuous grazing regime on a given pasture after a major nuclear accident can be considered as a possible countermeasure which can be easily applied. Mainly to get more synchronised growth rates and a homogeneous distribution of radiocontamination plot experiments were performed to simulate the influence of grazing intensity. Under the experimental design used here no effect of grazing intensity on the transfer of radionuclides to vegetation could be found. Effects of grazing intensity as found for the farm experiment, therefore must be due to other sources than vegetation activities, and are presumably due to soil ingestion preventing uptake of soluble plant incorporated radiocaesium in the animal rumen. (orig./MG)

  17. Investigations of the emission of radionuclides from coal fired power plants

    International Nuclear Information System (INIS)

    Chatterjee, B.; Hoetzl, H.; Rosner, G.; Winkler, R.

    1980-02-01

    Samples of coal, brown coal, bottom ash, collected fly ash and 4 sieve fractions of collected fly ash from various electrostatic filter stages as well as samples of escaping fly ash, all taken simultaneously on 3 operating-days, have been investigated. In samples from coal through fly ash sieve fractions U-238, Th-232, Ra-226, Pb-210 and K-40 have been determined by γ-spectrometry, Po-210 by chemical separation with subsequent α-spectrometry. In escaping fly ash samples, which are available in small amounts only (ca. 1 g or less), after chemical separation U-238, U-234, Th-232, Th-230, Th-228 and Po-210 were determined by α-spectrometry and Pb-210 by low-level β-counting. Furthermore, Po-210 has been determined by direct α-spectrometry in several particle size fractions collected with a cascade impactor from the exhaust stream. The analytical procedures, which partially had to be developed for the purposes of the present study, are presented shortly. Specific activities of escaping fly ash are in good agreement with specific activities of the fly ash collected from the last electrostatic precipitator stage, provided that, for the latter, the particle size distribution in escaping fly ash is taken into account. Using these specific activities annual air-borne radionuclide emissions are calculated. The resulting activity concentrations in ground level air are compared to values of natural radioactivity. (orig./HP) [de

  18. Radionuclide adsorption distribution coefficients measured in Hanford sediments for the low level waste performance assessment project

    International Nuclear Information System (INIS)

    Kaplan, D.I.; Serne, R.J.; Owen, A.T.

    1996-08-01

    Preliminary modeling efforts for the Hanford Site's Low Level Waste-Performance Assessment (LLW PA) identified 129 I, 237 Np, 79 Se, 99 Tc, and 234 , 235 , 238 U as posing the greatest potential health hazard. It was also determined that the outcome of these simulations was very sensitive to the parameter describing the extent to which radionuclides sorb to the subsurface matrix, i.e., the distribution coefficient (K d ). The distribution coefficient is a ratio of the radionuclide concentration associated with the solid phase to that in the liquid phase. The objectives of this study were to (1) measure iodine, neptunium, technetium, and uranium K d values using laboratory conditions similar to those expected at the LLW PA disposal site, and (2) evaluate the effect of selected environmental parameters, such as pH, ionic strength, moisture concentration, and radio nuclide concentration, on K d values of selected radionuclides. It is the intent of these studies to develop technically defensible K d values for the PA. The approach taken throughout these studies was to measure the key radio nuclide K d values as a function of several environmental parameters likely to affect their values. Such an approach provides technical defensibility by identifying the mechanisms responsible for trends in K d values. Additionally, such studies provide valuable guidance regarding the range of K d values likely to be encountered in the proposed disposal site

  19. Radionuclide cisternography

    International Nuclear Information System (INIS)

    Staab, E.V.

    1984-01-01

    Cerebrospinal fluid (CSF) scanning, or cisternography, is a diagnostic technique that entails injection of an appropriate radiopharmaceutical into the subarachnoid space and sequential imaging of the spinal and cranial distribution. Radionuclide imaging techniques were originally named according to the spaces of greatest interest and the methods of administration (i.e., myeloscintigraphy, cisternography, and ventriculography). An all-inclusive term, CSF imaging, is now used. The initial studies were made in animals to investigate the physiology of the CSF. DiChiro et al. pioneered the subsequent clinical use in humans to investigate a variety of disorders, including hydrocephalus, leaks, shunt patency, and miscellaneous intracranial cysts

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

    Directory of Open Access Journals (Sweden)

    Muslim

    2015-04-01

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

  1. Lognormal distribution of natural radionuclides in freshwater ecosystems and coal-ash repositories

    International Nuclear Information System (INIS)

    Drndarski, N.; Lavi, N.

    1997-01-01

    This study summarizes and analyses data for natural radionuclides, 40 K, 226 Ra and 'Th, measured by gamma spectrometry in water samples, sediments and coal-ash samples collected from regional freshwater ecosystems and near-by coal-ash repositories during the last decade, 1986-1996, respectively. The frequency plots of natural radionuclide data, for which the hypothesis of the regional scale log normality was accepted, exhibited single population groups with exception of 226 Ra and 232 Th data for waters. Thus the presence of break points in the frequency distribution plots indicated that 226 Ra and 232 Th data for waters do not come from a single statistical population. Thereafter the hypothesis of log normality was accepted for the separate population groups of 226 Ra and '-32 Th in waters. (authors)

  2. Effect of industrial pollution on the distribution dynamics of radionuclides in boreal understorey ecosystems (EPORA). Final report

    International Nuclear Information System (INIS)

    Suomela, M.; Rahola, T.; Bergman, R.; Bunzl, K.; Jaakkola, T.

    1999-08-01

    The project EPORA 'Effects of Industrial Pollution on Distribution Dynamics of Radionuclides in Boreal Understorey Ecosystems' is a part of the Nuclear Fission Safety Research programme of the European Union. A suitable environment for the study was found in the surroundings of the Cu-Ni smelter in Monchegorsk, in NW Russia where the huge atmospheric emissions from the smelter have polluted the environment since the 1930's. Samples of soil, litter, plants and runoff water were taken. Total concentrations of the main pollutants, Ni and Cu, in the organic soil increased from about 10 mg kg -1 at the reference site in Finland to about 5000 mg kg -1 at the most polluted site in Russia. Similar trends were observed for exchangeable fractions and plant concentrations of the same elements. Concentrations of exchangeable K, Ca, and Mg in the organic soil decreased strongly with increased input of chemical pollutants. The radionuclides studied were 137 Cs, 90 Sr and 239+240 Pu, mainly originating from the atmospheric nuclear weapons tests. The contribution of the Chernobyl derived 137 Cs deposition was about 10% but insignificant for the other nuclides. The activity distribution of all three radionuclides in the soil, their corresponding residence half-times as well as their aggregated trencher factors for various plants depended on the degree of pollution: Activity distribution: in the litter layer, the activity of all three radionuclides increased continually from the reference site to the most polluted site. This effect was most pronounced for 239+240 Pu and least for 90 Sr and could, at least partly, be explained by the increase of the thickness of this layer. In the root zone, the opposite effect was observed: the largest fraction of all radionuclides was found at the reference site. In the organic layer, the exchangeable fractions of 137 Cs, 90 Sr and 239+240 Pu decreased with increasing pollution. Residence half-times: in the root zone, the residence half-times of 90

  3. Ways of investigating radionuclide migration processes in the lithosphere and hydrosphere

    International Nuclear Information System (INIS)

    Belousova, A.P.; Shmakov, A.I.; Galaktionova, O.V.

    1994-01-01

    In Russia, until recently, it was considered that groundwater was protected from surface radioactive contamination by soil and rocks in the zone aeration. Groundwater was not a subject of radiation control. The accident at the Chernobyl Nuclear Power Plant showed, however, that groundwater is vulnerable to radioactive contamination. In this connection, the vulnerability of groundwater to and the problems of protecting groundwater from radioactive contamination became urgent. The assessment of natural protection of groundwater from radioactive contamination is now considered a top priority. The zone of aeration is generally considered to be the zone separating groundwater from surface contamination. In respect to radioactive contamination, soils that may fix a large quantity of radionuclides serve as a protection zone of a higher order. The mapping of protectibility was done for each radionuclide taking into consideration the specific structure of the flow medium and migration properties of a radionuclide. 90 Sr and 137 Cs have different mechanisms of transport; convective transport is characteristic of the former and diffusive transfer of the latter. This is conditioned by different physico-chemical properties of the radionuclides and principally by their sorption capacities. The coefficient of distribution of 90 Sr is in many times less than the coefficient of distribution of 137 Cs. The environmental protection problem in regions with nuclear power plants and in areas subjected to radioactive contamination may be solved using a monitoring, system including interrelated systems of observation and prediction of the lithosphere and the hydrosphere. The problem of mathematical modeling of migration processes is related to the complexities of modeling the processes of flow, mass transfer, and the accompanying physicochemical processes in zones of full and partial saturation, as well as difficulties in mathematical calculations. 4 refs

  4. Calculation of age-dependent dose conversion coefficients for radionuclides uniformly distributed in air

    International Nuclear Information System (INIS)

    Hung, Tran Van; Satoh, Daiki; Takahashi, Fumiaki; Tsuda, Shuichi; Endo, Akira; Saito, Kimiaki; Yamaguchi, Yasuhiro

    2005-02-01

    Age-dependent dose conversion coefficients for external exposure to photons emitted by radionuclides uniformly distributed in air were calculated. The size of the source region in the calculation was assumed to be effectively semi-infinite in extent. Firstly, organ doses were calculated with a series of age-specific MIRD-5 type phantoms using MCNP code, a Monte Carlo transport code. The calculations were performed for mono-energetic photon sources of twelve energies from 10 keV to 5 MeV and for phantoms of newborn, 1, 5, 10 and 15 years, and adult. Then, the effective doses to the different age-phantoms from the mono-energetic photon sources were estimated based on the obtained organ doses. The calculated effective doses were used to interpolate the conversion coefficients of the effective doses for 160 radionuclides, which are important for dose assessment of nuclear facilities. In the calculation, energies and intensities of emitted photons from radionuclides were taken from DECDC, a recent compilation of decay data for radiation dosimetry developed at JAERI. The results are tabulated in the form of effective dose per unit concentration and time (Sv per Bq s m -3 ). (author)

  5. Distribution of radionuclides in the sediments of Cananeia-Iguape Estuarine Complex (SP, Brazil)

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Andreza P.; Ferreira, Paulo A.L.; Mahiques, Michel M., E-mail: andrezpr@usp.br, E-mail: paulo.alves.ferreira@usp.br, E-mail: mahiques@usp.br, E-mail: rfigueira@usp.br [Universidade de Sao Paulo (IO/USP), Sao Paulo, SP (Brazil). Instituto Oceanografico; Franca, Elvis J.; Figueira, Rubens C.L., E-mail: ejfranca@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2013-07-01

    With the advent of techniques that enabled the detection of radioactivity, a new frontier was opened in the many areas of Earth sciences, as the radionuclides can be used as tracers for processes of physical, chemical and biological natures. In this context, natural ({sup 40}K, {sup 232}Th and {sup 238}U) and artificial ({sup 137}Cs) radionuclides were measured through the means of high-resolution gamma spectrometry, a non-destructive technique, in the Cananeia-Iguape Estuarine Complex (Sao Paulo, Brazil). The activities obtained are 107.61 - 573.84 Bq kg{sup -1} for {sup 40}K, 11.11 - 73.65 Bq kg{sup -1} for {sup 232}Th, 2.27 - 60.76 Bq kg{sup -1} for {sup 238}U, and 0.23 - 3.49 Bq kg{sup -1} for {sup 137}Cs, with {sup 137}Cs content within the observed range for samples environmentally affected only by the fallout of past nuclear tests. Also, these radionuclides presented a significant (α = 0.05) correlation with grain size distribution and organic carbon content as well. (author)

  6. Distribution of 137Cs radionuclide in seawater and sediments of Pari Island Seribu Islands Jakarta

    International Nuclear Information System (INIS)

    Herni Kusuma; Sri Yulina Wulandari; Mohammad Nur Yahya

    2016-01-01

    The 137 Cs Radionuclide which has a long half-life (30 years), has been dispersed and deposited into ocean areas, so its spread needs to be known. Research for distribution of 137 Cs radionuclide in Pari Island is indispensable because it is located in the southern part of Seribu Islands waters located adjacent to Jakarta Bay. There are much domestic and industrial sewage coming from the rivers to Jakarta Bay. Beside there are some possibility of radiological substances entry derived from laboratory activities at BATAN-Serpong through Cisadane River. These study was aimed to get the value and distribution of 137 Cs in the seawater and sediments also their relation to the general character of the sediment that were grain size and carbon content, as well as current patterns. Seawater and bottom sediment sampling were conducted on March 26, 2016 respectively of 7 station. Analysis of the samples in order to measure the concentration of 137 Cs were conducted in PTKMR-BATAN. The results showed the activity of 137 Cs in the water ranging from 0.01 to 1.16 mBq/l and in sediments ranging from 0.265-0.653 Bq/kg. Flow modeling results indicate that the distribution of 137 Cs in seawater were affected by current direction and speed. Activities and distribution of 137 Cs in bottom sediments of Pari Island waters were less affected by grain size and carbon content. (author)

  7. New ecological mechanism of formation of spatial distribution of radionuclides in river ecosystem

    International Nuclear Information System (INIS)

    Degermendzhy, A.G.; Shevyrnogov, A.P.; Kosolapova, L.G.; Levin, L.A.; Chernousov, A.V.; Vlasik, P.V.

    1996-01-01

    Radioecological expeditions on the Yenissei river revealed 'spotty' distribution of radioisotopes in bottom sediments and along the coastline of the river. This work presents results of theoretical analysis of the formation mechanism of stable spatial non-uniformities of river ecosystem components by population interactions of 'predator-prey' type between the phytoplukton and zooplankton. 'Patchiness contrast' (i.e. the amplitude of the radionuclide spatial propagation wave in the water) for the large oscillations control by increasing or decreasing current velocity depends both on the boundary concentrations of phytoplankton and zooplankton and on the established nature of their interpopulation interactions (or coefficients of interactions). Variation of the below given interaction parameters within the 'phytoplanbon-zooplankton' system makes increase the amplitude of spatial distribution wave: decrease of algal growth rate; increase of algal death rate; decrease of zooplankton death rate; increase of interaction coefficients. It was shown for small oscillations that the period of component distribution waves is in proportion to the current velocity and the amplitude of 'small' waves does not depend on the water current velocity. Theoretically it has been also found that with deep limitation of phytoplankton growth by biogenous elements the 'standing wave' is observed to deteriorate and monotonous distribution of radionuclide concentration fields is found to form. (author)

  8. Elemental and radionuclides distribution in the production and use of phosphate fertilizers in Brazil

    International Nuclear Information System (INIS)

    Saueia, Catia Heloisa Rosignoli

    2006-01-01

    Fertilizer is considered an essential component for agriculture, because its use increases the natural soil nutrients, which are lost slow waste or erosion. The Brazilian phosphate fertilizer is obtained by wet reaction of igneous phosphate rock with concentrated sulphuric acid, giving as final product, phosphoric acid and dihydrated calcium sulphate (phosphogypsum) as by-product. Phosphoric acid is the starting material for triple superphosphate (TSP), single superphosphate (SSP), monoammonium phosphate (MAP) and diammonium phosphate (DAP). The phosphate rock used as raw material presents in its composition, radionuclides of the U and Th natural series in. During the chemical attack of the phosphate rock, this equilibrium is disrupted and the radionuclides and the elements migrate to intermediate, final products and byproducts, according to their solubility and chemical properties. While the fertilizers are commercialized, the phosphogypsum is disposed in stack piles and can cause an impact in the environment. In order to evaluate the radionuclides and the elements distribution in the industrial process of phosphate fertilizer production, samples of concentrated rock, fertilizers (SSP, TSP, MAP and DAP) and phosphogypsum from three national industries (A, B and C), were analyzed. The characterization of the elements Ba, Co, Cr, Fe, Hf, Na, Sc, Ta, Th, U, Zn and Zr, and the rare earths La, Ce, Nd, Sm, Eu, Tb, Yb and Lu, were performed by instrumental neutron activation analysis. The results obtained showed that, in general, the rare earth elements are distributed uniformly in the fertilizers and phosphogypsum, except for Lu. The elemental concentration present in the fertilizers SSP and TSP are of the same order of magnitude of the source rock. The same behavior was observed in the fertilizers MAP and DAP, except for the elements Co, Sc and U. The radionuclides of the U series ( 238 U, 234 U, 230 Th, 226 Ra, 210 Pb) and of the Th series ( 232 Th, 228 Ra, 228 Th

  9. Vertical distribution of Pu radionuclides, 241Am and 99Sr in soil Samples from Romania

    International Nuclear Information System (INIS)

    Breban, D.; Mocanu, N.; Moreno-Bermudez, J.

    2002-01-01

    The investigated area is a natural alpine pasture located in the South chain of the Carpathian Mountains, which was found as one of the most contaminated areas in Romania after the Chernobyl accident.Radioactive concentrations of Pu radioisotopes, 2 41Am and 9 0Sr were determined in successive layers from 4 soil sections downward a depth of 6-8 cm, providing for the first time information on the effect of fallout acumulation of these radionuclides in soil samples from Romania. Pu and Am were separated by using a combined sequential procedure based on anion exchange and extraction chromatography. The measurements of 241Pu were performed by Liquid Scintillation Counting. 9 0Sr was determined by chemical separation of Sr using the classical precipitation method and Cerenkov counting of 9 0Y. For Quality Control IAEA reference materials were analyzed along with the samples. In a soil section of 8 cm depth radioactive inventories were approximately 500 Bq/m 2 for 2 41Pu, 115 Bq/m 2 for 2 39 +2 40Pu, 8 Bq/m 2 for 2 38Pu, 50 Bq/m2 for 2 41Am and 2500 Bq/m 2 for 9 0Sr. The data on each of the radioisotopes vertical distribution profile are compared between themselves and give an idea for their migration. On the basis of activity isotopic ratios in the soil depth profile, the origin of the contamination (Chernobyl accident and nuclear weapon test fallout) is discussed. The results are also compared to previous data on Cs-137

  10. Assimilation of spatio-temporal distribution of radionuclides in early phase of radiation accident

    Czech Academy of Sciences Publication Activity Database

    Hofman, Radek; Šmídl, Václav

    2010-01-01

    Roč. 18, 7/8 (2010), s. 226-228 ISSN 1210-7085 R&D Projects: GA MŠk(CZ) 1M0572; GA ČR(CZ) GA102/07/1596 Institutional research plan: CEZ:AV0Z10750506 Keywords : decision support * early phase * Gaussian model * radioactive pollution transport Subject RIV: DL - Nuclear Waste, Radioactive Pollution ; Quality http://library.utia.cas.cz/separaty/2010/AS/hofman-assimilation of spatio-temporal distribution of radionuclides in early phase of radiation accident.pdf

  11. Influence of plowing on the depth distribution of various radionuclides in the soil

    International Nuclear Information System (INIS)

    Meisel, S.; Mueller, H.K.

    1991-07-01

    The present work deals with a comparison of the vertical distribution of 137 Cs, 134 Cs, 106 Ru, 125 Sb, and 90 Sr at two agricultural sites in Styria (Austria) in the first two years after the Chernobyl fallout. Three months after deposition the Chernobyl derived radionuclides had their maximum concentrations in the first cm. Detectable amounts, however, had penetrated down to a depth of 12 cm (Stagno-Dystric Gleysol, site A) and 20 cm (Dystric Cambisol, site B). Significant differences between the two sites were observed after the first plowing. At site A a new concentration maximum at 15 to 18 cm depth was observed due to an extreme turnover effect. Even the second plowing in 1988 did not yield a homogeneous radionuclide distribution over the tillage depth. At site B the furrow slice was twisted only 60 o against the slope gradient. This resulted in a slight mixing in the first 12 cm. From this it may be concluded that plowing does not lead to a thorough mixing in any case. At least two or three plowing steps may be needed to obtain an uniform nuclide distribution at certain sites. (Authors) Also appeared in 'Z. Pflanzenernaehr. Bodenk.' v. 154 p. 211-215; (1991)

  12. Using fallout radionuclides to investigate recent overbank sedimentation rates on river floodplains: an overview

    Directory of Open Access Journals (Sweden)

    V. Golosov

    2015-03-01

    Full Text Available Information on rates of overbank sedimentation on river floodplains is needed for a variety of purposes. Use of 137Cs and 210Pbex measurements provides an effective means of estimating medium-term floodplain sedimentation rates and that approach has now been successfully used in many areas of the world. This contribution reviews the use of 137Cs and 210Pbex measurements in floodplain sedimentation investigations and discusses some of the important sampling requirements and key issues associated with interpreting the measurements, and subsequently deriving reliable estimates of sedimentation rates. The potential use of other radionuclides, including 241Am, 238,239+240Pu, and 7Be is considered, and the advantages of using two or more radionuclides, in combination, is highlighted.

  13. Estimating the distribution of radionuclides in agricultural soils - dependence on soil parameters.

    Science.gov (United States)

    Hormann, Volker; Fischer, Helmut W

    2013-10-01

    In this study it is shown how radionuclide distributions in agricultural soils and their dependence on soil parameters can be quantitatively estimated. The most important sorption and speciation processes have been implemented into a numerical model using the geochemical code PHREEQC that is able to include specific soil and soil solution compositions. Using this model, distribution coefficients (Kd values) for the elements Cs, Ni, U and Se have been calculated for two different soil types. Furthermore, the dependencies of these Kd values on various soil parameters (e.g. pH value or organic matter content) have been evaluated. It is shown that for each element, an individual set of soil parameters is relevant for its solid-liquid distribution. The model may be used for the calculation of input parameters used by reference biosphere models (e.g. used for the risk assessment of nuclear waste repositories). Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. A preliminary investigation of radiation level and some radionuclides in imported food and food products

    International Nuclear Information System (INIS)

    Sinakhom, F.; Mongkolphantha, S.

    1980-04-01

    A preliminary study of gross beta activity and content of some long-lived radionuclides associated with fission products in various types of imported food and food-products was carried out. Food samples were purchased monthly during 1976-1977 from general well-known supermarkets and local grocery stores up to a total of 89 samples. The gamma spectrum of long-lived radionuclides was searched using a 128 channel analyzer coupled with 3'' x 3'' NaI (T1) crystal detector. Two radionuclides were frequently found to be present in these food samples, viz. potassium-40 and cesium-137 and their concentrations were subsequently determined. The limits of detection under the conditions used for potassium-40 and cesium-137 were 0.04 and 0.03 pCi/g-wet weight, respectively. Samples were dry-ashed and counted for gross beta activity utilizing a low background anti-coincidence G.M. counter. The content of strontium-90 was also investigated concurrently by solvent extraction technique employing tri-n-butyl phosphate as an extractant. Results of the study are tabulated. (author)

  15. Radionuclide cisternography

    International Nuclear Information System (INIS)

    Song, H.H.

    1980-01-01

    The purpose of this thesis is to show that radionuclide cisternography makes an essential contribution to the investigation of cerebrospinal fluid (CSF) dynamics, especially for the investigation of hydrocephalus. The technical details of radionuclide cisternography are discussed, followed by a description of the normal and abnormal radionuclide cisternograms. The dynamics of CFS by means of radionuclide cisternography were examined in 188 patients in whom some kind of hydrocephalus was suspected. This study included findings of anomalies associated with hydrocephalus in a number of cases, such as nasal liquorrhea, hygromas, leptomeningeal or porencephalic cysts. The investigation substantiates the value of radionuclide cisternography in the diagnosis of disturbances of CSF flow. The retrograde flow of radiopharmaceutical into the ventricular system (ventricular reflux) is an abnormal phenomenon indicating the presence of communicating hydrocephalus. (Auth.)

  16. A Monte Carlo program converting activity distribution to absorbed dose distributions in a radionuclide treatment planning system

    International Nuclear Information System (INIS)

    Tagesson, M.; Ljungberg, M.; Strand, S.E.

    1996-01-01

    In systemic radiation therapy, the absorbed dose distribution must be calculated from the individual activity distribution. A computer code has been developed for the conversion of an arbitrary activity distribution to a 3-D absorbed dose distribution. The activity distribution can be described either analytically or as a voxel based distribution, which comes from a SPECT acquisition. Decay points are sampled according to the activity map, and particles (photons and electrons) from the decay are followed through the tissue until they either escape the patient or drop below a cut off energy. To verify the calculated results, the mathematically defined MIRD phantom and unity density spheres have been included in the code. Also other published dosimetry data were used for verification. Absorbed fraction and S-values were calculated. A comparison with simulated data from the code with MIRD data shows good agreement. The S values are within 10-20% of published MIRD S values for most organs. Absorbed fractions for photons and electrons in spheres (masses between 1 g and 200 kg) are within 10-15% of those published. Radial absorbed dose distributions in a necrotic tumor show good agreement with published data. The application of the code in a radionuclide therapy dose planning system, based on quantitative SPECT, is discussed. (orig.)

  17. Natural radionuclides distribution in the shelf and upper slope of southeast Brazil

    International Nuclear Information System (INIS)

    Cordero, Luisa M.; Figueira, Rubens C.L.; Mahiques, Michel M.; Tessler, Moyses G.

    2009-01-01

    In recent decades, Oceanography has been using a variety of radionuclides as tracers to understand the ocean dynamic processes, handling and disposal of sediments of seabed. In this context, the determination of natural radionuclides distributions ( 238 U, 232 Th and 40 K) has been carried out with sediments samples from the shelf and upper slope off Southeast Brazil using a gamma spectrometry technique. The samples were sliced into strata of 2 cm, dried, ground and properly packed to be analysed. The concentration of activities was performed in a hyperpure Ge detector with a resolution of 1,9 keV for the peak of 1332,3 keV of 60 Co, model GEM50P by EGG and ORTEC. The study area is located between latitudes 28 deg 40'S and 23 deg 00'S and extends from Cabo Frio (RJ) to Cabo de Santa Marta Grande (SC). The activity concentrations varied from 0,6 to 52,8 BqKg -1 for 238 U, from 1,6 to 50,9BqKg -1 for 232 Th and from 65,4 to 873,3 BqKg -1 for 40 K. From these results it is possible to establish a correlation between the depositional area dynamics and the samples size parameters. (author)

  18. Natural radionuclides distribution in the shelf and upper slope of southeast Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Cordero, Luisa M.; Figueira, Rubens C.L., E-mail: luisa.cordero@usp.b, E-mail: rfigueira@usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. Oceanografico. Lab. de Quimica Inorganica Marinha; Mahiques, Michel M., E-mail: mahiques@usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. Oceanografico. Lab. de Analise de Materia Organica; Tessler, Moyses G., E-mail: mgtessle@usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. Oceanografico. Lab. de Espectrometria Gama

    2009-07-01

    In recent decades, Oceanography has been using a variety of radionuclides as tracers to understand the ocean dynamic processes, handling and disposal of sediments of seabed. In this context, the determination of natural radionuclides distributions ({sup 238}U, {sup 232}Th and {sup 40}K) has been carried out with sediments samples from the shelf and upper slope off Southeast Brazil using a gamma spectrometry technique. The samples were sliced into strata of 2 cm, dried, ground and properly packed to be analysed. The concentration of activities was performed in a hyperpure Ge detector with a resolution of 1,9 keV for the peak of 1332,3 keV of {sup 60}Co, model GEM50P by EGG and ORTEC. The study area is located between latitudes 28 deg 40'S and 23 deg 00'S and extends from Cabo Frio (RJ) to Cabo de Santa Marta Grande (SC). The activity concentrations varied from 0,6 to 52,8 BqKg{sup -1} for {sup 238}U, from 1,6 to 50,9BqKg{sup -1} for {sup 232}Th and from 65,4 to 873,3 BqKg{sup -1} for {sup 40}K. From these results it is possible to establish a correlation between the depositional area dynamics and the samples size parameters. (author)

  19. Radionuclides for investigating the accumulation of toxic elements in algae and fish

    International Nuclear Information System (INIS)

    Stary, J.; Zeman, A.

    1983-01-01

    Radionuclides are very suitable for investigating the accumulation of toxic elements in algae and fish. The most important results obtained from using 51 Cr(III) (VI), 65 Zn, 74 As(III) (V), CH 3 74 AsO(OH) 2 , (CH 3 ) 2 74 AsO(OH), (CH 3 ) 3 74 As, 85 Sr, 86 Rb, /sup 115m/Cd, 133 Ba, 137 Cs, 203 Hg(II), CH 3 203 HgCl and C 6 H 5 203 HgCl for the study of the accumulation, release and chemical transformation of the above species in algae and fish are summarized. (author)

  20. Radionuclide distributions in deep-ocean sediment cores. Progress report, 1 October 1976 -- 31 December 1977

    International Nuclear Information System (INIS)

    Bowen, V.T.

    1978-04-01

    Disruption, in the past year, of the supply of 237 Pu tracer from Oak Ridge caused us to put more of effort into analyses of core samples previously collected, and into data collation, than into the laboratory experiments originally projected. Accompanying this report are two review papers, one for a Congressional Committee and one in press, a report in press of a device for conducting microbiological tracer experiments under controlled atmospheres, and a description of radionuclide distributions in sediments of Atlantic and Pacific solid waste dump sites. Described in the body of the report are experiments relating the time course of association of 237 Pu tracer with diatoms (dead or alive) or glass beads, to the constitution of the media, the history of the cells, or the presence of exometabolites. Also described are studies of the differential removal of 239 240 Pu, 241 Am, and 137 Cs from coastal seawater currents contaminated by waste released from a fuel-reprocessing facility

  1. Distribution and behavior of radionuclides in the coastal ecosystem in Rokkasho Village

    International Nuclear Information System (INIS)

    Kondo, Kunio; Kawabata, Hitoshi; Ueda, Shinji; Hasegawa, Hidenao; Inaba, Jiro

    2001-01-01

    The aim of the present study was to elucidate, through both field studies and laboratory experiments, the mechanism for the elution of radionuclides and other materials from suspended organic matter that accompanies the decomposition of organic matter, consisting mainly of phytoplankton, in the coastal sea region off Rokkasho Village. The effect of water temperature on the decomposition rate of organic matter suspended in seawater was investigated in laboratory experiments. The results demonstrated that the decomposition process was divided into two steps for each of the items of dry weight (SS), particulate organic carbon (POC), and particulate organic nitrogen (PON). The first step in decomposition progressed rapidly over several days. The second step of decomposition occurred at a slower rate than the first step. The decomposition rate of organic material was found to be strongly dependent on temperature, with decomposition progressing faster the higher the temperature. The amounts of Mn, Zn, Cu, Pb, Sn, Ni, Be, V, Ti, Ba, Cr, Sr, and the radionuclides 232 Th and 238 Ur eluted from organic matter by decomposition (30 days) of suspended organic matter were in the range of 31-72% of the amounts contained in the organic matter. (author)

  2. Direct investigations of the immobilization of radionuclides in the alteration phases of spent nuclear fuel. 1998 annual progress report

    International Nuclear Information System (INIS)

    Burns, P.C.; Finch, R.J.

    1998-01-01

    'In an oxidizing environment, such as in the proposed repository at Yucca Mountain, rapid alteration rates are expected for spent nuclear fuel. Lab.-scale simulations have repeatedly shown that the dominant alteration products under repository conditions will be uranyl phases. There is an inadequate database that relates to the effects of the alteration products on the release of radionuclides, but this information is essential to provide a radionuclide release estimate. It is likely that many of the radionuclides contained in the fuel will be incorporated into the alteration products that form, potentially with a profound impact on the future mobility of radionuclides in the repository. The authors objective is to characterize the incorporation of radionuclides into alteration products by synthesis of uranyl phases doped with radionuclides, appropriate surrogate elements, or non-radioactive isotopes, followed by detailed phase characterization by diffraction and spectroscopic techniques. The research will permit a more realistic estimate of the release rates of the radionuclides from the near-field environment. This report summarizes work after 8 months of a 3-year project. The objective of investigating radionuclide incorporation in uranyl phases has required the development of synthesis techniques for various uranyl phases that are expected to form under repository conditions. The authors have synthesized and determined the structures of several uranyl phases that are new to science and that may be important alteration products under repository conditions. They have also undertaken the determination and refinement of the crystal structures of various uranyl phases that are likely to form under repository conditions. Other experiments include the investigation of the ion-exchange properties of uranyl phases under repository conditions.'

  3. Radionuclide distribution of Holocene sediments and its effects on the habitat of recent foraminifers: A case study from the Western Marmara Sea (Turkey)

    Science.gov (United States)

    Ünal Yumun, Zeki; Kam, Erol; Murat Kılıc, Ali

    2017-04-01

    ABSTRACT Radionuclides cause radioactive contamination in aquatic environments just as other non-biodegradable pollutants, such as heavy metals, sink to the seafloor and accumulate in the sediments. These radioactive pollutants especially affect benthic foraminifera living on the sediment surface or in the sediments in the seafloor. Foraminifera were used as bioindicators to analyze the effect of radioactivity pollution on ecosystems. In this study, we have investigated natural and artificial radionuclide (232Th, 226Ra, 40K and 137Cs) distribution in sediment samples taken in the living areas of benthic foraminifera in the Western Marmara Sea by means of gamma spectrometry. Accordingly, 29 core samples taken in 2016 from depths of about 20-35 m close to the shores of the Marmara Sea were used. Core samples representing the pollution of the study area were collected at locations such as discharge points for domestic and industrial areas, port locations, and others. Other samples were taken from areas unaffected or less affected by pollution. The radionuclide concentration activity values in the sediment samples obtained from the locations, in Bq/kg, were 137Cs, 0.9-9.4; 232Th, 18.9-86; 226Ra, 10-50; 40K, 24.4-670. These values were compared with the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) data, and an environmental analysis was carried out. The 226Ra series, the 232Th series, and the 40K radionuclides accumulate naturally, and they are also increasing continuously due to anthropogenic pollution. Although the 226Ra values obtained throughout the study areas remained within normal limits according to the UNSCEAR values, the 40K and 232Th series values were found to be higher in almost all locations. According to these results, the main causes of radioactive pollution in the investigation area are agricultural and mining activities. Keywords: Ra-226, Th-232, K-40, Cs-137, radionuclide, Western Marmara Sea, Foraminifera

  4. 3D dose and TCP distribution for radionuclide therapy in nuclear medicine

    Science.gov (United States)

    Valente, M.; Malano, F.; Pérez, P.

    2010-08-01

    A common feature to any radiant therapy is that lesion and health tissue dosimetry provides relevant information for treatment optimization along with dose-efficacy and dose-complication correlation studies. Nowadays, different radionuclide therapies are commonly available, assessing both systemic and loco-regional approach and using different alfa-, beta-and gamma-emitting isotopes and binding molecules. It is well established, that specific dosimetric approaches become necessary according to each therapy modality. Sometimes, observed activity distribution can be satisfactory represented by simple geometrical models. However, Monte Carlo techniques are capable of better approaches, therefore becoming sometimes the only way to get dosimetric data since the patient-specific situation can not be adequately represented by conventional dosimetry techniques. Therefore, due to strong limitations of traditional and standard methods, this work concentrates on the development of a dedicated and novel calculation system in order to assess the dose distribution within the irradiated patient. However, physical dose may not be enough information in order to establish real deterministic biological/metabolic effects; therefore complementary radiobiological models have been suitably introduced with the aim of performing realistic 3D dose as well as corresponding Tumor Control Probability distribution calculation.

  5. Use of 137Cs and other fallout radionuclide in soil erosion investigations: progress, problems and prospects

    International Nuclear Information System (INIS)

    Walling, D.E.

    1998-01-01

    Accelerated erosion and soil degradation currently represent serious problems for the global environment. Against this background there is a need to assemble reliable information on the rates of soil loss involved. Existing techniques for documenting rates of soil loss possess many limitations and there is increasing interest in the potential for using fallout radionuclides, particularly 137 Cs, to obtain such information. An example of the application of the 137 Cs approach to a cultivated field at Rufford Forest Farm, Nottinghamshire, UK, is presented to illustrate its value. The key advantages of the approach are that it provides a means of assembling retrospective estimates of medium-term (ca. 40 years) rates of soil loss and the spatial pattern of erosion and deposition involved, on the basis of a single site visit. There are, however, currently a number of problems and uncertainties associated with the use of 137 Cs in soil erosion investigations, and these are reviewed and needs for further research identified. Potential developments of the approach, including the use of other fallout radionuclides such as unsupported 210 Pb and 7 Be are also considered. (author)

  6. Natural and anthropogenic radionuclide distributions in the Nansen Basin, Artic Ocean: Scavenging rates and circulation timescales

    Science.gov (United States)

    Kirk Cochran, J.; Hirschberg, David J.; Livingston, Hugh D.; Buesseler, Ken O.; Key, Robert M.

    Determination of the naturally occurring radionuclides 232Th, 230Th, 228 Th and 210Pb, and the anthropogenic radionuclides 241Am, 239,240Pu, 134Cs and 137Cs in water samples collected across the Nansen Basin from the Barents Sea slope to the Gakkel Ridge provides tracers with which to characterize both scavenging rates and circulation timescales in this portion of the Arctic Ocean. Large volume water samples (˜ 15001) were filtered in situ to separate particulate (> 0.5 μm) and dissolved Th isotopes and 241Am. Thorium-230 displays increases in both particulate and dissolved activities with depth, with dissolved 230Th greater and particulate 230Th lower in the deep central Nansen Basin than at the Barents Sea slope. Dissolved 228Th activities also are greater relative to 228Ra, in the central basin. Residence times for Th relative to removal from solution onto particles are ˜1 year in surface water, ˜10 years in deep water adjacent to the Barents Sea slope, and ˜20 years in the Eurasian Basin Deep Water. Lead-210 in the central basin deep water also has a residence time of ˜20 years with respect to its removal from the water column. This texture of scavenging is reflected in distributions of the particle-reactive anthropogenic radionuclide 241Am, which shows higher activities relative to Pu in the central Nansen Basin than at the Barents Sea slope. Distributions Of 137Cs show more rapid mixing at the basin margins (Barents Sea slope in the south, Gakkel Ridge in the north) than in the basin interior. Cesium-137 is mixed throughout the water column adjacent to the Barents Sea slope and is present in low but detectable activities in the Eurasian Basin Deep Water in the central basin. At the time of sampling (1987) the surface water at all stations had been labeled with 134Cs released in the 1986 accident at the Chernobyl nuclear power station. In the ˜1 year since the introduction of Chernobyl 134Cs to the Nansen Basin, it had been mixed to depths of ˜800 m at

  7. Stable tracer investigations in humans for assessing the biokinetics of ruthenium and zirconium radionuclides

    International Nuclear Information System (INIS)

    Veronese, I.; Cantone, M.C.; Giussani, A.; Maggioni, T.; Birattari, C.; Bondardi, M.; Groppi, F.; Garlaschelli, I.; Werner, E.; Roth, P.; Hoellriegl, V.; Louvat, P.; Felgenhauer, N.; Zilker, Th.

    2003-01-01

    The interest in the biokinetics of ruthenium and zirconium in humans is justified by the potential radiological risk represented by their radionuclides. Only a few data related to the biokinetics of ruthenium and zirconium in humans are available and, accordingly, the biokinetic models currently recommended by the ICRP for these elements are mainly based on data from animal experiments. The use of stable isotopes as tracers, coupled with a proper analytical technique (nuclear activation analysis with protons) for their determination in biological samples, represents an ethically acceptable methodology for biokinetic investigations, being free from any radiation risk for the volunteer subjects. In this work, the results obtained in eight biokinetic investigations for ruthenium, conducted on a total of three healthy volunteers, and six for zirconium, performed on a total of three subjects, are presented and compared to the predictions of the ICRP models. (author)

  8. Investigations and technical reviews on the reliability of prediction for migration behavior of radionuclides (H15)

    International Nuclear Information System (INIS)

    Tachikawa, Hirokazu

    2004-02-01

    The research plan of the validation on effects of colloids and organic materials drawn up by the Japan Nuclear Fuel Cycle Development Institute and its' research outcome were reviewed comprehensively by an expert committee established in the Nuclear Safety Research Association. Additionally, experimental investigations for the migration behavior of actinide elements and fission products in engineering barrier and natural barrier medias, and for solution chemistry of them were carried out and discussed by the committee, in order to enhance the reliability of prediction for migration behavior of radionuclides. The subjects investigated by the expert committee are as follows: (1) Research on solubility products of An(III) hydroxide. (2) Diffusion and electromigration behavior of plutonium in buffer material. (3) Analysis of the nuclide solubility in compacted bentonite. (4) Survey of the actual contamination by alpha emitters in steel materials. (author)

  9. Effect of industrial pollution on the distribution dynamics of radionuclides in boreal understorey ecosystems (EPORA). Final report

    Energy Technology Data Exchange (ETDEWEB)

    Suomela, M.; Rahola, T. [Radiation and Nuclear Safety Authority, Helsinki (Finland); Bergman, R. [National Defence Research Establishment (Sweden); Bunzl, K. [National Research Center for Environmental and Health (Germany); Jaakkola, T. [Helsinki Univ. (Finland). Radiochemical Lab.; Steinnes, E. [Norwegian University of Science and Technology (Norway)

    1999-08-01

    The project EPORA 'Effects of Industrial Pollution on Distribution Dynamics of Radionuclides in Boreal Understorey Ecosystems' is a part of the Nuclear Fission Safety Research programme of the European Union. A suitable environment for the study was found in the surroundings of the Cu-Ni smelter in Monchegorsk, in NW Russia where the huge atmospheric emissions from the smelter have polluted the environment since the 1930's. Samples of soil, litter, plants and runoff water were taken. Total concentrations of the mainpollutants, Ni and Cu, in the organic soil increased from about 10 mg kg{sup -1} at the reference site in Finland to about 5000 mg kg{sup -1} at the most polluted site in Russia. Similar trends were observed for exchangeable fractions and plant concentrations of the same elements. Concentrations of exchangeable K, Ca, and Mg in the organic soil decreased strongly with increased input of chemical pollutants. The radionuclides studied were {sup 137}Cs, {sup 90}Sr and {sup 239+240}Pu, mainly originating from the atmospheric nuclear weapons tests. The contribution of the Chernobyl derived {sup 137}Cs deposition was about 10% but insignificant for the other nuclides. The activity distribution of all three radionuclides in the soil, their corresponding residence half-times as well as their aggregated trencher factors for various plants depended on the degree of pollution: Activity distribution: in the litter layer, the activity of all three radionuclides increased continually from the reference site to the most polluted site. This effect was most pronounced for {sup 239+240}Pu and least for {sup 90}Sr and could, at least partly, be explained by the increase of the thickness of this layer. In the root zone, the opposite effect was observed: the largest fraction of all radionuclides was found at the reference site. In the organic layer, the exchangeable fractions of {sup 137}Cs, {sup 90}Sr and {sup 239+240}Pu decreased with increasing pollution

  10. THEORETICAL INVESTIGATION OF STRESSES DISTRIBUTIONS ...

    African Journals Online (AJOL)

    The relationship between cavity size and number on one hand and combinations of web thicknesses were investigated theoretically. The least number of cavities was 4 for end-web to centre web ratio of 1:2 at constant shell thickness with the least web thickness equal to 12.5mm. The effects of the number of cavities and ...

  11. Investigation of concentrations of radionuclides in some public water used in middle belt region of Nigeria

    International Nuclear Information System (INIS)

    Isikwue, B.C.; Danduwa, T.F.; Isikwue, M.O.

    2007-01-01

    This work investigates the amount of radioactive elements found in some public water samples collected in the Middle Belt Region of Nigeria, using Makurdi metropolis of Benue State as a case study. Within the limits of experimental error,the mean radiation exposure dose level for the various sources of domestic water in the area was found to be within the range of 0.20 x 10''-''2 to 1.05 x 10''-''2 mSv/yr, which is less than 0.04 mSv/yr, the maximum acceptable concentration of radionuclides in public water supplies set up by Environmental Protection Agency (EPA). It was observed that when this small amount accumulates over a long period in human body, it becomes a threat to human health

  12. A systematic investigation of PET Radionuclide Specific Activity on Miniaturization of Radiochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Jeanne M Link, PhD

    2012-03-08

    The PET radionuclides, 18F and 11C consist of very high radiation to mass amounts and should be easily adapted to new technologies such as chip chemistry with nanofluidics. However, environmental contamination with nonradioactive fluorine, carbon and other trace contaminants add sufficient mass, micrograms to milligrams, to prevent adapting PET radiochemistry to the nanochip technologies. In addition, the large volumes of material required for beam irradiation make it necessary to also remove the 18F and 11C from their chemical matrices. These steps add contaminants. The work described in this report was a systematic investigation of sources of these contaminants and methods to reduce these contaminants and the reaction volumes for radiochemical synthesis. Several methods were found to lower the contaminants and matrices to within a factor of 2 to 100 of those needed to fully implement chip technology but further improvements are needed.

  13. VOLTAMMETRIC INVESTIGATION OF THE DISTRIBUTION OF ...

    African Journals Online (AJOL)

    VOLTAMMETRIC INVESTIGATION OF THE DISTRIBUTION OF HYDROXO-, CHLORO-, EDTA AND CARBOHYDRATE COMPLEXES OF LEAD, CHROMIUM, ZINC, CADMIUM AND COPPER: POTENTIAL APPLICATION TO METAL SPECIATION STUDIES IN BREWERY WASTEWATER.

  14. Distribution and mode of occurrence of radionuclides in phosphogypsum derived from Aqaba and Eshidiya Fertilizer Industry, South Jordan

    Science.gov (United States)

    Al-Hwaiti, M. S.; Zielinski, R.A.; Bundham, J.R.; Ranville, J.F.; Ross, P.E.

    2010-01-01

    Phosphogypsum (PG) is a by-product of the chemical reaction called the "wet process" whereby sulphuric acid reacts with phosphate rock (PR) to produce phosphoric acid, needed for fertilizer production. Through the wet process, some impurities naturally present in the PR become incorporated in PG, including U decay-series radionuclides, are the main important concern which could have an effect on the surrounding environment and prevent its safe utilization. In order to determine the distribution and bioavailability of radionuclides to the surrounding environment, we used a sequential leaching of PG samples from Aqaba and Eshidiya fertilizer industry. The results showed that the percentages of 226Ra and 210Pb in PG are over those in the corresponding phosphate rocks (PG/PR), where 85% of the 226Ra and 85% of the 210Pb fractionate to PG. The sequential extraction results exhibited that most of 226Ra and 210Pb are bound in the residual phase (non-CaSO4) fraction ranging from 45-65% and 55%-75%, respectively, whereas only 10%-15% and 10%-20% respectively of these radionuclides are distributed in the most labile fraction. The results obtained from this study showed that radionuclides are not incorporated with gypsum itself and may not form a threat to the surrounding environment. ?? 2010 Science Press, Institute of Geochemistry, CAS and Springer Berlin Heidelberg.

  15. Distribution coefficient data and preliminary estimates of movement of radionuclides, Tatum salt dome, Lamar County, Mississippi. Technical letter: Dribble 31

    Energy Technology Data Exchange (ETDEWEB)

    Beetem, W.A.; Janzer, V.J.

    1963-04-10

    Estimates are made relating radionuclide movement to ground water velocity as part of the safety program for a proposed experiment to detonate nuclear devices within the Tatum salt dome. The estimates are based on distribution coefficients obtained from laboratory studies. Core samples obtained from hydrologic test well HT-3, Tatum salt dome, Lamar County, Mississippi, were equilibrated with radionuclides in solutions simulating aquifer waters found in the area. The combinations of Cenozoic sand and silty clay, and quality of water of the area were studied and summarized. The distribution coefficients obtained for different radionuclides were tested and indicate retardation factors from 1.3 to 857 for the travel time of these radionuclides when compared to the travel time of water in the aquifer system. Laboratory results indicate that migration of any radioisotope inadvertently introduced to the aquifers in the vicinity of the dome as a result of proposed nuclear test explosions would be extremely slow. Revised estimates of the rate of dissolved radioisotope movement will be made on the basis of further laboratory studies utilizing chromatographic adsorption columns of 0.5 to 4.0 feet in length.

  16. Monte Carlo investigation of single cell beta dosimetry for intraperitoneal radionuclide therapy

    International Nuclear Information System (INIS)

    Syme, A M; Kirkby, C; Riauka, T A; Fallone, B G; McQuarrie, S A

    2004-01-01

    Single event spectra for five beta-emitting radionuclides (Lu-177, Cu-67, Re-186, Re-188, Y-90) were calculated for single cells from two source geometries. The first was a surface-bound isotropically emitting point source and the second was a bath of free radioactivity in which the cell was submerged. Together these represent a targeted intraperitoneal radionuclide therapy. Monoenergetic single event spectra were calculated over an energy range of 11 keV to 2500 keV using the EGSnrc Monte Carlo system. Radionuclide single event spectra were constructed by weighting monoenergetic single event spectra according to radionuclide spectra appropriate for each source geometry. In the case of surface-bound radioactivity, these were radionuclide beta decay spectra. For the free radioactivity, a continuous slowing down approximation spectrum was used that was calculated based on the radionuclide decay spectra. The frequency mean specific energy per event increased as the energy of the beta emitter decreased. This is because, at these energies, the stopping power of the electrons decreases with increasing energy. The free radioactivity produced a higher frequency mean specific energy per event than the corresponding surface-bound value. This was primarily due to the longer mean path length through the target for this geometry. This information differentiates the radionuclides in terms of the physical process of energy deposition and could be of use in the radionuclide selection procedure for this type of therapy

  17. The distribution of radionuclides in the upper soil horizons in lower Saxony, Saxony and Thuringia, Germany

    International Nuclear Information System (INIS)

    Barthel, F.; Thoste, V.; Borsdorf, K.H.

    1997-01-01

    After the Chernobyl accident the Federal Institute for Geoscience and Natural Resources carried out a scintillometer and soil sampling survey to monitor the terrestrial gamma radiation in the states of Lower Saxony (1987-1988), Thuringia (1991) and Saxony (1992). Within the scope of terrestrial radiation assessment the main interest was to differentiate gamma radiation caused by geogene radionuclides from that caused by fallout nuclides or contamination from uranium mining and milling. The isoline maps show anomalous exposure rates of 100 to 60 Bq/kg in soil samples. In Thuringia and Saxony it is difficult to detect eight years after the Chernobyl accident any correlation of the regional distribution pattern of Cs-137 fallout with heavy rainfalls in May 1986. Only one anomaly in the western Erzgebirge shows the well known NNW trend, which was recognized from fallout measurements directly after the accident in Lower Saxony. No anomalous contaminations were detected around the uranium mining areas of the former WISMUT SDAG in the Ronneburger and Aue districts. The environmental exposure rates fall in the range of < 200 nGy/h. The general results indicate, that today there is no large scale contamination existent, either from fallout or from uranium mining, which could cause radiological health hazards to the population

  18. Collection and presentation of animal data relating to internally distributed radionuclides

    International Nuclear Information System (INIS)

    Lathrop, K.A.

    1981-01-01

    Data obtained from laboratory animals on the distribution of an internally administered radionuclide may be put to use by various people in ways quite different from the one for which the original observations were made. Consideration for these other scientists, sometimes in unrelated fields, can be shown by attention to a few details in the method of data collection and reporting that may improve the author's credibility, the reader's comprehension, and the value of the data. Briefly stated, two rules should be followed: (1) Account for 100% of the administered radioactivity; and (2) Report data as fraction of administered activity per organ. The first rule serves as an internal check on the proper functioning of counting equipment, and may disclose excretion, contamination of counting tubes, or failure to inject the desired amount of activity. The second rule allows anyone to make use of the raw data. Adherence to these two principles will permit the reader to follow through on any permutations of the data that the author may make, and to apply the data in unrelated situations. In addition to the above, reality testing should be carried out continuously, especially when presenting data graphically. Techniques used to account for all of the administered activity are discussed in detail, and illustrations of pitfalls to avoid and examples to follow are given for presentation of data

  19. Effective dose conversion coefficients for radionuclides exponentially distributed in the ground

    International Nuclear Information System (INIS)

    Saito, Kimiaki; Ishigure, Nobuhito; Petoussi-Henss, Nina; Schlattl, Helmut

    2012-01-01

    In order to provide fundamental data required for dose evaluation due to environmental exposures, effective dose conversion coefficients, that is, the effective dose rate per unit activity per unit area, were calculated for a number of potentially important radionuclides, assuming an exponential distribution in ground, over a wide range of relaxation depths. The conversion coefficients were calculated for adults and a new-born baby on the basis of dosimetric methods that the authors and related researchers have previously developed, using Monte Carlo simulations and anthropomorphic computational phantoms. The differences in effective dose conversion coefficients due to body size between the adult and baby phantoms were found to lie within 50 %, for most cases; however, for some low energies, differences could amount to a factor of 3. The effective dose per unit source intensity per area was found to decrease by a factor of 2-5, for increasing relaxation depths from 0 to 5 g/cm 2 , above a source energy of 50 keV. It is also shown that implementation of the calculated coefficients into the computation of the tissue weighting factors and the adult reference computational phantoms of ICRP Publication 103 does not significantly influence the effective dose conversion coefficients of the environment. Consequently, the coefficients shown in this paper could be applied for the evaluation of effective doses, as defined according to both recommendations of ICRP Publications 103 and 60. (orig.)

  20. Effective dose conversion coefficients for radionuclides exponentially distributed in the ground

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Kimiaki [Japan Atomic Energy Agency, Tokyo (Japan); Ishigure, Nobuhito [Nagoya University, Graduate School of Medicine, Nagoya City (Japan); Petoussi-Henss, Nina; Schlattl, Helmut [Helmholtz Zentrum Muenchen-German Research Center for Environmental Health, Department of Radiation Physics and Diagnostics, Neuherberg (Germany)

    2012-11-15

    In order to provide fundamental data required for dose evaluation due to environmental exposures, effective dose conversion coefficients, that is, the effective dose rate per unit activity per unit area, were calculated for a number of potentially important radionuclides, assuming an exponential distribution in ground, over a wide range of relaxation depths. The conversion coefficients were calculated for adults and a new-born baby on the basis of dosimetric methods that the authors and related researchers have previously developed, using Monte Carlo simulations and anthropomorphic computational phantoms. The differences in effective dose conversion coefficients due to body size between the adult and baby phantoms were found to lie within 50 %, for most cases; however, for some low energies, differences could amount to a factor of 3. The effective dose per unit source intensity per area was found to decrease by a factor of 2-5, for increasing relaxation depths from 0 to 5 g/cm{sup 2}, above a source energy of 50 keV. It is also shown that implementation of the calculated coefficients into the computation of the tissue weighting factors and the adult reference computational phantoms of ICRP Publication 103 does not significantly influence the effective dose conversion coefficients of the environment. Consequently, the coefficients shown in this paper could be applied for the evaluation of effective doses, as defined according to both recommendations of ICRP Publications 103 and 60. (orig.)

  1. Geomorphological applications of environmental radionuclides

    International Nuclear Information System (INIS)

    Quine, T.A.; Walling, D.

    1998-01-01

    Geomorphologists have shown increasing interest in environmental radionuclides since pioneering studies by Ritchie and McHenry in the USA and Campbell, Longmore and Loughran in Australia. Environmental radionuclides have attracted this interest because they provide geomorphologists with the means to trace sediment movement within the landscape. They, therefore, facilitate investigation of subjects at the core of geomorphology, namely the rates and patterns of landscape change. Most attention has been focussed on the artificial radionuclide caesium-137 ( 137 Cs) but more recently potential applications of the natural radionuclides lead-210 ( 210 Pb) and beryllium-7( 7 Be) have been investigated (Walling et al., 1995; Wallbrink and Murray, 1996a, 1996b). The origin, characteristics and applications of these radionuclides are summarised. These radionuclides are of value as sediment tracers because of three important characteristics: a strong affinity for sediment; a global distribution and the possibility of measurement at low concentration. Geomorphological applications of environmental radionuclides provide unique access to detailed qualitative data concerning landscape change over a range of timescales

  2. 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)

  3. Distribution of artificial radionuclides in particle-size fractions of soil on fallout plumes of nuclear explosions.

    Science.gov (United States)

    Kabdyrakova, A M; Lukashenko, S N; Mendubaev, A T; Kunduzbayeva, A Ye; Panitskiy, A V; Larionova, N V

    2018-06-01

    In this paper are analyzed the artificial radionuclide distributions ( 137 Cs, 90 Sr, 241 Am, 239+240 Pu) in particle-size fractions of soils from two radioactive fallout plumes at the Semipalatinsk Test Site. These plumes were generated by a low-yield surface nuclear test and a surface non-nuclear experiment with insignificant nuclear energy release, respectively, and their lengths are approximately 3 and 0,65 km. In contrast with the great majority of similar studies performed in areas affected mainly by global fallout where adsorbing radionuclides such as Pu are mainly associated with the finest soil fractions, in this study it was observed that along both analyzed plumes the highest activity concentrations are concentrated in the coarse soil fractions. At the plume generated by the surface nuclear test, the radionuclides are concentrated mainly in the 1000-500 μm soil fraction (enrichment factor values ranging from 1.2 to 3.8), while at the plume corresponding to the surface non-nuclear test is the 500-250 μm soil fraction the enriched one by technogenic radionuclides (enrichment factor values ranging from 1.1 to 5.1). In addition, the activity concentration distributions among the different soil size fractions are similar for all radionuclides in both plumes. All the obtained data are in agreement with the hypothesis indicating that enrichment observed in the coarse fractions is caused by the presence of radioactive particles resulted from the indicated nuclear tests. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. A voxel-dose algorithm of heterogeneous activity distribution for Monte-Carlo simulation of radionuclide therapy dosimetry.

    Science.gov (United States)

    Lin, Hui; Jing, Jia; Cai, Jinfeng; Xu, Liangfeng

    2012-08-01

    The organ or tumor activity is not uniform due to inhomogeneous expression/distributions of receptors/antigens and the nonuniform vascularization of the tumor tissue. However, most patient-specific three-dimensional Monte-Carlo methods for radionuclide dosimetry have dealt with quasi-homogeneous activity distributions. A voxel-by-voxel activity sample algorithm (VM) without artifacts is presented to calculate the dose of the heterogeneous activity distribution for radionuclide dosimetry. The source particle location is sampled according to the activity spatial distribution. The source particle weight is imparted by the relative activity concentration of its origination voxel. This algorithm is applied to calculate the dose volume histogram for multiple independent activity regions with Gauss diffusion activity distributions and then compared with the level partition method (LM). The minimal response and the mean tolerant initial total activity threshold required by tumor control probability and normal tissue complication probability for radioimmunotherapy ((131)I-RIT) also were evaluated by the voxel-by-voxel sample algorithm and the LM. The effective clearance half-time is assumed to be equal to its physical half-life (i.e., 8.02 days for (131)I). The result shows that the new algorithm is more consistent with the weighted superposition of the quasi-homogeneous activity distribution than the LM, especially for the multiple independent activity regions composed of different amounts of voxels. The new algorithm effectively avoids the leveling/binning artifacts to the heterogeneous activity distribution. The (131)I-RIT simulation also showed that the minimal response initial total activity threshold of tumors will be much more than the mean tolerant initial total activity threshold of normal organs (e.g., kidney) with the activity heterogeneous grade deteriorating. A VM is presented to simulate the dose of the heterogeneous activity distribution for radionuclide

  5. Modelling of metastatic cure after radionuclide therapy: influence of tumor distribution, cross-irradiation, and variable activity concentration.

    Science.gov (United States)

    Bernhardt, Peter; Ahlman, Hakan; Forssell-Aronsson, Eva

    2004-09-01

    The objective was to study the influence of tumor number and size, cross-irradiation from normal tissue, and of variable activity concentration on metastatic cure after radionuclide therapy. A model to calculate the metastatic cure probability (MCP) was developed, in which it was assumed that the tumor response was an exponential function of the absorbed dose. All calculations were performed for monoenergetic electron emitters with different energies (10-1000 keV). The influence of tumor size and number of tumors were investigated with different log uniform distributions; the basic tumor distribution consisted of tumors with 1, 10, ..., 10(11) cells. The influence of cross-irradiation was assessed by calculating MCP for various tumor-to-normal tissue activity concentration ratios (TNC). The influence of variable activity concentration between tumors was calculated by assuming that the activity concentration in tumors was an inverse power law function of tumor mass. The required activity concentration (C0.9) and absorbed dose (D0.9) to obtain MCP=0.9 was calculated in the different models. The C0.9 and D0.9 needed to obtain MCP were very high; more than 25 MBq/g and 80 Gy, respectively. The lowest C0.9 and D0.9 for equal activity concentration in the different tumor sizes were obtained for electron energies less than 80 keV. For higher energies the low absorbed energy fraction in small tumors will increase the required C0.9 and D0.9 markedly. Cross-irradiation from normal cells surrounding the tumor will cause sterilization of the smallest tumors and decrease the required C0.9 and D0.9 for higher electron energies. Assuming that the activity concentration decreased with increased tumor mass caused a marked increase in C0.9 and D0.9 in favor of higher electron energies. With the MCP model we demonstrated significant influence of the number of tumors, their size, TNC and variable activity concentration on MCP. The results are valuable when evaluating optimal choices

  6. Radionuclides in terrestrial ecosystems

    International Nuclear Information System (INIS)

    Allen, S.E.; Horrill, A.D.; Howard, B.J.; Lowe, V.P.W.; Parkinson, J.A.

    1983-07-01

    The subject is discussed under the headings: concentration and spatial distribution of radionuclides in grazed and ungrazed saltmarshes; incorporation of radionuclides by sheep grazing on an estuarine saltmarsh; inland transfer of radionuclides by birds feeding in the estuaries and saltmarshes at Ravenglass; radionuclides in contrasting types of coastal pastures and taken up by individual plant species found in west Cumbria; procedures developed and used for the measurement of alpha and gamma emitters in environmental materials. (U.K.)

  7. The use of classical and radionuclide methods to investigate soil erosion in the Beskidy Mts

    International Nuclear Information System (INIS)

    Froehlich, W.

    1997-01-01

    Information concerning the spatial patterns of erosion and deposition on cultivated hillslopes is difficult to obtain using conventional soil loss monitoring techniques. The use of the fallout radionuclides 134 Cs and 137 Cs as a sediment tracers offers considerable potential for elucidating patterns of soil redistribution. This paper presents the results of an investigation of soil erosion on a cultivate hillslope within the Homerka drainage basin in the Polish Flysch Carpathians, based on 134 Cs and 137 Cs measurements. The 137 Cs inventories of soils in this region reflect inputs from both bomb and Chernobyl-derived fallout. The high degree of spatial variability associated with Chernobyl fallout deposition poses considerable limitations on the potential for using radiocesium measurements to elucidate detailed patterns of soil loss. With an application of cesium method it was stated that during the last 35 years sediment storage within the edge of agricultural terraces is ca. 4 mm year -1 on the average on agricultural experimental slope in the drainage basin of Homerka. This value reflects tillage and dispersed wash and is comparable with the intensity of erosion on agricultural plots. The results provided by the 137 Cs measurements are consistent with other process-based measurements undertaken on the slopes and with available evidence concerning the dominant sources of suspended sediment transported by the local streams. A general model of soil loss and sediment delivery from cultivated slopes in the Polish Flysch Carpathians is proposed. (author)

  8. Radionuclide distributions in vertical soil cross sections of the Chernobyl NPP 30-kilometer zone along the western fallout track. II. Chernozem

    International Nuclear Information System (INIS)

    Rogozin, Yu.M.; Smirnova, E.A.; Krivokhatskii, A.S.; Bryzgalova, R.V.; Alekseev, V.A.; Avdeev, V.A.; Kuksov, A.A.; Zudova, I.Yu.

    1993-01-01

    Radionuclide distributions in vertical cross sections taken from chernozem in a former garden and tillable field along the western fallout track at distances of 5, 13.5, and 22 km from the fourth block of the Chernobyl NPP are studied. The distributions through the chernozem cross sections are more complicated than those of sandy soil. Although the main mass of radionuclides in the cross sections is concentrated at depths of 0-3 cm, instances are observed where up to 5-15% of the radionuclides penetrate to greater depths

  9. Beta Autoradiography. An analytical technique to investigate radionuclides contamination on surface

    International Nuclear Information System (INIS)

    Ficher, P.; Goutelard, F.; Siitari-Kauppi, M.

    2012-01-01

    In decommissioning of old buildings and after disposal of nuclear facilities (materials, glove boxes,...), the inventory of the radioactive contamination of various building materials needs to be obtained in order to fix the working condition for dismantling. The challenge of this study was to classify different building materials of a whole research laboratory that was dedicated to research on organic molecules labeled with H-3 and C-14. The problem of waste classification is essential for safety treatment of waste and also for its cost. The analytical technique of beta autoradiography particularly well known for biological researches has been tested to investigate radionuclides contamination on surface. This technique is mainly interesting for beta and alpha emitters but also sensitive to gamma radiation. The first step of this technique is the deposit of a film on the surface of material to be analyzed. Films can be deposited on the ground or also fixed on the walls or even on the ceiling. The film is a plastic sheet covered with an emulsion containing photostimulable crystals and Eu that is activated when the film is exposed on radioactive source. The exposed films are then scanned with the Cyclone Plus equipment to get a digitized image. This image represents the radioactivity of the surface studied. The possibility to re-use the films is very important to investigate a large area. This autoradiography technique has retained our attention for its sensitivity and moreover the possibility of 2-dimensional investigation has been found as a real advantage. However it remains now as a qualitative technique and new studies must be launched to prove its quantitative potentialities. The high spatial resolution was not as important as in biological observation, and the mm resolution is totally sufficient

  10. Distribution and speciation of radionuclides in the environment: their implication in radioecology

    International Nuclear Information System (INIS)

    Cigna, A.A.

    2000-01-01

    Following the discovery of X-ray and radioactivity, radioecological researches were initiated all over the world. But only after the 2nd World War the knowledge of the effects of ionizing radiations on the organisms and the processes of the diffusion of radionuclides in the environment achieved an outstanding level. On account of the great sensitivity of the radioactivity measurements, negligible amounts of radionuclides could be easily identified and measured in different environmental compartments without any slight interference with the metabolisms of living organisms. Many processes and phenomena could then be detected and studied. Ecology took advantage from such studies and its growth in a few years was probably greater than in the whole of the previous century. As a result a great interest in the determination of concentration factors in any organism spread widely in many laboratories, a large number of values were available in a few years time. Further it appeared that the transfer of the radionuclides from the environment to man could be better evaluated and monitored through the definition of some 'critical' quantity: a critical group, a critical radionuclide, a critical pathway, etc. The fallout dispersed by the experimental detonation of nuclear weapons and, more recently, the contamination due to the Chernobyl accident, were the most important sources of radionuclides in most of the environmental compartments. Undoubtedly in the post Chernobyl situation radioecology is in a better position because the description of the environment is presently much closer to reality and its conclusions much more reliable. But, as it is usual in science development, new problems appeared and new questions were asked. Speciation of radionuclides and other pollutants is considered and some of the effects on the diffusion and consequences are discussed. Finally, the application of the great amount of knowledge obtained by the radioecological research to a better

  11. Experimental investigation of Cs 137 distribution in a system of aquatic solution - solid phase - plant

    International Nuclear Information System (INIS)

    Marchiulioniene, D.; Kiponas, D.; Lukshiene, B.

    2005-01-01

    Investigation of Cs 137 accumulation in the plant Lepidium sativum L. (seeds, roots, aboveground part) and in the solid phase from the aquatic solution under laboratory conditions was performed. According to the obtained results, evaluation of Cs 137 distribution in the system aquatic solution - solid phase - plant and transfer of this radionuclide from the root system to the plant aboveground part during the plant growth process was done. (authors)

  12. Investigation of radionuclides and anthropic tracer migration in groundwater at the Chernobyl site

    Science.gov (United States)

    Le Gal La Salle, Corinnne; Simonucci, Caroline; Roux, Céline; Bugai, Dmitry; Aquilina, Luc; Fourré, Elise; Jean-Baptiste, Philippe; Labasque, Thierry; Michelot, Jean-Luc; Fifield, Keith; Team Aster Team; Van Meir, Nathalie; Kashparov, Valeriy; Diez, Olivier; Bassot, Sylvain; Lancelot, Joel

    2013-04-01

    Following the reactor 4 explosion of the Chernobyl Nuclear Power Plant (ChNPP), at least 1019 Bq of radionuclides (RN) were released in the environment. In order to protect workers and prevent further atmospheric RN dispersion in the area adjacent to the ChNPP, contaminated wastes including fuel particles, topsoil layer and forest remains were buried in approximately 800 shallow trenches in the sand formation in the Red Forest waste dump site [1]. No containment measures were taken, and since then RN have leaked to the unsaturated zone and to the groundwater. Since 1999, migration of RN in the vicinity of the trench 22 at Red Forest site has been investigated within the frame of the EPIC program carried out by IRSN in collaboration with UIAR and IGS [2, 3]. A plume of 90Sr was shown downgradient from the trench 22 with activites reaching 3750 Bq/L [2]. In 2008, further studies were initiated through the TRASSE research group, based on a collaboration between IRSN and CNRS. These programs aim at combining groundwater dating with RN migration monitoring studies in order to constrain RN transport models [3]. Groundwater residence time was investigated based on 3H/He and CFC. Both tracers led to ages ranging from modern (1-3 y) at 2 m depth below the groundwater table to significantly higher apparent ages of 50-60 y at 27 m below the groundwater table [3]. 36Cl/Cl ratios 2 to 4 orders of magnitude higher than the theoretical natural ratio are measured in groundwater. Similarly, SF6 shows concentrations as high as 1200 pptv while natural concentrations are in the order of 6-7 pptv. Based on apparent groundwater ages, both contaminations are linked to the Chernobyl explosion. Hence those tracers show excellent potential to constrain conservative and reactive transport, respectively. In contrast, 238U/235U ratio down gradient from trench 22 remains similar to the natural ratio. This suggests that either most of the U contained in the trench is in a non soluble form

  13. Distribution of artificial radionuclides in abandoned cattle in the evacuation zone of the Fukushima Daiichi nuclear power plant.

    Directory of Open Access Journals (Sweden)

    Tomokazu Fukuda

    Full Text Available The Fukushima Daiichi Nuclear Power Plant (FNPP accident released large amounts of radioactive substances into the environment. In order to provide basic information for biokinetics of radionuclides and for dose assessment of internal exposure brought by the FNPP accident, we determined the activity concentration of radionuclides in the organs of 79 cattle within a 20-km radius around the FNPP. In all the specimens examined, deposition of Cesium-134 ((134Cs, half-life: 2.065 y and (137Cs (30.07 y was observed. Furthermore, organ-specific deposition of radionuclides with relatively short half-lives was detected, such as silver-110m ((110mAg, 249.8 d in the liver and tellurium-129m ((129mTe, 33.6 d in the kidney. Regression analysis showed a linear correlation between the radiocesium activity concentration in whole peripheral blood (PB and that in each organ. The resulting slopes were organ dependent with the maximum value of 21.3 being obtained for skeletal muscles (R(2 = 0.83, standard error (SE = 0.76. Thus, the activity concentration of (134 Cs and (137Cs in an organ can be estimated from that in PB. The level of radioactive cesium in the organs of fetus and infants were 1.19-fold (R(2 = 0.62, SE = 0.12, and 1.51-fold (R(2 = 0.70, SE = 0.09 higher than that of the corresponding maternal organ, respectively. Furthermore, radiocesium activity concentration in organs was found to be dependent on the feeding conditions and the geographic location of the cattle. This study is the first to reveal the detailed systemic distribution of radionuclides in cattle attributed to the FNPP accident.

  14. Distribution of artificial radionuclides in animals in and around the evacuation zone of the Fukushima Daiichi Nuclear Power Plant

    International Nuclear Information System (INIS)

    Fukumoto, Manabu

    2014-01-01

    The Fukushima Daiichi Nuclear Power Plant (FNPP) accident released large amounts of radioactive substances into the environment. We collected organ specimens from over 200 cattle, 50 pigs and 100 monkeys within and adjacent to the 20-km radius previously set as the evacuation zone of FNPP. We have been performing determination of the concentration of radionuclides in the organs of animals. In all the specimens examined, both Cesium-134 ( 134 Cs) and 137 Cs were detectable in a gamma-ray spectrometer and the level of their radioactivity concentrations in each organ was quite similar after the decay correction to March 15, 2011, the day of major release of radionuclides. Linear correlation was found between radioactivity concentration of 137 Cs in whole peripheral blood (PB) and that in each organ. The slope of the regression line was organ dependent and was the highest in the skeletal muscles. The level of 137 Cs in an organ of both fetus and infants was higher than that of the corresponding maternal organ. Over all levels of radioactivity concentration of 137 Cs were dependent on the geological location, the environment and species. Organ-specific deposition of radionuclides with the relatively short half-life was detected, such as 110m Ag in the liver and 129m Te in the kidney of adult cattle. However both 110m Ag and 129m Te were not detectable in any organ of pigs or monkeys. This study is the first to reveal in detail the distribution of radionuclides attributed to the FNPP accident through the entire body of animals. (author)

  15. Investigation on the relationship between systemic burden and annual limits on intake of radionuclides

    International Nuclear Information System (INIS)

    Zhou Yongzeng

    1984-01-01

    The concept of systemic burden and the calculation of annual limits on intake (ALI) of radionuclides are discussed. The relationship between these two quantities is also described. Using this relationship, the ratio of actual amount of intake to ALI can be obtained for the assessment of the risk to internal exposure

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

    International Nuclear Information System (INIS)

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

    2009-01-01

    Artificial radionuclides enter the Mediterranean Sea mainly through atmospheric deposition following nuclear weapons tests and the Chernobyl accident, but also through the river discharge of nuclear facility effluents. Previous studies of artificial radionuclides impact of the Mediterranean Sea have focussed on shallow, coastal sediments. However, deep sea sediments have the potential to store and accumulate pollutants, including artificial radionuclides. Deep sea marine sediment cores were collected from Mediterranean Sea abyssal plains (depth > 2000 m) and analysed for 239,240 Pu and 137 Cs to elucidate the concentrations, inventories and sources of these radionuclides in the deepest areas of the Mediterranean. The activity - depth profiles of 210 Pb, together with 14 C dating, indicate that sediment mixing redistributes the artificial radionuclides within the first 2.5 cm of the sedimentary column. The excess 210 Pb inventory was used to normalize 239,240 Pu and 137 Cs inventories for variable sediment fluxes. The 239,240 Pu/ 210 Pb xs ratio was uniform across the entire sea, with a mean value of 1.24 x 10 -3 , indicating homogeneous fallout of 239,240 Pu. The 137 Cs/ 210 Pb xs ratio showed differences between the eastern (0.049) and western basins (0.030), clearly significant impact of deep sea sediments from the Chernobyl accident. The inventory ratios of 239,240 Pu/ 137 Cs were 0.041 and 0.025 in the western and eastern basins respectively, greater than the fallout ratio, 0.021, showing more efficient scavenging of 239,240 Pu in the water column and major sedimentation of 137 Cs in the eastern basin. Although areas with water depths of > 2000 m constitute around 40% of the entire Mediterranean basin, the sediments in these regions only contained 2.7% of the 239,240 Pu and 0.95% of the 137 Cs deposited across the Sea in 2000. These data show that the accumulation of artificial radionuclides in deep Mediterranean environments is much lower than predicted by

  17. Distribution and migration of cesium and strontium radionuclides in Estonian scots pine stands

    International Nuclear Information System (INIS)

    Martin, L.; Tekko, S.; Aaspollu, J.; Martin, J.; Vilde, R.; Nifontova, M.

    1994-01-01

    Radioactive pollution from the Chernobyl NPS reactor accident in 1986 has wide scale impact through radionuclides fallout over large areas. We used mushrooms, macrolichenes, mosses and pine needles, forest litter and soil for the investigaton of 137 Cs and 90 Sr accumulation and migration in pine ecosystems. Systematic collections were made on 63 field sites, total amount of samples analyzed is 350. Highest concentrations of radiocaesium were determined in mushrooms (41.8 kBq/kg) in north-east of Estonia, in macrolichens at the Lahemaa National Park (6.2 kBq/kg). At the Rumpo Botanical Reserve the level of radiocaesium exceeded background concentration (1985) 1.3-1.8 times and at the Koljaku 4.0-4.4 times. During five years of observations (1986-1991) decrease of radionuclides pollution revealed 15 times the Rumpo and Koljaku. Radiostrontium concentrations in different ecosystem compartments all over the territory did not exeed harmful levels. (author). 2 tabs

  18. Preliminary investigation of naturally occurring radionuclides in some traditional medicinal plants used in Nigeria

    Directory of Open Access Journals (Sweden)

    R.L. Njinga

    2015-04-01

    Full Text Available The preliminary investigation of the activity concentration of Naturally Occurring Radioactive Materials (NORMs in seven different medicinal plants; Anacardium occidentale, Azadirachta indica, Daniella oliveri, Moringa oleifera, Psidium guajava, Terminalia catappa and Vitellaria paradoxa by means of gamma spectroscopic analysis using a NaI[Tl] detector shows that the activity concentration of 40K in the medicinal plants ranges from 74.59 ± 2.19 Bq/Kg to 324.18 ± 8.69 Bq/Kg with an average of 171.72 ± 6.09 Bq/Kg. The highest activity concentration of 40K was recorded for A. indica while A. occidentale had the lowest activity concentration. 226Ra activity concentration varies from 10.79 ± 4.24 Bq/Kg to 42.47 ± 2.76 Bq/Kg with an average of 25.02 ± 3.18 Bq/Kg. The lowest activity was recorded for P. guajava while the highest activity was recorded for V. paradoxa. For the activity concentration of 232Th, it ranges from 27.76 ± 1.02 Bq/Kg to 41.05 ± 1.05 Bq/Kg, with an average of 35.09 ± 0.71 Bq/Kg. The lowest activity was recorded for V. paradoxa while the highest activity was recorded for T. catappa. The average annual committed effective doses due to ingestion of 226Ra, 232Th and 40K in the plants ranges from 0.00426 ± 0.00050 mSv/yr to 0.00686 ± 0.00044 mSv/yr with an average of 0.00538 ± 0.00035 mSv/yr, the highest value was recorded for A. occidentale while P. guajava has the lowest, the results determined for all the plants are far below the worldwide average annual committed effective dose of 0.3 mSv/yr for an individual provided in UNSCEAR 2000 report indicating that the associated radiological health risk resulting from the intake of radionuclides in the medicinal plants is insignificant. Consequently, the medicinal plants of this study are considered safe in terms of the radiological health hazards.

  19. Direct Investigations of the Immobilization of Radionuclides in the Alteration Products of Spent Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Peter C. Burns; Robert J. Finch; David J. Wronkiewicz

    2004-12-27

    Safe disposal of the nation's nuclear waste in a geological repository involves unique scientific and engineering challenges owing to the very long-lived radioactivity of the waste. The repository must retain a variety of radionuclides that have vastly different chemical characters for several thousand years. Most of the radioactivity that will be housed in the proposed repository at Yucca Mountain will be associated with spent nuclear fuel, much of which is derived from commercial reactors. DOE is custodian of approximately 8000 tons of spent nuclear fuel that is also intended for eventual disposal in a geological repository. Unlike the spent fuel from commercial reactors, the DOE fuel is diverse in composition with more than 250 varieties. Safe disposal of spent fuel requires a detailed knowledge of its long-term behavior under repository conditions, as well as the fate of radionuclides released from the spent fuel as waste containers are breached.

  20. Immunological and epidemiological investigations in regions contaminated by radionuclides after the Chernobyl accident

    International Nuclear Information System (INIS)

    Shubik, V.M.

    1997-01-01

    We have carried out in Novozybkov district of Bryansk region, Russia, immunologic inspection of residents with simultaneous evaluation of radionuclides content in the body and individual dose burden. We have not found any correlation between the dose and immune characteristics: amount of T and B lymphocytes, antibodies level. Only 3 months after the accident increased level of antibodies against thyroid antigens, thyroglobulin and microsomes was found at thyroid doses over 75 cGy. 3 tabs

  1. Statistical Approach for Determination of Compliance with Clearance Criteria Based upon Types of Radionuclide Distributions in a Very Low-Level Radioactive Waste

    International Nuclear Information System (INIS)

    Cheong, Jae Hak

    2010-01-01

    A statistical evaluation methodology was developed to determine the compliance of candidate waste stream with clearance criteria based upon distribution of radionuclide in a waste stream at a certain confidence level. For the cases where any information on the radionuclide distribution is not available, the relation between arithmetic mean of radioactivity concentration and its acceptable maximum standard deviation was demonstrated by applying widely-known Markov Inequality and One-side Chebyshev Inequality. The relations between arithmetic mean and its acceptable maximum standard deviation were newly derived for normally or lognormally distributed radionuclide in a waste stream, using probability density function, cumulative density function, and other statistical relations. The evaluation methodology was tested for a representative case at 95% of confidence level and 100 Bq/g of clearance level of radioactivity concentration, and then the acceptable range of standard deviation at a given arithmetic mean was quantitatively shown and compared, by varying the type of radionuclide distribution. Furthermore, it was statistically demonstrated that the allowable range of clearance can be expanded, even at the same confidence level, if information on the radionuclide distribution is available.

  2. Radionuclide antisense therapy

    International Nuclear Information System (INIS)

    Ou Xiaohong

    2002-01-01

    Radionuclide antisense therapy achieves the joint goals of antisense therapy and internal radiation therapy. There have been a small number of investigations on the radionuclide antisense therapy in tissue culture and in animal studies. Considerable research is required before this novel technique can become a working practice. The authors reviewed some question and development on the radionuclide antisense therapy, such as selection of the target gene sequence, labelling the antisense oligonucleotide, improvement of the uptake and target of radionuclide antisense oligonucleotides and evaluation of the toxicity of the radionuclide antisense therapy

  3. Speciation analysis of radionuclides

    International Nuclear Information System (INIS)

    Salbu, B.

    2010-01-01

    Full text: Naturally occurring and artificially produced radionuclides in the environment can be present in different physico-chemical forms (i. e. radionuclide species) varying in size (nominal molecular mass), charge properties and valence, oxidation state, structure and morphology, density, complexing ability etc. Low molecular mass (LMM) species are believed to be mobile and potentially bioavailable, while high molecular mass (HMM) species such as colloids, polymers, pseudocolloids and particles are considered inert. Due to time dependent transformation processes such as mobilization of radionuclide species from solid phases or interactions of mobile and reactive radionuclide species with components in soils and sediments, however, the original distribution of radionuclides deposited in ecosystems will change over time and influence the ecosystem behaviour. To assess the environmental impact from radionuclide contamination, information on radionuclide species deposited, interactions within affected ecosystems and the time-dependent distribution of radionuclide species influencing mobility and biological uptake is essential. The development of speciation techniques to characterize radionuclide species in waters, soils and sediments should therefore be essential for improving the prediction power of impact and risk assessment models. The present paper reviews fractionation techniques which should be utilised for radionuclide speciation purposes. (author)

  4. Radionuclide ventilation-perfusion studies in pediatric respiratory diseases: 157 measurements of the distribution of ventilation and perfusion in 130 children

    International Nuclear Information System (INIS)

    Guillet, J.; Basse-Cathalinat, B.; Christophe, E.; Saudubray, F.

    1983-01-01

    Radionuclide investigations provide regional quantitative and kinetic data with a very low exposure. Results are dissonant with roentgenographic findings in 52% of cases and enhance diagnostic and prognostic accuracy. Although it provides poor quality images. The use of 133 Xe is preferable for ventilation studies to ensure correct evaluation of washout and trapping. According to the patient's age and position, 50% washout times vary from 5.6 to 8.7 seconds in the upper segments and from 5.6 to 8.5 seconds in the lower segments. Distribution of blood flow can be studied after intravenous injection of either sup(99m)Tc labelled microspheres of human albumin or 133 Xe saline solution. The former provides better quality images with studies of all incidences but may be contraindicated in cases of severe pulmonary hypertension or major right-to-left shunts. The latter allows a better sequential study. Radionuclide ventilation-perfusion studies are one of the major advances in pediatric pneumology in recent years [fr

  5. Distribution of natural radionuclides in surface soils in the vicinity of abandoned uranium mines in Serbia.

    Science.gov (United States)

    Momčilović, Milan; Kovačević, Jovan; Tanić, Milan; Dorđević, Milan; Bačić, Goran; Dragović, Snežana

    2013-02-01

    The activity concentrations of natural radionuclides in soils from the area affected by uranium mining at Stara Planina Mountain in Serbia were studied and compared with the results obtained from an area with no mining activities (background area). In the affected area, the activity concentrations ranged from 1.75 to 19.2 mg kg(-1) for uranium and from 1.57 to 26.9 mg kg(-1) for thorium which is several-fold higher than those in the background area. The Th/U, K/U, and K/Th activity ratios were also determined and compared with data from similar studies worldwide. External gamma dose rate in the air due to uranium, thorium, and potassium at 1 m above ground level in the area affected by uranium mining was found to be 91.3 nGy h(-1), i.e., about two-fold higher than that in background area. The results of this preliminary study indicate the importance of radiological evaluation of the area and implementation of remedial measures in order to prevent further dispersion of radionuclides in the environment.

  6. Vertical random variability of the distribution coefficient in the soil and its effect on the migration of fallout radionuclides

    International Nuclear Information System (INIS)

    Bunzl, K.

    2002-01-01

    In the field, the distribution coefficient, K d , for the sorption of a radionuclide by the soil cannot be expected to be constant. Even in a well defined soil horizon, K d will vary stochastically in horizontal as well as in vertical direction around a mean value. The horizontal random variability of K d produce a pronounced tailing effect in the concentration depth profile of a fallout radionuclide, much less is known on the corresponding effect of the vertical random variability. To analyze this effect theoretically, the classical convection-dispersion model in combination with the random-walk particle method was applied. The concentration depth profile of a radionuclide was calculated one year after deposition assuming constant values of the pore water velocity, the diffusion/dispersion coefficient, and the distribution coefficient (K d = 100 cm 3 x g -1 ) and exhibiting a vertical variability for K d according to a log-normal distribution with a geometric mean of 100 cm 3 x g -1 and a coefficient of variation of CV 0.53. The results show that these two concentration depth profiles are only slightly different, the location of the peak is shifted somewhat upwards, and the dispersion of the concentration depth profile is slightly larger. A substantial tailing effect of the concentration depth profile is not perceivable. Especially with respect to the location of the peak, a very good approximation of the concentration depth profile is obtained if the arithmetic mean of the K d -values (K d = 113 cm 3 x g -1 ) and a slightly increased dispersion coefficient are used in the analytical solution of the classical convection-dispersion equation with constant K d . The evaluation of the observed concentration depth profile with the analytical solution of the classical convection-dispersion equation with constant parameters will, within the usual experimental limits, hardly reveal the presence of a log-normal random distribution of K d in the vertical direction in

  7. Investigation into kinetics of sorption of some radionuclides by mixed sorbents based on amorphous niobium phosphate

    International Nuclear Information System (INIS)

    Belkina, R.M.; Sukharev, Yu.I.; Egorov, Yu.V.; Plotnikov, V.I.

    1977-01-01

    A study has been made of kinetics of sorption of radionuclides 110 Ag, 60 Co, and 51 Cr by samples of amorphous stoichiometric niobium (5) phosphate. Ratios of the concentration conductivity to the mean radius of sorbent particles were calculated which are proportional to diffusivities. Increased specificity towards Cr 3+ ions of samples of ion exchangeable niobium phosphate containing cerium and treated with 0.1N HCl was established. This effect was explained by formation and subsequent destruction of the copolymer oxo-ol matrix of niobium and cerium, as a result of which a gel is formed with mosaic structure being favourable for sorption of three-charged ions

  8. Radionuclide method for determination of gastric content proteolytic activity, (Clinical investigation)

    International Nuclear Information System (INIS)

    Sergienko, V.B.; Popova, L.V.; Khodarev, N.N.; Mel'nikov, N.A.

    1988-01-01

    Clinical testing of a new tubeless radionuclide rapid method for measuring gastric content proteolytic activity (GCPA) using a protein (gelatin) capsule filled with a radiopharmaceutical (RP) labelled with 99m Tc is described. The solution time of a capsule with a radiotracer determined by its clearance, corresponded to GCPA measured after Mett's method. The testing has shown that the above method is physiological, causes no complications and unpleasant sensations in patients, is simple to perform, and can be recommended for a wide clinical use in gastroenterology

  9. Laboratory experiments to investigate radionuclide enrichment in the sea-surface microlayer

    International Nuclear Information System (INIS)

    Hickmott, S.J.B.

    1982-02-01

    Samples of simulated seawater, and seawater from the Irish Sea, were contained in a plastic tank in the laboratory, and bubbles were passed through them to burst at the water surface. The emitted jet droplets, as representing the surface microlayer, were collected on filter papers. Such measurements are easier to perform than similar measurements at sea, and the lack of waves enables greater collection efficiencies to be obtained. The droplet samples were analysed for stable Na, 137 Cs and actinides, and compared with the concentrations in the bulk tank water, in order to examine possible concentration factors for radionuclides in the surface microlayer. (author)

  10. Distribution of radionuclides in soil samples from a petrified wood forest in El-Qattamia, Cairo, Egypt

    International Nuclear Information System (INIS)

    Nada, A.; Abd-El Maksoud, T.M.; Abu-Zeid Hosnia, M.; El-Nagar, T.; Awad, S.

    2009-01-01

    The concentrations and distribution of radionuclides in a petrified wood forest in El-Qattamia have been determined using high-resolution gamma spectrometry to evaluate the environmental radioactivity. The mean activity concentrations of 238 U, 232 Th and 40 K were 65.26±12.99, 23.66±0.95 and 146.33±1.50 Bq kg -1 , respectively. Data of the soil samples show evidence of possible deposition and accumulation of 137 Cs. The mean activity concentration of 137 Cs in the soil samples was 4.37±0.16 Bq kg -1 with a range of 0.00-35.70 Bq kg -1 . The measured activity concentration range of 137 Cs was compared with reported ranges in the literature from some of the other locations in the world. The radium-equivalent, dose rate in air and annual effective dose rate were evaluated. The mean activity concentrations of the γ-ray emissions from radionuclides in El-Qattamia petrified wood forest region were relatively low

  11. Determination of distribution coefficients for 134 Cs, 60 Co and 234 Th radionuclides in Pinheiro river sediment

    International Nuclear Information System (INIS)

    Lima, M.F.

    1992-01-01

    The distribution coefficients (K α) were determined in order to foresee the fate of the radionuclides discharged to the environment. Based upon the source-term released by IPEN's facilities in Pinheiros River during the year of 1988, three radionuclides were chosen as being the more critical, according to the radiation protection standards: 137 Cs, 60 Co and 232 Th. Their K α were determined experimentally in laboratory by using the corresponding radioactive tracers 134 Cs, 60 Co and 234 Th. Three different experimental methodologies were used: the static method, the shaken method and the dynamic method. The parameters studied were the effects of pH, aerobic condition and time of contact. The results obtained experimentally for the Kds confirm the predictions that: the cesium is slowly retained by the sediment along the Pinheiros River, the cobalt is an unstable element, therefore its retention by the sediment is affected by variations in the pH values, and finally, the thorium is almost completely retained in the vicinity of the discharge point. (author)

  12. Simulation of deposition and activity distribution of radionuclides in human airways

    International Nuclear Information System (INIS)

    Farkas, A.; Balashazy, I.; Szoke, I.; Hofmann, W.; Golser, R.

    2002-01-01

    The aim of our research activities is the modelling of the biological processes related to the development of lung cancer at the large central-airways observed in the case of uranium miners caused by the inhalation of radionuclides (especially alpha-emitting radon decay products). Statistical data show that at the uranium miners the lung cancer has developed mainly in the 3-4.-5. airway generations and especially in the right upper lobe. Therefore, it is rather important to study the physical and biological effects in this section of the human airways to find relations between the radiation dose and the adverse health effects. These results may provide useful information about the validity or invalidity of the currently used LNT (Linear-No-Threshold) dose-effect hypothesis at low doses

  13. The Spatial Distribution of Heavy Metals and Radionuclides in the South Ural

    CERN Document Server

    Smirnov, L I; Staines, E; Lyapunov, S M; Cherdintsev, V D; Romanov, S A; Samosadnyi, V T

    2003-01-01

    Samples of the mosses Hylocomium splendens, Pleurozium schreberi and surface soil, collected in 1997-2001, were used to study the atmospheric deposition of heavy metals and radionuclides in the South Ural Mountains characterized by intense anthropogenic impact from various industries. A total of 38 elements in soil and 33 elements in moss were determined by epithermal neutron activation analysis. The elements Cu, Cd and Pb were determined in moss samples only by atomic absorption spectrometry. ^{90}Sr and ^{137}Cs activity was measured in surface soil samples also. VARIMAX rotated principal component analysis and GIS maps of factor scores were used to identify and characterise different pollution sources and to point out the most polluted areas.

  14. Studies on parameters influencing quantitative scintillation camera measurements of in vivo radionuclide distributions

    International Nuclear Information System (INIS)

    Strand, S.E.

    1979-01-01

    Counting losses and image artifacts occurring in single-crystal NaI(T1) scintillation cameras at high photon fluence rates were investigated. Distinguishing between correctly and falsely positioned events the amount of pile-up in the image was measured experimentally. A theoretical model based on the scintillation properties of the NaI(T1) crystal was developed. Three methods of correcting for attenuation have been investigated: 1. The dual photopeak-area method was used for studies of the uptake of 123 I in the thyroid. An average effective depth for use in calculating the attenuation correction factor was determined. 2. The anterior-posterior method was used to estimate the effective depths of kidneys and lymph nodes, these being correlated with 3. lateral views. A technique for quality control of radiopharmaceuticals has been developed using the gel-chromatography-scanning technique. The activity-size distribution of different colloids was correlated with their biological ability to be trapped in the lymph nodes after subcutaneous injection. (author)

  15. Radionuclides in terrestrial ecosystems

    International Nuclear Information System (INIS)

    Bocock, K.L.

    1981-01-01

    This report summarizes information on the distribution and movement of radionuclides in semi-natural terrestrial ecosystems in north-west England with particular emphasis on inputs to, and outputs from ecosystems; on plant and soil aspects; and on radionuclides in fallout and in discharges by the nuclear industry. (author)

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

    International Nuclear Information System (INIS)

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

    2008-01-01

    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

  17. Assessment of function of the cardiovascular system in arterial hypertension using radionuclide methods of investigation

    International Nuclear Information System (INIS)

    Oganesyan, N.M.; Babayan, A.S.; Mikaehlyan, R.S.; Mnatsakyan, Eh.L.

    1986-01-01

    Proceeding from a study of the nature of changes in hemodynamics during development of hypertensive disease (HD) at its different stages it was shown that hemodynamic changes in 42.1% of the patients with Stage 1-2A HD were of hypertensive type, in the patients with Stage 2B-3 HD normal and hypokinetic types of the blood circulation prevailed. After bicycle ergometry exercise the reactivity of the cardiovascular system was revealed more completely. The most complete information on function of the cardiovascular system and myocardial contractility can be obtained with the help of radioangiocardiography and radionuclide ventriculography. However in the absence of a gamma-chamber radiocardiography can provide necessary information on function of the cardiovascular system in case it is used in one and the same patient over time using bicycle ergometry testing

  18. Radionuclides distribution in blooming of the permian sediments from the Irati Formation of the Parana Basin

    International Nuclear Information System (INIS)

    Ferreira, Ademar de Oliveira

    2008-02-01

    The objective of this work is to study natural radionuclides in sedimentary rocks. The concentration of them reflects the origin of the sediments, the depositional environment as well as some mineralogical characteristics of the rock matrix, and also more recent events as weathering and erosion. Using gamma ray high resolution spectrometry, the profile of activity concentration of the natural radionuclides was assessed for 226 Ra, 238 U, 32 Th and 40 K in rocks of the Irati Formation belonging to Parana Sedimentary Basin. The samples were collected at a limestone abandoned mine, in the city of Sapopema, (PR). 24 samples were collected, eleven from the exposed vertical profile with approximately 5.50 m, whose stratigraphy is represented by an alternation among decimetrics layers of limestones, bituminous shales, and some rhythmits layers (milimetric sheets of limestone and bituminous shales), 9 repetitions of a sample to study the variability, and three rigolits samples in sequential apprenticeships of weathering. Each sample was dried in the sun during about 48 hours, broken, drizzled in a sieve of 4 mesh and put, in a cylindrical container. The measures were accomplished using a Germanium Hyper Pure detector (HPGe) with relative efficiency of 66%, connected to a standard spectrometry electronic chain. The measured concentrations of activity of 238 U were smaller for the limestones (17.80 ±0.09 Bq.Kg -1 ), larger for the bituminous shales (125.5 ± 2.6 Bq.Kg -1 with enrichment of uranium in the sample (200), 548 ± 16 Bq.Kg -1 , upper part of the column), and intermediate for the rhythmits (23.0 ± 1,3 Bq.Kg -1 . The ratio eTh/K obtained for the studied profiles has equivalent values, indicating similar mineralogical characteristics for the limestones, bituminous shales, rhythmits and studied rigolits. On the other hand, to the ratio eTh/eU showed that two of the three regolits samples belong to oxidizer atmospheres, favoring the leaching of uranium, what can be

  19. Study on plutonium distribution in Palomares ecosystem after an accidental aerosol release of transuranic radionuclides

    International Nuclear Information System (INIS)

    Gasco Sanchez, L.

    1990-01-01

    A discharge of plutonium and transuranic elements accidentally ocurred near Palomares (Almeria, Spain) in 1966. After decontamining operations, about 10 g of finely dispersed plutonium remained on the soil and was spreaded on the sorroundings and into Mediterranean sea. An analytical study including a 34 sampling sites of marine sediments, chemical clean-up, analytical methods for isolating plutonium from interfering radionuclides in the alfa-spectra was carried out. The detection limit level reached for the 239 u+ 240 Pu was 10 mBq/Kg one of the lowest cited in the Spanish analytical literature until now. These results were attained following a careful electroplating Pu deposition method developed by our laboratory as result of the high signal/noise rates measured and a 20 KeV resolution. Several analytical assurance quality procedures specially developed for the Palomares ecological system were applied to the results, at the CIEMAT laboratories using reference standard certified samples. The values were unbiased and with no differences statistically significants between them. Interlaboratory comparisons were carried out. After 20 years of plutonium traces environmental transport their concentration were from two at three times the leves of radionuclides in the fallout of the zone studied. The plutonium concentration range in surface sediments was 0.3-5.0 Bq/Kg. The highest values corresponding in the coastal sediments and the lowest in the deep sea. Plutonium concentrations are highly correlated with the sediments structure, grain size composition and distance from the mouth of Almanzora river. The most important contribution at the transport from the land into sea could be the freshet occured at 1973. For this reason the plutonium ecologycal path has been from Palomares sorroundings into the sea. Sites in the Mediterranean sea not affected by plutonium apportation from Almanzora river showed Pu levels approximately the same as the mean value for the whole

  20. Investigations of radionuclide production in a spallation target carried out in the frame of MUSE and SAD projects

    Energy Technology Data Exchange (ETDEWEB)

    Pohorecki, W.; Janczyszyn, J; Taczanowski, S. [AGH-University of Science and Technology, Faculty of Nuclear Physics, Al Mickiewicza 30, PL-30059 Krakow (Poland); Mirokhin, I.V.; Molokanov, A.G. [Dzhelepov Laboratory of Nuclear Problems, Joint Institute of Nuclear Research, JINR, 6 Joliot Curie Street, Dubna, Moscow Region 141980 (Russian Federation); Horwacik, T. [Institute of Nuclear Physics, ul. Radzikowskiego 152 31-342 Cracow (Poland); Polanki, A. [Laboratory of Information Technologies, Joint Institute for Nuclear Research, 6 Joliot Curie Street, Dubna, Moscow Region 141980 (Russian Federation)

    2004-07-01

    Designing of an accelerator driven system needs a thorough evaluation of build-up of long-lived radioactivity and changes in elemental composition in construction materials. This data can be only calculated with the use of experimentally verified computer codes and data libraries. The present experiment is thought as a part of such validation. Two types of detectors were irradiated inside and/or on the surface of a cylindrical Pb targets irradiated with 660 MeV protons: activation detectors made of typical target materials - Pb, Bi, and track detectors with heavy metal radiators - Bi, Pb, Au, W, Ta. Activities of several radionuclides in Pb and Bi samples were determined and compared with values obtained from LAHET, MCNPX and FLUKA-2002 calculations. In the track detectors density of tracks and their size distributions were measured. (authors)

  1. Distribution of Natural (U-238, Th-232, Ra-226) and Technogenic (Sr-90, Cs-137) Radionuclides in Soil-Plants Complex Near Issyk-Kul Lake, Kyrgyzstan

    Science.gov (United States)

    Jovanovic, L.; Kaldybaev, B.; Djenbaev, B.; Tilenbaev, A.

    2012-04-01

    Researches on radionuclides distribution in the soil-plants complex provide essential information in understanding human exposure to natural and technogenic sources of radiation. It is necessary in establishing regulation relating to radiation protection. The aim of this study was the radiochemical analysis of the content natural radionuclides 238U, 232Th,226Ra and technogenic radionuclides content (90Sr, 137Cs) in soils near Issyk-Kul lake (Kyrgyzstan). Results of radiochemical analyses have shown, that the concentrations of thorium-232 are fluctuating in the limits (11.7-84.1)-10-4% in the soils. The greatest concentration of thorium-232 has been found in the light chestnut soils. The content of uranium-238 in the soils near Issyk-Kul lake is fluctuating from 2.8 up to 12.7-10-4%. Radium-226 has more migration ability in comparison with other heavy natural radionuclides. According to our research the concentrations of radium-226 are fluctuating in the limits (9.4-43.0)-10-11%. The greatest concentration of radium-226 (43,0±2,8)-10-11% has been determined in the light chestnut soil. In connection with global migration of contaminating substances, including radioactive, the special attention is given long-lived radionuclides strontium-90 and caesium-137 in food-chains, and agroecosystems. Results of radiochemical analyses have shown, that specific activity of strontium-90 is fluctuating in the range of 2.9 up to 11.1 Bq/kg, and caesium-137 from 3.7 up to 14,3 Bq/kg in the soil of agroecosystems in the region of Issyk-Kul. In soil samples down to 1 meter we have observed vertical migration of these radionuclides, they were found to accumulate on the surface of soil horizon (0-5 cm) and their specific activity sharply decreases with depth. In addition in high-mountain pastures characterized by horizontal migration of cattle in profiles of soil, it was discovered that specific activity of radionuclides are lower on the slope than at the foot of the mountain. The

  2. Distribution of natural and anthropogenic radionuclides in beach sand samples from Mediterranean Coast of Turkey

    International Nuclear Information System (INIS)

    Özmen, S.F.; Cesur, A.; Boztosun, I.; Yavuz, M.

    2014-01-01

    Following Fukushima Dai-ichi Nuclear Power Plant accident, a huge amount of radionuclides were released in atmosphere and ocean. It's impact on the environment is of great concern to the good of the public at large. In this regard environmental radioactivity monitoring such as external dose rate and radioactivity measurements in environmental samples has been carried out. For this purpose, several beach sand samples were collected from south coast of the Turkey in September 2011 and radioactivity concentrations of 226 Ra ( 238 U), 228 Ac ( 232 Th), 40 K, 134 Cs and 137 Cs were determined by gamma spectrometry using a high-purity Germanium detector. The measured activity concentrations in beach sand samples ranged from 4.0±0.5 to 21.5±1.8 Bq/kg, 1.8±0.4 to 27.9±2.4 Bq/kg, 19.0±2.2 to 590.3±28.6 Bq/kg and 0.1±0.0 to 1.0±0.1 Bq/kg for 226 Ra, 232 Th, 40 K and 137 Cs, respectively. However there was no sign of 134 Cs in the sample spectrum after Fukushima Dai-ichi Nuclear Power Plant accident. Hence we can safely conclude that there was no significant material transfer from Fukushima to Turkey. The other activities are in good agreement with the published results of neighboring areas. The absorbed gamma dose rate (D) and the annual effective dose (AED) of beach sand samples were below the world wide average implying that the radiation hazard is insignificant. The data presented in this study would also be very useful to determine the possible future effects of the nuclear power plant to the environment. - Highlights: • Activity values of all samples are lower than the world wide average values. • Gamma dose rates of beach sand samples are in the range of 10–200 nGy/h. • Ra eq activity and AED values of samples are less than world wide average values. • No significant material transfer from Fukushima to Turkey. • Strong correlations detected in between elemental and radioactivity concentration

  3. Elementary analyses in behalf of the project: Orientating investigation to Polonium-210 and other radionuclides in Dutch aquatic ecosystems

    International Nuclear Information System (INIS)

    Hart, M.J. 't; Breugem, P.M.; Koester, H.W.

    1989-11-01

    In this report, results of the determinations of total, organic and inorganic carbon analysis are reported for the project 'Orientating investigations of Polonium-210 and other natural radionuclides in Dutch aquatic ecosystems', projectnumber 248476. The method used is a modification of the method described by Froelich and is based on elemental analysis. Sediment samples from several locations of sea and river water show a large variation of the carbon content. The organic carbon concentration varies from 2.78 to 22.42 percent; the inorganic carbon varies from 1.25 to 5.66 percent. The analyses were run in duplicate with a mean standard deviation of 0.1 percent. (author). 4 refs.; 5 figs.; 7 tabs

  4. Marine biogeochemistry of radionuclides

    International Nuclear Information System (INIS)

    Fowler, S.W.

    1997-01-01

    Radionuclides entering the ocean from runoff, fallout, or deliberate release rapidly become involved in marine biogeochemical cycles. Sources, sinks and transport of radionuclides and analogue elements are discussed with emphasis placed on how these elements interact with marine organisms. Water, food and sediments are the source terms from which marine biota acquire radionuclides. Uptake from water occurs by surface adsorption, absorption across body surfaces, or a combination of both. Radionuclides ingested with food are either assimilated into tissue or excreted. The relative importance of the food and water pathway in uptake varies with the radionuclide and the conditions under which exposure occurs. Evidence suggests that, compared to the water and food pathways, bioavailability of sediment-bound radionuclides is low. Bioaccumulation processes are controlled by many environmental and intrinsic factors including exposure time, physical-chemical form of the radionuclide, salinity, temperature, competitive effects with other elements, organism size, physiology, life cycle and feeding habits. Once accumulated, radionuclides are transported actively by vertical and horizontal movements of organisms and passively by release of biogenic products, e.g., soluble excreta, feces, molts and eggs. Through feeding activities, particles containing radionuclides are ''packaged'' into larger aggregates which are redistributed upon release. Most radionuclides are not irreversibly bound to such particles but are remineralized as they sink and/or decompose. In the pelagic zones, sinking aggregates can further scavenge particle-reactive elements thus removing them from the surface layers and transporting them to depth. Evidence from both radiotracer experiments and in situ sediment trap studies is presented which illustrates the importance of biological scavenging in controlling the distribution of radionuclides in the water column. (author)

  5. Vertical and horizontal distribution of radionuclides (232Th, 238U and 40K) in sediment from Manjung coastal water area Perak, Malaysia

    Science.gov (United States)

    Abdullah, Anisa; Hamzah, Zaini; Saat, Ahmad; Wood, Ab. Khalik

    2016-01-01

    Distribution of radionuclides from anthropogenic activities has been widely studied in marine coastal area. Due to rapid population growth and socio-economic development in Manjung area such as coal fired power plant, iron foundries, port development, waste discharged from factories and agriculture runoff may contribute to increase in pollution rate. The radioactive materials from anthropogenic activities could deteriorate the quality of the marine ecosystem and thus lead to possible radiological health risk to the population. Radionuclides (232Th, 238U and 40K) content in surface and profile sediment from Manjung coastal area was determined in this study. Radionuclides in sediment from seven locations were collected using sediment core sampling and measurements were carried out using Energy Dispersive X-ray Fluorescence (EDXRF) spectroscopy. The results show that the concentration of radionuclides in surface sediment and distribution trend of depth vertical profile sediment generally varies depending on locations. Enrichment factors (EF), geo-accumulation index (Igeo) and pollution index (PI) were applied to determine level of pollution of this study area. The radiological risks related to human exposure were evaluated based on external hazard index (Hex).

  6. Vertical and horizontal distribution of radionuclides ({sup 232}Th, {sup 238}U and {sup 40}K) in sediment from Manjung coastal water area Perak, Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Abdullah, Anisa, E-mail: coppering@ymail.com; Hamzah, Zaini; Wood, Ab. Khalik [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450, Shah Alam, Selangor (Malaysia); Saat, Ahmad [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450, Shah Alam, Selangor (Malaysia); Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)

    2016-01-22

    Distribution of radionuclides from anthropogenic activities has been widely studied in marine coastal area. Due to rapid population growth and socio-economic development in Manjung area such as coal fired power plant, iron foundries, port development, waste discharged from factories and agriculture runoff may contribute to increase in pollution rate. The radioactive materials from anthropogenic activities could deteriorate the quality of the marine ecosystem and thus lead to possible radiological health risk to the population. Radionuclides ({sup 232}Th, {sup 238}U and {sup 40}K) content in surface and profile sediment from Manjung coastal area was determined in this study. Radionuclides in sediment from seven locations were collected using sediment core sampling and measurements were carried out using Energy Dispersive X-ray Fluorescence (EDXRF) spectroscopy. The results show that the concentration of radionuclides in surface sediment and distribution trend of depth vertical profile sediment generally varies depending on locations. Enrichment factors (EF), geo-accumulation index (I{sub geo}) and pollution index (PI) were applied to determine level of pollution of this study area. The radiological risks related to human exposure were evaluated based on external hazard index (H{sub ex})

  7. Vertical and horizontal distribution of radionuclides (232Th, 238U and 40K) in sediment from Manjung coastal water area Perak, Malaysia

    International Nuclear Information System (INIS)

    Abdullah, Anisa; Hamzah, Zaini; Wood, Ab. Khalik; Saat, Ahmad

    2016-01-01

    Distribution of radionuclides from anthropogenic activities has been widely studied in marine coastal area. Due to rapid population growth and socio-economic development in Manjung area such as coal fired power plant, iron foundries, port development, waste discharged from factories and agriculture runoff may contribute to increase in pollution rate. The radioactive materials from anthropogenic activities could deteriorate the quality of the marine ecosystem and thus lead to possible radiological health risk to the population. Radionuclides ( 232 Th, 238 U and 40 K) content in surface and profile sediment from Manjung coastal area was determined in this study. Radionuclides in sediment from seven locations were collected using sediment core sampling and measurements were carried out using Energy Dispersive X-ray Fluorescence (EDXRF) spectroscopy. The results show that the concentration of radionuclides in surface sediment and distribution trend of depth vertical profile sediment generally varies depending on locations. Enrichment factors (EF), geo-accumulation index (I geo ) and pollution index (PI) were applied to determine level of pollution of this study area. The radiological risks related to human exposure were evaluated based on external hazard index (H ex )

  8. Investigations of the uptake of transuranic radionuclides by humic and fulvic acids chemically immobilized on silica gel and their competitive release by complexing agents

    International Nuclear Information System (INIS)

    Bulman, R.A.; Szabo, G.; Clayton, R.F.; Clayton, C.R.

    1998-01-01

    The chemistry of the interactions of transuranic elements (TUs) with humic substances needs to be understood so that humate-mediated movement of transuranic radionuclides through the environment can be predicted. This paper reports the chemical immobilization on silica gel of humic and fulvic acids and evaluates the potential of these new materials for the retention of Pu and Am. In addition to the preparation of the foregoing immobilized humic substances, other low molecular weight metal-binding ligands have also been immobilized on silica gel to investigate the binding sites for transuranic elements (TUs) in humic substances. The X-ray photoelectron spectra (XPS) of Th(IV) complexed by humic acid and the immobilized humic acid are similar thus it appears that immobilization of humic acid does not generate any configurational changes in the Th(IV)-binding sites of the macromolecule. A variety of chelating agents partly mobilize these TUs sorbed on the solid phases. A batch method was used to determine the distribution coefficients (R d ) of Pu and Am between the silica gels and aqueous solutions of phosphate and citrate. The effects of the immobilized ligands, the anions and pH in the solution on sorption were assessed. Distributed coefficients (R d ) for the uptake of Pu and Am by these prepared solid phases are, in some cases, of a similar order of magnitude as those determined for soil and particles suspended in terrestrial surface waters

  9. Determination of distribution coefficients (K{sub d}) of various radionuclides on UTEVA resin

    Energy Technology Data Exchange (ETDEWEB)

    Marinov, Genko M.; Marinova, Atanaska P. [Joint Institute for Nuclear Research, DLNP, Dubna (Russian Federation); Sofia Univ. (Bulgaria). Faculty of Chemistry and Pharmacy; Medvedev, Dmitry V.; Filosofov, Dmitry V. [Joint Institute for Nuclear Research, DLNP, Dubna (Russian Federation); Dadakhanov, Jahangir A. [Joint Institute for Nuclear Research, DLNP, Dubna (Russian Federation); AS RUz, Tashkent (Uzbekistan). Inst. of Nuclear Physics; Milanova, Maria M. [Sofia Univ. (Bulgaria). Faculty of Chemistry and Pharmacy; Happel, Steffen [Triskem International, Bruz (France); Radchenko, Valery I. [Mainz Univ. (Germany)

    2016-07-01

    Using radioisotope markers the distribution coefficients (K{sub d}) of the following elements In, Sn, Sb, Te, Bi, Co, Fe, Nb, Sr, Ba, Ag, Cd, Zr, Hf and Ti were determined with different concentrations of HCl, H{sub 2}SO{sub 4} and HNO{sub 3} for the extraction chromatographic resin Uranium and TEtraValent Actinides (UTEVA). This data can be used for separation of elements in complex mixtures, as well as for correct assessment of the elements chemistry with higher valences such as 3, 4, 5 or 6.

  10. The CdZnTe Detector with Slit Collimator for Measure Distribution of the Specific Activity Radionuclide in the Ground

    Science.gov (United States)

    Stepanov, V. E.; Volkovich, A. G.; Potapov, V. N.; Semin, I. A.; Stepanov, A. V.; Simirskii, Iu. N.

    2018-01-01

    From 2011 in the NRC "Kurchatov Institute" carry out the dismantling of the MR multiloop research reactor. Now the reactor and all technological equipment in the premises of the reactor were dismantled. Now the measurements of radioactive contamination in the reactor premises are made. The most contaminated parts of premises - floor and the ground beneath it. To measure the distribution of specific activity in the ground the CdZnTe detector (volume 500MM3) was used. Detector placed in a lead shielding with a slit collimation hole. The upper part of shielding is made movable to close and open the slit of the collimator. At each point two measurements carried out: with open and closed collimator. The software for determination specific activity of radionuclides in ground was developed. The mathematical model of spectrometric system based on the Monte-Carlo method. Measurements of specific activity of ground were made. Using the results of measurements the thickness of the removed layer of ground and the amount of radioactive waste were calculated.

  11. Identification and Angular Distribution of Residual Radionuclides Detected on the Wall of BATAN’s Cyclotron Cave

    Directory of Open Access Journals (Sweden)

    I. Kambali

    2016-04-01

    Full Text Available Detection and measurement of radiation sources around BATAN’s cyclotron facilities in Serpong are required as an early step to avoid radiation impacts on the radiation employees who work with the cyclotron. In this paper, radiation emitted from the wall of the CS-30 cyclotron cave are detected and measured using an NaI(Tl detector coupled with a pocket multichannel analyzer (MCA at a counting time of 30 minutes for each sampling point on the wall. The sampling points were in the directions of within ±150o with respect to the incoming proton beams, and the measurements were conducted at heights between 1.2 m and 1.8 m off the floor for every sampling point. The experimental results indicate that Co-60 and Cs-134 detected on the cyclotron cave wall are major radionuclides that contribute to the emitted gamma radiation. The distribution of the gamma ray intensities given off by Co-60 and Cs-134 depend on the angle and position of the sampling points. In general the highest gamma ray rates can be found in the area around 0o relative to the incoming proton beams. In addition, no other radioactive sources are significantly detected on the wall. The maximum exposure measured on the wall surface was much less than the permissible occupational exposure for radiation workers and general public.

  12. New best estimates for radionuclide solid-liquid distribution coefficients in soils, Part 1: radiostrontium and radiocaesium

    Energy Technology Data Exchange (ETDEWEB)

    Gil-Garcia, C.; Rigol, A. [Departament de Quimica Analitica - Universitat de Barcelona, Marti i Franques 1-11, 3a Planta, 08028 Barcelona (Spain); Vidal, M. [Departament de Quimica Analitica - Universitat de Barcelona, Marti i Franques 1-11, 3a Planta, 08028 Barcelona (Spain)], E-mail: miquel.vidal@ub.edu

    2009-09-15

    Best estimates for the solid-liquid distribution coefficients (K{sub d}) of radiostrontium and radiocaesium for various soil types, were derived from geometric means (GM) calculated from grouping soils by texture and organic matter content, and also using soil cofactors governing soil-radionuclide interaction. The K{sub d} (Sr) GM for Sand, Loam, Clay and Organic groups were similar, although the value for the Sand group was significantly lower. The Sr cofactor approach, based on the ratios of cation exchange capacity (CEC) to Ca and Mg concentrations in the soil solution, leads to K{sub d} (Sr) GM with a lower variability, from which best estimates could be proposed. The K{sub d} (Cs) GM for Sand and Organic groups differed, although similar values were obtained for Loam and Clay groups. Grouping the K{sub d} (Cs) according to the Radiocaesium Interception Potential (RIP) and the RIP divided by the K concentration in the soil solution also allows to suggest K{sub d} (Cs) best estimates with a lower variability.

  13. Investigation of CTBT OSI Radionuclide Techniques at the DILUTED WATERS Nuclear Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Baciak, James E.; Milbrath, Brian D.; Detwiler, Rebecca S.; Kirkham, Randy R.; Keillor, Martin E.; Lepel, Elwood A.; Seifert, Allen; Emer, Dudley; Floyd, Michael

    2012-11-01

    Under the Comprehensive Nuclear-Test-Ban Treaty (CTBT), a verification regime that includes the ability to conduct an On-Site Inspection (OSI) will be established. The Treaty allows for an OSI to include many techniques, including the radionuclide techniques of gamma radiation surveying and spectrometry and environmental sampling and analysis. Such radioactivity detection techniques can provide the “smoking gun” evidence that a nuclear test has occurred through the detection and quantification of indicative recent fission products. An OSI faces restrictions in time and manpower, as dictated by the Treaty; not to mention possible logistics difficulties due to the location and climate of the suspected explosion site. It is thus necessary to have a good understanding of the possible source term an OSI will encounter and the proper techniques that will be necessary for an effective OSI regime. One of the challenges during an OSI is to locate radioactive debris that has escaped an underground nuclear explosion (UNE) and settled on the surface near and downwind of ground zero. To support the understanding and selection of sampling and survey techniques for use in an OSI, we are currently designing an experiment, the Particulate Release Experiment (PRex), to simulate a small-scale vent from an underground nuclear explosion. PRex will occur at the Nevada National Security Site (NNSS). The project is conducted under the National Center for Nuclear Security (NCNS) funded by the National Nuclear Security Agency (NNSA). Prior to the release experiment, scheduled for Spring of 2013, the project scheduled a number of activities at the NNSS to prepare for the release experiment as well as to utilize the nuclear testing past of the NNSS for the development of OSI techniques for CTBT. One such activity—the focus of this report—was a survey and sampling campaign at the site of an old UNE that vented: DILUTED WATERS. Activities at DILUTED WATERS included vehicle-based survey

  14. Determination of the distribution coefficients for the radionuclides 134Cs, 60Co and 234Th in the Pinheiros river sediment

    International Nuclear Information System (INIS)

    Lima, Marina Ferreira

    1992-01-01

    The distribution coefficients (Kd) were determined in order to foresee the fate of the radionuclides discharged to the environment. Based upon the source-term released by IPEN's facilities in Pinheiros River during the year of 1988, three radionuclides were chosen as being the more critical, according to the radiation protection standards: 137 Cs, 60 Co and 232 Th. Their Kd were determined experimentally in laboratory by using the corresponding radioactive tracers 134 Cs, 60 Co and 234 Th. Three different experimental methodologies were used: the static method. the shaken method and the dynamic method. The parameters studied were the effects of pH, aerobic condition and time of contact. No considerable changes were observed for the cesium Kd with the variation of pH and aerobic condition, the kd extreme values being 20 ml/g and 30 ml/g for the pH range between 4 and 8. The study of the time of contact showed that the equilibrium between the cesium concentration in the water and sediment was achieved in a few days. For the cobalt, the pH effect was considerable, since the Kd increased from 46 ml/g for pH 4 to 2,25x10 3 ml/g for pH 8. The Kd observed with the agitation with air was around 420 ml/g, rising to 670 ml/g with the agitation with N 2 . The results obtained in the study of the time of contact effect showed that the equilibrium between the cobalt concentration in the water and sediment was not achieved even after 15 days of contact. For the thorium, also, the pH effect was considerable, since the Kd increased fram 1,40 x 10 5 ml/g for pH 4 to 2,55 x 10 6 ml/g for pH 8. No effect was observed, on the other hand, for the kd values obtained in the experiment carried out with air agitation or N 2 agitation, around 2,75 x 10 6 ml/g. The results obtained in the study of the time of contact effect showed that the equilibrium between the thorium concentration in the water and sediment was achieved after just one hour of contact. The results obtained can be

  15. Radionuclide distributions in sediment cores retrieved from marine radioactive waste dumpsites

    International Nuclear Information System (INIS)

    Bowen, V.T.; Livingston, H.D.

    1981-01-01

    The concentrations, distributions and inventories of 55 Fe, 60 Co, 137 Cs, 134 Cs, 238 Pu, sup(239,240)Pu, 241 Am, 244 Cm and 242 Cm were measured in sediment samples collected in 1975-1976 from some Atlantic and Pacific sites used by the United States of America from 1946-1970 to dump solidified radioactive waste. Criteria used to distinguish waste-contaminated sediments from fallout-contaminated sediments include deviations of nuclide concentrations, inventories, internuclide ratios and depth distributions. The detection of nuclides absent from fallout is a further indicator. The data set used in comparing dumpsite sediment radioactivity with non-dumpsite radioactivity comes from a population of 11 North Atlantic cores in the depth range 2000-4000 m. A further set of 19 cores from the central North Pacific provides an interesting contrast to the data set for the shallower sediments closer to the coasts. The principal conclusion drawn from consideration of a large body of data, especially for 15 sediment cores from the Atlantic dumpsite, is that contamination is extremely localized with respect to the sources from which the waste is believed to originate. The majority of cores from both dumpsites are indistinguishable from populations of cores contaminated only by world-wide fallout. Clearly, contaminated sediments from both dumpsites show evidence of the introduction of waste radioactivity below the sediment surface before subsequent redistribution by in-sediment processes. These findings have significance for the selection and monitoring of sites to be used in connection with the ocean disposal of radioactive waste. (author)

  16. 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)

  17. A new method for the determination of radionuclide distribution in the soil by in situ gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Zombori, P.; Andrasi, A.; Nemeth, I.

    1995-01-01

    In case of major nuclear accidents when larger amount of radioactive material is released into the atmosphere vast areas can become contaminated by the nuclear fallout. The deposited radioactivity penetrates the soil in a complex manner: dry and wet deposition lead to different initial distribution patterns which are further modified by the later transport processes in the upper layers of the soil. The distribution is influenced by various factors (physico-chemical characteristics of the radioisotopes, soil type, weather conditions, environment etc.), the resulting soil profile is hardly predictable. An important lesson we learned from the Chernobyl reactor accident is the great variability of the contamination both in the extent of the deposition and in the penetration features. In recent years - following the reactor accident in Chernobyl - an increased interest for rapid methods of monitoring environmental radioactivity was expressed. The International Atomic Energy Agency initiated a research project to co-ordinate the activities carried out in various laboratories aiming at the development of rapid monitoring procedures. The Co-ordinated Research Project (CRP) G6 10 01 under the title Rapid Instrumental and Separation Methods for Monitoring Radionuclides in Food and the Environment has given a frame for 11 research programs. The Health Physics Department of the KFKI Institute for Atomic Energy Research (the former Central Research Institute for Physics) has taken a part in this CRP with a project titled: Rapid In Situ Gamma Spectrometric Determination of Fallout Radioactivity in the Environment. The main objective of our study was to find a method to estimate the penetration characteristics of the fallout radioactivity by using only spectral information obtained by the in situ spectrometric measurement thus avoiding the need for a long and tiresome sampling and sample analysis procedure

  18. The distribution of gamma-emitting radionuclides in surface subtidal sediments near the Sellafield plant

    Science.gov (United States)

    Jones, D. G.; Roberts, P. D.; Miller, J. M.

    1988-08-01

    Detailed distributions of total gamma activity, 137Cs, 106Ru and 95Zr + 95Nb in surface seabed sediments near the Sellafield plant are presented. The results are derived from a towed seabed gamma-ray spectrometer survey in September, 1982. All the distributions are similar, with contours of equal activity parallel to the coast defining a 'ridge' of higher activity which is displaced northwards relative to the outfall. This pattern appears to be largely a response to the transport of particle-associated radioeffluent modified in places by the type of seabed sediment present. At greater distance from Sellafield, the uptake of nuclides from solution seems to be more important. Nuclide concentrations decrease with increasing distance from Sellafield; rates of decrease being in the order Zr + Nb > Ru > Cs. This can be related to the levels of the nuclides discharged, their sorption characteristics and their half lives. The pattern of seabed activity seems to have been fairly stable over the period 1978 - 1985, but there is evidence of a small northward shift. Concentrations of 137Cs and 106Ru in 1985 were considerably lower than in 1978 or 1982. This is explicable in terms of the fall in discharge levels allied, in the case of Ru, to its short half life and, for Cs, the desorption observed in laboratory experiments. Nuclide ratios in sediment samples yield apparent transit times for the transport of nuclides in the survey area of 1·7 - 3·7 years. These times are generally greater than those obtained from sediments in the more distant Solway Firth and Ravenglass Estuary. It is suggested that they reflect fairly intense bioturbation causing mixing of relatively recent effluent with that from earlier discharges. This is supported by structures observed in X-radiographs of box cores, an abundant burrowing benthos and by interpretations of nuclide profiles and radiocarbon dating of sediment cores by other workers. A lag effect, of up to two years across the survey area

  19. Antibodies labeled with metallic radionuclides: influence of nuclide chemistry on dose distribution

    International Nuclear Information System (INIS)

    Vaughan, A.T.; Yankuba, S.C.; Anderson, P.

    1987-01-01

    An antibody with human CEA specificity has been labeled with either yttrium-90, scandium-47, or indium-111, via a diethylenetriamine pentaacetic acid (DTPA) link covalently bound to the protein. The clearance of these proteins from the blood of mice can be described by a single exponential; the half-life decreases in the order indium-111 greater than yttrium-90 greater than scandium-47. Associated with the blood clearance is an uptake of radioactivity into the liver; scandium-47 has the highest concentration, indium-111 has the least, and yttrium-90 is intermediate. There is no correlation between these results and the equilibrium stability constants of the metals with DTPA-like ligands. The results obtained show that, in vivo, scandium-47 and yttrium-90 are more easily displaced from DTPA by other ions than is indium-111. They also show that free DTPA is able to extract yttrium-90 and scandium-47, but not indium-111, from the liver of treated animals, indicating that indium-111 is resistant to ligand exchange reactions in vivo. These data indicate that 1) the equilibrium stability constant is not a good indicator of the in vivo stability of metal-labeled proteins and 2) it is possible to manipulate the ion distribution and therefore the dose from scandium-47 and yttrium-90 after injection of the labeled proteins

  20. Plan for radionuclide tracer studies of the residence time distribution in the Wilsonville dissolver and preheater

    Energy Technology Data Exchange (ETDEWEB)

    Jolley, R.L.; Begovich, J.M.; Brashear, H.R.; Case, N.; Clark, T.G.; Emery, J.F.; Patton, B.D.; Rodgers, B.R.; Villiers-Fisher, J.F.; Watson, J.S.

    1983-12-01

    Stimulus-response measurements using radiotracers to measure residence time distribution (RTD) and hydrodynamic parameters for the preheaters and dissolvers at the Ft. Lewis Solvent Refined Coal (SRC) and the Exxon Donor Solvent (EDS) coal conversion pilot plants are reviewed. A plan is also presented for a series of radioactive tracer studies proposed for the Advanced Coal Liquefaction Facility at Wilsonville, Alabama, to measure the RTD for the preheater and dissolvers in the SRC-I mode. The tracer for the gas phase will be /sup 133/Xe, and /sup 198/Au (on carbonized resin or as an aqueous colloidal suspension) will be used as the slurry tracer. Four experimental phases are recommended for the RTD tracer studies: (1) preheater; (2) dissolver with 100% takeoff; (3) dissolver with 100% takeoff and solids withdrawal; and (4) dissolver with 50% takeoff. Eighteen gas-tracer and 22 liquid-tracer injections are projected to accomplish the four experimental phases. Two to four tracer injections are projected for preliminary tests to ensure the capability of safe injection of the radiotracers and the collection of statistically significant data. A complete projected cost and time schedule is provided, including procurement of necessary components, preparation of the radiotracers, assembly and testing of tracer injection apparatus and detection systems, onsite work and tracer injections, laboratory experimentation, data analysis, and report writing.

  1. Occupational health experience in the production and distribution of radionuclides used in medicine

    International Nuclear Information System (INIS)

    Gaburo, J.C.; Sanches, M.P.; Gian, M.A.A.

    1994-01-01

    A brief description of the main operations performed in the Radioisotope Production Facility at IPEN-CNEN/SP is presented. This facility is provided with hot cells which must be periodically replaced due to deterioration by reagent processing and hard treatment to which they are submitted. When the lifetime of these hot cells are at their limit, leaking of airborne materials arises bringing forth incorporation by workers. As a safe control, a series of procedures have been implemented in a program of internal monitoring by urine sampling and external monitoring by film badge. From this program it became possible to evaluate the radiation dose received by workers. The results obtained within the last 10 years where analyzed against the lifetime of the hot cells and studies were made to verify possible explicit or implicit relations between doses and the natural stress of these hot cells. In the distribution of the effective dose equivalent among 304 workers submitted for individual monitoring of internal exposure by urine samples, some significant exposures higher than 4.5 mSv. The sum of effective doses and doses from external exposures can lead to levels close to regulatory limits. The internal effective dose equivalent is small when compared with whole body external dose equivalent, however it is not negligible

  2. Plan for radionuclide tracer studies of the residence time distribution in the Wilsonville dissolver and preheater

    International Nuclear Information System (INIS)

    Jolley, R.L.; Begovich, J.M.; Brashear, H.R.

    1983-12-01

    Stimulus-response measurements using radiotracers to measure residence time distribution (RTD) and hydrodynamic parameters for the preheaters and dissolvers at the Ft. Lewis Solvent Refined Coal (SRC) and the Exxon Donor Solvent (EDS) coal conversion pilot plants are reviewed. A plan is also presented for a series of radioactive tracer studies proposed for the Advanced Coal Liquefaction Facility at Wilsonville, Alabama, to measure the RTD for the preheater and dissolvers in the SRC-I mode. The tracer for the gas phase will be 133 Xe, and 198 Au (on carbonized resin or as an aqueous colloidal suspension) will be used as the slurry tracer. Four experimental phases are recommended for the RTD tracer studies: (1) preheater; (2) dissolver with 100% takeoff; (3) dissolver with 100% takeoff and solids withdrawal; and (4) dissolver with 50% takeoff. Eighteen gas-tracer and 22 liquid-tracer injections are projected to accomplish the four experimental phases. Two to four tracer injections are projected for preliminary tests to ensure the capability of safe injection of the radiotracers and the collection of statistically significant data. A complete projected cost and time schedule is provided, including procurement of necessary components, preparation of the radiotracers, assembly and testing of tracer injection apparatus and detection systems, onsite work and tracer injections, laboratory experimentation, data analysis, and report writing

  3. Concentration and distribution of heavy metals and radionuclides in topsoils from Middle Jiu Valley surface coal exploitations sourrounding area (Gorj County, Romania)

    Science.gov (United States)

    Corneanu, Mihaela; Corneanu, Gabriel; Lacatusu, Anca-Rovena; Cojocaru, Luminita; Butnariu, Monica

    2013-04-01

    Middle Jiu Valley is one of the largest surface coal exploitation area in Romania. The coal exploitation area is a dense populated one, along the valleys are villages and the inhabitants produce for their own consumption fruits and vegetables, in their personal gardens, or cereals in the fields, nearby the villages. There was considered to be of great interest to investigate the heavy metals and radionuclides content in gardens and cropfield soils from the villages sourrounding the Thermo Electric Power Plants (TEPP) and coal surface exploitation, as well as in crude /cultivated sterile soil or ash. The topsoil samples (104) were harvested from population gardens (58), cropfields sourronding Thermo Electric Power Plants (24), crude sterile dumps (7), cultivated sterile dumps (9) and ash dumps (6). The content in radionuclides in soil was performed by Duggan (1988) method. Radionuclide activity was expressed in Bqkg-1, confidence level 95%. The total content of heavy metals in soil (Zn, Cu, Fe, Mn, Pb, Cd, Ni, Cr, Co) was measured with flame atomic mass spectrometry. The content in heavy metals was expressed in mgkg-1. Soil analysis revealed the presence of natural radionuclides, beloging from ash and coal dust, as well as of Cs-137, of Cernobal provenance. In the cropfields radionuclides content in topsoil is lower than in gardens, due to the deepper soil mobilisation. Radionuclides content over the normal limits for Romania were registered for Th-234, Pb-210, U-235 and in few locations for Ra-226. The soil content for all analysed metals was over the normal limits in most samples, in few cases with values close to allert limits. Concentrations between allert and intervention limits were registered in samples collected from 15-20 km North of TEPP Turceni, in population gardens.

  4. Distribution of natural radionuclides in soil around Sultan Azlan Shah Coal-Fired Power Plant at Manjung, Perak

    International Nuclear Information System (INIS)

    Zaini Hamzah; Fetri Zainal; Ahmad Saat; Abdul Khalik Wood

    2013-01-01

    Full-text: A radionuclide is an atom with an unstable nucleus which is created by excess energy. This radionuclide will undergo radioactive decay where gamma ray or sub atomic particles are released making them radioactive which can be harmful if the safe level is exceeded. This study was carried out in Manjung, Perak near Sultan Azlan Shah coal-fired power plant. Coal combustion from power plant generates emissions of potentially toxic radionuclides besides major pollutants which are particulates, sulphur and nitrogen oxides. It is noted that emission of particulates, sulphur and nitrogen oxides are strictly control. Soil is one of the most important media for plant to growth however soil is subject to contamination and its quality must be protected. The concentration of natural radionuclides in soil can be affected from coal combustion process from power plant in order to generate electricity. In this study, natural radionuclides concentration such as 238 U and 232 Th concentration in soil at nine points around this power plant were determined to assess radioactivity level and the possible radiation hazard to local population that residence in that area will be carried out in future study. Concentrations of natural radionuclides have been determined by using Energy Dispersive X-ray Fluorescence (EDXRF) technique. The concentration of 238 U in the area were in the ranged between 3.42 mg/ kg to 7.59 mg/ kg. While the concentration of 232 Th ranged from 12.19 mg/ kg to 21.67 mg/ kg respectively. (author)

  5. Distribution of natural occurring radionuclide in some industral residues used in new type wall materials

    International Nuclear Information System (INIS)

    Chen Yingmin; Li Fusheng; Xu Jiaang; Deng Daping; Yuan Ming; Ma Shi; Chen Yue

    2006-01-01

    Objective: To study the natural radioactive nuclide distribution characteristic of fly ash, gangue and various kinds of slag used in the new-type wall material and offer scientific basis for reducing the radiation dosage that the public suffers. Methods: The activity concentrations of the contents of natural radioactive nuclides of different industral waste residues have been determined by HPGe gamma-ray spectrometry. Results: The mean Raeq is successively fly ash (279.13 Bq kg -1 ), slag (225.69 Bq kg -1 ), gangue (141.26 Bq kg -1 ) from high to low and all of the samples is lower than the limit set in the OECD. The arithmetic mean activities of 236 Ra, 232 Th, 40 K in fly-ash samples are 127.88, 93.83, 221.75 Bq kg -1 ; for coal slag samples are 73.89, 97.13, 283.44 Bq kg -1 and for coal gangue samples are 47.85, 45.21, 413.56 Bq kg -1 . For the same power plant, the radioactive nuclide activity of the fly ash gathered in different time may have very great differences, the maximum can reach more than 2 times of the minimum. Conclusion: the fly ash and slag should be controlled strictly on rational proportion, which should not exceed 70% of the total mass. The mixing of the average radioactive level of the gangue is nearly equal that of to clay, it can be unrestricted in the mixing proportion in process of production. The manufacturer of new-type wall materials should often measure the radioactive level of the industrial waste residue in production. Make the content of radioactive nuclide in the products reach the rational level as low as possible. (authors)

  6. Transfer parameters of radionuclides in the marine environment

    International Nuclear Information System (INIS)

    1996-03-01

    To increase the accuracy of estimation of exposure dose by radionuclides in the marine, the informations of environmental parameter data in the marine were collected, arranged and discussed. The informations were discussed by 'a sectional committee of marine suspended solids and sediment'. The following problems were investigated and the studies were recorded in this report, clear explanation about the distribution factor (kd), the estimation method of kd, the fluctuating factor of kd data (properties of suspension and sediment, differences among the experimental methods), the physical and chemical behavior of radionuclides, sediment of radionuclides by means of sorption to the suspended particles in the marine, sorption of radionuclides into the marine soil (sediment), re-eluent of radionuclides sorpted in the marine soil (sediment), and relation between marine organism and marine suspended materials and sediment. (S.Y.)

  7. Sorption of radionuclides on geological samples from the Bradwell, Elstow, Fulbeck and Killingholme site investigations

    International Nuclear Information System (INIS)

    Berry, J.A.; Coates, H.A.; Green, A.; Littleboy, A.K.

    1988-06-01

    The sorption of chloride, caesium, calcium, nickel and americium on geological samples collected during the site investigations at Bradwell, Elstow, Fulbeck and Killingholme has been studied. Through-diffusion and batch sorption techniques were used and experiments were designed to give a direct comparison between the sorptive behaviour of material from each site. (author)

  8. Radionuclide carriers

    International Nuclear Information System (INIS)

    Hartman, F.A.; Kretschmar, H.C.; Tofe, A.J.

    1977-01-01

    The invention provides physiologically acceptable particulate radionuclide carriers comprising a reducing agent bound to an anionic starch derivative, useful in the preparation of organ-specific diagnostic radiopharmaceuticals

  9. Distribution of natural radionuclides in sediment around Sultan Azlan Shah coal-fired power plant coastal water area in Manjung, Perak

    International Nuclear Information System (INIS)

    Zaini Hamzah; Anisa Abdullah; Abdul Khalik Wood; Ahmad Saat

    2013-01-01

    Full-text: A rapid and simple analytical method for the determination of the natural radionuclides in sediment around Sultan Azlan Shah Coal-Fired Power Plant coastal water area in Manjung, Perak of Malaysia was carried out by Energy Dispersive X-ray Fluorescence (EDXRF) technique. The concentration of radionuclides contents in the marine ecosystem can be adversely affect human health and the environment when exposed through food chain. Furthermore, radionuclide is an atom with an unstable nucleus and they are naturally origin undergoes radioactive decay and emits a gamma ray or subatomic particles radiated from a coal fired power plant activity that contained in raw coal, fly ash and bottom ash, where a potential risk exposed into the atmosphere. However, coal is a heat source for electric power generation and operation of a coal burning power plant is one of the sources radiation contaminations and leads to a distributes of natural radionuclides. Sediment particle is a common pollutant that settles at the bottom of body water can be degrades water quality and demanding of oxygen in the marine ecosystem. Ten points of sediment cores will be taken along the coastal area in the study. The results of present study showed the concentration of natural radionuclides 238 U and 232 Th in surface sediment samples were in the ranged between 2.47 to 3.80 mg/ kg and 8.84 to 12.49 mg/ kg respectively. Thus, based on the concentration value obtained it can be determines assessment of potential hazard and radioactivity level in the future. (author)

  10. Behaviour of Chernobyl fallout radionuclides deposited on peat and urban surfaces in Finland

    International Nuclear Information System (INIS)

    Reponen, A.

    1992-10-01

    In the thesis the impact of the Chernobyl nuclear reactor accident on Finland was studied in three aspects: (1) the areal distribution of Chernobyl fallout in Finland was determined by measuring peat samples, (2) the behaviour of fallout radionuclides was investigated in the combustion of peat in power plants, and (3) the removal rates of fallout radionuclides on urban surfaces were resolved

  11. Measurement excursions for the purpose of surveillance of near-border regions. Radioiodide- and aerosols immission measurements. Soil investigation for plutonium, strontium and gamma-emitting radionuclides

    International Nuclear Information System (INIS)

    Steger, F.; Lovranich, E.; Urbanich, E.; Streit, S.; Kozuh-Schneeberger, J.

    1991-04-01

    The aim of this investigation was to find out if additional radionuclide deposition, above those from the nuclear weapons tests in the 60-ties and from the Chernobyl accident, and caused by nuclear power plants in neighbouring countries can be found. Methods and results of investigations at several near-border sites in Austria for iodine, plutonium and strontium are presented. The question of frontier-crossing contamination from nuclear power plants is to be answered to the negative. (Quittner)

  12. Grimsel test site investigation Phase IV. The Nagra-JAEA in situ study of safety relevant radionuclide retardation in fractured crystalline rock. III: The RRP project final report

    International Nuclear Information System (INIS)

    Alexander, W. R.; Frieg, B.; Ota, K.

    2009-11-01

    possible under conditions closely resembling the final experiment. The EP began in 1990 with the Phase I feasibility study and continued in Phase II with an extensive campaign of laboratory and field tests between 1994 and 1996. This final report provides a summary of the Phase II work, which included: a) Injection of four different radionuclide cocktails into the EP test zone that was established in the AU96 experimental shear zone (MI shear zone) at the GTS; b) Continuous monitoring of radiotracer breakthrough at the outlet borehole followed by stabilisation of the rock volume containing the retarded radionuclides by in situ resin impregnation; c) Excavation of the stabilised rock volume by shear zone-parallel overcoring for sample recovery and laboratory investigations; d) Radiochemical analysis on solid shear zone samples and detailed structural geological investigation of the flow-path geometry within the dipole. One of the aims of EP was to examine the behaviour of performance assessment (PA) relevant radionuclides and so those nuclides selected for consideration in Nagra's Kristallin-l PA and JAEA's TRU-I PA were examined. The final selection considered the nuclides 238 U, 235 U, 234 U, 237 Np and 99 Tc because they are safety relevant; 152 Eu is considered to be a good chemical analogue for other lanthanides and trivalent actinides; 60 Co is a good chemical analogue for the safety relevant 59 Ni and easier to obtain and simpler to analyse than 59 Ni; 75 Se is a complete chemical analogue of the safety relevant 79 Se, but with a much shorter half-life (120 days against 65 ka); 113 Sn is a complete chemical analogue of the safety relevant 126 Sn, but with a much shorter half-life (115 days against 100 ka); and finally the stable Mo is a complete chemical analogue of the safety relevant 93 Mo (half-life of 3.5 ka). Scoping calculations indicated that the low natural solubilities of these radionuclides in the Grimsel groundwater/rock system meant that the likely

  13. Migration of radionuclides in the soil-crop-food product system and assessment of agricultural countermeasures

    International Nuclear Information System (INIS)

    Bogdevitch, I.; Ageyets, V.

    1996-01-01

    Studies on dynamics of redistribution of radionuclides through of profile of the different soils on uncultivated agricultural lands of Belarus during the 1986-1995 period show that vertical migration occurs with low rate. In arable soils the radionuclides are distributed in comparatively uniform way through the whole depth of the 25-30 cm cultivated layer. Investigations on migration of radionuclides with wind erosion on the drained series of wet sandy and peat soils and water erosion on sloping lands show that one should take into consideration the secondary contamination of soils while forecasting a possible accumulation of radionuclides in farm products

  14. Technogenic radionuclides of Chernobyl NPP accidental release and their physical and chemical forms

    Directory of Open Access Journals (Sweden)

    A. I. Lypska

    2015-10-01

    Full Text Available Distribution of radionuclides in the vertical soil profile on the nearest Chernobyl NPP zone of alienation was investigated. It is showed experimentally that the main activity of radionuclides is concentrated in the topsoil (10 сm. Coefficients of accumulation of 137Cs and 90Sr radionuclides by plants are estimated. The physico-chemical forms of radionuclides in soil and plants were defined using the method of sequential chemical extraction. It was established that the main contents of 137Cs and 90Sr in soils are represented in non-exchange and fixed forms, in plants - mainly in exchange-adsorption and organic forms.

  15. Therapeutic radionuclides

    International Nuclear Information System (INIS)

    Choi, Sun Ju; Hong, Young Don; Lee, So Young

    2006-01-01

    Since the development of sophisticated molecular carriers such as octereotides for peptide receptor targeting and monoclonal antibodies against various associated with specific tumor types, radionuclide therapy (RNT) employing open sources of therapeutic agents is promising modality for treatment of tumors. Furthermore, the emerging of new therapeutic regimes and new approaches for tumor treatment using radionuclide are anticipated in near future. In targeted radiotherapy using peptides and other receptor based carrier molecules, the use of radionuclide with high specific activity in formulating the radiopharmaceutical is essential in order to deliver sufficient number of radionuclides to the target site without saturating the target. In order to develop effective radiopharmaceuticals for therapeutic applications, it is crucial to carefully consider the choice of appropriate radionuclides as well as the carrier moiety with suitable pharmacokinetic properties that could result in good in vivo localization and desired excretion. Up to date, only a limited number of radionuclides have been applied in radiopharmaceutical development due to the constraints in compliance with their physical half-life, decay characteristics, cost and availability in therapeutic applications. In this review article, we intend to provide with the improved understanding of the factors of importance of appropriate radionuclide for therapy with respect to their physical properties and therapeutic applications

  16. Radionuclide cystography

    International Nuclear Information System (INIS)

    Sty, J.R.; Wells, R.G.

    1990-01-01

    This paper reports on radionuclide cystography in infants and children for the detection of vesicoureteral reflux. Vesicoureteral reflux represents a common and potentially serious form of urinary tract pathology. Reflux accompanied by asymptomatic or inadequately treated urinary tract infections has been associated with significant sequelae, including renal scarring, hypertension, and end- stage renal disease. Although there are several advantages and disadvantages to both radionuclide and radiographic techniques for detection of reflux, radionuclide cystography has been found to be at least as sensitive as the voiding cystourethrogram (VCUG) for the detection of clinically significant reflux. The major advantage of radionuclide cystography is a significantly lower radiation dose as compared to VCUG. Both indirect and direct techniques for radionuclide cystography have been developed. In addition to detection of vesicoureteral reflux, indirect radionuclide cystography allows evaluation of differential renal function. Supplemental parameters that may be evaluated with direct radionuclide cystography include: quantitation of reflux, determination of bladder volume at which reflux occurs, evaluation of the dynamics of bladder emptying, and determination of residual bladder volume following voiding

  17. Effects of arctic temperatures on distribution and retention of the nuclear waste radionuclides 241Am, 57Co, and 137Cs in the bioindicator bivalve Macoma balthica

    Science.gov (United States)

    Hutchins, D.A.; Stupakoff, I.; Hook, S.; Luoma, S.N.; Fisher, N.S.

    1998-01-01

    The disposal of radioactive wastes in Arctic seas has made it important to understand the processes affecting the accumulation of radionuclides in food webs in coldwater ecosystems. We examined the effects of temperature on radionuclide assimilation and retention by the bioindicator bivalve Macoma balthica using three representative nuclear waste components, 241Am, 57Co, and 137Cs. Experiments were designed to determine the kinetics of processes that control uptake from food and water, as well as kinetic constants of loss. 137Cs was not accumulated in soft tissue from water during short exposures, and was rapidly lost from shell with no thermal dependence. No effects of temperature on 57Co assimilation or retention from food were observed. The only substantial effect of polar temperatures was that on the assimilation efficiency of 241Am from food, where 10% was assimilated at 2??C and 26% at 12??C. For all three radionuclides, body distributions were correlated with source, with most radioactivity obtained from water found in the shell and food in the soft tissues. These results suggest that in general Arctic conditions had relatively small effects on the biological processes which influence the bioaccumulation of radioactive wastes, and bivalve concentration factors may not be appreciably different between polar and temperate waters.

  18. Radionuclide and colloid transport in the Culebra Dolomite and associated complementary cumulative distribution functions in the 1996 performance assessment for the Waste Isolation Pilot Plant

    Energy Technology Data Exchange (ETDEWEB)

    RAMSEY, JAMES L.; BLAINE,R.; GARNER,J.W.; HELTON,JON CRAIG; JOHNSON,J.D.; SMITH,L.N.; WALLACE,M.

    2000-05-22

    The following topics related to radionuclide and colloid transport in the Culebra Dolomite in the 1996 performance assessment for the Waste Isolation Pilot Plant (WIPP) are presented: (1) mathematical description of models, (2) uncertainty and sensitivity analysis results arising from subjective (i.e., epistemic) uncertainty for individual releases, and (3) construction of complementary cumulative distribution functions (CCDFs) arising from stochastic (i.e., aleatory) uncertainty. The presented results indicate that radionuclide and colloid transport in the Culebra Dolomite does not constitute a serious threat to the effectiveness of the WIPP as a disposal facility for transuranic waste. Even when the effects of uncertain analysis inputs are taken into account, no radionuclide transport to the boundary with the accessible environment was observed; thus the associated CCDFs for comparison with the boundary line specified in the US Environmental Protection Agency's standard for the geologic disposal of radioactive waste (40 CFR 191, 40 CFR 194) are degenerate in the sense of having a probability of zero of exceeding a release of zero.

  19. Chernobyl nuclear accident hydrologic analysis and emergency evaluation of radionuclide distributions in the Dnieper River, Ukraine, during the 1993 summer flood

    Energy Technology Data Exchange (ETDEWEB)

    Voitsekhovitch, O.V. [Ukrainian Hydrometeorological Inst., Kiev (Ukraine); Zheleznyak, M.J. [Ukrainian Academy of Sciences, Kiev (Ukraine). Cybernetics Center; Onishi, Y. [Pacific Northwest Lab., Richland, WA (United States)

    1994-06-01

    This report describes joint activities of Program 7.1.F, ``Radionuclide Transport in Water and Soil Systems,`` of the USA/Commonwealth of Independent States (CIS) Joint Coordinating Committee of Civilian Nuclear Reactor Safety to study the hydrogeochemical behavior of radionuclides released to the Pripyat and Dnieper rivers from the Chernobyl Nuclear Power Plant in Ukraine. These joint activities included rapid evaluation of radionuclide distributions in the Pripyat and Dnieper river system and field data evaluation and modeling for the 1993 summer flood to assist the Ukrainian government in their emergency response during the flood. In July-August 1993, heavy rainfall over the Pripyat River Catchment in Belarus and Ukraine caused severe flooding, significantly raising {sup 90}Sr concentrations in the river. Near the Chernobyl area, the maximum {sup 90}Sr concentration in the Pripyat River reached 20--25 PCi/L in early August; near the Pripyat River mouth, the concentration rose to 35 pCi/L. The peak {sup 90}Sr concentration in the Kiev Reservoir (a major source of drinking water for Kiev) was 12 pCi/L. Based on these measured radionuclide levels, additional modeling results and the assumption of water purification in a water treatment station, {sup 90}Sr concentrations in Kiev`s drinking water were estimated to be less than 8 pCi/L. Unlike {sup 90}Sr, {sup 137}Cs concentrations in the Pripyat River during the flood did not rise significantly to the pre-flood levels. Estimated {sup 137}Cs concentrations for the Kiev drinking water were two orders of magnitude lower than the drinking water standard of 500 pCi/L for {sup 137}Cs.

  20. A study of the distribution of gamma-emitting radionuclides in coastal biological indicators of the Channel and Northern sea shores from February 1976 to February 1978

    International Nuclear Information System (INIS)

    Germain, Pierre; Masson, Michel; Baron, Yves

    1979-11-01

    Samples of fauna and flora from the French coast of the Channel and Northern Sea were taken for GeLi gamma spectrometry, from February 1978. The measurements as a whole showed that 144 Ce-Pr, 125 Sb, 7 Be, 103 Ru, 106 Ru-Rh, 137 Cs, 95 Zr-Nb, sup(110m)Ag, 134 Cs, 54 Mn, 65 Zn, 60 Co, 140 La, 140 Ba, 131 I, 147 Nd and 40 K could be detected. Quantitatively, 106 Ru-Rh and 144 Ce-Pr were the prevailing elements. At Goury, a station close to the emissary of the fuel reprocessing plant of La Hague, throughout the period of investigation, radioactivity levels were in the range of 10-100 pCi/g dry and 1-10 pCi/g dry for 106 Ru-Rh and 144 Ce-Pr respectively. The recorded levels of the other man-made radionuclides can be considered quantitatively as very low, under 1 pCi/g dry, which comparatively is lower than the natural radioactivity of 40 K ranging between 1 and 100 pCi/d dry. The values observed in 1976-1978 are lower than in 1975. It is difficult to set up monthly relations between levels in species and amounts of releases. In spite of these low levels, a decrease was observed in the coastal biological indicators a a function of the distance from the release point, especially clear for 106 Ru-Rh. However, this observation is not general; for instance 137 Cs a soluble element, easily dispersed in seawater, showed a rather homogeneous distribution in each coastal species. Besides, 125 Sb in the alga species Pelvetia canaliculata, seemed, to present a gradient in opposition to common dispersion laws; this process might result from a slow evolution of the element from a non-adsorbable to a slightly adsorbable form [fr

  1. Behaviour of uranium series radionuclides in surface water (Crouzille, Limousin). Geochemical implications

    International Nuclear Information System (INIS)

    Moulin, J.

    2008-06-01

    Understanding natural radionuclides behaviour in surface water is a required step to achieve uranium mine rehabilitation and preserve water quality. The first objective of this thesis is to determine which are the radionuclides sources in a drinking water reservoir. The second objective is to improve the knowledge about the behaviour of uranium series radionuclides, especially actinium. The investigated site is a brook (Sagnes, Limousin, France) which floods a peat bog contaminated by a former uranium mine and which empties into the Crouzille lake. It allows studying radionuclides transport in surface water and radionuclides retention through organic substance or water reservoir. Radionuclides distribution in particulate, colloidal and dissolved phases is determined thanks to ultra-filtrations. Gamma spectrometry allows measuring almost all natural radionuclides with only two counting stages. However, low activities of 235 U series radionuclides impose the use of very low background well-type Ge detectors, such as those of the Underground Laboratory of Modane (France). Firstly, this study shows that no or few radionuclides are released by the Sagnes peat bog, although its radioactivity is important. Secondly, it provides details on the behaviour of uranium series radionuclides in surface water. More specifically, it provides the first indications of actinium solubility in surface water. Actinium's behaviour is very close to uranium's even if it is a little less soluble. (author)

  2. SPECT/CT: can it be helpful in the evaluation of the distribution of the radionuclide in the joint following radio-synovectomy?

    International Nuclear Information System (INIS)

    Ozulker, F.; Kucukoz Uzun, A.; Ozulker, T.

    2015-01-01

    Full text of publication follows. Planar control scintigraphies have been used for the detection of any possible extra articular leakage after radio-synovectomy in patients with haemophilic arthropathy. In this study we aimed at assessing whether utilization of SPECT-CT for the same purpose can provide additional information. Patients who fulfilled the following prerequisites were included for radio synovectomy application: (1) more than four hemorrhagic episodes in six months, (2) at least a Stage II haemophilic arthropathy according to the classification of Arnold and Haltering, and (3) persistent synovitis. Six male patients (5 hemophilia A, 1 hemophilia B) who suffered from haemophilic arthropathy with a mean age of 10.5 (range between 8-15) were included in this study. We administered 148-185 MBq Yttrium 90 silicate (Y-90) to 5 knee joints, 74 MBq Rhenium 186 (Re-186) to 1 elbow joint and 74 MBq Re-186 to two ankle joints of these patients. The median number of bleedings into the target joints was 10.1 ± 1.4 in the six months prior to the procedure. All patients were admitted to the hospital and treated with factor replacement so as to raise the factor level of the patient to 80% the following morning and 50% for three days thereafter. The effusion in the joint was evacuated before the injection of the radiocolloid. Intra-articular injections in ankle and elbow joints were done under fluoroscopic guidance. The joint was moved rapidly a few times to distribute the radiocolloid, after which a plaster of paris cast was applied for 72 hours. One hour after the RS, planar images of the treated joints and the regional lymph nodes were obtained with gamma camera and SPECT-BT acquisitions were obtained from treated joints to confirm the appropriate distribution of the radionuclide in the joint. Distribution of the radionuclide in joint spaces was normal and we haven't encountered any extra articular leakage. In one patient there was loculation at activity in

  3. Investigation of acupuncture-point injection combined with intratumor injection of radionuclide phosphorus 32 in treatment of metastatic carcinoma

    International Nuclear Information System (INIS)

    Chou, H.C.

    1986-01-01

    Seventeen patients with carcinoma and three patients with benign lesions of the head were studied by acupuncture-point injection combined with intratumor injection of radionuclide P-32 for treatment of metastatic carcinoma. The metastatic cervical nodules shrank to half their original sizes within 2-3 weeks in five cases of nasopharyngeal carcinoma. The injected dose ranged from 0.222 to 0.421 mCi, approximately 10 times less than that given by the ordinary method. The acupuncture points are selected according to the Theory of Channels and Collaterals of Chinese traditional medicine. The mechanism of therapeutic action of radionuclide P-32 is possibly by the delivery of destructive ionizing radiation from beta emission properties of P-32. This method appears to offer a low-dose means of P-32 treatment of metastatic carcinoma

  4. Investigation of natural radionuclides in foods and waters in China and evaluation of internal dose to public

    International Nuclear Information System (INIS)

    Zhu Changshou; Liu Yulan; Xu Ning; Hu Aiying; Kou Tiluo; Shi Zhongxin

    1992-12-01

    In order to obtain background radiation levels of natural radionuclides in foods and waters in China, the determination and analysis of water and food samples have been completed by organizations of radiological protection from 28 provinces, autonomous regions and three major cities. Ranges of specific activity of natural radionuclides for U, Th, Ra, K, Pb and Po are (2.2 ∼ 25.5) x 10 -2 Bq/kg, (0.5 ∼ 6.9) x 10 -2 Bq/kg, (3.4 ∼ 25.5) x 10 -2 Bq/kg, (25 ∼ 420) x 10 -2 Bq/kg, (3.9 ∼ 55) x 10 -2 Bq/kg and (2.7 ∼ 58) x 10 -2 Bq/kg, respectively. Samples of drinking water were taken from tap water or well. The average concentrations in tap water and well water are 2.8 x 10 -2 Bq/L and 3.7 x 10 -2 Bq/L for U, 0.8 x 10 -2 Bq/L and 1.3 x 10 -2 Bq/L for Ra, 0.07 x 10 -2 Bq/L and 0.06 x 10 -2 Bq/L for Th, 0. 3 x 10 -2 Bq/L and 1.1 x 10 -2 Bq/L for Pb and 0.3 Bq/L and 0.5 Bq/L for Po respectively. The annual intakes by ingestion have been calculated. The annual intake of male adult from six main natural radionuclides is about 205 Bq. Among them 64% of total intake of U is from drinking water. The contributions from grains to the total intake of Ra, Pb and Po are 55.7%, 59.7% and 70% respectively. The total annual average effective dose equivalent of 6 natural radionuclides for male adult in China is about 310 μSv

  5. Investigating the distribution of the value of travel time savings

    DEFF Research Database (Denmark)

    Fosgerau, Mogens

    2006-01-01

    . Increasing the implicit price of time leads to an increased share of respondents who decline to pay to save time. But a significant proportion of respondents, 13%, remain willing to pay to save time at the highest price of time in the design. This means that the right tail of the VTTS distribution...... is not observed and hence the mean VTTS cannot be evaluated without additional assumptions. When socio-economic and situational variables are introduced into a semiparametric model it becomes possible to accept that the whole VTTS distribution is observed. Sixteen candidates for parametric VTTS distributions...... are investigated. Some distributions are simply not able to fit to the empirical distribution while others have very long tails. The mean VTTS is shown to be extremely dependent on the choice of parametric distribution. Requiring that the parametric distribution should be accepted against the nonparametric...

  6. A random walk model to simulate the atmospheric dispersion of radionuclide

    Science.gov (United States)

    Zhuo, Jun; Huang, Liuxing; Niu, Shengli; Xie, Honggang; Kuang, Feihong

    2018-01-01

    To investigate the atmospheric dispersion of radionuclide in large-medium scale, a numerical simulation method based on random walk model for radionuclide atmospheric dispersion was established in the paper. The route of radionuclide migration and concentration distribution of radionuclide can be calculated out by using the method with the real-time or historical meteorological fields. In the simulation, a plume of radionuclide is treated as a lot of particles independent of each other. The particles move randomly by the fluctuations of turbulence, and disperse, so as to enlarge the volume of the plume and dilute the concentration of radionuclide. The dispersion of the plume over time is described by the variance of the particles. Through statistical analysis, the relationships between variance of the particles and radionuclide dispersion characteristics can be derived. The main mechanisms considered in the physical model are: (1) advection of radionuclide by mean air motion, (2) mixing of radionuclide by atmospheric turbulence, (3) dry and wet deposition, (4) disintegration. A code named RADES was developed according the method. And then, the European Tracer Experiment (ETEX) in 1994 is simulated by the RADES and FLEXPART codes, the simulation results of the concentration distribution of tracer are in good agreement with the experimental data.

  7. Use of the bleeding sap for investigation of radionuclide transfer to crops through root and translocation of the nuclide in the crops

    International Nuclear Information System (INIS)

    Uchida, Shigeo; Sumiya, Misako; Yanagisawa, Kei; Ohmomo, Yoichiro.

    1991-01-01

    Adsorption and translocation characteristics of radionuclides in the root of tomato plant were investigated. Mature tomato plant was transplanted to culture solution containing 85 Sr, 137 Cs, 131 I, 54 Mn, 60 Co and 65 Zn. Immediately after transplantation, the tomato plant was cut at 10 cm above the surface of the culture solution in order to collect bleeding sap solution (Experiment-1). Another mature tomato plant was cultured for 3 days in culture solution containing radionuclides as mentioned above and then transplanted to fresh culture solution. Bleeding sap solution was also collected in the same way as shown in Experiment-1 (Experiment-2). Activity ratios of bleeding sap to culture solution were measured for several hours. Adsorption and removement of those radionuclides in tomato plant were summarized as follows; 137 Cs was taken up by the root almost at the same speed as that of water and accumulated in the lowest among the six nuclides used in the experiments. The concentrations of 85 Sr, 54 Mn and 65 Zn in the bleeding sap of 3 days' uptake experiment were higher than the initial concentrations of the culture solution for several hours even after the tomato plant was transplanted to fresh culture solution. 131 I and 60 Co were accumulated much in the root and found extremely low in the bleeding sap during the experiment, suggesting that the nuclide were absorbed on the surface of the roots and scarcely moved. (author)

  8. ASSESSMENTOF BETA PARTICLE FLUX FROM SURFACE CONTAMINATION AS A RELATIVE INDICATOR FOR RADIONUCLIDE DISTRIBUTION ON EXTERNAL SURFACES OF A MULTI-STORY BUILDING IN PRIPYAT

    Energy Technology Data Exchange (ETDEWEB)

    Farfan, E.

    2009-11-17

    How would we recover if a Radiological Dispersion Device (e.g., dirty bomb) or Improvised Nuclear Device were to detonate in a large city? In order to assess the feasibility of remediation following such an event, several issues would have to be considered, including the levels and characteristics of the radioactive contamination, the availability of the required resources to accomplish decontamination, and the planned future use of the city's structures and buildings. Presently little is known about the distribution, redistribution, and migration of radionuclides in an urban environment. However, Pripyat, a city substantially contaminated by the Chernobyl Nuclear Power Plant accident, may provide some answers. The main objective of this study was to determine the radionuclide distribution on a Pripyat multi-story building, which had not been previously decontaminated and therefore could reflect the initial fallout and its further natural redistribution on external surfaces. The 7-story building selected was surveyed from the ground floor to the roof on horizontal and vertical surfaces along seven ground-to-roof transections. Some of the results from this study indicate that the upper floors of the building had higher contamination levels than the lower floors. The authors consequently recommend that existing decontamination procedures for tall structures be re-examined and modified accordingly.

  9. Sorption of radionuclides from Pb-Bi melt. Report 1

    International Nuclear Information System (INIS)

    Konovalov, Eh.E.; Il'icheva, N.S.; Trifonova, O.E.

    2015-01-01

    Results of laboratory investigations of sorption and interfacial distribution of 54 Mn, 59 Fe, 60 Co, 106 Ru, 125 Sb, 137 Cs, 144 Ce, 154,155 Eu and 235,238 U radionuclides in the system Pb-Bi melt - steel surface are analyzed. It is shown that 106 Ru and 125 Sb are concentrated in Pb-Bi melt and other radionuclides with higher oxygen affinity are sorbed on oxide deposits on structural materials. Temperature dependences of sorption efficiency of radionuclides are studied. It is shown that there is sharp increase of this value for all radionuclides near the temperature range 350-400 deg C. Recommendations are given on the use of 106 Ru and 125 Sb as a reference for fuel element rupture detection system with radiometric monitoring of coolant melt samples and 137 Cs, 134 Cs, 134m Cs with radiometric monitoring of sorbing samples [ru

  10. Laboratory studies of radionuclide distributions between selected groundwaters and geologic media. Progress report, October 1, 1979-September 30, 1980

    International Nuclear Information System (INIS)

    Daniels, W.R.

    1981-01-01

    During FY-1980, Los Alamos Scientific Laboratory contributions to the Waste/Rock Interactions Technology program were primarily in the areas of migration-rate studies using crushed rock, whole core, and fractured core columns; parametric studies of variables which may influence radionuclide sorption-desorption behavior; and initial studies of actinide chemistry in near-neutral solutions and Eh control. Batch experiments in both air and a controlled atmosphere (nitrogen, less than or equal to 0.2 ppM oxygen, less than or equal to 20 ppM carbon dioxide) for the sorption of several radionuclides on granite and argillite were completed. These data also provided informaton on the effects of other parameters, such as particle size and contact time. All nine elements studied had different sorption ratios for argillite when measured under the controlled atmosphere than when measured in air, except possibly for americium where any effect was smaller than the standard deviations. As expected, strontium, cesium, and barium are least affected by the presence or absence of oxygen and carbon dioxide. Columns of crushed rock and solid and cracked cores were used to study the migration of radionuclides through such materials. In general, sorption ratios measured by batch techniques are 2 to 3 times greater than those for columns; however, a wide variation in behavior was observed, depending upon the element and the mineralogy. Work has begun on a system wherein traced groundwater is circulated through a crushed rock column; this should provide a link between the usual, single-pass, crushed rock columns and the batch experiments. Materials characterization has continued, and techniques for the determination of Fe(II) in silicate rocks and groundwater have been made operational. Work on the fundamental solution chemistry of the actinides has been started

  11. Examinations on the removal of natural radionuclides from drinking water and overview on their distribution in Austria

    International Nuclear Information System (INIS)

    Staubmann, K.

    2002-09-01

    The objective of the thesis was to give an overview about available data regarding natural radioactivity in Austrian ground and spring water and to examine the capability of membrane processes, ion exchange processes and processes for iron and manganese removal to remove natural radionuclides from drinking water. There are already Austrian-wide data existing for the activity concentrations of radon-222 in ground- and spring water, only few values are available for radium-226 (Ra-226), lead-210 (Pb-210), uranium (U) and polonium-210 up til now. From the existing data it is to be expected that in Austria only in exceptions water treatment will be necessary. The tested reverse osmosis and nanofiltration systems removed between 95.6 % and 99.8 % of Ra-226, U and Pb-210 on the average. Laboratory scale experiments for ion exchange showed an essential influence of the concurrent ions in the water on the removal of the radionuclides. With water softeners (cation exchangers) Ra-226 to more than 90 % and Pb to more than 80 % could be removed. By the use of other ones than the standard cartridge fillings for pour-through-filters (ion exchangers) the radionuclides could be removed more selectively and more effectively and the influence on the chemical composition of the water could be minimized. In a laboratory scale experiment simulating the planned treatment process at a waterwork for the removal of iron and manganese Ra-226 was removed to 61%. At the examined processes often disadvantageous side effects onto the water quality which require a subsequent treatment were observed. During the operation of the systems it should be aimed at keeping the activity in the produced waste low so that no radiation protection relevant risk starts from that. (author)

  12. Vertical soil migration of radionuclide fallout from the Chernobyl' accident

    International Nuclear Information System (INIS)

    Silant'ev, A.N.; Shkuratova, I.G.; Bobovnikova, T.I.

    1989-01-01

    The most suitable model for describing the behavior of radionuclide fallout on a soil surface is quasidiffusion transfer with directional transfer taken into account. The parameter values for this have been determined previously and are supplemented by the results of this work. To investigate the initial radionuclide distribution along the soil profile, monolithic soil samples 5 cm thick were taken in June-September 1986 in areas which had been subjected to contamination due to the Chernobyl' accident. The samples taken were cut up into layers. The first layer, 0.5 cm thick, was cut off from the surface of the soil monolith together with the grass. The next layer cut off was also 0.5 cm thick. Then two layers, each 1 cm in thickness, were cut off. The thickness of the last layer was 2 cm. The vertical distribution of radionuclides along the soil profile which was examined may be called the initial distribution, which will then change due to nonimmediate migration of radionuclides in the soil. Based on the research which has been performed, the following conclusions may be drawn. One portion of the radionuclides resulting from fallout is trapped by plant cover, while the other enters immediately into the soil. For a thick plant covering, about 80% of the radionuclide fallout is sorbed by the grass; for sparse cover, about 40%. The radionuclides entering the soil along with rainwater penetrate into the soil depths, producing contamination which falls off exponentially with depth. The exponent index is close to 1 cm -1 . In a forest, the main amount of radionuclide fallout is trapped by litter. Approximately 10% of the contamination fallout penetrates beneath the litter

  13. Natural radionuclides distribution in the products obtained in the phosphoric acid fabrication from the phosphate rock of Itataia, Ceara State, Brazil

    International Nuclear Information System (INIS)

    Fukuma, Henrique Takuji

    1999-11-01

    The Itataia-Ceara deposit is important as the largest uranium reserve presently known in Brazil exhibiting geological characteristics of the phosphorus and uranium association as uraniferous apatite. The total reserve of Itataia is about 13.8 million tons of P 2 O 5 and 142.5 thousand tons of U 3 O 8 . The uranium content in the Itataia phosphate rock is about ten time higher than commercial phosphate rock concentrates produced in the main Brazilian mines. The Itataia phosphate rock was milled in a pilot plant for wet-process phosphoric acid production by dihydrate method. The uranium contained in the phosphoric acid was recovered by solvent extraction using the DEHPA and TOPO mixture as extractant. After separation from the phosphoric acid, the uranium was precipitated as ammonium diuranate. In this work, the distribution of radionuclides with long physical half-life of the 238 U and 232 Th decay series was evaluated in the products and wastes generated during the Itataia phosphate rock milling. The results obtained will be useful to establish the program of environmental and occupational radiological protection for the future Itataia industrial complex. In addition, the knowledge of activity of the radionuclides contained in the uranium-free phosphoric acid that will be commercially available will allow the previous estimation of the radiological impact due to the use of fertilizers produced from this raw material. The radionuclides 226 Ra, 228 Ra and 210 Pb were preferentially concentrated in the phosphogypsum, while 228 Th, 230 Th and 232 Th remained in the phosphoric acid after uranium extraction. (author)

  14. Investigation of the potential of fuzzy sets and related approaches for treating uncertainties in radionuclide transfer predictions

    International Nuclear Information System (INIS)

    Shaw, W.; Grindrod, P.

    1989-01-01

    This document encompasses two main items. The first consists of a review of four aspects of fuzzy sets, namely, the general framework, the role of expert judgment, mathematical and computational aspects, and present applications. The second consists of the application of fuzzy-set theory to simplified problems in radionuclide migration, with comparisons between fuzzy and probabilistic approaches, treated both analytically and computationally. A new approach to fuzzy differential equations is presented, and applied to simple ordinary and partial differential equations. It is argued that such fuzzy techniques represent a viable alternative to probabilistic risk assessment, for handling systems subject to uncertainties

  15. An investigation of some heavy metals and radionuclides in sediments from the Sudanese coast of the red sea

    International Nuclear Information System (INIS)

    Idris, Abubakr Mustafa

    1999-07-01

    In this study, surface sediments from port Sudan and Sawakin harbors and the fringing reefs area, located the Sudanese coast of the Red Sea, were analyzed for some heavy metals and radionuclides. The sampling was performed to provide good spatial coverage taking into account man's activity in Port Sudan harbor and the fringing reefs sea. A total of 31 bulk sediments samples were fractionated to five fractions using dry sieving method. A total of of 155 sub-samples (fractions) were digested by wet digestions and analyzed for Mn, Fe, Ni, Cu, Zn, and Pb content using flame atomic absorption spectrometry. For radioactivity measurement, a total of 26 bulk sediment samples were treated and analyzed for natural and anthropogenic radionuclides 2 26Ra, 2 28Ra, 2 28K, 1 37Cs) using direct gamma-ray spectrometry. Quality assurance of the data was achieved through the analysis of certified reference materials. The range of concentration for Mn, Fe, Ni, Zn, and Pb are 53.3-819 μg/g, 1.4-51 mg/g, 8-131μg/g, 9.5-113 μg/g, 18.4-142 μg/g, and 4.0-26.6 μg/g respectively. The ranges of radioactivity concentration of 2 26Ra, 2 28Ra, and 4 0K are 2.5-25.1 Bq/kg, 2.1-13.1 Bq/kg, respectively, while most of the measurements for 1 37Cs were below detection limits and the highest value is 8.3 Bq/kg. With respect to heavy metals for some samples the metal content increasing with decreasing particle-size, this results obtained by statistical multi-variant analysis methods. factor analysis indicates that: the silt/clay fraction (≥63 μm) the is dominant source for the emission form anthropogeic activities. the results from cluster analysis showed that the samples fell into two clusters based on minerological composition variations. Dominant elements in sediments recorded significant positive correlation with both trace elements and natural radionuclides. From the comparative study it appeared that: the fringing reefs area and few locations in Port Sudan and Sawakin harbors can be

  16. The biological transport of radionuclides in grassland and freshwater ecosystems

    International Nuclear Information System (INIS)

    Rudge, S.A.

    1989-12-01

    This thesis examines the biological transport of radionuclides through terrestrial and aquatic ecosystems, with particular reference to radiocaesium. The semi-natural grassland habitat was located at Drigg, W. Cumbria, contaminated primarily by radioactive fallout, from several sources over the past decade. Advantage was made of the deposition of radionuclides from the Chernobyl reactor incident, which occurred during the early stages of the investigation. The study examined the distribution of radiocaesium for the major components of the grassland ecosystem, within the soil-plant-invertebrate-small mammal food chain. Data concerning temporal fluctuation of radionuclide transfer factors between food chain components are presented. The final section examines the spatial distribution of radiocaesium in sediment and the freshwater eel (Anguilla anguilla) in a small stream contaminated by radioactive effluent. The relationship between activity levels in eels and the sediments in which they rest and forage was investigated. Factors influencing uptake of radiocaesium in freshwater fish were also examined. (author)

  17. Radionuclide carriers

    International Nuclear Information System (INIS)

    Hartman, F.A.; Kretschmar, H.C.

    1976-01-01

    A new carrier for radionuclide technetium 99m has been prepared for scintiscanning purposes. The new preparate consists of physiologically acceptable water-insoluble Tcsup(99m)-carrier containing from 0.2 to 0.8 weight percent of stannic ion as reductor, bound to an anionic starch derivative with about 1-20% of phosphate substituents. (EG)

  18. Radionuclide studies in impotence

    Energy Technology Data Exchange (ETDEWEB)

    Hilson, A.J.; Lewis, C.A. (St. Peter' s Hospitals, London (England))

    1991-04-01

    Impotence may be of physiological origin with causes including vascular or neurological pathology. Alternatively, it may be of psychogenic origin. Clinicians can distinguish between psychological and organic impotence by observing nocturnal penile tumescence. Non-radionuclide investigations for organic impotence include penile plethysmography or pulse Doppler analysis for arterial supply, cavernosometry for venous drainage, and biothesiometry or evoked potentials for neurological pathology. Radionuclide studies are primarily based on the use of technetium 99m-pertechnetate, 99mTc-red blood cells, or xenon 133 to study the blood flow, with or without pharmacological intervention, commonly papaverine. 26 references.

  19. Biological targeting of radionuclides

    International Nuclear Information System (INIS)

    Wheldon, T.E.; Glasgow Univ.

    1993-01-01

    Targeted radionuclide therapy in several forms has now been investigated in the clinic for more than 10 years. Despite some promising indications, targeted radiotherapy has not yet had a large impact on cancer therapy. Theoretical analysis shows that tumour cure would not often be expected using existing treatments. Addition of external-beam irradiation appears to be a robust strategy, which is appropriate in a wide range of situations. In future, many new agents will be made available by progress in molecular biology. However, integration of targeted radionuclide therapy with other modalities, especially radiotherapy, may still be required. (Author)

  20. Investigation of the tube side flow distribution in heat exchangers

    International Nuclear Information System (INIS)

    AbuRomia, M.M.; Pyare, R.

    1977-01-01

    The tube side flow distribution in heat exchangers is being investigated through the solution of the governing equations of fluid mechanics with distributed resistances that simulate the presence of the tubes. The modeling scheme used in the analysis and the numerical methods of solving the governing equations are described. The analysis is applied to the CRBRP-Intermediate Heat Exchanger (IHX), where its tube side plenum is simulated by several models that approximate its spherical boundary. The flow field within the plenum and the distribution of the total flow rate among the tubes are determined by the analysis

  1. Power Quality Investigation of Distribution Networks Embedded Wind Turbines

    Directory of Open Access Journals (Sweden)

    A. Elsherif

    2016-01-01

    Full Text Available In recent years a multitude of events have created a new environment for the electric power infrastructure. The presence of small-scale generation near load spots is becoming common especially with the advent of renewable energy sources such as wind power energy. This type of generation is known as distributed generation (DG. The expansion of the distributed generators- (DGs- based wind energy raises constraints on the distribution networks operation and power quality issues: voltage sag, voltage swell, voltage interruption, harmonic contents, flickering, frequency deviation, unbalance, and so forth. Consequently, the public distribution network conception and connection studies evolve in order to keep the distribution system operating in optimal conditions. In this paper, a comprehensive power quality investigation of a distribution system with embedded wind turbines has been carried out. This investigation is carried out in a comparison aspect between the conventional synchronous generators, as DGs are widely in use at present, and the different wind turbines technologies, which represent the foresightedness of the DGs. The obtained results are discussed with the IEC 61400-21 standard for testing and assessing power quality characteristics of grid-connected wind energy and the IEEE 1547-2003 standard for interconnecting distributed resources with electric power systems.

  2. Radionuclides in house dust

    CERN Document Server

    Fry, F A; Green, N; Hammond, D J

    1985-01-01

    Discharges of radionuclides from the British Nuclear Fuel plc (BNFL) reprocessing plant at Sellafield in Cumbria have led to elevated concentrations radionuclides in the local environment. The major routes of exposure of the public are kept under review by the appropriate Government departments and monitoring is carried out both by the departments and by BNFL itself. Recently, there has been increasing public concern about general environmental contamination resulting from the discharges and, in particular, about possible exposure of members of the public by routes not previously investigated in detail. One such postulated route of exposure that has attracted the interest of the public, the press and Parliament arises from the presence of radionuclides within houses. In view of this obvious and widespread concern, the Board has undertaken a sampling programme in a few communities in Cumbria to assess the radiological significance of this source of exposure. From the results of our study, we conclude that, alt...

  3. Investigation of Pockels Cells Crystal Contrast Ratio Distribution

    Directory of Open Access Journals (Sweden)

    Giedrius Sinkevičius

    2017-07-01

    Full Text Available The BBO Pockel’s cell has been investigated. The investigation results of optimal operating area on the surface of the crystal dependent of intrinsic contrast ratio (ICR and voltage contrast ratio (VCR for Pockel’s cell are presented. The block diagram of Pockel’s cells contrast measurement stand and measurement methodology are introduced and discussed. The graphs of intrinsic contrast ratio distribution on crystal surface, contrast ratio with voltage dependency and voltage contrast ratio distribution on crystal surface with half-wave voltage are presented.

  4. Elemental and radionuclides distribution in the production and use of phosphate fertilizers in Brazil; Distribuicao elementar e de radionuclideos na producao e uso de fertilizantes fosfatados no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Saueia, Catia Heloisa Rosignoli

    2006-07-01

    Fertilizer is considered an essential component for agriculture, because its use increases the natural soil nutrients, which are lost slow waste or erosion. The Brazilian phosphate fertilizer is obtained by wet reaction of igneous phosphate rock with concentrated sulphuric acid, giving as final product, phosphoric acid and dihydrated calcium sulphate (phosphogypsum) as by-product. Phosphoric acid is the starting material for triple superphosphate (TSP), single superphosphate (SSP), monoammonium phosphate (MAP) and diammonium phosphate (DAP). The phosphate rock used as raw material presents in its composition, radionuclides of the U and Th natural series in. During the chemical attack of the phosphate rock, this equilibrium is disrupted and the radionuclides and the elements migrate to intermediate, final products and byproducts, according to their solubility and chemical properties. While the fertilizers are commercialized, the phosphogypsum is disposed in stack piles and can cause an impact in the environment. In order to evaluate the radionuclides and the elements distribution in the industrial process of phosphate fertilizer production, samples of concentrated rock, fertilizers (SSP, TSP, MAP and DAP) and phosphogypsum from three national industries (A, B and C), were analyzed. The characterization of the elements Ba, Co, Cr, Fe, Hf, Na, Sc, Ta, Th, U, Zn and Zr, and the rare earths La, Ce, Nd, Sm, Eu, Tb, Yb and Lu, were performed by instrumental neutron activation analysis. The results obtained showed that, in general, the rare earth elements are distributed uniformly in the fertilizers and phosphogypsum, except for Lu. The elemental concentration present in the fertilizers SSP and TSP are of the same order of magnitude of the source rock. The same behavior was observed in the fertilizers MAP and DAP, except for the elements Co, Sc and U. The radionuclides of the U series ({sup 238}U, {sup 234}U, {sup 230}Th, {sup 226}Ra, {sup 210}Pb) and of the Th series

  5. The analysis of impact of irregularity in radionuclide coating of scaffold on the distribution of absorbed dose produced by grid of microsources

    Directory of Open Access Journals (Sweden)

    N. A. Nerosin

    2015-01-01

    Full Text Available The impact of irregularity in radionuclide coating of scaffold on the distribution of absorbed dose produced by grid of microsources was analyzed. On engineering software MATHCAD the program for calculation of absorbed dose produced by grid of microsources was created. To verify this algorithm the calculation model for MCNP code was established and represented the area consisted of soft biological tissue or any other tissue in which the grid of microsources was incorporated. Using the developed system the value of possible systematic irregular coating of radioactivity on the microsource’s core was analyzed. The distribution of activity along the surface of microsource was simulated to create distribution of absorbed dose rate corresponding to experimental data on radiation injury. The obtained model of microsource with irregular distribution of activity was compared to conventional microsource with core coated regularly along the entire area of the silver stem by main dosimetry characteristics. The results showed that even for extremely irregular distribution of activity the distribution of dose rate produced by microsource in the tumor area was not substantially different from dose-rate field obtained for microsource with regularly coated activity. The differences in dose rates (up to 10% in areas which were the nearest to the center of the grid were significantly lower than its decline from center to periphery of the grid. For spatial distribution of absorbed dose for specific configuration of microsource set and tracing of curves of equal level by selected cut-off the program SEEDPLAN was developed. The developed program represents precisely enough the spatial distribution of selected configuration set of microsources using results of calculation data for absorbed dose around the single microsource as basic data and may be used for optimal planning of brachytherapy with microsources. 

  6. Isotopic ratio and vertical distribution of radionuclides in soil affected by the accident of Fukushima Dai-ichi nuclear power plants

    International Nuclear Information System (INIS)

    Fujiwara, Takeshi; Saito, Takumi; Muroya, Yusa; Sawahata, Hiroyuki; Yamashita, Yuji; Nagasaki, Shinya; Okamoto, Koji; Takahashi, Hiroyuki; Uesaka, Mitsuru; Katsumura, Yosuke; Tanaka, Satoru

    2012-01-01

    The results of γ analyses of soil samples obtained from 50 locations in Fukushima prefecture on April 20, 2011, revealed the presence of a spectrum of radionuclides resulted from the accident of the Fukushima Dai-ichi nuclear power plant (FDNPP). The sum γ radioactivity concentration ranged in more than 3 orders of magnitude, depending on the sampling locations. The contamination of soils in the northwest of the FDNPP was considerable. The 131 I/ 137 Cs activity ratios of the soil samples plotted as a function of the distance from the F1 NPPs exhibited three distinctive patterns. Such patterns would reflect not only the different deposition behaviors of these radionuclides, but also on the conditions of associated release events such as temperature and compositions and physicochemical forms of released radionuclides. The 136 Cs/ 137 Cs activity ratio, on the other hand, was considered to only reflect the difference in isotopic compositions of source materials. Two locations close to the NPP in the northwest direction were found to be depleted in short-lived 136 Cs. This likely suggested the presence of distinct sources with different 136 Cs/ 137 Cs isotopic ratios, although their details were unknown at present. Vertical γ activity profiles of 131 I and 137 Cs were also investigated, using 20–30 cm soil cores in several locations. About 70% or more of the radionuclides were present in the uppermost 2-cm regions. It was found that the profiles of 131 I/ 137 Cs activity ratios showed maxima in the 2–4 cm regions, suggesting slightly larger migration of the former nuclide. - Highlights: ► We report the results of γ analyses of soil samples around Fukushima Dai-ichi NPPs. ► The contamination of soils in the northwest of the power plant was considerable. ► The 131 I/ 137 Cs activity ratios exhibited three distinctive patterns. ► Most of 131 I and 137 Cs were present in the uppermost 2-cm regions of soil.

  7. Spatial and vertical distribution and risk assessment of natural radionuclides in soils surrounding the lignite-fired power plants in Megalopolis basin, Greece.

    Science.gov (United States)

    Papaefthymiou, H V; Manousakas, M; Fouskas, A; Siavalas, G

    2013-01-01

    Twenty soil profile samples and fourteen surface soil samples collected from the vicinity of the lignite-fired power plants in the Megalopolis basin (Greece) were analysed for their natural radionuclide concentration and (137)Cs, since fossil fuels are associated with naturally occurring radioactive materials and hence with radiological impact. No significant enhancement of surface soil radioactivity levels in the vicinity of lignite-fired plants was observed. A downcore decreasing trend of (137)Cs was observed in a number of cores reflecting its atmospheric origin, whereas the uniform distribution observed in a number of other cores gave information on the mechanical alteration of the soil. The average dose rate value was found to be 63 ± 22 nGy h(-1), while the annual average effective dose from the terrestrial gamma radiation was found to be 0.08 ± 0.03 mSv.

  8. Radionuclide techniques

    International Nuclear Information System (INIS)

    Alazraki, N.

    1988-01-01

    During approximately 25 years of experience with bone scanning, broad expansions in the clinical impact of radionuclide imaging on disorders of bones, joints, and soft tissues have occurred. This increased impact had its groundwork laid by advances in radiopharmaceuticals and instruments that are used for bone imaging. The progression from /sup 85/Sr- to /sup 99m/Tc-labeled phosphate and phosphonate compounds, coupled with the advance from crude rectilinear scanning techniques to whole body scintillation imaging with large crystal cameras and sophisticated electronics, has encourage use of radionuclide techniques in the evaluation of muscoloskeletal diseases. Many clinical studies have documented the high degree of sensitivity of the bone scan compared with that of the radiograph in detecting osseous and articular abnormalities

  9. Radionuclide therapy.

    Science.gov (United States)

    Chatal, J F; Hoefnagel, C A

    1999-09-11

    Nuclear medicine therapy uses unsealed radioactive sources for the selective delivery of radiation to tumours or target organs. For benign disorders such as thyrotoxicosis and arthritis radionuclide therapy provides an alternative to surgery or medical treatment. In cancer treatment, it often combines the advantage of target selectivity (like brachytherapy or external beam radiotherapy) with that of being systemic, as with chemotherapy, and it may be used as part of a therapeutic strategy with curative intent or for disease control and palliation. Toxicity is generally limited to the haematopoietic tissue and few side-effects are observed. When cure is feasible, the long-term consequences of radionuclide therapy (eg, fertility disorders and leukaemia or other secondary cancers) do compare favourably with the risks associated with and accepted for chemotherapy and radiotherapy.

  10. Experimental investigation of long-lived radionuclide migration in floodplain soils of Chernobyl NPP 10-km zone and risk estimation of ground water pollution

    International Nuclear Information System (INIS)

    Zhirnov, V.G.; Popov, V.E.

    1993-01-01

    Heavily polluted with long-lived radionuclides, the floodplain soils of Chernobyl NPP 30-km zone is a potential danger for the river system and reservoirs of the Ukraine. In 1991, the building of a dam along the river left bank was started to isolate the river-bed. However, during the spring rise of water in the river body, the water will all the same infiltrate through the soil to the floodplain because of hydraulic pressure. The main goal of this work was to estimate the strontium 90 content in the top water and it's dependence on the depth of water over the soil surface. We studied the strontium 90 different chemical forms distribution in the left bank part of the floodplain and experimentally determined the strontium 90 washing out by river water taken into account it's upward flow

  11. General investigation of radionuclide retention in migration pathways at the West Valley, New York low-level burial site. Final report 1 Oct 78-14 Feb 80

    International Nuclear Information System (INIS)

    Dana, R.H. Jr; Ragan, V.S.; Molello, S.A.; Bailey, H.H.; Fickies, R.H.

    1980-10-01

    This final report evaluates the containment capabilities of the low-level, solid radioactive waste burial ground at West Valley, New York. The investigation included a surface water study, a trench water study, geotechnical and radiochemical studies of soils, a geotechnical analysis of a research trench and analysis of subtrench core data. Tritium is the most abundant beta emitter in trench water while strontium-90 is the predominant beta emitter in surface water. Strontium-90 ranks as the second most abundant trench water radionuclide in 6 of the 11 trenches studied. Four radionuclides were found to have either definite or possible migration. Carbon-14 was found to migrate at a much slower rate than tritium, which migrated to a depth slightly greater than 3.2m below the trench flow. There is also inconclusive evidence for strontium-90 migration beneath the trenches. Plutonium-238 was detected immediately beneath all 3 trenches studied and in 4 of the 5 trench cores. Results predicted by testing performed in 1977 were confirmed by standard engineering tests on soils fron the site. Soil samples taken from the north burial area trench caps and analyzed for tritium showed approximate background levels at the surface and above background levels at depths of 20 to 50 centimeters

  12. Influence of marine sediments in the distribution of the main radionuclides of the effluent from the nuclear power plant Almirante Alvaro Alberto (Unit 1)

    International Nuclear Information System (INIS)

    Brugnara, Miriam

    1977-01-01

    This study aimed to: 1) Characterize bottom sediments of the Angra dos Reis region, in the dispersion area of the effluent of the central Almirante Nuclear Alvaro Alberto, Unit 1. 2) Determining the adsorption capacity of these sediments to the long half-life and mean radionuclides to be released in the reactor effluent in a higher concentration. 3) Estimate the fraction of the different studied radionuclides that will be immobilized in sediments. 4) Identify critical radionuclides available for food chain

  13. Radionuclides (40K, 232Th and 238U) and Heavy Metals (Cr, Ni, Cu, Zn, As and Pb) Distribution Assessment at Renggam Landfill, Simpang Renggam, Johor, Malaysia

    Science.gov (United States)

    Zaidi, E.; FahrulRazi, MJ; Azhar, ATS; Hazreek, ZAM; Shakila, A.; Norshuhaila, MS; Omeje, M.

    2017-08-01

    The assessment of radioactivity levels and the distribution of heavy metals in soil samples at CEP Farm landfill, Renggam in Johor State was to determine the activity concentrations of naturally occurring radionuclides and heavy metal concentrations of this landfill. The background radiation was monitored to estimate the exposure level. The activity concentrations of radionuclides in soil samples were determined using HPGe gamma ray spectroscopy whereas the heavy metal concentration was measured using X-RF analysis. The mean exposure rate at the landfill site was 36.2±2.4 μR hr-1 and the annual effective dose rate at the landfill site was 3.19 ± 0.22 mSv yr-1. However, residential area has lower mean exposure dose rate of about 16.33±0.72 μR hr-1 and has an annual effective dose rate of 1.43±0.06 mSv yr-1 compared to landfill sites. The mean activity concentration of 40K, 238U and 232Th at landfill site were 239.95±15.89 Bq kg-1, 20.90±2.49 Bq kg-1 and 40.61±4.59 Bq kg-1, respectively. For heavy metal compositions, Cr, Ni and Cu have mean concentration of 232±10 ppm, 23±2 ppm, and 46±19 ppm, respectively. Whereas, Zn has concentration of 64±9 ppm and concentration of 12±1 ppm and 71±2 ppm was estimated for As and Pb respectively. The higher activity concentration of 40K down the slope through leaching process whereas the higher activity level of 238U content at the landfill site may be attributed to the soil disruption to local equilibrium.

  14. Fractionation of radionuclide species in the environment

    International Nuclear Information System (INIS)

    Salbu, Brit

    2009-01-01

    Naturally occurring and artificially produced radionuclides in the environment may be present in different physico-chemical forms (i.e., radionuclide species) varying in size (nominal molecular mass), charge properties and valence, oxidation state, structure and morphology, density, degree of complexation, etc. Low molecular mass (LMM) species are believed to be mobile and potentially bioavailable, while high molecular mass (HMM) species such as colloids, polymers, pseudocolloids and particles are considered inert. Due to time-dependent transformation processes such as mobilisation of radionuclide species from solid phases or interactions of mobile and reactive radionuclide species with components in soils and sediments, the original distribution of radionuclides deposited in ecosystems will change over time. To assess the environmental impact from radionuclide contamination, information on radionuclide species deposited, interactions within affected ecosystems and the time-dependent distribution of radionuclide species influencing mobility and biological uptake is essential. The development of speciation techniques to characterize radionuclide species in waters, soils and sediments should therefore be essential for improving the prediction power of impact and risk assessment models. The present paper reviews available fractionation techniques which can be utilised for radionuclide speciation purposes

  15. Technogenic and natural radionuclides in the bottom sediments of the Sea of Azov: regularities of distribution and application to the study of pollutants accumulation chronology

    Science.gov (United States)

    Kuznetsov, A. N.; Fedorov, Yu A.; Yaroslavtsev, V. M.

    2018-01-01

    The study of pollutants vertical distribution in seabed sediments is of high interest as they conserve the information on the chronology of pollution level in the past. In the present paper, the results of layer by layer study of Cs-137, Am-241, Pb-210 specific activities as well as concentrations of petroleum components, lead and mercury in 48 sediment cores of the Sea of Azov, the Don River and the Kuban River are examined. In most sediment cores, two peaks of Cs-137 and Am-241 are detected. The upper of them was formed due to the Chernobyl accident in 1986 and the other is related to the global nuclear fallout of 1960s. The specific activity of naturally occurring atmospheric Lead-210 decreases exponentially with the sediment core depth. However, it is influenced by fluvial run-off, coastal erosion, Radium-226 and Radon-222 decay. The data on the radionuclides distribution in the seabed sediments is used to date them. According to the results of dating, most of petroleum components, lead and mercury quantities are concentrated in the upper sediment layer formed in the last 50 to 70 years i.e. in the period of the most important anthropogenic pressure.

  16. Investigation of plutonium concentration and distribution in burrowing crayfish from the White Oak Creek floodplain

    Energy Technology Data Exchange (ETDEWEB)

    Delaney, M.S.; Dahlman, R.C.; Craig, R.B.

    1979-01-01

    The White Oak floodplain was contaminated with several radionuclides, including /sup 239/Pu, during the Manhattan Project in 1944. Plutonium distribution in the soil is nonhomogeneous. An investigation was conducted to deterine Pu accumulation in a resident animal population. Crayfish were chosen because they complete their life-cycle within the contaminated environment, they directly contact contaminated muds, and they function in a food chain of significance to man. Two major conclusions of the research were that Pu concentrations in contaminated crayfish typically exceed those of control crayfish by two orders of magnitude and that if an incident were to occur in which a standard man ingested the soft tissues of ten crayfish from the floodplain, an insignificant whole body dose would accrue over the subsequent 50 years of life. The digestive tract of contaminated crayfish contained 21 to 33% of the Pu body burden, soft tissues contained 11 to 31% of the Pu body burden, and 48 to 62% of the Pu body burden of contaminated crayfish was associated with the carapace. Therefore, at a molt a large proportion of its accumulated Pu is deposited in the environment. A supplementary laboratory investigation using /sup 237/Pu included a chronic Pu uptake study by uncontaminated crayfish. In these crayfish, from 64 to 82% of the /sup 237/Pu was associated with the body tissues. Complementary data for /sup 237/Pu associated with the carapace ranged from 18 to 37% of the distribution. An inventory of /sup 239/Pu in crayfish at two sites on the floodplain was calculated by multiplying the estimated biomass of the crayfish by their average /sup 239/Pu concentration. This evaluation of Pu associated with the crayfish population was compared to an inventory of /sup 239/Pu in the soil in which they burrow and was found to be eight orders of magnitude less.

  17. Investigation of plutonium concentration and distribution in burrowing crayfish from the White Oak Creek floodplain

    International Nuclear Information System (INIS)

    Delaney, M.S.; Dahlman, R.C.; Craig, R.B.

    1979-01-01

    The White Oak floodplain was contaminated with several radionuclides, including 239 Pu, during the Manhattan Project in 1944. Plutonium distribution in the soil is nonhomogeneous. An investigation was conducted to deterine Pu accumulation in a resident animal population. Crayfish were chosen because they complete their life-cycle within the contaminated environment, they directly contact contaminated muds, and they function in a food chain of significance to man. Two major conclusions of the research were that Pu concentrations in contaminated crayfish typically exceed those of control crayfish by two orders of magnitude and that if an incident were to occur in which a standard man ingested the soft tissues of ten crayfish from the floodplain, an insignificant whole body dose would accrue over the subsequent 50 years of life. The digestive tract of contaminated crayfish contained 21 to 33% of the Pu body burden, soft tissues contained 11 to 31% of the Pu body burden, and 48 to 62% of the Pu body burden of contaminated crayfish was associated with the carapace. Therefore, at a molt a large proportion of its accumulated Pu is deposited in the environment. A supplementary laboratory investigation using 237 Pu included a chronic Pu uptake study by uncontaminated crayfish. In these crayfish, from 64 to 82% of the 237 Pu was associated with the body tissues. Complementary data for 237 Pu associated with the carapace ranged from 18 to 37% of the distribution. An inventory of 239 Pu in crayfish at two sites on the floodplain was calculated by multiplying the estimated biomass of the crayfish by their average 239 Pu concentration. This evaluation of Pu associated with the crayfish population was compared to an inventory of 239 Pu in the soil in which they burrow and was found to be eight orders of magnitude less

  18. Feasibility of disposal of high-level radioactive waste into the seabed. volume 7: Review of laboratory investigations of radionuclide migration through deep-sea sediments

    International Nuclear Information System (INIS)

    Brush, L.H.

    1988-01-01

    One of the options suggested for disposal of high-level radioactive waste resulting from the generation of nuclear power is burial beneath the deep ocean floor in geologically stable sediment formations which have no economic value. The 8-volume series provides an assessment of the technical feasibility and radiological safety of this disposal concept based on the results obtained by ten years of co-operation and information exchange among the Member countries participating in the NEA Seabed Working Group. This volume contains a review of the laboratory investigations of radionuclide migration through deep-sea sediments. In addition, it discusses the data selected for the radiological assessment, on the basis of both field and laboratory studies

  19. Effects of grain size, mineralogy, and acid-extractable grain coatings on the distribution of the fallout radionuclides 7Be, 10Be, 137Cs, and 210Pb in river sediment

    Science.gov (United States)

    Singleton, Adrian A.; Schmidt, Amanda H.; Bierman, Paul R.; Rood, Dylan H.; Neilson, Thomas B.; Greene, Emily Sophie; Bower, Jennifer A.; Perdrial, Nicolas

    2017-01-01

    Grain-size dependencies in fallout radionuclide activity have been attributed to either increase in specific surface area in finer grain sizes or differing mineralogical abundances in different grain sizes. Here, we consider a third possibility, that the concentration and composition of grain coatings, where fallout radionuclides reside, controls their activity in fluvial sediment. We evaluated these three possible explanations in two experiments: (1) we examined the effect of sediment grain size, mineralogy, and composition of the acid-extractable materials on the distribution of 7Be, 10Be, 137Cs, and unsupported 210Pb in detrital sediment samples collected from rivers in China and the United States, and (2) we periodically monitored 7Be, 137Cs, and 210Pb retention in samples of known composition exposed to natural fallout in Ohio, USA for 294 days. Acid-extractable materials (made up predominately of Fe, Mn, Al, and Ca from secondary minerals and grain coatings produced during pedogenesis) are positively related to the abundance of fallout radionuclides in our sediment samples. Grain-size dependency of fallout radionuclide concentrations was significant in detrital sediment samples, but not in samples exposed to fallout under controlled conditions. Mineralogy had a large effect on 7Be and 210Pb retention in samples exposed to fallout, suggesting that sieving sediments to a single grain size or using specific surface area-based correction terms may not completely control for preferential distribution of these nuclides. We conclude that time-dependent geochemical, pedogenic, and sedimentary processes together result in the observed differences in nuclide distribution between different grain sizes and substrate compositions. These findings likely explain variability of measured nuclide activities in river networks that exceeds the variability introduced by analytical techniques as well as spatial and temporal differences in erosion rates and processes. In short, we

  20. Experimental investigation of statistical models describing distribution of counts

    International Nuclear Information System (INIS)

    Salma, I.; Zemplen-Papp, E.

    1992-01-01

    The binomial, Poisson and modified Poisson models which are used for describing the statistical nature of the distribution of counts are compared theoretically, and conclusions for application are considered. The validity of the Poisson and the modified Poisson statistical distribution for observing k events in a short time interval is investigated experimentally for various measuring times. The experiments to measure the influence of the significant radioactive decay were performed with 89 Y m (T 1/2 =16.06 s), using a multichannel analyser (4096 channels) in the multiscaling mode. According to the results, Poisson statistics describe the counting experiment for short measuring times (up to T=0.5T 1/2 ) and its application is recommended. However, analysis of the data demonstrated, with confidence, that for long measurements (T≥T 1/2 ) Poisson distribution is not valid and the modified Poisson function is preferable. The practical implications in calculating uncertainties and in optimizing the measuring time are discussed. Differences between the standard deviations evaluated on the basis of the Poisson and binomial models are especially significant for experiments with long measuring time (T/T 1/2 ≥2) and/or large detection efficiency (ε>0.30). Optimization of the measuring time for paired observations yields the same solution for either the binomial or the Poisson distribution. (orig.)

  1. Radionuclide co-precipitation

    International Nuclear Information System (INIS)

    Bruno, J.; Sandino, A.

    1987-12-01

    The thermodynamic and kinetic behaviour of the minor components of the spent fuel matrix has been theoretically and experimentally investigated. Two different situations have been studied: Part I, the near field scenario, where the release and migration of the minor components is dependent on the solubility behaviour of UO 2 (s); Part II, the far field, where the solubility and transport of the radionuclides is related to the major geochemical processes occurring. (orig.)

  2. Combined use of fallout radionuclides and stable isotopes for investigating soil erosion processes in a Moroccan watershed

    Science.gov (United States)

    Benmansour, Moncef; Mabit, Lionel; Zouagui, Anis; Amenzou, Nouredinne; Sabir, Mohamed; Nouira, Asmae; Brandt, Christian; Rasche, Frank; Naimi, Mustapha; Chikhaoui, Mohamed; Marah, Hamid; Benkdad, Azzouz; Taous, Fouad

    2015-04-01

    On-site and off-site impacts associated with land degradation by soil erosion are a major concern in Morocco. This study aimed to use fallout radionuclides (FRNs): Caesium-137 (137Cs), excess Lead-210 (210Pbex) and Beryllium-7 (7Be) in combination with carbon and nitrogen stable isotopes (i.e. Carbon-13 (13C) and Nitrogen-15 (15N)) in estimating soil loss in the "My Bouchta" watershed and the origin of sediment deposits in a downstream water reservoir (i.e. "Talembout"). Using 137Cs, the net soil erosion rate, for the "My Bouchta" watershed over a period of 50 years, was estimated at 23 t/ha/yr with a main sediment contribution (> 90{%}) from the agricultural fields, the forest and shrub fields contributing to less than 10{%} of the overall sediment production. This result indicates clearly the role and the effectiveness of the forest plantations and vegetation cover to protect soil resource against erosion processes. The use of the 210Pb^ex technique in three different fields further highlighted that soil erosion rates over a period of 100 years were lower than those obtained by 137Cs reflecting the increase of soil loss during the last decades. Tests of fallout 7Be associated with short rainfall events in four fields confirmed the results obtained with 137Cs, that areas under natural vegetation were protected against erosion. Sedimentation rates were assessed for the "Talembout" water reservoir and the mean values obtained for two sediment cores using 210Pbex and the Constant Rate of Supply (CRS) model were about 0.51-0.58 g/cm^2/yr. The obtained results showed also a significant yearly increase of the sedimentation rate. The results derived from the stable isotopes depth profiles indicated similar behavior for forest and shrub fields. Furthermore, strong correlation between δ13C and total C was observed for this type of land use while for the agricultural fields, the correlation was not significant. In addition, the sediment profile of N-15 indicated an

  3. Initial Radionuclide Inventories

    Energy Technology Data Exchange (ETDEWEB)

    H. Miller

    2004-09-19

    The purpose of this analysis is to provide an initial radionuclide inventory (in grams per waste package) and associated uncertainty distributions for use in the Total System Performance Assessment for the License Application (TSPA-LA) in support of the license application for the repository at Yucca Mountain, Nevada. This document is intended for use in postclosure analysis only. Bounding waste stream information and data were collected that capture probable limits. For commercially generated waste, this analysis considers alternative waste stream projections to bound the characteristics of wastes likely to be encountered using arrival scenarios that potentially impact the commercial spent nuclear fuel (CSNF) waste stream. For TSPA-LA, this radionuclide inventory analysis considers U.S. Department of Energy (DOE) high-level radioactive waste (DHLW) glass and two types of spent nuclear fuel (SNF): CSNF and DOE-owned (DSNF). These wastes are placed in two groups of waste packages: the CSNF waste package and the codisposal waste package (CDSP), which are designated to contain DHLW glass and DSNF, or DHLW glass only. The radionuclide inventory for naval SNF is provided separately in the classified ''Naval Nuclear Propulsion Program Technical Support Document'' for the License Application. As noted previously, the radionuclide inventory data presented here is intended only for TSPA-LA postclosure calculations. It is not applicable to preclosure safety calculations. Safe storage, transportation, and ultimate disposal of these wastes require safety analyses to support the design and licensing of repository equipment and facilities. These analyses will require radionuclide inventories to represent the radioactive source term that must be accommodated during handling, storage and disposition of these wastes. This analysis uses the best available information to identify the radionuclide inventory that is expected at the last year of last emplacement

  4. Evaluation of energy spectral information in nuclear imaging and investigation of protein binding of cationic radionuclides by lactoferrin. Comprehensive progress report, October 1, 1977-September 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Hoffer, P. B.

    1980-06-10

    Construction of an Anger camera-computer system which allows collection of both the position and energy signals from events detected by the scintillation camera has been completed. The system allows correction of energy response non-uniformity of the detector and facilitates research related to effects of energy discrimination in radionuclide scintigraphy. The system consists of electronic hardware to transmit and digitize the energy signal, software to record and process that signal in conjunction with spatial positioning signals, and additional hardware for recording the processed images so that they can be evaluated by observers. Preliminary results indicate that the system is useful in evaluating clinical images. Assymetric (eccentric) energy windows do improve image quality and are of value in improving detection of lesions on liver scintigraphs. The mechanisms by which Ga-67 is taken up in infection and tumor has been elucidated, and the uptake of radiogallium in microorganisms as a function of its interaction with siderophores was also studied. The primary function of these low molecular weight compounds is to trap ferric ion. However, gallium may be substituted for ferric ion and becomes trapped within the microorganism. The uptake of radiogallium by neutrophils and the role that lactoferrin plays in both intracellular localization of radiogallium and subsequent deposition of the radionuclide at sites of infection were also studied. Investigation of ferric ion analogs reveals definate differences in the affinity of these metals for binding molecules which helps explain their biologic activity. While ferric ion has the strongest affinity for such molecules, gallium has very high affinity for siderophores, moderate affinity for lactoferrin, and lower affinity for transferrin. The relative affinity of indium for these molecules is in approximately the reverse order.

  5. Dispersion of long-lived radionuclides from uranium mining, milling and fuel fabrication facilities

    International Nuclear Information System (INIS)

    Pettersson, H.B.L.

    1990-11-01

    The principal aim of the study was to gain further insight into the environmental dispersion of long-lived U series radionuclides from selected part of the nuclear fuel cycle and to assess the resulting exposure of members of the public. The specific objectives of this study were: 1. To determine the levels of natural radioactivity in the vicinity of two U deposits in Sweden and to establish whether U prospecting had generated significant radiological impact on man. 2. To investigate the spatial distributions of long-lived U series radionuclides caused by the dispersion of dust from the Ranger open-pit U mine in Australia. 3. To study the uptakes of long-lived U and T series radionuclides by the waterlily in order to facilitate assessment of natural exposures to the public and predictions of exposures arising from consumption of the plant due to any subsequent discharges of water from the Ranger U mine. 4. To investigate the spatial distributions of U isotopes in environmental air as a result of the release of radionuclides from the ABB-ATOM nuclear fuel factory at Vaesteraas in Sweden. In these investigations special emphasis was given to - activity ratio techniques suitable for distinguishing between natural and operation-related concentrations and for facilitating determination of the source of radionuclide uptake in the waterlily, and - the use of passive air samplers such as 'sticky vinyl' and bioindicators in investigating the aerial dispersion of radionuclides. (author)

  6. Research leadership and investigators: gender distribution in the federal government.

    Science.gov (United States)

    McCarren, Madeline; Goldman, Steven

    2012-08-01

    The National Academies reported in Beyond Bias and Barriers: Fulfilling the Potential of Women in Academic Science and Engineering (2006) that "women are very likely to face discrimination." In academic medicine, gender distribution is becoming more balanced. In the federal government, women also have made progress, doubling their representation in professional positions to 44%. The Department of Veterans Affairs (VA) has a research program and a mission to train health care professionals; however, its gender distribution has not been described. We conducted a descriptive study using public data for positions in the VA, National Institutes of Health (NIH), and Agency for Healthcare Research and Quality (AHRQ). We followed with a case-control analysis of predictors of receipt of grant funding in the VA. Participants were 224 leadership positions and 132 principal investigators. Women comprised 33% (AHRQ), 27% (NIH), and 0% (VA) of the top research leadership. Across all VA research levels, women comprised 45% to 0%, depending on the service. In the case-control analysis of principal investigators, men had greater odds (odds ratio 8.0) of a Cooperative Studies Program (CSP) trial award. History of first, last, or any authorship on a clinical trial publication in the 10 years before the index trial was only weakly associated with award of a CSP trial. The gender imbalance was not explained by publication history. Marked gender disparities were seen in the VA, except in Health Services Research. Organizations must investigate their practices to reveal disparities, investigate underlying factors, and intervene as needed. Published by Elsevier Inc.

  7. 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.

  8. Ten years of investigation on radioactive contamination of the marine environment. Incorporation, by marine algae and animals, of hydrogen-3 and other radionuclides present in effluents of nuclear or industrial origin

    International Nuclear Information System (INIS)

    Bonotto, S.; Colard, J.; Koch, G.; Kirchmann, R.; Strack, S.; Luettke, A.; Carraro, G.

    1981-01-01

    Several marine plants and animals were investigated for their capability of incorporating the main radionuclides present in selected effluents. Accumulation factors are reported for 3 H, 134 Cs, 136 Cs, 137 Cs, 58 Co, 60 Co, 54 Mn, 131 I 226 Ra and 124 Sb. Marine algae, which are involved in food chains leading to man, show the highest accumulation factors. The stable element composition of the alga Acetabularia was determined by gamma-activation analysis. The preferential accumulation of particular radionuclides by marine organisms suggests that they may have a significant role in the turnover rate of elements in the marine environment. (author)

  9. Total absorption gamma-ray spectrometer for measurement of beta-decay intensity distributions for fission product radionuclides

    International Nuclear Information System (INIS)

    Greenwood, R.C.; Helmer, R.G.; Lee, M.A.; Putnam, M.H.; Oates, M.A.; Struttmann, D.A.; Watts, K.D.

    1992-01-01

    A total absorption γ-ray spectrometer (TAGS), based on a 25.4 cm diameterx30.5 cm long NaI(Tl) well detector, has been developed at the INEL on-line isotope separator facility. A Si detector in the well of the NaI(Tl) detector allows one to collect β-particle-gated coincidence spectra as well as singles spectra. With this system, measurements of the total absorption spectra have been made for a number of fission product nuclei. The analysis of the measured spectra is based on response functions for single γ rays that are computed with a Monte Carlo code. Routines have been written to use these response functions to simulate the response to a cascade of several γ rays and by extension to a whole decay scheme. The bremsstrahlung from a ground-state β branch can also be simulated. The quality of the simulation is demonstrated for test spectra of 137 Cs, 24 Na, 60 Co, and 110m Ag. As examples of the operation of this system, the measurements and analyses of the β-decay feeding distributions are described for the decay of 141 Ba, 139 Cs and 140 Cs. (orig.)

  10. Radionuclides in thyroid cancer

    International Nuclear Information System (INIS)

    Mahadev, V.

    1980-01-01

    The three main areas of application of radionuclides in thyroid disease will be reviewed. Firstly thyroid radionuclide imaging in thyroid swellings, in relationship to lumps in the neck and ectopic thyroid tissue such as retrosternal goitre, and lingual goitre will be described. Future developments in the field including tomographic scanning, using the coded aperture method, and fluorescent scans and ultrasound are reviewed. The second area of application is the assessment and evaluation of thyroid function and the therapy of Grave's Disease and Plummer's Disease using radioiodine. The importance of careful collection of the line of treatment, results of treatment locally and the follow-up of patients after radioiodine therapy will be described. The third area of application is in the diagnosis and therapy of thyroid cancer. Investigation of thyroid swelling, and the diagnosis of functioning metastases are reported. The therapeutic iodine scan as the sole evidence of functioning metastatic involvement is recorded. Histological thyroid cancer appears to be increasingly encountered in clinical practice and the plan of management in relation to choice of cases for therapeutic scanning is discussed with case reports. Lastly the role of whole body scanning in relationship to biochemical markers is compared. In the changing field of nuclear medicine radionuclide applications in thyroid disease have remained pre-eminent and this is an attempt to reassess its role in the light of newer developments and local experience in the Institute of Radiotherapy, Oncology and Nuclear Medicine. (author)

  11. Monitoring and characterization of radionuclide transport in the hydrogeologic system

    International Nuclear Information System (INIS)

    Phillips, S.J.; Raymond, J.R.

    1975-01-01

    Historical records pertaining to the 300 North and Wye Burial Grounds at the Hanford Reservation were reviewed as a prerequisite to determining programs for land reclamation. All available historical documents, agency communications, and engineering drawings related to the study areas were located, reviewed, and analyzed. An inventory of recorded location, type, and quantity of radionuclides and associated materials in each burial ground was completed and distributed to cooperating investigators. A geophysical survey of the 300 North Burial Ground was conducted as a basis for detecting the composition, size, distribution, and depth of buried objects and characterizing the sediments in which they are buried. Acoustic, radar, magnetic, and metal detection surveys were completed and their applicability evaluated; drilling techniques and equipment for recovering and characterizing sediments and radioactive contaminated material were developed. Drilling will also determine the amount and dimensional extent of radionuclide migration; sediment-fluid interaction and fluid migration through the unsaturated zone at the 300 North Burial Ground were characterized. A study to determine biological transport of radionuclides at the Wye Burial Ground was also initiated. This study involved a preliminary survey of present flora and fauna inhabiting the Wye Burial Ground site. Plant tissue was chemically and radiochemically analyzed to determine radionuclide migration and possible dose effects and population dynamics of burrowing animals that could potentially be exposed to buried waste materials were investigated

  12. Radionuclide migration studies in soil

    International Nuclear Information System (INIS)

    Marumo, J.T.

    1989-01-01

    In this work a brief description about retention and migration parameters of radionuclides in soil, including main methods to determine the distribution coefficient (K) are given. Some of several factors that can act on the migration are also mentioned. (author) [pt

  13. Radionuclide migration through fractured granite

    International Nuclear Information System (INIS)

    Grondin, D.M.; Vandergraaf, T.T.; Drew, D.J.

    1988-01-01

    Radionuclide migration has been studied in natural fractures in granite blocks of up to 30 cm in length. Results are reported for four migration experiments involving synthetic groundwaters containing tritiated water, 95m Tc, 75 Se, 137 Cs, or 60 Co-labelled natural colloids, which were injected into the fractures at flow rates of 0.4-0.45 mL/h, giving residence times in the fractures of up to 15 h. Also presented are the results of the post-experiment analyses, including an autoradiograph of one of the fracture surfaces, and the spatial distribution of the sorbed radionuclides determined by γ-scanning and selective chemical extractions

  14. Microbial Transformations of Actinides and Other Radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Francis,A.J.; Dodge, C. J.

    2009-01-07

    Microorganisms can affect the stability and mobility of the actinides and other radionuclides released from nuclear fuel cycle and from nuclear fuel reprocessing plants. Under appropriate conditions, microorganisms can alter the chemical speciation, solubility and sorption properties and thus could increase or decrease the concentrations of radionuclides in solution in the environment and the bioavailability. Dissolution or immobilization of radionuclides is brought about by direct enzymatic action or indirect non-enzymatic action of microorganisms. Although the physical, chemical, and geochemical processes affecting dissolution, precipitation, and mobilization of radionuclides have been extensively investigated, we have only limited information on the effects of microbial processes and biochemical mechanisms which affect the stability and mobility of radionuclides. The mechanisms of microbial transformations of the major and minor actinides U, Pu, Cm, Am, Np, the fission products and other radionuclides such as Ra, Tc, I, Cs, Sr, under aerobic and anaerobic conditions in the presence of electron donors and acceptors are reviewed.

  15. A study on the radionuclide transport by bacteria in geologic media

    International Nuclear Information System (INIS)

    Han, Byoung Sub

    1997-02-01

    The purpose of this paper is to provide a methodology to develop a predictive model based on a conceptual three phase system and to investigate the influence of bacteria and their generation on the transport of radionuclide in porous and fractured media. The mass balance for bacteria, substrate and radionuclide were formulated. To illustrate the model simply, an equilibrium condition was assumed to partition the substrate, bacteria and radionuclide concentrations between the solid soil matrix, aqueous phase, rock matrix and bacterial surface. From the numerical calculation of the radionuclide transport in the presence of bacteria, it was found that the growth of bacteria and supplied primary substrate as limiting or stimulating growth factor of bacteria are the most important factors of the radionuclide transport. We also found that, depend on the transport of bacteria the temporal and spatial distribution of radionuclide concentration was significantly altered. The model proposed in this study will improve the evaluation of the role of the bacteria in the transport of radionuclide in groundwater systems. Furthermore, this model would be usefully utilized in analyzing the important role of colloidal particulate on the overall performance of radioactive waste safety

  16. Investigations of the corrosion behaviour of the Si-containing stainless steel 1.4361 with combined surface analysis, electrochemistry and radionuclide technique

    International Nuclear Information System (INIS)

    Maar-Stumm, M.

    1990-03-01

    The present work aimed at detailed information on the corrosion behaviour and particularly the corrosion mechanism of the steel 1.4361 in concentrated nitric acid by use of a combination of electrochemical methods, radionuclide technique and surface analysis. For comparison steel samples corroded by other methods were investigated by surface analysis, too. At the beginning of the corrosion in nitric acid Fe and Ni are dissolved preferentially. Cr and Si are enriched in the surface region. A primary corrosion layer is formed which is equivalent to the oxidic overlayer of atmospherically oxidized samples. It consists of the oxides of chromium and iron mixed up with glass-like SiO 2 . Ni does not contribute to the formation of the oxidic overlayer. On top of this primary corrosion layer there is an isolating gel-like SiO 2 -layer with a thickness depending on strength and duration of the corrosive attack. Its mechanical stability decreases with increasing layer thickness. At the boundary to the primary corrosion layer this gel-like SiO 2 -layer is closed, mechanically stable and conducting. Samples corroded under the standardized conditions of the Huey-test show a similar structure of the overlayer with the exception that the primary corrosion layer consists only of glass-like SiO 2 . The combination of several methods revealed detailed information about mass loss and structure of the overlayer at different electrode potentials. (orig./MM) [de

  17. A surface energy-budget model coupled with a Skewed Puff Model for investigating the dispersion of radionuclides in a sub-tropical area of Brazil

    International Nuclear Information System (INIS)

    Oliveira, A.P.; Soares, J.; Tirabassi, T.; Rizza, U.

    1998-01-01

    An air pollution model (Skewed Puff Model, SPM) based on the Monin-Obukhov similarity theory was applied to investigate the atmospheric dispersion of radionuclides at Ipero' in Brazil, the location of a nuclear industrial installation. The SPM numerical simulation were carried out using an input 5-minute averaged wind speed and direction observed at 11. m, friction velocity and the Monin-Obukhov length supplied by the surface energy-budget model, along with PBL height, estimated for the daytime. The agreement between the observed and simulated sensible and latent heat fluxes, friction velocity and the Monin-Obukhov length, within a level of confidence of 99.9% indicates that the internal parameters chosen for the surface energy-budget model are representative of the interface soil-vegetation conditions at Ipero'. The mean concentration field at the surface was estimated assuming that a hypothetical accident at Ipero' produced a continuous emission from a 10 m high point source for 18 hours during the summer of 1993 and of 36 hours during the winter of 1992. The results indicated that, in the case of an accident, the highest concentration values are located near to the source and most of the contaminated area is within a 5 km range, in both seasons. The shape of the contaminated area is defined by the wind and speed pattern

  18. Investigation of the Velocity Distribution in Sediment-Laden Flow

    Directory of Open Access Journals (Sweden)

    S. Khodadoust Siuki

    2016-02-01

    -law is also applied in the sediment-laden flows and von Karman constantly decreases with increasing sediment concentration. Such researchers as Vanoni (1946, Einstein and Chen (1955, Elata and Ippen (1961 supported this idea. Another view is that von Karman constantly does not decrease with increasing sediment concentration and velocity distribution deviates from the main region of the flow. Because of these contradictions about the effects of suspended sediments on characteristics of the flow and given the existence of several developed models , this question may be raised whether which one is markedly superior to the others or what model gives accurate results in the sediment-laden flow. No attempt was made to make an exhaustive comparison of the models with available experimental data. The present study evaluates and discusses the performance of seven models, by comparing these with experimental data selected from four sources. Then these equations will be assessed using the experimental data, and the best model will be introduced by means of statistical analysis. Materials and Methods: In this paper, the velocity distribution of sediment-laden flow has been investigated. Such equations as Log-law, modified log-law, wake-law, modified log-wake, log-modified wake, and parabolic law have been studied. The accuracy of each equation has been assessed by using statistical analysis. The mean average error (MAE is a quantity used to measure how close predictions are to the eventual outcomes. The root-mean-square error (RMSE is a frequently used measure of the differences between value predicted by a model or an estimator and the values actually observed. Determination coefficient (R2 is a number that indicates how well data fit a statistical model. Experiment data related to Wang and Qian (1989, Vanoni (1946, and Coleman (1981 have been used to test the proposed models. In most data sets, the width-depth ratios are less than 5, i.e., the maximum velocity occurs below the

  19. Radionuclide Sensors for Water Monitoring

    International Nuclear Information System (INIS)

    Grate, Jay W.; Egorov, Oleg B.; DeVol, Timothy A.

    2004-01-01

    Radionuclide contamination in the soil and groundwater at U.S. Department of Energy (DOE) sites is a severe problem that requires monitoring and remediation. Radionuclide measurement techniques are needed to monitor surface waters, groundwater, and process waters. Typically, water samples are collected and transported to an analytical laboratory, where costly radiochemical analyses are performed. To date, there has been very little development of selective radionuclide sensors for alpha- and beta-emitting radionuclides such as 90Sr, 99Tc, and various actinides of interest. The objective of this project is to investigate novel sensor concepts and materials for sensitive and selective determination of beta- and alpha-emitting radionuclide contaminants in water. To meet the requirements for loW--level, isotope-specific detection, the proposed sensors are based on radiometric detection. As a means to address the fundamental challenge of the short ranges of beta and alpha particle s in water, our overall approach is based on localization of preconcentration/separation chemistries directly on or within the active area of a radioactivity detector. Automated microfluidics is used for sample manipulation and sensor regeneration or renewal. The outcome of these investigations will be the knowledge necessary to choose appropriate chemistries for selective preconcentration of radionuclides from environmental samples, new materials that combine chemical selectivity with scintillating properties, new materials that add chemical selectivity to solid-state diode detectors, new preconcentrating column sensors, and improved instrumentation and signal processing for selective radionuclide sensors. New knowledge will provide the basis for designing effective probes and instrumentation for field and in situ measurements

  20. Radionuclide Sensors for Water Monitoring

    International Nuclear Information System (INIS)

    Grate, Jay W.; Egorov, Oleg B.; DeVol, Timothy A.

    2001-01-01

    Radionuclide contamination in the soil and groundwater at U.S. Department of Energy (DOE) sites is a severe problem requiring monitoring and remediation. Radionuclide measurement techniques are needed to monitor surface waters, groundwater, and process waters. Typically, water samples are collected and transported to the analytical laboratory where costly radiochemical analyses are performed. To date, there has been very little development of selective radionuclide sensors for alpha- and beta-emitting radionuclides such as 90 Sr, 99 Tc, and various actinides of interest. The objective of this project is to investigate novel sensor concepts and materials for sensitive and selective determination of beta- and alpha-emitting radionuclide contaminants in water. To meet the requirements for low-level, isotope-specific detection, the proposed sensors are based on radiometric detection. As a means to address the fundamental challenge of short ranges of beta and alpha particles in water, our overall approach is based on localization of preconcentration/separation chemistries directly on or within the active area of a radioactivity detector, using automated microfluidics for sample manipulation and sensor regeneration or renewal. The outcome of these investigations will be the knowledge necessary to choose appropriate chemistries for selective preconcentration of radionuclides from environmental samples, new materials that combine chemical selectivity with scintillating properties, new materials that add chemical selectivity to solid-state diode detectors, new preconcentrating column sensors, and improved instrumentation and signal processing for selective radionuclide sensors. New knowledge will provide the basis for designing effective probes and instrumentation for field analytical chemistry

  1. Radionuclide Sensors for Water Monitoring

    International Nuclear Information System (INIS)

    Grate, Jay W.; Egorov, Oleg B.; DeVol, Timothy A.

    2003-01-01

    Radionuclide contamination in the soil and groundwater at U.S. Department of Energy (DOE) sites is a severe problem that requires monitoring and remediation. Radionuclide measurement techniques are needed to monitor surface waters, groundwater, and process waters. Typically, water samples are collected and transported to an analytical laboratory, where costly radiochemical analyses are performed. To date, there has been very little development of selective radionuclide sensors for alpha- and beta-emitting radionuclides such as 90Sr, 99Tc, and various actinides of interest. The objective of this project is to investigate novel sensor concepts and materials for sensitive and selective determination of beta- and alpha-emitting radionuclide contaminants in water. To meet the requirements for low-level, isotope-specific detection, the proposed sensors are based on radiometric detection. As a means to address the fundamental challenge of the short ranges of beta and alpha particles in water, our overall approach is based on localization of preconcentration/separation chemistries directly on or within the active area of a radioactivity detector. Automated microfluidics is used for sample manipulation and sensor regeneration or renewal. The outcome of these investigations will be the knowledge necessary to choose appropriate chemistries for selective preconcentration of radionuclides from environmental samples, new materials that combine chemical selectivity with scintillating properties, new materials that add chemical selectivity to solid-state diode detectors, new preconcentrating column sensors, and improved instrumentation and signal processing for selective radionuclide sensors. New knowledge will provide the basis for designing effective probes and instrumentation for field and in situ measurements

  2. The influence of soil type and climate on the uptake of radionuclides into wheat

    International Nuclear Information System (INIS)

    Mitchell, N.G.

    1992-03-01

    The study investigated the uptake by winter wheat of radionuclides deposited onto the soil surface following a hypothetical accidental release to atmosphere from a nuclear power station. A series of lysimeters were filled with four soil types characteristic of wheat growing areas of Europe. Four radionuclides ( 137 Cs, 144 Ce, 106 Ru, 125 Sb) were watered onto the soil surface and the subsequent contamination of winter wheat crops was monitored over two seasons. Subsidiary experiments considered: effects of ploughing and pot size on root uptake; movement of radionuclides in soil profiles; soil contamination of wheat plants and of grain leaving the field; the influence of climate on root uptake; and, the availability of radionuclides. Compared with the literature, this study found a smaller range of transfer factors appropriate to agricultural soils that predominate in the wheat growing areas of the EEC. The use of pots or tubes to investigate soil-to-plant transfer was justified. The study showed that resuspension of radionuclides bound to soil particles must be considered when assessing soil-to-plant transfer. It was demonstrated that the contribution of soil-bound activity to the radionuclide content of combine harvested grain is underestimated in existing dose assessment methodologies by at least an order of magnitude on average and by over two orders of magnitude in extreme cases. Climatic conditions simulated in a growth chamber had little impact on radionuclide transfer. The relative availability of radionuclides for extraction by ammonium acetate did not reflect percentage transfer to grain. Ploughing reduced uptake by winter wheat, resulted in different patterns of transfer between cultivation treatments and influenced the distribution of activity between grain and straw. Results of this work were used in the development of a multi-compartmental time-dependent model called WHEAT which predicts radionuclide transfer from soil to winter wheat. (author)

  3. [Use of radionuclides in therapy].

    Science.gov (United States)

    Vucina, J; Han, R

    2001-01-01

    In nuclear medicine therapy is based on deposition of certain doses of ionizing radiation in tumors or organ tissues. Regarding their linear energy transfer (LET) values and relative biological effectiveness (RBE), principal radiotherapeuticals are alpha-, beta-, beta/gamma- or electron-emitters. In principle, to achieve the desired therapeutic effect, a particular radionuclide should exhibit adequate physical, chemical and biological properties. However, considerable efforts are required in selecting an optimal radionuclide for a specific application and then, in the development of methods for its routine production. The paper reviews several aspects of use, properties and production of unsealed radiation sources which are intended to be administered for therapeutic purposes. It covers scientific and practical criteria involved in selecting the radionuclide from medical point of view. The main indications for use of radiotherapeuticals are in oncology and rheumathology. Besides well known, like 32P, 89Sr, 90Y and 131I, several other radionuclides are also listed. Some of them are already in routine use while the others are still under investigation. The main chemical forms of radionuclides and indications are revealed. Particular emphasis is put on the discussion on criteria which a radionuclide should fulfill regarding its physical properties (type, energy, half life, ratio and abundance of the particulate and gamma ray emission). Ideally, they should, together with chemical and biological properties, match with the in-vivo pharmacokinetics and localization of the radionuclide and/or radiopharmaceutical. The trend in modern nuclear medicine is introduction of radionuclides of very specific properties. This, on the other side, opens a question of their availability on the routine basis and at reasonable prices. This matter is also discussed in the present review. Production of radionuclides for therapeutic purposes (as well as those for diagnostics) is performed

  4. Distribution of the Fukushima-derived radionuclides in seawater in the Pacific off the coast of Miyagi, Fukushima, and Ibaraki Prefectures, Japan

    Directory of Open Access Journals (Sweden)

    S. Oikawa

    2013-07-01

    Full Text Available The activities of artificial radionuclides in seawater samples collected off the coast of Miyagi, Fukushima, and Ibaraki Prefectures were measured as part of a monitoring program initiated by the Japanese Ministry of Education, Sports, Science and Technology immediately after the Fukushima Dai-ichi Nuclear Power Plant accident. The spatial and temporal distributions of those activities are summarized herein. The activities of strontium-90, iodine-131, cesium-134 and -137 (i.e. 90Sr, 131I, 134Cs, and 137Cs derived from the accident were detected in seawater samples taken from areas of the coastal ocean adjacent to the power plant. No 131I was detected in surface waters (≤ 5 m depth or in intermediate and bottom waters after 30 April 2011. Strontium-90 was found in surface waters collected from a few sampling stations in mid-August 2011 to mid-December 2011. Temporal changes of 90Sr activity in surface waters were evident, although the 90Sr activity at a given time varied widely between sampling stations. The activity of 90Sr in surface waters decreased slowly over time, and by the end of December 2011 had reached background levels recorded before the accident. Radiocesium, 134Cs and 137Cs, was found in seawater samples immediately after the accident. There was a remarkable change in radiocesium activities in surface waters during the first 7 months (March through September 2011 after the accident; the activity reached a maximum in the middle of April and thereafter decreased exponentially with time. Qualitatively, the distribution patterns in surface waters suggested that in early May radiocesium-polluted water was advected northward; some of the water then detached and was transported to the south. Two water cores with high 137Cs activity persisted at least until July 2011. In subsurface waters radiocesium activity was first detected in the beginning of April 2011, and the water masses were characterized by σt (an indicator of density values

  5. Distribution of the Fukushima-derived radionuclides in seawater in the Pacific off the coast of Miyagi, Fukushima, and Ibaraki Prefectures, Japan

    Science.gov (United States)

    Oikawa, S.; Takata, H.; Watabe, T.; Misonoo, J.; Kusakabe, M.

    2013-07-01

    The activities of artificial radionuclides in seawater samples collected off the coast of Miyagi, Fukushima, and Ibaraki Prefectures were measured as part of a monitoring program initiated by the Japanese Ministry of Education, Sports, Science and Technology immediately after the Fukushima Dai-ichi Nuclear Power Plant accident. The spatial and temporal distributions of those activities are summarized herein. The activities of strontium-90, iodine-131, cesium-134 and -137 (i.e. 90Sr, 131I, 134Cs, and 137Cs) derived from the accident were detected in seawater samples taken from areas of the coastal ocean adjacent to the power plant. No 131I was detected in surface waters (≤ 5 m depth) or in intermediate and bottom waters after 30 April 2011. Strontium-90 was found in surface waters collected from a few sampling stations in mid-August 2011 to mid-December 2011. Temporal changes of 90Sr activity in surface waters were evident, although the 90Sr activity at a given time varied widely between sampling stations. The activity of 90Sr in surface waters decreased slowly over time, and by the end of December 2011 had reached background levels recorded before the accident. Radiocesium, 134Cs and 137Cs, was found in seawater samples immediately after the accident. There was a remarkable change in radiocesium activities in surface waters during the first 7 months (March through September 2011) after the accident; the activity reached a maximum in the middle of April and thereafter decreased exponentially with time. Qualitatively, the distribution patterns in surface waters suggested that in early May radiocesium-polluted water was advected northward; some of the water then detached and was transported to the south. Two water cores with high 137Cs activity persisted at least until July 2011. In subsurface waters radiocesium activity was first detected in the beginning of April 2011, and the water masses were characterized by σt (an indicator of density) values of 25

  6. Distribution of the Fukushima-derived radionuclides in seawater in the Pacific off the coast of Miyagi, Fukushima, and Ibaraki Prefectures, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Oikawa, S.; Takata, H.; Watabe, T.; Misonoo, J.; Kusakabe, M. [Marine Ecology Research Institute, Tokyo (Japan). Head Office

    2013-07-01

    The activities of artificial radionuclides in seawater samples collected off the coast of Miyagi, Fukushima, and Ibaraki Prefectures were measured as part of a monitoring program initiated by the Japanese Ministry of Education, Sports, Science and Technology immediately after the Fukushima Dai-ichi Nuclear Power Plant accident. The spatial and temporal distributions of those activities are summarized herein. The activities of strontium-90, iodine-131, cesium-134 and -137 (i.e. {sup 90}Sr, {sup 131}I, {sup 134}Cs, and {sup 137}Cs) derived from the accident were detected in seawater samples taken from areas of the coastal ocean adjacent to the power plant. No {sup 131}I was detected in surface waters (≤ 5 m depth) or in intermediate and bottom waters after 30 April 2011. Strontium-90 was found in surface waters collected from a few sampling stations in mid-August 2011 to mid-December 2011. Temporal changes of {sup 90}Sr activity in surface waters were evident, although the {sup 90}Sr activity at a given time varied widely between sampling stations. The activity of {sup 90}Sr in surface waters decreased slowly over time, and by the end of December 2011 had reached background levels recorded before the accident. Radiocesium, {sup 134}Cs and {sup 137}Cs, was found in seawater samples immediately after the accident. There was a remarkable change in radiocesium activities in surface waters during the first 7 months (March through September 2011) after the accident; the activity reached a maximum in the middle of April and thereafter decreased exponentially with time. Qualitatively, the distribution patterns in surface waters suggested that in early May radiocesium-polluted water was advected northward; some of the water then detached and was transported to the south. Two water cores with high {sup 137}Cs activity persisted at least until July 2011. In subsurface waters radiocesium activity was first detected in the beginning of April 2011, and the water masses were

  7. General characterisation of study area and definition of experimental protocols. WP 1 in the project 'Effect of industrial pollution on the distribution dynamics of radionuclides in boreal understorey ecosystems'

    Energy Technology Data Exchange (ETDEWEB)

    Rahola, T. [Radiation and Nuclear Safety Authority, Helsinki (Finland); Albers, B. [National Research Center for Environmental and Health (Georgia); Bergman, R. [National Defence Research Establishment (Germany)] [and others

    1999-08-01

    The research project EPORA (Effects of Industrial Pollution on the Distribution Dynamics of Radionuclides in Boreal Understorey Ecosystems) is part of the EU Nuclear Fission Safety Programme 1994 - 1998. The main purpose of EPORA is to study the influence of strong chemical pollution on the behaviour of artificial radionuclides ({sup 137}Cs,{sup 90}Sr, {sup 239},{sup 240}{sub Pu}) in a northern boreal ecosystem and subsequently to assess the significance of the findings to the radiation exposure of the population in such areas. The present report is a documentation of the selection of study areas based on the assessment of available information on pollution in the Kola Peninsula and Northern Fennoscandia and of sampling and analysing methods. (orig.)

  8. The analytical investigation of temperature distribution in off-central ...

    Indian Academy of Sciences (India)

    Temperature distribution in off-central diode-pumped lasers. Figure 2. Temperature distribution in. Nd:YAG crystal for 1 mm pump radius,. 5 mm crystal radius and δ = 0.5 mm. Figure 3. Temperature distribution in. Nd : YVO4 crystal for 1 mm pump radius,. 5 mm crystal radius and δ = 0.5 mm. T2(r, ϕ) = δ. Qa2. 2b2K. (. Hb − K.

  9. Potential for post-closure radionuclide redistribution due to biotic intrusion: aboveground biomass, litter production rates, and the distribution of root mass with depth at material disposal area G, Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    French, Sean B [Los Alamos National Laboratory; Christensen, Candace [Los Alamos National Laboratory; Jennings, Terry L [Los Alamos National Laboratory; Jaros, Christopher L [Los Alamos National Laboratory; Wykoff, David S [Los Alamos National Laboratory; Crowell, Kelly J [Los Alamos National Laboratory; Shuman, Rob [URS

    2008-01-01

    Low-level radioactive waste (LLW) generated at the Los Alamos National Laboratories (LANL) is disposed of at LANL's Technical Area (T A) 54, Material Disposal Area (MDA) G. The ability of MDA G to safely contain radioactive waste during current and post-closure operations is evaluated as part of the facility's ongoing performance assessment (PA) and composite analysis (CA). Due to the potential for uptake and incorporation of radio nuclides into aboveground plant material, the PA and CA project that plant roots penetrating into buried waste may lead to releases of radionuclides into the accessible environment. The potential amount ofcontamination deposited on the ground surface due to plant intrusion into buried waste is a function of the quantity of litter generated by plants, as well as radionuclide concentrations within the litter. Radionuclide concentrations in plant litter is dependent on the distribution of root mass with depth and the efficiency with which radionuclides are extracted from contaminated soils by the plant's roots. In order to reduce uncertainties associated with the PA and CA for MDA G, surveys are being conducted to assess aboveground biomass, plant litter production rates, and root mass with depth for the four prominent vegetation types (grasses, forbs, shrubs and trees). The collection of aboveground biomass for grasses and forbs began in 2007. Additional sampling was conducted in October 2008 to measure root mass with depth and to collect additional aboveground biomass data for the types of grasses, forbs, shrubs, and trees that may become established at MDA G after the facility undergoes final closure, Biomass data will be used to estimate the future potential mass of contaminated plant litter fall, which could act as a latent conduit for radionuclide transport from the closed disposal area. Data collected are expected to reduce uncertainties associated with the PA and CA for MDA G and ultimately aid in the assessment and

  10. Compton scattering: the investigation of electron momentum distributions

    International Nuclear Information System (INIS)

    Williams, B.

    1977-01-01

    A collection of review papers is presented on Compton scattering. The history, theory, experimentation, multiple scattering, atoms, solids, chemistry, electron scattering, positron annihilation, and the reconstruction of the three-dimensional distributions are the topics considered. 88 references

  11. Radionuclide impurities in proton-irradiated [18O]H2O for the production of 18F-: activities and distribution in the [18F]FDG synthesis process.

    Science.gov (United States)

    Bowden, Louise; Vintró, Luis León; Mitchell, Peter I; O'Donnell, Ruairi G; Seymour, Anne Marie; Duffy, George J

    2009-02-01

    Proton- and neutron-induced activation products in the components of a high-pressure [(18)O]H(2)O target vessel used for the production of (18)F(-) in a medical cyclotron have been identified using high resolution gamma spectrometry. The activities leached from the target vessel into the [(18)O]H(2)O during irradiation, and the distribution of the identified radionuclide impurities in the various cartridges and solutions used in the [(18)F]FDG synthesis process have been measured and are discussed from the perspective of waste disposal. The results indicate that, at the energies and beam currents employed, only a few, relatively short-lived radionuclides are present in the irradiated [(18)O]H(2)O, and that the activities involved (irradiated [(18)O]H(2)O, produced via the (18)O(p,(3)H)(16)O reaction, have also been determined using liquid scintillation spectrometry. Measured activity concentrations, in the range 150-180 kBq g(-1), are consistent with those reported by other workers. Analyses of the synthesised [(18)F]FDG confirm the radiochemical purity of the product, both for (3)H and for gamma-emitting radionuclides in the energy range 25-1650 keV.

  12. Radionuclide impurities in proton-irradiated [18O]H2O for the production of 18F-: Activities and distribution in the [18F]FDG synthesis process

    International Nuclear Information System (INIS)

    Bowden, Louise; Leon Vintro, Luis; Mitchell, Peter I.; O'Donnell, Ruairi G.; Seymour, Anne Marie; Duffy, George J.

    2009-01-01

    Proton- and neutron-induced activation products in the components of a high-pressure [ 18 O]H 2 O target vessel used for the production of 18 F - in a medical cyclotron have been identified using high resolution gamma spectrometry. The activities leached from the target vessel into the [ 18 O]H 2 O during irradiation, and the distribution of the identified radionuclide impurities in the various cartridges and solutions used in the [ 18 F]FDG synthesis process have been measured and are discussed from the perspective of waste disposal. The results indicate that, at the energies and beam currents employed, only a few, relatively short-lived radionuclides are present in the irradiated [ 18 O]H 2 O, and that the activities involved ( 3 H in irradiated [ 18 O]H 2 O, produced via the 18 O(p, 3 H) 16 O reaction, have also been determined using liquid scintillation spectrometry. Measured activity concentrations, in the range 150-180 kBq g -1 , are consistent with those reported by other workers. Analyses of the synthesised [ 18 F]FDG confirm the radiochemical purity of the product, both for 3 H and for gamma-emitting radionuclides in the energy range 25-1650 keV

  13. Uptake of radionuclides from soil

    International Nuclear Information System (INIS)

    Keller, C.

    1980-01-01

    The field studies by the KFA Juelich to determine the transfer factors for the radionuclides 90 Sr, 137 Cs, 60 Co and 54 Mn are reported about. Potatoes, sugar beets, winter wheat, spring barley, clover, alfalfa and ray grass, and in some cases also field vegetables were used. The influence of soil properties on the transfer factors is investigated. (MG) [de

  14. Effect of industrial pollution on behaviour of radionuclides in forest ecosystems

    International Nuclear Information System (INIS)

    Outola, I.

    2009-01-01

    To investigate how and to what extent industrial pollution affects the behaviour of radionuclides in forest ecosystems, studies were conducted in the vicinity of two Cu-Ni smelters: one in a pine forest at Harjavalta, Finland, and the other in a spruce forest at Monchegorsk, Russia. Industrial pollution had significant effects on the distribution of radionuclides in soil horizons. With the increase in pollution towards the smelter, radionuclides were accumulated more in the litter layer because the conversion of litter into organic material was diminished due to inhibited microbial activity. As a result, the organic layer contained less radionuclides towards the smelter. The effect of industrial pollution on soil-to-plant transfer was complex. The effect varied with radionuclide, plant species and also on forest type. For 137 Cs, soil-to-plant transfer decreased significantly as industrial pollution increased in pine forest, whereas the decrease was less pronounced in spruce forest. Root uptake of 239,240 Pu by plants is extremely small, and plant contamination by resuspended soil is an important factor in considering the soil-to-plant transfer of this radionuclide. In spruce forest, more plutonium was transferred into plants when pollution load increased due to resuspension of litter particles, which contained higher concentrations of plutonium in the vicinity of the smelter. Soil-to-plant transfer of plutonium was much less affected in pine forests contaminated with industrial pollution. This research clearly indicates the sensitivity of the northern forest ecosystem to inorganic pollutants. Prediction of the soil-to-plant transfer of radionuclides in industrially polluted forest ecosystems requires detailed information on the total deposition, vertical distribution of radionuclides in soil, soil microbiological factors, other soil parameters as well as the rooting depths of the plants. (LN)

  15. Automation of radionuclide analysis in nuclear industry

    International Nuclear Information System (INIS)

    Gostilo, V.; Sokolov, A.; Kuzmenko, V.; Kondratjev, V.

    2009-01-01

    The development results for the automated precise HPGe spectrometers and systems for radionuclide analyses in nuclear industry and environmental monitoring are presented. Automated HPGe spectrometer for radionuclide monitoring of coolant in primary circuit of NPPs is intended for technological monitoring of the radionuclide specific activity in liquid and gaseous flows in the on-line mode. The automated spectrometer based on flowing HPGe detector with the through channel is intended for control of the uniformity of distribution of uranium and/or plutonium in fresh fuel elements, transferred through the detector, as well as for on-line control of the fluids and gases flows with low activity. Automated monitoring system for radionuclide volumetric activity in outlet channels of NPPs is intended for radionuclide monitoring of water reservoirs in the regions of nuclear weapons testing, near nuclear storage, nuclear power plants and other objects of nuclear energetic. Autonomous HPGe spectrometer for deep water radionuclide monitoring is applicable for registration of gamma radionuclides, distributed in water depth up to 3000 m (radioactive wastes storage, wreck of atomic ships, lost nuclear charges, atomic industry technological waste release etc.).(authors)

  16. Radionuclide behavior in water saturated porous media: Diffusion and infiltration coupling of thermodynamically and kinetically controlled radionuclide water - mineral interactions

    International Nuclear Information System (INIS)

    Spasennykh, M.Yu.; Apps, J.A.

    1995-05-01

    A model is developed describing one dimensional radionuclide transport in porous media coupled with locally reversible radionuclide water-mineral exchange reactions and radioactive decay. Problems are considered in which radionuclide transport by diffusion and infiltration processes occur in cases where radionuclide water-solid interaction are kinetically and thermodynamically controlled. The limits of Sr-90 and Cs-137 migration are calculated over a wide range of the problem variables (infiltration velocity, distribution coefficients, and rate constants of water-mineral radionuclide exchange reactions)

  17. Sediment distribution coefficients (KD) and concentration factors (CF) in fish for natural radionuclides in a pond of a tropical region and their contributions to estimations of internal absorbed dose rate in fish

    International Nuclear Information System (INIS)

    Souza Pereira, Wagner de; Kelecom, Alphonse

    2008-01-01

    Attention has been paid only recently to the protection of biota against radiation effects. Protection is being considered through modeling of the calculation of absorbed dose rate. In these models, the inputs are the fluxes of radionuclides of environmental concern and their resulting distribution between environmental compartments. Such distribution is estimated for dispersion models. In freshwater systems and when fish is used as biomaker, relevant environmental transfer parameters are transfer between sediment and water (sediment distribution coefficients KD, in l kg -1 ), and between water and fish (concentration factor CF, in l kg -1 ). These coefficients are under the influence of a number o physical, chemical and biological factors, and display following the literature a great variability. The present work establishes the KD's and CF's for uranium, thorium, radium and lead for two ponds: one that receives treated effluents from an ore treatment unit (UTM) situated at Pocos de Caldas, Minas Gerais, Brazil and the other pond from the uranium concentration unit (URA) situated at Caetite, Bahia, Brazil, and for fish used as biomarker. It intends also to compare these parameters with the values recommended by IAEA. Depending on considered radionuclide and on the site, CF's (l kg -1 ) observed values were of the same magnitude as, or one order of magnitude lower than recommended by IAEA. KD's (l kg -1 ) observed values were found of the same magnitude as those recommended by IAEA, approximately 10 times lower or up to 100 times higher than recommended by IAEA, again depending on the radionuclides and on the site. It can be concluded that local parameters should be established in order to obtain a more accurate estimative of biota exposition from man activities. (author)

  18. Investigation of Spatial Distribution Properties of Mid-Infrared ...

    African Journals Online (AJOL)

    The spatial distribution properties of quantum cascade lasers with emission wavelengths around 7 µm were measured. In addition, the emission profile on a plane orthogonal to the propagation axis of the beam were measured and the full width at half maximum (FWHM) on the orthogonal and lateral directions calculated.

  19. Intercomparison of measurements of distribution coefficient. Investigation of factors affecting variability of measured values

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Tomoyuki; Takebe, Shinichi; Kimura, Hideo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    1997-10-01

    The distribution coefficient(Kd), which is defined as partitioning of solute between a solid and liquid phases, is used for various models which describe the migration behavior of nuclides in the environment. Therefore it is a very important parameter for safety assessment of nuclear facilities. Aiming at the recommendation of standard methodologies for measurement and application of Kd, we have discussed a procedure of standardization in `WG on Parameters for Safety Assessment` of `Technical Committee on Behavior of Environmental Radioactivity` which belongs to `Research Committee on Environmental Radioactivity` organized by Japan Atomic Energy Research Institute. As a first step for recommendation of a standard methodology for measurement, intercomparisons on measurement of Kd for radionuclides ({sup 60}Co, {sup 137}Cs, {sup 85}Sr and {sup 54}Mn) were carried out by four groups to evaluate the cause of variability in measured Kds. As a result of five different experiments under various conditions, it was found that the difference of chemical property of radionuclide solution, form of vessels and method of shaking have strong influence on the measured values of Kd. (author)

  20. The main trends in clinical use of radionuclides in oncology

    International Nuclear Information System (INIS)

    Agranat, V.Z.

    1979-01-01

    The main trends of using radionuclide methods in clinical oncology are shown. Two main aspects of using radionuclide methods are pointed out: radionuclide investigation of the primary tumour as ''local'' manifestation of the cancer disease, radionuclide investigation of the body ''response'' to the tumour process. Each of the aspects of the problem is briefly considered on some examples. Examples of positive scintigraphy of tumours are given. It is shown that tumorotropic properties of some radionuclides make possible using visualization methods realizing the differential diagnosis of some tumours. Considered are direct and indirect signs which allow determining the presence of metastases and testifying to the tumour process spread

  1. Radionuclides in plankton from the South Pacific Basin

    International Nuclear Information System (INIS)

    Marsh, K.V.; Buddemeier, R.W.

    1984-01-01

    An investigation has been initiated of the utility of marine plankton as bioconcentrating samplers of low-level marine radioactivity in the southern hemisphere. A literature review has shown that both freshwater and marine plankton have trace element and radionuclide concentration factors (relative to water) of up to 10 4 . In 1956 and 1958 considerable work was done on the accumulation and distribution of a variety of fission and activation products produced by nuclear tests in the Marshall Islands. Since then, studies, have largely been confined to a few radionuclides, and most of the work in the last twenty years has been done in the northern hemisphere. The authors participated in Operations Deepfreeze 1981 and 1982, collecting a total of 48 plankton samples from the USCGC Glacier on its Antarctic cruises. Battelle Pacific Northwest Laboratories sampled air, water, rain, and fallout. The authors were able to measure concentrations in plankton of the naturally-occurring radionuclides 7 Be, 40 K, and the U and Th series, and they believe that they have detected low levels of 144 Ce and 95 Nb in seven samples ranging as far south as 68 0 . Biological identification of the plankton suggests a possible correlation between radionuclide concentration and the protozoa content of the samples. 7 references, 5 figures, 1 table

  2. Preliminary investigations on TINI based distributed instrumentation systems

    International Nuclear Information System (INIS)

    Bezboruah, T.; Kalita, M.

    2006-04-01

    A prototype web enabled distributed instrumentation system is being proposed in the Department of Electronics Science, Gauhati University, Assam, India. The distributed instrumentation system contains sensors, legacy hardware, TCP/IP protocol converter, TCP/IP network Ethernet, Database Server, Web/Application Server and Client PCs. As part of the proposed work, Tiny Internet Interface (TINI, TBM390: Dallas Semiconductor) has been deployed as TCP/IP stack, and java programming language as software tools. A feature supported by Java, that is particularly relevant to the distributed system is its applet. An applet is a java class that can be downloaded from the web server and can be run in a context application such as web browser or an applet viewer. TINI has been installed as TCP/IP stack, as it is the best suited embedded system with java programming language and it has been uniquely designed for communicating over One Wire Devices (OWD) over network. Here we will discuss the hardware and software aspects of TINI with OWD for the present system. (author)

  3. Osnovnye zakonomernosti raspredelenija, migracii i nakoplenija radionuklidov v donnyh otlozhenijah Baltijskogo morja [The basic patterns of the distribution, migration and accumulation of radionuclides in the bottom sediment of the Baltic Sea

    Directory of Open Access Journals (Sweden)

    Grigoryev Andrey

    2011-01-01

    Full Text Available This paper focuses on the impact of certain factors on the contemporary distribution of natural (226Ra, 232Th, 40К and anthropogenic (137Cs, 60Co radionuclides in the sediments of the Baltic Sea. The results of the study suggest that the distribution of 137Cs is determined by the content of hydromica of silty-clay and clay grain-size fractions, while radiocaesium is mainly accumulated by silty fractions. The accumulation of 226Ra by bottom sediments is mainly determined by the pH geochemical barrier at the water-seafloor boundary. The accumulation of 232Th occurs mainly in clayey fractions of the sediment. The distribution and accumulation of 40K is predominantly determined by the ratio of potassium contained in hydromica minerals. Significant 60Co activity was registered only in a few samples.

  4. Radionuclides in forest biogeocenose elements

    International Nuclear Information System (INIS)

    Bulavik, I.M.; Zhuchenko, T.A.

    1992-01-01

    In 1991 year investigations are made on a studying of the radionuclide distribution (CS-137 and Sr-90) through the main forest biogeocenose elements (a litter a mineral soil layer, overground trees parts) on 5 experimental objects of Gomel' region with a various contamination. Radiation characters of the objects are done. As compared with 1989 year cesium and strontium migration from tress into the litter and from the litter to the soil is shown. In the litter and upper soil layer (5 m) contents of Cs-137 and Sr-90 are 95 and 80% accordingly. The Sr-90 concentration in the wood and the isotope concentration change through yearly layers (1986-1991 years) are studied. Wood layers formed to the accident have a lesser cesium concentration, especially in the oax-tree. The highest Cs and Se translocation, into the wood is noted in the pine the lesse one in the oax-tree. Among all elements of the biogeocenose the highest Cs-137 concentration the litter has and then one-year-old shoots, needles, lives, the bark and the wood go on. Even on the sixth year after the accident Cs concentration in the wood was 20-30 times less, than the one in needes and one-year-old shoot of this year. 4 refs.; 5 tabs

  5. Supplementary investigations on the validation of the atmospheric radionuclide transport model (ARTM); Ergaenzende Untersuchungen zur Validierung des Atmosphaerischen Radionuklid-Transport-Modells (ARTM)

    Energy Technology Data Exchange (ETDEWEB)

    Richter, Cornelia; Thielen, Harald; Sogalla, Martin

    2015-09-15

    In the medium-term time scale the Gaussian plume model used so far for atmospheric dispersion calculations in the General Administrative Provision (AVV) relating to Section 47 of the Radiation Protection Ordinance (StrISchV) as well as in the Incident Calculation Bases (SBG) relating to Section 49 StrISchV is to be replaced by a Lagrangian particle model. Meanwhile the Atmospheric Radionuclide Transportation Model (ARTM) is available, which allows the simulation of the atmospheric dispersion of operational releases from nuclear installations. ARTM is based on the program package AUSTAL2000 which is designed for the simulation of atmospheric dispersion of non-radioactive operational releases from industrial plants and was adapted to the application of airborne radioactive releases. The research project 3612S50007 serves, on the one hand, to validate ARTM systematically. On the other hand, the development of science and technology were investigated and, if reasonable and possible, were implemented to the program system. The dispersion model and the user interface were advanced and optimized. The program package was provided to the users as a free download. Notably t he work program comprises the validation of the approach used in ARTM to model short emission periods, which are of interest in view of the SBG. The simulation results of the diagnostic wind and turbulence model TALdia, which is part of the GO-ARTM program package, were evaluated with focus on the influence of buildings on the flow field. The user interface was upgraded with a wind field viewer. To simplify the comparison with the model still in use, a Gaussian plum e model was implemented into the graphical user interface. The ARTM web page was maintained, user questions and feedback were answered and analysed concerning possible improvements and further developments of the program package. Numerous improvements were implemented. An ARTM user workshop was hosted by the Federal Office for Radiation

  6. Status report on radionuclide transfer

    International Nuclear Information System (INIS)

    1980-01-01

    At the suggestion of the Federal Minstry of the Interior, in June 1978, a group of scientists from several institutions who are active in the field of radionuclide transfer or are interested in these problems got together. During the discussions of the work team, especially the transfer soil/plants was emphasized. Then the work team set up a status report on the transfer of the radionuclides relevant in the sense of the radiation protection act. The nuclides H 3 and C14, the isotopes of the Sr, J, and Cs, Tc99, the so-called corrosion nuclides Mn54, Fe59, co-isotopes and Zn65, and isotopes of Pu, Am, and Cm were regarded as important for a possible radiation exposition. Recent investigations revealed that also the natural radionuclides Ra226, Po210, and Pb210 should be covered by the investigations. The goal of this status report is to present the level of knowledge on the transfer of these radionuclides to man in a brief form, giving hints at the most important literature. It was requested by the Federal Ministry of the Interior, as fas as possible, to indicate transfer factors which are necessary for the radio-occology act to be decreed according to Para. 45 of the radiation protection act. Another goal of the report was to show the gap in the knowledge on the radio nuclide transfer. This was thought to help to create a basis for the decisions of the Federal Ministry concerning the support of other investigation projects in the field of transfer of radionuclides. (orig./MG) [de

  7. Quantitative radionuclide angiocardiography

    International Nuclear Information System (INIS)

    Scholz, P.M.; Rerych, S.K.; Moran, J.F.; Newman, G.E.; Douglas, J.M.; Sabiston, D.C. Jr.; Jones, R.H.

    1980-01-01

    This study introduces a new method for calculating actual left ventricular volumes and cardiac output from data recorded during a single transit of a radionuclide bolus through the heart, and describes in detail current radionuclide angiocardiography methodology. A group of 64 healthy adults with a wide age range were studied to define the normal range of hemodynamic parameters determined by the technique. Radionuclide angiocardiograms were performed in patients undergoing cardiac catherization to validate the measurements. In 33 patients studied by both techniques on the same day, a close correlation was documented for measurement of ejection fraction and end-diastolic volume. To validate the method of volumetric cardiac output calcuation, 33 simultaneous radionuclide and indocyanine green dye determinations of cardiac output were performed in 18 normal young adults. These independent comparisons of radionuclide measurements with two separate methods document that initial transit radionuclide angiocardiography accurately assesses left ventricular function

  8. AN INVESTIGATION ON PATHOGENIC VIBRIOS DISTRIBUTION IN DOMESTIC WASTEWATER

    Directory of Open Access Journals (Sweden)

    A. Almasi

    2005-07-01

    Full Text Available Municipal wastewater is one of the most important pollution sources for water supply resources. Identification and enumeration of pathogenic agents particularly pathogenic Vibrios are beneficial for controlling and prevention planning of the infectious diseases. This research was carried out to identify the distribution of the recognized pathogenic Vibrios with emphasizing on identification of Vibrio cholera in the wastewater of Kermanshah city western Iran in 2002. The method of study was cross sectional descriptive. There were 8 discharge outlet domestic wastewaters, which had been chosen as sampling sites. Samples were collected weekly in randomized manner in daytime. Three hundred and thirty nine samples were collected and analyzed. The results indicated site 7 with 5 positives, sites 4 and 8 each with 3, site 5 with 2, sites 2, 3 and 6 each with one positive, whereas, there was not any Vibrio detected in site 1. The most positive samples were seen in spring, late summer and early autumn. The positive results were detected on May, June, September, and October. Among positive samples, Vibrio parahemolyticus, could be regarded based on differentiation tests. Vibrio cholera was not seen. It seems that the presence of Vibrio parahemolyticus was due to some food store deal with distribution of seafood. Hence it is suggested that this relationship could be considered through analytical study using PCR for detection of Vibrios.

  9. Radionuclides in air, water, and biota

    International Nuclear Information System (INIS)

    Seymour, A.H.; Nelson, V.A.

    1977-01-01

    Air, water, and biological samples collected before and after the 1965, 1969, and 1971 underground nuclear detonations at Amchitka Island were analyzed for natural and fallout radionuclides by gamma spectrometry. Selected samples were also analyzed for tritium, 55 Fe, and 90 Sr. The objectives were to search for and identify radionuclides of Amchitka origin in the samples and to contribute to the general knowledge of the distribution of radionuclides in the environment. The studies showed that there has been no escape of radionuclides from the underground sites of the three nuclear detonations at Amchitka Island except for trace quantities of radionuclides, principally tritium, in water and soil gas samples from the immediate vicinity of the surface ground zero for the 1965 event. Two naturally occurring radionuclides, 40 K and 7 Be, were the most abundant radionuclides in the samples, usually by a factor of 10 or more, except for 137 Cs in lichen samples. All levels were well below applicable Radiation Protction Guides, often being near the statistical limit of detection

  10. Investigation of induction motor temperature distribution in traction applications

    Science.gov (United States)

    Pugachev, A. A.; Kosmodamianskiy, A. S.

    2017-10-01

    The relevance of thermal behavior investigation of traction induction motors is shown. The brief survey of techniques to monitor the temperature of an induction motors is carried out. The detailed multi-node equivalent thermal circuit of an induction motor is designed for steady state. The calculation technique of some units’ thermal resistances by using of construction features and geometric sizes of an induction motor is shown. Results of thermal processes calculation for 14 kWAO-63-4 induction motor are shown. The adequacy of proposed thermal model is proved by means of good convergence of calculated results with the results obtained by the experimental investigation on the same induction motor. As a result of investigation, it is established that the slot winding of the stator located about on 2/3 of its length from the cooling air entrance has the highest value of temperature.

  11. Investigating the Impact of Wind Turbines on Distribution System Stability

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Rishabh; Zhang, Yingchen; Hodge, Bri-Mathias

    2016-12-12

    Modern wind turbines utilize power electronic converters to regulate their output and optimize their performance. Their impact on the distribution system is not as well understood as for transmission system. The novelty of this work is in studying the impact of wind turbines given its proximity to faults or severe voltage events, and the influence on system stability given its location relative to the substation (representing the conventional grid). This paper presents the frequency and voltage swing plots for various study scenarios. The responses are analyzed two fold - Steady state operation, and performance given a fault or voltage events occurs in the system. The findings are presented, with crucial differences from transmission systems highlighted.

  12. Experimental evaluation of admission and disposition of artificial radionuclides including transuranium elements in agricultural plants

    Energy Technology Data Exchange (ETDEWEB)

    Kozhakhanov, T.; Lukashenko, S. [Institute of radiation safety and ecology (Kazakhstan)

    2014-07-01

    Processes of radionuclides migration and transfer to agricultural plants are quite well developed worldwide, but the information on character of accumulation of {sup 241}Am and {sup 239+240}Pu transuranium radionuclides in agricultural plants is still fragmentary. Even in generalized materials of worldwide studies, IAEA guide, accumulation coefficient (AC) can have wide range of values (5-6 orders), no data exists on radionuclides' distribution in different organs of plants and they are given for joined groups of plants and types of soils. That is why the main aim of this work was to obtain basic quantitative parameters of radionuclides' migration in 'soil-plant' system, and firs of all- for transuranium elements.. In 2010 a series of experiments with agricultural plants was started at the territory of the former Semipalatinsk Test Site aimed to investigate entry of artificial radionuclides by crop products in natural climatic conditions. To conduct the experiment for study of coefficient of radionuclides' accumulation by agricultural corps, there was chosen a land spot at the STS territory, characterized by high concentration of radionuclides: {sup 241}Am - n*10{sup 4} Bq/kg, {sup 137}Cs - n*10{sup 3} Bq/kg, {sup 90}Sr - n*10{sup 3} Bq/kg and {sup 239+240}Pu- n*10{sup 5} Bq/kg. As objects of investigation, cultures, cultivated in Kazakhstan have been selected: wheat (Triticum vulgare), barley (Hordeum vulgare), oat (Avena sativa L.), water melon (Citrullus vulgaris), melon (Cucumis melo), potato (Solanum tuberosum), eggplant (Solanum melongena), pepper (Capsicum annuum), tomato (Solanum lycopersicum), sunflower (Helianthus cultus), onion (Allium cepa), carrot (Daucus carota), parsley(Petroselinum vulgare)and cabbage (Brassica oleracea). Investigated plants have been planted within the time limits, recommended for selected types of agricultural plants. Cropping system included simple agronomic and amelioration measures. Fertilizers were not

  13. Distribution and Multivariate Pollution Risks Assessment of Heavy Metals and Natural Radionuclides Around Abandoned Iron-Ore Mines in North Central Nigeria

    Science.gov (United States)

    Isinkaye, Omoniyi Matthew

    2018-02-01

    The Itakpe abandoned iron-ore mines constitute the largest iron-ore deposits in Nigeria with an estimated reserve of about three million metric tons of ore. The present effort is a part of a comprehensive study to estimate the environmental and radiological health hazards associated with previous mining operations in the study area. In this regard, heavy metals (Fe, Zn, Cu, Cd, Cr, Mn, Pb, Ni, Co and As) and natural radionuclides (U, Th and K) were measured in rock, soil and water samples collected at different locations within the mining sites. Atomic absorption and gamma-ray spectrometry were utilized for the measurements. Fe, Mn, Zn, Cu, Ni, Cd, Cr, Co Pb and As were detected at varying concentrations in rock and soil samples. Cd, Cr, Pb and As were not detected in water samples. The concentrations of heavy metals vary according to the following pattern; rock ˃ soil ˃ water. The mean elemental concentrations of K, U and Th are 2.9%, 0.8 and 1.2 ppm and 1.3%, 0.7 and 1.7 ppm, respectively, for rock and soil samples. Pearson correlation analyses of the results indicate that the heavy metals are mostly negatively correlated with natural radionuclides in the study area. Cancer and non-cancer risks due to heavy metals and radiological hazards due to natural radionuclides to the population living within the vicinity of the abandoned mines are lower than acceptable limits. It can, therefore, be concluded that no significant environmental or radiological health hazard is envisaged.

  14. Investigating the Statistical Distribution of Learning Coverage in MOOCs

    Directory of Open Access Journals (Sweden)

    Xiu Li

    2017-11-01

    Full Text Available Learners participating in Massive Open Online Courses (MOOC have a wide range of backgrounds and motivations. Many MOOC learners enroll in the courses to take a brief look; only a few go through the entire content, and even fewer are able to eventually obtain a certificate. We discovered this phenomenon after having examined 92 courses on both xuetangX and edX platforms. More specifically, we found that the learning coverage in many courses—one of the metrics used to estimate the learners’ active engagement with the online courses—observes a Zipf distribution. We apply the maximum likelihood estimation method to fit the Zipf’s law and test our hypothesis using a chi-square test. In the xuetangX dataset, the learning coverage in 53 of 76 courses fits Zipf’s law, but in all of 16 courses on the edX platform, the learning coverage rejects the Zipf’s law. The result from our study is expected to bring insight to the unique learning behavior on MOOC.

  15. Investigation of the statistical distance to reach stationary distributions

    International Nuclear Information System (INIS)

    Nicholson, S.B.; Kim, Eun-jin

    2015-01-01

    The thermodynamic length gives a Riemannian metric to a system's phase space. Here we extend the traditional thermodynamic length to the information length (L) out of equilibrium and examine its properties. We utilise L as a useful methodology of analysing non-equilibrium systems without evoking conventional assumptions such as Gaussian statistics, detailed balance, priori-known constraints, or ergodicity and numerically examine how L evolves in time for the logistic map in the chaotic regime depending on initial conditions. To this end, we propose a discrete version of L which is mathematically well defined by taking a set theoretic approach. We identify the areas of phase space where the loss of information of the system takes place most rapidly. In particular, we present an interesting result that the unstable fixed points turn out to most efficiently drive the logistic map towards a stationary distribution through L. - Highlights: • Define a set theoretic version of the discrete thermodynamic length. • These sets allow one to analyse systems having zero probabilities in their evolution. • Numerically analyse the Logistic map using the thermodynamic length. • Show how the unstable fixed points most efficiently lead the system to equilibrium

  16. Life-span health effects of relatively soluble forms of internally deposited beta-emitting radionuclides

    International Nuclear Information System (INIS)

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

    1991-01-01

    As part of a large research effort to study the lifetime health risks of inhaled radionuclides, Beagle dogs inhaled 90 SrCl 2 or 144 CeCl 3 or were injected intravenously with 137 CsCl. Because these three compounds were soluble in body fluids, the resulting widely differing patterns of radionuclide distribution and dose reflected tissue affinities of the elements involved. Long-term health effects, predominantly cancers, were seen in the organs receiving the highest doses. Investigations are continuing on the extent to which other less irradiated organs may have also been affected

  17. Radionuclide cinematography of the heart

    International Nuclear Information System (INIS)

    Adam, W.E.; Sigel, H.; Geffers, H.; Bitter, F.; Meyer, G.; Kampmann, H.; Stauch, M.

    1976-01-01

    Radionuclide cinematography is described as a procedure making use of radiation-level variations above the heart after equipartitioning of sup(99m)Tc-labelled human serum albumin in the blood pool. Regional ventricular and vestibular variations are phase-shifted. This procedure permits delineation of aneurysmas with interphasic course, cicatrization of the cardiac wall not producing any cyclical variation. The study included normal subjects and 16 patients with full course infarction. Characteristic disturbances of motility distribution were found in all cases of scarred or aneurysmic alterations in the frontal and side walls of the left ventricle. The procedure was unable to detect two small infarction scars on the rear wall. The possibility of using radionuclide cinematography to prove coronary insufficiency as well as a comparison with other methods are discussed

  18. Terrestrial pathways of radionuclide particulates

    International Nuclear Information System (INIS)

    Boone, F.W.; Ng, Y.C.

    1981-01-01

    Formulations are developed for computing potential human intake of 13 radionuclides via the terrestrial food chains. The formulations are an extension of the NRC methodology. Specific regional crop and livestock transfer and fractional distribution data from the southern part of the U.S.A. are provided and used in the computation of comparative values with those computed by means of USNRC Regulatory Guide 1.109 formulations. In the development of the model, emphasis was also placed on identifying the various time-delay compartments of the food chains and accounting for all of the activity initially deposited. For all radionuclides considered, except 137 Cs, the new formulations predict lower potential intakes from the total of all food chains combined than do the comparable Regulatory Guide formulations by as much as a factor of 40. For 137 Cs the new formulations predict 10% higher potential intakes. (author)

  19. Experimental investigation of leak detection using mobile distributed monitoring system

    Science.gov (United States)

    Chen, Jiang; Zheng, Junli; Xiong, Feng; Ge, Qi; Yan, Qixiang; Cheng, Fei

    2018-01-01

    The leak detection of rockfill dams is currently hindered by spatial and temporal randomness and wide monitoring range. The spatial resolution of fiber Bragg grating (FBG) temperature sensing technology is related to the distance between measuring points. As a result, the number of measuring points should be increased to ensure that the precise location of the leak is detected. However, this leads to a higher monitoring cost. Consequently, it is difficult to promote and apply this technology to effectively monitor rockfill dam leakage. In this paper, a practical mobile distributed monitoring system with dual-tubes is used by combining the FBG sensing system and hydrothermal cycling system. This dual-tube structure is composed of an outer polyethylene of raised temperature resistance heating pipe, an inner polytetrafluoroethylene tube, and a FBG sensor string, among which, the FBG sensor string can be dragged freely in the internal tube to change the position of the measuring points and improve the spatial resolution. In order to test the effectiveness of the system, the large-scale model test of concentrated leakage in 13 working conditions is carried out by identifying the location, quantity, and leakage rate of leakage passage. Based on Newton’s law of cooling, the leakage state is identified using the seepage identification index ζ v that was confirmed according to the cooling curve. Results suggested that the monitoring system shows high sensitivity and can improve the spatial resolution with limited measuring points, and thus better locate the leakage area. In addition, the seepage identification index ζ v correlated well with the leakage rate qualitatively.

  20. Modeling Radionuclide Transport in Clays

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Liange [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Li, Lianchong [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rutqvist, Jonny [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Liu, Hui -Hai [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Birkholzer, Jens [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-05-01

    Clay/shale has been considered as potential host rock for geological disposal of high-level nuclear waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures induced by tunnel excavation. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus Clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at the Mol site, Belgium (Barnichon and Volckaert, 2003) have all been under intensive scientific investigation (at both field and laboratory scales) for understanding a variety of rock properties and their relationships to flow and transport processes associated with geological disposal of nuclear waste. Clay/shale formations may be generally classified as indurated or plastic clays (Tsang and Hudson, 2010). The latter (including Boom clay) is a softer material without high cohesion; its deformation is dominantly plastic. During the lifespan of a clay repository, the repository performance is affected by complex thermal, hydrogeological, mechanical, chemical (THMC) processes, such as heat release due to radionuclide decay, multiphase flow, formation of damage zones, radionuclide transport, waste dissolution, and chemical reactions. All these processes are related to each other. An in-depth understanding of these coupled processes is critical for the performance assessment (PA) of the repository. These coupled processes may affect radionuclide transport by changing transport paths (e.g., formation and evolution of excavation damaged zone (EDZ)) and altering flow, mineral, and mechanical properties that are related to radionuclide transport. While radionuclide transport in clay formation has been studied using laboratory tests (e,g, Appelo et al. 2010, Garcia-Gutierrez et al., 2008, Maes et al., 2008), short-term field

  1. Investigation of the cooling film distribution in liquid rocket engine

    Directory of Open Access Journals (Sweden)

    Luís Antonio Silva

    2011-05-01

    Full Text Available This study presents the results of the investigation of a cooling method widely used in the combustion chambers, which is called cooling film, and it is applied to a liquid rocket engine that uses as propellants liquid oxygen and kerosene. Starting from an engine cooling, whose film is formed through the fuel spray guns positioned on the periphery of the injection system, the film was experimentally examined, it is formed by liquid that seeped through the inner wall of the combustion chamber. The parameter used for validation and refinement of the theoretical penetration of the film was cooling, as this parameter is of paramount importance to obtain an efficient thermal protection inside the combustion chamber. Cold tests confirmed a penetrating cold enough cooling of the film for the length of the combustion chamber of the studied engine.

  2. The glass block site radionuclide migration study

    International Nuclear Information System (INIS)

    Killey, R.W.D.; Champ, D.R.

    1990-01-01

    In 1960 25 nepheline syenite glass blocks containing 14 TBq of mixed fission products in 50 kg of glass were placed below the water table in a shallow sand aquifer at Chalk River Laboratories. Experimental studies undertaken at the site since 1960 have included detailed mapping of the plume of 90 Sr in 1963, 1966 and 1971. Mathematical modeling studies have employed the radiostrontium plume data in determining the split between ion exchange and chemisorption of 90 Sr, and in obtaining reaction rate data for chemisorption. The distribution of 137 Cs on downgradient soils was mapped in 1963 and 1979. An extended plume of low-level 137 Cs contamination observed in the 1979 study prompted an investigation of the role of particulate materials in radionuclide transport. IN 1983, large volume groundwater sampling and separation of cationic, anionic, and neutral dissolved species, as well as particulates, detected anionic and cationic dissolved europium isotopes (154 and 155), and again encountered particulate 137 Cs. A variety of investigations of cesium and strontium sorption have provided a data base on sediment mineralogy, particle surface features, and information on sorption sites and processes. The year 1990 saw the inauguration of a three-year program to update investigations of radionuclide release, transport, and sorption at the glass block site. The first stage of the program has been a detailed definition and simulation of the hydrogeologic setting. Plume mapping and aqueous speciation studies are in progress. This paper summarizes past investigations, reviews the status of the current program, and discusses components of future studies, including investigations of sediment sorption mechanisms. (Author) (17 refs., 8 figs.)

  3. A review on studies of the transport and the form of radionuclides in the fluvial environment

    Energy Technology Data Exchange (ETDEWEB)

    Matsunaga, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-06-01

    The Japan Atomic Energy Research Institute has conducted studies with an aim to contribute to understanding the long-term behavior of atmospherically-derived radionuclides deposited on the ground. The present report reviews a series of studies among them which have especially dealt with the behavior of those radionuclides in a fluvial environment. The studies cited here include investigations of 1) the evaluation of the transport rate of the atmospherically-derived radionuclides from the ground via a river to the downstream areas where the affected water is consumed; 2) the physico-chemical form of the radionuclides in the fluvial environment. An investigation in the Kuji river watershed with {sup 137}Cs, {sup 210}Pb and {sup 7}Be has validated i) the importance of suspended particulate materials in the fluvial discharge of those radionuclides, and ii) a methodology to estimate the discharge of those radionuclides based on the regression analysis with the river water flow rate. From a viewpoint of their distribution between water and suspended particles, the form of radionuclides released by the Chernobyl accident in rivers and lakes in the vicinity of the Chernobyl Nuclear Power Plant were analyzed. As a result, a general reasonability and some cautions were suggested when commonly reported distribution ratios obtained in the laboratory and the different environment are applied to describe the partitioning of the radionuclides in specific natural environmental conditions. This experimental investigation in Chernobyl also revealed the role of natural dissolved organics in affecting the dissolution and transport of {sup 239,240}Pu, {sup 241}Am through complexation to form soluble species. Further, a chemical equilibrium model was applied to describe this complexation. The similar model was also applied for the behavior of iron and manganese (hydr)oxides in river recharged aquifers which can bear riverborne radionuclides and can influence their migration. The

  4. Multiscale Investigation on Biofilm Distribution and Its Impact on Macroscopic Biogeochemical Reaction Rates: BIOFILM DISTRIBUTION AND RATE SCALING

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Zhifeng [Institute of Surface-Earth System Science, Tianjin University, Tianjin China; Pacific Northwest National Laboratory, Richland WA USA; Liu, Chongxuan [Pacific Northwest National Laboratory, Richland WA USA; School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen China; Liu, Yuanyuan [Pacific Northwest National Laboratory, Richland WA USA; School of Earth Science and Engineering, Nanjing University, Nanjing China; Bailey, Vanessa L. [Pacific Northwest National Laboratory, Richland WA USA

    2017-11-01

    Biofilms are critical locations for biogeochemical reactions in the subsurface environment. The occurrence and distribution of biofilms at microscale as well as their impacts on macroscopic biogeochemical reaction rates are still poorly understood. This paper investigated the formation and distributions of biofilms in heterogeneous sediments using multiscale models, and evaluated the effects of biofilm heterogeneity on local and macroscopic biogeochemical reaction rates. Sediment pore structures derived from X-ray computed tomography were used to simulate the microscale flow dynamics and biofilm distribution in the sediment column. The response of biofilm formation and distribution to the variations in hydraulic and chemical properties was first examined. One representative biofilm distribution was then utilized to evaluate its effects on macroscopic reaction rates using nitrate reduction as an example. The results revealed that microorganisms primarily grew on the surfaces of grains and aggregates near preferential flow paths where both electron donor and acceptor were readily accessible, leading to the heterogeneous distribution of biofilms in the sediments. The heterogeneous biofilm distribution decreased the macroscopic rate of biogeochemical reactions as compared with those in homogeneous cases. Operationally considering the heterogeneous biofilm distribution in macroscopic reactive transport models such as using dual porosity domain concept can significantly improve the prediction of biogeochemical reaction rates. Overall, this study provided important insights into the biofilm formation and distribution in soils and sediments as well as their impacts on the macroscopic manifestation of reaction rates.

  5. Critical review: Radionuclide transport, sediment transport, and water quality mathematical modeling; and radionuclide adsorption/desorption mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Y.; Serne, R.J.; Arnold, E.M.; Cowan, C.E.; Thompson, F.L. [Pacific Northwest Lab., Richland, WA (United States)

    1981-01-01

    This report describes the results of a detailed literature review of radionuclide transport models applicable to rivers, estuaries, coastal waters, the Great Lakes, and impoundments. Some representatives sediment transport and water quality models were also reviewed to evaluate if they can be readily adapted to radionuclide transport modeling. The review showed that most available transport models were developed for dissolved radionuclide in rivers. These models include the mechanisms of advection, dispersion, and radionuclide decay. Since the models do not include sediment and radionuclide interactions, they are best suited for simulating short-term radionuclide migration where: (1) radionuclides have small distribution coefficients; (2) sediment concentrations in receiving water bodies are very low. Only 5 of the reviewed models include full sediment and radionuclide interactions: CHMSED developed by Fields; FETRA SERATRA, and TODAM developed by Onishi et al, and a model developed by Shull and Gloyna. The 5 models are applicable to cases where: (1) the distribution coefficient is large; (2) sediment concentrations are high; or (3) long-term migration and accumulation are under consideration. The report also discusses radionuclide absorption/desorption distribution ratios and addresses adsorption/desorption mechanisms and their controlling processes for 25 elements under surface water conditions. These elements are: Am, Sb, C, Ce, Cm, Co, Cr, Cs, Eu, I, Fe, Mn, Np, P, Pu, Pm, Ra, Ru, Sr, Tc, Th, {sup 3}H, U, Zn and Zr.

  6. Distribution of radionuclides in a marine sediment core off the waterspout of the nuclear power plants in Daya Bay, northeastern South China Sea.

    Science.gov (United States)

    Zhou, Peng; Li, Dongmei; Li, Haitao; Fang, Hongda; Huang, Chuguang; Zhang, Yusheng; Zhang, Hongbiao; Zhao, Li; Zhou, Junjie; Wang, Hua; Yang, Jie

    2015-07-01

    A sediment core was collected and dated using (210)Pbex dating method off the waterspout of nuclear power base of Daya Bay, northeastern South China Sea. The γ-emitting radionuclides were analyzed using HPGe γ spectrometry, gross alpha and beta radioactivity as well as other geochemical indicators were deliberated to assess the impact of nuclear power plants (NPP) operation and to study the past environment changes. It suggested that NPP provided no new radioactivity source to sediment based on the low specific activity of (137)Cs. Two broad peaks of TOC, TC and LOI accorded well with the commercial operations of Daya Bay NPP (1994.2 and 1994.5) and LNPP Phase I (2002.5 and 2003.3), implying that the mass input of cooling water from NPP may result into a substantial change in the ecological environment and Daya Bay has been severely impacted by human activities. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Process for encapsulating radionuclides

    International Nuclear Information System (INIS)

    Brownell, L.E.; Isaacson, R.E.

    1976-01-01

    Radionuclides are immobilized in virtually an insoluble form by reacting at a temperature of at least 90 0 C as an aqueous alkaline mixture having a solution pH of at least 10, containing a source of silicon, the radionuclide waste, and a metal cation. The molar ratio of silicon to the metal cation is on the order of unity to produce a gel from which complex metalosilicates crystallize to entrap the radionuclides within the resultant condensed crystal lattice. The product is a silicious stone-like material which is virtually insoluble and nonleachable in alkaline or neutral environment. One embodiment provides for the formation of the complex metalo-silicates, such as synthetic pollucite, by gel formation with subsequent calcination to the solid product; another embodiment utilizes a hydrothermal process, either above ground or deep within basalt caverns, at greater than atmospheric pressures and a temperature between 90 and 500 0 C to form complex metalo-silicates, such as strontium aluminosilicate. Another embodiment provides for the formation of complex metalo-silicates, such as synthetic pollucite, by slurrying an alkaline mixture of bentonite or kaolinite with a source of silicon and the radionuclide waste in salt form. In each of the embodiments a mobile system is achieved whereby the metalo-silicate constituents reorient into a condensed crystal lattice forming a cage structure with the condensed metalo-silicate lattice which completely surrounds the radionuclide and traps the radionuclide therein; thus rendering the radionuclide virtually insoluble

  8. Radionuclide therapy practice and facilities in Europe

    International Nuclear Information System (INIS)

    Hoefnagel, C.A.; Clarke, S.E.M.; Fischer, M.; Chatal, J.F.; Lewington, V.J.; Nilsson, S.; Troncone, L.; Vieira, M.R.

    1999-01-01

    Using a questionnaire the EANM Task Group Radionuclide Therapy in 1993 collected data on the current practice of radionuclide therapy in European countries. Subsequently, at the request of the EANM Executive Committee, the EANM Radionuclide Therapy Committee has made an inventory of the distribution of facilities for radionuclide therapy and undertaken an assessment of the total number of patients treated throughout Europe and of the types of treatment provides, with the aim of supporting the development of policy to adjust the available capacity to the needs by the year 2000. For this purpose, a second, more detailed questionnaire was sent out the members and national advisors of the Committee (see below), who gathered the data for each country that was a member of the EANM at the time. It is concluded that a wide bariation in therapy practice exists across Europe, particularly in the utilisation of radionuclide therapy, the requirement and availability of proper isolation facilities and the background training of those undertaking therapy. More uniform guidelines and legislation are required, although changes in legislation may have a significant impact in some countries. Although there is wide variation in the therapies used in each country, one the whole it appears that there is an underutilisation of nuclear medicine as a therapeutic modality. A rapidly increasing role may be expected, in particular for oncological indications requiring high-dose radionuclide treatment. Therefore there is an urgent need for a greater number of isolation beds in dedicated centers throughout Europe

  9. Radionuclide therapy practice and facilities in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Hoefnagel, C.A.; Clarke, S.E.M.; Fischer, M.; Chatal, J.F.; Lewington, V.J.; Nilsson, S.; Troncone, L.; Vieira, M.R.

    1999-03-01

    Using a questionnaire the EANM Task Group Radionuclide Therapy in 1993 collected data on the current practice of radionuclide therapy in European countries. Subsequently, at the request of the EANM Executive Committee, the EANM Radionuclide Therapy Committee has made an inventory of the distribution of facilities for radionuclide therapy and undertaken an assessment of the total number of patients treated throughout Europe and of the types of treatment provides, with the aim of supporting the development of policy to adjust the available capacity to the needs by the year 2000. For this purpose, a second, more detailed questionnaire was sent out the members and national advisors of the Committee (see below), who gathered the data for each country that was a member of the EANM at the time. It is concluded that a wide bariation in therapy practice exists across Europe, particularly in the utilisation of radionuclide therapy, the requirement and avilability of proper isolation facilities and the background training of those undertaking therapy. More uniform guidelines and legislation are required, although changes in legislation may have a significant impact in some countries. Although there is wide variation in the therapies used in each country, one the whole it appears that there is an underutilisation of nuclear medicine as a therapeutic modality. A rapidly increasing role may be expected, in particular for oncological indications requiring high-dose radionuclide treatment. Therefore there is an urgent need for a greater number of isolation beds in dedicated centers throughout Europe. With 8 tabs.

  10. Radionuclide concentration processes in marine organisms: A comprehensive review.

    Science.gov (United States)

    Carvalho, Fernando P

    2018-06-01

    The first measurements made of artificial radionuclides released into the marine environment did reveal that radionuclides are concentrated by marine biological species. The need to report radionuclide accumulation in biota in different conditions and geographical areas prompted the use of concentration factors as a convenient way to describe the accumulation of radionuclides in biota relative to radionuclide concentrations in seawater. Later, concentration factors became a tool in modelling radionuclide distribution and transfer in aquatic environments and to predicting radioactivity in organisms. Many environmental parameters can modify the biokinetics of accumulation and elimination of radionuclides in marine biota, but concentration factors remained a convenient way to describe concentration processes of radioactive and stable isotopes in aquatic organisms. Revision of CF values is periodically undertaken by international organizations, such as the International Atomic Energy Agency (IAEA), to make updated information available to the international community. A brief commented review of radionuclide concentration processes and concentration factors in marine organisms is presented for key groups of radionuclides such as fission products, activation products, transuranium elements, and naturally-occurring radionuclides. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Assessment of impact to effective dose due to radionuclide carriers

    International Nuclear Information System (INIS)

    Lujaniene, G.; Gudelis, A.

    2002-01-01

    Peculiarities of contamination of the Lithuanian territory after the Chernobyl accident were investigated. Evaluation based on measurements of activity concentration of 137 Cs, 239,240 Pu, 238 Pu, 241 Am and 90 Sr their activity ratio and physical chemical characteristics of their aerosol carriers indicated that the pollution was caused both by condensed and fuel components with different their contribution to the total atmospheric activity on different phases of the Chernobyl NPP accident. Studies of physical chemical forms of actinides showed that two type of fraction distribution were characteristic of aerosol samples Chernobyl origin. They could be interpreted as presence of fuel particles themselves in aerosol samples and possible transport of highly dispersed fuel component on the graphite particles and their burning products. Later the increase in activity concentration in the atmosphere in Lithuania was conditioned by two main sources of radionuclides. They are forest fires and resuspension products transferred from polluted regions. In order to understand better the influence of forest fires on the radionational situation the special fire experiment was performed in the highly contaminated Briansk region (Russia). Data on activity concentration, size distribution and physical chemical forms of aerosol carriers of radionuclides obtained from this experiment were used to estimate effective doses received from inhalation and ingestion of emitted radioactive particles. The calculations of effective doses received from inhalation of 137 Cs, 239,240 Pu, 238 Pu, 90 Sr and 241 Am during the Chernobyl accident in Vilnius showed that the activity concentrations of insoluble radionuclides contributed considerably into effective dozes received from inhalation. The results of calculation indicated that contribution of activities of water soluble and insoluble cesium and plutonium to the total effective dose differed more than by factor. The calculation of effective

  12. Characterization of Discharge Areas of Radionuclides Originating From Nuclear Waste Repositories

    Science.gov (United States)

    Marklund, L.; Xu, S.; Worman, A.

    2009-05-01

    If leakages in nuclear waste repositories located in crystalline bedrock arise, radionuclides will reach the biosphere and cause a risk of radiological impact. The extent of the radiological impact depends on in which landscape elements the radionuclides emerge. In this study, we investigate if there are certain landscape elements that generally will act as discharge areas for radionuclides leaking from subsurface deposits. We also characterize the typical properties that distinguish these areas from others. In humid regions, landscape topography is the most important driving force for groundwater flow. Because groundwater is the main transporting agent for migrating radionuclides, the topography will determine the flowpaths of leaking radionuclides. How topography and heterogeneities in the subsurface affect the discharge distribution of the radionuclides is therefore an important scope of this study. To address these issues, we developed a 3-D transport model. Our analyses are based on site-specific data from two different areas in Sweden, Forsmark, Uppland, and Oskarshamn, Småland. The Swedish Nuclear Waste Management Company (SKB) has selected these two areas as candidate areas for a deep repository of nuclear waste and the areas are currently subject to site investigations. Our results suggest that there are hot-spots in the landscape i.e. areas with high probability of receiving large amounts of radionuclides from a leaking repository of nuclear waste. The hot-spots concentrate in the sea, streams, lakes and wetlands. All these elements are found at lower elevations in the landscape. This pattern is mostly determined by the landscape topography and the locations of fracture zones. There is a relationship between fracture zones and topography, and therefore the importance of the topography for the discharge area distribution is not contradicted by the heterogeneity in the bedrock. The varieties of landscape elements which have potential for receiving

  13. Review of radionuclide treatment for neuroendocrine tumors

    International Nuclear Information System (INIS)

    Jeong, Hwan Jeong

    2006-01-01

    Neuroendocrine tumors (NETs) consist of a heterogeneous group of tumors that are uptake neuroamine and/or specific receptors, such as somatostatin receptors, which can play important roles of the localization and treatment of these tumors. When considering therapy with radionuclides, the best radioligand should be carefully investigated. 131 I-MIBG and beta-particle emitter labeled somatostatin analogs are well established radionuclide therapy modalities for NETs. 111 In, 90 Y and 177 Lu radiolabelled somatostatin analogues have been used for treatment of NETs. Further, radionuclide therapy modalities, for example, radioimmunotherapy, radiolabeled peptides such as minigastrin are currently under development and in different phases of clinical investigation. For all radionuclides used for therapy, long-tem and survival statistics are not yet available and only partial tumour responses have been obtained using 131 I-MIBG and 111 In-octreotide. Experimental results using 90 Y-DOTA-lanreotide as well as 90 Y-DOTA-D -Phe1-Tyr 3 -octreotide and/or 177 Lu-DOTA-Tyr 3 -octreotate have indicated the possible clinical potential of radionuclides receptor-targeted radiotherapy. It may be hoped that the efficacy of radionuclide therapy will be improved by co-administration of chemotherapeutic drugs whose antitumoral properties may be synergistic with that of irradiation

  14. Mathematical simulation of sediment and radionuclide transport in estuaries

    International Nuclear Information System (INIS)

    Onishi, Y.; Trent, D.S.

    1982-11-01

    The finite element model LFESCOT (Flow, Energy, Salinity, Sediment and Contaminant Transport Model) was synthesized under this study to simulate radionuclide transport in estuaries to obtain accurate radionuclide distributions which are affected by these factors: time variance, three-dimensional flow, temperature, salinity, and sediments. Because sediment transport and radionuclide adsorption/desorption depend strongly on sizes or types of sediments, FLESCOT simulates sediment and a sediment-sorbed radionuclide for the total of three sediment-size fractions (or sediment types) of both cohesive and noncohesive sediments. It also calculates changes of estuarine bed conditions, including bed elevation changes due to sediment erosion/deposition, and three-dimensional distributions of three bed sediment sizes and sediment-sorbed radionuclides within the bed. Although the model was synthesized for radionuclide transport, it is general enough to also handle other contaminants such as heavy metals, pesticides, or toxic chemicals. The model was checked for its capability for flow, water surface elevation change, salinity, sediment and radionuclide transport under various simple conditions first, confirming the general validity of the model's computational schemes. These tests also revealed that FLESCOT can use large aspect ratios of computational cells, which are necessary in handling long estuarine study areas. After these simple tests, FLESCOT was applied to the Hudson River estuary between Chelsea and the mouth of the river to examine how well the model can predict radionuclide transport through simulating tidally influenced three-dimensional flow, salinity, sediment and radionuclide movements with their interactions

  15. Investigation on the development of measurement techniques, the behavior in the environment and the estimation of internal radiation dose by inhalation for some typical atmospheric radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Amano, Hikaru [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-06-01

    Radionuclides in surface atmosphere on the earth are {sup 222}Rn, {sup 220}Rn and their short lived progeny, {sup 7}Be, {sup 85}Kr, {sup 3}H, {sup 14}C, {sup 137}Cs, {sup 90}Sr and so on. In this paper, among them, {sup 222}Rn, their short lived progeny ({sup 218}Po, {sup 214}Pb, {sup 214}Bi, {sup 214}Po), {sup 7}Be, {sup 3}H, and {sup 90}Sr are focused on as follows based on the experimental and observed results, 1. Development of their measurement techniques, 2. Analysis of their variation of atmospheric concentration with time and places, 3. Analysis of their interaction characteristics with surface environment including plants, 4. Estimation of internal radiation doses by inhalation of them. (author). 228 refs.

  16. Radionuclide evaluation of the liver in diabetes

    International Nuclear Information System (INIS)

    Abdel-Razzak, M.; El-Ashmawy, A.

    1982-01-01

    Hepatic involvement in diabetes has been previously demonstrated in experimental animals and in patients by clinical examination as well as by autopsy. The aim of the present work is to investigate the extent and type of hepatic involvement in diabetics by radionuclide scanning which is objective and not liable to the errors and difficulties inherent in the method of physical examination. The present study was performed on 40 diabetics, comprising 24 females and 16 males, aged between 17 and 80 years. Scanning was performed with 99m - Tc sulphur colloid using a rectilinear scanner and the gamma camera. The liver size was assessed from the scan pictures by the application of certain measurements and by surface area determination. The obtained results demonstrated marked discrepancy between the liver size as determined clinically and that evaluated by radionuclide scanning. By scintiscanning, the incidence of hepatic enlargement varied according to the parameter used. It amounted to 48% on the basis of the maximum vertical dimension and 37% with hepatic surface area measurement. Using the vertical dimension at halfway between the xiphoid and right lateral hepatic margin, the incidence of liver enlargement was 35%. Uneven distribution of radioactivity was seen in the right and/or left lobe in 20/40 patients. Furthermore, in 10 patients the ratio of hepatic to splenic radioactivity was below one. These changes could be explained by fatty infiltration and/or cirrhosis. Accordingly, hepatic scanning could be used to select diabetes having abnormal scan picture whether regarding liver dimensions or distribution of radioactivity and subjecting them to liver biopsy in order to define the nature of liver involvement. (Author)

  17. Radionuclide Basics: Iodine

    Science.gov (United States)

    ... Search Radiation Protection Contact Us Share Radionuclide Basics: Iodine Iodine (chemical symbol I) is a chemical element. ... in the environment Iodine sources Iodine and health Iodine in the Environment All 37 isotopes of iodine ...

  18. Investigating The Neutron Flux Distribution Of The Miniature Neutron Source Reactor MNSR Type

    International Nuclear Information System (INIS)

    Nguyen Hoang Hai; Do Quang Binh

    2011-01-01

    Neutron flux distribution is the important characteristic of nuclear reactor. In this article, four energy group neutron flux distributions of the miniature neutron source reactor MNSR type versus radial and axial directions are investigated in case the control rod is fully withdrawn. In addition, the effect of control rod positions on the thermal neutron flux distribution is also studied. The group constants for all reactor components are generated by the WIMSD code, and the neutron flux distributions are calculated by the CITATION code. The results show that the control rod positions only affect in the planning area for distribution in the region around the control rod. (author)

  19. Marine plankton as an indicator of low-level radionuclide contamination in the Southern Ocean

    International Nuclear Information System (INIS)

    Marsh, K.V.; Buddemeier, R.W.

    1984-07-01

    We have initiated an investigation of the utility of marine plankton as bioconcentrating samplers of low-level marine radioactivity in the southern hemisphere. A literature review shows that both freshwater and marine plankton have trace element and radionuclide concentration factors (relative to water) of up to 10 4 . In the years 1956-1958, considerable work was done on the accumulation and distribution of a variety of fission and activation products produced by the nuclear tests in the Marshall Islands. Since then, studies have largely been confined to a few selected radionuclides, and by far most of this work has been done in the northern hemisphere. We participated in Operation Deepfreeze 1981, collecting 32 plankton samples from the U.S. Coast Guard Cutter Glacier on its Antarctic cruise, while Battelle Pacific Northwest Laboratories concurrently sampled air, water, rain and fallout. We were able to measure concentrations of the naturally occurring radionuclides 7 Be, 40 K and the U and th series, and we believe that we have detected low levels of 144 Ce and 95 Nb in seven samples ranging as far south as 68 0 . There is a definite association between the radionuclide content of plankton and air filters, suggesting that aerosol resuspension of marine radioactivity may be occurring. Biological identification of the plankton suggests a possible correlation between radionuclide concentration and foraminifera content of the samples. 38 references, 7 figures, 3 tables

  20. Marine plankton as an indicator of low-level radionuclide contamination in the Southern Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, K.V.; Buddemeier, R.W.

    1984-07-01

    We have initiated an investigation of the utility of marine plankton as bioconcentrating samplers of low-level marine radioactivity in the southern hemisphere. A literature review shows that both freshwater and marine plankton have trace element and radionuclide concentration factors (relative to water) of up to 10/sup 4/. In the years 1956-1958, considerable work was done on the accumulation and distribution of a variety of fission and activation products produced by the nuclear tests in the Marshall Islands. Since then, studies have largely been confined to a few selected radionuclides, and by far most of this work has been done in the northern hemisphere. We participated in Operation Deepfreeze 1981, collecting 32 plankton samples from the U.S. Coast Guard Cutter Glacier on its Antarctic cruise, while Battelle Pacific Northwest Laboratories concurrently sampled air, water, rain and fallout. We were able to measure concentrations of the naturally occurring radionuclides /sup 7/Be, /sup 40/K and the U and th series, and we believe that we have detected low levels of /sup 144/Ce and /sup 95/Nb in seven samples ranging as far south as 68/sup 0/. There is a definite association between the radionuclide content of plankton and air filters, suggesting that aerosol resuspension of marine radioactivity may be occurring. Biological identification of the plankton suggests a possible correlation between radionuclide concentration and foraminifera content of the samples. 38 references, 7 figures, 3 tables.

  1. Radionuclide Migration Program: strategy document

    International Nuclear Information System (INIS)

    1986-01-01

    The Radionuclide Migration Program (RNM) is composed of projects to obtain data that will define the hydrologic system on NTS and determine the radionuclides available for migration in that system. Specific objectives are: (1) determine the kinds and amounts of radionuclides available for migration in groundwater (Hydrologic Source Term); (2) determine regional and local hydrology; and (3) predict the direction and migration rates of radionuclides in groundwater and the radionuclide concentration at any given distance for the source

  2. Computation Of The Residual Radionuclide Activity Within Three Natural Waterways At The Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Hiergesell, R. A.; Phifer, M. A.

    2014-01-07

    In 2010 a Composite Analysis (CA) of the U.S. Department of Energy’s (DOE’s) Savannah River Site (SRS) was completed. This investigation evaluated the dose impact of the anticipated SRS End State residual sources of radionuclides to offsite members of the public. Doses were assessed at the locations where SRS site streams discharge into the Savannah River at the perimeter of the SRS. Although the model developed to perform this computation indicated that the dose constraint of 0.3 mSv/yr (30 mrem/yr), associated with CA, was not approached at the Points of Assessment (POAs), a significant contribution to the total computed dose was derived from the radionuclides (primarily Cs-137) bound-up in the soil and sediment of the drainage corridors of several SRS streams. DOE’s Low Level Waste Federal Review Group (LFRG) reviewed the 2010 CA and identified several items to be addressed in the SRS Maintenance Program. One of the items recognized Cs-137 in the Lower Three Runs (LTR) Integrator Operable Unit (IOU), as a significant CA dose driver. The item made the recommendation that SRS update the estimated radionuclide inventory, including Cs-137, in the LTR IOU. That initial work has been completed and its radionuclide inventory refined. There are five additional streams at SRS and the next phase of the response to the LFRG concern was to obtain a more accurate inventory and distribution of radionuclides in three of those streams, Fourmile Branch (FMB), Pen Branch (PB) and Steel Creek (SC). Each of these streams is designated as an IOU, which are defined for the purpose of this investigation as the surface water bodies and associated wetlands, including the channel sediment, floodplain sed/soil, and related biota. If present, radionuclides associated with IOUs are adsorbed to the streambed sediment and soils of the shallow floodplains that lie immediately adjacent to stream channels. The scope of this effort included the evaluation of any previous sampling and

  3. Distribution and inventories of fallout radionuclides (239+24Pu, 137Cs) and 21Pb to study the filling velocity of salt marshes in Donana National Park (Spain)

    International Nuclear Information System (INIS)

    Gasco, C.; Anton, M.P.; Pozuelo, M.; Clemente, L.; Rodriguez, A.; Yanez, C.; Gonzalez, A.; Meral, J.

    2006-01-01

    Within an extensive multinational and multidisciplinary project carried out in Donana National Park (Spain) to investigate its preservation and regeneration, the filling velocity of the salt marshes has been evaluated through the calculation of their average sediment accumulation rates. 239+24 Pu and 137 Cs from weapons testing fallout and total 21 Pb distribution profiles and inventories have been determined in some of the most characteristic zones of the park, namely, the ponds (or 'lucios') and the waterjets (or 'canos'). Plutonium inventories range from 16 to 101 Bq m -2 , 137 Cs values fluctuate between 514 and 3758 Bq m -2 and unsupported 21 Pb values comprise between 124 and 9398 Bq m -2 . Average sedimentation rates range from 3 to 5 mm y -1 (1952-2002). These data are higher than those obtained by carbon dating for the period 6500 AD-present, estimated as 1.5-2 mm y -1 , suggesting an increase in the accumulation of sediments and the alteration of the park's hydrodynamics caused by the re-channeling of the major rivers feeding the salt marshes

  4. Estimation of Total Error in DWPF Reported Radionuclide Inventories

    International Nuclear Information System (INIS)

    Edwards, T.B.

    1995-01-01

    This report investigates the impact of random errors due to measurement and sampling on the reported concentrations of radionuclides in DWPF's filled canister inventory resulting from each macro-batch. The objective of this investigation is to estimate the variance of the total error in reporting these radionuclide concentrations

  5. Radionuclide exercise ventriculography and levels of workload

    International Nuclear Information System (INIS)

    Wynchank, S.

    1982-01-01

    The wealth of useful information made available from the utilization of radionuclide cardiological investigations by non-invasive means is outlined and reasons for investigating results obtained under conditions of increased heart workload are explained. The lack of an accepted protocol for the determination of exercise levels is noted. A format for obtaining increasing heart loads dependent on increasing pulse rate is offered, with justification. Exercise radionuclide ventriculography examinations can be conducted which are simple, reproducible and allow appropriate levels of stress in patients who can benefit from such investigations

  6. Transcuticular translocation of radionuclides on plant leaf surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Ken-ichi; Watanabe, Tadakazu; Ambe, Shizuko; Yamaguchi, Isamu [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

    1996-12-31

    The cuticle covering all the outermost surfaces of the aerial parts of plants could play a selective role in uptake and translocation of radionuclides from air into plants. In this study, we investigated the transcuticular uptake and translocation behavior via water droplets of various radionuclides in red clover, orchard grass, Japanese radish and mung bean. Ten {mu}l of an aqueous solution of the multitracer generated from Au was applied to the upper surface of the 2nd leaf of the plants at the 5th leaf stage. The plants were then grown for 14 days at 25degC and 70% RH under illumination of artificial solar lights. The transcuticular uptake and translocation throughout the plant were periodically assayed by determining the radioactivity in the surface residue, the cuticle layer beneath the applied site, the leaf area outside the applied site, the other aerial parts and the root of the plant, using an HPGe detector. The applied radionuclides were absorbed into, in turn, the cuticle layer beneath the applied site and then translocated through the cuticle to the inner tissue and eventually to the other aerial parts and finally to the roots, of the plant. The distribution and accumulation in the plant seems to depend upon the characteristics of each radionuclide and plant species. Ca{sup *} and Te{sup *} tended to remain on leaf surfaces without being absorbed into the cuticle. On the other hand, Sc{sup *}, Co{sup *}, Zn{sup *}, Se{sup *}, Rb{sup *}, and Eu{sup *} were easily absorbed and translocated to every part of the plant including the root. The other radionuclides such as Be{sup *}, Mn{sup *}, Sr{sup *}, Y{sup *}, Ba{sup *}, Ce{sup *}, Pm{sup *}, Gd{sup *}, Hf{sup *}, Yb{sup *}, Lu{sup *}, Os{sup *}, Ir{sup *}, and Pt{sup *} remained in the region close to the site of their application. The above results possibly indicate the existence of mechanisms common to these plants for selective transcuticular uptake and translocation of radionuclides within plant

  7. Investigation of Effect of Different Run-Time Distributions on Smartnet Performance

    National Research Council Canada - National Science Library

    Armstrong, Robert

    1997-01-01

    This thesis investigates, using in-line simulation, the effect of non-deterministic runtime distributions on the performance of SmartNet's schedule execution using the Opportunistic Load Balancing (OLB...

  8. Investigations of Wind Shear Distribution on the Baltic Shore of Latvia

    Science.gov (United States)

    Bezrukovs, V.; Zacepins, A.; Bezrukovs, Vl.; Komashilovs, V.

    2016-06-01

    The paper presents a review of wind parameter measurement complexes and investigation methods used for potential wind energy evaluation. Based on results of long-term investigations of wind shear distribution regularities are shown up to 160 m height on the Baltic Sea shore. Distribution of potential wind energy in Latvia is shown as a map and table of average and average cubic wind speed values. Database of wind parameter measurements is available at a public website.

  9. Stochastic approach for radionuclides quantification

    Science.gov (United States)

    Clement, A.; Saurel, N.; Perrin, G.

    2018-01-01

    Gamma spectrometry is a passive non-destructive assay used to quantify radionuclides present in more or less complex objects. Basic methods using empirical calibration with a standard in order to quantify the activity of nuclear materials by determining the calibration coefficient are useless on non-reproducible, complex and single nuclear objects such as waste packages. Package specifications as composition or geometry change from one package to another and involve a high variability of objects. Current quantification process uses numerical modelling of the measured scene with few available data such as geometry or composition. These data are density, material, screen, geometric shape, matrix composition, matrix and source distribution. Some of them are strongly dependent on package data knowledge and operator backgrounds. The French Commissariat à l'Energie Atomique (CEA) is developing a new methodology to quantify nuclear materials in waste packages and waste drums without operator adjustment and internal package configuration knowledge. This method suggests combining a global stochastic approach which uses, among others, surrogate models available to simulate the gamma attenuation behaviour, a Bayesian approach which considers conditional probability densities of problem inputs, and Markov Chains Monte Carlo algorithms (MCMC) which solve inverse problems, with gamma ray emission radionuclide spectrum, and outside dimensions of interest objects. The methodology is testing to quantify actinide activity in different kind of matrix, composition, and configuration of sources standard in terms of actinide masses, locations and distributions. Activity uncertainties are taken into account by this adjustment methodology.

  10. Infusion of radionuclides throughout pregnancy

    International Nuclear Information System (INIS)

    Mountford-Lister, P.G.; Lambert, B.E.; Milner, A.C.; Kang, X.Z.

    1992-01-01

    This work is part of a long-term study to examine the cancer incidence in the offspring of mice exposed to 239 Pu or 147 Pm throughout pregnancy. The need to model the human intake scenario and the possibility of a critical period during uterine development necessitates constant availability of radionuclides throughout pregnancy. Various methods (multiple daily injections, infusion by external cannula and infusion by indwelling osmotic pump) have been examined and osmotic infusion pumps chosen. These pumps result in a near-constant blood concentration for up to 21 days. Part of the study is the estimation of dose to the critical haemopoietic tissues of the pup from a knowledge of the radionuclide distribution and kinetics. At present the distribution has been followed from birth to 180 days. Activity in the suckling pups at 7 days old is around 1 percent of the infused activity, though most of this is accounted for by the contents of the stomach and gastrointestinal tract. The liver and femur account for around 0.025 percent and 0.012 percent respectively per pup. Activity increases in both liver and femur during lactation after which both concentration and activity fall with time. Long-term studies with the pups of dams exposed to a range of 239 Pu concentrations between 0-70 kBq/kg are underway. Correlation of average organ dose with tumour incidence will be determined at completion of the life-span study. (Author) 39 refs., 5 tabs., 6 figs

  11. Radionuclide kinetics in irrigated agrophytocenosis when using waste waters

    International Nuclear Information System (INIS)

    Malikov, V.G.; Mel'chenko, A.I.; Aleksakhin, R.M.

    1992-01-01

    During experiments quantitative parameters of radionuclide kinetics as a result induced activity and radionuclide kinetics for natural heavy radionuclides from water used for irrigation into the vegetables crops for various kinds of irrigation depending on agrophytocenosis species have been investigated. Ways of reducing the radionuclide concentrations as far as economic and nutritive criteria are concerned using the simplest methods of treatment have been studied. It has been concluded that the highest radioactive contamination of vegetables crops takes place during sprinkling and the minimum one occurs during subsurface irrigation and gravity irrigation. 13 refs.; 3 tabs

  12. Radioactivity: radionuclides in foods

    International Nuclear Information System (INIS)

    Simpson, R.E.; Baratta, E.J.; Jelinek, C.F.

    1977-01-01

    The results are summarized of the analysis for strontium-90, cesium-137, iodine-131, ruthenium-106, and potassium-40, a naturally occurring radionuclide, in samples of total diet and selected import commodities in the foods compliance program of the Food and Drug Administration. On the basis of the radionuclide intake guidelines established by the Federal Radiation Council (FRC), the low content of radionuclides found in the total diet samples for fiscal years 1973 and 1974 demonstrates the need for surveillance only at the present level. The low levels of radionuclides found in a limited number of edible imported commodities indicate that their contribution to the total diet would not increase the levels of these radionuclides above those recommended for only periodic surveillance by the FRC. The potassium levels, determined from potassium-40 activity, found in meats and fish agree with the value for normal muscle tissue for the reference man reported by the International Commission on Radiation Protection. Of the other commodities, nuts contained the highest levels, while sugar, beverages, and processed foods contained the lowest levels of potassium. Although cesium and potassium are chemical analogs with similar metabolic properties, because of their variable content in some leafy samples as a result of surface contamination, a correlation between cesium-137 levels and the cesium-137-to-potassium ratio was inconclusive

  13. Suspended particles, colloids and radionuclide transport

    International Nuclear Information System (INIS)

    Chapman, N.; McKinley, I.; Shea, M.; Smellie, J.

    1993-01-01

    Radionuclide can be transported either in true solution or associated with suspended particles and colloids. The definitions of colloids and suspended particles are introduced and the mechanisms by which they can influence radionuclide transport discussed. The aim of the Pocos de Caldas investigations was to characterise the natural particulate material in the groundwater, to investigate the association of trace elements with this material and to obtain information on the stability and mobility of the particles. The concentration of suspended particles measured in the groundwater samples were low; the particles also appear to be immobile. (author) 4 figs

  14. Radionuclide interactions with marine sediments

    International Nuclear Information System (INIS)

    Higgo, J.J.W.

    1987-09-01

    A critical review of the literature on the subject of the interactions of radionuclides with marine sediments has been carried out. On the basis of the information available, an attempt has been made to give ranges and 'best estimates' for the distribution ratios between seawater and sediments. These estimates have been based on an understanding of the sediment seawater system and the porewater chemistry and mineralogy. Field measurements, laboratory measurements and estimates based on stable-element geochemical data are all taken into account. Laboratory measurements include distribution-ratio and diffusion-coefficient determinations. The elements reviewed are carbon, chlorine, calcium, nickel, selenium, strontium, zirconium, niobium, technetium, tin, iodine, caesium, lead, radium, actinium, thorium, protactinium, uranium, neptunium, plutonium, americium and curium. (author)

  15. Stable isotopes as tracers for radionuclides

    International Nuclear Information System (INIS)

    Giussani, A.; Bartolo, D. de; Cantone, M.C.; Zilker, T.; Greim, H.; Roth, P.; Werner, E.

    2000-01-01

    The assessment of internal dose after incorporation of radionuclides requires as input data the knowledge of the uptake into the systemic circulation, the distribution and retention in selected organs, the excretion pathways. Realistic biokinetic models are needed for reliable estimates, correct interpretation of bioassay measurements, appropriate decision-making in radiological emergencies. For many radionuclides, however, the biokinetic models currently recommended are often generic, with very few specific parameters, due to the lack of experimental human data. The use of stable isotopes as tracers enables to determine important biokinetic parameters such as the fractional uptake, the clearance from the transfer compartment, the excretion patterns under experimentally controlled conditions. The subjects investigated are not exposed to any radiation risk, so this technique enables to obtain biokinetic information also for sensitive groups of the population, such as children or pregnant women, and to determine age- and gender-specific model parameters. Sophisticated analytical method, able to discriminate and quantitate different isotopes of the same element in complex matrices such as biological fluids, have to be purposely developed and optimized. Activation analysis and mass spectrometry are the most proper techniques of choice. Experiments were conducted with molybdenum, tellurium, ruthenium and zirconium. Activation analysis with protons, thermal ionization mass spectrometry and inductively coupled mass spectrometry were employed for the determination of stable isotopes of these elements in blood plasma and urine samples. Several deviations from the predictions of the ICRP models were observed. For example, modifications to the current model for molybdenum have been suggested on the basis of these results. The dose coefficients to the target regions calculated with this proposed model are even of one order of magnitude different than the ICRP estimates

  16. Assessment of the potential for radionuclide migration from a nuclear explosion cavity

    International Nuclear Information System (INIS)

    Hoffman, D.C.; Daniels, W.R.

    1984-01-01

    A field study of the distribution of radionuclides around an underground nuclear explosion cavity was initiated in 1974, about 9 years after detonation of the nuclear test. This study is part of the Radionuclide Migration (RNM) Project, a broad investigation to determine the rates of migration underground in various media at the Nevada Test Site (NTS) and the potential for movement both on and off the NTS of radioactivity from underground nuclear explosions. It was also envisaged that the study might provide data applicable to the underground disposal of radioactive waste. The site of the 0.75 kiloton nuclear test Cambric was chosen for a number of reasons. The Cambric explosion cavity is within the NTS Area 5 water-supply aquifer, and there was particular interest in possible contamination of water supplies. Also, the Cambric detonation point is only 294 meters below the ground surface, and thus the re-entry drilling and sampling operations would be less difficult and expensive than from some of the more deeply buried tests. The Cambric cavity region was re-entered, and a well was completed to a depth of 370 meters. Samples were taken to determine the radionuclide distribution between the solid material and water at the time of the experiment was started. Water was then pumped from a nearby satellite well to induce an artificial gradient sufficient to draw water from the Cambric cavity and provide an opportunity for the study of radionuclide migration under field conditions

  17. Radionuclides in foods

    International Nuclear Information System (INIS)

    1994-01-01

    This report contains data on the levels of radionuclides in the UK foodchain. Most data derive from monitoring programmes that exist around nuclear sites, and in some cases date back to the 1960s. Some comparative data from site operator and government-run programmes are included. Data from monitoring undertaken after the Chernobyl accident are summarised. General monitoring of the foodchain for both artificial and natural radionuclides, and the results of relevant government-sponsored research are also described. The report includes basic information on radioactivity in the environment, radiation protection standards and describes what measures are taken to routinely monitor the foodchain and assess public risk. (Author)

  18. Targeted Radionuclide Therapy

    International Nuclear Information System (INIS)

    Ersahin, Devrim; Doddamane, Indukala; Cheng, David

    2011-01-01

    Targeted radiotherapy is an evolving and promising modality of cancer treatment. The killing of cancer cells is achieved with the use of biological vectors and appropriate radionuclides. Among the many advantages of this approach are its selectiveness in delivering the radiation to the target, relatively less severe and infrequent side effects, and the possibility of assessing the uptake by the tumor prior to the therapy. Several different radiopharmaceuticals are currently being used by various administration routes and targeting mechanisms. This article aims to briefly review the current status of targeted radiotherapy as well as to outline the advantages and disadvantages of radionuclides used for this purpose

  19. Treatment with radionuclides

    International Nuclear Information System (INIS)

    Radeva, M.

    2000-01-01

    The application of nuclides for therapy is a noninvasive treatment modality, which is characterized by the selective delivery of the radiation dose to target tissues (tumors or organs). Radionuclide therapy provides an alternative to surgical or medical treatment for several benign disorders. Basically, it is disease (metabolic radionuclide therapy). On the same principle is based the nuclide therapy of any endocrine tumors. The paper presents several methods for determination of the dose in treatment of thyroid diseases. A data of the '1'3'1' I therapy of thyroid diseases at the Medical University of Sofia are shown

  20. Sediment and radionuclide transport in rivers: radionuclide transport modeling for Cattaraugus and Buttermilk Creeks, New York

    International Nuclear Information System (INIS)

    Onishi, Y.; Yabusaki, S.B.; Kincaid, C.T.; Skaggs, R.L.; Walters, W.H.

    1982-12-01

    SERATRA, a transient, two-dimensional (laterally-averaged) computer model of sediment-contaminant transport in rivers, satisfactorily resolved the distribution of sediment and radionuclide concentrations in the Cattaraugus Creek stream system in New York. By modeling the physical processes of advection, diffusion, erosion, deposition, and bed armoring, SERATRA routed three sediment size fractions, including cohesive soils, to simulate three dynamic flow events. In conjunction with the sediment transport, SERATRA computed radionuclide levels in dissolved, suspended sediment, and bed sediment forms for four radionuclides ( 137 Cs, 90 Sr, 239 240 Pu, and 3 H). By accounting for time-dependent sediment-radionuclide interaction in the water column and bed, SERATA is a physically explicit model of radionuclide fate and migration. Sediment and radionuclide concentrations calculated by SERATA in the Cattaraugus Creek stream system are in reasonable agreement with measured values. SERATRA is in the field performance phase of an extensive testing program designed to establish the utility of the model as a site assessment tool. The model handles not only radionuclides but other contaminants such as pesticides, heavy metals and other toxic chemicals. Now that the model has been applied to four field sites, including the latest study of the Cattaraugus Creek stream system, it is recommended that a final model be validated through comparison of predicted results with field data from a carefully controlled tracer test at a field site. It is also recommended that a detailed laboratory flume be tested to study cohesive sediment transport, deposition, and erosion characteristics. The lack of current understanding of these characteristics is one of the weakest areas hindering the accurate assessment of the migration of radionuclides sorbed by fine sediments of silt and clay

  1. Carrier density distribution in silicon nanowires investigated by scanning thermal microscopy and Kelvin probe force microscopy.

    Science.gov (United States)

    Wielgoszewski, Grzegorz; Pałetko, Piotr; Tomaszewski, Daniel; Zaborowski, Michał; Jóźwiak, Grzegorz; Kopiec, Daniel; Gotszalk, Teodor; Grabiec, Piotr

    2015-12-01

    The use of scanning thermal microscopy (SThM) and Kelvin probe force microscopy (KPFM) to investigate silicon nanowires (SiNWs) is presented. SThM allows imaging of temperature distribution at the nanoscale, while KPFM images the potential distribution with AFM-related ultra-high spatial resolution. Both techniques are therefore suitable for imaging the resistance distribution. We show results of experimental examination of dual channel n-type SiNWs with channel width of 100 nm, while the channel was open and current was flowing through the SiNW. To investigate the carrier distribution in the SiNWs we performed SThM and KPFM scans. The SThM results showed non-symmetrical temperature distribution along the SiNWs with temperature maximum shifted towards the contact of higher potential. These results corresponded to those expressed by the distribution of potential gradient along the SiNWs, obtained using the KPFM method. Consequently, non-uniform distribution of resistance was shown, being a result of non-uniform carrier density distribution in the structure and showing the pinch-off effect. Last but not least, the results were also compared with results of finite-element method modeling. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Preparation of Radiopharmaceuticals Labeled with Metal Radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Welch, M.J.

    2012-02-16

    The overall goal of this project was to develop methods for the production of metal-based radionuclides, to develop metal-based radiopharmaceuticals and in a limited number of cases, to translate these agents to the clinical situation. Initial work concentrated on the application of the radionuclides of Cu, Cu-60, Cu-61 and Cu-64, as well as application of Ga-68 radiopharmaceuticals. Initially Cu-64 was produced at the Missouri University Research Reactor and experiments carried out at Washington University. A limited number of studies were carried out utilizing Cu-62, a generator produced radionuclide produced by Mallinckrodt Inc. (now Covidien). In these studies, copper-62-labeled pyruvaldehyde Bis(N{sup 4}-methylthiosemicarbazonato)-copper(II) was studied as an agent for cerebral myocardial perfusion. A remote system for the production of this radiopharmaceutical was developed and a limited number of patient studies carried out with this agent. Various other copper radiopharmaceuticals were investigated, these included copper labeled blood imaging agents as well as Cu-64 labeled antibodies. Cu-64 labeled antibodies targeting colon cancer were translated to the human situation. Cu-64 was also used to label peptides (Cu-64 octriatide) and this is one of the first applications of a peptide radiolabeled with a positron emitting metal radionuclide. Investigations were then pursued on the preparation of the copper radionuclides on a small biomedical cyclotron. A system for the production of high specific activity Cu-64 was developed and initially the Cu-64 was utilized to study the hypoxic imaging agent Cu-64 ATSM. Utilizing the same target system, other positron emitting metal radionuclides were produced, these were Y-86 and Ga-66. Radiopharmaceuticals were labeled utilizing both of these radionuclides. Many studies were carried out in animal models on the uptake of Cu-ATSM in hypoxic tissue. The hypothesis is that Cu-ATSM retention in vivo is dependent upon the

  3. Semipalatinsk test site: Parameters of radionuclide transfer to livestock and poultry products under actual radioactive contamination

    Energy Technology Data Exchange (ETDEWEB)

    Baigazinov, Z.; Lukashenko, S. [Institute of Radiation Safety and Ecology (Kazakhstan)

    2014-07-01

    The IAEA document 'Handbook of Parameter Values for the Prediction of Radionuclide Transfer in Terrestrial and Freshwater Environments' published in 2010 is one of the major sources of knowledge about the migration parameters of radionuclides in the agro-ecosystems that is necessary to assess the dose loads to the population. It is known from there that Sr and Cs transfer has been studied thoroughly, however the factors vary over a wide range. Few studies were conducted for Pu and Am transfer. It should be noted that the studies carried out in real conditions of radioactive contamination, i.e. under natural conditions is also very few. In this regard, since 2007 the territory of the former Semipalatinsk Test Site has been used for comprehensive radioecological studies, where the major radionuclides to be investigated are {sup 90}Sr, {sup 137}Cs, {sup 239+240}Pu, {sup 241}Am. The objects for these studies are birds and animals typical for the region, as well as products obtained from them (lamb, beef, horse meat, chicken, pork, cow's milk, mare's milk, eggs, chicken, chicken feathers, wool, leather). It should be noted that these products are the main agricultural goods that are available in these areas. The studies have been conducted with grazing animals in the most contaminated areas of the test site. Some groups of animals and birds were fed to contaminated feed, soil, contaminated water. Radionuclide intake by animal body with air were studied. Husbandry periods for animals and birds ranged from 1 to 150 days. The transfer parameters to cow and mare's milk have been investigated at single and prolonged intake of radionuclides, also their excretion dynamics has been studied. The studies revealed features of the radionuclide transfer into organs and tissues of animals and birds intaken with hay, water and soil. The results showed that the transfer factors vary up to one order. A relationship has been identified between distribution of

  4. Multiscale Investigation on Biofilm Distribution and Its Impact on Macroscopic Biogeochemical Reaction Rates

    Science.gov (United States)

    Yan, Zhifeng; Liu, Chongxuan; Liu, Yuanyuan; Bailey, Vanessa L.

    2017-11-01

    Biofilms are critical locations for biogeochemical reactions in the subsurface environment. The occurrence and distribution of biofilms at microscale as well as their impacts on macroscopic biogeochemical reaction rates are still poorly understood. This paper investigated the formation and distributions of biofilms in heterogeneous sediments using multiscale models and evaluated the effects of biofilm heterogeneity on local and macroscopic biogeochemical reaction rates. Sediment pore structures derived from X-ray computed tomography were used to simulate the microscale flow dynamics and biofilm distribution in the sediment column. The response of biofilm formation and distribution to the variations in hydraulic and chemical properties was first examined. One representative biofilm distribution was then utilized to evaluate its effects on macroscopic reaction rates using nitrate reduction as an example. The results revealed that microorganisms primarily grew on the surfaces of grains and aggregates near preferential flow paths where both electron donor and acceptor were readily accessible, leading to the heterogeneous distribution of biofilms in the sediments. The heterogeneous biofilm distribution decreased the macroscopic rate of biogeochemical reactions as compared with those in homogeneous cases. Operationally considering the heterogeneous biofilm distribution in macroscopic reactive transport models such as using dual porosity domain concept can significantly improve the prediction of biogeochemical reaction rates. Overall, this study provided important insights into the biofilm formation and distribution in soils and sediments as well as their impacts on the macroscopic manifestation of reaction rates.

  5. Experimental investigation of particle size distribution influence on diffusion controlled coarsening

    International Nuclear Information System (INIS)

    Fang, Zhigang; Patterson, B.R.

    1993-01-01

    The influence of initial particle size distribution on coarsening during liquid phase sintering has been experimentally investigated using W-14Ni-6Fe alloy as a model system. It was found that initially wider size distribution particles coarsened more rapidly than those of an initially narrow distribution. The well known linear relationship between the cube of the average particle radius bar r -3 , and time was observed for most of the coarsening process, although the early stage coarsening rate constant changed with time, as expected with concomitant early changes in the tungsten particle size distribution. The instantaneous transient rate constant was shown to be related to the geometric standard deviation, 1nσ, of the instantaneous size distributions, with higher rate constants corresponding to larger 1nσ values. The form of the particle size distributions changed rapidly during early coarsening and reached a quasi-stable state, different from the theoretical asymptotic distribution, after some time. A linear relationship was found between the experimentally observed instantaneous rate constant and that computed from an earlier model incorporating the effect of particle size distribution. The above results compare favorably with those from prior theoretical modeling and computer simulation studies of the effect of particle size distribution on coarsening, based on the DeHoff communicating neighbor model

  6. A pilot study on the feasibility of real-time calculation of three-dimensional dose distribution for (153)Sm-EDTMP radionuclide therapy based on the voxel S-values.

    Science.gov (United States)

    Feng, Gan; Lixin, Chen; Xiaowei, Liu; Tsao, Shiu Ying; Weiguang, Zhang; Wei, Fan

    2010-06-01

    Using (153)Sm-EDTMP therapy for bone metastases from nasopharyngeal cancer (NPC), we attempted a real-time three-dimensional (3D) dose calculation based on the S-value for voxels. The 3D radionuclide uptake data on SPECT images were factored into the precalculations by the Monte Carlo (MC) method. For the nuclide (153)Sm, the S-value for voxels of size 3.45 x 3.45 x 3.45 mm(3) in a soft tissue phantom was precalculated on a self-developed program built from the MC program EGS4. Based on the SPECT/CT image of the patient, the 3D dose rate distributions were calculated with the S-value method and compared with the direct MC calculation results. The total volume of the whole calculation region and the bone were chosen as the regions of interest (ROIs); additionally, the dose rate volume histograms (DVHs) for the ROIs were also calculated. The iso-dose was administered based on the scan images obtained at 6 hours following injection with the nuclide. In the calculation region, the maximum dose rate was 5.98 x 10(-5) and 6.26 x 10(-5) mGy/(MBq S) for S-value and direct MC calculations, respectively. Once the dose rate was normalized to the maximum dose rate point, the iso-dose curves for both methods of calculation were similar in most regions and reasonably matched the functional image as well. The DVHs of the ROIs indicated that the dose rate distributions were nonuniform, that is, approximately 30% of the bone-ROI volume received 10% of the maximum dose rate; however, only 3.8% volume received 50% of the maximum dose rate. Using (153)Sm-EDTMP therapy for bone metastases from NPC, we attempted to supplement the current dosimetry work at the image-level by a pragmatic and real-time dosimetry calculation based on S-value and functional imaging. More accurate dose calculations for patients undergoing radionuclide therapy will depend on the development of higher image resolution in nuclear medicine and warrant further studies to optimize the pharmacokinetics model.

  7. Radionuclide evaluation of tubal function

    Energy Technology Data Exchange (ETDEWEB)

    Stone, S.C.; McCalley, M.; Braunstein, P.; Egbert, R.

    1985-05-01

    The tubal capacity to transport radioactively labeled human albumin microspheres deposited in the vaginal fornix and cervical canal and to concentrate them on the ovarian surface was evaluated in a group of 34 patient-volunteers. One millicurie of /sup 99m/Tc was used to label human albumin microspheres of 20 ..mu.. in diameter, suspended in 1 ml of saline. The distribution of the radioactive material was imaged on a gamma camera at different intervals between 15 and 240 minutes. The radiation dose to the ovaries was estimated to be similar to that of a hysterosalpingogram. The results of the radionuclide evaluation were compared with the surgical findings at the time of laparoscopy or laparotomy performed for diagnostic or therapeutic reasons. The overall correlation was 87.1%. It would appear that as opposed to the traditional hysterosalpingogram, a radionuclide test may give a better understanding of the functional capacity of the tube and may also prove a useful method in the evaluation of the results of tubal microsurgical procedures.

  8. Radionuclides and agriculture

    International Nuclear Information System (INIS)

    Gasia, M.C.

    1987-01-01

    The pollution of agricultural ecosystems by radionuclides is reviewed. Examples are taken from the measurements performed in Belgium after the Chernobyl accident. Radioisotopes, however, can also play a useful role in agriculture. Their use as tracers or as ionizing radiation sources is described. (M.C.B.)

  9. Investigations of excretion rates of the radionuclides 230Th, 226Ra, 210Pb and 210Po of persons of the general population and of workers in selected regions in Germany

    International Nuclear Information System (INIS)

    Schaefer, I.; Seitz, G.; Hartmann, M.

    2006-01-01

    According to ICRP 60 and European-Directive 96/29, Naturally Occurring Radioactive Materials (NORM) and Technical Enriched Naturally Occurring Radioactive Materials (TENORM) have to take the radiation protection of the general population as well as of workers into account. The German radiation protection regulations stress that particularly. In connection with these regulations, various measurement programs have been and still are performed to investigate the relevant exposure paths. One of these programs is the determination of the intake of natural occurring radionuclides of the uranium decay series in individuals of the public, in exposed regions and houses and also at NORM workplaces by excretion analysis. Excretion analysis surveillance is one of the common tools for internal dosimetry. Sources of primordial radionuclides could be the ingestion of foodstuff and water and the incorporation of (mostly airborne) pollution on work places. The main focus in this report is set upon the excretion rate in faeces and urine. A cohort of about 100 persons was selected in five regions in Germany. One of these regions we chose to be the reference area. It is situated in the northern part of Germany with low background radiation. The other regions are in the south-west and south-east mountain areas. Workers were selected from drinking water providers, natural gas providers, balneologic facilities and exhibition mines and museum pits. In the same region also persons of public were recruited for the study. The paper presents selected data of the above mentioned nuclides in urine and faeces samples which were collected during 2002 to 2005. The results are grouped due the parameters like regions and working fields and are discussed in detail. These are 15 mBq/d in urine and 70 mBq/d in faeces and are not as different for the different nuclides as one may expect. (authors)

  10. Assessment of waste management of volatile radionuclides

    International Nuclear Information System (INIS)

    Altomare, P.M.; Barbier, M.; Lord, N.; Nainan, D.

    1979-05-01

    This document presents a review of the Technologies for Waste Management of the Volatile Radionuclides of iodine-129, krypton-85, tritium, and carbon-14. The report presents an estimate of the quantities of these volatile radionuclides as are produced in the nuclear power industry. The various technologies as may be used, or which are under investigation, to immobilize these nuclides and to contain them during storage and in disposal are discussed. Also, the alternative disposal options as may be applied to isolate these radioactive wastes from the human environment are presented. The report contains information which was available through approximately January 1978

  11. Radionuclide migration as a function of mineralogy

    International Nuclear Information System (INIS)

    Triay, I.R.; Mitchell, A.J.; Ott, M.A.

    1991-01-01

    The migration of radionuclides is studies as a function of mineralogy utilizing batch sorption and column experiments. The transport behavior of alkaline, alkaline-earth, and transition metals, and actinide species is studies in pure mineral separates. The solid phases utilized for these investigations are silicates, alumino-silicates, carbonates, and metal oxides and oxyhydroxides. The results of this effort are utilized to aid in the elucidation of the dominant chemical mechanisms of radionuclide migration, the prediction of radionuclide transport in conditions similar to those expected at the proposed high-level nuclear waste repository at Yucca Mountain, Nevada, and the identification of materials that act as natural geological barriers or that can be utilized as strong sorbers in engineered barriers. 9 refs., 2 figs., 2 tabs

  12. U.S. Department of Energy approaches to the assessment of radionuclide migration for the geologic repository program

    International Nuclear Information System (INIS)

    Luik, A.E. van; Apted, M.J.

    1988-01-01

    Potential radionuclide migration in geologic repositories is being addressed by the U.S. Department of Energy's Office of Civilian Radioactive Waste Management through its Office of Geologic Repositories (OGR). A diversity of geohydrologic settings is being investigated: unsaturated tuff, saturated basalt, and bedded salt. A number of approaches to assessing potential migration are being considered. Mass transfer is prominent among near-field approaches. For far-field analysis of migration in the geosphere, detailed characterizations of potential repository sites will lead to site-specific models describing radionuclide migration for a variety of postulated release scenarios. Finite-element and finite-difference codes are being used and developed to solve the mathematical equations pertinent to far-field assessments. Computational approaches presently in use generally require distribution coefficients to estimate the retardation of specific radionuclides with respect to the transport rate of water. 26 refs

  13. Radionuclide cardiography in medical practice

    International Nuclear Information System (INIS)

    Strangfeld, D.; Mohnike, W.; Schmidt, J.; Heine, H.; Correns, H.J.

    1986-01-01

    This publication is a compendium on all aspects of radionuclide diagnostics concerning cardiovascular system diseases. Starting with introductory remarks on the control of cardiovascular diseases the contribution of radionuclide cardiology to functional cardiovascular diagnostics as well as pathophysiological and pathobiochemical aspects of radiocardiography are outlined. Radiopharmaceuticals used in radiocardiography, physical and technical problems in application of radionuclides and their measuring techniques are discussed. In individual chapters radionuclide ventriculography, myocardial scintiscanning, circulatory diagnostics, radionuclide diagnostics of arterial hypertension, of thrombosis and in vitro diagnostics of thrombophilia are treated in the framework of clinical medicine

  14. The distribution of soluble radionuclide-relevant trace elements between salt minerals and saline solutions; Die Verteilung loeslicher Radionuklid-relevanter Spurenelemente zwischen Salzmineralen und salinaren Loesungen

    Energy Technology Data Exchange (ETDEWEB)

    Voss, Ina

    2015-07-16

    The research platform ENTRIA (Disposal options for radioactive residues Interdisciplinary analyses and development of evaluation principles) includes the sub-project ''Final disposal in deep geological formations without any arrangements for retrieval''. This approach considers rock salt (beside clay and granite) as host rock formation for disposal of heat-producing long-live waste. Most rock salt formations contain Mg-rich brines derived from highly evolved sea water evaporation processes now included in the rock salt mass. If such brines get access to metal-canister corrosion will allow release of soluble nuclides to the brine. In this scenario, it cannot be excluded that contaminated brines leave the deep seated disposal area and move along geological or technical migration pathways towards the rock salt/cap rock contact. The temperature of the brine will drop from near 80 C to 25 or 30 C. The deceasing temperature of the brine causes precipitation of magnesian chloride and sulfate phase in equilibrium with the brine. In order to understand the salt precipitation and the retention mechanism of dissolved trace elements experiments have been set up which allow formation of sylvite, carnallite, kainite, and hydrous Mg-sulphates under controlled conditions. The retention capacity of crystallizing salt minerals based occurring in magnesian brine solutions at decreasing temperature within a salt dome is best measured as the distribution coefficient D. This concept assumes incorporation of trace elements into the lattice of salt minerals. The distribution coefficients of the trace elements, Rb, Cs, Co, Ni, Zn, Li and B between sylvite, carnallite, kainite, and MgSO{sub 4} phases have been determined at experimental temperatures of 25, 35, 55 and 83 C. The results clearly indicate the following range of distribution coefficients (D): Sylvite D > 1 Rb and Br, D < 1 Co, Ni, Zn, Li and B, Carnallite D > 1 Rb and Cs, D < 1 Co, Ni, Zn, Li and B, Kainite D

  15. A Limiting Factor for the Progress of Radionuclide-based Cancer Diagnostics and Therapy - Availability of Suitable Radionuclides

    International Nuclear Information System (INIS)

    Tolmachev, Vladimir; Carlsson, Joergen; Lundqvist, Hans

    2004-01-01

    Advances in diagnostics and targeted radionuclide therapy of haematological and neuroendocrine tumours have raised hope for improved radionuclide therapy of other forms of disseminated tumours. New molecular target structures are characterized and this stimulates the efforts to develop new radiolabelled targeting agents. There is also improved understanding of factors of importance for choice of appropriate radionuclides. The choice is determined by physical, chemical, biological, and economic factors, such as a character of emitted radiation, physical half-life, labelling chemistry, chemical stability of the label, intracellular retention time, and fate of radiocatabolites and availability of the radionuclide. There is actually limited availability of suitable radionuclides and this is a limiting factor for further progress in the field and this is the focus in this article. The probably most promising therapeutic radionuclide, 211 At, requires regional production and distribution centres with dedicated cyclotrons. Such centres are, with a few exceptions in the world, lacking today. They can be designed to also produce beta- and Augeremitters of therapeutic interest. Furthermore, emerging satellite PET scanners will in the near future demand long-lived positron emitters for diagnostics with macromolecular radiopharmaceuticals, and these can also be produced at such centres. To secure continued development and to meet the foreseen requirements for radionuclide availability from the medical community it is necessary to establish specialized cyclotron centres for radionuclide production

  16. Mobility of radionuclides in soil

    International Nuclear Information System (INIS)

    Gee, G.W.; Rai, D.; Serne, R.J.

    1983-01-01

    Recent public interest in nuclear power production and waste disposal has led to increased awareness and concern about the biological hazards of radionuclide cycling in soil. Various radionuclides found in soils are shown and can be seen to originate from numerous sources including: radioisotopes formed during earth genesis, cosmic irradiation, fallout from atmospheric testing, uranium mill tailings, phosphate mill wastes, nuclear and coal fired power plants, defense activities, medical, industrial and research use. The objectives of this review are to summarize the factors that affect radionuclide mobility in soil, including adsorption-desorption, precipitation-dissolution reactions for liquid phase radionuclides as well as the transport of gaseous radionuclides in soils. Areas where more information is needed are also discussed. The mobility of selected radionuclides including isotopes of Sr, Cs, Co, Tc, I, Se, Pu, Am, Np, and Rn are discussed in additional detail. Two brief examples of waste management systems to control radionuclide mobility are presented

  17. Radiation dosimetry for radionuclide therapy

    International Nuclear Information System (INIS)

    Kim, Eun Hee

    2001-01-01

    The radionuclide therapy is a protocol for tumor control by administering radionuclides as the cytotoxic agents. Radionuclides concentrated at the site of cancerous lesion are expected to kill the cancerous cells with minimal injury to the normal tissue. The efficacy of every radionuclide treatment can be evaluated by examining the toxicity to the lesion differentiated from that to the normal tissue. Radiation dosimerty is the procedure of quantitating the energy absorbed by target volumes of interest. Dosimetric information plays an indicator of the expected radiation damage and thus the therapeutic efficacy. This paper summarizes the dosimetric aspects in radionuclide therapy in terms of radionuclides of use, radionuclides of use, radiation dosimetry methodology and considerations for each treatment in practical use

  18. Experimental investigation of residual stress distribution during turning of weak stiffness revolving parts

    Science.gov (United States)

    Jiao, Sicheng; Zhang, Chengyan; Liu, Guancheng; Lu, Jiping; Tang, Shuiyuan

    2017-08-01

    A series of turning experiments have been carried out to study the effect of different cutting speed, feed rate and pre-tightening torque on residual stress distribution during turning of weak stiffness revolving parts. Surface residual stress and the peak residual compressive stress are selected from the typical residual stress distribution profile. The residual stress by turning was measured by X-ray diffraction method. In order to get the distribution of residual stress along depth direction, the specimens need to be etched layer by layer. From this investigation, it can be concluded that it is practicable to control the distribution of residual stress by changing the pre-tightening torque and cutting parameters during turning of weak stiffness revolving parts.

  19. Radionuclides in food

    International Nuclear Information System (INIS)

    Fernandez Gomez, Isis Maria

    2008-01-01

    The sources of the presence of radionuclides in food are presented: natural radiation and artificial radiation. The transfer of radionuclides through food chains, intakes of radionuclides to the body with its partners effective doses and typical consumption of basic foods of a rural adult population are exposed as main topics. Also the radiation doses from natural sources and exposure to man by ingestion of contaminated food with radionuclides of artificial origin are shown. The contribution of the food ingestion to the man exposure depends on: characteristics of radionuclide, natural conditions, farming practices and eating habits of the population. The principal international organizations in charge of setting guide levels for radionuclides in food are mentioned: standards, rules and the monitoring. It establishes that a guide is necessary for the food monitoring; the alone CODEX ALIMENTARIUS is applicable to emergency situations and the generic action levels proposed by the CODEX not satisfy all needs (no guiding international levels for planned or existing situations such as NORM). There are handled mainly socio-economic and political aspects. Among the actions to be taken are: to assure a public comprehensive information over the risk evaluation in food; to reinforce the collaboration among the different international organizations (WHO, IAEA, ICRP, EC) in relation with the food of set; to give follow-up to the control of the drinkable water and NORM's presence in the food. In addition, it is possible to create the necessary mechanisms to reduce the number of irrelevant measures and bureaucratic useless steps (certificates); to promote the exchange between the different institutions involved in the topic of the food, with relation to the acquired experiences and learned lessons. Likewise, it might examine the possibility of a multidisciplinary approximation (radioactive and not radioactive pollutants); to elaborate a technical guide to assure the

  20. EBS Radionuclide Transport Abstraction

    International Nuclear Information System (INIS)

    J. Prouty

    2006-01-01

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment (TSPA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers advective transport and diffusive transport

  1. EBS Radionuclide Transport Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    J. Prouty

    2006-07-14

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment (TSPA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers advective transport and diffusive transport

  2. Radionuclides in pharmaceutical researches

    International Nuclear Information System (INIS)

    Khujaev, S.

    2005-01-01

    Full text: The development of modern stage of nuclear medicine is characterized by the increasing role of methods using radionuclides. Radioactive nuclides used in nuclear medicine may be divided into 2 groups. Radionuclides used for diagnostic researches and radionuclides used for therapeutic purposes. These two directions are considered to be the main ones in usage of radionuclides in medicine. However there is one more direction in the research of new medical products where it is possible to use radionuclides to study their pharmacological kinetics. In these researches radionuclide is applied as a radioactive label at the stage of studying pharmacological kinetics of a new medical product. In Institute of Nuclear Physics AS RUz the works are being carried out in the recent years focused on studying pharmacology of some new medical preparations, which are synthesized in Tashkent Pharmaceutical Institute. Syntheses these preparations are based on use microelements. Its compounds are possessed expressed biological activity and be of great importance in the pharmaceutical science of Uzbekistan. Introducing a radioisotope at the stage of synthesis carried out reception of labeled connections of all preparations. The output of the final product reached the yield of no less than 80 % in all cases of synthesis. This work presents the results of research on synthesis and study of pharmacology of radioactively labeled preparations - Piracin, labeled by radioisotope 69m Zn; Pheramed, labeled by radioisotope 59 Fe; Cobavit, labeled by radioisotope 57 Co; VUC, labeled by radioisotope 57 Co, CO-101, labeled by radioisotope 57 Co. Received radioisotope - labeled compounds of medical preparations were used in the study of their pharmacological kinetics on experimental rats. In all cases, preliminary irradiation of corresponding nuclear targets in the nuclear reactor and cyclotron, radiochemical procedures on separation, purification and concentration oi radioactive isotopes

  3. EBS Radionuclide Transport Abstraction

    International Nuclear Information System (INIS)

    Schreiner, R.

    2001-01-01

    The purpose of this work is to develop the Engineered Barrier System (EBS) radionuclide transport abstraction model, as directed by a written development plan (CRWMS M and O 1999a). This abstraction is the conceptual model that will be used to determine the rate of release of radionuclides from the EBS to the unsaturated zone (UZ) in the total system performance assessment-license application (TSPA-LA). In particular, this model will be used to quantify the time-dependent radionuclide releases from a failed waste package (WP) and their subsequent transport through the EBS to the emplacement drift wall/UZ interface. The development of this conceptual model will allow Performance Assessment Operations (PAO) and its Engineered Barrier Performance Department to provide a more detailed and complete EBS flow and transport abstraction. The results from this conceptual model will allow PA0 to address portions of the key technical issues (KTIs) presented in three NRC Issue Resolution Status Reports (IRSRs): (1) the Evolution of the Near-Field Environment (ENFE), Revision 2 (NRC 1999a), (2) the Container Life and Source Term (CLST), Revision 2 (NRC 1999b), and (3) the Thermal Effects on Flow (TEF), Revision 1 (NRC 1998). The conceptual model for flow and transport in the EBS will be referred to as the ''EBS RT Abstraction'' in this analysis/modeling report (AMR). The scope of this abstraction and report is limited to flow and transport processes. More specifically, this AMR does not discuss elements of the TSPA-SR and TSPA-LA that relate to the EBS but are discussed in other AMRs. These elements include corrosion processes, radionuclide solubility limits, waste form dissolution rates and concentrations of colloidal particles that are generally represented as boundary conditions or input parameters for the EBS RT Abstraction. In effect, this AMR provides the algorithms for transporting radionuclides using the flow geometry and radionuclide concentrations determined by other

  4. Investigations on 3-dimensional temperature distribution in a FLATCON-type CPV module

    Science.gov (United States)

    Wiesenfarth, Maike; Gamisch, Sebastian; Kraus, Harald; Bett, Andreas W.

    2013-09-01

    The thermal flow in a FLATCON®-type CPV module is investigated theoretically and experimentally. For the simulation a model in the computational fluid dynamics (CFD) software SolidWorks Flow Simulation was established. In order to verify the simulation results the calculated and measured temperatures were compared assuming the same operating conditions (wind speed and direction, direct normal irradiance (DNI) and ambient temperature). Therefore, an experimental module was manufactured and equipped with temperature sensors at defined positions. In addition, the temperature distribution on the back plate of the module was displayed by infrared images. The simulated absolute temperature and the distribution compare well with an average deviation of only 3.3 K to the sensor measurements. Finally, the validated model was used to investigate the influence of the back plate material on the temperature distribution by replacing the glass material by aluminum. The simulation showed that it is important to consider heat dissipation by radiation when designing a CPV module.

  5. LABORATORY AND NUMERICAL INVESTIGATIONS OF RESIDENCE TIME DISTRIBUTION OF FLUIDS IN LAMINAR FLOW STIRRED ANNULAR PHOTOREACTOR

    Science.gov (United States)

    Laboratory and Numerical Investigations of Residence Time Distribution of Fluids in Laminar Flow Stirred Annular PhotoreactorE. Sahle-Demessie1, Siefu Bekele2, U. R. Pillai11U.S. EPA, National Risk Management Research LaboratorySustainable Technology Division,...

  6. An investigation of the Spatial Distribution of Soil Erosion in the ...

    African Journals Online (AJOL)

    Soil erosion is widespread in Swaziland and is very severe on small holder farms and communal grazing areas. The Middleveld of Swaziland is the most ... The paper investigates the spatical distribution of soil eriosion in the Mbuluzi river basin through a visual interpretation of satellite imagery. The results indicate that soil ...

  7. An investigation of the Spatial Distribution of Soil Erosion in the ...

    African Journals Online (AJOL)

    The erosion upstream of drainage basins affects economic activities downstream especially irrigated agriculture because it contributes sediment yield hence reducing the lifespan of dams and reservoirs. Water and soil pollution is also involved. The paper investigates the spatical distribution of soil eriosion in the Mbuluzi ...

  8. An overview of BORIS: Bioavailability of Radionuclides in Soils

    International Nuclear Information System (INIS)

    Tamponnet, C.; Martin-Garin, A.; Gonze, M.-A.; Parekh, N.; Vallejo, R.; Sauras-Yera, T.; Casadesus, J.; Plassard, C.; Staunton, S.; Norden, M.; Avila, R.; Shaw, G.

    2008-01-01

    The ability to predict the consequences of an accidental release of radionuclides relies mainly on the level of understanding of the mechanisms involved in radionuclide interactions with different components of agricultural and natural ecosystems and their formalisation into predictive models. Numerous studies and databases on contaminated agricultural and natural areas have been obtained, but their use to enhance our prediction ability has been largely limited by their unresolved variability. Such variability seems to stem from incomplete knowledge about radionuclide interactions with the soil matrix, soil moisture, and biological elements in the soil and additional pollutants, which may be found in such soils. In the 5th European Framework Programme entitled Bioavailability of Radionuclides in Soils (BORIS), we investigated the role of the abiotic (soil components and soil structure) and biological elements (organic compounds, plants, mycorrhiza, and microbes) in radionuclide sorption/desorption in soils and radionuclide uptake/release by plants. Because of the importance of their radioisotopes, the bioavailability of three elements, caesium, strontium, and technetium has been followed. The role of one additional non-radioactive pollutant (copper) has been scrutinised in some cases. Role of microorganisms (e.g., K d for caesium and strontium in organic soils is much greater in the presence of microorganisms than in their absence), plant physiology (e.g., changes in plant physiology affect radionuclide uptake by plants), and the presence of mycorrhizal fungi (e.g., interferes with the uptake of radionuclides by plants) have been demonstrated. Knowledge acquired from these experiments has been incorporated into two mechanistic models CHEMFAST and BIORUR, specifically modelling radionuclide sorption/desorption from soil matrices and radionuclide uptake by/release from plants. These mechanistic models have been incorporated into an assessment model to enhance its

  9. Artificial radionuclides in the Northern European Marine Environment. Distribution of radiocaesium, plutonium and americium in sea water and sediments in 1995

    International Nuclear Information System (INIS)

    Groettheim, Siri

    2000-01-01

    This study considers the distribution of radiocaesium, plutonium and americium in the northern marine environment. The highest radiocaesium activity in sea water was observed in Skagerrak, 26 Bq/m 3 , and in surface sediments in the Norwegian Sea, 60 Bq/kg. These enhanced levels were related to Chernobyl. The highest 239,240Pu activity in surface water was measured in the western North Sea, 66 mBq/m 3 . In sea water, sub-surface maxima were observed at several locations with an 239,240Pu activity up to 160 mBq/m 3 , and were related to Sellafield. With the exception to the North Sea, surface sediments reflected Pu from global fallout from weapons tests only. (author)

  10. METHODS OF THE GEOMORPHOMETRY, REMOTE SENSING AND GIS IN STUDY OF THE 40K RADIONUCLIDE DISTRIBUTION IN SOIL OF ARABLE SLOPES, COMPLICATED WITH EROSION NETWORK

    Directory of Open Access Journals (Sweden)

    L. N. Trofimetz

    2016-01-01

    Full Text Available The 40K radioisotope is involved into the erosion processes on the arable slopes. Application of the very high resolution satellite images, GISs, geomorphometry methods and traditional agrochemical research techniques helped to identify the location of areas on the concave parts of the slopes, where 40K radioactivity in the soil is increased; and location of areas on the convex parts, where 40K radioactivity is low. High content of humus or high content of clay fractions in the soil can cause increase of the radioisotope content. The application prospects are shown for all abovementioned methods in study of the 40K isotope lateral distribution in the soils of agrocenoses.

  11. Artificial radionuclides in the Northern European Marine Environment. Distribution of radiocaesium, plutonium and americium in sea water and sediments in 1995

    Energy Technology Data Exchange (ETDEWEB)

    Groettheim, Siri

    2000-07-01

    This study considers the distribution of radiocaesium, plutonium and americium in the northern marine environment. The highest radiocaesium activity in sea water was observed in Skagerrak, 26 Bq/m{sub 3}, and in surface sediments in the Norwegian Sea, 60 Bq/kg. These enhanced levels were related to Chernobyl. The highest 239,240Pu activity in surface water was measured in the western North Sea, 66 mBq/m{sub 3}. In sea water, sub-surface maxima were observed at several locations with an 239,240Pu activity up to 160 mBq/m{sub 3}, and were related to Sellafield. With the exception to the North Sea, surface sediments reflected Pu from global fallout from weapons tests only. (author)

  12. Distributed decision making in action: diagnostic imaging investigations within the bigger picture.

    Science.gov (United States)

    Makanjee, Chandra R; Bergh, Anne-Marie; Hoffmann, Willem A

    2018-03-01

    Decision making in the health care system - specifically with regard to diagnostic imaging investigations - occurs at multiple levels. Professional role players from various backgrounds are involved in making these decisions, from the point of referral to the outcomes of the imaging investigation. The aim of this study was to map the decision-making processes and pathways involved when patients are referred for diagnostic imaging investigations and to explore distributed decision-making events at the points of contact with patients within a health care system. A two-phased qualitative study was conducted in an academic public health complex with the district hospital as entry point. The first phase included case studies of 24 conveniently selected patients, and the second phase involved 12 focus group interviews with health care providers. Data analysis was based on Rapley's interpretation of decision making as being distributed across time, situations and actions, and including different role players and technologies. Clinical decisions incorporating imaging investigations are distributed across the three vital points of contact or decision-making events, namely the initial patient consultation, the diagnostic imaging investigation and the post-investigation consultation. Each of these decision-making events is made up of a sequence of discrete decision-making moments based on the transfer of retrospective, current and prospective information and its transformation into knowledge. This paper contributes to the understanding of the microstructural processes (the 'when' and 'where') involved in the distribution of decisions related to imaging investigations. It also highlights the interdependency in decision-making events of medical and non-medical providers within a single medical encounter. © 2017 The Authors. Journal of Medical Radiation Sciences published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Medical Imaging and Radiation

  13. Fukushima Daiichi Radionuclide Inventories

    Energy Technology Data Exchange (ETDEWEB)

    Cardoni, Jeffrey N. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jankovsky, Zachary Kyle [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-09-01

    Radionuclide inventories are generated to permit detailed analyses of the Fukushima Daiichi meltdowns. This is necessary information for severe accident calculations, dose calculations, and source term and consequence analyses. Inventories are calculated using SCALE6 and compared to values predicted by international researchers supporting the OECD/NEA's Benchmark Study on the Accident at Fukushima Daiichi Nuclear Power Station (BSAF). Both sets of inventory information are acceptable for best-estimate analyses of the Fukushima reactors. Consistent nuclear information for severe accident codes, including radionuclide class masses and core decay powers, are also derived from the SCALE6 analyses. Key nuclide activity ratios are calculated as functions of burnup and nuclear data in order to explore the utility for nuclear forensics and support future decommissioning efforts.

  14. Bioavailability of anthropogenic radionuclides in mussels along the french mediterranean coast

    International Nuclear Information System (INIS)

    Thebault, H.; Arnaud, M.; Charmasson, S.; Andral, B.; Dimeglio, Y.; Barker, E.

    2004-01-01

    Within the framework of the Water Management Master-plan, a bio-indicator network (RINBIO) was deployed all along the French Mediterranean coast (1,800 km), using man-made cages containing mussels (Mytilus galloprovincialis) to assess contamination by heavy metals, persistent organic products and radionuclides. The caging technique compensated for the scarcity of natural shellfish stocks in significant parts of the coast and enable comparison between sites regardless of their physicochemical and trophic characteristics. Among the 103 stations of the entire program, 40 were selected for the measurement of anthropogenic radionuclides by high-efficiency gamma-spectrometry. Biometrics parameters of the each mussel samples, including 'condition index' as an indicator of soft part growth, will be correlated with radionuclides activities, allowing to correct raw data from differences in bioaccumulation between the various sites in relation to their trophic levels. A comprehensive picture of the distribution of radionuclides at a such a large spatial scale will be provided and the contribution of the Rhone river input, so far the main source for the coastal zone, will be investigated. (author)

  15. Study on the distribution and chemism of medium- and long-lived radionuclides in relation to corresponding microelements in the marine environment, algae and sediment on the Romanian cost. Part of a coordinated programme on marine radioactivity studies

    International Nuclear Information System (INIS)

    Georgescu, I.

    1976-09-01

    Comprehensive baseline data on various radionuclides as well as trace elements are presented for sea water, sediments and marine organisms collected from the Romanian coast of the Black Sea. Similar data are also presented for the samples collected along the Danube River. While no artificial radionuclide was found in the Black Sea water collected at 200m depth, where the anerobic condition prevails, the bottom sediment at the same station contained 137 Cs and other radionuclides. These results suggest that some precipitation process, most probably related to the occurrence of H 2 S, is taking place at this depth. The occurrence of divalent as well as trivalent iron in the bottom sediments proves possible reduction of various metals in this layer. In the Danube water some activation products such as 54 Mn, 60 Co, 65 Zn etc. were found in addition to the fission products radionuclides found normally in fallout. This finding may be related to the radioactive effluent release into the river

  16. Radionuclides in the oceans inputs and inventories

    International Nuclear Information System (INIS)

    Guegueniat, P.; Germain, P.; Metivier, H.

    1996-01-01

    Ten years after Chernobyl, following the decision by France to end nuclear weapon testing in the Pacific ocean, after the end of the OECD-NEA Coordinated Research and Environmental Surveillance programme related to low-level waste dumping in the deep ocean, and one hundred years after the discovery of radioactivity, the IPSN wanted to compile and review the available information on artificial radioactivity levels in seas and oceans. International experts have been invited to present data on inputs and inventories of radionuclides in the marine environment, and to describe the evolution of radioactivity levels in water, sediments and living organisms. Different sources of radionuclides present in the aquatic environment are described: atmospheric fallout before and after Chernobyl, industrial wastes, dumped wastes and ships, nuclear ship accidents, river inputs, earth-sea atmospheric transfers and experimental sites for nuclear testing. Radioactivity levels due to these sources are dealt with at ocean (Atlantic, Pacific and Indian) and sea level (Channel, North Sea, Irish Sea, Mediterranean, Baltic, Black Sea and Arctic seas). These data collected in the present book give an up-to-date assessment of radionuclide distributions which will be very useful to address scientific and wider public concerns about radionuclides found in the aquatic environment. It gives many references useful to those who want to deepen their understanding of particular aspects of marine radioecology. (authors)

  17. Proficiency testing for radionuclides

    International Nuclear Information System (INIS)

    Faanhof, A.; Kotze, O.; Louw, I.

    2010-01-01

    Proficiency testing in general is only useful when it suites a certain purpose. With regards to radionuclides basically three fields of interest can be identified: (I)Foodstuffs-Introduced in the early 1960's to monitor the fall-out of nuclear tests and eventually the pathway to foodstuffs fit for human consumption. The demand for analysis increased substantially after the Chernobyl accident. (II) Natural radioactivity-Associated with mining and mineral processing of uranium and thorium baring mineral resources throughout the world where the radionuclides from the natural uranium and thorium decay series are found to pose concern for professional and public exposure. (III) Artificial radioactivity-This category covers mostly the long-lived nuclides generated by nuclear fission of the fuel used in nuclear power plants, research reactors and nuclear bomb tests. All three categories require a specific approach for laboratories to test their ability to analyze specific radio nuclides of interest in a variety of matrices. In this lecture I will give a compiled overview of the required radioanalytical skills, analysis sensitivity needed and radionuclides of interest, with more specific emphasis on QAQC of water sources and the recommended monitoring approach. And provide information on available reference materials and organizations/institutes that provide regular exercises for participating laboratories. I will also briefly communicate on the advantages and disadvantages of ISO/IEC 17025 accreditation for test laboratories, which is these days a prerequisite in national and international trade especially where foodstuffs and mineral products are concerned.

  18. Radionuclide therapy beyond radioiodine.

    Science.gov (United States)

    Gabriel, Michael

    2012-10-01

    For decades, Iodine-131 has been used for the treatment of patients with thyroid cancer. In recent years, increasingly, other radiopharmaceuticals are in clinical use in the treatment of various malignant diseases. Although in principle these therapies-as in all applications of radionuclides-special radiation protection measures are required, a separate nuclear medicine therapy department is not necessary in many cases due to the lower or lack of gamma radiation. In the following article, four different radionuclide therapies are more closely presented which are emerging in the last years. One of them is the "Peptide Receptor Radionuclide Therapy," the so-called PRRT in which radiolabeled somatostatin (SST)-receptor(R) ligands are used in patients with neuroendocrine tumors. On the basis of radiolabeled antibodies against CD20-positive cells, the so-called radioimmunotherapy is used in the treatment of certain forms of malignant lymphoma. In primary or secondary liver tumors, the (90)Y-labeled particles can be administered. Last but not the least, the palliative approach of bone-seeking radiopharmaceuticals is noted in patients with painful bone metastases.

  19. Radionuclide therapy of diseases

    International Nuclear Information System (INIS)

    Endo, Keigo

    1998-01-01

    Radionuclide therapy has a long history of more than 50 years. Radioiodine (I-131) is specifically taken up by the thyroid and has been still used for the therapy of Graves' disease and thyroid cancer. In the western country, I-131 is the first choice of the therapy of Graves' disease and it is well known that Mr. Geroge Bush, the former president of the United States, was suffered from Graves' disease and treated with I-131. I-131 therapy is cheap, safe, effective, but little adverse effects. On the contrary, in Japan I-131 therapy is less frequently used than the anti-thyroid drugs due to the national sentiments of allergy to radionuclides, and the strict regulation by the government. Bone pain is commonly seen in patients with bone metastasis, which occurs in prostate, breast and lung cancers. Strontium-89 is an effective treatment of bone pain palliation and widely used in the western countries. In Japan clinical use of strontium-89 is planned to be approved by this coming summer on the out-patients basis. Still we have many problems for the radionuclide therapy of diseases, although it is very useful method of treatment. (author)

  20. Radionuclides in terrestrial ecosystems

    International Nuclear Information System (INIS)

    Howard, B.J.; Kennedy, V.H.; Nelson, A.

    1983-06-01

    A bibliographical database has been developed to provide quick access to research and background literature in the field of radioecology. This is a development of an earlier database described by Nelson (Bocock 1981). ITE's particular fields of interest have led to a subject bias in the bibliography towards studies in Cumbria, especially those concerned with radionuclides originating from the reprocessing plant at Sellafield, and towards ecological research studies that are complementary to radionuclide studies. Other subjects covered, include the chemistry of radionuclides, budgets and transfers within ecosystems and techniques for the analysis of environmental samples. ITE's research objectives have led to the establishment of a specialized database which is intended to complement rather than compete with the large international databases made available by suppliers such as IRS-DIALTECH or DIALOG. Currently the database holds about 1900 references which are stored on a 2 1/2 megabyte hard disk on a Digital PDP11/34 computer operating under a time shared system. The references follow a standard format. (author)

  1. Investigating the Impact of Item Parameter Drift for Item Response Theory Models with Mixture Distributions

    Directory of Open Access Journals (Sweden)

    Yoon Soo ePark

    2016-02-01

    Full Text Available This study investigates the impact of item parameter drift (IPD on parameter and ability estimation when the underlying measurement model fits a mixture distribution, thereby violating the item invariance property of unidimensional item response theory (IRT models. An empirical study was conducted to demonstrate the occurrence of both IPD and an underlying mixture distribution using real-world data. Twenty-one trended anchor items from the 1999, 2003, and 2007 administrations of Trends in International Mathematics and Science Study (TIMSS were analyzed using unidimensional and mixture IRT models. TIMSS treats trended anchor items as invariant over testing administrations and uses pre-calibrated item parameters based on unidimensional IRT. However, empirical results showed evidence of two latent subgroups with IPD. Results showed changes in the distribution of examinee ability between latent classes over the three administrations. A simulation study was conducted to examine the impact of IPD on the estimation of ability and item parameters, when data have underlying mixture distributions. Simulations used data generated from a mixture IRT model and estimated using unidimensional IRT. Results showed that data reflecting IPD using mixture IRT model led to IPD in the unidimensional IRT model. Changes in the distribution of examinee ability also affected item parameters. Moreover, drift with respect to item discrimination and distribution of examinee ability affected estimates of examinee ability. These findings demonstrate the need to caution and evaluate IPD using a mixture IRT framework to understand its effect on item parameters and examinee ability.

  2. Investigating the Impact of Item Parameter Drift for Item Response Theory Models with Mixture Distributions.

    Science.gov (United States)

    Park, Yoon Soo; Lee, Young-Sun; Xing, Kuan

    2016-01-01

    This study investigates the impact of item parameter drift (IPD) on parameter and ability estimation when the underlying measurement model fits a mixture distribution, thereby violating the item invariance property of unidimensional item response theory (IRT) models. An empirical study was conducted to demonstrate the occurrence of both IPD and an underlying mixture distribution using real-world data. Twenty-one trended anchor items from the 1999, 2003, and 2007 administrations of Trends in International Mathematics and Science Study (TIMSS) were analyzed using unidimensional and mixture IRT models. TIMSS treats trended anchor items as invariant over testing administrations and uses pre-calibrated item parameters based on unidimensional IRT. However, empirical results showed evidence of two latent subgroups with IPD. Results also showed changes in the distribution of examinee ability between latent classes over the three administrations. A simulation study was conducted to examine the impact of IPD on the estimation of ability and item parameters, when data have underlying mixture distributions. Simulations used data generated from a mixture IRT model and estimated using unidimensional IRT. Results showed that data reflecting IPD using mixture IRT model led to IPD in the unidimensional IRT model. Changes in the distribution of examinee ability also affected item parameters. Moreover, drift with respect to item discrimination and distribution of examinee ability affected estimates of examinee ability. These findings demonstrate the need to caution and evaluate IPD using a mixture IRT framework to understand its effects on item parameters and examinee ability.

  3. Investigation of distribution of elements in a Korean ginseng by using a neutron activation method

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yu Na; Sun, Gwang Min; Chung, Yong Sam; Kim, Young Jin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-10-15

    The Distinction of production areas of Korean ginsengs has been tried by using neutron activation techniques such as an instrumental neutron activation analysis (INAA) and a prompt gamma activation analysis (PGAA). This study was done as a part of those efforts. As is well known, the distribution of elements varies according to the part of plant due to the difference of enrichment effect and influence from a soil where the plants have been grown. So a correlation study between plants and soil is an important issue. In this study, the distribution of trace elements within a Korean ginseng was investigated by using an instrumental neutron activation analysis.

  4. Safety-related investigations on power distribution in MOX fuel elements in LWR cores

    International Nuclear Information System (INIS)

    Kramer, E.; Langenbuch, S.

    1991-01-01

    For the concept of thermal recycling various fuel assembly designs have been developped during the last years. An overview is given describing the present status of MOX-fuel assembly design for PWR and BWR. The local power distribution within the MOX-fuel assembly and influences between neighbouring MOX- and Uranium fuel assemblies have been analyzed by own calculations. These investigations are limited to specific aspects of the spatial power distribution, which are related to the use of MOX-fuel assemblies within the reactor core of LWR. (orig.) [de

  5. SU-E-T-514: Investigating the Dose Distributions of Equiangular Spaced Noncoplanar Beams

    International Nuclear Information System (INIS)

    Mitchell, T; Maxim, P; Hadsell, M; Loo, B

    2015-01-01

    Purpose It has been demonstrated that the use of noncoplanar beams in radiation therapy may Result in dose distributions that are comparable or better than standard coplanar beams [Pugachev, 2001]. A radiation therapy system designed with a noncoplanar beam geometry could allow for a full ring diagnostic quality imaging system to be placed around the patient. Additionally, if the noncoplanar beams were fixed in number and in their angle with respect to the patient’s axial plane, then both treatment and imaging could be achieved concurrently without the need for moving parts, which could greatly reduce treatment times. For such a system to be designed, it is necessary to determine the appropriate number of beams and the beam angles to achieve optimal dose distributions. For simplicity, the beam angles are assumed to be equiangular in the patient’s axial plane, and only the beam angle with respect to the axial plane are varied. This study aims to investigate the dose distributions produced by equiangular noncoplanar beams for multiple beam numbers and beam angles, and to compare these dose distributions with distributions achieved in coplanar volumetric arc therapy (VMAT). Methods Dose distributions produced by noncoplanar beams were calculated using the Varian Eclipse treatment planning system by varying the gantry, collimator, and couch angles to simulate the noncoplanar delivery method. Noncoplanar intensity-modulated (NC-IMRT) beams using 8, 12, and 16 beams with angles varying from 45 degrees to 54 with respect to the patient’s axial plane were studied. Results The NC-IMRT beams produced dose distributions comparable to VMAT plans for a number of treatment sites, and were capable of meeting similar dose-volume histogram constraints. Conclusion This study has demonstrated that a noncoplanar beam delivery method with fixed beam numbers and beam angles is capable of delivering dose distributions comparable to VMAT plans currently in use

  6. Radionuclide migration in the Chernobyl contamination zone

    International Nuclear Information System (INIS)

    Golosov, V.N.; Panin, A.V.; Ivanova, N.N.

    1998-01-01

    It is well known that fallout of 137 Cs reaching the land soils with precipitation was rapidly and tightly sorbed to the fine fraction of sediment or soils. The majority of the 137 Cs is retained in the top few centimetres of the soil or sediment profiles (Loughran et al, 1993, Owens et al, 1996). In the absence of strong variations in precipitation over a relatively small area the total bomb-derived 137 Cs fallout can assumed to be spatial uniform. The Chernobyl 137 Cs fallout was mostly connected with one or two rains. So the spatial variability of this 137 Cs can be higher. Furthermore because the explosion on the Chernobyl nuclear plant happen together with fire, a lot of ashes particles with radionuclide were distributed within vast areas. So even microvariability of Chernobyl 137 Cs can be very high in some places. The horizontal migration of 137 Cs connects with soil erosion processes that dominate on the agricultural lands of the Central Russia. The main goal of this investigation is to evaluate the caesium-137 horizontal and vertical migration within typical landscape of the Central Russia 11 years after the Chernobyl accident

  7. Cellular water distribution, transport, and its investigation methods for plant-based food material.

    Science.gov (United States)

    Khan, Md Imran H; Karim, M A

    2017-09-01

    Heterogeneous and hygroscopic characteristics of plant-based food material make it complex in structure, and therefore water distribution in its different cellular environments is very complex. There are three different cellular environments, namely the intercellular environment, the intracellular environment, and the cell wall environment inside the food structure. According to the bonding strength, intracellular water is defined as loosely bound water, cell wall water is categorized as strongly bound water, and intercellular water is known as free water (FW). During food drying, optimization of the heat and mass transfer process is crucial for the energy efficiency of the process and the quality of the product. For optimizing heat and mass transfer during food processing, understanding these three types of waters (strongly bound, loosely bound, and free water) in plant-based food material is essential. However, there are few studies that investigate cellular level water distribution and transport. As there is no direct method for determining the cellular level water distributions, various indirect methods have been applied to investigate the cellular level water distribution, and there is, as yet, no consensus on the appropriate method for measuring cellular level water in plant-based food material. Therefore, the main aim of this paper is to present a comprehensive review on the available methods to investigate the cellular level water, the characteristics of water at different cellular levels and its transport mechanism during drying. The effect of bound water transport on quality of food product is also discussed. This review article presents a comparative study of different methods that can be applied to investigate cellular water such as nuclear magnetic resonance (NMR), bioelectric impedance analysis (BIA), differential scanning calorimetry (DSC), and dilatometry. The article closes with a discussion of current challenges to investigating cellular water

  8. Investigation of the State of Radionuclides in Ultramicroconcentrations by the Method of a Horizontal Zone Electrophoresis in a Free Electrolyte. Ions of In(III) in Aqueous Solutions

    CERN Document Server

    Bontchev, G D; Priemyshev, A N; Bozhikov, G A; Filossofov, D V; Ivanov, P I; Maslov, O D; Milanov, M V; Dmitriev, S N

    2000-01-01

    Using the electromigration method in a free electrolyte the behaviour of In(III) in some water solutions has been investigated. Data on electrophoretic mobility of In(III) as well as its complexes with DTPA and EDTA in a wide range of pH and temperature have been collected. On the basis of experimental results the diffusion coefficient of In(III) and concentration stability constant of a complex [InDTPA]^2- have been estimated.

  9. Radionuclide sorption on Savannah River Plant burial ground soil: a summary and interpretation of laboratory data

    International Nuclear Information System (INIS)

    Hoeffner, S.L.

    1985-06-01

    This report is a summary of radionuclide sorption studies conducted to determine the performance of the low-level waste burial ground at the Savannah River Plant. Distribution coefficients for 60 Co, 90 Sr, 99 Tc, 106 Ru, 125 Sb, 129 I, 137 Cs, and /sup 238/239/Pu are reported. The effects of cations, anions, pH, radionuclide concentration and other variables on radionuclide sorption were evaluated. The pH and radionuclide concentration are the two major factors influencing radionuclide sorption. The pH range observed in the burial ground indicates that a wide range in the amount of radionuclide sorption is to be expected in the burial ground. These laboratory studies are useful for setting upper and lower limits on radionuclide mobility. 30 refs., 15 figs., 16 tabs

  10. Investigating the impact of uneven magnetic flux density distribution on core loss estimation

    DEFF Research Database (Denmark)

    Niroumand, Farideh Javidi; Nymand, Morten; Wang, Yiren

    2017-01-01

    . The presented work in this paper has been carried out for two common excitation waveforms in power electronics applications, sinusoid and square-wave and for two different core shapes, toroid and E-cores. Results show that ±10% discrepancy should be expected in loss estimation of the core using effective...... is calculated according to an effective flux density value and the macroscopic dimensions of the cores. However, the flux distribution in the core can alter by core shapes and/or operating conditions due to nonlinear material properties. This paper studies the element-wise estimation of the loss in magnetic...... cores. FEM has been used to investigate the flux density distribution in the core and the loss has been estimated considering this distribution. Finally, comparative results are shown between the classical macroscopic core loss estimation using effective dimensions and the element-wise loss estimation...

  11. Effects of hydrodynamic chromatography on colloid-facilitated migration of radionuclides in the fractured rock.

    Science.gov (United States)

    Jen, C P; Li, S H

    2001-01-01

    The performance assessment of high level radioactive waste disposal has emphasized the role of colloids in the migration of radionuclides in the geosphere. Previous literature [Nagasaki S, Tanaka S, Suzuki A. Fast transport of colloidal particles through quartz-packed columns. J. Nucl. Sci. Technol. 1975;30(11):1136] indicates that owing to hydrodynamic chromatography the colloid velocity may not be equal to that of groundwater. Using hydrodynamic chromatography, this work investigates the effects of the size of colloidal particles on the radionuclide migration facilitated by colloids in a single fractured porous rock. Also, a methodology is proposed to develop a predictive model to assess transport within the fracture rock as well as various other phenomenological coefficients, particularly the size of colloidal particles. In addition, a fully developed concentration profile for non-reactive colloids in the fracture is developed to elucidate hydrodynamic chromatography of colloids in geological media. The external forces acting on colloidal particles hypothesized in the model proposed herein include inertial force, van der Waals attractive force, double layer force as well as gravitational force. The dispersion coefficient of colloids and the distribution coefficient for radionuclides with colloids are also considered as they pertain to the size of the colloid. In addition, the size distributions of colloids are utilized to investigate the effects of polydispersed colloids.

  12. Radionuclide fractionation in organic matter-enriched soils

    International Nuclear Information System (INIS)

    Rigol, A.; Vidal, M.; Rauret, G.

    1995-01-01

    Sequential extraction scheme was proposed in order to obtain radionuclide distribution and predict its mobility in soil-plant system. This scheme is useful to be able to explain changes of the radionuclide behaviour over time, i.e., decrease in exchangeable-available fraction and increase in fixed-mineral-fraction. A sequential extraction scheme which considers the different interactions between organic matter in radionuclide may give information about the role of organic matter in radionuclide retention. Such scheme has been designed and it defines a series of fractions from the sequential use of different extractant reagents. The extraction scheme allows to estimate, in a operational way, the fraction of radionuclide associated with exchangeable sites (Fraction 1), with humic and fulvic acids (Fraction 2 and 3), the amount of radionuclide related to passive organic matter like humine, non-humic substances or mineral organic matter (Fraction 4) and the radionuclide highly fixed to soil mineral matter (residual fraction). The results allowing to ascertain which are sites responsible for radiocesium retention

  13. Technical Advances in Image Guidance of Radionuclide Therapy.

    Science.gov (United States)

    Beijst, Casper; Kunnen, Britt; Lam, Marnix G E H; de Jong, Hugo W A M

    2017-12-01

    Internal radiation therapy with radionuclides (i.e., radionuclide therapy) owes its success to the many advantages over other, more conventional, treatment options. One distinct advantage of radionuclide therapies is the potential to use (part of) the emitted radiation for imaging of the radionuclide distribution. The combination of diagnostic and therapeutic properties in a set of matched radiopharmaceuticals (sometimes combined in a single radiopharmaceutical) is often referred to as theranostics and allows accurate diagnostic imaging before therapy. The use of imaging benefits treatment planning, dosimetry, and assessment of treatment response. This paper focuses on a selection of advances in imaging technology relevant for image guidance of radionuclide therapy. This involves developments in nuclear imaging modalities, as well as other anatomic and functional imaging modalities. The quality and quantitative accuracy of images used for guidance of radionuclide therapy is continuously being improved, which in turn may improve the therapeutic outcome and efficiency of radionuclide therapies. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  14. Tumor Immunotargeting Using Innovative Radionuclides

    OpenAIRE

    Françoise Kraeber-Bodéré; Caroline Rousseau; Caroline Bodet-Milin; Cédric Mathieu; François Guérard; Eric Frampas; Thomas Carlier; Nicolas Chouin; Ferid Haddad; Jean-François Chatal; Alain Faivre-Chauvet; Michel Chérel; Jacques Barbet

    2015-01-01

    This paper reviews some aspects and recent developments in the use of antibodies to target radionuclides for tumor imaging and therapy. While radiolabeled antibodies have been considered for many years in this context, only a few have reached the level of routine clinical use. However, alternative radionuclides, with more appropriate physical properties, such as lutetium-177 or copper-67, as well as alpha-emitting radionuclides, including astatine-211, bismuth-213, actinium-225, and others a...

  15. Investigation on velocity distribution of TFM and DEM phase in hybrid model of CBFB in mining

    Science.gov (United States)

    Zhang, Tianyu; Feng, Ying; Zhao, Zhening

    2017-05-01

    As a novel model for gas solid flow simulation, the investigation of TFM-DEM hybrid model is far from completely, including mutual interaction of TFM and DEM phase, selection of DEM portion and coherence of the predicted results from both phases. Therefore, in present study, the consistency of velocity distribution between TFM and DEM phase is investigated. The correlation of instantaneous and time-averaged velocity distribution of TFM and DEM phase in specific area in CBFB for mining is studied. And the differences of the axial and radial velocity between the particles of different sizes are discussed. The influence of particle diameter and the ratio of DEM and TFM phase on the correlation of velocity, both instantaneous and time-averaged, are taken into consideration.

  16. The Numerical Investigation of Temperature and Velocity Distribution in the High-Bay Depot

    Directory of Open Access Journals (Sweden)

    Xuehong Wu

    2014-07-01

    Full Text Available High-bay depot plays an important role in the storage industry. Due to large and high space of high-bay depot, it is difficult to make temperature distribution uniform, which will influence the storage time of raw materials. In this paper, the aim is to find the reasonable air supply and energy-saving method; a supply-air method of high-bay depot is investigated as an example. The results show the radius and spacing of the supply-air inlet have great influence on temperature distribution. The temperature nonuniformity coefficient of summer is smaller than that of winter. The investigated results can provide a theoretical reference for the high-bay depot design and economic operation.

  17. Discontinuous pore fluid distribution under microgravity--KC-135 flight investigations

    Science.gov (United States)

    Reddi, Lakshmi N.; Xiao, Ming; Steinberg, Susan L.

    2005-01-01

    Designing a reliable plant growth system for crop production in space requires the understanding of pore fluid distribution in porous media under microgravity. The objective of this experimental investigation, which was conducted aboard NASA KC-135 reduced gravity flight, is to study possible particle separation and the distribution of discontinuous wetting fluid in porous media under microgravity. KC-135 aircraft provided gravity conditions of 1, 1.8, and 10(-2) g. Glass beads of a known size distribution were used as porous media; and Hexadecane, a petroleum compound immiscible with and lighter than water, was used as wetting fluid at residual saturation. Nitrogen freezer was used to solidify the discontinuous Hexadecane ganglia in glass beads to preserve the ganglia size changes during different gravity conditions, so that the blob-size distributions (BSDs) could be measured after flight. It was concluded from this study that microgravity has little effect on the size distribution of pore fluid blobs corresponding to residual saturation of wetting fluids in porous media. The blobs showed no noticeable breakup or coalescence during microgravity. However, based on the increase in bulk volume of samples due to particle separation under microgravity, groups of particles, within which pore fluid blobs were encapsulated, appeared to have rearranged themselves under microgravity.

  18. Radionuclide Sensors for Water Monitoring

    International Nuclear Information System (INIS)

    Grate, Jay W.; Egorov, Oleg B.; DeVol, Timothy A.

    2005-01-01

    Radionuclide contamination in the soil and groundwater at U.S. Department of Energy (DOE) sites is a severe problem that requires monitoring and remediation. Radionuclide measurement techniques are needed to monitor surface waters, groundwater, and process waters. Typically, water samples are collected and transported to an analytical laboratory, where costly radiochemical analyses are performed. To date, there has been very little development of selective radionuclide sensors for alpha- and beta-emitting radionuclides such as 90Sr, 99Tc, and various actinides of interest

  19. History of medical radionuclide production.

    Science.gov (United States)

    Ice, R D

    1995-11-01

    Radionuclide production for medical use originally was incidental to isotope discoveries by physicists and chemists. Once the available radionuclides were identified they were evaluated for potential medical use. Hevesy first used 32P in 1935 to study phosphorous metabolism in rats. Since that time, the development of cyclotrons, linear accelerators, and nuclear reactors have produced hundreds of radionuclides for potential medical use. The history of medical radionuclide production represents an evolutionary, interdisciplinary development of applied nuclear technology. Today the technology is represented by a mature industry and provides medical benefits to millions of patients annually.

  20. Radionuclide diagnosis of allograft rejection

    International Nuclear Information System (INIS)

    George, E.A.

    1982-01-01

    Interaction with one or more anatomical and physiopathological characteristics of the rejecting renal allograft is suggested by those radioagents utilized specifically for the diagnosis of allograft rejection. Rejection, the most common cause of declining allograft function, is frequently mimicked clinically or masked by other immediate or long term post transplant complications. Understanding of the anatomical pathological features and kinetics of rejection and their modification by immunosuppressive maintenance and therapy are important for the proper clinical utilization of these radioagents. Furthermore, in selecting these radionuclides, one has to consider the comparative availability, preparatory and procedural simplicity, acquisition and display techniques and the possibility of timely report. The clinical utilities of radiofibrinogen, /sup 99m/Tc sulfur colloid and 67 Ga in the diagnosis of allograft rejection have been evaluated to a variable extent in the past. The potential usefulness of the recently developed preparations of 111 In labeled autologous leukocytes and platelets are presently under investigation

  1. EBS Radionuclide Transport Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    J.D. Schreiber

    2005-08-25

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in ''Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration'' (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment for the license application (TSPA-LA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA-LA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport

  2. EBS Radionuclide Transport Abstraction

    International Nuclear Information System (INIS)

    J.D. Schreiber

    2005-01-01

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in ''Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration'' (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment for the license application (TSPA-LA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA-LA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers

  3. Modifying radionuclide effects

    International Nuclear Information System (INIS)

    Sasser, L.B.

    1983-01-01

    This project involves a study of the relationship of physiological and environmental factors to the metabolism and effects of radionuclides. We have studied placental transfer and suckling as pathways of americium entry into the newborn or juvenile rat. Rats were injected intravenously with 5 μCi of 241 Am while nulliparous (30 days prior to mating), pregnant (day 19 of gestation), or lactating (1 day after parturition), and subsequent litters were killed to determine 241 Am retention. A deficit in reproductive performance was observed in the group injected before mating, as evidenced by reduced number and weight of offspring

  4. Radionuclide therapy in Slovenia

    International Nuclear Information System (INIS)

    Fettich, J.

    2005-01-01

    Full text: In Slovenia 1260 radionuclide therapies are performed per year for a population of 2,000,000 (63/100,000 inhabitants). Approximately half of the patients (691) were treated as outpatients. There are 7 nuclear medicine departments in the country and 4 of them are licensed to perform radionuclide therapy and two have specialised wards for patients receiving radionuclide treatment (10 beds). 131-I is used by far most commonly for benign thyroid diseases and differentiated thyroid Ca treatment. The patients receiving doses of radioactivity below 550 MBqs, i.e. mostly patients with Graves' disease, are treated as outpatients i.e. 610/year, (31/100 000 inhabitants). The patients treated with doses between 740 1110 MBq, mostly hyperthyroid patients with autonomous thyroid tissue (Plummer's disease), 300/year (15/100 000 inhabitants) are hospitalised for 3-5 days in a specialised wards. (Fractionated therapy is not used). 137 therapies were performed for ablation and treatment of metastases in patients with differentiated thyroid cancer receiving 1850 5550 MBq, in 2004 as inpatients. 131-I mIBG is used for treatment of neuroblastoma very occasionally, less than 1/year due to low number of patients. Such patient has to be hospitalised in an adult radiotherapy ward, a situation not preferred by paediatricians. 186-Re HEDP, 153-Sm EDTPM and 89-Sr were used for palliation of bone pain due to bony metastasis usually as outpatients, depending on patient's condition, in only 14 patients in 2004. 186-Re colloid and 90-Y colloid are used for radiosynovectomies in patients with rheumatic and (32/year) and hemophilic (25/year) arthropathies. These patients are not hospitalised. 5 patients were treated with 90-Y anti CD20 MoAB for NHLymphoma, all on outpatient basis and 2 patients received 90-Y Octreotide for metastatic carcinoid also as outpatients. 12 patients received 90-Y colloid intraperitoneally for experimental treatment of carcinosis due to ovarian Ca in 2004

  5. Osteopetrosis: Radiological & Radionuclide Imaging

    International Nuclear Information System (INIS)

    Sit, Cherry; Agrawal, Kanhaiyalal; Fogelman, Ignac; Gnanasegaran, Gopinath

    2015-01-01

    Osteopetrosis is a rare inherited bone disease where bones harden and become abnormally dense. While the diagnosis is clinical, it also greatly relies on appearance of the skeleton radiographically. X-ray, radionuclide bone scintigraphy and magnetic resonance imaging have been reported to identify characteristics of osteopetrosis. We present an interesting case of a 59-year-old man with a history of bilateral hip fractures. He underwent 99m Tc-methylene diphosphonate whole body scan supplemented with single-photon emission computed tomography/computed tomography of spine, which showed increased uptake in the humeri, tibiae and femora, which were in keeping with osteopetrosis

  6. The behavior of radionuclides in the soils of Rocky Flats, Colorado

    International Nuclear Information System (INIS)

    Litaor, M.I.; Barth, G.; Zika, E.M.; Litus, G.; Moffitt, J.; Daniels, H.

    1998-01-01

    Radionuclide contamination of soils in Rocky Flats, Colorado, resulted from leaking drums of Pu-contaminated oil stored at an outdoor area. To evaluated the mechanisms of radionuclide transport from the contaminated soils to groundwater, an advanced monitoring system was installed across a toposequence. The impact of natural rain, snowmelt, and large-scale rain simulations on the mobility and distribution of the radionuclides in soil interstitial water was studied. The distribution of radionuclides during the monitoring period from 1993 to 1995 suggested that Pu-239 + 240 and Am-241 are largely immobile in semi-arid soils. Fractionation of Pu-239 + 240 and Am-241 to different particle sizes in the soil interstitial water suggested that most of the radionuclides (83-97%) were associated with suspended particles, whereas the level of radionuclides associated with colloidal (0.45 μm > X > 1 nm) and nonfilterable (< 1 nm) fractions ranged from 1.5 to 15%. (author)

  7. Exposure-dose research for radionuclides in natural gas

    International Nuclear Information System (INIS)

    McNelis, D.N.; Patzer, R.G.

    1969-01-01

    The fate determination of specific radionuclides in natural gas stimulated by underground engineering applications is being examined. An experimental program, now in its initial stages, is using gas artificially labeled with krypton-85 and tritium under simulated domestic situations. The following topics are being investigated in this study: 1. The concentration of the radionuclides in a gas-heated home. 2. The build-up of contamination on appliances in the kitchen environment. 3. The concentration in foods as a function of radionuclide, food type and preparation. 4. The maximum exposure plausible under specified conditions. (author)

  8. Determination of dose rates from natural radionuclides in dental materials

    Energy Technology Data Exchange (ETDEWEB)

    Veronese, I. [Dipartimento di Fisica, Universita degli Studi di Milano, Milan (Italy) and INFN, Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milan (Italy)]. E-mail: ivan.veronese@unimi.it; Guzzi, G. [AIRMEB - Italian Association for Metal and Biocompatibility Research, Milan (Italy); Giussani, A. [Dipartimento di Fisica, Universita degli Studi di Milano, Milan (Italy); INFN, Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milan (Italy); Cantone, M.C. [Dipartimento di Fisica, Universita degli Studi di Milano, Milan (Italy); INFN, Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milan (Italy); Ripamonti, D. [Dipartimento di Fisica, Universita degli Studi di Milano, Milan (Italy)

    2006-07-01

    Different types of materials used for dental prosthetics restoration, including feldspathic ceramics, glass ceramics, zirconia-based ceramics, alumina-based ceramics, and resin-based materials, were investigated with regard to content of natural radionuclides by means of thermoluminescence beta dosimetry and gamma spectrometry. The gross beta dose rate from feldspathic and glass ceramics was about ten times higher than the background measurement, whereas resin-based materials generated negligible beta dose rate, similarly to natural tooth samples. The specific activity of uranium and thorium was significantly below the levels found in the period when addition of uranium to dental porcelain materials was still permitted. The high-beta dose levels observed in feldspathic porcelains and glass ceramics are thus mainly ascribable to {sup 4}K, naturally present in these specimens. Although the measured values are below the recommended limits, results indicate that patients with prostheses are subject to higher dose levels than other members of the population. Alumina- and zirconia-based ceramics might be a promising alternative, as they have generally lower beta dose rates than the conventional porcelain materials. However, the dosimetry results, which imply the presence of inhomogeneously distributed clusters of radionuclides in the sample matrix, and the still unsuitable structural properties call for further optimization of these materials.

  9. Investigation of the velocity distribution in the flow of a journal bearing model

    Science.gov (United States)

    Nobis, Matthias; Reinke, Peter; Schmidt, Marcus; Riedel, Marco; Redlich, Marcel

    2014-03-01

    In many previous studies the main focus was put on the pressure distribution in the lubricating gap. Due to the limited space in the gap an investigation of the velocity distribution is very difficult or rather impossible. Based on the geometrical shapes of a real journal bearing, a bearing model test rig with an increased relative gap width has been developed. Thus, it is possible to detect the distribution of the flow speed within the gap by using a Laser Doppler Velocimeter (LDV). The comparability of the flow to the flow in a real journal bearing is ensured by observing the Reynolds similarity. Due to a targeted eccentricity in the system and the circumferential groove over 180°, there is in connection with the outlet hole in the rotating shaft a permanent change in the outflow conditions. The consequence is a periodically varying system pressure with effects to the pressure and volumetric flow rate at the inlet and outlet. The velocity measurements with a triggered LDV are done by considering these transient boundary conditions at the system boundaries. In this paper the experimental setup, the expiration of the investigations and some exemplary results are presented. Attendant to the experiment, numerical simulations are carried out and the results are compared with the experimental data.

  10. Investigation of the velocity distribution in the flow of a journal bearing model

    Directory of Open Access Journals (Sweden)

    Nobis Matthias

    2014-03-01

    Full Text Available In many previous studies the main focus was put on the pressure distribution in the lubricating gap. Due to the limited space in the gap an investigation of the velocity distribution is very difficult or rather impossible. Based on the geometrical shapes of a real journal bearing, a bearing model test rig with an increased relative gap width has been developed. Thus, it is possible to detect the distribution of the flow speed within the gap by using a Laser Doppler Velocimeter (LDV. The comparability of the flow to the flow in a real journal bearing is ensured by observing the Reynolds similarity. Due to a targeted eccentricity in the system and the circumferential groove over 180°, there is in connection with the outlet hole in the rotating shaft a permanent change in the outflow conditions. The consequence is a periodically varying system pressure with effects to the pressure and volumetric flow rate at the inlet and outlet. The velocity measurements with a triggered LDV are done by considering these transient boundary conditions at the system boundaries. In this paper the experimental setup, the expiration of the investigations and some exemplary results are presented. Attendant to the experiment, numerical simulations are carried out and the results are compared with the experimental data.

  11. Flight Investigation of the Effects of Pressure-Belt Tubing Size on Measured Pressure Distributions

    Science.gov (United States)

    Rivers, Natale A.; vanDam, Cornielious P.; Brown, Phillip W.; Rivers, Robert A.

    2001-01-01

    The pressure-belt technique is commonly used to measure pressure distributions on lifting and nonlifting surfaces where flush, through-the-surface measurements are not possible. The belts, made from strips of small-bore, flexible plastic tubing, are surface-mounted by a simple, nondestructive method. Additionally, the belts require minimal installation time, thus making them much less costly to install than flush-mounted pressure ports. Although pressure belts have been used in flight research since the early 1950s, only recently have manufacturers begun to produce thinner, more flexible tubing, and thin, strong adhesive tapes that minimize the installation-induced errors on the measurement of surface pressures. The objective of this investigation was to determine the effects of pressure-belt tubing size on the measurement of pressure distributions. For that purpose, two pressure belts were mounted on the right wing of a single-engine, propeller-driven research airplane. The outboard pressure belt served as a baseline for the measurement and the comparison of effects. Each tube had an outer diameter (OD) of 0.0625 in. The inboard belt was used to evaluate three different tube sizes: 0.0625-, 0.1250-, and 0.1875-in. OD. A computational investigation of tube size on pressure distribution also was conducted using the two-dimensional Multielement Streamtube Euler Solver (MSES) code.

  12. Natural radionuclide distribution in Brazilian commercial granites

    International Nuclear Information System (INIS)

    Anjos, R.M.; Veiga, R.; Soares, T.; Santos, A.M.A.; Aguiar, J.G.; Frasca, M.H.B.O.; Brage, J.A.P.; Uzeda, D.; Mangia, L.; Facure, A.; Mosquera, B.; Carvalho, C.; Gomes, P.R.S.

    2005-01-01

    The dimension stones sector in Brazil produces several varieties of granites, marbles, slates and basalts. More than half of this production corresponds to around 200 different commercial types of granites with specific names, geographical and geological origins and mineral compositions. The well-known natural radioactivity present in rocks, where high radiation levels are associated with igneous rocks such as granite, can be used to determine their general petrologic features. This subject is important in environmental radiological protection, since granites are widely used as building and ornamental stones. In this paper, it is applied to correlate the petrographic characteristics of commercial granites with their corresponding dose rates for natural radioactivity. Amounts of thorium, uranium and potassium concentrations have been reported in several Brazilian commercial granite samples

  13. Radionuclides in marine sediments - Distribution and processes

    Energy Technology Data Exchange (ETDEWEB)

    Rudjord, A.L. [Norwegian Radiation Protection Authority, Oesteraas (Norway); Oughton, D. [Agricultural Univ., Aas (Norway); Bergan, T.D.; Christensen, G. [IFE, Kjeller (Norway)

    2001-04-01

    The NO-1 part of EKO-1 involved both laboratory and field studies. The laboratory studies have been discribed earlier in this report. The following is a summary of the field studies. At station 26 (Norwegian Sea) the sediments seem to be influenced by radiocesium from the Chernobyl accident. This may be due to direct fallout deposition to the sea surface and followed by a rapid sinking and sedimentation. At station 16 (North Sea) some influence from Sellafield plutonium is suggested, as the plutonium ratio is significantly higher (0.07-0.09) than would be expected from global fallout (0.03). Sedimentation rates based on analysis of {sup 210}Pb or {sup 210}Po varied between 0.03 cm/year - 0.25 cm/year. A surprisingly low sedimentation rate was found in the tenisey Bay (0.05 cm/year). It is possible that the dating method is less suited in this area, due to the long winter ice cover. In general, the rough estimates on K{sub d} values for {sup 137}Cs obtained empirically are highter than K{sub d} values obtained from the alboratory studies. This may be due to the fact that the 2 cm surface sediment in most cases has accumulated over many years, carrying contamination from the early eighties when levels of {sup 137}Cs in the sea water were higher. The {sup 137}Cs in the sediments it now fixed, or being remobilized only very slowly. Burial of the contamination by sedimentation may also make it unavailable for exchange with free water masses. (EHS)

  14. Radionuclides in nephrology

    International Nuclear Information System (INIS)

    Lausanne, A.B.D.

    1987-01-01

    In 47 expert contributions, this volume provides a summary of the latest research on radionuclides in nephro-urology together with current and new clinical applications especially in renovascular hypertension, kidney transplantation, and metabolic and urological diseases. In addition, attention is given to aspects of basic renal physiology and function and possible applications of nuclear magnetic resonance and spectroscopy in nephro-urology. New testing procedures which promise to improve diagnosis, and new radiopharmaceuticals are described. The reports are divided into eight sections, the first of which features studies on the renin-angiotensin system, cisplatin, atrial natriuretic factor and determining plasma oxalate. Four papers describe a number of new radiopharmaceuticals which have the potential to replace hippuran. In the third section, radionuclide methods for the measurement of renal function parameters are discussed. The book then focuses on the potential role of captopril in the improved diagnosis of renovascular hypertension. Applications of nuclear magnetic resonance and spectroscopy are demonstrated in the diagnosis of acute pyelonephritis, kidney assessment after lithotripsy, kidney evaluation prior to transplantation, and in monitoring renal ischemia during hypotension

  15. A Bayesian Algorithm for Assessing Uncertainty in Radionuclide Source Terms

    Science.gov (United States)

    Robins, Peter

    2015-04-01

    Inferring source term parameters for a radionuclide release is difficult, due to the large uncertainties in forward dispersion modelling as a consequence of imperfect knowledge pertaining to wind vector fields and turbulent diffusion in the Earth's atmosphere. Additional sources of error include the radionuclide measurements obtained from sensors. These measurements may either be subject to random fluctuations or are simple indications that the true, unobserved quantity is below a detection limit. Consequent large reconstruction uncertainties can render a "best" estimate meaningless. A Markov Chain Monte Carlo (MCMC) Bayesian Algorithm is presented that attempts to account for uncertainties in atmospheric transport modelling and radionuclide sensor measurements to quantify uncertainties in radionuclide release source term parameters. Prior probability distributions are created for likely release locations at existing nuclear facilities and seismic events. Likelihood models are constructed using CTBTO adjoint modelling output and probability distributions of sensor response. Samples from the resulting multi-isotope source term parameters posterior probability distribution are generated that can be used to make probabilistic statements about the source term. Examples are given of marginal probability distributions obtained from simulated sensor data. The consequences of errors in numerical weather prediction wind fields are demonstrated with a reconstruction of the Fukushima nuclear reactor accident from International Monitoring System radionuclide particulate sensor data.

  16. Transport and accumulation of radionuclides in the marine sediment of Urazoko Bay

    International Nuclear Information System (INIS)

    Nagaya, Yutaka; Nakamura, Kiyoshi

    1976-01-01

    Concentrations of 60 Co and other radionuclides in surface sediment samples were investigated in and around Urazoko Bay, Fukui Prefecture, where a nuclear power plant has been operating since 1969 and the radioactive waste effluent has been released into the sea. The main source of 90 Sr and 137 Cs was recognized to be radioactive fallout from nuclear explosions, whereas 60 Co was considered to originate from the nuclear power reactor. For evaluating radioactive pollution characteristics of the sea bottom, the behaviour of 60 Co was investigated using the 137 Cs concentration as an indicator of the radionuclide sorption capability or accumulation capability of the sediment. No seasonal variation was observed in the distribution pattern of the 60 Co/ 137 Cs ratio and the retention of the heavy initial discharge in 1969 is considered to dominate the radionuclide level in the sediment. The 60 Co contamination in the sediment, expressed as the 60 Co/ 137 Cs ratio, in this narrow and semi-closed bay was found to vary according to a simple exponential function of the distance from the discharge outlet. It was found that the contamination is spreading out gradually from Urazoko Bay to outer regions. Also the correlation between the amount of discharged radioactive waste and the variation of the 60 Co level in the sediment was investigated. (auth.)

  17. Radionuclides in peat bogs and energy peat

    International Nuclear Information System (INIS)

    Helariutta, K.; Rantavaara, A.; Lehtovaara, J.

    2000-06-01

    The study was aimed at improving the general view on radionuclides contents in energy peat produced in Finland. The annual harvest of fuel peat in 1994 was studied extensively. Also thirteen peat bogs used for peat production and one bog in natural condition were analysed for vertical distributions of several radionuclides. These distributions demonstrate the future change in radioactivity of energy peat. Both natural nuclides emitting gamma radiation ( 238 U, 235 U, 232 Th, 226 Ra, 40 K) and radiocaesium ( 137 Cs, 134 Cs) origin in fallout from a nuclear power plant accident (1986) and in atmospheric nuclear weapon tests were analysed. The beta and alpha active natural nuclides of lead and polonium ( 210 Pb, 210 Po) were determined on a set of peat samples. These nuclides potentially contribute to radiation exposure through inhalation when partially released to atmosphere during combustion of peat. The activity concentrations of natural radionuclides often increased towards the deepest peat bog layers whereas the radioactive caesium deposited from atmosphere was missing in the deep layers. In undisturbed surface layers of a natural bog and peat production bogs the contents of 210 Pb and 210 Po exceeded those of the deeper peat layers. The nuclides of the uranium series in the samples were generally not in radioactive equilibrium, as different environmental processes change their activity ratios in peat. Radiation exposure from handling and utilisation of peat ash was estimated with activity indices derived from the data for energy peat harvested in 1994. Intervention doses were exceeded in a minor selection of samples due to 137 Cs, whereas natural radionuclides contributed very little to the doses. (orig.)

  18. Radionuclide - Soil Organic Matter Interactions

    DEFF Research Database (Denmark)

    Carlsen, Lars

    1985-01-01

    Interactions between soil organic matter, i.e. humic and fulvic acids, and radionuclides of primary interest to shallow land burial of low activity solid waste have been reviewed and to some extent studied experimentally. The radionuclides considered in the present study comprise cesium, strontium...

  19. Some parameters of radionuclide kinetics

    International Nuclear Information System (INIS)

    Prokof'ev, O.N.; Smirnov, V.A.; Belen'kij, E.I.

    1978-01-01

    Numerical values of the rates of radionuclide absorption into, and elimination from, bovine organs were determined. Kinetic rate constants of radionuclides such as 89 Sr, 99 Mo, 131 I, 132 Tl, and 140 Be were calculated. The calculations were done for muscle, liver, and kidney

  20. Investigation of Colorless Distributed Combustion (CDC) with Swirl for Gas Turbine Application

    Science.gov (United States)

    Khalil Hasan, Ahmed Essam ElDin

    Colorless Distributed Combustion (CDC) with swirl is investigated for gas turbine engine applications due to its benefits for ultra-low pollutants emission, improved pattern factor and thermal field uniformity, low noise emission, and stable combustion with the alleviation of combustion instabilities. Adequate and fast mixing between the injected air and internally recirculated hot reactive gases to form hot and diluted oxidant is critical for CDC, followed by rapid mixing with the fuel. This results in distributed reaction zone instead of a concentrated thin flame front as observed in conventional diffusion flames, leading to avoidance of hot spot regions and providing reduced NOx and CO emissions. The focus of this dissertation is to develop and demonstrate CDC in a cylindrical combustor for application to stationary gas turbine combustors. The dissertation examines the sequential development of ultra-low emission colorless distributed combustor operating at a nominal thermal intensity of 36MW/m3-atm. Initially, the role of swirl is evaluated through comparing the performance of swirling and non-swirling configurations with focus on pollutants emission, stability, and isothermal flowfield through particle image velocimetry. Different fuel injection locations have also been examined, and based on performance a swirling configuration have been down selected for further investigations demonstrating emissions as low as 1 PPM of NO with a 40% reduction compared to non-swirling configuration. Further investigations were performed to outline the impact of inlet air temperature and combustor pressure on reaction distribution and combustor performance. Next, Fuel flexibility has been examined with view to develop CDC combustors that can handle different gaseous and liquid fuels, both traditional and renewable. These fuels included diluted methane, hydrogen enriched methane, propane, ethanol, kerosene, JP-8, Hydrogenated Renewable Jet fuel, and novel biofuel. Swirling CDC

  1. Investigation of mineral distribution in bone by synchrotron X-ray fluorescence microscopy after tibolone therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lima, I. [Rio de Janeiro State Univ., Nova Friburgo, RJ (Brazil). Dept. of Mechanical Engineering and Energy; Federal Univ. of Rio de Janeiro, RJ (Brazil). Nuclear Instrumentation Lab. - COPPE; Carvalho, A.C.B.; Henriques, H.N.; Guzman-Silva, M.A. [Fluminense Federal Univ., Niteroi, RJ (Brazil). Lab. of Experimental Pathology; Sales, E.; Lopes, R.T. [Federal Univ. of Rio de Janeiro, RJ (Brazil). Nuclear Instrumentation Lab. - COPPE; Granjeiro, J.M. [Fluminense Federal Univ., Niteroi, RJ (Brazil). Dept. of Cellular and Molecular Biology

    2011-07-01

    Tibolone is a synthetic steroid with estrogenic, androgenic, and progestagenic properties used for the prevention of postmenopausal osteoporosis and treatment of climacteric symptoms. Tibolone shows almost no action on breast and endometrium, which are target-organs for estrogens and progesterone activity. The aim of this work was to investigate the spatial distribution of calcium and zinc minerals in the femoral head of ovariectomized rat in order to evaluate the effects of the long-term administration of tibolone. For that purpose X-ray microfluorescence was used with synchrotron radiation imaging technique which was performed at Brazilian Light Synchrotron Laboratory, Campinas, SP. Minerals were not homogeneously distributed in trabecular bone areas; a higher concentration of calcium in the trabecular regions at femoral heads was found in ovariectomized and tibolone-treated rats compared to ovariectomized and control groups. (orig.)

  2. Decontamination of radionuclides in food

    International Nuclear Information System (INIS)

    Ohmomo, Yoichiro

    1994-01-01

    The release of radionuclides arising from the Chernobyle accident led to widespread contamination of the northern hemisphere through fallout. This accident provided again an opportunity to investigate how and to what extent the radionuclides contamination in crops and animal derived foods could be reduced. The following topics are included in this paper. (1) How to reduce the transfer of radiostrontium and/or cesium from soil to crops: A pH increase of soil is effective for reducing their plant uptake. (2) How to reduce the transfer of radiocesium to animal derived foods: Ammonium-ferric-cyanoferrate (AFCF) should be the most effective compound for radiocesium excretion in the feces. Experiments with lactating cows and/or poultry gave extremely good results with respect to low radiocesium concentrations in milk, meat and eggs. (3) Removal coefficients of radiostrontium, cesium and iodine from contaminated leaf vegetables and cereals during food processing and culinary preparation: Though different by species, more than 80% of cesium and about 50% of strontium and iodine can be removed during culinary preparation of washing and boiling. (4) Simultaneous decontamination of radiocesium and iodine from drinking water and liquid milk: Metal ferrocyanide-anion exchange resin, specifically Fe ferrocyanide one, was successfully used for a rapid and simple decontamination of radiocesium and iodine in the liquid samples arising from the Chernobyle accident. (5) Removal of radiocesium from meat: The meat structurally contaminated with radiocesium is easily and very successfully decontaminated by pickling in NaCl solution and the decontamination is much speeded up by freezing meat before pickling. (author)

  3. Mass spectrometry of long-lived radionuclides

    International Nuclear Information System (INIS)

    Becker, Johanna Sabine.

    2003-01-01

    The capability of determining element concentrations at the trace and ultratrace level and isotope ratios is a main feature of inorganic mass spectrometry. The precise and accurate determination of isotope ratios of long-lived natural and artificial radionuclides is required, e.g. for their environmental monitoring and health control, for studying radionuclide migration, for age dating, for determining isotope ratios of radiogenic elements in the nuclear industry, for quality assurance and determination of the burn-up of fuel material in a nuclear power plant, for reprocessing plants, nuclear material accounting and radioactive waste control. Inorganic mass spectrometry, especially inductively coupled plasma mass spectrometry (ICP-MS) as the most important inorganic mass spectrometric technique today, possesses excellent sensitivity, precision and good accuracy for isotope ratio measurements and practically no restriction with respect to the ionization potential of the element investigated--therefore, thermal ionization mass spectrometry (TIMS), which has been used as the dominant analytical technique for precise isotope ratio measurements of long-lived radionuclides for many decades, is being replaced increasingly by ICP-MS. In the last few years instrumental progress in improving figures of merit for the determination of isotope ratio measurements of long-lived radionuclides in ICP-MS has been achieved by the application of a multiple ion collector device (MC-ICP-MS) and the introduction of the collision cell interface in order to dissociate disturbing argon-based molecular ions, to reduce the kinetic energy of ions and neutralize the disturbing noble gas ions (e.g. of 129 Xe + for the determination of 129 I). The review describes the state of the art and the progress of different inorganic mass spectrometric techniques such as ICP-MS, laser ablation ICP-MS vs. TIMS, glow discharge mass spectrometry, secondary ion mass spectrometry, resonance ionization mass

  4. Investigating the spatial distribution and effects of nearshore topography on Acropora cervicornis abundance in Southeast Florida

    Directory of Open Access Journals (Sweden)

    Nicole L. D’Antonio

    2016-09-01

    Full Text Available Dense Acropora cervicornis aggregations, or patches, have been documented within nearshore habitats in Southeast Florida (SE FL despite close proximity to numerous anthropogenic stressors and subjection to frequent natural disturbance events. Limited information has been published concerning the distribution and abundance of A. cervicornis outside of these known dense patches. The first goal of this study was to conduct a spatially extensive and inclusive survey (9.78 km2 to determine whether A. cervicornis distribution in the nearshore habitat of SE FL was spatially uniform or clustered. The second goal was to investigate potential relationships between broad-scale seafloor topography and A. cervicornis abundance using high resolution bathymetric data. Acropora cervicornis was distributed throughout the study area, and the Getis-Ord Gi* statistic and Anselin Local Moran’s I spatial cluster analysis showed significant clustering along topographic features termed ridge crests. Significant clustering was further supported by the inverse distance weighted surface model. Ordinal logistic regression indicated 1 as distance from a ridge increases, odds of reduced A. cervicornis abundance increases; 2 as topographic elevation increases, odds of increased abundance increases; and 3 as mean depth increases, odds of increased abundance increases. This study provides detailed information on A. cervicornis distribution and abundance at a regional scale and supports modeling its distributions in similar habitats elsewhere throughout the western Atlantic and Caribbean. Acropora cervicornis is frequently observed and in areas an abundant species within the nearshore habitat along the SE FL portion of the Florida Reef Tract (FRT. This study provides a better understanding of local habitat associations thus facilitating appropriate management of the nearshore environment and species conservation. The portion of the FRT between Hillsboro and Port Everglades

  5. Estimation of total error in DWPF reported radionuclide inventories. Revision 1

    International Nuclear Information System (INIS)

    Edwards, T.B.

    1995-01-01

    The Defense Waste Processing Facility (DWPF) at the Savannah River Site is required to determine and report the radionuclide inventory of its glass product. For each macro-batch, the DWPF will report both the total amount (in curies) of each reportable radionuclide and the average concentration (in curies/gram of glass) of each reportable radionuclide. The DWPF is to provide the estimated error of these reported values of its radionuclide inventory as well. The objective of this document is to provide a framework for determining the estimated error in DWPF's reporting of these radionuclide inventories. This report investigates the impact of random errors due to measurement and sampling on the total amount of each reportable radionuclide in a given macro-batch. In addition, the impact of these measurement and sampling errors and process variation are evaluated to determine the uncertainty in the reported average concentrations of radionuclides in DWPF's filled canister inventory resulting from each macro-batch

  6. Distribution of cesium between colloid-rock phases-establishment of experimental system and investigation of Cs distribution between colloid and rock

    International Nuclear Information System (INIS)

    Nakata, Kotaro

    2006-01-01

    Distribution and re-distribution of cesium between 3-phases (colloid, rock and water) was investigated. Analcite and bentonite colloid ware used as colloid phase and muscovite was used as rock phase. Before investigating the distribution between 3-phases, sorption and desorption behavior of Cs on analcite colloid, bentonite colloid and muscovite was investigated. It was found some fraction of Cs sorbed irreversibly on analcite colloid, while Cs sorbed reversibly on bentonite colloid. The experimental system was established for assessment of the distribution of nuclides between 3-phases by using combination of membrane filter and experimental cell. Since colloid and muscovite were separated by membrane filter, sorption of colloid on muscovite could be prevented and we could obtain distribution of Cs as ion. The distribution of Cs between 3-phases were obtained by this experimental system. Furthermore, re-distribution experiment was also carried out by using this system. After 7 days contact of colloid with Cs, distribution of sorbed Cs on colloid to liquid or muscovite phase was investigated. Comparing sorption and desorption isotherm with the distribution of Cs between 3-phases, it was found that Kd value of colloid (ratio of Cs concentration in liquid phase to amount of sorbed Cs on colloid phase) estimated in 2-phases (water and colloid) is different from that in 3-phases. Furthermore, in the case of analcite colloid, Kd value of colloid obtained in 3-phases distribution experiment was different from that obtained in re-distribution experiment. This is considered because of the irreversibility of Cs sorption on analcite colloid. Thus, it was found distribution of Cs in 3-phases was not predictable from sorption and desorption isotherm or Kd value of 2-phases (water-rock, water-colloid). (author)

  7. Evaluation of spontaneous intracranial hypotension using radionuclide cisternography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Su Zy; Park, Chan H.; Pai, Moon Sun; Yoon, Seok Nam; Oh, Yun Min; Kim, Jang Sung [College of Medicine, Ajou Univ., Suwon (Korea, Republic of)

    1999-02-01

    We report four cases of spontaneous intracranial hypotension that were investigated by radionuclide cisternography. {sup 99m}Tc-diethylenetriamine pentaacetic acid radionuclide cisternography of all our patients showed direct sign of cerebrospinal fluid leakage as well as indirect signs of less activity than expected over the cerebral convexities and rapid appearance of bladder activity. The headache of all patients was eventually controlled with bed rest and hydration.

  8. Verification and improvement of predictive algorithms for radionuclide migration

    International Nuclear Information System (INIS)

    Carnahan, C.L.; Miller, C.W.; Remer, J.S.

    1984-01-01

    This research investigated the adequacy of current numerical codes in simulating geochemical interactions affecting radionuclide migration, the level of complexity required in chemical algorithms of transport models, and the validity of the constant-k/sub D/ concept in chemical transport modeling. An initial survey of the literature led to the conclusion that existing numerical codes did not encompass the full range of chemical and physical phenomena influential in radionuclide migration

  9. Proton therapy treatment monitoring with in-beam PET: Investigating space and time activity distributions

    Science.gov (United States)

    Brombal, L.; Barbosa, D.; Belcari, N.; Bisogni, M. G.; Camarlinghi, N.; Cristoforetti, L.; Guerra, A. Del; Fracchiolla, F.; Morrocchi, M.; Sportelli, G.; Righetto, R.; Schwarz, M.; Topi, A.; Rosso, V.

    2017-07-01

    In this study the possibility of retrieving composition information in proton therapy with a planar in-beam PET scanner is investigated. The analysis focuses both on spatial activity distributions and time dependence of the recorded signal. The experimental data taking was performed at the Trento Proton Therapy Center (IT) by irradiating three different phantoms. We show that different phantom compositions reflect into different activity profile shapes. We demonstrate that the analysis of the event rate can provide significant information on the phantom elemental composition, suggesting that elemental analysis could be used along with activity profile analysis to achieve a more accurate treatment monitoring.

  10. Beta-emitting radionuclides for peptide receptor radionuclide therapy.

    Science.gov (United States)

    Parus, J L; Mikolajczak, R

    2012-01-01

    The paper focuses on the β-emitting radionuclides which might be useful for peptide receptor radionuclide therapy, PRRT. For the effective design of the radiopharmaceutical, the choice of radionuclide will depend on the purpose for which the radioligand is being used and on the physicochemical properties of the radionuclide. The important factor is also the availability and the cost of production. The physical characteristics of several radionuclides which are currently used or can be considered as potential candidates for PRRT is provided, followed by short description of production methods and chemical aspects of their use in preparation of peptide-based radiopharmaceuticals. Somatostatin analogues labeled with radionuclides have been a successful example of PRRT. For treatment of patients with inoperable or metastasized neuroendocrine tumors, somatostatin analogues labeled with the radioisotopes (111)In, (90)Y and (177)Lu have been used so far. Labeling with (111)In, mainly an Auger electron emitter, resulted in no reduction of tumor size while somatostatin analogues labeled with (90)Y and (177)Lu gave overall positive response and improved the patients' quality of life. These promising results together with the increasing availability of other β-emitting radionuclides are a good basis for further studies.

  11. Investigation of Sodium Distribution in Phosphate Glasses Using Spin-Echo {sup 23}Na NMR

    Energy Technology Data Exchange (ETDEWEB)

    ALAM, TODD M.; BOYLE, TIMOTHY J.; BROW, RICHARD K.; CLICK, CAROL C.; CONZONE, SAM; McLAUGHLIN, JAY; ZWANZIGER, JOE

    1999-09-16

    The spatial arrangement of sodium cations for a series of sodium phosphate glasses, xNa{sub 2}O(100-x)P{sub 2}O{sub 5} (x<55), were investigated using {sup 23}Na spin-echo NMR spectroscopy. The spin-echo decay rate is a function of the Na-Na homonuclear dipolar coupling and is related to the spatial proximity of neighboring Na nuclei. The spin-echo decay rate in these sodium phosphate glasses increases non-linearly with higher sodium number density, and thus provides a measure of the Na-Na extended range order. The results of these {sup 23}Na NMR experiments are discussed within the context of several structural models, including a decimated crystal lattice model, cubic dilation lattice model, a hard sphere (HS) random distribution model and a pair-wise cluster hard sphere model. While the experimental {sup 23}Na spin-echo M{sub 2} are described adequately by both the decimated lattice and the random HS model, it is demonstrated that the slight non-linear behavior of M{sub 2} as a function of sodium number density is more correctly described by the random distribution in the HS model. At low sodium number densities the experimental M{sub 2} is inconsistent with models incorporating Na-Na clustering. The ability to distinguish between Na-Na clusters and non-clustered distributions becomes more difficult at higher sodium concentrations.

  12. Investigating the impact of visuohaptic simulations for the conceptual understanding of electric field for distributed charges

    Science.gov (United States)

    Shaikh, Uzma Abdul Sattar

    The present study assessed the benefits of a multisensory intervention on the conceptual understanding of electric field for distributed charges in engineering and technology undergraduate students. A novel visuohaptic intervention was proposed, which focused on exploring the forces around the different electric field configurations for distributed charges namely point, infinitely long line and uniformly charged ring. The before and after effects of the visuohaptic intervention are compared, wherein the intervention includes instructional scaffolding. Three single-group studies were conducted to investigate the effect among three different populations: (a) Undergraduate engineering students, (b) Undergraduate technology students and (c) Undergraduate engineering technology students from a different demographic setting. The findings from the three studies suggests that the haptic modality intervention provides beneficial effects by allowing students to improve their conceptual understanding of electric field for distributed charges, although students from groups (b) and (c) showed a statistically significant increase in the conceptual understanding. The findings also indicate a positive learning perception among all the three groups.

  13. Investigations of cations distributions and morphology of cobalt ferrite magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Chandekar, Kamlesh V., E-mail: chandekar.kamlex@gmail.com; Kant, K. Mohan [Dept. of Applied Physics, Visvesvaraya National Institute of Technology, Nagpur, - 440010 (India)

    2016-05-06

    Cobalt ferrite nanoparticles were synthesized by co-precipitation method and structural properties was investigated by X-ray diffraction (XRD) at room temperature. X-ray diffraction data was used to determine lattice parameter, X-ray density, distributions of cations among tetrahedral and octahedral sites, site radii, ionic radii and bond length of inverse spinel cobalt ferrite. XRD analysis revealed crystallinity and high intense peak correspond to cubic inverse spinel structure with average crystalline size measured by X-ray line profile fitting was found to be 13nm for most intense peak (311). The surface morphology and microstructural feature was investigated by TEM analysis which revealed that particle size varying from 12-22 nm with selected electron diffraction pattern (SAED).

  14. Radionuclide transverse section imager

    International Nuclear Information System (INIS)

    Stoddart, H.F.

    1980-01-01

    A radioisotope scanning apparatus for use in nuclear medicine is described in detail. The apparatus enables the quantification and spatial location of the radioactivity in a body section of a patient to be determined with high sensitivity. It consists of an array of highly focussed collimators arranged such that adjacent collimators move in the same circumferential but opposite radial directions. The explicit movements of the gantry are described in detail and may be controlled by a general purpose computer. The use of highly focussed collimators allows both a reasonable solid angle of acceptance and also high target to background images; additionally, dual radionuclide pharmaceutical studies can be performed simultaneously. It is claimed that the high sensitivity of the system permits the early diagnosis of pathological changes and the images obtained show accurately the location and shape of physiological abnormalities. (UK)

  15. Radionuclide reporter gene imaging

    International Nuclear Information System (INIS)

    Min, Jung Joon

    2004-01-01

    Recent progress in the development of non-invasive imaging technologies continues to strengthen the role of molecular imaging biological research. These tools have been validated recently in variety of research models, and have been shown to provide continuous quantitative monitoring of the location(s), magnitude, and time-variation of gene expression. This article reviews the principles, characteristics, categories and the use of radionuclide reporter gene imaging technologies as they have been used in imaging cell trafficking, imaging gene therapy, imaging endogenous gene expression and imaging molecular interactions. The studies published to date demonstrate that reporter gene imaging technologies will help to accelerate model validation as well as allow for clinical monitoring of human diseases

  16. Radioactivity, radionuclides, radiation

    CERN Document Server

    Magill, Joseph

    2005-01-01

    RADIOACTIVITY – RADIONUCLIDES – RADIATION is suitable for a general audience interested in topical environmental and human health radiological issues such as radiation exposure in aircraft, food sterilisation, nuclear medicine, radon gas, radiation dispersion devices ("dirty bombs")… It leads the interested reader through the three Rs of nuclear science, to the forefront of research and developments in the field. The book is also suitable for students and professionals in the related disciplines of nuclear and radiochemistry, health physics, environmental sciences, nuclear and astrophysics. Recent developments in the areas of exotic decay modes (bound beta decay of ‘bare’ or fully ionized nuclei), laser transmutation, nuclear forensics, radiation hormesis and the LNT hypothesis are covered. Atomic mass data for over 3000 nuclides from the most recent (2003) evaluation are included.

  17. Modeling and experimental investigation of lightning arcs and overvoltages for medium voltage distribution lines

    Energy Technology Data Exchange (ETDEWEB)

    Omidiora, M. A.

    2011-07-01

    In this dissertation, lightning overvoltages in Medium Voltage (MV) lines are thoroughly investigated. The other goal is to propose new protection schemes for the designs. The lines consist of overhead lines, underground cables and covered conductors. These overvoltage problems range from direct and indirect strokes to lightning arcs. All the models and simulations are developed using the Electromagnetic Transient Program (EMTP) and Finite Element Method (FEM), while MATLAB is used for post-processing the results and identification of the model parameters. Improvement in the surge protection of MV overhead lines is demonstrated with a combination of surge arresters and a shield wire. Using the IEEE 34-node feeder injected with multiple lightning strokes, the feeder is simulated using EMTP. The response of the line is modeled both with and without the surge protection devices. The simulation study extends to the performance of a MV underground cable due to a nearby lightning discharge using FEM. The use of shield wire for limiting the overvoltage stress in the cables is proposed. A numerical analysis and simulations are performed to determine the outage rate of MV covered conductors due to lightning strokes of different characteristics. The optimum distance for surge protective devices on the conductors is also assessed. An enhancement in the surge analysis of distribution lines with the shielding effect of trees is proposed. An experimental study shows that a tree can intercept a lightning stroke in the vicinity of a distribution line. This study also analyzes experimental results of the shielding effectiveness of a tree and the induced voltages existing between the tree and the distribution line. The study is extended to evaluate the induced voltage on a distribution line for larger clearances using a Rusck model. This work investigates the lightning arc between an overhead line and a nearby tree under artificial rainfall. A full-scale laboratory experiment

  18. Impact of kinetics and flow path heterogeneity on nanoparticle/radionuclide migration

    International Nuclear Information System (INIS)

    Huber, Florian M.

    2011-01-01

    The prevailing PhD thesis experimentally investigates the impact of both sorption/desorption (reversibility) and reduction kinetics on radionuclide migration in synthetic and natural systems from the nano-to the centimeter scale. Furthermore, the impact of fracture heterogeneity on flow and solute/nanoparticle transport as a potential additional retardation mechanism is examined both on an experimental and numerical basis. The process of sorptive reduction of U(VI) to sparingly soluble tetravalent uranium by structural bound Fe(II) in magnetite shows fast kinetics (hours to a few days contact time). A clear correlation between the Fe(II) content on the magnetite surface and the amount of U(VI) was observed, that is, increasing U(IV) with increasing Fe(II). Moreover, a congruency between the measured Eh(SHE) and the U valence state can partly been derived within the analytical uncertainties of the redox potential measurements. Thus, secondary phases as the stainless steel corrosion product magnetite can have beneficial effects on radionuclide migration as an effective retardation pathway for redox sensitive radionuclides. Beside, the studies on U(VI) maghemite sorption show that oxidized surfaces can possess long-term reduction capacities further enhancing radionuclide retention. Concerning the colloid-facilitated radionuclide transport, the batch sorption reversibility studies revealed the significance of kinetically controlled radionuclide desorption from the colloidal phase and subsequent sorption to the fracture filling materials (independent of the mineralogy and/or size fraction). By this process, initially colloidal associated radionuclides like the tri-and tetravalent radionuclides Th, Pu and Am are effectively retarded leading to an increase in the residence time. These reversibility results need to be included in codes for simulating colloid-facilitated radionuclide transport to reduce the conservatism and degree of uncertainties in input parameters

  19. Transfer of radionuclides to animal products following ingestion or inhalation

    International Nuclear Information System (INIS)

    Coughtrey, P.J.

    1996-01-01

    Contamination of animal products forms an important pathway in the transfer of radionuclides from source to man. Simulation of radionuclide transfer via animal products requires an understanding of the processes and mechanisms involved in absorption, distribution, turnover and excretion of radionuclides and related elements in animals as well as knowledge of animal grazing habits and husbandry. This paper provides a summary of the metabolism of important radionuclides in typical domestic animals and of the mathematical approaches that have been used to simulate transfer from diet to animal product. The equilibrium transfer factor approach has been used widely but suffers a number of disadvantages when releases or intakes are variable with time or when intakes are short relative to the lifetime of the animal of interest. Dynamic models, especially those of the compartmental type, have been developed and used widely. Both approaches have benefited from experiences obtained after the Chernobyl accident but a number of uncertainties still exist. Whereas there is now extensive knowledge on the behaviour of radiocaesium in both domestic and wild animals, knowledge of the behaviour of other potentially important radionuclides remains limited. Further experimental and metabolic studies will be required to reduce uncertainties associated with the transfer of radionuclides other than radiocaesium and thereby produce a sound basis for radiological assessments. (author)

  20. Radionuclides sorption in clay soils

    International Nuclear Information System (INIS)

    Siraky, G.; Lewis, C.; Hamlat, S.; Nollmann, C.E.

    1987-01-01

    The sorption behaviour of clay soils is examined through a parametric study of the distribution coefficient (Kd) for the radionuclides of interest, Cs and Sr. This work is a preliminary stage of the migration studies of these nuclides in a porous medium (ground of Ezeiza, Argentina) and the evaluation of radiologic impact of the removal of low and intermediate activity wastes in shallow trenches. The determination of Kd is performed by a static technique or batch. The phases are separated by centrifugation at 20000 g during 1 hour. The activity of supernatant solution of Cs-137 and Sr-85 is measured in a detecting system of I Na(Tl) well-type. Two types of parameters were changed: a) those related to the determination method: phase separation (centrifugation vs. centrifugation plus filtration); equilibrium period, ratio solid/liquid; b) those related to the geochemical system: pH of contact solution, carrier concentration, competitive ions, ionic strength, desorption. It was observed that the modification of parameters in the Kd-measurement does not change the order of magnitude of results. (Author)

  1. Radionuclide composition in the surface layer of particles in the troposphere and stratosphere falls

    International Nuclear Information System (INIS)

    Prokof'ev, O.N.

    1977-01-01

    Radionuclide content in troposphere and stratosphere fall-outs as well as radionuclide washing-off from fall-out particle; are important to determine internal irradiation doses received by separate critical organs of human body. In surface-contaminated products (floury products of grain contaminated while in ears, vegetables, fruits, berries, noncovered or insufficiently covered products during fall-outs) radionuclides initially (in an initial state) are connected with fall-out particles. Radionuclides in biologically contaminated products (milk, meat etc.) are not connected with the particles and have the assimilable form. However, the degree of radionuclide transition from forage (grasses, hay etc.) surface-contaminated as a results of fall-outs into animal produce (milk, meat etc.) also depends on radionuclide washing-off from fall-out particles, which in the latter results from the formation nature and a kind of particles of the main substance. Radionuclide washing-off degree (and, consequently, biological availability) by glazed silicate particles is caused by radionuclide distribution between particle volume and surface in an appropriate sample. According to Israel Yu.A. method calculated were the shares of surface-bound atoms for all the particle totality in an explosion cloud for mass chains, which composition includes biologically important radionuclides. Particle solidification time is taken to equal 7 and 40s. Independent yields of chain radionuclides and its total yield are taken for 228 U fission under 14 MeV neutron effect. The calculation results are presented in the tables

  2. Correlation Water Velocity and TSS with Natural Radionuclides Activity

    International Nuclear Information System (INIS)

    Tri Harningsih; Muzakky; Agus Taftazani

    2007-01-01

    Correlation water velocity and TSS with natural radionuclides activity has been studied. For that purpose, the study is to correlation water velocity and TSS with radionuclides on water and sediment samples in alongside river Code Yogyakarta. This research selected radionuclides, for examples Ra-226, Pb-212, Ac- 228, and K-40. Election of this radionuclides to spread over gamma gross composition alongside river of Code. Gamma gross influenced by water velocity and TSS, so that require to correct between water velocity and TSS to radionuclides. Sampling water and sediment conducted when dry season of August, 2006 at 11 locations, start from Boyong Bridge until Pacar Bridge. Result of analysis showed that water velocity range from 8-1070 L/dt and TSS range from 2.81 E-06 - 8.02 E-04 mg/L. The accumulation of radionuclides in water samples non correction water velocity for Ra-226: 0.302-2.861 Bq/L, Pb-212: 0.400-3.390 Bq/L, Ac- 228: 0.0029-0.0047 Bq/L and K-40: 0.780-9.178 Bq/L. The accumulation of radionuclide in water samples correction water velocity for Ra-226: 1.112-70.454 Bq/L, Pb-212: 0.850-77.113 Bq/L, Ac-228: 0.7187- 60.859 Bq/L and K-40: 2.420-208.8 Bq/L. While distribution of radionuclide in sediment for the Ra-226: 0.0012-0.0211 Bq/kg, Pb-212: 0.0017-0.0371 Bq/kg, Ac-228: 0.0021-0.0073 Bq/kg and K-40: 0.0006-0.0084 Bq/kg. (author)

  3. Short lived radionuclides in therapy

    International Nuclear Information System (INIS)

    Spencer, R.P.

    1987-01-01

    A brief article examines some of the arguments for using shorter lived radionuclides in therapy. Shorter lived radionuclides would 1) reduce over-saturation of the target lesions and consequently reduce irradiation of other parts of the body, 2) reduce the DNA repair capacity of the target cells, 3) reduce the 'escape' of the radionuclide from the major therapeutic locale, 4) reduce the portion of the patient's life span during which the patient is receiving radiotherapy and 5) be useful in evaluating the radiation effects of fractionated radiotherapy. (U.K.)

  4. Radionuclides accumulation in milk and its products

    International Nuclear Information System (INIS)

    Marmuleva, N.I.; Barinov, E.Y.; Petukhov, V.L.

    2003-01-01

    The problem of radioactive pollution is extremely urgent in Russia in connection with presence of territories polluted by radionuclides on places of nuclear tests, in zones around the enterprises on production, processing and storage of radioactive materials, and also in areas of emergency pollution (Barakhtin, 2001). The aim of our investigation was a determination of the levels of the main radioactive elements - 137 Cs and 90 Sr in diary products. 363 samples of milk, dry milk, butter, cheese and yogurt from Novosibirsk region were examined. 137 Cs level was 3.7 to 9.2 times higher than 90 Sr one in milk, cheese and yogurt. At the same time the level of these radio-nuclides in butter was identical (8.03 Bk/kg). (authors)

  5. Removal of radionuclides from liquid streams by reverse osmosis

    International Nuclear Information System (INIS)

    Deshmukh, U.A.; Ramachandhran, V.; Misra, B.M.

    1987-01-01

    Separation of radionuclides in trace concentrations by cellulose acetate membranes has been under investigation in this laboratory, and the behaviour of some important radionuclides such as 137 Cs and 90 Sr under reverse osmosis has been reported earlier. The present work deals with a few other typical radionuclides such as 60 Co, 103 Ru and 131 I which are not fully amenable to conventional methods for their removal. Separation of these radionuclides from liquid streams by the reverse osmosis process was studied using a small reverse osmosis test cell. Various parameters like membrane porosity, applied pressure and feed activity levels were investigated. Cellulose acetate membranes offer reasonable separation of 60 Co, 103 Ru and 131 I radionuclides, indicating the potential of reverse osmosis for treatment of effluents containing these radioisotopes. The percent separation is found to be in the order of Co > Ru > I. The percent radioactive separation improves with increases in feed activity. The performance data are explained in terms of solution-diffusion mechanism. It appears that the separation of radionuclides is not governed by diffusion alone, but by the interaction of solutes with the membranes. (author)

  6. Relationships between tumor size and curablity for uniformly targeted therapy with beta-emitting radionuclides

    International Nuclear Information System (INIS)

    O'Donoghue, J.A.; Bardies, M.; Wheldon, T.E.

    1995-01-01

    Targeted radionuclide therapy is a new form of radiotherapy that differs in some important respects from external beam irradiation. One of the most important differences is due to the finite range of ionizing beta particles emitted as a result of radionuclide disintegration. The effects of particle range have important implications for the curability of tumors. We used a mathematical model to examine tumor curability and its relationship to tumor size for 22 beta-emitting radionuclides that may have therapeutic potential. The model assumed a uniform distribution of radionuclide throughout. For targeted radionuclide therapy, the relationship between tumor curability and tumor size is different from that for conventional external beam radiotherapy. With targeted radionuclides, there is an optimal tumor size for cure. Tumors smaller than the optimal size are less vulnerable to irradiation from radionuclides because a substantial proportion of the disintegration energy escapes and is deposited outside the tumor volume. We found an optimal tumor size for radiocurability by each of the 22 radionuclides considered. Optimal cure diameters range from less than 1 mm for short-range emitters such as 199 Au and 33 P to several centimeters for long-range emitters such as 90 Y and 188 Re. The energy emitted per disintegration may be used to predict optimal cure size for uniform distributions of radionuclide. 17 refs., 8 figs., 3 tabs

  7. 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)

  8. Radionuclide chain migration in fissured rock

    International Nuclear Information System (INIS)

    Rasmuson, A.; Neretnieks, I.

    1982-04-01

    Diffusion into the rock matrix has a large impact on the migration of radionuclides in the geosphere. The aim of the present study is to investigate the effect of this mechanism on radionuclide chain migration. For this purpose a previously used numerical code TRUMP is extended to incorporate chain decay. The algorithm is also changed to directly include the decay terms. The extended version was given the acronym TRUCHN. Numerical solutions from TRUCHN are compared with the analytical solutions developed by Lester et al. A good agreement is obtained. To illustrate the impact of matrix diffusion on the arrival times to the biosphere of the members of a radionuclide chain a number of numerical calculations were done for the two chains U-238 to Th-230 to Ra-226 and Pu-239 to U-235 to Pa-231. The resulting curves are compared with the results for surface sorption (penetration depth 10 - 4 m) and volume sorption (complete penetration) obtained with the computer program GETOUT. The difference in first arrival times are very large. The arrival times in the surface and volume sorption cases, differ with as much as four orders of magnitude. The corresponding times for instationary diffusion are located between these extreme values. A daughter nuclide which is strongly sorbed may be heavily retarded if it is produced far inside the rock matrix and has a long way to diffuse before it reaches the flowing water. This effect is investigated, by considering diffusion only of a radionuclide chain, with analytical and numerical (TRUCHN) methods. Finally, in connection with the reconcentration effect, some means of describing the outflow of a daughter nuclide in terms of the outflow of its parent nuclide are proposed. (Authors)

  9. Diode laser for endodontic treatment: investigations of light distribution and disinfection efficiency

    Science.gov (United States)

    Stock, Karl; Graser, Rainer; Udart, Martin; Kienle, Alwin; Hibst, Raimund

    2011-03-01

    Diode lasers are used in dentistry mainly for oral surgery and disinfection of root canals in endodontic treatment. The purpose of this study was to investigate and to improve the laser induced bacteria inactivation in endodontic treatment. An essential prerequisite of the optimization of the irradiation process and device is the knowledge about the determinative factors of bacteria killing: light intensity? light dosis? temperature? In order to find out whether high power NIR laser bacterial killing is caused by a photochemical or a photothermal process we heated bacteria suspensions of E. coli K12 by a water bath and by a diode laser (940 nm) with the same temporal temperature course. Furthermore, bacteria suspensions were irradiated while the temperature was fixed by ice water. Killing of bacteria was measured via fluorescence labeling. In order to optimize the irradiation of the root canal, we designed special fiber tips with radial light emission characteristic by optical ray tracing simulations. Also, we calculated the resulting light distribution in dentin by voxelbased Monte Carlo simulations. Furthermore, we irradiated root canals of extracted human teeth using different fiber tip geometries and measured the resulting light and heat distribution by CCD-camera and thermography. Comparison of killing rates between laser and water based heating shows no significant differences, and irradiation of ice cooled suspensions has no substantial killing effect. Thus, the most important parameter for bacterial killing is the maximum temperature. Irradiation of root canals using fiber tips with radial light emission results in a more defined irradiated area with minor irradiation of the apex and higher intensity and therefore higher temperature increase on root canal surface. In conclusion, our experiments show that at least for E. coli bacteria inactivation by NIR laser irradiation is solely based on a thermal process and that heat distribution in root canal can be

  10. Using Peptide Aptamer Targeted Polymers as a Model Nanomedicine for Investigating Drug Distribution in Cancer Nanotheranostics.

    Science.gov (United States)

    Zhao, Yongmei; Houston, Zachary H; Simpson, Joshua D; Chen, Liyu; Fletcher, Nicholas L; Fuchs, Adrian V; Blakey, Idriss; Thurecht, Kristofer J

    2017-10-02

    Theranostics is a strategy that combines multiple functions such as targeting, stimulus-responsive drug release, and diagnostic imaging into a single platform, often with the aim of developing personalized medicine.1,2 Based on this concept, several well-established hyperbranched polymeric theranostic nanoparticles were synthesized and characterized as model nanomedicines to investigate how their properties affect the distribution of loaded drugs at both the cell and whole animal levels. An 8-mer peptide aptamer was covalently bound to the periphery of the nanoparticles to achieve both targeting and potential chemosensitization functionality against heat shock protein 70 (Hsp70). Doxorubicin was also bound to the polymeric carrier as a model chemotherapeutic drug through a degradable hydrazone bond, enabling pH-controlled release under the mildly acid conditions that are found in the intracellular compartments of tumor cells. In order to track the nanoparticles, cyanine-5 (Cy5) was incorporated into the polymer as an optical imaging agent. In vitro cellular uptake was assessed for the hyperbranched polymer containing both doxorubicin (DOX) and Hsp70 targeted peptide aptamer in live MDA-MB-468 cells, and was found to be greater than that of either the untargeted, DOX-loaded polymer or polymer alone due to the specific affinity of the peptide aptamer for the breast cancer cells. This was also validated in vivo with the targeted polymers showing much higher accumulation within the tumor 48 h postinjection than the untargeted analogue. More detailed assessment of the nanomedicine distribution was achieved by directly following the polymeric carrier and the doxorubicin at both the in vitro cellular level via compartmental analysis of confocal images of live cells and in whole tumors ex vivo using confocal imaging to visualize the distribution of the drug in tumor tissue as a function of distance from blood vessels. Our results indicate that this polymeric carrier shows

  11. FPGA-based distributed computing microarchitecture for complex physical dynamics investigation.

    Science.gov (United States)

    Borgese, Gianluca; Pace, Calogero; Pantano, Pietro; Bilotta, Eleonora

    2013-09-01

    In this paper, we present a distributed computing system, called DCMARK, aimed at solving partial differential equations at the basis of many investigation fields, such as solid state physics, nuclear physics, and plasma physics. This distributed architecture is based on the cellular neural network paradigm, which allows us to divide the differential equation system solving into many parallel integration operations to be executed by a custom multiprocessor system. We push the number of processors to the limit of one processor for each equation. In order to test the present idea, we choose to implement DCMARK on a single FPGA, designing the single processor in order to minimize its hardware requirements and to obtain a large number of easily interconnected processors. This approach is particularly suited to study the properties of 1-, 2- and 3-D locally interconnected dynamical systems. In order to test the computing platform, we implement a 200 cells, Korteweg-de Vries (KdV) equation solver and perform a comparison between simulations conducted on a high performance PC and on our system. Since our distributed architecture takes a constant computing time to solve the equation system, independently of the number of dynamical elements (cells) of the CNN array, it allows us to reduce the elaboration time more than other similar systems in the literature. To ensure a high level of reconfigurability, we design a compact system on programmable chip managed by a softcore processor, which controls the fast data/control communication between our system and a PC Host. An intuitively graphical user interface allows us to change the calculation parameters and plot the results.

  12. Chemical and structural investigation of lipid nanoparticles: drug-lipid interaction and molecular distribution

    International Nuclear Information System (INIS)

    Anantachaisilp, Suranan; Smith, Siwaporn Meejoo; Treetong, Alongkot; Ruktanonchai, Uracha Rungsardthong; Pratontep, Sirapat; Puttipipatkhachorn, Satit

    2010-01-01

    Lipid nanoparticles are a promising alternative to existing carriers in chemical or drug delivery systems. A key challenge is to determine how chemicals are incorporated and distributed inside nanoparticles, which assists in controlling chemical retention and release characteristics. This study reports the chemical and structural investigation of γ-oryzanol loading inside a model lipid nanoparticle drug delivery system composed of cetyl palmitate as solid lipid and Miglyol 812 as liquid lipid. The lipid nanoparticles were prepared by high pressure homogenization at varying liquid lipid content, in comparison with the γ-oryzanol free systems. The size of the lipid nanoparticles, as measured by the photon correlation spectroscopy, was found to decrease with increased liquid lipid content from 200 to 160 nm. High-resolution proton nuclear magnetic resonance ( 1 H-NMR) measurements of the medium chain triglyceride of the liquid lipid has confirmed successful incorporation of the liquid lipid in the lipid nanoparticles. Differential scanning calorimetric and powder x-ray diffraction measurements provide complementary results to the 1 H-NMR, whereby the crystallinity of the lipid nanoparticles diminishes with an increase in the liquid lipid content. For the distribution of γ-oryzanol inside the lipid nanoparticles, the 1 H-NMR revealed that the chemical shifts of the liquid lipid in γ-oryzanol loaded systems were found at rather higher field than those in γ-oryzanol free systems, suggesting incorporation of γ-oryzanol in the liquid lipid. In addition, the phase-separated structure was observed by atomic force microscopy for lipid nanoparticles with 0% liquid lipid, but not for lipid nanoparticles with 5 and 10% liquid lipid. Raman spectroscopic and mapping measurements further revealed preferential incorporation of γ-oryzanol in the liquid part rather than the solid part of in the lipid nanoparticles. Simple models representing the distribution of γ-oryzanol and

  13. Food web transport of trace metals and radionuclides from the deep sea: a review

    International Nuclear Information System (INIS)

    Young, J.S.

    1979-06-01

    This report summarizes aspects of the potential distribution pathways of metals and radionuclides, particularly Co and Ni, through a biological trophic framework after their deposition at 4000 to 5000 meters in the North Atlantic or North Pacific. It discusses (a) the basic, deep-sea trophic structure of eutrophic and oligotrophic regions; (b) the transport pathways of biologically available energy to and from the deep sea, pathways that may act as accumulators and vectors of radionuclide distribution, and (c) distribution routes that have come into question as potential carriers of radionuclides from the deep-sea bed to man

  14. Radionuclide Retention in Concrete Wasteforms

    Energy Technology Data Exchange (ETDEWEB)

    Bovaird, Chase C.; Jansik, Danielle P.; Wellman, Dawn M.; Wood, Marcus I.

    2011-09-30

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. The information present in the report provides data that (1) measures the effect of concrete wasteform properties likely to influence radionuclide migration; and (2) quantifies the rate of carbonation of concrete materials in a simulated vadose zone repository.

  15. Radionuclides in the food chain

    International Nuclear Information System (INIS)

    Harley, J.H.; Schmidt, G.D.

    1988-01-01

    Radionuclides in the Food Chain reviews past experience in meeting the challenge of radionuclide contamination of foodstuffs and water sources and, in the wake of the reactor accidents at Chernobyl and Three Mile Island, presents current concepts and programs relating to measurement, surveillance, effects, risk management, evaluation guidelines, and control and regulatory activities. This volume, based on a symposium sponsored by the International Life Sciences Institute in association with the International Institute for Applied Systems Analysis, which brought together both radiation experts and food industry policymakers, examines such vital topics as structural problems in large-scale crisis-managment systems; dose assessment from man-made sources; international recommendations on radiation protection; airborne contamination, as well as aquatic and soilborne radionuclides; food-chain contamination from testing nuclear devices; long-term health effects of radionuclides in food and water supplies; and use of mathematical models in risk assessment and management. (orig.)

  16. Radionuclide methods in pediatric cardiology

    International Nuclear Information System (INIS)

    Reich, O.; Ruth, C.; Samanek, M.

    1990-01-01

    The use of radionuclide methods in pediatric cardiology is discussed for non-invasive evaluation of myocardial function and perfusion, regional lung perfusion and ventilation, and for measuring central and peripheral hemodynamics. (H.W.). 16 refs

  17. Investigation of phyotographic distribution of anti-P-gp antibody PHMA02 in nude mice

    International Nuclear Information System (INIS)

    Qin Lan; Shao Menglin

    2006-01-01

    Objective: To investigate the photographic distribution of anti-P-gp monoclonal antibody PHMA02 in nude mice transplanted with K562/A02 cell tumor. Methods: PHMA02 were prepared by hybridoma technique, sodium dodecyl sulfate-polyacrylamide gel electrophorsis and Western-blot were used to analyzed its purity, fluorescence-activated cell sorting (FACS) was also used to determine its binding with K562 and K562/A02 cells. Nude mice were injected i.v with 125 I labeled PHMA02, and were scanned on different time by SPECT. Results: The purity and binding affinity of PHMA02 were both satisfactory. On the second day from injection, radioactivity appeared in all tumor regions of the P-gp + (K562/A02) group nude mice, and intensified in the following days. Concludsion: The photographic difference of PHMA02 distribution between P-gp + (K562/A02) and P-gp - (K562) group could specifically distinguish the P-gp + tumor tissue. (authors)

  18. Defining the Morphology and Distribution of the Alar Fascia: A Sheet Plastination Investigation.

    Science.gov (United States)

    Scali, Frank; Nash, Lance G; Pontell, Matthew E

    2015-10-01

    This study aims to delineate the morphology, integrity, and distribution of the alar fascia using dissection and E12 sheet plastination. This is the first study that employs E12 sheet plastination to investigate the alar fascia and its adjacent potential spaces. Twenty-nine manual dissections and 3 sets of E12 sheet plastinations were used to examine the posterior pharyngeal region for the architecture and distribution of the alar fascia. Specimens were examined from the inferior nuchal line to C6. The alar fascia originated as a well-defined midline structure at the level of C1 and could be identified down to C6. There was no evidence of the alar fascia between the inferior nuchal line and the base of the skull. Notably, the alar fascia permitted resistance to manual traction. E12 sheet plastination allowed for visualization of the alar fascia's superior attachments within the deep cervical region. Resistance to traction suggests that the alar fascia may be more than just a loose fibroareolar matrix. The findings in this study suggest an alternative point of entry into the danger space. Understanding the continuity of this fascial layer is critically important with regard to the pathophysiology of deep neck space infections. © The Author(s) 2015.

  19. Investigation of elemental distribution in human femoral head by PIXE and SRXRF microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.X. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)]. E-mail: yxzhang@sinap.ac.cn; Wang, Y.S. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)]. E-mail: wangyinsong@sinap.ac.cn; Zhang, Y.P. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)]. E-mail: zhangyongping@sinap.ac.cn; Zhang, G.L. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)]. E-mail: zhangguilin@sinap.ac.cn; Huang, Y.Y. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039 (China)]. E-mail: huangyy@mail.ihep.ac.cn; He, W. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039 (China)]. E-mail: hew@mail.ihep.ac.cn

    2007-07-15

    In order to study the distribution and possible degenerative processes inducing the loss of inorganic substances in bone and to provide a scientific basis for the prevention and therapy of osteoporosis, proton induced X-ray emission (PIXE) method is used for the determination of elemental concentrations in femoral heads from five autopsies and seven patients with femoral neck fractures. Synchrotron radiation X-ray fluorescence (SRXRF) microprobe analysis technique is used to scan a slice of the femoral head from its periphery to its center, via cartilage, compact and spongy zones. The specimen preparation and experiment procedure are described in detail. The results show that the concentrations of P, Ca, Fe, Cu, Sr in the control group are higher than those in the patient group, but the concentrations of S, K, Zn, Mn are not significantly different. The quantitative results of elemental distribution, such as Ca, P, K, Fe, Zn, Sr and Pb in bone slice tissue including cartilage, substantial compact and substantial spongy, are investigated. The data obtained show that the concentrations of Ca, P, K, (the major elements of bone composition), are obviously low in both spongy and cartilage zones in the patient group, but there are no remarkable differences in the compact zone. Combined with the correlations between P, K, Zn, Sr and Ca, the loss mechanism of minerals and the physiological functions of some metal elements in bone are also discussed.

  20. Investigation on efficiency of stable iodine distribution around Golfech nuclear power station

    International Nuclear Information System (INIS)

    Payoux, P.; Simon, J.; Campana Briault, H.; Fenolland, J.L.

    2003-01-01

    Background. In order to prevent thyroid cancer radio induced during civil nuclear accident french regulations plan stable iodine distribution for populations living near nuclear power stations. We evaluate availability of stable iodine and understanding of such measure with investigation around Golfech nuclear power station. Methods. In 2001, 1148 families living in a 10 km perimeter around power station were questioned through their schooled child. Our anonymous questionnaire (22 questions, 91 items) was linked with stable iodine availability, organ protection, most exposed persons, dosage and time of stable iodine ingestion. Results. 72,1 % families replied. Among them, 60,8% could easily and quickly find stable iodine in case of emergency, 87,8% know that such measure is to protect thyroid, 80,5% know that children and pregnant women (62,7%) are the most exposed people, 82,3% know that such ingestion is allowed by Prefect order. Conclusion. Answer rate and stable iodine prophylaxis knowledge are satisfactory. On the other hand, in case of necessity about 40% of the concerned families don't have a rapid access to stable iodine, which will forced authorities to distribute as a matter of urgency supplementary stable iodine. Statistical analysis of the answers demonstrate that the most iodine prophylaxis ignorant people are the most refractory to this approach. (author)

  1. Investigation of omnidirectional reflection band in ZnTe/ZnSe distributed Bragg reflector

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Ying-Shin [Department of Electrical Engineering, National Taiwan Ocean University, Keelung 20224, Taiwan (China); Hu, Sheng-Yao [Department of Digital Technology Design, Tungfang Design University, Kaohsiung 82941, Taiwan (China); Lee, Yueh-Chien, E-mail: jacklee@mail.tnu.edu.tw [Department of Electronic Engineering, Tungnan University, New Taipei City 22202, Taiwan (China); Chang, Chung-Cheng; Tiong, Kwong-Kau [Department of Electrical Engineering, National Taiwan Ocean University, Keelung 20224, Taiwan (China); Shen, Ji-Lin [Department of Physics, Chung Yuan Christian University, Chung-Li 32023, Taiwan (China); Chou, Wu-Ching [Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan (China)

    2015-11-15

    We report the characteristics of reflectance spectra of the 15- and 20-period ZnTe/ZnSe distributed Bragg reflector grown on GaAs (001) substrates by molecular beam epitaxy. The reflectance spectra measured at various incident angles and polarizations were investigated by the theoretical curves simulated using transfer matrix method. The wavelength variation of the refractive indices described by Sellmeier equation and random thickness model were also considered for the interpretation of the experimentally observed curves. An omnidirectional reflection range defined from the edge of incident-angle-dependent reflection band with TE and TM polarizations is about 15 nm, and is consistent with the observed experimental curves. The results showed that the selected ZnTe and ZnSe materials are suitable for constructing multilayer structures having omnidirectional reflection band. - Highlights: • ZnTe/ZnSe distributed Bragg reflector grown by molecular beam epitaxy. • The reflectance spectra are measured at various incidence angles and polarizations. • The theoretical curves are considered by Sellmeier and random thickness models. • An observed omnidirectional reflection range in ZnTe/ZnSe DBR is about 15 nm.

  2. Inversionless gain via six-wave mixing and the investigation of distributed feedback

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hong [College of Physics and Electronic Engineering, Hainan Normal University, Haikou, 571158 (China); Zhang, Ting-Gui [School of Mathematics and Statistics, Hainan Normal University, Haikou, 571158 (China); Zou, Xu [College of Physics and Electronic Engineering, Hainan Normal University, Haikou, 571158 (China); Zhang, Yan, E-mail: zhangy345@nenu.edu.cn [School of Physics and Center for Quantum Sciences, Northeast Normal University, Changchun 130024 (China)

    2017-05-10

    In the present paper, we investigate the spectral-line enhancement of a coherently driven treble-Λ type atomic system. The numerical results show that the amplitudes and the amplification region of probe fields can be all-optically manipulated by modulating the detunings and intensities of coupling fields. In this case, we trap the cold atoms of treble-Λ type in a one-dimensional optical lattice to study the intensity envelopes by the modulation of gain or simultaneous modulation of gain and index. - Highlights: • There are three advantages in this model. • Firstly, it can simultaneously control the three-color probe fields. • Secondly, it allows synchronous nonlinear manipulation of treble-light signals at one network node. • Thirdly, it can be realized distributed feedback lasers.

  3. Contact pressure distribution during the polishing process of ceramic tiles: A laboratory investigation

    International Nuclear Information System (INIS)

    Sani, A S A; Hamedon, Z; Azhari, A; Sousa, F J P

    2016-01-01

    During the polishing process of porcelain tiles the difference in scratching speed between innermost and peripheral abrasives leads to pressure gradients linearly distributed along the radial direction of the abrasive tool. The aim of this paper is to investigate such pressure gradient in laboratory scale. For this purpose polishing tests were performed on ceramic tiles according to the industrial practices using a custom-made CNC tribometer. Gradual wear on both abrasives and machined surface of the floor tile were measured. The experimental results suggested that the pressure gradient tends to cause an inclination of the abraded surfaces, which becomes stable after a given polishing period. In addition to the wear depth of the machined surface, the highest value of gloss and finest surface finish were observed at the lowest point of the worn out surface of the ceramic floor tile corresponding to the point of highest pressure and lowest scratching speed. (paper)

  4. Investigation of scavenging activities and distribution of paramagnetic species in Zanthoxylum limonella seeds.

    Science.gov (United States)

    Nakagawa, Kouichi; Promjareet, Apichet; Priprem, Aroonsri; Netweera, Vassana; Hara, Hideyuki

    2016-12-01

    We investigated the scavenging activities of methanol-extracted oil and the distribution of paramagnetic species in Zanthoxylum limonella (ZL) seeds using noninvasive 9 GHz electron paramagnetic resonance (EPR) imaging and continuous wave EPR. EPR detected three different stable paramagnetic species that were assigned to stable organic radicals, Mn 2+ , and other paramagnetic metal complexes. Two-dimensional EPR imaging showed that the stable paramagnetic species were located in the pigmented seed region with a strong intensity. Gas chromatography-mass spectrophotometric (GC-MS) analyses were then performed to identify the compound possibly related to the scavenging activity. The DPPH scavenging activities of ZL were slightly higher than those of Piper nigrum and Coriandrum sativum. Based on the results of EPR, GC-MS, and other methods, limonene in ZL is one of the major compounds that can be related to the scavenging activities.

  5. Investigation of real field application issues for resistive type SFCLs for distribution electric power networks

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, S.B. [School of Information and Communication Engineering, Sungkyunkwan University, Suwon-shi, Gyeonggi-do 440-746 (Korea, Republic of); Lee, B.W., E-mail: bangwook@hanyang.ac.k [School of Electrical Engineering and Computer Science, Hanyang University, Ansan-shi, Gyeonggi-do 426-791 (Korea, Republic of)

    2010-11-01

    Conventional electric power networks were designed and operated not considering fault current limiting devices. Therefore, the performance and characteristics of resistive superconducting fault current limiter (SFCL) should be reviewed considering the coordination with other electric circuit protecting devices. In this paper, real field application issues of resistive SFCL were investigated considering utilities' demands and coordination with other protection devices. Pure resistive SFCL and hybrid resistive SFCL were compared in order to determine suitable solutions for electric power systems. SFCLs were modeled and analyzed using electro-magnetic transients program (EMTP) and their performances were compared to identify the adaptability to the conventional power networks. Consequently, Simulation results showed that hybrid resistive SFCL have more advantages than pure resistive SFCL considering the requirements and specification for the distribution networks.

  6. Investigation of real field application issues for resistive type SFCLs for distribution electric power networks

    Science.gov (United States)

    Rhee, S. B.; Lee, B. W.

    2010-11-01

    Conventional electric power networks were designed and operated not considering fault current limiting devices. Therefore, the performance and characteristics of resistive superconducting fault current limiter (SFCL) should be reviewed considering the coordination with other electric circuit protecting devices. In this paper, real field application issues of resistive SFCL were investigated considering utilities' demands and coordination with other protection devices. Pure resistive SFCL and hybrid resistive SFCL were compared in order to determine suitable solutions for electric power systems. SFCLs were modeled and analyzed using electro-magnetic transients program (EMTP) and their performances were compared to identify the adaptability to the conventional power networks. Consequently, Simulation results showed that hybrid resistive SFCL have more advantages than pure resistive SFCL considering the requirements and specification for the distribution networks.

  7. Communication: Investigation of the electron momentum density distribution of nanodiamonds by electron energy-loss spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Zhenbao; Yang, Bing; Lin, Yangming; Su, Dangsheng, E-mail: dssu@imr.ac.cn [Shenyang National Laboratory of Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Wenhua Road 72, Shenyang 110016 (China)

    2015-12-07

    The electron momentum distribution of detonation nanodiamonds (DND) was investigated by recording electron energy-loss spectra at large momentum transfer in the transmission electron microscope (TEM), which is known as electron Compton scattering from solid (ECOSS). Compton profile of diamond film obtained by ECOSS was found in good agreement with prior photon experimental measurement and theoretical calculation that for bulk diamond. Compared to the diamond film, the valence Compton profile of DND was found to be narrower, which indicates a more delocalization of the ground-state charge density for the latter. Combining with other TEM characterizations such as high-resolution transmission electron spectroscopy, diffraction, and energy dispersive X-ray spectroscopy measurements, ECOSS was shown to be a great potential technique to study ground-state electronic properties of nanomaterials.

  8. Contact pressure distribution during the polishing process of ceramic tiles: A laboratory investigation

    Science.gov (United States)

    Sani, A. S. A.; Sousa, F. J. P.; Hamedon, Z.; Azhari, A.

    2016-02-01

    During the polishing process of porcelain tiles the difference in scratching speed between innermost and peripheral abrasives leads to pressure gradients linearly distributed along the radial direction of the abrasive tool. The aim of this paper is to investigate such pressure gradient in laboratory scale. For this purpose polishing tests were performed on ceramic tiles according to the industrial practices using a custom-made CNC tribometer. Gradual wear on both abrasives and machined surface of the floor tile were measured. The experimental results suggested that the pressure gradient tends to cause an inclination of the abraded surfaces, which becomes stable after a given polishing period. In addition to the wear depth of the machined surface, the highest value of gloss and finest surface finish were observed at the lowest point of the worn out surface of the ceramic floor tile corresponding to the point of highest pressure and lowest scratching speed.

  9. The biotic factors role in radionuclide migration of natural-vegetable complexes

    International Nuclear Information System (INIS)

    Yakushev, B.I.; Kazej, A.I.; Sak, M.M.; Kuz'mich, O.T.; Golushko, R.M.

    1992-01-01

    In Byelorussiyn from first months after the Chernobyl' accident investigation are conducting on the radionuclide de dynamics in the soil-plant-soil system. The isotope composition of soil contamination density and specific plants radioactivity are studying, the radionuclide migration dynamic through the soil profile is investigating. The data are shown on considerable reduction of the plants radioactivity (1986-91 years) in connection with the reduction in the soil contamination density with gamma-spectrum radionuclides, accounting for Ce-144, Pr-144, Ru-106, Cs-134 decay; information is done on gamma-spectrum radionuclides of organs in natural pine and meadows system. It is shown, that the radionuclides are actively absorbed by roots in a zone of the highest radionuclide concentration and are delivered into the overground plant parts, then actively are removed into environment in the breathing process. 11 refs.; 4 tabs

  10. A New Catalogue of Galactic Novae: Investigation of the MMRD relation & Spatial Distribution

    Science.gov (United States)

    Özdönmez, Aykut; Ege, Ergün; Güver, Tolga; Ak, Tansel

    2018-02-01

    In this study, a new Galactic novae catalogue is introduced collecting important parameters of these sources such as their light curve parameters, classifications, full width half maximum (FWHM) of Hα line, distances and interstellar reddening estimates. The catalogue is also published on a website with a search option via a SQL query and an online tool to re-calculate the distance/reddening of a nova from the derived reddening-distance relations. Using the novae in the catalogue, the existence of a maximum magnitude-rate of decline (MMRD) relation in the Galaxy is investigated. Although an MMRD relation was obtained, a significant scattering in the resulting MMRD distribution still exists. We suggest that the MMRD relation likely depends on other parameters in addition to the decline time, as FWHM Hα, the light curve shapes. Using two different samples depending on the distances in the catalogue and from the derived MMRD relation, the spatial distributions of Galactic novae as a function of their spectral and speed classes were studied. The investigation on the Galactic model parameters implies that best estimates for the local outburst density are 3.6 and 4.2 × 10-10 pc-3 yr-1 with a scale height of 148 and 175 pc, while the space density changes in the range of 0.4 - 16 × 10-6 pc-3. The local outburst density and scale height obtained in this study infer that the disk nova rate in the Galaxy is in the range of ˜20 to ˜100 yr-1 with an average estimate 67^{+21}_{-17} yr-1.

  11. Radionuclide deposition and migration within the Gideaa and Finnsjoen study sites, Sweden: A study of the fallout after the Chernobyl accident

    International Nuclear Information System (INIS)

    Gustafsson, E.; Sundblad, B.; Karlberg, O.; Lampe, S.; Tullborg, E.L.

    1987-12-01

    Radionuclides originating from the Chernobyl accident in April 1986 were deposited over large areas of Sweden. The distribution and migration of the radionuclides during the first months after deposition were measured in a comprehensive survey within two study sites, Gideaa in Aangermanland county and Finnsjoen in Uppland county. The sites are previously investigated in the SKB site characterization programme and well defined regarding geology and hydrology. Radionuclides analysed are: Mn-54, Co-60, Sr-90, Zr-95, Nb-95, Mo-99, Ru-103, Ru-106, Ag-110m, Sb-125, I-131, Cs-134, Cs-136, Cs-137, Ba-140, La-140, Ce-141 and Ce-144. The CS-137 surface activity gave a range of 30-100 kBq/m 2 in Gideaa and 20-40 kBq/m 2 in Finnsjoen. Radionuclide migration is observed in soil profiles, groundwater and rock fissures. An active transport by surface water is also evident from sediment samples. Radionuclides have been absorbed in different types of vegetation. (orig./DG)

  12. Anthropogenic radionuclides in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Q; Weng, J; Wang, J

    2007-11-15

    Studies of radionuclides in the environment have entered a new era with the renaissance of nuclear energy and associated fuel reprocessing, geological disposal of high-level nuclear wastes, and concerns about national security with respect to nuclear non-proliferation. This work presents an overview of anthropogenic radionuclide contamination in the environment, as well as the salient geochemical behavior of important radionuclides. We first discuss the following major anthropogenic sources and current development that contribute to the radionuclide contamination of the environment: (1) nuclear weapons program; (2) nuclear weapons testing; (3) nuclear power plants; (4) commercial fuel reprocessing; (5) geological repository of high-level nuclear wastes, and (6) nuclear accidents. Then, we summarize the geochemical behavior for radionuclides {sup 99}Tc, {sup 129}I, and {sup 237}Np, because of their complex geochemical behavior, long half-lives, and presumably high mobility in the environment. Biogeochemical cycling and environment risk assessment must take into account speciation of these redox-sensitive radionuclides.

  13. Radionuclide brain scanning

    International Nuclear Information System (INIS)

    Abdel-Dayem, H.

    1992-01-01

    At one stage of medical imaging development, radionuclide brain scanning was the only technique available for imaging of the brain. Advent of CT and MRI pushed it to the background. It regained some of the grounds lost to ''allied advances'' with the introduction of brain perfusion radiopharmaceuticals. Positron emission tomography is a promising functional imaging modality that at present will remain as a research tool in special centres in developed countries. However, clinically useful developments will gradually percolate from PET to SPECT. The non-nuclear imaging methods are totally instrument dependent; they are somewhat like escalators, which can go that far and no further. Nuclear imaging has an unlimited scope for advance because of the new developments in radiopharmaceuticals. As the introduction of a radiopharmaceutical is less costly than buying new instruments, the recent advances in nuclear imaging are gradually perfusing through the developing countries also. Therefore, it is essential to follow very closely PET developments because what is research today might become routine tomorrow

  14. Radionuclide salivary gland imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mishkin, F.S.

    1981-10-01

    Salivary gland imaging with 99mTc as pertechnetate provides functional information concerning trapping and excretion of the parotid and submandibular glands. Anatomic information gained often adds little to clinical evaluation. On the other hand, functional information may detect subclinical involvement, which correlates well with biopsy of the minor labial salivary glands. Salivary gland abnormalities in systemic disease such as sarcoidosis, rheumatoid arthritis, lupus erythematosus, and other collagenvascular disorders may be detected before they result in the clinical manifestaions of Sjoegren's syndrome. Such glands, after initially demonstrating increased trapping in the acute phase, tend to have decreased trapping and failure to discharge pertechnetate in response to an appropriate physiologic stimulus. Increased uptake of gallium-67 citrate often accompanies these findings. Inflammatory parotitis can be suspected when increased perfusion is evident on radionuclide angiography with any agent. The ability of the salivary gland image to detect and categorize mass lesions, which result in focal areas of diminished activity such as tumors, cysts, and most other masses, is disappointing, while its ability to detect and categorize Warthin's tumor, which concentrates pertechnetate, is much more valuable, although not specific.

  15. Estimation of metastatic cure after radionuclide therapy.

    Science.gov (United States)

    Bernhardt, P; Forssell-Aronsson, E

    2007-12-01

    Targeted radionuclide therapy of disseminated tumor disease involves many factors that will affect the therapeutic outcome. For optimization of such therapy, it is important to know how these factors affect the therapeutic outcome. In this paper, the metastatic cure probability (MCP) model is described. The MCP model is a valuable tool for analyses of the various factors influencing the metastatic cure. The factors discussed are: 1) the physical parameters (the energy and range of emitted particles, absorbed dose-distributions, and cross-irradiation of tumors from the surrounding normal tissue) and 2) the biological parameters (radiosensitivity of tumors, tumor distributions, tumor growth rate, metastasis formation rate, variable tumor activity concentration and non-homogeneous tumor activity distributions).

  16. Radionuclide transfer from soil to plants

    International Nuclear Information System (INIS)

    Teufel, D.; Steinhilber-Schwab, B.; Hoepfner, U.; Ratka, R.; Sand, H. van de; Franke, B.

    1979-01-01

    The planned nuclear reprocessing plant (NEZ) Gorleben will fundamentally differ from actually operating nuclear power plants with regard to its radioactive emissions because relatively long-life isotopes will play a greater role in the emissions. The longevity of the radionuclides emitted in the planned NEZ implies that there will be an accumulation of radionuclides in the surroundings of the plant and long-term effects of the plant on the environment will get higher significance. As radionuclides mainly reach milk and meat via the food of farm animals the transfer of cesium and strontium from the ground into plants was amply investigated. The results show that the correlation calculations are suitable to describe the effect of different parameters on the transfer factor. They are not suited for a forecast of the transfer conditions on a certain location for the reasons explained before. Location-specific measurements seem to be indispensable for these purposes. Besides the greenhouse tests open air measurements of fall-out nuclides with and without elimination of external contamination seem to represent a realistic possibility for the determination of transfer factors. Great attention has to be paid in this kind of tests to the growth conditions (especially fertilization) which have to be accurately registered. (orig./MG) [de

  17. Sorption of radionuclides on Yucca Mountain tuffs

    International Nuclear Information System (INIS)

    Meijaer, A.; Triay, I.; Knight, S.; Cisneros, M.

    1989-01-01

    A substantial database of sorption coefficients for important radionuclides on Yucca Mountain tuffs has been obtained by Los Alamos National Laboratory over the past ten years. Current sorption studies are focussed on validation questions and augmentation of the existing database. Validation questions concern the effects of the use of crushed instead of solid rock samples in the batch experiments, the use of oversaturated stock solutions, and variations in water/rock ratios. Sorption mechanisms are also being investigated. Database augmentation activities include determination of sorption coefficients for elements with low sorption potential, sorption on psuedocolloids, sorption on fracture lining minerals, and sorption kinetics. Sorption can provide an important barrier to the potential migration of radionuclides from the proposed repository within Yucca Mountain to the accessible environment. In order to quantify this barrier, sorption coefficients appropriate for the Yucca Mountain groundwater system must be obtained for each of the important radionuclides in nuclear waste. Los Alamos National Laboratories has conducted numerous batch (crushed-rock) sorption experiments over the past ten years to develop a sorption coefficient database for the Yucca Mountain site. In the present site characterization phase, the main goals of the sorption test program will be to validate critical sorption coefficients and to augment the existing database where important data are lacking. 11 refs., 1 fig., 3 tabs

  18. UPTAKE OF RADIONUCLIDE METALS BY SPME FIBERS

    Energy Technology Data Exchange (ETDEWEB)

    Duff, M; S Crump, S; Robert02 Ray, R; Keisha Martin, K; Donna Beals, D

    2006-08-28

    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) and fire debris (FD) evidence while maintaining evidentiary value. One experimental method for the isolation of HE and FD residue involves using solid phase microextraction or SPME fibers to remove residue of interest. Due to their high affinity for organics, SPME fibers should have little affinity for most metals. However, no studies have measured the affinity of radionuclides for SPME fibers. The focus of this research was to examine the affinity of dissolved radionuclide ({sup 239/240}Pu, {sup 238}U, {sup 237}Np, {sup 85}Sr, {sup 133}Ba, {sup 137}Cs, {sup 60}Co and {sup 226}Ra) and stable radionuclide surrogate metals (Sr, Co, Ir, Re, Ni, Ba, Cs, Nb, Zr, Ru, and Nd) for SPME fibers at the exposure conditions that favor the uptake of HE and FD 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 and FD residue uptake with subsequent analysis by liquid or gas phase chromatography with mass spectrometric detection.

  19. Methods for determining radionuclide retardation factors: status report

    International Nuclear Information System (INIS)

    Relyea, J.F.; Serne, R.J.; Rai, D.

    1980-04-01

    This report identifies a number of mechanisms that retard radionuclide migration, and describes the static and dynamic methods that are used to study such retardation phenomena. Both static and dynamic methods are needed for reliable safety assessments of underground nuclear-waste repositories. This report also evaluates the extent to which the two methods may be used to diagnose radionuclide migration through various types of geologic media, among them unconsolidated, crushed, intact, and fractured rocks. Adsorption is one mechanism that can control radionuclide concentrations in solution and therefore impede radionuclide migration. Other mechanisms that control a solution's radionuclide concentration and radionuclide migration are precipitation of hydroxides and oxides, oxidation-reduction reactions, and the formation of minerals that might include the radionuclide as a structural element. The retardation mechanisms mentioned above are controlled by such factors as surface area, cation exchange capacity, solution pH, chemical composition of the rock and of the solution, oxidation-reduction potential, and radionuclide concentration. Rocks and ground waters used in determining retardation factors should represent the expected equilibrium conditions in the geologic system under investigation. Static test methods can be used to rapidly screen the effects of the factors mentioned above. Dynamic (or column) testing, is needed to assess the effects of hydrodynamics and the interaction of hydrodynamics with the other important parameters. This paper proposes both a standard method for conducting batch Kd determinations, and a standard format for organizing and reporting data. Dynamic testing methods are not presently developed to the point that a standard methodology can be proposed. Normal procedures are outlined for column experimentation and the data that are needed to analyze a column experiment are identified

  20. Decontamination of spent ion-exchangers contaminated with cesium radionuclides using resorcinol-formaldehyde resins

    Energy Technology Data Exchange (ETDEWEB)

    Palamarchuk, Marina, E-mail: marina_p@ich.dvo.ru; Egorin, Andrey; Tokar, Eduard; Tutov, Mikhail; Marinin, Dmitry; Avramenko, Valentin

    2017-01-05

    Highlights: • Cesium radionuclides not removable by regeneration are bound to silicate deposits. • Application of RFR substantially increases cesium desorption from an ion-exchanger. • The radwaste volume was reduced at least 2-fold for zeolites and 10-fold for SIER. • The distribution coefficient values for RFR were high (K{sub d} > 10{sup 4}) after 6 regenerations. • The volume of secondary waste formed after regeneration of RFR was reduced 600-fold. - Abstract: The origin of the emergence of radioactive contamination not removable in the process of acid-base regeneration of ion-exchange resins used in treatment of technological media and liquid radioactive waste streams has been determined. It has been shown that a majority of cesium radionuclides not removable by regeneration are bound to inorganic deposits on the surface and inside the ion-exchange resin beads. The nature of the above inorganic inclusions has been investigated by means of the methods of electron microscopy, IR spectrometry and X-ray diffraction. The method of decontamination of spent ion-exchange resins and zeolites contaminated with cesium radionuclides employing selective resorcinol-formaldehyde resins has been suggested. Good prospects of such an approach in deep decontamination of spent ion exchangers have been demonstrated.

  1. Decontamination of spent ion-exchangers contaminated with cesium radionuclides using resorcinol-formaldehyde resins

    International Nuclear Information System (INIS)

    Palamarchuk, Marina; Egorin, Andrey; Tokar, Eduard; Tutov, Mikhail; Marinin, Dmitry; Avramenko, Valentin

    2017-01-01

    Highlights: • Cesium radionuclides not removable by regeneration are bound to silicate deposits. • Application of RFR substantially increases cesium desorption from an ion-exchanger. • The radwaste volume was reduced at least 2-fold for zeolites and 10-fold for SIER. • The distribution coefficient values for RFR were high (K d > 10 4 ) after 6 regenerations. • The volume of secondary waste formed after regeneration of RFR was reduced 600-fold. - Abstract: The origin of the emergence of radioactive contamination not removable in the process of acid-base regeneration of ion-exchange resins used in treatment of technological media and liquid radioactive waste streams has been determined. It has been shown that a majority of cesium radionuclides not removable by regeneration are bound to inorganic deposits on the surface and inside the ion-exchange resin beads. The nature of the above inorganic inclusions has been investigated by means of the methods of electron microscopy, IR spectrometry and X-ray diffraction. The method of decontamination of spent ion-exchange resins and zeolites contaminated with cesium radionuclides employing selective resorcinol-formaldehyde resins has been suggested. Good prospects of such an approach in deep decontamination of spent ion exchangers have been demonstrated.

  2. Hydrology and Radionuclide Migration Program, 1985--1986 progress report

    International Nuclear Information System (INIS)

    Buddemeier, R.W.

    1988-09-01

    This report presents results from the Lawrence Livermore National Laboratory's participation in the Hydrology and Radionuclide Migration Program (formerly the Radionuclide Migration Project) at the Nevada Test Site (NTS) during fiscal years 1985 and 1986. The report discusses studies of the partitioning and movement of dissolved and colloidal radionuclides at the Cheshire (U20n) site; tracer studies of shallow recharge and of plant-water uptake at the Cambric-site ditch carrying the effluent water pumped from well RNM-2; development of a rapid and sensitive assay for 99 Tc in groundwater and its application to a survey of technetium activities at a variety of test wells; and a series of methodological studies directed toward calibration, understanding, and improving our low-level radionuclide determinations. Groundwater sampled from the Cheshire cavity and from adjacent aquifers contains substantial concentrations (mg/L) of colloids that appear to consist primarily of natural minerals. These colloids were found to contain detectable amounts of strongly sorbed radionuclides, leading to the hypothesis that radionuclides are being transported by the groundwater in colloidal form. The RNM ditch at the Cambric site has provided a unique tritium-labeled, irrigated test plot in the desert. One study at this site continued earlier investigations of water and tritium migration in the shallow vadose (unsaturated-soil) zone adjacent to the ditch and extended that study to include using a tracer to determine the velocity of vertical water flow in the recharge zone directly below the ditch. 57 refs., 15 figs., 23 tabs

  3. Assessment of the important radionuclides in nuclear waste

    International Nuclear Information System (INIS)

    Kerrisk, J.F.

    1985-10-01

    The relative importance of the various radionuclides contained in nuclear waste has been assessed by consideration of (1) the quantity of each radionuclide present, (2) the Environmental Protection Agency's release limits for radionuclides, (3) how retardation processes such as solubility and sorption affect radionuclie transport, and (4) the physical and chemical forms of radionuclides in the waste. Three types of waste were reviewed: spent fuel, high-level waste, and defense high-level waste. Conditions specific to the Nevada Nuclear Waste Storage Investigations project potential site at Yucca Mountain were used to describe radionuclide transport. The actinides Am, Pu, Np, and U were identified as the waste elements for which solubility and sorption data were most urgently needed. Other important waste elements were identified as Sr, Cs, C, Ni, Zr, Tc, Th, Ra, and Sn. Under some conditions, radionuclides of three elements (C, Tc, and I) may have high solubility and negligible sorption. The potential for transport of some waste elements (C and I) in the gas phase must also be evaluated for the Yucca Mountain Site. 12 refs., 17 tabs

  4. Radionuclide transfer from feed to camel milk.

    Science.gov (United States)

    Al-Masri, M S; Al-Hamwi, A; Amin, Y; Safieh, M B; Zarkawi, M; Soukouti, A; Dayyoub, R; Voigt, G; Fesenko, S

    2014-06-01

    The transfer of (137)Cs, (85)Sr, (131)I, (210)Po, (210)Pb and (238)U from feed to camel's milk was investigated in a pilot experiment with three lactating camels. For a period of 60 days, the animals were fed on spiked feed containing the studied radionuclides. They were subsequently returned to a contamination-free diet and monitored for another 90 days. The activity concentrations of (137)Cs, (85)Sr and (131)I in milk decreased with time and reached background levels after 20 days. Equilibrium transfer coefficients and biological half-lives were estimated and transfer coefficients were calculated as (8.1 ± 3.6) × 10(-4), (4.4 ± 1.6) × 10(-2), (7.8 ± 3.9) × 10(-4), (2.7 ± 3.5) × 10(-4), (1.8 ± 1.5) × 10(-4) and (7.0 ± 3.6) × 10(-3) d L(-1) for (85)Sr, (131)I, (137)Cs, (210)Po, (210)Pb and (238)U, respectively. The biological half-lives were estimated to be 6.4, 4.2, 8.9, and 53.3 days for (85)Sr, (131)I, (137)Cs, and (238)U, respectively. Estimates of the half-lives were based on a one component model: it was found that the half-life values measured for artificial radionuclides were slightly shorter than those for natural radionuclides. The data obtained in the study are the first published experimental data on radionuclide transfer to camel milk. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Experimental Investigation on Aerodynamic Control of a Wing with Distributed Plasma Actuators

    International Nuclear Information System (INIS)

    Han Menghu; Li Jun; Liang Hua; Zhao Guangyin; Niu Zhongguo

    2015-01-01

    Experimental investigation of active flow control on the aerodynamic performance of a flying wing is conducted. Subsonic wind tunnel tests are performed using a model of a 35° swept flying wing with an nanosecond dielectric barrier discharge (NS-DBD) plasma actuator, which is installed symmetrically on the wing leading edge. The lift and drag coefficient, lift-to-drag ratio and pitching moment coefficient are tested by a six-component force balance for a range of angles of attack. The results indicate that a 44.5% increase in the lift coefficient, a 34.2% decrease in the drag coefficient and a 22.4% increase in the maximum lift-to-drag ratio can be achieved as compared with the baseline case. The effects of several actuation parameters are also investigated, and the results show that control efficiency demonstrates a strong dependence on actuation location and frequency. Furthermore, we highlight the use of distributed plasma actuators at the leading edge to enhance the aerodynamic performance, giving insight into the different mechanism of separation control and vortex control, which shows tremendous potential in practical flow control for a broad range of angles of attack. (paper)

  6. Migration of radionuclides in porous rock in the presence of colloids: effects of kinetic interactions.

    Science.gov (United States)

    Li, S H; Jen, C P

    2001-01-01

    This work investigates the colloid-facilitated migration of radionuclides with radioactive decay in porous media. The sorption processes for radionuclides with both the solid matrix and colloids are treated as equilibrium or nonequilibrium. An analytical solution is obtained from a simplified linear equilibrium interaction mechanism. In addition, the adsorption processes for radionuclides with colloids and porous rock can be assumed as nonequilibrium and modeled by the linear kinetic adsorption. The numerical method is employed to solve the coupled colloid and radionuclide transport equations under nonequilibrium sorption assumption. Moreover, the reaction rates of the adsorption processes for radionuclides with the solid matrix and colloids affect the transport characteristics of radionuclides. The fast reaction rate of radionuclides with colloids causes a higher concentration of radionuclides adsorbed on colloids in a dispersed phase and enlarges acceleration caused by colloids. However, the fast reaction rate for radionuclides with solid matrix increases the retardation effect caused by the solid matrix. This work developed a predictive model for the transport of colloid-facilitated radionuclides in porous medium and to assess the importance of various phenomenological coefficients, particularly parameters for the adsorption interactions.

  7. Radionuclides in the clinical study of renal physiology

    International Nuclear Information System (INIS)

    Britton, K.E.

    1975-01-01

    A view is presented of the use and misuse of some techniques using radionuclides in the measurement of total renal blood flow, the individual contribution of each kidney to total uptake function and the distribution of function between two populations of nephrons in each kidney

  8. External exposure to radionuclides in air, water, and soil

    International Nuclear Information System (INIS)

    Eckerman, K.F.; Ryman, J.C.

    1996-01-01

    Federal Guidance Report No. 12 tabulates dose coefficients for external exposure to photons and electrons emitted by radionuclides distributed in air, water, and soil. The dose coefficients are intended for use by Federal Agencies in calculating the dose equivalent to organs and tissues of the body

  9. Dendrimer-coated magnetic particles for radionuclide separation

    NARCIS (Netherlands)

    Grüttner, Cordula; Böhmer, Volker; Casnati, Alessandro; Dozol, Jean-Francois; Reinhoudt, David; Reinoso garcia, M.M.; Rudershausen, Sandra; Teller, Joachim; Ungaro, Rocco; Verboom, Willem; Wang, Pingshan

    2005-01-01

    Magnetic particles were synthesised for radionuclide removal from nuclear wastes by magnetic separation. Dendrimers with terminal amino groups attached to the particle surface were used to bind chelating groups for lanthanides and actinides. This led to a 50–400-fold increase of the distribution

  10. The biokinetic of incorporates radionuclides; Die Biokinetik von inkorporierten Radionukliden

    Energy Technology Data Exchange (ETDEWEB)

    Breustedt, Bastian [Karlsruher Institut fuer Technologie (KIT), Eggenstein-Leopoldshafen (Germany). Inst. fuer Strahlenforschung; Giussani, Augusto [Bundesamt fuer Strahlenschutz, Oberschleissheim (Germany). Arbeitsgruppe ' ' Externe und interne Dosimetrie, Biokinetik' '

    2017-08-01

    Incorporated radionuclides from nuclear accidents, fission product releases or nuclear medical administration are distributed in the human body in organs and tissue, absorbed 9or excreted. The interpretation of incorporation monitoring results and the estimation of the internal doses that cannot be measured directly need mathematical methods and the formulation of biokinetic models.

  11. Model for radionuclide transport in running waters

    Energy Technology Data Exchange (ETDEWEB)

    Jonsson, Karin; Elert, Mark [Kemakta Konsult AB, Stockholm (Sweden)

    2005-11-15

    Two sites in Sweden are currently under investigation by SKB for their suitability as places for deep repository of radioactive waste, the Forsmark and Simpevarp/Laxemar area. As a part of the safety assessment, SKB has formulated a biosphere model with different sub-models for different parts of the ecosystem in order to be able to predict the dose to humans following a possible radionuclide discharge from a future deep repository. In this report, a new model concept describing radionuclide transport in streams is presented. The main difference from the previous model for running water used by SKB, where only dilution of the inflow of radionuclides was considered, is that the new model includes parameterizations also of the exchange processes present along the stream. This is done in order to be able to investigate the effect of the retention on the transport and to be able to estimate the resulting concentrations in the different parts of the system. The concentrations determined with this new model could later be used for order of magnitude predictions of the dose to humans. The presented model concept is divided in two parts, one hydraulic and one radionuclide transport model. The hydraulic model is used to determine the flow conditions in the stream channel and is based on the assumption of uniform flow and quasi-stationary conditions. The results from the hydraulic model are used in the radionuclide transport model where the concentration is determined in the different parts of the stream ecosystem. The exchange processes considered are exchange with the sediments due to diffusion, advective transport and sedimentation/resuspension and uptake of radionuclides in biota. Transport of both dissolved radionuclides and sorbed onto particulates is considered. Sorption kinetics in the stream water phase is implemented as the time scale of the residence time in the stream water probably is short in comparison to the time scale of the kinetic sorption. In the sediment

  12. INVESTIGATION OF INFLUENCE OF ENCODING FUNCTION COMPLEXITY ON DISTRIBUTION OF ERROR MASKING PROBABILITY

    Directory of Open Access Journals (Sweden)

    A. B. Levina

    2016-03-01

    Full Text Available Error detection codes are mechanisms that enable robust delivery of data in unreliable communication channels and devices. Unreliable channels and devices are error-prone objects. Respectively, error detection codes allow detecting such errors. There are two classes of error detecting codes - classical codes and security-oriented codes. The classical codes have high percentage of detected errors; however, they have a high probability to miss an error in algebraic manipulation. In order, security-oriented codes are codes with a small Hamming distance and high protection to algebraic manipulation. The probability of error masking is a fundamental parameter of security-oriented codes. A detailed study of this parameter allows analyzing the behavior of the error-correcting code in the case of error injection in the encoding device. In order, the complexity of the encoding function plays an important role in the security-oriented codes. Encoding functions with less computational complexity and a low probability of masking are the best protection of encoding device against malicious acts. This paper investigates the influence of encoding function complexity on the error masking probability distribution. It will be shownthat the more complex encoding function reduces the maximum of error masking probability. It is also shown in the paper that increasing of the function complexity changes the error masking probability distribution. In particular, increasing of computational complexity decreases the difference between the maximum and average value of the error masking probability. Our resultshave shown that functions with greater complexity have smoothed maximums of error masking probability, which significantly complicates the analysis of error-correcting code by attacker. As a result, in case of complex encoding function the probability of the algebraic manipulation is reduced. The paper discusses an approach how to measure the error masking

  13. Investigating vertical distribution patterns of lower tropospheric PM2.5 using unmanned aerial vehicle measurements

    Science.gov (United States)

    Li, Xiao-Bing; Wang, Dong-Sheng; Lu, Qing-Chang; Peng, Zhong-Ren; Wang, Zhan-Yong

    2018-01-01

    A lightweight unmanned aerial vehicle (UAV) was outfitted with miniaturized sensors to investigate the vertical distribution patterns and sources of fine aerosol particles (PM2.5) within the 1 000 m lower troposphere. A total of 16 UAV flights were conducted in the Yangtze River Delta (YRD) region, China, from the summer to winter in 2014. The associated ground-level measurements from two environmental monitoring stations were also used for background analysis. The results show that ground-level PM2.5 concentrations demonstrated a decreasing trend from Feb. to Jul. and an increasing trend from Aug. to Jan. (the following year). Higher PM2.5 concentrations during the day were mainly observed in the morning (Local Time, LT 05-09) in the spring and summer. However, higher PM2.5 concentrations occurred mainly in the late afternoon and evening (LT 16-20) in the autumn and winter, excluding severe haze pollution days when higher PM2.5 concentrations were also observed during the morning periods. Lower tropospheric PM2.5 concentrations exhibited similar diurnal vertical distribution patterns from the summer to winter. The PM2.5 concentrations decreased with height in the morning, with significantly large vertical gradients from the summer to winter. By contrast, the aerosol particles were well mixed with PM2.5 concentrations of lower than 35 μg ṡm-3 in the early afternoon (LT 12-16) due to sufficient expansions of the planetary boundary layer. The mean vertical PM2.5 concentrations within the 1 000 m lower troposphere in the morning were much larger in the winter (∼87.5 μg ṡm-3) than in the summer and autumn (∼20 μg ṡm-3). However, subtle differences of ∼11 μg ṡm-3 in the mean vertical PM2.5 concentrations were observed in the early afternoon from the summer to winter. The vertical distribution patterns of black carbon and its relationships with PM2.5 indicated that the lower tropospheric aerosol particles might be mainly derived from fossil